Distribution Of Worms Research Articles

Computer Viruses, Attacks, and Security Methods

with the fast growth of the Internet, computer threats and viruses have become a very serious issue for us, which attract public attention. Therefore, the distribution of computer viruses and worms were discussed in this study. This paper focuses on the effects of computer viruses. The main area of this paperis a brief discussion on computer viruses and security or detection methods. This study is very useful and helpful for computer users to use the different methods, possible steps to protect their system and information from any kind of possible attacks on their system.

The Distribution of Goat Gastrointestinal Tractus Worm Egg at Rambon District of Nganjuk Regency

This study aims to determine the distribution of worm tract infection in foat digestion in Sub-district of Prambon, Nganjuk Regency. This research was conducted in Agustus 2018-Januari 2019 with 108 samples of stool examination iin laboratory of Helmintologi Airlangga University Department of Parasitology, were examinated by native, sedimentation. Floatation techniques, and distribution of worm types of feces. The results showed that 66 samples were positive infected by gastrointestinal worm, its indicated that helminthiasis was 61,11%. On examination it was found some kind of worm eggs, which are: Oesophagustomum spp., Bunostomum spp., Haemonchus spp., Trichostrongylus spp., Strongyloides spp., Trichuris spp., Chabertia spp and Moniezia benedini. The results of study showed the most of worm distribution in feces is Haemonchus spp.

Chaetopterus antarcticus (Polychaeta: Chaetopteridae) in Argentinian shelf scallop beds: from infaunal to epifaunal life habits

ABSTRACT. Introduction: The shelf-break frontal area in the Argentine Sea, between 37º S and 40º S, is characterized by high frequency and abundance of the parchment worm Chaetopterus antarcticus Kinberg, 1866 associated to Zygochlamys patagonica scallop beds. This polychaete was usually collected within its U tubes, typical of infaunal habit. During 2007, a surprising massive settlement of worms on scallops was observed. Objective: Our objectives is to report the variability of life habits of C. antarcticus in scallop grounds distributed between 37º S and 40º S in Argentinean waters. Methods: The presence of the parchment tube worms on Z. patagonica was analyzed in 892 scallops coming from three samples collected in September (previously obtained for other purposes) and November 2007 and April 2008, between 99-106 m depth in Management Unit B (16.186 km2, 38º S - 39º 52’ S). Polychaetes were identified and quantified on both valves. In addition, both epibiont and infaunal worms were registered through time. The settlement of C. antarcticus on scallops was monitored during the period 2007-2015 and the presence of free tubes, both empty and inhabited by worms, were registered during the period 2008-2015 from a total of 374 representative subsamples (10 l) collected with trawling tools between 37º S and 40º S. Results: Scallops collected in 2007 and 2008 showed that 468 (> 50 %) specimens were encrusted; in 66 % (311 specimens) of them C. antarcticus was settled. The temporal analysis showed that the spatial distribution of epibiotic worms decreased in 2009, 2010 and 2012, with its total absence in 2013, 2014 and 2015 in the study area. During the period 2007 - 2015, infaunal worms were registered throughout the area, collected in part of the locations monitored. Conclusions: The variability of life habits of C. antarcticus was not commonly registered previously in the study area; epibiotic behavior could be the result of intensive soft sediment disturbance due to trawling and hence, the selection of other available primary settlement substrate.

Numerical Modelling of C. elegans L1 Aggregation

We attempt to explain the aggregation behavior of starved C. elegans L1s (Artyukhin et al., 2015) by a variation of the Keller-Segel chemotaxis model (1970). Each worm releases a diffusible, unstable attractant. The worms chemotax towards the attractant. By using a continuous density function to approximate the spatial distribution of worms, behavior may be described by a nonlinear system of partial differential equations. To determine whether such a model can account for C. elegans L1 behavior, we solve this PDE system numerically. In the original Keller-Segel model, density is unbounded, leading to unrealistic results. We modified the model in such a way as to limit the maximum density. We also developed numerical methods designed to work well near equilibrium. With these changes our model can reproduce some but not all aspects of the behavior.

