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Comment by Dr. Krishna Kumari Challa on January 7, 2015 at 8:30am

Comment by Dr. Krishna Kumari Challa on January 6, 2015 at 8:08am

The loss of estrogen efficacy against cerebral ischemia in aged postmenopausal female mice
Physiological doses of E2 show neuroprotective effects in adult female mice but not in aged female mice.
ERα and ERβ expression in the cortex significantly decreased in the aged female mice.
Estrogen replacement treatment could not recover ERα and ERβ expression in the aged female mice.
Abstract

Estrogen has been shown to have neuroprotective effects in numerous experimental studies involving young and adult animals. However, several clinical trials have found that in aged postmenopausal women who received estrogen replacement therapy, there did not appear to be a reduction in the incidence of stroke. The aim of this study was to investigate the effects of physiological dosages of estrogen on aged female mice subjected to ischemia-reperfusion injury. Adult ovariectomized (OVX) female mice and 22-month-old female mice received daily subcutaneous injections of 100 μg/kg or 300 μg/kg 17β-estradiol (E2) at the back of the neck for four weeks, and the expression levels of estrogen receptor (ER) α and β in the cerebral cortex were determined using real-time PCR and Western blotting analyses. To mimic ischemic stroke, the mice received middle cerebral artery occlusion (MCAO) treatment for 1 h followed by a 24-h reperfusion period. The mice were then subjected to neurological deficit testing and infarct volume evaluation. The aged mice showed higher neurological deficit scores and larger infarct volumes compared with the adult mice. Both the lower and higher physiological dosages of E2 significantly improved the neurological test scores and decreased the infarct volume in the adult mice; however, E2 showed no neuroprotective effects in the aged mice. Furthermore, the protein expression of ERα and ERβ in the cerebral cortex was significantly decreased in the aged mice compared with the adult mice, and this decrease was not rescued by E2 treatment. These results indicate that the down-regulation of ERα and ERβ in the cerebral cortex may contribute to the loss of estrogen efficacy against ischemic injury in aged females and may point to new therapies for ischemic stroke in aged postmenopausal women.
http://www.sciencedirect.com/science/article/pii/S0304394013009981

Comment by Dr. Krishna Kumari Challa on January 2, 2015 at 7:35am

Comment by Dr. Krishna Kumari Challa on January 2, 2015 at 6:58am

Neuronal encoding of the switch from specific to generalized fear
Abstract:
Fear memories are crucial for survival. However, excessive generalization of such memories, characterized by a failure to discriminate dangerous from safe stimuli, is common in anxiety disorders. Neuronal encoding of the transition from cue-specific to generalized fear is poorly understood. We identified distinct neuronal populations in the lateral amygdala (LA) of rats that signaled generalized versus cue-specific associations and determined how their distributions switched during fear generalization. Notably, the same LA neurons that were cue specific before the behavioral shift to generalized fear lost their specificity afterwards, thereby tilting the balance of activity toward a greater proportion of generalizing neurons. Neuronal activity in the LA, but not the auditory cortex, was necessary for fear generalization. Furthermore, targeted activation of cAMP–PKA signaling in the LA increased neuronal excitability of LA neurons and led to generalized fear. These results provide a cellular basis in the amygdala for the alteration of emotional states from normal to pathological fear.
http://www.nature.com/neuro/journal/v18/n1/full/nn.3888.html

Comment by Dr. Krishna Kumari Challa on January 1, 2015 at 10:16am

India’s major science funders join open-access push
Two of India’s major science funding agencies are joining the push to make the results of the research they fund freely available to the public.

India’s Ministry of Science & Technology earlier this month announced it will require researchers who receive even just part of their funding from its biotechnology and science and technology departments to deposit copies of their papers in publicly accessible depositories. The two departments are the primary government sources for life science research funding in India.

Researchers are required to submit papers to a repository within 2 weeks of acceptance by a peer-reviewed journal. Some papers may not become freely available for 6 to 12 months, however, if the journal asks for a delay to protect its subscription revenue. In including such delays, India’s policy tracks similar policies adopted by many other public and private funding agencies around the world.

