What utility is provided by the Bloch sphere visualization?

Question: The Bloch sphere is a mainstay of introductions to quantum computing, but what utility does it actually provide? It can't usefully represent multiple qbits because of entanglement and requires a weird transformation to map to & from a state vector. Sure it's a visual representation but I've never seen it actually assist anyone's acquisition of the material. Is it just a holdover from earlier days of the field and the reason why we'll be calling Rx/Ry/Rz with doubled theta values until the stars die out?
Answer: Some people really do visualise single qubit operations by thinking about the Bloch sphere, and they work out everything based on that picture. Those who like thinking in that way are often incredibly quick at these sorts of manipulations, and have more intuitive understandings for why things work.
But here's one concrete example where I use it: averaging over single qubit states. Let's say I've implemented some quantum operation on a single qubit state, and I want to compare it to the ideal, so perhaps I calculate a fidelity. (For instance, I might be trying to implement optimal cloning.) Perhaps that fidelity varies depending on what the input state is, and so I want to calculate the average fidelity. How do I average over all possible single-qubit states? It's the same as integrating over the surface of the Bloch sphere, and that conversion helps me to get the correct volume element, with the correct factors of 2.
Of course, I could memorise that function, just as everything that can be done with the Bloch sphere can be done another way. Personally, I don't usually use the Bloch sphere, but this is the most obvious instance where I have stuck with it.
There are other topics where I believe the Bloch sphere is particularly natural. For example, in the topic of magic states - single-qubit states that when combined with Clifford operations provide universal, fault-tolerant quantum computation. There's a lovely convexity argument that eliminates a particular geometric region of the Bloch sphere from consideration, and I think various subsequent results describe regions of the Bloch sphere that either can or can't act as magic states.
Comment: What vectors are used in the Bloch sphere? I mean, how are they represented? If I want to act , say, rotation on them , what's the format of the vector should be used?
Comment: @bilanush you've posted a question, it's my choice to answer it or not. You don't need to go chasing answers elsewhere.
Comment: It's not the same question, here I only ask what are the vectors. Far more concice and doesn't include many parts of the question. I am sorry if it interrupted you. It wasn't about chasing you, it was because I thought it's related to this question & answer. Anyways...


Can't Connect via SSH

Question: I just got a RPi, and I'm using this site to try and connect my Pi, so I allowed other users to connect via the connection, and my Pi is connected, but when I try to put the IP address into PuTTY, it says "Network Error: Connection refused". I think it may have to do with the port, because I'm just using the default in PuTTY, but I don't know what else to use.
Comment: related: http://raspberrypi.stackexchange.com/questions/33431/connect-to-raspberry-pi-over-ssh-connection-refused-from-putty
Answer: If you can access your RPi directly (plug in a keyboard and a mouse), make sure the ssh service is running. Try checking sudo service ssh status (I think there is also sshd as an alias so sudo service sshd status should give the same result).
If it says SSH server is not running, then this is the cause of your problem. Otherwise it might be something else (for example you put the IP of another computer that is online but doesn't have SSH).
You shouldn't have to change the port number, the default is 22 and Raspbian uses the default.
Comment: HDMI connection to a television will work. You should just need to get into the configuration to enable the SSH server:

"You can enable or disable the SSH server on your Raspberry Pi (it is enabled by default). This is done using raspi-config:

Enter sudo raspi-config in the terminal, then navigate to ssh, hit Enter and select Enable or disable ssh server." [https://www.raspberrypi.org/documentation/remote-access/ssh/README.md] Raspberry Pi Docs
Comment: It sounds like this is the problem - I haven't been able to access the terminal on my Pi to set up the SSH, which I thought using PuTTY might solve. But it sounds like I'll just need to set it up with HDMI?

Can't Connect via SSH


After Effects CC Audio Playback not working

Question: So I've been having this problem with my After Effects CC recently and it's actually cheesing my right off. I need to edit a frame by frame storyboard animatic and I can't edit to the sound because the sound refuses to playback. I've tried everything, there is no ''RAM PREVIEW'' button in the new version of AE and the period button simply resizes the window now. What do I need to do to make this work?
Answer: If you're on a machine with a number pad, then by default num-pad 0 is the ram preview button. If you're on a laptop with no num-pad, then try crtl0.
If you look in the Window menu you'll find a Previews panel that will let you set the keyboard shortcuts and their behaviours. More if you want to RTFM here.
Comment: I have figured it out, but just to note I did all of that anyway. Used ever shortcut there was. Turns out, my speakers were not selected under Audio Hardware outputs....
Answer: So, it turns out that I had to change my Audio Hardware output because my partner was editing a video and using his gaming chair as the output, I was at uni and didn't have it connected up, didn't realise AE has to have its audio output set up manually!
Answer: Try checking the "cache before playback" checkbox.  It is on the right hand side in the first screen shot near the playback controls (in the panel highlighted in blue.)  That looks like it should be the same as RAM preview.
Comment: No clue where that check box is!
Comment: It is right in your screen shot, on the right side in the box that is highlighted in blue.


Binary classification with strongly unbalanced classes

Question: I have a data set in the form of (features, binary output 0 or 1), but 1 happens pretty rarely, so just by always predicting 0, I get accuracy between 70% and 90% (depending on the particular data I look at). The ML methods give me about the same accuracy, and I feel, there should be some standard methods to apply in this situation, that would improve the  accuracy over the obvious prediction rule.
Comment: I've found this article to be very helpful on the subject: http://www.svds.com/learning-imbalanced-classes/
Comment: @J.O'BrienAntognini That is a really nice article!
Comment: Some useful discussion here: https://stats.stackexchange.com/questions/285231/what-problem-does-oversampling-undersampling-and-smote-solve?r=SearchResults&s=3|0.0000 and https://stats.stackexchange.com/questions/283170/when-is-unbalanced-data-really-a-problem-in-machine-learning
Comment: This post [here](https://stats.stackexchange.com/questions/247871/what-is-the-root-cause-of-the-class-imbalance-problem) has a very clear answer on _why_ class imbalance causes problems.
Comment: @StephenG At present, the post you've linked to has three answers. Which one are you referring to?
Comment: @Sycorax the first answer specifically.
Answer: Both hxd1011 and Frank are right (+1).
Essentially resampling and/or cost-sensitive learning are the two main ways of getting around the problem of imbalanced data; third is to use kernel methods that sometimes might be less effected by the class imbalance.
Let me stress that there is no silver-bullet solution. By definition you have one class that is represented inadequately in your samples.
Having said the above I believe that you will find the algorithms SMOTE and ROSE very helpful. SMOTE effectively uses a $k$-nearest neighbours approach to exclude members of the majority class while in a similar way creating synthetic examples of a minority class. ROSE tries to create estimates of the underlying distributions of the two classes using a smoothed bootstrap approach and sample them for synthetic examples. Both are readily available in R, SMOTE in the package DMwR and ROSE in the package with the same name. Both SMOTE and ROSE result in a training dataset that is smaller than the original one.
I would probably argue that a better (or less bad) metric for the case of imbalanced data is using Cohen's $k$ and/or Receiver operating characteristic's Area under the curve.
Cohen's kappa directly controls for the expected accuracy, AUC as it
is a function of sensitivity and specificity, the curve is insensitive to disparities in the class proportions. Again, notice that these are just metrics that should be used with a large grain of salt. You should ideally adapt them to your specific problem taking account of the gains and costs correct and wrong classifications convey in your case. I have found that looking at lift-curves is actually rather informative for this matter.
Irrespective of your metric you should try to use a separate test to assess the performance of your algorithm; exactly because of the class imbalanced over-fitting is even more likely so out-of-sample testing is crucial.
Probably the most popular recent paper on the matter is Learning from Imbalanced Data by He and Garcia. It gives a very nice overview of the points raised by myself and in other answers. In addition I believe that the walk-through on Subsampling For Class Imbalances, presented by Max Kuhn as part of the caret package is an excellent resource to get a structure example of how under-/over-sampling as well as synthetic data creation can measure against each other.
Comment: For a python implementation of a variety of data re-sampling techniques I recommend the imbalance-learn package: https://github.com/scikit-learn-contrib/imbalanced-learn
Comment: A third somewhat popular (and again not too appropriate) metric is the Area-Under-the-Curve of the Precision-Recall curve. [Davis & James, 2006](https://www.biostat.wisc.edu/~page/rocpr.pdf) paper is consider a classic on the matter; CV has a good thread [too](http://stats.stackexchange.com/questions/7207). I recently saw a paper with the somewhat hammy title "[The Precision-Recall Plot Is More Informative than the ROC Plot When Evaluating Binary Classifiers on Imbalanced Datasets](http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118432)", so one might want to check that too.
Comment: For highly imbalanced class distributions, AUPRC is more informative than AUROC. Details not includedhere as this is a comment. Among many sources, one is [here](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349800/).
Answer: First, the evaluation metric for imbalanced data would not be accuracy. Suppose you are doing fraud detection, that 99.9% of your data is not fraud. We can easy make a dummy model that have 99.9% accuracy. (just predict all data non-fraud).
You want to change your evaluation metric from accuracy to something else, such as F1 score or precision and recall. In the second link I provided. there are details and intuitions on why precision recall will work.
For highly imbalanced data, building a model can be very challenging. You may play with weighted loss function or modeling one class only. such as one class SVM or fit a multi-variate Gaussian (As the link I provided before.)
Comment: +1. Nice example and good mention on the one-class SVM. I think though that the $F_1$-score is a bit too heavy-handed ignoring true negative all-together.
Comment: the link to "precision and recall" is dead?
Answer: Class imbalance issues can be addressed with either cost-sensitive learning or resampling. See advantages and disadvantages of cost-sensitive learning vs. sampling, copypasted below:

{1} gives a list of advantages and disadvantages of cost-sensitive learning vs. sampling:

