共查询到20条相似文献,搜索用时 203 毫秒
1.
Erin Henry Luca Santini Mark A. J. Huijbregts Ana Benítez-López 《Global Ecology and Biogeography》2023,32(2):267-280
Aim
Whether intraspecific spatial patterns in body size are generalizable across species remains contentious, as well as the mechanisms underlying these patterns. Here we test several hypotheses explaining within-species body size variation in terrestrial vertebrates including the heat balance, seasonality, resource availability and water conservation hypotheses for ectotherms, and the heat conservation, heat dissipation, starvation resistance and resource availability hypotheses for endotherms.Location
Global.Time period
1970–2016.Major taxa studied
Amphibians, reptiles, birds and mammals.Methods
We collected 235,905 body size records for 2,229 species (amphibians = 36; reptiles = 81; birds = 1,545; mammals = 567) and performed a phylogenetic meta-analysis of intraspecific correlations between body size and environmental variables. We further tested whether correlations differ between migratory and non-migratory bird and mammal species, and between thermoregulating and thermoconforming ectotherms.Results
For bird species, smaller intraspecific body size was associated with higher mean and maximum temperatures and lower resource seasonality. Size–environment relationships followed a similar pattern in resident and migratory birds, but the effect of resource availability on body size was slightly positive only for non-migratory birds. For mammals, we found that intraspecific body size was smaller with lower resource availability and seasonality, with this pattern being more evident in sedentary than migratory species. No clear size–environment relationships were found for reptiles and amphibians.Main conclusions
Within-species body size variation across endotherms is explained by disparate underlying mechanisms for birds and mammals. Heat conservation (Bergmann's rule) and heat dissipation are the dominant processes explaining biogeographic intraspecific body size variation in birds, whereas in mammals, body size clines are mostly explained by the starvation resistance and resource availability hypotheses. Our findings contribute to a better understanding of the mechanisms behind species adaptations to the environment across their geographic distributions. 相似文献2.
Telomere length determined by the fluorescence in situ hybridisation distinguishes malignant and benign cells in cytological specimens
下载免费PDF全文
![点击此处可从《Cytopathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Y. Matsuda A. Suzuki S. Esaka Y. Hamashima M. Imaizumi M. Kinoshita H. Shirahata Y. Kiso H. Kojima M. Matsukawa Y. Fujii N. Ishikawa J. Aida K. Takubo T. Ishiwata M. Nishimura T. Arai 《Cytopathology》2018,29(3):262-266
Background
Telomeres are tandem repeats of TTAGGG at the end of eukaryotic chromosomes that play a key role in preventing chromosomal instability. The aim of the present study is to determine telomere length using fluorescence in situ hybridisation (FISH) on cytological specimens.Methods
Aspiration samples (n = 41) were smeared on glass slides and used for FISH.Results
Telomere signal intensity was significantly lower in positive cases (cases with malignancy, n = 25) as compared to negative cases (cases without malignancy, n = 16), and the same was observed for centromere intensity. The difference in DAPI intensity was not statistically significant. The ratio of telomere to centromere intensity did not show a significant difference between positive and negative cases. There was no statistical difference in the signal intensities of aspiration samples from ascites or pleural effusion (n = 23) and endoscopic ultrasound‐guided FNA samples from the pancreas (n = 18).Conclusions
The present study revealed that telomere length can be used as an indicator to distinguish malignant and benign cells in cytological specimens. This novel approach may help improve diagnosis for cancer patients. 相似文献3.
4.
Jun Nagano Chikage Kakuta Chikako Motomura Hiroshi Odajima Nobuyuki Sudo Sankei Nishima Chiharu Kubo 《BioPsychoSocial medicine》2010,4(1):12
Objective
To examine relationships between a mother's stress-related conditions and parenting attitudes and their children's asthmatic status. 相似文献5.
