Agriculture Minister V.S. Sunil Kumar has asked agriculture scientists to find solutions for problems of farmers in distress.

He was speaking after inaugurating the 57th national conference on Plant Physiology on Plant Productivity and Stress Management, organised by the Indian Society of Plant Physiologists (ISPP) at the Kerala Agricultural University on Thursday. The Minister highlighted the challenge to food security and livelihoods posed by climate vagaries.

Around 350 delegates from all over the country are attending the three-day conference.

The survival of the farmer should be the focus of all scientific deliberations and if the researches do not address the farmers issues, we will be failing both as scientists and as a community. Scientists should not fall prey to the vested interests of industrial lobbies, he said.

We do not need any complicated technology that will put more burden on the farmers. What we need is simple, but effective farming methods. That is the challenge before the farm scientists. We need farmer-friendly researches. Fruits of the research should reach the farmers, the Minister told the scientists.

At a time when climate change posed new challenges to the farm sector, scientists needed to develop new methods. The farm scientists had a huge responsibility to support the farmers and crops to adapt to climatic changes.

The Minister distributed the ISPP awards for outstanding contributions in the field of Plant Physiology to Narendra Kumar Gupta (JJ Chinoy Medal Award); Sneh Lata Singla Pareek (J.C. Bose Gold Medal Award); and Sharad Kumar Dwivedi (R.D. Asana Gold Medal award). Deepu Mathew and Gomathi R. were selected as ISPP Fellows.

R. Chandrababu, Vice Chancellor, KAU, who himself is a plant physiologist, highlighted the importance of using physiological criteria in plant breeding programmes, especially in the context of climate change.

The inaugural function commemorated the works and achievements of the late S. Sheadrinath, founder of the Department of Plant Physiology at Kerala Agricultural University. Senior plant physiologists T.V.R. Nair and Nandini K. were also felicitated.

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Find solution to issues of farmers, scientists told - The Hindu

Minke whale. Image via Jeremy Goldbogen.

By Matthew Savoca, Stanford University; Jeremy Goldbogen, Stanford University, and Nicholas Pyenson, Smithsonian Institution

Both toothed and baleen (filter-feeding) whales are among the largest animals ever to exist. Blue whales, which measure up to 100 feet (30 meters) long and can weigh over 150 tons, are the largest animals in the history of life on Earth.

Although whales have existed on this planet for some 50 million years, they only evolved to be truly gigantic in the past five million years or so. Researchers have little idea what limits their enormous size. What is the pace of life at this scale, and what are the consequences of being so big?

As scientists who study ecology, physiology and evolution, we are interested in this question because we want to know the limits to life on Earth, and what allows these animals to live at such extremes. In a newly published study, we show that whale size is limited by the largest whales very efficient feeding strategies, which enable them to take in a lot of calories compared to the energy they burn while foraging.

EarthSky 2020 lunar calendars are available! They make great gifts. Order now. Going fast!

A humpback whale approaches scientists in the Antarctic. Image via Goldbogen Laboratory, Stanford University/ Duke University Marine Robotics and Remote Sensing, taken under permit ACA/ NMFS #14809.

Ways to be a whale

The first whales on Earth had four limbs, looked something like large dogs and lived at least part of their lives on land. It took about 10 million years for their descendants to evolve a completely aquatic lifestyle, and roughly 35 million years longer for whales to become the giants of the sea.

Once whales became completely aquatic some 40 million years ago, the types that succeeded in the ocean were either baleen whales, which fed by straining seaweater through baleen filters in their mouths, or toothed whales that hunted their prey using echolocation.

As whales evolved along these two paths, a process called oceanic upwelling was intensifying in the waters around them. Upwelling occurs when strong winds running parallel to the coast push surface waters away from the shore, drawing up cold, nutrient-rich waters from the deep ocean. This stimulates plankton blooms.

Upwelling occurs when winds displace surface waters, which are replaced by cold, nutrient-rich water that wells up from below. Image via NOAA.

Stronger upwelling created the right conditions for baleen whale prey, such as krill and forage fish, to become concentrated in dense patches along coastlines. Whales that fed on these prey resources could forage efficiently and predictably, allowing them to grow larger. Fossil records showing that baleen whale lineages separately became gigantic all at the same time support this view.

Really big gulps

Is there a limit to how big whales can become? We tackled this question by drawing on animal energetics the study of how efficiently organisms ingest prey and turn the energy it contains into body mass.

Getting large is based on simple math: If a creature can gain more calories than it spends, it gets bigger. This may seem intuitive, but demonstrating it with data collected from free-living whales was a gargantuan challenge.

