The fate of Amazonian forest fragments: A 32-year investigation   总被引：2，自引：0，他引：2  

William F. Laurance  José L.C. Camargo  Regina C.C. Luizão  Susan G. Laurance  Stuart L. Pimm  Emilio M. Bruna  Philip C. Stouffer  G. Bruce Williamson  Julieta Benítez-Malvido  Heraldo L. Vasconcelos  Kyle S. Van Houtan  Charles E. Zartman  Sarah A. Boyle  Raphael K. Didham  Ana Andrade  Thomas E. Lovejoy 《Biological conservation》2011,(1):56-67

We synthesize findings to date from the world’s largest and longest-running experimental study of habitat fragmentation, located in central Amazonia. Over the past 32 years, Amazonian forest fragments ranging from 1 to 100 ha have experienced a wide array of ecological changes. Edge effects have been a dominant driver of fragment dynamics, strongly affecting forest microclimate, tree mortality, carbon storage, fauna, and other aspects of fragment ecology. However, edge-effect intensity varies markedly in space and time, and is influenced by factors such as edge age, the number of nearby edges, and the adjoining matrix of modified vegetation surrounding fragments. In our study area, the matrix has changed markedly over the course of the study (evolving from large cattle pastures to mosaics of abandoned pasture and regrowth forest) and this in turn has strongly influenced fragment dynamics and faunal persistence. Rare weather events, especially windstorms and droughts, have further altered fragment ecology. In general, populations and communities of species in fragments are hyperdynamic relative to nearby intact forest. Some edge and fragment-isolation effects have declined with a partial recovery of secondary forests around fragments, but other changes, such as altered patterns of tree recruitment, are ongoing. Fragments are highly sensitive to external vicissitudes, and even small changes in local land-management practices may drive fragmented ecosystems in markedly different directions. The effects of fragmentation are likely to interact synergistically with other anthropogenic threats such as logging, hunting, and especially fire, creating an even greater peril for the Amazonian biota.  相似文献   

Using BCG,MPT-51 and Ag85 as antigens in an indirect ELISA for the diagnosis of bovine tuberculosis     

Ediane Batista da Silva  Bruna Daniella de Souza Silva  Jerônimo Rafael Ruiz Leon  André Kipnis  Isabel K.F. de Miranda Santos  Ana Paula Junqueira-Kipnis 《Veterinary journal (London, England : 1997)》2011,187(2):276-278

This study evaluated the Mycobacterium tuberculosis protein antigen MPT-51, the trimeric antigen 85 (Ag85) complex, and Bacillus Calmette-Guérin (BCG) in an indirect ELISA to diagnose bovine tuberculosis (TB) from serum samples. Serum was collected from 208 intra-dermal tuberculin test (ITT)-positive and 54 ITT-negative animals from a region where bovine TB is endemic. Using the Ag85 and BCG antigens, the indirect ELISA was able to discriminate ITT-positive from ITT-negative animals. This level of discrimination was not achieved when using the MPT-51 antigen. The highest sensitivity (Se) and specificity (Sp) of the test was found when BCG was used (Se, 82%; Sp, 91%). Further work in different epidemiological settings and with larger numbers of animals will be required to validate these findings.  相似文献   

Interleukin-8 as a prognostic serum marker in canine mammary gland neoplasias     

Gelaleti GB  Jardim BV  Leonel C  Moschetta MG  Zuccari DA 《Veterinary immunology and immunopathology》2012,146(2):106-112

Mammary gland tumors in female dogs are an excellent model for the clinic-pathological, diagnostic and prognostic investigation of mammary neoplasias. Prognostic and predictive markers are effective in research and routine diagnosis. Interleukins play a fundamental role in cancer, with a particular function in tumor growth, invasion and metastatic potential. Interleukin-8 (IL-8) is known to possess tumorigenic and pro-angiogenic properties, and its overexpression is seen in a number of human tumors. IL-8 serum levels were determined and correlated with the clinic-pathological features and clinical evolution of mammary gland neoplasias in female dogs. IL-8 was measured by an immunoenzymatic assay in 30 female dogs with mammary neoplasias within a 12 month follow-up and in 50 control animals. The correlation between IL-8 concentration and clinical parameters was investigated. A statistically significant difference in the IL-8 serum levels was found in tumor-bearing dogs compared to the controls. In addition, when the individual parameters were evaluated, IL-8 content showed a positive correlation with the tumor progression, lymph node involvement, recurrence and death. Single and multivariate analyses showed associations between tumor recurrence, metastasis, high clinical staging and high IL-8, and also with the death risk. This was also consistent with the high IL-8 content in dogs showing tumor recurrence and metastasis. IL-8 superexpression has been detected in a number of human tumors, usually associated with a poor prognostic. Besides promoting angiogenesis, IL-8 is strongly related with the metastatic phenotype of mammary tumor cells. High IL-8 concentration was found in mammary gland cancer patients with advanced disease stages. Our results show that IL-8 can be used as a non-invasive prognostic marker for mammary gland cancer, and can be useful for the prediction of disease progression and recurrence in dogs with mammary neoplasias. The increased level of this cytokine acts as an independent prognostic marker of survival and the identification of animals with the poor prognostic.  相似文献   

