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Competition for food in 2 populations of a wild-caught fish

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Current Zoology 2018年第5期64卷 615-622页

作者： Pierre j.C. CHUARD grant E. BROWN j.mes W.A. grant Research School of Biology The Australian National University Canberra ACT 0200 Australia Departmentof Biology Concordia University 7141 Sherbrooke Street West Montreal Quebec Canada H4B 1R6

Aggressive behavior when competing for resources is expected to increase as the ratio of competitors-to-resource ratio （CRR） units increases. Females are expected to be more aggressive than males when competing for food when body size is more strongly related to reproductive suc- cess in females than in males, whereas aggression is predicted to decrease under high ambient predation risk by natural selection. Under the risk allocation model, however, individuals under high ambient predation risk are expected to be more aggressive, and forage more in the absence of imminent risk than their low risk counterparts. An interaction between adult sex ratio （i.e., adult males/females）, ambient predation risk （high vs. low）, and sex on intrasexual competition for mates in Trinidadian guppies Poecilia reticulata has been shown. The interaction suggested an increase in aggression rates as CRR increased, except for males from the high predation population. To compare the patterns of competition for food versus mates, we replicated this study by using food patches. We allowed 4 male or 4 female guppies from high and low predation populations to com- pete for 5, 3, or 1 food patches. The foraging rate was higher in a high rather than low ambient pre- dation risk population. Surprisingly, CRR, sex, and population of origin had no effect on aggression rates. Despite other environmental differences between the 2 populations, the effect of ambient predation risk may be a likely explanation for differences in foraging rates. These results highlight the importance for individuals to secure food despite the cost of competition and predation.

关键词： aggression competitor-to-resource ratio foraging Poecifia reticulata population differences predation risk sex

Olfaction and reaction: The role of olfactory and hypothalamic investment in the antipredator responses to chemical alarm cues by northern redbelly dace

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Current Zoology 2023年第6期69卷 738-746页

作者： Brendan j.j.yce grant E.Brown Department of Biology Concordia UniversityMontrealQuebecCanada

Neuroplasticity enables teleosts to promote or downregulate the growth of their brains *** compensate for the effects of predation pressure,teleosts may alter their brain morphology and behavioral responses to mitigate its impact on individual ***-predation environ-ments often promote specific patterns of brain growth and produce bolder and more proactive *** to the expense of maintaining neural tissue,relative size indicates the regions most relied *** northern redbelly dace Chrosomus eos,as little as 2 weeks of elevated predation pressure,resulted in increased investment in their olfactory bulbs and optic tecta,while the imposition of captivity produced smaller,less symmetric *** together,these results suggest that an individual could potentially become better able to detect a threat,and simultaneously less inclined to react to it,making the impact of either change in isolation is difficult to ***,we compared interindividual variation in gross brain morphology,risk-taking tactics in a novel arena(shy-bold personality),and responding to olfactory cues(proactive/reac-tive stress-coping style).We hypothesized that olfactory investment would positively correlate with response intensity to predator cue concen-tration and respond across a wider range of cue concentrations,while hypothalamus size would correlate with shyness and *** to heightened risk produced more bold/proactive individuals,with larger olfactory bulbs and smaller ***,the direction of the correlation between hypothalamus size and behavior varied by treatment,and olfactory investment only corresponded with response intensity amongst proactive *** findings illustrate the potential pitfalls of relating gross brain morphology to complex behavior and suggest that stress-coping style is a relevant consideration in future studies.

关键词： boldness brainmorphology neuroplasticity predation proactivity stress-coping style

Stability Analysis and Performance Evaluation of Additive Mixed-Precision Runge-Kutta Methods

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Communications on Applied Mathematics and Computation 2024年第1期6卷 705-738页

作者： Ben Burnett Sigal Gottlieb Zachary j.grant Center for Scientific Computing and Data Science Research UMass DartmouthNorth DartmouthMassachusettsUSA CSME Michigan State UniversityEast LansingMichiganUSA

Additive Runge-Kutta methods designed for preserving highly accurate solutions in mixed-precision computation were previously proposed and *** specially designed methods use reduced precision for the implicit computations and full precision for the explicit *** this work,we analyze the stability properties of these methods and their sensitivity to the low-precision rounding errors,and demonstrate their performance in terms of accuracy and *** develop codes in FORTRAN and j.lia to solve nonlinear systems of ODEs and PDEs using the mixed-precision additive Runge-Kutta(MP-ARK)*** convergence,accuracy,and runtime of these methods are *** show that for a given level of accuracy,suitably chosen MP-ARK methods may provide significant reductions in runtime.