To get the information, our international team of scientists attached high-resolution tags with suction cups to whales so that we could track their orientation and movement. The tags recorded hundreds of data points per second, then detached for recovery after about 10 hours.

Like a Fitbit that uses movement to record behavior, our tags measured how often whales fed below the oceans surface, how deep they dove and how long they remained at depth. We wanted to determine each species energetic efficiency the total amount of energy that it gained from foraging, relative to the energy it expended in finding and consuming prey.

Tagged blue whale off the coast of Big Sur, California. Image via Duke Marine Robotics & Remote Sensing under NMFS permit 16111.

Data in this study was provided by collaborators representing six countries. Their contributions represent tens of thousands of hours of fieldwork at sea collecting data on living whales from pole to pole.

In total, this meant tagging 300 toothed and baleen whales from 11 species, ranging from five-foot-long harbor porpoises to blue whales, and recording more than 50,000 feeding events. Taken together, they showed that whale gigantism is driven by the animals ability to increase their net energy gain using specialized foraging mechanisms.

Our key finding was that lunge-feeding baleen whales, which engulf swarms of krill or forage fish with enormous gulps, get the most bang for their buck. As these whales increase in size, they use more energy lunging but their gulp size increases even more dramatically. This means that the larger baleen whales get, the greater their energetic efficiency becomes. We suspect the upper limit on baleen whales size is probably set by the extent, density and seasonal persistence of their prey.

Large toothed whales, such as sperm whales, feed on large prey occasionally including the fabled giant squid. But there are only so many giant squid in the ocean, and they are hard to find and capture. More frequently, large toothed whales feed on medium-sized squid, which are much more abundant in the deep ocean.

Because of a lack of large enough prey, we found that toothed whales energetic efficiency decreases with body size the opposite of the pattern we documented for baleen whales. Therefore, we think the ecological limits imposed by a lack of giant squid prey prevented toothed whales from evolving body sizes greater than sperm whales.

Scaling of energetic efficiency in toothed whales and baleen whales. Image via Alex Boersma.

One piece of a larger puzzle

This work builds on previous research about the evolution of body size in whales. Many questions remain. For example, since whales developed gigantism relatively recently in their evolutionary history, could they evolve to be even larger in the future? Its possible, although there may be other physiological or biomechanical constraints that limit their fitness.

For example, a recent study that measured blue whale heart rates demonstrated that heart rates were near their maximum even during routine foraging behavior, thereby suggesting a physiological limit. However, this was the first measurement and much more study is needed.

We would also like to know whether these size limits apply to other big animals at sea, such as sharks and rays, and how baleen whales consumption of immense quantities of prey affect ocean ecosystems. Conversely, as human actions alter the oceans, could they affect whales food supplies? Our research is a sobering reminder that relationships in nature have evolved over millions of years but could be disrupted far more quickly in the Anthropocene.

Matthew Savoca, Postdoctoral researcher, Stanford University; Jeremy Goldbogen, Assistant Professor of Biology, Stanford University, and Nicholas Pyenson, Research Geologist and Curator of Fossil Marine Mammals, Smithsonian Institution

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Explanation of why whales are so big, but not even bigger.

Originally posted here:
Why are whales big, but not bigger? - EarthSky

Signal problems: Mice missing a copy of a gene called CUL3 have overly excitable neurons.

A shortage of CUL3, a leading autism gene, impairs social behavior in mice by ramping up protein production in neurons, a new study suggests1.

CUL3 helps tag superfluous proteins for destruction. Several studies have tied rare, spontaneous variants in the gene to autism. But little is known about how the variants lead to the condition.

The new study shows that deleting a copy of CUL3 impairs communication between neurons and alters brain development. These problems seem to arise because certain proteins are no longer degraded properly, causing them to accumulate.

One of these proteins activates the machinery that makes proteins, exacerbating the problem. The results were published in November in Neuron.

This identifies the physiological function of CUL3 and provides pathological mechanisms of possibly autism, says lead investigator Lin Mei, professor and chair of neurosciences at Case Western Reserve University in Cleveland, Ohio.

The findings align with the theory that excess protein production at neuronal connections, or synapses, underlies many forms of autism.

However, the mechanisms in the new work differ from those reported in August by another team studying a different set of CUL3 mutants2. That team tied the loss of CUL3 to an increase in a protein that controls gene expression.

It would be important to dig into the convergences and divergences between these two studies, says Silvia De Rubeis, assistant professor of psychiatry at the Icahn School of Medicine at Mount Sinai in New York City, who was not involved in either study.

