154 research outputs found

    Efficacy of controlled atmosphere treatments to manage arthropod pests of dry-cured hams

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    Citation: Hasan, M. M., Aikins, M. J., Schilling, W., & Phillips, T. W. (2016). Efficacy of controlled atmosphere treatments to manage arthropod pests of dry-cured hams. Insects, 7(3). doi:10.3390/insects7030044Research here explored the use of controlled atmospheres (CA) for managing arthropod pests that infest dry-cured hams. Experiments were conducted with low oxygen (O2) achieved with low pressure under a vacuum, high carbon dioxide (CO2), and ozone (O3). Results showed that both low O2 and high CO2 levels required exposures up to 144 h to kill 100% of all stages of red-legged ham beetle, Necrobia rufipes (De Geer) (Coleoptera: Cleridae) and ham mite Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) at 23 °C. In addition, both low O2 and high CO2 had no significant mortality against the ham beetle and ham mites at short exposures ranging from 12 to 48 h. Ham beetles were more tolerant than ham mites to an atmosphere of 75.1% CO2 and low pressure of 25 mm Hg, which imposed an atmosphere estimated at 0.9% O2. Both low O2 and high CO2 trials indicated that the egg stages of both species were more tolerant than other stages tested, but N. rufipes eggs and pupae were more susceptible than larvae and adults to high concentration ozone treatments. The results indicate that O3 has potential to control ham beetles and ham mites, particularly at ≈166 ppm in just a 24 h exposure period, but O3 is known from other work to have poor penetration ability, thus it may be more difficult to apply effectively than low O2 or high CO2. would be. CA treatment for arthropod pests of dry-cured hams show promise as components of integrated pest management programs after methyl bromide is no longer available for use. © 2016 by the authors; licensee MDPI, Basel, Switzerland

    Fumigation of bed bugs (Hemiptera: Cimicidae): effective application rates for sulfuryl fluoride

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    Citation: Phillips, Thomas W., Michael J. Aikins, Ellen Thoms, Joe Demark, and Changlu Wang. 2014. “Fumigation of Bed Bugs (Hemiptera: Cimicidae): Effective Application Rates for Sulfuryl Fluoride.” Journal of Economic Entomology 107 (4): 1582–89. https://doi.org/10.1603/EC13471.The bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), has resurged recently as a domestic pest in North America with very limited options for decisive control. We report efficacy studies with sulfuryl fluoride (SF) toward use as a structural fumigant to control bed bugs. Laboratory studies were conducted in which eggs, adults, and nymphs from a pesticide susceptible laboratory population were fumigated for 24 h using SF at 99.8% purity in airtight, 3.8-liter glass containers under two temperatures, 25°C and 15°C. Bed bugs were placed in separate ventilated glass vials and wrapped in mattress padding before fumigation. The gas concentration within each jar was determined using quantitative gas chromatography‐mass spectrometry. Dose‐response trials using eggs of known age (48‐96 h) were conducted at five or six target concentrations measured as concentration × time accumulated dosages (g-h/m³) and one untreated control at each temperature. Each target dose was replicated in four different fumigation containers (replicates), with at least 32 eggs per replicate. The number of hatched and unhatched eggs postfumigation, and number of live and dead nymphs that resulted from hatched eggs, were evaluated daily for at least 1 wk after egg hatch. The lethal accumulated dosage (LAD99) for bed bug eggs was 69.1 (95% fiducial limits [FLs] of 62.9‐79.5) g-h/m³ at 25°C and 149.3 (95% FLs of 134.4‐177.9) g-h/m³ at 15°C. Confirmatory trials with dosages of 1.5× the LAD99 were conducted at 25°C and 1.5× the threshold mortality dose at 15°C with at least 15 adults, 13 late-instar nymphs and 79 eggs of known age per replicate. At 25°C, a target dosage of 103.7 g-h/m³ resulted in 100% mortality of adults and late-instar nymphs. Nymphs emerged and survived from two of 439 eggs treated with SF dosages that were 6‐7 g-h/m³ less than the target dosage. No nymphs emerged from eggs fumigated with dosages >97.9 g-h/m³ in the validation study. Therefore, the threshold dosage for complete egg mortality (97.9 g-h/m³) was used, rather than the LAD99, to calculate the monitored field dosage rate of 148.2 g-h/m³ (= 1.5 × 97.9 g-h/m³) for control of all life stages of bed bugs at 25°C. Based on these results, at 15°C, 1.5× the threshold dosage for complete egg control (189.7 g-h/m³) was used to calculate a target dosage of 285 g-h/m³ for the confirmatory trial, which resulted in 100% mortality of adults, late-instar nymphs, and eggs

    Mosquito Abundance, Bed net Coverage and Other Factors Associated with Variations in Sporozoite Infectivity Rates in Four Villages of Rural Tanzania.

