46,168 research outputs found
The Freshwater Biological Association at Wray Castle: Recollections of its first director
In 1937 the Development Commission provided an annual grant to the Freshwater Biological Association to pay for a director and secretary. The author moved to the Lake District in the same year, and at that time T.T. Macan was working on invertebrates; K.R. Allen on fish; C.H. Mortimer on chemistry and physics of the aquatic environment, and Marie Rosenberg on phytoplankton. They were backed by George Thompson as laboratory assistant and Rosa Bullen as secretary. The work of the Association continued and expanded throughout the Second World War with some far-reached discoveries made. For example, the recovery of lake sediment cores and the examination of diatom remains, so starting the discipline of archaeo-limnology. Also, a hydrological survey of the Windermere catchment area found significant traces of sulphuric acid in rain gauges. This was more than 30 years before "acid rain" became fashionable
Towards Convergence: How to Do Transdisciplinary Environmental Health Disparities Research.
Increasingly, funders (i.e., national, public funders, such as the National Institutes of Health and National Science Foundation in the U.S.) and scholars agree that single disciplines are ill equipped to study the pressing social, health, and environmental problems we face alone, particularly environmental exposures, increasing health disparities, and climate change. To better understand these pressing social problems, funders and scholars have advocated for transdisciplinary approaches in order to harness the analytical power of diverse and multiple disciplines to tackle these problems and improve our understanding. However, few studies look into how to conduct such research. To this end, this article provides a review of transdisciplinary science, particularly as it relates to environmental research and public health. To further the field, this article provides in-depth information on how to conduct transdisciplinary research. Using the case of a transdisciplinary, community-based, participatory action, environmental health disparities study in California's Central Valley provides an in-depth look at how to do transdisciplinary research. Working with researchers from the fields of social sciences, public health, biological engineering, and land, air, and water resources, this study aims to answer community residents' questions related to the health disparities they face due to environmental exposure. Through this case study, I articulate not only the logistics of how to conduct transdisciplinary research but also the logics. The implications for transdisciplinary methodologies in health disparity research are further discussed, particularly in the context of team science and convergence science
Rolling of Coxeter polyhedra along mirrors
The topic of the paper are developments of -dimensional Coxeter polyhedra.
We show that the surface of such polyhedron admits a canonical cutting such
that each piece can be covered by a Coxeter -dimensional domain.Comment: 20pages, 15 figure
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Exploring information lifecycle management in the Nigerian financial sector: A case study
This research paper presents theoretical and practical approaches at how the banking sector manages financial information, with emphasis being placed on financial service operations of cheque processing and securities trading. The banking sector was identified as it is presently the most vibrant and emerging sector in the financial services in Nigeria, which mentioned in the Financial Times. The banking sector has been the driving force behind Nigeria’s equity, which is in access of $3.3bn in equity capital markets a transaction in 2007. The banks that were investigated in this research paper included banks that incorporate functions in the equity market as part of their daily operations and in the possession of relevant information on securities trading as well as information on cheque processing procedures. One of the main findings is that, there is above average knowledge and understanding of ILM within the financial sector in Nigeria. Therefore, it was recommended that the application of ILM techniques should be improved upon in the management of information in the Nigeria financial sector and to obtain the best results at every stage of the information lifecycle
Isotopic ecology of coyotes from scat and road kill carcasses: A complementary approach to feeding experiments.
Scat is frequently used to study animal diets because it is easy to find and collect, but one concern is that gross fecal analysis (GFA) techniques exaggerate the importance of small-bodied prey to mammalian mesopredator diets. To capitalize on the benefits of scat, we suggest the analysis of scat carbon and nitrogen isotope values (δ13C and δ15N). This technique offers researchers a non-invasive method to gather short-term dietary information. We conducted three interrelated studies to validate the use of isotopic values from coyote scat: 1) we determined tissue-to-tissue apparent C and N isotope enrichment factors (ε13* and ε15*) for coyotes from road kill animals (n = 4); 2) we derived diet-to-scat isotope discrimination factors for coyotes; and 3) we used field collected coyote scats (n = 12) to compare estimates of coyote dietary proportions from stable isotope mixing models with estimates from two GFA techniques. Scat consistently had the lowest δ13C and δ15N values among the tissues sampled. We derived a diet-to-scat Δ13C value of -1.5‰ ± 1.6‰ and Δ15N value of 2.3‰ ± 1.3‰ for coyotes. Coyote scat δ13C and δ15N values adjusted for discrimination consistently plot within the isotopic mixing space created by known dietary items. In comparison with GFA results, we found that mixing model estimates of coyote dietary proportions de-emphasize the importance of small-bodied prey. Coyote scat δ13C and δ15N values therefore offer a relatively quick and non-invasive way to gain accurate dietary information
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Concomitant induction of the cell surface expression of Ia determinants and accessory cell function by a murine macrophage tumor cell line.
