Nematode Parasites of Rockfish (Sebastes spp.) and Cod (Gadus spp.) from Waters near Kodiak Island Alaska, USA

Distribution and abundance of common parasitic nematodes in marine fishes is not well documented in many geographic regions. Understanding the influence of large-scale environmental changes on infection rates of fish by nematodes requires quantitative assessments of parasite abundance for multiple host species. We collected samples of two species of cod and eight species of rockfish (total of 232 specimens) from waters near Kodiak Island, Alaska, USA during Spring and Summer of 2015, and dissected and recorded all internal nematode parasites. We quantified the prevalence and intensity of nematode parasites in the ten host species, and tested for differences in prevalence among host species. We found three species of nematode: Anisakis simplex, sensu lato (Van Thiel), Pseudoterranova decipiens, sensu lato (Krabbe), and Hysterothylacium sp. (Ward and Magath). Eighty-two percent of the examined fish were infected with at least one parasitic nematode. The overall prevalence of P. decipiens, A. simplex, and Hysterothylacium sp. was 56%, 62%, and 2%, respectively. Anisakis simplex and P. decipiens were abundant and present in all ten species of host fish examined, whereas Hysterothylacium sp. was rare and found in only five of the host fish species. Prevalence and mean intensity of P. decipiens and A. simplex varied across the ten host species, and the number of parasites varied substantially among individual hosts within host species. The mean intensity of P. terranova and A. simplex in our study was substantially higher than the mean intensity for these same species from multiple other locations in a recent meta-analysis. This study provides a baseline of nematode parasite abundance in long-lived fish in waters near Kodiak Island, AK, and fills an important gap in our quantitative understanding of patterns of occurrence and abundance of these common and widespread parasites of marine fish.

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Digenetic Trematode Parasites in Two Fresh Water Fishes Ophiocephalus Punctatus and Xenentodon Cancila From North West Himalayas

10.21203/rs.3.rs-271485/v1 ◽

2021 ◽

Author(s):

Sukanya Rajput ◽

Seema Langer

Keyword(s):

Fresh Water ◽

Digenetic Trematode ◽

Host Fish ◽

Mean Intensity ◽

North West ◽

Trematode Infection ◽

Xenentodon Cancila ◽

The Mean ◽

Union Territory ◽

Trematode Parasites

Abstract The study was conducted during September 2018-August 2019 to study the digenetic trematode infection in fresh water fishes of some of the water bodies viz. Gho-manhasan, Chakrali and Chadwal of Jammu region of J&K union territory A total of 220 fishes comprising Ophiocephalus punctatus and Xenentodon cancila belonging to families Channidae and Belonidae respectively were examined. A total of 4 digenetic trematode parasites belonging to 4 different families i.e., Euclinostomum heterostomum (Clinostomidae Luhe, 1901); Phyllodistomum tripathi (Gorgoderidae Looss, 1901); Genarchopsis piscicola (Hemiuridae, Luhe, 1901), and Bucephalopsis karvei (Bucephalidae Poche, 1907) were detected. The overall prevalence of digenetic trematode infection was 65.90% and the mean intensity was 3.58. Among these Genarchopsis piscicola showed the highest prevalence (40.38%) with mean intensity 2.95 in the host fish Xenentodon cancila, while in other species the prevalence ranged between 26.23% and 34.62%. Present study authenticates the presence of several species of digenetic trematode parasites in the fishes inhabiting freshwater of J&K union territory.

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Aggregations of nematode parasites within Drosophila: proximate causes

Parasitology ◽

10.1017/s003118200007743x ◽

1994 ◽

Vol 108 (5) ◽

pp. 569-577 ◽

Cited By ~ 11

Author(s):

J. Jaenike

Keyword(s):

Host Species ◽

Parasitic Nematode ◽

Infective Stage ◽

Mushroom Species ◽

Nematode Parasites ◽

Sources Of Variation ◽

The Mean ◽

Proximate Causes ◽

Random Distributions ◽

A Site

SummaryMacroparasites almost invariably exhibit overdispersed distributions of parasites/host, yet the specific causes of such aggregations remain poorly understood. The present study focused on the distribution of the parasitic nematode Howardula aoronymphium among its hosts, several species of mycophagous Drosophila. The distribution of parasites/host is close to random for cohorts of flies of a given host species emerging from single mushrooms. At the level of Howardula populations, overdispersion of parasites among hosts results primarily from variation among subgroups of hosts in their exposure to infective-stage nematodes. The sources of variation identified in this study include Drosophila host species, the site where flies bred, mushroom species within sites, and, most importantly, individual mushrooms within mushroom species at a site. For the mean intensity of parasitism observed in this study, the degree of aggregation is typical of macroparasites in general. Combinations of random distributions with different means, resulting from variation among groups in exposure to parasites, may be a common cause of the overdispersion of macroparasites among hosts.

