Analysis of correlation structure in Lymantria dispar L. larvae from locally adapted populations

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Mrdaković Marija

2013-01-01

Full Text Available The influence of allelochemical stress and population origin on the patterns of phenotypic and genetic correlations among life history traits and digestive enzyme activities were investigated in larvae of the gypsy moth (Lymantria dispar L.; Lepidoptera: Lymantriidae. Thirty-two full-sib families from oak (suitable host plant, Quercus population, and twenty-six full-sib families from locust-tree (unsuitable host plant, Robinia population forests were reared on an artificial diet, with or without a 5% tannic acid supplement. Comparison of correlation matrices revealed significant similarity between the two populations in the structure of phenotypic and genetic correlations of life history traits and of digestive enzyme activities. The patterns of correlations of the examined traits, within each of the two locally adapted populations and in the presence of allelochemical stress, remained stabile despite the different selection pressures that mold these traits. [Projekat Ministarstva nauke Republike Srbije, br. 173027

Susceptibility of larvae of nun moth, Lymantria monacha (Linnaeus 1758) (Lepidoptera), to the entomopathogenic fungus, Entomophaga maimaiga Humber, Shimazu and Soper (Entomophthorales) under laboratory and field conditions

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Daniela Pilarska; Ann E. Hajek; Melody Keena; Andreas Linde; Manana Kereselidze; Georgi Georgiev; Margarita Georgieva; Plamen Mirchev; Danail Takov; Slavimira. Draganova

2016-01-01

Susceptibility of Lymantria monacha larvae to Entomophaga maimaiga was investigated under laboratory and field conditions, using larvae of the natural host, Lymantria dispar, as positive controls. In laboratory bioassays, L. monacha and L. dispar were injected with...

Data for increase of Lymantria dispar male survival after topical application of single-stranded RING domain fragment of IAP-3 gene of its nuclear polyhedrosis virus

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Oberemok, Volodymyr V.; Laikova, Kateryna V.; Zaitsev, Aleksei S.; Gushchin, Vladimir A.; Skorokhod, Oleksii A.

2016-01-01

This data article is related to the research article entitled “The RING for gypsy moth control: topical application of fragment of its nuclear polyhedrosis virus anti-apoptosis gene as insecticide” [1]. This article reports on significantly higher survival of gypsy moth Lymantria dispar male individuals in response to topical application of single-stranded DNA, based on RING (really interesting new gene) domain fragment of LdMNPV (L. dispar multicapsid nuclear polyhedrosis virus) IAP-3 (inhibitor of apoptosis) gene and acted as DNA insecticide. PMID:27054151

The influence of increased rearing density on medial protocerebral neurosecretory neurons of Lymantria dispar L. caterpillars

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Ilijin Larisa

2010-01-01

Full Text Available Morphometric changes of A1, A1' and A2 protocerebral dorsomedial neurosecretory neurons, total brain protein content and brain protein profiles were analyzed in 4th instar Lymantria dispar larvae under elevated rearing density, i.e. under intense stress when 5 larvae were kept in a petri dish (V = 80 ml, less intense stress when 5 larvae were kept in a plastic cup (V = 300 ml. In the control samples the larvae were reared in isolated conditions. Protein pattern changes in the brain were observed. Proteins with the following molecular masses: 30, 14, 10 and 3.4-2.5 kD were detected in the experimental groups. The size and cytological characteristics of protocerebral dorsomedial neurosecretory neurons were changed under elevated rearing density.

Assessing the potential of genotyping-by-sequencing-derived single nucleotide polymorphisms to identify the geographic origins of intercepted gypsy moth (Lymantria dispar) specimens: A proof-of-concept study

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Sandrine Picq; Melody Keena; Nathan Havill; Don Stewart; Esther Pouliot; Brian Boyle; Roger C. Levesque; Richard C. Hamelin; Michel Cusson

2018-01-01

Forest invasive alien species are a major threat to ecosystem stability and can have enormous economic and social impacts. For this reason, preventing the introduction of Asian gypsy moths (AGM; Lymantria dispar asiatica and L. d. japonica) into North America has been identified as a top priority by North American authorities....

Effects of temperature and dietary nitrogen on genetic variation and covariation in gypsy moth larval performance traits

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Janković-Tomanić Milena

2012-01-01

Full Text Available To assess the plastic and genetic components of variation in responses of gypsy moth (Lymantria dispar 4th instar larvae to temperature and food quality, we applied a split-family four-environment experimental design where full-sibs were reared on two constant temperatures (23°C and 28°C and two concentrations of dietary nitrogen (1.5 and 3.7% dry weight. A temperature of 28°C and low dietary nitrogen decreased larval weight and prolonged larval developmental time, while viability was not affected. Only a marginally significant interaction between the two environmental factors was found for larval weight. The broad-sense heritability for larval developmental time did not change across environments, and across-environment genetic correlations were close to one. Heritability for larval weight depended on environmental and across-environmental genetic correlations that were not significant. There was no evidence of a trade-off between developmental time and larval weight. The implications of the obtained results for the evolution of phenotypic plasticity in complex environments are discussed. [Acknowledgments. This work was supported by Ministry of Education and Science of Serbia, grant No. 173027.

Antifeeding Activity of Several Plant Extracts Against Lymantria dispar L. (Lepidoptera: Lymantriidae Larvae

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Sonja Gvozdenac

2012-01-01

Full Text Available Lymantria dispar L. is the most devastating polyphagous pest of deciduous forests, orchardsand urban greenery. To prevent damages that L. dispar larvae cause in forestry, agriculture andhorticulture, mechanical measures and the use of biological insecticides are the most frequentlyapplied practices. However, the use of conventional insecticides is inevitable in crop protectionand forest management on smaller areas, especially in gradation years. However, inadequateuse of these chemicals has led to disturbance of biocoenotic balance, outbreaks of somepreviously less harmful organisms and pesticide residues in soil and watercourses in someregions. To mitigate these consequences it is necessary to harmonize L. dispar control withintegrated management principles by applying selective and less toxic insecticides. Therefore,the potential of botanical insecticides and antifeeding substances is gaining in importance.The aim of this study was to assess the influence of ethanol extracts (1, 2 and 5% of Ambrosiaartemisiifolia L., Erigeron canadensis L., Daucus carota L., Morus alba L. and Aesculus hippocastanumL. on the feeding intensity of L. dispar larvae, i.e. to evaluate their antifeeding activity underthe conditions of “no-choice” test. Ten larvae per repetition were placed in Petri dishes andoffered oak leaf slices (2 x 9 cm2/repetition previously dipped in plant extract or ethanol (1, 2,and 5% for the control. Feeding intensity, expressed as a percentage of consumed leaf area (%,was measured after 48 h. For assessing the antifeeding activity of plant extracts AFI was calculatedand the extracts were classified according to scale: no antifeeding activity, slight antifeedingactivity, moderate antifeeding activity and strong antifeeding activity. Data were analyzedusing a two-way ANOVA and Duncan`s multiple range test. The results indicate that plantspecies, i.e. the origin of extracts, had a significant influence on the feeding intensity of L

A pheromone analogue affects the evaporation rate of (+)-disparlure in Lymantria dispar.

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Sollai, Giorgia; Murgia, Sergio; Secci, Francesco; Frongia, Angelo; Cerboneschi, Anna; Masala, Carla; Liscia, Anna; Crnjar, Roberto; Solari, Paolo

2014-04-01

The gypsy moth Lymantria dispar L. is a widespread pest that causes economic damage to cork oak forests. Females produce the sex pheromone (+)-(7R,8S)-epoxy-2-methyloctadecane, known as (+)-disparlure [(+)D], for long-distance attraction of conspecific males. A (+)D analogue, 2-decyl-1-oxaspiro[2.2]pentane (OXP-01), neither stimulating nor attractive by itself, causes short-time inhibition of male response in a 1:1 blend with (+)D. The authors investigated whether and how the biological activity of the natural pheromone is affected by OXP-01 on a long-time basis (up to 16 days), also by looking at possible physicochemical reciprocal interactions. Blending of (+)D with OXP-01 decreased, under low evaporation rate, the pheromone effectiveness, as assessed by electroantennogram recordings. In male trappings, within the first 24 h, OXP-01 decreased and later enhanced the blend attractiveness, but only under high evaporation rate. Gas chromatography-mass spectroscopy indicates that quantitative retrieval of (+)D from blend cartridges is higher than for pure pheromone, and nuclear magnetic resonance measurements show that OXP-01 produces, possibly by Van der Waals interactions, a bimolecular entity with pheromone causing retention and lengthening of its attractiveness over time. The biological and physicochemical interactions between (+)D and OXP-01 may provide valuable information for the optimisation of pheromone-based control strategies for gypsy moths. © 2013 Society of Chemical Industry.

Cloning, Site-Directed Mutagenesis, and Functional Analysis of Active Residues in Lymantria dispar Chitinase.