This study demonstrates that an uncharacterized soluble factor produced in concanavalin A-induced rat spleen cell suspensions has the capacity to induce the increased expression of cell surface H-2K and H-2D molecules and the expression of I-region gene products on murine monocyte-macrophage lineage tumors that are not Ia positive in the absence of the factor. In parallel with induction of serologically defined Ia specificities, Ia-induced WEHI-3 macrophage tumor cells are capable of providing accessory cell function in stimulating IL-2 production by T-T hybridomas that are activated in a major histocompatibility complex-restricted, antigen-dependent fashion. The uninduced Ia-negative WEHI-3 tumor cells do not trigger a comparable response in this assay system
The Impact of Immunization Control Activities on Measles Outbreaks in Akwa Ibom State, South-South, Nigeria
Background: The increase of vaccination rates means that fewer children will be vulnerable to vaccine preventable diseases such as measles, which will invariably result in a drop in the infant mortality and morbidity rates. Objective: To assess the impact of the implementation of measles reduction strategies from 2006 to 2008 using the quarterly national program for immunization (NPI) in Akwa Ibom state, Nigeria. Method: Following informed consent, individuals presenting with febrile rash illnesses were routinely bled and tested for measles specific IgM using commercially available ELISA kit-MV-ELISA (Enzygnost; Behring Diagnostics, Marburg, Germany) in accordance with the manufacturer’s instructions. Results: A total of four hundred and four individuals comprising of 216 vaccinated and 188 unvaccinated, presenting with febrile rash illness were screened for measles specific IgM antibodies as indication of active infection between January 2006 and December 2008 out of which 122 (30.2%) had detectable levels of measles antibodies. Among the vaccinated and unvaccinated groups, 32 (14.8%) and 90 (47.9%) respectively were detected with measles IgM antibodies. The highest and lowest antibody levels were detected in 2006 (vaccinated: 54.7%; unvaccinated: 78.4%) and 2008 (vaccinated: 1.2%; unvaccinated: 12%) respectively. The distribution of measles burden by year show an overall decline in prevalence from 70% in 2006, 8.9% in 2007 to 3.7% in 2008. While, children under the age of 5 similarly had a decline in measles incidence of 73.3%, 10.7% and 3.3% respectively. Sex distribution of infection within the 3-year period shows that more females (37.4%) than males (21.2%) expressed measles IgM antibodies, and active infection was detected more in the rural (31.4%) than urban area (27.7%). However, findings indicate a tremendous decline in active infection in the rural areas from 67% in 2006 to 0% in 2008, and in the urban areas from 78% in 2006 to 9.3% in 2008 among both vaccinated and unvaccinated groups. A highly significant reduction in measles infection was observed more among males than females (P=0.009). Infection distribution by location did not show any significant difference (P=0.65) even though more individuals in the rural areas were noted with active infection. Conclusion: The study shows a highly significant reduction in measles burden among vaccinated individuals (P=0.0001) and invariably increases protective coverage of measles vaccination most especially among children under 5 years of age (P=0.0066) in the state. Findings justify effort by government and WHO in carrying immunization campaigns in children, 5-years and below irrespective of vaccination status and experience
Parallel and overlapping Human Immunodeficiency Virus, Hepatitis B and C virus Infections among pregnant women in the Federal Capital Territory, Abuja, Nigeria
Background: Risk factors that are associated with HIV infection are also associated with HBV and HCV infections in sub-Saharan Africa. The HIV-infected pregnant cohort represents a unique population and infection with the hepatitis virus is considered a public health problem worldwide. Objective: The purpose of this study was to evaluate the prevalence of Human Immunodeficiency Virus, Hepatitis B and C virus parallel and overlapping infections among pregnant women attending antenatal clinics in Federal Capital Territory (FCT), Abuja. Method: Five hundred (500) blood samples were collected from three district hospitals in the FCT and tested at Wuse General Hospital, Abuja for the presence of antibodies to HIV and Hepatitis C virus, and HBsAg by ELISA technique in accordance with the manufacturer’s instructions. HIV seropositive sera were confirmed by Western blot. Result: Of the 500 pregnant women, those detected with HIV antibodies, HBsAg and anti-HCV antibodies were 42 (8.4%), 19 (3.8%) and 8 (1.6%) respectively. The overall seroprevalence of HIV and HBV or HCV co-infection was 9.5% while 7.1% and 2.4% HIV positive pregnant women were specifically co-infected with HBV and HCV respectively. Those within the age bracket of 15-20 years had the highest prevalence of HIV (13.4%), HBV (5.1%) and HCV (1.9%) infections. Among the occupation characteristics of the women, those of them involved in trading recorded the highest prevalence of HIV (60.6%), HBV (30.3) and HCV (6.1%). HIV was higher among the married women than the singles ((8.6% vs 6.5%); with HBV infection the reverse was the case (3.0% vs 9.8%) while HCV was same for both groups. History of blood transfusion did not reflect a higher rate of HIV and HBV (1.4% vs 9.6%; 2.8% vs 4.0% respectively) unlike HCV infection with 0.5% recorded only among those that had transfusion experience. Conclusion: When monitoring the risk of hepatotoxicity to antiretroviral drugs among these group of patients caution should be maintained. Moreover, evidence of parallel and overlapping HIV, HBsAg and HCV infections among this cohort should motivate inclusion of HBV and HCV among the diseases of surveillance in the national sentinel survey in order to ascertain the bigger picture of these infections in Nigeria
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