Can I Download a Free Wordpress Theme, Edit it and Use it?

Question: I read that all themes on the wordpress.org site are GPL compatible. So can I download the theme, edit it and use it? Can I remove the links that point to the theme developer's website? Does the GPL license allow this?
Answer: Yes. Use it. Edit it however you like. Redistribute it, modified or unmodified. Sell it. The GPL explicitly allows all of these things, provided that any such distribution is done also under GPL.
While the GPL requires inline-documented author attribution and copyright/license information must remain intact, there is absolutely nothing wrong with removing public-facing "credit links". Anyone implying otherwise is acting contrary to the Free Software philosophy from which the GPL itself is derived.
If a developer wishes to compel users to retain a public-facing credit link, then the developer should release his work under a license other than GPL. But to release a work under GPL and then attempt, through appeals to moral propriety, to restrict the very rights granted by that license, is an act that is itself morally repugnant.
Answer: It is entirely legally possible to do so; check the wikipedia article on GPL, and if you are really boring read the GPL license in a few of the themes you want to use. But it is very morally questionable to take someone's work without giving them credit for it.
The usual solution that satisfies both moral and legal requirements is to give the theme developer a donation for their theme and then modify as you will.
Oh and if you like a theme, email the creator and tell them. Nobody minds a compliment!
Comment: It's a copyright license. There are no moral implications. Front-end attribution links are not required, but rather only the inline code attribution and copyright/license notices. To the contrary: implying moral implications to coerce someone to leave a public-facing "credit link" is contrary to the very Free Software philosophy from which the GPL itself was inspired.
Comment: While attribution links and donations are appreciated by theme developers, there are NO MORAL REQUIREMENTS what-so-ever.
Answer: GPL license Does allow to remove credit links, but that is just not cool, it a small appreciation to the hard word of the theme developer/designer and if you do remove then please consider a donation to that theme developer/designer.
Answer: You can remove credit links (although it's a fairly scummy thing to do), but you cannot remove the GPL licence text in the source code.
Also, unless specifically excepted, you cannot do the same for CSS files and any included images.


Do custom kernels constitute off-topicness?

Question: Originally, this question was closed due to a mis-wording, and is now in the process of being reopened. Another user pointed out to me that they believe that a custom kernel makes a post off-topic (while the original post may have been mentioning a proxy configuration, that is beside the point). So, I would like some opinions (including discussion, and debating if necessary) of whether a custom kernel makes a post off-topic.
Comment: Related: [Can I ask about a problem with a non-Ubuntu kernel here?](https://meta.askubuntu.com/questions/17049/can-i-ask-about-a-problem-with-a-non-ubuntu-kernel-here)
Answer: From the Ask Ubuntu FAQ page:

We welcome questions about:

Using and administering Ubuntu, including official Ubuntu derivatives.

Running third-party applications on Ubuntu.
Development on Ubuntu.
Services provided by Ubuntu
Any question not mentioned below or here are great! There are no "dumb" questions!

What are custom kernels? Can't I compile my own kernel and use it in Ubuntu, is that not considered usage of Ubuntu?
What if I needed to develop something that has no support while using the default kernel? Does that not follow the development line?
What if it's coming from a PPA? There can be a lot of issues simply solved by reverting to official packages, shall we ban questions that involve PPAs?
What about if I compiled the package from source and the features changed (ie: not an issue, just something different)?
If the problem is to be solved using a standard kernel, then great, we can further try to solve it and help knowing that fact, if it can't even be connect to a custom kernel, then ignore that fact. That single fact that an user is using a custom kernel should not make a post OT on this site.
Answer: I propose a simple rule for us to apply, to figure out if someone's operating system is really Ubuntu, and thus within the scope of Ask Ubuntu.
We should ask ourselves what the best answer is to the question:

What is the name of their operating system?

If the best answer is "Ubuntu" or the name of an official derivative of Ubuntu (e.g., "Kubuntu") then it's really about Ubuntu.
If the best answer is something else, then it's not really about Ubuntu.
Answer: As someone who has some experience compiling kernels, I think in general supporting custom kernels is beyond the scope of Ask Ubuntu.
Perhaps on other stack exchange sites, I am not sure.
The reasons are:

As far as I know, the Ubuntu kernel team does not support custom kernels.
The Ubuntu documentation clearly states custom kernels are not supported.
Compiling a custom kernel involves a configuration file with 6, 000 lines of options, let alone actually modifying the underlying C code. Many of these options are hardware dependent and the Ubuntu Kernel team already releases a kernel that is already very generic.
Actual kernel bugs, if they exist in the code, are reported to kernel.org. The Ubuntu kernel team supports only a minor portion of the code, such as apparmor.

As with all rules, there may be some exceptions such as applying a patch or perhaps a trivial configuration change, that could be considered on a case-by-case basis.
In summary, in general, IMO custom kernels are highly specialized and it is easy to break, and hard to fix a kernel.config
Comment: `As far as I know, the Ubuntu kernel team does not support custom kernels.` We have no relation to them, do we ? `Actual kernel bugs . . .` Bugs are off-topic anyway. This is different from using and administering a system
Answer: Who knows what was changed as https://help.ubuntu.com/community/Kernel/Compile states:

Building and using a custom kernel will make it very difficult to get
  support for your system.
While it is a learning experience to compile your own kernel, you will
  not be allowed to file bugs on the custom-built kernel (if you do,
  they will be Rejected without further explanation).

But I don't think this question is about a custom kernel, the wording the user used was

My workplace desktop uses a special customized distro of Ubuntu, but I
  can't get my hands on its installer in < 2 months notice, and I need
  to install this distro on my work laptop
Comment: You have a *bug* in a custom kernel, you see if it also happens in a normal Ubuntu kernel or a kernel.org kernel. If it does, report it downstream or upstream respectively. As answering people's *questsions*, it may be *hard* for people to get help, and the best answer will sometimes be, "this could be happening due to your custom kernel, because with custom kernels X can be different." Such an answer is helpful and I see no reason for us to prevent people from getting it. Sometimes the issue is unrelated and they'll get an answer that solves it. But yeah, it seems s/he had no custom kernel.
Comment: That's a good quote, but do we agree with *their* methodology?
Comment: Bugs are off topic on this site anyway, so we don't need to worry about that. Our site  is about using and administering Ubuntu. We're not supposed to be fixing anything per se.
Answer: We should at a minimum allow questions about the tools that Ubuntu provides for building custom kernels, just as we try support any software provided by Ubuntu.
Answer: I understand that some folks want custom kernels to be on-topic.  The question then becomes, at what point is it an unofficial derived distribution?
For practical intents and purposes, I could grab the source debs for the Backtrack kernel from the Offensive Security repo and apply them to my local kernel.  This effectively makes it Ubuntu with a custom kernel, not Backtrack.  So at what point is something not Ubuntu?
I don't see a more fundamental change to the OS than changing the base kernel everything else is built upon.
Just my 2 cents.
Answer: I would only consider custom kernels off-topic if it does not have to do with creating them. If it is about something not working, then it probably should not be considered off topic. Take this as a grain of salt though.
Answer: No, it should be on topic. Recompiling a custom kernel is within the purview of any Linux user, Ubuntu included. I don't see why this would be considered off topic. I think there is a somewhat over-protective attitude on this forum which discourages users from straying from the "one true path". I think we should not perpetuate such an attitude. If a user needs to compile a custom kernel then fine, they are still a user of Ubuntu, and it should remain on topic on this forum.


Ubuntu installing issue

Question: I've tried two ways to install Ubuntu!
The one that I used more times, is via bootable usb drive! I've downloaded the iso from the authorized site!
I have a 500 GB HDD and I've partitioned it firstly in 2 partitions one with my Windows 7 OS and my programs and another with my media, files, etc.
Then I took free space (25 gb) from the second partition and i made it free space.
I installed Ubuntu 13.04 via the usb stick using 18gb from the free space for the Ubuntu OS using mounting point of "/" formatted as "Ext4".
I also used 8192 gb of my free space for swap!
The installation completed successfully but after the reboot I am not shown the options to choose which OS to use and windows start automatically.
I've also tried to find the partition in the boot menu but it is not visible even there! I did the same thing 5-6 times with the same result!
The second way that I tried to install Ubuntu 12.04 Lts was via windows installer! I installed it on a new partition this time, because I don't want to have Windows 7 OS and Ubuntu OS in the same partition, and at the end of the installation an error message appeared. I pressed "OK" and then my PC rebooted again!
Please can you take a look at the methods I used above and tell me where I am going wrong, especially for the 1st method of installation?
Answer: I think this can Help you out;
Run Win 7
Click Start >> View advanced system settings >> Advanced Tab >> Startup and Recovery >> Settings >> Change the Default Operating System
Comment: its doesnt appear even in this menu! :/

Ubuntu installing issue


How Oracle is related with GIS (Professional wise)

