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81.
Mariano de Miguel Artal Olga Roca Chacón Montse Martínez-Alonso Marcos Serrano Godoy Jaume Mas Atance Roberto García Gutiérrez 《Revista espa?ola de geriatría y gerontología》2018,53(5):247-254
Objective
The aim of this study is to identify the risks factors for mortality and functional recovery in elderly patients admitted to hospital with a hip fracture.Materials and methods
Longitudinal prospective study in patients 80 years old or more and patients between 75 and 79 in residential home care with a hip fracture and with a past medical history of dementia or followed-up by the Geriatric Unit. A total of 359 patients were included, and the demographic data, previous functional status, comorbidity, type of fracture, and dementia were recorded. The data collected during admission included time to surgery, delirium, functional recovery, length of stay, placement at discharge, and mortality. Patients were followed-up for one year and details were collected on placement at the end of follow-up, functional recovery, medical complications, and mortality.Results
The baseline characteristics of the patients with a strong association with mortality after a hip fracture were old age (> 92 years), medical complications delaying surgery (HR 2.17; 95% CI; 1.27-3.73), diagnosis of dementia (HR 1.78; 95% CI; 1.15-2.75), or heart failure (HR 1.75; 95% CI; 1.12-2.75). The fitted multivariable regression models showed that functional impairment before the hip fracture or lack of functional recovery are associated with higher mortality, and patients with increased age, delirium, dementia, and previous functional impairment showed worse functional recovery.Conclusion
In the elderly patients with a hip fracture, increased age, comorbidity and previous functional status is associated with mortality. Functional recovery prognosis will depend on age, previous functional status, past medical history of dementia, and the presence of delirium during admission. 相似文献82.
Mayumi Fujiwara Nonio Nagao Kazuaki Monden Masashi Misumi Katsuhiro Kageyama Kiyotaka Yamamoto Nobuhiko Miwa 《Free radical research》1997,27(1):97-104
Bovine aortic endothelial BAE-2 cells exposed to the peroxidizing agent, tert-butylhydroperoxide (t-BuOOH) or 2,4-nonadienal (NDE), suffered from disruption of cell membrane integrity and from reduction of mitochondrial dehydrogenase activity as assessed by fluorometry using ethidium homodimer and photometry using WST-1, respectively. The cells were protected from t-BuOOH-induced injury more markedly by L-ascorbic acid-2-O-phosphate (Asc2P) stably masked at the 2,3-enediol moiety, which is responsible for the antioxidant ability of L-ascorbic acid (Asc), than by Asc itself. In contrast, NDE-induced membrane disruption but not mitochondrial dysfunction was prevented by Asc2P, whereas Asc exhibited no prevention against both types of injury. The amount of intracellular Asc was 7.2- to 9.0-fold larger in Asc2P-administered BAE-2 cells, where the intact form Asc2P was not detected, than in Asc-administered cells as assessed by HPLC of cell extract with detection by coulometric ECD and W. During transmembrane influx into the cell, Asc2P was concentrated as highly as 70- to 90-fold relative to the extracellular Asc2P concentration, whereas Asc was 8-to 13-fold concentrated as estimated based on an intracellular water content of 0.59 pL/cell determined by [14C]PEG/gas chromatography. Thus, Asc2P but not Asc is highly concentrated in the aqueous phase of the cell after prompt dephosphorylation, and may thereby render the cell more resistant to t-BuOOH-peroxidation assumedly via scavenging of intracellular reactive oxygen species than to peroxidation with the less hydroplulic agent NDE. 相似文献
83.
Abstract. Aesculus turbinata is a tree species with large seeds (6.2 g mean dry weight). We studied the demography of its seeds and seedlings in a temperate deciduous forest in northern Japan to elucidate the ecological significance of large seeds with special reference to herbivory and secondary dispersal. Both seed and seedling stages suffered greatly from herbivores. Seedling herbivory was important judged from experiments with shoot clipping and hypogeal cotyledon removal. However, some seedlings survived through re-sprouting after herbivory. Survival rate and percentage resprouting seedlings were lower than those with remaining cotyledons, though seedling size was not affected. This suggests that stored resources in hypogeal cotyledons are working as a kind of ‘risk hedge’ against severe aboveground shoot clipping experienced by A. turbinata. The spatial distribution of seedlings was expanded via seed scatter-hoarding by rodents. Seedling survival rate was higher within canopy gaps than under closed canopy, indicating that canopy gaps are safe sites for establishment, and was negatively correlated with seedling density. Therefore, secondary seed dispersal in this species seems to be effective in ‘finding’ safe sites and in ‘escaping’ density-dependent mortality. The large seeds and seedlings of A. turbinata are attractive to herbivores, but the high resistance of seedlings to herbivory due to large reserves and the effective secondary dispersal appear to mitigate these disadvantages. 相似文献
84.
