Sobreexplotación del acuífero del Valle de Toluca y su incidencia en el medio ambiente

El agua es uno de los recursos naturales más importantes para el hombre y las diferentes actividades antrópicas (agrícola, urbana e industrial) han generado un uso incontrolado de este recurso. A medida que la población aumenta, surge el incremento de la demanda de agua y una extracción intensiva en los acuíferos. De los 653 acuíferos que existen en México, 106 acuíferos están sobreexplotados, entre los cuales se encuentra el Acuífero del Valle de Toluca (AVT) (CONAGUA, 2013). El uso del agua subterránea es la principal fuente de agua potable para la población del Valle de Toluca, lo que ha llevado a dicha sobreexplotación del acuífero y al desarrollo de efectos ambientales negativos, tales como la extinción de zonas húmedas y el agrietamiento del terreno. El AVT se encuentra en la poción central del Altiplano Mexicano, dentro de la cuenca Alta del Río Lerma y cubre un área de 2,768 km2. La altitud va a partir de los 2000 msnm correspondientes a la planicie del valle hasta los 4680 msnm en el Nevado de Toluca (CNA-GTZ, 2008)

Diseño de una red de monitoreo del nivel piezométrico mediante el análisis multicriterio

El agua subterránea es un recurso natural vital para el suministro confiable y económico de agua para el consumo humano en zonas urbanas y rurales. De acuerdo con la UNESCO (2009), los sistemas de agua subterránea suministran el 48.23% del agua potable del mundo. Hoy en día, la mitad de las megalópolis del mundo y grandes ciudades en todos los continentes dependen del agua subterránea. El agua subterránea es susceptible a sufrir cambios en su cantidad y calidad, siendo estos cambios frecuentemente procesos muy lentos por lo que necesitan ser monitoreados. El monitoreo de un acuífero es un programa de medición continua y observación de la situación actual del agua subterránea en el espacio y tiempo

Caracterización hidrogeoquímica de los manantiales del área geotermal de Ixtapan de la Sal-Tonatico (México)

La composición química del agua subterránea es el resultado de continuos procesos de interacción entre el agua de precipitación, que se infiltra en el terreno, y los minerales presentes en las rocas por donde circula. Parte de las características químicas del agua son adquiridas en la zona no saturada y otras más a lo largo de su recorrido dentro de la zona saturada, hasta donde pueden ser captadas o bien emerger como agua de manantial. Estos últimos según sus características, puede ser empleados para consumo humano, como generadores de energía o bien para fines recreativos, como es el caso de los manantiales termales de Ixtapan de la Sal y Tonatico. Los estudios hidrogeoquímicos de manantiales termales han permitido ampliar el conocimiento del origen, edad, composición físico-química de las aguas, de las condiciones de recarga y posibles mezclas de agua, así como identificar los procesos que tienen lugar en el acuífero y que permiten obtener una visión más completa del comportamiento del acuífero. También permiten deducir las características de la roca, composición mineralógica, textura, porosidad, grado de alteración, fracturación y compactación, tiempo de residencia o de contacto, temperatura y presión..

CD32 is expressed on cells with transcriptionally active HIV but does not enrich for HIV DNA in resting T cells

The persistence of HIV reservoirs, including latently infected, resting CD4+ T cells, is the major obstacle to cure HIV infection. CD32a expression was recently reported to mark CD4+ T cells harboring a replication-competent HIV reservoir during antiretroviral therapy (ART) suppression. We aimed to determine whether CD32 expression marks HIV latently or transcriptionally active infected CD4+ T cells. Using peripheral blood and lymphoid tissue of ART-treated HIV+ or SIV+ subjects, we found that most of the circulating memory CD32+ CD4+ T cells expressed markers of activation, including CD69, HLA-DR, CD25, CD38, and Ki67, and bore a TH2 phenotype as defined by CXCR3, CCR4, and CCR6. CD32 expression did not selectively enrich for HIV- or SIV-infected CD4+ T cells in peripheral blood or lymphoid tissue; isolated CD32+ resting CD4+ T cells accounted for less than 3% of the total HIV DNA in CD4+ T cells. Cell-associated HIV DNA and RNA loads in CD4+ T cells positively correlated with the frequency of CD32+ CD69+ CD4+ T cells but not with CD32 expression on resting CD4+ T cells. Using RNA fluorescence in situ hybridization, CD32 coexpression with HIV RNA or p24 was detected after in vitro HIV infection (peripheral blood mononuclear cell and tissue) and in vivo within lymph node tissue from HIV-infected individuals. Together, these results indicate that CD32 is not a marker of resting CD4+ T cells or of enriched HIV DNA–positive cells after ART; rather, CD32 is predominately expressed on a subset of activated CD4+ T cells enriched for transcriptionally active HIV after long-term ART