Meis team made mice that lack one or both copies of the gene in their neurons and star-shaped cells called astrocytes.

Mice that lack both copies die young and have unusually small brains, suggesting that the gene is crucial for brain development.

Those missing only one copy of the gene have a normal lifespan and brain size. These mice tend to avoid spending time with other mice. They are also anxious, preferring to stick to the perimeter of an open chamber and rarely crossing through the center.

Brain slices from the hippocampus, a brain area important for learning and memory, show that the mice have an unusually high density of dendritic spines tiny nubs that receive signals from other neurons. A mouse model of fragile X syndrome, a condition related to autism, shows a similar surplus in these structures.

Neurons in the hippocampus of the CUL3 mice are also overly excitable, resulting in a signaling imbalance, which is often associated with autism.

The mice show elevated levels of several proteins, including one called EIF4G1, which controls protein production and so worsens the protein buildup. Blocking EIF4G1 with an experimental drug injected into the brain eases the mices social difficulties.

The researchers also found evidence that a subset of cells called pyramidal neurons are responsible for many of the features caused by CUL3 deficiency.

The mice in the August study also show social problems, but they lack a copy of CUL3 only from excitatory neurons in the cerebral cortex, the brains outer layer. The mices social problems seem to stem from an accumulation of a protein called SMYD3, which controls gene expression, rather than from EIF4G1.

The differences have stumped researchers.

I dont know why the results are different, says Zhen Yan, professor of physiology and biophysics at the State University of New York at Buffalo; Yan led the August study but was not involved in the new work. CUL3 probably has different functions in different brain areas and cell types.

Mice in both studies lack a copy of CUL3 only in the brain, whereas autistic people would lack a copy in all cells of the body.

While these models are great to investigate the brain-specific impact of CUL3 deficiency, they do not accurately recapitulate the genetics of individuals with CUL3 mutations, De Rubeis says.

A third team has made mice that carry a CUL3 mutation identified in an autistic person. Their unpublished results suggest that CUL3s loss decreases brain size and neuronal firing, says the teams leader, Lilia Iakoucheva. The results link changes in the mices brain and behavior to an increase in a protein called RhoA, which regulates the structural skeleton of cells.

Read more:
Loss of autism gene may lead to pile-up of proteins in neurons - Spectrum

Professors in the humanities and social sciences offer expert perspectives into important, sometimes controversial issues that captured the publics interest this past year.

Addressing a range of timely and relevant topics, USC Dornsife faculty shared their expertise and offered scholarly observations and perspectives through op-eds in 2019. (Composite: Dennis Lan. Image source: iStock.)

On a wide variety of issues, ranging from the impact of Californias aging infrastructure on the environment to cellphone addiction, scholars at the USC Dornsife College of Letters, Arts and Sciences published opinion articles in 2019 that provided fresh insight on important issues, helping to shape a national dialogue about them.

Following are just a few notable articles.

California is uniquely fire-prone thanks to its long romance with high-voltage power lines Los Angeles Times

Published in January 2019, this prescient article by Peter Westwick, adjunct professor (research) of history, explains how and why California became dependent on high-voltage power lines. Westwick also warns that increasingly, fires will remind us that all electricity comes with a cost, beyond what we pay in our utility bills. Westwick is also director of the Aerospace History Project at the Huntington-USC Institute on California and the West.

Proposition 187s anti-immigrant cruelty was a California tradition Los Angeles TimesOn the 25th anniversary of the passage of Californias divisive Prop. 187, Professor of American Studies and Ethnicity Natalia Molina reflects on Californias anti-immigrant history, dating back to the Great Depression, a time of mass repatriations, deportations and general scapegoating for Mexican immigrants.

Why I Teach The New York TimesIf our leaders should be teachers, our teachers should also be leaders, understanding that what we do in our universities is not simply to research or teach, but to model what a democracy should be, writes University Professor Viet Thanh Nguyen, Aerol Arnold Chair of English and professor of English, American Studies and Ethnicity and Comparative Literature.

How to kick your cellphone addiction and other bad habits, too Los Angeles Times

Changing old habits or forming new ones is hard, writes Wendy Wood, Provost Professor of Psychology and Business, in this article. Woods explains the psychology and physiology of habit formation and offers helpful tips on breaking bad habits, like the increasingly common addiction to cellphones.

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Scholarship matters: Influential faculty op-eds tackle weighty topics in 2019 > News > USC Dornsife - USC Dornsife College of Letters, Arts and...