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Fan, Xiao-Jun; Yang, Chun; Zhang, Chang; Ren, Hui; Zhang, Jian-Dong

2018-01-01

Chitinases are glycosyl hydrolases that catalyze the hydrolysis of β-(1,4)-glycosidic bonds in chitin, the major structural polysaccharide presented in the cuticle and gut peritrophic matrix of insects. Two aspartate residues (D143, D145) and one tryptophan (W146) in the Lymantria dispar chitinase are highly conserved residues observed within the second conserved motif of the family 18 chitinase catalytic region. In this study, a chitinase cDNA, LdCht5, was cloned from L. dispar, and the roles of the three residues were investigated using site-directed mutagenesis and substituting them with three other amino acids. Seven mutant proteins, D143E, D145E, W146G, D143E/D145E, D143E/W146G, D145E/W146G, and D143E/D145E/W146G, as well as the wild-type enzyme, were produced using the baculovirus-insect cell line expression system. The enzymatic and kinetic properties of these mutant enzymes were measured using the oligosaccharide substrate MU-(GlcNAc) 3 . Among the seven mutants, the D145E, D143E/D145E, and D145E/W146G mutations kept some extant catalytic activity toward MU-(GlcNAc) 3 , while the D143E, W146G, D143E/W146G, and D143E/D145E/W146G mutant enzymes were inactivated. Compared with the mutant enzymes, the wild-type enzyme had higher values of k cat and k cat / K m . A study of the multiple point mutations in the second conserved catalytic region would help to elucidate the role of the critical residues and their relationships.

BACULOVIRUS REPLICATION ALTERS HORMONE-REGULATED HOST DEVELOPMENT.

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The baculovirus Lymantria dispar nuclear polyhedrosis virus interferes with insect larval development by altering the host's hormonal system. The level of haemolymph ecdysteroids, the insect moulting hormone, was found to be higher in virus-infected larvae than in uninfected cont...

Development of gypsy moth (Lymantria dispar L on the foliage of Quercus cerris L., Q. Petraea (matt Liebl. and Q. Robur L. in the controlled conditions

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Milanović Slobodan

2007-01-01

Full Text Available The development of Gypsy moth (Lymantria dispar L was monitored in laboratory conditions, on the foliage of the species Quercus cerris L. Quercus petraea (Matt Liebl. and Quercus robur L. The experiment was established in the controlled environmental conditions, at the temperature of 25°C, photoperiod 14:10 (day: night and relative humidity 70%. The objective of the research was to determine the suitability of the study host plant species for gypsy moth development. The study results show that Gypsy moth caterpillars cultivated on Q. petraea foliage had a lower survival, higher number of moultings, longer preadult development and lower fecundity, which makes this species less suitable compared to the other two. Gypsy moth caterpillars cultivated on Q. cerris foliage had the highest survival degree the lowest number of moultings, the shortest preadult development and the highest fecundity, which makes this species the most favourable for gypsy moth development. Q. robur was between the former two species in this respect.

Juvenile hormone biosynthesis and secretion by the female Corpora allata of the larval gypsy moth, Lymantria dispar (L.) utilizing in vitro organ culture

International Nuclear Information System (INIS)

Jones, G.L.

1986-01-01

Junvenile hormone synthesis and secretion in the female larval gypsy moth was investigated. In vitro culturing methods were developed including: incubating 2 pair of CC-CA gland complexes in 50 ul of osmotically balanced Grace's insect medium containing 1 uCi 3 H-methyl-methionine for 6 hr. JH homologues were identified and quantified using TLC and HPLC. In vitro methods were employed to investigate trends of JH secretion in 4th and ultimate female larval instar CA. Fourth instar CA produced JH peaks of 0.15 pmole/pr/hr between days 2 and 3, but the rate declined to half by day 4. Ultimate instar larvae began secreting 0.48 pmole/pr/hr, but by day 10, had decreased JH output to negligible levels which continued until pupation. Effects upon in vitro JH secretion produced by precocene II and caffeine were examined. Feulgen staining techniques revealed an equal number of cells (30) in 4th and last instar CA. Last instar Ca were 3 times larger than 4th in volume but their actual in vitro JH secretion at peak levels was only 20% greater. In vitro methods demonstrated that JH secretory trends differ in younger versus mature larval instars. Glandular volume increased in last instars but JH secretion was only 20% greater than in 4th's when compared on the basis of volume. Precocene II elicited a negative response on in vivo JH secretion at levels 10 times less than caffeine. Caffeine was judged not to significantly alter JH secretion

Effects of benzylisoquinoline alkaloids on the larvae of polyphagous Lepidoptera.

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Miller, James S; Feeny, Paul

1983-06-01

Six benzylisoquinoline alkaloids were fed to the larvae of three polyphagous Lepidoptera species: Hyphantria cunea, Spodoptera eridania, and Lymantria dispar. Exposure of last instar larvae to alkaloid-containing diets over a 24-h period resulted in reduced feeding rates and reduced growth efficiencies. Lymantria dispar larvae reared from eggs on alkaloid diets took longer to reach the fifth instar, attained lower larval weights, and showed reduced survivorship. The benzylisoquinolines tested were not equally effective as toxins or feeding inhibitors. Some produced dramatic effects while others produced no effects. The relative responses of the three caterpillar species to the six alkaloids were similar. Those benzylisoquinolines with a methylene-dioxyphenyl (1,3-benzodioxole) group were consistently the most toxic or repellent while laudanosine, a relatively simple benzylisoquinoline, was generally innocuous. Available host records indicate that benzylisoquinoline-containing plants are avoided by the larvae of these moth species.

Localization of Bacillus thuringiensis Cry1A toxin-binding molecules in gypsy moth larval gut sections using fluorescence microscopy

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Algimantas P. Valaitis

2011-01-01

The microbial insecticide Bacillus thuringiensis (Bt) produces Cry toxins, proteins that bind to the brush border membranes of gut epithelial cells of insects that ingest it, disrupting the integrity of the membranes, and leading to cell lysis and insect death. In gypsy moth, Lymantria dispar, two toxin-binding molecules for the...

Baculovirus replication: characterization of DNA and proteins synthesized by a nuclear polyhedrosis virus of Lymantria dispar, the gypsy moth, in a homologous cell line

International Nuclear Information System (INIS)

McClintock, J.T.

1985-01-01

A multiple-embedded nuclear polyhedrosis virus (NPV) of the gypsy moth, Lymantria dispar (LdMNPV), is used for biological control. However, LdMNPV has low natural virulence and a long infection cycle in relation to other NPVs. Therefore, the replicative cycle of LdMNPV was investigated using a homologous cell line, IPLB-LD-652Y. Based on analyses of virus growth curves LdMNPV nonoccluded virus and polyhedral inclusion bodies appeared approximately 20 and 50 hr postinfection (p.i.), respectively. LdMNPV polypeptides, identified by autoradiography of [ 35 S]-methionine labeled fractions in SDS-PAGE, were synthesized in sequential phases: (1) an early α phase of replication (4 polypeptides from 4 to 12 hr p.i.), (2) an intermediate β phase (20 polypeptides from 12 to 24 hr p.i.), and a late γ phase (4 polypeptides from 24 to 28 hr p.i.). In infected cells at least four polypeptides were post-translational cleaved and/or modified. Pulse-labeling with [ 3 H]-mannose, [ 3 H]-N-acetyl-glucosamine or [ 32 P]-monosodium phosphate revealed several viral polypeptides which were glycosylated and/or phosphorylated. DNA:DNA dot hybridization experiments suggested that LdMNPV DNA synthesis was initiated between 12 to 16 hr p.i., increasing significantly thereafter

Effects of Lymantria dispar feeding and mechanical wounding on ...

African Journals Online (AJOL)

Jane

2011-07-18

Jul 18, 2011 ... MATERIALS AND METHODS. Plants and L. dispar. The plants used were poplar (P. ... relative humidity and an average temperature of 24°C. Fully expanded leaves were treated by feeding and .... transition rate of 0.1°C s-1 to generate a melting curve. All samples were also electrophoresed in agarose ...

LYMANTRIA MONACHA L. SPECIES MONITORING WITH THE AID OF SEXUAL ATTRACTANTS

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I OLTEAN

2003-12-01

Full Text Available An extremely dangerous pest especially for the resinous species (spruce fir, pine tree, fir tree, larice, duglas which can also attack leafy trees is Lymantria monacha. The larva of this pest attacks as of the beginning of spring. In the beginning they attack the barely open buds which they gnaw, then the needles are partially or totally eaten. The studies shows the situation of Lymantria monacha adults caucht with the aid of ATRALYMON sexual attractant in 2001 and 2002.

