586 research outputs found
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Experimental and Theoretical Studies of the Environmental Sensitivity of the Absorption Spectra and Photochemistry of Nitenpyram and Analogs
Neonicotinoid (NN) pesticides have widespread use, largely replacing other pesticides such as the carbamates. Hence, there is a need to understand their environmental fates at a molecular level in various media, especially water. We report here the studies of a nitroenamine NN, nitenpyram (NPM), in aqueous solution where the absorption cross sections in the actinic region above 290 nm are observed to dramatically decrease compared to those in nonaqueous solvents. Quantum chemical calculations show that addition of a proton to the tertiary amine nitrogen in NPM breaks the conjugation in the chromophore, shifting the absorption to shorter wavelengths, consistent with experiment. However, surprisingly, adding a proton to the secondary amine nitrogen leads to its immediate transfer to the NO2 group, preserving the conjugation. This explains why the UV absorption of ranitidine (RAN), which has a similar chromophore but only secondary amine nitrogens, does not show a similar large blue shift in water. Photolysis quantum yields in aqueous NPM solutions were measured to be φ = 0.18 ± 0.07 at 254 nm, (9.4 ± 1.6) × 10-2 with broadband radiation centered at 313 nm and (5.2 ± 1.1) × 10-2 for broadband radiation centered at 350 nm (errors are 2σ). The major products in aqueous solutions are an imine that was also formed in the photolysis of the solid and a carboxylic acid derivative that is unique to the photolysis in water. Combining the larger quantum yields in water with the reduced absorption cross sections results in a calculated lifetime of NPM of only 5 min at a solar zenith angle of 35°, typical of 40°N latitude on April 1. The products do not absorb in the actinic region and hence will be long-lived with respect to photolysis
Political control and policy-making uncertainty in executive orders: the implementation of environmental justice policy
Environmental justice (EJ) has represented an important equity challenge in policymaking for decades. President Clinton’s executive order (EO) 12898 in 1994 represented a significant federal action, requiring agencies to account for EJ issues in new rulemakings. We examine the impact of EO 12898 within the larger question of how EO are implemented in complex policymaking. We argue that presidential preferences will affect bureaucratic responsiveness and fire alarm oversight. However, EJ policy complexity produces uncertainty leading to bureaucratic risk aversion, constraining presidential efforts to steer policy. We utilise an original data set of nearly 2,000 final federal agency rules citing EO 12898 and find significant variation in its utilisation across administrations. Uncertainty over the nature of the order has an important influence on bureaucratic responsiveness. Our findings are instructive for the twin influences of political control and policy-making uncertainty and raise useful questions for future EJ and policy implementation research
Retroperitoneal haemorrhage in renal angiomyolipoma causing hepatic functional decompensation: a case report
Renal angiomyolipomata usually present as incidental findings on routine imaging, but rarely they may give rise to significant haemorrhage. If bleeding occurs, first-line treatment is currently angiography with selective embolisation. Prophylactic embolisation may be considered in some cases, depending on lesion size and patient co-morbidities
Design agency:prototyping multi-agent systems in architecture
This paper presents research on the prototyping of multi-agent systems for architectural design. It proposes a design exploration methodology at the intersection of architecture, engineering, and computer science. The motivation of the work includes exploring bottom up generative methods coupled with optimizing performance criteria including for geometric complexity and objective functions for environmental, structural and fabrication parameters. The paper presents the development of a research framework and initial experiments to provide design solutions, which simultaneously satisfy complexly coupled and often contradicting objectives. The prototypical experiments and initial algorithms are described through a set of different design cases and agents within this framework; for the generation of façade panels for light control; for emergent design of shell structures; for actual construction of reciprocal frames; and for robotic fabrication. Initial results include multi-agent derived efficiencies for environmental and fabrication criteria and discussion of future steps for inclusion of human and structural factors
Automated left ventricular diastolic function evaluation from phase-contrast cardiovascular magnetic resonance and comparison with Doppler echocardiography
