Combined Effect of Temperature and Relative Humidity on the Survival of Salmonella Isolates on Stainless Steel Coupons

The survival on stainless steel of ten Salmonella isolates from food factory, clinical and veterinary sources was investigated. Stainless steel coupons inoculated with Salmonella were dried and stored at a range of temperatures and relative humidity (RH) levels representing factory conditions. Viability was determined from 1 to 22 days. Survival curves obtained for most isolates and storage conditions displayed exponential inactivation described by a log-linear model. Survival was affected by environmental temperatures and RH with decimal reduction times (DRTs) ranging from <1 day to 18 days. At 25 °C/15% RH, all isolates survived at levels of 103 to 105 cfu for >22 days. Furthermore, temperatures and RH independently influenced survival on stainless steel; increasing temperatures between 10 °C and 37 °C and increasing RH levels from 30–70% both decreased the DRT values. Survival curves displaying a shoulder followed by exponential death were obtained for three isolates at 10 °C/70% RH. Inactivation kinetics for these were described by modified Weibull models, suggesting that cumulative injury occurs before cellular inactivation. This study highlights the need to control temperature and RH to limit microbial persistence in the food manufacturing environment, particularly during the factory shut-down period for cleaning when higher temperature/humidity levels could be introduced.

Mate Selection Behavior of GED Recipients

The General Educational Development (GED) degree is designed to be a credential equivalent to the high school diploma. However, growing evidence indicates that GED recipients have worse outcomes than high school graduates. Such findings raise the question: is the GED socially equivalent to the high school diploma? Although educational assortative mating patterns have long been used as a barometer of the social distance across educational groups, there has not been a study that has addressed this question by examining the marital sorting patterns of GED recipients. Using log-linear models, our study shows that the odds of intermarriage between GED recipients and high school graduates resemble those between GED recipients and those without a secondary degree. Racial/ethnic minorities had greater difficulty crossing the GED/high school graduate boundary when they married. Our findings detract from the purported view that the GED degree is equivalent to a traditional high school diploma.

Characteristics of severely malnourished under-five children immunized with Bacillus Calmette-Guérin following Expanded Programme on Immunization schedule and their outcomes during hospitalization at an urban diarrheal treatment centre, Bangladesh

Background Bacillus Calmette-Guérin (BCG) vaccination has recently been found to have beneficial effects among children infected other than Mycobacterium tuberculosis. Due to the paucity of data on the outcomes of children who had successful BCG vaccination following Expanded Programme on Immunization (EPI) schedule, we aimed to investigate the characteristics of such children and their outcomes who were hospitalized for severe malnutrition. Methods A prospective observational study was conducted to determine the viral etiology of pneumonia in severely malnourished children those were admitted to the Dhaka Hospital of International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) between April 2015 and December 2017, constituted the study population. Using a case-control design for the analysis, children having BCG vaccination prior hospital admission were treated as cases (n = 611) and those without vaccination, constituted as controls (n = 83). Bi-variate analysis was conducted using socio-demographic, clinical, laboratory, and treatment characteristics on admission and outcomes during hospitalization. Finally, log-linear binomial regression analysis was done to identify independent impact of BCG vaccination. Results The cases more often presented with older age, have had lower proportion of maternal illiteracy, higher rate of breastfeeding, severe wasting and lower rate of hypoglycemia, compared to the controls. The cases were also found to have lower risk of severe sepsis and deaths, compared to the controls (for all, p<0.05). However, in log-linear binomial regression analysis, after adjusting for potential confounders, BCG vaccination following EPI schedule (RR:0.54; 95%CI = 0.33–0.89; p = 0.015) and breastfeeding (RR:0.53; 95%CI = 0.35–0.81; p = 0.003) were found to be protective for the development of severe sepsis. Conclusion BCG vaccination and breastfeeding were found to be protective for the development of severe sepsis in hospitalized severely malnourished under-five children which underscores the importance of continuation of BCG vaccination at birth and breastfeeding up to two years of age.

Thyroid-stimulating hormone levels in euthyroid patients 8 years following bariatric surgery