Question: I am GIS B.Tech Graduate. In the aiming of becoming GIS Developer .I temporairly changed my profession from GIS Analyst to Software Engineer. But what I got in this software company is oracle (not .net or Python). I want know with gaining oracle experience how Can I comeback To GIS Domain any suggestions?
Comment: So, you want to know how Oracle DBMS can be used with various GIS software?
Comment: Ya definately yes by gaining oracle experience what are the positions i am eligible for applying in our GIS field?
Answer: Oracle DBMS is is capable of storing spatial data either through custom formats (like Esri) or native (Oracle Spatial). This means it is worth learning for GIS Analyst because you will be able to interact with the DBMS either by using SQL/PLSQL/spatial SQL functions (for analysis and data retrieval, and you can do a lot with those spatial functions without using any desktop GIS interface).
As a GIS Database Administrator/GIS DBA, you will be able to administer the database (both database per se but also geospatial bits which involves spatial indices, multiuser editing, and geodata replication workflows). Oracle is used widely within multiple organizations who use Esri software together with ArcSDE to enable storing ArcGIS native enterprise geodatabase within Oracle database.
Natually, by learning Oracle you master SQL which can be used for any other SQL RDBMS. I find it especially useful to master spatial functions to be able to answer geographical questions with SQL, worth learning, too. A lot of those spatial functions are similar to PostGIS functions (and PostGIS is used very widely in GIS industry), so it will be a less steep learning curve to master PostGIS after getting savvy with Oracle.
You might be surprised, but there are routing and geocoding engines built into Oracle, too. So, a lot of GIS consultancy / GIS Analyst jobs are opened to those who have skills with that.
Answer: I would say that there are two ways. The most obvious is that Oracle has an Oracle Spatial module with lot's of GIS functionnalities. The second is that Oracle, as a RDBMS, is also used as a third party software for the table storage and analysis.
The experience you get by managing an RDBMS like Oracle should thus be easy to valorize for a GIS job.
Answer: To follow up the top answer, a lot of online company's use Oracle real time scheduling systems (formerly Sidewinder) to organise and route their deliveries, (which uses the oracle spatial routing functionality). They are usually looking for GIS analysts to keep the underlying maps up to date.


Attachment to body and bodily sensations

Question: Right from the birth we are so attached to our body.Unwanted sensations easily disrupt the peace of our mind.Why is the mind so attached to the body and how to overcome such attachments ?
Answer: Almost every single one of us are in this very same boat, though we never say so openly. One can free from this Sakkāya-ditthi (personality-belief) by realizing suffering as a noble truth. The Satipatthāna is there for this purpose. The realization one gets out of it is the understanding of Paticca Samuppāda (dependent origination or the universal law of cause and effect). That is, the ability of seeing things in life according to cause and effect. Once a person acquires that skill, he will be able to free from the idea of 'me' by seeing it as a deceit (the true nature). Then, he understands that the concept of 'me' is just a (false) view. The first step toward the Noble Eightfold Path is for one to become Saddhānusārī (faith-devoted). It is a person who accepts this path of Dhamma who then becomes Saddhānusārī . He admits suffering of this Samsara. He accepts there exists a cause and effect. He accepts the fact that one needs to be free from suffering. He also accepts that the Supreme Buddha has freed Himself from suffering and the Dhamma can free us from that suffering. He accepts that the disciples (of the Buddha) will have to follow the Dhamma and that there are disciples who have attained the Arahantship by practicing the Dhamma. One who comes to these notions will become Saddhānusārī . One needs to come to these views if he wants to come to the Dhamma and be free from this personality belief - to be free from this Sakkāya-ditthi.
Answer: Meditation is the key. But there are two components of it. First is the way of living and second is the meditation technique(s). You will find these two components in every religion, sect, mysticism. Since you have asked in this forum it is Buddha's percepts and Vipassna. If you can alter your lifestyle according to Buddha's teachings and practise Vipassna on  a daily basis you will be observe detachment arising in you. Final detachment will happen when you are able to see your past lives. By that experience all worldly attachments will fall to sides because that will clearly establish that you are not a mind-body phenomenon but something much greater. Welcome to the world of meditation.
Answer:
Right from the birth we are so attached to our body.Unwanted sensations easily disrupt the peace of our mind.

That's right.

Why is the mind so attached to the body ...

You are born due to attachment to the body. If it was not so you will not be re born.

... and how to overcome such attachments?

This is though the pratice of Vipassana.
You have to be mindful of arising and passing of sensation pertaining to:

Body - Posture, Elements, Beauty
Feeling
Mental state
Mental content
Answer: I would say it is not correct to say the mind is inherently attached to the body, particularly from child birth (since the Buddha taught a new born child does not have the view of 'self' - MN 64).
What is happening is the body is producing painful sensations, such as hunger, pain & discomfort. For example, the body of baby children often have trouble breathing so the mind is afflicted with discomfort & starts to cry. These painful sensations cause cravings (desires), which then make the mind attach to the painful sensations. If the body never had painful sensations, there would never be any attachment.
The Buddha taught as follows about what is happening:

"Who, O Lord, feels?"
"The question is not correct," said the Exalted One. "I do not say
that 'he feels.' The correct way to ask the question will be 'What is
the condition of feeling?' And to that the correct reply is:
'sense-contact is the condition of feeling; and feeling is the
condition of craving.'"
"Who, O Lord, craves?"
"The question is not correct," said the Exalted One. "I do not say
that 'he craves.' The correct way to ask the question will be 'What is
the condition of craving?' And to that the correct reply is:
'Feeling is the condition of craving, and craving is the
condition of clinging.'"
"Who, O Lord, clings?"
"The question is not correct," said the Exalted One, "I do not say
that 'he clings.' The correct way to ask the question will be 'What is
the condition of clinging?'
And to that the correct reply is:
'Craving is the condition of clinging; and clinging is the
condition of the process of becoming.' Such is the origin of this
entire mass of suffering.
Phagguna
Sutta


The effect of depth on net primary production in aquatic ecosystems

Question: The figure shows the relationship between the water depth and net primary production (=P-R). I want to know why the production (P) initially increases with water depth near the surface? I have seen similar relationships from other sources but never seen a clear explanation.
Comment: Is the figure referring to gross primary production or primary production per capita?
Comment: Textbooks don't give details. At first, I thought the pattern of the productivity correlates with the abundance of phytoplankton. But because the rate of respiration is constant, now I think it is the per capita effect. If it is not the per capita effect, I like to know why the total respiration is constant.
Comment: But the texts in the figure (and other similar figuers from different sources) imply that the figure shows NPP = P - R. So I think it is probably not the per-capita effect. But this figure (http://www.jochemnet.de/fiu/Ink1.jpg) shows that the pattern does not emerge from difference in the concentration of phytoplankton.
Comment: Ok, a bit hard to answer if it is unclear whether the effect is per capita or the total productivity. For experts in the field I suspect it is obvious though (I'm not an aquatic ecologist). My initial guess was however that the graph showed total primary productivity (for the entire "ecosystem"), and that the dip towards the surface is related to the density of primary producers. Lower density at the surface could then be related to both turbulence (waves) and predator avoidance (among other things).
Comment: It looks like the result like the one shown in the figure is based on a controlled experiment using the dark/like bottle method (http://www.jochemnet.de/fiu/Ink1.jpg). Because the density of phytoplankton is controlled in each bottle, we can qualitatively interpret the result as the per-capita effect too. Because of this, the effect should be entirely based on physical factors (e.g., there are no predators in the bottles). Turbulence can still influence the bottles, though.
Comment: What book is the figure in the question from, and the figure you link to in the comments? This would be useful to know, so that people can read for themselves and get some context.
Answer: After a quick glance at the book "Light and Photosynthesis in Aquatic Ecosystems" by Kirk (2010), I think that the cause for the productivity dip towards the surface partially lies in photoinhibition, due to high light intensities at the surface. Here are a couple of relevant quotes from the book (Google books: p. 371):

In this light saturated state, the electron transport and/or CO2 fixing enzymes (most likely, the latter) are working as fast as they are capable, and so any additional absorbed quanta are not used for photosynthesis at all. From the end of the linear region through to the light-saturated region ([i.e. close to the surface, my addition]), since photosynthetic rate does not increase in proportion to irradiance, (P/Ed steadily falls, see Fig. 10.3) the quantum yield and conversion efficiency necessarily undergoes a progressive fall in value. This is accentuated further if, at even higher light intensities, photoinhibition sets in. If the cells contain photoprotective carotenoids, in which absorbed light energy is dissipated as heat rather than being transferred to the reaction centre...

However, the suspended bottle methods often used to estimate these depth gradients might be part of the problem, by overestimating the effect of photoinhibition, by forcing plancton to stay at the same depth (p 358):

Depth profiles of phytoplancton photosynthesis, such as those in Fig. 10.4, determined by the suspended bottle method, tend to overestimate the extent to which photoinhibition diminished primary production. In nature, the phytoplancton are not forced to remain at the same depth for prolonged periods. Some, such as dinoflagellates and blue-green algae, can migrate to a depth where light intensity is more suitable. Even non-motile algae will only remain at the same depth for extended periods under rather still conditions.