2-Methyl-(Z)-7-Octadecene - the sex pheromone of allopatric Lymantria serva and Lymantria lucescens: two potential invasive species in the Orient

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Paul W. Schaefer; Gerhard Gries; Regine Gries; Yasutomo Higashiura; Yi-Bin Fan

2003-01-01

Our objective was to identify the sex pheromones of two allopatric Lymantria species (Lepidoptera: Lymantriidae): (1) L. serva (Fabricius) in Taiwan whose larvae attack and occasionally defoliate Ficus spp. and (2) L. lucescens (Fabricius) in Honshu, Japan, whose larvae feed on Quercus...

Contributions of gut bacteria to Bacillus thuringiensis-induced mortality vary across a range of Lepidoptera

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Holt Jonathan

2009-03-01

Full Text Available Abstract Background Gut microbiota contribute to the health of their hosts, and alterations in the composition of this microbiota can lead to disease. Previously, we demonstrated that indigenous gut bacteria were required for the insecticidal toxin of Bacillus thuringiensis to kill the gypsy moth, Lymantria dispar. B. thuringiensis and its associated insecticidal toxins are commonly used for the control of lepidopteran pests. A variety of factors associated with the insect host, B. thuringiensis strain, and environment affect the wide range of susceptibilities among Lepidoptera, but the interaction of gut bacteria with these factors is not understood. To assess the contribution of gut bacteria to B. thuringiensis susceptibility across a range of Lepidoptera we examined larval mortality of six species in the presence and absence of their indigenous gut bacteria. We then assessed the effect of feeding an enteric bacterium isolated from L. dispar on larval mortality following ingestion of B. thuringiensis toxin. Results Oral administration of antibiotics reduced larval mortality due to B. thuringiensis in five of six species tested. These included Vanessa cardui (L., Manduca sexta (L., Pieris rapae (L. and Heliothis virescens (F. treated with a formulation composed of B. thuringiensis cells and toxins (DiPel, and Lymantria dispar (L. treated with a cell-free formulation of B. thuringiensis toxin (MVPII. Antibiotics eliminated populations of gut bacteria below detectable levels in each of the insects, with the exception of H. virescens, which did not have detectable gut bacteria prior to treatment. Oral administration of the Gram-negative Enterobacter sp. NAB3, an indigenous gut resident of L. dispar, restored larval mortality in all four of the species in which antibiotics both reduced susceptibility to B. thuringiensis and eliminated gut bacteria, but not in H. virescens. In contrast, ingestion of B. thuringiensis toxin (MVPII following antibiotic

Towards a global barcode library for Lymantria (Lepidoptera: Lymantriinae) tussock moths of biosecurity concern

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Jeremy R. deWaard; Andrew Mitchell; Melody A. Keena; David Gopurenko; Laura M. Boykin; Karen F. Armstrong; Michael G. Pogue; Joao Lima; Robin Floyd; Robert H. Hanner; Leland M. Humble

2010-01-01

This study demonstrates the efficacy of DNA barcodes for diagnosing species of Lymantria and reinforces the view that the approach is an under-utilized resource with substantial potential for biosecurity and surveillance. Biomonitoring agencies currently employing the NB restriction digest system would gather more information by transitioning to the...

Modification of a Pollen Trap Design To Capture Airborne Conidia of Entomophaga maimaiga and Detection of Conidia by Quantitative PCR.

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Bittner, Tonya D; Hajek, Ann E; Liebhold, Andrew M; Thistle, Harold

2017-09-01

The goal of this study was to develop effective and practical field sampling methods for quantification of aerial deposition of airborne conidia of Entomophaga maimaiga over space and time. This important fungal pathogen is a major cause of larval death in invasive gypsy moth ( Lymantria dispar ) populations in the United States. Airborne conidia of this pathogen are relatively large (similar in size to pollen), with unusual characteristics, and require specialized methods for collection and quantification. Initially, dry sampling (settling of spores from the air onto a dry surface) was used to confirm the detectability of E. maimaiga at field sites with L. dispar deaths caused by E. maimaiga , using quantitative PCR (qPCR) methods. We then measured the signal degradation of conidial DNA on dry surfaces under field conditions, ultimately rejecting dry sampling as a reliable method due to rapid DNA degradation. We modified a chamber-style trap commonly used in palynology to capture settling spores in buffer. We tested this wet-trapping method in a large-scale (137-km) spore-trapping survey across gypsy moth outbreak regions in Pennsylvania undergoing epizootics, in the summer of 2016. Using 4-day collection periods during the period of late instar and pupal development, we detected variable amounts of target DNA settling from the air. The amounts declined over the season and with distance from the nearest defoliated area, indicating airborne spore dispersal from outbreak areas. IMPORTANCE We report on a method for trapping and quantifying airborne spores of Entomophaga maimaiga , an important fungal pathogen affecting gypsy moth ( Lymantria dispar ) populations. This method can be used to track dispersal of E. maimaiga from epizootic areas and ultimately to provide critical understanding of the spatial dynamics of gypsy moth-pathogen interactions. Copyright © 2017 American Society for Microbiology.

The Relationship between Insect Resistance and Tree Age of Transgenic Triploid Populus tomentosa Plants.

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Ren, Yachao; Zhang, Jun; Wang, Guiying; Liu, Xiaojie; Li, Li; Wang, Jinmao; Yang, Minsheng

2018-01-01

To explore the stability of insect resistance during the development of transgenic insect-resistant trees, this study investigated how insect resistance changes as transgenic trees age. We selected 19 transgenic insect-resistant triploid Populus tomentosa lines as plant material. The presence of exogenous genes and Cry1Ac protein expression were verified using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) analyses. The toxicity for Clostera anachoreta and Lymantria dispar was evaluated by feeding fresh leaves to first instar larvae after the trees were planted in the field for 2 years and after the sixth year. Results of PCR showed that the exogenous genes had a long-term presence in the poplar genome. ELISA analyses showed significant differences existed on the 6-year-old transgenic lines. The insect-feeding experiment demonstrated significant differences in the mortality rates of C. anachoreta and L. dispar among different transgenic lines. The average corrected mortality rates of C. anachoreta and L. dispar ranged from 5.6-98.7% to 35.4-7.2% respectively. The larval mortality rates differed significantly between the lines at different ages. Up to 52.6% of 1-year-old transgenic lines and 42.1% of 2-year-old transgenic lines caused C. anachoreta larval mortality rates to exceed 80%, whereas only 26.3% of the 6-year-old transgenic lines. The mortality rates of L. dispar exhibited the same trend: 89.5% of 1-year-old transgenic lines and 84.2% of 2-year-old transgenic lines caused L. dispar larval mortality rates to exceed 80%; this number decreased to 63.2% for the 6-year-old plants. The proportion of 6-year-old trees with over 80% larval mortality rates was clearly lower than that of the younger trees. The death distribution of C. anachoreta in different developmental stages also showed the larvae that fed on the leaves of 1-year-old trees were killed mostly during L 1 and L 2 stages, whereas the proportion of larvae that died in L 3

Phenology of Lymantria monacha (Lepidoptera:Lymantriidae) laboratory reared on spruce foliage or a newly developed artificial diet

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Melody A. Keena; Alice Vandel; Oldrich. Pultar

2010-01-01

Lymantria monacha (L.) (Lepidoptera: Lymantriidae) is a Eurasian pest of conifers that has potential for accidental introduction into North America. The phenology over the entire life cycle for L. monacha individuals from the Czech Republic was compared on Picea glauca (Moench) Voss (white spruce) and a newly...

African Journal of Biotechnology - Vol 10, No 36 (2011)

African Journals Online (AJOL)

Effect of different fertilizers on the microbial activity and productivity of soil under potato ... Preparation of productive and highly purified mogrosides from Siraitia grosvenorii ... Effects of Lymantria dispar feeding and mechanical wounding on ...

Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

Science.gov (United States)

Keena, M A

2003-02-01

Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas.

Revision of the genus Dinotoperla Tillyard, 1921 (Plecoptera: Gripopterygidae) using morphological characters and molecular data: Establishes two new genera, three new species and updates the larval taxonomy.

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Mynott, Julia H; Suter, Phillip J; Theischinger, Gunther

2017-01-23

The larval taxonomy of Australian stoneflies (Plecoptera) shows a large disparity in knowledge when compared to the adult taxonomy with many species having undescribed larval forms. The importance of stoneflies as an indicator group for monitoring aquatic ecosystems means knowledge of the larval taxonomy and the ability to identify species is essential. This study combined morphology and mitochondrial gene sequences to associate the adult and larval life-stages for species of Dinotoperla Tillyard. Morphological identification of adult males was recognised for 17 of the 35 Dinotoperla species and combining molecular data with morphology confirmed eight new adult-larval life stage associations. Further, molecular data supported the larval taxonomy for five morphospecies which remain unassociated. The combination of molecular and morphological methods enabled the larval morphology to be reassessed for the genus Dinotoperla and this has led to the establishment of two new genera, Odontoperla, gen. nov. and Oedemaperla, gen. nov., and the new species Dinotoperla aryballoi, sp. nov, D. tasmaniensis, sp. nov. and Oedemaperla shackletoni, sp. nov. as well as the new or updated descriptions of the larvae of 31 species and a comprehensive dichotomous key to these larvae.

