1,164 research outputs found

    Importance of space and competition in optimizing genetic control strategies.

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    Advances in the genetic modification of organisms are creating new opportunities for the control of insect pests of both agriculture and public health significance. The timing and sex specificity of lethal transgene activation can be tailored to enhance the pest population control efficiency of mass-released, genetically modified insects. We developed mathematical models to determine the optimal timing and sex specificity of lethal transgene activation for the control of different types of pest population. We show that optimal release strategies are not only sensitive to the parameters governing growth of the population but also can be drastically affected by the inclusion of insect stage structuring, competition, and space. We emphasize the necessity of including these additional levels of complexity in future theoretical assessments as they are likely important considerations for designing transgenic organisms as well as their application in genetic control

    GLOBALIZING LEARNERS’ LOCAL LANGUAGES FROM LOCAL CONTEXTS: AN OVERVIEW OF LANGUAGE PLANNING AT THE ENGLISH EDUCATION PROGRAM OF ARTHA WACANA CHRISTIAN UNIVERSITY KUPANG

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    In the development of local language studies and current issues beyond, much attention of the literacy weights on the language status. Despite of the implications and effects, less attention rests on languages planning at the education unit. This study presents a comprehensive overview of local language (s) planning on the plane of the developing programs by the English Education Program of Artha Wacana Christian University Kupang, West Timor. The current study utilized participant observation and documentation as of data collection approaches. The use of the approaches permits deeper understanding of the target community. The findings indicates that language planning at this education unit promotes a number of concrete programs, such as building local partnerships, realizing national acts through curriculum development, and accessing global access seek for the revitalization of the local languages. More practically, learners with different backgrounds have a wide range of opportunity and tools to document their local languages. All these practices nurture to learners with awareness, motivation, and confidence that their local languages survivedon their academic and non-academic tasks and roles. Several recommendations and implications lies on the study

    The Economic Importance of Draught Oxen on Small Farms in Namibia\u27s Eastern Caprivi Region

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    The main aim of this study was to analyse and document the value of smallholder farmers’ use of Draught Animal Power (DAP) systems in the Eastern Caprivi Region and to test the economic viability of DAP usage versus using tractors. This study applied Rapid Rural Appraisal techniques (RRA), including a survey. Semi-structured interviews were conducted with 312 farmers at their farms and data was gathered on the use of and economics related to the draught animal power system. Crop enterprise budgets, project reports, expert opinions and group discussions were analysed. The research found that the use of animal power performs better in terms of physical productivity per ha compared to tractor usage. Furthermore, agricultural production in Sibinda village area, with the use of oxen outperformed the other systems when it was evaluated with parametric analysis. From a financial perspective, faremrs in Sibinda and Linyanti using oxen ranked above their counterparts using tractors. Further, the exercise indicated that farmers are facing a multitude of challenges such as damage incurred from wild animals and high input costs. There were many difficulties facing the next generation in entering commericial agricultural production in Caprivi within the current cost-price squeeze environment. Therefore, understanding the role draught oxen power can play as a tool to increase the level of success for new farmers’ in agricultural production and management was noted

    Endectocide-treated cattle for malaria control: A coupled entomological-epidemiological model

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    The malaria vector landscape is dynamic and dependence on indoor control tools has drastically affected both species compositions and local mosquito biting behaviours. In the advent of spreading behavioural resilience and physiological resistance to insecticidal nets and house spray, approaches to target more zoophilic, outdoor-biting vectors are being sought with increased urgency. Endectocides are insecticides applied to hosts which are taken up by the vectors during biting, and recent field assessments have demonstrated favourable results of cattle treated with ivermectin, diflubenzuron, eprinomectin and fipronil. Models were constructed to account for the modern, diverse vector feeding behaviours and assess their role in shaping malaria transmission and control with cattle-treated endectocides. Efficacy of this novel approach to malaria control is shown to be strongly dependent not only on intrinsic host preferences of the vector but also on how this preference is augmented by variation in the encounter rates with alternative blood-hosts. Ecological scenarios are presented whereby endectocides used on cattle yield equivalent, and in some cases improved, efficacy over nets and spray in controlling malaria transmission. Interactions between mosquito biting behaviours and relative availabilities of alternative blood-host species have largely been neglected in malaria programmatic strategy but will increasingly underlie sustaining the successes of vector control initiatives

    How do biting disease vectors behaviourally respond to host availability?

