Crops gone wild: evolution of weeds and invasives from domesticated ancestors.

The evolution of problematic plants, both weeds and invasives, is a topic of increasing interest. Plants that have evolved from domesticated ancestors have certain advantages for study. Because of their economic importance, domesticated plants are generally well-characterized and readily available for ecogenetic comparison with their wild descendants. Thus, the evolutionary history of crop descendants has the potential to be reconstructed in some detail. Furthermore, growing crop progenitors with their problematic descendants in a common environment allows for the identification of significant evolutionary differences that correlate with weediness or invasiveness. We sought well-established examples of invasives and weeds for which genetic and/or ethnobotanical evidence has confirmed their evolution from domesticates. We found surprisingly few cases, only 13. We examine our list for generalizations and then some selected cases to reveal how plant pests have evolved from domesticates. Despite their potential utility, crop descendants remain underexploited for evolutionary study. Promising evolutionary research opportunities for these systems are abundant and worthy of pursuit

Spectrophotometric Study of Polymeric DyesGels After a Gamma Irradiation Process for its Possible Use as a Radiation Dosimeter

This work aims to evaluate a dosimetric system composed of green malachite supported in agarose. Previous work showed that solutions of green malachite irradiated at 1 to 40 kGy present a linear behavior. This system is a gel composed of green malachite (2.5×10–3 M), sodium benzoate (1%),and agarose (1%) that was exposed tovarious doses of gamma irradiation. The irradiated systems were measured with a UV-V is spectrophotometer at 619 nm. Experimental parameters (such as dose rate, doses, and temperature) were controlled and optimized for reproducible and reliable results. More studies are needed to propose a dosimeter in the system in the range of 1.8 to 4.0 kGy

Use of Native Grassland in Small-Scale Dairy Systems in the Highlands of Central Mexico. A Case Study

Small-scale dairy systems in Mexico comprise 78% of specialized dairy farms and provide 37% of national production. They are small farms with herds 3-35 cows plus replacements, and rely on family labour (Posadas-Domínguez et al., 2014). In the highlands, many farms have native grasslands, grazed during the rainy season, and supplemented with other feeds as maize straw, maize grain and maize ears. Native grasslands have not been studied in this context. This is a case study on the use of native grassland in a small-scale dairy farm. The objective was to determine how native grasslands are integrated in feeding milking dairy cows, and the feeding costs involved

Gamma Dosimetry Using Some Dyes in Organic Solvents Solutions at 295 and 77 K

The aim of this work is to study the behavior under irradiation of different dyes (green malachite, methyl orange, red cresol, and bromothymol blue) in organic solvents (acetone and methanol) at different gamma doses and different temperatures to propose them as possible dosimeters for low-temperature applications. For this purpose, organic dissolutions were irradiated with gamma rays in the kiloGray (kGy) range at 77 and 295 K, and the color bleaching of the solutions was followed spectrophotometrically (UV-Vis range). The response curves at different temperatures show the linear range interval from 10 to 40 kGy with correlation coefficients of 0.999 and 0.998 for some systems. This is the main reason to continue carrying out studies that allow the proposal of these systems as chemical dosimeters

Campesinato e “plantation” no nordeste

O sistema de plantation supõe, para o seu desenvolvimento, o fechamento dos recursos (terra e mão de obra), parecendo portanto excluir a existência de um campensinato livre, isto é, de trabalhadores agrícolas que têm acesso direto à terra, dela extraindo, mediante o trabalho familiar, o produto de sua subsistência. No entanto, como a literatura o assinala e como pudemos observar em pesquisas realizadas anteriormente, sempre existiu um campesinato ligado à plantation e a ela subordinado: as transformações da plantation nordestina, se por um lado provocaram a proletarização de grande parte dos seus trabalhadores, deram origem ao mesmo tempo, pelo mesmo movimento, ao surgimento de novas gerações camponesas. Porém, a expansão desse campesinato que surgiu nessas condições tem limites que o afetam na sua própria reprodução

