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981.
982.
Diversity within a Colony Morphotype: Implications for Ecological Research 总被引:5,自引:4,他引:1
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Sets of bacterial isolates with the same colony morphologies were selected from spread plates of bacteria from deep subsurface rock samples; each set had a unique morphology. API-rapid-NFT analysis revealed that isolates within a set were the same. Fatty acid methyl ester analysis of one set of isolates clustered organisms within the same species, defining variation between isolates at the biotype (subspecies) and strain levels. Metal resistances consistently tracked with colony morphology, while antibiotic resistances were less reliable. 相似文献
983.
Teresa Liu-Ambrose Janice J Eng Lara A Boyd Claudia Jacova Jennifer C Davis Stirling Bryan Philip Lee Penny Brasher Ging-Yuek R Hsiung 《BMC neurology》2010,10(1):14
Background
Sub-cortical vascular ischaemia is the second most common etiology contributing to cognitive impairment in older adults, and is frequently under-diagnosed and under-treated. Although evidence is mounting that exercise has benefits for cognitive function among seniors, very few randomized controlled trials of exercise have been conducted in populations at high-risk for progression to dementia. Aerobic-based exercise training may be of specific benefit in delaying the progression of cognitive decline among seniors with vascular cognitive impairment by reducing key vascular risk factors associated with metabolic syndrome. Thus, we aim to carry out a proof-of-concept single-blinded randomized controlled trial primarily designed to provide preliminary evidence of efficacy aerobic-based exercise training program on cognitive and everyday function among older adults with mild sub-cortical ischaemic vascular cognitive impairment. 相似文献984.
985.
Each edge in a weighted colored tree has a nonnegative weight corresponding to the colors of its incident vertices. The sum of these weights is the weight of the tree. Algorithms of O(n) are known to find minimal colorings, that is, to assign colors from a given finite set to the vertices of a tree so as to minimize the weight of the tree. In this paper generating functions are used to find the number of minimal colorings and the average weight of each edge over such colorings, also using O(n) operations. Applications to evolutionary trees are given. 相似文献
986.
John A Luckenbach Dimitar B Iliev Frederick W Goetz Penny Swanson 《Reproductive biology and endocrinology : RB&E》2008,6(1):2
Background
The aim of this study was to identify differentially expressed ovarian genes during primary and early secondary oocyte growth in coho salmon, a semelparous teleost that exhibits synchronous follicle development. 相似文献987.
The purpose of this investigation was to develop a decellularised human dermis suitable for allografting. Samples of human skin were obtained from deceased donors and taken through a series of steps to remove all cellular material. The steps were: chemical removal of the epidermis, disinfection, lysing of cells in hypotonic buffer, a detergent treatment and a nuclease buffer to remove residual nuclear material. Histological preparations of the decellularised dermis produced were then investigated. In addition residual DNA content, structural strength, collagen denaturation, cytotoxicity and in vivo tissue reactivity following implantation in a murine model were examined. For all donors tested there was no change in morphology as viewed by light microscopy. Mean DNA removal was evaluated at 92.1 %. There were no significant changes in structural strength or evidence of collagen degradation. The tissue did not appear to be cytotoxic or elicit an immune response when implanted in the mouse model. A decellularised tissue has been developed that would appear to be suitable for a range of surgical procedures. 相似文献
988.
989.
Females make large investments in their children and compete among themselves to establish and maintain privileged relationships with male allies who demonstrate both an ability and a willingness to provide fitness-enhancing advantages. Various “strategies” and their more numerous, associated “tactics” are utilized in the competition. Alleged strategies include using sexuality, producing offspring, assisting the male in his own intrasexual contests, and harassing female competitors. The strategies in question are documented in multiple primate species, including humans living in various times and places. Some variables are discussed that influence the degree to which human females rely upon them. 相似文献
990.
Abbey Poirier Melissa Gendron Jennifer Vriend Fiona Davidson Penny Corkum 《Attention deficit and hyperactivity disorders》2016,8(1):53-58
The current study investigated the link between poor sleep and ADHD symptomatology. The effects of extending versus restricting sleep on subjective (questionnaires) and objective (actigraphy) measures of daytime movement were examined in 25 typically developing children aged 8–12 years. Subjective measures demonstrated an increase in ADHD symptomology following sleep restriction, with follow-up analyses indicating that findings were due to poorer attention, not changes in hyperactivity. The results of actigraphy data indicated that there were no differences found for mean or median daytime activity, but the standard deviation of activity was found to be significantly higher following sleep restriction. Contrary to the popular belief that sleep restriction results in increased overall activity, this study instead found an increase in variability of activity. This suggests that a sleep-restricted child’s activity level may appear as alternating periods of high and low activity levels throughout the day. 相似文献