Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. That is, there is a difference in the energy required for electric charges to move from the internal to exterior cellular environments and vice versa, as long as there is no acquisition of kinetic energy or the production of radiation. The concentration gradients of the charges directly determine this energy requirement. For the exterior of the cell, typical values of membrane potential, normally given in units of milli volts and denoted as mV, range from –80 mV to –40 mV.

All animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of ions. Transmembrane proteins, also known as ion transporter or ion pump proteins, actively push ions across the membrane and establish concentration gradients across the membrane, and ion channels allow ions to move across the membrane down those concentration gradients. Ion pumps and ion channels are electrically equivalent to a set of batteries and resistors inserted in the membrane, and therefore create a voltage between the two sides of the membrane.

Almost all plasma membranes have an electrical potential across them, with the inside usually negative with respect to the outside. The membrane potential has two basic functions. First, it allows a cell to function as a battery, providing power to operate a variety of "molecular devices" embedded in the membrane. Second, in electrically excitable cells such as neurons and muscle cells, it is used for transmitting signals between different parts of a cell. Signals are generated by opening or closing of ion channels at one point in the membrane, producing a local change in the membrane potential. This change in the electric field can be quickly sensed by either adjacent or more distant ion channels in the membrane. Those ion channels can then open or close as a result of the potential change, reproducing the signal.

In non-excitable cells, and in excitable cells in their baseline states, the membrane potential is held at a relatively stable value, called the resting potential. For neurons, resting potential is defined as ranging from –80 to –70 millivolts; that is, the interior of a cell has a negative baseline voltage of a bit less than one-tenth of a volt. The opening and closing of ion channels can induce a departure from the resting potential. This is called a depolarization if the interior voltage becomes less negative (say from –70 mV to –60 mV), or a hyperpolarization if the interior voltage becomes more negative (say from –70 mV to –80 mV).  In excitable cells, a sufficiently large depolarization can evoke an action potential, in which the membrane potential changes rapidly and significantly for a short time (on the order of 1 to 100 milliseconds), often reversing its polarity.  Action potentials are generated by the activation of certain voltage-gated ion channels.

In neurons, the factors that influence the membrane potential are diverse. They include numerous types of ion channels, some of which are chemically gated and some of which are voltage-gated. Because voltage-gated ion channels are controlled by the membrane potential, while the membrane potential itself is influenced by these same ion channels, feedback loops that allow for complex temporal dynamics arise, including oscillations and regenerative events such as action potentials.

Physical basis
The membrane potential in a cell derives ultimately from two factors: electrical force and diffusion. Electrical force arises from the mutual attraction between particles with opposite electrical charges (positive and negative) and the mutual repulsion between particles with the same type of charge (both positive or both negative). Diffusion arises from the statistical tendency of particles to redistribute from regions where they are highly concentrated to regions where the concentration is low.

Voltage

Voltage, which is synonymous with difference in electrical potential, is the ability to drive an electric current across a resistance. Indeed, the simplest definition of a voltage is given by Ohm's law: V=IR, where V is voltage, I is current and R is resistance. If a voltage source such as a battery is placed in an electrical circuit, the higher the voltage of the source the greater the amount of current that it will drive across the available resistance. The functional significance of voltage lies only in potential differences between two points in a circuit. The idea of a voltage at a single point is meaningless. It is conventional in electronics to assign a voltage of zero to some arbitrarily chosen element of the circuit, and then assign voltages for other elements measured relative to that zero point. There is no significance in which element is chosen as the zero point—the function of a circuit depends only on the differences not on voltages per se. However, in most cases and by convention, the zero level is most often assigned to the portion of a circuit that is in contact with ground.

The same principle applies to voltage in cell biology. In electrically active tissue, the potential difference between any two points can be measured by inserting an electrode at each point, for example one inside and one outside the cell, and connecting both electrodes to the leads of what is in essence a specialized voltmeter. By convention, the zero potential value is assigned to the outside of the cell and the sign of the potential difference between the outside and the inside is determined by the potential of the inside relative to the outside zero.

In mathematical terms, the definition of voltage begins with the concept of an electric field , a vector field assigning a magnitude and direction to each point in space. In many situations, the electric field is a conservative field, which means that it can be expressed as the gradient of a scalar function , that is, .  This scalar field  is referred to as the voltage distribution.  The definition allows for an arbitrary constant of integration—this is why absolute values of voltage are not meaningful.  In general, electric fields can be treated as conservative only if magnetic fields do not significantly influence them, but this condition usually applies well to biological tissue.

Because the electric field is the gradient of the voltage distribution, rapid changes in voltage within a small region imply a strong electric field; on the converse, if the voltage remains approximately the same over a large region, the electric fields in that region must be weak. A strong electric field, equivalent to a strong voltage gradient, implies that a strong force is exerted on any charged particles that lie within the region.

Ions and the forces driving their motion

Electrical signals within biological organisms are, in general, driven by ions.  The most important cations for the action potential are sodium (Na+) and potassium (K+). Both of these are monovalent cations that carry a single positive charge.  Action potentials can also involve calcium (Ca2+), which is a divalent cation that carries a double positive charge.  The chloride anion (Cl−) plays a major role in the action potentials of some algae, but plays a negligible role in the action potentials of most animals.

Ions cross the cell membrane under two influences: diffusion and electric fields. A simple example wherein two solutions—A and B—are separated by a porous barrier illustrates that diffusion will ensure that they will eventually mix into equal solutions. This mixing occurs because of the difference in their concentrations. The region with high concentration will diffuse out toward the region with low concentration. To extend the example, let solution A have 30 sodium ions and 30 chloride ions. Also, let solution B have only 20 sodium ions and 20 chloride ions. Assuming the barrier allows both types of ions to travel through it, then a steady state will be reached whereby both solutions have 25 sodium ions and 25 chloride ions. If, however, the porous barrier is selective to which ions are let through, then diffusion alone will not determine the resulting solution. Returning to the previous example, let's now construct a barrier that is permeable only to sodium ions. Now, only sodium is allowed to diffuse cross the barrier from its higher concentration in solution A to the lower concentration in solution B. This will result in a greater accumulation of sodium ions than chloride ions in solution B and a lesser number of sodium ions than chloride ions in solution A.

This means that there is a net positive charge in solution B from the higher concentration of positively charged sodium ions than negatively charged chloride ions. Likewise, there is a net negative charge in solution A from the greater concentration of negative chloride ions than positive sodium ions. Since opposite charges attract and like charges repel, the ions are now also influenced by electrical fields as well as forces of diffusion. Therefore, positive sodium ions will be less likely to travel to the now-more-positive B solution and remain in the now-more-negative A solution. The point at which the forces of the electric fields completely counteract the force due to diffusion is called the equilibrium potential. At this point, the net flow of the specific ion (in this case sodium) is zero.

Plasma membranes

Every cell is enclosed in a plasma membrane, which has the structure of a lipid bilayer with many types of large molecules embedded in it.  Because it is made of lipid molecules, the plasma membrane intrinsically has a high electrical resistivity, in other words a low intrinsic permeability to ions. However, some of the molecules embedded in the membrane are capable either of actively transporting ions from one side of the membrane to the other or of providing channels through which they can move.

In electrical terminology, the plasma membrane functions as a combined resistor and capacitor. Resistance arises from the fact that the membrane impedes the movement of charges across it. Capacitance arises from the fact that the lipid bilayer is so thin that an accumulation of charged particles on one side gives rise to an electrical force that pulls oppositely charged particles toward the other side. The capacitance of the membrane is relatively unaffected by the molecules that are embedded in it, so it has a more or less invariant value estimated at 2 μF/cm2 (the total capacitance of a patch of membrane is proportional to its area).  The conductance of a pure lipid bilayer is so low, on the other hand, that in biological situations it is always dominated by the conductance of alternative pathways provided by embedded molecules.  Thus, the capacitance of the membrane is more or less fixed, but the resistance is highly variable.

The thickness of a plasma membrane is estimated to be about 7-8 nanometers. Because the membrane is so thin, it does not take a very large transmembrane voltage to create a strong electric field within it. Typical membrane potentials in animal cells are on the order of 100 millivolts (that is, one tenth of a volt), but calculations show that this generates an electric field close to the maximum that the membrane can sustain—it has been calculated that a voltage difference much larger than 200 millivolts could cause dielectric breakdown, that is, arcing across the membrane.

Facilitated diffusion and transport

The resistance of a pure lipid bilayer to the passage of ions across it is very high, but structures embedded in the membrane can greatly enhance ion movement, either actively or passively, via mechanisms called facilitated transport and facilitated diffusion. The two types of structure that play the largest roles are ion channels and ion pumps, both usually formed from assemblages of protein molecules. Ion channels provide passageways through which ions can move. In most cases, an ion channel is permeable only to specific types of ions (for example, sodium and potassium but not chloride or calcium), and sometimes the permeability varies depending on the direction of ion movement. Ion pumps, also known as ion transporters or carrier proteins, actively transport specific types of ions from one side of the membrane to the other, sometimes using energy derived from metabolic processes to do so.

Ion pumps

Ion pumps are integral membrane proteins that carry out active transport, i.e., use cellular energy (ATP) to "pump" the ions against their concentration gradient. Such ion pumps take in ions from one side of the membrane (decreasing its concentration there) and release them on the other side (increasing its concentration there).

The ion pump most relevant to the action potential is the sodium–potassium pump, which transports three sodium ions out of the cell and two potassium ions in.  As a consequence, the concentration of potassium ions K+ inside the neuron is roughly 30-fold larger than the outside concentration, whereas the sodium concentration outside is roughly five-fold larger than inside. In a similar manner, other ions have different concentrations inside and outside the neuron, such as calcium, chloride and magnesium.

If the numbers of each type of ion were equal, the sodium–potassium pump would be electrically neutral, but, because of the three-for-two exchange, it gives a net movement of one positive charge from intracellular to extracellular for each cycle, thereby contributing to a positive voltage difference.  The pump has three effects:  (1) it makes the sodium concentration high in the extracellular space and low in the intracellular space; (2) it makes the potassium concentration high in the intracellular space and low in the extracellular space; (3) it gives the intracellular space a negative voltage with respect to the extracellular space.

The sodium-potassium pump is relatively slow in operation. If a cell were initialized with equal concentrations of sodium and potassium everywhere, it would take hours for the pump to establish equilibrium. The pump operates constantly, but becomes progressively less efficient as the concentrations of sodium and potassium available for pumping are reduced.

Ion pumps influence the action potential only by establishing the relative ratio of intracellular and extracellular ion concentrations.  The action potential involves mainly the opening and closing of ion channels not ion pumps.  If the ion pumps are turned off by removing their energy source, or by adding an inhibitor such as ouabain, the axon can still fire hundreds of thousands of action potentials before their amplitudes begin to decay significantly.  In particular, ion pumps play no significant role in the repolarization of the membrane after an action potential.

Another functionally important ion pump is the sodium-calcium exchanger. This pump operates in a conceptually similar way to the sodium-potassium pump, except that in each cycle it exchanges three Na+ from the extracellular space for one Ca++ from the intracellular space. Because the net flow of charge is inward, this pump runs "downhill", in effect, and therefore does not require any energy source except the membrane voltage. Its most important effect is to pump calcium outward—it also allows an inward flow of sodium, thereby counteracting the sodium-potassium pump, but, because overall sodium and potassium concentrations are much higher than calcium concentrations, this effect is relatively unimportant. The net result of the sodium-calcium exchanger is that in the resting state, intracellular calcium concentrations become very low.

Ion channels

Ion channels are integral membrane proteins with a pore through which ions can travel between extracellular space and cell interior. Most channels are specific (selective) for one ion; for example, most potassium channels are characterized by 1000:1 selectivity ratio for potassium over sodium, though potassium and sodium ions have the same charge and differ only slightly in their radius. The channel pore is typically so small that ions must pass through it in single-file order.    Channel pores can be either open or closed for ion passage, although a number of channels demonstrate various sub-conductance levels. When a channel is open, ions permeate through the channel pore down the transmembrane concentration gradient for that particular ion. Rate of ionic flow through the channel, i.e. single-channel current amplitude, is determined by the maximum channel conductance and electrochemical driving force for that ion, which is the difference between the instantaneous value of the membrane potential and the value of the reversal potential.

