1,622 research outputs found
Maternal parity and its effect on adipose tissue deposition and endocrine sensitivity in the postnatal sheep
Maternal parity influences size at birth, postnatal growth and body composition with firstborn infants being more likely to be smaller with increased fat mass, suggesting that adiposity is set in early life. The precise effect of parity on fat mass and its endocrine sensitivity remains unclear and was, therefore, investigated in the present study. We utilised an established sheep model in which perirenal–abdominal fat mass (the major fat depot in the neonatal sheep) increases ∼10-fold over the first month of life and focussed on the impact of parity on glucocorticoid sensitivity and adipokine expression in the adipocyte. Twin-bearing sheep of similar body weight and adiposity that consumed identical diets were utilised, and maternal blood samples were taken at 130 days of gestation. One offspring from each twin pair was sampled at 1 day of age, coincident with the time of maximal recruitment of uncoupling protein 1 (UCP1), whilst its sibling was sampled at 1 month, when UCP1 had disappeared. Plasma leptin was lower in nulliparous mothers than in multiparous mothers, and offspring of nulliparous mothers possessed more adipose tissue with increased mRNA abundance of leptin, glucocorticoid receptor and UCP2, adaptations that persisted up to 1 month of age when gene expression for interleukin-6 and adiponectin was also raised. The increase in fat mass associated with firstborn status is therefore accompanied by a resetting of the leptin and glucocorticoid axis within the adipocyte. Our findings emphasise the importance of parity in determining adipose tissue development and that firstborn offspring have an increased capacity for adipogenesis which may be critical in determining later adiposity
Stage-Fall-Discharge Relations For Flood Flows Over Highway Embankments
At Utah State University, considerable effort has been devoted to the analysis of submerged flow at open channel constrictions. A method of analyzing submerged flow was first developed for a trapezoidal flume by Hyatt (1965). Later studies verified the method of analysis for a rectangular flume (Skogerboe, Walker, and Robinson, 1965) and Parshall flumes (Skogerboe, Hyatt, England, and Johnson, 1965). Because of the previous findings, it was felt this method of analyzing submerged flow could be applied to highway embankments.
A highway embankment is a form of broad-crested weir when overtopped by flood waters. Being a weir, the flood discharge over the embankment is only a function of the upstream depth for free flow conditions. This report will present a method for determining the discharge under submerged flow conditions using the upstream and downstream depths. Thus, post flood field measurements and observations, when properly obtained, will provide the necessary information for an accurate determination of the flood discharge for either free or submerged flow conditions.
The concepts involved in the analysis of submerged flow at open channel constrictions were originally developed by dimensional analysis for flow measuring flumes. The parameters describing submerged flow in flumes have been further verified by the development of theoretical submerged flow equations which utilize momentum theory and energy relationships.
The experimental models studied by Kindsvater (1964) are comparable to a secondary highway embankment. The models were constructed to a scale of 1/9 a typical secondary roadway. The data resulting from the model studies has been subjected to the method of submerged flow analysis previously employed with flow measuring flumes. The consistency of the data, both fro free flow and submerged flow, reflects the quality of the experimental design and produces employed in collecting the data. Although the data presented in this report applies only various forms of secondary road embankments, the methods of analysis are general. The development of calibration curves for other embankment geometries requires only the generation of additional data employing model studies
Reform in Motion: The Promise and Perils of Incorporating Risk Assessments and Cost-Benefit Analysis into Pennsylvania Sentencing
Subcritical Flow Over Various Weir Shapes
Submerged flow exists for any given structure when a change in flow depth downstream from the structure causes a change in flow depth upstream from the structure for any given constant value of discharge. The two flow depths, normally measured when submerged flow exists, consist of a depth upstream from the structure, which is used also for free flow conditions, and a depth of flow located any place downstream from the structure. The initial studies in which the submerged flow analysis was developed were made on flat-bottomed flumes (Hyatt, 1965; and Skogerboe, Walker, and Robinson, 1965). Later studies verified the method of analysis for Parshall flumes (Skogerboe, Hyatt, England, and John son, 1965; and Hyatt, Skogerboe, and Eggleston, 1966). Because of previous findings, it was felt this method of analyzing submerged flow could be applied to various types and kinds of weirs. Original development of the parameters and relationships which describe submerged flow came from a combination of dimensional analysis and empiricism. Further verification of the parameters developed in this manner are obtained by employing momentum relationships. Both approaches to the submerged flow problem are discussed in this report. Considerable effort and study has been expended on free and submerged flow weirs by other authors in previous years. For this reason the authors of this report went to the literature as a source of data. Various studies typifying a particular type of weir structure were investigated and the data selected from these studies were subjected to the submerged flow analysis developed by the authors. The data from these studies provide further verification of validity of the approach to the submerged flow problem made by the authors. Acknowledgement is given and appreciation expressed to those authors whose studies provided the data used in the analysis presented in this report. Although no investigation was made of a contracted weir, the authors feel that the submerged flow analysis as explained in this report would be just as valid for this type of structure