I hope I got the quotes right (quick manual retyping). There are many more relevant sections in the book as well, which seems to cover all kinds of aspects of aquatic photosynthetic efficiency and how this can be a function of depth.
Answer: I think it has to do with what wavelength of light is absorbed by photosynthetic organisms at what depth.
Ultraviolet light with short wavelength is absorbed closest to the surface. Red light (which is responsible for photosynthesis) is absorbed at a deeper point in aquatic systems by the primary producers like phytoplankton and metaphyta which increase the productivity of that particular depth.
[I'll include citations, references and diagrams as soon as I find enough time]
Comment: The amount of red light monotonically decreases with the depth. So it still does not explain the hump shaped productivity pattern.
Answer: Compared to the surface, slightly below the surface in the water column the availability of nutrients increases as winds and ocean currents cause increased mixing of nutrient rich deep water. The photic zone of the water column is quick to use up the macronutrients necessary to sustain primary production, however upwelling of nutrient rich deep water becomes a significant factor in determining an area's production.
[ I will provide citation later. ]
Comment: But according to this figure (http://www.jochemnet.de/fiu/Ink1.jpg), the result is based on controlled experiments (the dark/light bottle method). Therefore, the available nutrients are the same along the depth (even if they are naturally variable).
Comment: If this is the experiment I believe it is, then the bottles filled at different depths and returned to the same depth they were filled at. This would have a difference in available macronutrients. However this article about the experiment also details that primary production increases just deeper than the surface because "Primary production is usually suppressed just at the surface because the light is too strong there, but reaches a maximum just below the surface because this is where the light optimum occurs. Below the light optimum, production declines rapidly with light."
Comment: Article location: http://www-personal.umich.edu/~gwk/teaching/limno/lab/onlinemanual/primaryoxy.html


Apache2 Virtual Hosts Overriding One Another

Question: I am not exactly sure what I am doing wrong. I have been able to get subdomains to work on my server, running Ubuntu 10.04 Server. I am running like a Ubuntu recommends with the VirtualHost information in the sites-available/ folder. It was confusing at first how it worked, but after playing with it for over 8 hours things are making more sense.
My biggest problem I feel is I am missing something basic. I just don't know what it is. Here are my virtual host files.
sites-available/net.percent20.net
<VirtualHost *:80>
    ServerName net.percent20.net
    DocumentRoot /srv/www/net.percent20.net/public_html/

    MonoServerPath net.percent20.net "/usr/bin/mod-mono-server2"
    MonoDebug net.percent20.net true
    MonoSetEnv net.percent20.net MONO_IOMAP=all
    MonoApplications net.percent20.net "/:/srv/www/net.percent20.net/public_html"
    <Location "/">
            Allow from all
            Order allow,deny
            MonoSetServerAlias net.percent20.net
            SetHandler mono
            SetOutputFilter DEFLATE
            SetEnvIfNoCase Request_URI "\.(?:gif|jpe?g|png)$" no-gzip dont-vary
    </Location>
    <IfModule mod_deflate.c>
            AddOutputFilterByType DEFLATE text/html text/plain text/xml text/javascript
    </IfModule>
</VirtualHost>

sites-available/percent20.net
<VirtualHost *:80>
    ServerName percent20.net
    ServerAlias www.percent20.net
    DocumentRoot /srv/www/percent20.net/public_html
</VirtualHost>

sites-available/languagesamurai
<VirtualHost *:80>
    ServerName languagesamurai.com
    ServerAlias www.languagesamurai.com
    DocumentRoot /srv/www/languagesamurai/
</VirtualHost>

The current problem I come up against is if I am trying to add a domain that isn't a subdomain it shows what is should be on net.percent20.net. However, net.percent20.net works too.
This is a real confusing problem and lack of knowledge about Apache on my part is a real hamper.
Any ideas would be greatly appreciated. If more information is needed I can provide that too.
Comment: Have you enabled the second site? sudo a2ensite languagesamurai
Comment: @LukeR use answer section so that percent20 can accept it
Answer: I forgot to activate the site with:
sudo a2ensite languagesamurai

Comment: this should not be an answer, or should contain more then that...


Does orange transfrom categorial variables into dummy variables when using hierarchical clustering?

Question: I am using Orange to cluster a large amount of data consisting of three attributes. Each attribute only contains categorical unordered variables. My question is does Orange transform categorical variables into dummy variables when using Distances and Hierarchical clustering widgets on such a data set?
Answer: The documentation states this is not the case. Categorical values are compared as either same or different.


Test strategy and Test scenarios for data-migration testing

Question: We are converting one of our standalone windows application to a web application, Once this is completed we need need to do a data migration . How to prepare test strategy for this ? What are the facts we need to consider ? What are the test scenarios ?
Answer: In a similar situation, I designed few critical end to end business scenarios and ran through both systems and compared the end results as well as crucial mid steps results in terms of output data.
The selection of scenarios will be dictated by the level of data transformation as they go through the system.
Also if the system supports search and reporting feature where it shows detailed data reports based on search parameters so that can be utilized intensively after data migration to compare both systems.
Answer: It will involve much more than data-migration testing.
The first thing you should consider is perhaps how your customers (both internal and external) are affected. What do your customers need to do if this transition happens.

If the application looks different, can the customers adjust to the new interfaces? The best way is to involve customers from day one, having them providing you with constant end-user experience feedbacks.

Data-migration testing strategies can be easily found on the internet, for example, please have a read of this one. http://datamigrationpro.com/data-migration-testing-strategy/
Security testing, a web application can be a target of online hacking; you may consider hiring a security testing expert to help you with penetration testing. Please feel free to have a read of this link, https://www.owasp.org/index.php/Top_10-2017_Top_10
Without knowing exact details of your application, I can only provide information on a relative high abstract level.
Answer: As per your requiremnet, two type of migration is taking place:-
First one is Application and second one is Database migration.
Following are the few strategy that are performed by top software testing companies for ensuring
efficient migration testing:-
1. Application Migration:
Testing Activities here will be:
Analyzing requirements and identifying the stable requirements
Analyze and test all the flows in legacy application against the new
application
Test the new flows in the migrated application if any
Test Scenarios, in general, would be as below:
Validate all the previous functionalities along with the upgraded
features – everything should work correctly
Test the application for the existing data as well as the new data –
both should work correctly
Example:
Try updating the existing data, deleting the existing data,
searching for the existing data, and generating reports for the existing
data.
With new data, validate creating accounts /data, update newly
added data, delete newly added data, search with the newly added data,
and generate reports for newly added data
Verify whether the entire application works correctly
Verify if the new technology still supports all the components of the
application. For example, plug-ins /add-ons /environment values /path
are not changed and should work correctly without any errors
Verify if it is compatible with all possible Operating Systems, Browser
versions etc.
Verify if the old data is retained in the application and new data works
fine on new technology
2. Database migration
For this type of migration, the application should be stable and the
data in the database should be correct and valid.  Hence, the format,
type, value etc., matters while migrating between databases.
Testing activities here will be:
Ensure if the legacy database is not updated during tests after migration
Ensure whether the mapping at field and table levels do not change
Ensuring if data is migrated accurately and completely
Test Scenarios would be as below:
I) If the migration is to the same type of Database, then,
Verify if the queries executed in the new database yield same results as
in the older one
Verify if the number of records in the old database and new database is
the same. Here use appropriate automation tool
Verify that there are no redundancies and new database works exactly as
the older one
Verify if the schema, relationships, table structures are unaltered or
set back to match the old database image
Verify whether the changes made in application updates new database with
correct values and type
Verify if after the new database connection is provided to all the
components of the application. Application, server, interfaces,
firewall, network connectivity etc.
Verify the query performance (time-taken to execute complex queries) of
the new database is not more than earlier performance
II) If the migration is a different type of Database, then along with
above validation points, few or more has to be taken care:
Verify data handling for all the fields. Major challenges will be
handling data for calendar dates, floating numbers, hexadecimal etc.
Answer: In Pre-migration testing, developer and QA team must be extremely familiar with state and functionality of application. The most important is to know all existing issues which haven't been fixed for various reasons. Testers must create main testing scenarios with use flows which users do the most. Also they must cover the rare workflows with some good scenarios. They will later reproduce these scenarios to confirm application works as expected.
In Migration testing, developers are trying to integrate components of application writing code changes. They must coordinate with server administrators which plays crucial role in this step. QA team catch important functional issues in this phase, overtime hours are expected for all teams involved. Occasionally there would be downtime for servers, so project manager must use the old servers until the new production is ready for customers.
In Post-migration testing, less important issues are found (e.g. content and visual bugs) and user acceptance testing is implemented. Developers are taking break after exhaustive work and QA managers are collecting issues into reports to present it to Product owner or other business representative in the team.
QA team must pay attention to common errors which caused defects:
Missing databases and resources (images, documents).
Hardware configurations and setup.
Domain change in code and in descriptions.
Settings of application under test which haven't replicate because of missing database.
Different branch of code is pushed (new one override old one or vice-versa).
Management must decide:
Would they allow access to the databases to testers if project have    deadlines?  What is the scope of testing?  If there are unresolved issues, should they be reported along the new ones?
Development team must:
Be 100% familiar with technologies and languages in which they're working.
Heavily cooperate with server administrators and database developers during migration.
Focus on functional issues immediately.


