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Comment by Dr. Krishna Kumari Challa on September 4, 2020 at 6:13am

In butterfly battle of sexes, males deploy 'chastity belts' but females fight back

Some male butterflies go to extreme lengths to ensure their paternity—sealing their mate's genitalia with a waxy "chastity belt" to prevent future liaisons. But female butterflies can fight back by evolving larger or more complex organs that are tougher to plug. Males, in turn, counterattack by fastening on even more fantastic structures with winglike projections, slippery scales or pointy hooks.

It's a battle that pits male and female reproductive interests against one another, with the losing sex evolving adaptations to thwart the winner's strategies.

Could this sexual one-upmanship ultimately result in new species? It's a longstanding hypothesis and one that would help explain how butterflies became so diverse. But this last one proved wrong, as species evolution has other factors too to consider. 

 

Found in about 1% of butterfly species, external mating plugs, also known as sphragis, can resemble a scab or a blob of petroleum jelly in some species while others take astonishingly architectural forms.

But they all serve the same purpose: enforcing female monogamy. Because a female butterfly fertilizes the majority of her eggs with sperm from her last partner, males have a vested interest in blocking rivals. Females, however, stand to benefit by mating with more than one male. Another partner may provide higher-quality sperm, and multiple mating events can increase the genetic diversity of offspring. Plus, females get a health.

To help guarantee their own successors, males in plug-producing species omit the courtship behavior that often precedes mating in other butterflies. Instead, "males pursue the females, grab them midair and drag them to the ground," Carvalho said. After depositing their sperm, males excrete a pre-molded mating plug, which hardens on the female's abdomen.

Plugs may indirectly constrain males as well. Making a mating plug is an expensive investment of time and resources, potentially limiting how many females a male can inseminate. Whether females can remove the plug requires further study, but in her fieldwork and museum specimen analysis, Carvalho noted the structures were often partially broken or missing in species with smaller, more delicate plugs. In species with large, complex plugs, she usually found the structures intact and rarely encountered a female without one—a sign that males may be "winning."

This study revealed some female victories as well. In the evolutionary family tree constructed for Acraeini butterflies, evidence ‘s found that mating plugs originated once across the tribe and were subsequently lost in some species, suggesting a successful female counteroffensive. Wide variations in the shape and size of female genitalia also hint at attempts to render mating plugs ineffective.

Ana Paula S Carvalho et al, Is Sexual Conflict a Driver of Speciation? A Case Study With a Tribe of Brush-footed Butterflies, Systematic Biology (2020). DOI: 10.1093/sysbio/syaa070

https://phys.org/news/2020-09-butterfly-sexes-males-deploy-chastity...

Comment by Dr. Krishna Kumari Challa on September 4, 2020 at 5:53am

LHC creates matter from light

The Large Hadron Collider plays with Albert Einstein's famous equation, E = mc², to transform matter into energy and then back into different forms of matter. But on rare occasions, it can skip the first step and collide pure energy—in the form of electromagnetic waves.

Last year, the ATLAS experiment at the LHC observed two photons, particles of light, ricocheting off one another and producing two new photons. This year, they've taken that research a step further and discovered photons merging and transforming into something even more interesting: W bosons, particles that carry the weak force, which governs nuclear decay.

This research doesn't just illustrate the central concept governing processes inside the LHC: that energy and matter are two sides of the same coin. It also confirms that at high enough energies, forces that seem separate in our everyday lives—electromagnetism and the weak force—are united.

Inside CERN's accelerator complex, protons are accelerated close to the speed of light. Their normally rounded forms squish along the direction of motion as special relativity supersedes the classical laws of motion for processes taking place at the LHC. The two incoming protons see each other as compressed pancakes accompanied by an equally squeezed electromagnetic field (protons are charged, and all charged particles have an electromagnetic field). The energy of the LHC combined with the length contraction boosts the strength of the protons' electromagnetic fields by a factor of 7500.

