335 research outputs found

    Ion Exchange Chromatography - An Overview

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    Biomarkers

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    Reconstruction of a latest Paleocene shallow-marine eutrophic paleoenvironment at Sidi Nasseur (Central Tunisia) based on foraminifera, ostracoda, calcareous nannofossils and stable isotopes (d13C, d18O)

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    In order to unravel faunal and paleoenvironmental parameters in shallow marine settings prior to the Paleocene- Eocene thermal maximum, we investigated the Sidi Nasseur section (NAS) in Central Tunisia. This section exposes Paleocene to lower Eocene shales and marls of the El Haria Formation. The uppermost Paleocene part of the Sidi Nasseur section is marked by poor to moderately rich, but fairly diversified nannofossil associations, containing the typical latest Paleocene taxa of the top of NP9a. The ostracode record displays an almost continuous record in the uppermost Paleocene part of the section. Representatives of Aegyptiana, Paracosta, Reticulina and Reymenticosta make up the major part of the ostracode fauna. The benthic foraminiferal assemblage consists of numerous small calcareous benthic foraminifera, like Anomalinoides midwayensis and Lenticulina spp. and many large Frondicularia phosphatica, Pyramidulina spp. These, together with the non-calcareous agglutinated foraminifera and the rare planktic foraminifera, indicate an inner neritic to coastal environment with eutrophic conditions, regularly interrupted by oxygen deficiency. The dominance of non-calcareous benthic foraminifera between intervals with abundant calcareous benthic foraminifera suggests post-mortem dissolution. The foraminiferal d13C record (based upon Pyramidulina latejugata) of the latest Paleocene in the Sidi Nasseur area is very similar to these from coeval sediments at Gebel Duwi and Gebel Aweina in Egypt. Oxygen isotopic ratios indicate a marine setting with a water composition affected by evaporation. During the latest Paleocene, the highly productive shallow water environment evolved to shallower water depths with higher salinity and increasing dominance of A. midwayensis

    An attempt to identify the extended synchrotron structure associated with the micro-quasar GRS 1915+105

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    The energy ejected from the galaxy micro-quasar GRS1915+105 in the form of jets is expected to lead to formation of an extended double lobe/hot-spot structure with the energy content comparable to an average supernova remnant. We used the Effelsberg 100m telescope at 10.45 GHz in attempt to identify such structures. For this distant galactic plane source any definite identification was not possible due to high confusion by numerous background sources, however, a few suspect structures were pointed out.Comment: LaTeX uses a new 2001 A&A macro, 4 pages, 2 figures, A&A accepte

    Propositional calculus for adjointness lattices

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    Recently, Morsi has developed a complete syntax for the class of all adjointness algebras (L,≤,A,K,H)\left( L,\leq ,A,K,H\right) . There, (L,≤)\left( L,\leq \right) is a partially ordered set with top element 11, KK is a conjunction on (L,≤)\left( L,\leq \right) for which 11 is a left identity element, and the two implication-like binary operations AA and HH on LL are adjoints of KK. In this paper, we extend that formal system to one for the class ADJLADJL of all 9-tuples (L,≤,1,0,A,K,H,∧,∨)\left( L,\leq ,1,0,A,K,H,\wedge ,\vee \right) , called \emph{% adjointness lattices}; in each of which (L,≤,1,0,∧,∨)\left( L,\leq ,1,0,\wedge ,\vee \right) is a bounded lattice, and (L,≤,A,K,H)\left( L,\leq ,A,K,H\right) is an adjointness algebra. We call it \emph{Propositional Calculus for Adjointness Lattices}, abbreviated AdjLPCAdjLPC. Our axiom scheme for AdjLPCAdjLPC features four inference rules and thirteen axioms. We deduce enough theorems and inferences in AdjLPCAdjLPC to establish its completeness for ADJLADJL; by means of a quotient-algebra structure (a Lindenbaum type of algebra). We study two negation-like unary operations in an adjointness lattice, defined by means of 00 together with AA and HH. We end by developing complete syntax for all adjointness lattices whose implications are SS-type implications

    The potential gonadoprotective effects of grape seed extract against the histopathological alterations elicited in an animal model of cadmium-induced testicular toxicity

