The neurobiology of splitbrain crayfish

Background: They crayfish brain is segmented into two symmetrical hemiganglia. Normally both hemiganglia are in direct communication through a series of well-defined neural bridges that cross de midline to form reciprocal cross connections.Methods: An original study was carried out in the Department of Physiology of the Faculty of Medicine, UNAM during the period from August 2019 to August 2020. 13 Crayfish Procambarus clarkii weighing between 1g to 30g were used. Each eyestalk of the animals was tied to a displacement transducer coupled with a polygraph so that optomotor or electrical activity was bilaterally recorded. The separation of the right from the left hemiganglia from the cerebral or supraesophageal ganglion was performed with a sagittal section, splitbrain (SB).Results: The normal photo motor reflex in crayfish eye is measured as a gradual decrease in the ERG amplitude. During tactile stimulation, the visual activation of both eyestalks in normal crayfish leads to a highly regular bilateral activity. The regular activity can only be altered by disturbing the mechanoreceptors located in the shell surrounding the eyestalks.Conclusions: The procedure presented in this article provides unique characteristics for the study of the nervous system such as a detailed response of the bilateral optomotor reflex

Chronic venous insufficiency: a review

Chronic venous insufficiency (CVI) comprises a complete spectrum of morphological and functional abnormalities of the venous system1 including any long-term functional and morphological alteration. CVI accounts for several abnormalities of the venous system. It is a highly prevalent disease that causes serious economic consequences, a decrease in the quality of life and can lead to serious complications. An exhaustive review was performed with the available literature, using the PubMed, ScienceDirect, Scopus and Cochrane databases from 2004 to 2021. The search criteria were formulated to identify reports related to chronic venous insufficiency. The pathophysiology of chronic venous insufficiency begins with chronic venous hypertension and the dilation of the vessel, this leads to a series of pathological changes in the venous wall and surrounding tissues, in advanced stages of CVI, skin lesions are associated with an increased proliferation of skin capillaries and microcirculatory abnormalities that may be the result of an altered level of factors responsible for the angiogenic response, such as vascular endothelial growth factor (VEGF), fibroblast growth factor 2 (FGF2) and angiostatin. In this review, updates on pathophysiology, clinic, diagnosis, classification and treatment of this disease are analyzed, with special emphasis on therapeutic options. Chronic venous insufficiency is a disease that affects the patient at several levels, mainly diminishing his/her quality of life. Currently there are various treatments ranging from habit modifications, pharmacological, to endovenous and surgical treatment.

Transformar para educar 5: ambientes de aprendizaje naturalmente críticos

Este quinto libro de la colección "Transformar para Educar''.-producto de las investigaciones de aula adelantadas por docentes de la Universidad del Norte, con el apoyo del Centro para la Excelencia Docente (CEDU), en el marco del programa Transformación de curso-, busca difundir innovaciones en la práctica pedagógica, con el fin de mejorar las experiencias educativas de los estudiantes con base en la implementación de ambientes de aprendizaje naturalmente críticos. Son críticos porque los estudiantes razonan con sus propios argumentos y naturales porque se da de manera espontánea. Contiene nueve capítulos que recopilan las experiencias realizadas por los docentes del área de introducción a la Ingeniería. Confiamos en que los hallazgos que aquí se presentan sean de interés para los lectores y puedan ser compartidos de manera amplia entre distintos públicos

Temporal variability in potentially toxic elements (PTE’s) and benthic Foraminifera in an estuarine environment in Puerto Rico.

Bulk concentrations of PTEs (potentially toxic elements) were assessed and compared with foraminiferal assemblages from core sediments from TL (Torrecillas Lagoon), on the north coast of Puerto Rico. Temporal distributions of mud, Fe, Al (proxy for terrigenous sedimentation), and rhenium (proxy for anoxia) reflected changes in land use within the drainage basin associated with human activities over the past century. The mud-dominated sediments provided a major “sink” for PTEs, while Fe oxides and sulfides served as a secondary “sinks”. Temporal variability of Re revealed intervals of aerobic vs anaerobic conditions in the lagoon. The dominant foraminiferal taxa, Ammonia beccarii, Quinqueloculina rhodiensis, Quinqueloculina seminula, and Ammobaculites agglutinans, coupled with low foraminiferal densities and species diversities, as well as barren samples, are characteristic of stressed estuarine environments. Overall bulk concentrations of Cu and Zn negatively correlated with foraminiferal absolute/relative abundances, diversity indices and incidences of test deformities. However, there are no correlations with the assumed bioavailable counterparts (F2Tess-Cu and F2Tess-Zn) were observed. These results indicate that fractionation of PTEs need to be considered in relation to their biological significance to foraminiferal ecology, which may differ substantially from bioavailability to metazoans that ingest sediments. The application of the acid-soluble F2Tess is not recommended in environmental studies using foraminifers as bioindicators, as PTEs in this fraction are likely not bioavailable to these protists

