426 results match your criteria: "St. John's College.[Affiliation]"

Molecular Dynamics (MD) simulations are now widely utilized in pharmaceutical nanotechnology to gain deeper understanding of nanoscale processes imperative to drug design. This review has also detailed how MD simulation can be employed in the study of drug-nanocarrier interactions, controlling release of chemical compounds from drug delivery systems and increasing solubility and bioavailability of nanocarriers. Furthermore, MD contributes to examining the drug delivery systems, measuring the toxic effects, and determining biocompatibility of nanomedical systems.

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Comparative genomics, whereby the genomes of different species are compared, has the potential to address broad and fundamental questions at the intersection of genetics and evolution. However, species, genomes and genes cannot be considered as independent data points within statistical tests. Closely related species tend to be similar because they share genes by common descent, which must be accounted for in analyses.

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Metastable Oscillatory Modes as a Signature of Entropy Management in the Brain.

Entropy (Basel)

December 2024

Center for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford OX3 9BX, UK.

Entropy management, central to the Free Energy Principle, requires a process that temporarily shifts brain activity toward states of lower or higher entropy. Metastable synchronization is a process by which a system achieves entropy fluctuations by intermittently transitioning between states of collective order and disorder. Previous work has shown that collective oscillations, similar to those recorded from the brain, emerge spontaneously from weakly stable synchronization in critically coupled oscillator systems.

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Different whole-brain computational models have been recently developed to investigate hypotheses related to brain mechanisms. Among these, the Dynamic Mean Field (DMF) model is particularly attractive, combining a biophysically realistic model that is scaled up via a mean-field approach and multimodal imaging data. However, an important barrier to the widespread usage of the DMF model is that current implementations are computationally expensive, supporting only simulations on brain parcellations that consider less than 100 brain regions.

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Metastability demystified - the foundational past, the pragmatic present and the promising future.

Nat Rev Neurosci

December 2024

Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.

Healthy brain function depends on balancing stable integration between brain areas for effective coordinated functioning, with coexisting segregation that allows subsystems to express their functional specialization. Metastability, a concept from the dynamical systems literature, has been proposed as a key signature that characterizes this balance. Building on this principle, the neuroscience literature has leveraged the phenomenon of metastability to investigate various aspects of brain function in health and disease.

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Article Synopsis
  • - Speciation is complicated and often misunderstood, leading researchers to unintentionally promote misconceptions about how species form and evolve.
  • - Six common misconceptions include the oversimplification of species definitions, viewing speciation as a positive goal of evolution, and the false idea that evolution is always tree-like rather than network-like due to hybridization.
  • - The authors urge caution in scientific communication to prevent the spread of these misconceptions, which can distort how speciation is perceived by the public.
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Background: The Italic Iron Age is characterized by the presence of various ethnic groups partially examined from a genomic perspective. To explore the evolution of Iron Age Italic populations and the genetic impact of Romanization, we focus on the Picenes, one of the most fascinating pre-Roman civilizations, who flourished on the Middle Adriatic side of Central Italy between the 9 and the 3 century BCE, until the Roman colonization.

Results: More than 50 samples are reported, spanning more than 1000 years of history from the Iron Age to Late Antiquity.

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The genomic diversity of a parasite population is shaped by its transmission dynamics but superinfection, cotranmission and recombination make this relationship complex and hard to analyse. This paper aims to simplify the problem by introducing the concept of a genomic transmission graph with three basic parameters: the effective number of hosts, the quantum of transmission and the crossing rate of transmission chains. This enables rapid simulation of coalescence times in a recombining parasite population with superinfection and cotransmission, and it also provides a mathematical framework for analysis of within-host variation.

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Adaptive cognition relies on cooperation across anatomically distributed brain circuits. However, specialised neural systems are also in constant competition for limited processing resources. How does the brain's network architecture enable it to balance these cooperative and competitive tendencies? Here we use computational whole-brain modelling to examine the dynamical and computational relevance of cooperative and competitive interactions in the mammalian connectome.

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At this critical juncture in the development of NeuroAI, we outline challenges and training needs of junior researchers working across AI and neuroscience. We also provide advice and resources to help trainees plan their NeuroAI careers.

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  • Bidirectional communication between neurons and glial cells is essential for proper brain function, but the effects of sudden changes in neuronal activity on these interactions are not well understood.
  • In this study, researchers used a technique called DREADD to manipulate specific neuron populations in mouse brains, discovering that activating neurons leads to reduced synaptic density and increased glial cell reactivity, while silencing them has the opposite effect.
  • The findings highlight rapid and dynamic interactions between neurons and glial cells that are influenced by neuronal activity, contributing to our understanding of brain function and potential implications for neurological conditions.
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  • Stress is a common issue among college students, significantly affecting their mental health and academic performance, leading to the need for better understanding and interventions.
  • A study conducted on 160 undergraduate students at St. John's College in Agra, India, found that 64.4% experienced moderate stress, with higher stress reported among female and urban students.
  • The research highlights the urgent need for targeted stress management programs and further investigation into the causes of stress among students.
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Solvent effect, DFT and NLO studies of A-π-D-π-A and A-π-D-π-D push-pull chromophore of 1,2-diazepin-4-ol based derivatives with optical limiting application.

Spectrochim Acta A Mol Biomol Spectrosc

January 2025

Department of Physics, St. John's College of Arts and Science, M.S. University, Kanyakumari 629204, Tamil Nadu, India.