2.2 Sampling
Oversampling and undersampling can be used to alter
  the class distribution of the training data and both methods
  have been used to deal with class imbalance [1, 2, 3, 6, 10,
  11]. The reason that altering the class distribution of the
  training data aids learning with highly-skewed data sets is
  that it effectively imposes non-uniform misclassification
  costs. For example, if one alters the class distribution of the
  training set so that the ratio of positive to negative examples
  goes from 1:1 to 2:1, then one has effectively assigned
  a misclassification cost ratio of 2:1. This equivalency
  between altering the class distribution of the training data
  and altering the misclassification cost ratio is well known
  and was formally described by Elkan [9].
There are known disadvantages associated with the
  use of sampling to implement cost-sensitive learning. The
  disadvantage with undersampling is that it discards potentially
  useful data. The main disadvantage with oversampling,
  from our perspective, is that by making exact copies
  of existing examples, it makes overfitting likely. In fact,
  with oversampling it is quite common for a learner to generate
  a classification rule to cover a single, replicated, example.
  A second disadvantage of oversampling is that it
  increases the number of training examples, thus increasing
  the learning time.
2.3 Why Use Sampling?
Given the disadvantages with sampling, it is worth
  asking why anyone would use it rather than a cost-sensitive
  learning algorithm for dealing with data with a skewed
  class distribution and non-uniform misclassification costs.
  There are several reasons for this. The most obvious reason
  is there are not cost-sensitive implementations of all learning
  algorithms and therefore a wrapper-based approach
  using sampling is the only option. While this is certainly
  less true today than in the past, many learning algorithms
  (e.g., C4.5) still do not directly handle costs in the learning
  process.
A second reason for using sampling is that many
  highly skewed data sets are enormous and the size of the
  training set must be reduced in order for learning to be
  feasible. In this case, undersampling seems to be a reasonable,
  and valid, strategy. In this paper we do not consider
  the need to reduce the training set size. We would point
  out, however, that if one needs to discard some training
  data, it still might be beneficial to discard some of the majority
  class examples in order to reduce the training set size
  to the required size, and then also employ a cost-sensitive
  learning algorithm, so that the amount of discarded training
  data is minimized.
A final reason that may have contributed to the use of
  sampling rather than a cost-sensitive learning algorithm is
  that misclassification costs are often unknown. However,
  this is not a valid reason for using sampling over a costsensitive
  learning algorithm, since the analogous issue
  arises with sampling—what should the class distribution of
  the final training data be? If this cost information is not
  known, a measure such as the area under the ROC curve
  could be used to measure classifier performance and both
  approaches could then empirically determine the proper
  cost ratio/class distribution.

They also did a series of experiments, which was inconclusive:

Based on the results from all of the data sets, there is
  no definitive winner between cost-sensitive learning, oversampling
  and undersampling

They then try to understand which criteria in the datasets may hint at which technique is better fitted.
They also remark that SMOTE may bring some enhancements:

There are a variety of enhancements that people have
  made to improve the effectiveness of sampling. Some of
  these enhancements include introducing new "synthetic"
  examples when oversampling [5 -> SMOTE], deleting less useful majority-
  class examples when undersampling [11] and using
  multiple sub-samples when undersampling such than each
  example is used in at least one sub-sample [3]. While these
  techniques have been compared to oversampling and undersampling,
  they generally have not been compared to
  cost-sensitive learning algorithms. This would be worth
  studying in the future.

{1} Weiss, Gary M., Kate McCarthy, and Bibi Zabar. "Cost-sensitive learning vs. sampling: Which is best for handling unbalanced classes with unequal error costs?." DMIN 7 (2007): 35-41. https://scholar.google.com/scholar?cluster=10779872536070567255&hl=en&as_sdt=0,22 ; https://pdfs.semanticscholar.org/9908/404807bf6b63e05e5345f02bcb23cc739ebd.pdf
Comment: So to summarize the link: there results on which method is better are inconclusive, and it is easier to use the under/over-sampling. Right?
Comment: @LazyCat right.
Comment: Okay--that's a persuasive argument!
Comment: Yes, the platform has limitations.  But many of them are also features.  For instance, I would suppose that if one lengthy, detailed answer like this could reply adequately to two questions, *then those questions must be duplicates.*  And if they are not duplicates, then it should be possible to vary one's answers in a meaningful way so they are not just copy-pasted.  Which action should be taken in this case?  (cc @gung)
Comment: @whuber The other question has already been closed :-)
Answer: Several answers to this query have already provided several different approaches, all valid. This suggestion is from a paper and associated software by Gary King, eminent political scientist at Harvard. He has co-authored a paper titled Logistic Regression in Rare Events Data which provides some fairly cogent solutions.
Here's the abstract:

We study rare events data, binary dependent variables with dozens to
  thousands of times fewer ones (events, such as wars, vetoes, cases of
  political activism, or epidemiological infections) than zeros
  ("nonevents"). In many literatures, these variables have proven
  difficult to explain and predict, a problem that seems to have at
  least two sources. First, popular statistical procedures, such as
  logistic regression, can sharply underestimate the probability of rare
  events. We recommend corrections that outperform existing methods and
  change the estimates of absolute and relative risks by as much as some
  estimated effects reported in the literature. Second, commonly used
  data collection strategies are grossly inefficient for rare events
  data. The fear of collecting data with too few events has led to data
  collections with huge numbers of observations but relatively few, and
  poorly measured, explanatory variables, such as in international
  conflict data with more than a quarter-million dyads, only a few of
  which are at war. As it turns out, more efficient sampling designs
  exist for making valid inferences, such as sampling all variable
  events (e.g., wars) and a tiny fraction of nonevents (peace). This
  enables scholars to save as much as 99% of their (nonfixed) data
  collection costs or to collect much more meaningful explanatory
  variables. We provide methods that link these two results, enabling
  both types of corrections to work simultaneously, and software that
  implements the methods developed.

Here's a link to the paper ... http://gking.harvard.edu/files/abs/0s-abs.shtml
Comment: This is a good paper, I have read it more than once! (+1) I think though you should point out that the paper is also interested in inference. This is why a GBM would be less useful to a political scientist compared to a GLM. For example if tree-methodologies are used: "*...two recursive partitioning algorithms can achieve the same prediction accuracy but, at the same time, represent structurally different regression relationships, i.e., different models and thus may lead to different conclusions about the influence of certain covariates on the response.*" (Hothorn et al. 2006)
Comment: Thank you, - if you read the paper, do they suggest anything important beyond under-sampling suggested above?
Answer: I have to disagree with all of the answers.  The original problem is not appropriate for classification at all but calls for an analysis of tendencies.  See http://fharrell.com/post/classification
Miscasting the task as a classification task is what has caused so much work for everyone, and has caused invalid statistical methods that discard valuable data to be considered.
Comment: More discussion in this vein can be found here https://stats.stackexchange.com/questions/285231/what-problem-does-oversampling-undersampling-and-smote-solve?r=SearchResults&s=3|0.0000 and https://stats.stackexchange.com/questions/283170/when-is-unbalanced-data-really-a-problem-in-machine-learning
Comment: Not at all and this is not semantics.  When a method fully respects uncertainty it will not attempt to use the term "positive" and will have no "false positives".  Think rainfall forecasts and credit risk scoring, and sports betting (the latter is based on odds (converted probabilities) and not classification of "winners").
Comment: @LazyCat It sounds like a good feature of the method if it gives a low posterior probability of being in a rare class (low prior probability).
Comment: Don't want to argue about semantics, but if I read your linked post correctly, you basically argue for probabilistic answers. That's fine, but you still end up with the same issue: you can take the overall fraction of positive outcomes and it will be pretty hard to beat that probabilistic forecast.
Answer: Development of classifiers for datasets with imbalanced classes is a common problem in machine learning. Density-based methods can have significant merits over "traditional classifers" in such situation.
A density-based method estimates the unknown density $\hat{p}(x|y \in C)$, where $C$ is the most dominant class (In your example, $C = \{x: y_i = 0\}$).
Once a density estimate is trained, you can predict the probability that an unseen test record $x^*$ belongs to this density estimate or not. If the probability is sufficiently small, less than a specified threshold (usually obtained through a validation phase), then $\hat{y}(x^*) \notin C$, otherwise $\hat{y}(x^*) \in C$
You can refer to the following paper:
"A computable Plug-in estimator of Minimum Volume Sets for Novelty Detection," C. Park, J. Huang and Y. Ding, Operations Research, 58(5), 2013.
Answer: This is the sort of problem where Anomaly Detection is a useful approach. This is basically what rodrigo described in his answer, in which you determine the statistical profile of your training class, and set a probability threshold beyond which future measurements are determined not to belong to that class.
Here is a video tutorial, which should get you started. Once you have absorbed that, I would recommend looking up Kernel Density Estimation.
Comment: I think you'll find that a device that has a thermometer type of continuous risk display will be more useful to decision makers who have different risk thresholds depending on daily situations.
Comment: The link is dead. Can you renew it if the video still exists somewhere on YouTube?
Comment: @andreyuhai Link updated.
Comment: _Anomaly detection_ as you've used the term can be shown to be inconsistent with optimal decision making.  The probability threshold is illusory.
Comment: @frankharrell That is an interesting statement, in what way is the probability threshold illusory?
Comment: Because no one will agree on what the threshold would be and because setting a threshold on a basis other than optimizing expected utility will be inconsistent with optimum decision making.
Comment: @frankharrell ah yes, quite right, there is definitely an optimization to be done between false positives and false negatives which is dependent upon how costly such errors will be.
Comment: What does "positive" mean?
Comment: @frankharrell In this case, I was thinking of a physical device where a measured anomaly would mean a fault. A false positive would be a reported fault on a functioning device.


How true is the statement "Soviet troops got into Berlin riding American trucks, walking in American boots and using American trains"?

Question: In other words, how significant was American lend-lease in helping the Soviet front? Would the Soviets be suffering a lot more had lend-lease not happen, or was it not as significant as people make out?
Comment: This is my opinion, so not really an answer: As much as it is true, Americans won the war out of soviet blood. Let's be honest about history. If soviets don't get help, they lose the war. If soviets don't sacrifise their blood, americans lose the war. Winning the war needed both sides, including UK's refusal of surrender.
Comment: answered in large part here: http://history.stackexchange.com/questions/8687/did-american-policymakers-seriously-consider-scaling-down-lend-lease-aid-to-the might even be considered a duplicate.
Comment: The answer only has figures for 1941-43, Berlin was taken over in 1945...
Comment: I don't have the figures handy, but total value of U.S. Lend Lease aid was comparable to Axis war production. The Soviet Union got about a third of that, or about one year's worth. Maybe two years' worth of trucks, clothing and food, less of actual weaponry.
Comment: and the percentage of logistical equipment rather than weapons systems increased over time until at the end of the war it was the vast majority of aid, allowing the entire Soviet industrial effort to focus on productions of weapons and munitions.
Answer: As others have pointed out, it will never be possible to answer this question conclusively based on documents, because the Soviet officials have always been eager to downplay (for the propaganda reasons) the importance of the Allied contribution to the war in general and Lend-Lease in particular, so all the official Soviet sources are suspect (as, by the nature of the USSR, they cannot be independently verified).
The only way to evaluate the impact of L-L is based on circumstantial evidence.