New paleoscolecid worms from the early Cambrian north margin of the Yangtze Platform, South China

AbstractThe Cambrian Yanwangbian assemblage (Series 2, Stage 4) in South Shaanxi, China, is one of the Burgess Shale–type faunas as it represents the only relatively diverse Cambrian biota from the north margin of the Yangzte Platform, South China. The paleoscolecids (Cycloneuralia) illustrated herein are one of the major components of the fauna, although they appear to be much less abundant than skeletonized fossils, according to available collections. A new taxon,Shaanxiscolex xixiangensisnew genus new species, is described based on the scleritome pattern: each annulus has two rows of alternatingHadimopanella-type plates positioned close to the borders, and a mosaic pattern of microplates occurs between the plates and within intersegmental furrows. The occurrence of the new taxon confirms a fairly diversified and widespread distribution of paleoscolecidan worms recognized in the early Cambrian of South China. Moreover, the ecology of paleoscolecids is reappraised based on burial position of theS. xixiangensisand gut contens of Cambrian taxa from South China, hinting that paleoscolecids (at least some taxa) were both deposit feeders and carnivores, as well as active bioturbators in the substrates of the Cambrian sea, which sheds new light on the ‘Cambrian Substrate Revolution.’

Evolution: Velvet Worm Biogeography

The present-day distribution of velvet worms corresponds neatly to the ancient supercontinent Gondwana - except for a puzzling outpost in southeast Asia. Jaw-dropping new fossil material now establishes when and how peripatid onychophorans reached this isolated spot.

The Dynamics of Ascaris lumbricoides Infections.

The Anderson-May model of human parasite infections and specifically that for the intestinal worm Ascaris lumbricoides is reconsidered, with a view to deriving the observed characteristic negative binomial distribution which is frequently found in human communities. The means to obtaining this result lies in reformulating the continuous Anderson-May model as a stochastic process involving two essential populations, the density of mature worms in the gut, and the density of mature eggs in the environment. The resulting partial differential equation for the generating function of the joint probability distribution of eggs and worms can be partially solved in the appropriate limit where the worm lifetime is much greater than that of the mature eggs in the environment. Allowing for a mean field nonlinearity, and for egg immigration from neighbouring communities, a negative binomial worm distribution can be predicted, whose parameters are determined by those in the continuous Anderson-May model; this result assumes no variability in predisposition to the infection.

An investigation into the potential effects of infrapopulation structure and other sources of sampling error, on population genetic studies of the transmission of Schistosoma japonicum (Trematoda: Digenea).

BackgroundSchistosoma japonicum remains a major challenge to human and animal health. Earlier microsatellite-based studies reported possible definitive-host-specific private alleles within S. japonicum, opening the possibility that different definitive hosts might harbour different parasite strains. Previous investigations have also detected near-identical multilocus genotypes in populations of adult worms - possibly the result of mutations occurring during the asexual (intramolluscan) phase of clonal expansion. Research has also revealed extensive deviations from Hardy-Weinberg Proportions (HWP) and conflicting results among studies. The present study was performed to examine some of the potential effects of infrapopulation structure on microsatellite-based studies of the transmission ecology of S. japonicum. Potential sources of bias considered included organotropic distribution of worms, non-random mating and corrections for clonal expansion.ResultsStool samples from naturally infected hosts were used to infect snails in the laboratory and thereby expose mice. 274 individual worms were typed at seven microsatellite loci. Removal of individuals bearing duplicate MLGs (as a correction for presumed clonal expansion) had an impact on both HWP and organotropic genetic differentiation. The study found no evidence that heterozygote deficiencies were caused by a Wahlund effect. Female-male pairings appeared to be random and there was no evidence for mate choice by heterozygosity. There was some indication that excess heterozygosity, induced by clonal expansion, can offset heterozygote deficiencies caused by small population size or populations fragmented by parasite control efforts.ConclusionsThe view is supported that miracidia are preferable to adult worms in investigations into host-specific parasite lineages. Where adults must be used, extreme care should be taken with regard to sampling if infrapopulations of small animals are compared with those of larger animals; this is because of organotropic patterns in genetic variation and the tendency to sample from different organs in differently sized hosts. As corrections for clones may accentuate signals of population subdivision, corrections should only be made if tests for clonal expansion prove positive. Finally, evidence for heterozygote deficiency caused by small sample size, calls for carefully designed random and comprehensive sampling strategies for S. japonicum in China, where control efforts have greatly fragmented parasite populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1454-0) contains supplementary material, which is available to authorized users.

