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4,288 questions with no upvoted or accepted answers
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26
votes
1answer
2k views

Additive genetic variance components from LMER in R

I've set up some dummy data in R which makes 40 genetically related lines, they are all siblings within a line so are genetically related by a factor of ½ thus additive genetic variance should be ...
17
votes
0answers
223 views

Effect of Aging on SA node's sympathetic fibers

I am trying to understand the effect of aging on the sympathetic fibers of SA node. I know that aging shifts the vagal curve to left in frequency due to aging. However, I am interested if aging has ...
15
votes
1answer
297 views

At which step should I apply a detection filter when preprocessing microarray data? (Before/After normalization, batch effects removal)

What is the best practice when preprocessing microarray data using a detection filter (on scanner p-value)? Suppose I have a microarray dataset that I have to normalize with Loess and correct with ...
13
votes
0answers
296 views

Identifying Some Kind Of Fossil

This was found off the coast of Ireland by a friend of mine. The running gag is it's some kind of fetish or totem and should be immediately discarded, but we're interested in whether it's perhaps a ...
12
votes
4answers
318 views

How do antibiotics combined with a non-Western diet affect weight loss?

Wikipedia describes a Western diet as: ... higher intakes of red and processed meat, butter, high-fat dairy products, eggs, refined grains, white potatoes, french fries, and high-sugar drinks. In ...
11
votes
0answers
363 views

What is this thing that is growing in my yard? And should I get rid ot if?

I live in Wilmington, Delaware (Mid-Atlantic USA). The north side of my yard is largely shaded by my house and grass is spotty. Periodically when I go into the yard I will find as many as four pod-...
10
votes
1answer
178 views

Are there certain symmetric-pair muscles that are slightly bigger and NOT due to handedness?

Ok, hear me out, I was just thinking about an article in Nature I read in the past titled "Scrotal asymmetry in man and in ancient sculpture"$^{\dagger}$ and more recently an entire medical textbook ...
10
votes
0answers
302 views

Help identify this creature

I found this strange insect while on Son Tra, Da Nang in central Vietnam. It was about 4cm long and although it was on the ground, was obviously capable of flying. I've never seen anything like this ...
10
votes
0answers
308 views

Anatomical Angle Made by the Fingers of an Extended Palm

Does the angle made by the fingers (excluding the thumb) of an extended palm (as shown in the figure below) have a name (such as the Lovibond or Cobb angle, for instance) ? I have already checked ...
9
votes
1answer
85 views

What kind of fish is this white blue-stained fish?

This fish has been spotted at the Great Barrier Reef near Cairns (Queensland). I put a big effort to find it via Google but never could encounter anything similar. I have also made an attempt to find ...
9
votes
0answers
205 views

Do ring species exist?

In trying to understand evolution better, I have been looking at examples of speciation, and have thus come across the topic of ring species. I have tried to find concrete examples of how these work, ...
9
votes
0answers
140 views

I am trying to identify this plant

I am trying to identify this medium arching shrub growing to about 1.5m high x 2m wide in the subtropical climate of the Mt Coot-tha Botanic Gardens in Brisbane, Australia. Unfortunately there was no ...
9
votes
0answers
274 views

What is the half-life of dNTPs at 95⁰C?

I'm looking for the half-life of dNTPs, either as a whole or broken into individual bases, at 95 degrees C (or similar). A titration would be great if that exists. I can provide more specifics if need ...
9
votes
1answer
357 views

What percentage of the genetic variance is explained by the 'n'- most important loci?

Introduction Standard models in population genetics look up at the evolution of few loci which impact fitness. The variance in fitness is determined by the genetic variance and the environmental ...
8
votes
0answers
149 views

What is this underwater creature?

West Bali, about 10 meters deep. Body is roughly 10 cm across. Does not move.
8
votes
0answers
915 views

Did I just watch a spider die?