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    Background: Grape seed extract (GSE) is a powerful antioxidant containing high levels of bioflavonoids, vitamin C and vitamin E. The aim of the work is to study the possible protective and ameliorative effects of grape seed extract in an animal model of cadmium (Cd)-induced testicular toxicity in rats.Materials and methods: A thirty-day oral gavage study in adult male albino rats was performed using 32 animals, randomly divided into four equal groups; negative control, Cd (5 mg/k/day), GSE (100 mg/k/day), and Cd + GSE. Testicular weights were measured. Haematoxylin and eosin (H&E) staining and proliferating nuclear cell antigen (PCNA) immunohistochemistry, as a marker for proliferation were done. Morphometric parameters were assessed and subjected to statistical analysis.Results: The H&E results showed atrophy and distortion of the seminiferous tubules (STs) with sloughing of the spermatogenic epithelium in cadmium group. The interstitial spaces were widened and showed oedema and mononuclear cell infiltrations. No remarkable changes were observed in the GSE-only group when compared to the control group. In Cd + GSE group, maintaining of the STs and their lining cells was evident. The immunohistochemical results showed marked positive PCNA immunoreactivity in both control and GSE groups, while negative immunoreaction was noticed in Cd group. Limited positive PCNA immunoreactivity was ameliorated in Cd + GSE group.Conclusions: Grape seed extract protected against cadmium-induced testicular toxicity in rats, reducing induced histopathological changes, and maintaining testicular histoarchitecture

    Assessment and Comparison of Aviation Manufacturing Industries throughout Mexico and Brazil

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    This literature review serves to provide insight and understanding in regards to the evolving aviation manufacturing industry throughout the globe and more specifically, Mexico and Brazil. Increased demand for aircraft units both in the commercial and private sectors have led to unprecedented expansions in aircraft manufacturing across the industry. In order to illuminate certain potentials and current growth levels of such industries, this review will delve into an array of information and specifications in regards to economic, political, and cultural influences throughout both Mexican and Brazilian markets respectively. In conclusion, the review will identify the transformation of an aviation manufacturing stronghold from one nation to another

    Management of root rot and wilt diseases of date palm offshoots using certain biological control agents and its effect on growth parameters in the New Valley Governorate, Egypt

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    Root Rot and wilt diseases were observed on different date palm offshoots in nurseries and new orchards in New Valley Governorate, Egypt. Pathogenicity tests showed that Fusarium oxysporum, F. solani and F. moniliforme were the causal agents of root rot and wilt diseases on date palm offshoots (cv. Saidy). In addition, the isolates of the three Fusarium spp. differed in their pathogenic capabilities. The effect of Bacillus subtilis (BSM1), B. megaterium (BMM5), B. cereus (BCM8), Trichoderma viride (TVM2), T. harzianum (THM4) as bioagents against root rot/wilt disease complex of date palm offshoots under natural infection in nursery cultivated in two location (Al-Kharga and El-Dakhla) and also, on growth of the tested pathogenic fungi under laboratory were evaluated. Under laboratory conditions, all the tested bioagents inhibited the growth of the pathogenic fungi with different percentages. Bacillus megaterium and B. subtilis showed the highest percentage of fungal growth inhibition, while T. harzianum gave the lowest ones. At the field level, the application of bioagents significantly reduced the disease severity compared with untreated offshoots (control) in both locations. Bacillus megaterium and T. viride showed the highest protection against fungal causal agents, while B. cereus and T. harzianum gave the lowest ones in this respect. Moreover, the bioagents significantly improved the growth parameters of offshoots viz. plant height, number of leaves plant-1, leaflet number leaf-1, and leaf thickness. Bacillus megaterium and T. viride recorded the highest values of all growth parameters in El-Kharga and El-Dakhla locations, while B. cereus and T. harzianum gave the lowest ones.

    EXTRACTION, FRACTIONATION AND CHARACTERIZATION OF COWPEA (VIGNA UNGUICULATA) GLOBULINS

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    The proteins were extracted from cowpea seeds by buffered saline solution and the globulins were separated by dialyzing the protein extract against distilled water. Fractionation of the total globulins on Sephacryl S-200 column produced two major and one minor components. The molecular weight of the major globulin components were estimated to be greater than 250000 and 178 000 for the globulin component (a) and (b) respectively and the latter component was the predominant globulin. The two major globulin components were free from contamination of other proteins as shown by polyacrylamide gel electrophoresis. Spectrophotometry and amino acid analyses were used as tools for characterizing the globulin components
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