A channel may have several different states (corresponding to different conformations of the protein), but each such state is either open or closed. In general, closed states correspond either to a contraction of the pore—making it impassable to the ion—or to a separate part of the protein, stoppering the pore. For example, the voltage-dependent sodium channel undergoes inactivation, in which a portion of the protein swings into the pore, sealing it.  This inactivation shuts off the sodium current and plays a critical role in the action potential.

Ion channels can be classified by how they respond to their environment. For example, the ion channels involved in the action potential are voltage-sensitive channels; they open and close in response to the voltage across the membrane. Ligand-gated channels form another important class; these ion channels open and close in response to the binding of a ligand molecule, such as a neurotransmitter. Other ion channels open and close with mechanical forces. Still other ion channels—such as those of sensory neurons—open and close in response to other stimuli, such as light, temperature or pressure.

Leakage channels
Leakage channels are the simplest type of ion channel, in that their permeability is more or less constant. The types of leakage channels that have the greatest significance in neurons are potassium and chloride channels. Even these are not perfectly constant in their properties: First, most of them are voltage-dependent in the sense that they conduct better in one direction than the other (in other words, they are rectifiers); second, some of them are capable of being shut off by chemical ligands even though they do not require ligands in order to operate.

Ligand-gated channels

Ligand-gated ion channels are channels whose permeability is greatly increased when some type of chemical ligand binds to the protein structure. Animal cells contain hundreds, if not thousands, of types of these. A large subset function as neurotransmitter receptors—they occur at postsynaptic sites, and the chemical ligand that gates them is released by the presynaptic axon terminal. One example of this type is the AMPA receptor, a receptor for the neurotransmitter glutamate that when activated allows passage of sodium and potassium ions.  Another example is the GABAA receptor, a receptor for the neurotransmitter GABA that when activated allows passage of chloride ions.

Neurotransmitter receptors are activated by ligands that appear in the extracellular area, but there are other types of ligand-gated channels that are controlled by interactions on the intracellular side.

Voltage-dependent channels
Voltage-gated ion channels, also known as voltage dependent ion channels, are channels whose permeability is influenced by the membrane potential. They form another very large group, with each member having a particular ion selectivity and a particular voltage dependence. Many are also time-dependent—in other words, they do not respond immediately to a voltage change but only after a delay.

One of the most important members of this group is a type of voltage-gated sodium channel that underlies action potentials—these are sometimes called Hodgkin-Huxley sodium channels because they were initially characterized by Alan Lloyd Hodgkin and Andrew Huxley in their Nobel Prize-winning studies of the physiology of the action potential. The channel is closed at the resting voltage level, but opens abruptly when the voltage exceeds a certain threshold, allowing a large influx of sodium ions that produces a very rapid change in the membrane potential. Recovery from an action potential is partly dependent on a type of voltage-gated potassium channel that is closed at the resting voltage level but opens as a consequence of the large voltage change produced during the action potential.

Reversal potential
The reversal potential (or equilibrium potential) of an ion is the value of transmembrane voltage at which diffusive and electrical forces counterbalance, so that there is no net ion flow across the membrane. This means that the transmembrane voltage exactly opposes the force of diffusion of the ion, such that the net current of the ion across the membrane is zero and unchanging. The reversal potential is important because it gives the voltage that acts on channels permeable to that ion—in other words, it gives the voltage that the ion concentration gradient generates when it acts as a battery.

The equilibrium potential of a particular ion is usually designated by the notation Eion.The equilibrium potential for any ion can be calculated using the Nernst equation. For example, reversal potential for potassium ions will be as follows:

where
 Eeq,K+= equilibrium potential for potassium, measured in volts
 R = universal gas constant, equal to 8.314 joules·K−1·mol−1
 T = absolute temperature, measured in kelvins (= K = degrees Celsius + 273.15)
 z = number of elementary charges of the ion in question involved in the reaction
 F = Faraday constant, equal to 96,485 coulombs·mol−1 or J·V−1·mol−1
 [K+]o= extracellular concentration of potassium, measured in mol·m−3 or mmol·l−1
 [K+]i= intracellular concentration of potassium

Even if two different ions have the same charge (i.e., K+ and Na+), they can still have very different equilibrium potentials, provided their outside and/or inside concentrations differ. Take, for example, the equilibrium potentials of potassium and sodium in neurons. The potassium equilibrium potential EK is −84 mV with 5 mM potassium outside and 140 mM inside. On the other hand, the sodium equilibrium potential,  ENa, is approximately +66 mV with approximately 12 mM sodium inside and 140 mM outside.

Changes to membrane potential during development
A neuron's resting membrane potential actually changes during the development of an organism. In order for a neuron to eventually adopt its full adult function, its potential must be tightly regulated during development. As an organism progresses through development the resting membrane potential becomes more negative. Glial cells are also differentiating and proliferating as development progresses in the brain. The addition of these glial cells increases the organism's ability to regulate extracellular potassium. The drop in extracellular potassium can lead to a decrease in membrane potential of 35 mV.

Cell excitability

Cell excitability is the change in membrane potential that is necessary for cellular responses in various tissues. Cell excitability is a property that is induced during early embriogenesis. Excitability of a cell has also been defined as the ease with which a response may be triggered. The resting and threshold potentials forms the basis of cell excitability and these processes are fundamental for the generation of graded and action potentials.

The most important regulators of cell excitability are the extracellular electrolyte concentrations (i.e. Na+, K+, Ca2+, Cl−, Mg2+) and associated proteins. Important proteins that regulate cell excitability are voltage-gated ion channels, ion transporters (e.g. Na+/K+-ATPase, magnesium transporters, acid–base transporters), membrane receptors and hyperpolarization-activated cyclic-nucleotide-gated channels. For example, potassium channels and calcium-sensing receptors are important regulators of excitability in neurons, cardiac myocytes and many other excitable cells like astrocytes. Calcium ion is also the most important second messenger in excitable cell signaling. Activation of synaptic receptors initiates long-lasting changes in neuronal excitability. Thyroid, adrenal and other hormones also regulate cell excitability, for example, progesterone and estrogen modulate myometrial smooth muscle cell excitability.

Many cell types are considered to have an excitable membrane. Excitable cells are neurons, muscle (cardiac, skeletal, smooth), vascular endothelial cells, pericytes, juxtaglomerular cells, interstitial cells of Cajal, many types of epithelial cells (e.g. beta cells, alpha cells, delta cells, enteroendocrine cells, pulmonary neuroendocrine cells, pinealocytes), glial cells (e.g. astrocytes), mechanoreceptor cells (e.g. hair cells and Merkel cells), chemoreceptor cells (e.g. glomus cells, taste receptors), some plant cells and possibly immune cells. Astrocytes display a form of non-electrical excitability based on intracellular calcium variations related to the expression of several receptors through which they can detect the synaptic signal. In neurons, there are different membrane properties in some portions of the cell, for example, dendritic excitability endows neurons with the capacity for coincidence detection of spatially separated inputs.

Equivalent circuit

Electrophysiologists model the effects of ionic concentration differences, ion channels, and membrane capacitance in terms of an equivalent circuit, which is intended to represent the electrical properties of a small patch of membrane.  The equivalent circuit consists of a capacitor in parallel with four pathways each consisting of a battery in series with a variable conductance.  The capacitance is determined by the properties of the lipid bilayer, and is taken to be fixed.  Each of the four parallel pathways comes from one of the principal ions, sodium, potassium, chloride, and calcium.  The voltage of each ionic pathway is determined by the concentrations of the ion on each side of the membrane; see the Reversal potential section above.  The conductance of each ionic pathway at any point in time is determined by the states of all the ion channels that are potentially permeable to that ion, including leakage channels, ligand-gated channels, and voltage-gated ion channels.

For fixed ion concentrations and fixed values of ion channel conductance, the equivalent circuit can be further reduced, using the Goldman equation as described below, to a circuit containing a capacitance in parallel with a battery and conductance.  In electrical terms, this is a type of RC circuit (resistance-capacitance circuit), and its electrical properties are very simple.  Starting from any initial state, the current flowing across either the conductance or the capacitance decays with an exponential time course, with a time constant of , where  is the capacitance of the membrane patch, and  is the net resistance.  For realistic situations, the time constant usually lies in the 1—100 millisecond range.  In most cases, changes in the conductance of ion channels occur on a faster time scale, so an RC circuit is not a good approximation; however, the differential equation used to model a membrane patch is commonly a modified version of the RC circuit equation.

Resting potential
When the membrane potential of a cell goes for a long period of time without changing significantly, it is referred to as a resting potential or resting voltage.  This term is used for the membrane potential of non-excitable cells, but also for the membrane potential of excitable cells in the absence of excitation.  In excitable cells, the other possible states are graded membrane potentials (of variable amplitude), and action potentials, which are large, all-or-nothing rises in membrane potential that usually follow a fixed time course.  Excitable cells include neurons, muscle cells, and some secretory cells in glands.  Even in other types of cells, however, the membrane voltage can undergo changes in response to environmental or intracellular stimuli. For example, depolarization of the plasma membrane appears to be an important step in programmed cell death.

The interactions that generate the resting potential are modeled by the Goldman equation.  This is similar in form to the Nernst equation shown above, in that it is based on the charges of the ions in question, as well as the difference between their inside and outside concentrations. However, it also takes into consideration the relative permeability of the plasma membrane to each ion in question.

The three ions that appear in this equation are potassium (K+), sodium (Na+), and chloride (Cl−). Calcium is omitted, but can be added to deal with situations in which it plays a significant role.  Being an anion, the chloride terms are treated differently from the cation terms; the intracellular concentration is in the numerator, and the extracellular concentration in the denominator, which is reversed from the cation terms. Pi stands for the relative permeability of the ion type i.

In essence, the Goldman formula expresses the membrane potential as a weighted average of the reversal potentials for the individual ion types, weighted by permeability. (Although the membrane potential changes about 100 mV during an action potential, the concentrations of ions inside and outside the cell do not change significantly. They remain close to their respective concentrations when then membrane is at resting potential.) In most animal cells, the permeability to potassium is much higher in the resting state than the permeability to sodium.  As a consequence, the resting potential is usually close to the potassium reversal potential.  The permeability to chloride can be high enough to be significant, but, unlike the other ions, chloride is not actively pumped, and therefore equilibrates at a reversal potential very close to the resting potential determined by the other ions.

Values of resting membrane potential in most animal cells usually vary between the potassium reversal potential (usually around -80 mV) and around -40 mV. The resting potential in excitable cells (capable of producing action potentials) is usually near -60 mV—more depolarized voltages would lead to spontaneous generation of action potentials. Immature or undifferentiated cells show highly variable values of resting voltage, usually significantly more positive than in differentiated cells. In such cells, the resting potential value correlates with the degree of differentiation: undifferentiated cells in some cases may not show any transmembrane voltage difference at all.

Maintenance of the resting potential can be metabolically costly for a cell because of its requirement for active pumping of ions to counteract losses due to leakage channels. The cost is highest when the cell function requires an especially depolarized value of membrane voltage. For example, the resting potential in daylight-adapted blowfly (Calliphora vicina) photoreceptors can be as high as -30 mV. This elevated membrane potential allows the cells to respond very rapidly to visual inputs; the cost is that maintenance of the resting potential may consume more than 20% of overall cellular ATP.

On the other hand, the high resting potential in undifferentiated cells does not necessarily incur a high metabolic cost. This apparent paradox is resolved by examination of the origin of that resting potential. Little-differentiated cells are characterized by extremely high input resistance, which implies that few leakage channels are present at this stage of cell life. As an apparent result, potassium permeability becomes similar to that for sodium ions, which places resting potential in-between the reversal potentials for sodium and potassium as discussed above. The reduced leakage currents also mean there is little need for active pumping in order to compensate, therefore low metabolic cost.