When two protons graze each other, their squished electromagnetic fields intersect. These fields skip the classical "amplify" etiquette that applies at low energies and instead follow the rules outlined by quantum electrodynamics. Through these new laws, the two fields can merge and become the "E" in E=mc².

"If you read the equation E=mc² from right to left, you'll see that a small amount of mass produces a huge amount of energy because of the c² constant, which is the speed of light squared. But if you look at the formula the other way around, you'll see that you need to start with a huge amount of energy to produce even a tiny amount of mass.

The LHC is one of the few places on Earth that can produce and collide energetic photons, and it's the only place where scientists have seen two energetic photons merging and transforming into massive W bosons.

The generation of W bosons from high-energy photons exemplifies the discovery that won Sheldon Glashow, Abdus Salam and Steven Weinberg the 1979 Nobel Prize in physics: At high energies, electromagnetism and the weak force are one in the same.

https://phys.org/news/2020-09-lhc.html?utm_source=nwletter&utm_...

https://www.symmetrymagazine.org/article/lhc-creates-matter-from-light

Comment by Dr. Krishna Kumari Challa on September 4, 2020 at 5:43am

Scientists discover new rules about 'runaway' transcription

Grace E. Johnson et al. Functionally uncoupled transcription–translation in Bacillus subtilis, Nature (2020). DOI: 10.1038/s41586-020-2638-5

https://phys.org/news/2020-09-scientists-runaway-transcription.html...

https://www.quora.com/q/sciencecommunication/Scientists-discover-ne...;  - Check %%

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Could plants help us find dead bodies? Forensic botanists want to know

https://phys.org/news/2020-09-dead-bodies-forensic-botanists.html?u...

Trends in Plant Science, Brabazon et al.: "Plants to remotely detect human decomposition?" www.cell.com/trends/plant-scie … 1360-1385(20)30243-0 , DOI: 10.1016/j.tplants.2020.07.013

https://www.quora.com/q/sciencecommunication/Could-plants-help-us-f...;   --check %%

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** The Dangers of Intellectual Territorialism

Narrow expertise has its value, but it’s also vital to let scientists step out of their “lanes”

https://www.scientificamerican.com/article/the-dangers-of-intellect...

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How Groups of Cells Cooperate to Build Organs and Organisms

Understanding biology’s software—the rules that enable great plasticity in how cell collectives generate reliable anatomies—is key to advancing tissue engineering and regenerative medicine.

https://www.the-scientist.com/features/how-groups-of-cells-cooperat...

Comment by Dr. Krishna Kumari Challa on September 4, 2020 at 5:26am

Researchers warn of food-web threats from common insecticides

In light of emerging evidence showing how a commonly used class of insecticides can spread through the environment to pollinators, predators and other insects they are not intended to kill, researchers are warning about the potential for widespread environmental contamination.

They argued for curbing the use of neonicotinoid insecticides by discontinuing the practice of applying them preventively on crop seeds.

They argue that reducing this and other common preventive practices could reduce cascading effects on the environment from insecticides whose risks have not been fully characterized.  Neonicotinoids are among the most toxic insecticides to insects ever developed. These insecticides are used in crops, lawns and landscapes, livestock production and even in pet flea and tick products. They are also used in lawns, commercial landscapes and to protect trees.

They are applied to hundreds of thousands of trees each year for protection from exotic pests, which can be lethal to trees, but also from cosmetic pests, which generally are not lethal.

Recently, a study uncovered a new way that neonicotinoids can spread through the food chain. We've known that neonicotinoids can be transmitted through nectar and pollen and can harm pollinators that way—directly from the plants. We've known that if herbivores feed on the plants and predators eat those herbivores, that they could be harmed because the neonicotinoids accumulate in the herbivores' bodies. This was a new revelation that it could be transmitted through the herbivore to the environment as a carbohydrate that a lot of animals feed on.

this raises the potential for additional off-target effects to other organisms as the toxin is spread by organisms that are not killed as they ingest it.

