950 research outputs found
A truncation error model and its application to the accuracy analysis of constraint violations
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77162/1/AIAA-1993-3707-458.pd
Dietary Prebiotics and Bioactive Milk Fractions Improve NREM Sleep, Enhance REM Sleep Rebound and Attenuate the Stress-Induced Decrease in Diurnal Temperature and Gut Microbial Alpha Diversity.
Severe, repeated or chronic stress produces negative health outcomes including disruptions of the sleep/wake cycle and gut microbial dysbiosis. Diets rich in prebiotics and glycoproteins impact the gut microbiota and may increase gut microbial species that reduce the impact of stress. This experiment tested the hypothesis that consumption of dietary prebiotics, lactoferrin (Lf) and milk fat globule membrane (MFGM) will reduce the negative physiological impacts of stress. Male F344 rats, postnatal day (PND) 24, received a diet with prebiotics, Lf and MFGM (test) or a calorically matched control diet. Fecal samples were collected on PND 35/70/91 for 16S rRNA sequencing to examine microbial composition and, in a subset of rats; Lactobacillus rhamnosus was measured using selective culture. On PND 59, biotelemetry devices were implanted to record sleep/wake electroencephalographic (EEG). Rats were exposed to an acute stressor (100, 1.5 mA, tail shocks) on PND 87 and recordings continued until PND 94. Test diet, compared to control diet, increased fecal Lactobacillus rhamnosus colony forming units (CFU), facilitated non-rapid eye movement (NREM) sleep consolidation (PND 71/72) and enhanced rapid eye movement (REM) sleep rebound after stressor exposure (PND 87). Rats fed control diet had stress-induced reductions in alpha diversity and diurnal amplitude of temperature, which were attenuated by the test diet (PND 91). Stepwise multiple regression analysis revealed a significant linear relationship between early-life Deferribacteres (PND 35) and longer NREM sleep episodes (PND 71/72). A diet containing prebiotics, Lf and MFGM enhanced sleep quality, which was related to changes in gut bacteria and modulated the impact of stress on sleep, diurnal rhythms and the gut microbiota
An experiment of the impact of a neonicotinoid pesticide on honeybees : the value of a formal analysis of the data
This work received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) and their support is gratefully acknowledged. MASTS is funded by the Scottish Funding Council (Grant reference HR09011) and contributing institutions.Background: We assess the analysis of the data resulting from a field experiment conducted by Pilling et al. (2013) on the potential effects of thiamethoxam on honey bees. The experiment had low levels of replication, so Pilling et al. concluded that formal statistical analysis would be misleading. This would be true if such an analysis merely comprised tests of statistical significance and if the investigators concluded that lack of significance meant little or no effect. However, an analysis that includes estimation of the size of any effectsâwith confidence limitsâallows one to reach conclusions that are not misleading and that produce useful insights. Main Body: For the data of Pilling et al. we use straightforward statistical analysis to show that the confidence limits are generally so wide that any effects of thiamethoxam could have been large without being statistically significant. Instead of formal analysis, Pilling et al. simply inspected the data and concluded that they provided no evidence of detrimental effects and from this that thiamethoxam poses a âlow riskâ to bees. Conclusions: Conclusions derived from inspection of the data were not just misleading in this case but are unacceptable in principle, for if data are inadequate for a formal analysis (or only good enough to provide estimates with wide confidence intervals) then they are bound to be inadequate as a basis for reaching any sound conclusions. Given that the data in this case are largely uninformative with respect to the treatment effect, any conclusions reached from such informal approaches can do little more than reflect the prior beliefs of those involved.Publisher PDFPeer reviewe
Stroke-Like Presentation Following Febrile Seizure in a Patient with 1q43q44 Deletion Syndrome
Hemiconvulsionâhemiplegiaâepilepsy syndrome (HHE) is a rare outcome of prolonged hemiconvulsion that is followed by diffuse unilateral hemispheric edema, hemiplegia, and ultimately hemiatrophy of the affected hemisphere and epilepsy. Here, we describe the case of a 3-year-old male with a 1;3 translocation leading to a terminal 1q43q44 deletion and a terminal 3p26.1p26.3 duplication that developed HHE after a prolonged febrile seizure and discuss the pathogenesis of HHE in the context of the patientâs complex genetic background