Density-dependent regulation of fecundity in Syngamus trachea infrapopulations in semi-naturally occurring ring-necked pheasants (Phasianus colchicus) and wild Carrion Crows (Corvus corone).

Previous work has highlighted increased opportunities for the transmission of Syngamus trachea within pheasant release pens, due in part to high levels of environmental contamination around communal areas. Despite this, the distribution of adult worms within their definitive hosts is not significantly different from predicted distributions under Taylor's power law. Therefore, density-dependent processes are probably acting to regulate S. trachea population dynamics. Patterns of nematode fecundity were investigated in a semi-naturally occurring population of ring-necked pheasants (Phasianus colchicus) and a wild population of carrion crows (Corvus carone). Worm length was a reliable indicator of nematode fecundity, and a negative association between mean worm length and mean worm burden was identified within both the species. The stunting of worms at greater parasite densities was present in both immunologically naïve and previously exposed pheasants, so is unlikely to be a function of age-dependent acquired immunity. Interestingly, the effect of parasite crowding in the crow population explained more of the variation in mean worm length, apparently driven by a greater mean worm burden when compared with pheasants. The findings of the present study suggest that fecundity is a function of parasite density, i.e. parasite-mediated competition and not host-mediated heterogeneities in immunocompetence.

The Role of Temperature in the Distribution of the Glacier Ice Worm, Mesenchytraeus solifugus (Annelida: Oligochaeta: Enchytraeidae)

ABSTRACTThe North American glacier ice worm, Mesenchytraeus solifugus (Emery, 1898), is restricted to coastal glaciers in the American Pacific Northwest with a puzzling 400 km distribution gap along the Alaska–British Columbia border and several disjunct populations of northern clades in southern latitudes. We illustrate the role of minimum temperatures in ice worm behavior, abundance, and distribution. The study included 200 glaciers and 25 mitochondrial CO1 haplotypes from the species' 5 × 105 km2 geographic range. Minimum winter temperatures on the previous summer surface appear to determine: (1) the elevations ice worms occupy, (2) the glaciers that can support them, and (3) the mountain ranges they inhabit. Ice worms do not inhabit glaciers with over-winter temperatures below −7 °C on the previous summer surface. An annelid molecular clock in a Bayesian phylogeny suggests ice worms diverged from an aquatic ancestor 2.23 Ma, emerging as three clades 1.6–1.7 Ma. Cold sensitivity, together with southeast Alaska’s geography and past climate, likely created the distribution gap, a hypothesis supported by their phylogeography.

What impact will the achievement of the current World Health Organisation targets for anthelmintic treatment coverage in children have on the intensity of soil transmitted helminth infections?