This adds one more example of how the material can move in a three-part food chain from the plant to an herbivore to a predator. If ingested by organisms that are not killed directly, those organisms could pass the toxin on to insects, birds, amphibians or others. Even though the neonicotinoids have relatively low mammalian toxicity, which makes them safer for applicators, there is still risk of some toxicity, and there could be toxicity for other vertebrates.

S. D. Frank et al, Opinion: Neonicotinoids pose undocumented threats to food webs, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2017221117

https://phys.org/news/2020-09-food-web-threats-common-insecticides....

Comment by Dr. Krishna Kumari Challa on September 3, 2020 at 8:11am

Scientific American vs. the Supernatural

This magazine launched a contest to prove, or disprove, the existence of ghosts

https://www.scientificamerican.com/article/scientific-american-vs-t...

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https://www.nationalgeographic.com/science/2020/08/gertrude-elion-a...

Meet the woman who gave the world antiviral drugs

Fifty years ago, few scientists believed a drug could fight viruses with low side effects. Then Gertrude Elion showed the doubters "what I could do on my own."

Comment by Dr. Krishna Kumari Challa on September 3, 2020 at 5:53am

Weekly injection could treat type 2 diabetes, new enzyme discovery suggests

A newly discovered protein produced by the liver, and which helps to control blood sugar levels, could potentially revolutionise treatment for type 2 diabetes.

https://theconversation.com/weekly-injection-could-treat-type-2-dia...

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How ‘elite controllers’ tame HIV without drugs

In a handful of people living with HIV, the virus remains at undetectable levels, sometimes for many years, even though HIV genes still lurk in their chromosomes. These ‘elite controllers’ seem to be able to stash the viral DNA in quiet corners of the chromosome, where it struggles to replicate. Scientists managed to gather dozens of these individuals to analyse their genomes in an effort to better understand their superpower.

https://www.sciencemag.org/news/2020/08/how-elite-controllers-tame-...

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A Molecule in Honeybee Venom Destroys Breast Cancer Cells in The Lab, Study Shows

https://www.sciencealert.com/bees-formidable-weapons-could-successf...

Comment by Dr. Krishna Kumari Challa on September 3, 2020 at 5:46am

 The widespread footprint of blue jean microfibers

Blue jeans are a more popular wardrobe choice undoubtdly. But most people don't think about microscopic remnants of their comfy jeans and other clothing that are shed during laundering. Now, researchers reporting in ACS' Environmental Science & Technology Letters have detected indigo denim microfibers not only in wastewater effluent, but also in lakes and remote Arctic marine sediments.

Samantha N. Athey et al. The Widespread Environmental Footprint of Indigo Denim Microfibers from Blue Jeans, Environmental Science & Technology Letters (2020). DOI: 10.1021/acs.estlett.0c00498

https://phys.org/news/2020-09-widespread-footprint-blue-jean-microf...

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  Viruses could be harder to kill after adapting to warm environments

Enteroviruses and other pathogenic viruses that make their way into surface waters can be inactivated by heat, sunshine and other microbes, thereby reducing their ability to spread disease. But researchers report now that global warming could cause viruses to evolve, rendering them less susceptible to these and other disinfectants, such as chlorine. They also say that this greater hardiness could increase the length of time heat-adapted viruses would be infectious enough to sicken someone who comes in contact with contaminated water.

Anna Carratalà et al. Adaptation of Human Enterovirus to Warm Environments Leads to Resistance against Chlorine Disinfection, Environmental Science & Technology (2020). DOI: 10.1021/acs.est.0c03199

https://phys.org/news/2020-09-viruses-harder-environments.html?utm_...

Comment by Dr. Krishna Kumari Challa on September 3, 2020 at 5:44am

Massive release of methane gas from the seafloor discovered for the first time in the Southern Hemisphere

Gas hydrate is an ice-like substance formed by water and methane at depths of several hundred meters at the bottom of our oceans at high pressure and low temperatures. Methane is a potent greenhouse gas, roughly 25 times more potent than carbon dioxide, and it is estimated that methane frozen in these sediments constitute the largest organic carbon reservoir on Earth. The fact that methane gas has now started leaking out through gas hydrate dissociation is not good news for the climate.