Multiplex real-time PCR SYBR Green for detection and typing of group III Clostridium botulinum     

Anniballi F  Auricchio B  Delibato E  Antonacci M  De Medici D  Fenicia L 《Veterinary microbiology》2012,154(3-4):332-338

Clostridium botulinum type C and type D belonging to the group III organisms, are mainly responsible for animal botulism outbreaks. Clinical signs alone are often insufficient to make a diagnosis of botulism and a laboratory confirmation is required. Laboratory confirmation can be performed by demonstrating the presence of botulinum neurotoxins in serum, gastrointestinal contents, liver, wound of sick or dead animals, or by demonstrating the presence of C. botulinum in gastrointestinal contents, liver, and wound. Demonstration of spores in gastrointestinal contents or tissue of animals with clinical signs indicative of botulism reinforces the clinical diagnosis. With the aim of detecting and typing C. botulinum group III organisms, a multiplex real-time PCR SYBR Green was developed and in-house validated. Selectivity, limit of detection, relative accuracy, relative specificity, relative sensitivity, and repeatability of the method were investigated. The multiplex real-time PCR SYBR green used showed a 100% selectivity, 100% relative accuracy, 100% relative specificity, 100% relative sensitivity and a limit of detection of 277 and 580 DNA copies for C. botulinum type C and C. botulinum type D, respectively. The method reported here represents a suitable tool for laboratory diagnosis of type C and D botulism and for testing a large number of samples collected during the animal botulism surveillance and prevention activities.  相似文献   

A fast quantitative identification algorithm of colorimetric visual-sensor-array based on basic units matching          下载免费PDF全文

LUO Xiaogang  LIU Jingjing  HOU Changjun  HUO Danqun  FA Huanbao  YANG Mei 《保鲜与加工》2013,(10):89-93

There are many difficulties to process a colorimetric visual-sensor-array by traditional processing methods, such as complicated manual analysis due to many data and hard to finish varieties and concentrations identification simultaneously, etc. In view of colorimetric-sensor-array’s same location response to the same gas, a fast quantitative identification algorithm of colorimetric visual-sensor-array based on basic units matching which can solve these problems is proposed. First, denoising and feature extraction are processed by setting experienced threshold to reduce redundancies and lessen manual analysis. Second, a creative qualitative analysis method based on basic units is put forward, which not only reduces computation, but also increases efficiency and precision. Finally, a ANFIS of NH3 concentration recognition utilizing advantages of fuzzy logic and neural network is used to distinguish low concentration NH3. The advantage of this algorithm is that varieties and concentrations of different gases could be detected successively, solving the problem of recognition errors caused by characteristic data infection when varieties and concentrations of different gases are detected simultaneously.The results of template matching based on basic units show that the classification accuracy of NH3, Cl2 and SO2 are 100%. The low concentration NH3 classification accuracy is also very high after species identification with measurement errors below 5%.  相似文献   

Induction of phase II enzymes and hsp70 genes by copper sulfate through the electrophile-responsive element (EpRE): insights obtained from a transgenic zebrafish model carrying an orthologous EpRE sequence of mammalian origin     

Daniela Volcan Almeida  Bruna Félix da Silva Nornberg  Laura A. Geracitano  Daniela Martí Barros  José Maria Monserrat  Luis Fernando Marins 《Fish physiology and biochemistry》2010,36(3):347-353

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Anabolism,catabolism and proteomic analysis in the slow‐twitch muscle of pacu (Piaractus mesopotamicus) submitted to prolonged fasting followed by refeeding     

Maria Laura Gabriel Kuniyoshi  Rafaela Nunes da Silva‐Gomes  Bruna Tereza Thomazini Zanella  Lucilene Delazari dos Santos  Maeli Dal‐Pai‐Silva 《Aquaculture Research》2020,51(3):1101-1112