“[I]t is important that the information and knowledge generated through the use of [public] funds are made publicly available as soon as possible,” states the 12 December statement announcing the new policy.
Under the policy, any institution that receives funding from the two departments will be required to set up a digital repository that will archive papers written by researchers at that institution. The ministry, in turn, will maintain a “central harvester” linked to each of the institutional repositories; it will allow users to search for papers across the entire system. If an institution does not yet have its own institutional repository, researchers can temporarily use central repositories maintained by the two funding departments.

The policy is retroactive; it applies to all papers that are the products of funding awarded since fiscal year 2012 to 2013. “Authors are recommended to also deposit manuscripts of their earlier publications even if they are unrelated to current projects” funded by the departments, the policy states.

The policy also requires researchers to submit “metadata and supplementary materials” associated with a paper, but does not directly articulate a policy requiring the public posting and free use of all publicly funded data. “The current policy in India does not demand open data,” Jameel notes. “But the global mood today is shifting toward open data.”

Posting a paper in a repository is no substitute for publishing in a peer-reviewed journal, the policy suggests. Officials “expect that the recipients of funding will publish their research in high quality, peer-reviewed journals,” it states.

Institutions will also have to plan annual “Open Access Day” activities that promote the free sharing of research results, the policy states. The activities, which could include “sensitizing lectures, programmes, workshops and taking new open access initiatives,” should occur during International Open Access Week, which in 2015 is set for 19 to25 October.

Comment by Dr. Krishna Kumari Challa on January 1, 2015 at 9:58am

Nest decorations: an ‘extended’ female badge of status?

A study suggests that ...
Nest ornamentation (feathers) by rock sparrows using experimental data has been studies in detail.

Males in the experimental group (feathers addition) invested more in nest defence.
Females spent more time guarding nests with experimental feathers.

Experimental nests were visited less by intruders.

the researchers propose that nest decoration can act as both a sexual and a status signal.
http://www.sciencedirect.com/science/article/pii/S0003347214004102

Comment by Dr. Krishna Kumari Challa on January 1, 2015 at 7:31am

Comment by Dr. Krishna Kumari Challa on December 31, 2014 at 10:03am

Prediction of antibiotic resistance by gene expression profiles
Abstract:

Although many mutations contributing to antibiotic resistance have been identified, the relationship between the mutations and the related phenotypic changes responsible for the resistance has yet to be fully elucidated. To better characterize phenotype–genotype mapping for drug resistance, here we analyse phenotypic and genotypic changes of antibiotic-resistant Escherichia coli strains obtained by laboratory evolution. We demonstrate that the resistances can be quantitatively predicted by the expression changes of a small number of genes. Several candidate mutations contributing to the resistances are identified, while phenotype–genotype mapping is suggested to be complex and includes various mutations that cause similar phenotypic changes. The integration of transcriptome and genome data enables us to extract essential phenotypic changes for drug resistances.
http://www.nature.com/ncomms/2014/141217/ncomms6792/full/ncomms6792...

Comment by Dr. Krishna Kumari Challa on December 30, 2014 at 9:12am

Inspirational words some guides told their Ph.D students:

"PhD is a Marathon not a Sprint"!

"What doesn't kill you makes you stronger.
" My Advisor told me, Dont worry about what you are going to do? Just select the area and start reading. The more you read the more you will know what needs to be done and how it needs to be done. One more thing is don't be obsessed about what you are going to achieve, enjoy the journey of learning where you will learn a lot about life as well as about research.
1. Don't reinvent the wheel.
2. Don't even think of a model till you have seen your data.
Life is a race without a victory line, so beware of complacency.
In science , Failure is also a result, the one you should achieve at least once to succeed. "
If you don't feel guilty when you're watching TV, you should consider getting into another field not science.
When you are going through hell, keep going. "Winston Churchill"
3Ds of a doctoral degree - discipline, determination and dedication.
You should be all or nothing.
In science "There is no such thing as low hanging fruit"
--
Depend on 'your' gray matter not on 'mine'! Yes, this is exactly what my supervisor told me to do and what I followed very religiously.

Comment by Dr. Krishna Kumari Challa on December 30, 2014 at 9:09am

Imagine you're at the foot of a mountain. Initially, when you look up, all you can see is a part of the mountain, not even all of it. As you start climbing, the perspective changes. By the time you reach the peak, you can see a whole range in front of you. The point of climbing the mountain is to see the whole range, but that realization doesn't hit home until after you have climbed it. Doing a piece of research is exactly like that.

"Nothing is as easy as it sounds in research".

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