Merotelic Kinetochore Orientation Is a Major Mechanism of Aneuploidy in Mitotic Mammalian Tissue Cells

In mitotic cells, an error in chromosome segregation occurs when a chromosome is left near the spindle equator after anaphase onset (lagging chromosome). In PtK1 cells, we found 1.16% of untreated anaphase cells exhibiting lagging chromosomes at the spindle equator, and this percentage was enhanced to 17.55% after a mitotic block with 2 μM nocodazole. A lagging chromosome seen during anaphase in control or nocodazole-treated cells was found by confocal immunofluorescence microscopy to be a single chromatid with its kinetochore attached to kinetochore microtubule bundles extending toward opposite poles. This merotelic orientation was verified by electron microscopy. The single kinetochores of lagging chromosomes in anaphase were stretched laterally (1.2–5.6-fold) in the directions of their kinetochore microtubules, indicating that they were not able to achieve anaphase poleward movement because of pulling forces toward opposite poles. They also had inactivated mitotic spindle checkpoint activities since they did not label with either Mad2 or 3F3/2 antibodies. Thus, for mammalian cultured cells, kinetochore merotelic orientation is a major mechanism of aneuploidy not detected by the mitotic spindle checkpoint. The expanded and curved crescent morphology exhibited by kinetochores during nocodazole treatment may promote the high incidence of kinetochore merotelic orientation that occurs after nocodazole washout

CENP-E as an Essential Component of the Mitotic Checkpoint In Vitro

AbstractAccurate chromatid separation is monitored by a checkpoint mechanism that delays anaphase onset until all centromeres are correctly attached to the mitotic spindle. Using Xenopus egg extracts, the kinetochore-associated microtubule motor protein CENP-E is now found to be required for establishing and maintaining this checkpoint. When CENP-E function is disrupted by immunodepletion or antibody addition, extracts fail to arrest in response to spindle damage. Mitotic arrest can be restored by addition of high levels of soluble MAD2, demonstrating that the absence of CENP-E eliminates kinetochore-dependent signaling but not the downstream steps in checkpoint signal transduction. Because it directly binds both to spindle microtubules and to the kinetochore-associated checkpoint kinase BUBR1, CENP-E is a central component in the vertebrate checkpoint that modulates signaling activity in a microtubule-dependent manner

Immune reconstitution disease associated with parasitic infections following antiretroviral treatment

HIV-associated immune reconstitution disease (IRD) is the clinical presentation or deterioration of opportunistic infections that results from enhancement of pathogen-specific immune responses among patients responding to antiretroviral treatment (ART). The vast majority of reported cases of IRD have been associated with mycobacterial, chronic viral and invasive fungal infections; such cases result from dysregulated augmentation of cell-mediated type 1 cytokine-secreting host immune responses. However, the spectrum of infections now recognized as associated with IRD is expanding and includes a number of parasitic infections, which may be mediated by different immunopathological mechanisms. These include leishmaniasis (visceral, cutaneous, mucosal and post kala azar dermal leishmaniasis), schistosomiasis and strongyloidiasis. Since the major burden of HIV lies in resource-limited countries where access to ART is now rapidly expanding, increased awareness and knowledge of these phenomena is important. Here we review the clinical spectrum and pathogenesis of IRD associated with parasitic infections

