149 research outputs found

    Insecticidal effects of Cassia tora and Cassia alata against cowpea weevil (Callosobruchus maculatus)

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    A study on the effects of Cassia tora and Cassia alata against cowpea weevil (Callosobruchus maculatus) was conducted from April to July, 2016 and aimed at evaluating the effects of Cassia tora and Cassia alata in the control of cowpea weevil (Callosobruchus maculatus). The percentage mortality of Callosobruchus maculatus in white variety seeds of cowpea treated with concentrations 2g, 3g, 4g and 5g powder of Cassia alata are 40%, 50%, 70% and 90% respectively and Cassia tora of the same concentrations gave mortality percentage of 30%, 40%, 60% and 70% respectively. The mortality of adult C. maculatus was higher in both varieties treated with powdered mixture of both plant materials in ratio of Ca80%:Ct20% showed (90%) mortality followed by Ca50%:Ct50% with 80%. C. maculatus mortality according to variety was higher in the white variety than the brown variety with Ca20%:Ct80% mixture as (3.00±1.00) and (2.50±0.50) respectively. The weevil perforation index (WPI), increase as the concentration of the plant increased with Cassia alata having the highest weevil perforation index when compared to Cassia tora. There was significant difference (P<0.05) between combination of the two plants (Cassia alata and Cassia tora) and weevil perforation index for both varieties of cowpea seeds. Since the plant species showed efficacy and are cheap and readily available, it therefore be recommended, that the leaf powders of these two plants can be used in the control of adult C. maculates in storage of cowpea

    Understanding key vectors and vector-borne diseases associated with freshwater ecosystem across Africa: Implications for public health

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    The emerging and re-emerging vector-borne diseases transmitted by key freshwater organisms have remained a global concern. As one of the leading biodiversity hotspots, the African ecoregion is suggested to harbour the highest number of freshwater organisms globally. Among the commonly found organisms in the African ecoregion are mosquitoes and snails, with a majority of their life cycle in freshwater, and these freshwater organisms can transmit diseases or serve as carriers of devastating diseases of public health concerns. However, synthetic studies to link the evident abundant presence and wide distribution of these vectors across the freshwater ecosystems in Africa with the increasing emerging and re-emerging vector-borne diseases in Africa are still limited. Here, we reviewed documented evidence on vector-borne diseases and their transmission pathways in Africa to reduce the knowledge gap on the factors influencing the increasing emerging and re-emerging vector-borne diseases across Africa. We found the population distributions or abundance of these freshwater organisms to be increasing, which is directly associated with the increasing emerging and re-emerging vector-borne diseases across Africa. Furthermore, we found that although the current changing environmental conditions in Africa affect the habitats of these freshwater organisms, current changing environmental conditions may not be suppressing the population distributions or abundance of these freshwater organisms. Instead, we found that these freshwater organisms are extending their geographic ranges across Africa, which may have significant public health implications in Africa. Thus, our study demonstrates the need for future studies to integrate the environmental conditions of vectors' habitats to understand if these environmental conditions directly or indirectly influence the vectorial capacities and transmission abilities of vectors of diseases. We propose that such studies will be necessary to guide policymakers in making informed policies to help control vector-borne diseases

    Neutrons describe ectoine effects on water H-bonding and hydration around a soluble protein and a cell membrane

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    Understanding adaptation to extreme environments remains a challenge of high biotechnological potential for fundamental molecular biology. The cytosol of many microorganisms, isolated from saline environments, reversibly accumulates molar concentrations of the osmolyte ectoine to counterbalance fluctuating external salt concentrations. Although they have been studied extensively by thermodynamic and spectroscopic methods, direct experimental structural data have, so far, been lacking on ectoine-water-protein interactions. In this paper, in vivo deuterium labeling, small angle neutron scattering, neutron membrane diffraction and inelastic scattering are combined with neutron liquids diffraction to characterize the extreme ectoine-containing solvent and its effects on purple membrane of H. salinarum and E. coli maltose binding protein. The data reveal that ectoine is excluded from the hydration layer at the membrane surface and does not affect membrane molecular dynamics, and prove a previous hypothesis that ectoine is excluded from a monolayer of dense hydration water around the soluble protein. Neutron liquids diffraction to atomic resolution shows how ectoine enhances the remarkable properties of H-bonds in water-properties that are essential for the proper organization, stabilization and dynamics of biological structures

