bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tidal‐channel deposits on a delta plain from the Upper Miocene Nauta Formation, Marañón Foreland Sub‐basin, Peru
Authors: REBATA‐H. LUISA A. , GINGRAS MURRAY K. , RÄSÄNEN MATTI E. , BARBERI MAIRA 
Published: July 2006

AbstractMiocene siliciclastic sediments of the Marañón Foreland Sub‐basin in Peru record the sedimentary response to regional marine incursions into Amazonia. Contrary to previous interpretations, the Late Miocene Nauta Formation provides evidence of the last known marine incursion before the current Amazonia river basin became established. Sedimentological, ichnological and palynological data from well‐exposed outcrops along a ca 100 km road transect suggest that the Nauta Formation represents a shallow, marginal‐marine channel complex dominated by tidal channels developed in the inactive, brackish‐water portions of a delta plain. The main facies associations are: FA1 – slightly bioturbated mud‐draped trough cross‐stratified sand; FA2 – locally, pervasively bioturbated inclined heterolithic stratification (IHS); and FA3 – moderately bioturbated horizontally bedded sand–mud couplets. These identify subtidal compound dunes, tidal point bars and shallow subtidal to intertidal flats, respectively. Bi‐seasonal depositional cycles are ascribed to the abundant metre‐ to decimetre‐scale sand–mud couplets that are found mainly in the IHS association: semi‐monthly to daily tidal rhythmicity is inferred from centimetre‐ and millimetre‐scale couplets in the mud‐dominated parts of the decimetre‐scale couplets. The ichnology of the deposits is consistent with brackish depositional conditions; the presence of Laminites, a variant of Scolicia, attests to episodic normal marine conditions. Trace fossil suites are assigned to the Skolithos, Cruziana and mixed Skolithos–Cruziana ichnofacies. Pollen assemblages related to mangrove environments (e.g. Retitricolporites sp., Zonocostites sp., Psilatricolporites maculosus, Retitricolpites simplex) support a brackish‐water setting. Uplift of the Mérida Andes to the North and the consequent closure of the Proto‐Caribbean connection, and the onset of the transcontinental Amazon drainage, constrain the deposition of the Nauta sediments with around 10 to 8 Ma, probably contemporaneous to similar marine incursions identified in the Cuenca (Ecuador), Acre (Brazil) and Madre de Dios (Southern Peru) (sub)basins, and along the Chaco‐Paranan corridor across Bolivia, Paraguay and Argentina.
Mapping malaria transmission in West and Central Africa
Authors: Gemperli Armin , Sogoba Nafomon , Fondjo Etienne , Mabaso Musawenkosi , Bagayoko Magaran , Briët Olivier J. T. , Anderegg Dan , Liebe Jens , Smith Tom , Vounatsou Penelope 
Published: July 2006

SummaryWe have produced maps of Plasmodium falciparum malaria transmission in West and Central Africa using the Mapping Malaria Risk in Africa (MARA) database comprising all malaria prevalence surveys in these regions that could be geolocated. The 1846 malaria surveys analysed were carried out during different seasons, and were reported using different age groupings of the human population. To allow comparison between these, we used the Garki malaria transmission model to convert the malaria prevalence data at each of the 976 locations sampled to a single estimate of transmission intensity E, making use of a seasonality model based on Normalized Difference Vegetation Index (NDVI), temperature and rainfall data. We fitted a Bayesian geostatistical model to E using further environmental covariates and applied Bayesian kriging to obtain smooth maps of E and hence of age‐specific prevalence. The product is the first detailed empirical map of variations in malaria transmission intensity that includes Central Africa. It has been validated by expert opinion and in general confirms known patterns of malaria transmission, providing a baseline against which interventions such as insecticide‐treated nets programmes and trends in drug resistance can be evaluated. There is considerable geographical variation in the precision of the model estimates and, in some parts of West Africa, the predictions differ substantially from those of other risk maps. The consequent uncertainties indicate zones where further survey data are needed most urgently. Malaria risk maps based on compilations of heterogeneous survey data are highly sensitive to the analytical methodology.Keywords  entomological inoculation ratekrigingmalariaMarkov chain Monte Carloparasite prevalencevectorial capacity
Feasibility and acceptability of the use of artemether‐lumefantrine in the home management of uncomplicated malaria in children 6–59 months old in Ghana
Authors: Chinbuah Amanua M. , Gyapong John O. , Pagnoni Franco , Wellington Edith K. , Gyapong Margaret 
Published: July 2006