Background Bariatric surgery (BS) was shown to promote a decline in thyroid-stimulating hormone (TSH) in euthyroid patients with severe obesity in the short-term. Aim of the present study was to assess the effect of weight loss on thyroid function in euthyroid patients in the long-term following different bariatric procedures. Methods In a retrospective cohort study including 135 patients at baseline, thyroid function was assessed at six time points up to 8 years after surgery. Patients were stratified by TSH levels at baseline and divided into two groups to compare the change in TSH at long-time. We used log-linear regression to assess the relation between thyroid hormones and TSH and linear regression analyses to identify variables that were thought to determine TSH and fT3/fT4-ratio as well as their change long-term. Results Over a mean follow-up of 8 years, TSH and fT3/fT4-ratio declined (both p < 0.001). Patients with high-normal TSH showed a greater decline in TSH than those with normal TSH compared to baseline. Thyroid hormones and TSH displayed a negative log-linear correlation at long-term follow-up. Change in TSH at long-time showed a negative correlation with TSH at baseline (B = −0.55; p < 0.001). With regard to type of surgery, there were no significant differences in TSH. Conclusion BS promotes a decline of TSH in euthyroid patients up to 8 years after intervention despite weight regain. The greatest change in TSH was seen among patients with high-normal baseline-TSH. Results of log-linear regression suggest recovery of the pituitary-thyroid axis. Type of surgery did not affect the change in TSH levels over time.

Redução do número de empreendimentos agrícolas no Brasil

Resumo: Questões relacionadas aos empreendimentos agrícolas vêm sendo discutidas em todo o mundo, o que ocorre pela importância deles no desenvolvimento econômico das nações, por estarem diretamente relacionados às transformações sociais dentro e fora do campo e por serem imprescindíveis para a produção e a oferta de alimentos, bem como para a segurança alimentar. Neste contexto, o objetivo deste estudo foi caracterizar as tendências de variação no número de empreendimentos agrícolas no Brasil, por tipo de atividade principal e por estrato de área, para o período de 2004 a 2015. Para tanto, foram utilizados dados da Pesquisa Nacional por Amostra de Domicílios e calculadas as taxas médias de variação anual, por meio do teste t de Student, utilizando uma regressão dos mínimos quadrados ordinários na forma log-linear. Entre 2004 e 2015, foi constatada queda de 3,3% a.a. no número de empreendimentos agropecuários no Brasil, totalizando uma redução de 1.382.700 unidades produtivas. Também foi observado que as reduções mais intensas ocorreram nos empreendimentos agrícolas dedicados à produção de arroz (–13,4% a.a.), nos de lavouras temporárias (–12,5% a.a.) e naqueles com área de ≥ 50 a < 100 hectares (–4,5% a.a.). Tais constatações são relevantes e permitem o delineamento de ações voltadas à segurança alimentar e nutricional no Brasil.

Urinary Biomarkers and Attainment of Cefepime Therapeutic Targets in Critically Ill Children

INTRODUCTION: The recommended therapeutic target for cefepime (FEP) is the time above MIC (fT>MIC). The frequency of target attainment and risk factor for sub-therapeutic concentrations in children have not been extensively studied. METHODS: We performed a prospective observational pilot study in children in our PICU receiving standard dosing of FEP for suspected sepsis (≥2 SIRS criteria). Three FEP concentrations were measured per subject and a urine sample was collected prior to PK sampling for measurement of urinary biomarkers. We used log linear regression to calculate the fT>MIC for each subject across a range of MIC values (1-16 µg/mL). We compared clinical factors/biomarkers between patients who did and did not achieve 100% fT>MIC for 8 µg/mL (cut-point for Pseudomonas) and tested the correlation between covariates and FEP troughs. RESULTS: 21 subjects were enrolled (median SIRS criteria: 3). PK sampling occurred after a median of 5 doses (range: 3-9). 43% of subjects achieved 100% fT>MIC for an MIC of 8 µg/mL. Younger age (p=.005), higher estimated GFR (p=.03), and lower urinary NGAL (p=.006) and KIM-1 (.03) were associated with failure to attain 100% fT>8 µg/mL. Age (r = 0.53), eGFR (r = -0.58), urinary NGAL (r = 0.42) and KIM-1 (r = 0.50) were significantly correlated with FEP troughs. CONCLUSIONS: A significant proportion of critically ill children failed to attain target concentrations for treatment of Pseudomonas aeruginosa with FEP. Younger patients and those with good kidney function (high GFR, low urinary biomarkers) may be at highest risk for subtherapeutic FEP concentrations.

Disposição a Pagar por Espaços Verdes Urbanos

O artigo buscou responder: quanto os frequentadores do parque Araçá (Recife - Pernambuco) estão dispostos a pagar por melhorias propostas - cenário com melhoria da qualidade ambiental - na área de estudo? Aplicamos o método de valoração contingente para estimar o valor econômico da área, avaliando a Disposição a pagar (DAP) de seus frequentadores. Buscamos entender quais os fatores socioeconômicos contribuem nas preferências dos usuários por visitação ao parque. O modelo adotado foi um Probit Bivariado com perguntas duplas (dicotômicas). Calculamos dois modelos para estimar a DAP – forma funcional linear na renda e forma funcional log linear na renda. O primeiro teve DAP de R$ 11,71, enquanto o segundo foi de R$ 11,23. O resultado de ambos os modelos mostrou que o valor do lance oferecido a exerce maior influência sobre probabilidade de os entrevistados dizerem sim. E que, fatores como o sexo, a idade e o nível de escolaridade dos entrevistados não se mostraram bons fatores explicativos da aceitação do lance. A distância da moradia em relação parque, o dia em que ocorre a visita e o tempo de visita são variáveis que explicaram bem a aceitação do lance. Ao final calculamos o excedente do consumidor, R$ 545.151,90 (modelo logLinear) e R$ 568.075,52 (modelo linear).