A meta‐analysis of the association between Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum
下载免费PDF全文
![点击此处可从《Helicobacter》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Qin Xiang Ng Nandini Venkatanarayanan Michelle Lee Zhi Qing De Deyn Collin Yih Xian Ho Yin Mo Wee‐Song Yeo 《Helicobacter》2018,23(1)
Background
Hyperemesis gravidarum remains a common, distressing, and significant yet poorly understood disorder during pregnancy. The association between maternal Helicobacter pylori (H. pylori) infection and hyperemesis gravidarum has been increasingly recognized and investigated. This study thus aimed to provide an updated review and meta‐analysis of the topic.Methods
Using the search terms (H. pyloriOR Helicobacter ORHelicobacter pyloriOR infection) AND (pregnancy OR emesis OR hyperemesis gravidarum OR nausea OR vomiting), a preliminary search on the PubMed, Ovid, Web of Science, Google Scholar, and WanFang database yielded 372 papers published in English between January 1st, 1960 and June 1st, 2017.Results
A total of 38 cross‐sectional and case‐control studies, with a total of 10 289 patients were eligible for review. Meta‐analysis revealed a significant association between H. pylori infection and hyperemesis gravidarum during pregnancy, with a pooled odds ratio of 1.348 (95% CI: 1.156‐1.539, P < .001). Subgroup analysis found that serologic and stool antigen tests were comparable methods of detecting H. pylori as they yielded similar odds ratios.Limitations
Although the studies did not have high heterogeneity (I2 = 28%), publication bias was observed, and interstudy discrepancies in the diagnostic criteria adopted for hyperemesis gravidarum limit the reliability of findings. Also, 15 of the included studies were from the same country (Turkey), which could limit the generalizability of current findings. The prevalence of H. pylori infection varies throughout the world, and there may also be pathogenic differences as most strains of H. pylori in East Asia carry the cytotoxin‐associated gene A gene.Conclusion
H. pylori infection was associated with an increased likelihood of hyperemesis gravidarum during pregnancy. Given the high prevalence of H. pylori infections worldwide, detecting H. pylori infection and the eradication of maternal H. pylori infection could be part of maternal hyperemesis gravidarum management. Further confirmation with robust longitudinal studies and mechanistic investigations are needed. 相似文献6.
Shift from facilitative to neutral interactions by the cushion plant Silene acaulis along a primary succession gradient
下载免费PDF全文
![点击此处可从《植被学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Background
The stress‐gradient hypothesis predicts a shift from facilitative to competitive plant interactions with decreasing abiotic stress. This has been supported by studies along elevation and temperature gradients, but also challenged by the hypothesis of a facilitation collapse at extremely harsh sites. Although facilitation is known to be important in primary succession, few studies have examined these hypotheses along primary succession gradients.Aim
To examine whether there is a relationship between the presence of the circumpolar cushion plant Silene acaulis and other species, and if so, whether there is a shift between positive and negative interactions along a primary succession gradient in a glacier foreland.Location
Finse, southern Norway.Methods
We examined the performance of the common alpine forb Bistorta vivipara, species richness of vascular plants, bryophytes and lichens, and the number of seedlings and fertile vascular plants in S. acaulis cushions, and control plots without S. acaulis, along a succession gradient with increasing distance from a glacier front, and thus decreasing abiotic stress. To examine if S. acaulis cushions modify the abiotic environment, we recorded soil temperature, moisture, organic content and pH in cushions and control plots.Results
Bistorta vivipara performed better, as shown by bigger leaves in S. acaulis cushions compared to control plots in the harshest part of the gradient close to the glacier. There were few differences in B. vivipara performance between cushion and control plots in the more benign environment further away from the glacier. This suggests a shift from facilitative to mainly neutral interactions by S. acaulis on the performance of B. vivipara with decreasing abiotic stress. A trend, although not significant, of higher vascular species richness and fertility inside S. acaulis cushions along the whole gradient, suggests that S. acaulis also facilitates community‐level species richness. The causal mechanism of this facilitation is likely that the cushions buffer extreme temperatures.Conclusions
Our results support the stress‐gradient hypothesis for the relationship between the cushion plant S. acaulis and the performance of a single species along a primary succession gradient in a glacier foreland. S. acaulis also tended to increase vascular plant species richness and fertility regardless of stress level along the gradient, suggesting facilitation at the community level. We found no collapse of facilitation at the most stressful end of the gradient in this alpine glacier foreland. 相似文献7.
Cortical beta EEG oscillations related to changes in muscle tone activity during sleep in spider monkey (Ateles geoffroyi)
下载免费PDF全文
![点击此处可从《Journal of medical primatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Manuel Alejandro Cruz‐Aguilar Miguel Angel Guevara Marisela Hernández‐González Ignacio Ramírez‐Salado Enrique Hernández‐Arteaga Fructuoso Ayala‐Guerrero 《Journal of medical primatology》2018,47(1):67-74
Background
The physiological mechanisms that allow for sleeping in a vertical position, which is primordial for arboreal primates, have not been studied yet.Methods
A non‐invasive polysomnographic study of 6 spider monkeys (Ateles geoffroyi) was conducted. The relative beta power of the motor cortex and its linear relation with muscle tone in the facial mentalis muscle and the abductor caudae medialis muscle of the tail during wakefulness and sleep stages were calculated.Results
A strong negative linear relationship (r = ?.8, P = .03) was found between the relative power of the beta2 band in the left motor cortex and abductor caudae medialis muscle tone during delta sleep.Conclusions
The left motor cortex, through beta2 band activity, interacts with abductor caudae medialis muscle tonicity during delta sleep. This interaction takes part in the mechanisms that regulate the sleep postures. 相似文献8.