Acute Appendicitis: Hispanics and the Hamburger Sign

Objective: To describe the presenting clinical findings of patients with acute appendicitis and compare them with those described in the medical literature. To corroborate a common medical myth among Hispanic physicians regarding the presentation of acute appendicitis. Methods: This was a retrospective multicenter chart review of patients diagnosed post-operatively with appendicitis after presenting to five different Emergency Departments in Southern Puerto Rico (PR). Results: A total of 1,540 patients with pathologically confirmed cases of appendicitis were enrolled in our study. Of the study population, 45% were female, and 55% were male, and 43% were over 21 years old. Reported symptoms in our study showed that 98% of the patients had abdominal pain, 47% had nausea, and only 17.6% presented with anorexia. Conclusion: It was our main objective to compare the presenting signs and symptoms of patients with acute appendicitis in our Hispanic population in southern PR with those found in primary medical textbooks and literature. We gathered information regarding signs and symptoms, as well as laboratory and radiographic data of patients with positive pathologic exams for appendicitis. Of the 1,540 patients with confirmed appendicitis, only 17.6% presented with anorexia. Our findings demonstrate that the rate of anorexia in the studied population is significantly lower when compared to current literature. The absence of anorexia, once considered a hallmark of appendicitis, must not lead the physician to rule out this diagnosis in the Hispanic population

Clotting factor genes are associated with preeclampsia in high-altitude pregnant women in the Peruvian Andes.

Preeclampsia is a multi-organ complication of pregnancy characterized by sudden hypertension and proteinuria that is among the leading causes of preterm delivery and maternal morbidity and mortality worldwide. The heterogeneity of preeclampsia poses a challenge for understanding its etiology and molecular basis. Intriguingly, risk for the condition increases in high-altitude regions such as the Peruvian Andes. To investigate the genetic basis of preeclampsia in a population living at high altitude, we characterized genome-wide variation in a cohort of preeclamptic and healthy Andean families (n = 883) from Puno, Peru, a city located above 3,800 meters of altitude. Our study collected genomic DNA and medical records from case-control trios and duos in local hospital settings. We generated genotype data for 439,314 SNPs, determined global ancestry patterns, and mapped associations between genetic variants and preeclampsia phenotypes. A transmission disequilibrium test (TDT) revealed variants near genes of biological importance for placental and blood vessel function. The top candidate region was found on chromosome 13 of the fetal genome and contains clotting factor genes PROZ, F7, and F10. These findings provide supporting evidence that common genetic variants within coagulation genes play an important role in preeclampsia. A selection scan revealed a potential adaptive signal around the ADAM12 locus on chromosome 10, implicated in pregnancy disorders. Our discovery of an association in a functional pathway relevant to pregnancy physiology in an understudied population of Native American origin demonstrates the increased power of family-based study design and underscores the importance of conducting genetic research in diverse populations

El sistema de protección social en la Argentina y en América Latina contemporánea : el rol del Estado frente a la cuestión social

Este documento constituye un aporte significativo al estudio de los Sistemas de Protección Social, por la rigurosidad académica de cada uno de los artículos que componen la compilación, por la actualidad en el análisis, la diversidad de los temas que abarcan y por esta interesante combinación de aportes de especialistas de reconocida trayectoria junto con jóvenes investigadores. Una de las principales contribuciones de este Documento de Trabajo es echar luz sobre los Sistemas de Protección Social en la región y destacar sus características, alcances y modificaciones más recientes desde una perspectiva que articula el análisis de los procesos políticos, económicos, sociales e institucionales con elementos históricos y de coyuntura