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At least 883 records · Page 49Linked to original sources

PubMed2002

Vitamin E supplementation can alleviate negative effects of heat stress on egg production, egg quality, digestibility of nutrients and egg yolk mineral concentrations of Japanese quails.

The aim of this study was to determine if the negative effects of high ambient temperature (34 degrees C) on egg production, egg quality, digestibility of nutrients, and mineral content of egg yolk could be alleviated by dietary vitamin E (dl-alpha-tocopheryl acetate) supplementation in laying Japanese quails (Coturnix coturnix japanica). Japanese quails (n=240; 7-week-old) were divided into eight groups, 30 birds per group. The quails were fed either a basal diet or the basal diet supplemented with either 125, 250 or 500 mg of dl-alpha-tocopheryl acetate/kg of diet. Birds were kept at 22 degrees C and 55% relative humidity (RH). At 14 weeks of age, the thermo-neutral (TN) group remained in the same temperature as at the beginning of the experiment, whereas the heat stress (HS) group was kept at an environment-controlled room at 34 degrees C and 44% RH for 3 weeks. Heat exposure decreased performance when basal diet was fed (P=0.001). With 250 and 500 mg/kg of diet, an increase in body weight (P=0.01), feed intake (P=0.01), egg production (P=0.001), and improvement in feed efficiency (P=0.01) was found with vitamin E supplementation in quails reared under heat stress conditions (HS). Similarly, egg weight (P=0.01), egg specific gravity (P=0.01), egg shell thickness (P=0.05) and Haugh unit (P=0.01) were positively influenced by vitamin E supplementation. Heat exposure decreased digestibility of dry matter (DM) (P=0.03), organic matter (OM) (P=0.05), crude protein (CP) (P=0.02), ether extract (EE) (P=0.05) and were elevated by supplemental vitamin E (P<or=0.02). Egg yolk concentrations of Zn, Fe, and Mn decreased under high environmental temperature and were increased to values of the control group (P=0.001) when dietary vitamin E was supplemented. No significant differences in any values were observed in TN groups. Results of the present study conclude that supplementation with 250mg alpha-tocopherol acetate/kg of diet can be considered to be protective management practice in a quail diet, reducing the negative effects of heat stress.

Animal Feed↗

PubMed2001

The storage of acetate under anoxic conditions.

Till now the role of storage in activated sludge processes under transient conditions has been deeply investigated under anaerobic (EBPR processes) or aerobic (bulking control) environments. Little attention has been given to the role of storage in processes including anoxic environments. Hence, the aim of the present work was to investigate the anoxic storage along with other substrate removal mechanisms under transient conditions. Several mixed culture were ad hoc selected under anoxic environment and periodic feeding (acetate as carbon source) at different organic load rate (OLR) and feed length; then their transient response to substrate spike was investigated by batch tests under both anoxic and aerobic conditions. The relative role of different mechanisms in the substrate removal was established on the basis of COD balance assuming that the acetate COD removed from the liquid phase could be oxidised for energy needs or recovered into solids as poly-3-hydroxybutyric acid (PHB) (storage), other internal precursors or intermediates (accumulation) and active biomass (growth, as estimated by ammonium uptake). In all tested conditions, growth response was very little while PHB storage was prevailing. In some operating conditions, indirect evidence of accumulation (in forms still to be identified) was also found. The transient response was not affected by the presence of free amino acids, at least for the unacclimated mixed culture under observation. Transient response under aerobic condition was quite similar to the anoxic one.

Acetates↗

PubMed1998

Bioavailability in rats of bound pesticide residues from tolerant or susceptible varieties of soybean and canola treated with metribuzin or atrazine.

Susceptible or tolerant varieties of soybean treated with metribuzin, or canola treated with atrazine were grown in a controlled environment. Shoots and fruits were harvested at maturity and extracted exhaustively with methanol. The extracted materials containing bound 14C residues were subsequently fed to rats for two days. The elimination of 14C in urine and feces was monitored for 4 days and the distribution of radioactivity in liver, kidney and heart was studied. Higher 14C residues in urine were present in animals fed fruits compared to shoots of soybean or canola of both susceptible and tolerant varieties. The bound atrazine residues from the pods of Atr Tower (tolerant variety of canola) were more bioavailable than Tower (susceptible variety of canola). Bioavailability of bound atrazine from the shoots of canola in both varieties was very low. In soybean fed animals, bound metribuzin derived 14C from the susceptible variety (Maple Amber) was more bioavailable than from the resistant variety (Maple Arrow). However, feeding the animals with susceptible or tolerant varieties of soybean or canola containing bound residues of 14C metribuzin or 14C atrazine for two days did not result in the accumulation of radioactivity in the body organs studied. Thus our data show that the bioavailability of these bound pesticides was dependent on the type of plant parts ingested and the variety of plant species.