The nonlinear optical properties of push-pull chromophores, namely (E)-7-(4-bromophenyl)-2,5-bis(4-nitrophenyl)-3,4,5,6-tetrahydro-2H-1,2-diazepin-4-ol (A-π-D-π-A) and (E)-7-(4-bromophenyl)-5-(4-nitrophenyl)-2-phenyl-3,4,5,6-tetrahydro-2H-1,2-diazepin-4-ol (A-π-D-π-D), have been investigated using the z-scan technique. NMR, FT-IR, and UV-visible spectral analysis have been performed. The results were compared with density functional theory calculations employing the B3LYP/6-311++G (d, p) basis set.

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The Roman period saw the empire expand across Europe and the Mediterranean, including much of what is today Great Britain. While there is written evidence of high mobility into and out of Britain for administrators, traders, and the military, the impact of imperialism on local, rural population structure, kinship, and mobility is invisible in the textual record. The extent of genetic change that occurred in Britain during the Roman military occupation remains underexplored.

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Introduction: Incorporating rare and threatened healing plants from Traditional Chinese Medicine (TCM) into modern medicine is a hopeful way to expand treatment choices and encourage the long-term use of plant resources. These plants have been used in Traditional Chinese Medicine for a long time. They have powerful healing properties, including the ability to reduce inflammation and fight cancer.

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Groundwater quality assessment in upper Kabul basin and Paghman aquifer.

J Environ Sci Health A Tox Hazard Subst Environ Eng

September 2024

Water, Energy and Environmental Engineering Research Unit, Faculty of Technology, University of Oulu, Oulu, Finland.

In Afghanistan, groundwater is widely used for drinking water, but its quality poses a health threat. This study investigates the physical, chemical, and bacteriological characteristics of groundwater in the Upper Kabul Sub-basin. Fifteen samples were collected and analyzed from different parts of the study area.

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We consider a nearly collisionless plasma consisting of a species of "test particles" in one spatial and one velocity dimension, stirred by an externally imposed stochastic electric field-a kinetic analog of the Kraichnan model of passive advection. The mean effect on the particle distribution function is turbulent diffusion in velocity space-known as stochastic heating. Accompanying this heating is the generation of fine-scale structure in the distribution function, which we characterize with the collisionless (Casimir) invariant C_{2}∝∫∫dxdv〈f^{2}〉-a quantity that here plays the role of (negative) entropy of the distribution function.

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Engineering for a clear image: a comparative focus on accommodation.

Eye (Lond)

July 2024

Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge CB3 0ES and St John's College, Cambridge, CB2 1TP, England, UK.

The eye requires the ability to focus images near and far and throughout evolution numerous mechanisms have developed to allow this accommodation. From primitive organisms which use a small pupil to effect pinhole camera optics without a lens through more complex eyes with a lens that is moved antero-posteriorly along the visual axis or the shape of which is changed, the eye has engineered numerous accommodative mechanisms. Human inventors have developed cameras with remarkable accommodative abilities but none match the remarkable focussing abilities of the four-eyed fish Anableps or the cormorant which similarly manages to focus above and below water, to give just two examples from the animal kingdom, perfectly adapted to their environments and behaviours.

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The Merovingian period (5th to 8th cc AD) was a time of demographic, socioeconomic, cultural, and political realignment in Western Europe. Here, we report the whole-genome shotgun sequence data of 30 human skeletal remains from a coastal Late Merovingian site of Koksijde (675 to 750 AD), alongside 18 remains from two Early to Late Medieval sites in present-day Flanders, Belgium. We find two distinct ancestries, one shared with Early Medieval England and the Netherlands, while the other, minor component, reflecting likely continental Gaulish ancestry.

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Removing 65 Years of Approximation in Rotating Ring Disk Electrode Theory with Physics-Informed Neural Networks.

J Phys Chem Lett

June 2024

Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, Great Britain.

The rotating Ring Disk Electrode (RRDE), since its introduction in 1959 by Frumkin and Nekrasov, has become indispensable with diverse applications in electrochemistry, catalysis, and material science. The collection efficiency () is an important parameter extracted from the ring and disk currents of the RRDE, providing valuable information about reaction mechanism, kinetics, and pathways. The theoretical prediction of is a challenging task: requiring solution of the complete convective diffusion mass transport equation with complex velocity profiles.

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Exploring the intricate relationship between brain's structure and function, and how this affects subjective experience is a fundamental pursuit in neuroscience. Psychedelic substances offer a unique insight into the influences of specific neurotransmitter systems on perception, cognition and consciousness. Specifically, their impact on brain function propagates across the structural connectome - a network of white matter pathways linking different regions.

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We propose silver oxide as a cost-effective and sustainable alternative to noble metals for the catalytic reduction of nitroaromatics. In the present investigation, we adopt a facile and green synthetic route for the synthesis of silver oxide nanostructures. The prepared nanostructures were found to crystallize in the cuprite phase and exhibit absorbance across the entire visible range of the electromagnetic spectrum.

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Article Synopsis
  • Neuroscientists are using network science to study interactions between brain regions, focusing on how to reconstruct these networks from resting-state functional MRI data.
  • The study evaluates 768 different data-processing pipelines, considering factors like brain parcellation and sensitivity to movement, to identify which are best for analyzing brain function without producing misleading results.
  • Results show significant variability in pipeline effectiveness, with many failing to meet key criteria, but a select group of optimal pipelines consistently perform well across various datasets, providing guidance for future research in functional connectomics.
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