Here, we aimed to study the slow muscle of the fish Piaractus mesopotamicus submitted to 30 days of fasting (D30) followed by 1 day (D31) or 30 days of refeeding (D60). Histological analysis of fibre diameter was performed in D30 and D60. The gene expression of parvalbumin (pvalb), atrogenes (murf1a, murf1b, mafbx) and anabolic genes (igf‐1, mtor) was analysed using RT‐qPCR in D30, D31 and D60. The proteome was obtained by shotgun proteomics at D30 and D60, and the set of differentially expressed proteins was analysed by bioinformatics. In all experiments, the control was regularly fed fish. The histological analysis showed no changes in muscle fibre diameter. The expression of catabolic and anabolic genes was not changed, except for the downregulation of igf‐1 in D30 and of mafbx in D31. The expression of pvalb was not changed in D30 and D60 but was decreased in D31. The proteomic analysis identified 169 proteins in D30 (24 upregulated and 18 downregulated) and 170 proteins in D60 (17 upregulated and 21 downregulated); many of them were related to energetic metabolism and intracellular Ca²⁺ homoeostasis. Overall, our results indicate that the slow‐twitch muscle presented few changes upon prolonged fasting and refeeding condition.  相似文献   

种间关系对中条山油松人工林天然更新及群落稳定性的影响          下载免费PDF全文

裴顺祥  法蕾  杜满义  郭嘉  辛学兵 《林业科学研究》2022,35(1):150-157

[目的]为了揭示种间关系对中条山油松人工林天然更新及群落稳定性的影响,为油松人工林经营管理提供理论依据.[方法]基于中条山油松人工林群落样地调查数据,分析油松人工林下主要植物的种间关联性、生态位重叠及群落稳定性,并在此基础上探讨种间关联和生态位理论在油松人工林天然更新障碍及群落稳定性形成机制中的作用.[结果]中条山油松...  相似文献   

Leucocyte profile and growth rates as indicators of crowding stress in pejerrey fingerlings (Odontesthes bonariensis)          下载免费PDF全文

Yuri Dornelles Zebral  Bruna Zafalon‐Silva  Mabel Wiegand Mascarenhas  Ricardo Berteaux Robaldo 《Aquaculture Research》2015,46(9):2270-2276

Crowding is one of the most common stressors found in intensive aquaculture, compromising growth rates and immune function. Plasmatic cortisol is a classic stress biomarker for fish, but its quantification is expensive and demands blood volumes that small individuals do not provide, constraining the usage of this technique to assess stress in fingerlings. The leucocyte profile is an alternative methodology to quantify stress with reduced costs and volumes of blood. Stress conditions promote neutrophilia and lymphocytopenia as response to elevated glucocorticoids levels. Considering the difficulties to assess stress imposed by intensive fish farming using measurement of glucocorticoid hormones, this study aimed to evaluate the stress‐induced changes in leucocyte profiles and growth rates imposed by crowding in fingerlings of Odontesthes bonariensis, a promising South‐American candidate for freshwater aquaculture. To meet these objectives, fingerlings (initial weight 0.05 ± 0.06 g and length 1.68 ± 0.13 cm) were reared for 45 days under three rearing densities (1, 5 and 10 fingerlings L^?1). At the end of this period, fish were anaesthetized and euthanized to obtain the leucocyte profile, neutrophil:lymphocyte ratio (N:L) and growth rate. Increasing density promoted: significant reduction in growth (final length, weight and specific growth rate); neutrophilia and lymphocytopenia; and increased N:L ratio. Concluding, the tested rearing densities imposed distinct levels of stress characterized by different N:L ratio, demonstrating that the leucocyte profile is a reliable alternative to measure stress levels in O. bonariensis fingerlings and probably in other fish species.  相似文献   

Uterine adenomyosis in an orang-utan (Pongo abelii/pygmaeus)     

KJ Graham  FA Hulst  L Vogelnest  IS Fraser  CM Shilton 《Australian veterinary journal》2009,87(1-2):66-69

A 48-year-old, multiparous, female hybrid orang-utan ( Pongo abelii/pygmaeus ) was investigated after a 3-year history of irregular and excessively heavy menstrual bleeding. Opportunistic pelvic examinations over a 2.5-year period were non-diagnostic. Medical therapy was not effective. A subtotal hysterectomy with bilateral salpingo-ovariectomy was performed. A pedunculated mass spanning 90% of the uterine lumen was seen grossly, and histopathology confirmed uterine adenomyosis. Adenomyosis is defined as the ectopic occurrence or diffuse implantation of endometrial tissue, including glands and stroma, into the myometrium. It is common in older, usually premenopausal, multiparous women and is frequently associated with other uterine pathology, including endometrial hyperplasia and leiomyomas. The most common clinical signs are dysmenorrhoea and heavy menstrual bleeding; however, up to 35% of women are asymptomatic. Diagnosis is difficult and requires myometrial sampling and an experienced pathologist. A hysterectomy in this case was diagnostic and curative. There have been few reports of uterine adenomyosis in non-human primates and none reported in an orang-utan. Uterine adenomyosis should be considered in the differential diagnosis in any multiparous, aged, non-human female primate with irregular and excessively heavy menstrual bleeding, and hysterectomy with bilateral salpingo-ovariectomy is recommended as a diagnostic and therapeutic solution.  相似文献