The purpose of extinction training is to subject the animals to the tone enough times to allow them to form a new memory. They realize that the tone is not followed by a shock and therefore is not associated with a threat. This concept forms the basis of exposure therapy, which is used to treat humans with anxiety disorders by progressively re-exposing them to a traumatic memory while in a safe environment.

In this experiment, the BDNF animals show reduced freezing prior to extinction training. This allows the authors to conclude that at least some of the effects that BDNF infusion has on fear expression occur regardless of whether the animals receive extinction training.

Extinction memory is tested on the third day, when the animals are subjected to another round of tones without footshocks. If the animals freeze less in response to the tones, it means that they have successfully extinguished their perceived association between the conditioned stimulus (tone) and unconditioned stimulus (footshock).

BDNF infusions reduced freezing relative to controls, indicating that the extinction memory in these animals was strengthened.

The latency to door opening as well as the likelihood of door opening to free a trapped cagemate were used as readouts for empathy. Based on these criteria the authors conclude that rats are capable of feeling empathy and will act on those feelings.

Here is a nice summary video of the authors' work, narrated by one of the authors, Dr. Peggy Mason.

[https://www.youtube.com/watch?v=3jkOwYKBJEI]

Rats took about 6 days to learn to open the chocolate containing restrainer. In the earlier experiment with the trapped cagemate, the rats took about 7 days to open the restrainer.

The length of time it takes for the rats to master this door-opening maneuver indicates that this action took some effort and didn't come naturally.

Once rats learned to open the door, they were just as likely to open the door to the chocolate-containing restrainer as to the restrainer holding their cagemate.

The helper rats' motivation to set their trapped cagemates free does not depend on social contact with their freed cagemates.

This is evidenced by the fact that helper rats freed their trapped cagemates even when there was no possibility of interaction after freeing.

Rats that showed bolder traits may be more likely to act to help their fellow rat. The second panel of figure S1 shows this. However, although a trend is there, it did not reach statistical significance. http://www.sciencemag.org/content/suppl/2011/12/07/334.6061.1427.DC1/Bartal.SOM.pdf

The rats that displayed more boldness, (as measured by a shorter time to emerge from a half-opened cage) were the ones who freed their cagemates.

http://www.sciencemag.org/content/suppl/2011/12/07/334.6061.1427.DC1/Bartal.SOM.pdf

When their cagemate was trapped in the restrainer, female rats moved around the arena faster than males and also opened the door of their trapped cagemates quicker than males.

The trapped rats emitted ultrasonic alarm calls, which is a measure of stress in rats.

Rats in an arena with a trapped cagemate:

A. moved more frequently around the arena

B. moved faster around the arena

C. spent a longer time in the arena center near the<br> restrainer

D. moved more after the restrainer was opened and the previously confined rat was freed

All these findings point toward the movement and activity of the free rat being linked to the presence of a rat in the restrainer.

The authors rule out the alarm calls as an indicator of stress and the source for door opening.

QUESTION: What other criteria could the trapped rat use to communicate its distress to the helper rat?

The amount of time the helper rat remained frozen after door opening significantly decreased by day 6.

This suggests the helper rat expected the door to fall as a result of its action.

The free rat moved around much more quickly after the door opening that freed the trapped rat. The authors interpret this increase in activity as an indication of the importance of the freeing event in the mind of the rescuing rat.

Since 2006, most ivory poaching occurred in just two key areas.

Poaching activity is highest in a few key regions.

The authors offered sugar solutions containing increasing amounts of caffeine to honeybees. They found that the honeybees preferred not to drink the sugar solutions containing higher amounts of caffeine. At caffeine concentrations greater than 1 mM, the sugar solutions were too bitter for the honeybees.

As shown in Figure 1, the amounts of caffeine in the nectar of the plants tested were lower than this amount, indicating that the honeybees would have had no problem drinking their nectar.

From their PCR genotyping experiment, the authors confirmed that F1 male MCR flies only had DNA bands from the PCR reactions that amplify the MCR insertion. F1 females had bands in all reactions, indicating that some females had one wildtype copy of the y+ allele and one MCR target copy.

From this result, the authors concluded that these females were mosaic.

Because their strategy is so efficient and powerful, many people are raising concerns about whether or not such a tool should be used. It is a hotly debated issue as to whether or not this strategy should be used for research on human tissues in the future.

Additionally, can you imagine what the consequences would be if a research animal carrying an MCR mutation were to accidentally be released into the environment? Essentially 100% of the offspring of that animal would have that mutation, and it would propagate rapidly through the native population.