Animals↗

PubMed1999

2,3,7,8-Substituted PCDDs and PCDFs in sea lion (Otaria flavescens) skin biopsies from two South-western Atlantic populations.

Congener specific 2,3,7,8-chlorinated PCDDs and PCDFs were determined in skin biopsies taken from sea lions (Otaria flavescens) living in two areas of the South-western Atlantic on the coast of Argentina (Mar del Plata and Punta Bermeja). This is the first report on PCDDs and PCDFs in sea lion skin biopsies from the southern hemisphere. Differences were found in the congener pattern according to the sampling area. Animals living in the polluted area (Mar del Plata harbour) had detectable levels of all seventeen 2,3,7,8-substituted congeners. Sea lions living in a control environment (Punta Bermeja, Patagonia) only exhibited 5 detectable congeners out of all seventeen 2,3,7,8-substituted congeners. However, total levels were low in both colonies studied. These data are consistent with previous work which has indicated that dioxins occur at relatively low levels in marine mammals, possibly due to rapid catabolism or elimination.

Animals↗

PubMed2000

Some potential errors in the measurement of mercury gas exchange at the soil surface using a dynamic flux chamber.

A series of controlled environment experiments were conducted to examine the use of a dynamic flux chamber to measure soil emission and absorption of total gaseous mercury (TGM). Uncertainty about the appropriate airflow rates through the chamber and chamber exposure to ambient wind are shown to be major sources of potential error. Soil surface mercury flux measurements over a range of chamber airflow rates showed a positive linear relationship between flux rates and airflow rate through the chamber. Mercury flux measurements using the chamber in an environmental wind tunnel showed that exposure of the system to ambient winds decreased the measured flux rates by 40% at a wind speed of 1.0 m s(-1) and 90% at a wind speed of 2 m s(-1). Wind tunnel measurements also showed that the chamber footprint was limited to the area of soil inside the chamber and there is little uncertainty of the footprint size in dry soil.

Air Pollutants↗

PubMed2006

Electrophysiological analysis of interactions between carbohydrates and transmitter receptors reconstituted in lipid bilayers.

The investigation of functional interactions between carbohydrates and neurotransmitter receptors is a challenging task. The presence of a wide variety of carbohydrates in the nervous system may preclude electrophysiological analysis using intact brain slice preparations or isolated neurons. The purification of transmitter receptors and their subsequent reconstitution into an artificial lipid bilayer can serve as a valuable tool to study carbohydrate and transmitter receptor interaction in a controlled environment. The "tip-dip" bilayer technique along with patch clamp electronics provides a unique means to explore carbohydrate interactions with a single transmitter receptor channel. This technique is also helpful in analyzing the interaction of carbohydrates with synaptic transmitter receptors using isolated synaptosomal preparations. Here, we illustrate the methods involved in reconstituting transmitter receptors in tip-dip bilayers and the subsequent study of carbohydrate interaction with the receptors.

Carbohydrates↗

PubMed2001

Influence of nutrient availability and tree wildling density on nutrient uptake by Oxalis acetosella and Acer saccharum.

Loss of nutrients following pulses of nutrient input in northern hardwood forests and the general effects of atmospheric deposition on forest communities are of concern. Uptake of nutrients by ground layer vegetation, including herbs and tree wildlings, may be important in both of these processes. We brought plants from the field (Catskill Mts, New York) and grew them under controlled environment conditions at two nutrient input levels to determine responses of Oxalis acetosella and Acer saccharum to increased nutrient input and tree wildling density. Oxalis nutrient concentration increased for many nutrients compared to field plants. Both species doubled their P concentration when P input doubled. Biomass of Oxalis was unaffected by both nutrient input level and Acer wildling density. Acer showed a similar response to increased nutrient input and its density did not affect the response of Oxalis to increased nutrient input. Results indicate that both species may be important to nutrient retention in northern hardwood forests.