Prevention of bone mineral changes induced by bed rest: Modification by static compression simulating weight bearing, combined supplementation of oral calcium and phosphate, calcitonin injections, oscillating compression, the oral diophosphonatedisodium etidronate, and lower body negative pressure
The phenomenon of calcium loss during bed rest was found to be analogous to the loss of bone material which occurs in the hypogravic environment of space flight. Ways of preventing this occurrence are investigated. A group of healthy adult males underwent 24-30 weeks of continuous bed rest. Some of them were given an exercise program designed to resemble normal ambulatory activity; another subgroup was fed supplemental potassium phosphate. The results from a 12-week period of treatment were compared with those untreated bed rest periods. The potassium phosphate supplements prevented the hypercalciuria of bed rest, but fecal calcium tended to increase. The exercise program did not diminish the negative calcium balance. Neither treatment affected the heavy loss of mineral from the calcaneus. Several additional studies are developed to examine the problem further
Deeply sequenced metagenome and metatranscriptome of a biogas-producing microbial community from an agricultural production-scale biogas plant
Bremges A, Maus I, Belmann P, et al. Deeply sequenced metagenome and metatranscriptome of a biogas-producing microbial community from an agricultural production-scale biogas plant. GigaScience. 2015;4(1): 33.Background
The production of biogas takes place under anaerobic conditions and involves microbial decomposition of organic matter. Most of the participating microbes are still unknown and non-cultivable. Accordingly, shotgun metagenome sequencing currently is the method of choice to obtain insights into community composition and the genetic repertoire.
Findings
Here, we report on the deeply sequenced metagenome and metatranscriptome of a complex biogas-producing microbial community from an agricultural production-scale biogas plant. We assembled the metagenome and, as an example application, show that we reconstructed most genes involved in the methane metabolism, a key pathway involving methanogenesis performed by methanogenic Archaea. This result indicates that there is sufficient sequencing coverage for most downstream analyses.
Conclusions
Sequenced at least one order of magnitude deeper than previous studies, our metagenome data will enable new insights into community composition and the genetic potential of important community members. Moreover, mapping of transcripts to reconstructed genome sequences will enable the identification of active metabolic pathways in target organisms
Are chimpanzees really so poor at understanding imperative pointing? Some new data and an alternative view of canine and ape social cognition
There is considerable interest in comparative research on different species’ abilities to respond to human communicative cues such as gaze and pointing. It has been reported that some canines perform significantly better than monkeys and apes on tasks requiring the comprehension of either declarative or imperative pointing and these differences have been attributed to domestication in dogs. Here we tested a sample of chimpanzees on a task requiring comprehension of an imperative request and show that, though there are considerable individual differences, the performance by the apes rival those reported in pet dogs. We suggest that small differences in methodology can have a pronounced influence on performance on these types of tasks. We further suggest that basic differences in subject sampling, subject recruitment and rearing experiences have resulted in a skewed representation of canine abilities compared to those of monkeys and apes
The photometric variability of massive stars due to gravity waves excited by core convection
Massive stars die in catastrophic explosions, which seed the interstellar
medium with heavy elements and produce neutron stars and black holes.
Predictions of the explosion's character and the remnant mass depend on models
of the star's evolutionary history. Models of massive star interiors can be
empirically constrained by asteroseismic observations of gravity wave
oscillations. Recent photometric observations reveal a ubiquitous red noise
signal on massive main sequence stars; a hypothesized source of this noise is
gravity waves driven by core convection. We present the first 3D simulations of
massive star convection extending from the star's center to near its surface,
with realistic stellar luminosities. Using these simulations, we make the first
prediction of photometric variability due to convectively-driven gravity waves
at the surfaces of massive stars, and find that gravity waves produce
photometric variability of a lower amplitude and lower characteristic frequency
than the observed red noise. We infer that the photometric signal of gravity
waves excited by core convection is below the noise limit of current
observations, so the red noise must be generated by an alternative process.Comment: As accepted for publication in Nature Astronomy except for final
editorial revisions. Supplemental materials available online at
https://doi.org/10.5281/zenodo.7764997 . We have also sonified our results to
make them more accessible, see
https://github.com/evanhanders/gmode_variability_paper/blob/main/sound/gmode_sonification.pd
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