Graded potentials
As explained above, the potential at any point in a cell's membrane is determined by the ion concentration differences between the intracellular and extracellular areas, and by the permeability of the membrane to each type of ion. The ion concentrations do not normally change very quickly (with the exception of Ca2+, where the baseline intracellular concentration is so low that even a small influx may increase it by orders of magnitude), but the permeabilities of the ions can change in a fraction of a millisecond, as a result of activation of ligand-gated ion channels. The change in membrane potential can be either large or small, depending on how many ion channels are activated and what type they are, and can be either long or short, depending on the lengths of time that the channels remain open. Changes of this type are referred to as graded potentials, in contrast to action potentials, which have a fixed amplitude and time course.

As can be derived from the Goldman equation shown above, the effect of increasing the permeability of a membrane to a particular type of ion shifts the membrane potential toward the reversal potential for that ion. Thus, opening Na+ channels shifts the membrane potential toward the Na+ reversal potential, which is usually around +100 mV. Likewise, opening K+ channels shifts the membrane potential toward about –90 mV, and opening Cl− channels shifts it toward about –70 mV (resting potential of most membranes). Thus, Na+ channels shift the membrane potential in a positive direction, K+ channels shift it in a negative direction (except when the membrane is hyperpolarized to a value more negative than the K+ reversal potential), and Cl− channels tend to shift it towards the resting potential.

Graded membrane potentials are particularly important in neurons, where they are produced by synapses—a temporary change in membrane potential produced by activation of a synapse by a single graded or action potential is called a postsynaptic potential. Neurotransmitters that act to open Na+ channels typically cause the membrane potential to become more positive, while neurotransmitters that activate K+ channels typically cause it to become more negative; those that inhibit these channels tend to have the opposite effect.

Whether a postsynaptic potential is considered excitatory or inhibitory depends on the reversal potential for the ions of that current, and the threshold for the cell to fire an action potential (around –50mV). A postsynaptic current with a reversal potential above threshold, such as a typical Na+ current, is considered excitatory. A current with a reversal potential below threshold, such as a typical K+ current, is considered inhibitory. A current with a reversal potential above the resting potential, but below threshold, will not by itself elicit action potentials, but will produce subthreshold membrane potential oscillations. Thus, neurotransmitters that act to open Na+ channels produce excitatory postsynaptic potentials, or EPSPs, whereas neurotransmitters that act to open K+ or Cl− channels typically produce inhibitory postsynaptic potentials, or IPSPs. When multiple types of channels are open within the same time period, their postsynaptic potentials summate (are added together).

Other values
From the viewpoint of biophysics, the resting membrane potential is merely the membrane potential that results from the membrane permeabilities that predominate when the cell is resting.  The above equation of weighted averages always applies, but the following approach may be more easily visualized.
At any given moment, there are two factors for an ion that determine how much influence that ion will have over the membrane potential of a cell:
 That ion's driving force
 That ion's permeability

If the driving force is high, then the ion is being "pushed" across the membrane.  If the permeability is high, it will be easier for the ion to diffuse across the membrane.
 Driving force is the net electrical force available to move that ion across the membrane.  It is calculated as the difference between the voltage that the ion "wants" to be at (its equilibrium potential) and the actual membrane potential (Em). So, in formal terms, the driving force for an ion = Em - Eion
 For example, at our earlier calculated resting potential of −73 mV, the driving force on potassium is 7 mV : (−73 mV) − (−80 mV) = 7 mV.  The driving force on sodium would be (−73 mV) − (60 mV) = −133 mV.
 Permeability is a measure of how easily an ion can cross the membrane.  It is normally measured as the (electrical) conductance and the unit, siemens, corresponds to 1 C·s−1·V−1, that is one coulomb per second per volt of potential.

So, in a resting membrane, while the driving force for potassium is low, its permeability is very high.  Sodium has a huge driving force but almost no resting permeability.  In this case, potassium carries about 20 times more current than sodium, and thus has 20 times more influence over Em than does sodium.

However, consider another case—the peak of the action potential.  Here, permeability to Na is high and K permeability is relatively low.  Thus, the membrane moves to near ENa and far from EK.

The more ions are permeant the more complicated it becomes to predict the membrane potential.  However, this can be done using the Goldman-Hodgkin-Katz equation or the weighted means equation.  By plugging in the concentration gradients and the permeabilities of the ions at any instant in time, one can determine the membrane potential at that moment.  What the GHK equations means is that, at any time, the value of the membrane potential will be a weighted average of the equilibrium potentials of all permeant ions.  The "weighting" is the ions relative permeability across the membrane.

Effects and implications
While cells expend energy to transport ions and establish a transmembrane potential, they use this potential in turn to transport other ions and metabolites such as sugar. The transmembrane potential of the mitochondria drives the production of ATP, which is the common currency of biological energy.

Cells may draw on the energy they store in the resting potential to drive action potentials or other forms of excitation. These changes in the membrane potential enable communication with other cells (as with action potentials) or initiate changes inside the cell, which happens in an egg when it is fertilized by a sperm.

Changes in the dielectric properties of plasma membrane may act as hallmark of underlying conditions such as diabetes and dyslipidemia.

In neuronal cells, an action potential begins with a rush of sodium ions into the cell through sodium channels, resulting in depolarization, while recovery involves an outward rush of potassium through potassium channels. Both of these fluxes occur by passive diffusion.

 A dose of salt may trigger the still-working neurons of a fresh cut of meat into firing, causing muscle spasms.

See also
 Bioelectrochemistry
 Chemiosmotic potential
 Electrochemical potential
 Goldman equation
 Membrane biophysics
 Microelectrode array
 Saltatory conduction
 Surface potential
 Gibbs–Donnan effect
 Synaptic potential

Notes

References

Further reading
 Alberts et al. Molecular Biology of the Cell. Garland Publishing; 4th Bk&Cdr edition (March, 2002). . Undergraduate level.
 Guyton, Arthur C., John E. Hall. Textbook of medical physiology. W.B. Saunders Company; 10th edition (August 15, 2000). . Undergraduate level.
 Hille, B. Ionic Channel of Excitable Membranes  Sinauer Associates, Sunderland, MA, USA; 1st Edition, 1984.
 Nicholls, J.G., Martin, A.R. and Wallace, B.G.  From Neuron to Brain Sinauer Associates, Inc. Sunderland, MA, USA  3rd Edition, 1992.
 Ove-Sten Knudsen. Biological Membranes: Theory of Transport, Potentials and Electric Impulses. Cambridge University Press (September 26, 2002). . Graduate level.
 National Medical Series for Independent Study. Physiology. Lippincott Williams & Wilkins. Philadelphia, PA, USA  4th Edition, 2001.

External links
 Functions of the Cell Membrane
 Nernst/Goldman Equation Simulator
 Nernst Equation Calculator
 Goldman-Hodgkin-Katz Equation Calculator
 Electrochemical Driving Force Calculator
 The Origin of the Resting Membrane Potential - Online interactive tutorial (Flash)

Cell communication
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Cellular neuroscience
Electrochemical concepts
Electrophysiology
Membrane biology

Membrane potential


نادي ستاد نيون لكرة القدم  نادي كرة قدم سويسري يلعب في دوري التحدي . تم تأسيس النادي في سنة 1901 .

مراجع

أندية كرة قدم أسست في 1901
أندية كرة قدم أسست في 1905
أندية كرة قدم في سويسرا
تأسيسات سنة 1905 في سويسرا
مدينة نيون

نادي نيون


كلية العقبة الجامعية أنشأت عام 2001 استجابة لتوجيهات الملك عبد الله الثاني ملك الأردن في مجال التعليم العالي والمتمثلة بتوفير فرص الدراسة الجامعية لأبناء منطقة العقبة بأقل تكلفة، وبأيسر الطرق ولرفد إقليم الجنوب بكوادر مؤهلة علمياً وعملياً.

افتتحت الكلية عند بدء الفصل الدراسي الثاني من العام الجامعي 2000–2001 بقبول شعبة واحدة في تخصص إدارة الفنادق، ثم جرى التوسع في التخصصات بحسب حاجة السوق المحلي على مستوى مرحلة البكالوريوس والدبلوم. عقدت الكلية اتفاقية توأمة مع كلية كوموسون الكندية في مجال العلوم الفندقية.

تبلغ المساحة الإجمالية لموقع الكلية 156 دونم، وتم انجاز المرحلة الأولى والتي تمثل مبنى الإدارة ومبنى كلية الفندقة ومبنى التميز الذي يضم مختبرات وقاعات تدريسية. ومن مرافق الكلية قاعات للتدريس، ومختبرات الحاسوب، ومختبرات اللغات، ومختبر تجهيز وإعداد الطعام، ومختبر الإيواء، والمطبخ، ومختبر التمريض، والكافتيريا، والعيادة، ومختبرات ومحاكيات بحرية وقاعة الخرائط والفن البحري، وقاعة ذكية.

يصل عدد أعضاء هيئة التدريس في الكلية 46 عضواً و50 عضو هيئة إدارية، فيما يبلغ العدد الإجمالي لطلبة الكلية 1500 طالب وطالبة منهم 963 طالبا لمرحلة البكالوريوس، و546 طالبا لمرحلة الشهادة الجامعية المتوسطة.

وسعت الكلية من نشاطتها التعليمي وبدأت برمجة تخصصاتها وأدرجت التخصصات التالية في الكلية، تكنولوجيا المعلومات، العلوم المالية والمصرفية، إدارة نظام المعلومات، إدارة المكتبات، المحاسبة. وفي العام الدراسي 2004/2005 بدأت الكلية بإدخال تخصص إدارة السياحة ولحقها التمريض المشارك وتربية الطفل، والآن هناك تخصص جديد وهو «إدارة المستودعات» حيث تعد ثاني كلية يدرس بها هذا التخصص في الأردن.

شراكات الكلية

 سلطة منطقة العقبة الاقتصادية الخاصة لرعاية المساحة الخضراء في الكلية من خلال إعادة تدوير المياه.
 مؤسسة إنجاز لتهيئة الفرص الإقتصادية للشباب الأردني في مجالات تدريب وتأهيل الشباب لدخول سوق العمل.
 برنامج انا اشارك / المعهد الديمقراطي الوطني للشؤون الدولية والوكالة الأمريكية للتنمية الدولية NDI.
 الجمعية الملكية لحماية البيئة البحرية في إطار الصحافة البيئية في المملكة الأردنية الهاشمية والعقبة بشكل خاص وبالتعاون مع مؤسسة هاينريش بول فلسطين والأردن.
 هيئة شباب كلنا الأردن.

البحث العلمي
تعتبر كلية العقبة من الكليات البارزة بالفندقة، فكل مشاريع التخرج والأبحاث تأخذها الإدارة بعين الاعتبار، عدا عن الدعم المعنوي للطلاب من أعضاء الهيئة التدريسية.

التخصصات المتوفرة بالكلية حاليا

الدبلوم

1- إدارة الفنادق

2- إدارة المستودعات

3- علوم مالية ومصرفية

4- تكنولوجيا المعلومات

5-نظم المعلومات الإدارية

6- المحاسبة

7- التمريض المشارك

8-تربية الطفل

9-إدارة الأعمال

10- الخدمة الاجتماعية

البكالوريوس

1- إدارة الفنادق

2- نظم المعلومات الإدارية

3- علوم مالية ومصرفية

4- المحاسبة

5- علم الحاسوب

6- تكنولوجيا نقل بحري

7-إدارة الشحن والتخليص

روابط خارجية

 الموقع الرسمي للكلية

مراجع

التعليم في الأردن
جامعات حسب المدينة
جامعات وكليات
كليات تابعة لجامعة البلقاء التطبيقية
كليات حسب البلد

كلية العقبة الجامعية


NGC 5608 est une galaxie irrégulière de type magellanique relativement rapprochée et située dans la constellation du Bouvier. Sa vitesse par rapport au fond diffus cosmologique est de , ce qui correspond à une distance de Hubble de . NGC 5608 a été découverte par l'astronome germano-britannique William Herschel en 1787.

Avec une brillance de surface égale à , on peut qualifier NGC 5608 de galaxie à faible brillance de surface (LSB en anglais pour ). Les galaxies LSB sont des galaxies diffuses (D) avec une brillance de surface inférieure de moins d'une magnitude à celle du ciel nocturne ambiant.

La classe de luminosité de NGC 5608 est V-VI et elle présente une large raie HI. Elle renferme également des régions d'hydrogène ionisé. De plus, c'est une galaxie du champ, c'est-à-dire qu'elle n'appartient pas à un amas ou un groupe et qu'elle est donc gravitationnellement isolée.