As mentioned by @Kunikov, the Soviets stopped truck production - but they could not produce anything comparable to Studebakers they were receiving from the US anyway.
The Soviets stopped locomotive production too - and the factories producing them switched to medium and heavy tank production (in fact, given the nature of the Soviet industry, tanks were the main output of the "locomotive plants" from the get go, locomotives were just a side show).
The Soviets could not produce "aviation-grade" (high-octane) gasoline. Savitsky in his memoirs writes that when the US stopped delivering the aviation gasoline in June 1945, the speed of his fighter planes dropped by 10-20%. This seems enormously significant.
Zhukov in his private conversations admits that the L-L was crucial wrt gunpowder, explosives, steel, trucks.
Mikoyan said that without the L-L the war would have lasted for an extra 1-1.5 years. This is a very critical admission: the Soviet resources, especially the human ones (the army was huge, but there were no men left at home), were largely exhausted by 1945, so it is quite possible that, without L-L, the SU would have been forced to settle for a stalemate to avoid a national collapse (circumstantial evidence of the danger of the regime collapse is provided by the concessions to the church in 1943).

The bottom line is that, yes, "Soviet troops got into Berlin riding American trucks, walking in American boots and using American trains" (and eating American food), but they also flew both American and Soviet aircraft, rode mostly Soviet tanks, fired Soviet rifles and canons (with US gunpowder) &c &c &c. Without the Western Allies, both their military action and Lend-Lease, the SU would have certainly not been in Berlin in 1945, and might not even been there in 1946, if ever.
PS. This is a very touchy subject for the Russians, so be careful what you believe...
PPS. See Did Russia Really Go It Alone? How Lend-Lease Helped the Soviets Defeat the Germans and the very entertaining flamewar in comments.
Comment: -1 entirely for the bullshit 5th point. The USSR ended the war with much more troops than it had at any point. Also, how one can compare 1943 to 1945? And even in 1943 there was no threat of a collapse, the only such threat was in 1941.
Comment: Regarding point 5, that's doubtful.  The Red Army contained some 12 million men in 1945 and had enough resources to take on a close to million man Kwantung Army in the Far East within a matter of a few weeks.
Comment: @Kunikov: Kwantung Army was grossly overrated by the Soviet propaganda. RKKA had 12M men in 1945 in part because of LL (w/o LL the losses would have been larger &c). The mobilization resources at home were largely exhausted.
Comment: Precisely what I was looking for; Soviet factories were able to switch to producing tanks instead of logistics. Thanks for the answer.
Comment: Bellamy's book *Absolute War* supports this, and concludes (putting words in the author's mouth a little) that while the impact was somewhat marginal, the Red Army's survival in 1941 was pretty damn marginal too, and without lend lease the Russians may well have collapsed.  Page 423: "Russian war industry was by now [1941-1942] at its lowest ebb, and although the [Allied] aid during the war as a whole might appear relatively insignificant...it was very significant in these critical years, and would remain so in certain areas throughout the entire war."  By 1945 things had changed, of course.
Comment: About your 2nd edit: I think it was this answer that ultimately started my flamewar with @Kunikov such that he seems to have left the site now for close to 3 years. Atleast Anixx is willing to concede a few points here and there, that Kunikov guy labels everything remotely critical of the USSR as revisionist and whatever or, if really backed into a corner, will engage in dramatic 'whataboutisms' that has nothing to do with the question, e.g. his answer below.
Comment: Kwantung Army's abilities don't much matter since what the Germans were putting out in 1945 were on par and hardly comparable to the first two years of the war.  As for mobilization, it was exhausted in some respects but there were also plenty of territories ripe for mobilization.  Two Polish armies fought with the Red Army, as did other units from Eastern European states, more could have been utilized if the need arose.
Comment: @Kunikov: it is not obvious that RKKA would have reached the Curzon line without LL. This argument is pointless: I will not convince you, and vv. I you *really* feel like fighting this one out, let us move to chat.
Answer:
In other words, how significant was American lend-lease in helping the Soviet front? Would the Soviets be suffering a lot more had lend-lease not happen, or was it not as significant as people make out?

This is a very hard question to answer for numerous reasons and one that will never be answered to everyone's satisfaction.  Here are some things to consider and some problems that frequently come up when you're dealing with Lend Lease.
First off, significant Lend Lease aid was not felt until 1943.  The Lend Lease that arrived before was nowhere near enough to make a decisive difference on how 1941 and 1942 turned out.  There are some articles/arguments that have recently come out which attempt to argue that the Lend Lease tanks that did make it in 1941 played a decisive role in the defense of Moscow, but I don't believe they are conclusive enough (see the following article: British "Lend-Lease" Tanks and the Battle for Moscow, November–December 1941—A Research Note).
Secondly, the immediate problems that come up when attempting to qualify Lend Lease are the following.  Just quoting numbers of what was sent is not enough.  One needs to account for what was sent, when it arrived (and how much arrived), and when it was actually incorporated into the Red Army and used in the field.  Additionally, one has to keep in mind that the Soviets began to scale back production of certain things because they knew they would receive them through Lend Lease.  One example is trucks.  The Soviets were producing practically none because they knew to expect them through Lend Lease, but that doesn't mean they couldn't produce more if they needed to.  Many former truck producing factories were switched over to light tank production.  Since the Red Army moved to relying on medium and heavy tanks, light tanks were something the Red Army could in theory do without or with less of.  This type of analysis needs to be applied to everything the Soviet Union received.  Specifically, what they received, if it was not coming through Lend Lease what were the alternatives?  Meaning could they produce it internally or import it from another state/country (England, Canada, etc.).  The Soviet Union did not just receive Lend Lease from the US.
Finally, the Soviet Union participated in reverse Lend Lease, sending back materials to the US.  All of the above is just the tip of the huge iceberg that studying Lend Lease means, it's simply impossible to account for all the variables.
Comment: You seem to be interpreting my question as an attack on Soviet contributions to the 2nd world war and that they couldn't have won without US help...this is absolutely not the case. I just would like to know how much L-L aided the Soviet war effort, and from sds' answer, it seems quite alot.
Comment: Also, what exactly did the Soviets supply to the US? Do you mean the gold shipments they sent and later tried to claim back (as regards to shipments which were sunk)?
Comment: The U.S. Department of State claims (http://iipdigital.usembassy.gov/st/english/article/2010/05/20100518114619zjsredna0.3529736.html#axzz2wqqtuSNc) that the value of Soviet "reverse lend-lease" was frankly insignificant.
Comment: I'm not interpreting your question as anything.  I provided an answer that addresses how difficult it is to qualify the contributions of Lend Lease.  As for reverse Lend Lease, I don't have a source off-hand as this is something I haven't looked into in a long time, but it also included the renting of bases, fixing US equipment, etc.
Answer: Here are the numbers and no speculations.
The share of lend-lease supplies to the total number of produced and delivered to the USSR products -

12%  - tanks
8%   - Self-propelled gun
12%  - Airplanes
3%   - Guns and mortars
22%  - Ships
63%  - Cars and trucks
1%   - Firearms
3%   - Gasoline
40%  - Aviation petrol
35%  - Rails
72%  - Locomotives
35%  - Explosives
55%  - Aluminium
45%  - Сopper
30%  - Tyres
30%  - Sugar
5%   - Cotton
24%  - Metal-working machines and presses

Numbers are taken from many sources and most of them in Russian language. But confirmation to most of numbers can be found in book of Stettinius E.R. Jr. Lend-Lease: Weapon For Victory. — New York: Macmillan Co.; 1944.
Stettinius E.R. was United States Secretary of State from 1944 to 1945
Comment: If I understand well, your source was published in 1944 ? Any indication about how the L-L evolved during the last year of the war ?
Comment: in 1944-45, L-L included landing ships and even small warships, which were used to invade the Kuril Islands. Russian crews were trained in Alaska by the US navy. It was part of the deal to have stalin declare war to japan. Some speculate that the Kuril invasion would not be possible without the L-L ships. So the Kuril islands status is another (relatively small) international issue that relates from L-L
Answer: As for those Soviet Built Tanks.
Armor steel had a special place in these shipments, especially in the
production of tanks, self-propelled guns and other equipment. Mobilization
reserve of armored steel in the Soviet Union before the war was small and
did not cover even 6-month industry needs. According to some data, 525.4
thousand tons of rolled steel of all types was delivered to the USSR under
Lend-Lease. Every month, the country received about half of average amount
of Soviet production of armored steel. Special steel for gun barrel drifting was
also delivered".
https://histrf.ru/uploads/media/default/0001/12/df78d3da0fe55d965333035cd9d4ee2770550653.pdf
Answer: Firstly let's talk about the total aide that Russia was provided with through the Lend/Lease Act. It appears as though by 1946, the United States had lent about $51 billion in total with $11 billion going to aide the Soviet Union. That's a substantial proportion. Almost 25% of American aide going to the Soviets.
But with the total amount of Soviet military production unknown, it's difficult to say exactly how much the Americans contributed.
With a little more digging, I can give you some estimates of what the Soviets attacked Berlin with and we can make some extrapolations from that. In 1945 it was estimated that the Russians had produced approximately 57,300 tanks (See Zaloga, Steven J., Jim Kinnear (1996). T-34-85 Medium Tank 1944–94, Oxford: Osprey Publishing.). According to this article on wikipedia 20,000 tanks and artillery pieces* were deployed to the battle. Among them were the Russian T34, SU-152, ISU-122 and the Iosif Stalin tank or the IS2. All of these were Russian tanks. Based on the known production numbers and the sheer force of Soviet troops mustered for the battle, it seems that roughly a third of the Red Army's tanks being deployed is not an unfeasible amount.
Further, eyewitness accounts of Soviet troops going into battle with nothing but tattered rags, the looted boots of SS troops clutching their battered Mosin-Nagant rifles lends credence to the idea I am suggesting. Namely that by the invasion of Berlin, Soviet troops had marched into the city with Soviet equipment, or the lack thereof. What they didn't have they did without. Even boots it seemed were scavenged from SS troops.
In short, if someone could find data on the total military prowess of the Russian industrial complex we could equate that to how much the Americans provided and determine if the American aide contributed significantly to Russian military operations leading up to the fall of Berlin. But bsed on my cursory research it seems unlikely that the Red Army derived such a significant advantage from US supply as to lend the quotation any real weight. It seems by 1945, the Soviets were on their own.
As a sidenote, the US lent over $31 billion to England, totaling over 60% of the Lend/Lease act.
*Although it is disputed by this site which cites Russian artillery pieces totaling 41,600. Note that while the Soviets made the trek to Russia they also encountered foreign tanks which were commandeered or joined the invasion of Berlin.
Though outside your time frame, this article details the termination of lend/lease a mere weeks after the capture of Berlin. Interpret it as you will.
Comment: I doubt if the eyewitness account about the boots is really significant. First, it deals with one isolated incident which might or might not indicate the general state of Soviet logistics in the battle for Berlin. Second, the soldiers who took the SS boots might have done so for their moral trophy value; and it stands to reason that SS equipment was simply better than standard army issue of either of the belligerents. Third, what the German woman took for rags and tatters on the Soviet soldiers' feet could very likely be *portyanki*, footwraps worn by Russian soldiers under their boots.
Comment: Since she saw the soldiers in what was apparently a moment of rest, it's likely that they took off their boots and remained in their footwraps. http://en.wikipedia.org/wiki/Footwraps#Eastern_Europe
Comment: Not answering the question so I voted down
Comment: @franklin I know from personal experience that russian soldiers preferred footwraps over socks - even in 80ties. When properly folded (they told me) it protects foot better.
Comment: interesting...I wonder if footwraps still convey any practical advantage over socks...