M. K. Mukerji 《Population Ecology》1973,15(2):50-63
Summary The relationship of ‘mean crowding’ to mean density showed that counts of nymphs and adults of the tarnished plant bug,Lygus lineolaris (Beauv.), on birdsfoot trefoil were aggregated and that the index of basic contagion approached zero for each developing stage. Aggregation
increased gradually from the first to the fourth instar and then decreased through the adult stage. The mortality process
from the first to the fifth instar was inversely density dependent.
Inter-sample variance was the major source of population variance although significant variance was occasionally associated
with blocks and plots owing to heterogeneity of the host stand. The most appropriate sample unit was a 3 sq. ft. area of foliage
and substrate. This was divided into four quarters; application of the variance component technique indicated that in most
cases one quarter drawn at random was optimal for sampling different stages. The number of samples required to attain a given
level of precision varied inversely with population density. The cost function for sampling was determined for specified levels
of precision. 相似文献
85.
Akio Hagihara 《Population Ecology》1999,41(2):151-159
A model for describing the competition–density (C-D) effect in self-thinning populations was developed on the basis of the
following three basic assumptions: (1) the growth of mean phytomass follows a general logistic equation; (2) final yield is
independent of initial population density; and (3) there exists a functional relationship between actual and initial population
densities at any given time. The resultant equation takes the same reciprocal form as the reciprocal equation of the C-D effect
derived from Shinozaki–Kira's theory (i.e., the logistic theory of the C-D effect), which deals with the density effect in
nonself-thinning populations. However, one of the two time-dependent coefficients is quite different in mathematical interpretation
between the two reciprocal equations. The reciprocal equation for self-thinning populations is essentially the same as the
reciprocal equation assumed in the derivation of the functional relationship between actual and initial population densities.
The establishment of the reciprocal equation is supported by the empirical facts that the reciprocal relationship between
mean phytomass and population density is discernible in not only nonself-thinning populations but also in self-thinning populations.
The present model is expected to systematically interpret underlying mechanisms between the C-D effect, which is observed
at a time constant among populations with various initial densities, and self-thinning, which is observed along a time continuum
in a given population.
Received: August 5, 1998 / Accepted: January 7, 1999 相似文献
86.
The population density of herbivores depends on the spatial scale as well as the temporal scale. In a small-scale, short-term
experiment, the number of individuals entering from the surrounding area will be most influential in determining the herbivore
density. In large-scale, long-term experiments, however, the density of herbivores will rather be influenced by the survival
rate of individuals inside the field because most of the herbivorous population derives from the parents that developed inside
the field. If we want to predict the large-scale long-term density of herbivores, therefore, emphasis should be placed on
the estimation of survival rate. To elucidate the effects of plant density on the large-scale long-term abundance of cabbage
pests, we examined the survival rates of three lepidopterous pests, the small white butterfly Pieris rapae crucivora Boisduval (Pieridae), the beet semi-looper Autographa nigrisigna (Walker) (Noctuidae), and the diamondback moth Plutella xylostella (Linnaeus) (Yponomeutidae) under two levels of plant spacing (sparse plot, 2 m × 2 m interval; dense plot, 0.5 m × 0.5 m
interval). The experiment with four blocks was repeated in two seasons. The number of eggs per plant was larger in the sparse
plots than in the dense plots for all species. The survival rate of eggs and larvae, on the contrary, was lower in the sparse
plots than in the dense plots. The lower survival rate of eggs in the sparse plots was mainly caused by the density dependency,
while the lower survival rate of larvae in the sparse plots was mainly caused by the direct effects of plant density. It was
thus suggested that the density of herbivores may become lower in the sparsely planted field in the long run because of the
higher mortality of larvae.