Transferring a lossless image from an iPhone

Question: asking for a friend. He has an iPhone 5 with a number of crisp photos on it that he wants to move to his computer. However, on moving them to his PC via file explorer, they appear to lose a certain degree of quality. Is this an actual loss in quality or is it just the differences in screens (size, resolution, etc.), and if it is a loss in quality, is there a way to avoid this loss of quality?
Comment: Can you describe the nature of the apparent quality loss?  (Resolution?  Sharpness?  Contrast?  Saturation?  Etc.)  Also, what file format are the images on the phone, and what format do they end up as on the computer?  (JPEG?  HEIC?)
Answer: Moving the images via file explorer almost certainly moves the image as-is. If you're looking at the image on a bigger screen, of course it seems to have lower quality because you're seeing a much bigger image, with more magnification. You could verify this by seeing whether the file size in megabytes is the same on the computer and on the iPhone. You could also check the resolution of the image files after moving them to the computer.
iPhone 5 camera (and all mobile phone cameras) have a limited sensor size. This means that even though the megapixels rating may be good, noise, diffraction, long exposure and other factors limit the quality of the images. If the quality of the images is not good enough for your use cases, the only solution is to purchase a bigger digital system camera (DSLR or mirrorless) with bigger sensor, unfortunately. Carrying such a big camera isn't going to be as easy as carrying an iPhone.
iPhone 5 does not appear to have image stabilization. The following could perhaps improve the mobile phone images:

Take the picture with a flash
Mount the iPhone on a tripod
Move closer instead of zooming, because the zoom in iPhone is digital, not optical
Consider a mobile phone with image stabilization in the camera -- but don't expect miracles
Comment: "...only solution is to purchase a bigger DSLR camera..." It's not quite that dire - there are options other than DSLRs - mirrorless, bridge, even point-n-shoot. Most any of these will have a bigger sensor, and many will have some of the other favorable features you mention - flash, stabilization, optical zoom, better performance regarding noise, diffraction, etc.... I wouldn't recommend jumping directly from an iPhone 5 to a Canon EOS 1D-X II...
Comment: It is also possible that 1) the iPhone display has a stronger contrast than the PC one and 2) that the photo viewer app increases the contrast and saturation when displaying the image.
Comment: A lot of PC monitors are pretty bad and fee can show an iPhone image at full resolution.


Deduction theorem

Question: Is there an axiomatic system where the deduction theorem does not hold?
Comment: @François: How come? A is derivable from A by a one-line proof consisting of just A, even if your system has no logical axioms or rules. More generally, every Hilbert system defines a Tarski-style consequence relation, irrespective of the presence of any particular rules.
Comment: Corollary 9.12 of Kohlenbach's Applied Proof Theory states that WE-HA$^\omega$ and hence WE-PA$^\omega$ fail to satisfy the deduction theorem. However, I must admit that I never fully understood what was going on there.
Comment: @abo: If you're willing to loosen the rules that much then "A always follows from A" is not even true: in a Hilbert system with just modus ponens and no axioms, A does not follow from A.
Comment: Perhaps one should include "interesting" in front of "axiomatic system"? Even in an empty axiomatic system, A always follows from A, but in an empty axiomatic system, one cannot prove anything, much less A => A. By considering any set of axioms which do not allow the proof of A => A, the deduction theorem would still evidently not hold.
Comment: I think for this question to make sense, we need a definition of "axiomatic system." For example, personally I would consider taking the deduction theorem as part of the definition of "axiomatic system;" I could in principle be talked out of it, but it seems like a reasonable requirement to make.
Comment: @Francois. I wasn't aware I was loosening the rules.  Looking at Mendelson, he defines a formal axiomatic theory for the propositional calculus with three axioms.  Keep only the first of the three, which is A => (B => A).  Then A => A isn't provable, but at least according to Mendelson's definition, it is a formal axiomatic theory (just not an interesting one).  Point taken that there are some systems where not even A follows from A.
Comment: You're right Emil, what I wrote doesn't make sense to me this morning. I don't know if I was just too tired to think or thinking something other than what I wrote.
Comment: @abo I have to wonder what you mean by "interesting" when you say that  [A => (B => A)] (under detachment and uniform substitution) is not interesting as an axiomatic system.  If you know how that system works, you can "observe" that *anytime* you have an axiom set for a logic L with [A => (B => A)] as either an axiom or theorem, you can form at least a countably infinite class C of axiom sets (given countably infinite variables), where each member of C axiomitizes L also, such that no axiom set belonging to C has a member in common with any other axiom set.
Comment: @EmilJeřábek But, what if the only derivations permitted in the Hilbert System are the theses which are detachable from other theses in the system?
Comment: Short answer is [paraconsistent logic](https://en.wikipedia.org/wiki/Paraconsistent_logic#Tradeoff)
Comment: Deduction theorem also does not hold in [epistemic logic](http://en.wikipedia.org/wiki/Epistemic_modal_logic).
Answer: Failures of the deduction theorem are one of the more mysterious topics in logic, in my experience. The motto is that axioms are stronger than rules.
Here is the simplest nontrivial example that I know. Start with propositional logic with two variables $A$ and $B$. Add the single new rule of inference $A \vdash B$ to the usual Hilbert-style deductive system, with no new axioms. Note that this does not in any way change the collection of formulas that can be derived. (Proof: the first time you use the new rule, you already had to derive $A$ in the original system, but you cannot, because the original system only derives tautologies. So you can never use the new rule.)  Thus the new system has the rule $A \vdash B$ but does not derive $A \to B$, and hence the deduction theorem fails.
But this new system is not completely trivial. If we add $A$ as a new axiom, then we can derive $B$ in the expanded logic, which we cannot do in ordinary propositional logic. So there is an interplay between the rules of inference and the axioms of a given theory.
The deduction theorem for first order logic shows that this interplay is very well behaved in that context: an arbitrary first-order theory $\Delta$ with the usual deductive system has the derived rule $\phi \vdash \psi$ if and only if it has the derived rule $\vdash \phi \to \psi$.  In retrospect, there is no reason to expect this to hold for arbitrary sets of deduction rules, because new axioms may give additional strength to the existing rules.
As François G. Dorais has mentioned in the comments, more complicated examples are known in proof theory. They are similar to the above example in that they weaken an axiom by replacing it with a rule. The general idea is that an extensionality axiom of the form $x = y \to f(x) = f(y)$ might be replaced with a rule $x = y \vdash f(x) = f(y)$. This suggests immediately how the deduction theorem can fail: if $x$ and $y$ are terms that are not provably equal, but are equal in some interpretation, then the extensionality axiom might fail in that interpretation even if the rule of inference is satisfied in some sense. But this is just a heuristic sketch of the argument. For a short, rigorous explanation, see "A note on Spector's quantifier-free rule of extensionality" by Ulrich Kohlenbach, Archive for Mathematical Logic 40:2 (2001),  pp 89-92.
Comment: I am probably late, but consider the first system you described. Say you assume $A$ and you want to prove $B$. You could easily do it by your rule $A \vdash B$. However, this proof is not ok since $B$ does not have to be true. Hence, this system is unsound. Am I maybe misinterpreting your text?
Comment: @bellpeace: the original system is sound for a particular class of models, namely those in which $A \to B$ holds. Whenever we add new rules of inference, we have to restrict the set of models to those for which the new rules are sound. Of course the system I described, with the additional inference rule, is not complete, and no example that answers the question can be complete in that sense.
Comment: The link is broken; here is a [pdf version](http://brics.dk/RS/99/20/BRICS-RS-99-20.pdf)
Comment: @Mahmud: thank you. The link did work when I wrote the answer originally, so it must be an issue with the migration.
Comment: Do you have an interesting (i.e. non-trivial) example of a Fitch-style system with a Fitch-style rule that is weaker than the corresponding axiom? I ask because the examples you provided crucially rely on the rule only applying in the 'universal context', whereas in a Fitch-style system the rules hold in every subcontext.
Answer: Abstract Algebraic Logic has studied the connections between various forms of the Deduction Theorem, for a given algebraizable logic, and universal algebraic notions such as the existence of definable principal congruence relations for its equivalent quasivariety. For a careful explanation of this, see "Abstract Algebraic Logic and the Deduction Theorem", by Blok and Pigozzi. Such tools help showing that the Deduction Theorem fails for some linear logics, or for orthomodular logic.
Comment: Bemvindo ao MO!
Comment: Danke sehr, Peter!
Comment: This is *the* answer. I'm sorry I can only upvote it once.
Answer: Carl's answer is very good, but I will add something which I think may be useful from point of view of understanding the problem. As an example you may take as well some standard axiomatic formalization of first-order logic with the rule of generalization:
$$\frac{\varphi}{\forall x\varphi}$$
Then for any formula $\varphi(x)$ with $x$ free it is the case that $\varphi(x)\vdash\forall x\varphi(x)$, but in general it is not the case that $\vdash\varphi(x)\rightarrow\forall x\varphi(x)$. So deduction theorem does hold but in a slightly modified form:

If $\varphi\vdash\forall x\varphi$, then $\vdash\varphi\rightarrow\forall x\varphi$, provided that the rule of generalization was not applied with respect to variables free in $\varphi$.