Adjusting road brake levers

Question: Recently I got my bar tape, brake cables and brake levers changed, but when I picked up the bike I noticed that the brake levers were to low (at the tip of the drops) is there any way I can put them in the right position without damaging the bar tape or the brake cables?
Comment: Go to a sporting goods place and buy some "hockey tape", in a color that complements your bar tape.  Use it to repair the damage after you cut the bar tape and move the levers.
Comment: @DanielRHicks I suspect that "hockey tape" is hard to get hold of in countries where ice hockey isn't a big thing, which is to say, in most countries.
Comment: @David is right but there's always ebay
Answer: Answer: No - you can't just move the brake levers up the curve of the handlebar drops.   If you did this, the bar tape would be bunched up above the hoods and skinnied-out below the hoods.
Tools: You'll need a 5mm hex driver (maybe 4mm or 6mm, maybe a philips if its old, or flathead if its ancient)  Some tape to finish the bartape wrap, and sharp scissors to cut the tape.
Method: Unwind the bar tape carefully, reposition the brakes, then do up the bar tape again.  You'll probably put one, maybe two turns of bar tape below the brake hoods that were above the hoods when you started.
The brake cables should move okay - you might need to remove and refix some temporary tape.
Comment: @andy256  The first paragraph is the answer to the question asked..  The rest is a suggested approach.    I have clarified it though.
Comment: I think this would better with the first para removed.
Answer: depending on the bar tape, you may be able to undo it carefully without tearing it. Ive had success in the past. Some have very little or no adhesive. Some it takes a while for the adhesive to stick firm so if its new it may peel off just fine. Try it and see. You could also loosen the handlebar at the stem and move them up a bit to raise the hoods. This may effect cable tension for your outer cables so check that. Also you may not like having the drops angled down although some do.
personal preferencesort of thing..
Comment: Bartape is generally quite forgiving, so the only part that probably needs redoing is whatever holds the end of the bartape in place.   Also, if it was started in the middle and wrapped outwards then most if not all the tape has to come off.  If the wrap was started at the end and went inwards there will be less to remove.

Adjusting road brake levers


Are memory updates local in mammals?

Question: What I mean is, during long term potentiation (LTP) or long term depression (LTD) for a particular memory, do the strengthening and/or weakening of neuronal connections only occur in a small patch of neurons or regions spread out in the cortex?
Comment: LTD and LTP happen at individual synapses (not even whole of neurons). However LTP/LTD at one synapse can affect others in the vicinity.
Comment: OK I meant something like when a single episodic memory episode is stored, is the memory stored in diffuse locations or rather localized?
Answer: LTP and LTD are processes that operate on single synapses. We don't know how "memories" (there are several types of "memory") are encoded in the human nervous system. As a consequence, we don't yet understand the explicit link between some group of synaptically connected neurons, and a given memory.
So the short answer is "we don't know". Take a look at some of the other questions about memories in human brains: 1, 2

Are memory updates local in mammals?


Can Steam downloads be set to run consecutively instead of concurrently?

Question: This is more of a general question about the best way to expedite Steam downloads. I'm on a slower DSL line at home so if I end up with multiple downloads from Steam running at the same time it bogs them all down. If one of the updates happens to be a game I want to play, I end up having to juggle the downloads by pausing the ones I am willing to wait on, then un-pause them later. I'm away from my home PC so I can't really dig through the menus on Steam right now, but is there an option somewhere that will force Steam to queue up the downloads so that they run one after the other instead of it being all of them rushing for the door at the same time?
Comment: As Steam now sets downloads to run consecutively instead of concurrently, this question is now obsolete. Thanks to everyone who helped when I originally asked it!
Answer: As far as I know the Steam client does not have this feature. However it is a popular request in the forums, and it does appear that they are working on implementing this in a future Steam client update.
Excerpt from last link:

In addition, the new content system will allow us to build several new
  features that we've often heard requested. Upcoming client releases
  will include things like download scheduling, bandwidth throttling,
  and prioritizing which games get downloaded first. You'll also be
  able to download an update to a game while you're playing that game;
  Steam will apply the update after you exit the game.
Comment: Just a note that said Steam client update has been available for a very long time, and thus this question is mostly obsolete - as the answer below states, downloads happen pretty much consecutively now
Answer: Steam used to set downloads to run concurrently instead of consecutively. However, there is no need for a workaround anymore, thanks to the new content system: it is now rarely possible to download more than two games at the same time, and most of the time, there is even at most one download possible at a time. In other words, you are forced to download games and patches consecutively, with at most two concurrent downloads.
Answer: Sadly, no.
There have been a lot of requests regarding this and other features related to downloads, eg. maximum rates for download speed, scheduled download times, forced updates while playing games instead of pausing when starting a game, and many more. These requests have been more or less actively voiced for many years now, but steam has not yet announced to implement anything in that regard.


Grassy weed with seeds on spidery stalks

Question: I have a weed growing in my yard that is distinguished by its spindly seed stalks with individual seeds at the ends of branching fingerlets. It grows in distinct clumps. In the picture below, note the seed stalk to the lower left. Does anyone know what this is? Looking at other similar questions, this does not look to me like dallisgrass or annual bluegrass.
Comment: This has helped me tremendously in the past.  https://turf.purdue.edu/tool/
Comment: Excellent site, Evil Elf!  I saved that one.  Grass ID is the toughest of all ID's (next would be roses).  This is a great site. @Mark Foskey go through this grass key as you are the only one that is able to touch, cut this plant.  Is this area in a bit of shade?  That would make the leaves wider but those seed heads and light green color and shallow roots indicate Poa annua.  Awful weed for lawns.  Yet I know lots of golf courses that have their entire grass crop made of this stuff.  Hell on lawns of those people who live by those golf courses
Answer: It's not Poa annua, Annual Bluegrass. I believe it might be Dichanthelium laxiflorum, a well-behaved native that pops up in disturbs sites. Soft Tuft Witchgrass.
https://plants.usda.gov/core/profile?symbol=DILA9
Answer: My guess is Poa annua, annual bluegrass. Why do you think this is not a viable ID? Usually spread by birds.  A favorite grass for golf courses.  Shallow rooted, light green color, the seeds lighten this plant even more causing a larger contrast to the grasses in a lawn.  Easiest way to deal with annual bluegrass is to water your garden and lawns deeply and make sure you allow the soil to dry out in between watering. The grasses with deeper roots by being forced to grow deeper to reach the moisture will be able to out compete the shallow rooted grasses as they are not able to find moisture.  Allowing your grasses to never get shorter than 3" will curb any germination of Poa annua by shading the soil.


why do I keep getting 403 and 404 errors in the MIDDLE of downloads using DownThemAll? Very frustrating

Question: looking up 404 error code, I find that it's supposed to only occur when a file or http source is no longer available at the specified location. but I'm getting it in the middle of downloads! makes no sense. and it happens to 1 out of every 4 or 5 downloads. especially if they're larger than 100MB.
Answer: Depending on where the downloads are coming from, the link you're using may be expiring.
If I recall correctly, download managers like DownLoadThemAll will use multiple connections to download different parts of a given file. Many download sites use a system where when a user opens the download page they are given a randomly generated download link which points to the real file (i.e. http://www.example.com/download.php?file=randomstring, though it could appear to be anything). This random link will expire after a short period of time so that anyone trying to use it will get an error. They do this to keep people from hotlinking directly to the file.
If DTA is initiating a new connection after the link has expired, then that could explain why it's erroring out, especially if the errors occur only on a few websites.
Answer: I did experienced this and I was able to resolve the problem by clearing ALL browser history (cache, downloadthemall history, etc). Then restart FF. Worked for me.


How to make a RHEL5 VM visible by hostname to host OS

Question: I believe the correct networking option is to use bridged so that the guest OS gets its own IP address, but I'm still only able to ssh by ip address.
Comment: I do not want to add an entry to the host file on the host os because I want the guest OS to be able to get a dynamic address when I move between work and home networks.
Answer: In order to get to it by name, that name has to be registered in DNS or the name has to be in your hosts file.  If the address is being dynamically assigned by DHCP, then DHCP can be configured to do the registration.  If you don't have control of DNS or DHCP, then a hosts file is the only option.
Answer: You could try to run Avahi on the CentOS 5 guest and have it respond to mDNS queries, and hopefully your host os will query .local via mDNS/ZeroConf. I haven't tested this, but it's worth a shot if you don't have control over DNS/dhcp.
It's important that you refer to the host with the .local domain, otherwise this will likely not end up with mDNS but rather have search-domain appended to it and the query sent to the configured nameserver(s). I.e. ssh box would fail, where ssh box.local would work.
Answer: I just put it in my hosts file, then make sure the VM has a static IP assigned by the hypervisor, such as http://www.stereoplex.com/two-voices/vmware-fusion-guests-with-a-static-ip
Oh, you're bridged.  DNS should work assuming it works with other "real" machines on your LAN.  Make sure RHEL is configured to use whatever provides DNS on your LAN.  At work, I would assume this to be easier.  At home, you'll need a DNS server.  Some SOHO routers can do this.
Answer: edited /etc/dhclient-eth0.conf to have the line
send host-name "atrupewebdev";

edited /etc/sysconfig/network-scripts/ifcfg-eth0 to have the line
DHCP_HOSTNAME=atrupewebdev

edited /etc/sysconfig/network to have the line
HOSTNAME=atrupewebdev

edited /etc/hosts to have the line
127.0.0.1 atrupewebdev ...

then executed
service network restart

Answer: If /etc/hosts is out of the question, you have to put them in the respective DNS zones for your home and work networks.
Alternatively, if you don't need to access the VM from outside the host machine, you could use a private host-only network which has the same network addresses regardless of where you are, or you could even use port forwarding, depending on what you plan to do with the VM.


