Calcareous Nannofossil Biostratigraphy and Stage Boundaries of the Santonian-Eocene Successions in Wadi El Mizeira Northeastern Sinai, Egypt

The stratigraphic successions exposed in Wadi El Mizeira have been dated through the analysis of the calcareous nannofossil assemblages. The results of this study indicate that the successions comprise the Santonian-Late Maastrichtian (Sudr Formation), the Paleocene (Esna Formation) and the Early Eocene (Thebes Formation). The following biozones were recognized: Late Santonian, CC16 Zone; Late Santonian/Early Campanian, CC17 Zone; Early Campanian, Aspidolithus parcus Zone (CC18) Zone; Late Maastrichtian, CC25c Zone; Early Paleocene (Late Danian), NP3 Zone and NP4 Zone; Late Paleocene (Thanethian-Selandian), NP5 Zone; Early Eocene, NP9b Zone, NP10a Zone, NP11 Zone, NP12 Zone and NP14 Zone. Several stratigraphic hiatus were recorded in the studied interval including the absence of Cretaceous nannofossil Zones CC19 to CC25b and CC26 as well as the early Paleocene Zones NP1 and NP2 and probably the basal part of Zone NP3, in addition to the absence of the Zones NP6 and NP7/8. These hiatus may be attributed to environmental conditions, structural activity and/or post depositional processes. This work represents the first attempt to evaluate the nannofossil taxa of the Wadi El Mizeira, Northeastern Sinai

Mathematical analysis of HIV/HTLV-I co-infection model with saturated incidence rate

Direct contact with specific contaminated body fluids is how both the human immunodeficiency virus (HIV) and the human T-lymphotropic virus type I (HTLV-I) are transmitted from one person to another. Therefore, the two viruses can co-infect same person. In the literature all the HIV/HTLV-I co-infection models assume that the infection rate is given by bilinear incidence. However, for high concentration of pathogens, the bilinear incidence is not suitable. Therefore, this study will focus on the dynamical behavior of an HIV/HTLV-I co-infection model with saturated incidence. The model includes the effect of Cytotoxic T lymphocytes (CTL) immune response. Through the non-negativity and boundedness of the solutions, we demonstrated that our proposed model is biologically acceptable. We calculate the threshold parameters which determine when the equibrium point exists and when it is globally asymptotically stable. Utilizing the Lyapunov function and Lyapunov-LaSalle asymptotic stability, we demonstrate the global asymptotic stability of all equilibrium. We performed numerical simulations to confirm the analytical solutions. The effect of saturation on The dynamics of HIV/HTLV-I co-infection are discussed

On fractional order models for Hepatitis C

In this paper we present a fractional order generalization of Perelson et al. basic hepatitis C virus (HCV) model including an immune response term. We argue that fractional order equations are more suitable than integer order ones in modeling complex systems which include biological systems. The model is presented and discussed. Also we argue that the added immune response term represents some basic properties of the immune system and that it should be included to study longer term behavior of the disease

Time-Fractional KdV Equation: Formulation and Solution using Variational Methods

In this work, the semi-inverse method has been used to derive the Lagrangian of the Korteweg-de Vries (KdV) equation. Then, the time operator of the Lagrangian of the KdV equation has been transformed into fractional domain in terms of the left-Riemann-Liouville fractional differential operator. The variational of the functional of this Lagrangian leads neatly to Euler-Lagrange equation. Via Agrawal's method, one can easily derive the time-fractional KdV equation from this Euler-Lagrange equation. Remarkably, the time-fractional term in the resulting KdV equation is obtained in Riesz fractional derivative in a direct manner. As a second step, the derived time-fractional KdV equation is solved using He's variational-iteration method. The calculations are carried out using initial condition depends on the nonlinear and dispersion coefficients of the KdV equation. We remark that more pronounced effects and deeper insight into the formation and properties of the resulting solitary wave by additionally considering the fractional order derivative beside the nonlinearity and dispersion terms.Comment: The paper has been rewritten, 12 pages, 3 figure