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Temporal and latitudinal 5577 Å airglow variations

Canadian Journal of Physics ◽

10.1139/p81-170 ◽

1981 ◽

Vol 59 (10) ◽

pp. 1296-1307 ◽

Cited By ~ 54

Author(s):

L. L. Cogger ◽

R. D. Elphinstone ◽

J. S. Murphree

Keyword(s):

Large Scale ◽

Emission Rate ◽

The Other ◽

Local Production ◽

Meridional Transport ◽

Mean Intensity ◽

Global Correlation ◽

The Mean ◽

Temporal And Spatial ◽

Winter Hemisphere

From 32 000 [O1] 5577 Å airglow limb observations made between April 1971 and December 1972 from the ISIS-2 satellite, the major temporal and spatial night airglow features have been identified. Two methods of analysis were employed: harmonic fitting and global correlation. Airglow emission rate maxima occurred in mid-October and mid-April at all latitudes. The intensities peaked near 35° in the winter and near 25° in the summer and showed a symmetry with latitude centred about 5° in the winter hemisphere. The mean intensity at mid-latitudes was 175 R and near the equator was 120 R. From the global correlation analysis it was shown that there are two distinct contributions to the temporal and spatial airglow variations: one is from local production which dominates during the post-solstice period, and the other is from large scale meridional transport which dominates during the post-equinox period.

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Sphincterodiplostomum musculosum (Digenea, Diplostomidae) infecting Steindachnerina insculpta(Characiformes, Curimatidae) in the Chavantes Reservoir, Southeastern Brazil

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612013000100018 ◽

2013 ◽

Vol 22 (1) ◽

pp. 98-103 ◽

Cited By ~ 3

Author(s):

Aline Cristina Zago ◽

Lidiane Franceschini ◽

Igor Paiva Ramos ◽

Érica de Oliveira Penha Zica ◽

Alison Carlos Wunderlich ◽

...

Keyword(s):

Intermediate Host ◽

Standard Length ◽

Condition Factor ◽

Southeastern Brazil ◽

Intensity Of Infection ◽

Parasite Abundance ◽

Mean Intensity ◽

Parasitism Rates ◽

The Mean ◽

First Time

This study aimed to report the infection bySphincterodiplostomum musculosum metacercariae inSteindachnerina insculpta from the Chavantes Reservoir, medium Paranapanema River, municipality of Ipaussu, State of São Paulo, Brazil. Thirty specimens of S. insculpta were collected and 29 were infected with S. musculosum metacercariae (prevalence = 96.67%) in the eyes and visceral cavity. The mean intensity of infection and abundance were 96.6 ± 29.41 (7-846) and 93.3 ± 28.6 (0-846), respectively. Positive correlation was observed between parasite abundance in the eyes and standard length (rs = 0.5, p = 0.005), total weight (rs = 0.649, p = 0.0001), and condition factor (rs = 0.439, p = 0.0154). The high parasitism rates by S. musculosummetacercariae in S. insculpta can be an indicative that this fish species is highly susceptible to infection by this diplostomid, and even reflect the presence of a large abundance of the intermediate host. Moreover,S. musculosum metacercariae are reported for the first time in S. insculpta.

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An analysis of gizzard worm infections in fall migrant ducks at Delta, Manitoba, Canada

Canadian Journal of Zoology ◽

10.1139/z87-229 ◽

1987 ◽

Vol 65 (6) ◽

pp. 1470-1477 ◽

Cited By ~ 7

Author(s):

J. Daniel McLaughlin ◽

Brian P. McGurk

Keyword(s):

