Towards the Improvement of Soil Salinity Mapping in a Data-Scarce Context Using Sentinel-2 Images in Machine-Learning Models.

Several recent studies have evidenced the relevance of machine-learning for soil salinity mapping using Sentinel-2 reflectance as input data and field soil salinity measurement (i.e., Electrical Conductivity-EC) as the target. As soil EC monitoring is costly and time consuming, most learning databases used for training/validation rely on a limited number of soil samples, which can affect the model consistency. Based on the low soil salinity variation at the Sentinel-2 pixel resolution, this study proposes to increase the learning database's number of observations by assigning the EC value obtained on the sampled pixel to the eight neighboring pixels. The method allowed extending the original learning database made up of 97 field EC measurements (OD) to an enhanced learning database made up of 691 observations (ED). Two classification machine-learning models (i.e., Random Forest-RF and Support Vector Machine-SVM) were trained with both OD and ED to assess the efficiency of the proposed method by comparing the models' outcomes with EC observations not used in the models´ training. The use of ED led to a significant increase in both models' consistency with the overall accuracy of the RF (SVM) model increasing from 0.25 (0.26) when using the OD to 0.77 (0.55) when using ED. This corresponds to an improvement of approximately 208% and 111%, respectively. Besides the improved accuracy reached with the ED database, the results showed that the RF model provided better soil salinity estimations than the SVM model and that feature selection (i.e., Variance Inflation Factor-VIF and/or Genetic Algorithm-GA) increase both models´ reliability, with GA being the most efficient. This study highlights the potential of machine-learning and Sentinel-2 image combination for soil salinity monitoring in a data-scarce context, and shows the importance of both model and features selection for an optimum machine-learning set-up.

Endocarditis bacteriana a propósito de un caso / Bacterial endocarditis case report

OBJETIVO: informar acerca de un caso de endocarditis bacteriana. Paciente varón de 34 años de edad, con único antecedente de rinitis alérgica con tratamiento irregular. Él es procedente de Valparaiso Chile, se encuentra en sus vacaciones en la ciudad de La Paz, acude al servicio de medicina interna ­ emergencias, con clínica compatible con edema agudo de pulmón de la altura y edema cerebral de la altura, asociado a sepsis de foco pulmonar, que progresa a choque séptico, durante su internación intercurre con alzas térmicas continuas, asociado a hallazgo ecocardiográfico de vegetación en ventrículo derecho con hemocultivo positivo, por lo que se llega al diagnóstico de endocarditis bacteriana, se realizó el tratamiento correspondiente, y resolución del cuadro.

OBJECTIVE: to report a case of bacterial endocarditis A 34-year-old male patient with a unique history of allergic rhinitis with irregular treatment. He comes from Valparaiso Chile, is on vacation in the city of La Paz, goes to the service of internal medicine - emergencies with compatible clinical with acute pulmonary edema of height and cerebral edema of height, associated with sepsis of focus pulmonary disease, which progresses to septic shock, during internment with continuous hyperthermia, associated vegetation in right ventricle for echocardiography, also positive blood culture, so that a diagnosis of bacterial endocarditis is reached, Corresponding treatment was carried out, and resolution of pathology..

ODZ1 allows glioblastoma to sustain invasiveness through a Myc-dependent transcriptional upregulation of RhoA.

Long-term survival remains low for most patients with glioblastoma (GBM), which reveals the need for markers of disease outcome and novel therapeutic targets. We describe that ODZ1 (also known as TENM1), a type II transmembrane protein involved in fetal brain development, plays a crucial role in the invasion of GBM cells. Differentiation of glioblastoma stem-like cells drives the nuclear translocation of an intracellular fragment of ODZ1 through proteolytic cleavage by signal peptide peptidase-like 2a. The intracellular fragment of ODZ1 promotes cytoskeletal remodelling of GBM cells and invasion of the surrounding environment both in vitro and in vivo. Absence of ODZ1 by gene deletion or downregulation of ODZ1 by small interfering RNAs drastically reduces the invasive capacity of GBM cells. This activity is mediated by an ODZ1-triggered transcriptional pathway, through the E-box binding Myc protein, that promotes the expression and activation of Ras homolog family member A (RhoA) and subsequent activation of Rho-associated, coiled-coil containing protein kinase (ROCK). Overexpression of ODZ1 in GBM cells reduced survival of xenografted mice. Consistently, analysis of 122 GBM tumour samples revealed that the number of ODZ1-positive cells inversely correlated with overall and progression-free survival. Our findings establish a novel marker of invading GBM cells and consequently a potential marker of disease progression and a therapeutic target in GBM.

Child health and living at high altitude.

The health of children born and living at high altitude is shaped not only by the low-oxygen environment, but also by population ancestry and sociocultural determinants. High altitude and the corresponding reduction in oxygen delivery during pregnancy result in lower birth weight with higher elevation. Children living at high elevations are at special risk for hypoxaemia during infancy and during acute lower respiratory infection, symptomatic high-altitude pulmonary hypertension, persistence of fetal vascular connections, and re-entry high-altitude pulmonary oedema. However, child health varies from one population group to another due to genetic adaptation as well as factors such as nutrition, intercurrent infection, exposure to pollutants and toxins, socioeconomic status, and access to medical care. Awareness of the risks uniquely associated with living at high altitude and monitoring of key health indicators can help protect the health of children at high altitude. These considerations should be incorporated into the scaling-up of effective interventions for improving global child health and survival.

Antimalarial activity and cytotoxicity of (-)-roemrefidine isolated from the stem bark of Sparattanthelium amazonum.

(-)-Roemrefidine, an aporphine alkaloid isolated from Sparattanthelium amazonum Martius (Hernandiaceae) a vine from Bolivia, has been found to be active against both resistant and sensitive strains of Plasmodium falciparum in vitro and against P. berghei in mice. The compound demonstrated no cytotoxic activity against three cell lines (KB, HEp-2 and HeLa).

Pharmacological properties of Moringa oleifera. 1: Preliminary screening for antimicrobial activity.

The antimicrobial activities of Moringa oleifera leaves, roots, bark and seeds were investigated in vitro against bacteria, yeast, dermatophytes and helminths pathogenic to man. By a disk-diffusion method, it was demonstrated that the fresh leaf juice and aqueous extracts from the seeds inhibit the growth of Pseudomonas aeruginosa and Staphylococcus aureus and that extraction temperatures above 56 degrees C inhibited this activity. No activity was demonstrated against four other pathogenic Gram-positive and Gram-negative bacteria and Candida albicans. By a dilution method, no activity was demonstrated against six pathogenic dermatophytes. A method was standardized for studying the effect of aqueous extracts on Ascaris lumbricoides eggs, but no activity was exhibited by any part of the tree in contrast to Chenopodium ambrosioides leaf extracts.

Síndrome retroviral agudo / Acute retroviral syndrome: case report

A 37 years old male developed fever for 20 days, along with headache, anorexia malaise, sweating, pharyngitis, lymphadenopathy and splenomegaly. At this stage, Ag p 24 was positive and anti HIV was negative. The patient recovered fully but 6 monts later positive HIV titers were demonstrated by immunofluorescence and Westernblot. A retrospective HIV titers were demonstrated by immunofluorescence and Westernblot. A retrospective diagnosis of acute retroviral syndrome was made. The dioddicult