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1.
African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.  相似文献   
2.
Cement-bonded particleboards of 6 mm in thickness were manufactured using maize stalk (Zea mays) particles of uniform sizes at three levels of board density and additive concentrations respectively. The bending strength and dimensional properties were assessed. Increase in board density and additive concentration caused increase in Modulus of rupture (MOR), Modulus of elasticity (MOE), and decrease in Thickness swelling (TS) and Water absorption (WA). The MOR, MOE and TS of the boards were significantly affected by board density except for WA, but additive concentration affected all the boards’ properties examined at p ≥ 0.05. Strong and dimensional stable cement-bonded boards could be manufactured from maize stalk particles with Portland cement as the binder after hot water treatment. Although the dimensional stability and mechanical strength properties of the boards were affected by the board density and additive concentration, the study revealed that cement-bonded particleboards could be manufactured from maize stalk (Zea mays) particles. However, the increase in board density and additive concentration could cause the increase in MOR and MOE, and cause the decrease in TS and WA of boards.  相似文献   
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4.
This study analyzed the influence of government policy and tenure issues on farm and village forest use practices in Ekiti State, Nigeria. Three rural communities that were still far from urban influence were selected from each of the 16 local government areas of the state. In each community, 20 household heads were selected and interviewed with the aid of a semi-structured matrix. The interviews aimed at the determination of respondents' socioeconomic status, awareness and belief in the effectiveness or otherwise of the forest laws and regulations, land use, tenure and property rights. Results obtained revealed that the awareness of forest laws and regulations cut across the socio-economic categories. Most of these laws and regulations that were considered to be necessary could also constitute disincentives to sustainable forest development. Three types of land tenure niches—private holdings, commons, and government reserves—exist in the state. These led to land fragmentations in which individuals are now left with small holdings. Individuals with small and medium landholdings found it difficult to invest in tree planting; hence, they meet their subsistence use of wood and non-wood forest products from diverse sources. Individuals with large landholdings were found cultivating cash tree crops; timber species were not cultivated though their wildlings were preserved. Also, when land is let or leased out, tenants were not allowed to invest in tree planting on such land.  相似文献   
5.
The aim of this study was to detect evidence for signatures of recent selection in the Jinhua pig genome. These results can be useful to better understand the regions under selection in Jinhua pigs and might shed some lights on groups of genes that control production traits. In the present study, we performed extended haplotype homozygosity(EHH) tests to identify significant core regions in 202 Jinhua pigs. A total of 26 161 core regions spanning 636.42 Mb were identified, which occupied approximately 28% of the genome across all autosomes, and 1 158 significant(P0.01) core haplotypes were selected. Genes in these regions were related to several economically important traits, including meat quality, reproduction, immune responses and exterior traits. A panel of genes including ssc-mir-365-2, KDM8, RABEP2, GSG1L, RHEB, RPH3AL and a signal pathway of PI3K-Akt were detected with the most extreme P-values. The findings in our study could draw a comparatively genome-wide map of selection signature in the pig genome, and also help to detect functional candidate genes under positive selection for further genetic and breeding research in Jinhua and other pigs.  相似文献   
6.
Two experiments were completed to compare the supplemental effects of yeast Saccharomyces cerevisiae and sub-therapeutic antibiotics in high-fibre and low-protein diets for broiler chicks. In experiment 1, yeast was added at 1.5, 3.0 and 6.0 g kg-1 while penicillin, tylosin or neoterramycin were added at 150 mg kg-1 into different batches of a high-fibre diet containing 250 g kg-1 palm kernel meal. Saccharomyces cerevisiae and antibiotics increased BW, BWG, FCR, feed intake, carcass and breast weights above the control. Small intestine weight was reduced by antibiotics, while yeast caused a lower deposition of abdominal fat. Liver weights of different treated broilers were similar. The performance indices were superior on penicillin and 3.0 g kg-1 yeast compared to other supplements evaluated. In the second experiment, 1.5 and 3.0 g kg-1 of yeast, and 0.75 mg kg-1 of procaine penicillin, zinc bacitracin and tylosin were separately added to a 180 g kg-1 crude protein diet. Performance of the chicks with additives was compared with unsupplemented negative and positive controls containing 180 and 210 g kg-1 crude protein respectively. Broilers fed with supplements had superior BW, BWG, FCR and feed intake compared to the negative control, but carcass data were similar. Dietary penicillin increased BW, BWG, feed intake more than other supplements, but yeast stimulated higher FCR. Data from both studies indicated that Saccharomyces cerevisiae comparatively increased growth and carcass weight and reduce abdominal fat, therefore, it can serve as a natural substitute for antibiotics in broiler diet.  相似文献   
7.
