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1.
One way to disperse waste from large commercial feedlots is to spread large amounts of the waste on limited areas nearby. The effects of this practice on the soil microbial populations was assessed. Feedlot waste (FLW) was applied for 5 yr at rates of 0, 22, 67, 134, and 269 t ha?1 yr?1. Additional treatments were 538 t ha?1 yr?1 for 1 and 3 years and applications of N and NPK fertilizer. Soil cores from plots were sampled for microbial analysis before, during, and after the fifth growing season. April, July. and December soil samples were analyzed to 180-, 20-, and 480-cm depths, respectively. The following utritional and physiological groups of microorganisms were counted: soil fungi on Rose Bengal agar; bacteria on a basal mineral salts medium, on nutrient agar (both aerobically and in BBL GasPak jars), and on EMB agar (Escherichia coli-type colonies and total counts); and nitrifying and denitrifying organisms. Little effect due to FLW application rates was found, and organisms producing coliform-type colonies on EMB agar did not persist in the soil. The results indicated that applying large amounts of feedlot waste will not deleteriously affect soil microorganisms.  相似文献   
2.
Silicon has been reported to reduce drought stress on many crops, but limited studies have evaluated this effect with rice using calcium silicate slag from the phosphorus fertilizer industry as a source of Si. A greenhouse study was performed to address this issue. Four slag rates (0, 1,000, 2,000 and 4,000 mg/kg) and two application methods (surface application and incorporation) were evaluated under two moisture regimes (flood and 50% field capacity) for drought stress mitigation in a mineral soil that is typical for rice production. Slag application significantly elevated plant‐available Si in the soil and Si accumulation in plant tissues, and tended to improve rice shoot and root biomass relative to the untreated control under both flooding and drought stress. Increased carbon isotope discrimination (△13C) and decreased proline in rice leaves subjected to drought stress indicate that this slag may reduce drought stress in rice, which was supported by restoration of foliage density, transpiration, photosynthesis rate and sugar accumulation to at or near flooded levels following the highest slag application. This study supports the usage of calcium silicate slag in rice production as it could improve Si availability and reduce drought stress.  相似文献   
3.
The frequency of documented endocrine diseases in rodents and other small mammals varies considerably among the species maintained as pets, biomedical research animals, or display animals in zoos. The clinical diagnosis of endocrine diseases almost never occurs in free-ranging animals in their native habitat. Feral animals that have clinical endocrine disease, such as neoplasia, adrenal cortical hyperplasia, or diabetes, would exhibit clinical signs of altered behavior that would result in their removal by predators. The diagnosis of endocrine disease thus takes place in the relatively protective environment of captivity. This observation should forewarn pet owners and clinicians caring for these animals that the environment contributes to the development of endocrine diseases in these animals.  相似文献   
4.
Data management in food supply chains to facilitate product traceability has gained importance in recent years. This paper presents a relational database model to facilitate internal traceability at a grain elevator, which is one of the first nodes in a food supply chain. This approach for modeling traceability information in bulk food supply chains has not been studied in past. At an elevator, grain lots (inbound deliveries) are blended to meet buyer specifications, and individual lot identity is not maintained. As a result, an outbound shipment to a customer likely contains grain from many different sources. In a food safety related emergency, tracing the source of a problem or tracking other affected shipments would be nearly impossible. An efficient internal data management system could mitigate these problems by recording all grain lot transformations/activities, including movement, aggregation, segregation, and destruction as well as supplier and customer information. In this paper, a relational database management system is proposed that stores all necessary information, including product and quality information, related to the grain lots in order to enable product traceability. The system can be queried to retrieve information related to incoming, internal and outgoing lots and to retrieve information that connects the individual incoming grain lots to an outgoing shipment. Furthermore, this system can be used both to trace back to the source of a given lot and to track information about previously shipped lots forward. In addition to traceability application, the information stored in this database provides a comprehensive dataset for many applications including mass flow optimization, resource optimization and improved operational efficiency of the grain elevator.  相似文献   
5.
Barium, Be, Co, Cr, Cu, Li, Mn, Ni, Pb, Sr, and V concentrations were determined in 97 surface soil samples collected 1000 m apart on a regular grid in Madison county, Missouri, U.S.A. The data were normalized by a log10 transformation and a matrix of correlation coefficients computed. Strong correlations were observed between several metals and statistically significant correlations were found between others. The data were then analyzed by R-mode factor analysis. Three factors satisfactorily explained the data variance and were interpreted as follows. Factor 1 (55% variance) comprised a group of elements which contaminated local soils as a consequence of operations connected with non-ferrous metal mining. Factor 2 (33 % variance) contained elements which accumulate in soils during weathering. The remaining elements were grouped together in factor 3 (12% variance) and here soil contents appeared to be controlled by rock composition.  相似文献   
6.
Parkin is an E3 ubiquitin ligase involved in the ubiquitination of proteins that are important in the survival of dopamine neurons in Parkinson's disease (PD). We show that parkin is S-nitrosylated in vitro, as well as in vivo in a mouse model of PD and in brains of patients with PD and diffuse Lewy body disease. Moreover, S-nitrosylation inhibits parkin's ubiquitin E3 ligase activity and its protective function. The inhibition of parkin's ubiquitin E3 ligase activity by S-nitrosylation could contribute to the degenerative process in these disorders by impairing the ubiquitination of parkin substrates.  相似文献   
7.
Staphylococcus aureus is a common cause of mastitis and other diseases in camels. In order to obtain data on population structure as well as on the carriage of toxin genes and resistance markers, a collection of 45 isolates from dromedaries of Dubai, United Arab Emirates, were genotyped. These isolates belonged to clonal complexes CC6 (twenty isolates; 44.44%), CC30 (sixteen isolates; 35.56%), CC188 (five isolates; 11.11%), CC152 (1 isolate, 2.2%) and to a previously un-described sequence type (ST1755: arcc-18, aroe-115, glpf-6, gmk-2 pta-109, tpi-50 and yqil-2; three isolates; 6.67%). Resistance genes proved to be rare. Only three out of 45 isolates (6.67%) carried the beta-lactamase operon. The tetracycline resistance gene tetK was also detected in three isolates (6.67%). Neither the mecA gene, defining MRSA, nor other resistance genes were found. Common virulence markers included leukocidin genes lukD+lukE (in twenty-five isolates; 55.56%), the staphylokinase gene sak (twenty-two isolates; 48.89%), the enterotoxin gene cluster egc (fifteen isolates; 33.33%), and a distinct variant of the enterotoxin A gene (sea-320E, GenBank AY196686.1; thirteen isolates; 28.89%). One CC152 isolate was positive for genes encoding the Panton-Valentine leukocidin (lukF-PV+lukS-PV). This study provides first genotyping data on the population structure and the presence of toxin genes and resistance markers of S. aureus strains in Middle Eastern camels.  相似文献   
8.
Calcium silicate slag from the phosphorus fertilizer industry has the potential to be used as a liming agent or for silicon (Si) fertilization in rice production, but it contains trace elements that may contaminate rice grain and straw. A greenhouse study was performed to evaluate the bioavailability of Si and trace elements from slag (0, 1000, 2000, and 4000 mg kg?1) surface-applied or incorporated to a mineral soil and an organic soil. Slag application increased Si availability and rice grain yield relative to the control. Trace element and radioactivity in soil and rice grain were not significantly affected by slag supplementation. The applied slag showed minimal influence on plant available cadmium (Cd), chromium (Cr), or lead (Pb); however, copper (Cu) and zinc (Zn) in the organic soil increased, whereas Ni in the mineral soil decreased. Results indicate that the evaluated slag may be used as a Si fertilizer or liming amendment for rice with minimal environmental risks.  相似文献   
9.
The ivory-billed woodpecker (Campephilus principalis), long suspected to be extinct, has been rediscovered in the Big Woods region of eastern Arkansas. Visual encounters during 2004 and 2005, and analysis of a video clip from April 2004, confirm the existence of at least one male. Acoustic signatures consistent with Campephilus display drums also have been heard from the region. Extensive efforts to find birds away from the primary encounter site remain unsuccessful, but potential habitat for a thinly distributed source population is vast (over 220,000 hectares).  相似文献   
10.
We have studied the ability of human peripheral blood lymphocytes (HuPBL)4 to interact with IgG from several animal species. Three functions or activities that are reported to depend on an interaction between complexed IgG and HuPBL receptors (R) for the Fc piece of IgG (FcγR) were compared: (1) antibody-dependent cell-mediated cytotoxicity (ADCC); (2) binding of heat-aggregated IgG (aggG); and (3) rosette formation with IgG-sensitized erythrocytes [RBC-A(γ)]. IgG (and IgM) antibodies to chicken erythrocytes (CRBC) were purified from the sera of the following species after injection with CRBC stroma: (1) horse (Ho); (2) goat (Go); (3) rabbit (Ra); and (4) guinea pig (Gp). Good IgG-agglutinating antibody titers were obtained from each injected species.