How much rain falls on the Earth each year?

Question: In this resource, it says that the average amount of precipitation falling on the Earth per year is approximately 100 cm.  Integrated across the surface of the Earth, that yields approximately 5.1 × 1014 m3 of water volume that falls to earth. However, it does not give an estimate of how much of that precipitation is specifically rain. So, how much rain falls on the Earth each year?
Comment: So you want to know what fraction of that value is rain and what fraction is snow/hail?
Comment: The fraction of all precipitation on Earth that is rain would certainly be one step away from the answer.
Answer: That's a tricky question, it will vary from year to year but we can narrow it down with some assumptions so I can give an answer. The assumptions will be:

All precipitation over the sea will become liquid in contact with the sea surface and will be considered as rain.
Precipitation over Antarctica is negligible at a global scale.

The second one is pretty reasonable: look at the global distribution of precipitation on the era of satellite data (reference).

With these assumptions we only need to compute the amount of solid precipitation on land (outside Antarctica) and subtract it from the global total. And we can do so using the data provided by the Global Precipitation Climatology Centre, which provide both the global mean precipitation on land:

And the fraction of liquid precipitation on land:

I've downloaded both datasets in ASCII format, and computed that the mean percentage of liquid precipitation is 74.1%, but we can't use that value, because it might be strongly affected by areas with little precipitation. So if we compute a cell by cell total SOLID precipitation per year, and multiply that for the surface of a 1°x 1° cell (considering the effects of latitude), we get a total of solid precipitation for 2016 of 1.5e13 m³.
So with the additional assumption that 2016 was a representative year. That will take your total precipitation of 5.1e14 m³ per year to 5.0e14 m³ per year of RAIN only.
Perhaps we should have expected that there is not much of a difference given that most of the rainfall happen on the sea (The total precipitation on land for 2016 was 1.1e14 m³ meaning that the 13.6% was solid and 86.4% was rain).
Now if you want to consider snowfall over the sea, I don't know of a model with such output product. Therefore, you can make a simple model or make some assumptions to use Sea Surface Temperature to figure out if precipitation will turn to rain at some high above the surface.
But again, if you look at the map of global distribution of precipitation, the fraction coming from latitudes at which you could expect sea surface snow is rather small, so the correction coming from snowfall over the sea is likely to be a pretty small one too.
Comment: @farrenthorpe I guess the very rainy places are in general fairly warm. By the way. Why are you interested in this particular value?
Comment: That's actually quite surprising to me.  I would've thought that rain was the majority... but not by that much.
Comment: In general, I'm curious what the net increase in rainfall will be in the future.  I had postulated that there could be a significant increase due to less snow in warmer conditions.  Though, with such a small fraction of precip being frozen, perhaps the question is better suited in a regional context.


Mount Ubuntu's partition on Windows 7

Question: Is it possible to mount Ubuntu 10.10's partition on Windows 7?
Comment: That depends on the underlying partition format. Ext2 has widespread support. Btrfs probably dooesn't have any.
Answer: You have a couple that can Read And/Or Write to Ext2 And/Or Ext3 And/Or Ext4 file systems and can mount this fyle systems in windows. Some are:
Ext2Read - http://sourceforge.net/projects/ext2read/files/  (Most updated)
Ext2fsd - http://www.ext2fsd.com/  (Second Most Updated)
Fs Driver - http://www.fs-driver.org/
Disk Internals (Linux Read) - http://www.diskinternals.com/linux-reader/ (Popular several years ago)
Explore2FS - http://www.chrysocome.net/explore2fs (Super Popular some years ago)
Now for the compatibility with Windows 7:
Ext2Read - Confirmed Windows 7
Ext2fsd - Confirmed on Windows 7
FS Driver - Confirmed on Windows 7
Disk Internals (Linux Read) - Confirmed on Windows 7
Explore2FS - Confirmed on Windows 7
Now for the "problems" you should watch out.
Even though you can read and maybe write to linux files and directories from windows there has been several problems regarding the issue of reading/writing from windows to Linux via tools like this. For example:

Information lost
Corrupted Information that was copied
Corrupted File System (Inodes, Complete Directories, Etc)
Garbage Read/Write (Like strange symbols)

Maybe others. Some small cases include loosing a lot of information. So this is a big warning if you want to use tools like this. Anyway if has been also tested by several people and to them it worked good. So it all depends on you.
Comment: Note that since none of those are made/maintained by Microsoft, they don't have any official support, and are not particularly well integrated into windows.  I would consider most of them to be experimental and would be careful when using any of them.
Comment: None of these allow mounting an Ext4 partition... and as far as I can tell, only one can even read from it.
Comment: Ext2Read supports or at least it says it supports Ext4. that is why (The only reason why actually) i mention Ext4.
Answer: The most reliable way to access Linux filesystems from Windows is to do it via a virtual machine. There are several options. CoLinux is the lightest one, but might be difficult to install (I don't think there's an up-to-date distribution, so if you want ext4 and btrfs you have to assemble the pieces), and I think CoLinux doesn't work on 64-bit Windows. Otherwise you can use a hosted virtual machine such as VirtualBox, see for example How to import existing Linux partition into VirtualBox as guest?.
Answer: The simple answer is "it's very tricky and not polished." assuming you're 10.10 is installed on ext4 (which I believe is the default).
What you could do is mount your /home dir on a fat32 file system and that would allow you to mount it on the windows side. This should help some if you decided to go with that route. Remember to back up the data already in your /home dir before switching where the OS looks for it.
https://help.ubuntu.com/community/InstallingANewHardDrive

Mount Ubuntu's partition on Windows 7


Manufacturing the Sound of Water

Question: i'm working on a piece of music/sound art in which i'm creating an artificial soundscape.  my next task is to recreate the sound of running water and i'm having trouble coming up with things to record and process... so far my main idea is to record the sound of sharpies on paper and (lightly) rub my fingernails on my wooden desk... obviously i'll have to play with processing these sounds to get them to sound right, but i'm wondering if anyone might have some ideas that i can play with
Answer: When you say "artificial soundscape" does this mean you can use anything BUT the sound of water? So, you couldn't record different kinds of running water sounds? Instead you would have to create that sound with an alternative source?
I suppose the question I would ask myself is "what does running water sound like?" I think that's a very loaded question. Water is one of my favourite sounds to record, and my response would be "what kind of running water?"
A babbling brook? A stream? A bath tap? A hose? Rain in the gutter? Gentle waves running over rocks? A trickling fountain?
Water is a very versatile sound reallly. By that I mean there are lots of tonal qualities to draw from. Deep low glugs and plops. High fizzy splashes. Roaring white noise.
What kind of water sound are you trying to recreate?
Comment: I'm trying to do it without using ANY water at all. It's been quite the task, and pretty intriguing tbh. Perhaps some light foamy waves, but just the sound of a stream
Answer: You could use a VST like Uhe Zebra2, it works great with for organic Fx.
I successfully created sea waves sounds using this VST and water like effect with a slightly bubbled sound.
Answer: Maybe this is too simple but pink noise would be the first place I'd turn to, and then modulate from there, maybe utilizing some worldizing?

Manufacturing the Sound of Water


upgrading an old bike gears and shifter

Question: I don't have a whole lot of knowledge on this, but here goes. I have an old Murray Ultra mountain bike (prob. 15 yrs.+). It is a 15 speed bike, with a 5 speed freewheel. The whole Shimano system is the 515 which includes front and rear derailleurs.I really don't want to spend a lot of money on an upgrade, but an up grade of some sort is necessary because of simple wear and tear. All i'm asking is there a set,or equivalent where i can replace - at least the shifters to a more modern ones,and front derailleur without having to break the bank. At the very least the front derailleur and shifters.
Answer: Having restored a number of old cheap bikes, I can tell you that the biggest problem is almost never the derailleurs/shifters. Usually these bikes have not been ridden much and have spent most of their time in a garage exposed to the elements. The biggest problems are rusted parts, poor lubrication, and horrifically bad tuning. Frequently, on a bike like this you're likely to find that it was never properly put together.
Here's a quick checklist of things to go over that can be fixed economically:

Buff all rusted parts with steel wool, regrease all bushings on derailleurs & brake calipers/levers.
Clean/lube chain & freewheel or replace with similar if worn out (unlikely).
Replace cables and housings for brakes and shifters with inexpensive new ones (example) ~$10-20
Replace brake pads ~$10
Adjust brakes-- following readily available instructions
Adjust shifters-- following readily available instructions
disassemble/re-grease/re-pack hubs, headset, bottom bracket-- following readily available instructions
True the wheel, tighten spokes if needed.
Replace inner tubes, tires, rim-tape (If they're in bad shape) ~$30-50

If you have to replace the shifters or derailleurs, just try to find cheap replacements or used parts that are similar. You'll want to stick with 5-speed stuff, you aren't going to be upgrading to a 10 speed freewheel (they don't exist!).
Comment: You'll want to invest in a can of penetrating oil and a good deal of patience. Removing seized BB and headset locknuts has always resulted in much anguish and bloodshed for me.
Answer: Sorry for the answer to an old post, but I've done this exact upgrade recently on my rear.
The bike is a 60cm frame, so it was worth saving.  Originally it had a 5 speed freewheel and 3 front chainrings.   Wheel rims were alloy.  The rear spokes were made of spaghetti so I was replacing one or two a month.
I scored a rear wheel with a freehub and QR skewer in it, which just fit inside the frame with some minor encouragement.
I bought a 7 speed cassette for $45 NZ, and had to fit 3.5mm of spacers because it was actually an 8 speed freehub.  Spacers cost $5.
The old 5 speed indexed shifter was useless so I fitted a Shimano one with a lever that clicks to go up, and a push button to drop a gear.  Works well and cost about $25 NZ  I also fitted a new gear inner wire because I could, cost $6 NZ.
I soldered the end of the gear cable rather than using a crimp-on cap.
I reused all the old outers, except I trimmed 10mm off where some of them were a bit sharp exiting the frame mounts.  All outers were lubed with Wolf's oil (a cheap and lightweight chinese oil.)
Definitely worth doing, and I have not yet broken a spoke in 3 months of riding.
You should find your rear derailereuyueyrueyruer will work fine over 7 or 8 gears, but do take the change to clean and lube it.
I did not do anything with the front chainrings other than a clean and paint, and tweak up the limit screws.  They're still on a friction shifter, which is fine for my needs.

upgrading an old bike gears and shifter


In exwm (Emacs X Window Manager) how can I assign apps to particular workspaces?