À ce jour, trois mesures non basées sur le décalage vers le rouge (redshift) donnent une distance de , ce qui est à l'intérieur des valeurs de la distance de Hubble. Puisque cette galaxie est relativement rapprochée du Groupe local, cette distance est peut-être plus près de sa distance réelle que la distance de Hubble. Notons que c'est avec la valeur moyenne des mesures indépendantes, lorsqu'elles existent, que la base de données NASA/IPAC calcule le diamètre d'une galaxie.

Notes et références

Notes

Références

Voir aussi

Articles connexes
 Liste des objets du New General Catalogue

Liens externes

 NGC 5608 sur le site du professeur C. Seligman

5608
Constellation du Bouvier
Galaxie irrégulière
Galaxie irrégulière magellanique
Galaxie du champ
Galaxie à faible brillance de surface
Objet céleste découvert en 1787
Objet céleste découvert par William Herschel

NGC 5608


ලුණුගල ශ්‍රී ලංකාවේ ඌව පළාතේ ලුණුගල ප්‍රාදේශීය ලේකම් කොට්ඨාශයේ පිහිටි සුන්දර කුඩා නගරයකි. කදු පන්ති රාශියකින් වටවි මධ්‍ය ප්‍රදේශයේ ලුණුගල නගරය පිහිටා ඇත.අතිතයේදි ලුණුගල "පට්ටිපොල" ලෙස හදුන්වන ලදි.එහි ප්‍රධාන කෘෂිකාර්මික නිෂ්පාදනය වන්නේ තේ ය

පාසල්
 ලුණුගල මහා විද්‍යාලය
 ලුණුගල යපම්ම කණිටු විදුහල
 රාම ක්‍රිෂ්ණා දමිල විද්‍යාලය
 මුස්ලිම් විද්‍යාලය
 ජනතාපුර විද්‍යාලය
 ජයබිම ප්‍රාථමික විද්‍යාලය

රෝහල්

ආගමික ස්ථාන
 ලුණුගල ශ්‍රි ලෝණගිරි පුරාණ රජමහා විහාරය
 යපම්ම ශ්‍රී රම්‍ය විජයාරාම විහාරය
 ලුණුගල ශ්‍රී කදිරේශන් කොවිල
 ජුම්මා මුස්ලිම් පල්ලිය
 ලුණූගල කතෝලික පල්ලිය

මූල්‍ය ආයතන
 ලංකා බැංකුව
 මහජන බැංකුව
 ප්‍රාදේශිය සංවර්ධන බැංකුව

ගැලරිය

ආශ්‍රිත ලිපි
 ලුණුගල ප්‍රාදේශීය ලේකම් කොට්ඨාශය

සබැදියන්

ශ්‍රී ලංකාවේ නගර සහ ගම්මාන

ලුණුගල


ස්ත්‍රීපුර උමග සංකීර්ණය යනු ඌවපරණගම ප්‍රදේශීය ලේකම් කොඨ්ඨාශය තුල පිහිටි උමං සංකීර්ණයක් වේ. රාම - සීතා පුරාවෘත්තයට අනුව රාමකුමරු සීතා දේවිය රාවණා රජු හා හනුමාන් චරිතවලට සම්බන්ධ වැදගත් ඓතිහාසික ස්ථාන රැසක් වැලිමඩ සානුව තුළ විවිධ ප්‍රදේශ තුලින් වාර්තා වේ.

රාවණා රජු විසින් ඉන්දියාවෙන් පැහැරගෙන එන ලදැයි කියනු ලබන සීතා දේවිය ආරක්ෂා සහිතව රඳවා තබන ලද්දේ ඌව පරණගම කිරවනාගම ප්‍රදේශයේ පිහිටි ස්ත්‍රීපුර කන්දේ ඇති බිංගෙයක බව පැවසේ.

පිහිටීම
ස්ත්‍රීපුර යනු ඌව පරණගම පිහිටි විශාල කන්දකි. ඌවපරණගම, මූදනාව හා සපුගොල්ල යන ගම් ප්‍රදේශ 2න් ම මෙම කන්දට පිවිසිය හැක. මෙහි කදුමුදුනට ගමන් කිරීමේදී අඩි 8-10 ක පමණ විශ්කම්භයකින් යුත් වංගු සහිත විශාල බිංග 3ක් පොළව මතුපිටින් දැකගත හැක. ත්‍රිකෝණාකාරව පිහිටි මෙම බිංග 3න් 2ක් පස්වලින් වැසී පැවතීම නිසා ඇතුලුවීම තරමක් අපහසු වේ. නමුත් පැරැන්න් මෙම බිංග 3ම තරණය කර ඇත. ඇතුලු විය හැකි බිංගය තුල මචක් ගමන් කිරීමේදී දෙපසට ගමන් කරන ප්‍රධාන භූගත මාර්ග 2 ක් හා ඇතුලත විවිධ දිශාවන් ඔස්සේ වූ භූගත මාර්ග පවතී. මෙම බිංග තුලින් කිලෝමීටර ගනනක් දුරට පොලොව යටින් ගමන් කල හැකි වේ.

ඉතිහාසය
සීතා දේවිය ඇතුලු රාවණා රජුගේ අන්තඞපුර කාන්තාවන් 700ක් මේ බිංගෙයෙහි රඳවා සිටි බව පැවැසේ. සීතා දේවිය ස්නානය කළායි කියනු ලබන සුන්දර මනා දියඇල්ල ස්ත්‍රීපුර කන්දට කි.මී. 3 පමණ දකුණු දෙසින් ලුණුවත්ත ප්‍රාදේශීය ලේකම් කාර්යාලය ආසන්නයේ පිහිටා ඇත. මෙම උමගෙහි එක් අන්තයක් මනා දියඇල්ල වෙත ගමන් කරනබව ගම්මු සදහන් කරයි.

මෙම ස්ථානයේ පර්යේෂන කල බොහෝ දෙනා සදහන් කරන ආකාරයට රාම - සීතා පුරාවෘත්තයට නෑකම් කියන වලපනේ රාගල සහ බණ්ඩාරවෙල දෝව පන්සල තුල පිහිටා ඇති උමග මේ සමග සම්බන්ධ වෙන බව සදහන්වේ.

මූලාශ්‍ර

 වැලිමඩ සානුවේ රාමා-සීතා පුරාවෘත්තයේ මං සලකුණු
 About Stripura
 පුරා විද්‍යාව

සටහන්

පුරා විද්‍යාව - ශ්‍රී ලංකාව
උමං මාර්ග

ස්ත්‍රීපුර උමග


Chickasaw County er navnet på 2 counties i USA:

 Chickasaw County, Iowa
 Chickasaw County, Mississippi

Chickasaw County


Ravnstrup Kirke er sognekirke i Ravnstrup Sogn, beliggende i landsbyen Ravnstrup vest for Viborg.

Historie
Kirken blev opført omkring år 1200 i romansk stil, med kampesten fundet i lokalområdet. Klokketårnet og våbenhuset er senere tilbygninger.

I tårnet hænger to klokker. Den ældste er fra 1614, og bærer indskriften "SI DEUS PRO NOBIS QUIS CONTRA NOS". ("Er Gud for os, hvem kan da være imod os?"), der er et citat fra Romerbrevet. Den største klokke blev i 1973 skænket til kirken af den lokale gårdejer Jørgen Jørgensen. Prædikestolen i kirken er fra 1634

I årene 1996-97 brugte menighedsrådet 1.500.000 kr. på en indendørs renovering.

Før kommunalreformen i 1970 hørte kirken under Nørlyng Herred.

Referencer

Eksterne henvisninger

 Ravnstrup Kirkes hjemmeside
 Ravnstrup Kirke  på visitviborg.dk
 Ravnstrup Kirke hos KortTilKirken.dk
 Kirkens beskrivelse i Trap – Kongeriget Danmark, 3. Udgave 4. Bind, s. 694 hos Projekt Runeberg

Kirker i Viborg Kommune
Kirker i Viborg Stift
Kirker i Viborg Amt

Ravnstrup Kirke


Christopher Columbus Kraft Jr. () a fost un inginer aerospațial american și manager al NASA, care a avut un rol esențial pentru misiunile de control ale agenției.

Biografie profesională
După absolvirea Virginia Tech în 1944, Kraft a fost angajat de National Advisory Committee for Aeronautics (NACA), organizația predecesoare Administrației Naționale Aeronautice și Spațiale (NASA). A lucrat timp de peste un deceniu în cercetarea aeronautică înainte de a fi cooptat  în Space Task Group (în 1958), o mică echipă însărcinată cu trimiterea primului om în spațiu. Kraft a devenit primul director de zbor al NASA, fiind în funcție în timpul unor misiuni istorice, precum Mercury-Redstone 3, Mercury-Atlas 6 sau Gemini 4.

Note

Bibliografie

Legături externe

 National Aviation Hall of Fame reveals names of four to be inducted in Class of 2016 la National Aviation Hall of Fame

Nașteri în 1924
Nașteri pe 28 februarie
Decese în 2019
Decese pe 22 iulie
Americani de origine germană
Episcopalieni americani
Ingineri aerospațiali americani
Programul Apollo

Christopher C. Kraft Jr.


A Alliance of Motion Picture and Television Producers (AMPTP) é uma associação comercial com sede em Sherman Oaks, na Califórnia, que representa mais de 350 empresas estadunidenses de produção de televisão e cinema nas negociações coletivas com sindicatos da indústria do entretenimento que incluem, entre outros, SAG-AFTRA, o , o Writers Guild of America West, o Writers Guild of America, East, a American Federation of Musicians e a International Alliance of Theatrical Stage Employees.

Sobre
A AMPTP foi fundada em 1924 como a Association of Motion Picture Producers ou AMPP e se fundiu com outras organizações ao longo dos anos. É responsável por negociar cerca de oitenta acordos coletivos de trabalho em nome de centenas de produtores de cinema e televisão. Alguns dos membros da AMPTP incluem os principais estúdios de cinema (como Paramount Pictures, Sony Pictures, Universal Pictures, Walt Disney Studios e Warner Bros.), as principais redes de televisão aberta (como ABC, CBS, FOX e NBC), serviços de sob demanda como Netflix, Apple TV+ e Amazon, certas redes de televisão a cabo e outras empresas independentes de produção de cinema e televisão.

A atual presidente do grupo é Carol Lombardini.

Conflitos
A AMPTP é a representante oficial da indústria do entretenimento nas negociações coletivas com os sindicatos dos trabalhadores do setor, como roteiristas, diretores, atores, músicos e técnicos. A AMPTP já enfrentou vários conflitos e greves com esses sindicatos ao longo dos anos, sobre questões como salários, benefícios, direitos autorais e novas tecnologias.

Um dos conflitos mais recentes foi a greve dos roteiristas de 2023, que começou em maio após o impasse nas negociações entre a AMPTP e o Writers Guild of America (WGA). Um dos pontos de divergência foi o uso da inteligência artificial (IA) na criação de conteúdo audiovisual. O WGA queria regular o uso da IA e garantir os direitos dos roteiristas sobre o material gerado por ela. A AMPTP disse que a IA levanta questões criativas e legais complexas que precisam de mais discussão.

Produtores de cinema dos Estados Unidos
Empresas de produção cinematográfica dos Estados Unidos
Organizações fundadas em 1924


Dutschke puede referirse a:

 La germanización de un apellido sorbio (Dučk, Dučka, Dučko):
 Rudi Dutschke (1940 - 1979), líder de la revolución de 1968.
 Dutschke (película), película de 2009 sobre su vida.
 Gretchen Dutschke-Klotz (1942-), mujer de Rudi Dutschke.

Notas

Dutschke


ගූගල් ඉමේජස් යනු 2001 ජූලි මාසයේදී හඳුන්වාදෙනු ලැබූ, ගූගල් සමාගමට අයත් සෙවුම් සේවාවකි. එමගින් පරිශීලකයන්ට අන්තර්ජාලය තුල අඩංගු ඡායාරූප පහසුවෙන් සොයාගත හැක.