SummaryObjective  We assessed the feasibility and acceptability of and the willingness to use artemether‐lumefantrine (Coartem) during early, appropriate treatment of malaria/fever in children aged 6–59 months at the community and household level in a rural malaria‐endemic area in Ghana.Method  In this descriptive study with a pre‐ post‐evaluation of an intervention, community perceptions of fever, health‐seeking behaviour and current treatment practices for children aged 6–59 months were ascertained through qualitative research and surveys. The children were counted in a household census and given identification cards. Community‐based agents (who were supervised monthly) dispensed a 6‐dose‐treatment formulation of Coartem over a 4 months period and counseled caregivers on case management and referral. Caregivers who consulted were followed up after 4 days to determine adherence to the treatment regimen. Blister packs of the drugs were inspected where available. The performance of the agents in terms of counselling, advising on referral and reporting was evaluated. Community satisfaction was also assessed qualitatively through focus group discussions and interviews.Results  Three hundred and sixty‐three children sought care during the intervention period. All 235 children aged 6–35 months were correctly provided the one tablet per dose per treatment package compared with 119 of 125 children 36–59 months (95.2%). Only 5 of 17 children were referred appropriately. All 334 caregivers followed the correct drug administration schedule, i.e. twice a day for 3 days. Validation of drugs received indicates that all 204 children aged 6–35 months and 103/118 (87.3%) children aged 36–59 months received the correct drug dose. Adherence of agents and caregivers to the treatment was 308/334 (92.5%). Delay in seeking care was reduced from 3 to 2 days. No serious adverse drug reactions were reported. Community members were enthusiastic about the performance of the agents.Conclusion  A Home Management of Malaria (HMM) strategy with Coartem using trained community‐based agents supervised monthly is feasible, acceptable, and can achieve high levels of compliance within Dangme, West District of Ghana. However, if the intervention is to be sustainable, the agents need to be paid.
Chromosomal variation and genome size support existence of cryptic species of Triatoma dimidiata with different epidemiological importance as Chagas disease vectors
Authors: Panzera F. , Ferrandis I. , Ramsey J. , Ordòñez R. , Salazar‐Schettino P. M. , Cabrera M. , Monroy M. C. , Bargues M. D. , Mas‐Coma S. , O'Connor J. E. , Angulo V. M. , Jaramillo N. , Cordón‐Rosales C. , Gómez D. , Pérez R. 
Published: July 2006

SummaryThe wide geographical distribution of Triatoma dimidiata, one of the three major vectors of Chagas disease, ranges from Mexico to northern Peru. Since this species occupies a great diversity of artificial and natural ecotopes, its eradication is extremely difficult. In order to assist control efforts, we used chromosome analyses and DNA amount as taxonomic markers to study genetic variability in populations of T. dimidiata from Mexico, Guatemala, El Salvador and Colombia. We differentiated three groups or cytotypes defined by characteristic chromosome C‐banding patterns and genome size measured by flow cytometry. The three cytotypes are restricted to different geographic locations. Cytotype 1 occurs in Mexico (excluding Yucatán), Guatemala (excluding Petén), El Salvador and Colombia. Cytotype 2 occurs in Yucatán and cytotype 3 occurs in Petén. Cytotype 1, commonly associated with domestic and peridomestic environments but also inhabiting sylvatic ecotopes, is the most widespread and with major epidemiological significance. In contrast, the Yucatán cytotype inhabits wild ecotopes but increasingly enters houses, while the Petén cytotype appears exclusively sylvatic. We suggest that these cytotypes represent cryptic species of T. dimidiata with different epidemiological relevance as Chagas disease vectors. Poor ability to colonize human dwellings, together with their restricted geographic distribution, indicate that the Yucatán and Petén putative species probably have much less epidemiological significance than cytotype 1. Thus, the genetic markers we describe are powerful tools to differentiate cryptic species in T. dimidiata with different epidemiological significance, contributing to planning the most effective control measures.
Review: Intermittent preventive treatment – a new approach to the prevention of malaria in children in areas with seasonal malaria transmission
Authors: Greenwood Brian 
Published: July 2006