Question: For example, no matter in which workspace I start Firefox, I want it to launch in workspace 2. In i3wm I can do this with assign [class="(?i)firefox"] $workspace2.
Answer: You can use exwm-manage-finish-hook to perform functions when a window has loaded. Combine that with exwm-class-name and exwm-workspace-move-window and you could do something like this:
(require 'subr-x)  ;; Because of when-let

(defvar exwm-workspace-window-assignments
  '(("Firefox" . 2)
    ("Thunderbird" . 3))
  "An alist of window classes and which workspace to put them on.")

(add-hook 'exwm-manage-finish-hook
          (lambda ()
            (when-let ((target (cdr (assoc exwm-class-name exwm-workspace-window-assignments))))
              (exwm-workspace-move-window target))))

So now a window named Firefox would end up on workspace 2, while Thunderbird would end up on workspace 3. You could add more entries to exwm-workspace-window-assignments if you want. Keep in mind that the workspace need to exist before trying to move a window to it.
The code snippet above needs Emacs 25, because of when-let.
Answer: There is a way to set this using EXWM settings (it is possible that this option did not exist at the time the question was first answered):
(setq exwm-manage-configurations
   '((string= exwm-instance-name "firefox")
      workspace 2))

You can also set this variable with M-x customize-variable Ret exwm-manage-configurations.


Taskbar icons in juno dont work

Question: in juno you can put the icons in the taskbar as in loki ?, example i install slack, discord, telegram... and the application icon does not come out. Any idea how to fix it?
Answer: Daniel, this has already been answered. Check out this thread:
Missing icons in the wingpanel
Comment: I've tried it and it works, but the icons come out very apart from each other
Comment: I agree. We have to wait for Elementary to bring this back.
Answer: Jorge, Ayatana should solve that. Skype, Telegram, Megasync, etc. They all work for me, just like regular taskbar icons.

Taskbar icons in juno dont work


linux mint: waiting for network configuration

Question: I went to another place and my network(either wired or wi-fi) starts not working... For now, I have a workaround solution that every time I logged in I have to run sudo service network-manager start which give me the following information:
stop: Unknown instance:
network-manager start/running, process 2410

Before I start network-manager, I ran status network-manager which give me this:
network-manager stop/waiting

Before I log in, I'm stuck here for around 1 and half minutes.. Here is a screenshot:

I Googled and found a workaround solution to change /etc/init/failsafe.conf, but since I didn't touch it before and my wifi works... there must be something wrong somewhere else...
BTW, this is my content of /etc/network/interfaces

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp
Answer: the "auto eth0" line forces the boot up to wait for eth0 to become available. the "dhcp" means that it has to talk to a dhcp server first.
So if at this new location you either don't plug in the Ethernet cable or there is no dhcp server there (maybe they use static addresses) then this fails.
Change the "auto eth0" to "allow-hotplug eth0" this way the boot will not wait, but the interface will come up whenever it is ready.


Front Matter in a Work in Two Volumes

Question: I am writing a thesis, and the material of said work naturally splits into two self-consistent volumes. Which front matter (abstract, preface, dedication, synopsis, table of contents, list of tables/figures, etc.) should remain the same between the two volumes and which should differ (or stand alone with specific material to that volume)?
Answer: The answer really depends on how your content is split. If you look at the entire work, I would recommend keeping the abstract, the preface, and the dedication in the first volume. Both volumes would have their own table of contents and list of tables, etc. to specify the actual content in each book.
If each book is diversified enough to be consider as two distinctly separate topics, then you might consider having a separate abstract, preface, and deication for each book. Either way, they should both have their own distinct TOC and list of tables.
Comment: TOC can be shared

Front Matter in a Work in Two Volumes


Error in catchment area calculation

Question: I downloaded a DEM based on the ASTER Global Digital Elevation Model (resolution 30 m; ASTGTM2_N42W009_dem.tif) from the Earth Explorer website (https://earthexplorer.usgs.gov/). I am trying to calculate the catchment area in QGIS 2.18.10 with the SAGA (version 2.3.2) geoalgorithm "Catchment Area" available in QGIS toolbox. However, when I apply the algorithm, I get the following error (in bold):
The following layers were not correctly generated.
Catchment Area
You can check the log messages to find more information about the execution of the algorithm
Several SAGA algorithms yield the same error, while others work well apparently such as "clip raster with a polygon". I have been looking in the internet for potential solutions and I think it may be a mismatch between the QGIS and SAGA versions. I am running QGIS in Windows. Find below the log message that I obtain after running the "Catchment Area" algorithm:
<code>Algorithm Catchment area starting...
ta_hydrology "Flow Accumulation (Top-Down)" -ELEVATION "C:\Users\Andre\AppData\Local\Temp\processingd042cd5855714f1aa9738be490723d02\22c5c81d5cb14560a14a1139b0c46106\ASTGTM2N42W009dem30m.sgrd" -METHOD 0 -CAREA "C:\Users\Andre\AppData\Local\Temp\processingd042cd5855714f1aa9738be490723d02\c9f6dd80b5f0406ba2b3170a06d7a314\CAREA.sdat"

C:\PROGRA~1\QGIS2~1.18\bin>set SAGA=C:/PROGRA~1/QGIS2~1.18/apps\saga-ltr

C:\PROGRA~1\QGIS2~1.18\bin>set SAGA_MLB=C:/PROGRA~1/QGIS2~1.18/apps\saga-ltr\modules

C:\PROGRA~1\QGIS2~1.18\bin>PATH=C:\PROGRA~1\QGIS2~1.18\apps\Python27\lib\site-packages\Shapely-1.2.18-py2.7-win-amd64.egg\shapely\DLLs;C:\PROGRA~1\QGIS2~1.18\apps\Python27\DLLs;C:\PROGRA~1\QGIS2~1.18\apps\Python27\lib\site-packages\numpy\core;C:\PROGRA~1\QGIS2~1.18\apps\qgis\bin;C:\PROGRA~1\QGIS2~1.18\apps\grass\grass-7.2.1\lib;C:\PROGRA~1\QGIS2~1.18\apps\grass\grass-7.2.1\bin;{app};C:\PROGRA~1\QGIS2~1.18\apps\Python27\Scripts;C:\PROGRA~1\QGIS2~1.18\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32\WBem;C:\Program Files\R\R-3.4.0\bin\x64;C:\Program Files\RStudio\bin;C:/PROGRA~1/QGIS2~1.18/apps\saga-ltr;C:/PROGRA~1/QGIS2~1.18/apps\saga-ltr\modules

C:\PROGRA~1\QGIS2~1.18\bin>saga_cmd ta_hydrology "Flow Accumulation (Top-Down)" -ELEVATION "C:\Users\Andre\AppData\Local\Temp\processingd042cd5855714f1aa9738be490723d02\22c5c81d5cb14560a14a1139b0c46106\ASTGTM2N42W009dem30m.sgrd" -METHOD 0 -CAREA "C:\Users\Andre\AppData\Local\Temp\processingd042cd5855714f1aa9738be490723d02\c9f6dd80b5f0406ba2b3170a06d7a314\CAREA.sdat"
Unknown option 'CAREA'
____________________________

##### ## ##### ##
### ### ## ###
### # ## ## #### # ##
### ##### ## # #####
##### # ## ##### # ##
____________________________

SAGA Version: 2.3.2 (64 bit)

____________________________
library path: C:\PROGRA~1\QGIS2~1.18\apps\saga-ltr\modules\
library name: ta_hydrology
library : Hydrology
tool : Flow Accumulation (Top-Down)
author : O.Conrad (c) 2001-2016, T.Grabs portions (c) 2010
processors : 4 [4]
____________________________

Usage: saga_cmd ta_hydrology 0 [-ELEVATION ] [-SINKROUTE ] [-WEIGHTS ] [-FLOW ] [-VAL_INPUT ] [-VAL_MEAN ] [-ACCU_MATERIAL ] [-ACCU_TARGET ] [-ACCU_TOTAL ] [-ACCU_LEFT ] [-ACCU_RIGHT ] [-STEP ] [-FLOW_UNIT ] [-FLOW_LENGTH ] [-LINEAR_VAL ] [-LINEAR_DIR ] [-METHOD ] [-LINEAR_DO ] [-LINEAR_MIN ] [-CONVERGENCE ] [-NO_NEGATIVES ] [-WEIGHT_LOSS ]
-ELEVATION: Elevation
Grid (input)
-SINKROUTE: Sink Routes
Grid (optional input)
-WEIGHTS: Weights
Grid (optional input)
-FLOW: Flow Accumulation
Grid (output)
-VAL_INPUT: Input for Mean over Catchment
Grid (optional input)
-VAL_MEAN: Mean over Catchment
Grid (output)
-ACCU_MATERIAL: Material for Accumulation
Grid (optional input)
-ACCU_TARGET: Accumulation Target
Grid (input)
-ACCU_TOTAL: Accumulated Material
Grid (optional output)
-ACCU_LEFT: Accumulated Material (Left Side)
Grid (optional output)
-ACCU_RIGHT: Accumulated Material (Right Side)
Grid (optional output)
-STEP: Step
Integer
Minimum: 1
Default: 1
-FLOW_UNIT: Flow Accumulation Unit
Choice
Available Choices:
[0] number of cells
[1] cell area
Default: 1
-FLOW_LENGTH: Flow Path Length
Grid (optional output)
-LINEAR_VAL: Linear Flow Threshold Grid
Grid (optional input)
-LINEAR_DIR: Channel Direction
Grid (optional input)
-METHOD: Method
Choice
Available Choices:
[0] Deterministic 8
[1] Rho 8
[2] Braunschweiger Reliefmodell
[3] Deterministic Infinity
[4] Multiple Flow Direction
[5] Multiple Triangular Flow Directon
[6] Multiple Maximum Downslope Gradient Based Flow Directon
Default: 4
-LINEAR_DO: Thresholded Linear Flow
Boolean
Default: 0
-LINEAR_MIN: Linear Flow Threshold
Integer
Default: 500
-CONVERGENCE: Convergence
Floating point
Minimum: 0.000000
Default: 1.100000
-NO_NEGATIVES: Prevent Negative Flow Accumulation
Boolean
Default: 1
-WEIGHT_LOSS: Loss through Negative Weights
Grid (optional output)

C:\PROGRA~1\QGIS2~1.18\bin>exit
Converting outputs
Loading resulting layers

The following layers were not correctly generated.
Catchment Area
You can check the log messages to find more information about the execution of the algorit
</code>
EDIT: Following Kazuhito's comment, I installed SAGA 2.1.4 and the algorithm produced a raster layer. However, I am not sure if the algorithm ran properly because during the process, some errors were identified because the algorithm was not finding specific libraries. Despite this, I installed the most recent release of QGIS (2.18.13), which has incorporated SAGA 2.3.2, and apparently the algorithm "Catchment area" works well without any specific errors appearing in the log.
Comment: Yes, I can post it as an answer. Thanks again for the help
Comment: I share the same view with you that this is due to SAGA version. Could you try an older one, say SAGA 2.1.4? ["Unknown option 'CAREA'" in SAGA Catchment area algorithm for QGIS](https://gis.stackexchange.com/questions/241439/unknown-option-carea-in-saga-catchment-area-algorithm-for-qgis)
Comment: Thanks André Lourenço, that's great. I will try QGIS 2.18.13 myself. By the way will you post your edit (actually solved the issue), as answer and accept it for our future reference?
Comment: André Lourenço QGIS2.18.13 does work!
Answer: Following Kazuhito's comment, I installed SAGA 2.1.4 and the algorithm produced a raster layer. However, I am not sure if the algorithm ran properly because during the process, some errors were identified because the algorithm was not finding specific libraries. Despite this, I installed the most recent release of QGIS (2.18.13), which has incorporated SAGA 2.3.2, and apparently the algorithm "Catchment area" works well without any specific errors appearing in the log.