    Reduced-bias estimator of the Conditional Tail Expectation of heavy-tailed distributions

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    International audienceSeveral risk measures have been proposed in the literature. In this paper, we focus on the estimation of the Conditional Tail Expectation (CTE). Its asymptotic normality has been first established in the literature under the classical assumption that the second moment of the loss variable is finite, this condition being very restrictive in practical applications. Such a result has been extended by Necir {\it et al.} (2010) in the case of infinite second moment. In this framework, we propose a reduced-bias estimator of the CTE. We illustrate the efficiency of our approach on a small simulation study and a real data analysis

    Studia Litteraria

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    Barta JĂĄnos, GĂ©niuszok talĂĄlkozĂĄsa, PetƑfi Ă©s Arany barĂĄtsĂĄga, 3-32. Sonkoly IstvĂĄn, MegzenĂ©sĂ­tett PetƑfi-versek, 33-50. PĂĄlfy G. IstvĂĄn, A TempefƑi dramaturgiĂĄja, 51-62. Görömbei AndrĂĄs, Csokonai Ă©s a honfoglalĂĄsi eposz, 63-76. BĂĄrczi KlĂĄra, A nĂ©piessĂ©g Csokonai Ă©s Burns költĂ©szetĂ©ben, 77-92. Julow Viktor, Csokonai Ă©s PetƑfi között, A debreceni kĂ©sƑ-felvilĂĄgosodĂĄsrĂłl, 93-106. TĂłth BĂ©la, MarĂłthi György albuma, 107-126. Deme ZoltĂĄn, Verseghy Ă©s a jambusi kettƑs ritmus, 127-136. PĂ©terffy Ida, KovĂĄts SĂĄmuel, Csokonai jĂł barĂĄtja, 137-155

    Composition and Distribution of Mosquito Vectors in a Peri-Urban Community Surrounding an Institution of Learning in Lafia Metropolis, Nasarawa State, Central Nigeria

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    Vector surveillance is very key in solving mosquito-borne health problems in Nigeria. To this end, the composition and distribution of mosquito vectors in a peri-urban community surrounding an institution of learning in Lafia metropolis, Nasarawa State, Central Nigeria was carried out between December 2016 and June 2017. The Prokopack Aspirator was used to collect indoor resting mosquitoes between 6:00 a.m. and 9:00 a.m. from 30 randomly selected houses. Mosquitoes collected were knocked down and transferred into a well labelled petri-dish and taken to the laboratory for processing. A total of 664 mosquitoes were collected which spread across Culex quinquefasciatus 572 (86.14%), Anopheles gambiae 88 (13.25%) and Aedes aegypti 4 (0.60%). The abundance of mosquitoes in relation to seasons, species, sex, abdominal conditions as well as transmission indices across seasons significantly varied (P 0.05). The inhabitants of the area should ensure that all drainages flow through so as to reduce mosquito breeding grounds. Also, members of the community should always protect themselves by sleeping under insecticide treated bed nets

    Exchange of Best Practices Within the European Union:Surgery Standardization of Abdominal Organ Retrieval

