PETROLOGY AND GEOCHEMISTRY OF SANDSTONE FROM LOWER CRETACEOUS KIKHLA FORMATION, NW LIBYA: IMPLICATIONS FOR PROVENANCE AND DEPOSITIONAL SETTING: Petrologia e geoquímica de arenitos da Formação Kikhla (Cretáceo Inferior), Noroeste da Líbya: implicações para proveniência e ambiente deposicional

This study aims to determine and investigate the provenance of the source rocks and the depositional setting of the Kikhla Formation, northwestern Libya. It is mainly composed of mature quartzitic sandstone alternating with conglomerate and clay. The study proved that the sandstone is yellow-white in color and commonly carries quartz granular and small fragments of silicified wood. The environmental deposition is under differing fluvial conditions and by a large braided river. Texturally, the Kikhla sandstone is poorly cemented, coarse to very coarse grained and strongly unimodal and is classified as litharenite and subarkose by the modal composition, which is supported by geochemical studies. According to petrography and geochemistry, the Kikhla sandstone was deposited in a passive continental margin basin, mainly from granitic sources. On the basis of major elements ratios, and petrographic interpretation, the source rocks are most likely recognized as Proterozoic granites that were exposed via rifting. The CIA values (73.28-93.97) indicate a high degree of chemical weathering, which could be attributed to the arid climate conditions in the source area and mainly controlled by the source-rock provenance, hydraulic sorting during transport and deposition, diagenesis and depositional environment. According to chemical investigations, sandstone exhibits significant concentrations of SiO2, Na2O> K2O, and Fe2O3, which is compatible with the modal data.ABSTRACT - This study aims to determine and investigate the provenance of the source rocks and the depositional setting of the Kikhla Formation, Lower Cretaceous, northwestern Libya. It is mainly composed of mature quartzitic sandstone alternating with conglomerate and clay. The study proved that the sandstone is yellow-white in color and commonly carries quartz granular and small fragments of silicified wood. The environmental deposition is under differing fluvial conditions and by a large braided river. Texturally, the Kikhla sandstone is poorly cemented, coarse to very coarse grained and strongly unimodal and is classified as litharenite and subarkose by the modal composition, which is supported by geochemical studies. According to petrography and geochemistry, the Kikhla sandstone was deposited in a passive continental margin basin, mainly from granitic sources. On the basis of major elements ratios, and petrographic interpretation, the source rocks are most likely recognized as granites that were exposed via rifting. The CIA (Chemical Index of Alteration) values (73.28-93.97) indicate a high degree of chemical weathering, which could be attributed to the arid climate conditions in the source area and mainly controlled by the source-rock provenance, hydraulic sorting during transport and deposition, diagenesis and depositional environment. According to chemical investigations, sandstone exhibits significant concentrations of SiO2, Na2O>K2O, and Fe2O3, which is compatible with the modal data.   RESUMO - Este estudo visa determinar e investigar a proveniência das rochas geradoras e o ambiente deposicional da Formação Kikhla, Cretáceo Inferior, noroeste da Líbia. É composta principalmente de arenito quartzítico maduro alternando com conglomerado e argila. O estudo reconheceu arenito com coloração amarelo-esbranquiçada e comumente carrega quartzo granular e pequenos fragmentos de madeira silicificada. A deposição ambiental ocorreu sob diferentes condições fluviais e por um grande rio entrelaçado. Texturalmente, o arenito Kikhla é mal cimentado, de granulação grossa a muito grossa, fortemente unimodal e é classificado como litarenito e subarcósio pela composição modal, que é suportada por estudos geoquímicos. De acordo com petrografia e geoquímica, o arenito Kikhla foi depositado em uma bacia de margem continental passiva, principalmente a partir de fontes graníticas. Com base nas proporções dos principais elementos e na interpretação petrográfica, as rochas-fonte são provavelmente reconhecidas como granitos que foram expostos por meio de rifteamento. Os valores do CIA (Índice Químico de Alteração) (73,28-93,97) indicam um alto grau de intemperismo químico, que pode ser atribuído às condições climáticas áridas na área de origem e controladas principalmente pela proveniência da rocha fonte, seleção hidráulica durante o transporte e deposição, diagênese e ambiente deposicional. De acordo com as investigações químicas, o arenito apresenta concentrações significativas de SiO2, Na2O>K2O e Fe2O3, o que é compatível com os dados modais

Trends in Secondary Prevention of Coronary Heart Disease in Tunisia: Prevention of Recurrences of MI and Stroke

