342 research outputs found
Anomalous Spin-Orbit Torques in Magnetic Single-Layer Films
Spin-orbit interaction (SOI) couples charge and spin transport, enabling
electrical control of magnetization. A quintessential example of SOI-induced
transport is the anomalous Hall effect (AHE), first observed in 1880, in which
an electric current perpendicular to the magnetization in a magnetic film
generates charge accumulation on the surfaces. Here we report the observation
of a counterpart of the AHE that we term the anomalous spin-orbit torque
(ASOT), wherein an electric current parallel to the magnetization generates
opposite spin-orbit torques on the surfaces of the magnetic film. We interpret
the ASOT as due to a spin-Hall-like current generated with an efficiency of
0.053+/-0.003 in Ni80Fe20, comparable to the spin Hall angle of Pt. Similar
effects are also observed in other common ferromagnetic metals, including Co,
Ni, and Fe. First principles calculations corroborate the order of magnitude of
the measured values. This work suggests that a strong spin current with spin
polarization transverse to magnetization can exist in a ferromagnet, despite
spin dephasing. It challenges the current understanding of spin-orbit torque in
magnetic/nonmagnetic bilayers, in which the charge-spin conversion in the
magnetic layer has been largely neglected.Comment: 23 pages, 3 figures and 1 tabl
Validation of Potential Fishing Zone (PFZ) Advisories (2006 – 2007)
The Potential Fishing Zone (PFZ) Advisories are being generated and disseminated by Indian National Centre for Ocean Information Services (INCOIS). The methodology used for generation of these advisories and the scientific basis behind the identification of the PFZ locations was described. With a view to validate these PFZ Advisories and to assess the potential benefits to the fishing community, INCOIS had undertaken PFZ validation experiments at
various places under the leadership of fishery experts. Simultaneous fishing operations have been conducted within the PFZ Areas and outside PFZ Areas using identical vessels. The quantitative results of the experiments were described
Multiparametric, Longitudinal Optical Coherence Tomography Imaging Reveals Acute Injury and Chronic Recovery in Experimental Ischemic Stroke
Progress in experimental stroke and translational medicine could be accelerated by high-resolution in vivo imaging of disease progression in the mouse cortex. Here, we introduce optical microscopic methods that monitor brain injury progression using intrinsic optical scattering properties of cortical tissue. A multi-parametric Optical Coherence Tomography (OCT) platform for longitudinal imaging of ischemic stroke in mice, through thinned-skull, reinforced cranial window surgical preparations, is described. In the acute stages, the spatiotemporal interplay between hemodynamics and cell viability, a key determinant of pathogenesis, was imaged. In acute stroke, microscopic biomarkers for eventual infarction, including capillary non-perfusion, cerebral blood flow deficiency, altered cellular scattering, and impaired autoregulation of cerebral blood flow, were quantified and correlated with histology. Additionally, longitudinal microscopy revealed remodeling and flow recovery after one week of chronic stroke. Intrinsic scattering properties serve as reporters of acute cellular and vascular injury and recovery in experimental stroke. Multi-parametric OCT represents a robust in vivo imaging platform to comprehensively investigate these properties
Survey of green mussel seed resources of Kerala and Karnataka
Farming of marine mussels Is practiced
extensively in the temperate and Southeast
Asian countries. In India two species of
mussels, Perna viridis and Perna indica
commonly known as the green and brown
mussels respectively have been reported
Neural networks embrace learned diversity
Diversity conveys advantages in nature, yet homogeneous neurons typically
comprise the layers of artificial neural networks. Here we construct neural
networks from neurons that learn their own activation functions, quickly
diversify, and subsequently outperform their homogeneous counterparts.
Sub-networks instantiate the neurons, which meta-learn especially efficient
sets of nonlinear responses. Such learned diversity provides examples of
dynamical systems selecting diversity over uniformity and elucidates the role
of diversity in natural and artificial systems.Comment: 6 pages, 6 figure
Genome-Wide Association Studies of Schizophrenia and Bipolar Disorder in a Diverse Cohort of US Veterans
Background: Schizophrenia (SCZ) and bipolar disorder (BIP) are debilitating neuropsychiatric disorders, collectively affecting 2% of the world\u27s population. Recognizing the major impact of these psychiatric disorders on the psychosocial function of more than 200 000 US Veterans, the Department of Veterans Affairs (VA) recently completed genotyping of more than 8000 veterans with SCZ and BIP in the Cooperative Studies Program (CSP) #572.