SummaryIntermittent preventive treatment, the administration of a full course of an anti‐malarial treatment to a population at risk at specified time points regardless of whether or not they are known to be infected, is now a recommended approach to the prevention of malaria in pregnancy and is being explored as a potential way of preventing malaria in infants. However, in many malaria endemic areas, the main burden of malaria is in older children and increasing use of insecticide treated bednets is likely to increase further the proportion of episodes of malaria that occur in older children. Recently, it has been shown in Senegal and in Mali that intermittent preventive treatment given to older children during the malaria transmission season can be remarkably effective in preventing malaria. This approach to malaria control is likely to be most effective in areas with a high level of malaria transmission concentrated in a short period of the year. However, several issues need to be addressed before intermittent preventive treatment in children can be advocated for use in malaria control programmes. These include: (1) determination of whether intermittent preventive treatment adds to the protection afforded by other control measures such as insecticide‐treated bednets; (2) whether an effective and sustainable delivery system can be found; (3) choice of drug to be used; (4) optimum timing of drug administration; (5) the requisite interval between treatments. The potential benefits of intermittent preventive treatment in children are substantial; more research is needed to determine if this is a practical approach to malaria control.
Economic costs of endemic non‐filarial elephantiasis in Wolaita Zone, Ethiopia
Authors: Tekola Fasil , Mariam Damen H. , Davey Gail 
Published: July 2006

SummaryBackground Endemic non‐filarial elephantiasis or podoconiosis is a chronic and debilitating geochemical disease occurring in individuals exposed to red clay soil derived from alkalic volcanic rock. It is a major public health problem in countries in tropical Africa, Central America and North India.Objective To estimate the direct and the average productivity cost attributable to podoconiosis, and to compare the average productivity time of podoconiosis patients with non‐patients.Methods Matched comparative cross sectional survey involving 702 study subjects (patients and non‐patients) supplemented by interviews with key informants in Wolaita Zone, southern Ethiopia.Results Total direct costs of podoconiosis amounted to the equivalent of US$ 143 per patient per year. The total productivity loss for a patient amounted to 45% of the total working days per year, causing a monetary loss equivalent to US$ 63. In Wolaita zone, the overall cost of podoconiosis exceeds US$ 16 million per year.Conclusions Podoconiosis has enormous economic impact in affected areas. Simple preventive measures (such as use of robust footwear) must be promoted by health policy makers.
Socio‐cultural determinants of treatment delay for childhood malaria in southern Ghana
Authors: Ahorlu Collins K. , Koram Kwadwo A. , Ahorlu Cynthia , De Savigny Don , Weiss Mitchell G. 
Published: July 2006

SummaryWe studied socio‐cultural determinants of timely appropriate treatment seeking for children under 5 years suspected of having a perceived malaria‐related illness. Caretakers of children with suspected malaria were interviewed about illness‐related experiences, meanings and behaviour in two endemic villages in southern Ghana. Only 11% of children suspected of having a perceived malaria‐related illness received timely appropriate treatment consistent with the Abuja target of treating malaria within 24 h of illness onset; 33% of children received appropriate treatment within 48 h. Reported perceived causes of phlegm predicted timely, appropriate treatment within 24 h of illness onset (P = 0.04) in a multivariate logistic regression model; playing on the ground (P < 0.01) predicted such treatment within 48 h. Two categories of distress, paleness or shortage of blood (P = 0.05) and sweating profusely (P = 0.03), also predicted timely, appropriate treatment within 24 h in a multivariate logistic regression model. Knowing that mosquitoes transmit malaria was not associated with timely, appropriate help seeking for the children, even though such knowledge may promote personal protective measures, especially use of bednets. Patterns of distress and PC were related to timely, appropriate help seeking, but not as expected. Effects on health seeking of illness‐related experience and meaning are complex, and explaining their role may strengthen interventions for childhood malaria.
Cytogenetic and PCR‐based identification of S. damnosum‘Nkusi J’ as the anthropophilic blackfly in the Uluguru onchocerciasis focus in Tanzania
Authors: Krueger A. , Kalinga A. K. , Kibweja A. M. , Mwaikonyole A. , Maegga B. T. A. 
Published: July 2006