Yet another example may be some systems of modal logic with the rule of necessitation:
$$\frac{\varphi}{\square\varphi}$$
$\varphi\rightarrow\square\varphi$ usually is NOT a thesis of such systems.
Answer: Non-classical logics, such as paraconsistent logic etc.., usually
don't have a problem with the deduction theorem, as long as they
have no relevancy based implication, i.e. if they are based on
residuated lattices and don't try to avoid the positive paradox.
Many people on the other hand believe that the deduction theorem
does not hold in modal logics, especially not in interesting logics
such as temporal logic. A typical argument goes as follows.
In modal logic we would have an inference rule:
<code>  P
----
[] P
</code>
And therefore if a deduction theorem would be available, we
could proof P -> [] P, which is not desired. This argument
is for example informally repeated in Temporal Logic,
The Lesser of Three Evils, Leslie Lamport, Microsoft Research,
MSR-TR-2004-104.
Fortunately matters are not that worse. A more detailed
analysis is given by Does the deduction theorem fail for
modal logic? Raul Hakli, Sara Negri, November 10, 2010.
In a Hilbert Style calculus HK the above rule should be
more precisely formulated as follows:
<code>    |- A
 ---------
 G |- [] A
</code>
The deduction theorem then holds. And we cannot prove
|- P in the first place, and therefore also not go to
|- P -> [] P. Besides a Hilbert Style calculus, the paper
also presents an equivalent Gentzen Style calculus which
has the deduction theorem already as an inference rule.
It is the right implication introduction rule.
Bye
Comment: I don't know why is it that many people believe otherwise, but modal logics do have a perfectly simple deduction theorem: $\Gamma,A\vdash B$ iff $\Gamma\vdash\Box^{\le n}A\to B$ for some $n$. While this is only a parametrized deduction theorem in the AAL sense, this is no different from the form of deduction theorem needed for most other nonclassical logics (in particular, noncontractive).
Comment: +1. The solution of Negri and Hakli is elegant - they redefine the meaning of $\vdash$ so that what they have is not quite the standard Hilbert system (because they have changed the N rule to a weaker rule), but which does have a deduction theorem. Of course the original Hilbert system, with the full N rule, does not satisfy the deduction theorem, in that it admits $A \vdash \Box A$ as a derived rule but not $\vdash A \to \Box A$. Presumably one could apply a similar method to certain systems for first order logic as well.
Answer: As it seems that on the research level notation is the biggest problem for some of people, I will share a link to classical notation of Łukasiewicz L3 system, where deductive theorem i classical meaning does not hohold ( but modified version - holds) - just take a look here: L3 Łukasiewicz logic and here: Łukasiewicz L3 system
and reference:

Bergmann, Merrie (2008). An introduction to many-valued and fuzzy
  logic: semantics, algebras, and derivation systems. Cambridge
  University Press. p. 114. ISBN 978-0-521-88128-9.
Answer: I use Polish notation here, where "C" indicates a conditional which is an operator of two arguments.  The formation rules go:
1) all lower case letters with or without numerical subscripts are formulas.
2) If "x" and "y" are formulas, then Cxy is a formula.
3) For the present purpose, only strings which are formulas according to 1) and 2) are formulas.
I'll assume that if the deduction theorem holds, then the system has CpCqp (Simp) and CCpCqrCCpqCpr (Frege) as theses ("theorems" in the object logic).  If that assumption holds, you only need to find logical calculi where either Frege or Simp do not hold, and the deduction theorem will fail.
Now let's concentrate our attention on axiomatic systems A where the axiom(s) are tautologies in classical propositional logic, and the only rule of inference of any system belonging to A is condensed detachment "D" (perhaps we could allow ordinary substitution of variables and ordinary modus ponens here and things will still work as follows).  Consequently, we can generate as many (countable) systems where the deduction theorem fails as we want from a single thesis of classical propositional logic (though not necessarily any thesis of classical logic, since, for example, (CCNppp, D) has only one thesis).
The axiom I choose here is CCpqCCqrCpr (Syll) (plenty of others will do also!).  Syll holds for Lukasiewicz's 3-valued logic, but Frege does not hold for such a system.  Consequently, Frege fails for the entire system (Syll, D).  But, since Frege fails for (Syll, D), Frege will also fail for (Syll', D) where Syll' is a thesis obtainable in (Syll, D).  Thus, any system (Syll*, D) will not have the deduction theorem.  How many systems (Syll', D) exist?  Well, the variable "r" in Syll does not appear anywhere in Syll's antecedent Cpq (and every thesis of syll is of this type).  Thus, given countably infinite variables, we can observe the sequence (Syll, CCCCqrCprsCCpqs, ...) where any thesis x after Syll is obtained from D(Syll).(x-1) (if x=1, then we have D(Syll).Syll, if x=2, then we have D(Syll).(CCCCqrCprsCCpqs), and so on).  Thus, (Syll, D) has countably infinite theses, which, with the above implies at least countably infinite systems where the deduction theorem fails.
Lukasiewicz-Wajsberg 3-valued logic, BCI, BCK, relevant calculi, Lukasiewicz infinite-valued logic, and equivalential calculi constitute some of the systems studied where the deduction theorem fails (or has a modified form).
Comment: I admire your insistence in voluntarily writing in a way which is essentially opaque to pretty much everyone else... :-/
Comment: @Mariano, why don't you represent just yourself, and don't worry about your imagined *pretty much everyone else*.
Comment: It would help if you explained strings like CCCCqrCprsCCpqs - perhaps they are standard, but Octavio hasn't given any indication that s/he knows what that would mean.
Comment: I agree with @David; meanwhile, there is this: http://en.wikipedia.org/wiki/Polish_notation
Comment: @DavidRoberts I'm not sure what you're looking for in terms of an explanation here.  That said, I did add a small part on formation rules, if that helps.
Comment: If notation is Your problem - just learn how to use it. It is research level site! https://en.wikipedia.org/wiki/Polish_notation#Polish_notation_for_logic
Comment: @DougSpoonwood That's great, thanks.

Deduction theorem


What happened just before the Big bang?

Question: Does the CMB contain any clues to what caused the Big Bang? Does a mathematical model theorize it?
Comment: I won't vote-to-close yet, but please look at all the other times a similar question has been asked and try to make your question more focused. E.g. http://astronomy.stackexchange.com/questions/1484/how-do-we-know-the-big-bang-didnt-happen-in-an-existing-universe. http://astronomy.stackexchange.com/questions/13541/what-was-space-like-before-big-bang
Comment: I know for sure 100% that all mass definitely was as small as a little pinhole...
Comment: @GambleNerd Be careful with what you "know". The Big Bang didn't happen at a single point. It was the expansion of the Universe in the sense that objects moved away from each other.
Answer: Caveat: I'm not a cosmologist, so this answer may not reflect the forefront of scientific knowledge/accuracy, but I have some knowledge so thought I'd share it and hopefully someone can correct me if I'm wrong.
The Big Bang theory states that everything is moving away from everything else, so it must have started closer together. We know from the Cosmic Microwave Background that everything was very dense and hot and small.
You may have heard that the universe started in a singularity. This means one point at which all matter was in the same place. In this state, all information in matter is lost. No particle can be labelled as having a position or size or spin, because every particle is in the same state as every other particle. This means we lose all possibility of having any information about what happened before this. There are many theories of what could have been before this, but no matter how simple/beautiful/mathematically rigorous the theory, it is physically impossible to know anything about it so they are impossible to test. In some definitions this makes these theories not actually science, as the scientific method involves making testable predictions.
Comment: @kubanczyk If you would take the time to actually read my answer, you would see that this is essentially what I said.
Comment: "This means one point at which all matter was in the same place." Incorrect. The Big Bang singularity is different than say, a gravitational singularity. The Big Bang is an expansion of _spacetime_ itself- all matter was not at one point in the universe, but all spacetime (that's to say, the universe itself) was infinitesimally "close" with respect to the space-time interval.
Comment: @ FJC thanks for answering. Instead of physical proof are mathematical proofs used by Astronomers to rule out possibilities? Maybe simulations on powerful supercomputers?
Comment: "universe started in a singularity. This means" that's where I stopped reading... We don't know what is a singularity. Our current theories fail there; they fail to give us predictions of any future experimental results; thus current theories are scientifically useless in saying anything practical about singularity. What you say is unfalsifiable, thus it is not science at all, only an opinion or a story.
Answer: We don't really know what happened before the big bang, but it is logical to think that just like the the mass was released when the big bang happened, it also got crushed to that single point, and since energy can't be created or destroyed, there was also mass before the big bang. And this is also a lot similar to a black hole, leading us to think that the big bang might have been a black hole

What happened just before the Big bang?


What is the difference between credit score and debt rating?

Question: Why is it that the credit worthiness of individuals is tracked via 'credit rating (score)' while that of nations (soverign debt) is tracked via 'debt rating'?
Answer: While they are generally analogous, they have different objectives.  According to Wikipedia "the performance definition of the FICO risk score (its stated design objective) is to predict the likelihood that a consumer will go 90 days past due or worse in the subsequent 24 months after the score has been calculated."  Meanwhile debt ratings revolve around the entity's perceived ability to meet its financial obligations.  Debt rating emphasizes that the score is on the underlying security (bond), which is purchased by investors.
It is also a matter of semantics.  Both Investopedia and Wikipedia consider credit rating to be an umbrella term which encompasses the credit worthiness of individuals and large entities.  Both also view debt rating to mean bond credit rating and credit score to refer to an individual's credit rating.
It's also a question of practicality. They need to have different names to differentiate them. It would be odd to think of investing in most individual's debt.  So, it makes sense that the rating of such debt would have a different name.  (Bear in mind that securitized mortgage and credit card debt are aggregated, not sold on an individual basis.)
Comment: Well, it's not exactly "ability" to pay, it's actual likelihood to pay.  In the [recent US debt downgrade](http://blogs.reuters.com/felix-salmon/2011/08/08/the-downgrade-faq/), there was no real question that the US would be able to make its interest payments, but considerable doubt about whether it would pay them.  Analogously, if I have money in the bank but I still fail to pay my bills by the due date, I get a poor credit score.
Comment: (Though, it gets a bit philosophical about whether someone is "able" if they have the resources but not the will.)
Answer: An individual "credit score" is a purely quantitative formula applied to various relevant statistics such as payment history, credit utilization, income, etc.  In the United States, the three major agencies that assign these scores are TransUnion, Equifax, and Experian, and all three use a formula originally developed by Fair Isaac Co (FICO).  A corporate/sovereign "credit rating" is a much more thorough and subjective analysis which incorporates an assessment of future profitability or economic growth.
There are certainly plenty of similarities.  In both cases, each scoring/rating agency has its own methodology or set of data, and the more sophisticated market participants understand this and adjust for these differences themselves when using the scores/ratings.  The terms used are a bit different, in that "scores" tend to be numbers and "ratings" tend to be on a letter scale.
As to why the terms are different, it is simply a semantic difference driven by history.