Two forms of rhodanese were purified from the liver of Clarias gariepinus Burchell, designated catfish rhodanese I (cRHD I) and rhodanese II (cRHD II), by ion-exchange chromatography on a CM-Sepharose CL-6B column and gel filtration through a Sephadex G-75 column. The apparent molecular weight obtained for cRHD I and cRHD II was 34,500 ± 707 and 36,800 ± 283 Da, respectively. The subunit molecular weight determined by sodium dodecyl sulphate–polyacrylamide gel electrophoresis was 33,200 ± 283 and 35,100 ± 141 Da for cRHD I and cRHD II, respectively. Atomic absorption spectrophotometric analysis revealed that cRHD II contained a high level of iron (Fe), which presumably was responsible for the brownish colour of the preparation. In contrast, no Fe was identified in cRHD I, and its preparation was colourless. Further characterization of cRHD II gave true Michaelis–Menten constant (K m) values of 25.40 ± 1.70 and 18.60 ± 1.68 mM for KCN and Na2S2O3, respectively, an optimum pH of 6.5 and an optimum temperature of 40°C. The Arrhenius plot of the effects of temperature on the reaction rate consisted of two linear segments with a break occurring at 40°C. The apparent activation energy values from these slopes were 7.3 and 72.9 kcal/mol. Inhibition studies on the cRHD II enzyme showed that the activity of the enzyme was not affected by Mn2+, Co2+, Sn2+, Ni2+ and NH4 +, but Zn2+ inhibited the enzyme considerably.  相似文献   
8.
A research was conducted to assess the effects of three different drying techniques, namely open sun drying (OSD), solar dryers (SD) and solar tent dryers (STD). Data on physical characteristics such as weight, total length and standard length were recorded and proximate composition of the fish sample Clarias gariepinus (Burchell, 1822) was carried out before, during and after drying to assess changes on physical characteristics and nutrient composition at different level. After drying, the samples were subjected to storage for eight weeks. The result obtained shows that there was no significant (P 〉 0.01) difference in the drying weight of the fish samples between the direct SD and the STD. However, for the total and standard length there was significant (P 〈 0.01) difference in the drying techniques, but no significant difference (P 〉 0.05) in the drying period. There was no significant (P 〉 0.05) difference on the physical parameters, storage period, proximate composition of both direct SD and STD and the drying period, respectively. Therefore, direct SD can be substituted with the STD without altering the quality of the product.  相似文献   
9.
The objective of this study was to estimate group- and breed-specific genetic parameters for reproductive traits in Chinese Duroc, Landrace, and Yorkshire populations. Records for reproductive traits between April 1998 and December 2017 from 92 nucleus pig breeding farms, which were involved in the China Swine Genetic Improvement Program, were analysed. Due to weak genetic connectedness across all farms, connectedness groups consisting of related farms were used. Three, two and four connectedness groups for Duroc, Landrace and Yorkshire were firstly established according to the genetic connectedness rating among farms. For each connectedness group a five-trait animal model was implemented, and via restricted maximum likelihood procedure the genetic parameters were estimated for five reproductive traits i.e., total number born (TNB), number born alive (NBA), litter weight at farrowing (LWF), farrowing interval (FI) and age at first farrowing (AFF). The average of heritabilities among connectedness groups ranged from .01 (for FI in Yorkshire) to .30 (for AFF in Duroc). Estimates of repeatability for litter traits ranged from .14 to .20 and were consistent for each breed, and for FI, the estimates varied from .01 to .11 across breeds and groups. The estimated genetic correlations among litter traits (i.e., TNB, NBA and LWF) were all significantly high (>.56) and similar across breeds. Averaged genetic correlations over three breeds were −.25, −.27, −.18, −.04, −.10, −.02, and .28 for FI-TNB, FI-NBA, FI-LWF, AFF-TNB, AFF-NBA, AFF-LWF and FI-AFF, respectively. The standard errors of the estimates were all very low (<0.01) in most situations. Results from this study suggest that selection based on TNB which is currently used in dam line selection index can improve NBA and LWF simultaneously. However, care should be taken on FI and AFF as they are both greatly influenced by non-genetic factors such as management and measurement.  相似文献   
10.
Tropical Animal Health and Production - The experiment was conducted to evaluate changes in feed consumption and water intake among broiler chickens subjected to melatonin treatment during the...  相似文献   
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