SummaryA combined molecular and cytogenetic analysis was used to identify the local blackfly vectors of onchocerciasis in the Uluguru Mts. focus, Morogoro region, central Tanzania. Cytotaxonomic identification revealed the occurrence of three cytospecies of the Simulium damnosum complex, along altitudinal gradients. The cytoform ‘Nkusi’ was found breeding at low to mid‐altitudes (100–500 m), while S. kilibanum was found at mid‐ and high altitudes (300–1260 m), being sympatric with ‘Sebwe’ only in the highlands. The analyses further revealed the cytoform ‘Nkusi’ from the nearby Kilosa focus. Simulium kilibanum and ‘Nkusi’ are potential vectors of onchocerciasis, while the ‘Sebwe’ form is considered non‐anthropophilic and therefore not a vector. By means of molecular typing of wild‐caught females, ‘Nkusi’ was incriminated as the man‐biting fly at all catching sites, and consequently, is the assumed vector of onchocerciasis over the full altitude range. In the high altitude zones, however, S. neavei group species may act as secondary vectors at the edge of the forest reserve, if transmission actually occurs there at all. Our results also suggest that vector control could be feasible because of the vector species breeding in the foothills below 500 m in relatively accessible open country.
Cost‐description of a pilot parenteral vaccination campaign against rabies in dogs in N'Djaména, Chad
Authors: Kayali U. , Mindekem R. , Hutton G. , Ndoutamia A. G. , Zinsstag J. 
Published: July 2006

SummaryIn the discussion about policies and strategies for rabies prevention in developing countries, intervention costs arise as a major issue. In a pilot mass vaccination campaign against rabies in N'Djaména, Chad, 3000 dogs were vaccinated. We assessed vaccination coverage and cost, showing the cost per dog vaccinated for the public sector and for society. An extrapolation to city level calculated the approximate cost of vaccinating all 23 600 dogs in N'Djaména. In the pilot mass campaign with 3000 dogs the average cost per dog was 1.69 €. to the public and the full societal cost was 2.45 €. If all 23 600 dogs in N'Djaména were vaccinated, the average cost would fall to 1.16 € to the public and 1.93 € to society. Private sector costs account for 31% of the cost to vaccinate 3000 dogs, and 40% of the cost to vaccinate 23 600 dogs. Mass dog vaccination could be a comparatively cheap and ethical way to both control the disease in animals and prevent human cases and exposure, especially in developing countries. The cost‐effectiveness of dog vaccination compared with treating victims of dog bites for prevention of human rabies should be further assessed and documented.
Equine cutaneous fungal granuloma: a study of 44 lesions from 34 horses
Authors: Valentine Beth A. , Taylor George H. , Stone Jeffrey K. , Halse Richard R. 
Published: July 2006

AbstractForty‐four nodular and noninvasive cutaneous fungal granulomas were identified in 34 horses over a 14.5‐year period. Cutaneous fungal granulomas were most common in young horses (mean age 6.1 ± 4.2 years; range 1–19 years). There was no apparent breed or sex bias. Granulomas were either single or multiple, and most often occurred in the skin of the head and neck. The characteristic histological finding was a nodular dermal mass with a mean diameter of 7.3 mm (range 2.5–20 mm) and an intact overlying epithelium. Lesions most often exhibited intense lymphocytic inflammation, with admixed pyogranulomatous inflammation associated with a small to moderate number of fungal elements. Causative fungi were both pigmented and nonpigmented organisms of variable morphology. Penetrating plant material was identified in three cases. Granulomas caused by nonpigmented fungi were most common in horses from wet regions. Both pigmented and nonpigmented fungi were found in granulomas from horses in dry regions. Cutaneous fungal granulomas occurred in February through November, with peaks in April and July. No correlation of yearly incidence with annual average temperature or rainfall was detected. This study confirms that equine cutaneous fungal granuloma is relatively common in horses in the Pacific Northwest. Morphology of causative fungi was variable, but the signalment, history, and clinical and overall histological features were very similar. Surgical excision was curative.
Mechanical and cultural strategies to control Cirsium arvense in organic arable cropping systems
Authors: GRAGLIA E , MELANDER B , JENSEN R K 
Published: July 2006

