Intestinal obstruction an uncommon complication of biliary ileus: a case report

Biliary ileus is a rare entity in our setting despite the high incidence of cholecystitis in the Mexican population. Currently, the treatment for those presenting with intestinal obstruction is surgical. Although there are many management options, it should be individualized according to the patient, symptoms, and their hemodynamic status. In this case report, we present an approach to management in a hemodynamically stable patient, who showed appropriate postoperative evolution

Metachronous multiple primary malignancies: a case report of colon and thyroid cancer

Cancer remains a challenging disease for our profession despite the medical and technological advances achieved in recent years. This challenge increases when we encounter multiple primary tumors that significantly modify the prognosis of our patients

Evidence for widespread hydrated minerals on asteroid (101955) Bennu

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM-type carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of metres observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu’s spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids

Mexico's methamphetamine precursor chemical interventions: Impacts on drug treatment admissions

Aims: To help counter problems related to methamphetamine, Mexico has implemented interventions targeting pseudoephedrine and ephedrine, the precursor chemicals commonly used in the drug's synthesis. This study examines whether the interventions impacted methamphetamine treatment admissions-an indicator of methamphetamine consequences. Design: Quasi-experiment: autoregressive integrated moving average (ARIMA)-based intervention time-series analysis. Interventions: precursor chemical restrictions implemented beginning November 2005; major rogue precursor chemical company closed (including possibly the largest single drug-cash seizure in history) March 2007; precursor chemicals banned from Mexico (North America's first precursor ban) August 2008. Settings: Mexico and Texas (1996-2008). Measurements: Monthly treatment admissions for methamphetamine (intervention series) and cocaine, heroin and alcohol (quasi-control series). Findings: The precursor restriction was associated with temporary methamphetamine admissions decreases of 12% in Mexico and 11% in Texas. The company closure was associated with decreases of 56% in Mexico and 48% in Texas; these decreases generally remained to the end of the study period. Neither intervention was associated with significant changes in the Mexico or Texas quasi-control series. The analysis of Mexico's ban was indeterminate due largely to a short post-ban series. Conclusions: This study, one of the first quasi-experimental analyses of an illicit-drug policy in Mexico, indicates that the country's precursor interventions were associated with positive impacts domestically and in one of the Unites States' most populous states-Texas. These interventions, coupled with previous US and Canadian interventions, amount to a new, relatively cohesive level of methamphetamine precursor control across North America's largest nations, raising the possibility that the impacts found here could continue for an extended period. © 2010 The Authors, Addiction © 2010 Society for the Study of Addiction

Características de los principales suelos de la cuenca del Rio Mololoa, Tepic, Nayarit, México

Mololoa river basin has an area of 56 937 hectares and represents a socially, environmentally and agroproductively significant region for Tepic city, the capital of Nayarit state. In recent years, some edaphological investigations have been performed in this region and the following soil referential groups have been reported: Andosols, Alisols, Luvisols, Cambisols, Phaeozems, Regosols, Leptosols, Gleysols and Fluvisols. This work provides characteristics of the main soils (Andosols, Alisols, Luvisols, Phaeozems, Regosols and Gleysols), emphasizing Andosols and Alisols, two of the most important basin soils, which are different in their genesis and properties, essentially due to soil formation conditions. In case of Andosols, they are recently-formed AC profile soils from quaternary deposits of pumice stone and some ash of San Juan volcano, whereas Alisols are highlyevolved ABtC profile soils formed in ancient and steady reliefs from quaternary basic rock materials of Sangangüey volcano.La cuenca del río Mololoa tiene una extensión de 56 937 ha y representa una región de gran importancia social, ambiental y agroproductiva para la ciudad de Tepic, capital del estado de Nayarit. En los últimos años, se han realizado algunas investigaciones edafológicas en esta región y se ha informado que se presentan grupos referenciales de suelos que son: Andosoles, Alisoles, Luvisoles, Cambisoles, Feozems, Regosoles, Leptosoles, Gleysoles y Fluvisoles. En este trabajo se dan las características de los principales suelos (Andosoles, Alisoles, Luvisoles, Feozems, Regosoles y Gleysoles), con énfasis en Andololes y Alisoles, dos de los suelos más importantes de la cuenca, mostrando que estos se diferencian en su génesis y propiedades, dado principalmente por las condiciones de formación de los suelos. En el caso de los Andosoles, son suelos de formación más recientes, de perfil AC, a partir de depósitos cuaternarios de piedra pómez y algo de ceniza del volcán San Juan, mientras que los Alisoles son suelos de perfil ABtC, más evolucionados, formados en relieves estables y más antiguos de materiales de rocas básicas del cuaternario del volcán Sangangüe