Phytotherapeutic effects of Echinacea purpurea in gamma-irradiated mice

Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group

A niche perspective on the range expansion of symbionts

Range expansion results from complex eco-evolutionary processes where range dynamics and niche shifts interact in a novel physical space and/or environment, with scale playing a major role. Obligate symbionts (i.e. organisms permanently living on hosts) differ from free-living organisms in that they depend on strong biotic interactions with their hosts which alter their niche and spatial dynamics. A symbiotic lifestyle modifies organism–environment relationships across levels of organisation, from individuals to geographical ranges. These changes influence how symbionts experience colonisation and, by extension, range expansion. Here, we investigate the potential implications of a symbiotic lifestyle on range expansion capacity. We present a unified conceptual overview on range expansion of symbionts that integrates concepts grounded in niche and metapopulation theories. Overall, we explain how niche-driven and dispersal-driven processes govern symbiont range dynamics through their interaction across scales, from host switching to geographical range shifts. First, we describe a background framework for range dynamics based on metapopulation concepts applied to symbiont organisation levels. Then, we integrate metapopulation processes operating in the physical space with niche dynamics grounded in the environmental arena. For this purpose, we provide a definition of the biotope (i.e. living place) specific to symbionts as a hinge concept to link the physical and environmental spaces, wherein the biotope unit is a metapopulation patch (either a host individual or a land fragment). Further, we highlight the dual nature of the symbionts' niche, which is characterised by both host traits and the external environment, and define proper conceptual variants to provide a meaningful unification of niche, biotope and symbiont organisation levels. We also explore variation across systems in the relative relevance of both external environment and host traits to the symbiont's niche and their potential implications on range expansion. We describe in detail the potential mechanisms by which hosts, through their function as biotopes, could influence how some symbionts expand their range – depending on the life history and traits of both associates. From the spatial point of view, hosts can extend symbiont dispersal range via host-mediated dispersal, although the requirement for among-host dispersal can challenge symbiont range expansion. From the niche point of view, homeostatic properties of host bodies may allow symbiont populations to become insensitive to off-host environmental gradients during host-mediated dispersal. These two potential benefits of the symbiont–host interaction can enhance symbiont range expansion capacity. On the other hand, the central role of hosts governing the symbiont niche makes symbionts strongly dependent on the availability of suitable hosts. Thus, environmental, dispersal and biotic barriers faced by suitable hosts apply also to the symbiont, unless eventual opportunities for host switching allow the symbiont to expand its repertoire of suitable hosts (thus expanding its fundamental niche). Finally, symbionts can also improve their range expansion capacity through their impacts on hosts, via protecting their affiliated hosts from environmental harshness through biotic facilitation.info:eu-repo/semantics/publishedVersio

Basic Subsistence Needs and Overall Health Among Human Immunodeficiency Virus-infected Homeless and Unstably Housed Women

Some gender differences in the progression of human immunodeficiency virus (HIV) infection have been attributed to delayed treatment among women and the social context of poverty. Recent economic difficulties have led to multiple service cuts, highlighting the need to identify factors with the most influence on health in order to prioritize scarce resources. The aim of this study was to empirically rank factors that longitudinally impact the health status of HIV-infected homeless and unstably housed women. Study participants were recruited between 2002 and 2008 from community-based venues in San Francisco, California, and followed over time; marginal structural models and targeted variable importance were used to rank factors by their influence. In adjusted analysis, the factor with the strongest effect on overall mental health was unmet subsistence needs (i.e., food, hygiene, and shelter needs), followed by poor adherence to antiretroviral therapy, not having a close friend, and the use of crack cocaine. Factors with the strongest effects on physical health and gynecologic symptoms followed similar patterns. Within this population, an inability to meet basic subsistence needs has at least as much of an effect on overall health as adherence to antiretroviral therapy, suggesting that advances in HIV medicine will not fully benefit indigent women until their subsistence needs are met

Assessing the construct validity of the Italian version of the EQ-5D: preliminary results from a cross-sectional study in North Italy

BACKGROUND: Information on health related quality of life (HR-QOL) can be integrated with other classical health status indicators and be used to assist policy makers in resource allocation decisions. For this reason instruments such as the SF-12 and EQ-5D have been widely proposed as assessment tools to monitor changes in HR-QOL in general populations and very recently in general practice settings as well AIM: The primary goal of our study was to assess the construct validity of the Italian version of the EQ-5D in a general population of North Italy using socio-demographic factors and diagnostic sub-groups. Our secondary goal was to assess the concurrent validity of the EQ-5D and SF-12. METHODS: The SF-12, the EQ-5D plus an additional questionnaire on socio-demographic characteristics, clinical conditions and symptoms were completed by 1,622 adults, randomly selected from the Registry of the Health Authorities of the city of Bologna, Italy. The primary care physician of each subject was contacted to report on the subject's health status. RESULTS: Our findings indicate that the Italian version of the EQ-5D is well accepted by the general population (91% response rate), has good reliability (Cronbach's alpha 0.73), and shows evidence of construct validity. CONCLUSION: Our data provide a basis for further research to be conducted to assess the validity of the EQ-5D in Italy. In particular future studies should focus on assessing its ability to detect a clinically important change in health related quality of life over time (responsiveness)