Although the authors found a strikingly high frequency of entirely y- flies (indicating that the MCR had been successful), they saw a few rare cases in which the flies were only partially y-. This suggests that the CRISPR-Cas9 MCR strategy doesn't work 100% of the time. Sometimes, the CRISPR gRNA doesn't successfully direct the Cas9 protein to the target region of the DNA.

Another potential explanation for the wild-type appearance of some flies is that the non-MCR allele was mutated in a way that made it impossible for the MCR allele to direct it's mutation.

Based on Mendelian inheritance rules, you would predict that a cross between a y- male and a wildtype female (as diagrammed in Figure 2A) would generate all brown progeny; females would inherit one recessive allele from their father and one wildtype allele from their mother, while males would inherit one widltype allele from their mother. But the authors found that nearly all of the female progeny were yellow!

For this to happen, the mutated allele the females inherited from their father subsequently mutated the wildtype allele they obtained from their mother, giving them two copies of a mutated allele and a yellow color. This is further support that the mutagenic chain reaction was successful.

When all conclusions are put together the authors found that the immune-amnesia resulting from measles virus infections could be indirectly responsible for up to half of all childhood deaths from infectious disease.

The authors determined this using statistics and found that when all of the deaths associated with the measles immune-amnesia lasting for 2-3 years were removed, then the overall rate of non-measles infectious disease deaths was calculated to be only half the rate of deaths measured without 'controlling' for the effects of measles.

This study makes it clear that summer jobs do not reduce violent activity because jobs keep youth occupied.

If this was true, then rates of violence would be expected to return to normal rates soon after the program ends.

However, violent activity continues to drop during the 13 months after the summer jobs program ends.

So if social-emotional learning is capable of reducing violence when it's not part of a summer jobs program, how can we understand why it did not provide even more of an influence in this study?

The author suggests that even without the formality of social-emotional learning curriculum, these skills were still taught on the job, perhaps through the job mentors.

Another idea the author presents is that the act of working helps youth develop better skills for handing conflict.

An important part of interpreting results from data is to consider what other possible explanations might exist. This study concludes that summer jobs have a significant effect on reducing violent crime arrests and that this effect could be attributable to the preventative nature of the program.

Other explanations for why this summer jobs program might reduce violent activity include consideration of the mentorship provided in this program. Mentorship is unique to this program and has not been part of previous jobs programs.

Another possible explanation might be how crime was measured. This study considered crimes by type. Previous studies have only measured crime as a generic category. Because of that kind of measurement, those studies might have been constrained in their ability to detect an effect.

The contribution of this study is to show how a relatively short jobs program can have a substantial and significant effect on youth violent crime behavior.

Previous studies have focused on more long-term jobs programs that are very costly to implement. These previous studies have also been implemented in a remediating manner.

This study, by contrast, operates in a preventative manner. It shows how short and preventative oriented jobs programs can have a significant effect on reducing rates of violent crime among young adults.

One of the hypotheses about why summer jobs can reduce violent activity (the "incapacitation effect) is youth lack the time or opportunity to engage in violence.

If this was the case we would expect to see that arrest rates for violent crime would occur during and most immediately after the summer jobs program. The researcher tests this hypothesis and finds that the 13 months after the summer program has concluded have an effect on violence.

This suggests that the incapacitation effect is not at work in this study.

This study is testing whether or not replacing some work hours with social-emotional learning has a different effect on violent behavior than the effect of only participating in a jobs program.

The findings show that there is no statistically significant difference between the groups who only participated in the summer jobs program and those who participated in both the summer jobs program and the social-emotional learning.

About 70% of the cells extracted from the limb blastema had Prod1 expressed on the cell surface. This is an interesting finding showing exactly how many cells would be under the influence of nAG in the living organism.

Skeletal muscle, like limb regeneration itself, is dependent on a nerve being present. When the authors rescue the denervated limb with nAG they don't see normal muscle regeneration.

They conclude that nAG alone is not sufficient to regenerate the muscle tissue. So although nAG can regenerate the limb structure, it does not necessarily create it exactly as in an innervated limb.

This shows that nAG likely has no effect on the nerve itself, instead it has its effect by some other means. Not by simply making the nerve regenerate, which would go on to allow the limb regenerate.

This was an important experiment to show. Focal point electroporation is by no means a 100% successful procedure. Some cells in that region will just simply not pick up the exogenous DNA.

Here the authors conclude that 30%–50% of cells in the region appear to take in the plasmid DNA. This information can help "temper" our expectations when looking at future data in their paper that use this technique. This may help explain variable results.

Furthermore, the authors show that expression of red fluorescent protein (RFP) lasts 3 weeks. This is important because this demonstrates that RFP is turned on for a long period of time and does not get shut off within minutes, hours, or days. If this were the case, one would expect much different results.

