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51.
52.
Mingshi Li Chengquan Huang Wenjuan Shen Xinyu Ren Yingying Lv Jingrui Wang Zhiliang Zhu 《林业研究》2016,27(6):1329-1341
Forest losses or gains have long been recognized as critical processes modulating the carbon flux between the biosphere and the atmosphere. Timely, accurate and spatially explicit information on forest disturbance and recovery history is required for assessing the effectiveness of existing forest management. The major objectives of our research focused on testing the mapping efficacy of the vegetation change tracker (VCT) model over a forested area in China. We used a new version of VCT algorithm built upon the Landsat time series stacks (LTSS). The LTSS consisted of yearly image acquisitions to map forest disturbance history from 1987 to 2011 over the Ning-Zhen Mountains, Jiangsu Province of east China. The LTSS consisted of TM and ETM+ scenes with different projections due to distinct data sources (Beijing remote sensing ground station and the USGS EROS Center). The validation results of the disturbance year maps showed that most spatial agreement measures ranged from 70 to 86 %, comparable with the VCT accuracies reported for many places in USA. Very low accuracies were identified in 1995 (38.3 %) and 1992 (56.2 %) in the current analysis. These resulted from the insensitivity of the VCT algorithm to detect low intensity disturbances and also from the mis-registration errors of the image pairs. Major forest disturbance types existing in our study area were identified as agricultural expansion (39.8 %), urbanization (24.9 %), forest management practice (19.3 %), and mining (12.8 %). In general, there was a gradual decreasing trend in forest cover throughout this region, caused principally by China’s economic, demographic, environmental and political policies and decisions, as well as some weather events. While VCT has largely been used to assess long term changes and trends in the USA, it has great potential for assessing landscape level change elsewhere throughout the world. 相似文献
53.
The effects of ammonia and nitrite on vigour, survival rate, moulting rate of zoea of blue swimming crab, Portunus pelagicus, were studied. A total of five nitrite-N treatments (26.67, 53.34, 106.68, 213.36, 426.72 mg/l) and a control (no nitrite-N added) were
set up for the acute nitrite-N toxicity experiment; a total of five ammonia-N treatments (8.43, 16.86, 33.72, 67.44, 134.88 mg/l)
and a control (no ammonia-N added) were set up for the acute ammonia-N toxicity experiment. The results showed that the vigour,
survival rate and moulting rate of zoea of the blue swimming crabs exposed to over 53.34 mg/l were significantly different
(P < 0.05) from the control group. The zoea LC50 values (mg/l) of nitrite-N were 179.47, 76.56, 66.70, 37.49, 25.01, 25.35, 25.34 mg/l for 24, 36, 48, 60, 72, 84, 96 h, respectively.
The vigour, survival rate and moulting rate of zoea of the blue swimming crabs exposed to over 16.86 mg/l were significantly
different (P < 0.05) from the control group. The zoea LC50 values (mg/l) of ammonia-N were 51.04, 39.62, 38.72, 24.43, 16.90, 13.42, 11.16 mg/l for 24, 36, 48, 60, 72, 84, 96 h, respectively.
The zoeae are highly sensitive to ammonia and nitrite, and the toxicity of ammonia and nitrite on Portunus pelagicus decrease with development of this crab. 相似文献
54.
55.