මේවාද බලන්න
 TinEye
 Picsearch
 Yahoo Image Search
 Bing Images
 Image search
 Google Image Search Features

මූලාශ්‍ර

බාහිර සබැඳි
 Google Image Search website
 Google Image Labeler Beta
 The Official Google Blog

ගූගල් ඉමේජස්


Marth ist ein Einschlagkrater im Südwesten der Mondvorderseite in der Ebene des Palus Epidemiarum, südwestlich des Kraters Mercator, nahe den Rimae Ramsden.
Der kleine Krater weist einen doppelten Wall auf, indem sich ein etwas kleinerer innerer Krater genau im Zentrum des äußeren Kraters befindet.

Der Krater wurde 1935 von der IAU nach dem deutschen Astronomen Albert Marth offiziell benannt.

Weblinks

 Marth auf The-Moon Wiki

Einzelnachweise

Einschlagkrater (Mond)

Marth (Mondkrater)


Jerry Rivera (d. Geraldo Rivera Rodríguez, 31 Temmuz 1973, Humacao), Porto Rikolu salsa ve Latin pop şarkıcısıdır.

Dış bağlantılar

 Twitter'da Jerry Rivera
 Allmusic'te Jerry Rivera
 Discogs'ta Jerry Rivera
 Last.fm'de Rivera Jerry Rivera
 IMDB'de Jerry Rivera

Yaşayan insanlar
1973 doğumlular
Humacao doğumlular
Porto Rikolu erkek şarkıcılar
Porto Rikolu pop şarkıcıları
Latin pop şarkıcıları
21. yüzyıl erkek şarkıcıları
21. yüzyılda Amerikalı şarkıcılar

Jerry Rivera


Nonet may refer to:

nonet (music), a composition which requires nine musicians for a performance
Nonet (Farrenc) (1849) by Louise Farrenc
Nonet (Lachner) (1875) by Franz Lachner
Nonet (Villa-Lobos) (1923) by Heitor Villa-Libos
Wind Nonet (Parry) (1877) by Hubert Parry
nonet, a nine line poem, with the first line containing nine syllables, the next eight, so on until the last line has one syllable; see glossary of poetry terms
Nonet, a proton nuclear magnetic resonance spectrum structure with nine peaks
Nonet, a representation of subatomic particles in the quark model
Nonet, another term for a box or region in Sudoku, usually a 3x3 subsection

Nonet


ජෙනීලියා ද'සූසා (උපත 1987 අගෝස්තු 5)  ඉන්දීය ජාතික නිළියක සහ නිරූපිකාවක වේ. ඇය දකුණු ඉන්දීය සිනමාව තුළ සහ බොලිවුඩ් සිනමාව තුළින් දැකගත හැක.

මූලාශ්‍ර

1987 උපත්
සිනමාව
ඉන්දියානු සිනමාව

ජෙනීලියා ඩි'සූසා


Plenarno predavanje (keynote predavanje), predavanje na znanstvenom ili stručnom skupu. Da bi imalo taj status mora kao takvo biti označeno na programu skupa. Drže ih eminentni znanstvenici odnosno stručnjaci iz pojedinih područja i obično su to ključna predavanja oko čijih tema se gradi ostali sadržaj skupova.

Izvori

Znanost

Plenarno predavanje


Volmer Erik Reinholdt Nissen (3. november 1918 i Frederiksborg Slotssogn - 8. april 2008, Arresødal Hospice, Frederiksværk) var en dansk politiadvokat og juridiske chef for Københavns Narkotikapoliti fra 1968-1988.

Tidlige år
Som student fra Frederiksborg Statskole påbegyndte han sit jurastudium i 1936 på Københavns Universitet. I juni 1941 færdiggjorde han sine studier med det, der dengang hed første karakter – som dengang Danmarks yngste cand.jur., kun 22 år gammel.

Efter en kort tid i Københavns magistrats 1st. afdeling, tiltrådte han 1. maj 1942 en stilling som politifuldmægtig ved Københavns politis undersøgelseskamre. Som politifuldmægtig havde dengang et nært samarbejde med de tilknyttede kriminalfolk, hvor man kunne lære et og andet.

Politifuldmægtig i Københavns Politi og modstandsmand
Indledningsvis var de sager, Volmer Nissen beskæftigede sig med, ret ukomplicerede. Sagerne var i høj grad påvirket af besættelsen, således at eksempelvis cykeltyverier ikke blot var en lille ting. Cykler var en mangelvare, og straffen var stærkt afhængig af, om der var tale om brugstyveri, der kunne straffes med hæfte – og gøres betinget -, eller om reelt tyveri, der betød fængsel i et halvt år. Ubetinget.

Senere kom han også til at beskæftige sig med blandt andet Magstrædemordet samt overskridelser af rejsetilladelser, hvor han for første gang gjorde erfaring med fænomenet politifuldmægtig Leifer, chef for politiets visumkontor. Ved besættelsen blev den almindelige danske borger afskåret fra frit at rejse til Sverige uden nogen særlig anledning; tyskerne ønskede ikke ukontrolleret færdsel over Øresund. Man overlod det til dansk politi at administrere rejsetilladelserne, der stort set kun blev givet til forretningsrejser af en vis størrelse og markante familiebegivenheder. Rejste man uden lovlig tilladelse og blev opdaget, kunne man regne med at få fængselsstraf.

Omend ingen var i tvivl om, hvor Volmer Nissens sympatier lå under besættelsen, spillede han dog indledningsvis ingen aktiv rolle i modstandsarbejdet indtil en dag, hvor hans barndomskammerat Helge Mogensen fra Studenternes Efterretningstjeneste dukkede op i undersøgelseskammeret. Han ville gerne have hjælp til at få repareret våben, hvilket Volmer Nissen fik fasciliteret. Derudover, havde Helge Mogensen brug for at få tjekket nogle folk, der var blevet udpeget som stikkere. En rolle, som Volmer Nissen tog på sig frem til krigens slutning.

19. september 1944
19. september 1944 måtte Volmer Nissen flygte henover tagene ved Københavns byret. Tyskerne havde bestemt, at det danske politi skulle fjernes. Volmer Nissen levede under jorden frem til december 1944 med en ny identitet som forsikringsagent. I forbindelse med et tandlægebesøg, blev han klar over, at statsadvokat Jørgen Trolle var i gang med at sammensætte et korps af jurister, som anklagere ved sit kontor og derfor gerne ville i kontakt med Volmer Nissen. Juristerne skulle tage sig af ikke-politiske sager, dvs. almindelige kriminalsager. At politiet ikke eksisterede var jo ikke ensbetydende med mindre kriminalitet. Snarere tværtimod.

Statsadvokatfuldmægtig i statsadvokaturen for Sjælland 1944-1945
Om et mord var politisk eller et udslag af almindelig kriminalitet kunne typisk afgøres ved et besøg på Retsmedicinsk Institut og en besigtigelse af liget, omend flere og flere rovmord hen mod krigens slutning blev kamuflere som stikkerlikvideringer. Politiske sager blev ikke efterforsket, men henlagt til efter krigen. Ellers måtte man forsøge at efterforske. Det indsatte vagtværn måtte udelukkende pågribe folk og aflevere dem. Efterforskningen var overladt til juristerne.

Forbindelser inden for modstandsbevægelsen mente, at det ville være en god ide, hvis Volmer Nissen flyttede til Hillerød den sidste tid før befrielsen sammen med sin kone og lille søn. Her meldte han sig hos kammeraterne i ventegruppen "Kulsvierbataillonen", Frederiksborg Amt Vest, som han havde haft løbende samarbejde med i weekenderne. Og det var blandt andet med dem, at han deltog i opgøret med tyskerne, da befrielsesbudskabet havde lydt.

Han vendte derefter tilbage til København, hvor han blev, i lighed med kammeraterne inden for modstandsbevægelsen, der hovedsageligt tilhørte den af Arne Sejr stiftede "Studenternes Efterretningstjeneste", S. E., indrulleret i Den Danske Brigade. Også kaldet Danforces feltpolitidetachement. Relativt kort tid herefter blev han kaldt tilbage til statsadvokaturen, hvor man havde behov for hans aktive bistand.

Efter befrielsen
Statsadvokat Jørgen Trolle ønskede ikke at deltage i retsopgøret mod folk, der havde samarbejdet med besættelsesmagten. Dels fordi det kriminaliserede handlinger, der havde været anset som fuldt lovlige på gerningstidspunktet, dels fordi det omfattede alt for mange handlinger af ringe strafværdighed. Han mente, man burde koncentrere sig om en hurtig retsforfølgning i de grove sager om landsforræderi, så retsopgøret kunne færdiggøres på få år.

Volmer Nissen fulgte Trolle og begyndte nu at møde i landsretten i stedet for byretten som anklager i en del af de sager, der lå efter 7 måneder uden politi. Såvel almindelige sager som politisager, der var en overtrædelse af særlovgivningen, heriblandt sagen om de falske britiske pund, der var produceret i Sacsenhausen under krigen. Sagen medførte en rejse til London for Volmer Nissen og afsløringen af en historie, der var en kriminalroman værdig.

Tilbage til Københavns Politi og Edderkopsagen
Da Statsadvokat Trolle blev udnævnt til landsdommer, valgte Volmer Nissen at vende tilbage til politiadvokaturen, hvor han blev inviteret til at deltage i efterforskningen af sagen mod blandt andre Johannes Linde og Svend Aage Hasselstrøm. Sagen der blev døbt Edderkop-sagen. Det blev en sag, der på mange måder rystede Danmark, ikke mindst Volmer Nissen i kraft af sagens efterspil for en ikke-korrupt kriminalassistent.

Ved Edderkopsagens afslutning fik Volmer Nissen sit eget undersøgelseskammer, hvor sagerne bedst kunne karakteriseres som en blandet landhandel med alt fra mord, sædelighedsforbrydelser, potentiel kunstsvindel, pengeskabssprængninger og trafikdrab.

Juridisk chef for Københavns Narkotikapoliti
Københavns Narkotikapoliti
I september 1968 tiltrådte Volmer Nissen stillingen som juridisk leder af 8. undersøgelsekammer i Københavns politi, afdeling N. Narkotikaafdelingen – en stilling han bestred frem til sin pension i 1988. Volmer Nissen kæmpede her indædt for at skaffe politiet de fornødne redskaber imod narkokriminalitetens mordere engros med et stærk fokus på bagmændene. Han kæmpede for en ændret lovgivning områder som brugen af anonyme vidner og undercover agenter samt narkohæleri. Et arbejde, der i særdeleshed blev officielt værdsat af DEA i USA, der inviterede Volmer Nissen på en storslået og spændende rundrejse, der kunne virke som inspiration for et fremtidigt yderligere samarbejde.

Det skulle ligeledes blive DEA, der i første omgang aktivt hjalp med at skaffe "flash rolls", dvs. kontanter i store mængder, til fremvisning i forbindelse med køb af større narkopartier fra narkoens underverden. Og som til tider hjalp med at agere agenter ved handelen.

Politiadvokat Volmer Nissen, var en for nogen kontroversiel for andre populær leder af narkotikapolitiet i København, hvor han i næsten samme periode var justitsministeriet repræsentant ved FN's årlige møder i først Geneve og siden Wien i "Commission on Narcotic Drugs", dvs. fra 1970-1988. Her var det i særdeleshed samarbejdet landene imellem, der var i fokus – nogle med større samarbejdsvilje end andre.

Volmer Nissen fortsatte med at være i pressens søgelys frem til sin død i 2008. Indledningsvis primært vedrørende narkopolitikken, men senere i særdeleshed om Edderkopsagen, stikkerlikvideringer under besættelsen med mere. Han medvirkede i DRs dokumentarfilm Edderkop-affæren i 2000 og i 2001 udkom Peter Øvig Knudsens bog "Efter drabet", hvor Volmer Nissen fortæller om sin deltagelse i modstandsarbejdet i kapitlet "De kalkede grave". Volmer Nissen deltog endvidere i Peter Øvig Knudsen og Martin Henriksens dokumentarfilm "Med ret til at dræbe", der ligeledes omhandlede stikkerlikvideringerne under besættelsen.

