A 4-year field study monitoring the evolution of Trp574Leu-resistant plants in an Echinochloa crus-galli population under different crop rotation and herbicide programs in maize.

BACKGROUND: A 4-year experiment evaluated the effects of different integrated weed management (IWM) programs on the evolution of a Echinochloa crus-galli population resistant to acetolactate synthase (ALS) inhibitors in a maize cropping system. The programs included the continued use of ALS inhibitors, mixing them with alternative herbicides, or without ALS-inhibitors, in all cases under maize monocrop or a biennial crop rotation. RESULTS: IWM programs that relied solely on non-ALS-inhibitors usually achieved high control levels across years (> 90%). Additionally, Trp574Leu-resistant plants became prevalent (> 90%) in programs only using ALS inhibitors, while in the rest the frequency of susceptible plants did not substantially decrease below 40%. Regarding the other monitored grass weeds, Digitaria sanguinalis and Panicum dichotomiflorum were effectively controlled in programs using ALS-inhibitors without soybean rotation or in programs without ALS-inhibitors altogether, excepting the program relying on an 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibitor under maize monocrop for the latter species (0%). CONCLUSION: At the end of the experiment, the only IWM programs that reduced infestation levels were the one without ALS-inhibitors under soybean rotation, and the one with standard pre-emergence treatments. These findings highlight the effectiveness of crop rotation and alternative herbicides both pre- or post-emergence in controlling E. crus-galli. ALS-inhibitors, while challenged by resistance in E. crus-galli, remain valuable tools for managing other grass weed species in maize. It is crucial to adapt IWM strategies for herbicide-resistant E. crus-galli and other grass weed populations to mitigate the further evolution of resistance. © 2024 Corteva Agriscience. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Intestinal obstruction secundary to gallstone ileus: case report.

Gallstone ileus is an intestinal obstruction that is secondary to the presence of gallstones in the small intestine. It is a rare complication of cholelithiasis, which represents 1-3% of the causes of intestinal obstruction. The diagnosis is difficult given that the symptoms are nonspecific with intermittent intestinal obstruction, Rigler's triad (pneumobilia, stone and abdominal distention) is pathognomonic. Among the diagnostic aids are abdominal radiography, ultrasound and abdominal tomography. Treatment should be individualized depending on the patient's conditions, with laparotomy with enterotomy being the treatment of choice.

El íleo biliar es una obstrucción intestinal secundaria a la presencia de cálculos biliares en el intestino delgado. Es una complicación rara de la colelitiasis y representa el 1-3% de las causas de obstrucción intestinal. El diagnóstico es difícil dado que la clínica es inespecífica, con un cuadro de oclusión intestinal intermitente; la tríada de Rigler (neumobilia, lito y distensión abdominal) es patognomónica. Dentro de los auxiliares diagnósticos se encuentran la radiografía de abdomen, el ultrasonido y la tomografía computarizada abdominal. El tratamiento debe individualizarse dependiendo de las condiciones del paciente, siendo de elección la laparotomía con enterotomía.

LKTA and PlpE small fragments fusion protein protect against Mannheimia haemolytica challenge.

Bovine respiratory disease (BRD) complex is a major cause of economic losses for the cattle backgrounding and feedlot industries. Mannheimia haemolytica is considered the most important pathogen associated with this disease. Vaccines against M. haemolytica have been prepared and used for many decades, but traditional bacterins have failed to demonstrate effective protection and their use has often exacerbated disease in vaccinated animals. Thus, the BRD complex continues to exert a strong adverse effect on the health and wellbeing of stocker and feeder cattle. Therefore, generation of recombinant proteins has been helpful in formulating enhanced vaccines against M. haemolytica, which could confer better protection against BRD. In the present study, we formulated a vaccine preparation enriched with recombinant small fragments of leukotoxin A (LKTA) and outer-membrane lipoprotein (PlpE) proteins, and demonstrated its ability to generate high antibody titers in rabbits and sheep, which protected against M. haemolytica bacterial challenge in mice.

Effects of rapid global warming at the Paleocene-Eocene boundary on neotropical vegetation.