Error in catchment area calculation


challenge: desafío vs. reto

Question: The English word "challenge" can be translated to Spanish as desafío (desafiar) or reto (retar). Is there any difference between these words, or are they exact synonyms? If there is a difference, when is each used, or what is the difference in meaning?
Answer: I disagree with Rafael. Although both are in many countries considered as synonyms it really depends on context and there are some inherent subtilities that distinguish them from each other.
Here are the RAE definitions for both:

reto.

m. Provocación o citación al duelo o desafío.
m. Acción de amenazar.
m. Dicho o hecho con que se amenaza. Echar retos.
m. regañina.
m. Objetivo o empeño difícil de llevar a cabo, y que constituye por ello un estímulo y un desafío para quien lo afronta.
m. desus. Acusación de alevoso que un noble hacía a otro delante del rey, obligándose a mantenerla en el campo.

And

desafío.

m. Acción y efecto de desafiar.
m. Rivalidad, competencia.
m. ant. Carta o recado verbal en que los reyes de Aragón manifestaban la razón o motivo que tenían para desafiar a un
  ricohombre o caballero.

reñir un ~.

loc. verb. ant. Reñir en un desafío.

First the subtilities and then the old meanings. For example you can see on meaning 5 of reto that reto is something that constitutes an objective that is difficult to achieve, that it is a desafío to someone, so the meaning of desafío that is taken here is the one of rivalry and competition. Desafío is something you want to achieve, and reto is something that can be compared with a goal or an obstacle. A difficulty. To help clear this difference: all desafíos are retos but not all retos are desafíos.
Edit
For example:

Para seguir por este camino tengo que destruir esta pared. Es un reto que me veo obligado a realizar.

Here reto is in the sense of an obstacle that you have no choice but to surmount. Something tough and difficult unrelated to a goal. The goal is to continue through this way, but the reto is destroying the wall.

Te reto a meterte desnudo en el lago congelado.
¿Es un desafío?

Here reto is something difficult to do. And the other person asks if it is a challenge that he is posing to him. So if the other person accepts it is a desafío because it becomes a goal.
Another difference that I just noticed and is new to me is regañina which means to ground someone. To tell a child that he was bad for example. I am unaware of in which region is this word used, but I can guarantee that it is not used in Ecuador or Colombia.
So second, there are some old meanings in which it is specified that in royalty desafío was used as a missive of the king of Aragón to challenge a noble, richman or knight. And reto was an accusation of a noble against another noble made in front of the king, obliging him to face him on the field. So desafío is a challenge of the king against a noble, richman or knight, and reto is noble vs noble in court. (As I understand it)
Comment: Interesting. Could you give a concrete example or two of a *reto* that's not a *desafío*?
Comment: Look on the edits section. :-)
Comment: _Retar_ in the sense of _regañina_ is used in Argentina, and this, along with _amenaza_ are the senses in which _reto_ and _desafío_ are not synonyms. Your examples work equally well swapping the words: _"Te desafío a X"_ _"¿Es un reto?"_ or _"Destruir esta pared es un desafío"_ (I don't think _realizar_ goes well with either word).
Answer: They are pretty much synonyms, so there is no specific situations where you should use one instead of the other.
Answer: "Desafío" is equivalent to the English word "defy," which is to say that it is a challenge thrown down by another person. "Reto" has more of the connotation of "obstacle," something you want to overcome, but maybe set by "nature" rather than another person.
Comment: Then how would explain the use in this article title: [El desafío de las nuevas generaciones: ¿Más juventud o más sociedad?](http://www.revistahumanum.org/revista/el-desafio-de-las-nuevas-generaciones-mas-juventud-o-mas-sociedad/)

challenge: desafío vs. reto


Can Asuras or Rakshasas be summoned by any ritual?

Question: In certain Pagan traditions in the West especially Goetia, demons are summoned by rituals mainly for material purposes. Can Asuras and Rakshasas be summoned in Hinduism by rituals? If yes, for what purposes?
Comment: There are tamasik methods (or rajasik methods) of doing Betala sadhana or Yaksha, Gandharva sadhana.. etc.... But all of these too require Guru. Nothing can be learned online. They are done basically to acquire worldly pleasures and not generally for harming others.
Answer: Not sure if there are many but found couple of instances that sort of invoke Asura/Asuri:
The Book 1 of Ṛgveda describes Savitr as an Asura who is a "kind leader" and help is asked from him against Rākṣasas and Yatudhanas.

हिरण्यहस्तो असुरः सुनीथः सुमृळीकः स्ववाँ यात्वर्वाङ् । अपसेधन्रक्षसो
  यातुधानानस्थाद्देवः प्रतिदोषं गृणानः ॥१०॥

Meaning:
May he, gold-handed Asura, kind leader, come hither to us with his help and favor.
Driving off Rākṣasas and Yatudhanas, [he] the god is present, praised in hymns at evening.
May the golden-handed, life-bestowing, well-guiding, exhilarating and affluent Savitri [Asura] be present;
for the deity, if worshipped in the evening, is at hand, driving away Raksasas and Yatudhanas.
In Book 7, Asuri is a powerful female with the special knowledge of herbs, who uses that knowledge to seduce Deva Indra in Atharva Veda. A hymn invokes this special power in Asuri, and this hymn is stipulated for a woman as a charm to win over the lover she wants.

I dig this Healing Herb that makes my lover look on me and weep, That
  bids the parting friend return and kindly greets him as he comes. This
  Herb wherewith the Asuri drew Indra downward from the Gods, With this
  same Herb I draw thee close that I may be most dear to thee. Thou art
  the peer of Soma, yea, thou art the equal of the Sun, The peer of all
  the Gods art thou: therefore we call thee hitherward. I am the speaker
  here, not thou: speak thou where the assembly meets. Thou shalt be
  mine and only mine, and never mention other dames. If thou art far
  away beyond the rivers, far away from men, This Herb shall seem to
  bind thee fast and bring thee back my prisoner. — A maiden's
  love-charm, Atharva Veda, Hymn 7.38,

The powers of an Asuri are projected into plants offering a remedy against leprosy.

First, before all, the strong-winged Bird was born, thou wast the gall
  thereof. Conquered in fight, the Asuri took then the shape and form of
  plants. The Asuri made, first of all, this medicine for leprosy, this
  banisher of leprosy. She banished leprosy, and gave one general colour
  to the skin. — A charm against leprosy, Atharva Veda, Hymn 1.24,

Refer 1 and 2
Comment: in vedas asura word is used positively also. Example mitra, varuna, maruta etc also referred as asura means full of life. check wiki for vedic asura.


How close can dyed mulch be to a vegetable garden raised bed?

Question: I have a raised cedar garden bed, roughly 10 inches high.  In the surrounding area is black dyed mulch.  If I fill the beds with good topsoil should I worry about the dyed mulch leaking into the soil?  Could I even put the garden bed on top of the dyed mulch?  I only plan to plant tomatoes, peppers, etc., no root type vegetables.
Answer: Dyes mulch is not made from trees.
Dyed mulches (black, red, green and other colors) are usually (with few exceptions) made up of recycled wood waste. This trash wood can come from old hardwood pallets, old decking, demolished buildings or worse yet pressure treated CCA lumber. CCA stands for Chromium, Copper and Arsenic; chemicals used to preserve wood. This ground up trash wood is then sprayed with a tint to cover up inconsistencies in the wood and give it a uniform color.
This dyed wood mulch does not break down to enrich the soil as good mulch should. Instead it leaches the dye along with the possible contaminants (chromium, copper, arsenic and others) into the soil harming or even killing beneficial soil bacteria, insects, earthworms and sometimes the plants themselves. These wood mulches actually rob the soil of nitrogen by out-competing the plants for the nitrogen they need for their own growth. Dr. Harry Hoitink, Professor Emeritus at Ohio State University, warns that dyed mulches are especially deadly when used around young plants and in newer landscapes.
Do not allow children or pets in areas in which dyes mulch has been or is being used.
Answer: Can't tell you how safe it is for a variety of reasons. Definitely don't put the raised bed on top of the mulch. That's pointless.
The dye may contain toxins but I did contact one dye manufacturer and was assured that they're black dye was safe to use around edible plants but not sure that applies to all black mulch dies. One common ingredient is carbon black which is made using petroleum products and may possibly be carcinogenic.
Even play wood mulch can be toxic at least to plants. The wood itself can contain harmful substances. Cheaper wood mulches can contain scraps from all sorts of sourced including pressure treated wood. If it's not a wood mulch, rubber mulch has it's own issues. Sometimes if the mulch isn't handled/stored correctly toxic gases can form in it so if it smells bad don't use it.
If you want to be on the safe side I'd avoid dyed mulch near vegetables. I personally like to use natural cedar mulch.
Comment: Who's the dye manufacturer you contacted?
Comment: @Danger14 I don't recall.


Old French song lyrics with the word "baiser."