How to cut wood panel for angled ceiling?

Question:
I am adding wood paneling to the wall, as you can see above. Starting with the next panel in the coming row I will need to cut the left end to fit the angle of the ceiling. How to I determine the angle I need to set my miter saw to?
Comment: A digital laser level would be a high-tech solution.  Another would be to hang a weight by a string from the roof. That gives you your vertical line (and an angle).  You could similarly use a regular level to draw a horizontal line from that left corner.  That gives you another angle.  You really only need one of those angles, though.  Do whichever you prefer.
Answer: Here is how I have done it before without anything more than what I was already using, the material, pencil, a tape measure and a miter box.
Comment: +1 Love step 4 (first version.) Seems closely related to "I cut it off twice and it's still too short."
Comment: Good technical answer but I use cereal boxes and a utility knife.
Answer: A sliding bevel, which is a fairly low-cost tool designed for exactly this type of job - the blade can be set to match an unknown angle and locked, then it can either be measured, or used directly in setting, or used to draw a line.

No affiliation with or recommendation of the image source.
Or, a piece of cardboard or stiff paper (fold or cut to match the angle of the ceiling - set saw to match.)
Comment: +1, a carpenters bevel should be a standard toolbox item for this type of work.
Comment: Excellent answer. When I was reading the question I was thinking I would post a picture exactly like this.....and then I scrolled down and saw your answer.
Answer: In addition to the two previous answers (which can be used on the same project; some boards are easier with one method or the other), I'd like to point out another idea that is good for especially tricky spots or boosting confidence.  Even when well-practised, there will be cuts you do not want to mess up or extreme cases like a brick fireplace surround.
Use paper to cut a template.  Spread it out and smooth it and fold it in place.  Add painter's tape to join, stiffen, or produce a cleaner straight edge.
Prototype the cut using cardboard. It's easy to cut so it's not more work, and I've used the box that the boards came in as a source!
FWIW, I have a continuous rule of floorboards on the entire upstairs with no thresholds or breaks in the pattern, even around doors into closets.  A couple of rows go from one bedroom down the hall through another bedroom, the entire length of the house with a laser-straight joint.
The angle blade thing can be a lot cheaper and plainer than the one pictured. Like two bucks at the Home Depot, plastic handle with a protruding wingnut.  I have two cheap ones and a nice rosewood/brass one from Lee Valley Tools' Verritas brand.
Another tip: put painter's tape on the wood board in the approximate place of the mark, then draw on that with a nice Sharpie or Black Beauty pencil. The overlap-row idea can sometimes work flipped over, and is excellent for slicing the last row down lengthwise to meet the wall (which is never straight when measured down to a quarter-inch tolerance).
Comment: If you hit the right yard sales you can sometimes get a nice brass and rosewood one for 50 cents, though it may need a little cleaning up.


How might I reduce wind noise and ambient noise when mic-ing a video interview?

Question: I produce short documentary videos, and often need to film interviews outdoors. I typically use either a lavalier or shotgun mic. My lavalier is good at isolating the subject's voice, but is vulnerable to wind. The shotgun—once I cover it in foam and a "dead kitty"—doesn't have wind interference, but does pick up ambient noise. I'd like to minimize both the wind noise and ambient noise. How might I do this?
Answer: There are a few ways to do this.
For one you can pull it out in post production with some mixing tricks. EQ and noise gates can be your friend here. Keep in mind that you wont want to go too crazy since some background noise is nice.
You can try tucking the lav behind a collar or in the neck of the shirt. this may help to block some of the wind. You can try one of these, looks like it may work but I have never used one so I don't know.
You can wait the weather out. This of course is not optimal but you can wait for a windless day to film (if you have that kind of time).
You can play with the shot so that the subject has their back to the wind. This may break the wind over them and help mitigate the noise at the element.
Reducing the ambient noise on the shotgun mic can be tough as you have less control over that. Again it can be touched up in post but I can't think of any ways to seriously mitigate it in production shy of actually having control over the noise sources. You may find that boosting the voice (using the lav track) is enough to make the ambient noise sit well in the background. You will want to keep some of that ambient noise as you don't want the soundscape to seem plain.
Answer: The whole idea of the shotgun is that it mainly picks up ambient noise that is in the direction it's pointed. Have the speaker stand with their backs to the quietest area around. If there are trees, walls, hedges, etc., that's where you want the speaker. A truck rolling by or a jet flying over is going to get all over your audio no matter what, so you have to wait that out. Road noise in general is usually a big problem and your best bet is to get as far away from it and have the speaker face the road. Sometimes it helps to bring the boom below the sight line of the camera and point it up at the speaker's mouth, so that the background behind the speaker is the sky, which won't reflect anything.
Lavs are tricky things and a lot of times when two people are talking face-to-face, person A's lav actually picks up person B better than person A (and vice-versa). This means if one person is talking, the lav will pick up things in front of the speaker better than the speaker. In this case you want the speaker facing away from noises, which is counter to the normal positioning for a boom (with shotgun).
The shotgun is almost always the better quality audio, especially if you have a competent boom operator. The lav would normally be a safety for the boom sound, and might be mixed in to fill out the low end of the voices since the boom can be a bit lacking in that area.
The more you want high-quality audio, the more you want a great boom operator, and the more you want to listen to them. When they say they didn't get the sound or there's ambient, you want pause until they are happy, and take their advice on where to film and record. The challenge and also beauty of documentaries is that there's no ADR that can be done later, so it's important to make sure you're getting what you need right at the start. A boom operator's entire job is making sure that happens.


Linked StackExchange Accounts

Question: I have an account on StackOverflow, ServerFault, and SuperUser all linked to the same OpenID. I originally did not think much of it until I noticed I started gaining reputation/badges individually on each site. Are you supposed to gain reputation per each site, or if the accounts are linked is it supposed to be summed across all of StackExchange? I can see all of my accounts in the 'Accounts' tab of my profile, so I am guessing they are linked together (but not merged? if that means anything).
Comment: You can look at your [network profile](http://stackexchange.com/users/fec90be8-2dfb-4916-a8dc-db39990b5117?tab=accounts) to see everything at once.
Answer:
Are you supposed to gain reputation per each site

Yes.
Answer: The only area I know of where your aggregate reputation has meaning is in Area51 when it comes time to commit to new proposals. The more rep you have across the entire StackExchange, the more weight your committment has to that proposal.
Comment: @Nicholi, you get all the basic abilities for free (via account association bonus) once you reach 200 rep on one site.  To get the bonus just re-associate all your accounts after you have reached 200 on one site.  The more advanced abilities like question closing and moderating really do need a lot of commitment to a specific site.  For example I really would not be a good judge about what should or should not be considered a good question on english.stackexchange.
Comment: Ok thanks. I guess for reputation earned per each site/community it makes sense. As it shows how much you have worked there specifically. It just seems weird that you have to consistently earn the same privileges at each site with a linked account.
Comment: @Nicholi Believe me, I know. When I drop by Security.se where I'm pretty low rep, the user experience is markedly different than it is on SF where I'm a moderator. And I still can't vote-to-close on SU.

Linked StackExchange Accounts


Bitter Cucumbers

Question: I was watching a cooking show and the chef made the comment that if you use a large basic cucumber (not hot house, persian, kirbys, english, etc.) before you peel it, cut off about half an inch of the ends and rub them on the opposite sides, then throw the cut off ends away and peel as usual.  I normally buy persian, hot house, english or other types but I purchased some of these larger cucumbers.  I did what the chef said and they were great.  I did this a few times, and I take my time picking out long, slender, firm, green fresh cucumbers.  I started buying these when I thought the price was right but then I thought taste them first to see if they were good to start off with.  They were.  I pickled about 4 gallons of persian cucumbers last week and tasted the ones I thought might be bad, they were and tried the trick.  Did not work.  All cucumbers were USA products and grown in California.  My friend brought me some big cucumbers last night and we tried the trick.  Well, she eats anything but it did not work.  Has anyone heard of this trick or knows why it works sometimes?  Maybe the age, the girth of the cucumber, not straight or even in size, any ideas?
Comment: Just a link to the trick : http://lifehacker.com/remove-a-cucumber-s-bitterness-by-chopping-and-rubbing-1632826153
Comment: You peel the cucumber before eating it?
Comment: Thanks to the link and yes I have to peel.  My Mom is elderly and her digestive tract is bad.  I peel everything and process and cut teeney tiny most hard foods for her.
Answer: I think you are supposed to do it until white milky stuff comes out, but I never had a bitter cucumber, and I have even grown them too big and old and yellowing before picking, like the size of a big fat baseball bat. I just peel and scoop the seeds out of the cucumber just like it was any other melon and the flesh tastes just fine.
Comment: I didn't do anything except harvest it late. They keep growing until you pick them or they start to rot. When they get older the skins yellows and toughens and the seeds get firmer like melon seeds are supposed to. You see, a cucumber is normally harvested before its ripe, that's when it's good to eat. If you let it ripen, you can't use it the same way anymore because it's become a ripened melon at that point and you have to treat it as a melon
Comment: You have made my day...but really... as big as a fat baseball bat? It tasted good?  What on earth did you do to it?  My Dad use to grow veges and once in a great while we would get zuchinni that looked like watermelons.  They were awful no matter what we tried to do to them.