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    Entomological surveys are of great importance in decision-making processes regarding malaria control strategies because they help to identify associations between vector abundance both species-specific ecology and disease intervention factors associated with malaria transmission. Sporozoite infectivity rates, mosquito host blood meal source, bed net coverage and mosquito abundance were assessed in this study. A longitudinal survey was conducted in four villages in two regions of Tanzania. Malaria vectors were sampled using the CDC light trap and pyrethrum spray catch methods. In each village, ten paired houses were selected for mosquitoes sampling. Sampling was done in fortnight case and study was undertaken for six months in both Kilimanjaro (Northern Tanzania) and Dodoma (Central Tanzania) regions. A total of 6,883 mosquitoes were collected including: 5,628 (81.8%) Anopheles arabiensis, 1,100 (15.9%) Culex quinquefasciatus, 89 (1.4%) Anopheles funestus, and 66 (0.9%) Anopheles gambiae s.s. Of the total mosquitoes collected 3,861 were captured by CDC light trap and 3,022 by the pyrethrum spray catch method. The overall light trap: spray catch ratio was 1.3:1. Mosquito densities per room were 96.5 and 75.5 for light trap and pyrethrum spray catch respectively. Mosquito infectivity rates between villages that have high proportion of bed net owners and those without bed nets was significant (P < 0.001) and there was a significant difference in sporozoite rates between households with and without bed nets in these four villages (P < 0.001). Malaria remains a major problem in the study areas characterized as low transmission sites. Further studies are required to establish the annual entomological inoculation rates and to observe the annual parasitaemia dynamics in these communities. Outdoor mosquitoes collection should also be considered

    Influencing policy change: the experience of health think tanks in low- and middle-income countries

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    In recent years there has been a growth in the number of independent health policy analysis institutes in low- and middle-income countries which has occurred in response to the limitation of government analytical capacity and pressures associated with democratization. This study aimed to: (i) investigate the contribution made by health policy analysis institutes in low- and middle-income countries to health policy agenda setting, formulation, implementation and monitoring and evaluation; and (ii) assess which factors, including organizational form and structure, support the role of health policy analysis institutes in low- and middle-income countries in terms of positively contributing to health policy. Six case studies of health policy analysis institutes in Bangladesh, Ghana, India, South Africa, Uganda and Vietnam were conducted including two NGOs, two university and two government-owned policy analysis institutes. Case studies drew on document review, analysis of financial information, semi-structured interviews with staff and other stakeholders, and iterative feedback of draft findings. Some of the institutes had made major contributions to policy development in their respective countries. All of the institutes were actively engaged in providing policy advice and most undertook policy-relevant research. Relatively few were engaged in conducting policy dialogues, or systematic reviews, or commissioning research. Much of the work undertaken by institutes was driven by requests from government or donors, and the primary outputs for most institutes were research reports, frequently combined with verbal briefings. Several factors were critical in supporting effective policy engagement. These included a supportive policy environment, some degree of independence in governance and financing, and strong links to policy makers that facilitate trust and influence. While the formal relationship of the institute to government was not found to be critical, units within government faced considerable difficulties

    Systematic reviews of complementary therapies - an annotated bibliography. Part 1: Acupuncture

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    Background Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with acupuncture. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of acupuncture; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pretested form and summarized descriptively. Results From a total of 48 potentially relevant reviews preselected in a screeening process 39 met the inclusion criteria. 22 were on various pain syndromes or rheumatic diseases. Other topics addressed by more than one review were addiction, nausea, asthma and tinnitus. Almost unanimously the reviews state that acupuncture trials include too few patients. Often included trials are heterogeneous regarding patients, interventions and outcome measures, are considered to have insufficient quality and contradictory results. Convincing evidence is available only for postoperative nausea, for which acupuncture appears to be of benefit, and smoking cessation, where acupuncture is no more effective than sham acupuncture. Conclusions A large number of systematic reviews on acupuncture exists. What is most obvious from these reviews is the need for (the funding of) well-designed, larger clinical trials