Transition between Variscan and Alpine cycles in the Pyrenean-Cantabrian Mountains (N Spain): Geodynamic evolution of near-equator European Permian basins

In the northern Iberian Peninsula, the Pyrenean-Cantabrian orogenic belt extends E-W for ca. 1000 km between the Atlantic Ocean and Mediterranean Sea. This orogen developed from the collision between Iberia and Eurasia, mainly in Cenozoic times. Lower-middle Permian sediments crop out in small, elongated basins traditionally considered independent from each other due to misinterpretations on incomplete lithostratigraphic data and scarce radiometric ages. Here, we integrate detailed stratigraphic, sedimentary, tectonic, paleosol and magmatic data from well-dated lithostratigraphic units. Our data reveal a similar geodynamic evolution across the Pyrenean-Cantabrian Ranges at the end of the Variscan cycle. Lower-middle Permian basins started their development under an extensional regime related to the end of the Variscan Belt collapse, which stars in late Carboniferous times in the Variscan hinterland. This orogenic collapse transitioned to Pangea breakup at the middle Permian times in the study region. Sedimentation occurred as three main tectono-sedimentary extensional phases. A first phase (Asselian-Sakmarian), which may have even started at the end of the Carboniferous (Gzhelian) in some sections, is mainly represented by alluvial sedimentation associated with calc-alkaline magmatism. A second stage (late Artinskian-early Kungurian), represented by al-luvial, lacustrine and palustrine sediments with intercalations of calc-alkaline volcanic beds, shows a clear up-ward aridification trend probably related to the late Paleozoic icehouse-greenhouse transition. The third and final stage (Wordian-Capitanian) comprised of alluvial deposits with intercalations of alkaline and mafic beds, rarely deposited in the Cantabrian Mountains, and underwent significant pre-and Early Mesozoic erosion in some segments of the Pyrenees. This third stage can be related to a transition towards the Pangea Supercontinent breakup, not generalized until the Early/Middle Triassic at this latitude because the extensional process stopped about 10 Myr (Pyrenees) to 30 Myr (Cantabrian Mountains). When compared to other well-dated basins near the paleoequator, the tectono-sedimentary and climate evolution of lower-middle Permian basins in Western and Central Europe shows common features. Specifically, we identify coeval periods with magmatic activity, extensional tectonics, high subsidence rates and thick sedi-mentary record, as well as prolonged periods without sedimentation. This comparison also identifies some evolutionary differences between Permian basins that could be related to distinct locations in the hinterland or foreland of the Variscan orogen. Our data provide a better understanding of the major crustal re-equilibration and reorganization that took place near the equator in Western-Central Europe during the post-Variscan period

Oxigenoterapia de alto flujo y ventilación no invasiva en pacientes extubados por COVID-19 y riesgo de reintubación

