5,901 research outputs found
Onset, timing, and exposure therapy of stress disorders: mechanistic insight from a mathematical model of oscillating neuroendocrine dynamics
The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that
regulates numerous physiological processes. Disruptions in the activity of the
HPA axis are correlated with many stress-related diseases such as
post-traumatic stress disorder (PTSD) and major depressive disorder. In this
paper, we characterize "normal" and "diseased" states of the HPA axis as basins
of attraction of a dynamical system describing the inhibition of peptide
hormones such as corticotropin-releasing hormone (CRH) and adrenocorticotropic
hormone (ACTH) by circulating glucocorticoids such as cortisol (CORT). In
addition to including key physiological features such as ultradian oscillations
in cortisol levels and self-upregulation of CRH neuron activity, our model
distinguishes the relatively slow process of cortisol-mediated CRH biosynthesis
from rapid trans-synaptic effects that regulate the CRH secretion process.
Crucially, we find that the slow regulation mechanism mediates external
stress-driven transitions between the stable states in novel, intensity,
duration, and timing-dependent ways. These results indicate that the timing of
traumatic events may be an important factor in determining if and how patients
will exhibit hallmarks of stress disorders. Our model also suggests a mechanism
whereby exposure therapy of stress disorders such as PTSD may act to normalize
downstream dysregulation of the HPA axis.Comment: 30 pages, 16 figures, submitted to BMC Biology Direc
Genome-wide functional analysis using the barcode sequence alignment and statistical analysis (Barcas) tool
Pipelines of pooled library screen analysis. Table S1. Public library sets of shRNA, sgRNA and deletion mutant strains. Figure S2. A list of wrong barcodes from 1,230 shRNAs of TRC library. Table S2. Sequences of 25 barcodes with abnormally increased mapping counts by imperfect matching. Table S3. A list of the used options for each tool. Table S4. Comparison of mapping results and speed by three tools. (PDF 7691 kb
Statistiques de pêche en lagune Ebrié (Côte d'Ivoire): 1976 et 1977
In the Ebrié lagoon fishes are mostly caught by means of 6 kinds of fishing gear: small and large mesh gillnets (respectively 1.5-2 and 6.5-8 inches stretched mesh), cast-nets and multi-hooked lines for individual fishermen, and beach seines and ring-nets for collective fishing. Statistical data gathered during 1977 allowed an estimation of total catches: about 6700 tons. The bulk of the catch, 4800 tons, came from beach nets and ring nets, the contribution of which is nearly the same. Individual fishing gear, small mesh gillnets repesenting the main part, account for 25 to 30% of total catch; about 1900 tons for year 1977. Six species, or species groups, comprise more than 85% of the catch. In the Abidjan area, where marine influence is the more noticeable, ring nets are more numerous and their catches increased since 1975. On the other hand, fish captures in unsalted and brackish waters seem to show a stagnancy and a decrease in fish lengths; this phenomenon is probably in connection with beach-seine excessive fishing effort and/or their small meshes (one inch stretched)
Multiplexed Force and Deflection Sensing Shell Membranes for Robotic Manipulators
Force sensing is an essential requirement for dexterous robot manipulation, e.g., for extravehicular robots making vehicle repairs. Although strain gauges have been widely used, a new sensing approach is desirable for applications that require greater robustness, design flexibility including a high degree of multiplexibility, and immunity to electromagnetic noise. This invention is a force and deflection sensor a flexible shell formed with an elastomer having passageways formed by apertures in the shell, with an optical fiber having one or more Bragg gratings positioned in the passageways for the measurement of force and deflection
Process for manufacturing shell membrane force and deflection sensor
A sensor for force is formed from an elastomeric cylinder having a region with apertures. The apertures have passageways formed between them, and an optical fiber is introduced into these passageways, where the optical fiber has a grating for measurement of tension positioned in the passageways between apertures. Optionally, a temperature measurement sensor is placed in or around the elastomer for temperature correction, and if required, a copper film may be deposited in the elastomer for reduced sensitivity to spot temperature variations in the elastomer near the sensors
- …