So I'm sitting in my office and all of a sudden a small spider is gliding down on a web string from the ceiling, right in front of my eyes, and down onto my desk. It proceeds to make a few awkward ...
8
votes
1answer
708 views

Genetic expression in interspecific hybrids

Referring to interspecific hybrids, I have the following two questions:- Quoting from wikipedia:- The offspring of an interspecific cross are very often sterile; thus, hybrid sterility prevents ...
8
votes
1answer
365 views

Identify this vertebra

I was walking on the beach in New Jersey (U.S.), at about 40 degrees longitude, and found this bone. It's not a fish. The long process in the front is interesting. It is likely a C2 vertebra. I looked ...
8
votes
2answers
691 views

How does LCR compare to Assembly PCR

The question pretty much explains itself. How do the two methods compare? I've always used Assembly PCR but the method is prone to mistakes and I'm curious how it compares to Ligase Chain Reaction (...
7
votes
2answers
113 views

Never caught this fish before

After catching a bunch of mangrove snapper using live shrimp, my son caught this fish in about a foot of brackish saltwater water off a dock near a rock wall in Vero Beach at around 10:00 AM on July ...
7
votes
0answers
96 views

Where does Darwin state his “principle of multiple utility”?

I have never heard of Darwin's 'principle of multiple utility', but several papers refer to it. For example, from Darwin at the molecular scale: selection and variance in electron tunnelling proteins ...
7
votes
1answer
89 views

What species is this aromatic plant found in a mountainous region of Greece?

This plant was found in the Taygetos mountains, Greece, and had a lemony smell. Small plant about a foot high. The shiny recurved leaves are reminiscent of rosemary, and the dry seed-heads seem ...
7
votes
0answers
111 views

Cold water sour taste

Recently I underwent a wisdom tooth extraction, and while there is still numbness I have observed something peculiar. If I drink cold water, it tastes sour, however the same effect is not observed ...
7
votes
1answer
671 views

Why do earthworms surface after a rain?

Googling, I find two different explanations for why earthworms tend to surface after a rain. This page from UCSB, for example, gives both answers, contradicting itself: The first explanation is ...
7
votes
0answers
96 views

Could these be Mycetozoa?

I found this on a forest in Mexico City. It was kind of a warm day (around 15°C). It had been raining a few days prior and it was quite humid, but not suffocating. This orange thing was on top of a ...
7
votes
1answer
801 views

Squirrel nest construction

I've often wondered how squirrels -- specifically, eastern grey squirrels (Sciurus carolinensis) make their nests. Specifically, I've been curious about how they "weave" everything together to make ...
7
votes
0answers
258 views

How to estimate heritability from breeding data

I have a lot of plant-breeding data (tens of thousands of results) that are composed of phenotypes of parents and offspring. The plants however went trough years of selection and it is not balanced. ...
7
votes
1answer
209 views

Does depolymerisation take place at the minus end of microtubule?

Wikipedia says that Dynamic instability refers to the coexistence of assembly and disassembly at the 'ends' of a microtubule. but Karp's Cell Biology, 7th edition says Dynamic instability is ...
7
votes
0answers
885 views

Is there a karyotype database for human cell lines?

I'm looking for the karyotype of a specific cell line. Some karyotypes are well known, such as HeLa or some carcinomas, but some are very hard to find, such as LG2 (B cells). Is there a database ...
7
votes
1answer
240 views

Insect identification (Brazil, orthoptera?)

This insect appeared in my indoor yard, in southeastern Brazil. The body is roughly 2cm in length and it makes very distinct beeping sounds, in a pattern that sounds almost like morse code, unlike the ...
6
votes
0answers
68 views

Examples of environmentally influenced gene-expression in humans?

In discussions of the relevant importance of genetic and environmental influences on the development of the individual, it's often stated that the genetic and environmental influences interact. An ...
6
votes
0answers
49 views

Correlation brain size and muscle volume

I have 3 dogs that weigh ≈ 5 kg, ≈ 20 kg and ≈ 45 kg. The smallest dogs whole head would fit in the mouth of the biggest dog. Although I haven't measured it exactly but by just looking at the dogs I ...
6
votes
1answer
135 views

Why do bulls-eye rashes look like they do?

People infected with Lyme Disease often present with an erythema migrans ("migrating redness") rash. Most often, these rashes are in the shape of a bulls-eye. Rash image. Presumably, this is a ...
6
votes
0answers
55 views

What is the fastest way to crystallise lysozyme (for student course)?