The authors showed that when the nerve was removed and the limb amputated, there was very little nAG present compared with the amputated limb with intact nerves.

This correlation between the presence of the nerve versus nAG presence suggests that nAG may be a molecule necessary for limb regeneration. Further follow-up studies needed to be performed to help support this idea.

The authors demonstrated that Prod1 and nAG do in fact bind to each other. This is a major conclusion of their paper and is an important first study.

For the authors' background and follow-up experiments to make sense, these data needed to be shown first.

Using yeast two-hybrid screening the authors determine that there are two secreted proteins that could potentially bind to Prod1.

Because the yeast two-hybrid screens can sometime give false positives, the authors followed up with experiments to confirm this in later panels of figure 1.

What is the significance of finding a secreted protein that binds two Prod1? Remember, where exactly do we find Prod1 in the cell? Why would a cytoplasmic protein probably be a false positive?

Many papers that are limited in word count, such as the ones in Science and Nature, often cut to the chase and state their major conclusions at the end of the introduction or background section. This acts as a "hook" for readers to look at the data supporting these claims.

This paper had important implications for cancer treatment. p53 is required to stop the cell cycle and allow cells to repair DNA damage. Many cancer cells have mutated versions of p53 that are unable to activate this cell cycle arrest. As a result, DNA damage that normally causes cells to arrest and fix the damage may be ignored in cancer cells.

Therefore, if we treat a patient with DNA-damaging agents, their normal cells will stop dividing and repair the damage, but the cancer cells will keep going. DNA replication or cell division in the presence of major DNA damage can be lethal to the cell. So, in theory, the treatment selectively kills only cancer cells.

Unfortunately, though, it is not that simple. In practice, such drugs have many effects on both normal cells and cancer cells, beyond the ones that impact the cell cycle.

Another checkpoint in the cell cycle occurs during mitosis. This checkpoint prevents division until all chromosomes are correctly attached to the mitotic spindle, a network of microtubules that pull sister chromatids to opposite sides of the cell.

When cells are treated with nocodazole, which prevents chromatid attachment, they arrest at the spindle checkpoint. The authors conclude that the two proteins do not play a role at this checkpoint, because cells that lack p53 or p21 still arrest when the attachment is disrupted by nocodazole.

The authors have conclusively shown that p53 and p21 are important regulators at the G2-M checkpoint. Previously, these proteins were thought to only play an important regulatory role at the G1-S checkpoint.

The parental cells are those that did not have disrupted p53 or p21 genes. It was important that the authors used the same cell line as a control because different cell lines have different features that could influence the studied effect.

This result supported the conclusion that p53 and p21 are important in preventing cells from entering mitosis in the presence of DNA damage.

The authors conclude that the absence of functional p53 allows cells to eventually enter mitosis (M phase) despite DNA damage. Although the authors observed a brief arrest in cells with mutant p53, the arrest was only temporary, and the cells eventually progressed to M phase.

Because the p53 mutant cells were progressing into mitosis when they shouldn't be, the researchers concluded that in cells with intact p53 genes, p53 must be responsible for preventing mitotic entry in the presence of DNA damage.

Microglia observed in the adult brain under nonpathological conditions trace their origin to yolk sac macrophages.

In contrast to previous reports that relied on bone marrow irradiation that created experimental artifacts, this study showed that the pool of brain microglia arises from the yolk sac macrophages and is not replenished by circulating blood cells in an adult organism.

The influx of yolk sac macrophages into the brain occurs between embryonic days 8.5 and 9.5.

This indicated that yolk sac progenitors infiltrate the brain via a developed and functional vascular network.

This indicates that blood cells such as granulocytes and lymphocytes, as well as others tissue macrophages, do not arise from the same Runx1 yolk sac progenitors as microglia.

The partial labeling would explain about 60% of F4/80-positive cells not expressing YFP (Figure 3, panel A: brain rudiment).

This indicated that the obtained results could not be attributed to the confounding effect of the genetic model used by the authors.

Although microglia do not form in mice lacking a CSF-1 receptor, they are present in mice with a mutation in the CSF-1 gene that codes for the ligand.

As it turns out, presence of another ligand IL-34 (cytokine interleukin 34) is sufficient to activate CSF-1R on microglial cells to compensate for the loss of CSF-1. In contrast, some tissue macrophages fail to form in mice with a mutated ligand.

CSF-1R is required for the development of yolk sac macrophages and microglia.

Both yolk sac macrophages and microglia depend on the presence of CSF-1R receptor on their surface for their differentiation. Absence of this receptor did not affect development of circulating monocytes.

This suggests that CSF-1R expression is not essential for monocyte differentiation outside the central nervous system (CNS).