Keneisenuo Keneisenuo MVSc Om Prakash Choudhary PhD Pranab Chandra Kalita PhD Priyanka Choudhary PhD Arup Kalita PhD Probal Jyoti Doley MVSc Jitendra Kumar Chaudhary PhD 《Anatomia, histologia, embryologia》2021,50(3):500-511
The present study reports data on the skull bone morphometry of barking and sambar deer. The skulls of adult barking deer (n = 6) and sambar deer (n = 6) of either sex (n = 3 males and n = 3 females) were collected from the Aizawl Zoological Park, Aizawl, Mizoram, India, with official permission from the Government of Mizoram. Anatomically, barking and sambar deer's skulls were elongated, pyramid-like, dolichocephalic and consisted of thirty-two cranial and facial bones. The cranial bones were eleven (three single and four paired), comprising of occipital, sphenoid, ethmoid, frontal, interparietal, parietal and temporal. The facial bones were twenty-one (one single and ten were paired), consisting of the maxilla, premaxilla (incisive), palatine, pterygoid, nasal, lacrimal, zygomatic (malar), vomer, turbinates, mandible and hyoid. In the present study, altogether 41 different measurements were taken morphologically and 6 different indices were applied. The obtained morphometrical parameters were significantly (p < .01, p < .05) higher in males than females of both species. Species wise, all obtained parameters were higher in sambar deer than barking deer. The obtained 41 different skull parameters and 6 indices showed statistically significant differences (p < .01 and p < .05) between both sexes of barking and sambar deer; however, practically these differences were meagre. The present morphometrical study on the skull of both species can help the wildlife professionals and zoo veterinarians determine the sex of these animals and differentiate it from other domestic and wild small ruminants for solving veterolegal cases. This study's findings will also motivate and assist other comparative studies with various domestic and wild small ruminants. 相似文献
56.
Amália Turner Giannico Elaine Mayumi Ueno Gil Daniela Aparecida Ayres Garcia Marlos Gonçalves Sousa Tilde Rodrigues Froes 《Veterinary research communications》2016,40(1):11-19
The aim of this study was to develop regression models for correlation of canine fetal heart development with body size to characterize normal development or suggest cardiac anomalies. Twenty clinically healthy pregnant bitches, either brachycephalic and non-brachycephalic, were examined ultrasonographically. Transabdominal fetal echocardiography was conducted every 4 days from the beginning of cardiac chambers differentiation until parturition. Ten cardiac parameters were measured: length, width and diameter of the heart; heart area; left and right ventricular dimensions; left and right atrial dimensions; and aortic and pulmonary artery diameter. Femoral length, biparietal diameter and abdominal cross-sectional area were also recorded. Regression equations were developed for each parameter of fetal body size, and linear and logarithmic models were compared. The model with the highest correlation coefficient was chosen to produce equations to calculate relative dimensions based on the correlations. Only the left-ventricular chamber differed between the two racial groups. Biparietal diameter was the independent parameter that produced the highest correlation coefficient for the most fetal cardiac dimensions, although good correlations were also observed using femoral length and abdominal cross-sectional area. Heart width and heart diameter were used as surrogates of cardiac development, as these measurements showed the best statistical correlation. Quantitative evaluation of fetal cardiac structures can be used to monitor normal and abnormal cardiac development. 相似文献
57.
Chiara Gomiero Giulia Bertolutti Tiziana Martinello Nathalie Van Bruaene Sarah Y. Broeckx Marco Patruno Jan H. Spaas 《Veterinary research communications》2016,40(1):39-48
Tendons regenerate poorly due to a dense extracellular matrix and low cellularity. Cellular therapies aim to improve tendon repair using mesenchymal stem cells and tenocytes; however, a current limitation is the low proliferative potential of tenocytes in cases of severe trauma. The purpose of this study was to develop a method useful in veterinary medicine to improve the differentiation of Peripheral Blood equine mesenchymal stem cells (PB-MSCs) into tenocytes. PB-MSCs were used to study the effects of the addition of some growth factors (GFs) as TGFβ3 (transforming growth factor), EGF2 (Epidermal growth factor), bFGF2 (Fibroblast growth factor) and IGF-1 (insulin-like growth factor) in presence or without Low Level Laser Technology (LLLT) on the mRNA expression levels of genes important in the tenogenic induction as Early Growth Response Protein-1 (EGR1), Tenascin (TNC) and Decorin (DCN). The singular addition of GFs did not show any influence on the mRNA expression of tenogenic genes whereas the specific combinations that arrested cell proliferation in favour of differentiation were the following: bFGF2 + TGFβ3 and bFGF2 + TGFβ3 + LLLT. Indeed, the supplement of bFGF2 and TGFβ3 significantly upregulated the expression of Early Growth Response Protein-1 and Decorin, while the use of LLLT induced a significant increase of Tenascin C levels. In conclusion, the present study might furnish significant suggestions for developing an efficient approach for tenocyte induction since the external administration of bFGF2 and TGFβ3, along with LLLT, influences the differentiation of PB-MSCs towards the tenogenic fate. 相似文献
58.
