Fluorescence quenching of biologically active carboxamide by aniline and carbon tetrachloride in different solvents using Stern-Volmer plots

Fluorescence quenching of biologically active carboxamide namely (E)-2-(4-chlorobenzylideneamino)-N-(2-chlorophenyl)-4,5,6,7-tetrahydrobe nzo[b]thiophene-3-carboxamide [ECNCTTC] by aniline and carbon tetrachloride (CCl(4)) quenchers in different solvents using steady state method and time resolved method using only one solvent has been carried out at room temperature to understand the role of quenching mechanisms. The Stern-Volmer plot has been found to be linear for all the solvents studied. The probability of quenching per encounter p (p') was determined in all the solvents and was found to be less than unity. Further, from the studies of rate parameters and life time measurements in n-heptane and cyclohexane with aniline and carbon tetrachloride as quenchers have been shown that, the phenomenon of quenching is generally governed by the well-known Stern-Volmer (S-V) plot. The activation energy E(a) (or E(a)') of quenching was determined using the literature values of activation energy of diffusion E(d) and the experimentally determined values of p (or p'). It has been found that, the activation energy E(a) (E(a)') is greater than the activation energy for diffusion E(d) in all solvents. Hence, from the magnitudes of E(a) (or E(a)') as well as p (or p') infer that, the quenching mechanism is not solely due to the material diffusion, but there is also contribution from the activation energy. (C) 2011 Elsevier B.V. All rights reserved.

Multi-decadal variation of the net downward shortwave radiation over south Asia: The solar dimming effect

The solar radiation flux at the earth's surface has gone through decadal changes of decreasing and increasing trends over the globe. These phenomena known as dimming and brightening, respectively, have attracted the scientific interest in relation to the changes in radiative balance and climate. Despite the interest in the solar dimming/brightening phenomenon in various parts of the world, south Asia has not attracted great scientific attention so far. The present work uses the net downward shortwave radiation (NDSWR) values derived from satellites (Modern Era Retrospective-analysis for Research and Applications, MERRA 2D) in order to examine the multi-decadal variations in the incoming solar radiation over south Asia for the period of 1979-2004. From the analysis it is seen that solar dimming continues over south Asia with a trend of -0.54 Wm(-2) yr(-1). Assuming clear skies an average decrease of -0.05 Wm(-2)yr(-1) in NDSWR was observed, which is attributed to increased aerosol emissions over the region. There is evidence that the increase in cloud optical depth plays the major role for the solar dimming over the area. The cloud optical depth (MERRA retrievals) has increased by 10.7% during the study period, with the largest increase to be detected for the high-level (atmospheric pressure P < 400 hPa) clouds (31.2%). Nevertheless, the decrease in solar radiation and the role of aerosols and clouds exhibit large monthly and seasonal variations directly affected by the local monsoon system, the anthropogenic and natural aerosol emissions. All these aspects are examined in detail aiming at shedding light into the solar dimming phenomenon over a densely populated area. (C) 2011 Elsevier Ltd. All rights reserved.

Solvatochromic Effect on the Photophysical Properties of Two Coumarins

The absorption and emission spectra of two coumarins namely 7, 8 benzo-4-azidomethyl coumarin (C-1) and 6-methoxy-4-azidomethyl coumarin (C-2) have been recorded at room temperature in solvents of different polarities. The ground state dipole moments (mu(g)) of two coumarins were determined experimentally by Guggenheim method. The exited state (mu(e)) dipole moments were estimated from Lippert's, Bakhshievs and Chamma-Viallet's equations by using the variation of Stoke's shift with the solvent dielectric constant and refractive index. The ground and excited state dipole moments were calculated by means of solvatochromic shift method and also the excited state dipole moments are determined in combination with ground state dipole moments. It was observed that dipole moments of excited state were higher than those of the ground state, indicating a substantial redistribution of the pi-electron densities in a more polar excited state for two coumarins.

Synthesis and evaluation of 2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazoles as anti-cancer agents

A series of 2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazoles 9a-j were obtained via multistep synthesis from hydroxybenzophenones 4a-e. The cytotoxicity of compounds 9a-j was evaluated against human leukemia cell lilies (K562 and CEM). The compounds exhibited moderate to good anti-cancer activity with compounds 9b and 9i having a chloro group exhibiting the best activity (IC50 = 10 mu M). Compound 9i exhibited activity against both the cell lines and 9b only exhibited activity against CEM. Further, a lactate dehydrogenase (LDH) assay and DNA fragmentation studies of the compounds 9a-j were also performed. (C) 2013 Elsevier Masson SAS. All rights reserved.

Synthesis and evaluation of 2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazoles as anti-cancer agents

A series of 2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazoles 9a-j were obtained via multistep synthesis from hydroxybenzophenones 4a-e. The cytotoxicity of compounds 9a-j was evaluated against human leukemia cell lilies (K562 and CEM). The compounds exhibited moderate to good anti-cancer activity with compounds 9b and 9i having a chloro group exhibiting the best activity (IC50 = 10 mu M). Compound 9i exhibited activity against both the cell lines and 9b only exhibited activity against CEM. Further, a lactate dehydrogenase (LDH) assay and DNA fragmentation studies of the compounds 9a-j were also performed. (C) 2013 Elsevier Masson SAS. All rights reserved.

Differential proteomic and genomic profiling of mouse striatal cell model of Huntington's disease and control; probable implications to the disease biology

Huntington's disease (HD) is an autosomal dominant disorder of central nervous system caused by expansion of CAG repeats in exon1 of the huntingtin gene (Htt). Among various dysfunctions originated from the mutation in Htt gene, transcriptional deregulation has been considered to be one of the most important abnormalities. Large numbers of investigations identified altered expressions of genes in brains of HD patients and many models of HD. In this study we employed 2D SDS-PAGE/MALDI-MS coupled with 2D-DIGE and real-time PCR experiments of an array of genes focused to HD pathway to determine altered protein and gene expressions in STHdh(Q111)/Hdh(Q111) cells, a cell model of HD and compared with STHdh(Q7)/Hdh(Q7) cells, its wild type counterpart. We annotated 76 proteins from these cells and observed differential expressions of 31 proteins (by 2D-DIGE) involved in processes like unfolded protein binding, negative regulation of neuron apoptosis, response to superoxides etc. Our PCR array experiments identified altered expressions of 47 genes. Altogether significant alteration of 77 genes/proteins could be identified in this HD cell line with potential relevance to HD biology. Biological significance: In this study we intended to find out differential proteomic and genomic profiles in HD condition. We used the STHdh cells, a cellular model for HD and control. These are mouse striatal neuronal cell lines harboring 7 and 111 knock -in CAG repeats in their two alleles. The 111Q containing cell line (STHdh(Q111)/Hdh(Q111)) mimics diseased condition, whereas the 7Q containing ones (STHdh(Q7)/Hdh(Q7)), serves as the proper control cell line. Proteomic experiments were performed earlier to obtain differential expressions of proteins in R6/2 mice models, Hdh(Q) knock -in mice and in plasma and CSF from HD patients. However, no earlier report on proteomic alterations in these two HD cell lines and control was available in literature. It was, therefore, an important objective to find out differential expressions of proteins in these two cell lines. In this study, we annotated 76 proteins from STHdh(Q7)/Hdh(Q7) and STHdh(Q111)/Hdh(Q111) cells using 2D-gel/mass spectrometry. Next, by performing 2D-DIGE, we observed differential expressions of 31 proteins (16 upregulated and 15 downregulated) between these two cell lines. We also performed customized qRT-PCR array focused to HD pathway and found differential expressions of 47 genes (8 gene exptessions increased and 39 genes were decreased significantly). A total of 77 genes/proteins (Htt downregulated in both the studies) were found to be significantly altered from both the experimental paradigms. We validated the differential expressions of Vim, Hypk, Ran, Dstn, Hspa5 and Sod2 either by qRT-PCR or Western blot analysis or both. Out of these 77, similar trends in alteration of 19 out of 31 and 38 out of 47 proteins/genes were reported in earlier studies. Thus our study confirmed earlier observations on differential gene/protein expressions in HD and are really useful. Additionally, we observed differential expression of some novel genes/proteins. One of this was Hypk, a Htt-interacting chaperone protein with the ability to solubilize mHtt aggregated structures in cell lines. We propose that downregulation of Hypk in STHdh-Qm (Q111)/Hdh(Q111) has a causal effect towards HD pathogenesis. Thus the novel findings from our study need further research and might be helpful to understand the molecular mechanism behind HD pathogenesis. (C) 2015 Elsevier B.V. All rights reserved.

Assessment of driver vision functions in relation to their crash involvement in India

Among the human factors that influence safe driving, visual skills of the driver can be considered fundamental. This study mainly focuses on investigating the effect of visual functions of drivers in India on their road crash involvement. Experiments were conducted to assess vision functions of Indian licensed drivers belonging to various organizations, age groups and driving experience. The test results were further related to the crash involvement histories of drivers through statistical tools. A generalized linear model was developed to ascertain the influence of these traits on propensity of crash involvement. Among the sampled drivers, colour vision, vertical field of vision, depth perception, contrast sensitivity, acuity and phoria were found to influence their crash involvement rates. In India, there are no efficient standards and testing methods to assess the visual capabilities of drivers during their licensing process and this study highlights the need for the same.

"Diagnóstico de suelos y aguas superficiales de la subcuenca del Río Waswalí, Matagalpa, Nicaragua"

El estudio se desarrolló en la subcuenca intermunicipal del Río Waswalí, Matagalpa y Jinotega. El objetivo principal fue determinar las restricciones, limitantes y potencialidades de los recursos edáficos y recursos hídricos superficiales, con el fin de proponer la mejor organización funcional del territorio y la posibilidad de usos múltiples, que contribuya a mejorar la calidad y nivel de vida de sus habitantes. La metodología empleada consistió en: la caracterización del estado actual de los recursos edáficos e hídricos superficiales, mediante el diagnostico biofísico el cual se realizó en las ocho microcuencas adscritas al área de estudio. Entre los resultados: Se evidenció que los suelos en la subcuenca han sido utilizados de manera incorrecta 59.79% del área de la subcuenca esta sobreutilizada, aumentando en los últimos años de forma general por factores socioeconómicos y políticos entre estos la falta de planificación y/o explotación inadecuada de los recursos naturales; lo cual ha afectado el ciclo hidrológico provocando la disminución de la disponibilidad del recurso agua y aumentado la vulnerabilidad a eventos que provocan desastres naturales inundaciones, sequías, deslizamientos de tierras. Debido al paisaje heterogéneo existe una mezcla generalizada de usos de suelo, identificando cuatro categorías de las cuales predominan el pasto más cultivos anuales 64.01 % del área total y solo un 35.92 está con café con sombra y bosque, encontrándose en diferentes estados de intervención por las actividades desarrolladas, con el propósito de garantizar la subsistencia alimentaria. Respecto a los recursos híd ricos superficiales según los parámetros morfométricos de la subcuenca permiten que la respuesta ante los eventos lluviosos sea de forma moderada. Así la pendiente media de la subcuenca es del 28%, lo que favorece los procesos erosivos. Según los balances hídricos el período de déficit de agua inicia en la segunda semana de diciembre y finaliza en mayo así mismo estos cálculos nos indican que el almacenamiento máximo (reserva más exceso), aumenta a medida que se da la época lluviosa que corresponde a partir de junio a noviembre. La oferta hídrica es positiva en el área sin embargo, la mayor cantidad de agua se pierde por escorrentía. El Río Apalilí es el que más agua aporta al cauce principal (Río Waswalí).

Harmful algal research and response: A human dimensions strategy

Harmful Algal Research and Response: A Human Dimensions Strategy (HARR-HD) justifies and guides a coordinated national commitment to human dimensions research critical to prevent and respond to impacts of harmful algal blooms (HABs). Beyond HABs, it serves as a framework for developing hu-man dimensions research as a cross-cutting priority of ecosystem science supporting coastal and ocean management, including hazard research and mitigation planning. Measuring and promoting commu-nity resilience to hazards require human dimensions research outcomes such as effective risk commu-nication strategies; assessment of community vulnerability; identification of susceptible populations; comprehensive assessment of environmental, sociocultural, and economic impacts; development of effective decision support tools; and improved coordination among agencies and stakeholders. HARR-HD charts a course for human dimensions research to achieve these and other priorities through co-ordinated implementation by the Joint Subcommittee on Ocean Science and Technology (JSOST) In-teragency Working Group on HABs, Hypoxia and Human Health (IWG-4H); national HAB funding programs; national research and response programs; and state research and monitoring programs. (PDF contains 72 pages)

A kinematic subgrid scale model for large-eddy simulation of turbulence generated sound

In the hybrid approach of large-eddy simulation (LES) and Lighthill’s acoustic analogy for turbulence-generated sound, the turbulence source fields are obtained using an LES and the turbulence-generated sound at far fields is calculated from Lighthill’s acoustic analogy. As only the velocity fields at resolved scales are available from the LES, the Lighthill stress tensor, serving as a source term in Lighthill’s acoustic equation, has to be evaluated from the resolved velocity fields. As a result, the contribution from the unresolved velocity fields is missing in the conventional LES. The sound of missing scales is shown to be important and hence needs to be modeled. The present study proposes a kinematic subgrid-scale (SGS) model which recasts the unresolved velocity fields into Lighthill’s stress tensors. A kinematic simulation is used to construct the unresolved velocity fields with the imposed temporal statistics, which is consistent with the random sweeping hypothesis. The kinematic SGS model is used to calculate sound power spectra from isotropic turbulence and yields an improved result: the missing portion of the sound power spectra is approximately recovered in the LES.

Falling through the cracks: are European directives and international conventions the panacea for freshwater nature conservation?

There are many ways of practising freshwater nature conservation: from strict legislative protection of individual species considered rare or threatened to protecting whole lakes or long stretches of rivers; from practical conservation management at a local scale to integrated catchment management at the river basin scale; and from the encouragement of better habitat management through codes of good practice to statutory control of pollution or abstraction. Whatever the mechanism, an essential pre-requisite is a way of choosing where to put the effort, especially when resources for nature conservation are severely limited. The aim of this article is to review the contribution from four specific international measures to the task of assigning priorities for conservation. The 1990s saw the introduction of two European directives (the Habitats Directive (HD) and the Water Framework Directive (WFD)) and one international convention (the Biodiversity Convention (CBD)) each with the potential for influencing, to a greater or lesser extent, the conservation of freshwater habitats and species. This article also discusses a much older convention – the Ramsar Convention – adopted in 1971 specifically to help tackle the conservation and management of wetlands and aquatic ecosystems. Although the authors have focused mainly on the UK, the subject is relevant to other parts of Europe and beyond. The article explores the degree to which these measures help in identifying the most important fresh waters for conservation, and asks whether or not they present the right conservation message to a wide audience.