Stroke-Like Presentation Following Febrile Seizure in a Patient with 1q43q44 Deletion Syndrome
Hemiconvulsionâhemiplegiaâepilepsy syndrome (HHE) is a rare outcome of prolonged hemiconvulsion that is followed by diffuse unilateral hemispheric edema, hemiplegia, and ultimately hemiatrophy of the affected hemisphere and epilepsy. Here, we describe the case of a 3-year-old male with a 1;3 translocation leading to a terminal 1q43q44 deletion and a terminal 3p26.1p26.3 duplication that developed HHE after a prolonged febrile seizure and discuss the pathogenesis of HHE in the context of the patientâs complex genetic background
Did A Rising Tide Lift All Boats? The NIH Budget And Pediatric Research Portfolio
This paper examines National Institutes of Health (NIH) pediatric research spending in absolute terms and relative to the doubling of the NIH overall budget between fiscal years 1998 and 2003. Pediatric spending increased by an average annual rate of 12.8 percent during the doubling period (almost on par with the NIH average annual growth rate of 14.7 percent). However, the proportion of the total NIH budget devoted to the pediatric portfolio declined from 12.3 to 11.3 percent. We offer recommendations for implementing existing commitments to strengthen the pediatric research portfolio and to protect the gains of the doubling period
Strong variation in weathering of layered rock maintains hillslopeâscale strength under high precipitation
The evolution of volcanic landscapes and their landslide potential are both dependent upon the weathering of layered volcanic rock sequences. We characterize critical zone structure using shallow seismic Vp and Vs profiles and vertical exposures of rock across a basaltic climosequence on Kohala peninsula, Hawaiâi, and exploit the dramatic gradient in mean annual precipitation (MAP) across the peninsula as a proxy for weathering intensity. Seismic velocity increases rapidly with depth and the velocityâdepth gradient is uniform across three sites with 500â600âmm/yr MAP, where the transition to unaltered bedrock occurs at a depth of 4 to 10âm. In contrast, velocity increases with depth less rapidly at wetter sites, but this gradient remains constant across increasing MAP from 1000 to 3000âmm/yr and the transition to unaltered bedrock is near the maximum depth of investigation (15â25âm). In detail, the profiles of seismic velocity and of weathering at wet sites are nowhere monotonic functions of depth. The uniform average velocity gradient and the greater depths of low velocities may be explained by the averaging of velocities over intercalated highly weathered sites with less weathered layers at sites where MAP > 1000âmm/yr. Hence, the main effect of climate is not the progressive deepening of a nearâsurface altered layer, but rather the rapid weathering of high permeability zones within rock subjected to precipitation greater than ~1000âmm/yr. Although weathering suggests mechanical weakening, the nearly horizontal orientation of alternating weathered and unweathered horizons with respect to topography also plays a role in the slope stability of these heterogeneous rock masses. We speculate that where steep, rapidly evolving hillslopes exist, the subâhorizontal orientation of weak/strong horizons allows such sites to remain nearly as strong as their less weathered counterparts at drier sites, as is exemplified by the 50°â60° slopes maintained in the amphitheater canyons on the northwest flank of the island. Copyright Š 2017 John Wiley & Sons, Ltd.Seismic velocity profiles across a basalt climosequence in Hawaiâi reveal that above a particular precipitation threshold, rapid weathering of highâpermeability layers produces intercalated lowâvelocity horizons and dramatically lowers the average seismic velocity of the rock section. However, less permeable layers remain relatively unweathered and thus still contribute significantly to the mechanical competence of the profile, which may explain maintenance of steepâwalled canyons under high precipitation rates. Such observations challenge a topâdown model of progressive weathering (i.e. weakening) of the substrate and therefore suggest that high strength can be maintained even under high precipitation rates, if horizontally layered horizons of different weathering potential exist.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143701/1/esp4290.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143701/2/esp4290_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143701/3/esp4290-sup-0001-SupplementaFiles_FINAL.pd
Effect of Mesh Phasing on the Transmission Efficiency and Dynamic Performance of Wheel Hub Planetary Gear Sets
