206 research outputs found
Recommended from our members
Simultaneous mesoscopic and two-photon imaging of neuronal activity in cortical circuits.
Spontaneous and sensory-evoked activity propagates across varying spatial scales in the mammalian cortex, but technical challenges have limited conceptual links between the function of local neuronal circuits and brain-wide network dynamics. We present a method for simultaneous cellular-resolution two-photon calcium imaging of a local microcircuit and mesoscopic widefield calcium imaging of the entire cortical mantle in awake mice. Our multi-scale approach involves a microscope with an orthogonal axis design where the mesoscopic objective is oriented above the brain and the two-photon objective is oriented horizontally, with imaging performed through a microprism. We also introduce a viral transduction method for robust and widespread gene delivery in the mouse brain. These approaches allow us to identify the behavioral state-dependent functional connectivity of pyramidal neurons and vasoactive intestinal peptide-expressing interneurons with long-range cortical networks. Our imaging system provides a powerful strategy for investigating cortical architecture across a wide range of spatial scales
Assisting patients experiencing family violence: A survey of training levels, perceived knowledge, and confidence of clinical staff in a large metropolitan hospital
Tracking individual nanodiamonds in Drosophila melanogaster embryos
Tracking the dynamics of fluorescent nanoparticles during embryonic
development allows insights into the physical state of the embryo and,
potentially, molecular processes governing developmental mechanisms. In this
work, we investigate the motion of individual fluorescent nanodiamonds
micro-injected into Drosophila melanogaster embryos prior to cellularisation.
Fluorescence correlation spectroscopy and wide-field imaging techniques are
applied to individual fluorescent nanodiamonds in blastoderm cells during stage
5 of development to a depth of ~40 \mu m. The majority of nanodiamonds in the
blastoderm cells during cellularisation exhibit free diffusion with an average
diffusion coefficient of (6 3) x 10 \mu m/s, (mean SD).
Driven motion in the blastoderm cells was also observed with an average
velocity of 0.13 0.10 \mu m/s (mean SD) \mu m/s and an average
applied force of 0.07 0.05 pN (mean SD). Nanodiamonds in the
periplasm between the nuclei and yolk were also found to undergo free diffusion
with a significantly larger diffusion coefficient of (63 35) x10
\mu m/s (mean SD). Driven motion in this region exhibited similar
average velocities and applied forces compared to the blastoderm cells
indicating the transport dynamics in the two cytoplasmic regions are analogous.Comment: 20 pages, 6 figure
Nanomechanical sensing using spins in diamond
Nanomechanical sensors and quantum nanosensors are two rapidly developing
technologies that have diverse interdisciplinary applications in biological and
chemical analysis and microscopy. For example, nanomechanical sensors based
upon nanoelectromechanical systems (NEMS) have demonstrated chip-scale mass
spectrometry capable of detecting single macromolecules, such as proteins.
Quantum nanosensors based upon electron spins of negatively-charged
nitrogen-vacancy (NV) centers in diamond have demonstrated diverse modes of
nanometrology, including single molecule magnetic resonance spectroscopy. Here,
we report the first step towards combining these two complementary technologies
in the form of diamond nanomechanical structures containing NV centers. We
establish the principles for nanomechanical sensing using such
nano-spin-mechanical sensors (NSMS) and assess their potential for mass
spectrometry and force microscopy. We predict that NSMS are able to provide
unprecedented AC force images of cellular biomechanics and to, not only detect
the mass of a single macromolecule, but also image its distribution. When
combined with the other nanometrology modes of the NV center, NSMS potentially
offer unparalleled analytical power at the nanoscale.Comment: Errors in the stress susceptibility parameters present in the
original arXiv version have been correcte
Evaluation of pregnancy and delivery in 13 women who underwent resection of a sacrococcygeal teratoma during early childhood
Recommended from our members
Author Correction: Expanded encyclopaedias of DNA elements in the human and mouse genomes
Online Correction for: https://doi.org/10.1038/s41586-020-2493-4 | Erratum for https://bura.brunel.ac.uk/handle/2438/21299In the version of this article initially published, two members of the ENCODE Project Consortium were missing from the author list. Rizi Ai (Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA) and Shantao Li (Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT, USA) are now included in the author list. These errors have been corrected in the online version of the article : 'Expanded encyclopaedias of DNA elements in the human and mouse genomes'.https://www.nature.com/articles/s41586-021-04226-3https://www.nature.com/articles/s41586-021-04226-
The genome of the Trinidadian guppy, Poecilia reticulata, and variation in the Guanapo population
For over a century, the live bearing guppy, Poecilia reticulata, has been used to study sexual selection as well as local adaptation. Natural guppy populations differ in many traits that are of intuitively adaptive significance such as ornamentation, age at maturity, brood size and body shape. Water depth, light supply, food resources and predation regime shape these traits, and barrier waterfalls often separate contrasting environments in the same river. We have assembled and annotated the genome of an inbred single female from a high-preda- tion site in the Guanapo drainage. The final assembly comprises 731.6 Mb with a scaffold N50 of 5.3 MB. Scaffolds were mapped to linkage groups, placing 95% of the genome assembly on the 22 autosomes and the X-chromosome. To investigate genetic variation in the population used for the genome assembly, we sequenced 10 wild caught male individu- als. The identified 5 million SNPs correspond to an average nucleotide diversity (π) of 0.0025. The genome assembly and SNP map provide a rich resource for investigating adap- tation to different predation regimes. In addition, comparisons with the genomes of other Poeciliid species, which differ greatly in mechanisms of sex determination and maternal resource allocation, as well as comparisons to other teleost genera can begin to reveal how live bearing evolved in teleost fish
A phylogeny of Cichlidogyrus spp. (Monogenea, Dactylogyridea) clarifies a host-switch between fish families and reveals an adaptive component to attachment organ morphology of this parasite genus
Evolution of sex-specific pace-of-life syndromes: genetic architecture and physiological mechanisms
Sex differences in life history, physiology, and behavior are nearly ubiquitous across taxa, owing to sex-specific selection that arises from different reproductive strategies of the sexes. The pace-of-life syndrome (POLS) hypothesis predicts that most variation in such traits among individuals, populations, and species falls along a slow-fast pace-of-life continuum. As a result of their different reproductive roles and environment, the sexes also commonly differ in pace-of-life, with important consequences for the evolution of POLS. Here, we outline mechanisms for how males and females can evolve differences in POLS traits and in how such traits can covary differently despite constraints resulting from a shared genome. We review the current knowledge of the genetic basis of POLS traits and suggest candidate genes and pathways for future studies. Pleiotropic effects may govern many of the genetic correlations, but little is still known about the mechanisms involved in trade-offs between current and future reproduction and their integration with behavioral variation. We highlight the importance of metabolic and hormonal pathways in mediating sex differences in POLS traits; however, there is still a shortage of studies that test for sex specificity in molecular effects and their evolutionary causes. Considering whether and how sexual dimorphism evolves in POLS traits provides a more holistic framework to understand how behavioral variation is integrated with life histories and physiology, and we call for studies that focus on examining the sex-specific genetic architecture of this integration
- …