It has been estimated that there are more organic carbon in the form of methane in hydrates than in all fossil fuels combined. The leakage of methane could lead to a feedback loop in which the ocean warming melts gas hydrates resulting in the release of methane from the ocean floor into the water. The warmer it gets, the more methane leaks out.

This process is believed to have triggered and amplified climate changes in our geological past.

Marcelo Ketzer et al. Gas hydrate dissociation linked to contemporary ocean warming in the southern hemisphere, Nature Communications (2020). DOI: 10.1038/s41467-020-17289-z

https://phys.org/news/2020-09-massive-methane-gas-seafloor-southern...

Comment by Dr. Krishna Kumari Challa on September 3, 2020 at 5:37am

Revolutionary quantum breakthrough paves way for safer online communication

The world is one step closer to having a totally secure internet and an answer to the growing threat of cyber-attacks, thanks to a team of international scientists who have created a unique prototype which could transform how we communicate online.

S.K. Joshi el al., "A trusted node–free eight-user metropolitan quantum communication network," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.aba0959

https://phys.org/news/2020-09-revolutionary-quantum-breakthrough-pa...

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Asphalt adds to air pollution, especially on hot, sunny days

Asphalt is a near-ubiquitous substance—it's found in roads, on roofs and in driveways—but its chemical emissions rarely figure into urban air quality management plans.

A new study finds that asphalt is a significant source of air pollutants in urban areas, especially on hot and sunny days.

Researchers observed that common road and roofing asphalts produced complex mixtures of organic compounds, including hazardous pollutants, in a range of typical temperature and solar conditions.

 P. Khare el al., "Asphalt-related emissions are a major missing nontraditional source of secondary organic aerosol precursors," Science Advances (2020). advances.sciencemag.org/lookup … .1126/sciadv.abb9785

https://phys.org/news/2020-09-asphalt-air-pollution-hot-sunny.html?...

Comment by Dr. Krishna Kumari Challa on September 3, 2020 at 5:30am

Oldest radiocarbon dated temperate hardwood tree in the world discovered

https://phys.org/news/2020-08-oldest-radiocarbon-dated-temperate-ha...

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How to remove unwanted components from the cell nucleus

The organization of cells into specific compartments is critical for their function. For instance, by separating the nucleus from the cytoplasm, the nuclear envelope prevents premature translation of immature RNAs.

During mitosis, however, thenuclear envelope disassembles, allowing large cytoplasmic components such as ribosomes to mix with nuclear material. When the nuclear envelope reassembles following mitosis, these cytoplasmic components must once again be removed. "The nuclear envelope can contribute to this by actively importing or exporting substrates up to a certain size, but it was not clear what happens with very large cytoplasmic components Until now.

A research team from has now shown that large components such as ribosomes are in fact removed from the forming nucleus before the nuclear envelope is assembled again. This exclusion process requires the protein Ki-67. In a older study it was discovered that Ki-67 was responsible for keeping chromosomes separated in early stages of mitosis by acting as a surfactant. Remarkably, it was now found that it changes its properties at the end of mitosis and performs the opposite function, namely clustering of chromosomes.

By coming together into a dense cluster at the end of cell division, chromosomes are able to exclude large cytoplasmic components before the nuclear envelope reforms.

This work shows how a single protein can dynamically change the surface properties of chromosomes.

Ultimately, this facilitates effective compartmentalisation of key processes within the cell.

Daniel Gerlich et al. Chromosome clustering by Ki-67 excludes cytoplasm during nuclear assembly. Nature, published on 02 September 2020. DOI: 10.1038/s41586-020-2672-3

https://phys.org/news/2020-08-unwanted-components-cell-nucleus.html...

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