Transmission efficiency and refinement of planetary wheel hub gearing system are key design attributes for heavy and off-highway vehicles. Reduction of power loss, directly leading to the development of new generation ECO-axles requires analysis of gear contacting conditions for lubricated conjunctions to determine frictional performance. This is also affected by gear dynamics, which is a prerequisite for assessment of noise, vibration and harshness performance. Therefore, a combined tribo-dynamic analysis is essential. There is a dearth of such holistic analysis, particularly for the case of wheel hub planetary systems. The paper presents such an analysis, which has not hitherto been reported in literature. The inexorable interplay of transmission efficiency and noise, vibration and harshness refinement is demonstrated. The key attributes of noise, vibration and harshness refinement and transmission efficiency can pose contrary requirements and near-optimal conditions can be highlighted by mesh phasing of gearing contacts, thus alleviating the need for more complex gear teeth modifications entailing prohibitive manufacturing costs
Predicting Left Ventricular Assist Device Outcomes Utilizing the Stanford Integrated Psychosocial Assessment for Transplant Measure
Objective: Durable mechanical circulatory support is a proven therapy to extend survival for patients with end-stage heart failure (HF). The International Society for Heart and Lung Transplantation guidelines recommend a detailed psychosocial assessment when selecting candidates for durable mechanical circulatory support. Currently, there are no formally validated psychosocial evaluation tools for left ventricular assist device (LVAD) candidacy. The Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) uses a multidisciplinary algorithm to evaluate the impact of pre-transplant risk factors on post-transplant outcomes. Emerging literature suggests that the SIPAT might be useful for assessing psychosocial risk factors for LVAD outcomes.
Methods: A total of 268 consecutive patients (median age 66 years, 84.6% male) with terminal HF were evaluated before LVAD implantation with a SIPAT assessment. Key outcomes included readmission and mortality rates at 30 days and two years.
Results: After screening, 234 subjects met the inclusion criteria and were analyzed. The Patient Readiness subscale of the SIPAT was statistically significant in predicting two-year mortality (B = .167, P \u3c .001; Nagelkerke r2 = .106). Scores on the SIPAT did not correlate to 30-day readmission, 30-day mortality, or two-year readmission rates.
Discussion: In this study, only the Patient Readiness score was associated with mortality at two-years post-implantation. This research elucidates the potential longer-term impact of psychosocial factors on LVAD outcomes and the SIPATâs utility in evaluating LVAD candidacy
Triple oxygen isotopic composition of the high-<sup>3</sup>He/<sup>4</sup>He mantle
Measurements of Xe isotope ratios in ocean island basalts (OIB) suggest that Earthâs mantle accreted heterogeneously, and that compositional remnants of accretion are sampled by modern, high-3He/4He OIB associated with the Icelandic and Samoan plumes. If so, the high-3He/4He source may also have a distinct oxygen isotopic composition from the rest of the mantle. Here, we test if the major elements of the high-3He/4He source preserve any evidence of heterogeneous accretion using measurements of three oxygen isotopes on olivine from a variety of high-3He/4He OIB locations. To high precision, the Î17O value of high-3He/4He olivines from Hawaii, Pitcairn, Baffin Island and Samoa, are indistinguishable from bulk mantle olivine (Î17OBulk Mantle â Î17OHigh 3He/4He olivine = â0.002 Âą 0.004 (2 Ă SEM)â°). Thus, there is no resolvable oxygen isotope evidence for heterogeneous accretion in the high-3He/4He source. Modelling of mixing processes indicates that if an early-forming, oxygen-isotope distinct mantle did exist, either the anomaly was extremely small, or the anomaly was homogenised away by later mantle convection.
The δ18O values of olivine with the highest 3He/4He ratios from a variety of OIB locations have a relatively uniform composition (âź5â°). This composition is intermediate to values associated with the depleted MORB mantle and the average mantle. Similarly, δ18O values of olivine from high-3He/4He OIB correlate with radiogenic isotope ratios of He, Sr, and Nd. Combined, this suggests that magmatic oxygen is sourced from the same mantle as other, more incompatible elements and that the intermediate δ18O value is a feature of the high-3He/4He mantle source. The processes responsible for the δ18O signature of high-3He/4He mantle are not certain, but δ18Oâ87Sr/86Sr correlations indicate that it may be connected to a predominance of a HIMU-like (high U/Pb) component or other moderate δ18O components recycled into the high-3He/4He source
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