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1.
Jeremy D. Hogan Katharine M. Jack Fernando A. Campos Urs Kalbitzer Linda M. Fedigan 《American journal of primatology》2019,81(7)
Primates have long been used as indicator species for assessing overall ecosystem health. However, area‐wide census methods are time consuming, costly, and not always feasible under many field conditions. Therefore, it is important to establish whether monitoring a subset of a population accurately reflects demographic changes occurring in the population at large. Over the past 35 years, we have conducted 15 area‐wide censuses in Sector Santa Rosa, Costa Rica. These efforts have revealed important trends in population growth patterns of capuchin monkeys following the protection and subsequent regeneration of native forests. During this same period, we have also intensively studied a subset of the capuchin groups. Comparing these two datasets, we investigate whether the population structures of the closely monitored groups are reliable indicators of area‐wide demographic patterns. We compare the overall group size and the individual age/sex class compositions of study groups and nonstudy groups (i.e., those contacted during area‐wide censuses only). Our study groups contained more individuals overall with a larger proportion of infants, and there were indications that the proportion of adult and subadult males was lower. These differences can be ascribed either to sampling errors or real differences attributable to human presence and/or better habitat quality for the study groups. No other sex/age classes differed, and major demographic changes were simultaneously evident in both study and nonstudy groups. This study suggests that the Santa Rosa capuchin population is similarly impacted by large‐scale ecological patterns observable within our study groups. 相似文献
2.
This paper is concerned with gene survival in a population which may increase without density dependence according to a generalization of the Moran model for haploid individuals. A selective advantage to one allele and the possibility of differential reproductive rates are allowed. Simple conditions are given for ultimate homozygosity to be certain and for the possibility of ultimate polymorphism. The results complement and extend those of Heyde (1981, 1982). 相似文献
3.
JUN YOKOYAMA TATSUYA FUKUDA AKIKO YOKOYAMA MASAYUKI MAKI 《Botanical journal of the Linnean Society. Linnean Society of London》2002,138(3):369-380
Morphologically intermediate plants between Weigela hortensis (Siebold & Zucc.) K.Koch and W. maximowiczii (S.Moore) Rehder have been found in Miyagi and Yamagata Pref., northern Japan. Quantitative character analyses of flowers, pollen stainability and molecular analyses indicated that the intermediate plants were hybrids of those two species. This is the first record of an intersectional hybrid with W. maximowiczii (sect. Weigelastrum ) as one of the parent species. The morphological differences among hybrid individuals imply the possibility of backcrosses or formation of second or later generations of hybrids, although those may be quite rare because of a low frequency of viable pollen grains. Causes of hybridization between two distantly-related species in Weigela are discussed. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 369–380. 相似文献
4.
Minjuan Shen Mingli Lin Mengqi Zhu Wenxin Zhang Danyang Lu Huanhuan Liu Jingjing Deng Kehua Que Xu Zhang 《Biochimica et Biophysica Acta (BBA)/General Subjects》2019,1863(1):167-181
Since their discovery, matrix vesicles (MVs) containing minerals have received considerable attention for their role in the mineralization of bone, dentin and calcified cartilage. Additionally, MVs' association with collagen fibrils, which serve as the scaffold for calcification in the organic matrix, has been repeatedly highlighted. The primary purpose of the present study was to establish a MVs–mimicking model (PEG-S-ACP/micelle) in vitro for studying the exact mechanism of MVs-mediated extra/intra fibrillar mineralization of collagen in vivo. In this study, high-concentration serine was used to stabilize the amorphous calcium phosphate (S-ACP), which was subsequently mixed with polyethylene glycol (PEG) to form PEG-S-ACP nanoparticles. The nanoparticles were loaded in the polysorbate 80 micelle through a micelle self-assembly process in an aqueous environment. This MVs–mimicking model is referred to as the PEG-S-ACP/micelle model. By adjusting the pH and surface tension of the PEG-S-ACP/micelle, two forms of minerals (crystalline mineral nodules and ACP nanoparticles) were released to achieve the extrafibrillar and intrafibrillar mineralization, respectively. This in vitro mineralization process reproduced the mineral nodules mediating in vivo extrafibrillar mineralization and provided key insights into a possible mechanism of biomineralization by which in vivo intrafibrillar mineralization could be induced by ACP nanoparticles released from MVs. Also, the PEG-S-ACP/micelle model provides a promising methodology to prepare mineralized collagen scaffolds for repairing bone defects in bone tissue engineering. 相似文献
5.
