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1.
The effects of a physical activity intervention on strength, balance, motor coordination, and mobility were tested in a quasi-experiment at rural congregate nutrition sites. Twice-weekly sessions of low intensity movements were conducted for one year. Logistic regression results showed significant differences between intervention (n = 61) and comparison (n = 49) groups on several performance-based measures. Intervention subjects perceived significantly greater improvements in physical functioning over the previous year than did comparison subjects. A qualitative evaluation revealed perceived program benefits of pain reduction, increased flexibility, muscle strengthening, increased walking speed, and improved mental outlook.  相似文献   

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As the subject of neuroethological studies, arthropods offer several advantages to elucidate the neural processes that generate and control behavioural acts. The relative simplicity of their neural organization and their identifiable neurones are particularly advantageous. The crayfish, Procambarus clarkii, uropods are paired appendages of the last abdominal segment that show bilateral closing movement in response to mechanical stimulation. This movement, the avoidance "dart" response, is mediated by a cascade and parallel organization of local circuit neurones in the terminal abdominal ganglion. Thirty intersegmental ascending interneurones and 20 spiking local interneurones have been identified both morphologically and physiologically. They receive exteroceptive inputs directly from the sensory afferents. Two complementary groups of unilateral nonspiking local interneurones have also been functionally identified. They exert fine control over the wide range of activity of motor neurones in a graded and sustained manner. These nonspiking interneurones form opposing and parallel pathways that are essential in modulating the pattern of movement of the uropods.  相似文献   

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Xenopus blastula cells activate different mesodermal genes as a concentration-dependent response to activin, which behaves like a morphogen. To understand how cells recognize morphogen concentration, we have bound naturally labeled activin to cells and related this to choice of gene activation. We find that the increasing occupancy of a single receptor type can cause cells to switch gene expression. Cells sense ligand concentration by the absolute number of occupied receptors per cell (100 and 300 molecules of bound activin induce Xbra and Xgsc, respectively, i.e., 2% and 6% of the total receptors) and not by a ratio of occupied to unoccupied receptors. The long duration of occupancy explains a previously described ratchet effect. Our results suggest a new concept of morphogen gradient formation and interpretation that is particularly well suited to the needs of early development.  相似文献   

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Turkey rhinotracheitis (TRT) virus was first isolated from a commercial broiler chicken with swollen head syndrome (SHS) in Japan. At the same time, Newcastle disease virus (NDV), infectious bronchitis virus (IBV), avian reovirus (ARV), Escherichia coli (E.coli), Morganella morganii, and Proteus mirabilis were also isolated from the same broiler chicken. The presence of antibodies to TRT virus was confirmed in the sera of 34-day-old chickens of the flock with SHS, however the antibodies to TRT virus were undetectable in the sera of 17-day-old chickens. In this investigation, we confirmed avian pneumovirus infection in chickens in Japan, and the virus and other agents may be considered as a cause of SHS.  相似文献   

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Haemagglutination of purified F42 fimbriae was found to be inhibited by N-acetyl-galactosamine. Purified F42 fimbrial adhesin reacted with distinct membrane components from chicken erythrocytes (35, 37 and 40 kDa) in immunoblot analysis, suggesting that the binding occurred to proteins or glycoproteins.  相似文献   

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The growing percentage of Americans who are elderly and the prevalence of chronic medical conditions will soon necessitate an expanded system of home health care. Presently, the financial and physical burden of this care falls on the elder and the family. This article discusses the issues surrounding elder caregiving.  相似文献   

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OBJECTIVE: Informed consent, as practiced in Australian chiropractic practice, was explored by means of a collective case study. DESIGN: Twenty-one chiropractic practices were visited and 25 chiropractor-patient units explored. Purposive sampling of practitioners was undertaken using a maximum variation strategy. Convenience sampling of patients was performed within each participating practice. Data was gathered from each chiropractor-patient unit, consisting of one practitioner and usually five patients, by means of practitioner interview, patient questionnaire and interview and, in certain cases, practice observation. Thematic analysis of the interviews were correlated with information derived from the patient questionnaires and validated by selective practice observation. Data was compared within and across chiropractor-patient units. RESULTS: Consent for chiropractic care was usually implied. Chiropractors in this study seldom obtained formal verbal, and never written, informed consent. New chiropractic patients were nonetheless informed about the procedures that the chiropractor intended to perform, and their acquiescence was taken as consent. Participants seldom discussed the potentially serious consequences of chiropractic adjustment but did actively attempt to identify and avoid exposing at-risk patients. Patients were often counseled about potential muscle soreness after the chiropractic adjustment. The behavior of chiropractors in this study was consistent with their patients' expectations. CONCLUSION: This study suggests that chiropractic behavior in Australian clinical practice meets the moral, but not all of the legal, requirements for informed consent.  相似文献   