Soundscapes and Larval Settlement: Larval Bivalve Responses to Habitat-Associated Underwater Sounds.

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Eggleston, David B; Lillis, Ashlee; Bohnenstiehl, DelWayne R

2016-01-01

We quantified the effects of habitat-associated sounds on the settlement response of two species of bivalves with contrasting habitat preferences: (1) Crassostrea virginicia (oyster), which prefers to settle on other oysters, and (2) Mercenaria mercenaria (clam), which settles on unstructured habitats. Oyster larval settlement in the laboratory was significantly higher when exposed to oyster reef sound compared with either off-reef or no-sound treatments. Clam larval settlement did not vary according to sound treatments. Similar to laboratory results, field experiments showed that oyster larval settlement in "larval housings" suspended above oyster reefs was significantly higher compared with off-reef sites.

Soundscapes and Larval Settlement: Characterizing the Stimulus from a Larval Perspective.

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Lillis, Ashlee; Eggleston, David B; Bohnenstiehl, DelWayne R

2016-01-01

There is growing evidence that underwater sounds serve as a cue for the larvae of marine organisms to locate suitable settlement habitats; however, the relevant spatiotemporal scales of variability in habitat-related sounds and how this variation scales with larval settlement processes remain largely uncharacterized, particularly in estuarine habitats. Here, we provide an overview of the approaches we have developed to characterize an estuarine soundscape as it relates to larval processes, and a conceptual framework is provided for how habitat-related sounds may influence larval settlement, using oyster reef soundscapes as an example.

Anopheline larval habitats seasonality and species distribution: a prerequisite for effective targeted larval habitats control programmes.

Directory of Open Access Journals (Sweden)

Eliningaya J Kweka

Full Text Available Larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. Understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. This study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western Kenya.A total of 51 aquatic habitats positive for anopheline larvae were surveyed and visited once a week for a period of 85 weeks in succession. Habitats were selected and identified. Mosquito larval species, physico-chemical parameters, habitat size, grass cover, crop cycle and distance to nearest house were recorded. Polymerase chain reaction revealed that An. gambiae s.l was the most dominant vector species comprised of An.gambiae s.s (77.60% and An.arabiensis (18.34%, the remaining 4.06% had no amplification by polymerase chain reaction. Physico-chemical parameters and habitat size significantly influenced abundance of An. gambiae s.s (P = 0.024 and An. arabiensis (P = 0.002 larvae. Further, larval species abundance was influenced by crop cycle (P≤0.001, grass cover (P≤0.001, while distance to nearest houses significantly influenced the abundance of mosquito species larvae (r = 0.920;P≤0.001. The number of predator species influenced mosquito larval abundance in different habitat types. Crop weeding significantly influenced with the abundance of An.gambiae s.l (P≤0.001 when preceded with fertilizer application. Significantly higher anopheline larval abundance was recorded in habitats in pasture compared to farmland (P = 0.002. When habitat stability and habitat types were considered, hoof print were the most productive followed by disused goldmines.These findings suggest that implementation of effective larval control programme should be targeted with larval

Recovery of Bacillus thuringiensis and related spore-forming bacteria from soil after application for gypsy moth control

Science.gov (United States)

Phyllis A.W. Martin; Elizabeth A. Mongeon; Michael B. Blackburn; Dawn E. Gundersen-Rindal

2011-01-01

Bacillus thuringiensis Berliner (Bt) has been applied for gypsy moth (Lymantria dispar L.) control in forests in the northeastern U.S. for many years. The subspecies of Bt that is used (urstaki) is not common in U.S. soil. We attempted to recover Bt from...

Coping with the gypsy moth on new frontiers of infestation

Science.gov (United States)

David A. Gansner; Owen W. Herrick; Garland N. Mason; Kurt W. Gottschalk

1987-01-01

Forest managers on new frontiers of infestation are searching for better ways to cope with the gypsy moth (Lymantria dispar). Presented herea are information and guidelines for remedial action to minimize future losses. Methods for assessing potential stand defoliation (susceptibility) and mortality (vulnerability), monitoring insect populations, and...

Response of gypsy moth larvae to homologous and heterologous nuclear polyhedrosis virus

Science.gov (United States)

Kathleen S. Shields; Edward M. Dougherty

1991-01-01

The gypsy moth, Lymantria dispar, is not particularly susceptible to baculoviruses other than the nuclear polyhedrosis virus originally isolated from the species (LdMNPV). The multiple enveloped nuclear polyhedrosis virus of Autographa californica (AcMNPV), a very virulent baculovirus that replicates in a large number of...

Effects of elevated CO2 leaf diet on gypsy moth (Lepidoptera: Lymantriidae) respiration rates

Science.gov (United States)

Anita R. Foss; William J. Mattson; Terry M. Trier

2013-01-01

Elevated levels of CO2 affect plant growth and leaf chemistry, which in turn can alter host plant suitability for insect herbivores. We examined the suitability of foliage from trees grown from seedlings since 1997 at Aspen FACE as diet for the gypsy moth (Lymantria dispar L.) Lepidoptera: Lymantriidae: paper birch (...

Assessment of MODIS NDVI time series data products for detecting forest defoliation by gypsy moth outbreaks

Science.gov (United States)

Joseph P. Spruce; Steven Sader; Robert E. Ryan; James Smoot; Philip Kuper; al. et.

2011-01-01

This paper discusses an assessment of Moderate Resolution Imaging Spectroradiometer (MODIS) time-series data products for detecting forest defoliation from European gypsy moth (Lymantria dispar). This paper describes an effort to aid the United States Department of Agriculture (USDA) Forest Service in developing and assessing MODIS-based gypsy moth defoliation...

Effects of invasive insects and fire on energy exchange and evapotranspiration in the New Jersey pine lands

Science.gov (United States)

Kenneth L. Clark; Nicholas Skowronski; Michael Gallagher; Hedi Renninger; Karina. Schafer

2012-01-01

We used eddy covariance and meteorological measurements to quantify energy exchange and evapotranspiration (Et) in three representative upland forest stands in the New Jersey Pinelands that were either defoliated by gypsy moth (Lymantria dispar L.) or burned in prescribed fires during the study period. Latent (λE) and sensible heat (H)...

Isolation and partial characterization of gypsy moth BTR-270, an anionic brush border membrane glycoconjugate that binds Bacillus thuringiensis Cry1A toxins with high affinity

Science.gov (United States)

Algimantas P. Valaitis; Jeremy L. Jenkins; Mi Kyong Lee; Donald H. Dean; Karen J. Garner

2001-01-01

BTR-270, a gypsy moth (Lymantria dispar) brush border membrane molecule that binds Bacillus thuringiensis (Bt) Cry1A toxins with high affinity, was purified by preparative gel electrophoresis. Rabbit antibodies specific for the Bt toxin-binding molecule were raised. Attempts to label BTR-270 by protein-directed techniques were...

Genetically-engineered baculovirus pesticides and their environmental safety

Science.gov (United States)

H. Alan Wood; Yu Zailin

1991-01-01

Baculoviruses such as the Lymantria dispar nuclear polyhedrosis virus (LdMNPV) are ecologically attractive alternatives to chemical insect pesticides but have a slow rate of control. To overcome this we have developed and are field testing an environmentally acceptable strategy which can be used for the introduction and expression of pesticide-...

"Slow the spread" a national program to contain the gypsy moth

Science.gov (United States)

Alexei A. Sharov; Donna Leonard; Andrew M. Liebhold; E. Anderson Roberts; Willard Dickerson; Willard Dickerson

2002-01-01

Invasions by alien species can cause substantial damage to our forest resources. The gypsy moth (Lymantria dispar) represents one example of this problem, and we present here a new strategy for its management that concentrates on containment rather than suppression of outbreaks. The "Slow the Spread" project is a combined federal and state...

Persistent effects of aerial applications of disparlure on gypsy moth: trap catch and mating success

Science.gov (United States)

Kevin W. Thorpe; Ksenia S. Tcheslavskaia; Patrick C. Tobin; Laura M. Blackburn; Donna S. Leonard; E. Anderson Roberts

2007-01-01

In forest plots treated aerially with a plastic laminated flake formulation (Disrupt® II) of the gypsy moth sex pheromone disparlure to disrupt gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), mating was monitored the year of treatment and 1-2 years after treatment to determine the effects of the treatment on suppression of...

Effects of gypsy moth infestation on aesthetic preferences and behavior intentions

Science.gov (United States)

Samuel M. Brock; Steve Hollenhorst; Wayne Freimund

1991-01-01

Using the Scenic Beauty Estimator (SBE) approach, within-stand color photographs were taken of 27 forested sites representative of the Central Appalachian Plateau. These sites had been repeatedly infested by gypsy moth (Lymantria dispar) (GM) to varying degrees since 1985, with resulting tree mortality from 6% - 97%. Eighty-one slides (3 slides/site...