However, it does not exclude the possibility that monocytes require CSF-1R after they enter the CNS and could serve as microglial precursors.

Similarity in phenotype between two cell types suggests they have common origin.

The possibility of introducing systemic factors present in young blood to remodel vasculature and increase neurogenesis is an exciting prospect for many neurodegenerative disorders.

Treatment with GDF11, along with other key factors, may be able to reverse numerous detrimental effects associated with the decline of neural activity.

GDF11, is a key systemic factor that contributes to neurogenesis and declines with increased age. However, exposing this circulating factor in old mice improves vascular remodeling and increases neural stem cell populations.

The young mice were transgenic for green fluorescent protein, so all the cells of the young mice were green. The authors didn't see any green blood vessels in the old mice, meaning that the endothelial progenitor cells didn't travel from the young mice to the old.

Because heterochronic old (Het-O) mice and isochronic young mice indicated similar levels of high smell sensitivity in the olfaction assay, this indicates that Het-O mice have increased functional olfaction due to being exposed to young systemic factors.

Exposure of old mice to young systemic factors restores the neurogenic potential of neural stem cells and increases their ability to proliferate and differentiate into neurons in the olfactory bulb.

The elastic properties of cellular materials with random porosity degrade when the density decreases. This is because of a nonlinear relationship between strength and density.

That is why, in this paper, the authors proposed materials with a linear relationship, which maintain mechanical performance for a broad range of densities.

In this paper, the authors presented a new class of materials based on a specific microlattice.

These materials exhibit interesting mechanical properties for a range of constituent materials and densities.

That made them suitable for a wide range of applications.

Unlike previously developed materials, the proposed new materials present a higher specific stiffness (stiffness per unit of mass density), which remains nearly constant.

The elastic behavior of the materials, for the ultralow densities, depends on the fabrication process: Hollow-tube microlattices and solid ceramic lattices present different responses to a compression load.

The marked difference is a result of nanoscale wall thickness in microscale hollow tubes as apposed to solid microscale struts in higher density samples.

The developed materials also present the valuable specificity of being isotropic.

The structures created by the authors present two interesting properties: They are both ultralight and ultrastiff, and the stiffness-to-weight ratio is not strongly affected by the density.

A viscoelastic behavior is an intermediate between a purely elastic behavior (like a spring) and a purely viscous behavior (like an absorber).

Polymers are known to exhibit a viscoelastic behavior, and the authors actually observed this phenomenon in the microlattices they produced.

The authors designed and characterized a new category of light structures presenting ultrastiff properties for a wide range of densities and for different materials.

These experiments conclude that even in the brain, interactions between neutrophils and platelets is mediated by PSGL-1.

The authors examine other tissues to show that wherever they observe neutrophil-mediated inflammation it is regulated by PSGL-1. Also, functions of neutrophils (such as formation of extracellular traps that can bind pathogen) are also regulated by PSGL-1.

These experiments provided evidence that interactions of neutrophils with platelets occurs via PSGL-1 and in its absence, recruitment of neutrophils to tissue decreases, and thus inflammation induced because of neutrophils decreases.

The authors used another model of pathogenic inflammation. They injected a higher dose of LPS into the blood stream to induce endotoxemia (toxins in the blood). This can lead to sepsis because of drastic activation of the immune system.

The authors confirmed the results obtained earlier with TNF-a–induced inflammation was consistent even during pathogenic inflammation, such as ALI.

The authors reach this conclusion because the original localization of the chemotactic receptor (CXCR2) and adhesive receptor (MAC-1) is disturbed in PSGL-1–deficient mice.

Previously, the authors described that neutrophils from Mac-1–deficient mice and PSGL-1–deficient mice show reduced crawling.

However, inhibiting PSGL-1 in Mac-1–deficient mice (these neutrophils are now deficient in both) did not result in an additive reduction in crawling. This might be possible if signaling through these receptors leads to the same pathway downstream.

Without intact signaling through PSGL-1, neutrophils were unable to migrate into the blood vessels. The loss of signaling through PSGL-1, however, did not affect the polarization of neutrophils.

Because of lack of Cdc-42, neutrophils were not able to interact with platelets and their crawling ability was affected.

The authors were able to conclude that the interaction between neutrophils and platelets occurred because of recognition of PSGL-1 on neutrophils and P-selectin on platelets.

The PSGL-1–bearing end of the neutrophils were in a way poking through the blood vessel wall into the inside of the vessel (luminal space). This positioned the cells in an ideal way to interact with cells in circulations (flowing through the blood vessel).

Rac GTPases are known to be involved in cell motility and cytoskeletal dynamics in a cells. Thus, regions where they observe Dock-2 fluorescence would suggest "active structural dynamics."