关键词： Mixed precision Runge-Kutta methods Additive methods Accuracy

POWER CONSUMPTION COMPARISON OF FIVE BUILDING ENVELOPES IN THE NORTHERN PRAIRIE CLIMATE OF MANITOBA

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j.urnal of Green Building 2014年第4期9卷 147-160页

作者： Kris j.Dick Hossein Safavian grant Rayner Director-The Alternative Village Department of Biosystems EngineeringFaculty of EngineeringUniversity of ManitobaRm E1-344 EITC75 Chancellors CircleWinnipegManitobaCanada Department of Biosystems Engineering Faculty of EngineeringUniversity of Manitoba

The energy efficiency of a building depends on building envelope *** results presented in this paper are the first of a long-term building envelope research proj.ct at the Alternative Village at the University of Manitoba in Winnipeg,Manitoba,*** test buildings were constructed using the following systems:two wood frames with fiberglass batt insulation and dense pack cellulose,one polyurethane structural insulated panels(PUR SIP),and two with the Stay in place PVC concrete form building system using 102mm and 204mm of concrete externally insulated with 102mm of expanded polystyrene *** of the buildings had a common foundation and roof system with a footprint of 23.8 *** door tests were conducted to determine air *** structure was heated with an electrical resistance heater and maintained at a constant internal *** thermal gradient through the wall and power consumption were *** study period discussed in this report represents the main heating season from October 2011 to April 2012 consisting of 209 *** on the power consumption,the PUR SIP consumed the least at 2498 kWh,while the 204 mm Stay in place PVC concrete form building used the most at 2898 kWh for the same time *** thermal gradient through the cross section of the wood frame structures was compared through the cavity insulation and at the *** was found that the cellulose building provided better thermal resistance along the stud when compared to the fiberglass batt insulation.

关键词： fiberglass insulation cellulose insulation polyurethane structural insulated panels power consumption mass walls

Effect of Si,Cu and Fe on mechanical properties of cast semi-solid 206 alloys

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1555-1560页

作者： A.LEMIEUX j.LANGLAIS D.BOUCHARD X.grant CHEN Rio Tinto Alcan Arvida Research and Development Centre Rio Tinto Alcan Laterrière Works NRC-Aluminium Technology Centre Université du Québec à Chicoutimi

The development of a modified 206 alloy whose composition was optimized to minimize hot tearing during semi-solid forming was reported. The effect of varying silicon, copper and iron contents was investigated using a design of experiment (DOE) approach. Semi-solid slurries were prepared using the SEED process and inj.cted into a high pressure die casting press. The hot tearing sensitivity results were reported for different alloy variants. The microstructure evolution during the semi-solid preparation was presented along with actual die cast components. The effects of silicon, copper and iron on mechanical properties in the T7 condition were also analyzed. Beyond the benefit of reducing hot tearing, it is shown that the tensile and fatigue properties remain compatible with the automotive industry requirements.

关键词： semi-solid forming 206 aluminum alloy SEED process hot tearing mechanical properties

Temporal dynamics of neonatal hypoxic-ischemic encephalopathy inj.ries on magnetic resonance imaging

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Neural Regeneration Research 2025年第11期20卷 3144-3150页

作者： Holly Flyger Samantha j.Holdsworth Alistair j.Gunn Laura Bennet Hamid Abbasi Mātai Medical Research Institute Tairāwhiti GisborneNew Zealand Department of Anatomy&Medical Imaging Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand Center for Brain Research The University of AucklandAucklandNew Zealand Auckland Bioengineering Institute The University of AucklandAucklandNew Zealand

Moderate to severe perinatal hypoxic-ischemic encephalopathy occurs in~1 to 3/1000 live births in high-income countries and is associated with a significant risk of death or neurodevelopmental *** assessment is important to help identify highrisk infants,to help families,and to support appropriate interventions.A wide range of monitoring tools is available to assess changes over time,including urine and blood biomarkers,neurological examination,and *** present,magnetic resonance imaging is unique as although it is expensive and not suited to monitoring the early evolution of hypoxic-ischemic encephalopathy by a week of life it can provide direct insight into the anatomical changes in the brain after hypoxic-ischemic encephalopathy and so offers strong prognostic information on the long-term outcome after hypoxic-ischemic *** review investigated the temporal dynamics of neonatal hypoxic-ischemic encephalopathy inj.ries,with a particular emphasis on exploring the correlation between the prognostic implications of magnetic resonance imaging scans in the first week of life and their relationship to long-term outcome prediction,particularly for infants treated with therapeutic hypothermia.A comprehensive literature search,from 2016 to 2024,identified 20 pertinent *** review highlights that while the optimal timing of magnetic resonance imaging scans is not clear,overall,it suggests that magnetic resonance imaging within the first week of life provides strong prognostic *** challenges limit the timing consistency,particularly the need for intensive care and clinical ***,although most reports examined the prognostic value of scans taken between 4 and 10 days after birth,there is evidence from small numbers of cases that,at times,brain inj.ry may continue to evolve for weeks after *** suggests that in the future it will be important to explore a wider range of times after hypo

关键词： magnetic resonance imaging neonatal hypoxic-ischemic encephalopathy neurodevelopmental outcomes prognostic biomarkers in neuroimaging scan timing therapeutic hypothermia

c-MET immunohistochemical expression in sporadic and inflammatory bowel disease associated lesions

