Campylobacter spp. in conventional broiler flocks in Northern Ireland: epidemiology and risk factors     

McDowell SW  Menzies FD  McBride SH  Oza AN  McKenna JP  Gordon AW  Neill SD 《Preventive veterinary medicine》2008,84(3-4):261-276

Risk factors for Campylobacter infection in conventional broiler flocks in the time period up to the first removal of birds to slaughter were investigated over a maximum of five consecutive production cycles in a cohort of 88 broiler farms in Northern Ireland. Samples for Campylobacter culture, which consisted of 14 cloacal swabs per flock, were collected from one house on each farm prior to the first depopulation of birds. In total 388 flocks were sampled, of which 163 tested positive for Campylobacter spp. (42.0%; 95% CI 35.1–48.9%).

Data on farm and flock variables were obtained from questionnaires and random-effects logistic regression modelling used to investigate the association between these and the Campylobacter status of flocks. Six variables, all of which were significant at p < 0.05, were included in the final multivariable model. These included a combined variable on the presence of rodents on farms, which showed an increased odds of infection in flocks where the farmer reported having observed rodents during the production cycle (OR = 2.1) and/or where rodent droppings were observed at the sampling visit (OR = 2.9). Other variables that were significantly associated with an increased odds of infection included the age of the birds at sampling (odds ratio for its linear effect = 1.16 for each day of increase in age), season (summer versus other seasons OR = 2.0), farms with three or more broiler houses (OR = 2.9 compared to those with one house), the frequency of footbath disinfectant changes (OR = 2.5 for once weekly and OR = 4.0 for less than once weekly compared to twice weekly changes) and a categorical variable on the standard of tidiness and cleanliness of the broiler house ante-room (OR = 2.0 and OR = 4.9 for flocks from houses with poorer standards). There was no significant evidence of direct carry-over of infection from one production cycle to the next, neither was there evidence of other farm species acting as a source of infection.  相似文献   

VEGETABLE MORPHOLOGY A CENTURY AGO. -- Goethe     

McBride TH 《Science (New York, N.Y.)》1885,6(132):130-131

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Ingestion, Absorption, and Gonad Production of Adult Strongylocentrotus franciscanus Fed Different Rations of a Prepared Diet     

Susan C.  McBride John M.  Lawrence Addison L.  Lawrence Timothy J.  Mulligan 《Journal of the World Aquaculture Society》1999,30(3):364-370

Abstract.— Feed costs are a major portion of aqua-culture operations. Accurate estimates of daily ration are vital to prevent overfeeding which results in wasted feed. poor water quality, underfeeding, and reduced growth. Understanding the relationship of ingestion rate and absorption efficiency of Strongylocentrotus franciscanus should improve the cost effectiveness of aquaculture of this candidate species. Adult S. franciscanus were collected from a subtidal area devoid of algae and fed two rations of an extruded diet for 62 d. Mean test diameter and whole weight of an initial sample were 91 ± 2 mm and 295 ± 18.4 g (mean ± SEM; N = 16). The two rations used were l-g dry feed/d or 3 g/d. An unfed control group was also maintained. Eight urchins per treatment showed significant differences in food ingestion rate, total organic absorption, gonad index, gut index, and moisture content of the gonad (P < 0.001). Food intake was greatest in the high ration treatment, while total organic absorption was greatest in the low ration treatment. The gonad index of S. franciscanus in the high food ration was significantly greater than the initial gonad index and was also greater than the index of animals in the low ration and unfed treatments. The gonad index of animals in the low food ration treatment was significantly greater than the index of the initial sample and the index of animals in the unfed treatment. The gut index of urchins in the high food ration treatment was significantly greater than initially and was also greater than the gut index for animals in the low ration and unfed treatments. The gut index for urchins in the unfed treatment was significantly less than the initial index. The moisture content of the gonad of urchins fed the prepared diet was significantly greater than the gonad moisture content of the initial sample or unfed group. Test diameter. whole animal weight, and gonad production efficiency (increase in g dry gonad weight/g dry feed intake) were not significantly different (P > 0.200). Histological examination of the gonads showed S. franciscanus in the two ration treatments developed from the spent to the growing or premature stage while the unfed controls lost nutritive tissue and contained only relict gametes or remained in the spent condition. The results suggest S. franciscanus from food-limited environments can be fed appropriate rations to control gonad production.  相似文献   

Antibody-forming cells: population patterns after simultaneous immunization with different isoantigens     

R A McBride  L W Schierman 《Science (New York, N.Y.)》1966,154(749):655-657

Spleen cells were obtained from chickens stimulated simultaneously with different erythrocytic antigens, and the proportions producing one and two antibodies were determined by the hemolytic-plaque technique. Most cells from birds immunized with two antigens of the same system (B) appeared to produce only one antibody. In a population of cells from birds immunized with antigens of different systems (A and B), a relatively high proportion of cells produced two antibodies.  相似文献   

合肥城市森林减少大气污染的效果   总被引：19，自引：6，他引：13  

吴泽民  JoeR.McBride  David J.Nowak  杨军  Sheauchi Cheng 《中国城市林业》2003,1(1):39-43

树木主要通过气孔吸收气态污染物,同时通过滞留空气中的微粒而减轻污染,树木较高的覆盖率可能会减少挥发性有机物的释放量,定量研究表明,合肥市1998年吸收空气污染物约为151.5t,树木7月份(着叶季节)吸收污染量高达20t,具有相对较低臭氧生成潜力的植物有香樟属、女贞属、紫薇属、罗汉松属和李属。合肥城市森林总体的臭氧指标得分值为92.4。    相似文献   

