When You Wore A Tulip and I Wore A Big Red Rose

https://digitalcommons.library.umaine.edu/mmb-vp/2703/thumbnail.jp

I Love Her : Oh! Oh! Oh!

https://digitalcommons.library.umaine.edu/mmb-vp/3172/thumbnail.jp

Products and Ratios of Characteristic Polynomials of Random Hermitian Matrices

We present new and streamlined proofs of various formulae for products and ratios of characteristic polynomials of random Hermitian matrices that have appeared recently in the literature.Comment: 18 pages, LaTe

Perception of physicians about medical education received during their Nephrology residency

Introduction: In Peru there are different hospitals and university programs for training of specialists in nephrology. Objective: To assess the perception of physicians who attend such programs. Methods: We carried out a descriptive cross-sectional national-level study in physicians who were in the last two years of nephrology training during February 2012 and who had graduated from it in 2010 and 2011. A self-applied questionnaire was developed along with the Peruvian Society of Nephrology based on international standards. The questionnaire evaluated: mentoring, clinical training, procedures, external rotations, research and global perception. Results: Forty doctors were surveyed nationwide. 82.5% had tutors, 22.5% of them said their support was poor. A 27.5% described their theoretical formation as deficient. The practical training was perceived as acceptable globally; however, improvements in training on peritoneal dialysis and reading kidney transplant biopsies are necessary. A 90% have national external rotations and 65% reported to have an international rotation. In the assessment of research, 77.5% thought this is deficient. In addition, 82.5% believed that residency should last four years. However, 60% reported that their residency training was good. There is a decrease in the positive perception of the aspects studied among residents regarding graduates. Conclusion: The overall perception of nephrology residency training was considered good; however, areas of tutoring, and academic and research activities on average were deficient.Revisión por pare

Spots structure and stratification of helium and silicon in the atmosphere of He-weak star HD 21699

The magnetic star HD 21699 possesses a unique magnetic field structure where the magnetic dipole is displaced from the centre by 0.4 +/- 0.1 of the stellar radius (perpendicularly to the magnetic axis), as a result, the magnetic poles are situated close to one another on the stellar surface with an angular separation of 55$^o$ and not 180$^o$ as seen in the case of a centred dipole. Respectively, the two magnetic poles form a large "magnetic spot". High-resolution spectra were obtained allowing He I and Si II abundance variations to be studied as a function of rotational phase. The results show that the helium abundance is concentrated in one hemisphere of the star, near the magnetic poles and it is comparatively weaker in another hemisphere, where magnetic field lines are horizontal with respect to the stellar surface. At the same time, the silicon abundance is greatest between longitudes of 180 - 320$^o$, the same place where the helium abundance is the weakest. These abundance variations (with rotational phase) support predictions made by the theory of atomic diffusion in the presence of a magnetic field. Simultaneously, these result support the possibility of the formation of unusual structures in stellar magnetic fields. Analysis of vertical stratification of the silicon and helium abundances shows that the boundaries of an abundance jump (in the two step model) are similar for each element; $\tau_{5000}$ = 0.8-1.2 for helium and 0.5-1.3 for silicon. The elemental abundances in the layers of effective formation of selected absorption lines for various phases are also correlated with the excitation energies of low transition levels: abundances are enhanced for higher excitation energy and higher optical depth within the applied model atmosphere.Comment: accepted by MN, 7 pagers, 10 figs, 3 table

Microscale Quantification of the Absorption by Dissolved and Particulate Material in Coastal Waters with an ac-9

Measuring coastal and oceanic absorption coefficients of dissolved and particulate matter in the visible domain usually requires a methodology for amplifying the natural signal because conventional spectrophotometers lack the necessary sensitivity. The WET Labs ac-9 is a recently developed in situ absorption and attenuation meter with a precision better than ±0.001 m−1 in the raw signal, which is sufficient to make these measurements in pristine samples. Whereas the superior sensitivity of the ac-9 has been well documented, the accuracy of in situ measurements for bio-optical applications has not been rigorously evaluated. Obtaining accurate results with an ac-9 requires careful attention to calibration procedures because baselines drift as a result of the changing optical properties of several ac-9 components. To correct in situ measurements for instrument drift, a pressurized flow procedure was developed for calibrating an ac-9 with optically clean water. In situ, micro- (cm) to fine- (m) scale vertical profiles of spectral total absorption, at(λ), and spectral absorption of dissolved materials, ag(λ), were then measured concurrently using multiple meters, corrected for drift, temperature, salinity, and scattering errors and subsequently compared. Particulate absorption, ap(λ), was obtained from at(λ) − ag(λ). CTD microstructure was simultaneously recorded. Vertical profiles of ag(λ), at(λ), and ap(λ) were replicated with different meters within ±0.005 m−1, and spectral relationships compared well with laboratory measurements and hydrographic structure

