3,157 research outputs found
Habitat use by migrating and breeding shorebirds on the eastern Copper River delta, Alaska
Thesis (M.S.) University of Alaska Fairbanks, 1981This study examines the phenology, species composition, relative abundance, patterns of habitat use, and resource partitioning by migrating and breeding shorebirds on the eastern Copper River Delta. The peak of spring migration in 1978 occurred on 11 May, several days later than normal. Interspecific competition for foraging space on intertidal mudflats was minimized by temporal differences in the peaks of migration of the most abundant species and by spatial segregation during feeding. Fall migration differed from spring migration in several ways: 1) different species composition, 2) lower densities of staging birds, 3) different patterns of habitat use, and 4) less habitat segregation between species. Forty-five nests of six species of shorebirds were located along 52 km of transects. The peak of nest initiation was between 25 May and 31 May. Over 75% of the nests occurred in three habitat types, all of which were dominated by varying degrees of sedge, grass, and moss
Synergistic antibacterial effects of theaflavin in combination with ampicillin against hospital isolates of Stenotrophomonas Maltophilia
Stenotrophomonas maltophilia is an important opportunistic nosocomial pathogen that shows intrinsic resistance to many antibiotics. This often limits treatment options and can cause lengthy hospital stays. Combination treatments are often used to combat resistance and using natural compounds such as polyphenols could give increased treatment options and even the reuse of antibiotics to which high levels of resistance have been observed. A checkerboard assay was used to determine if any synergy exists between ampicillin and the polyphenol theaflavin against 9 clinical isolates and one control isolate (NCTC 13014) of S. maltophilia. It was discovered that significant synergy (P 0.05) does exist between theaflavin and ampicillin, reducing the mean MIC of ampicillin from 12.5-22.9 µg/mL, in liquid culture, to 3.125-6.25 µg/mL. The FIC index was calculated to be 0.22-0.35 confirming synergy. From these results, significant potential for medical applications can be seen and further investigation is recommended
Ferroelectric phase transition and the lattice thermal conductivity of Pb1-xGexTe alloys
We show how tuning the proximity to the soft optical mode phase transition via chemical composition affects the lattice thermal conductivity Îș of Pb1-xGexTe alloys. Using first-principles virtual-crystal simulations, we find that the anharmonic contribution to Îș is minimized at the phase transition due to the maximized acoustic-optical anharmonic interaction. Mass disorder significantly lowers and flattens the dip in the anharmonic Îș over a wide composition range, thus shifting the Îș minimum away from the phase transition. The total Îș and its anharmonic contribution vary continuously between the rocksalt and rhombohedral phases as expected for the second-order phase transition. The actual phase and its strength of resonant bonding play a less prominent role in reducing the Îș of Pb1-xGexTe alloys than the proximity to the phase transition and the atomic mass. Our results show that alloys with soft optical mode transitions are promising materials for achieving low thermal conductivity and possibly high thermoelectric efficiency
Innovative development of the Octopus (cf) tetricus fishery in Western Australia
In 2010 the broad-scale introduction of a new gear type, the trigger trap, saw a 260% (33 t in 2009 to 119 t in 2010) increase in octopus landings in the Western Australian Developmental Octopus Fishery (DOF). Deployed in waters previously unfished by the DOF, initial catches demonstrated that trigger traps were more efficient and captured a different component of the population, compared to open-ended shelter pots traditionally used in the fishery. This shift caused a surge of interest in commercial octopus fishing
Patterns of satellite tagged hen harrier disappearances suggest widespread illegal killing on British grouse moors
Natural England commenced a Hen Harrier Recovery Project in 2002. This tracking study was funded exclusively by Natural England and is part of their on-going work on hen harrier conservation. We thank Hamish Smith and staff at the Hawk and Owl Trust for contributing data from four hen harriers they have tracked. We are grateful for the time of many volunteers in the field who monitored and searched for harriers: Pat Martin, Gavin Craggs, Pete Davies, Derek Hayward, Martin Davison, Mick Carroll, Paul Howarth, Ian Thomson, and Elsie Ashworth. We thank Judith Smith and Phil Skinner for sponsoring tags. Also we would like to thank the Wildlife Crime Officers in Lancashire, Yorkshire, Co Durham and Northumberland for their assistance. Thanks also to Jeremy Wilson and Pat Thompson for useful comments on this manuscript. We are grateful to staff at Microwave Telemetry Inc. and CLS France for data archiving. The complete data sets analysed in this study are not publicly available due to the sensitivity of the locational data but are available from the corresponding author on reasonable request and with permission of Natural England. The source data for Figs. 1 and 2 have been provided as a Source Data file.Peer reviewedPublisher PD
