Trace metal concentrations in leachates from open dumpsites in Lokoja, Kogi state, Nigeria

Leachates from selected dumpsites and control site in Lokoja municipal were analyzed for trace metal concentrations. These parameters were compared with control samples and established international standards (FEPA) and (WHO). Dumpsite leachates contained very high concentrationsof iron (73.60±0.58)mg/L, manganese (16.53±0.309)mg/L, copper 1.00±0.02mg/L, zinc 2.41±0.042mg/L, and lead 1.55±0.097mg/L. All the parameters except nickel and cadmium were above the control and exceed FEPA and WHO guidelines. The study revealed that the dumpsite is amajor polluting source in the surrounding environment. This underlines the need for appropriate government agency of Kogi State, Nigeria to initiate active remediation process such as phytoremediation in combination with physiochemical methods to recover the dumpsite from contaminants and reduce the level of pollution in the surrounding environment.Keywords: Leachates, dumpsite, remediation, phyto remediation, trace metals

Parasites of crayfish (P. clarki) and lobsters (Macrobrachium vollenhovenic) as indicators of metallic pollution in great, Kwa river, Nigeria

Studies on parasites of crayfish and lobsters as indicators of metal pollution in Great Kwa River, Nigeria was evaluated using appropriate instruments for determination of Physicochemical parameters and detection of metals. Formol ether centrifugation method was used for isolation of parasites. A total of 150 crayfish and lobsters were analyzed for metals and tested for parasites. All samples of crayfish (100%) and 136 (90.66%) lobsters were positive with parasites. The distribution of parasitic infection in crayfish from the 5 sampling zones showed Paragonfmus uterobilateralis prevalence 6.0%, 8.7%, 15.3%, and 10.0% from zones 1-4 respectively and crayfish leech prevalence of 10.3%, 16.0% and 20.0% from zones 3-5 respectively. The distribution of parasites in Lobsters showed Polymorphus botulus, 3.3%, 6.0%, 3.6%, and 8.7% prevalence from zones 1-4 respectively. Nicothoic astaci, prevalence was 2.0%, 15.3% and 5.0% from zones 2-4 respectively. Prevalence of Hysterothylacium sp of 2.0% was observed in zone 3 while that of Porospora gigantic was 3.7% in zone 5. Parasite intensity ranged from 2 to 6. Metals detected included Lead (Pb). Copper (Cu), Iron (Fe), Cadmium (Cd), Asenium (As) and Zinc (Zn) with Iron being the commonest. Some parasites with high prevalence in zones where certain metals had high concentration were detected. These parasites can be used as indicators of pollution in the study area.KEYWORDS: Physicochemical, detected, pollution, concentration, indicator and prevalence

Exposure to cigarette smoke altered the cytoarchitecture and anti-oxidant activity of the frontal cortex in Wistar rats

This study was designed to determine the effects of cigarette smoke on the body weights of Wistar rats, anti-oxidant activity and the histology of the frontal cortex. Sixteen Wistar rats with mean weight of 131.40 ± 4.43 g were used. They were grouped into four. Group A had a stick of cigarette (Pall Mall brand ®) daily, group B had two sticks and group C had three sticks daily, while Group D served as the control group. They were exposed at 1800 hrs each day for thirty five days, and their weights were monitored. After sacrifice by cervical dislocation, the tissues were processed for histological and biochemical studies. The results showed minimal weight change in the exposed groups compared to the marked increase in the control group. The activity of glutathione peroxidase (GPx) enzyme increased while there was decrease in malondialdehyde (MDA) activity. The histology also showed decreased staining of the nucleic acids as well as increased vacuolations in the exposed groups. The authors suggested these findings could alter brain functions particularly those related to the frontal cortex.Keywords: Cigarette smoke, frontal cortex, GPx, MDA, nucleic acids

Mobile phones and wrong numbers: how Maasai agro-pastoralists form and use accidental social ties in East Africa

Mobile phones are recognized as important new tools for rural development in the Global South, but few studies have examined how phones can shape social networks. This study documents a new type of social tie, enabled by mobile phones, that to our knowledge has not previously been discussed in academic literature. In 2018, we discovered that Maasai pastoralists in northern Tanzania create new social ties through wrong numbers, a phenomenon with implications for theory on social networks and path dependency. We used a mixed ethnographic and survey-based design to examine the following: (1) the conditions under which wrong number connections (WNCs) are made; (2) the incidence of these connections in the study area; and (3) the association between WNCs and multiple livelihood strategies. Working in 10 rural communities in Tanzania, we conducted 16 group interviews with men about their phone use and found that WNCs are diverse and can provide households with important information, resources, and opportunities from an expansive geographic area. (Nine separate interviews with groups of women revealed that women do not create WNCs.) Based on early qualitative findings, we designed and conducted a standardized survey with 317 household heads. We found that 46% of respondents have had WNCs. Furthermore, multivariate regression models show a significant association between WNCs and the controversial practice of leasing land in one district. Taken together, our findings show that WNCs can be seen as innovations in social networking that reduce path dependency, increase the range of potential outcomes, and hold important implications for rural livelihoods in East Africa