The Need for Knowledge Extraction: Understanding Harmful Gambling Behavior with Neural Networks

Responsible gambling is a field of study that involves supporting gamblers so as to reduce the harm that their gambling activity might cause. Recently in the literature, machine learning algorithms have been introduced as a way to predict potentially harmful gambling based on patterns of gambling behavior, such as trends in amounts wagered and the time spent gambling. In this paper, neural network models are analyzed to help predict the outcome of a partial proxy for harmful gambling behavior: when a gambler “self-excludes”, requesting a gambling operator to prevent them from accessing gambling opportunities. Drawing on survey and interview insights from industry and public officials as to the importance of interpretability, a variant of the knowledge extraction algorithm TREPAN is proposed which can produce compact, human-readable logic rules efficiently, given a neural network trained on gambling data. To the best of our knowledge, this paper reports the first industrial-strength application of knowledge extraction from neural networks, which otherwise are black-boxes unable to provide the explanatory insights which are crucially required in this area of application. We show that through knowledge extraction one can explore and validate the kinds of behavioral and demographic profiles that best predict self-exclusion, while developing a machine learning approach with greater potential for adoption by industry and treatment providers. Experimental results reported in this paper indicate that the rules extracted can achieve high fidelity to the trained neural network while maintaining competitive accuracy and providing useful insight to domain experts in responsible gambling

Prevalence of chronic kidney disease in Peruvian primary care setting.

Background: Chronic Kidney Disease (CKD) is a worldwide public health problem. There are few studies in Latin America, especially in primary care settings. Our objective was to determine the prevalence, stages, and associated factors of CKD in primary care setting. Methods: We did a retrospective secondary analysis of a database from the Diabetes and Hypertension Primary Care Center of the Peruvian Social Security System (EsSalud) in Lima, Peru. We defined CKD as the presence of eGFR 30 mg/day in 24 h, according to Kidney Disease: Improving Global Outcomes (KDIGO). Factors associated with CKD were evaluated with Poisson Regression models; these factors included age, gender, type 2 diabetes mellitus (DM2), hypertension (HTN), body mass index (BMI), and uric acid. Associations were described as crude and adjusted prevalence ratios (PR) and their 95% confidence intervals (95% CI). Results: We evaluated 1211 patients (women [59%], mean age 65.8 years [SD: 12.7]). Prevalence of CKD was 18%. Using the estimated glomerular filtration rate (eGFR), the prevalence was 9.3% (95% CI 5.3 – 13.3) in patients without HTN or DM2; 20.2% (95% CI 17.6 – 22.8) in patients with HTN, and 23.9% (95% CI 19.4 – 28.4) in patients with DM2. The most common stages were 1 and 2 with 41.5% and 48%, respectively. Factors associated with CKD in the adjusted analysis were: age in years (PR = 1.03, 95% CI 1.01 – 1.04), DM2 (PR = 3.37, 95% CI 1.09 – 10.39), HTN plus DM2 (PR = 3.90, 95% CI 1.54 – 9.88), and uric acid from 5 to <7 mg/dL (PR = 2.04, 95% CI 1.31 – 3.19) and ≥7 mg/dL (PR = 5.19, 95% CI 3.32 – 8.11). Conclusions: Prevalence of CKD in the primary care setting population was high. CKD is more frequent in the early stages of the disease, and individuals with hypertension, DM2, older age and hyperuricemia have higher prevalence of CKD.Revisión por pare

In-hospital mortality among incident hemodialysis older patients in Peru.

BACKGROUND: Understanding the pattern of mortality linked to end stage renal disease (ESRD) is important given the increasing ageing population in low- and middle-income countries. METHODS: We analyzed older patients with ESRD with incident hemodialysis, from January 2012 to August 2017 in one large general hospital in Peru. Individual and health system-related variables were analyzed using Generalized Linear Models (GLM) to estimate their association with in-hospital all-cause mortality. Relative risk (RR) with their 95% confidence intervals (95% CI) were calculated. RESULTS: We evaluated 312 patients; mean age 69 years, 93.6% started hemodialysis with a transient central venous catheter, 1.7% had previous hemodialysis indication and 24.7% died during hospital stay. The mean length of stay was 16.1 days (SD 13.5). In the adjusted multivariate models, we found higher in-hospital mortality among those with encephalopathy (aRR 1.85, 95% CI 1.21-2.82 vs. without encephalopathy) and a lower in-hospital mortality among those with eGFR ≤7 mL/min (aRR 0.45, 95% CI 0.31-0.67 vs. eGFR>7 mL/min). CONCLUSIONS: There is a high in-hospital mortality among older hemodialysis patients in Peru. The presence of uremic encephalopathy was associated with higher mortality and a lower estimated glomerular filtration rate with lower mortality