    Decreased motivation in the use of insecticide-treated nets in a malaria endemic area in Burkina Faso

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    <p>Abstract</p> <p>Background</p> <p>The use of insecticide-treated nets (ITN) is an important tool in the Roll Back Malaria (RBM) strategy. For ITNs to be effective they need to be used correctly. Previous studies have shown that many factors, such as wealth, access to health care, education, ethnicity and gender, determine the ownership and use of ITNs. Some studies showed that free distribution and public awareness campaigns increased the rate of use. However, there have been no evaluations of the short- and long-term impact of such motivation campaigns. A study carried out in a malaria endemic area in south-western Burkina Faso indicated that this increased use declined after several months. The reasons were a combination of the community representation of malaria, the perception of the effectiveness and usefulness of ITNs and also the manner in which households are organized by day and by night.</p> <p>Methods</p> <p>PermaNet 2.0<sup>® </sup>and Olyset<sup>® </sup>were distributed in 455 compounds at the beginning of the rainy season. The community was educated on the effectiveness of nets in reducing malaria and on how to use them. To assess motivation, qualitative tools were used: one hundred people were interviewed, two hundred houses were observed directly and two houses were monitored monthly throughout one year.</p> <p>Results</p> <p>The motivation for the use of bednets decreased after less than a year. Inhabitants' conception of malaria and the inconvenience of using bednets in small houses were the major reasons. Acceptance that ITNs were useful in reducing malaria was moderated by the fact that mosquitoes were considered to be only one of several factors which caused malaria. The appropriate and routine use of ITNs was adversely affected by the functional organization of the houses, which changed as between day and night. Bednets were not used when the perceived benefits of reduction in mosquito nuisance and of malaria were considered not to be worth the inconvenience of daily use.</p> <p>Conclusion</p> <p>In order to bridge the gap between possession and use of bednets, concerted efforts are required to change behaviour by providing accurate information, most particularly by convincing people that mosquitoes are the only source of malaria, whilst recognising that there are other diseases with similar symptoms, caused in other ways. The medical message must underline the seriousness of malaria and the presence of the malaria vector in the dry season as well as the wet, in order to encourage the use of bednets whenever transmission can occur. Communities would benefit from impregnated bednets and other vector control measures being better adapted to their homes, thus reducing the inconvenience of their use.</p

    Elementary School Students’ Epistemic Perspective and Learning Strategies in History

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    The present study explores possible relations between students’ epistemic perspective, learning strategies and text comprehension. In Study 1, seventy-nine sixth graders completed paper-and-pencil instruments to measure their epistemic perspective and learning strategies. Students’ epistemic perspective was assessed using the Livian problem (Kuhn, Iordanou, Pease, & Wirkala, 2008), which presented two contradicting accounts about the fictitious fifth Livian war and asked students questions regarding the certainty of their knowledge. Students were epistemically profiled as Absolutists, Multiplists and Evaluativists in their approaches to knowing. Students’ learning strategies were assessed through the Motivated Strategies for Learning Questionnaire – MSLQ − (Pintrich & De Groot, 1990). In Study 2, twenty of the students who participated in Study 1 were individually interviewed to measure their learning strategies, where they were asked to read a text about Columbus’ uncovering of the New World. Results revealed that students who were profiled as Evaluativists showed greater self-efficacy, intrinsic value, use of cognitive strategies and self-regulation. In addition, students who were profiled as Evaluativists engaged in more effective learning strategies and exhibited better text comprehension compared to students who were profiled as Absolutists. In particular, students who exhibited an Evaluativist epistemic perspective engaged in the strategies of understanding vocabulary, summarizing and underlining, while students who exhibited an Absolutist epistemic perspective engaged more in repeating information and quick reading. Our findings show that a mature epistemic perspective is associated with effective usage of learning strategies and text comprehension

    Treatment choices for fevers in children under-five years in a rural Ghanaian district

