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A comparison of sea lice, Caligus rogercresseyi, fecundity in four areas in southern Chile.

A survey was carried out between March 2006 and February 2007 on the fecundity of Caligus rogercresseyi in four areas of Region X (Lat 42 degrees S) in Chile. An average length of 4.83 +/- 0.4 mm for gravid females and 4.78 +/- 0.56 mm for males was recorded from the four areas, with no significant differences in length between sexes. Although females were largest in spring and summer, egg strings were longer and there were higher number of eggs per string in winter. The lowest salinity values were recorded in the Hornopirén area, which had the largest gravid females and the highest number of

Population variables and life-history characteristics of the alligator pipefish Syngnathoides biaculeatus, in Papua New Guinea.

Population structure and life-history variables of the widely distributed alligator pipefish Syngnathoides biaculeatus were characterized in Bootless Bay, Papua New Guinea over the course of 11 months. There was little evidence of seasonality with four focal populations showing no significant change in abundance. Similarly, the sex ratio remained 1:1 for all but 1 month. Reproductive males carrying eggs (148-278 mm in total length, L(T)) were found in all months. Brood size was significantly, positively related to male L(T) for newly laid broods only. Maximum observed brood size was 351 and me

The science and management of the North Sea and the Baltic Sea: natural history, present threats and future challenges.

The review provides an overview of the features of the North Sea and the Baltic Sea in their European geographical and socio-political context. To reach sustainability in the wider sense the common society has to meet the 7 tenets - that management actions have to be environmentally sustainable, economically viable, technologically feasible, socially desirable (or at least tolerable), legally permissible, administratively achievable and politically expedient. Each of these are explained and discussed using examples from the two seas including pollution control, physical resource exploitation (

Экологические связи между риском и распространением вируса Западного Нила в Соединенных Штатах.

Вирус Западного Нила, недавно введённый в Северную Америку, является патогеном, передаваемым через комары, который заражает широкий круг носителей позвоночных, включая людей. Некоторые виды птиц, как представляется, являются первичными водохранилищами, в то время как другие виды птиц, а также другие виды позвоночных могут быть заражены, но являются менее компетентными водохранилищами. Одна гипотеза относительно динамики передачи вируса Западного Нила говорит о том, что высокое разнообразие птиц уменьшает передачу вируса Западного Нила, поскольку комарные мики распространяются среди широкого кр

Совпадение в аннотации оригинала
West Nile virus, which was recently introduced to North America, is a mosquito-borne pathogen that infects a wide range of vertebrate hosts, … us transmission will be reduced when either: (1) abundance of mosquito vectors is low; or (2) human population density is low. We assessed these hypotheses at two spatial scales: a regional scale near Saint Louis, MO, and a national scale (continental USA). We found that prevalence of West Nile virus infection in mosquito vectors and in humans increased with decreas …

Effects of distance moved during loading and floor space on the trailer during transport on losses of market weight pigs on arrival at the packing plant.

Effects of distance moved during loading and floor space on the trailer during transport on the incidence of transport losses (dead and nonambulatory pigs) on arrival at the packing plant were evaluated in a study involving 42 loads of pigs (average BW = 131.2 kg, SD 5.05). A split-plot design was used with a 2 x 6 factorial arrangement of the following treatments: 1) distance moved from the pen to the exit of the building [short (0 to 30.5 m) vs. long (61.0 to 91.4 m)] and 2) transport floor space (0.396, 0.415, 0.437, 0.462, 0.489, or 0.520 m(2)/pig). Loading distance treatments (sub-plots)

[Onchocerciasis in the area of Lastourville, Gabon. Clinical and entomological aspects].

The African Programme for Onchocerciasis Control (APOC) has implemented a series of surveys aimed at evaluating the long-term impact of its activities. The region of Lastourville (Gabon) is one of the selected sites for this study. A total of 886 persons was examined for skin lesions, and 459 out of them participated in detailed ocular examinations. Blackflies were collected during one year and dissected. Although the focus was found to be hypoendemic (prevalence of nodules: 7.7%), the frequency of onchodermatitis was relatively high. The lesions of the anterior segment of the eye were rare, b

Density-dependent host choice by disease vectors: epidemiological implications of the ideal free distribution.

The proportion of vector blood meals taken on humans (the human blood index, h) appears as a squared term in classical expressions of the basic reproduction ratio (R(0)) for vector-borne infections. Consequently, R(0) varies non-linearly with h. Estimates of h, however, constitute mere snapshots of a parameter that is predicted, from evolutionary theory, to vary with vector and host abundance. We test this prediction using a population dynamics model of river blindness assuming that, before initiation of vector control or chemotherapy, recorded measures of vector density and human infection ac

Spatio-temporal analyses of West Nile virus transmission in Culex mosquitoes in northern Illinois, USA, 2004.

After a severe outbreak of West Nile virus (WNV) in Cook County, Illinois, in 2002, detections of WNV in mosquitoes were frequent across the state in the following years despite small numbers of human cases. We conducted a spatio-temporal analysis of Culex (subgenus Culex) mosquitoes collected in 2004 in three mosquito abatement districts (MAD) in Cook County by calculating monthly estimates of mosquito density, prevalence of infected mosquitoes, and exposure intensity, which in turn is a product of mosquito density and infection rates. Mosquito infections were detected early at three sites in

A comparison of continuous and discrete-time West Nile virus models.

The first recorded North American epidemic of West Nile virus was detected in New York state in 1999, and since then the virus has spread and become established in much of North America. Mathematical models for this vector-transmitted disease with cross-infection between mosquitoes and birds have recently been formulated with the aim of predicting disease dynamics and evaluating possible control methods. We consider discrete and continuous time versions of the West Nile virus models proposed by Wonham et al. [Proc. R. Soc. Lond. B 271:501-507, 2004] and by Thomas and Urena [Math. Comput. Model

Life table study of Sitotroga cerealella (Lepidoptera: Gelichiidae), a strain from West Africa.