BackgroundIt is the aim of the World Health Organisation to eliminate soil-transmitted helminths (STH) as a health problem in children. To this end, the goal is to increase anthelmintic treatment coverage for soil transmitted helminths to reach 75 % in pre-school aged and school aged children by 2020 in endemic countries. In this paper, we use mathematical models to investigate the impact of achieving this goal on the burdens of Ascaris lumbricoides, Trichuris trichuria and hookworm.MethodsWe employ a deterministic fully age-structured model of STH transmission and mass drug administration to examine the changes in worm burden in response to the known and projected coverage trends in children up to 2020 and beyond. Parameters are estimated from worm expulsion data and age intensity profiles before treatment using maximum likelihood methods. Model validation is performed using reinfection studies for Ascaris and analyses are conducted to assess the sensitivity of the predicted outcomes to variation in parameter estimates including transmission intensity (R0), children’s contributions to the pool of infective stages and drug coverage levels.ResultsThe impact of the required increase in coverage trends are quite different across the three species. Ascaris burdens are reduced dramatically by 2020 with elimination predicted within studied the setting a further 10 years. For Trichuris and hookworm, however, impact is more limited, due to issues of drug efficacy (Trichuris) and distribution of worms in the population (hookworm). Sensitivity analysis indicates that results are largely robust. However, validation against Ascaris data indicates that assumptions concerning re-infection among children may have to be revised.ConclusionsThe 2020 coverage target is predicted to have a major impact on Ascaris levels by 2020. However, there is evidence from model validation that Ascaris in children is more resilient to treatment than currently assumed in the model. Broader coverage across all age classes is required to break transmission for hookworm and alternative dual drug treatment approaches are needed for Trichuris.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-1135-4) contains supplementary material, which is available to authorized users.

Assessing Helminth Community Structure and Patterns in Gizzard Helminths of Blue-Winged Teal (Anas Discors)

Helminth community structure (prevalence and abundance) and patterns (associations and distributions) of gizzard worms were examined in blue-winged teal (Anas discors) migrating through south Texas to their wintering grounds (n = 50) and as they migrated back to their breeding grounds (n = 50). Three species of nematodes (Amidostomum acutum, Epomidiostomum uncinatum, and Streptocara crassicauda) and 1 species of cestode (Gastrotaenia cygni) were recovered, representing 1,164 helminth individuals. Amidostomum acutum was the most prevalent (92%) and abundant (817 individuals; 70% of total worms), while G. cygni was the least prevalent (16%) and abundant (23 individuals; 2%). Ninety-eight blue-winged teal were infected with 1 to 4 species. Amidostomum acutum and E. uncinatum were the most frequently (45%) observed association of 2 or more species, followed by A. acutum, E. uncinatum, and S. crassicauda (19%), and A. acutum and S. crassicauda (14%). Significant positive correlations were mainly between A. acutum and E. uncinatum, whereas negative correlations were found between each of these 2 species and S. crassicauda. Prevalence and abundance of A. acutum and S. crassicauda were not influenced by season, host age, or host sex. However, E. uncinatum varied by season and host age. The percent similarity index indicated a relatively consistent component community pattern of high similarity irrespective of season, host age, and sex. The same helminth species were found in both fall and spring, indicating that other helminth species were not being acquired on the wintering grounds.

Effective classification of the prevalence of Schistosoma mansoni

To present an effective classification method based on the prevalence of Schistosoma mansoni in the community. We created decision rules (defined by cut-offs for number of positive slides), which account for imperfect sensitivity, both with a simple adjustment of fixed sensitivity and with a more complex adjustment of changing sensitivity with prevalence. To reduce screening costs while maintaining accuracy, we propose a pooled classification method. To estimate sensitivity, we use the De Vlas model for worm and egg distributions. We compare the proposed method with the standard method to investigate differences in efficiency, measured by number of slides read, and accuracy, measured by probability of correct classification. Modelling varying sensitivity lowers the lower cut-off more significantly than the upper cut-off, correctly classifying regions as moderate rather than lower, thus receiving life-saving treatment. The classification method goes directly to classification on the basis of positive pools, avoiding having to know sensitivity to estimate prevalence. For model parameter values describing worm and egg distributions among children, the pooled method with 25 slides achieves an expected 89.9% probability of correct classification, whereas the standard method with 50 slides achieves 88.7%. Among children, it is more efficient and more accurate to use the pooled method for classification of S. mansoni prevalence than the current standard method.

