Effect ofSolanum Glycoalkaloids on Potato Aphid,Macrosiphum euphorbiae

Macrosiphum euphorbiae, also known as the potato aphid, is a potato virus vector, associated with decreased tuber production. Feeding, toxicity, and reproductive effects of the major potato glycoalkaloids (α-chaconine and α-solanine), their common aglycone (solanidine), and a nonpotato glycoalkaloid (α-tomatine) and its aglycone (tomatidine) onM. euphorbiae were studied. As expected, neither α-chaconine nor α-solanine had a strong lethal effect on the aphid, but α-chaconine stimulated feeding at low concentrations. Both aglycones were deterrent and lethal at high concentrations and, like α-chaconine and α-tomatine, they delayed the appearance and decreased the number of nymphs.     

The relationship context of human behavior and development.

The influence of social relationships on human development and behavior is receiving increased attention from psychologists, who are central contributors to the rapidly developing multidisciplinary field of relationship science. In this article, the authors selectively review some of the significant strides that have been made toward understanding the effects of relationships on development and behavior and the processes by which relationships exert their influence on these, with the purpose of highlighting important questions that remain to be answered, controversial issues that need to be resolved, and potentially profitable paths for future inquiry. The authors' thesis is that important advances in psychological knowledge will be achieved from concerted investigation of the relationship context in which most important human behaviors are developed and displayed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement and analysis of unbound drug concentrations

The plasma protein binding of drugs has been shown to have significant effects on numerous aspects of clinical pharmacokinetics and pharmacodynamics. In many clinical situations, measurement of the total drug concentration does not provide the needed information concerning the unbound fraction of drug in plasma which is available for distribution, elimination, and pharmacodynamic action. Thus, accurate determination of unbound plasma drug concentrations is essential in the therapeutic monitoring of drugs. Many methodologies are available for determining the extent of plasma protein binding of drugs, however, in the clinical evaluation of drug therapy, equilibrium dialysis and ultrafiltration are the most routinely utilised methods. Both of these methods have been proven to be experimentally sound and to yield adequate protein binding data. Furthermore, the characterisation of the interactions between drug and protein molecules is essential for the assessment of the pharmacokinetic implications of drug-protein binding. Protein binding parameters which characterise the affinity of the drug-protein association, the number of classes of binding sites, the number of binding sites per class or protein and the binding capacity are useful for predicting unbound drug concentrations. Simple graphical methods have often been used to obtain protein binding parameters, but these methods have limitations and are not useful for drugs with more than 1 class of binding site. Therefore, the fitting of protein binding models which characterise the drug-protein binding interaction for experimental data is the preferred method of calculating binding parameters. Using the appropriate model, values for binding parameters are typically estimated by using nonlinear least-squares regression analysis.     

Methane output and lactation response in Holstein cattle with monensin or unsaturated fat added to the diet

We measured effects of continuous vs twice-daily feeding, the addition of unsaturated fat to the diet, and monensin on milk production, milk composition, feed intake, and CO2-methane production in four experiments in a herd of 88 to 109 milking Holsteins. Methane and CO2 production increased with twice-daily feeding, but the CO2:CH4 ratio remained unchanged. Soybean oil did not affect the milkfat percentages, but fatty acid composition was changed. All saturated fatty acids up to and including 16:0 decreased (P < .01), whereas 18:0 and trans 18:1 increased (P < .001). The 18:2 conjugated dienes also increased (P < .01) when the cows were fed soybean oil. Monensin addition to the diet at 24 ppm decreased methane production (P < .01); the CO2:CH4 ratios reached 15, milk production increased (P < .01), and milkfat percentage and total milkfat output decreased (P < .01), as did feed consumption, compared with cows fed diets without monensin (P < .05). Milk fatty acid composition showed evidence of depressed ruminal biohydrogenation: saturated fatty acids (P < .05) decreased and 18:1 increased (P < .001); most of the increase was seen in the trans 18:1 isomer. As with soybean oil feeding, addition of monensin also increased (P < .05) the concentration of conjugated dienes. The monensin feeding trial was repeated 161 d later with 88 cows, of which 67 received monensin in the diet in the first trial and 21 cows were newly freshened and had never received monensin. Methane production again decreased (P < .05), but this time the CO2:CH4 ratio did not change and all other monensin-related effects were absent. The ruminal microflora in the cows that had previously received monensin seemed to have undergone some adaptive changes and no longer responded as before.     