Journal Article↗

PubMedDate not supplied

Zinc concentration effect at the organismal, cellular and subcellular levels in the eastern oyster.

The purpose of this research was to demonstrate a concentration effect of zinc exposure at organismal, cellular and sub-cellular levels in the eastern oyster and to find associated protein expression signatures (PES) for each concentration of zinc. Oysters were exposed to six concentrations of zinc for 48 h in a controlled environment. At the organismal level, fecal material was observed as a measure of physiological health during metal exposures. At the cellular level, lysosomal destabilization was measured using hemolymph. This cellular response was significant only at the highest concentration, when the fecal index was lowest. Protein responses were monitored in the oyster following exposure to zinc. Gill tissue was excised and homogenized, and then analyzed using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and digital image analysis. Protein expression signatures were found to be specific to each concentration. The protein responses were linked to the other biological parameters measured, each of which followed a concentration gradient of zinc.

Animals↗

PubMed1997

Influence of growth conditions on barley starch properties.

Air equilibrated barley starch comprises amylopectin, amylose, lipid and water. The structure of amylose and amylopectin, and the proportion of amylose in granules is under genetic control and is therefore subject to genotypic variation. The amount of lipid (which is essentially all lysophospholipid) is similarly under genetic control. Environment and especially environmental temperature do, however, have a regulatory effect on the size of starch granules, the amylose to amylopectin ratio and the amount of lipid (which is essentially all complexed with amylose) within barley starch. High growth temperatures probably facilitate amylopectin crystallisation and increase gelatinisation temperatures, (and to some extent the enthalpy of gelatinisation), but delay the onset and depress the extent of swelling of granules when heated in water.

Food Technology↗

PubMed2003

Adhesive strength of marine mussel extracts on porcine skin.

The adhesive characteristics of marine mussel adhesive extracts were examined. Adhesive protein extracted from mussels (Mytilus edulis) was used to bond porcine skin in an end-to-end joint cured in controlled environments, without the use of chemical cross-linking reagents. The two curing conditions were similar to common surgical environments-"dry" (25 degrees C and 40% relative humidity) and "humid" (37 degrees C and 80% relative humidity). The first condition is similar to that of an external incision while the second is similar to conditions for internal incisions that are not exposed to significant flow of body fluids. Results were compared with performance of the commercial adhesive fibrin. Cyanoacrylate was also examined to validate the testing procedure. The tissue joint strength was approximately 1MPa for mussel extract joints cured for 24h under "humid" conditions. Under both conditions, joints bonded with mussel extract showed adhesive strengths similar to those bonded with fibrin, for cure times between 12 and 24h. For shorter cure times (<12h) the mussel adhesive bond was weaker than the fibrin bond under both conditions. The presence of moisture seemed to have a significant effect on the performance of both adhesives, especially mussel extracts. These results indicate that tissue joints formed using mussel extract adhesives have comparable strengths to those formed using fibrin (P=0.38), albeit with a slower curing rate. Further investigation of curing agents for the mussel adhesive extract is warranted.

Adhesives↗

PubMed2004

Management patterns and outcomes of patients with venous thromboembolism in the usual community practice setting.

OBJECTIVE: The objectives of this study were to observe a commercially insured sample diagnosed with a venous thromboembolism (VTE) event and treated postevent with warfarin and to detail the thromboembolic and bleeding outcomes in the time periods during warfarin therapy and after discontinuation of such therapy. METHODS: This retrospective, observational cohort study used medical, pharmacy, and eligibility data from 2 US health plans. Study inclusion required an inpatient diagnosis of deep venous thrombosis (DVT) or pulmonary embolism (PE) between January 1, 1998, and December 31, 2000; warfarin, heparin, or low-molecular-weight heparin within 30 days after diagnosis; no VTE diagnosis; and no anticoagulant use for 3 months preceding diagnosis. A random sample of medical charts was abstracted to validate VTE events and collect prothrombin time/international normalized ratio (INR) result data. Recurrent VTE events, bleeding events, and proportion of time within INR range were captured in the postindex VTE event time period. Univariate and multivariate statistical techniques were used to assess outcomes. RESULTS: A total of 2,090 patients were identified with a newly diagnosed VTE event (DVT only, 1450; PE with or without DVT, 640). Mean (SD) age was 61.7 (16) years; mean (SD) follow-up time after the index diagnosis was 21.3 (10) months. Overall mean (SD) length of warfarin therapy was 6.6 (6) months. During the follow-up period, 224 patients (10.7%) experienced a recurrent VTE event and 122 patients (5.8%) experienced a bleeding event requiring hospitalization. The cumulative incidence of recurrent VTE events over 3 and 6 months was 9.0% and 10.9%, respectively. Using the chart abstraction subset, patients were within the appropriate INR range 37.7% of the time while receiving warfarin. CONCLUSIONS: Negative outcomes associated with warfarin therapy-recurrent VTE events and bleeding requiring hospitalization-were experienced by 10.7% and 5.8% of patients, respectively. These data suggest that negative outcomes may be more prevalent in usual community medical practice compared with rates observed in the controlled environment of the clinical trial or specialized anticoagulation clinic.