Methods: We performed genome-wide association studies (GWAS) in CSP #572 and benchmarked the predictive value of polygenic risk scores (PRS) constructed from published findings. We combined our results with available summary statistics from several recent GWAS, realizing the largest and most diverse studies of these disorders to date.
Results: Our primary GWAS uncovered new associations between CHD7 variants and SCZ, and novel BIP associations with variants in Sortilin Related VPS10 Domain Containing Receptor 3 (SORCS3) and downstream of PCDH11X. Combining our results with published summary statistics for SCZ yielded 39 novel susceptibility loci including CRHR1, and we identified 10 additional findings for BIP (28 326 cases and 90 570 controls). PRS trained on published GWAS were significantly associated with case-control status among European American (P \u3c 10-30) and African American (P \u3c .0005) participants in CSP #572.
Conclusions: We have demonstrated that published findings for SCZ and BIP are robustly generalizable to a diverse cohort of US veterans. Leveraging available summary statistics from GWAS of global populations, we report 52 new susceptibility loci and improved fine-mapping resolution for dozens of previously reported associations
A coherent feed-forward loop drives vascular regeneration in damaged aerial organs of plants growing in a normal developmental context
Aerial organs of plants, being highly prone to local injuries, require tissue restoration to ensure their survival. However, knowledge of the underlying mechanism is sparse. In this study, we mimicked natural injuries in growing leaves and stems to study the reunion between mechanically disconnected tissues. We show that PLETHORA (PLT) and AINTEGUMENTA (ANT) genes, which encode stem cell-promoting factors, are activated and contribute to vascular regeneration in response to these injuries. PLT proteins bind to and activate the CUC2 promoter. PLT proteins and CUC2 regulate the transcription of the local auxin biosynthesis gene YUC4 in a coherent feed-forward loop, and this process is necessary to drive vascular regeneration. In the absence of this PLT-mediated regeneration response, leaf ground tissue cells can neither acquire the early vascular identity marker ATHB8, nor properly polarise auxin transporters to specify new venation paths. The PLT-CUC2 module is required for vascular regeneration, but is dispensable for midvein formation in leaves. We reveal the mechanisms of vascular regeneration in plants and distinguish between the wound-repair ability of the tissue and its formation during normal development.Peer reviewe
Sleeper Agents: Training Deceptive LLMs that Persist Through Safety Training
Humans are capable of strategically deceptive behavior: behaving helpfully in
most situations, but then behaving very differently in order to pursue
alternative objectives when given the opportunity. If an AI system learned such
a deceptive strategy, could we detect it and remove it using current
state-of-the-art safety training techniques? To study this question, we
construct proof-of-concept examples of deceptive behavior in large language
models (LLMs). For example, we train models that write secure code when the
prompt states that the year is 2023, but insert exploitable code when the
stated year is 2024. We find that such backdoor behavior can be made
persistent, so that it is not removed by standard safety training techniques,
including supervised fine-tuning, reinforcement learning, and adversarial
training (eliciting unsafe behavior and then training to remove it). The
backdoor behavior is most persistent in the largest models and in models
trained to produce chain-of-thought reasoning about deceiving the training
process, with the persistence remaining even when the chain-of-thought is
distilled away. Furthermore, rather than removing backdoors, we find that
adversarial training can teach models to better recognize their backdoor
triggers, effectively hiding the unsafe behavior. Our results suggest that,
once a model exhibits deceptive behavior, standard techniques could fail to
remove such deception and create a false impression of safety.Comment: updated to add missing acknowledgement
Appraisal of Marine Fisheries of Kerala
Kerala ranks first in marine fish production of India
forming nearly 25% (avg. 5.75 lakh tonnes) of the total
annual production. The annual export of marine
products from the state yields to the nation a foreign
exchange of Rs. 1100 crores. There has been
spectacular growth in the marine fisheries sector of
the state due to fisheries friendly government
policies, well developed harvest and post harvest
infrastructure and increased demand for sea food
both in the domestic and export markets. Kerala has
been in the forefront in absorbing innovative and new
technologies in fishing practices, which has led
marine fisheries to take a complex structure
Physical activity and inactivity patterns in India – results from the ICMR-INDIAB study (Phase-1) [ICMR-INDIAB-5]
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