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    AbstractConsidering the growing organ demand worldwide, it is crucial to optimize organ retrieval and training of surgeons to reduce the risk of injury during the procedure and increase the quality of organs to be transplanted. In the Netherlands, a national complete trajectory from training of surgeons in procurement surgery to the quality assessment of the procured organs was implemented in 2010. This mandatory trajectory comprises training and certification modules: E-learning, training on the job, and a practical session. Thanks to the ACCORD (Achieving Comprehensive Coordination in Organ Donation) Joint Action coordinated by Spain and co-funded under the European Commission Health Programme, 3 twinning activities (led by France) were set to exchange best practices between countries. The Dutch trajectory is being adapted and implemented in Hungary as one of these twinning activities. The E-learning platform was modified, tested by a panel of Hungarian and UK surgeons, and was awarded in July 2013 by the European Accreditation Council for Continuing Medical Education of the European Union of Medical Specialists. As a pilot phase for future national training, 6 Hungarian surgeons from Semmelweis University are being trained; E-learning platform was fulfilled, and practical sessions, training-on-the-job activities, and evaluations of technical skills are ongoing. The first national practical session was recently organized in Budapest, and the new series of nationwide selected candidates completed the E-learning platform before the practical. There is great potential for sharing best practices and for direct transfer of expertise at the European level, and especially to export this standardized training in organ retrieval to other European countries and even broader. The final goal was to not only provide a national training to all countries lacking such a program but also to improve the quality and safety criteria of organs to be transplanted

    A critical review of smaller state diplomacy

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    In The Peloponnesian War, Thucydides (1972: 402) highlights the effects of the general, overall weakness of smaller states vis-à-vis larger, more powerful ones in a key passage, where the Athenians remind the Melians that: “
 since you know as well as we do that, as the world goes, right is only in question between equals in power. Meanwhile, the strong do what they can and the weak suffer what they must.” Concerns about the vulnerability of small, weak, isolated states have echoed throughout history: from Thucydides, through the review by Machiavelli (1985) of the risks of inviting great powers to intervene in domestic affairs, through 20th century US-led contemporary political science (Vital, 1971; Handel, 1990) and Commonwealth led scholarship (Commonwealth Secretariat, 1985). In the context of 20th century ‘Balkanization’, the small state could also prove unstable, even hostile and uncooperative, a situation tempting enough to invite the intrusion of more powerful neighbours: a combination, according to Brzezinski (1997: 123-124) of a power vacuum and a corollary power suction2: in the outcome, if the small state is ‘absorbed’, it would be its fault, and its destiny, in the grand scheme of things. In an excellent review of small states in the context of the global politics of development, Payne (2004: 623, 634) concludes that “vulnerabilities rather than opportunities are the most striking consequence of smallness”. It has been recently claimed that, since they cannot defend or represent themselves adequately, small states “lack real independence, which makes them suboptimal participants in the international system” (Hagalin, 2005: 1). There is however, a less notable and acknowledged but more extraordinary strand of argumentation that considers ‘the power of powerlessness’, and the ability of small states to exploit their smaller size in a variety of ways in order to achieve their intended, even if unlikely, policy outcomes. The pursuance of smaller state goals becomes paradoxically acceptable and achievable precisely because such smaller states do not have the power to leverage disputants or pursue their own agenda. A case in point concerns the smallest state of all, the Vatican, whose powers are both unique and ambiguous, but certainly not insignificant (The Economist, 2007). Smaller states have “punched above their weight” (e.g. Edis, 1991); and, intermittently, political scientists confront their “amazing intractability” (e.g. Suhrke, 1973: 508). Henry Kissinger (1982: 172) referred to this stance, with obvious contempt, as “the tyranny of the weak”3. This paper seeks a safe passage through these two, equally reductionist, propositions. It deliberately focuses first on a comparative case analysis of two, distinct ‘small state-big state’ contests drawn from the 1970s, seeking to infer and tease out the conditions that enable smaller ‘Lilliputian’ states (whether often or rarely) to beat their respective Goliaths. The discussion is then taken forward to examine whether similar tactics can work in relation to contemporary concerns with environmental vulnerability, with a focus on two other, small island states. Before that, the semiotics of ‘the small state’ need to be explored, since they are suggestive of the perceptions and expectations that are harboured by decision makers at home and abroad and which tend towards the self-fulfilling prophecy.peer-reviewe
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