Received: September 16, 1998 / Accepted: March 22, 1999 相似文献
87.
A small-scale, “no-use zone policy” has been implemented since 1992 at Eilat’s Coral Nature Reserve (Northern Red Sea). Six
years later, the status of this closed-to-the-public reef area was compared to two nearby open-to-the-public sites, by evaluating
populations of the scleractinian coral Stylophora pistillata in the strolling zone (0.5–1.5 m depth). Results from the open sites show that: (1) Live coral cover was three times lower
than at the closed site; (2) numbers of small colonies (recruits) were significantly higher than in the closed site, while
numbers of medium and large size colonies (geometric mean radius, rˉ>4.1 cm) per m2 were significantly lower; (3) maximum rˉ was almost half than that in the closed site (9.6 cm versus 16.7 cm); (4) average number of broken colonies was three times
higher than in the closed site; (5) significantly fewer colonies were partially dead. The latter result may reflect senescence
processes in the large colonies of the closed site. Although colony breakage is reduced, it appears that the “no-use zone”
policy is not sufficient for protecting small reef areas. The intense exploitation of Eilat’s coral reef by the tourist industry
requires’ in addition to the conventional protective measures, the initiation of novel management solutions such as reef restoration
by sexual and asexual recruits.
Accepted: 11 August 1999 相似文献
88.
普氏野马(Equus przewalskii)和野驴(Equus hemionus)是许家窑遗址动物群中的优势属种。本文基于对这两种动物牙齿材料的测量与分析,确定了遗址中马科动物的死亡年龄,并对上、下文化层的死亡年龄分布进行了研究,以期探知古人类获取肉食资源的方式与特点。通过与马科动物在自然生存状态下以及死于不同原因(如疾病或营养衰竭、食肉动物猎杀、现代人类狩猎等)的年龄结构对比,结果表明:古人类在许家窑文化早期(下文化层)可能通过捡拾自然死亡的动物尸体、与食肉类动物抢夺猎物、主动狩猎等多种方式获取马科动物,而在许家窑文化晚期(上文化层)可能以主动狩猎作为获取马科动物的主要方式。此外,古人类在遗址的早期就可能已经具有捕获整个马科动物居群中任意年龄个体的能力,并能做出最优化判断,有选择地去捕猎脂肪和肉量较高的壮年动物群体。 相似文献
89.
The effects of powders from dry flower buds of Eugenia aromatica Baill., seeds of Piper guineense Schum and Thonn and fruits of Capsicum frutescens L. on adult behaviour, mortality and reproductive fitness of the cowpea seed beetle, Callosobruchus maculatus (Fab.) were investigated under ambient laboratory conditions. All experiments were carried out in glass Petri plates. All powders elicited aversion in adult beetles. The contact toxicity symptoms included restlessness, loss of coordination, knock down and eventual death of adult beetles. These behaviours were more pronounced with E. aromatica in which adult beetles died within 16 hours. P. guineense and C. frutescens powders did not cause 100% mortality of adult beetles, even after 24 hours. Each of the three powders significantly (P 〈 0.05) reduced the mating competition of adult males after sub-lethal exposure for one, two, and three hours, respectively. E. aromatica powder caused more reduction in male mating competition for females than any of the other two powders after each period of exposure. Receptiveness of treated females to courting males was also decreased by exposure to any of the three powders. Similarly, E. aromatica powder caused greater decreases in female receptiveness to males than any of the other two powders after each period of exposure. Exposure of either adult male or female C. maculatus to the powders for sub-lethal times of three, six and nine hours significantly reduced the fecundity of the beetles. E. aromatica powder caused the most reduction of eggs laid and also significantly reduced fertility of the eggs. 相似文献
90.
Biscuits are flour-based products,which areconsumed by majority of people,both old and young,throughout the world and most especially by children,teenagers and mid-adults(Majumder,1970).It can beserved as a desert or snacks and as a breakfast foodwhentaken with beverages.Its ready-to-serve state andlong shelf life contribute to its acceptability by themasses.Wheat as humanfoodis used principallyintheformof flour for baked products such as bread,bis-cuits,pastries and crackers(Kent,1983).In th… 相似文献