1,383 research outputs found
Hemoglobin genotype has minimal influence on the physiological response of juvenile atlantic cod (Gadus morhua) to environmental challenges
Hemoglobin (Hb) polymorphism in cod is associated with temperatureârelated differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbIâ1/1, HbIâ2/2, and HbIâ1/2) by crossing a single pair of heterozygous parents, and we compared their metabolic and cortisol responses to an acute thermal challenge (10°C to their critical thermal maximum [CTM] or 22°C, respectively) and tolerance of graded hypoxia. There were no differences in routine metabolism (at 10°C), maximum metabolic rate, metabolic scope, CTM (overall mean 22.9° ± 0.2°C), or resting and poststress plasma cortisol levels among Hb genotypes. Further, although the HbIâ1/1 fish grew more (by 15%–30% during the first 9 mo) when reared at 10° ± 1°C and had a slightly enhanced hypoxia tolerance at 10°C (e.g., the critical O2 levels for HbIâ1/1, HbIâ2/2, and HbIâ1/2 cod were 35.56% ± 1.24%, and 40.20% ± 1.99% air saturation, respectively), these results are contradictory to expectations based on HbI functional properties. Thus, our findings (1) do not support previous assumptions that growth rate differences among cod Hb genotypes result from a more efficient use of the oxygen supply—that is, reduced standard metabolic rates and/or increased metabolic capacity—and (2) suggest that in juvenile cod, there is no selective advantage to having a particular Hb genotype with regards to the capacity to withstand ecologically relevant environmental challenges.<br /
The Escherichia coli cysG promoter belongs to the âextended â10â class of bacterial promoters
Recommended from our members
Beam-broadening effects in STEM/EDS measurement of radiation-induced segregation in high-purity 304L stainless steel
Radiation-induced segregation (RIS) is the spatial redistribution of elements at defect sinks such as grain boundaries and free surfaces during irradiation. This phenomenon has been studied in a wide variety of alloys and has been linked to irradiation-assisted stress corrosion cracking (IASCC) of nuclear reactor core components. Therefore, accurate determination of the grain boundary composition is important in understanding its effects on environmental cracking. Radiation-induced segregation profiles are routinely measured by scanning-transmission electron microscopy using energy-dispersive X-ray spectroscopy (STEM-EDS) and Auger electron spectroscopy (AES). Because of the narrow width of the segregation profile (typically less than 10-nm full width at half-maximum), the accuracy of grain boundary concentration measurements using STEM/EDS depends on the characteristics of the analyzing instrument, specifically, the excited volume in which x-rays are generated. This excited volume is determined by both electron beam diameter and the primary electron beam energy. Increasing the primary beam energy in STEM/EDS produces greater measured grain boundary segregation, as the reduced electron beam broadening a smaller excited volume. In this work, the effect of beam broadening is assessed on segregation measurements in a 304L stainless steel sample irradiated with 3.2 MeV protons at 400 C to doses of 3.0 and 0.1 dpa. The STEM/EDS measurements are also compared to measurements made using AES
A Feasibility Study for An Integrated Approach to Fall Prevention in Community Care: Stay Up and Active in Orange County
Introduction: Falls amongst persons over 60 present significant risks for serious injury or debility. Falls place burdens on Emergency Medical Services (EMS), hospitals, and the adults themselves. Recognizing a need to provide interventions to minimize risk, Orange County Emergency Services (OCES), the Orange County Department on Aging (OCDoA), and the University of North Carolina at Chapel Hill (UNC) partnered to create the Stay Up and Active Program (SUAA). Methods: A streamlined workflow algorithm between the OCES and OCDoA was created and employed to provide falls risk assessment and necessary services. Qualitative techniques were used to assess the need for such a program and its potential impact. A subset of individuals were interviewed three months after the intervention to assess the impact of the intervention on their fall risk. Results: In the first seven months, 478 instances of individuals who called OCES screened positive for falls risk. Of the 478 positive screenings, 55 individuals were identified as having received more than one positive fall screen due to multiple calls. The maximum number of positive screenings by one individual was 14. More women (61.3%) than men screened positive for fall risk. Individuals 88 years of age (6.9%) represented the mode of the individuals with positive screens. Nineteen (4.0%) people who called OCES and received the intervention completed a three month follow up survey. Of the nineteen, 86% (n=16) reported no recurrent fall.Conclusion: The number of individuals who screened positive supports the need for early identification and intervention through EMS. This program identified several challenges connecting older adults with services already available to keep them independent which provided insight to all stakeholders regarding factors that inhibit the programâs success. The program evaluation should continue to provide suggestions for improvement and ensure sustainability