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World j.urnal of Gastroenterology 2022年第13期28卷 1338-1346页

作者： grant Halliday Ross j.Porter Catherine j.Black Mark j.Arends Shahida Din Department of Pathology Western General HospitalNHS LothianScotland EH42XUUnited Kingdom Centre for Inflammation Research Queen’s Medical Research InstituteUniversity of EdinburghEdinburgh EH164TJUnited Kingdom Edinburgh Inflammatory Bowel Disease Unit Western General HospitalNHS LothianEdinburgh EH42XUUnited Kingdom Cancer Research UK Edinburgh Centre Institute of Cancer&GeneticsWestern General HospitalUniversity of EdinburghEdinburgh EH42XUUnited Kingdom

BACKGROUND Post-colonoscopy colorectal cancer(CRC)rates for patients with inflammatory bowel disease(IBD)are unacceptably *** colonoscopy,an intravenous fluorescent anti-c-MET probe may improve endoscopic detection of ***,c-MET expression in IBD lesions is poorly defined,limiting translational *** To comprehensively define c-MET expression in sporadic and IBD-associated colorectal *** c-MET expression was immunohistochemically assessed in 319 formalin-fixed paraffin-embedded tissue specimens,colonoscopically or surgically retrieved between *** included:30 normal colorectal biopsies,30 hyperplastic polyps(HP),31 sessile serrated lesions(SSL),55 tubular/tubulovillous adenomas with low(TA-LGD,n=32)or high grade dysplasia(TA-HGD,n=23),26 sporadic(s)-CRCs,16 quiescent IBD biopsies,11 active/inflamed IBD biopsies,18 IBDassociated dysplastic lesions(IBD-dys),and 102 *** was scored by two independent observers as:0=absent,1=weak,2=moderate or 3=***-Whitney U and Kruskal-Wallis tests were used to assess *** Positive epithelial cytoplasmic and membranous c-MET expression was observed in all tissues,indicating there is ubiquitous expression in the colorectum.c-MET expression was weak in normal colonic epithelium compared with each of the sporadic colonic lesions,including TA-LGD(P<0.001),TA-HGD(P=0.004),HP(P<0.001),SSL(P<0.001),and s-CRC(P<0.001).Specifically,in sporadic(non-IBD)lesions,expression was stronger in TA-LGD compared with normal mucosa(P<0.001),and stronger in s-CRC compared with TA-HGD(P=0.004).However,there was no significant difference between TA-LGD and TA-HGD(P=0.852).Further,there was no difference in c-MET expression between HP and SSL(P=0.065).In IBD,expression was weaker in quiescent colonic mucosa compared with inflamed colonic mucosa(P<0.001).There was no difference between inflamed colonic mucosa and IBD-dys(P=0.512)or IBD-CRC(P=0.296).However,expression

关键词： Inflammatory bowel diseases Colorectal cancer Surveillance Detection c-MET Immunohistochemistry

Precambrian supercontinents,glaciations,atmospheric oxygenation,metazoan evolution and an impact that may have changed the second half of Earth history

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Geoscience Frontiers 2013年第3期4卷 247-261页

作者： grant M.Young Department of Earth Sciences Western University1151 Richmond Street NLondonOntarioCanada N6A 5B7

In more than 4 Ga of geological evolution, the Earth has twice gone through extreme climatic perturba- tions, when extensive glaciations occurred, together with alternating warm periods which were accom- panied by atmospheric oxygenation. The younger of these two episodes of climatic oscillation preceded the Cambrian ＂explosion＂ of metazoan life forms, but similar extreme climatic conditions existed between about 2.4 and 2.2 Ga. Over long time periods, changing solar luminosity and mantle temperatures have played important roles in regulating Earth＇s climate but both periods of climatic upheaval are associated with supercontinents. Enhanced weathering on the orogenically and thermally buoyed supercontinents would have stripped CO2 from the atmosphere, initiating a cooling trend that resulted in continental glaciation. Ice cover prevented weathering so that CO2 built up once more, causing collapse of the ice sheets and ushering in a warm climatic episode. This negative feedback loop provides a plausible explanation for multiple glaciations of the Early and Late Proterozoic, and their intimate association with sedimentary rocks formed in warm climates. Between each glacial cycle nutrients were flushed into world oceans, stimulating photosynthetic activity and causing oxygenation of the atmosphere. Accommodation for many ancient glacial deposits was provided by rifting but escape from the climatic cycle was predicated on break- up of the supercontinent, when flooded continental margins had a moderating influence on weathering. The geochemistry of Neoproterozoic cap carbonates carries a strong hydrothermal signal, suggesting that they precipitated from deep sea waters, overturned and spilled onto continental shelves at the termination of glaciations. Paleoproterozoic （Huronian） carbonates of the Espanola Formation were probably formed as a result of ponding and evaporation in a hydrothermally influenced, restricted rift setting. Why did metazoan evolution not take off a

关键词： Proterozoic supercontinents Glaciations Impacts Oxygenation Metazoa