Dynein-dependent transport of spindle assembly checkpoint proteins off kinetochores toward spindle poles

A predominant mechanism of spindle assembly checkpoint (SAC) silencing is dynein-mediated transport of certain kinetochore proteins along microtubules. There are still conflicting data as to which SAC proteins are dynein cargoes. Using two ATP reduction assays, we found that the core SAC proteins Mad1, Mad2, Bub1, BubR1, and Bub3 redistributed from attached kinetochores to spindle poles, in a dynein-dependent manner. This redistribution still occurred in metaphase-arrested cells, at a time when the SAC should be satisfied and silenced. Unexpectedly, we found that a pool of Hec1 and Mis12 also relocalizes to spindle poles, suggesting KMN components as additional dynein cargoes. The potential significance of these results for SAC silencing is discussed. (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.CESPU [02-GCQF-CICS-2011N]; national Portuguese funding through FCT - Fundacao para a Ciencia e a Tecnologia FCT [POCTI/BIA/PRO/60337/2004, PTDC/SAU-OBD/105234/2008]; FCT [PEst-OE/ EQB/LA0023/2013, SFRH/BD/90744/2012]; [EXPL/BEX-BCM/1104/2013

Axillary lymph node dissection versus radiotherapy in breast cancer with positive sentinelnodes after neoadjuvant therapy (ADARNAT trial)

Introduction: Breast cancer surgery currently focuses on de-escalating treatment without compromising patient survival. Axillary radiotherapy (ART) now replaces axillary lymph node dissection (ALND) in patients with limited sentinel lymph node (SLN) involvement during the primary surgery, and this has significantly reduced the incidence of lymphedema without worsening the prognosis. However, patients treated with neoadjuvant systemic treatment (NST) cannot benefit from this option despite the low incidence of residual disease in the armpit in most cases. Data regarding the use of radiotherapy instead of ALND in this population are lacking. This study will assess whether ART is non-inferior to ALND in terms of recurrence and overall survival in patients with positive SLN after NST, including whether it reduces surgery-related adverse effects. Methods and analyses: This multicenter, randomized, open-label, phase 3 trial will enroll 1660 patients with breast cancer and positive SLNs following NST in approximately 50 Spanish centers over 3 years. Patients will be stratified by NST regimen and nodal involvement (isolated tumoral cells or micrometastasis versus macrometastasis) and randomly assigned 1:1 to ART without ALND (study arm) or ALND alone (control arm). Level 3 and supraclavicular radiotherapy will be added in both arms. The primary outcome is the 5-year axillary recurrence determined by clinical and radiological examination. The secondary outcomes include lymphedema or arm dysfunction, quality of life based (EORTC QLQ-C30 and QLQ-BR23 questionnaires), disease-free survival, and overall survival. Discussion: This study aims to provide data to confirm the efficacy and safety of ART over ALND in patients with a positive SLN after NST, together with the impact on morbidity. Ethics and dissemination: The Research Ethics Committee of Bellvitge University Hospital approved this trial (Protocol Record PR148/21, version 3, 1/2/2022) and all patients must provide written informed consent. The involvement of around 50 centers across Spain will facilitate the dissemination of our results

Analysis of the P. lividus sea urchin genome highlights contrasting trends of genomic and regulatory evolution in deuterostomes

Sea urchins are emblematic models in developmental biology and display several characteristics that set them apart from other deuterostomes. To uncover the genomic cues that may underlie these specificities, we generated a chromosome-scale genome assembly for the sea urchin Paracentrotus lividus and an extensive gene expression and epigenetic profiles of its embryonic development. We found that, unlike vertebrates, sea urchins retained ancestral chromosomal linkages but underwent very fast intrachromosomal gene order mixing. We identified a burst of gene duplication in the echinoid lineage and showed that some of these expanded genes have been recruited in novel structures (water vascular system, Aristotle's lantern, and skeletogenic micromere lineage). Finally, we identified gene-regulatory modules conserved between sea urchins and chordates. Our results suggest that gene-regulatory networks controlling development can be conserved despite extensive gene order rearrangement