727 research outputs found
Guidance of a low l/d vehicle entering the earth's atmosphere at speeds up to 50,000 feet per second
Guidance of low lift-drag ratio vehicle during earth atmosphere reentr
Coexpression of Two Functional Odor Receptors in One Neuron
SummaryOne of the most fundamental tenets in the field of olfaction is that each olfactory receptor neuron (ORN) expresses a single odorant receptor. However, the one receptor-one neuron principle is difficult to establish rigorously. Here we construct a receptor-to-neuron map for an entire olfactory organ in Drosophila and find that two receptor genes are coexpressed in one class of ORN. Both receptors are functional in an in vivo expression system, they are only 16% identical in amino acid sequence, and the genes that encode them are unlinked. Most importantly, their coexpression has been conserved for >45 million years. Expression of multiple odor receptors in a cell provides an additional degree of freedom for odor coding
Guide to Understanding Drosophila Models of Neurodegenerative Diseases
Demystifying how genetic studies inDrosophila inform human disease conditions, this article highlights two studies that identify genetic modifiers of neurodegeneration
Recommended from our members
Structural Ceramic Composites for Nuclear Applications
A research program has been established to investigate fiber reinforced ceramic composites to be used as control rod components within a Very High Temperature Reactor. Two candidate systems have been identified, carbon fiber reinforced carbon (Cf/C) and silicon carbide fiber reinforced silicon carbide (SiCf/SiC) composites. Initial irradiation stability studies to determine the maximum dose for each composite type have been initiated within the High Flux Isotope Reactor at Oak Ridge National Laboratory. Test samples exposed to 10 dpa irradiation dose have been completed with future samples to dose levels of 20 and 30 dpa scheduled for completion in following years. Mechanical and environmental testing is being conducted concurrently at the Idaho National Laboratory and at Pacific Northwest National Laboratory. High temperature test equipment, testing methodologies, and test samples for high temperature (up to 1600º C) tensile strength and long duration creep studies have been established. Specific attention was paid to the architectural fiber preform design as well as the materials used in construction of the composites. Actual testing of both tubular and flat, "dog-bone" shaped tensile composite specimens will begin next year. Since there is no precedence for using ceramic composites within a nuclear reactor, ASTM standard test procedures will be established from these mechanical and environmental tests. Close collaborations between the U.S. national laboratories and international collaborators (i.e. France and Japan) are being forged to establish both national and international test standards to be used to qualify ceramic composites for nuclear reactor applications
Fabrication of Mullite Body Using Superplastic Transient Phase
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65799/1/j.1151-2916.1992.tb05542.x.pd
Identification and relative quantification of tyrosine nitration in a model peptide using two-dimensional infrared spectroscopy
Nitration of tyrosine in proteins and peptides is a post-translational modification that occurs under conditions of oxidative stress. It is implicated in a variety of medical conditions, including neurodegenerative and cardiovascular diseases. However, monitoring tyrosine nitration and understanding its role in modifying biological function remains a major challenge. In this work, we investigate the use of electron-vibration-vibration (EVV) two-dimensional infrared (2DIR) spectroscopy for the study of tyrosine nitration in model peptides. We demonstrate the ability of EVV 2DIR spectroscopy to differentiate between the neutral and deprotonated states of 3-nitrotyrosine, and we characterize their spectral signatures using information obtained from quantum chemistry calculations and simulated EVV 2DIR spectra. To test the sensitivity of the technique, we use mixed-peptide samples containing various levels of tyrosine nitration, and we use mass spectrometry to independently verify the level of nitration. We conclude that EVV 2DIR spectroscopy is able to provide detailed spectroscopic information on peptide side-chain modifications and to detect nitration levels down to 1%. We further propose that lower nitration levels could be detected by introducing a resonant Raman probe step to increase the detection sensitivity of EVV 2DIR spectroscopy. (Graph Presented)
The pursuit of happiness: the social and scientific origins of Hans Selye’s natural philosophy of life
© The Author(s) 2012. Open access article.In 1956, Hans Selye tentatively suggested that the scientific study of stress could ‘help us
to formulate a precise program of conduct’ and ‘teach us the wisdom to live a rich and
meaningful life’. Nearly two decades later, Selye expanded this limited vision of social
order into a full-blown philosophy of life. In Stress without Distress, first published in 1974,
he proposed an ethical code of conduct designed to mitigate personal and social
problems. Basing his arguments on contemporary understandings of the biological
processes involved in stress reactions, Selye referred to this code as ‘altruistic egotism’.
This article explores the origins and evolution of Selye’s ‘natural philosophy of life’,
analysing the links between his theories and adjacent intellectual developments in
biology, psychosomatic and psychosocial medicine, cybernetics and socio-biology, and
situating his work in the broader cultural framework of modern western societies.Wellcome Trus
Transmission of Staphylococcus aureus between health-care workers, the environment, and patients in an intensive care unit: a longitudinal cohort study based on whole-genome sequencing
Background: Health-care workers have been implicated in nosocomial outbreaks of Staphylococcus aureus, but the dearth of evidence from non-outbreak situations means that routine health-care worker screening and S aureus eradication are controversial. We aimed to determine how often S aureus is transmitted from health-care workers or the environment to patients in an intensive care unit (ICU) and a high-dependency unit (HDU) where standard infection control measures were in place.
Methods: In this longitudinal cohort study, we systematically sampled health-care workers, the environment, and patients over 14 months at the ICU and HDU of the Royal Sussex County Hospital, Brighton, England. Nasal swabs were taken from health-care workers every 4 weeks, bed spaces were sampled monthly, and screening swabs were obtained from patients at admission to the ICU or HDU, weekly thereafter, and at discharge. Isolates were cultured and their whole genome sequenced, and we used the threshold of 40 single-nucleotide variants (SNVs) or fewer to define subtypes and infer recent transmission.
Findings: Between Oct 31, 2011, and Dec 23, 2012, we sampled 198 health-care workers, 40 environmental locations, and 1854 patients; 1819 isolates were sequenced. Median nasal carriage rate of S aureus in health-care workers at 4-weekly timepoints was 36·9% (IQR 35·7–37·3), and 115 (58%) health-care workers had S aureus detected at least once during the study. S aureus was identified in 8–50% of environmental samples. 605 genetically distinct subtypes were identified (median SNV difference 273, IQR 162–399) at a rate of 38 (IQR 34–42) per 4-weekly cycle. Only 25 instances of transmission to patients (seven from health-care workers, two from the environment, and 16 from other patients) were detected.
Interpretation: In the presence of standard infection control measures, health-care workers were infrequently sources of transmission to patients. S aureus epidemiology in the ICU and HDU is characterised by continuous ingress of distinct subtypes rather than transmission of genetically related strains.
Funding: UK Medical Research Council, Wellcome Trust, Biotechnology and Biological Sciences Research Council, UK National Institute for Health Research, and Public Health England
- …