Gypsy moth in the southeastern U.S.: Biology, ecology, and forest management strategies

Science.gov (United States)

Bruce W. ​Kauffman; Wayne K. Clatterbuck; Andrew M. Liebhold; David R. Coyle

2017-01-01

The European gypsy moth (Lymantria dispar L.) is a non-native insect that was accidentally introduced to North America in 1869 when it escaped cultivation by a French amateur entomologist living near Boston, MA. Despite early efforts to eradicate the species, it became established throughout eastern Massachusetts. Since then, the gypsy moth has...

Identification and characterization of a RAPD-PCR marker for distinguishing Asian and North American gypsy moths

Science.gov (United States)

K.J. Garner; J.M. Slavicek

1996-01-01

The recent introduction of the Asian gypsy moth (Lymantria dispar L.) into North America has necessitated the development of genetic markers to distinguish Asian moths from the established North American population, which originated in Europe. We used RAPD-PCR to identify a DNA length polymorphism that is diagnostic for the two moth strains. The...

Turbulence-enhanced prey encounter rates in larval fish : Effects of spatial scale, larval behaviour and size

DEFF Research Database (Denmark)

Kiørboe, Thomas; MacKenzie, Brian

1995-01-01

Turbulent water motion has several effects on the feeding ecology of larval fish and other planktivorous predators. In this paper, we consider the appropriate spatial scales for estimating relative velocities between larval fish predators and their prey, and the effect that different choices of s...... in the range in which turbulent intensity has an overall positive effect on larval fish ingestion rate probability. However, experimental data to test the model predictions are lacking. We suggest that the model inputs require further empirical study....

Evaluating sampling strategies for larval cisco (Coregonus artedi)

Science.gov (United States)

Myers, J.T.; Stockwell, J.D.; Yule, D.L.; Black, J.A.

2008-01-01

To improve our ability to assess larval cisco (Coregonus artedi) populations in Lake Superior, we conducted a study to compare several sampling strategies. First, we compared density estimates of larval cisco concurrently captured in surface waters with a 2 x 1-m paired neuston net and a 0.5-m (diameter) conical net. Density estimates obtained from the two gear types were not significantly different, suggesting that the conical net is a reasonable alternative to the more cumbersome and costly neuston net. Next, we assessed the effect of tow pattern (sinusoidal versus straight tows) to examine if propeller wash affected larval density. We found no effect of propeller wash on the catchability of larval cisco. Given the availability of global positioning systems, we recommend sampling larval cisco using straight tows to simplify protocols and facilitate straightforward measurements of volume filtered. Finally, we investigated potential trends in larval cisco density estimates by sampling four time periods during the light period of a day at individual sites. Our results indicate no significant trends in larval density estimates during the day. We conclude estimates of larval cisco density across space are not confounded by time at a daily timescale. Well-designed, cost effective surveys of larval cisco abundance will help to further our understanding of this important Great Lakes forage species.

Potential defoliation of trees by outbreak populations of gypsy moth in the Chicago area

Science.gov (United States)

David W. Onstad; David J. Nowak; Michael R. Jeffords

1997-01-01

The gypsy moth, Lymantria dispar, will soon become established in much of the Midwest. If an outbreak with extremely high population levels of this serious defoliator is allowed to occur in the Chicago area, what kind of damage can be expected? A model for defoliation, refoliation and mortality was developed based on the number of trees and...

Dose responses of in vivo- and in vitro-produced strains of gypsy moth (Lepidoptera: Lymantriidae) nucleopolyhedrovirus (LdMNPV) applied with and without the virus enhancer Blankophor BBH

Science.gov (United States)

John D. Podgwaite; James M. Slavicek; Kevin W. Thorpe; Ralph E. Webb; Roger W. Fuester; Vincent D' Amico; Randel A. Peiffer; Michael A. Valenti

2013-01-01

The gypsy moth, Lymantria dispar L., nucleopolyhedrovirus (LdMNPV) product Gypchek is a microbial pesticide produced by the USDA Forest Service. Gypchek is a mixture of LdMNPV genotypes produced in vivo. Commercial interests prefer to develop a stable, high-potency genotype that can be produced at low cost, preferably in vitro. We sprayed 2 LdMNPV...

Fine structure of selected mouthpart sensory organs of gypsy moth larvae

Science.gov (United States)

Vonnie D.C. Shields

2011-01-01

Gypsy moth larvae, Lymantria dispar (L.), are major pest defoliators in most of the United States and destroy millions of acres of trees annually. They are highly polyphagous and display a wide host plant preference, feeding on the foliage of hundreds of plants, such as oak, maple, and sweet gum. Lepidopteran larvae, such as the gypsy moth, depend...

Identification of a non-LTR retrotransposon from the gypsy moth

Science.gov (United States)

K.J. Garner; J.M. Slavicek

1999-01-01

A family of highly repetitive elements, named LDT1, has been identified in the gypsy moth, Lymantria dispar. The complete element is 5.4 kb in length and lacks long-terminal repeats, The element contains two open reading frames with a significant amino acid sequence similarity to several non-LTR retrotransposons. The first open reading frame contains...

Impact of enhancin genes on potency of LdNPV in gypsy moth

Science.gov (United States)

Kelli Hoover; Jim McNeil; Alyssa Gendron; James. Slavicek

2011-01-01

Lymantria dispar nucleopolyhedrovirus (LdNPV) contains two enhancin genes (E1 and E2) encoding proteases that degrade key peritrophic matrix (PM) proteins, thereby promoting infection and mortality by the virus. In a previous study, gypsy moth larvae inoculated with LdNPV in which both E1 and E2 were deleted (double deletion virus) resulted in a non-...

Sampling low-density gypsy moth populations

Science.gov (United States)

William E. Wallner; Clive G. Jones; Joseph S. Elkinton; Bruce L. Parker

1991-01-01

The techniques and methodology for sampling gypsy moth, Lymantria dispar L., at low densities, less than 100 egg masses/ha (EM/ha), are compared. Forest managers have constraints of time and cost, and need a useful, simple predictable means to assist them in sampling gypsy moth populations. A comparison of various techniques coupled with results of...

The Gypsy Moth Event Monitor for FVS: a tool for forest and pest managers

Science.gov (United States)

Kurt W. Gottschalk; Anthony W. Courter

2007-01-01

The Gypsy Moth Event Monitor is a program that simulates the effects of gypsy moth, Lymantria dispar (L.), within the confines of the Forest Vegetation Simulator (FVS). Individual stands are evaluated with a susceptibility index system to determine the vulnerability of the stand to the effects of gypsy moth. A gypsy moth outbreak is scheduled in the...

Cost analysis and biological ramifications for implementing the gypsy moth Slow the Spread Program

Science.gov (United States)

Patrick C. Tobin

2008-01-01

The gypsy moth Slow the Spread Program aims to reduce the rate of gypsy moth, Lymantria dispar (L.), spread into new areas in the United States. The annual budget for this program has ranged from $10-13 million. Changes in funding levels can have important ramifications to the implementation of this program, and consequently affect the rate of gypsy...

An insect out of control? The potential for spread and establishment of the gypsy moth in new forest areas in the United States

Science.gov (United States)

Max W. McFadden; Michael E. McManus

1991-01-01

The gypsy moth, Lymantria dispar L., was introduced from Europe into North America near Boston, Massachusetts, in 1869, and is now well established as a serious defoliator of forest, shade, and fruit trees over much of the eastern United States. Despite substantial efforts to eradicate, contain, or control this pest, the gypsy moth has persisted and...

Activity of gypsy moth dorsolateral neurosecretory neurons under increased rearing density

Directory of Open Access Journals (Sweden)

Mrdaković Marija

2012-01-01

Full Text Available Lymantria dispar caterpillars were reared under two different rearing densities for the first three days of the 4th larval instar: 5 larvae that were kept in a Petri dish (V = 80 ml belonged to the intense stress (D1 group; 5 larvae that were kept in a plastic cup (V = 300ml belonged to the group exposed to less intense stress (D2 group. In the control group, single larvae were reared in a Petri dish. Morphometric changes in L1, L2 and L2’ dorsolateral neurosecretory neurons (nsn were analyzed. After keeping 5 larvae in a Petri dish, the size of L2 neurosecretory neurons (nsn significantly increased. Rearing 5 larvae in a plastic cup significantly increased the size of L1 nsn nuclei and the number of L2’nsn. A decrease in relative band densities in the region of molecular masses (11-15 kD that correspond to prothoracicotropic hormones in the gypsy moth was observed in the electrophoretic profiles that were obtained after both treatments in comparison to the control group. [Acknowledgments. This study was supported by the Serbian Ministry of Education and Science (Grant No. 173027.

A small molecule for a big transformation: Topical application of a 20-nucleotide-long antisense fragment of the DIAP-2 gene inhibits the development of Drosophila melanogaster female imagos

Directory of Open Access Journals (Sweden)

Nyadar Palmah M.