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    BACKGROUND: Ecological theory predicts a diverse range of functional responses of species to resource availability; but in the context of human blood consumption by disease vectors, a simplistic, linear response is ubiquitously assumed. A simple and flexible model formulation is presented that extends the Holling's Types to account for a wider range of qualitatively distinct behaviours, and used to examine the impact of different vector responses to the relative availability of multiple blood-host species. RESULTS: Epidemiological models of falciparum malaria, Chagas disease and Lyme disease demonstrate that the standard, often implicit, assumption of a linear functional response can lead to spurious under- or over-estimates in disease transmission potential, across a full range of pathogen life-cycles. It is shown how the functional response in vector biting can augment disease intervention outcomes. Interactions between vector biting behaviour and uneven pathogen transmission probabilities between alternative hosts, as is the case for Chagas disease, can render infection more resilient to control. CONCLUSIONS: Both the novel response formula and the nested vector-borne disease structure offer a flexible framework that can be applied to other vector-borne diseases in assessing the role of this newly identified aspect of biting behavioural ecology

    Associations between oral biofilm, periodontal disease, and systemic health: with a focus on atherosclerosis and breast cancer

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    The general hypothesis of this series of studies was that oral infections, particularly periodontal disease, by triggering inflammatory reactions detrimentally affect systemic health where inflammations are known to play a role in the pathogenesis, namely cardiovascular disease and cancer. Consequently, the general aim was to study the association between oral biofilm and certain oral micro-organisms, periodontal disease, and selected inflammatory markers with a focus on atherosclerosis and breast cancer (BC). In Study I, the aim was to examine the involvement of a high amount of dental plaque, severe gingival inflammation and periodontal disease in the development of early atherosclerotic lesions in women. The carotid arteries were examined with ultrasonography. Periodontal disease appeared to be a principal independent predictor in the development of atherosclerotic process women with periodontal disease. Our findings indicated that a high amount of dental plaque, severe gingival inflammation as well as periodontal disease seemed to be associated with the development of atherosclerotic lesions in women already at the early subclinical stage. In Study III, the aim was to examine early atherosclerotic changes in carotid arteries and relate the findings to the serum levels of high-sensitivity C-reactive protein (hsCRP) in subjects whose periodontal status have been followed for at least 18 years. Women had significantly lower hsCRP values and significantly higher highdensity lipoprotein (HDL) cholesterol values than men. Nevertheless, women with periodontal disease had significantly more atherosclerotic lesions than women without periodontal disease. Increased levels of hsCRP could not discriminate the patient group from the control group for either men or women. Periodontal disease was identified as the major independent predictor of increased carotid artery lesions. Hence, periodontal disease might nevertheless present a risk for atherosclerotic disease, particularly in women, irrespective of low hsCRP levels. In Study II, the aim was to evaluate the incidence of BC in subjects with periodontal disease and the characteristic tooth loss in a 16-year prospective investigation. Participants diagnosed with periodontal disease and BC had significantly more missing molars when compared with subjects with periodontal disease but without BC. The difference in the prevalence of BC in subjects with periodontal disease and with or without any missing molar in the mandible was significant. Thus, chronic periodontal disease indicated by missing molars seemed to be associated with the incidence of BC. In Study IV, the aim was to investigate in subjects with and without periodontal disease the levels of salivary albumin, total protein, and matrix metalloproteinases-8 (MMP-8), with or without the simultaneous presence of specific periodontal micro-organisms detected by polymerase chain reaction (PCR) in gingival crevicular fluid (GCF). The presence of both Treponema denticola and Tannerella forsythia associated with increased MMP-8 concentration in GCF. Furthermore, the presence of T. denticola associated with increased albumin and total protein concentrations in saliva. In Study V, the aim was to assess the association between site-specific subgingival micro-organisms and the levels of MMP-8 and MMP-9 at test sites. T. denticola was significantly more present at test sites in patients compared with the control group. Furthermore, the site -specific presence T. denticola in GCF appeared to increase the release of MMP-8 and MMP-9 at test sites. Thus, the results from Studies IV and V confirmed the assumption that periodontal micro-organisms might indeed trigger an inflammatory host-response. Summing up, periodontal disease was found to be associated with subclinical atherosclerotic lesions and also a higher incidence of BC. Furthermore, T. denticola associated with increased salivary albumin, total protein as well as with higher levels of MMP-8 and MMP-9 in GCF, indicating a possible inflammation triggering capacity of the oral biofilm. Thus, our findings did confirm our primary hypotheses. The associations indicate that periodontal disease might pose a threat to systemic health

    The relationship between price volatility, maturity and volume of trade of the Malaysian bond market

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    Kajian ini cuba membuat eksplorasi ke atas kesan tempoh matang dan volum dagangan ke atas kemeruapan pasaran bon Malaysia. Bon MGS, Cagamas clan Korporat yang aktif didagangkan merupakan data yang digunakan di dalam kajian ini. Perhubungan di antara pembolehubah-pembolehubah ini seterusnya dicerap dengan menggunakan analisa regresi. Tempoh kajian ini dibahagikan kepada tiga tempoh iaitu tempoh krisis (Mac 1996-Jun I997), tempoh semasa krisis sebelum pegging (Julai 1997-Ogos 1998) dan tempoh krisis selepas pegging (September 1998-Mac 1999). Adalah didapati bahawa tidak wujud perhubungan di antara kemeruapan harga dan tempoh matang bagi bon MGS dan Cagamas tetapi bagi bon Korporat, perhubungan di antara pemboleh ubah tersebut adalah positif dalam semua tempoh masa. Keputusan kajian juga menunjukkan bagi bon Korporat apabila volum dagangan dimasukkan ke dalam persamaan regresi, perhubungan di antara tempoh matang dan kemeruapan harganya menjadi tidak signifikan kecuali bagi tempoh semasa krisis sebelum pegging