59.
Galina P. Simeonova Svetozar Z. Krastev Radostin S. Simeonov 《Veterinary research communications》2016,40(3-4):107-115
Background
The pathogenic mechanism of equine recurrent uveitis (ERU) is still poorly defined and many variations between experimental animal models and spontaneous disease exist.Objectives
The aim of our study was to investigate if Th17 cell-mediated response plays role in the pathogenesis of the used experimental model in horses and to reveal its pathological findings.Methods
Experimental uveitis was induced in 6 healthy horses. The concentrations of retinal autoantigen CRALBP and IL-17 were measured using ELISA in aqueous humor and vitreous body of the 12 inflamed eyes as well as in 12 control non-inflamed eyes taken from 6 horses in slaughter house. After centrifugation of the two eye media, smears were prepared and cytological investigation was performed. Tissue specimens were taken from all eye globes and were submitted to histopathological investigation.Results
CRALBP and IL-17 concentrations were significantly elevated in eye media of horses with experimental uveitis in comparison with controls. Cytological and histopathological findings corresponded to the changes characteristic of chronic immune-mediated inflammation with mononuclear cell infiltration of uvea, choroid, retina, and eye media as well as severe retinal destruction.Conclusions
Our study demonstrated the involvement of the retinal autoantigen CRALBP as well as IL-17 in the pathogenesis of experimental uveitis in horses. These findings suggests that this experimental uveitis in horses may serve as a suitable animal model for investigation of IL-17- mediated immune response during spontaneous autoimmune uveitis in horses as well as in humans.60.
1. An experiment on 1-week-old, White Leghorn female chicks was conducted to study the effect of aflatoxin AFB1 on weight gain, feed intake, feed gain ratio, age at sexual maturity, production and quality of eggs, retention of nutrients, pathoanatomical and histopathological parameters, and also on AFB1 residues in eggs and muscles of hens. The chicks were assigned to 4 dietary treatments: D1 (without AFB1), D2 (2.50 mg/kg AFB1), D3 (3.13 mg/kg AFB1), D4 (3.91 mg/kg AFB1) up to the age of 40 weeks. 2. At the end of the experiment, the mean body weight gain and feed intake were significantly lower in all aflatoxin-fed groups compared to control. The feed gain ratios were noted as 13.41, 13.59, 13.82 and 14.71, with the group fed the highest concentration of AFB1 showing a significantly poorer ratio than other groups. 3. Age at sexual maturity was also affected adversely by dietary AFB1: 193 d for D4 as compared to as early as 148 d for D1. Hen-d egg production was recorded as 96.92, 74.67, 65.98 and 50.75 in D1, D2, D3 and D4, respectively. 4. Average egg weights at the end of the experiment were 57.77, 57.49, 57.54 and 54.66 for D1, D2, D3 and D4, respectively. Shape index was significantly lower in D4 as compared to control. Contrary to this, albumen index was significantly higher in D4 as compared to D1. The values of yolk indices and eggshell thickness did not differ significantly among treatment groups. However, colour of yolk was reduced in all aflatoxin-fed groups compared to control. 5. Retentions of dry matter, crude protein, ether extract, calcium and metabolisable energy were adversely affected at various levels of AFB1 compared to control. 6. Pathoanatomical and histopathological studies showed various adverse changes in liver, kidney, heart, ovaries and bursa of Fabricius in AFB1-fed groups. 7. Different amounts of aflatoxin residues were detected in eggs and breast muscles of hen in all AFB1-fed groups. 相似文献