Life table studies for the Angoumois grain moth, Sitotroga cerealella (Olivier), a pest on stored maize, Zea mays L., in West Africa, were conducted as part of the expansion of a mathematical simulation model that has been developed for two pests of stored maize. The effects of four temperatures (20, 25, 30, and 35 degrees C) and two relative humidity levels (44 and 80%) on developmental time, age-specific survivorship and fecundity, sex ratio, and intrinsic rate of natural increase (r(m)) of S. cerealella were investigated. Sex ratio was close to 1:1 at all temperatures and humidity. Minimum

Crowding and winter emergency feeding as predisposing factors for kerato-conjunctivitis in semi-domesticated reindeer in Norway.

Due to the hard environmental and climatic situation in late winter 1999, a herd of about 200 free-ranging, semi-domesticated reindeer was gathered in a paddock in northern Norway for emergency feeding. About the same number of reindeer was not corralled but supplementary fed on their winter pastures. The fodder was of relatively good quality but very dusty and fed in a very dry environment. Six weeks later, an outbreak of eye-infection was diagnosed in one third of the corralled reindeer; mild symptoms were observed in most of them, but 11 animals showed severe signs of disease. No signs of d

Freshwater snails and Schistosomiasis mansoni in the state of Rio de Janeiro, Brazil: III--Baixadas Mesoregion.

In this paper, the third of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Mesoregion Baixadas from 2000 to 2002 are presented. Twenty-two species, belonging to seven families, were found. As to the snail intermediate hosts of Schistosoma mansoni, the most frequent species was Biomphalaria tenagophila besides some new findings of Biomphalaria straminea. No specimens were found harboring larval forms of S. mansoni although different kinds of cercariae had been observed.

Seasonal studies on commensal rats and their ectoparasites in a rural area of Egypt: the relationship of ectoparasites to the species, locality, and relative abundance of the host.

The present study was carried out in 3 villages, namely Kafr Ayoub Soliman, Kafr Ibrahim El-Aidi, and El-Sa'adat, Sharqiya Governorate, Egypt. A total of 519 rats was collected from the 3 study sites: 46.6% Rattus rattus, and 53.4% Rattus norvegicus. A total of 20,643 ectoparasites was recovered from R. rattus: 33.3% mites, 33.8% fleas, and 32.9% lice. From R. norvegicus a total of 40,997 ectoparasites was recovered: 28.9% mites, 31% fleas, and 40.1% lice. Three common mite species were recovered from both rat hosts, i.e., Ornithonyssus bacoti, Radfordia ensifera, and Laelaps nuttalli. Three c

Japanese encephalitis in south Arcot district, Tamil Nadu, India: a three-year longitudinal study of vector abundance and infection frequency.

In the South Arcot district, an area endemic for Japanese encephalitis in Tamil Nadu, Culex tritaeniorhynchus Giles, Culex vishnui Theobald, Culex gelidus Theobald and Culex fuscocephala Theobald constituted 93.6% of 422,621 adult females representing 27 culicine species collected between August 1991 and July 1994. Vector abundance was lowest in the hot and dry season (April-June) and highest in the cool and wet season (October-December). Overall, 285,531 adult female mosquitoes (5,710 pools) were tested for virus using an enzyme-linked immunosorbent assay or by inoculation into larvae of Toxo

[The prediction of the activity of anthrax foci in Voronezh Province].

During the period of 1959-1985 the activity of the foci of anthrax in Voronezh Province was found to be related to the state of some meteorological factors in the previous year and the number of murine [correction of myomorphous] rodents in hayricks and stacks of straw in early spring of the current year, this relationship being stable and statistically significant. Multiple regression equations permitting the annual quantitative prognostication of the intensity of the epizootic and epidemic situations were worked out.

Host-feeding patterns and behaviour of 4 Culex species in an endemic area of Japanese encephalitis.

Studies were made on the host-feeding patterns and behaviour of 4 Culex species in China (Province of Taiwan) to further assess their importance as vectors of Japanese encephalitis. A relatively unbiased, non-attractant technique (vacuum sweep-net) was used for collecting mosquitos resting outdoors on rural premises; blood meals from engorged specimens were identified by precipitin tests. Additional information was obtained by analysing data from related studies. Precipitin-test results indicated that C. annulus, C. tritaeniorhynchus, and C. fuscocephalus feed principally on mammals, the first

[Density-specific distribution of erythrocytes in different types of anemia].

AIM: To study density-specific distribution of erythrocytes (DSDE) in different types of anemia. MATERIAL AND METHODS: DSDE was determined in anemic patients by fractionation of the whole blood in hematocritic capillaries in the presence of mixtures of dimethyl- and dibutylphthalates with known density. RESULTS: Parameters are proposed which characterize DSDE changes typical for each type of anemia: mean erythrocyte density (MED)--mean density of total erythrocytic population; DSDE width (W)--a characteristic of erythrocytic population heterogeneity; light fraction of erythrocytes (LEF)--% o

Advances in the diagnosis and treatment of osteoporosis.

Although severely low bone density is relatively rare in the pediatric population, it can be a significant problem in many patients with chronic illness. As peak bone formation occurs during adolescence, it is crucial that pediatricians and other care providers for this patient population recognize the significance of attainment of adequate bone. Dietary intake of vitamin D and calcium should be optimized, and correction of underlying causes of poor bone density should occur whenever possible. Assessment of bone density is difficult, as each technology available has problems, and none of the t