Through IVM the authors observed that the uropod of neutrophils was constantly bumping with the platelets and some of these collisions lasted long enough for them to measure.

ERRATUM: actually no difference between the sexes. See Volume 335 page 401

[https://www.youtube.com/watch?v=WzE0liAzr-8]

Throughout the night, sleepers experience many periods of slow-wave sleep and rapid-eye-movement sleep. The authors suggest that this cycle of SWS-REM-SWS-REM throughout the night may importantly contribute to consolidation (the transformation of memories to stable storage).

The authors found that the amount of time participants spent in slow-wave sleep and rapid-eye-movement sleep combined was related to how much less biased participants were one week after training.

From this result the authors conclude that sleep in particular was necessary for the bias reduction to last.

The authors found that compared to initial bias scores, bias scores one week later for the cued counterbias training were significantly less biased than for the uncued counterbias training.

From this result the authors conclude that without cueing, bias returned to pre-study levels while cueing the training during sleep resulted in a sustained bias reduction one week later.

The authors found that 1 week after the counterbias training and nap, participants continued to show reduced bias for the training that was cued during sleep. The uncued training, however, showed a significant increase in bias over the week back to baseline-levels.

From this result the authors conclude that cueing the counterbias training during sleep results in a lasting reduction in bias.

The more time participants spent in different kinds of sleep (i.e. slow-wave sleep and rapid-eye-movement sleep), the smaller their bias.

This finding suggests that the type of sleep specifically affected the training rather than simply the passage of time or some other factor.

That is, the plants use caffeinated nectar to make sure that pollinators keep returning back to them instead of going to other plants. This makes it more likely that their pollen and ovules will be used to produce new plants, and thus that their genes will be passed on to the next generation.

Chemicals like caffeine have traditionally been recognized as defense mechanisms for plants; if a predator eats too much of that plant, they will overdose on the chemical and get ill or die. Thus, the chemical acts as a deterrent against predation.

However, the authors of this study have now identified another role for caffeine, and maybe for other chemicals like it. These chemicals can change the behavior of their insect pollinators to the plants' advantage.

In this case, caffeine helped the insects remember that plant, thus causing them to return to it and increase the chances that its pollen will be brought to female reproductive structures. This increases the plant's fitness by increasing the chances that its genes will be passed on to the next generation.

That is, by helping pollinators remember that specific plant, it makes it more likely that the pollinator will return to it and transport its pollen to female reproductive structures. This helps the plant reproduce more often.

As shown in Figure 2. Bees were more likely to remember an odor presented to them while they fed on sugar and caffeine than if they were fed sucrose alone.

That is, in the seeds, stems, leaves, etc. of the plant.

Remember that in this study, the authors were only assessing the importance of nectar caffeine concentrations in altering honeybee behavior.

In other words, certain concentrations of caffeine help pollinators remember a plant's scent, and so the pollinators return to them. Those plants are therefore more likely to reproduce and generate many offspring with similar concentrations of caffeine in their nectar.

However, other plants with very high or very low levels of caffeine are less likely to have pollinators return to them. High amounts of caffeine are bitter and repellant to bees, whereas low amounts aren't as effective at stimulating scent memory. As a result, those plants will be less successful at reproducing, and won't generate as many offspring with very high or very low concentrations of caffeine in their nectar.

This means that over time, the population as a whole will have concentrations of caffeine in their nectar that are sufficient to have an effect on pollinator behavior, without being so high as to drive the pollinators away.

Thus, the pollinators have "driven selection" toward a specific range of nectar caffeine concentrations by specifically helping plants within that range produce more offspring than those outside it.

Like in Study 2, conservatives, compared with liberals, were likely to display less intense activation of the muscles around the eyes (the orbicularis oculi muscle), indicating a less intense/genuine smile.

Conservatives in this study were also more likely than liberals to not use those eye muscles at all (i.e., to display "insincere" or "non-Duchenne" smiles).

In Study 2, if you remember, this difference in likelihood of displaying non-Duchenne smiles was not statistically significant.

Climate change could increase the importance of sunlight-driven degradation of dissolved organic carbon (DOC)—both by releasing carbon that has been frozen in soils for years and by increasing the amount of time with no ice on the water surface.

If more DOC is processed into carbon dioxide, climate change could become more extreme.

To summarize, the authors found that 55% of organic carbon in arctic waters is broken down into carbon dioxide by either sunlight or microbes, while the other 45% is only partially broken down. (So it is still a form of dissolved organic carbon.)

The authors found that dissolved organic carbon (DOC) degrades differently depending on the type of water it is in.