Pooled Testing for Effective Estimation of the Prevalence of Schistosoma mansoni

Rapid and accurate identification of the prevalence of schistosomiasis is key for control and eradication of this devastating disease. The current screening standard for intestinal schistosomiasis is the Katz-Kato method, which look for eggs on slides of fecal matter. Although work has been done to estimate prevalence using the number of eggs on a slide, the procedure is much faster if the laboratory only reports the presence or absence of eggs on each slide. To further help reduce screening costs while maintaining accuracy, we propose a pooled method for estimating prevalence. We compare it to the standard individualed method, investigating differences in efficiency, measured by the number of slides read, and accuracy, measured by mean square error of estimation. Complication is introduced by the unknown and varying sensitivity of the procedure with population prevalence. The DeVlas model for the worm and egg distributions in the population describes how test sensitivity increases with age of the epidemic, as prevalence and intensity of infection increase, making the problem fundamentally different from earlier work in pooling. Previous literature discusses varying sensitivity with the number of positive samples within a pool, known as the “dilution effect.” We model both the dilution effect and varying sensitivity with population prevalence. For model parameter values suited to younger age groups, the pooled method has less than half the mean square error of the individualed method. Thus, we can use half as many slides while maintaining accuracy. Such savings might encourage more frequent measurements in regions where schistosomiasis is a serious but neglected problem.

Prevalence of helminthes, pneumonia and hepatitis in Kirkuk slaughter house, Kirkuk, Iraq

The study was carried out in Kirkuk official slaughter house for the period from the beginning of July 2009 to end of June 2010. Macroscopic examination was performed to demonstrate the distribution of hydatid cyst, fascioliasis, lung worms, pneumonia and hepatitis and their impact on economic losses in the governorate. The number of animals slaughtered during the period of study was: sheep 50518, cattle 16177, goats 7662, buffalos 48 and camels 24. In sheep, the rate of hydatid cysts was 0.77%, with the highest rate was in autumn; liver flukes 0.36% with the highest rate in summer 0.33%; lung worms 0.19%, the highest was in winter 0.27%; pneumonia 0.58%, the highest was in summer 0.74% and hepatitis was 0.32%, the highest was in winter 0.42%. In cattle, the rate of hydatid cysts was 1.70%, the highest was in summer1.65%; liver fluke 1.27%, the highest was in winter 1.57%; lung worms 0.71%, the highest was in spring 0.94%; pneumonia 0.79%, the highest was in summer 0.88% and hepatitis 1.12%, the highest was in summer 1.16%. In goats, no hydatid cysts were seen; the rate of liver fluke was 0.14%, with the highest rate was in winter 0.51%; lung worms was 0.03% and only seen in winter and autumn; pneumonia 0.14%, the highest was in summer 0.25%; hepatitis 0.05% and only seen in summer and autumn. In buffaloes and camels, only 1 case of fascioliasis was seen for each in spring. The economic losses due to condemnation of organs of infected animals in Iraqi diners was: Sheep 4.840.00 millions, cattle 5.434.000 millions and goats 156.000 thousands. The overall economic losses were 10.430.000 Iraqi diners.

Historical biogeography of the North American glacier ice worm, Mesenchytraeus solifugus (Annelida: Oligochaeta: Enchytraeidae)

North American ice worms are the largest glacially-obligate metazoans, inhabiting coastal, temperate glaciers between southcentral Alaska and Oregon. We have collected ice worm specimens from 10 new populations, completing a broad survey throughout their geographic range. Phylogenetic analyses of 87 individuals using fragments of nuclear 18S rRNA, and mitochondrial 12S rRNA and cyctochrome c oxidase subunit 1 (CO1) identified 18 CO1 haplotypes with divergence values up to ∼10%. Phylogeographic interpretations suggest a St. Elias Range, Alaskan ancestry from an aquatic mesenchytraeid oligochaete during the early-Pliocene. A gradual, northward expansion by active dispersal from the central St. Elias clade characterizes a northern clade that is confined to Alaska (with one exception on Vancouver Island, British Columbia), while a distinct southern clade representing worms from British Columbia, Washington and Oregon was likely founded by a passive dispersal event originating from a northern ancestor. The geographic boundary between central and southern clades coincides with an ice worm distribution gap located in southern Alaska, which appears to have restricted active gene flow throughout the species’ evolutionary history.