Kilder
 Politikens Nekrolog: Markant pioner mod narkokriminalitet død - Volmer Nissen, fhv. politiadvokat, satte store præg på danmarkshistorien http://politiken.dk/indland/ECE492871/markant-pioner-mod-narkokriminalitet-doed/
 Om likvideringer i Information: "Det var ikke lovligt, det var krig" http://www.information.dk/58574
 Om likvideringer i Berlingske Tidende: Er et mord altid et mord? http://www.b.dk/kultur/er-et-mord-altid-et-mord

Eksterne henvisninger

Københavns Politi
Jurister fra Danmark
Modstandsfolk fra Danmark

Volmer Erik Reinholdt Nissen


Dame Ellen Patricia MacArthur  (born 8 July 1976) is a retired English sailor, from Whatstandwell near Matlock in Derbyshire, now based in Cowes, Isle of Wight.

MacArthur is a successful solo long-distance yachtswoman.  On 7 February 2005, she broke the world record for the fastest solo circumnavigation of the globe, a feat which gained her international renown. Francis Joyon, the Frenchman who had held the record before MacArthur, was able to recover the record again in early 2008.

Following her retirement from professional sailing on 2 September 2010, MacArthur announced the launch of the Ellen MacArthur Foundation, a charity that works with business and education to accelerate the transition to a circular economy.

Early life

MacArthur was born in Derbyshire where she lived with her parents, who were both teachers, and two brothers Fergus, still in Whatstandwell, and Lewis, who now lives in Pennsylvania. She acquired her early interest in sailing, firstly by her desire to emulate her idol at the time, Sophie Burke, and secondly by reading Arthur Ransome's Swallows and Amazons series of books. She has since become the Patron of the Nancy Blackett Trust which owns and operates Ransome's yacht, Nancy Blackett.

Her first experience of sailing was on a boat owned by her aunt Thea MacArthur on the east coast of England. She saved her school dinner money for three years to buy her first boat, an eight-foot dinghy, which she named Threp'ny Bit even though decimalisation had taken place before she was born. She sellotaped a real 'threepenny bit' coin onto the bow.

MacArthur attended Wirksworth County Infants and Junior Schools and the Anthony Gell School and also worked at a sailing school in Hull. When she was 17, MacArthur bought a Corribee and named it Iduna; she described the first moment she saw it as "love at first sight". In 1995 she sailed Iduna single-handed on a circumnavigation of Great Britain.

In 1997, she finished 17th in the Mini Transat solo transatlantic race after fitting out her 21 ft (6.4 m) Classe Mini yacht Le Poisson herself while living in a French boatyard.

She was named 1998 British Telecom/Royal Yachting Association "Yachtsman of The Year" in the UK and "Sailing's Young Hope" in France.

Asteroid 20043 Ellenmacarthur is named after her.

Professional sailing career
MacArthur first came to general prominence in 2001 when she finished second in the Vendée Globe solo round-the-world sailing race in her Owen Clarke/Rob Humphreys designed Kingfisher (named after her sponsors, Kingfisher plc), and subsequently MacArthur was appointed a Member of the Order of the British Empire (MBE) for services to sport. At 24, she was the youngest competitor to complete the voyage.

In 2003, she captained a round-the-world record attempt for a crewed yacht in Kingfisher 2 (a catamaran formerly owned by Bruno Peyron and known as Orange), but was thwarted by a broken mast in the Southern Ocean.

A trimaran named B&Q/Castorama (after two companies in the Kingfisher group) unveiled in January 2004, was specially designed by Nigel Irens and Benoit Cabaret for her to break solo records. The 75-foot (23 m) trimaran was built in Australia, with many of the components specifically arranged to take into account MacArthur's 5-foot 2 inch (1.57 m) height.

Using the yacht, her first significant record attempt in 2004 to break the west–east transatlantic crossing time failed by around one and a quarter hours, after over seven days of sailing.

She began her attempt to break the solo record for sailing non-stop around the world on 28 November 2004. During her circumnavigation, she set records for the fastest solo voyage to the equator, past the Cape of Good Hope, past Cape Horn and back to the equator again.  She crossed the finishing line near the French coast at Ushant at 22:29 UTC on 7 February 2005 beating the previous record set by French sailor Francis Joyon by 1 day, 8 hours, 35 minutes, 49 seconds. Her time of 71 days, 14 hours, 18 minutes 33 seconds is world record for the  covered.  This is an average speed of .

On 8 February 2005, following her return to England, it was announced that she was to be made a Dame Commander of the Order of the British Empire (DBE) in recognition of her achievement. It is believed that she is the youngest ever recipient of this honour. Coming immediately after the event being recognised, rather than appearing in due course in the New Year's or Birthday Honours lists, this recognition was reminiscent of accolades previously bestowed upon Francis Drake and Francis Chichester when reaching home shores after their respective circumnavigations in 1580 and 1967. MacArthur was also granted the rank of Honorary Lieutenant Commander, Royal Naval Reserve on the same day.

In recognition of her achievement she was appointed a Knight (Chevalier) of the French Legion of Honour by President Nicolas Sarkozy in March 2008. She is a fluent French speaker.

In 2007 MacArthur headed up BT Team Ellen, a three-person sailing team which includes Australian Nick Moloney and Frenchman Sébastien Josse.

In October 2009 MacArthur announced her intention to retire from competitive racing to concentrate on the subject of resource and energy use in the global economy.

Sailing records
In June 2000, MacArthur sailed the monohull Kingfisher from Plymouth, UK to Newport, Rhode Island, USA in 14 days, 23 hours, 11 minutes.  This is the current record for a single-handed woman monohull east-to-west passage, and also the record for a single-handed woman in any vessel.

MacArthur's second place in the 2000–2001 edition of the Vendée Globe, with a time of 94 days, 4 hours and 25 minutes, was the world record for a single-handed, non-stop, monohull circumnavigation by a woman. The record stood for 20 years until Clarisse Crémer beat it in 2020-2021 edition of the Vendée Globe.

In June 2004, MacArthur sailed her trimaran B&Q/Castorama from Ambrose Light, Lower New York Bay, USA to Lizard Point, Cornwall, UK in 7 days, 3 hours, 50 minutes.  This set a new world record for a transatlantic crossing by women, beating the previous crewed record as well as the singlehanded version.

In 2005, MacArthur beat Francis Joyon's existing world record for a single-handed non-stop circumnavigation.  MacArthur in the trimaran B&Q/Castorama sailed  at an average speed of 15.9 knots. Her time of 71 days, 14 hours, 18 minutes 33 seconds beat Joyon's then world record time by 1 day, 8 hours, 35 minutes and 49 seconds. She had no more than 20 minutes' sleep at a time during the voyage, having to be on constant lookout day and night. On 23 November 2007 Joyon set off in IDEC 2 in an attempt to beat MacArthur's current world record for a single handed circumnavigation. He achieved his goal in 57 days, 13 hours 34 minutes and 6 seconds. Despite Joyon's reclamation of the record, Robin Knox-Johnston still described MacArthur's time as an "amazing achievement".

Her boat, now named USE IT AGAIN is skippered by French professional sailor, Romain Pilliard.

Popular culture
In 2009 McArthur appeared on BBC Radio 4's Desert Island Discs. Her chosen book was The SAS Survival Handbook by John "Lofty" Wiseman and her luxury item was a fluffy worm mascot.

MacArthur was referenced in the TV show The Thick Of It when Malcom Tucker (Peter Capaldi) referred to fictional Secretary of State for Social Affairs and Citizenship Nichola Murray (Rebecca Front) as 'Dame Ellen MacArse-ache'.

MacArthur was also the last record holder on Star in a Reasonably-Priced Car on the BBC's Top Gear television driving programme until the eighth series, when the car and rules were changed, and previous records were removed. The competition was a timed lap of a racetrack in a Suzuki Liana. She completed the lap in 1 minute 46.7 seconds, beating Jimmy Carr by 0.2 seconds. MacArthur won Top Gear'''s Fastest Driver of the Year award in 2005.

She also took part in 2011 TV series Jamie's Dream School.

There is a display about MacArthur at the Wirksworth Heritage Centre, Derbyshire.

Books
In 2002, MacArthur released her first autobiography entitled Taking on the World. Later she wrote Race Against Time, published in 2005, a day-by-day account of her record journey around the world. In September 2010, she published a second autobiography entitled Full Circle''.

Charities

Ellen MacArthur Cancer Trust

In 2003, MacArthur set up the Ellen MacArthur Trust (now the Ellen MacArthur Cancer Trust), a registered charity, to 8 to 24 year olds sailing to help them regain their confidence whilst recovering from cancer, leukaemia and other serious illnesses.

In 2008 MacArthur joined other sports celebrities to raise £4 million for the Rainbows children's hospice. The aim is to give terminally ill young people their own customised sleeping unit to enable children in separate age groups to have their families stay with them.

Ellen MacArthur Foundation

The Ellen MacArthur Foundation (EMF) is a UK registered charity which promotes the circular economy. It does this by developing and promoting the concept of a circular economy, working with business, policy makers and academics.

History
Founded on 23 June 2009, the foundation was publicly launched on 2 September 2010 by MacArthur at the Science Museum. The charity was inspired by MacArthur's sailing experiences.

On 17 May 2017, the Ellen MacArthur Foundation and Prince of Wales' International Sustainability Unit launched a US$2 million prize fund for innovations which work towards the management of waste plastics.

The Ellen MacArthur Foundation is a founding member and partner of the Platform for Accelerating the Circular Economy (PACE), which was launched out of the World Economic Forum.

References

External links

 Official website of Dame Ellen MacArthur

 Ellen MacArthur Foundation
 Wirksworth Heritage Centre

ISAF World Sailor of the Year (female)
English female sailors (sport)
Vendée Globe finishers
British Vendee Globe sailors
2000 Vendee Globe sailors
Single-handed circumnavigating sailors
Laureus World Sports Awards winners
Dames Commander of the Order of the British Empire
Sporting dames
People from Amber Valley
People from Cowes
1976 births
Living people
Knights of the Legion of Honour
English sailors
English explorers
Female explorers
Founders of charities
The Sunday Times Sportswoman of the Year winners
Royal Naval Reserve personnel

Ellen MacArthur


Zalama es la montaña más elevada de los montes de Ordunte. Tiene 1343 m de altitud y es fronterizo entre las provincias de Vizcaya y Burgos; separa los municipios de Carranza (Vizcaya) y Villasana de Mena (Burgos).

A escasos metros de la cima hay un monolito de piedra donde se puede leer: «Merindad de Montija, año 1886». En este punto convergen las fronteras de tres provincias: Vizcaya, Burgos y Cantabria. También próxima a la cima se desarrolla una comunidad vegetal peculiar y muy escasa hoy día, la turbera, una comunidad de musgos y hepáticas que se arraiga sobre un suelo casi siempre encharcado.

En la cara N de la montaña hay un gran barranco donde nace el río Calera, que da nombre a la aldea de La Calera del Prado, hoy casi deshabitada. Este arroyo de montaña hace frontera entre Vizcaya y Cantabria, y desemboca en el río Gándara que a su vez desagua en el río Asón. En su cara S se sitúa las aldeas de San Pelayo y Agüera desde donde parte la ruta de ascenso más común a esta montaña, que también puede subirse desde el puerto de Los Tornos situado al W de la misma.

En la cara Este de la cima de Zalama encontramos un enclave único en la geografía vasca, la turbera cobertor de Zalama. Esta turbera ha sido restaurada por la Diputación de Vizcaya y es objeto de diversas investigaciones de carácter internacional. Actualmente, la Universidad de Nottingham Trent está realizando una investigación de este hábitat para entender los procesos de degradación de este entorno y promover su conservación.

Montañas de Vizcaya
Montañas de la provincia de Burgos

Zalama


Davutlu, Sinop ilinin Ayancık ilçesine bağlı bir köydür.

Tarihçe
Köyün adı, 1487 yılı kayıtlarında Davud ya da Ziyal olarak geçmektedir. 14 Temmuz 1954'te tüzel kişiliği kaldırılarak Babaköy ile birleştirilen yerleşim, 1990'lı yıllarda yeniden köy statüsü kazandı.

Coğrafya
Köy, Sinop il merkezine 94 km, Ayancık ilçe merkezine 40 km uzaklıktadır.