9.
Cholinergic neurons in the basal forebrain are the focus of considerable interest because they are severely affected in Alzheimer's disease. However, both cholinergic and noncholinergic neurons are intermingled in this region. The goal of the present study was to characterize the morphology and in vivo electrophysiology of noncholinergic basal forebrain neurons. Neurons in the ventral pallidum and substantia innominata were recorded extracellularly, labeled juxtacellularly with biocytin and characterized for the presence of choline acetyltransferase immunoreactivity. Two types of ventral pallidal cells were observed. Type I ventral pallidal neurons had axons that rarely branched near the cell body and tended to have smaller somata and lower spontaneous firing rates than did type II ventral pallidal neurons, which displayed extensive local axonal arborizations. Subtypes of substantia innominata neurons could not be distinguished based on axonal morphology. These noncholineregic neurons exhibited local axon arborizations along a continuum that varied from no local collaterals to quite extensive arbors. Substantia innominata neurons had lower spontaneous firing rates, more variable interspike intervals, and different spontaneous firing patterns than did type II ventral pallidal neurons and could be antidromically activated from cortex or substantia nigra, indicating that they were projection neurons. Ventral pallidal neurons resemble, both morphologically and electrophysiologically, previously described neurons in the globus pallidus, whereas the substantia innominata neurons bore similarities to isodendritic neurons of the reticular formation. These results demonstrate the heterogeneous nature of noncholinergic neurons in the basal forebrain.  相似文献   

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简述了佛山城区不同人群体育健身消费者的购买行为心理特征及其消费类型,从消费行为类型的角度指出了不同人群体育消费者的消费方式,使不同体育消费人群都能快乐消费.  相似文献   

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Following the first report of avian Giardia infection in Australia, isolates of the parasite recovered from naturally infected straw-necked ibis (Theskiornis spinicollis) were characterized using median body morphology, scanning electron microscopy, multilocus enzyme electrophoresis, random amplified polymorphic DNA (RAPD), and small subunit ribosomal RNA (SSU-rRNA) analyses. Results were compared with Giardia from other birds and mammals, and the extent of genetic diversity between a range of ibis isolates collected in Western Australia was determined. The ibis isolates of Giardia were genetically relatively homogeneous, which is in contrast to the extensive genetic heterogeneity often displayed by mammalian Giardia isolates. Morphologically, Giardia from ibis were similar to Giardia ardeae although they differed genetically and by the fact that the ibis isolates could not be established in in vitro culture. Sequence data of the DNA coding for the SSU-rRNA found a 96% homology between the ibis isolates from Western Australia and G. ardeae, suggesting that they represent distinct strains of the same species. In contrast, the ibis isolates were genetically and morphologically very different than Giardia duodenalis and Giardia muris from mammals.  相似文献   

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Clinicomorphological characteristics of intrauterine chlamydiasis (IUC) are given. The authors describe a cottonwool-like meningochorioiditis the observation of which at necropsy allows IUC suspection. Chlamydial etiology of this condition is confirmed by means of electron microscopy and immunofluorescence. Fibroblast proliferation of the pia mater followed by intensive fibrillogenesis plays a most important role in morphogenesis of cottonwool-like nodules. The occurrence of IUC at the necropsies varies depending on the age of foetuses and newborns from 6.2 to 38.7%.  相似文献   

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We have isolated a novel, high Mr protein from human retinal pigment epithelial cells and endothelial cells by affinity chromatography on Sepharose 4B. Two polypeptides are present on SDS-gels of the 8 M urea eluent with apparent molecular mass of approximately 210 and 47 kDa. In the absence of dithiothreitol, the two polypeptides migrate as one protein band with an apparent molecular mass of approximately 550 kDa. "Piglet," as this molecule is tentatively named, is present in retinal pigment epithelial and endothelial cells of several species, but could not be detected in the nonepithelial cells we examined. Immunofluorescent localization using an antibody to the 210-kDa polypeptide revealed a filamentous network in the cytoplasm of cultured cells. This antibody was used to identify a cDNA for piglet in a bovine aortic endothelial cell expression library. Sequence data indicate a high degree of identity with non-muscle myosin II heavy chain. We subsequently found that piglet had an actin-activated ATPase activity, colocalized with actin in cells, and reacted on Western blots with a pan-non-muscle myosin II heavy chain antiserum. The protein was also recognized by antibodies specific for myosin heavy chain isoform A, but did not react with anti-isoform B antibodies. Although piglet has several features in common with known forms of non-muscle myosin II, the distinctly unconventional features it displays suggest that it is a novel myosin.  相似文献   

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The colonial morphology and other cultural characteristics of Branhamella ovis were studied. The current investigation showed that colonies could be designated R (rough) and S (smooth) dependent on their appearance on agar. The colonial variants were apparently stable and each produced distinct types of pitting when grown on agar. A CAMP-like reaction was also shown to be a characteristic of B. ovis.  相似文献   

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To investigate the effect of neodymium (Nd) on Microcystis aeruginosa, the growth and physiological changes were studied by lab cultured experiments. The results showed that the content of chlorophyll a (Chl-a), soluble protein and the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased compared with the control (Nd3+-free), and the growth of M. aeruginosa was stimulated in the treatments of initial Nd3+ concentration ≤1 mg/L; while the treatments of initial Nd3+ concentration was in the range of 5.00-10.00 mg/L, the content of malondiadehyde (MDA) increased immediately but the activity of CAT reduced, which resulted in weakened M. aeruginosa’s ability to eliminate the active oxygen and the ruin of antioxidant defense system, and stunting the growth of M. aeruginosa. With the initial Nd3+ concentration of 50 mg/L, the growth of M. aeruginosa was totally stunted. The ultrastructure showed that excess Nd3+ could lead to the decrease of thylakoid and the increase of fat particle in cells of M. aeruginosa, and the cell membrane became rough and even broken, causing an irreversible damage to algal cells.  相似文献   

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