The authors offer this possible explanation: When carbon dissolves out of the soil, it is most likely to enter a small stream first, then a larger river, then a lake.

DOC is degraded by light most easily when it is "new" and has not been exposed to light before (e.g., if it was previously buried in the soil).

DOC in small streams is "newest," so photodegradation is more important in small streams than in lakes or rivers.

Variability in daily weather and the decrease in sunlight over the course of the summer had a large effect on the rate of sunlight-driven dissolved organic carbon degradation.

The amount of organic carbon broken down or partially broken down by sunlight was between three and 19 times larger than the amount broken down by bacteria when not exposed to sunlight.

Based on this observation, the authors conclude that sunlight controls the break down of organic carbon in streams, lakes, and rivers.

This is different from what scientists previously thought.

Hansen and colleagues verify the changes in forest cover that they saw in the Landsat images by exploring news on natural disturbances.

In this case, they found that drastic and instantaneous reductions in forest cover in southern Sweden in 2005 and southwestern France in 2009 were caused by cyclones.

Brazil has historically had high rates of deforestation (e.g., cutting down the Amazon rainforest for agriculture and logging), however Hansen and colleagues show that this rate is steadily decreasing. Read on to find out why!

On the other side of things, Indonesia is steadily increasing the amount of forest that is cut down each year. Why might this be the case? Check out reference #23 for some potential explanations!

How much is 2.3 million square kilometers of land? For perspective, Alaska is the largest state in the United States and it is 1.7 million square kilometers.

Texas is the second largest state and it is 0.7 million square kilometers. Thus, imagine adding both Alaska and Texas together, and that is roughly how much forest was lost from 2000 to 2012.

Now, how much forest was gained in that same time? If you add the area of Texas to Kentucky (0.1 million square kilometers and the 37th largest state), you roughly have 0.8 million square kilometers.

Hansen and colleagues use Landsat data to evaluate changes in forest cover from 2000 to 2012. How do they communicate this information? Are these maps informative? Why or why not?

The authors don't believe that nAG has any effect on specifying tissues. In other words, it does not tell a stem cell to become bone or neurons or skin.

Instead, nAG has its effect simply by increasing the number of dividing cells.

The evidence from this figure suggests that nAG is able to cause more blastemal cells to divide. The authors propose that this is how nAG works in the salamander.

This gets at a possible mechanism for nAG's effect in the living organism and provides potential avenues for further study.

In other words, when sulfate is not used as a coagulant, sulfate concentrations of the water coming into the treatment plants were similar to the sulfate concentrations of the water leaving the plants.

By looking at the difference in violent behavior between youth who are involved in a summer jobs program and those who are not involved in a summer jobs program, this study finds that summer jobs do help reduce youth violence. Importantly, the reduction occurs after the summer jobs program ends.

Another consideration for the interpretation of these data is that analysis relies on arrest rates. Arrest rates only reflect a fraction of actual violent acts since many such acts are not reported and many do not result in an arrest.

One of the possible explanations for why violent crime arrests drop consistently after the end of the jobs program is that time spent in school increases. Testing for this effect, however, shows that this is not likely.

Because of the way this study is designed, it is not possible to make the claim that arrest rates decline even more for youth who can be categorized as at higher risk for violent activity. However, findings from this study show that this might be likely. This would make for interesting future research.

Even though there was a reduction in the arrest rates for violent crimes, there are no statistically significant changes in the arrest rates for property, drug, or other kinds of crimes. This indicates that there is something unique about the relationship between the summer jobs program and violent crime.

This is a significant finding of the study. When comparing violent crime arrests between the treatment group (summer jobs) and the control group (no summer jobs), there were 43% fewer arrests for the treatment group after they participated in this summer job program.

Conclusion 4: When the analyses in this paper were repeated using non-measles deaths due to specific infectious diseases (i.e. pneumonia, bronchitis, diarrheal disease, etc...) the results were consistent with the primary analyses, which were performed by pooling all of the non-measles infectious disease death counts together.

Conclusion 2 and 3: When the authors take into account that there is some extended duration to the measles induced immune-amnesia, they find that their math reveals an average 28.3 months duration. As explained above, this is because the prevalence of immune-amnesia had the strongest correlation with non-measles infectious disease mortality under the assumption that the immune-amnesia lasted for 28.3 months on average.

Conclusion 1 The authors observe a correlation in Europe and the United States between measles infections and overall mortality (death). These results meet their first hypothesis.

Blocking PSGL-1 did not affect the ability of neutrophils to adhere firmly to the blood vessels, but it affected the crawling.

Thus, the authors take a guess that indirectly the PSGL-1 on the uropod, although not interacting with the endothelium, is somehow helping the neutrophils crawl.