Bayesian Fatigue Life Prediction of Corroded Steel Reinforcing Bars

This paper presents a general method for fatigue life prediction of corroded steel reinforcing bars. A fatigue testing on standard specimens with pitting corrosion is carried out to obtain corrosion fatigue data. The maximum corrosion degree (MCD), characterizing the most severe site of the corrosion pit, is identified to have a log-linear relationship with the fatigue life. A fatigue life model incorporating the MCD and the stress range for corroded steel reinforcing bars is proposed. The model parameters are identified using the testing data, and the model is considered as the baseline model. To utilize the proposed model for life prediction of corroded steel reinforcing bars with different geometries and working conditions, the Bayesian method is employed to update the baseline model. The effectiveness of the overall method is demonstrated using independent datasets of realistic steel reinforcing bars.

Bending of the concentration discharge relationship can inform about in-stream nitrate removal

Nitrate (NO3-) excess in rivers harms aquatic ecosystems and can induce detrimental algae growths in coastal areas. Riverine NO3- uptake is a crucial element of the catchment-scale nitrogen balance and can be measured at small spatiotemporal scales, while at the scale of entire river networks, uptake measurements are rarely available. Concurrent, low-frequency NO3- concentration and streamflow (Q) observations at a basin outlet, however, are commonly monitored and can be analyzed in terms of concentration discharge (C–Q) relationships. Previous studies suggest that steeper positive log (C)–log (Q) slopes under low flow conditions (than under high flows) are linked to biological NO3- uptake, creating a bent rather than linear log (C)–log (Q) relationship. Here we explore if network-scale NO3- uptake creates bent log (C)–log (Q) relationships and when in turn uptake can be quantified from observed low-frequency C–Q data. To this end we apply a parsimonious mass-balance-based river network uptake model in 13 mesoscale German catchments (21–1450 km2) and explore the linkages between log (C)–log (Q) bending and different model parameter combinations. The modeling results show that uptake and transport in the river network can create bent log (C)–log (Q) relationships at the basin outlet from log–log linear C–Q relationships describing the NO3- land-to-stream transfer. We find that within the chosen parameter range the bending is mainly shaped by geomorphological parameters that control the channel reactive surface area rather than by the biological uptake velocity itself. Further we show that in this exploratory modeling environment, bending is positively correlated to percentage of NO3- load removed in the network (Lr.perc) but that network-wide flow velocities should be taken into account when interpreting log (C)–log (Q) bending. Classification trees, finally, can successfully predict classes of low (∼4 %), intermediate (∼32 %) and high (∼68 %) Lr.perc using information on water velocity and log (C)–log (Q) bending. These results can help to identify stream networks that efficiently attenuate NO3- loads based on low-frequency NO3- and Q observations and generally show the importance of the channel geomorphology on the emerging log (C)–log (Q) bending at network scales.

A halogen budget of the bulk silicate Earth points to a history of early halogen degassing followed by net regassing

Halogens are important tracers of various planetary formation and evolution processes, and an accurate understanding of their abundances in the Earth’s silicate reservoirs can help us reconstruct the history of interactions among mantle, atmosphere, and oceans. The previous studies of halogen abundances in the bulk silicate Earth (BSE) are based on the assumption of constant ratios of element abundances, which is shown to result in a gross underestimation of the BSE halogen budget. Here we present a more robust approach using a log-log linear model. Using this method, we provide an internally consistent estimate of halogen abundances in the depleted mid-ocean ridge basalts (MORB)-source mantle, the enriched ocean island basalts (OIB)-source mantle, the depleted mantle, and BSE. Unlike previous studies, our results suggest that halogens in BSE are not more depleted compared to elements with similar volatility, thereby indicating sufficient halogen retention during planetary accretion. According to halogen abundances in the depleted mantle and BSE, we estimate that ∼87% of all stable halogens reside in the present-day mantle. Given our understanding of the history of mantle degassing and the evolution of crustal recycling, the revised halogen budget suggests that deep halogen cycle is characterized by efficient degassing in the early Earth and subsequent net regassing in the rest of Earth history. Such an evolution of deep halogen cycle presents a major step toward a more comprehensive understanding of ancient ocean alkalinity, which affects carbon partitioning within the hydrosphere, the stability of crustal and authigenic minerals, and the development of early life.