Samples of marine pleuston were collected from the sea-surface along considerable sections of the track of Eye of the Wind during its 2-year circumnavigational expedition 'Operation Drake' from November 1978 to October 1980. One hundred and eleven of the tow samples contained insects of the genus Halobates . They were assigned to four oceanic species: H. micans, H. sericeus, H. germanus and H. splendens; two coastal species: H. maculatus, H. princeps, and one undescribed species. Various development stages of the oceanic species were found. The locations, time of collection and surface temperatures where sea-skaters were collected are tabulated. Distributional boundaries and population densities of the oceanic species collected are discussed. 相似文献
6.
T. J. Wojciechowski 《Biometrical journal. Biometrische Zeitschrift》1987,29(8):953-959
In this paper very simple nonparametric classification rule for mixtures of discrete and continuous random variables is described. It is based on the method of nearest neighbor proposed by Cover and Hart (1967). The bounds on the limit of the nearest neighbor rule risks are given. Both lower and upper bound depend on the Bayes risk and the loss function. Finally the method is compared with other existing methods on some practical data set. 相似文献
7.
《Molecular & cellular proteomics : MCP》2020,19(11):1767-1776
Highlights
- •N-glycan patterns are distinct in pediatric and adult urine.
- •Sex differences of N-glycans are much larger in adults.
- •Pediatric urine has almost no sex differences in N-glycan levels.
- •In adults, the majority of N-glycans were more abundant in males.
8.
D. Pangallo K. Chovanov H. Drahovska F. De Leo C. Urzì 《International biodeterioration & biodegradation》2009,63(7):868-872
The aim of this work was the evaluation of fluorescence ITS-PCR (f-ITS) as a molecular tool to analyze the microbial community involved in the biodeterioration of cultural heritage surfaces. As a case study we analyzed by f-ITS ninety-two bacterial strains isolated from a medieval fresco and the surrounding air environment. The internal transcribed spacer between the 16S and 23S rRNA genes was amplified, and then the fluorescently labeled PCR products were separated by capillary electrophoresis. Bacterial strains were identified by 16S rDNA sequencing. The f-ITS electropherograms showed different profiles coherent with the affiliation of the strains at the genus and species levels. Among the isolates obtained from the fresco surface, those belonging to the genus Bacillus were the most prevailing exhibiting 8 different f-ITS profiles. The airborne bacilli exhibited only 2 of these 8 profiles. Staphylococcus were mostly isolated from air and produced 4 different profiles. Pseudomonas isolates presented 3 different profiles, and one of them was typical of Pseudomonas putida. Members of the other genera produced their distinctive profiles. Our results show that f-ITS is a promising molecular tool for the rapid selection and clustering of strains isolated from different sources. 相似文献
9.
Adaptation of the tetrazolium method for testing the seed viability, and scanning electron microscopy study of some Western European orchids 总被引:3,自引:0,他引:3
A modified tetrazolium method was formulated for use with seeds of Western European orchids. The sequence of treatments which gave the highest percentage of coloured (i.e. viable) embryos was: (1) pretreatment in a solution of 5% (w/v) Ca(OCl)2 + 1% (v/v) Tween-80, (2) soaking for 1 day in sterile water, (3) the classical tetrazolium test. The optimal duration of the pretreatment in Ca(OCl)2 + Tween-80 depends upon the species, and to investigate the effect a scanning electron microscopy study was performed on the testa of 3 species. For a given species, the optimal pretreatment period was not affected by the year of harvest or the source of the seed lots. 相似文献
10.
Xiao‐Juan Yu Xiao‐Ren Peng Tong‐Huan Li 《Journal of cellular and molecular medicine》2014,18(12):2530-2535
Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta‐analysis were performed. The PubMed and CNKI database was searched for case‐control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild‐type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04–1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05–1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta‐analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians. 相似文献