Question: I've been learning the lyrics to the old song, "Mon Amant de Saint-Jean," because my French tutor loves old songs.  But would this song be considered just too embarrassing to ever be sung in public these days, since it uses the word "baiser" (in the sense of "kiss", of course) several times?  No point learning lyrics I could never sing!
Comment: There is a ton of french song using the verb "baiser", in the most delicate way. The most famous one will be Johnny Hallyday love song. Imo it's fine, it has a really classy meaning. The noun and verb are used almost every where in poesy, book, song.
Comment: "Baiser" depend of the context. It will not be embarrassing at all.
Answer: We are talking about this song, right?
The meaning has only shifted for the verb. The noun still has the original meaning of "a kiss".
So it's all fine :D
Answer: Trusting to this reference, we see that in this song the word "baiser" is the noun and so it is unmistakeably recognised as such in the song. This word, "baiser", is also a verb and it can be a coarse term only when it is used as a verb; therefore there is not a chance to induce in anyone's mind the slightest hint of the coarse meaning. Someone indulging in such plays on words would not only be deemed to have a naughty mind but as well to be silly. Let's not forget that in French there is no other equivalent for the noun "kiss" than "baiser" when you are talking of kisses on the mouth: the word "bise" and much more so the diminutive "bisou" are improper for that and can be used only for kisses on the cheeks; for kisses on other parts of the body you have to use the noun "baiser", which can also be used when the kiss is on the cheeks. Note that  "baiser" is a rather dignified term, much more so than the former two nouns.

Il lui donna un long baiser sur la bouche à en perdre haleine.
Après un baiser à sa mère elle se retira.

The problem you are raising can only occur when the verb is used and then again only in the company of persons of low morals. In fact you'll find the verb in the whole of the serious literature of the French language and it means strictly "to give a kiss";  you should never fear to use it as seems proper in that context as long as you keep to the company of person who are concerned with literature.

Elle baisa la main de sa bienfaitrice et la remercia. (such sentences are to be found in the older literature.)
Comment: Implying low morals from the usage of the verb is, ah, "old-fashioned", to say the very least.
Comment: @KonradRudolph Shouldn't we be concerned with morals any more? Whatever the degradation that took place in that domain there remains solid principles that make the difference between human and animal behaviour and that's morals; why deny a gradation of attitudes in the domain of morals then? If there is no low morals and high morals there are no morals at all; that's obviously not true. I can't explain this shying away from the term, unless by a subconscious motivation to  favour a climate of lax morals.
Comment: Drawing a link between sex and low morals is utterly bigoted. Morality is obviously an important concept (e.g. in the form of the categorical imperative) but "morals", rather than "morality", is a term without much usefulness, and almost exclusively used to meddle in affairs of other people without good reason.
Comment: @KonradRudolph Forcing abusive sexual connotations where they have nothing to do is lecherous.
Comment: Uh, where does "abusive" come from? Sex is not inherently abusive. And "lecherous" is another one of these words, like "moral", that's not as useful as you might think.
Comment: @KonradRudolph We'll soon be at the end of our alloted number of comments and still won't have come to any sensible exchange; it is better to leave off this conversation here.


Does chlorine kill yeast?

Question: Does chlorine in tap water kill yeast? Does chloramine kill yeast? Specifically Lalvin 71B wine yeast? Is it OK to use filtered tap water (Culligan filter) to re-hydrate yeast?
Comment: Culligan filters do filter chlorine, but it doesn't mention chloramine. https://images-na.ssl-images-amazon.com/images/I/8196eJNnErS.pdf
Answer: Yes and Yes. Chlorine and Chloramine are both used to sanitize. Killing bacteria, fungi, and yeast is why they are added to water supplies. They kill the things that make you sick...and things that make you happy. There is no discrimination.
Allowing your water to sit overnight or by filtering it (with filters that say they get Chlorine out) usually will get the job done for Chlorine.
Chloramine is a bit tougher. For it you need an activated-charcoal filter or use Campden tablets (potassium metabisulfite). I typically just use a Campden tablet. They are available in your local HBS and are not very expensive.
I have only used tablets. Typically I use 1 tablet for 20 gals of water.
Recommended dose of Campden Tablets to remove chloramine
For more information on getting rid of Chlorine and Chloramine see:
What are the various ways to remove chlorine/chloramine from tap water?
Comment: OK I have powder potassium metabisulfite. I saw that other answer, but I thought it might be about chlorine taste as it doesn't mention killing anything.
Answer: Chlorine and chloramine both kill microbes including yeast. Bleach is used as a disinfectant after all. But the key is chlorine concentration.
Bleach, for example. will kill microbes (including yeast) in two or three minutes. Tap water is chlorinated to a level where the chlorine and chloramine can take care of any remaining microbes while the tap water sits in the pipes (typically for several days before it reaches your home). The lower chlorine levels make it safe to drink, as opposed to bleach.
So chlorinated tap water won't kill your yeast. Higher levels of chlorine compounds will.
A much bigger problem with chlorinated tap tap water is that the chlorine will have a bad effect on the flavor of your beer by creating a compound known as TCP (trichlorophenol) during fermentation. This gives the beer an antiseptic, hospital-gauze like flavor.
Heavily chlorinated tap water should be carbon-filtered, treated with Campden tablets (sodium metabisulphite) or boiled and then cooled overnight to remove the chlorine compounds in order to avoid off-flavours in the beer. Your yeast, however, will not be in jeopardy if you don't do this, just the beer flavor.
Comment: OK. It's for a mead.
Comment: It's the yeast that creates TCP during fermentation. Whether you're fermenting a beer, a cider or a mead doesn't matter much; yeast will still create TCP (i.e. phenolic off flavors) in the presence of too much chlorine.

Does chlorine kill yeast?


Can the Applications or Files and Folders buttons be moved on the Unity Launcher?

Question: Is there a way to move the Applications or Files & Folders buttons on the Unity Launcher?  I can move every other button but those.  I'd like to move them to the top of the bar instead of their default at the bottom of it.
Thanks
Answer: Yes but they need to be within their group and files&folders and applications are 1 group. So you can put files&folders above or below applications. There are a few other launchers that are added to this group like the askubuntu (askububtu.place), google books (books.place) etc.
Basically we currently have 2 groups (hold the 'super' key while reading this and look at the launchers): digits and letters. And you can change the order of the group with digits and the group with letters.
Those digits and letters  are inside all the *.place files on your system.
For instance /usr/share/unity/places has 3:
applications.place  books.place  files.place
<code>$grep Shortcut *

applications.place:Shortcut=a
books.place:Shortcut=b
files.place:Shortcut=f
</code>
(Ofcourse changing the =a to =11 did not add applications to the other group so it will be something inside the Unity system the takes care of this...)


Would an advanced practitioner ever stop meditating?

Question: The founder of the Buddhist community I attend said in an interview that he doesn't meditate anymore. I kind of found this really surprising. If we can say (just for arguments sake) that he is an advanced practitioner - is there any precedence for people once they reach a particular advanced stage in the path stopping meditating? Do people do this? Does it depend on the individual or is he very unusual in this and even potentially doing the wrong thing?
Comment: what does that have to do with your practice?... maybe consider the possible effects it may have kammicly and how paticca sammupada may relate in relation to what you are learning and practicing. Best i got, very speculative.
Answer: Would an advanced practitioner ever stop meditating?
If we take the Buddha & his disciples as an example, I would say, no. I would also not see a reason why. In the texts, the jhānas are referenced as pleasant abidings here-&-now and that is what the arahats do.

"Bhikkhus, if wanderers of other sects ask you: 'In what dwelling,
  friends, did the Blessed One generally dwell during the rains
  residence?'-being asked thus, you should answer those wanderers thus:
  'During the rains residence, friends, the Blessed One generally dwelt
  in the concentration by mindfulness of breathing.'"
  ...
  "Those bhikkhus who are arahants, whose taints are destroyed, who have
  lived the holy life, done what had to be done, laid down the burden,
  reached their own goal, utterly destroyed the fetters of existence, those completely
  liberated through final knowledge: for them concentration by
  mindfulness of breathing, when developed and cultivated, leads
  to a pleasant dwelling in this very life and to mindfulness and
  clear comprehension."
-SN 54.11, At Icchanangala

But having heard that Dhamma, those bhikkhus who are arahants, whose
  taints are destroyed, who have lived the spiritual life, done what had
  to be done, laid down the burden, reached their own goal, utterly
  destroyed the fetters of existence, and are completely liberated
  through final knowledge, are devoted simply to a pleasant dwelling in
  this very life.
-AN 9.4, Nandaka

And how does the disciple of the noble ones obtain at will — without
  trouble or difficulty — the four jhanas that constitute heightened
  awareness and a pleasant abiding in the here-&-now? There is the case
  where, quite withdrawn from sensuality, withdrawn from unskillful
  mental qualities, the disciple of the noble ones enters & remains in
  the first jhana: rapture & pleasure born from withdrawal, accompanied
  by directed thought & evaluation. With the stilling of directed
  thoughts & evaluations, he enters & remains in the second jhana:
  rapture & pleasure born of composure, unification of awareness free
  from directed thought & evaluation — internal assurance. With the
  fading of rapture, he remains equanimous, mindful, & alert, and senses
  pleasure with the body. He enters & remains in the third jhana, of
  which the Noble Ones declare, 'Equanimous & mindful, he has a pleasant
  abiding.' With the abandoning of pleasure & pain — as with the earlier
  disappearance of elation & distress — he enters & remains in the
  fourth jhana: purity of equanimity & mindfulness, neither pleasure nor
  pain. This is how the disciple of the noble ones obtains at will —
  without trouble or difficulty — the four jhanas that constitute
  heightened awareness and a pleasant abiding in the here-&-now.
-MN 53, The Practice for One in Training
Answer: This is normal and even expected on very advanced stages of Vajrayana. Basically, as your meditation gets non-contrived, and your post-meditation awareness grows strong, the two converge. This is known as meditation of nonmeditation. Check out Lamp of Mahamudra by Tsele Natsok Rangdrol.
Answer: There was a Sri Lankan monk named Balangoda Ananda Maiythreya thero, and he mentioned in one of his meetings with lay people that he had attained until Sankarupekkha-nana in vipassana meditation and if he had continued further, he could have become a stream-winner. But he didn't carry on from there because he had a wish to become a Buddha. However, he didn't completely abandon his meditation, still practiced samatha meditation and went on to achieve much higher levels in that as well.
So I think it is possible for advanced practitioners to stop doing it when they want to achieve much higher goals like Buddhahood once they reached a particular state in vipassana meditation. I don't see a reason for giving up samatha meditation though. Some illness might also be a reason for stopping meditation. There are several examples in literature how monks abandoned their meditation because of lust and also clinging on to wrong views .
Answer: Meditation has the benefit of dissolving fabrications and conditioning. So practicing this even after achieving the goal has advantage in subduing would be bad Karma giving unpleasant results.
Also an Arahat can enjoy the Fruit of Attainment by meditating.
Answer: Mindful living is another form of meditation (typically an advanced one), if one no longer needs to formally sit or walk in meditation... then i guess that would be that. But the way you phrased it, it seems it could be any reason.