Bitter Cucumbers


Why do some recipes recommend a short rest after mixing but before kneading the bread?

Question: Some recipes I see for bread dough recommend a short rest between the mixing (just enough to make the ingredients homogeneous) and kneading stage - often 10 to 30 minutes.  The dough seems to be a little easier to work after the rest, but what is going on there in such a short time?
Answer: Besides the initial gluten relaxing that mrwienerdog wrote about, another important effect is the absorption of liquid.
It takes time for the flour to fully hydrate with the available liquid. Before it does the dough will be more sticky and there will be less gluten available for kneading. Giving the recently incorporated dough a short rest allows the flour to pull in all the liquid it can and become much easier to work with.
A similar effect can be seen with pastry doughs. Even though often the goal is to minimize gluten development, a short rest gives the flour time to hydrate and can turn pastry dough from difficult to work and crumbly to soft and smooth.
Comment: I have seen a variation of this process in some recipes: mix flour with water only and let it rest (and absorb the water) before continuing with other ingredients.
Answer: You give the gluten a chance to relax. If you work a bread too soon, the gluten tears. You should always allow your doughs to rest between makeup stages, for this very reason. Of course, if you are careful, you can skip it. However, as you mentioned, the dough will be far more 'bucky' (as my old instructor called it) and harder to work.
Comment: I don't think there is a lot of gluten to relax at this stage (just after just mixing the ingredients).


How can I delete orphan keys in WordPress database tables?

Question: In particular in table wp_options. After almost 2 years of blog production it seems increased a lot, and I don't know how many crap is in there.
Do you know a plugin that works with WordPress 3.0 or safe query to run to search orphan keys/rows?
Answer: There is no query that will be 100% certain to delete everything unused and not delete those things because any theme or plugin can add options to the wp_options table.  Still, with a little effort you can get a pretty good idea of what's not in use and then manually decide which of those things to delete and which not to.
You can put the following code temporarily into your theme's functions.php file and then visit every (type of) page on your public-facing site and more importantly all the admin pages in the admin console. Once you've done that you can open your wp_options table and look at the field use_count (added by the code below) to see which options have a use_count equals to zero (the use count is mostly meaningless other than anything greater than 1 has been read or updated at least once since you added this code.)
global $wpdb;
header('Content-Type:text/plain');
$results = $wpdb->get_results("SHOW COLUMNS FROM wp_options WHERE Field='use_count'");
if (count($results)==0) {
    $wpdb->query("ALTER TABLE {$wpdb->options} ADD COLUMN use_count int UNSIGNED NOT NULL DEFAULT '0' AFTER autoload");
}

add_action('all','monitor_get_option_usage');
function monitor_get_option_usage($filter){
    if (preg_match('#^option_(.*)$#',$filter)) {
        increment_option_use_count(substr($filter,7));
    }
}
add_action('updated_option','monitor_update_option_usage');
function monitor_update_option_usage($option){
    increment_option_use_count($option);
}
function increment_option_use_count($option) {
    global $wpdb;
    $wpdb->query("UPDATE {$wpdb->options} SET use_count = use_count + 1 WHERE option_name = '$option'");
}

With this you'll probably be able to identify options that are associated with long gone plugins, former themes and even options of your own you added early on but no longer use. Export them all to a backup (just in case) and then delete the ones you are comfortable deleting.  Once you are done you can remove the use_count field (if you want to, doesn't hurt for it to be there) and also remove the code above from your functions.php file too.
Although this is still not perfect it's much better than nothing. Hope it helps?
Comment: *@Denis* - Since memcached requires advanced server setup which isn't even possible on a shared server where most WordPress sites are hosted, and since this is an one-time or occasional diagnostic routine I don't see why you'd emphasize the need for memcached *for this use-case*?  Maybe I'm missing something, can you detail why someone who'd have to move to a VPS or dedicated server and get learn how to or get someone to configure memcached should do so just to avoid a large number of database hits for a rarely used maintenance routine?
Comment: I'd *strongly* recommend memcached/incr() for this instead of potentially massive amounts of db writes.
Answer: The plugin Clean Options has worked well for me. The author's description of the plugin seems to fit what you need: "Finds orphaned options and allows for their removal from the wp_options table."
I haven't tried WP-Optimize yet personally, but that one looks promising too. And it says it supports WP 2.7 (whereas Clean Options only mentions definite support for WP 2.3), nice!
Answer: This won't necessarily remove issues with wp_options but I've used WP-Optimize to fix a lot of database sizing issues on my 3.0 sites.  It clears out unneeded post revisions, spam comments, and can automatically fix a lot of issues.  On my main blog, the DB was reduced from 30MB to just under 6MB and runs much more smoothly now.
Answer: I run both Clean Options and WP_Optimize on my site, and the combo does a terrific job of keeping the database in great shape.


Which should I get a FAA glider licence or a Canadian glider licence?

Question: I plan to operate in the Caribbean (Antigua, under ECCAA jurisdiction, which does not have a glider rating of its own) and not in the USA or Canada. I am looking at which one would be require less work and time on my side. I plan to give rides in my country and practice the sport.
Comment: The Caribbean includes multiple jurisdictions/countries that may have their own aviation regulations on certificates they accept from out of country. Can you specify (country/jurisdiction) where you intend on operating.
Comment: The problem with my country (antigua and barbuda ) ECCAA is that they do not have any glider exams or glider clubs or schools.
Answer: This is heavily dependent on the local jurisdictions you plan to operate in and what their laws are.
First off you must find out if your desired countries of operation accept foreign certificates. This varies heavily all over the world and can range from full no questions asked acceptance, to you needing to simply take the test again (in that country) through any various case you can think of.
Second you need to find out what certificate you need. Here in the US to give rides (and receive compensation for such) you need a commercial certificate. This looks like it extends to gliders as well.
Hours.
The FAA requires a few more hours than the Canadian certificate will,
FAA

Are at least 16 years of age; and
Have logged at least 10 hours of
  flight time in a glider and that flight time must include at least 20
  total glider flights, and
Have 2 hours of solo flight time in a
  glider, and
Have passed the FAA written examination; and
Have passed the flight exam with a FAA Examiner.

Canada

A minimum of 6 hours of flight training under the direction and supervision of an instructor
At least 2 hours of solo flight time, including a minimum of 20 takeoffs and 20 landings

Right off the bad Canada requires 4 less hours which, no matter how you spin it will be cheaper (since you have to pay for less time).
Here is the US if you are not a citizen you will need to pass an NTSB background check to train. I do not know if Canada has a similar requirement.
Travel, assuming you are in the Caribbean already it may be cheaper to travel to Florida (or the like) to train then go all the way up to Canada for your training.
Edit:
According to this document the ECCAA does issue glider ratings

126.96.36.199 RATINGS ISSUED
(a) The Authority may issue the following ratings for pilots
  (i) Category ratings in the following aircraft:

(a) Aeroplane;
(b) Rotorcraft;
(c) Glider;
(d) Lighter-than-air;
(e) Power lift.
Comment: The difference in hours required only matters if you can complete the training within those hours.  If you need a few more hours to learn the material, then the legal minimums will become irrelevant.
Comment: Very true, but there are those that complete in the minimum time so I felt it appropriate to mention. For the record my PPL took well over the 40 required hours.
Comment: The problem with the canada one is that the glider license written exam is not public, in terms of questions, while in the usa the questions are public most of them. In the states it is 14 not 16 and they do not require a TSA clearance, for glider.
Comment: They might do but it does not make sense since there is not glider schools in the country but there is a pilot school for aircraft.


What are advantages and disadvantages of Tor with respect to JonDonym?

Question: Objectively, what are the advantages and disadvantages of Tor with respect to JonDonym (formerly known as JAP) in the sense of security and anonymity?
Answer: JonDonym and Tor differ greatly in both design and implementation. First, JonDonym is a mix network, whereas Tor is an onion-routing network. Quoting Syverson (2009) Why I'm not an Entropist:

Mix networks get their security from the mixing done by their component mixes, and may or may not use route unpredictability to enhance security. Onion routing networks primarily get their security from choosing routes that are difficult for the adversary to observe, which for designs deployed to date has meant choosing unpredictable routes through a network. And onion routers typically employ no mixing at all. This gets at the essence of the two even if it is a bit too quick on both sides. Mixes are also usually intended to resist an adversary that can observe all traffic everywhere and, in some threat models, to actively change traffic. Onion routing assumes that an adversary who observes both ends of a communication path will completely break the anonymity of its traffic. Thus, onion routing networks are designed to resist a local adversary, one that can only see a subset of the network and the traffic on it.

