1,465 research outputs found

    Seasonal abundance and host plants of coconut stick insect (Graeffea crouanii Le Guillou) in coconut plantations of Fiji islands

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    Field survey conducted in major coconut growing regions in the three Fiji islands viz., Viti Levu, Vanua Levu, and Taveuni, revealed the presence of only one pest species of stick insect, Graeffea crouanii. Temperature had a significant effect on the level of infestation in the farms surveyed, while the effect of rainfall and humidity on the infestation was insignificant. Severe infestation was observed in isolated pockets, and the pest distribution was discontinuous in the surveyed areas. On a damage scale index, the insect infestation on coconut palms ranged from 0 to 4 grades. The peak increase of G. crouanii populations was from November to April in wet season at each of the three hotspots: Namaumada (Viti Levu), Dawara (Vanua Levu), and Salialevu (Taveuni). The occurrence of G. crouanii at varying damage levels in the present study may be attributed to the presence of sparse coconut palms in isolated coconut plantations. The field survey identified many alternate host plants of G. crouanii in the two plant families viz., Arecaceae and Pandanaceae. The information on the seasonal abundance and infestation levels of G. crouanii and its alternate host plants are discussed in formulating location-specific pest management strategies

    The occupancy-abundance relationship and sampling designs using occupancy to monitor populations of Asian bears

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    Designing a population monitoring program for Asian bears presents challenges associated with their low densities and detectability, generally large home ranges, and logistical or resource constraints. The use of an occupancy-based method to monitor bear populations can be appropriate under certain conditions given the mechanistic relationship between occupancy and abundance. The form of the occupancy\u2013abundance relationship is dependent on species-specific characteristics such as home range size and population density, as well as study area size. To assess the statistical power of tests to detect population change of Asian bears, we conducted a study using a range of scenarios by simulating spatially explicit individual-based capture-recapture data from a demographically open model. Simulations assessed the power to detect changes in population density via changes in site-level occupancy or abundance through time, estimated using a standard occupancy model or a Royle-Nichols model, both with point detectors (representing camera traps). We used IUCN Red List criteria as a guide in selection of two population decline scenarios (20% and 50%), but we chose a shorter time horizon (10 years = 1 bear generation), meaning that declines were steeper than used for IUCN criteria (3 generations). Our simulations detected population declines of 50% with high power (>0.80) and low false positive rates (FPR: incorrectly detecting a decline) (<0.10) when detectors were spaced at > 0.67 times the home range diameter (home-range spacing ratio: HRSR, a measure of spatial correlation), such that bears would tend to overlap no more than two detectors. There was high (0.85) correlation between realized occupancy and N in these scenarios. The FPR increased as the HRSR decreased because of spatial correlation in the occupancy process induced when individual home ranges overlap multiple detectors. The mean statistical power to detect more gradual population declines (20% in 10 years) with HRSR > 0.67 was low for occupancy models 0.22 (maximum power 0.67) and Royle-Nichols models (0.24; maximum power 0.67), suggesting that declines of this magnitude may not be described reliably with 10 years of monitoring. Our results demonstrated that under many realistic scenarios that we explored, false positive rates were unacceptably high. We highlight that when designing occupancy studies, the spacing between point detectors be at least 0.67 times the diameter of the home range size of the larger sex (e.g., males) when the assumptions of the spatial capture-recapture model used for simulation are met

    Relationship between care-givers' misconceptions and non-use of ITNs by under-five Nigerian children

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    <p>Abstract</p> <p>Background</p> <p>Malaria has been a major public health problem in Nigeria and many other sub-Saharan African countries. Insecticide-treated nets have shown to be cost-effective in the prevention of malaria, but the number of people that actually use these nets has remained generally low. Studies that explore the determinants of use of ITN are desirable.</p> <p>Methods</p> <p>Structured questionnaires based on thematic areas were administered by trained interviewers to 7,223 care-givers of under-five children selected from all the six geo-political zones of Nigeria. Bivariate analysis and multinomial logit model were used to identify possible determinants of use of ITN.</p> <p>Results</p> <p>Bivariate analysis showed that under-five children whose care-givers had some misconceptions about causes and prevention of malaria were significantly less likely to use ITN even though the household may own a net (p < 0.0001). Education and correct knowledge about modes of prevention of malaria, knowing that malaria is dangerous and malaria can kill were also significantly associated with use of ITN (p < 0.0001). Knowledge of symptoms of malaria did not influence use of ITN. Association of non-use of ITN with misconceptions about prevention of malaria persisted with logistic regression (Odds ratio 0.847; 95% CI 0.747 to 0.960).</p> <p>Conclusions</p> <p>Misconceptions about causes and prevention of malaria by caregivers adversely influence the use ITN by under-five children. Appropriate communication strategies should correct these misconceptions.</p

