Evaluation of modelling approaches for predicting the spatial distribution of soil organic carbon stocks at the national scale

Soil organic carbon (SOC) plays a major role in the global carbon budget. It can act as a source or a sink of atmospheric carbon, thereby possibly influencing the course of climate change. Improving the tools that model the spatial distributions of SOC stocks at national scales is a priority, both for monitoring changes in SOC and as an input for global carbon cycles studies. In this paper, we compare and evaluate two recent and promising modelling approaches. First, we considered several increasingly complex boosted regression trees (BRT), a convenient and efficient multiple regression model from the statistical learning field. Further, we considered a robust geostatistical approach coupled to the BRT models. Testing the different approaches was performed on the dataset from the French Soil Monitoring Network, with a consistent cross-validation procedure. We showed that when a limited number of predictors were included in the BRT model, the standalone BRT predictions were significantly improved by robust geostatistical modelling of the residuals. However, when data for several SOC drivers were included, the standalone BRT model predictions were not significantly improved by geostatistical modelling. Therefore, in this latter situation, the BRT predictions might be considered adequate without the need for geostatistical modelling, provided that i) care is exercised in model fitting and validating, and ii) the dataset does not allow for modelling of local spatial autocorrelations, as is the case for many national systematic sampling schemes

Fertilité des sols: conclusions du rapport sur l'état des sols de France

Les sols constituent une ressource naturelle non renouvelable. Leurs usages et leur devenir représentent un enjeu collectif majeur, tant pour les activités agricoles ou sylvicoles que pour la préservation de la qualité de notre environnement. Après dix ans de travaux, le Groupement d’Intérêt Scientifique sur les sols, le Gis Sol, a dressé le premier bilan scientifiquement quantifié de l’état des sols de France métropolitaine et d’Outre-mer dans un rapport sur l’état des sols de France publié en 2011. Ce rapport relève des points positifs mais également un certain nombre de préoccupations du point de vue de la fertilité. Les sols agricoles ne présentent pas d’évolution mesurable de leur acidité, ce quiindique une bonne gestion du pH à l’échelle nationale. Le rapport fait en revanche état de teneurs en phosphore relativement faibles pour de nombreux sols, et à l’inverse de situations d’excédents très préoccupantes en raison de son impact sur la qualité des eaux et l’eutrophisation des milieux. Il pose ainsi la question de la durabilité à long terme du système agricole actuel et celle d’une meilleure valorisation des effluents d’élevage. D’assez nombreuses situations pourraient également être susceptibles de provoquer des carences en oligo-éléments pour des cultures exigeantes. Enfin, une inquiétude majeure concerne la progression de l’artificialisation des sols, qui s’est accélérée durant la dernière décennie et occasionne des pertes importantes de sols agricoles.Soils are a non-renewable, natural resource. Their uses and their future represent, therefore, a collective issue for agricultural and forestry production, as well as for the preservation of our environment. After ten years of work, the “Groupement d’intérêt scientifique sur les sols”, the Gis Sol (Soils Scientific Interest Group) has presented the first appraisal of soil quality in mainland France and its overseas territories in a report on the state of the soils in France published in 2011. This appraisal shows evidence for positive points but also highlights some concerns regarding soil fertility. Agricultural soils do not show a measurable change in their acidity, thus indicating an efficient management of pH at a national level. On the other hand, the report shows relatively low phosphorus levels for numerous soils, and inversely situations of structural excess which remain very worrying due to its impact on water quality and on the eutrophication of the environments. It also raises the questionsof the long-term sustainability of current cultivation systems and of a better treatment of effluents from livestock farming. Numerous situations also seem to be incompatible, for certain oligo-elements, with demanding cultures. At last, a major concern is the development of soil sealing, which has accelerated over the last decade and is responsible for the loss of large areas of agricultural soils

Phase II randomized, double-blind, placebo-controlled study of tivantinib in men with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC)

Background Tivantinib is a non-ATP competitive inhibitor of c-MET receptor tyrosine kinase that may have additional cytotoxic mechanisms including tubulin inhibition. Prostate cancer demonstrates higher c-MET expression as the disease progresses to more advanced stages and to a castration resistant state. Methods 80 patients (pts) with asymptomatic or minimally symptomatic mCRPC were assigned (2:1) to either tivantinib 360 mg PO BID or placebo (P). The primary endpoint was progression free survival (PFS). Results Of the 80 pts. enrolled, 78 (52 tivantinib, 26 P) received treatment and were evaluable. Median follow up is 8.9 months (range: 2.3 to 19.6 months). Patients treated with tivantinib had significantly better PFS vs. those treated with placebo (medians: 5.5 mo vs 3.7 mo, respectively; HR = 0.55, 95% CI: 0.33 to 0.90; p = 0.02). Grade 3 febrile neutropenia was seen in 1 patient on tivantinib while grade 3 and 4 neutropenia was recorded in 1 patient each on tivantinib and placebo. Grade 3 sinus bradycardia was recorded in two men on the tivantinib arm. Conclusions Tivantinib has mild toxicity and improved PFS in men with asymptomatic or minimally symptomatic mCRPC

Asociación entre consumo de alcohol y exceso de peso entre estudiantes universitarios de América Latina

