Effect of Water Scarcity and Its Remedy at Federal Polytechnic Oko

The project focuses on the investigation and remedy on its environment and geographic dynamic of polytechnic water scarcity. The administration grandiose under taking aims to produce some litres of fresh water in the institution by building borehole field to make vision of the current administration, a reality in the form of large expensive water schemeThe rapid growth in population notwithstanding, the administration has in its policies and maneuverability on this issue of water scarcity in spite of recent climate change promised to distribute large quantity of potable water to every nook and crannies of the polytechni

Impact of Human Urine Contamination on Soil Biota

The role of human urine as an organic pollutant to soil biota was examined in this study. Using standard methods, the impact of human urine on the physicochemical parameters, fauna and microbial load in the soil microcosm was considered. Ten replicates of Urine contaminated soil (UrCS) and Uncontaminated Agricultural soil (UnCS) samples respectively were collected from points pedestrian urine deposition within Olabisi Onabanjo University, Ago-Iwoye and University of Agriculture, Alabata both in Ogun State. pH was determined using the pH meter. Moisture content (MC) was determined by drying and difference in weight method. Organic Carbon (OC) was determined using the Walkey-Black method and Organic Matter (OM) was estimated by the formula %OC = %OC x 1.729. Phosphate and nitrate concentrations were determined by spectrophotometric method while sulphate concentration was determined by the turbidimetry method. Ammonium concentration was determined by distillation method using 40% boric acid with methyl red indicator. The fauna record was conducted by heat extraction into alcohol or normal saline while microbial load was estimated by the pour plate and serial dilution techniques. UrCS recorded a significantly higher MC, OC, OM, phosphate, nitrate, sulphate, ammonium concentrations and lower pH (p<0.05) than UnCS. A complete absence of microfauna (protozoa), mesofauna (mites, lion ants, insects, insect eggs) and macrofauna (beetle, beetle caterpillars, millipedes, pill millipedes, earthworms, earthworm castings) was recorded in UrCS while UnCS samples recorded their presence. UrCS recorded a significantly lower (p<0.05) microbial loads than UnCS. The most adverse impact of human urine on soil biota is the lowered pH and increased acidity which unleash a vicious cycle on soil biota persisting as long as urine deposition continues unhindered on the same spot

Chaos synchronization by resonance of multiple delay times

Chaos synchronization may arise in networks of nonlinear units with delayed couplings. We study complete and sublattice synchronization generated by resonance of two large time delays with a specific ratio. As it is known for single-delay networks, the number of synchronized sublattices is determined by the greatest common divisor (GCD) of the network loop lengths. We demonstrate analytically the GCD condition in networks of iterated Bernoulli maps with multiple delay times and complement our analytic results by numerical phase diagrams, providing parameter regions showing complete and sublattice synchronization by resonance for Tent and Bernoulli maps. We compare networks with the same GCD with single and multiple delays, and we investigate the sensitivity of the correlation to a detuning between the delays in a network of coupled Stuart-Landau oscillators. Moreover, the GCD condition also allows detection of time-delay resonances, leading to high correlations in nonsynchronizable networks. Specifically, GCD-induced resonances are observed both in a chaotic asymmetric network and in doubly connected rings of delay-coupled noisy linear oscillators

Embedding the dynamics of a single delay system into a feed-forward ring

We investigate the relation between the dynamics of a single oscillator with delayed self-feedback and a feed-forward ring of such oscillators, where each unit is coupled to its next neighbor in the same way as in the self-feedback case. We show that periodic solutions of the delayed oscillator give rise to families of rotating waves with different wave numbers in the corresponding ring. In particular, if for the single oscillator the periodic solution is resonant to the delay, it can be embedded into a ring with instantaneous couplings. We discover several cases where the stability of a periodic solution for the single unit can be related to the stability of the corresponding rotating wave in the ring. As a specific example we demonstrate how the complex bifurcation scenario of simultaneously emerging multi-jittering solutions can be transferred from a single oscillator with delayed pulse feedback to multi-jittering rotating waves in a sufficiently large ring of oscillators with instantaneous pulse coupling. Finally, we present an experimental realization of this dynamical phenomenon in a system of coupled electronic circuits of FitzHugh-Nagumo type

Transient dynamics and their control in time-delay autonomous Boolean ring networks

Biochemical systems with switch-like interactions, such as gene regulatory networks, are well modeled by autonomous Boolean networks. Specifically, the topology and logic of gene interactions can be described by systems of continuous piecewise-linear differential equations, enabling analytical predictions of the dynamics of specific networks. However, most models do not account for time delays along links associated with spatial transport, mRNA transcription, and translation. To address this issue, we have developed an experimental test bed to realize a time-delay autonomous Boolean network with three inhibitory nodes, known as a repressilator, and use it to study the dynamics that arise as time delays along the links vary. We observe various nearly periodic oscillatory transient patterns with extremely long lifetime, which emerge in small network motifs due to the delay, and which are distinct from the eventual asymptotically stable periodic attractors. For repeated experiments with a given network, we find that stochastic processes give rise to a broad distribution of transient times with an exponential tail. In some cases, the transients are so long that it is doubtful the attractors will ever be approached in a biological system that has a finite lifetime. To counteract the long transients, we show experimentally that small, occasional perturbations applied to the time delays can force the trajectories to rapidly approach the attractors

Strong and weak chaos in networks of semiconductor lasers with time-delayed couplings