Aged↗

PubMed2002

Rapid auditory processing and MGN morphology in microgyric rats reared in varied acoustic environments.

Adult male rats with induced microgyric lesions exhibit significant deficits in rapid auditory processing, as well as morphological alterations in the medial geniculate nucleus (MGN) of the thalamus. These findings are considered striking in light of similar anatomical and auditory processing anomalies in language disabled humans. Given evidence from clinical and animal studies that acoustic experience may alter sensory processing at behavioral and neurophysiological levels, the current study examined effects of developmental exposure to auditory stimulation on behavioral and anatomical indices in microgyric and sham rats. Stimulation (E7-P 70) included: (1). chronic white noise (80 dB) with standard housing; (2). 3 h/day of 78 dB filtered light classical music with social housing; or (3). standard acoustic environment (control) with standard housing. Microgyric effects on auditory processing and thalamic morphology were evident regardless of environmental condition. In sum, the effects of microgyria on brain and behavior appear to be robust, and largely orthogonal to any main effect of acoustic stimulation on auditory processing. These findings suggest that a more active form of acoustic stimulation (e.g., training) may be required to ameliorate the deleterious behavioral and anatomical consequences of focal microgyric lesions.

Acoustic Stimulation↗

PubMed2001

Enhanced osmotolerance of a wheat mutant selected for potassium accumulation.

A mutant of durum wheat was identified by screening a M4 population (sodium azide) for genotypes with enhanced capacity for potassium accumulation in leaves. The mutant (designated 422) was grown in field, controlled environment, hydroponic culture and NaCl salinized soil. Mutant 422 accumulates about 5 mg/g dry weight more K than the wild-type and is less salt sensitive, based on leaf growth and germination. During vegetative growth exists a specific tolerance of the 422 mutant to K(+) ion and a moderate tolerance to Cl(-) ion, in hydroponic culture. Under severe stress imposed by salts and mannitol, the mutant germinates better than wild type (WT). In soil containing increasing NaCl, mutant 422 had higher potassium amount than WT, but did not show augmented capacity to concentrate the ion in the leaves as salt stress increased. The capability to accumulate potassium could improve tissue hydration, because water content of 422 leaves was greater than WT and increased linearly in relation to leaf K(+) concentration.

Journal Article↗

PubMed2003

Towards knowledge-based systems in clinical practice: development of an integrated clinical information and knowledge management support system.

Given that clinicians presented with identical clinical information will act in different ways, there is a need to introduce into routine clinical practice methods and tools to support the scientific homogeneity and accountability of healthcare decisions and actions. The benefits expected from such action include an overall reduction in cost, improved quality of care, patient and public opinion satisfaction. Computer-based medical data processing has yielded methods and tools for managing the task away from the hospital management level and closer to the desired disease and patient management level. To this end, advanced applications of information and disease process modelling technologies have already demonstrated an ability to significantly augment clinical decision making as a by-product. The wide-spread acceptance of evidence-based medicine as the basis of cost-conscious and concurrently quality-wise accountable clinical practice suffices as evidence supporting this claim. Electronic libraries are one-step towards an online status of this key health-care delivery quality control environment. Nonetheless, to date, the underlying information and knowledge management technologies have failed to be integrated into any form of pragmatic or marketable online and real-time clinical decision making tool. One of the main obstacles that needs to be overcome is the development of systems that treat both information and knowledge as clinical objects with same modelling requirements. This paper describes the development of such a system in the form of an intelligent clinical information management system: a system which at the most fundamental level of clinical decision support facilitates both the organised acquisition of clinical information and knowledge and provides a test-bed for the development and evaluation of knowledge-based decision support functions.