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    <p>Abstract</p> <p>Background</p> <p>Health care demand studies help to examine the behaviour of individuals and households during illnesses. Few of existing health care demand studies examine the choice of treatment services for childhood illnesses. Besides, in their analyses, many of the existing studies compare alternative treatment options to a single option, usually self-medication. This study aims at examining the factors that influence the choices that caregivers of children under-five years make regarding treatment of fevers due to malaria and pneumonia in a rural setting. The study also examines how the choice of alternative treatment options compare with each other.</p> <p>Methods</p> <p>The study uses data from a 2006 household socio-economic survey and health and demographic surveillance covering caregivers of 529 children under-five years of age in the Dangme West District and applies a multinomial probit technique to model the choice of treatment services for fevers in under-fives in rural Ghana. Four health care options are considered: self-medication, over-the-counter providers, public providers and private providers.</p> <p>Results</p> <p>The findings indicate that longer travel, waiting and treatment times encourage people to use self-medication and over-the-counter providers compared to public and private providers. Caregivers with health insurance coverage also use care from public providers compared to over-the-counter or private providers. Caregivers with higher incomes use public and private providers over self-medication while higher treatment charges and longer times at public facilities encourage caregivers to resort to private providers. Besides, caregivers of female under-fives use self-care while caregivers of male under-fives use public providers instead of self-care, implying gender disparity in the choice of treatment.</p> <p>Conclusions</p> <p>The results of this study imply that efforts at curbing under-five mortality due to malaria and pneumonia need to take into account care-seeking behaviour of caregivers of under-fives as well as implementation of strategies.</p

    Organised crime and international aid subversion: evidence from Colombia and Afghanistan

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    Scholarly attempts to explain aid subversion in post-conflict contexts frame the challenge in terms of corrupt practices and transactions disconnected from local power struggles. Also, they assume a distinction between organised crime and the state. This comparative analysis of aid subversion in Colombia and Afghanistan reveals the limits of such an approach. Focusing on relations that anchor organised crime within local political, social and economic processes, we demonstrate that organised crime is dynamic, driven by multiple motives, and endogenous to local power politics. Better understanding of governance arrangements around the organised crime-conflict nexus which enable aid subversion is therefore required

    Multi-dimensional knowledge of malaria among Nigerian caregivers: implications for insecticide-treated net use by children

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    Abstract Background Poor malaria knowledge can negatively impact malaria control programmes. This study evaluates knowledge distribution in the domains of causation, transmission, vulnerability, symptoms, and treatment of malaria. It assesses the association between a caregiver’s knowledge about malaria and ownership and use of insecticide-treated nets (ITNs) by children. Methods Some 1939 caregivers of young children were recruited through a school-based survey in two Nigerian states. A 20-item, multi-dimensional survey instrument was developed and used to rank each caregiver’s knowledge in five dimensions (cause, transmission, vulnerability, symptoms, treatment of malaria). Scores for each domain were used to create an aggregate knowledge score for each caregiver. The outcome measures were ITN ownership, and ITN use the night and week before the study. Regression models were used to evaluate the relationship between caregiver’s knowledge (individual domains and aggregate score) and ownership and use of ITN after controlling for likely confounders. Results The main predictor of ITN use was ITN ownership (r = 0.653; p < 0.001); however, ownership only explains 43 % of variance in net use. Total knowledge index for the study population was significantly associated with both ITN ownership (r = 0.122; p = 0.001) and use (r = 0.095; p = 0.014). The spectrum of caregiver’s knowledge of malaria and its causes captured in the various domains was, however, found to be poor. Fifty percent of the respondents knew that malaria is transmitted by female mosquitoes and 65 % still believe that too much exposure to the sun is a risk factor for malaria. Knowledge of populations most vulnerable to malaria (83 %) and knowledge of malaria transmission (32 %) were the domains with the highest and lowest average correct answers. Conclusions There is a need to improve ITN coverage in Nigeria as ITN ownership was associated with ITN use. Additionally, treating knowledge as a multi-dimensional phenomenon revealed that a lot of misperceptions about malaria still exist. Distribution of ITNs through the public/private sector may need to be augmented with tailored behavioural change communication to dispel myths and improve the multi-dimensional knowledge of malaria in the local population.http://deepblue.lib.umich.edu/bitstream/2027.42/134666/1/12936_2016_Article_1557.pd
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