The authors were able to see the neutrophils and platelets interacting with each other (in close proximity of these cells). Having labeled the CD62L with blue color, they were able to distinguish between the leading edge and the uropod.

Overall, the authors can conclude that their mutagenic chain reaction strategy is very efficient at driving mutations in both chromosomes simultaneously, creating a homozygous mutant.

As the authors discuss, there are so many ways in which this MCR strategy could be used to speed up the creation of animal models for research or for potential therapeutic uses. It is certainly an exciting new tool for biomedical research and for clinical applications!

Among the F1 progeny (offspring from flies injected with the Mutagenic Chain Reaction construct mated to wildtype flies), the authors obtained females that were yellow (y-), meaning that they expressed two copies of the recessive yellow allele. This is not possible according to the Mendelian rules of inheritance, which predict that all females of this cross should be brown (they would inherit a y+ allele from the wildtype parent and since the y- allele is recessive, one is not sufficient to create the yellow color).

The fact that the authors obtained yellow female flies means that their mutagenic chain reaction worked! The mutant allele these females inherited from the F0 parent subsequently mutated the wildtype allele they inherited from the wildtype parent, giving them two copies of the mutated allele.

Their DNA sequencing experiment confirmed that all yellow flies from the F2 generation had insertion of the expected MCR construct, again confirming the success of the MCR targeting. The authors also DNA sequenced the y locus from flies that did not have the predicted yellow color. They found that these events likely resulted from failure of homology-directed repair to occur. Instead, it seems that the Cas9 cut the DNA, but non-homologous end joining occurred to repair the break, so the MCR construct could not be inserted.

This YouTube video (starting at 3:18) describes the difference between homology-directed repair and non-homologous end-joining.

https://www.youtube.com/watch?v=vP8-5Bhd2ag

The amount of bacterial respiration measured by the authors was lower than in previous studies in other areas, and the reactivity of the dissolved organic carbon with sunlight was higher. Therefore, sunlight-driven degradation was more important in this study than in others that took place in other locations.

Because most of the surface water in the study area is shallow, and there is little shade, sunlight-driven dissolved organic carbon (DOC) degradation is more important than in deep lakes, streams, and forests. The authors suggest that photodegradation of DOC may also be important in other areas with shallow surface water and little shade.

Final tally: Sunlight is responsible for 75% of dissolved organic carbon degradation and 55% of carbon dioxide production in the Kuparuk River basin.

To clarify, subtropical forests changed the most in terms of gain and loss, yet when looking at all subtropical regions as a whole, there isn't a clear trend as there is for tropical forests.

What might be causing these large changes in forest cover in the subtropics?

The authors' results and analyzed data are a great jumping off point for governments that want to better understand how their country's land is changing with time.

These results can then be used to implement policies that manage or protect land where needed.

To look at the maps of forest change data from Hansen and colleagues, click here.

When comparing across different climate domains (i.e., tropical, subtropical, temperate, or boreal), Hansen and colleagues found that only the tropics showed a clear change in the rate of forest loss during the time that they surveyed (2000–12).

In this case, forests are decreasing rapidly in the tropics and in the next sentence we find out exactly where this decrease is taking place; mainly in Malaysia, Paraguay, Bolivia, Zambia, and Angola.

Take a look at Google Maps to find the location of these countries.

Many subtropical forests are treated like crops (e.g., corn, soybean). As such, the trees are cut down and harvested for timber and then replanted for the next harvest season.

Thus, this climate domain experienced the most forest loss while also having the lowest ratio of loss to gain (because the trees that were harvested were subsequently replanted).

To see an example of this, check out an article on forest landowners in Mississippi here.

Out of all countries, Russia lost the most forest cover from 2000 to 2012. Why do you think Russia has lost more forest cover than any other country?

Look at this forest loss on this map (click on Forest Cover Loss 2000-2014).

These results indicate that the relationship between political conservatism and life satisfaction can be statistically explained by self-deceptive enhancement.

With this kind of mediation analysis, the effect is said to be significant when the 95% confidence interval (in this case, from 0.03 to 0.07) does not include zero within its range. See this website for some more information.

The results from this analysis indicate that, as political conservatism (according to voting record) increases, use of positive affect words decreases.

There is no statistical relationship between political conservatism and use of negative affect words, joviality words, or sadness words.

Critical thinking: Why do you think there was a relationship for positive affect, but not joviality?

The authors point out that previous research would suggest that self-reported happiness should match behavioral indications of happiness; the fact that their studies show the opposite finding, they argue, can be explained through self-enhancement.

Democrats tended to use one negative word for every 13.65 positive words. This negative word usage is less frequent than Republicans, who used one negative word for every 11.5 positive words.