    Interactions of Axion Photons in Magnetised Media

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    We have compared between the standard model and generational model of particle physics. By means of a special Lagrangian function we consider the interaction of photon axions in both magnetic field and magnetic medium. We also present a polynomial in powers of the external magnetic field with even and odd powers .... DOI: 10.7176/APTA/83-01 Publication date: February 29th 202

    Positive words carry less information than negative words

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    We show that the frequency of word use is not only determined by the word length \cite{Zipf1935} and the average information content \cite{Piantadosi2011}, but also by its emotional content. We have analyzed three established lexica of affective word usage in English, German, and Spanish, to verify that these lexica have a neutral, unbiased, emotional content. Taking into account the frequency of word usage, we find that words with a positive emotional content are more frequently used. This lends support to Pollyanna hypothesis \cite{Boucher1969} that there should be a positive bias in human expression. We also find that negative words contain more information than positive words, as the informativeness of a word increases uniformly with its valence decrease. Our findings support earlier conjectures about (i) the relation between word frequency and information content, and (ii) the impact of positive emotions on communication and social links.Comment: 16 pages, 3 figures, 3 table

    Podoconiosis and soil-transmitted helminths (STHs): double burden of neglected tropical diseases in Wolaita zone, rural southern Ethiopia

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    Background Both podoconiosis and soil-transmitted helminth (STH) infections occur among barefoot people in areas of extreme poverty; however, their co-morbidity has not previously been investigated. We explored the overlap of STH infection and podoconiosis in Southern Ethiopia and quantified their separate and combined effects on prevalent anemia and hemoglobin levels in podoconiosis patients and health controls from the same area. Methods and Principal Findings A two-part comparative cross-sectional study was conducted in Wolaita zone, southern Ethiopia. Data were collected from adult patients presenting with clinically confirmed podoconiosis, and unmatched adult neighborhood controls living in the same administrative area. Information on demographic and selected lifestyle factors was collected using interviewer-administered questionnaires. Stool samples were collected and examined qualitatively using the modified formalin-ether sedimentation method. Hemoglobin level was determined using two different methods: hemoglobinometer and automated hematology analyzer. A total of 913 study subjects (677 podoconiosis patients and 236 controls) participated. The prevalence of any STH infection was 47.6% among patients and 33.1% among controls (p<0.001). The prevalence of both hookworm and Trichuris trichiura infections was significantly higher in podoconiosis patients than in controls (AOR 1.74, 95% CI 1.25 to2.42, AOR 6.53, 95% CI 2.34 to 18.22, respectively). Not wearing shoes and being a farmer remained significant independent predictors of infection with any STH. There was a significant interaction between STH infection and podoconiosis on reduction of hemoglobin level (interaction p value = 0.002). Conclusions Prevalence of any STH and hookworm infection was higher among podoconiosis patients than among controls. A significant reduction in hemoglobin level was observed among podoconiosis patients co-infected with hookworm and ‘non-hookworm STH’. Promotion of consistent shoe-wearing practices may have double advantages in controlling both podoconiosis and hookworm infection in the study area

    The assessment of mitral valve disease: a guideline from the British Society of Echocardiography.

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    Mitral valve disease is common. Mitral regurgitation is the second most frequent indication for valve surgery in Europe and despite the decline of rheumatic fever in western societies, mitral stenosis of any aetiology is a regular finding in all echo departments. Mitral valve disease is therefore one of the most common pathologies encountered by echocardiographers, as both a primary indication for echocardiography and a secondary finding when investigating other cardiovascular disease processes. Transthoracic and transoesophageal echocardiography (TOE) play a crucial role in the assessment of mitral valve disease and are essential to identifying the aetiology, mechanism and severity of disease and for helping determine the appropriate timing and method of intervention. This guideline, from the British Society of Echocardiography (BSE), describes the assessment of mitral regurgitation and mitral stenosis and replaces previous BSE guidelines describing the echocardiographic assessment of mitral anatomy prior to mitral valve repair surgery and percutaneous mitral valvuloplasty. It provides a comprehensive description of the imaging techniques (and their limitations) employed in the assessment of mitral valve disease. It describes a step-wise approach to identifying: aetiology and mechanism, disease severity, reparability and secondary effects on chamber geometry, function and pressures. Advanced echocardiographic techniques are described for both transthoracic and transoesophageal modalities, including TOE and exercise testing
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