ObjectivesThe survival benefits achieved by prescription of antiplatelet agents, B-adrenoreceptor antagonists (beta-blockers), angiotensin II receptor blockers (ARB), and lipid lowering agents in patients surviving the myocardial infarction (MI) have been well documented in large clinical trial. Despite well-established benefits, these pharmacological agents continue to be underutilized. The main objective of this study was to evaluate the progress of cardiovascular secondary prevention practices in Tunisia.MethodsThe PREMISE (Prevention of Recurrence of Myocardial Infarction and Stroke) is a descriptive, cross-sectional study conducted in Tunisia in two phases (2002 and 2009). Seven hundred eighty two patients were recruited. The recruitment criteria were: previous MI, stable angina, unstable angina, percutaneous transluminal coronary angioplasty (PTCA), coronary artery bypass graft (CABG), stroke, transient ischemic attack (TIA) or carotid endarterectomy. This analysis is limited to coronary heart disease (CHD) patients. Five hundred hospital patients were interviewed and their medical records were reviewed: 250 in 2002 and 250 in 2009. Patients were included if they had confirmed diagnosis of MI, angina, CABG or PTCA, and if their first cardiovascular event had occurred more than one month but not later than 3 years ago. We compared the total of both patient groups, using the prevalence of Cardio-Vascular Risk Factors (CVRF) and the treatment prescribed at hospital discharge.ResultsThe proportion of patients with reported hypertension, diabetes, hypercholesterolemia and current smoker patients had decreased. Concerning pharmacological prescriptions, a significant increase was observed in prescribing statins (38.9% vs. 70.3%) and ACE inhibitors (49.3% vs. 69.9%), non pharmacological prescriptions as healthy diet or tobacco cessation had opposite trends. Adherence to treatment did not change substantially.ConclusionAlthough the use of cardioprotective drugs had increased in CHD patients, there are still gaps in secondary prevention in Tunisia. The recommended strategies of secondary prevention need to be applied more intensively in clinical practice

Alternative ATPase domain interactions in eukaryotic Hsp70 chaperones

Hsp70 molecular chaperones are essential components for maintaining protein homeostasis within cells. They interact with substrate or client proteins in a well characterised fashion that is regulated by ATP and supported by co-chaperones. In eukaryotes there is a vast array of Hsp70 isoforms that may facilitate adaption to a particular cellular compartment and distinct biological role. Emerging data indicate a novel type of interaction between Hsp70 and client protein that does not fit with the classical Hsp70 ATP regulated substrate mechanism. In this review, we highlight Hsp70 ATPase domain interactions with binding partners from various biological systems that we refer to as Hsp70 ATPase alternative binding proteins or HAAB proteins. We identify common mechanistic features that may define how Hsp70 operates when associating with proteins in this alternative HAAB mode of action

Ladder operators and coherent states for continuous spectra

The notion of ladder operators is introduced for systems with continuous spectra. We identify two different kinds of annihilation operators allowing the definition of coherent states as modified "eigenvectors" of these operators. Axioms of Gazeau-Klauder are maintained throughout the construction.Comment: Typos correcte

A Semidefinite Programming approach for minimizing ordered weighted averages of rational functions

This paper considers the problem of minimizing the ordered weighted average (or ordered median) function of finitely many rational functions over compact semi-algebraic sets. Ordered weighted averages of rational functions are not, in general, neither rational functions nor the supremum of rational functions so that current results available for the minimization of rational functions cannot be applied to handle these problems. We prove that the problem can be transformed into a new problem embedded in a higher dimension space where it admits a convenient representation. This reformulation admits a hierarchy of SDP relaxations that approximates, up to any degree of accuracy, the optimal value of those problems. We apply this general framework to a broad family of continuous location problems showing that some difficult problems (convex and non-convex) that up to date could only be solved on the plane and with Euclidean distance, can be reasonably solved with different $\ell_p$-norms and in any finite dimension space. We illustrate this methodology with some extensive computational results on location problems in the plane and the 3-dimension space.Comment: 27 pages, 1 figure, 7 table

Lagranulomatose De Wegener Apropos De Trois Localisations Orl Rares

La granulomatose de Wegener (GW) est une vascularite nécrosante granulomateuse présentant un tropisme particulier pour les voies aériennes supérieures. Nous rapportons 3 cas de la GW correspondants à des localisations ORL rares de la maladie : orbito-meningée, laryngée et linguale. Le but de nos études est d\'analyser les particularités épidemiologiques et cliniques de cette pathologie.Wegener\'s Granulomatosis (WG) is a necrotizing granulomatous vasculitis that has a strong affinity for the upper respiratory tract. We report 3cases of rare ORL locations of Wegener\'s Granulomatosis (orbit, larynx and tongue). The aim of our study is to analyse the characteristic features of WG. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 16 2006: pp. 26-2

Improving Data Collection and Analysis Interface for the Data Acquisition Software of the Spin Laboratory at NASA Glenn Research Center