2018-01-01

Full Text Available Several genes have been identified to play important roles associated with sex selection in Drosophila melanogaster. An essential part is attributed to the sex-lethal gene that depends on the expression of the X:A (number of chromosomes to autosomes ratio signal controlling both sex selection and dosage compensation processes in D. melanogaster. Interestingly, for sex selection in D. melanogaster there are no documented data addressing the role of the inhibitor of apoptosis (IAP genes and their signaling influence on this biological process. In this study, we found that topical application of a 20-nucleotide-long antisense DNA fragment (oligoDIAP-2 from the death-associated inhibitor of apoptosis (DIAP-2 gene interferes with D. melanogaster development and significantly decreases the number of female imagos and their biomass. We show that the applied antisense oligoDIAP-2 fragment downregulates the target DIAP-2 gene whose normal concentration is necessary for the development of female D. melanogaster. These data correspond to the results on downregulation of the target host IAP-Z gene of Lymantria dispar L. female imagos after topical treatment with an 18-nucleotide-long antisense DNA fragment from the L. dispar multicapsid nuclear polyhedrosis virus IAP-3 gene at the larval stage. The observed novel phenomenon linking the downregulation of insect IAP genes and the low rate of female imago development could have practical application, especially in insect pest control and molecular pathology.

Characterisation of Culex quinquefasciatus (Diptera: Culicidae larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

Directory of Open Access Journals (Sweden)

Marta Grech

2013-09-01

Full Text Available The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

Sandeel ( Ammodytes marinus ) larval transport patterns in the North Sea from an individual-based hydrodynamic egg and larval model

DEFF Research Database (Denmark)

Christensen, Asbjørn; Jensen, Henrik; Mosegaard, Henrik

2008-01-01

We have calculated a time series of larval transport indices for the central and southern North Sea covering 1970-2004, using a combined three-dimensional hydrodynamic and individual-based modelling framework for studying sandeel (Ammodytes marinus) eggs, larval transport, and growth. The egg phase...... is modelled by a stochastic, nonlinear degree-day model describing the extended hatch period. The larval growth model is parameterized by individually back-tracking the local physical environment of larval survivors from their catch location and catch time. Using a detailed map of sandeel habitats...... analyzed, and we introduce novel a scheme to quantify direct and indirect connectivity on equal footings in terms of an interbank transit time scale....

Gypsy moth (Lepidoptera: Lymantriidae) flight behavior and phenology based on field-deployed automated pheromone-baited traps

Science.gov (United States)

Patrick C. Tobin; Kenneth T. Klein; Donna S. Leonard

2009-01-01

Populations of the gypsy moth, Lymantria dispar (L.), are extensively monitored in the United States through the use of pheromone-baited traps.We report on use of automated pheromone-baited traps that use a recording sensor and data logger to record the unique date-time stamp of males as they enter the trap.We deployed a total of 352 automated traps...

Response of Adult Lymantriid Moths to Illumination Devices in the Russian Far East

Science.gov (United States)

William E. Wallner; Lee M. Humble; Robert E. Levin; Yuri N. Baranchikov; Ring T. Carde; Ring T. Carde

1995-01-01

In field studies in the Russian Far East, five types of illuminating devices were evaluated for attracting adult gypsy moth, Lymantria dispar (L.), pink gypsy moth, L. mathura Moore, and nun moth, L. monacha (L.). Our objective was to determine if light from commercial lamps suited to out-of-doors floodlighting could be modified to reduce their attractiveness to moths...

Biophysical models of larval dispersal in the Benguela Current ...

African Journals Online (AJOL)

We synthesise and update results from the suite of biophysical, larval-dispersal models developed in the Benguela Current ecosystem. Biophysical models of larval dispersal use outputs of physical hydrodynamic models as inputs to individual-based models in which biological processes acting during the larval life are ...

Rehydration of forensically important larval Diptera specimens.

Science.gov (United States)

Sanford, Michelle R; Pechal, Jennifer L; Tomberlin, Jeffery K

2011-01-01

Established procedures for collecting and preserving evidence are essential for all forensic disciplines to be accepted in court and by the forensic community at large. Entomological evidence, such as Diptera larvae, are primarily preserved in ethanol, which can evaporate over time, resulting in the dehydration of specimens. In this study, methods used for rehydrating specimens were compared. The changes in larval specimens with respect to larval length and weight for three forensically important blow fly (Diptera: Calliphoridae) species in North America were quantified. Phormia regina (Meigen), Cochliomyia macellaria (F.), and Chrysomya rufifacies (Macquart) third-instar larvae were collected from various decomposing animals and preserved with three preservation methods (80% ethanol, 70% isopropyl alcohol, and hot-water kill then 80% ethanol). Preservative solutions were allowed to evaporate. Rehydration was attempted with either of the following: 80% ethanol, commercial trisodium phosphate substitute solution, or 0.5% trisodium phosphate solution. All three methods partially restored weight and length of specimens recorded before preservation. Analysis of variance results indicated that effects of preservation, rehydration treatment, and collection animal were different in each species. The interaction between preservative method and rehydration treatment had a significant effect on both P. regina and C. macellaria larval length and weight. In addition, there was a significant interaction effect of collection animal on larval C. macellaria measurements. No significant effect was observed in C. rufifacies larval length or weight among the preservatives or treatments. These methods could be used to establish a standard operating procedure for dealing with dehydrated larval specimens in forensic investigations.

Cancer Disparities

Science.gov (United States)

Basic information about cancer disparities in the U.S., factors that contribute to the disproportionate burden of cancer in some groups, and examples of disparities in incidence and mortality among certain populations.

Models of prey capture in larval fish

NARCIS (Netherlands)

Drost, M.R.

1986-01-01

The food uptake of larval carp and pike is described from high speed movies with synchronous lateral and ventral views.

During prey intake by larval fishes the velocities of the created suction flow are high relative to their own size: 0.3 m/s for carp larvae of 6

Health Disparities

Science.gov (United States)

... Health and Health Disparities conduct transdisciplinary research involving social, behavioral, biological, and genetic research to improve knowledge of the causes of health disparities and devise effective methods of preventing, diagnosing, and treating disease and promoting ...

Stock-specific advection of larval walleye (Sander vitreus) in western Lake Erie: Implications for larval growth, mixing, and stock discrimination

Science.gov (United States)

Fraker, Michael E.; Anderson, Eric J.; May, Cassandra J.; Chen, Kuan-Yu; Davis, Jeremiah J.; DeVanna, Kristen M.; DuFour, Mark R.; Marschall, Elizabeth A.; Mayer, Christine M.; Miner, Jeffery G.; Pangle, Kevin L.; Pritt, Jeremy J.; Roseman, Edward F.; Tyson, Jeffrey T.; Zhao, Yingming; Ludsin, Stuart A

2015-01-01

Physical processes can generate spatiotemporal heterogeneity in habitat quality for fish and also influence the overlap of pre-recruit individuals (e.g., larvae) with high-quality habitat through hydrodynamic advection. In turn, individuals from different stocks that are produced in different spawning locations or at different times may experience dissimilar habitat conditions, which can underlie within- and among-stock variability in larval growth and survival. While such physically-mediated variation has been shown to be important in driving intra- and inter-annual patterns in recruitment in marine ecosystems, its role in governing larval advection, growth, survival, and recruitment has received less attention in large lake ecosystems such as the Laurentian Great Lakes. Herein, we used a hydrodynamic model linked to a larval walleye (Sander vitreus) individual-based model to explore how the timing and location of larval walleye emergence from several spawning sites in western Lake Erie (Maumee, Sandusky, and Detroit rivers; Ohio reef complex) can influence advection pathways and mixing among these local spawning populations (stocks), and how spatiotemporal variation in thermal habitat can influence stock-specific larval growth. While basin-wide advection patterns were fairly similar during 2011 and 2012, smaller scale advection patterns and the degree of stock mixing varied both within and between years. Additionally, differences in larval growth were evident among stocks and among cohorts within stocks which were attributed to spatiotemporal differences in water temperature. Using these findings, we discuss the value of linked physical–biological models for understanding the recruitment process and addressing fisheries management problems in the world's Great Lakes.

Location Isn't Everything: Timing of Spawning Aggregations Optimizes Larval Replenishment.

Directory of Open Access Journals (Sweden)

Megan J Donahue

Full Text Available Many species of reef fishes form large spawning aggregations that are highly predictable in space and time. Prior research has suggested that aggregating fish derive fitness benefits not just from mating at high density but, also, from oceanographic features of the spatial locations where aggregations occur. Using a probabilistic biophysical model of larval dispersal coupled to a fine resolution hydrodynamic model of the Florida Straits, we develop a stochastic landscape of larval fitness. Tracking virtual larvae from release to settlement and incorporating changes in larval behavior through ontogeny, we found that larval success was sensitive to the timing of spawning. Indeed, propagules released during the observed spawning period had higher larval success rates than those released outside the observed spawning period. In contrast, larval success rates were relatively insensitive to the spatial position of the release site. In addition, minimum (rather than mean larval survival was maximized during the observed spawning period, indicating a reproductive strategy that minimizes the probability of recruitment failure. Given this landscape of larval fitness, we take an inverse optimization approach to define a biological objective function that reflects a tradeoff between the mean and variance of larval success in a temporally variable environment. Using this objective function, we suggest that the length of the spawning period can provide insight into the tradeoff between reproductive risk and reward.