NDE Applications of Radio Wave Emission from Stress and Fracture

It is well-known [1], [2] that when materials are fractured, substantial local electric fields are generated. These fields are capable of accelerating charged particles from the nascent interfaces, giving rise to a class of phenomena known as “exo-emission” or “fracto-emission”. The released “exo-particles”, consisting of electrons, ions, and charged clusters or fragments, can be collected and analyzed directly. Usually, such experiments are performed under conditions of high or ultra-high vacuum. This type of particle emission has been extensively studied previously, most notably by Dickinson and his co-workers [2] — [7]. Except for previous studies of fracturing rock, performed in connection with early-warning detection of earthquakes [8], [9], and the work of Dickinson, little has been done to characterize the radio wave emission that attends material fractures. Furthermore, no previous studies of radio wave emission from the elastically or plastically strained materials have been reported. Early qualitative studies of the visible light and radio wave emission from delaminating layers of adhesively bonded polymers and metals were reported by Derjagun and his co-workers. Emission during deformation suggests itself as a possible method for diagnosing the state of dynamic material strain in situations where contact methods are not feasible or are undesirable. Examples of such potential applications are too numerous to delineate here; they include the detection of high speed particle impacts on spacecraft structures, dynamic test of radioactive, extremely hot or cold structures, and others. We also note that for the elucidation of the detailed mechanism of fracture, radio-wave emission may have advantages over other methods since, unlike acoustic or ultrasonic methods, the speed of propagation of the detected signal is much greater than the speed of the propagating crack-front in the material, so little or no deconvolution is required.</p

On the Use of Gene Ontology Annotations to Assess Functional Similarity among Orthologs and Paralogs: A Short Report

A recent paper (Nehrt et al., PLoS Comput. Biol. 7:e1002073, 2011) has proposed a metric for the “functional similarity” between two genes that uses only the Gene Ontology (GO) annotations directly derived from published experimental results. Applying this metric, the authors concluded that paralogous genes within the mouse genome or the human genome are more functionally similar on average than orthologous genes between these genomes, an unexpected result with broad implications if true. We suggest, based on both theoretical and empirical considerations, that this proposed metric should not be interpreted as a functional similarity, and therefore cannot be used to support any conclusions about the “ortholog conjecture” (or, more properly, the “ortholog functional conservation hypothesis”). First, we reexamine the case studies presented by Nehrt et al. as examples of orthologs with divergent functions, and come to a very different conclusion: they actually exemplify how GO annotations for orthologous genes provide complementary information about conserved biological functions. We then show that there is a global ascertainment bias in the experiment-based GO annotations for human and mouse genes: particular types of experiments tend to be performed in different model organisms. We conclude that the reported statistical differences in annotations between pairs of orthologous genes do not reflect differences in biological function, but rather complementarity in experimental approaches. Our results underscore two general considerations for researchers proposing novel types of analysis based on the GO: 1) that GO annotations are often incomplete, potentially in a biased manner, and subject to an “open world assumption” (absence of an annotation does not imply absence of a function), and 2) that conclusions drawn from a novel, large-scale GO analysis should whenever possible be supported by careful, in-depth examination of examples, to help ensure the conclusions have a justifiable biological basis

Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples

BACKGROUND: The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. METHODS: Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. RESULTS: Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft), and they were also those most likely to have injected drugs rather than administered them by any other route (p < 0.001). In addition, bisexual or homosexual identification was reported by more respondents in the sex exchange as primary source of income category. The number of sexual partners in the last three months followed a similar pattern, with those whose primary source of income was drug dealing or theft reporting relatively high partner numbers. CONCLUSIONS: These data suggest that social disadvantage is associated with HIV risk in part by its association with drug and sex work for survival, and offers one variable that may be associated with the concentration of disease among those at greatest disadvantage by having an illegal and unstable primary income source

Analysis of Signaling Mechanisms Regulating Microglial Process Movement

Microglia, the brain’s innate immune cells, are extremely motile cells, continuously surveying the CNS to serve homeostatic functions and to respond to pathological events. In the healthy brain, microglia exhibit a small cell body with long, branched and highly motile processes, which constantly extend and retract, effectively ‘patrolling’ the brain parenchyma. Over the last decade, methodological advances in microscopy and the availability of genetically encoded reporter mice have allowed us to probe microglial physiology in situ. Beyond their classical immunological roles, unexpected functions of microglia have been revealed, both in the developing and the adult brain: microglia regulate the generation of newborn neurons, control the formation and elimination of synapses, and modulate neuronal activity. Many of these newly ascribed functions depend directly on microglial process movement. Thus, elucidating the mechanisms underlying microglial motility is of great importance to understand their role in brain physiology and pathophysiology. Two-photon imaging of fluorescently labelled microglia, either in vivo or ex vivo in acute brain slices, has emerged as an indispensable tool for investigating microglial movements and their functional consequences. This chapter aims to provide a detailed description of the experimental data acquisition and analysis needed to address these questions, with a special focus on key dynamic and morphological metrics such as surveillance, directed motility and ramification