Temperatures in tropical regions are estimated to have increased by 3° to 5°C, compared with Late Paleocene values, during the Paleocene-Eocene Thermal Maximum (PETM, 56.3 million years ago) event. We investigated the tropical forest response to this rapid warming by evaluating the palynological record of three stratigraphic sections in eastern Colombia and western Venezuela. We observed a rapid and distinct increase in plant diversity and origination rates, with a set of new taxa, mostly angiosperms, added to the existing stock of low-diversity Paleocene flora. There is no evidence for enhanced aridity in the northern Neotropics. The tropical rainforest was able to persist under elevated temperatures and high levels of atmospheric carbon dioxide, in contrast to speculations that tropical ecosystems were severely compromised by heat stress.

Genotypification of bovine group A rotavirus in México.

Bovine scours, frequently provoked by rotavirus infection, causes significant economic losses. Nevertheless, no information exists about the bovine rotavirus genotypes present in Mexico. This information is necessary for designing efficient vaccines. In this work, 128 samples from diarrheic calves were collected between 2005 and 2006 in 26 dairy and/or beef cattle herds located in 10 regions of Mexico, and analyzed for the presence of group A rotavirus. G and P genotypes were determined by PCR in rotavirus-positive samples (12/128). Three different genotype combinations were found, G10, P[11]; G6, P[5]; and G10, P[5]; in 67, 25 and 8% of the positive samples, respectively. Some rotavirus-positive animals had been vaccinated with an inactivated rotavirus strain of a different genotype.

Carbon-isotopic composition of soil-respired carbon dioxide in static closed chambers at equilibrium.

The carbon-isotopic composition (delta13C) of soil-respired CO2 has been employed to evaluate soil carbon-cycling processes and the contribution of soil CO2 emissions to canopy and tropospheric air. These evaluations can be successful only when accurate isotope values of soil-respired CO2 are available. Here, we tested the robustness of delta13C values of soil-respired CO2 obtained after long incubations in static closed chambers that were initially flushed with soil air. The rationale of this approach is that the equilibrium carbon-isotope values of chamber-headspace CO2 are theoretically equal to those of CO2 produced within the soil. Static closed chambers were installed in replicated grass monocultures, and measurements of headspace CO2 concentrations and delta13C values were performed at regular time intervals for 24 h in July 2005. The results revealed no significant effects of grass species on headspace CO2 concentrations or delta13C values (repeated measures analysis of variance (ANOVA), P>0.1). As predicted by theory, isotope values asymptotically approached equilibrium conditions, which in our experimental setting occurred after 10 h. This good match between model predictions and our results suggests that an accurate determination of delta13C values of CO2 produced within soils is obtained through the isotopic measurement of chamber-headspace CO2 once equilibrium conditions have been reached with the underlying soils. An additional advantage of this approach is that only one sample per chamber is required, which, combined with the low uncertainties of these measurements, facilitates the investigation of the spatial (landscape) variability of soil-respired CO2.

Cenozoic plant diversity in the neotropics.

Several mechanisms have been proposed to explain the high levels of plant diversity in the Neotropics today, but little is known about diversification patterns of Neotropical floras through geological time. Here, we present the longest time series compiled for palynological plant diversity of the Neotropics (15 stratigraphic sections, 1530 samples, 1411 morphospecies, and 287,736 occurrences) from the Paleocene to the early Miocene (65 to 20 million years ago) in central Colombia and western Venezuela. The record shows a low-diversity Paleocene flora, a significantly more diverse early to middle Eocene flora exceeding Holocene levels, and a decline in diversity at the end of the Eocene and early Oligocene. A good correlation between diversity fluctuations and changes in global temperature was found, suggesting that tropical climate change may be directly driving the observed diversity pattern. Alternatively, the good correspondence may result from the control that climate exerts on the area available for tropical plants to grow.

Reduccion de la morbilidad y mortalidad materna en las Américas: guia para la vigilancia epidemiologica de la muerte materma / Reduction of maternal morbility and mortality in the Américas: guidelines for epidemiological surveillance on maternal mortality

Esta Guia presenta los lineamientos generales para la vigilancia epidemiologica de la muerte materna. El objeto principal del Sistema de Vigilancia de la Mortalidad Materna (SVEMM) es contribuir al mejor conocimiento de los factores medicos-sociales que determinan las muertes maternas y proveer informacion para el desarrollo de estrategias para mejorar la salud de la mujerEl proposito principal de esta Guia es ofrecer a los paise en una forma resumida, y lenguaje simple, las orientaciones mas importantes para establecer un SVEMM o perfeccionarlo en aquellos países que ya cuenten con el