See this JonDonym page for further discussion of differences.
Also, Tor is an open network of untrusted relays. Anyone can run a relay, and Tor is expressly designed to resist compromise by malicious relays. JonDonym is a closed network of trusted mixes. According to this JonDonym FAQ:

JonDonym is a development branch of the AN.ON project. And JAP is the
  predecessor of JonDo, the client software which connects users to the
  JonDonym/AN.ON mix network. JonDos is the company which is actively
  developing JonDo and is the billing instance between the users and the
  mix operators.

Mix operators must be certified, as outlined here:

JonDonym works in a different way than Tor or I2P. You cannot start a
  mix server and hope, you will be part of the anonymous proxy service.
  You have to become a verified mix operator first.

There are other differences as well. Tor provides notoriously low and variable bandwidth. That reflects its open design, and its price (free). JonDonym provides both free and premium versions. The free version is slower than most Tor circuits, while the premium version is faster than most Tor circuits.
JonDonym now accepts Bitcoins for premium accounts. For better anonymity, one can sign up using Tor, and pay with Bitcoins that have been throughly anonymized via Tor. Searching Tor.SE will lead you to more from me about that.
Given that JonDonym is more centralized than Tor, it's arguably more vulnerable to coercion by LEA and various TLAs. The FAQ referenced above addresses many of these issues.
JonDonym is still tarred by its cooperation in 2003 under a warrant from the German BKA. I gather that some of its relays logged IP addresses that accessed child pornography. The warrant was later judged unlawful. Also, JonDonym (then called JAP) made efforts to alert its users to the investigation.
Comment: > Many of its relays are run by JonDos GmbH NO - none relay is running by JonDos GmbH. JonDos GmbH develops the software and act as an intermediary billing instance between the JonDo users and the Mix operators. https://anonymous-proxy-servers.net/en/jondos.html
Comment: @cane: Thanks for pointing out my error. I've cited more from the JonDo website. If I have anything else wrong, please comment further.
Answer:
JonDo now accepts Bitcoins for premium accounts...

Anonymous payments for JonDonym premium accounts are possible by Paysafecard (Euro, Dollar) and by snake mail letter too. See "Available billing methods" at
https://shop.anonymous-proxy-servers.net/bin/payment
For better anonymity, one can sign up using JonDonym free services, but Tor works too.
Some other points for comparison of both services:
Funding: TorProject.org is mainly funded by US government over the last years (see financial reports of TorProject.org). JonDonym is funded only by users (premium users) and don't get money from governments any more. (Startup of JonDonym was funded by German government from 2000-2004).
Research: Both projects are supported by scientific research of universities. May be, Tor gets a bit more attention, I don't have a full list for counting publication.
Authority Servers / Infoservices: An anonymisation service doesn't contain only relays. Authority servers (Tor) and Infoservices (JonDo/JAP) are another component. (Only different names used by Tor and JonDo for same function - both provide information about running relays.)
3 of 5 Authority servers (Tor) are operated by members/developers of TorProject. 1 of 5 infoservices is operated by JonDos GmbH. I think, this fact may influence the point of centralization of main components in the discussion.
Sorry for my onesided view. It is only my input for the discussion. TorProject my feature out the advantages for Tor by self. ;-)
Comment: Ohh - something clutters - sorry. It should be: JonDonym is funded only by users (premium users) and don't get money from governments any more. (Startup of JonDonym was funded by German government from 2000-2004).
Comment: Dear cane, I have picked your answer and upvoted both yours and mirimir answers. However, there is one issue that make me somewhat uneasy. That is to say any payment in any form will leave a money trail and that can be used to de-anonymize the client. This is true about Bitcoins too, albeit maybe to a lesser degree. The only way to eliminate this problem is to use a free service. In this respect Tor is superior to JAP, although, JAP have a free service too, but it is extremely slow, in the range of dial up service.


What is replacement theology, and why do I hear it used with a negative connotation?

Question: Occasionally when discussing the modern nation of Israel I hear ideas accused of being "Replacement Theology".  What is Replacement Theology, and why is it almost always used in a negative light?
Comment: @C.Ross Many Dispensationalists, in my experience, paint the entirety of Covenant theology with one paintbrush, and they paint the whole system as "Replacement" theology, meaning that they believe Covenant theologians all believe that the Church has replaced Israel, when the majority of them typically believe that the Old Covenant has been fulfilled, and the New Covenant is now in place. From some people's perspective, this means the New Covenant has *replaced* the Old Covenant, and then it often gets extended to "The church replaces Israel." The actual view isn't usually that extreme.
Comment: Are you referring to the idea that modern Israel is or is not the successor to the Israel of the Bible, or that the church is or is not the successor to the same?
Comment: @AffableGeek I'm not entirely sure.  It seems to be used willy nilly by those who claim the Bible requires supporting modern Israel against critics.  The point of my question is trying to narrow down what the term *actually means*.
Comment: If you Could link to a claim (any claim) like they would have you do on skeptics it would be helpful.
Comment: The quick amswe, however, is that the problem is the uncritical acceptance of the idea the modern state of Israel is equivalent to the Israel in the Bible, despite 2000 years of being outside the land. Personally, I do subscribe to replacement theology, so I'm a bad person to ask.
Comment: Incidentally, I just read your profile.  If you're in a Reformed Presbyterian Church, such as the PCA, your church is probably an adherent to this theology, which would more than likely explain why you haven't heard the phrase "Replacement Theology" very often.  It's a term typically heard in Dispensational circles.
Comment: @DavidMorton We certainly don't use the term.  I also think we should say "fulfilled" rather than "replaced".
Comment: @AffableGeek I don't think "Replacement Theology" at all refers to the modern State of Israel being a replacement for the Kingdom of Israel. As for whether the Israelites were "outside" the land of Israel for more than 2000 years, well that is inaccurate. Jews have maintained their presence in Jerusalem (for one) since the time of David. Even during the Babylonian exile, not all Jews were exiled. This seems to be veering from the OP's question but we can discuss this if you'd like.
Answer: The term is typically applied by Dispensational Theologians when referencing Covenant Theology.
Dispensationalists believe that God is relating to the church during the church age, which we're in right now, however, he related to the Jews during the Mosaic period, using the Mosaic law.  They don't believe, however, that the church has replaced Israel, but rather that the Church is a separate entity to which God relates.  They view the church age as a "parenthesis" during which time, God brings about the salvation of the Gentiles, however, this is still mainly a story between God and Israel.  This theology was first systematized by John Darby, and popularized by Cyrus Scofield, via the Scofield Reference Bible, which was the first major study Bible published in the U.S., hence the theology's popularity today.  The epicenter of this theology today is likely Dallas Theological Seminary.
Many Covenant theologians believe the Church replaces Israel.  This is the reasoning for some of the differences we see between Covenant theology, and Dispensational theology, such as child baptism, which, in Covenant theology is the analogue to Israel's Circumcision, which is, of course viewed oddly by Dispensationalists who believe Baptism to have an entirely different meaning altogether.  Many people call Covenant theology, typically in a negative light, "Replacement Theology", because they view the theology as excluding and nullifying God's promises to Israel.  In this way, they view that the theology is making God out to be liar.  That being said, there's often some muddiness when it comes to understanding what exactly is replaced: the Old Covenant, or the Jews themselves.  I tend to believe it's the former, and not the latter, though there is seem to be some Biblical evidence to support the idea that the majority of Jews today are temporarily, or at least, partially blinded.  (Romans 9-11).
The danger of "Replacement Theology", like any theology, historically speaking, has been the misinterpretation and misuse of that theology for evil means.  A good example of this is the extermination of the Native Americans in North America.  Many of the rationalizations behind this ethnic cleansing revolved around the misunderstood and twisted idea that, since the Church replaces Israel, and many people coming to America at that time considered themselves Christians, then the Native Americans must be our Caananites who should be completely eliminated.  Obviously, this is a tragedy and a great misinterpretation of Scripture for selfish gain.
Now, Dispensationalism often comes hand-in-hand with pre-millenial eschatology, which believes in a relatively complicated timeline that includes several specific things that have been prophesied regarding end times.  These prophecies often include a physical return of the Jews to the land of Israel.  Many Covenant theologians, are Amillenial.  They tend to take Revelation more simply, viewing Christ's return as the overall gist of the book, and many of the details allegorical.  Because of this, they view the modern state of Israel as a different entity altogether than the Israelites of the Bible.  This effectively removes the eschatological viewpoint from the argument on whether or whether not to support Israel.
Ultimately, whether you hear this term at all, and what light it's put into, largely depends on the theological bent of those around you.  I've typically heard it more around Classical or Progressive Dispensationalists, whereas most of my Covenant Theology friends typically take it as an assumed truth, though many haven't really thought out all the implications or details of it.
Answer: To quote from a few sources (including the wikipedia article), Replacement Theology (or Supersessionism) basically states that the church is the fulfillment of Israel, and Israel as a nation no longer has a purpose, since God's chosen people are now the church.

It is a Christian interpretation of New Testament verses, viewing God's relationship with Christians as being the inheritance of the Christian Church of the promises made to the Jews (or Biblical Israelites) and Jewish Proselytes.

and

The tendency is to select those promises which fit church theology (like healing, prosperity, victory) and ignore those which do not (like punishment for rebellion, keeping of feasts, sacrifices). To set the record straight: the church did not yet exist when those promises were given, and they were not given to Israel as a "type" of the church until the church should inherit them. The Old Testament promises were given to Israel, and they apply to Israel. Many of them ALSO apply to the church in a general way, and many of them apply to all nations in a general way, and many of them apply only to Israel.