Strong links between metal contamination, habitat modification and estuarine larval fish distributions

Energy Technology Data Exchange (ETDEWEB)

McKinley, Andrew C., E-mail: andrew.mckinley@hotmail.com [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia); Miskiewicz, Anthony [Environment and Recreation, Wollongong City Council, 41 Burelli Street, Wollongong, New South Wales 2500 (Australia); Taylor, Matthew D.; Johnston, Emma L. [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia)

2011-06-15

Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: > We examine contamination/habitat modification impacts on larval fish. > Larvae communities differ between modified/unmodified estuaries. > Larvae are more abundant/diverse in modified areas. > Trends are strongly related to sediment metals/seagrass cover. > Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

Strong links between metal contamination, habitat modification and estuarine larval fish distributions

International Nuclear Information System (INIS)

McKinley, Andrew C.; Miskiewicz, Anthony; Taylor, Matthew D.; Johnston, Emma L.

2011-01-01

Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: → We examine contamination/habitat modification impacts on larval fish. → Larvae communities differ between modified/unmodified estuaries. → Larvae are more abundant/diverse in modified areas. → Trends are strongly related to sediment metals/seagrass cover. → Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

Rapid identification of the Asian gypsy moth and its related species based on mitochondrial DNA.

Science.gov (United States)

Wu, Ying; Du, Qiuyang; Qin, Haiwen; Shi, Juan; Wu, Zhiyi; Shao, Weidong

2018-02-01

The gypsy moth- Lymantria dispar (Linnaeus)-is a worldwide forest defoliator and is of two types: the European gypsy moth and the Asian gypsy moth. Because of multiple invasions of the Asian gypsy moth, the North American Plant Protection Organization officially approved Regional Standards for Phytosanitary Measures No. 33. Accordingly, special quarantine measures have been implemented for 30 special focused ports in the epidemic areas of the Asian gypsy moth, including China, which has imposed great inconvenience on export trade. The Asian gypsy moth and its related species (i.e., Lymantria monocha and Lymantria xylina ) intercepted at ports are usually at different life stages, making their identification difficult. Furthermore, Port quarantine requires speedy clearance. As such, it is difficult to identify the Asian gypsy moth and its related species only by their morphological characteristics in a speedy measure. Therefore, this study aimed to use molecular biology technology to rapidly identify the Asian gypsy moth and its related species based on the consistency of mitochondrial DNA in different life stages. We designed 10 pairs of specific primers from different fragments of the Asian gypsy moth and its related species, and their detection sensitivity met the need for rapid identification. In addition, we determined the optimal polymerase chain reaction amplification temperature of the 10 pairs of specific primers, including three pairs of specific primers for the Asian gypsy moth ( L. dispar asiatic ), four pairs of specific primers for the nun moth ( L. monocha ), and three pairs of specific primers for the casuarina moth ( L. xylina ). In conclusion, using our designed primers, direct rapid identification of the Asian gypsy moth and its related species is possible, and this advancement can help improve export trade in China.

Foraging behaviour and prey size spectra of larval herring Clupea harengus

DEFF Research Database (Denmark)

Munk, Peter

1992-01-01

size groups of larval herring Clupea harengus L. were studied when preying on 6 size groups of copepods. Larval swimming and attack behaviour changed with prey size and were related to the ratio between prey length and larval length. The effective search rate showed a maximum when prey length was about......, that the available biomass of food as a proportion of the predator biomass will not increase. In order to assess the uniformity of relative prey size spectra of herring larvae and their background in larval foraging behaviour, a set of experimental and field investigations has been carried out. In the experiments, 4...... in the biomass spectra of the environment is important to larval growth and survival....

Genetic diversity, classification and comparative study on the larval ...

African Journals Online (AJOL)

Genetic diversity, classification and comparative study on the larval phenotypic ... B. mori showed different performance based on larval phenotypic data. The analysis of variance regarding the studied traits showed that different strains have ...

Bipartite life cycle of coral reef fishes promotes increasing shape disparity of the head skeleton during ontogeny: an example from damselfishes (Pomacentridae

Directory of Open Access Journals (Sweden)

Vandewalle Pierre

2011-03-01

Full Text Available Abstract Background Quantitative studies of the variation of disparity during ontogeny exhibited by the radiation of coral reef fishes are lacking. Such studies dealing with the variation of disparity, i.e. the diversity of organic form, over ontogeny could be a first step in detecting evolutionary mechanisms in these fishes. The damselfishes (Pomacentridae have a bipartite life-cycle, as do the majority of demersal coral reef fishes. During their pelagic dispersion phase, all larvae feed on planktonic prey. On the other hand, juveniles and adults associated with the coral reef environment show a higher diversity of diets. Using geometric morphometrics, we study the ontogenetic dynamic of shape disparity of different head skeletal units (neurocranium, suspensorium and opercle, mandible and premaxilla in this fish family. We expected that larvae of different species might be relatively similar in shapes. Alternatively, specialization may become notable even in the juvenile and adult phase. Results The disparity levels increase significantly throughout ontogeny for each skeletal unit. At settlement, all larval shapes are already species-specific. Damselfishes show high levels of ontogenetic allometry during their post-settlement growth. The divergence of allometric patterns largely explains the changes in patterns and levels of shape disparity over ontogeny. The rate of shape change and the length of ontogenetic trajectories seem to be less variable among species. We also show that the high levels of shape disparity at the adult stage are correlated to a higher level of ecological and functional diversity in this stage. Conclusion Diversification throughout ontogeny of damselfishes results from the interaction among several developmental novelties enhancing disparity. The bipartite life-cycle of damselfishes exemplifies a case where the variation of environmental factors, i.e. the transition from the more homogeneous oceanic environment to the

Bipartite life cycle of coral reef fishes promotes increasing shape disparity of the head skeleton during ontogeny: an example from damselfishes (Pomacentridae)

Science.gov (United States)

2011-01-01

Background Quantitative studies of the variation of disparity during ontogeny exhibited by the radiation of coral reef fishes are lacking. Such studies dealing with the variation of disparity, i.e. the diversity of organic form, over ontogeny could be a first step in detecting evolutionary mechanisms in these fishes. The damselfishes (Pomacentridae) have a bipartite life-cycle, as do the majority of demersal coral reef fishes. During their pelagic dispersion phase, all larvae feed on planktonic prey. On the other hand, juveniles and adults associated with the coral reef environment show a higher diversity of diets. Using geometric morphometrics, we study the ontogenetic dynamic of shape disparity of different head skeletal units (neurocranium, suspensorium and opercle, mandible and premaxilla) in this fish family. We expected that larvae of different species might be relatively similar in shapes. Alternatively, specialization may become notable even in the juvenile and adult phase. Results The disparity levels increase significantly throughout ontogeny for each skeletal unit. At settlement, all larval shapes are already species-specific. Damselfishes show high levels of ontogenetic allometry during their post-settlement growth. The divergence of allometric patterns largely explains the changes in patterns and levels of shape disparity over ontogeny. The rate of shape change and the length of ontogenetic trajectories seem to be less variable among species. We also show that the high levels of shape disparity at the adult stage are correlated to a higher level of ecological and functional diversity in this stage. Conclusion Diversification throughout ontogeny of damselfishes results from the interaction among several developmental novelties enhancing disparity. The bipartite life-cycle of damselfishes exemplifies a case where the variation of environmental factors, i.e. the transition from the more homogeneous oceanic environment to the coral reef offering a wide

Diel and lunar variations in larval supply to Malindi Marine Park ...

African Journals Online (AJOL)

Understanding larval ecology and the mechanisms used in dispersal and habitat selection helps to better understand the population dynamics of coral reef communities. However, few studies have examined patterns of larval supply to reefs sites especially in the WIO region. Temporal patterns of fish larval occurrence in ...

File list: His.Lar.50.AllAg.Larval_brain [Chip-atlas[Archive

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Full Text Available His.Lar.50.AllAg.Larval_brain dm3 Histone Larvae Larval brain SRX1426943,SRX1426945... http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Lar.50.AllAg.Larval_brain.bed ...

File list: His.Lar.10.AllAg.Larval_brain [Chip-atlas[Archive

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Full Text Available His.Lar.10.AllAg.Larval_brain dm3 Histone Larvae Larval brain SRX1426945,SRX1426943... http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Lar.10.AllAg.Larval_brain.bed ...