Some features of the quantitative distribution of sipunculan worms (Sipuncula) in the central and southern Barents Sea

The article reports on the current state of the sipunculan fauna of the central and southern parts of the Barents Sea. The main quantitative parameters (biomass and abundance) of the sipunculan populations are obtained, and the contribution of sipunculids to the total benthos biomass is assessed. The major factors causing long-term variations in Sipunculidae distribution and abundance are evaluated for the area in question.The investigations show that the most commonly encountered sipunculan species are Nephasoma diaphanes diaphanes, N. abyssorum abyssorum and Phascolion strombus strombus. The main contribution to the total benthos biomass comes from the two species most typical of the Barents Sea benthic fauna: Golfingia margaritacea margaritacea and G. vulgaris vulgaris. It is possible that the reduction in Golfingia biomass between the 1970s and 1990s, described in the article, is due to changes in the sampling methodology.

The UK Glow Worm Survey and the Glow Worm Distribution Map

This month's featured perspective article; ‘The UK Glow Worm Survey and the Glow Worm Distribution Map’ is authored by Robin Scagell. The perspective traces the origins of Robin's popular UK Glow Worm Survey and provides a passionate and enlightening account of Glow Worm habitation and population distributions in the UK.

The UK Glow Worm Survey and the Glow Worm Distribution Map

LuminescenceVolume 27, Issue 1 p. 1-2 Special feature: perspective The UK Glow Worm Survey and the Glow Worm Distribution Map Robin Scagell, Corresponding Author Robin Scagell robin@galaxypix.com UK Glow Worm Survey, High Wycombe, UKR. Scagell, UK Glow Worm Survey, 34 Fennels Way, Flackwell Heath, High Wycombe, Bucks HP10 9BY, UK. E-mail: robin@galaxypix.comSearch for more papers by this author Robin Scagell, Corresponding Author Robin Scagell robin@galaxypix.com UK Glow Worm Survey, High Wycombe, UKR. Scagell, UK Glow Worm Survey, 34 Fennels Way, Flackwell Heath, High Wycombe, Bucks HP10 9BY, UK. E-mail: robin@galaxypix.comSearch for more papers by this author First published: 27 December 2011 https://doi.org/10.1002/bio.1391 Glow worm (Lampyris noctiluca). Photographed by Robin Scagell, the UK Glow Worm Survey. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume27, Issue1January/February 2012Pages 1-2 RelatedInformation

Utility of capsule endoscopy for evaluating anthelmintic efficacy in fully conscious dogs

The current accepted standard for evaluating the efficacy of gastrointestinal anthelmintic drugs is necropsy of infected animals followed by a comparison of worm counts between treated and non-treated groups. In this study capsule endoscopy, a minimally invasive method of imaging the small intestine of humans, is evaluated as a possible alternative to necropsy for the purposes of worm quantification in dogs. Eighteen Beagle dogs were included in this study. These dogs were part of a separate trial intended to determine the efficacy of various candidate parasiticides against Ancylostoma caninum via the necropsy standard. Dogs were inoculated with A. caninum L3s 4 weeks prior to treatment with one of the candidate compounds; a control group ( n = 8) received no treatment. Capsule endoscopy was performed 6–14 days post-treatment, followed by necropsy the following day. Seventeen dogs had complete examinations, i.e. the capsule traversed the small intestine and reached the colon within the battery life of the capsule. A strong correlation ( r s = 0.87, P < 0.0001) was observed between the worm counts acquired by capsule endoscopy and necropsy. There was no clear relationship between the ability of the capsule endoscope to detect hookworms and either visibility of the intestinal lumen or small intestinal transit time. Generation of a virtual spatial record of hookworm location from the capsule endoscopy data revealed a temporal trend, with the majority of worms present in the proximal small intestine in the morning versus the central to distal small intestine in the afternoon. Worm distribution as determined by capsule endoscopy closely resembled post-mortem findings. In conclusion, capsule endoscopy shows promise as an alternative to necropsy for the enumeration of A. caninum in the canine small intestine, although further work is required to improve completion rates and optimise intestinal examination.