High school sudents are going to visit my university and I plan to demonstrate crystallisation of lysozyme. I ordered pure lysozyme from VWR. I can easily crystallise this within 15 min in batch (4% w/...
6
votes
0answers
48 views

Does cheese contain cells of animal stomachs?

When cheese is made with calf rennet, is it possible that the cheese contains cells of this calf (stomach)? Dried and cleaned stomachs of young calves are sliced into small pieces and then put into ...
6
votes
0answers
107 views

Can anyone identify this seed or nut?

I found many of these nuts in a botanical garden in Sweden (outside, not in a greenhouse) but was unable to find the plant it belonged to. The garden has species from all over the world. I don't ...
6
votes
0answers
118 views

Found in blood sample - what is it? Hopefully not a nemotode-

After examining someone's blood - through microscope - I found these. There were some more that were not photographed. Could someone please inform me on what these are? Maybe abiotic material on the ...
6
votes
1answer
174 views

Are there any parasites that alter human behavior in a self destructive way?

There seems to be quite a few examples of parasites taking over the behavior of insects in a way that leads to the death of the host. A couple of examples include: Spinochordodes tellinii: A ...
6
votes
0answers
139 views

What spider is that in south of Brazil?

I'd like to know if it is possible to identify the spider in the photo below. In fact, as shown in the next picture, it is very small. Location: South of Brazil.
6
votes
0answers
138 views

What is the name of this plant or shrub?

I just found a plant in India. Here is its leaf. I tried looking it up on flowers of India & wikipedia, but both databases are too much to read manually. Physical description: Each Stem has 6 ...
6
votes
0answers
519 views

What is this strange worm-like creature?

Hi! While I was in my front yard this morning, I happened to look down and see this little guy wiggling thru the grass. He isn't like anything I've seen before. He is about 2 1/2 inches long. He has ...
6
votes
0answers
92 views

Any references contradicting Hormesis from low dose studies?

I've recently read some papers on Hormesis (the stimulatory effect of low doses of substances toxic at high doses). The papers are all published in respected peer-reviewed journals, here, here, and ...
6
votes
0answers
291 views

Do animals get “unhealthily” fat in the wild?

Looking at a picture of a seriously fat cat, apparently directly nurtured by humans, popping up in a language learning app, I started wondering: do animals "in the wild" (this might be ambiguous, but ...
6
votes
1answer
512 views

Phoresis and mechanical vectors

According to wikipedia and Human Parasitology By Burton Jerome Bogitsh, Clint Earl Carter, Thomas N. Oeltmann Phoresis: In this type of symbiotic relationship, the phoront, usually the smaller ...
6
votes
0answers
151 views

Identity by descent among unrelated individuals

I was reading a couple of papers which talk about IBD (Identity by descent) among unrelated individuals (for eg. http://www.pnas.org/content/109/4/1193.long). However they do not seem to clearly ...
6
votes
0answers
177 views

Comparative cost of RNA-seq vs sequencing full length cDNAs

I am in the process of assembling and annotating the genome of a non-model organism, using almost exclusively short read (paired-end Illumina) data. Throughput is one obvious benefit of these data (...
6
votes
0answers
120 views

What metabolically happens when an egg fuses with the nucleus of a somatic cell

In stem cell biology, it is recognized that embryonic stem cells are transcriptionally inactive for the first 3 days of development. However, during somatic cell nuclear transfer, the nucleus is ...
6
votes
1answer
867 views

Species identification - what kind of worm is this?

I am finding these worms in my bathroom since summer arrived. I have been finding these on floor, walls and damp towel I left hung overnight in bathroom couple of times. When these worms are squished, ...
6
votes
1answer
175 views

EnteroPluri test contamination

An EnteroPluri test has twelve different sectors. It seems odd to me that pulling the inoculating tip from the starting sector (citrate) all the way to the ending sector (glucose/gas) and then ...
6
votes
1answer
139 views

Why some tissues like small intestine epithelium are able to be replaced so often, yet they are not one of the most common cancers?

My small intestine epithelium cells are replaced thousands times more than my prostate. Yet I'm much more likely of getting a prostate cancer than cancer on my intestine epithelium. Is there a known ...

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