Using CDOM spectral shape information to improve the estimation of DOC concentration in inland waters: A case study of Andean Patagonian Lakes.

For the last two decades different scientific disciplines have focused on lacustrine dissolved organic matter (DOM) given its importance in the biogeochemistry of carbon and in ecosystem functioning. New satellites supply the appropriate resolutions to evaluate chromophoric dissolved organic matter (CDOM) in inland waters, opening the possibility to estimate DOM at appropriate spatiotemporal scales. This requires, however, a robust relationship between CDOM and dissolved organic carbon (DOC). In this work, we evaluated the use of CDOM as a proxy of DOC in 7 Andean Patagonian lakes. Considering the entire data set, CDOM absorption coefficients (a355 and a440) were linearly related with DOC. Shallow lakes, however, drove this relationship showing a moderate relationship, whereas, deep lakes with lower colour presented a weaker relationship. Therefore, we assessed the use of CDOM spectral shape information to improve DOC estimates regardless of observed DOM differences due to climatic seasonality and lakes' morphometry. The use of well-known CDOM spectral shape metrics (i.e., S275-295 and a250:a365 ratio) significantly improved DOC estimation. Particularly, using a Gaussian decomposition approach we found that much of the variation in the spectral shape, associated with the variability of CDOM:DOC ratio, was explained by differences in two dynamic regions centred at 270 and 320 nm. A strong nonlinear relationship was found between the a270:a320 ratio and the DOC-specific absorption coefficients a*355 and a*440. This was translated into a further improvement in DOC estimation yielding the higher R2 and lower mean absolute differences (MAPD < 16%), either considering the entire data set or shallow and deep lakes separately. Our results highlight that incorporating the CDOM spectral shape information improves the characterization of the DOC pool of inland waters, which is particularly relevant for remote and/or inaccessible sites and has significant implications for the environmental management, biogeochemical studies and future remote sensing applications.

Quality assessment of randomised controlled trials in oral and maxillofacial surgery.

Randomised controlled trials are the best way to study the evaluation of treatments. We have evaluated the quantity and quality of clinical trials in three of the main journals in the specialty of oral and maxillofacial surgery between January 2010 and December 2016, using a scientometric analysis, and evaluation by the Jadad scale. In this period, 303 randomised controlled trials (5% of the total) were identified; the largest number of studies were from Asia (45%) followed by Europe (32%). The subgroup that concerned most studies was oral surgery. The mean score on the Jadad scale was 3.06 points, which means that 32% of the total studies had a low risk of bias. Studies that declared funding and adherence to Consolidated Standards of Reporting Trials (CONSORT) were given significantly higher scores (p<0.001) than studies that did not. We conclude that randomised controlled trials in oral maxillofacial surgery have evolved in both quality and quantity since previous surveys were published. The quality of trials was related to the presence of funding and adherence to CONSORT.

Fluorescence components of natural dissolved organic matter (DOM) from aquatic systems of an Andean Patagonian catchment: Applying different data restriction criteria for PARAFAC modelling.

Fluorescence spectroscopy is a widely applied technique to characterize the composition of the fluorescent fraction of dissolved organic matter (DOM), allowing to infer sources and diagenetic state of soil, marine and freshwater DOM samples. The analysis of fluorescent DOM (FDOM) is often carried out by multi-way models such as parallel factor analysis (PARAFAC), which allows decomposing excitation-emission matrices (EEMs) obtained from DOM samples into their underlying chemical components. Some aspects of the performance/accuracy of the EEM-PARAFAC technique regarding the use of selective vs. non-selective EEM data are still in discussion. In this investigation, we evaluated the outcome of two different approaches (non-selective and selective) applied to study the composition of DOM from four headwater streams (Case 1) and from two neighboring shallow lakes (Case 2), all belonging to the same Andean watershed within Nahuel Huapi National Park in North Patagonia (Argentina). In both cases, the outcome of the PARAFAC performed to non-selective data (EEM datasets from all the streams and the two lakes) vs. selective datasets (EEMs from each stream and each lake treated separately) is compared on the basis of modelled fluorescent components. Regardless of the restriction criteria applied for the analyses, the results obtained indicated similar component loadings in the four streams and in the two lakes. The similarity of the outcomes likely relates to the low internal variation of the EEMs, since these are located in the same catchment, influenced by similar soils and vegetation which are the main DOM sources. Therefore, we conclude that the use of a small selective EEM dataset may not condition the validation of the FDOM components and their temporal dynamics.

