Characterization of isolated yeast growth response to methionine analogs

Methionine is one of the first limiting amino acids in poultry nutrition. The use of methionine-rich natural feed ingredients, such as soybean meal or rapeseed meal may lead to negative environmental consequences. Amino acid supplementation leads to reduced use of protein-rich ingredients. The objectives of this study were isolation of potentially high content methionine-containing yeasts, quantification of methionine content in yeasts and their respective growth response to methionine analogs. Minimal medium was used as the selection medium and the isolation medium of methionine-producing yeasts from yeast collection and environmental samples, respectively. Two yeasts previously collected along with six additional strains isolated from Caucasian kefir grains, air-trapped, cantaloupe, and three soil samples could grow on minimal medium. Only two of the newly isolated strains, K1 and C1, grew in minimal medium supplied with either methionine analogs ethionine or norleucine at 0.5% (w/v). Based on large subunit rRNA sequences, these isolated strains were identified as Pichia udriavzevii/Issatchenkia orientalis. P. kudriavzevii/I. orentalis is a generally recognized as a safe organism. In addition, methionine produced by K1 and C1 yeast hydrolysate yielded 1.3 ± 0.01 and 1.1 ± 0.01 mg g^?1 dry cell. Yeast strain K1 may be suitable as a potential source of methionine for dietary supplements in organic poultry feed but may require growth conditions to further increase their methionine content.     

A longitudinal study of the relationship between career management and organizational commitment among graduates in the first ten years at work

This paper reports the findings of a two‐wave longitudinal study investigating relationships between organizational and individual career management activities and organizational commitment in the early years of graduate careers. Several hypotheses are tested and receive mixed support. High organizational commitment predicts the practice of career management activities by graduates to further their career within the organization while low commitment is closely associated with behaviour aimed at furthering the career outside the organization. Graduates who manage their own careers also receive more career management help from their employer. This suggests that there may be the potential for employers to create a ‘virtuous circle’ of career management in which individual and organizational activities complement each other. Copyright © 2002 John Wiley & Sons, Ltd.     

Fetal blood group studies during mid-trimester pregnancy and the management of severe isoimmunization

Fetal blood samples collected at 14–22 weeks' gestation by fetoscopy have been analysed for 25 different red cell antigens and anti-A antibodies. The results obtained demonstrate that the technique can be used to determine fetal blood groups during mid-pregnancy and also to provide the opportunity to study the physiological and pathological developments of blood groups and their antibodies and to manage more rationally those pregnancies threatened by erythroblastosis fetalis.     

AN EFFICIENT METHOD OF APPLYING ALUMINUM SALTS FOR SEDIMENT PHOSPHORUS INACTIVATION IN LAKES1

ABSTRACT: Alum and sodium aluminate were injected into the hypolimnion of eutrophic Kezar Lake, New Hampshire, with a specially designed applicator mechanism. This new method of applying aluminum salts to achieve phosphorus inactivation included two separate chemical distribution systems mounted on a hydraulic weed harvester. The design of the applicator system is described, and its cost-effectiveness is compared with other aluminum salt injections.     

CUSUM environmental monitoring in time and space

We consider the situation where there are n sampling sites in an area, with an environmental variable measured at some or all of the sites at m sample times. We assume that there is interest in knowing whether the environmental variable displays systematic changes over time at the sites. A cumulative sum type of analysis with associated randomization tests has been proposed before for this situation, when there is negligible correlation between the observations in different times at one site, and no correlation between the results at different sites. A modification that allows for serial correlation at the individual sites but with no correlation between sites has also been proposed before. In the present paper we discuss how the method can be modified further to allow for spatial correlation between the sites, by applying it only to a reduced set of sites that are far enough apart to give effectively independent results. Simulation results indicate that this strategy is effective providing that the level of spatial correlation is not too high.     

Debromination of duroplastic flame-retarded polymers

Epoxy resins containing the flame retardant Tetrabromobisphenol A chemically bound to their structures were successfully dehalogenated with Na/NH₃ in an autoclave at elevated temperatures. Four loaded printed circuit boards of various origins and one unloaded circuit board were investigated. Debromination efficiencies of solvolysis with ethyl acetate (280°C, 15 MPa) and dehalogenation with Na/NH₃ (100°C, 6 MPa) are compared.     