Nüfus

Kaynakça

Dış bağlantılar

Ayancık belde ve köyleri

Davutlu, Ayancık


Gauss, 10−4 teslaya eşit manyetik alan birimidir. CGS sisteminin birimlerindendir. Adını Alman matematikçi ve fizikçi Johann Carl Friedrich Gauss' tan alır.

Manyetik alan birimleri
Alman icatları
Carl Friedrich Gauss
CGS birim sistemi

Gauss (birim)


Sally Kellerman (født 2. juni 1937, død 24. februar 2022) var en amerikansk skuespillerinde og sangerinde.

Hun blev bidt af teater efter at have medvirket i nogle skolekomedier og tog undervisning i skuespil på Actors Studio West. I mere end et årti fik hun kun små roller på tv og i film. Kellerman fik sit store gennembrud som major Margaret "Hot Lips" Houlihan i filmen MASH, en rolle, som hun blev nomineret til en Oscar for bedste kvindelige birolle, og hun fik siden haft en succesfuld karriere, hvor hun medvirkede i en række andre film samt talrige tv-produktioner.

Filmografi (udvalg)
 Back to school (1986)
 Køreskolen (1985)
 To uheldige helte (1978)
 Frygtens hus (1973)
 Tabte horisonter (1973)
 MASH (1970)
 Boston kvæleren (1968)

Eksterne henvisninger

Skuespillere fra USA
Sangere fra USA
Personer fra Long Beach (Californien)
Amerikanere i 1900-tallet
Amerikanere i 2000-tallet

Sally Kellerman


مدينة قدسيا الجديدة مدينة سورية تابعة لمحافظة ريف دمشق تقع على أطراف مدينة دمشق بالقرب من وادي العراد وترتفع 916 قدم عن سطح البحر وهي مركز ناحية .

تحدها البلدات والقرى التالية: البجاع - مساكن الديماس - جديدة الوادي - الهامة - ضاحية قدسيا، ومن الشرق مدينة دمشق .

مصادر

مراجع

أماكن مأهولة في منطقة قدسيا
مدن سوريا

قدسيا الجديدة


مُنَسْتِير (ب: Monastir) بلدة إيطالية بمقاطعة كالياري بسردينية. تبلغ مساحتها 31,76 ، وبلغ عدد سكانها 4.532 نسمة عام 2004.

السكان

في سنة 1861 بلغ عدد السكان  نسمة، وتطور العدد ليصل في سنة 2011 لـ  نسمة.

مراجع

بلديات مقاطعة جنوب سردينيا
مدن وبلدات في سردينيا

منستير (إيطاليا)


Gustav Guanella (* 21. Juni 1909 in Chur; † 12. Januar 1982 in Zürich) war ein Schweizer Elektroingenieur und Erfinder.

Leben

Guanella besuchte die Schulen bis und mit Matura in Luzern. Dann folgte das Studium zum Elektroingenieur an der ETH Zürich mit Abschluss 1933. Dort war er anschliessend bis 1937 Assistent von Fritz Fischer, dem Erfinder des Eidophor-Grossprojektionssystems, am Institut für Technische Physik. Danach war er freiberuflich als beratender Ingenieur tätig. Seit 1935 war er der Schwager von Albert Hofmann, dem Entdecker des LSD. 1938 heiratete er Hanni Zietzschmann. 1941 trat er in die Dienste der Firma Brown, Boveri & Cie (BBC), Baden, ein.

Bereits 1943 wurde er zum Vorstand der Abteilung Hochfrequenz-Kleingeräte ernannt. Er war bei BBC in dieser Funktion als ideenreicher Erfinder und geschätzter Vorgesetzter bis 1974 tätig. Er trug wesentlich zur Entwicklung der elektronischen Hochfrequenztechnik bei.

Leistungen

Am Institut von Fritz Fischer an der ETH waren neben Oberassistent Edgar Gretener (ab 1941 mit gleichnamiger eigener Firma) Guanella zusammen mit Werner Lindecker, Hugo Thiemann und Max Lattmann wissenschaftliche Mitarbeiter.

Guanella wagte 1937 als Erster den Schritt in die Selbständigkeit und machte vor dem späteren Eintritt bei BBC viele Erfindungen, welche unter seinem Namen oder dem Namen der damaligen Auftraggeber (Philips, SABA, AEG und auch schon BBC) zum Patent angemeldet wurden. Auf Espacenet des Europäischen Patentamtes finden sich bis 1941 über 40 Anmeldungen.

Am 23. August 1938 tätige Guanella beim Eidgenössischen Amt für Geistiges Eigentum in Bern eine Patentanmeldung, welche unter dem Titel Improvements in radio direction finding system 1941 zum Patent GB 534036 führte.

Mit Prioritätsdatum 26. September 1938 reichte er in der Schweiz eine Patentanmeldung mit dem Titel Verfahren und Einrichtung zum Nachweis und zur Messung der Entfernung von Reflexionsstellen ein. Sowohl in der Schweiz (CH 220877) wie auch in Frankreich, Grossbritannien und den USA wurden entsprechende Patente erteilt.

Am 12. Mai 1940 erfolgte eine verwandte Anmeldung zur Anzeige eines gesuchten Objektes auf einer Bildschirmröhre. Das entsprechende Patent CH 220780 trägt den Titel Verfahren und Einrichtung zur Richtungsanzeige von Wellen periodisch veränderlicher Frequenz.

Die erwähnten Patente beziehen sich auf die Ortungs- und spätere Radartechnik, welche zur Zeit des Zweiten Weltkrieges von Bedeutung waren.

Während seiner Tätigkeit bei BBC ab 1941 machte er viele weitere Erfindungen und Patentanmeldungen.

Am 3. Februar 1942 wurde in der Schweiz seine Patentanmeldung mit dem Titel Verfahren zur Übermittlung von Nachrichten, die mit Hilfe von Steuersignalen verschleiert werden eingereicht und 1952 erteilt. Das beschriebene Verfahren erlangte später als  (deutsch: Frequenzspreizverfahren) grosse Bedeutung in der abhörgesicherten drahtlosen Übertragung. Das entsprechende US-Patent 2405500 wurde 1946 erteilt.

Im Spread Spectrum Communications Handbook von M.Simon et al. wird Guanella mit Foto und Hinweisen (Seiten 43,44,121) als Swiss pioneer of noise-modulated radar and speech privacy systems gewürdigt.

Am bekanntesten wurde Guanella durch die Erfindung von Impedanzwandlern zur hochfrequenztechnischen Anpassung bei Schnittstellen, sogenannten Strom-Baluns, welche bis heute als Guanella-Balun bezeichnet werden. Die entsprechende Patentanmeldung unter dem Titel In einem elektrischen Netzwerk eingeschaltete Übertragungsvorrichtung mit Leitungscharakter wurde in der Schweiz am 25. Februar 1944 getätigt (CH 242060). Entsprechende Patente wurden in weiteren Ländern erteilt, insbesondere das US-Patent 2470307.

Weitere Erfindungen betrafen die Frequenzgegenkopplung für störungsfreien Empfang, Phasendiskriminatorschaltungen, die Leitstrahlsteuerung einer Flugabwehrrakete und die Impulsmodulation (Pulsphasenmodulation, PPM).

Sein Team bei BBC entwickelte erfolgreiche Produkte für die Richtfunkübertragung von Sprache und Daten, welche militärisch und zivil über viele Jahre im Einsatz standen. Dazu gehörten Sprachverschlüsselungsgeräte. Guanella schrieb das Vorwort zu einer Spezialausgabe der Brown Boveri Mitteilungen, welche den Stand auf dem Gebiet des Richtfunks 1956 schildert.

Auch Sonderfunksysteme für Polizei-, Feuerwehr-, Hafenverwaltungs- und Taxinetze im In- und Ausland gehörten zum Erfolgsausweis seiner Abteilung bei BBC. Insgesamt wurden von ihm, teilweise zusammen mit Arbeitskollegen als Erfinder, über 200 Patente (inklusive verwandte Auslandspatente) angemeldet.

Ehrungen

1965 wurde er vom Institute of Electrical and Electronics Engineers für seine Verdienste zum Fellow der IEEE ernannt.

1969 verlieh ihm die ETH, Zürich, gleichzeitig mit seinem Schwager Albert Hofmann (dem Schweizer Entdecker der Wirkung von LSD) den Titel Dr. Ing. ehrenhalber (Dr. Ing. h. c.).

Ein Labor- und Bürogebäude der Firma Asea Brown Boveri (ABB), dem Rechtsnachfolger von BBC, in Turgi im Kanton Aargau wurde zu Ehren von Guanella Gusti genannt.

Siehe auch
 Liste von Ingenieuren

Literatur
 Peter Josef Wild: Was war vor dem Handy? – Fernmeldetechnik bei der BBC. In: Franz Betschon et al. (Hrsg.): Ingenieure bauen die Schweiz – Technikgeschichte aus erster Hand, S. 408–414, Verlag Neue Zürcher Zeitung, Zürich 2013, ISBN 978-3-03823-791-4

Weblinks

Einzelnachweise

Hochfrequenz-Ingenieur
Ingenieur, Erfinder, Konstrukteur
Erfinder
IEEE Fellow
Ehrendoktor der ETH Zürich
Schweizer
Geboren 1909
Gestorben 1982
Mann

Gustav Guanella


La Convention sur l'imprescriptibilité des crimes de guerre et des crimes contre l'humanité (en anglais : Convention on the non-applicability of statutory limitations to war crimes and crimes against humanity) est un traité international qui émane de l'Organisation des Nations unies par lequel les pays signataires s'engagent à rendre imprescriptibles les crimes de guerre et les crimes contre l'humanité tels que définis dans la charte de Nuremberg du . Les États signataires s'engagent en outre à adopter toute mesure juridique requise pour permettre, selon les règles du droit international, l'extradition des personnes relevant de son Article II, qui énonce :

Entrée en vigueur
La convention, datée du , est soumise à la signature du  au . Conformément à son article VIII, la convention est entrée en vigueur  après le dépôt du dixième instrument de ratification ou d'adhésion, soit le .

Pays signataires
56 pays ont ratifié la convention. De nombreux États signalent en remarque qu'il est regrettable que la convention n'ait pas une portée plus universelle, les articles V et VII empêchant certains États de signer la Convention ou d'y adhérer et s'opposent ainsi au principe de l'égalité souveraine des États.

Cour pénale internationale
Le Statut de Rome de la Cour pénale internationale, entré en vigueur après la signature du soixantième État, le , comporte également en son article 29 une clause d'imprescriptibilité : .

Autres dispositions légales
 En France, depuis la Loi n° 64-1326 du , les crimes de guerre et les crimes contre l'humanité sont imprescriptibles.
 En Belgique, Le Titre Ibis du code pénal belge, « Des violations graves du droit international », entré en vigueur le , rend imprescriptibles les crimes relevant du droit international.
 La « Convention européenne sur l'imprescriptibilité des crimes contre l'humanité et des crimes de guerre » est régie par le traité n° 082 du .

Notes et références

Notes

Références

Traité entré en application en 1970
Traité signé en 1968
Traité des Nations unies
Crime de guerre
Crime contre l'humanité
Instrument international relatif aux droits de l'homme
Traité de droit international humanitaire
Traité de droit pénal international
Novembre 1968
Novembre 1970


A Dance to the Music of Time is a 12-volume roman-fleuve by English writer Anthony Powell, published between 1951 and 1975 to critical acclaim. The story is an often comic examination of movements and manners, power and passivity in English political, cultural and military life in the mid-20th century. The books were inspired by the painting of the same name by French artist Nicolas Poussin.

The sequence is narrated by Nicholas Jenkins. At the beginning of the first volume, Jenkins falls into a reverie while watching snow descending on a coal brazier. This reminds him of "the ancient world—legionaries ... mountain altars ... centaurs ..." These classical projections introduce the account of his schooldays, which opens A Question of Upbringing.

Over the course of the following volumes, he recalls the people he met over the previous half a century and the events, often small, that reveal their characters. Jenkins's personality is unfolded slowly, and often elliptically, over the course of the novels.

Poetry in the sequence has been explicated by Bernard Stacey who provides provenance and the poet as well as facts surrounding its use.