Endocarditis due to vancomycin-resistant Enterococcus raffinosus successfully treated with linezolid: case report and review of literature.

Enterococcus raffinosus is scarcely found in clinical samples and even less frequently as etiologic agent of endocarditis. We are herein presenting one case of mitral prosthetic-valve endocarditis in a 77-y-o male due to a vancomycin-resistant Enterococcus raffinosus isolate, successfully treated with 6 weeks of linezolid, and a two-year follow up.

Lateral sinus thrombosis associated with otitis media and mastoiditis in children.

Lateral sinus thrombosis (LST) is an infrequent complication of otitis media and mastoiditis in the antibiotic era. A recent case of LST in a 7-year-old boy, the third such case at our institutions in the past 5 years, prompted a review of the modern day English literature concerning LST in pediatric patients. Our goal was to highlight the clinical findings suggestive of LST in the antibiotic era as well as to analyze retrospectively the diagnostic and therapeutic modalities of greatest benefit based on the outcomes reported in the reviewed studies.

The kinetic mechanism of glutathione peroxidase from human platelets.

Human platelet glutathione peroxidase (GSH-Px) exhibits a ping-pong type kinetic mechanism. Peroxide changes the redox state of the enzyme and renders it highly stable against attack by alkylating agents. Peroxide seems also to act as a positive homotropic modulator modifying the allosteric kinetics of the enzyme. The combination of these two mechanisms accelerates response against peroxides. This finding reassesses importance of GSH-Px for the platelet protection.

Effectiveness of educational strategies preparing physician assistants, nurse practitioners, and certified nurse-midwives for underserved areas.

A study of physician assistant, nurse practitioner, and certified nurse midwifery programs was undertaken to identify and assess the effectiveness of recruitment, educational, and deployment strategies that programs use to prepare practitioners for medically underserved areas. The 51 programs studied were those having mission statements or known track records relating to this goal. A total of 170 interviews were conducted with faculty, students, graduates, and employers from 9 programs visited on-site and 42 programs surveyed by telephone. All programs had some recruitment and training activities in underserved sites. Only about half of the programs were able to submit data on their graduates' practice settings and specialties. These data suggest that older students who have backgrounds in underserved areas and clearly identified practice goals are more likely to practice in underserved areas. Programs that actively promote service to the underserved do so through publicly stated missions and recruitment and educational strategies that complement these missions. Such programs also are more likely to evaluate and document their success than programs that lack strategies.

Recruitment and retention of minority students in a physician assistant program.

The authors report two years of experience in the recruitment and retention of minority physician assistant students and the employment patterns of graduates from one physician assistant program. Recruitment strategies increased the proportion of minority students to 54 percent in the first year of the program and to 44 percent in the second year. The number of years of postsecondary education and clinical experience acquired by the minority students before admission to the program tended to have less impact on their performance in training than did their prior completion of formal academic degree programs and prior level of clinical responsibility. Attrition was higher for the minority students than nonminority students, and the minority students took longer than nonminority students to complete the program. The rates at which the students passed the certifying examination of the National Commission on Certification of Physician's Assistants were comparable for the two groups. Minority graduates tended to practice in areas of health manpower shortage.

Educational decentralization and deployment of physician's assistants.

A community-based educational network was established to improve the deployment of physician's assistants away from the original site of training in California's San Francisco Bay Area. The philosophy underlying the program decentralization, lessons learned during its implementation, and outcomes of the decentralization are discussed. The graduates' practice locations for a seven-year period are compared before and after the decentralization of the program. Before decentralization, 58 percent of the graduates established their first practice outside of the Bay Area. Following decentralization, 100 percent of the students trained entirely within community settings took their first jobs away from the Bay Area. Unique aspects of this decentralization experience compared with those reported previously included the lack of a required student-preceptor match at the time of entry into the program, the provision of clinical training in or near the site of student residence, and the opportunity to compare before and after effects of decentralizing educational components other than preceptorships.