Development an Artificial Neural Network Model for Estimating Cost of R/C Building by Using Life-Cycle Cost Function: Case Study of Mexico City

This paper addresses the importance of engineering asset management decisions and control. For this purpose, a Life-Cycle Cost (LCC) analysis is conducted for typical reinforced concrete (R/C) buildings located in Mexico City. The objective of this study is to develop an artificial neural network (ANN) model that can estimate the total expected cost of R/C buildings by using LCC functions. The total cost includes the initial cost and the cost of the damage caused by future possible ground motions at the site of interest. The present value of the cost includes: initial cost, repair or reconstruction cost, cost of damage to the contents, costs associated with the loss of life or injuries and economic losses. The structural performance is evaluated using probabilistic models, artificial neural networks models are used to obtain the seismic response of the buildings. The methodology is applied to a set of reinforced concrete buildings with 4, 8, and 12 stories which are located at the soft soil of Mexico City. Finally, it is concluded that the life-cycle cost is efficiently obtained using artificial neural network models for estimating the structural reliability of reinforced concrete buildings, in such a way that it can be used as an excellent planning tool that covers long spans of time

Características de los suelos cambisoles y fluvisoles de la llanura costera norte del estado de Nayarit, México

The northern coastal plain of Nayarit state, Mexico, represents one of the most important areas for livestock and agricultural development. For this reason, a soil classification and characterization was done for evaluating the limiting factors and potential use of this resource. In a previous paper, region characteristics as well as soil distribution in five plain levels were described as follows: delta plain or marine floodplain with three levels (high, medium and low), flooded plain of actual tides and the zone of parallel off-shore bars, beaches and coastal dunes. In this way, it could be determined that the main soils in the area are Cambisols, Fluvisols, Phaeozems, Gleysols, Regosols, Arenosols and Solonchaks. This paper presents the characteristics of Cambisols and Fluvisols in relation to different levels of the delta plain. Thus, it was defined that concerning both soil groups, there are no salt or sodium problems in the high plain. With regard to the medium plain, there are some salts in the lower section of the soil profile; however, in the low plain, where fluvic Cambisols and Fluvisols are predominant, most soils are affected by salt and sodium. This sequence in soil distribution is related to relief evolution, sedimentation and desalinization as well as interchangeable sodium washing under a tropical sub-humid climate within a time period dated from 4 000 to 4 500 years, when this plain was formed.La llanura costera norte del estado de Nayarit, México, representa una de las regiones más importantes para el desarrollo de la ganadería y la agricultura en ese estado. Por esta razón, se ha procedido a la clasificación y caracterización de los suelos, como fundamento para poder evaluar los factores limitantes y la evaluación potencial de ese recurso. En un trabajo anterior se dieron las características de la región y la distribución de los suelos en cinco niveles de llanura que son: llanura deltaica o fluvio marina con tres niveles (alta, media y baja), llanura de inundación mareal actual y la zona de barras paralelas, playas y dunas costeras. Así, se pudo determinar que los suelos principales son Cambisoles, Fluvisoles, Feozems, Gleysoles, Regosoles, Arenosoles y Solonchaks en la región. En el presente trabajo se dan las características de los Cambisoles y Fluvisoles en relación con los diferentes niveles de la llanura deltaica. De esta forma, se determina que en la llanura alta no hay problemas de salinidad ni de sodicidad para estos dos grupos de suelos. En la llanura media, existen algunas sales en la sección inferior del perfil del suelo; sin embargo, en la llanura baja, con predominio de Fluvisoles y Cambisoles flúvicos, la mayoría de los suelos tienen afectación de salinidad y sodicidad. Esta regularidad en la distribución de los suelos se relaciona con la evolución del relieve, la sedimentación y el lavado de las sales y del sodio cambiable en clima tropical subhúmedo, en períodos de tiempo que datan desde hace 4 000-4 500 años en que se formó esta llanura

Population size of the jumbo squid Dosidicus gigas in the central Gulf of California, Mexico, based on mark-recapture data

The use of mark-recapture data can be an alternative to other methods for estimating abundance of the jumbo squid Dosidicus gigas and can be used when catch-per-unit-effort data applied to depletion models or estimates from survey research are not available. Two mark-recapture events were analyzed in the central Gulf of California, Mexico, during October 2001 and April 2002 to assess the status of jumbo squid. Results from October 2001 yielded a population size of 20.2 million squid with a 95% CI of 16 to 26.5 million squid (p < 0.05). In April the population size was estimated at 132.6 million squid with a 95% CI of 85.5 to 222 million squid (p < 0.05). The results for October and April show 2 different periods of abundance. Estimates of tag return rates were higher in April (5.5%) than in October (1.7%), and recruitment is the most plausible explanation. In the Gulf of California, recruitment of jumbo squid commonly occurs during April and May