Introduction: High-flow oxygen therapy (HFO) and non-invasive ventilation (NIV) are non-invasive systems that are administered post-extubation in COVID-19 patients to avoid reintubation. However, the evidence on the choice of any of these devices is not very clear. The objective was to determine if the group that received OAF compared to the group that received NIV is associated with a lower risk of reintubation in adults with difficult weaning and extubated due to COVID-19. Material and methods: Retrospective cohort study in 206 records of patients in difficult weaning from mechanical ventilation in the Intensive Care Unit (ICU). The primary outcome was reintubation in patients who failed HFO or post-extubation NIV, and the secondary outcomes were ICU hospital stay and 90-day mortality. Results: Two hundred and six patients met the inclusion criteria, 102 patients in the OAF group and 104 patients in the NIV group. During the 72-h follow-up, the reintubation rate in the HFO group was higher [n=24 (64,9%)] compared to the NIV group [n=13 (35,1%)], showing in the analysis of Kaplan-Meier significant differences (Log-Rank-Test p=0,005). COX regression showed a higher risk of reintubation in the HFO group compared to NIV (HR 2,74; 95%CI 1,42-5,68; p=0,007). There were no differences in ICU hospitalization days (p=0,913) or in 90-day mortality (Log-Rank-Test p=0,49). Conclusion: This retrospective observational study suggested that HFO versus NIV was associated with a higher risk of reintubation, but not with 90-day mortality.Introducción: La oxigenoterapia de alto flujo (OAF) y la ventilación no invasiva (VNI) son sistemas no invasivos que se administran post-extubación en pacientes COVID-19 para evitar la reintubación. Sin embargo, la evidencia sobre la elección de alguno de estos dispositivos no está muy clara. El objetivo fue determinar si el grupo que recibió OAF comparado con el grupo que recibió VNI se asocia a menor riesgo de reintubación en adultos con destete difícil y extubados por COVID-19. Material y métodos: Estudio cohorte retrospectivo en 206 registros de pacientes en destete difícil de ventilación mecánica en la Unidad de Cuidados Intensivos (UCI). El resultado primario fue reintubación en pacientes que fracasaron con OAF o VNI post-extubación y los resultados secundarios fueron estancia hospitalaria en UCI y mortalidad a los 90 días. Resultados: Doscientos seis pacientes cumplieron los criterios de inclusión, 102 pacientes en el grupo OAF y 104 pacientes en el grupo VNI. Durante el seguimiento de 72 horas, la tasa de reintubación en el grupo OAF fue mayor [n=24 (64,9%)] comparado con el grupo VNI [n=13 (35,1%)], mostrando en el análisis de Kaplan-Meier diferencias significativas (Log-Rank-Test p=0,005). La regresión de COX mostró mayor riesgo de reintubación en el grupo de OAF frente a VNI (HR 2,74; IC95% 1,42-5,68; p=0,007). No hubo diferencias en los días de hospitalización UCI (p=0,913) ni en mortalidad a los 90 días (Log-Rank-Test p=0,49). Conclusión: Este estudio observacional retrospectivo sugirió que la OAF frente al VNI se asoció a mayor riesgo de reintubación, pero no a mortalidad a los 90 días

Taxing the Informal Economy: The Current State of Knowledge and Agendas for Future Research

This paper reviews the literature on taxation of the informal economy, taking stock of key debates and drawing attention to recent innovations. Conventionally, the debate on whether to tax has frequently focused on the limited revenue potential, high cost of collection, and potentially adverse impact on small firms. Recent arguments have increasingly emphasised the more indirect benefits of informal taxation in relation to economic growth, broader tax compliance, and governance. More research is needed, we argue, into the relevant costs and benefits for all, including quasi-voluntary compliance, political and administrative incentives for reform, and citizen-state bargaining over taxation

Search for Zgamma events with large missing transverse energy in ppbar collisions at sqrt(s)=1.96 TeV

We present the first search for supersymmetry (SUSY) in Zgamma final states with large missing transverse energy using data corresponding to an integrated luminosity of 6.2 fb-1 collected with the D0 experiment in ppbar collisions at sqrt(s)=1.96 TeV. This signature is predicted in gauge-mediated SUSY-breaking models, where the lightest neutralino is the next-to-lightest supersymmetric particle (NLSP) and is produced in pairs, possibly through decay from heavier supersymmetric particles. The NLSP can decay either to a Z boson or a photon and an associated gravitino that escapes detection. We exclude this model at the 95% C.L. for SUSY breaking scales of Lambda < 87 TeV, corresponding to neutralino masses of < 151 GeV.Comment: submitted to Phys. Rev. Let

Search for B0→π0π0B^{0}\to \pi^{0}\pi^{0} Decay

We have searched for the charmless hadronic decay of B0 mesons into two neutral pions. Using 9.13fb^-1 taken at the Upsilon(4S) with the CLEO detector, we obtain an improved upper limit for the branching fraction BR(B0-->pi0pi0) < 5.7*10^-6 at the 90% confidence level.Comment: pages postscript, also available through http://w4.lns.cornell.edu/public/CLN