    Pendekatan Kontekstual Dalam Tugas Misi Dan Komunikasi Injil Pasca Pandemi Covid-19

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    God reveals Himself in contextual ways. In revealing Himself, He sets forth to do His will and through His will, God materializes His word. Furthermore, God’s sovereign will is revealed in contextual ways in terms of today’s community life in regards to the history of every human civilation. God’s contextual self disclosure is not just an instrument that is used to display the essence of God, but it is also a method to comprehend His substance. In relation to God’s self disclosure, the contextualized self disclosure of God provides a basis for implementing His mission through bringing and communicating the Gospel to every community context. This concept is thoroughly explained within the discourse about “The contextual approach in doing missions and communicating the Gospel in Post Covid-19 Pandemic era”. This research underlies several important issues. These issues includes : First, Contextual Approach in Doing Missions; Second, Contextual Approach in Communicating the Gospel in Post Covid-19 Pandemic era. Hopefully through this discourse there is a broad overview about implementing the Great Commission of Christ Jesus in a contextual way in today’s world specifically in the Post Covid-19 period. ABSTRAKPenyataan TUHAN Allah dalam sejarah adalah kontektual. Penyataan Allah yang kontekstual melibatkan kehendak-Nya yang berdaulat sebagai landasan dari semua tindakan-Nya. Pada sisi lain, penyataan TUHAN yang berdaulat dinyatakan-Nya secara kontektual pada konteks kehidupan kekinian dalam sejarah setiap masyarakat. Penyataan TUHAN yang kontekstual bukan saja sebagai cara penyataan diri-Nya, tetapi sekaligus adalah metode untuk memahami Dia. Dalam kaitan ini, penyataan TUHAN yang kontekstual menyiapkan landasan bagi pelaksanaan misi-Nya dengan menghadirkan dan mengkomunikasikan Injil pada setiap konteks kehidupan masyarakat. Gagasan ini dituangkan melalui diskursus tentang “Pendekatan kontekstual dalam tugas misi dan komunikasi Injil Pasca Pandemi Covid-19” yang mengetengahkan beberapa pokok penting. Pokok-pokok dimaksud antara lain adalah: Pertama, Pendekatan Kontektual dalam Gerakan Misi; Kedua, Pendekatan Kontekstual dalam Komunikasi Injil pada Konteks Pasca Pandemi Covid-19. Diharapkan agar diskursus ini memberikan gambaran mengenai pelaksanaan Amanat Agung Yesus Kristus secara kontekstual dalam kondisi dunia kekinian khususnya pada konteks pasca Pandemi Covid-19

    Zika virus outbreak in the Americas: the need for novel mosquito control methods.

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    Local transmission of Zika virus (ZIKV) in the Americas was first confirmed in February, 2014, on Easter Island. In May, 2015, 16 patients from the Brazilian states of Bahia and Rio Grande do Norte were found to be ZIKV-positive. 22 countries and territories have subsequently identified autochthonous transmission within the region (figure). Until recently, ZIKV infection was only associated with mild symptoms (headache, rash, joint pain, conjunctivitis) but a possible link between ZIKV infection during pregnancy and subsequent birth defects (most notably microcephaly) was identified in November, 2015.1 Approaching 4000 cases of suspected ZIKV-related microcephaly have arisen in Brazil alone where initial figures suggest between 440 000 and 1·3 million people have been infected so far.2 Concern in the region is escalating, with public health authorities in Colombia, Ecuador, El Salvador, and Jamaica all issuing an unprecedented health notice warning their residents to avoid pregnancy until 2018

    The Influence of Trading Frequency on Lead-Lag Effect Between Index Futures and Stock Index in Malaysia

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    The presence of lead-lag effect between index futures and stock index has lead finance researchers to focus on identifying the source of such phenomenon.  In general, index futures play an important role in the price discovery process since it is found that index futures leads the stock index in reacting to the arrival of new information. Such phenomenon is attributed to the problem of stale prices among some components of stock index. The problem arises due to nonsynchronous trading as well as infrequent trading among inactive component stocks, resulting in stock index reporting weightage value of past prices unlike index futures, which is being updated constantly. This study examines the influence of trading frequency among component stocks on the presence of lead-lag effect between the two markets in Malaysia. The period of study runs from January 2000 to October 2003. It employs regression analysis using system estimators approach. The result shows that index futures does not only lead the inactive component stocks but also the active component stocks. As such, the finding contradicts the proposed theory, which stipulates that the presence of lead-lag effect is due to the problem of infrequent trading among inactive component stocks.  Therefore, consistent with Chan (1992) and Martikainen et al. (1995) who investigate the same issue in the United States and Finland, this study provides empirical evidence that trading frequency does not contribute towards the presence of lead-lag effect between index futures and stock index in Malaysia
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