Sociobiological hypotheses explored     

Howell N 《Science (New York, N.Y.)》1979,206(4424):1294-1295

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Aleut life expectancy     

Howell N 《Science (New York, N.Y.)》1976,192(4235):95-96

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Hunter-gatherers today     

Howell N 《Science (New York, N.Y.)》1979,205(4411):1122-1124

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Vaccination against experimental allergic encephalomyelitis with T cell receptor peptides   总被引：33，自引：0，他引：33  

M D Howell  S T Winters  T Olee  H C Powell  D J Carlo  S W Brostoff 《Science (New York, N.Y.)》1989,246(4930):668-670

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease of the central nervous system mediated by CD4+ T cells reactive with myelin basic protein (MBP). Rats were rendered resistant to the induction of EAE by vaccination with synthetic peptides corresponding to idiotypic determinants of the beta chain VDJ region and J alpha regions of the T cell receptor (TCR) that are conserved among encephalitogenic T cells. These findings demonstrate the utility of TCR peptide vaccination for modulating the activity of autoreactive T cells and represent a general therapeutic approach for T cell-mediated pathogenesis.  相似文献   

Persistence of memory in drop breakup: the breakdown of universality     

Doshi P  Cohen I  Zhang WW  Siegel M  Howell P  Basaran OA  Nagel SR 《Science (New York, N.Y.)》2003,302(5648):1185-1188

A low-viscosity drop breaking apart inside a viscous fluid is encountered when air bubbles, entrained in thick syrup or honey, rise and break apart. Experiments, simulations, and theory show that the breakup under conditions in which the interior viscosity can be neglected produces an exceptional form of singularity. In contrast to previous studies of drop breakup, universality is violated so that the final shape at breakup retains an imprint of the initial and boundary conditions. A finite interior viscosity, no matter how small, cuts off this form of singularity and produces an unexpectedly long and slender thread. If exterior viscosity is large enough, however, the cutoff does not occur because the minimum drop radius reaches subatomic dimensions first.  相似文献   

A scanning x-ray microscope using synchrotron radiation     

P Horowitz  J A Howell 《Science (New York, N.Y.)》1972,178(61):608-611

Focused synchrotron radiation collimated by means of a pinhole has been used to construct a scanning x-ray microscope capable of making stereoscopic element-discriminating pictures of relatively thick specimens in an atmospheric environment.  相似文献   

A survey of the threat of surface water acidification to the nature conservation interest of fresh waters on Sites of Special Scientific Interest in Britain     

Carrie A. Rimes  Andrew M. Farmer  David Howell 《水产资源保护:海洋与淡水生态系统》1994,4(1):31-44

This study collated information relating to acidification of running and standing waters on Sites of Special Scientific Interest (SSSIs) throughout Britain in acid-sensitive areas. Of those SSSIs which occur in acid-sensitive areas of Britain, 196 have water bodies. The following information was obtained for each site if available: details of local geology and soils, types of land use and management, water quality data and data relating to biological components of both the aquatic and riparian habitats. In addition, samples from 112 water bodies were collected for water chemistry and epilithic diatom analysis. Results from each site were placed into existing critical loads and species response models to determine whether acidification had occurred. Results showed that the fresh waters on 141 SSSIs had probably suffered acidification. This was most acute in north Wales, with mid Wales, south-west and north-east Scotland and northern England also being badly affected. A wide variety of changes in the biological status of water bodies relating to acidification were found to have been recorded on SSSIs, ranging from phytoplankton, invertebrate and macrophyte community changes to decline of fish, amphibian, bird and mammal populations. Catchment afforestation may be a problem in poorly buffered areas and has probably contributed to freshwater acidification on 40 SSSIs. Comparison with critical loads maps for acidity in UK fresh waters reveals that existing commitments on acidifying emissions (the EC Large Combustion Plant Directive) will not be sufficient to prevent further acidification on a number of SSSIs. In order to achieve a protection of the nature conservation interest of fresh waters further commitments to emission reductions will be necessary.  相似文献   

Salt poisoning in broiler chickens     

J. Howell  R.C. Gumbrell 《New Zealand veterinary journal》2013,61(2)

The clinical signs of salt poisoning in young chickens are thirst, diarrhoea and weakness. When 13 500 broilers are simultaneously affected, the deterioration that occurs in their physical condition and in the litter beneath their feet is dramatic. Two flocks of meat chickens on a small unit in North Otago were affected in this way.  相似文献   

The Perceptions of Dog Intelligence and Cognitive Skills (PoDIaCS) Survey     

Tiffani Josey Howell  Samia Toukhsati  Russell Conduit  Pauleen Bennett 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(6):418-424

Dog cognition research is expanding, but few studies have examined people's perceptions of specific cognitive abilities in dogs. The aim of this study was to explore owner perceptions of dog cognitive abilities across different cognitive domains and to determine whether these were associated with the dog–owner relationship. We developed an online questionnaire and analyzed the results from 565 dog owners. Dog owners generally indicated the belief that dogs are socially intelligent and possess the capacity to learn social and general cognitive skills. One quarter of dog owners agreed or strongly agreed that dogs were smarter than most people, and 45.7% indicated the belief that a dog's mental ability is equal to “3-5 year old human children.” Perceived emotional owner–dog closeness correlated with all cognition ratings. A better understanding of dog cognitive abilities may help owners interpret dog behavior more appropriately, which may lead to a reduction in the number of dogs relinquished to shelters because of behavioral problems.  相似文献   

The Influence of Stocking Density on the Swimming Behavior of Adult Atlantic Cod,Gadus morhua,in a Near Shore Net Pen     

Daniel Ward  Martin Føre  W. Huntting Howell  Winsor Watson III 《Journal of the World Aquaculture Society》2012,43(5):621-634

Cage design and stocking density are important aspects of aquaculture farm design, therefore understanding how fish behave at different stocking densities is critical information for farm managers. In this study, high resolution acoustic telemetry was used to investigate the swimming behavior of adult Atlantic cod, Gadus morhua, that were stocked at four densities (5, 10, 25, and 45 kg/m³). Acoustic tags were placed into the abdominal cavity of five fish per density treatment so their swimming behavior could be continuously monitored throughout the study. An array of hydrophones made it possible to calculate the position of each fish in three dimensions, at ～2–5 sec intervals, for 4–30 d. Three underwater cameras were used to obtain additional data about the distribution of fish in the cage during the daytime. At the lowest density, the cod spent the majority (64.3 ± 0.08%) of their time in the bottom third of the net pen. As density increased, the fish moved higher in the water column, and this behavior was most evident at night, at all densities. At no time throughout the entire study were there any obvious occurrences of schooling behavior, even at the highest density (45 kg/m³).  相似文献