Review of Engaging Education: Developing Emotional Literacy, Equity and Co-education. Brian Matthews. (Book Review)
The book is only about a fraction of its title Engaging Education. His section on âengaging the emotionsâ sums this up: whereas the book is largely about engaging the emotions positively, the definition of âEngagingâ is more far reaching: âthat pupils should be involved in their learning; be active and absorbed and not just passive recipients of a set curriculum. Additionally, they should feel engaged in the processes of education and have some input into creating their own agendas for learningâ (p.2). Exploring the full impact of this statement across the curriculum really needs a different book
The necessary future of chiropractic education: a North American perspective
The chiropractic educational system in North America is currently in a state of flux. The attempted conversion of some chiropractic schools into "universities" and the want of university affiliation for chiropractic schools suggests that we are searching for a better alternative to the present system. In the early 20(th )century, the Flexner Report helped transform modern medical education into a discipline that relies on scientific and clinical knowledge. Some have wondered if it is time for a Flexner-type report regarding the education of doctors of chiropractic. This article outlines the current challenges within the chiropractic educational system and proposes positive changes for that system
Complementary network-based approaches for exploring genetic structure and functional connectivity in two vulnerable, endemic ground squirrels
The persistence of small populations is influenced by genetic structure and functional connectivity. We used two network-based approaches to understand the persistence of the northern Idaho ground squirrel (Urocitellus brunneus) and the southern Idaho ground squirrel (U. endemicus), two congeners of conservation concern. These graph theoretic approaches are conventionally applied to social or transportation networks, but here are used to study population persistence and connectivity. Population graph analyses revealed that local extinction rapidly reduced connectivity for the southern species, while connectivity for the northern species could be maintained following local extinction. Results from gravity models complemented those of population graph analyses, and indicated that potential vegetation productivity and topography drove connectivity in the northern species. For the southern species, development (roads) and small-scale topography reduced connectivity, while greater potential vegetation productivity increased connectivity. Taken together, the results of the two network-based methods (population graph analyses and gravity models) suggest the need for increased conservation action for the southern species, and that management efforts have been effective at maintaining habitat quality throughout the current range of the northern species. To prevent further declines, we encourage the continuation of management efforts for the northern species, whereas conservation of the southern species requires active management and additional measures to curtail habitat fragmentation. Our combination of population graph analyses and gravity models can inform conservation strategies of other species exhibiting patchy distributions
Distinct and complementary functions of MDA5 and TLR3 in poly(I:C)-mediated activation of mouse NK cells
The double-stranded RNA (dsRNA) analogue poly(I:C) is a promising adjuvant for cancer vaccines because it activates both dendritic cells (DCs) and natural killer (NK) cells, concurrently promoting adaptive and innate anticancer responses. Poly(I:C) acts through two dsRNA sensors, Toll-like receptor 3 (TLR3) and melanoma differentiation-associated protein-5 (MDA5). Here, we investigated the relative contributions of MDA5 and TLR3 to poly(I:C)-mediated NK cell activation using MDA5â/â, TLR3â/â, and MDA5â/âTLR3â/â mice. MDA5 was crucial for NK cell activation, whereas TLR3 had a minor impact most evident in the absence of MDA5. MDA5 and TLR3 activated NK cells indirectly through accessory cells and induced the distinct stimulatory cytokines interferon-α and interleukin-12, respectively. To identify the relevant accessory cells in vivo, we generated bone marrow chimeras between either wild-type (WT) and MDA5â/â or WT and TLR3â/â mice. Interestingly, multiple accessory cells were implicated, with MDA5 acting primarily in stromal cells and TLR3 predominantly in hematopoietic cells. Furthermore, poly(I:C)-mediated NK cell activation was not notably impaired in mice lacking CD8α DCs, providing further evidence that poly(I:C) acts through diverse accessory cells rather than solely through DCs. These results demonstrate distinct yet complementary roles for MDA5 and TLR3 in poly(I:C)-mediated NK cell activation
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