Treatment of patients admitted to the hospital with congestive heart failure: specialty-related disparities in practice patterns and outcomes

OBJECTIVES: This study sought to define specialty-related differences in the care and outcome of patients admitted to the hospital with congestive heart failure (CHF). BACKGROUND: Congestive heart failure is the leading diagnosis-related group (DRG) discharge diagnosis in the United States and accounts for an estimated annual hospital cost in excess of $7 billion. The clinical impact of aggressive CHF management and the importance of the subspecialist in guiding this care have not been evaluated. METHODS: To define differences in physician practice patterns, we performed a chart review of consecutive patients admitted to a university teaching hospital with a primary DRG discharge diagnosis of CHF. We compared treatment and outcome of patients cared for by a generalist (n = 160) and those whose care was guided by a cardiologist (n = 138) during their index hospital period with CHF and over the next 6 months. RESULTS: At our institution, > 50% of patients admitted to the hospital with CHF cared for by generalists alone had minimal (New York Heart Association functional class I or II) symptoms, compared with < 15% of those cared for by a cardiologist (p < 0.01). Although generalists' patients underwent significantly fewer in-hospital diagnostic tests and had shorter lengths of stay, they had a 1.7-fold increased risk of readmission for CHF within 6 months (p < 0.05). Six-month cardiac and all-cause mortality were not significantly different between the groups. The type of physician caring for the patient and a history of diabetes, previous CHF or myocardial infarction were independent predictors of readmission for CHF. CONCLUSIONS: Involvement of a cardiologist in the care of patients admitted to the hospital with CHF is associated with increased use of diagnostic testing, longer hospital stays and improved clinical outcome. These results substantiate practice guidelines that suggest a role for cardiologists in the care of symptomatic patients with CHF.     

Long-term outcomes in open pelvic fractures

BACKGROUND: Open pelvic fractures represent one of the most devastating injuries in orthopedic trauma. The purpose of this study was to document the injury characteristics, complications, mortality, and long-term, health-related quality of life outcomes in patients with open pelvic fractures. METHODS: The trauma registry at an adult trauma center was used to identify all multiple system blunt trauma patients with a pelvic fracture from January of 1987 to August of 1995 (n = 1,179). Demographic data, mechanism of injury, and fracture type were determined from hospital records. Short-term outcome measures included infectious complications, mortality, and length of stay in hospital. Long-term outcomes of survivors were obtained by telephone interview using the SF-36 Health Survey and the Functional Independence Measure. RESULTS: Open pelvic fractures were uncommon, occurring in 44 patients (4%). Patients with open fractures were about 9 years younger, on average, than patients with closed fractures (30 vs. 39, p < 0.001). Similarly, patients with open fractures were more likely to be male (75 vs. 57%, p < 0.02), more likely to have been involved in a motorcycle crash (27 vs. 6%, p < 0.001), and more likely to have an unstable pelvic ring disruption (45 vs. 25%, p < 0.001). Open pelvic fracture patients required more blood than closed pelvic fracture patients, both in the first day (16 vs. 4 units, p < 0.001) and during the total hospital admission (29 vs. 9 units, p < 0.001). Five patients with perineal wounds did not receive a diverting colostomy; in turn, these individuals had a total of six pelvic infectious complications (one abscess, two with osteomyelitis, and three perineal wound infections). Overall, 11 patients died, six patients were lost to follow-up, and 27 were long-term survivors (mean duration of 4 years). Chronic disability was common after a pelvic fracture, with problems related to physical role performance and physical functioning, and was particularly severe after an open pelvic fracture (p < 0.05 for both as measured by the SF-36). CONCLUSIONS: Patients with open pelvic fractures often survive, need to be treated with massive blood transfusions, and often require a colostomy. They are frequently left with chronic pain and residual disabilities in physical functioning and physical roles, and many remain unemployed years after injury.     

Numerical prediction of the instantaneous regenerator and in-cylinder heat transfer of a stirling engine

The paper is concerned with the study of the effects of the in-cylinder and regenerator heat transfer characteristics of a single-acting opposed-piston Stirling engine, with heater and cooler both omitted, for which a simulation model has been developed. The engine thermodynamic cycle is divided into a number of time-steps, and a system of nonlinear ordinary differential equations, which describe the energy balances over the three basic control volumes (hot and cold cylinders and regenerator), is solved numerically. Empirical correlations are used to determine the instantaneous heat transfer coefficients in the regenerator (flow across a porous medium) and inside the cylinder space (gas confined in a cylindrical volume with a moving boundary). Numerical results from the model are presented.     

Characterization of two biodegradable polymers of potential application within the biomaterials field

An extensive characterization of two biodegradable polymers that may constitute an alternative, if one is aiming at orthopaedic applications, to the currently used poly(glicolic acid), poly(lactic acid) or polyhydroxybutyrate was carried out. A cellulose acetate and three different grades of a novel starch based polymer were studied. The characterization included: tensile and instrumented impact tests, rheological measurements, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infra-red spectroscopy (FTIR), differential scanning calorimetry (DSC), and long-term degradation trials in Hank's solution. The results show that both polymers, specially the starch based one, present a great potential for biomedical applications, on which adequate mechanical properties associated to a controlled degradation rate are required.