Host Species ◽

Foraging Strategy ◽

Dabbling Ducks ◽

Hunting Season ◽

Mean Intensity ◽

Lesser Scaup ◽

Foraging Tactics ◽

Males And Females ◽

The Mean ◽

Ruddy Ducks

Gizzards from 13 species of ducks collected during the 1979 hunting season at Delta, Manitoba, Canada, were examined for helminths. Of the 1196 gizzards examined, 77.7% harbored at least one species of helminth. Amidostomum acutum occurred in 53.3% of the gizzards (13 species); Epomidiostomum uncinatum, in 28.5% (10 species); Streptocara crassicauda, in 18.1% (12 species); Gastrotaenia cygni, in 17.8% (11 species); and Streptocara formosensis, in 3.7% (5 species). Infection levels in juveniles and adults and in males and females of the same age in each species were generally similar. Prevalence and abundance of A. acutum in dabbling ducks (Anas spp.) was greatest among species exhibiting intermediate or generalist foraging tactics. Redheads and canvasbacks had the heaviest infections among diving species. The intermediate and generalist Anas species also had the greatest prevalence and abundance of E. uncinatum. With the exception of ruddy ducks, divers were rarely infected with this helminth. Lesser scaup were the major hosts for the Streptocara species and prevalence in other hosts tended to reflect the importance of amphipods in the diet. Shovelers, which feed extensively on zooplankton, had the highest prevalence of G. cygni. Few significant differences were found in the mean intensity of each helminth among host species despite wide differences in prevalence. Thus while diet and (or) foraging strategy may affect a species' contact with the infective pool, it apparently has little effect on the size of the infection which results.

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Austrodiplostomum compactum metacercariae (Digenea: Diplostomidae) in Schizodon intermedius (Characiformes: Anostomidae) from Jurumirim reservoir, Brazil

Revista Brasileira de Parasitologia Veterinária ◽

10.1590/s1984-29612016035 ◽

2016 ◽

Vol 25 (2) ◽

pp. 240-243 ◽

Cited By ~ 1

Author(s):

Igor Paiva Ramos ◽

Lidiane Franceschini ◽

Aline Cristina Zago ◽

Érica de Oliveira Penha Zica ◽

Alison Carlos Wunderlich ◽

...

Keyword(s):

Freshwater Fish ◽

Standard Length ◽

Condition Factor ◽

Total Weight ◽

Intensity Of Infection ◽

Parasite Abundance ◽

Mean Intensity ◽

The Mean ◽

Discrepancy Index ◽

First Time

Abstract This study reports the occurrence of Austrodiplostomum compactum metacercariae in the freshwater fish Schizodon intermedius (ximborê/piava) from a Neotropical reservoir in the Paranapanema River, state of São Paulo, Brazil. From a total of 75 fish collected, we found 38 infected with A. compactum metacercariae (prevalence = 50.67%) in the eyes. The mean intensity of infection and mean abundance were 9.05 ± 4.26 (1-155) and 4.59 ± 2.20 (0-155), respectively. Poulin's Discrepancy Index was 0.87 and four specimens presented more than 10 metacercariae in their eyes. No correlation was observed between parasite abundance and standard length, total weight and condition factor (p>0.05). These metacercariae are reported for the first time in S. intermedius.

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Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

Materials ◽

10.3390/ma14041021 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1021

Author(s):

Bernhard Dorweiler ◽

Pia Elisabeth Baqué ◽

Rayan Chaban ◽

Ahmed Ghazy ◽

Oroa Salem

Keyword(s):

Wall Thickness ◽

Large Scale ◽

Fused Deposition Modeling ◽

Vascular Anatomy ◽

3D Models ◽

Patient Specific ◽

Stl File ◽

Fused Deposition ◽

3D Printed ◽

The Mean

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

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Relationship between large-scale ionospheric field-aligned currents and electron/ion precipitations: DMSP observations

Earth Planets and Space ◽

10.1186/s40623-020-01286-z ◽

2020 ◽

Vol 72 (1) ◽

Author(s):

Chao Xiong ◽

Claudia Stolle ◽

Patrick Alken ◽

Jan Rauberg

Keyword(s):

