429 research outputs found

    Bidirectional Relationship Between Sleep Disturbances and Parkinson's Disease

    Get PDF
    Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's disease (AD). Both diseases share common clinical and pathological features: the gradual progression of neurological and psychiatric symptoms caused by neuronal dysfunction and neuronal cell death due to the accumulation of misfolded and neurotoxic proteins. Furthermore, both of them are multifactorial diseases in which both genetic and non-genetic factors contribute to the disease course. Non-genetic factors are of particular interest for the development of preventive and therapeutic approaches for these diseases because they are modifiable; of these, sleep is a particularly intriguing factor. Sleep disturbances are highly prevalent among both patients with AD and PD. To date, research has suggested that sleep disturbances are a consequence as well as a risk factor for the onset and progression of AD, which implies a bidirectional relationship between sleep and AD. Whether such a relationship exists in PD is less certain, albeit highly plausible given the shared pathomechanisms. This review examines the current evidence for the bidirectional relationship between sleep and PD. It includes research in both humans and animal models, followed by a discussion of the current understanding of the mechanisms underlying this relationship. Finally, potential avenues of research toward achieving disease modification to treat or prevent PD are proposed. Although further efforts are crucial for preventing the onset and slowing the progress of PD, it is evident that sleep is a valuable candidate target for future interventions to improve the outcomes of PD patients

    The diving beetles of Kamchatka, with additional records from Sakhalin and the Kuril Islands (Coleoptera: Dytiscidae).

    Get PDF
    Die Dytiscidenfauna der nordostasiatischen Halbinsel Kamtschatka wird auf der Grundlage von Literaturnachweisen und neueren Aufsammlungen zusammengestellt. Die folgenden zehn Arten werden erstmals für Kamtschatka nachgewiesen: Hygrotus marklini (Gyllenhal), Hydroporus notabilis LeConte, H. submuticus Thomson, H. tristis (Paykull), H. uenoi Nakane, Oreodytes okulovi Lafer, Agabus balkei Fery & Nilsson, A. discolor Harris, Ilybius chishimanus Kôno, Rhantus suturellus (Harris), und Graphoderus perplexus Sharp. Insgesamt 38 Dytiscidenarten, davon 22 mit holarktischer Verbreitung, sind nun von Kamtschatka bekannt. Graphoderus perplexus wird erstmals aus der Paläarktis nachgewiesen. Weitere Nachweise werden für Sachalin und die Kurilen genannt. Die folgenden Arten sind Erstnachweise für Sachalin: Hydroporus nigellus Mannerheim, Agabus kholini Nilsson, Ilybius angustior (Gyllenhal), und Acilius canaliculatus (Nicolai). Zehn Arten werden erstmals für die Kurilen nachgewiesen: Hydroporus nigellus, H. notabilis, H. submuticus, H. tristis, Agabus clypealis (Thomson), A. confinis (Gyllenhal), A. costulatus (Motschulsky), A. discolor, Ilybius discedens Sharp, und Colymbetes dahuricus Aubé. Neun dieser Arten wurden auf den nördlichen, H. tristis dagegen auf den südlichen Kurilen gefunden. Damit sind jetzt von Sachalin 39 und von den Kurilen 36 Arten bekannt.The dytiscid fauna of the north-east Asian peninsula Kamchatka is reviewed based on literature records and more recent collections. The following ten species are here reported from Kamchatka for the first time: Hygrotus marklini (Gyllenhal), Hydroporus notabilis LeConte, H. submuticus Thomson, H. tristis (Paykull), H. uenoi Nakane, Oreodytes okulovi Lafer, Agabus balkei Fery & Nilsson, A. discolor Harris, Ilybius chishimanus Kôno, Rhantus suturellus (Harris), and Graphoderus perplexus Sharp. Altogether 38 species of Dytiscidae are now known from Kamchatka, and of these 22 have Holarctic distributions. Graphoderus perplexus is here reported for the Palearctic Region for the first time. Additional records are given for Sakhalin and the Kuril Islands. The following four species are here reported from Sakhalin for the first time: Hydroporus nigellus Mannerheim, Agabus kholini Nilsson, Ilybius angustior (Gyllenhal), and Acilius canaliculatus (Nicolai). The following ten species are here reported from the Kuril Islands for the first time: Hydroporus nigellus, H. notabilis, H. submuticus, H. tristis, Agabus clypealis (Thomson), A. confinis (Gyllenhal), A. costulatus (Motschulsky), A. discolor, Ilybius discedens Sharp, and Colymbetes dahuricus Aubé. Nine of the species were found in the North Kurils, whereas H. tristis was found in the South Kurils. With these additions, 39 species are now known from Sakhalin, and 36 from the Kuril Islands