Iron Age and Anglo-Saxon genomes from East England reveal British migration history
British population history has been shaped by a series of immigrations, including the early Anglo-Saxon migrations after 400 CE. It remains an open question how these events affected the genetic composition of the current British population. Here, we present whole-genome sequences from 10 individuals excavated close to Cambridge in the East of England, ranging from the late Iron Age to the middle Anglo-Saxon period. By analysing shared rare variants with hundreds of modern samples from Britain and Europe, we estimate that on average the contemporary East English population derives 38% of its ancestry from Anglo-Saxon migrations. We gain further insight with a new method, rarecoal, which infers population history and identifies fine-scale genetic ancestry from rare variants. Using rarecoal we find that the Anglo-Saxon samples are closely related to modern Dutch and Danish populations, while the Iron Age samples share ancestors with multiple Northern European populations including Britain
Global Governance Behind Closed Doors : The IMF Boardroom, the Enhanced Structural Adjustment Facility, and the Intersection of Material Power and Norm Change in Global Politics
Up on the 12th floor of its 19th Street Headquarters, the IMF Board sits in active session for an average of 7 hours per week. Although key matters of policy are decided on in the venue, the rules governing Boardroom interactions remain opaque, resting on an uneasy combination of consensual decision-making and weighted voting. Through a detailed analysis of IMF Board discussions surrounding the Enhanced Structural Adjustment Facility (ESAF), this article sheds light on the mechanics of power in this often overlooked venue of global economic governance. By exploring the key issues of default liability and loan conditionality, I demonstrate that whilst the Boardroom is a more active site of contestation than has hitherto been recognized, material power is a prime determinant of both Executive Directorsâ preferences and outcomes reached from discussions. And as the decisions reached form the backbone of the âinstruction sheetâ used by Fund staff to guide their everyday operational decisions, these outcomesâand the processes through which they were reachedâwere factors of primary importance in stabilizing the operational norms at the heart of a controversial phase in the contemporary history of IMF concessional lending
TNRT profiles with the Nucleus Research Platform 8 system
This study investigates the effect of the Nucleus CI24RE implant's neural response telemetry (NRT) system, which has less internal noise compared to its predecessor, the CI24M/R implant, on the NRT threshold (TNRT) profile across the array. CI24M/R measurements were simulated by ignoring CI24RE measurements with response amplitudes below 50 uV. Comparisons of the estimated TNRTs from the CI24RE measurements and the CI24M/R simulations suggest that, apart from a constant level difference, the TNRT profiles from the newer implant generally would not have differed very much from those of its predecessor. This view was also reflected by principal component analysis (PCA) results which revealed a 'shift' component similar to that reported by Smoorenburg et al (2002). On the whole, there is no indication that current practices of using the TNRT profiles for assisting with speech processor programming need to be revised for the CI24RE implant
Critical perspectives on âconsumer involvementâ in health research: epistemological dissonance and the know-do gap
Researchers in the area of health and social care (both in Australia and internationally) are encouraged to involve consumers throughout the research process, often on ethical, political and methodological grounds, or simply as âgood practiceâ. This paper presents findings from a qualitative study in the UK of researchersâ experiences and views of consumer involvement in health research.
Two main themes are presented in the paper. Firstly, we explore the âknow-do gapâ which relates to the tensions between researchersâ perceptions of the potential benefits of, and their actual practices in relation to, consumer involvement. Secondly, we focus on one of the reasons for this âknow-do gapâ, namely epistemological dissonance. Findings are linked to issues around consumerism in research, lay/professional knowledges, the (re)production of professional and consumer identities and the maintenance of boundaries between consumers and researchers
Limits on Gravitational-Wave Emission from Selected Pulsars Using LIGO Data
We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10^(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10^(-5) for the four closest pulsars
Upper Limits on a Stochastic Background of Gravitational Waves
The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of Ω_0<8.4Ă10^(-4) in the 69â156 Hz band is ~10^5 times lower than the previous result in this frequency range
- âŠ