International audienceBACKGROUND: Early detection of diastolic dysfunction is crucial for patients with incipient heart failure. Although this evaluation could be performed from phase-contrast (PC) cardiovascular magnetic resonance (CMR) data, its usefulness in clinical routine is not yet established, mainly because the interpretation of such data remains mostly based on manual post-processing. Accordingly, our goal was to develop a robust process to automatically estimate velocity and flow rate-related diastolic parameters from PC-CMR data and to test the consistency of these parameters against echocardiography as well as their ability to characterize left ventricular (LV) diastolic dysfunction. RESULTS: We studied 35 controls and 18 patients with severe aortic valve stenosis and preserved LV ejection fraction who had PC-CMR and Doppler echocardiography exams on the same day. PC-CMR mitral flow and myocardial velocity data were analyzed using custom software for semi-automated extraction of diastolic parameters. Inter-operator reproducibility of flow pattern segmentation and functional parameters was assessed on a sub-group of 30 subjects. The mean percentage of overlap between the transmitral flow segmentations performed by two independent operators was 99.7 ± 1.6%, resulting in a small variability ( 0.71) and receiver operating characteristic (ROC) analysis revealed their ability to separate patients from controls, with sensitivity > 0.80, specificity > 0.80 and accuracy > 0.85. Slight superiority in terms of correlation with echocardiography (r = 0.81) and accuracy to detect LV abnormalities (sensitivity > 0.83, specificity > 0.91 and accuracy > 0.89) was found for the PC-CMR flow-rate related parameters. CONCLUSIONS: A fast and reproducible technique for flow and myocardial PC-CMR data analysis was successfully used on controls and patients to extract consistent velocity-related diastolic parameters, as well as flow rate-related parameters. This technique provides a valuable addition to established CMR tools in the evaluation and the management of patients with diastolic dysfunction
Serum Penicillin G Levels Are Lower Than Expected in Adults within Two Weeks of Administration of 1.2 Million Units
When introduced in the 1950s, benzathine penicillin G (BPG) was shown to be effective in eradicating group A beta-hemolytic streptococcus (GAS) for at least 3 weeks after administration. Several studies since the 1990s suggest that at 3–4 weeks serum penicillin G levels are less than adequate (below MIC90 of 0.016 µg/ml). We studied these levels for 4 weeks after the recommended dose of BPG in military recruits, for whom it is used as prophylaxis against GAS. The 329 subjects (mean age 20 years) each received 1.2 million units BPG IM and gave sera 1 day post injection and twice more at staggered time points over 4 weeks. Serum penicillin G levels were measured by liquid chromatography/tandem mass spectometry. The half-life of serum penicillin G was 4.1 days. By day 11, mean levels were <0.02 µg/ml, and by day 15<0.01 µg/ml. Levels in more than 50% of the subjects were below 0.02 µg/ml on day 9, and <.01 µg/ml on day 16. There was no demonstrable effect of subject body-surface area nor of the four different lots of BPG used. These data indicate that in healthy young adults serum penicillin G levels become less than protective <2½ weeks after injection of 1.2 million units of BPG. The findings require serious consideration in future medical and public health recommendations for treatment and prophylaxis of GAS upper respiratory tract infections
The impact of preoperative anxiety and education level on long-term mortality after cardiac surgery
<p>Abstract</p> <p>Background</p> <p>Psychosocial factors have shown independent predictive value in the development of cardiovascular diseases. Although there is strong evidence to support the role of psychosocial factors in cardiovascular mortality, there is a scarcity of knowledge about how these factors are related. Therefore, we investigated the relationship between depression, anxiety, education, social isolation and mortality 7.5 years after cardiac surgery.</p> <p>Methods</p> <p>After informed consent, 180 patients undergoing cardiac surgery between July 2000 and May 2001 were prospectively enrolled and followed for ten years. During the follow-up period, the patients were contacted annually by mail. Anxiety (Spielberger State-Trait Anxiety Inventory, STAI-S/STAI-T), depression (Beck Depression Inventory, BDI) and the number and reason for rehospitalizations were assessed each year. Those patients who did not respond were contacted by telephone, and national registries were searched for deaths.</p> <p>Results</p> <p>During a median follow-up of 7.6 years (25<sup>th</sup> to 75<sup>th</sup> percentile, 7.4 to 8.1 years), the mortality rate was 23.6% (95% confidence interval [CI] 17.3-29.9; 42 deaths). In a Cox regression model, the risk factors associated with an increased risk of mortality were a higher EUROSCORE (points; Adjusted Hazard Ratio (AHR):1.30, 95%CI:1.07-1.58)), a higher preoperative STAI-T score (points; AHR:1.06, 95%CI 1.02-1.09), lower education level (school years; AHR:0.86, 95%CI:0.74-0.98), and the occurrence of major adverse cardiac and cerebral events during follow up (AHR:7.24, 95%CI:2.65-19.7). In the postdischarge model, the same risk factors remained.</p> <p>Conclusions</p> <p>Our results suggest that the assessment of psychosocial factors, particularly anxiety and education may help identify patients at an increased risk for long-term mortality after cardiac surgery.</p
Reliability, validity and psychometric properties of the Greek translation of the zung depression rating scale