Introducción: El sobrepeso y la obesidad son problemas de salud pública de nivel mundial. Si bien existe información respecto al consumo de alcohol en estudiantes universitarios durante la pandemia, pocos autores han señalado la asociación entre este hábito y el exceso de peso en esta población. El objetivo fue determinar la asociación entre el consumo de alcohol y el exceso de peso en estudiantes universitarios de 10 países de Latinoamérica durante la pandemia por COVID-19. Metodología: Se realizó un estudio transversal y multicéntrico con 4.539 estudiantes universitarios matriculados en diez países de América Latina. Para la valoración del consumo de alcohol se utilizó la pregunta ¿Consumes bebidas alcohólicas? (1 porción 1 vaso de 200 ml). El índice de masa corporal (IMC) se determinó a partir del peso y la altura auto informado. Para determinar si el exceso de peso (IMC ≥25 kg/m2 ) estaba asociado con el consumo de alcohol, se utilizó un análisis de regresión logística, ajustado por edad, sexo, año de estudio, nivel socioeconómico, actividad física y tabaquismo. Resultados: Entre los estudiantes con estado nutricional normal, un 59,6% no consumía alcohol, mientras entre los que presentaban un exceso de peso era un 55,1%. Los estudiantes que consumían 2 o más porciones de alcohol al día tenían 2,18 veces más riesgo de tener exceso de peso (OR: 2.18 [95% IC: 1,26 a 3,77]), comparado con aquellos que no consumían alcohol. Conclusión: Se observó que aquellos estudiantes que consumieron más alcohol tuvieron más probabilidades de tener exceso de peso. Palabras clave: Alcohol; Índice de masa corporal; Obesidad; Sobrepeso; Universitarios

Cabozantinib Versus Mitoxantrone-prednisone in Symptomatic Metastatic Castration-resistant Prostate Cancer: A Randomized Phase 3 Trial with a Primary Pain Endpoint

Background: Bone metastases in patients with metastatic castration-resistant prostate cancer (mCRPC) are associated with debilitating pain and functional compromise. Objective: To compare pain palliation as the primary endpoint for cabozantinib versus mitoxantrone-prednisone in men with mCRPC and symptomatic bone metastases using patient-reported outcome measures. Design, setting, and participants: A randomized, double-blind phase 3 trial (COMET-2; NCT01522443) in men with mCRPC and narcotic-dependent pain from bone metastases who had progressed after treatment with docetaxel and either abiraterone or enzalutamide. Intervention: Cabozantinib 60 mg once daily orally versus mitoxantrone 12 mg/m2 every 3 wk plus prednisone 5 mg twice daily orally. Outcome measurements and statistical analysis: The primary endpoint was pain response at week 6 confirmed at week 12 (≥30% decrease from baseline in patient-reported average daily worst pain score via the Brief Pain Inventory without increased narcotic use). The planned sample size was 246 to achieve ≥90% power. Results and limitations: Enrollment was terminated early because cabozantinib did not demonstrate any survival benefit in the companion COMET-1 trial. At study closure, 119 participants were randomized (cabozantinib: N =61; mitoxantrone-prednisone: N = 58). Complete pain and narcotic use data were available at baseline, week 6, and week 12 for 73/106 (69%) patients. There was no significant difference in the pain response with cabozantinib versus mitoxantrone-prednisone: the proportions of responders were 15%versus 17%,a −2%difference(95%confidenceinterval:−16%to11%, p = 0.8). Barriers to accrual included pretreatment requirements for a washout period of prior anticancer therapy and a narcotic optimization period to maximize analgesic dosing. Conclusions: Cabozantinib treatment did not demonstrate better pain palliation than mitoxantrone-prednisone in heavily pretreated patients with mCRPC and symptomatic bone metastases. Future pain-palliation trials should incorporate briefer timelines from enrollment to treatment initiation. Patient summary: Cabozantinib was not better than mitoxantrone-prednisone for pain relief in patients with castration-resistant prostate cancer and debilitating pain from bone metastases

Dietary Patterns and Dietary Recommendations Achievement From Latin American College Students During the COVID-19 Pandemic Lockdown

This study aimed to compare the diet quality of different dietary patterns among college students from Latin American countries, including vegetarians, vegans, and omnivores during the COVID-19 pandemic. A cross-sectional, observational, multicenter study was conducted including a non- probabilistic sample of university students from 10 countries. University students were invited to participate in the study through social network platforms. Participants were self-reported to have followed a specific dietary pattern; either the Prudent diet, Western diet, Ovo-dairy-vegetarian diet, Fish-vegetarian diet, Strict vegetarian diet (vegan) or other. The last three patterns (vegetarians and vegans) were grouped as following a plant-based diet. A self-assessment survey was used to evaluate healthy eating habits using a questionnaire with values between 1 (do not consume) and 5 (consume) for a total of 9–45 points (higher values represent better eating habits). Unhealthy habits were assessed with nine questions. A total of 4,809 students filled out the questionnaire, and the majority of them were females (73.7%). Murillo et al. College Dietary Patterns During COVID-19 A high percentage have been in lockdown for more than 5 months and were in lockdown when the survey was released. 74.3% were self-reported to follow a prudent diet, while 11.4% reported following a western dietary pattern and 8.8% a plant-based diet. When compliance with healthy and unhealthy dietary habits was analyzed, although all groups had low compliance, the plant-based diet group (56.09 ± 6.11) performed better than the Western diet group (48.03 ± 5.99). The total diet quality score was significantly higher for plant-based diet followers, who also tended to better achieve the recommendations than omnivorous students, especially the ones following a western diet. These results present evidence that young adults such as college-aged students have unhealthy dietary habits. However, the ones who follow a plant-based diet such as vegetarians and vegans exhibit better scores and healthier dietary conducts.UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin