Biochemical and Physiological Biomarkers in Aquatic Environmental Research

Biomarkers are used as tools to assess biological changes that may reveal exposure of organisms to environmental chemicals. In some cases, biomarkers are able to indicate that chemicals specifically affect metabolicpathways or physiological functions in exposed individuals. Therefore, biomarkers can be used as both diagnostic and predictive tools. More recently, the concept of “biomarkers” has gained popularity amongst environmental managers. There are many different biomarkers that occur at many different levels of organization from sub-cellular to wholeorganisms. Biomarkers at the molecular level tend to respond first, followed by responses at the cellular (biochemical and physiological), and whole-body levels. within this review, I will review the application of some biochemical and physiological biomarkers in aquatic environmental research. This review presents a synthesis of the state of the art in themethodology of biochemical and physiological biomarkers and its contribution in aquatic environmental research. The text explores the latest knowledge and thinking on this very important approach for the assessment of environmental health, management, and conservation. The primary concern of the present review is the measurement of biomarkers in aquatic organisms under field and laboratory conditions, where effects of chemicals at different levels of biological organization can be examined.Keywords: Biomarkers, aquatic organisms, biochemical biomarkers, physiological biomarker

STOCK MARKET DEVELOPMENT AND ECONOMIC GROWTH: THE CAUSAL LINKAGE

This paper addresses the question: does stock market development cause growth? It examines the causal linkage between stock market development, financial development and economic growth. The argument is that any inference that financial liberalisation causes savings or investment or growth, or that financial intermediation causes growth, drawn from bivariate causality tests may be invalid, as invalid causality inferences can result from omitting an important variable. The empirical part of this study exploits techniques recently developed by Toda and Yamamoto (1995) to test for causality in VARs, and emphasises the possibility of omitted variable bias. The evidence obtained from a sample of seven countries suggests that a well-developed stock market can foster economic growth in the long run. It also provides support to theories according to which well-functioning stock markets can promote economic development by fuelling the engine of growth through faster capital accumulation, and by tuning it through better resource allocation.Financial Development, Economic Growth, Stock Market, Causality Testing, VARs, Incomplete Systems

Biochemical and Physiological Biomarkers in Aquatic Environmental Research

Biomarkers are used as tools to assess biological changes that may reveal exposure of organisms to environmental chemicals. In some cases, biomarkers are able to indicate that chemicals specifically affect metabolicpathways or physiological functions in exposed individuals. Therefore, biomarkers can be used as both diagnostic and predictive tools. More recently, the concept of “biomarkers” has gained popularity amongst environmental managers. There are many different biomarkers that occur at many different levels of organization from sub-cellular to wholeorganisms. Biomarkers at the molecular level tend to respond first, followed by responses at the cellular (biochemical and physiological), and whole-body levels. within this review, I will review the application of some biochemical and physiological biomarkers in aquatic environmental research. This review presents a synthesis of the state of the art in themethodology of biochemical and physiological biomarkers and its contribution in aquatic environmental research. The text explores the latest knowledge and thinking on this very important approach for the assessment of environmental health, management, and conservation. The primary concern of the present review is the measurement of biomarkers in aquatic organisms under field and laboratory conditions, where effects of chemicals at different levels of biological organization can be examined.Keywords: Biomarkers, aquatic organisms, biochemical biomarkers, physiological biomarker

Effects of ultraviolet A on the activity of two metabolic enzymes, DNA damage and lipid peroxidation during early developmental stages of the African catfish, Clarias gariepinus (Burchell, 1822)

Many ultraviolet-A (UVA)-induced biochemical and physiological changes are valid as biomarkers using aquatic species for detection of the degree of stress. Changes in the concentration and activities of enzymes, such as glucose-6-phosphate dehyderogenase (G6PDH), lactate dehyderogenase (LDH), DNA damage and lipid peroxidation (LPO), can be used as biomarkers to identify possible environmental contamination in fish. This study aimed to investigate the impact of UVA on the activity of the selected enzymes, DNA damage and LPO during early developmental stages of the African catfish Clarias gariepinus. Embryo hemogenates were used for measurements of G6PDH, LDH, DNA damage and LPO concentrations and activities spectrophotometrically at 37°C. The normal ontogenetic variations in enzyme activities, DNA damage and LPO of the early developmental stages (24–168 h-PFS; hours-post fertilization stage) were studied. There was a significant decrease in the activity of G6PDH till 120 h-PFS. Then after 120 h-PFS, the activity of such enzymes insignificantly increased toward higher stages. The LDH activity was recorded with a pattern of decrease till 96 h-PFS, followed by a significant increase toward 168 h-PFS. The polynomial pattern of variations in DNA damage and LPO was also evident. The patterns of the enzyme activities, corresponding DNA damage and LPO of the early ontogenetic stages under the influence of three different UVA doses (15, 30 and 60 min), were recorded. The pattern of variations in G6PDH activity in UVA-induced groups was similar to that of the control group with variation in the magnitude of such activity. In all treated groups, LDH activity decreased till 96 h-PFS, then increased till 168 h-PFS. Within each of the embryonic stages, the increase in UVA led to a significant increase in DNA damage. A significant increase in lipid peroxidation under UVA doses was recorded. The variability in number and molecular weight of proteins under exposure to UVA was evident, reflecting some of the genetic and transcriptional changes during exposure and development

Uncovering protein interaction in abstracts and text using a novel linear model and word proximity networks

We participated in three of the protein-protein interaction subtasks of the Second BioCreative Challenge: classification of abstracts relevant for protein-protein interaction (IAS), discovery of protein pairs (IPS) and text passages characterizing protein interaction (ISS) in full text documents. We approached the abstract classification task with a novel, lightweight linear model inspired by spam-detection techniques, as well as an uncertainty-based integration scheme. We also used a Support Vector Machine and the Singular Value Decomposition on the same features for comparison purposes. Our approach to the full text subtasks (protein pair and passage identification) includes a feature expansion method based on word-proximity networks. Our approach to the abstract classification task (IAS) was among the top submissions for this task in terms of the measures of performance used in the challenge evaluation (accuracy, F-score and AUC). We also report on a web-tool we produced using our approach: the Protein Interaction Abstract Relevance Evaluator (PIARE). Our approach to the full text tasks resulted in one of the highest recall rates as well as mean reciprocal rank of correct passages. Our approach to abstract classification shows that a simple linear model, using relatively few features, is capable of generalizing and uncovering the conceptual nature of protein-protein interaction from the bibliome. Since the novel approach is based on a very lightweight linear model, it can be easily ported and applied to similar problems. In full text problems, the expansion of word features with word-proximity networks is shown to be useful, though the need for some improvements is discussed

Assessment of vehicular live load and load factors for design of short-span bridges according to the new Egyptian Code

AbstractThe new Egyptian Code (ECP-201:2012) introduces new vehicular live loads (VLL) and new load combinations for the design of roadway bridges. The new VLL and load combinations introduced in ECP-201:2012 are fundamentally different than those presented in previous versions of the code. The impact of these new loads and load combinations on the design of new bridges or the structural safety of the existing bridges that have been designed according to ECP-201:2003 or ECP-201:1993 has not been fully addressed for the different bridge deck systems. Three different bridge deck systems, i.e. concrete I-shaped girders, composite steel plate girders, and concrete box-girders with different spans were numerically modeled using two-dimensional grillage analogy. The bridge decks were analyzed under main gravity loads using VLL according to ECP-201:2012 and ECP-201:2003. The internal forces of individual load cases, total un-factored load combination, and total factored load combination of ECP-201:2012 and ECP-201:2003 were compared.The study shows that concrete box-girders designed according to ECP-201:2012 and ECP-201:2003 using the ultimate limit state method yield almost the same demand. Despite the increase in the VLL of ECP-201:2012, and consequently the live load forces, concrete I-shaped girder bridges will be subjected to less total factored internal forces in comparison to ECP-201:2003 This is attributed to the interaction between the live to dead loads ratio and the load combinations. Design of composite steel plate girder bridges according to ECP-201:2012 using the allowable stress design method yields over designed sections

Estudios ultraestructurales de las variaciones morfológicas de la superficie y envolturas del huevo de pez-gato africano Clarias gariepinus (Burchell, 1822) antes y después de la fertilización, con una discusión de los mecanismos de fertilización

Much of the existing knowledge of the mechanisms involved in teleost fertilisation is based on a few small model species that have no commercial value. Research is therefore urgently required to address mechanisms involved in fertilisation in species of great commercial value. In this study, the ultrastructural morphological variations in the surface of the egg of Clarias gariepinus were recorded before and after fertilisation by using electron microscopy. The outer surface of the unfertilised egg was smooth, whereas the fertilised egg acquired a network of projections on the vegetal hemisphere. Moreover, different patterns of ornamentation on the egg surface were evident. This pattern of ornamentation varied with the progress of embryonic development. The micropyle of the C. gariepinus egg consisted of a funnel-shaped vestibule, from the bottom of which a cylindrical micropylar canal extended. The micropylar canal decreased in diameter after completion of fertilisation, forming a micropylar disc. The sperm behaviour on the egg surface was oriented towards any depression on the chorion surface. The chorion of ovulated eggs consisted of one layer. After fertilisation the chorion was differentiated into three layers: the double-layered coat, the zona radiata externa and the zona radiata interna. Four protein subunits of the chorion of C. gariepinus were identified by SDS-PAGE. IR-spectra obtained from C. gariepinus chorion revealed that the vibration of chorion proteins exhibited different weak activities in the IR-spectra with minor difference between pre- and post-fertilisation chorion proteins.Gran parte del conocimiento existente sobre los mecanismos de fertilización en teleósteos se basa en unas pocas especies modelo, que no tienen valor comercial. Por ello, se requiere investigación dirigida a conocer los mecanismos involucrados en la fertilización de especies de gran valor comercial. En el presente estudio, mediante el uso del Microscopio Electrónico, se obtuvieron imagines de las variaciones en la morfología ultraestructural de la superficie de los huevos de Clarias gariepinus antes y después de la fertilización. La superficie externa de los huevos infertilizados era lisa, mientras que la de los huevos fertilizados adquiría una red de proyecciones en el hemisferio vegetativo. Además, fueron evidentes diferentes patrones de ornamentación de la superficie del huevo. Este patrón de ornamentación varió a lo largo del desarrollo embrionario. El micropilo de los huevos de C. gariepinus consistió en un vestíbulo con forma de embudo desde la base del cual se extendía un canal micropilar cilíndrico. El diámetro de dicho canal disminuía tras la finalización de la fertilización, formándose el disco micropilar. El comportamiento del esperma en la superficie de los huevos se orientaba hacia cualquier depresión de la superficie del corion. El corion de los ovocitos consistió en una sola capa. Tras la fertilización, el corion se diferenció en tres capas: la capa double-acodada, la zona radiada externa and y la zona radiada interna. Mediante SDS-PAGE se identificaron cuatro subunidades de proteínas en el corion de los huevos de C. gariepinus. Los espectros IR obtenidos del corion revelaron que la vibración de las proteínas del corion exhibía diversas débiles actividades en el espectro IR con menores diferencias entre pre- y post-fertilización proteínas del corion

Carum carvi mediated green synthesis of copper nanoparticles and its effect on Solanum lycopersicum seedlings

The present study aims to synthesis the copper nanoparticles (CuNPs) and their effect on the biochemical and physiological characteristics of Solanum lycopersicum. The results exhibited the color change in the Carum carvi aqueous extract from clear deep brown to a greenish color and this observation indicated the green-biosynthesis of CuNPs by reduction of Cu+ to Cu0. Also, the absorbance broadening band for the green-biosynthetic CuNPs appeared at the 340 nm wavelength using UV-Vis but the C. carvi aqueous extract not showed any peaks at this wavelength. SEM analysis exhibited the micrographic surface morphology and the shape of the green-biosynthetic CuNPs with a scan area of 50 μm and showed the spherical shape particles of CuNPs aggregation. The three-dimensional image and the surface morphology of green-biosynthesized CuNPs and C. carvi aqueous extract were examined using AFM analysis that showed the surface of C. carvi aqueous extract was 45.5 nm size with non-homologus and irregular form of distribution, but the green-biosynthesized CuNPs were 12.4 nm size in nanoscale with regular and homogenous distribution form. The results also showed that the effect of bio-synthesized copper nanoparticles was evident on the S. lycopersicum seedlings fresh and dry weight according to the different reading times after treatment with nanoparticles. Also, the concentration of 2.5 mg/mL (CuNPs) showed a significant increase in the chlorophyll content (58.51 μg/cm²) on the 21st day after treatment and a significant increase in the activity of peroxidase enzyme (35.12 U min-1 mg-1 protein) was obtained at the concentration of 2.5 mg/mL (CuNPs) at 21st day after germination

Discovery of a 6.4 keV Emission Line in a Burst from SGR 1900+14

We present evidence of a 6.4 keV emission line during a burst from the soft gamma-ray repeater SGR 1900+14. The Rossi X-ray Timing Explorer (RXTE) monitored this source extensively during its outburst in the summer of 1998. A strong burst observed on August 29, 1998 revealed a number of unique properties. The burst exhibits a precursor and is followed by a long (~ 1000 s) tail modulated at the 5.16 s stellar rotation period. The precursor has a duration of 0.85 s and shows both significant spectral evolution as well as an emission feature centered near 6.4 keV during the first 0.3 s of the event, when the X-ray spectrum was hardest. The continuum during the burst is well fit with an optically thin thermal bremsstrahlung (OTTB) spectrum with the temperature ranging from about 40 to 10 keV. The line is strong, with an equivalent width of 400 eV, and is consistent with Fe K-alpha fluorescence from relatively cool material. If the rest-frame energy is indeed 6.4 keV, then the lack of an observed redshift indicates that the source is at least 80 km above the neutron star surface. We discuss the implications of the line detection in the context of models for SGRs.Comment: AASTex preprint, 14 pages, 3 embedded figures. Accepted for Publication in Astrophysical Journal Letter