INTRODUCTION: The current study aimed to assess the reliability, validity and psychometric properties of the Greek translation of the Zung Depression Rating Scale (ZDRS). METHODS: The study sample included 40 depressed patients 29.65 ± 9.38 years old and 120 normal comparison subjects 27.23 ± 10.62 years old. In 20 of them (12 patients and 8 comparison subjects) the instrument was re-applied 1–2 days later. Translation and Back Translation was made. Clinical Diagnosis was reached by consensus of two examiners with the use of the SCAN v.2.0 and the IPDE. Statistical Analysis included ANOVA, the Pearson Product Moment Correlation Coefficient, Principal Components Analysis and Discriminant Function Analysis and the calculation of Cronbach's alpha (α) RESULTS: Both Sensitivity and specificity exceed 90.00 at 44/45, Chronbach's alpha for the total scale was equal to 0.09, suggesting that the scale covers a broad spectrum of symptoms. Factor analysis revealed five factors (anxiety-depression, thought content, gastrenterological symptoms, irritability and social-interpersonal functioning). The test-retest reliability was satisfactory (Pearson's R between 0.92). CONCLUSION: The ZDRS-Greek translation is both reliable and valid and is suitable for clinical and research use with satisfactory properties. Its properties are similar to those reported in the international literature, although the literature is limited. However one should always have in mind the limitations inherent in the use of self-report scales
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Weak Polygyny in California Sea Lions and the Potential for Alternative Mating Tactics
Female aggregation and male territoriality are considered to be hallmarks of polygynous mating systems. The development of genetic parentage assignment has called into question the accuracy of behavioral traits in predicting true mating systems. In this study we use 14 microsatellite markers to explore the mating system of one of the most behaviorally polygynous species, the California sea lion (Zalophus californianus). We sampled a total of 158 female-pup pairs and 99 territorial males across two breeding rookeries (San Jorge and Los Islotes) in the Gulf of California, Mexico. Fathers could be identified for 30% of pups sampled at San Jorge across three breeding seasons and 15% of sampled pups at Los Islotes across two breeding seasons. Analysis of paternal relatedness between the pups for which no fathers were identified (sampled over four breeding seasons at San Jorge and two at Los Islotes) revealed that few pups were likely to share a father. Thirty-one percent of the sampled males on San Jorge and 15% of the sampled males on Los Islotes were assigned at least one paternity. With one exception, no male was identified as the father of more than two pups. Furthermore, at Los Islotes rookery there were significantly fewer pups assigned paternity than expected given the pool of sampled males (p<0.0001). Overall, we found considerably lower variation in male reproductive success than expected in a species that exhibits behavior associated with strongly polygynous mating. Low variation in male reproductive success may result from heightened mobility among receptive females in the Gulf of California, which reduces the ability of males to monopolize groups of females. Our results raise important questions regarding the adaptive role of territoriality and the potential for alternative mating tactics in this species
Performance of two questionnaires to measure treatment adherence in patients with Type-2 Diabetes
<p>Abstract</p> <p>Background</p> <p>Most valid methods to measure treatment adherence require time and resources, and they are not easily applied in highly demanding Primary Health Care Clinics (PHCC). The objective of this study was to determine sensitivity, specificity, predictive values, likelihood ratios, and post-test probabilities of two novel questionnaires as proxy measurements of treatment adherence in Type-2 diabetic patients.</p> <p>Methods</p> <p>Two questionnaires were developed by a group of experts to identify the patient's medical prescription knowledge (knowledge) and their attitudes toward treatment adherence (attitudes) as proxy measurements of adherence. The questionnaires were completed by patients receiving care in PHCC pertaining to the Mexican Institute of Social Security in Aguascalientes (Mexico). Pill count was used as gold standard. Participants were selected randomly, and their oral hypoglycemic prescriptions were studied. The main outcome measures for each questionnaire were sensitivity, specificity, predictive values, likelihood ratios, and post-test probabilities, all as an independent questionnaire test and in a serial analysis.</p> <p>Results</p> <p>Adherence prevalence was 27.0% using pill count. Knowledge questionnaire showed the highest sensitivity (68.1%) and negative predictive value (82.2%), the lowest negative likelihood ratio (0.58) and post-test probability for a negative result (0.16). Serial analysis showed the highest specificity (77.4%) and positive predictive value (40.1%) as well as the highest positive likelihood ratio (1.8) and post-test probability for a positive result (0.39).</p> <p>Conclusion</p> <p>Medical Prescription Knowledge questionnaire showed the best performance as proxy measurement to identify non-adherence in type 2 diabetic patients regarding negative predictive value, negative likelihood ratio, and post-test probability for a negative result. However, Medical Prescription Knowledge questionnaire performance may change in contexts with higher adherence prevalence. Therefore, more research is needed before using this method in other contexts.</p
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