That is, the results indicate that although conservatives were not significantly more likely than liberals to not use the orbicularis oculi at all, conservatives were likely to display less muscle activation around the eyes, compared with liberals.

The authors found a decrease in bias from the beginning of the study to just after the counterbias training.

From this finding, the authors can conclude that their counterbias training had an immediate (before-nap) effect.

From this result the authors can conclude that the bias decrease after training was equally effective for both types of bias training (gender and race).

At the beginning of the study, participants showed:

1) a gender bias (preference for associating science words with male faces and art words with female faces)

2) a race bias (preference for associating good words with White faces and bad words with Black faces)

The authors ran a computer simulation to see how much of the human genome could possibly be targeted using this system.

The authors had previously inserted DNA into an artificially inserted target. Now they targeted a natural site.

The deletions were not always exactly on target, but they tended to center around the target thus providing evidence that the process itself targets specific DNA sequences.

The authors demonstrated that the system can edit various different genes in the human genome.

This provides support for the authors' description of the mechanism for the system earlier described.

The authors generated a database of about 190,000 guide RNAs which can potentially target about 40.5% of the human genome. This will be a resource for future experiments.

The authors had to show that the results follow the addition of specific components to the system. By demonstrating this, they support their explanation for what is happening on the microbiological level.

This is a microscopic process which cannot be directly observed, so it is important to show that the process really does rely on CRISPR components.

The counterstereotype training whose sound was played during sleep was more effective (bias was more reduced) than the training whose sound was not played.

This supports the authors' hypothesis!

The authors found that cueing reduced bias equally for both gender counterbias training and racial counterbias training.

From this the authors can conclude that the type of training did not deferentially affect bias reduction.

The authors found that for the counterbias training that was cued (the sound associated with it was played during the nap), the bias was smaller post-nap than pre-nap while for the training that was uncued (the sound wasn't played), the bias was no different post-nap than pre-nap.

From this finding the authors can conclude that the cueing during the nap decreased post-nap bias.

Conclusions

Conclusions test

Test test

Conclusions

test

Because the authors have demonstrated the ability to synthesize noncentrosymmetric structures through coronal cross-linking, they have set a foundation to expand the field of non-centrosymmetric nanostrctures when coupled with CDSA.

Upon synthesis of a triblock co-micelle comprised of three different types of unimers (all of which have a crystalline PFS core), the amphiphilic block co-micelle demonstrated the ability to self-assemble into a star-shaped "supermicelle".

The authors showed they were able to definitively deactivate the micelle ends from CDSA by employing coronal cross-linking. Figs. 3D, E, and F demonstrate the ability for elongation to occur from only the non-crosslinked end.

In order to test if the authors had successfully blocked the active micelle ends, the authors took TEM images before and after unimers were added to the cross-linked micelle solution. As the TEM figure shows, Fig. 2D, upon unimer addition the average micelle length did not increase.

The authors have previously presented the ability to cross-link micelles for increased micellar stability as well as for the synthesis of polymer gel networks (see references).

In this paper, they used this prior knowledge to cross-link the micelle corona to prevent CDSA and limit elongation by deactivating the ends of the micelles.

HDAC6 binds to the free ubiqiuitin associated with the capsid and, in turn, activates cytoskeletal molecules. The involvement of HDAC6 is crucial for the virus to undergo the uncoating and release the vRNPs into the cytosol.

By studying the correlation between HDAC6 and dynein/dynactin, the authors discovered that proteins belonging to the aggresome formation and disassembly machinery participate to the IAV uncoating step during the virus host cell entry.


While before authors explore the role of dynein, myosin II, microtubules and actin on IAV uncoating after plasma membrane fusion, another set of experiments were performed in order to study the effect of these proteins on IAV uncoating when the virus enters by endocytosis. Inhibition of dynein, myosin II, actin and microtubules resulted in reduction of uncoating.

Authors concluded that both dynactin 2 and dynein are essential for the viral uncoating step.

Authors established that HDAC6, through its ZnF-UBP domain but not its deacetylase activity domain, was essential for the uncoating step during the infectious process.

HDAC6 plays an important role during IAV infection after the fusion of the virus capsid to the endosome membrane.

The authors drew the conclusion that HDAC6 was playing an important role in helping the viral uncoating.

The authors observe: I) The process of domestication began in Europe between 18,800 and 32,100 years ago;

II) The population of proto-dog moved with human populations.

Therefore, the authors concluded of the European origin of the modern dogs.

Some domestication did not work, which is why we find traces of domesticated dogs that do not exist today.

This is based on the mitochondrial DNA; the autosomal DNA has not been analyzed yet.