SummaryInfestation with Cirsium arvense in organic cropping is an increasing problem in many parts of Europe. Non‐chemical management strategies against C. arvense, based on cultivation tactics and/or different cutting regimes, have received very little attention for many years. This study presents results from four experiments, undertaken under organic growing conditions, on the effects of repeated mowing or hoeing during the first part of the growing season, used in combination with competition from a suppressive crop (grass/white clover mixture or red clover). The strategies were mainly aimed at diminishing the regenerative capacity of C. arvense and the effects were thus measured in the subsequent year in spring barley crops, in the absence of any weed control. In general, number of passes of mowing and hoeing linearly reduced the amount of aboveground C. arvense biomass in the subsequent year. Increased competition induced by the competitive crops further reduced C. arvense biomass. Differences in barley yield were explained by the amount of C. arvense biomass only in one experiment, where this weed was most abundant. Our results suggest that an acceptable level of C. arvense control can be achieved through an intensive hoeing or mowing campaign, within one growing season only. This may lead to increased crop yield in the subsequent year.
Investigation of wheat as a trap crop for control of Orobanche minor
Authors: LINS R D , COLQUHOUN J B , MALLORY‐SMITH C A 
Published: July 2006

Summary Orobanche minor is a parasitic weed that attaches to the roots of red clover (Trifolium pratense) and a number of other broad‐leaved plant species in the Pacific Northwest USA. Orobanche minor seed must be stimulated by host plant exudates for germination and attachment to occur. However, plant species called false‐hosts can stimulate parasitic seed germination without attachment. These species could be utilized as trap crops to reduce the amount of parasitic seed in infested soil. Wheat (Triticum aestivum), was found to be a false‐host of O. minor; therefore, growth chamber, glasshouse and field soil experiments were conducted to evaluate the effect of six soft white winter wheats (T. aestivum), one durum wheat (Triticum turgidum), and one triticale (Triticale hexaploide) on O. minor germination. In growth chamber experiments, wheat and triticale induced 20–70% of O. minor seeds to germinate. In glasshouse studies, O. minor attachment was minimal on red clover plants grown in pots previously planted to wheat or triticale. In pots that did not receive a false‐host treatment, red clover plants averaged 4.2 O. minor attachments per plant. Red clover plants also had fewer O. minor attachments when grown in field soil taken from the plots where wheat or triticale were grown compared with plants grown in soil where no wheat or triticale were previously grown. Our results demonstrate that wheat may have the potential to be effectively integrated into an O. minor management system.
The effects of natural and manipulated density regimes on Alliaria petiolata survival, growth and reproduction
Authors: REBEK K A , O'NEIL R J 
Published: July 2006

SummaryKnowledge of the ecology of Alliaria petiolata, an alien invasive species in the USA, is essential to predict the efficacy of introduced biological control agents. Accordingly, we examined the growth and reproduction of second‐year A. petiolata rosettes under natural and manipulated density regimes. Plant survival was also studied under natural conditions. Similar survivorship patterns were observed for high‐ and low‐density populations, although survival in the low‐density populations was c. 10% higher. Under natural conditions, low‐density plants were larger and more fecund, on average, than high‐density plants; however, on a per‐area basis, high‐density populations were much more productive. When plant density was experimentally reduced, average seed production and plant size increased with thinning intensity, suggesting that thinning released plants from intra‐specific competition. Additionally, plants in thinned plots were able to recover from past competition and could approach production of the plants in un‐thinned lower density plots that had not experienced prior competition. However, seed production per unit area was lower in thinned versus un‐thinned plots of the same initial density. Results suggest herbivore‐induced plant mortality late in the life cycle, as might occur following the introduction of biological control agents, may reduce the contribution to the A. petiolata seedbank.