Artificial Intelligence↗

PubMed1992

Morphological responses of wheat to blue light.

Blue light significantly increased tillering in wheat (Triticum aestivum L.) plants grown at the same photosynthetic photon flux (PPF). Plants were grown under two levels of blue light (400-500 nm) in a controlled environment with continuous irradiation. Plants received either 50 micromoles m-2 s-1 of blue light or 2 micromoles m-2 s-1 blue light from filtered metal halide lamps at a total irradiance of 200 micromoles m-2 s-1 PPF (400-700 nm). Plants tillered an average of 25% more under the higher level of blue light. Blue light also caused a small, but consistent, increase in main culm development, measured as Haun stage. Leaf length was reduced by higher levels of blue light, while plant dry-mass was not significantly affected by blue light. Applying the principle of equivalent light action, the results suggest that tillering and leaf elongation are mediated by the blue-UV light receptor(s) because phytochrome photoequilibrium for each treatment were nearly identical.

Biomass↗

PubMed1983

Emergency drills in a pediatric residency training program.

A variety of common pediatric emergencies were created in anesthetized cats to provide pediatric house officers and practicing physicians with an opportunity to refine diagnostic and management skills in a controlled environment under supervision. We describe the format of the animal model drill, outline protocols for stimulating pediatric critical care emergencies, and present preliminary evaluation data from a continuing medical education workshop and from house staff drills regarding the efficacy of the program.

Animals↗

PubMed2003

The power of place.

OBJECTIVE: to describe the power that 'place' holds over the postnatal-care experiences of women. DESIGN: a study informed by phenomenology within a feminist framework was undertaken to examine the experiences of women electing early postnatal discharge. Three extended conversations with each woman participating in the study were audiotaped and transcribed. Journal notes made by the researcher added to the audiotaped data. Thematic analysis revealed major structures of experience. SETTING: data were obtained from conversations with women in their respective homes. PARTICIPANTS: five women, parity 1-3, living in the Sydney metropolitan area and birthing in their local hospitals participated in the study. FINDINGS: four major constructs of experience were revealed through analysis and include spatiality, corporeality, temporality and relationality. In this paper, components of spatiality expressed through the power place exerts in matters of physical environment,control, confidence, safety, time, talk and the heart of the matter are presented. KEY CONCLUSIONS: the experiences of women entering the foreign place of hospital to birth their children were those of alienation and disempowerment while the familiar territory of home offered stronger feelings of security and support. IMPLICATIONS FOR PRACTICE: failing to recognise the impact of place on the experiences of postnatal women reduces the likelihood that midwives will be able to offer sensitive and appropriate care.

Beds↗

PubMed2000

Responses of spruce seedlings (Picea abies) to exhaust gas under laboratory conditions--I. Plant-insect interactions.

The effects of motor vehicle exhaust gas on Norway spruce seedlings (Picea abies (L.) Karst) and plant-insect interaction of spruce shoot aphid (Cinara pilicornis Hartig) was studied. The exhaust gas concentrations in the fumigation chambers were monitored and controlled by measuring the concentration of nitrogen oxides (NO(x)) with a computer aided feedback system. The concentrations of major exhaust gas components (black carbon [BC], fine particles, VOCs and carbonyl compounds) in the chamber air were also measured. Responses of Norway spruce seedlings to a 2 and 3-week exhaust gas exposure and subsequent performance of spruce shoot aphid were studied using realistic exposure regimes; 50, 100 and 200 ppb NO(x). The feedback control system based on NO(x) concentrations proved an adequate and practical means for controlling the concentration of exhaust gases and studying plant responses in controlled environment chambers. The exhaust exposure resulted in increased concentrations of proline, glutamine, threonine, aspartic acid, glycine and phenylalanine and decreased concentration of arginine, serine, alanine and glycine in young needles. No changes in soluble N concentrations were observed. The results are interpreted as a stress response rather than use of NO(x) as a nitrogen source. No changes in total phenolics and only transient changes in some individual terpene concentrations were detected. The exhaust gas exposure stressed the exposed seedlings, but had no significant effect on N metabolism or the production of defence chemicals. Aphid performance was not significantly affected. Soluble N, secondary metabolism and aphid performance were not sensitive to exhaust gas exposure during shoot elongation in Norway spruce.

Journal Article↗