    Predatory capacity of a shorefly, Ochthera chalybescens, on malaria vectors

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Since <it>Ochthera chalybescens </it>had been reported to prey on African malaria vectors, the predatory capacity of adults of this species on <it>Anopheles gambiae </it>sensu stricto was explored.</p> <p>Method</p> <p>Predatory capacity of this fly on <it>A. gambiae </it>s.s. was tested at all developmental stages, including the adult stage in the laboratory setting. Effects of water depth on its predatory capacity were also examined.</p> <p>Results</p> <p>This study revealed that <it>O. chalybescens </it>preyed on mosquitoes at all life stages except eggs. It was able to prey on an average of 9.8 to 18.8 mosquito larvae in 24 hrs. Mosquito larva size and water depth did not affect predatory capacity. However, the predacious fly preyed on significantly more 2<sup>nd</sup>-instar larvae than on pupae when larvae and pupae were both available.</p> <p>Conclusion</p> <p><it>Ochthera chalybescens </it>is, by all indications, an important predator of African malaria vectors.</p

    The diving beetles of the Kuril Archipelago in the Far East of Russia (Coleoptera: Dytiscidae).

    Get PDF
    Nach Literaturangaben sowie Untersuchungen von Museumsmaterial und Ausbeuten der in den letzten Jahren durchgeführten Expeditionen sind die Schwimmkäfer (Dytiscidae) auf den Kurilen im Nordwest-Pazifik mit 24 Arten vertreten. Über die 357 adulten und 50 larvalen Dytisciden, die während der gemeinsamen amerikanisch-japanisch-russischen Expedition 1994 und 1995 auf den südlichen und mittleren Kurilen gesammelt wurden, wird detailliert berichtet. Die folgenden fünf Arten werden erstmals für die Kurilen nachgewiesen: Hydroporus uenoi Nakane, Platambus pictipennis (Sharp), Agabus japonicus Sharp, Ilybius nakanei Nilsson, und Graphoderus zonatus (Hoppe). Die Zahl der auf den einzelnen Inseln festgestellten Arten lag zwischen 1 und 11; den höchsten Artenreichtum zeigen die größten Inseln auf beiden Seiten des Großen Kurilen-Kamms. Auf den südlichen Kurilen dominieren die ussurisch-japanischen Arten, die auch von Sakhalin und Hokkaido bekannt sind, während sich die Fauna der nördlichen Kurilen durch einen hohen Anteil holarktischer und paläarktischer Arten auszeichnet, die auch in Kamtschatka vorkommen.The species of predaceous diving beetles (Coleoptera, Dytiscidae) ocurring in the Kuril Archipelago in the northwest Pacific are reviewed. Based on literature records, the study of museum collections, and material from recent expeditions 24 species are known from the archipelago. A detailed report is given on the 357 adult and 50 larval specimens collected in the South and Mid Kuril Islands by the joint American-Japanese-Russian expeditions in 1994 and 1995. The following five species are here recorded from the Kurils for the first time: Hydroporus uenoi Nakane, Platambus pictipennis (Sharp), Agabus japonicus Sharp, Ilybius nakanei Nilsson, and Graphoderus zonatus (Hoppe). The number of species recorded on individual islands ranged from 1 to 11, with the largest islands at either end of the Greater Kuril Ridge being the most diverse. The South Kurils are dominated by Ussurian-Japanese species known also from Sakhalin and Hokkaido, whereas the North Kuril fauna includes a high proportion of Holarctic or Palearctic species known also from Kamchatka