Time magazine included the novel in its list of the 100 best English-language novels from 1923 to 2005. The editors of Modern Library ranked the work as 43rd-greatest English-language novel of the 20th century. The BBC ranked the novel 36th on its list of the 100 greatest British novels. In 2019 Christopher de Bellaigue wrote in The Nation that A Dance to the Music of Time is "perhaps the supreme London novel of the 20th century, an examination of the human behavior that defines the upper echelons of this brash, resilient, often pitiless place."
Volumes 7-9, "The War Trilogy," --The Valley of Bones, The Soldier's Art and The Military Philosophers--are the focus of Bernard Stacey's War Dance.

Inspiration

Jenkins reflects on the Poussin painting in the first two pages of A Question of Upbringing:

These classical projections, and something from the fire, suddenly suggested Poussin's scene in which the Seasons, hand in hand and facing outward, tread in rhythm to the notes of the lyre that the winged and naked greybeard plays. The image of Time brought thoughts of mortality: of human beings, facing outward like the Seasons, moving hand in hand in intricate measure, stepping slowly, methodically sometimes a trifle awkwardly, in evolutions that take recognisable shape: or breaking into seemingly meaningless gyrations, while partners disappear only to reappear again, once more giving pattern to the spectacle: unable to control the melody, unable, perhaps, to control the steps of the dance.

Poussin's painting is housed at the Wallace Collection in London.

Analysis
 Powell's official biographer, Hilary Spurling, has published Invitation to the Dance – a Handbook to Anthony Powell's A Dance to the Music of Time. This annotates, in dictionary form, the characters, events, art, music, and other references. She has also calculated the timeline employed by the author: this is used in the synopses linked from the novels below.
 The various aspects of the novel-sequence are also analysed in An Index to 'A Dance to the Music of Time by B. J. Moule and D. McLeod  and Robert L. Selig.

The novels

Published dates are those of the first UK publication. The narrative is rarely specific about the years in which events take place. Those below are suggested by Hilary Spurling in Invitation to the Dance – a Handbook to Anthony Powell's A Dance to the Music of Time. Dust jackets of the first editions were designed by James Broom-Lynne.

Principal characters

Adaptations
The cycle was adapted by Frederick Bradnum as a Classic Serial on BBC Radio 4.
In order to fit the material in, it was broadcast as four separate serials each based on a set of three books: the first three serials had six episodes, the last eight. The series were broadcast between 1979 and 1982. The cycle was adapted again as a six-part Classic Serial on BBC Radio 4 from 6 April to 11 May 2008, directed by John Taylor. The cycle was adapted as a four-part TV series A Dance to the Music of Time by Anthony Powell and Hugh Whitemore for Channel 4 in 1997, directed by Christopher Morahan and Alvin Rakoff.

References

External links
 A synopsis of each novel from Anthony Powell Society
 "Models for Characters in Anthony Powell's A Dance to the Music of Time"
 Poussin's painting

Book series introduced in 1951
Dance to the Music of Time, A
Dance to the Music of Time, A
Modernist novels

A Dance to the Music of Time


National Center for Complementary and Integrative Health (på dansk: Det Nationale Center for Komplementær og Integrativ Sundhed) (NCCIH) er en amerikansk myndighed, som undersøger komplementær og alternativ medicin (KAM). Det blev oprindeligt skabt som Office for Alternative Medicine (OAM), og omdøbt til " the National Center for Complementary and Alternative Medicine (NCCAM), før de tog sit nuværende navn.

NCCIH er en af de 27 institutter og centre, der udgør National Institutes of Health (NIH) i Department of Health og Human Services i den føderale regering i USA.

Dens erklærede mission er: "at definere, gennem streng videnskabelig undersøgelse, anvendeligheden og sikkerheden af komplementære og alternative behandlingsinterventioner, og disse roller i at forbedre sundhed og sundhedspleje".

Organisation og historie

Navn og mission statement
NCCIH blev etableret i oktober 1991, som Office of Alternative Medicine (OAM), som blev re-etableret som NCCAM i oktober 1998 og igen som NCCIH i December 2014. Navneændringen til NCCIH har været diskuteret som et forsøg fra centeret for at afbøde kritik, eksempelvis for at undgå udtrykket "alternativ" og at distancere sig fra at have finansieret undersøgelser af tvivlsom værdi.

NCCAM's erklærede mission fortæller, at de er "dedikeret til at udforske komplementære og alternative helbredelsepraksisser ud fra et strengt videnskab synspunkt, uddanne forskere i  komplementær og alternativ behandling; og formidling af autoritativ information til offentligheden og fagfolk." Som NCCIH, er missionen "at definere, gennem en streng videnskabelig undersøgelse, anvendeligheden og sikkerheden af komplementære og alternative behandlingsinterventioner, og deres roller i at forbedre sundhed og sundhedspleje."

Kritik
NCCIH er blevet kritiseret af Steven E. Nissen, Stephen Barrett, og Kimball Atwood blandt andre, for, sammen med den National Heart, Lung and Blood Institute, at finansiere en undersøgelse af EDTA kelation terapi i forbindelse iskæmiske hjertesygdom, som varede i omkring 10 år og koste omkring $31 millioner, selv om mindre, kontrollerede forsøg vist at kelation er ineffektivt. Andre NCCIH-finansierede undersøgelser, har omfattet fordelene ved fjernbøn for AIDS-ramte, virkningerne af citron- og lavendel æteriske olier på sårheling, "energi kelation", og "rotter stresset af hvid støj".

Henvisninger

Eksterne links

 NCCIH hjemmeside
 NCCIH forskningsresultater
 NCCIH Clearinghouse, det offentlige kontaktpunkt for videnskabeligt baseret information på KAM, og for at få oplysninger om NCCIH
 NCCIH Kongressens bevillinger
 Hvorfor National Center for Complementary and Alternative Medicine (NCCAM), Bør Være Defunded Essay af Wallace I. Sampson, M. D.
 Udvalget for Skeptisk Undersøgelse

Etableret i 1991
USA's myndigheder


Radio Maria ist ein privater christlicher Radiosender katholischer Prägung mit Hauptsitz in Adliswil und mit Aussenstudio in Brig in der Schweiz. Bei Radio Maria arbeiten rund 15 Festangestellte und über 40 Ehrenamtliche. Radio Maria gehört zur Weltfamilie von Radio Maria und wurde von dieser bei der Gründung unterstützt. Der Sender finanziert sich durch die Spenden seiner Hörer.

Geschichte
Nachdem im Jahr 1997 zwei Gottesdienste aus dem Tessin für Radio Maria in Italien übertragen wurden, entstand der Wunsch, einen vergleichbaren Sender auch in der Schweiz zu gründen. Im Jahr 2005 wurde dazu der Verein «Amici Radio Maria Svizzera» gegründet. In einem ersten Schritt konnten andere Stationen der Weltfamilie finanziell unterstützt werden. Am 25. November 2008 wurde das Radio Studio von Radio Horeb in der Schweiz eingeweiht. Parallel dazu fanden Gespräche zur Gründung von Radio Maria Deutschschweiz statt. Am 9. Dezember 2009 bekam Radio Maria den Zuschlag, das Programm «Radio Maria Deutschschweiz» auf dem zweiten landesweiten Multiplex in der Region Deutschschweiz auszustrahlen. Der Sendestart am 13. Juni 2010 erfolgte in einem provisorischen Studio. Den Beginn des regulären Programms gibt der Sender mit dem 8. September desselben Jahres an.

Verbreitung
Das Programm ist über DAB+ (Kanal 7D in der ganzen Deutschschweiz), Internet (Website und Mobile Apps), Kabel (UPC Schweiz und Quickline) und Swisscom TV empfangbar.

Programm
Es werden täglich Gottesdienste und christliche Veranstaltungen oder Konferenzen auf dem Sender übertragen. In den Radio- und Fernsehstudios werden in Zusammenarbeit mit Referenten aus Kirche, Politik und Wirtschaft Sendungen produziert, um die Hörerinnen und Hörer auf ihrem Glaubensweg zu begleiten. Diese stehen auf der Webseite des Senders als Podcast zur Verfügung.

Die Sendung Guete Morge bi Radio Maria enthält Elemente aus dem Programmradio, die zu unterschiedlichen Uhrzeiten und teilweise im täglichen Wechsel geistliche Impulse, Lebensfragen, den Katechismus oder die katholische Sozial- und Gesellschaftslehre behandeln und weitere christliche Literatur vorstellen.

Zu den weiteren Sendungen gehört die Behandlung päpstlicher Dokumente, die Vorstellung von Personen des öffentlichen Lebens, Berichte und Talksendungen, sowie Reportagen über Glaubenszeugnisse.

Weblinks
 Radio Maria Deutsche Schweiz
 Radio Maria (Deutschschweiz) – Kurzeintrag zum Sender beim Bakom (mit Bakom-Meldung und weitere Dokumente)

Einzelnachweise

Maria Deutschschweiz
Maria Deutschschweiz
Römisch-katholisches Medium (Schweiz)
Schweiz
Medien (Kanton Zürich)
Adliswil
Maria Deutschschweiz
Neuevangelisierung
Sendestart 2010

Radio Maria (Deutschschweiz)


El intermedio (en italiano plural, intermedii) era una forma renacentista de entretenimiento teatral basado en la música, la danza, el canto o la declamación que se realizaba entre los actos de las tragedias, comedias, etc. En su momento, por su estilo amable y placentero, gozó de gran popularidad, sobre todo como contraste propio del drama que estaba siendo representado.

De origen italiano, consistía en principio, en un simple injerto de música instrumental o vocal, y más tarde se convirtió en género representantativo independiente, desarrollando tramas distintas a las del texto principal, en que era intercalado.

El intermedio fue uno de los precursores de la ópera e influyó en otras formas, como las mascaradas de las cortes europeas. Las bodas de las familias gobernantes y otras ocasiones similares fueron la ocasión habitual para lucir los intermedios más lujosos, en ciudades como Florencia o Ferrara. Alguna de la mejor documentación de los mismos proviene de las bodas celebradas en la familia Médici, en particular de la boda Médici celebrada en 1589, que ofrecería el conjunto más espectacular y conocido de intermedios, gracias, al menos, a 18 libros publicados contemporáneamente a la fiesta junto a magníficos grabados que fueron financiados por el Gran Duque.

Los intermedios fueron escritos e interpretados desde finales del  al , aunque el momento de mayor esplendor lo tuvo a lo largo del . A partir de 1600, se fusionó con la ópera, principalmente, aunque los intermedios se siguieron utilizando en obras no musicales en ciertos entornos (por ejemplo en las Academias), y también siguieron representándose entre los actos de las óperas.

Véase también
 Intermedio
 Entremés

Referencias

Bibliografía
 Artículo "Intermedio", en The New Grove Dictionary of Music and Musicians, ed. Stanley Sadie.  20 vol.  London, Macmillan Publishers Ltd., 1980.  ISBN 1-56159-174-2.
 The New Harvard Dictionary of Music, ed. Don Randel.  Cambridge, Massachusetts, Harvard University Press, 1986.  ISBN 0-674-61525-5.
 Reed, Sue Welsh & Wallace, Richard (ed.), Italian Etchers of the Renaissance and Baroque, 1989, Museum of Fine Arts, Boston, ISBN 0-87846-306-2 o 304-4 (pb).

Discografía
 La Pellegrina - Music for the Wedding of Ferdinando De Medici and Christine de Lorraine, Princess of France, Florence 1589, dirigida por Paul Van Nevel, solistas: Katelijne Van Laethem, Pascal Bertin, et al. (Sony/Columbia - 63362, 1998).  2 CD.
 La Pellegrina - Intermedii 1589, Capriccio Stravagante Renaissance Orchestra and Collegium Vocale Gent dirigida por Skip Sempe, solistas: Dorothée Leclair, Soprano / Monika Mauch, Soprano / Pascal Bertin, Alto / Stephan van Dyck, Tenor / Jean-François Novelli, Tenor / Antoni Fajardo, Bajo. (2 CD Paradizo PA0004 - 2007.

Música del Renacimiento
Drama
Teatro en el siglo XVI
Teatro en el siglo XVII
Géneros y formas musicales
Palabras y frases en italiano

Intermedio (música)