Study of the spatial variation of the biodegradation rate of the herbicide bentazone with soil depth using contrasting incubation methods

Vertical and horizontal spatial variability in the biodegradation of the herbicide bentazone was compared in sandy-loam soil from an agricultural field using sieved soil and intact soil cores. An initial experiment compared degradation at five depths between 0 and 80 cm using sieved soil. Degradation was shown to follow the first-order kinetics, and time to 50% degradation (DT50), declined progressively with soil depth from 56 d at 0–10 cm to 520 d at 70–80 cm. DT50 was significantly correlated with organic matter, pH and dehydrogenase activity. In a subsequent experiment, degradation rate was compared after 127 d in sieved soil and intact cores from 0 to 10 and 50 to 60 cm depth from 10 locations across a 160 × 90 m portion of the field. Method of incubation significantly affected mean dissipation rate, although there were relatively small differences in the amount of pesticide remaining in intact cores and sieved soil, accounting for between 4.6% and 10.6% of that added. Spatial variability in degradation rate was higher in soil from 0 to 10 cm depth relative to that from 50 and 60 cm depth in both sieved soil and intact core assessments. Patterns of spatial variability measured using cores and sieved soil were similar at 50–60 cm, but not at 0–10 cm depth. This could reflect loss of environmental context following processing of sieved soil. In particular, moisture content, which was controlled in sieved soil, was found to be variable in cores, and was significantly correlated with degradation rate in intact topsoil cores from 0 to 10 cm depth

Contenido polínico de algunas plantas entomófilas ornamentales en la atmósfera de Salamanca

XV lnternational A.P.L.E. Symposium of Palynolog

Estudio aeropalinológico de la familia Oleaceae en la atmósfera de Salamanca (1995-2003)

XV lnternational A.P.L.E. Symposium of Palynolog

Cuarto Congreso Latinoamericano y Octavo Congreso Boliviano de Mastozoología

The Fourth Latin American Congress and the Eighth Bolivian Congress of Mastozoology was held in the city of La Paz between July 10 and 13, 2018 and was the scenario in which researchers from the entire region converged in order to dialogue in around the conservation and investigation of mammals. According to official figures, more than 200 people from across the region gathered at a congress that, as predicted, was highlighted by the excellent keynote speakers who were part of the 8 sessions addressed, for the diversity of topics that were presented in each one of the generated symposiums, and especially for its excellent organization by the hand of the committee in charge, of the volunteers, and of the logistical support.El Cuarto congreso Latinoamericano y el Octavo congreso Boliviano de Mastozoología se llevó a cabo en la ciudad de La Paz entre el 10 y el 13 de julio de 2018 y fue el escenario en el cual confluyeron investigadores de toda la región con el fin de dialogar en torno a la conservación e investigación de los mamíferos. De acuerdo con cifras oficiales, más de 200 personas provenientes de toda la región se reunieron en un congreso que, como se pronosticaba, se destacó por losexcelentes conferencistas magistrales que hicieron parte de las 8 sesiones abordadas, por la diversidad de temáticas que fueron presentadas en cada uno de los simposios generados, y sobre todo por su excelente organización de la mano del comité encargado, de los voluntarios, y del apoyo logístico

Mitochondrial inhibitors activate influx of external Ca2+ in sea urchin sperm

AbstractSea urchin sperm have a single mitochondrion which, aside from its main ATP generating function, may regulate motility, intracellular Ca2+ concentration ([Ca2+]i) and possibly the acrosome reaction (AR). We have found that acute application of agents that inhibit mitochondrial function via differing mechanisms (CCCP, a proton gradient uncoupler, antimycin, a respiratory chain inhibitor, oligomycin, a mitochondrial ATPase inhibitor and CGP37157, a Na+/Ca2+ exchange inhibitor) increases [Ca2+]i with at least two differing profiles. These increases depend on the presence of extracellular Ca2+, which indicates they involve Ca2+ uptake and not only mitochondrial Ca2+ release. The plasma membrane permeation pathways activated by the mitochondrial inhibitors are permeable to Mn2+. Store-operated Ca2+ channel (SOC) blockers (Ni2+, SKF96365 and Gd2+) and internal-store ATPase inhibitors (thapsigargin and bisphenol) antagonize Ca2+ influx induced by the mitochondrial inhibitors. The results indicate that the functional status of the sea urchin sperm mitochondrion regulates Ca2+ entry through SOCs. As neither CCCP nor dicycloexyl carbodiimide (DCCD), another mitochondrial ATPase inhibitor, eliminate the oligomycin induced increase in [Ca2+]i, apparently oligomycin also has an extra mitochondrial target

Propiedades de las rocas volcánicas de Canarias (España) utilizadas como material de escollera

In the Canary Islands, there is a wide spectrum of volcanic rocks with different properties to be used in public works. The aim of this study is to analyse the physical-mechanical properties of all the volcanic rocks present in the Canary Island archipelago in order to determine their suitability for use in maritime construction works. The great variety of volcanic rocks present on the islands have been grouped into lithotypes based on similar geo-mechanical behaviour. The laboratory test results obtained for these lithotypes establish their suitability or not to be used as breakwater material in accordance with Spanish regulations.En el archipiélago canario existe un amplio espectro de rocas volcánicas con diferentes propiedades para ser utilizadas en obras públicas. El objetivo de este estudio es analizar las propiedades físico-mecánicas de todas las rocas volcánicas presentes en el archipiélago canario con el fin de determinar su idoneidad para ser utilizadas en obras de construcción marítima. La gran variedad de rocas volcánicas presentes en las islas, se han agrupado en litotipos basados en un comportamiento geomecánico similar. Los resultados de los ensayos de laboratorio obtenidos para estos litotipos establecen su idoneidad o no para ser utilizados como material de escollera de acuerdo con la normativa española

Flavor-changing top quark rare decays in the Bestest Little Higgs Model

This paper investigates the effects of parameters in the Bestest Little Higgs Model (BLHM) on rare flavor-changing decays of the top quark. As a result, flavor-changing phenomena are introduced in the BLHM for the first time. In this study, we incorporate new flavor mixing terms between the light quarks of the Standard Model (SM) and the fermions and bosons of the BLHM. We compute the one-loop contributions from the heavy quark $(B)$ and the heavy bosons $(W^{\prime\pm}, \phi^{\pm}, \eta^{\pm},H^{\pm})$. Our findings demonstrate that the branching ratios of decays $t\to qV$ and $t\to qh^0$, where $q=u,c$ and $V=Z, \gamma, g$, exhibit improvements compared to their counterparts in the SM, except for the gluon case. Moreover, we observe that the processes with higher sensitivity are $Br(t\to cZ)\sim 10^{-5}$, $Br(t\to c\gamma)\sim 10^{-6}$ and $Br(t \to ch^0) \sim 10^{-8}$ within the appropriate parameter space.Comment: 13 pages and 10 figure