Nonlinear networks with time-delayed couplings may show strong and weak chaos, depending on the scaling of their Lyapunov exponent with the delay time. We study strong and weak chaos for semiconductor lasers, either with time-delayed self-feedback or for small networks. We examine the dependence on the pump current and consider the question of whether strong and weak chaos can be identified from the shape of the intensity trace, the autocorrelations, and the external cavity modes. The concept of the sub-Lyapunov exponent λ0 is generalized to the case of two time-scale-separated delays in the system. We give experimental evidence of strong and weak chaos in a network of lasers, which supports the sequence of weak to strong to weak chaos upon monotonically increasing the coupling strength. Finally, we discuss strong and weak chaos for networks with several distinct sub-Lyapunov exponents and comment on the dependence of the sub-Lyapunov exponent on the number of a laser's inputs in a network

Sex differences in zonulin in affective disorders and associations with current mood symptoms

Zonulin measurement was funded by Institut Allergosan (Graz, Austria).Introduction: The bidirectional connection between the brain and the gut within psychiatric entities has gained increasing scientific attention over the last years. As a regulator of intestinal permeability, zonulin acts as a key player on the interface of this interplay. Like several psychiatric disorders, intestinal permeability was associated with inflammation in previous findings. Methods: In this study we explored differences in zonulin serum levels in currently depressed (n = 55) versus currently euthymic (n = 37) individuals with an affective disorder. Further, we explored sex differences and possible influences on zonulin and affective symptoms like medication, age, body mass index, and smoking status. Results: Serum zonulin was significantly higher in females than in men independent from affective status (z = -2.412, p = .016). More specifically, females in the euthymic subgroup had higher zonulin levels than euthymic men (z = -2.114, p = .035). There was no difference in zonulin serum levels in individuals taking or not taking a specific psychopharmacotherapy. We found no correlation between zonulin serum levels and depression severity. Discussion: Increased serum zonulin levels as a proxy for increased intestinal permeability in women may indicate a state of elevated susceptibility for depression-inducing stimuli.Publisher PDFPeer reviewe

Understanding the enhanced synchronization of delay-coupled networks with fluctuating topology

We study the dynamics of networks with coupling delay, from which the connectivity changes over time. The synchronization properties are shown to depend on the interplay of three time scales: the internal time scale of the dynamics, the coupling delay along the network links and time scale at which the topology changes. Concentrating on a linearized model, we develop an analytical theory for the stability of a synchronized solution. In two limit cases the system can be reduced to an “effective” topology: In the fast switching approximation, when the network fluctuations are much faster than the internal time scale and the coupling delay, the effective network topology is the arithmetic mean over the different topologies. In the slow network limit, when the network fluctuation time scale is equal to the coupling delay, the effective adjacency matrix is the geometric mean over the adjacency matrices of the different topologies. In the intermediate regime the system shows a sensitive dependence on the ratio of time scales, and specific topologies, reproduced as well by numerical simulations. Our results are shown to describe the synchronization properties of fluctuating networks of delay-coupled chaotic maps

Informing HIV prevention efforts targeting Liberian youth: a study using the PLACE method in Liberia

BACKGROUND: Preventing HIV infection among young people is a priority for the Liberian government. Data on the young people in Liberia are scarce but needed to guide HIV programming efforts. METHODS: We used the Priorities for Local AIDS Control Efforts (PLACE) method to gather information on risk behaviors that young people (ages 14 to 24) engage in or are exposed to that increase their vulnerability for HIV infection. Community informants identified 240 unique venues of which 150 were visited and verified by research staff. 89 of the 150 venues comprised our sampling frame and 571 females and 548 males were interviewed in 50 venues using a behavioral survey. RESULTS: Ninety-one percent of females and 86% of males reported being sexually active. 56% of females and 47% of males reported they initiated sexual activity before the age of 15. Among the sexually active females, 71% reported they had received money or a gift for sex and 56% of males reported they had given money or goods for sex. 20% of females and 6% males reported that their first sexual encounter was forced and 15% of females and 6% of males reported they had been forced to have sex in the past year. Multiple partnerships were common among both sexes with 81% females and 76% males reporting one or more sex partners in the past four weeks. Less than 1% reported having experiences with injecting drugs and only 1% of males reporting have sex with men. While knowledge of HIV/AIDS was high, prevention behaviors including HIV testing and condom use were low. CONCLUSION: Youth-focused HIV efforts in Liberia need to address transactional sex and multiple and concurrent partnerships. HIV prevention interventions should include efforts to meet the economic needs of youth

Stressful conditions reveal decrease in size, modification of shape but relatively stable asymmetry in bumblebee wings

Human activities can generate a wide variety of direct and indirect effects on animals, which can manifest as environmental and genetic stressors. Several phenotypic markers have been proposed as indicators of these stressful conditions but have displayed contrasting results, depending, among others, on the phenotypic trait measured. Knowing the worldwide decline of multiple bumblebee species, it is important to understand these stressors and link them with the drivers of decline. We assessed the impact of several stressors (i.e. natural toxin-, parasite-, thermic- and inbreeding-stress) on both wing shape and size and their variability as well as their directional and fluctuating asymmetries. The total data set includes 650 individuals of Bombus terrestris (Hymenoptera: Apidae). Overall wing size and shape were affected by all the tested stressors. Except for the sinigrin (e.g. glucosinolate) stress, each stress implies a decrease of wing size. Size variance was affected by several stressors, contrary to shape variance that was affected by none of them. Although wing size directional and fluctuating asymmetries were significantly affected by sinigrin, parasites and high temperatures, neither directional nor fluctuating shape asymmetry was significantly affected by any tested stressor. Parasites and high temperatures led to the strongest phenotype modifications. Overall size and shape were the most sensitive morphological traits, which contrasts with the common view that fluctuating asymmetry is the major phenotypic marker of stress