Aims
An extra‐long‐range quantitative PCR (LR‐qPCR) method was developed for estimating genome damage to adenovirus 2 caused by UV irradiation. The objective was to use LR‐qPCR as a rapid method to determine adenovirus UV inactivation.Methods
The LR‐qPCR consisted of two steps: a long‐range PCR (up to 10 kb fragment) and a real‐time, quantitative (q) PCR for quantifying the products of the first PCR. We evaluated LR‐qPCR with adenovirus irradiated with medium‐pressure (MP, polychromatic emission) and low‐pressure (LP, 254 nm) mercury vapour lamps and compared results with cell culture infectivity.Results
Using LR‐qPCR, a fragment of 6 kb estimated DNA damage in a linear relationship to doses between 0 and 20 mJ cm?2, and a 1‐kb fragment related linearly to doses between 20 and 100 mJ cm?2. The LR‐qPCR results for the 6‐kb fragment were similar to infectivity assays results for adenovirus exposed to MP UV. For adenovirus irradiated with LP lamps, LR‐qPCR results for the shorter fragment size (1 kb) were similar to reduction in viral infectivity. No difference was observed between 10 and 6 kb LR‐qPCR results.Conclusion
The LR‐qPCR can be used as a tool for estimating DNA damage caused by UV in adenovirus. The LR‐qPCR results were related to reduction in viral infectivity.Significance and Impact of the Study
The use of LR‐qPCR to determine DNA damage and estimate inactivation of adenovirus 2 from UV disinfection allows for same‐day results compared with >7 days required for cell culture. This accelerates adenovirus inactivation results for the water industry where adenovirus is used as a representative virus for crediting UV systems. This PCR approach provides a framework that can be used for other viral viability assays using the inhibition of amplification of viral nucleic acid after pretreatments, such as propidium monoazide, and for cellular biology studies of DNA damage. 相似文献9.
10.
Kim Kultima Birger Scholz Henrik Alm Karl Sköld Marcus Svensson Alan R Crossman Erwan Bezard Per E Andrén Ingrid Lönnstedt 《BMC bioinformatics》2006,7(1):475-27
Background
Two-Dimensional Difference In Gel Electrophoresis (2D-DIGE) is a powerful tool for measuring differences in protein expression between samples or conditions. However, to remove systematic variability within and between gels the data has to be normalized. 相似文献11.
REACH and LCA—methodological approaches and challenges 总被引:1,自引:0,他引:1
Cecilia Askham 《The International Journal of Life Cycle Assessment》2012,17(1):43-57
Purpose
This paper discusses issues associated with the research question: What are the similarities and differences between the REACH and life cycle assessment (LCA) approaches, and how can synergies between these two approaches be exploited to achieve environmental improvements in a holistic perspective? 相似文献12.
Miranda L Davies-Tuck Anita E Wluka Andrew Forbes Yuanyuan Wang Dallas R English Graham G Giles Richard O'Sullivan Flavia M Cicuttini 《Arthritis research & therapy》2010,12(1):R10
Introduction
To examine the relationship between development or resolution of bone marrow lesions (BMLs) and knee cartilage properties in a 2 year prospective study of asymptomatic middle-aged adults. 相似文献13.
Background
The mechanism by which the signals are transmitted between receptor and effector domains in multi-domain signaling proteins is poorly understood. 相似文献14.
Rune B Leistad Trond Sand Kristian B Nilsen Rolf H Westgaard Lars Jacob Stovner 《BMC neurology》2007,7(1):23
Background
The purpose of this study was to investigate the temporal relationship between autonomic changes and pain activation in migraine and tension-type headache induced by stress in a model relevant for everyday office-work. 相似文献15.
Background
Constipation and diarrhoea are common complaints and often reported as adverse drug reactions. This study aimed at finding associations between drugs and constipation and diarrhoea in a general population. 相似文献16.
Background
Dynamic cerebral autoregulation after intracerebral hemorrhage (ICH) remains poorly understood. We performed a case-control study to compare dynamic autoregulation between ICH patients and healthy controls. 相似文献17.
Takehiro Nozaki Chihiro Morita Sunao Matsubayashi Koich Ishido Hiroaki Yokoyama Keisuke Kawai Masahiro Matsumoto Masato Takii Chiharu Kubo 《BioPsychoSocial medicine》2009,3(1):1-8
Background
This cross-sectional and prospective study used a variety of psychological inventories to evaluate the relationship between psychosocial factors and the glycemic control of patients with type 2 diabetes. 相似文献18.
Nadir Alvarez Betty Benrey Martine Hossaert-McKey Andrea Grill Doyle McKey Nicolas Galtier 《Biology direct》2006,1(1):21-11
Background
We report on the probable horizontal transfer of a mitochondrial gene, cytb, between species of Neotropical bruchid beetles, in a zone where these species are sympatric. 相似文献19.
Background
Integrin-linked kinase (ILK) is a ubiquitously expressed protein kinase that has emerged as one of the points of convergence between integrin- and growth factor-signalling pathways. 相似文献20.
L.J. Pletinckx J. Dewulf Y. De Bleecker G. Rasschaert B.M. Goddeeris I. De Man 《Journal of applied microbiology》2013,114(6):1634-1641