In jet engines, turbines spin at high rotational speeds. The forces generated from these high speeds make the rotating components of the turbines susceptible to developing cracks that can lead to major engine failures. The current inspection technologies only allow periodic examinations to check for cracks and other anomalies due to the requirements involved, which often necessitate entire engine disassembly. Also, many of these technologies cannot detect cracks that are below the surface or closed when the crack is at rest. Therefore, to overcome these limitations, efforts at NASA Glenn Research Center are underway to develop techniques and algorithms to detect cracks in rotating engine components. As a part of these activities, a high-precision spin laboratory is being utilized to expand and conduct highly specialized tests to develop methodologies that can assist in detecting predetermined cracks in a rotating turbine engine rotor. This paper discusses the various features involved in the ongoing testing at the spin laboratory and elaborates on its functionality and on the supporting data system tools needed to enable successfully running optimal tests and collecting accurate results. The data acquisition system and the associated software were updated and customized to adapt to the changes implemented on the test rig system and to accommodate the data produced by various sensor technologies. Discussion and presentation of these updates and the new attributes implemented are herein reporte

Effect of width and temperature of a vertical parallel plate channel on the transition of the developing thermal boundary layer

Numerical simulations are performed to study the transition of the development of the thermal boundary layer of air along an isothermal heated plate in a large channel which is bounded by an adiabatic plate. In particular, the aim is to investigate the effects of the channel width (b) on the transition of the flow under various plate temperatures. Three different RANS based turbulent k–ε models namely standard, RNG and Realizable with an enhanced wall function are employed in the simulations. The channel width was varied from 0.04 m to 0.45 m and the numerical results of the maximum values of the flow velocity, turbulent kinetic energy were recorded along the vertical axis to examine the critical distance of the developing flow. The results show that the transition delays when the width is increased from 0.04 m to 0.08 m and particularly, the critical distance at b = 0.08 m reaches its maximum with the Grashof number of 2.8 × 1010. However, the critical distance drops when b is increased further from 0.08 m to 0.45 m, indicating an early transition of the flow. The transition remains unaffected by the adiabatic plate when b is greater than 0.45 m. Comparisons of selected numerical results are made with available experimental data of turbulent flow and a satisfied agreement is received

Facteurs predictifs de l’efficacite ablative de l’iode 131 dans les cancers differencies de la thyroïde

La prise en charge des cancers différenciés de la thyroïde (CDT) comporte souvent une radiothérapie métabolique à l’iode131 (IRA-thérapie). Le but de ce travail est d’évaluer le caractère prédictif des différents éléments anatomopathologiques, de la classification pTNM et de la stadification pronostique sur l’activité ablative requise d’iode131. Notre travail est une étude analytique rétrospective portant sur 275 cas de CDT ayant subit une thyroïdectomie totale. Tous ces patients ont eu une ou plusieurs activités ablatives. Nous avons cherché – au moyen d’une analyse statistique par test de Khi2 ou test Anova – toute corrélation entre les éléments de l’examen anatomopathologique de la tumeur, la classe pTNM, le stade pronostique correspondant d’une part  et l’efficacité de l’irathérapie ablative d’autre part. Dans notre série, une activité ablative plus élevée est nécessaire lorsque la taille du foyer tumoral dépasse les 6 cm (p=0,012), en cas de dépassement de la graisse péri thyroïdienne (

Menopause and metabolic syndrome in Tunisian women

Objectives. This study aimed to evaluate the effect of menopausal status on the risk of metabolic syndrome (MetS) in Tunisian women. Methods. We analyzed a total of 2680 women aged between 35 and 70 years. Blood pressure, anthropometric indices, fasting glucose, and lipid profile were measured. The MetS was assessed by the modified NCEP-ATPIII definition. Results. The mean values of waist circumference, blood pressure, plasma lipids, and fasting glucose were significantly higher in postmenopausal than in premenopausal women, a difference that was no longer present when adjusting for age. Except for hypertriglyceridaemia, the frequency of central obesity, hyperglycemia, high blood pressure, and high total cholesterol was significantly higher in postmenopausal than in premenopausal women. After adjusting for age, the significance persisted only for hyperglycemia. The overall prevalence of MetS was 35.9%, higher in postmenopausal (45.7% versus 25.6%) than in premenopausal women. A binary logistic regression analysis showed that menopause was independently associated with MetS (OR = 1.41, 95% CI 1.10-1.82) after adjusting for age, residence area, marital status, family history of cardiovascular disease, education level, and occupation. Conclusions. The present study provides evidence that the MetS is highly prevalent in this group of women. Menopause can be a predictor of MetS independent of age in Tunisian women