Using 51Cr-labeled CRBC targets and HuPBL effector cells, only Ra anti-CRBC IgG gave good ADCC at high dilutions. Ho and Go anti-CRBC (IgG) failed to give A C , and p anti-CRBC (IgG) gave approx. 30% of the level of kill as Ra. Ra Fab'2 fragments of IgG antibody failed to produce ADCC.

Treatment of HuPBL with Ra anti-lymphocyte serum (ALS) almost totally ablated ADCC, whereas HoALS failed to alter ADCC. Pretreatment of HuPBL with aggG showed that Ra or Hu aggG gave essentially equal inhibition of ADCC, Gp gave approx. 30% of the degree of inhibition as Hu and Ra, and Ho or Go aggG had essentially no effect of ADCC. These results confirmed the following order of ability of IgG to interact with HuPBL ADCC killer (K) cells: (Hu )Ra > Gp Ho, Go. The data suggest that Gp IgG interacts with only a subpopulation (≈ 30%) of HuPBL K cells.

The binding of aggG to total HuPBL failed to strictly correlate with the ADCC results or with the results of rosette formation between total HuPBL and CRBC-A(γ). The observations suggest that there is a heterogeneity of FcγR between K and non-K cell subpopulations of HuPBL both in terms of the type of complexed IgG they are able to bind, and in terms of the species of origin of the IgG. The data also support contentions that FcγR that bind RBCA(γ) complexes differ from those that bind aggG.  相似文献   

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