Time Distribution ◽

Large Scale ◽

Particle Flux ◽

Particle Energy ◽

Lower Latitude ◽

Particle Precipitation ◽

Data Set ◽

The Mean ◽

Two Parameters ◽

Meteorological Satellite

Abstract In this study, we have derived field-aligned currents (FACs) from magnetometers onboard the Defense Meteorological Satellite Project (DMSP) satellites. The magnetic latitude versus local time distribution of FACs from DMSP shows comparable dependences with previous findings on the intensity and orientation of interplanetary magnetic field (IMF) By and Bz components, which confirms the reliability of DMSP FAC data set. With simultaneous measurements of precipitating particles from DMSP, we further investigate the relation between large-scale FACs and precipitating particles. Our result shows that precipitation electron and ion fluxes both increase in magnitude and extend to lower latitude for enhanced southward IMF Bz, which is similar to the behavior of FACs. Under weak northward and southward Bz conditions, the locations of the R2 current maxima, at both dusk and dawn sides and in both hemispheres, are found to be close to the maxima of the particle energy fluxes; while for the same IMF conditions, R1 currents are displaced further to the respective particle flux peaks. Largest displacement (about 3.5°) is found between the downward R1 current and ion flux peak at the dawn side. Our results suggest that there exists systematic differences in locations of electron/ion precipitation and large-scale upward/downward FACs. As outlined by the statistical mean of these two parameters, the FAC peaks enclose the particle energy flux peaks in an auroral band at both dusk and dawn sides. Our comparisons also found that particle precipitation at dawn and dusk and in both hemispheres maximizes near the mean R2 current peaks. The particle precipitation flux maxima closer to the R1 current peaks are lower in magnitude. This is opposite to the known feature that R1 currents are on average stronger than R2 currents.

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Prevalence and genetic diversity of avian haemosporidian parasites in wild bird species of the order Columbiformes

Parasitology Research ◽

10.1007/s00436-021-07053-7 ◽

2021 ◽

Author(s):

Yvonne R. Schumm ◽

Dimitris Bakaloudis ◽

Christos Barboutis ◽

Jacopo G. Cecere ◽

Cyril Eraud ◽

...

Keyword(s):

Host Species ◽

Large Scale ◽

Phylogenetic Reconstruction ◽

Bird Species ◽

Avian Species ◽

Blood Parasites ◽

Migration Strategy ◽

Haemosporidian Parasites ◽

Multiplex Pcr Assay ◽

And Migration

AbstractDiseases can play a role in species decline. Among them, haemosporidian parasites, vector-transmitted protozoan parasites, are known to constitute a risk for different avian species. However, the magnitude of haemosporidian infection in wild columbiform birds, including strongly decreasing European turtle doves, is largely unknown. We examined the prevalence and diversity of haemosporidian parasites Plasmodium, Leucocytozoon and subgenera Haemoproteus and Parahaemoproteus in six species of the order Columbiformes during breeding season and migration by applying nested PCR, one-step multiplex PCR assay and microscopy. We detected infections in 109 of the 259 screened individuals (42%), including 15 distinct haemosporidian mitochondrial cytochrome b lineages, representing five H. (Haemoproteus), two H. (Parahaemoproteus), five Leucocytozoon and three Plasmodium lineages. Five of these lineages have never been described before. We discriminated between single and mixed infections and determined host species-specific prevalence for each parasite genus. Observed differences among sampled host species are discussed with reference to behavioural characteristics, including nesting and migration strategy. Our results support previous suggestions that migratory birds have a higher prevalence and diversity of blood parasites than resident or short-distance migratory species. A phylogenetic reconstruction provided evidence for H. (Haemoproteus) as well as H. (Parahaemoproteus) infections in columbiform birds. Based on microscopic examination, we quantified parasitemia, indicating the probability of negative effects on the host. This study provides a large-scale baseline description of haemosporidian infections of wild birds belonging to the order Columbiformes sampled in the northern hemisphere. The results enable the monitoring of future changes in parasite transmission areas, distribution and diversity associated with global change, posing a potential risk for declining avian species as the European turtle dove.

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Improved Visual Localization via Graph Filtering

Journal of Imaging ◽

10.3390/jimaging7020020 ◽

2021 ◽

Vol 7 (2) ◽

pp. 20

Author(s):

Carlos Lassance ◽

Yasir Latif ◽

Ravi Garg ◽

Vincent Gripon ◽

Ian Reid

Keyword(s):

Image Retrieval ◽

Large Scale ◽

Visual Localization ◽

Localization Accuracy ◽

Additional Information ◽

Feature Representations ◽

The Mean ◽

Classical Image ◽

Vision Based Localization ◽

Improve Reliability

Vision-based localization is the problem of inferring the pose of the camera given a single image. One commonly used approach relies on image retrieval where the query input is compared against a database of localized support examples and its pose is inferred with the help of the retrieved items. This assumes that images taken from the same places consist of the same landmarks and thus would have similar feature representations. These representations can learn to be robust to different variations in capture conditions like time of the day or weather. In this work, we introduce a framework which aims at enhancing the performance of such retrieval-based localization methods. It consists in taking into account additional information available, such as GPS coordinates or temporal proximity in the acquisition of the images. More precisely, our method consists in constructing a graph based on this additional information that is later used to improve reliability of the retrieval process by filtering the feature representations of support and/or query images. We show that the proposed method is able to significantly improve the localization accuracy on two large scale datasets, as well as the mean average precision in classical image retrieval scenarios.

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