Monitoring for 2,4-residues in fish species resident in treated lakes in east-central Ontario 1977–80

Authorized use of 2,4-D by cottage owners in Buckhorn Lake for the years 1977 to 1980 ranged from 124 to 280 kg of active ingredient, annually. This would give predicted average water concentrations of 2 to 4 g L^–1 during the June–July period. However, higher residues were observed in the Lake. Between 1977 and 1980, 353 individual fish, of eight species, were caught for analysis in Buckhorn and Chemong lakes. These fish belonged to eight edible species. Twelve percent of the fish caught during the pre-treatment period (i.e. May), had detectable residues of 2,4-D. Mean residues by species and year ranged from <5 to 30 g kg^–1 2,4-D. In the early post-treatment period (i.e. July), 69% of fish caught had mean residues by species which ranged from <5 to 136 g kg^–1 2,4-D. In the late post-treatment period (i.e. October), 19% of fish caught by year had detectable residues of 2,4-D. Mean residues by species during this period ranged from <5 to 60 g kg^–1 2,4-D. While 15 (i.e. 4%) of the 353 fish and fish composites had 2,4-D above the maximum residue limit of 100 g kg^–1 only six were of edible size.     

Economic costs of achieving current conservation goals in the future as climate changes

Conservation of biologically diverse regions has thus far been accomplished largely through the establishment and maintenance of protected areas. Climate change is expected to shift climate space of many species outside existing reserve boundaries. We used climate-envelope models to examine shifts in climate space of 11 species that are representative of the Mount Hamilton Project area (MHPA) (California, U.S.A.), which includes areas within Alameda, Santa Clara, San Joaquin, Stanislaus, Merced, and San Benito counties and is in the state's Central Coast ecoregion. We used Marxan site-selection software to determine the minimum area required as climate changes to achieve a baseline conservation goal equal to 80% of existing climate space for all species in the MHPA through 2050 and 2100. Additionally, we assessed the costs associated with use of existing conservation strategies (land acquisition and management actions such as species translocation, monitoring, and captive breeding) necessary to meet current species-conservation goals as climate changes. Meeting conservation goals as climate changes through 2050 required an additional 256,000 ha (332%) of protected area, primarily to the south and west of the MHPA. Through 2050 the total cost of land acquisition and management was estimated at US$1.67-1.79 billion, or 139-149% of the cost of achieving the same conservation goals with no climate change. To maintain 80% of climate space through 2100 required nearly 380,000 additional hectares that would cost $2.46-2.62 billion, or 209-219% of the cost of achieving the same conservation goals with no climate change. Furthermore, maintaining 80% of existing climate space within California for 27% of the focal species was not possible by 2100 because climate space for these species did not exist in the state. The high costs of conserving species as the climate changes-that we found in an assessment of one conservation project-highlights the need for tools that will aid in iterative goal setting given the uncertainty of the effects of climate change and adaptive management that includes new conservation strategies and consideration of the long-term economic costs of conservation.     

Spatial patterns of off-the-system traffic crashes in Miami–Dade County,Florida, during 2005–2010

Objective: The objective of this study is to analyze the spatial distribution of the vehicles involved in crashes in Miami–Dade County. In addition, we analyzed the role of time of day, day of the week, seasonality, drivers’ age in the distribution of traffic crashes.

Method: Off-the-system crash data acquired from the Florida Department of Transportation during 2005–2010 were divided into subcategories according to the risk factors age, time of day, day of the week, and travel season. Various spatial statistics methods, including nearest neighbor analysis, Getis-Ord hot spot analysis, and kernel density analysis revealed substantial spatial variations, depending on the subcategory in question.

Results: Downtown Miami and South Beach showed up consistently as hotspots of traffic crashes in all subcategories except fatal crashes. However, fatal crashes were concentrated in residential areas in inland areas.

Conclusion: This understanding of patterns can help the county target high-risk areas and help to reduce crash fatalities to create a safer environment for motorists and pedestrians.