    Unforeseen misuses of bed nets in fishing villages along Lake Victoria

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>To combat malaria, the Kenya Ministry of Health and nongovernmental organizations (NGOs) have distributed insecticide-treated nets (ITNs) for use over beds, with coverage for children under five years of age increasing rapidly. Nevertheless, residents of fishing villages have started to use these bed nets for drying fish and fishing in Lake Victoria. This study investigated the extent of bed net misuse in fishing villages.</p> <p>Methods</p> <p>Seven fishing villages along the lake were surveyed to estimate how widely bed nets were being used for fishing and drying fish. Villagers were asked why they used the bed nets for such purposes.</p> <p>Results</p> <p>In total, 283 bed nets were being used for drying fish. Of these, 239 were long-lasting insecticidal bed nets (LLIN) and 44 were non-long-lasting insecticidal bed nets (NLLIN). Further, 72 of the 283 bed nets were also being used for fishing. The most popular reasons were because the bed nets were inexpensive or free and because fish dried faster on the nets. LLINs were preferred to NLLINs for fishing and drying fish.</p> <p>Conclusion</p> <p>There is considerable misuse of bed nets for drying fish and fishing. Many villagers are not yet fully convinced of the effectiveness of LLINs for malaria prevention. Such misuses may hamper the efforts of NGOs and governmental health organizations.</p

    Malaria Vectors in Lake Victoria and Adjacent Habitats in Western Kenya

    Get PDF
    The prevalence of malaria among the residents of the Lake Victoria basin remains high. The environment associated with the lake may maintain a high number of malaria vectors. Lake habitats including water hyacinths have been suspected to be the source of vectors. This study investigated whether malaria vectors breed in the lake habitats and adjacent backwater pools. Anopheline larvae were collected within the littoral zone of the lake and adjacent pools located along approximately 24.3 km of the lakeshore in western Kenya, and their breeding sites characterized. Three primary vector species, Anopheles arabiensis, Anopheles gambiae s.s. and Anopheles funestus s.s., and three potential vectors, were found in the lake habitats. Unexpectedly, An. arabiensis was the most dominant vector species in the lake sampling sites. Its habitats were uncovered or covered with short grass. A potential secondary malaria vector, Anopheles rivulorum, dominated the water hyacinths in the lake. Most breeding sites in the lake were limited to areas that were surrounded by tall emergent plants, including trees, and those not exposed to waves. Nearly half of adjacent habitats were lagoons that were separated from the lake by sand bars. Lagoons contained a variety of microhabitats. Anopheles arabiensis dominated open habitats, whereas An. funestus s.s. was found mainly in vegetated habitats in lagoons. The current study confirmed that several breeding sites are associated with Lake Victoria. Given that Lake Victoria is the second largest lake in the world, the lake related habitats must be extensive; therefore, making targeted vector control difficult. Further exploration is necessary to estimate the effects of lake associated habitats on malaria transmission so as to inform a rational decision-making process for vector control

    Topography-derived wetness indices are associated with household-level malaria risk in two communities in the western Kenyan highlands

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Transmission of <it>Plasmodium falciparum </it>generally decreases with increasing elevation, in part because lower temperature slows the development of both parasites and mosquitoes. However, other aspects of the terrain, such as the shape of the land, may affect habitat suitability for <it>Anopheles </it>breeding and thus risk of malaria transmission. Understanding these local topographic effects may permit prediction of regions at high risk of malaria within the highlands at small spatial scales.</p> <p>Methods</p> <p>Hydrologic modelling techniques were adapted to predict the flow of water across the landscape surrounding households in two communities in the western Kenyan highlands. These surface analyses were used to generate indices describing predicted water accumulation in regions surrounding the study area. Households with and without malaria were compared for their proximity to regions of high and low predicted wetness. Predicted wetness and elevation variables were entered into bivariate and multivariate regression models to examine whether significant associations with malaria were observable at small spatial scales.</p> <p>Results</p> <p>On average, malaria case households (n = 423) were located 280 m closer to regions with very high wetness indices than non-malaria "control" households (n = 895) (t = 10.35, p < 0.0001). Distance to high wetness indices remained an independent predictor of risk after controlling for household elevation in multivariate regression (OR = 0.93 [95% confidence interval = 0.89–0.96] for a 100 m increase in distance). For every 10 m increase in household elevation, there was a 12% decrease in the odds of the house having a malaria case (OR = 0.88 [0.85–0.90]). However, after controlling for distance to regions of high predicted wetness and the community in which the house was located, this reduction in malaria risk was not statistically significant (OR = 0.98 [0.94–1.03]).</p> <p>Conclusion</p> <p>Proximity to terrain with high predicted water accumulation was significantly and consistently associated with increased household-level malaria incidence, even at small spatial scales with little variation in elevation variables. These results suggest that high wetness indices are not merely proxies for valley bottoms, and hydrologic flow models may prove valuable for predicting areas of high malaria risk in highland regions. Application in areas where malaria surveillance is limited could identify households at higher risk and help focus interventions.</p
    corecore