Radiological impact of airborne effluents of coal and nuclear plants     

McBride JP  Moore RE  Witherspoon JP  Blanco RE 《Science (New York, N.Y.)》1978,202(4372):1045-1050

Radiation doses from airborne effluents of model coal-fired and nuclear power plants (1000 megawatts electric) are compared. Assuming a 1 percent ash release to the atmosphere (Environmental Protection Agency regulation) and 1 part per million of uranium and 2 parts per million of thorium in the coal (approximately the U.S. average), population doses from the coal plant are typically higher than those from pressurized-water or boiling-water reactors that meet government regulations. Higher radionuclide contents and ash releases are common and would result in increased doses from the coal plant. The study does not assess the impact of non-radiological pollutants or the total radiological impacts of a coal versus a nuclear economy.  相似文献   

Polarized gamma-ray emission from the crab     

Dean AJ  Clark DJ  Stephen JB  McBride VA  Bassani L  Bazzano A  Bird AJ  Hill AB  Shaw SE  Ubertini P 《Science (New York, N.Y.)》2008,321(5893):1183-1185

Pulsar systems accelerate particles to immense energies. The detailed functioning of these engines is still poorly understood, but polarization measurements of high-energy radiation may allow us to locate where the particles are accelerated. We have detected polarized gamma rays from the vicinity of the Crab pulsar using data from the spectrometer on the International Gamma-Ray Astrophysics Laboratory satellite. Our results show polarization with an electric vector aligned with the spin axis of the neutron star, demonstrating that a substantial fraction of the high-energy electrons responsible for the polarized photons are produced in a highly ordered structure close to the pulsar.  相似文献   

Tumorigenicity in human melanoma cell lines controlled by introduction of human chromosome 6   总被引：32，自引：0，他引：32  

J M Trent  E J Stanbridge  H L McBride  E U Meese  G Casey  D E Araujo  C M Witkowski  R B Nagle 《Science (New York, N.Y.)》1990,247(4942):568-571

Chromosome banding analysis of human malignant melanoma has documented the nonrandom alteration of chromosome 6. To determine the relevance of chromosome 6 abnormalities in melanoma, a normal chromosome 6 was directly introduced into melanoma cell lines. The resulting (+6) microcell hybrids were significantly altered in their phenotypic properties in culture and lost their ability to form tumors in nude mice. The loss of the chromosome 6 from melanoma microcell hybrids resulted in the reversion to tumorigenicity of these cells in mice. The introduction of the selectable marker (psv2neo) alone into melanoma cell lines had no effect on tumorigenicity. These results support the idea that one or more genes on chromosome 6 may control the malignant expression of human melanoma.  相似文献   

Characterization and chromosomal localization of a cDNA encoding brain amyloid of Alzheimer's disease   总被引：109，自引：0，他引：109  

D Goldgaber  M I Lerman  O W McBride  U Saffiotti  D C Gajdusek 《Science (New York, N.Y.)》1987,235(4791):877-880

Four clones were isolated from an adult human brain complementary DNA library with an oligonucleotide probe corresponding to the first 20 amino acids of the beta peptide of brain amyloid from Alzheimer's disease. The open reading frame of the sequenced clone coded for 97 amino acids, including the known amino acid sequence of this polypeptide. The 3.5-kilobase messenger RNA was detected in mammalian brains and human thymus. The gene is highly conserved in evolution and has been mapped to human chromosome 21.  相似文献   

Molecular expression and identification of caprine estrogen receptor gene 1 for fertility status in bucks     

S Saraswat  SD Kharche  PK Rout  R Pawaiya  C Gangwar  DK Swain  R Kaushik 《Reproduction in domestic animals》2020,55(9):1080-1092

Estrogen and its receptors are essential for sexual development and reproduction. Oestrogen receptor alpha (ERα) is a nuclear receptor activated by the hormone oestrogen. In male, ERα is encoded by the gene ESR1 (oestrogen receptor1) responsible for better fertility. ESR1 is involved in the reabsorption of luminal fluid during the transit of spermatozoa from the testis to the head of the epididymis which is important for their survival and maturation during epididymal storage. The absence of ESR1 leads to reduced epididymal sperm content, reduced sperm motility and fertilizing ability. The present study was undertaken to investigate the expression and presence of ESR1 gene in fertile and low-fertile male goat breeds. We identified ESR1 gene through various molecular tools. Genotyping was carried out by high resonance melting analysis using Roche Light Cycler 480(LC-480) system and found three different genotypes. Genotypic frequency-AA (blue-0.67), BB(Red-0.2), AB(Green-0.08) with allele frequency A(0.71 and B (0.29). The predominance of this gene in head of epididymis in fertile bucks was confirmed by SDS-PAGE, Western blotting and immunohistochemistry. From the results, we corroborated that the present study provides a useful and effective way to predict male fertility in goat breeds, which in turn increases the percentage of fertility in flock leading to more number of offspring in a kidding season.  相似文献