File list: His.Lar.20.AllAg.Larval_brain [Chip-atlas[Archive

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Full Text Available His.Lar.20.AllAg.Larval_brain dm3 Histone Larvae Larval brain SRX1426943,SRX1426945... http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Lar.20.AllAg.Larval_brain.bed ...

Engendering health disparities.

Science.gov (United States)

Spitzer, Denise L

2005-01-01

How is gender implicated in our exploration of health disparities in Canada? Set against the backdrop of federal government policy, this review paper examines the ways in which gender intersects with other health determinants to produce disparate health outcomes. An overview of salient issues including the impact of gender roles, environmental exposures, gender violence, workplace hazards, economic disparities, the costs of poverty, social marginalization and racism, aging, health conditions, interactions with health services, and health behaviours are considered. This review suggests health is detrimentally affected by gender roles and statuses as they intersect with economic disparities, cultural, sexual, physical and historical marginalization as well as the strains of domestic and paid labour. These conditions result in an unfair health burden borne in particular by women whose access to health determinants is--in various degrees--limited. While progress has certainly been made on some fronts, the persistence of health disparities among diverse populations of women and men suggests a postponement of the vision of a just society with health for all that was articulated in the Federal Plan on Gender Equality. Commitment, creativity and collaboration from stakeholders ranging from various levels of government, communities, academics, non-governmental agencies and health professionals will be required to reduce and eliminate health disparities between and among all members of our society.

Effects of arginine vasotocin and mesotocin on the activation and development of amiloride-blockable short-circuit current across larval, adult, and cultured larval bullfrog skins.

Science.gov (United States)

Takada, Makoto; Fujimaki-Aoba, Kayo; Hokari, Shigeru

2010-03-01

Amphibian skin has osmoregulatory functions, with Na(+) crossing from outside to inside. Na(+) transport can be measured as the short-circuit current (SCC). We investigated the short-term and long-term effects of arginine vasotocin (AVT) and mesotocin (MT) (which modulate Na(+) transport) on the activation and development of an amiloride-blockable SCC (adult-type feature) in larval, adult, and corticoid-cultured larval bullfrog skins. We found: (1) AVT-receptor (AVT-R) and MT-receptor (MT-R) mRNAs could be detected in both larval and adult skins, (2) in the short term (within 60 min), the larval SCC (amiloride-stimulated SCC) was increased by AVT, forskolin, and MT, suggesting that AVT and MT did not activate the inactive ENaC (epithelial sodium channel) protein thought to be expressed in larval skin, (3) in the short term (within 90 min), AVT, forskolin, and MT stimulated the adult SCC (amiloride-blockable SCC), (4) AVT and MT increased both the larval and adult SCC via receptors insensitive to OPC-21268 (an antagonist of the V(1)-type receptor), OPC-31260 (an antagonist of the V(2)-type receptor), and ([d(CH(2))(5),Tyr(Me)(2),Thr(4),Orn(8),des-Gly-NH (2) (9) ]VT) (an antagonist of the oxytocin receptor), (5) culturing EDTA-treated larval skin with corticoids supplemented with AVT (1 microM) or MT (1 microM) for 2 weeks (long-term effects of AVT and MT) did not alter the corticoid-induced development of an amiloride-blockable SCC (adult-type feature). AVT and MT thus have the potential to stimulate SCC though channels that are already expressed, but they may not influence the development of the amiloride-blockable SCC (an adult-type feature) in larval skin.

Efficiency of selection methods for increased ratio of pupal-larval to adult-larval weight gains in Tribolium.

Science.gov (United States)

Campo, J L; Cobos, P

1994-01-12

Four lines of Tribolium castaneum were selected in each of three replicates for increased ratio of (pupal-larval) to (adult-larval) weight gains, using selection for increased (pupal-larval) weight gain (PL), selection for decreased (adult-larval) weight gain (AL), direct selection for the ratio (R) and linear selection index of larval, pupal and adult weights (I), respectively, for four generations. Linear index was calculated with economic weights of m(2) -m(3) , m(3) -m(1) and m(1) -m(2) , respectively, with m(1) , m(2) and m(3) being the means for larval, pupal and adult weights. Selection to increase the ratio is considered to be a method to maximize the mean response in (adult-larval) weight while controlling the response in (pupal-adult) weight, and as a form of antagonistic selection to increase the weight gain during a given age period relative to the gain at another age period. Larval, pupal and adult weights were measured at 14, 21 and 28 days after adult emergence, respectively. The selected proportion was 20 % in all lines. The response observed for the ratio differed significantly among lines (p adulto-peso de larva en Tribolium Cuatro líneas de Tribolium castaneum fueron seleccionadas en cada una de tres repeticiones para incrementar el cociente (peso de pupa-peso de larva)/(peso de adulto-peso de larva); la línea PL fue seleccionada para aumentar la diferencia (peso de pupa-pesp de larva), la línea AL fue seleccionada para disminuir la diferencia (peso de adulto-peso de larva), fa línea R fue seleccionada directamente para el cociente, y la línea I fue seleccionada por medio de un índice lineal basado en los pesos de larva, pupa y adulto, durante cuatro generaciones. El índice lineal se calculó con pesos económicos de (m(2) -m(3) ), (m(3) -m(1) ), y (m(1) -m(2) ) respectivamentee, siendo m(1) , m(2) , y m(3) los valores medios para el peso de larva, pupa y adulto. La selección para aumentar el cociente indicado es un método para maximizar

Cancer Disparities - Cancer Currents Blog

Science.gov (United States)

Blog posts on cancer health disparities research—including factors that influence disparities, disparities-related research efforts, and diversity in the cancer research workforce—from NCI Cancer Currents.

Effects of moisture content of food waste on residue separation, larval growth and larval survival in black soldier fly bioconversion.

Science.gov (United States)

Cheng, Jack Y K; Chiu, Sam L H; Lo, Irene M C

2017-09-01

In order to foster sustainable management of food waste, innovations in food waste valorization technologies are crucial. Black soldier fly (BSF) bioconversion is an emerging technology that can turn food waste into high-protein fish feed through the use of BSF larvae. The conventional method of BSF bioconversion is to feed BSF larvae with food waste directly without any moisture adjustment. However, it was reported that difficulty has been experienced in the separation of the residue (larval excreta and undigested material) from the insect biomass due to excessive moisture. In addition to the residue separation problem, the moisture content of the food waste may also affect the growth and survival aspects of BSF larvae. This study aims to determine the most suitable moisture content of food waste that can improve residue separation as well as evaluate the effects of the moisture content of food waste on larval growth and survival. In this study, pre-consumer and post-consumer food waste with different moisture content (70%, 75% and 80%) was fed to BSF larvae in a temperature-controlled rotary drum reactor. The results show that the residue can be effectively separated from the insect biomass by sieving using a 2.36mm sieve, for both types of food waste at 70% and 75% moisture content. However, sieving of the residue was not feasible for food waste at 80% moisture content. On the other hand, reduced moisture content of food waste was found to slow down larval growth. Hence, there is a trade-off between the sieving efficiency of the residue and the larval growth rate. Furthermore, the larval survival rate was not affected by the moisture content of food waste. A high larval survival rate of at least 95% was achieved using a temperature-controlled rotary drum reactor for all treatment groups. The study provides valuable insights for the waste management industry on understanding the effects of moisture content when employing BSF bioconversion for food waste recycling

File list: ALL.Lar.50.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: ALL.Lar.20.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: ALL.Lar.05.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: ALL.Lar.10.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

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Correlated evolution between mode of larval development and habitat in muricid gastropods.

Directory of Open Access Journals (Sweden)

Paula Pappalardo

Full Text Available Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule, which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in

Correlated evolution between mode of larval development and habitat in muricid gastropods.

Science.gov (United States)

Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

2014-01-01

Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids gastropods.

Fish larval transport in the coastal waters through ecological modelling

Digital Repository Service at National Institute of Oceanography (India)

George, G.

are as follows: (i) to find out the influence of environmental parameters on the biology of the given ecosystem (ii) to track larval transport and biological abundance in relation to environmental vari- ables (iii) to compare biological abundance and fish larval... include the following investigations: (i) analysis of satellite chlorophyll data along the southwest coastal waters of India to derive a biological calender for sardine (ii) tracking the larval survival and establish a link between food and sardine inter...

Ethnic and Racial Disparities in Education: Psychology's Role in Understanding and Reducing Disparities

Science.gov (United States)

Quintana, Stephen M.; Mahgoub, Lana

2016-01-01

We review the scope and sources of ethnic and racial disparities in education with a focus on the the implications of psychological theory and research for understanding and redressing these disparities. We identify 3 sources of ethnic and racial disparities including (a) social class differences, (b) differential treatment based on ethnic and…

Role of serotonergic neurons in the Drosophila larval response to light

Directory of Open Access Journals (Sweden)

Campos Ana

2009-06-01

Full Text Available Abstract Background Drosophila larval locomotion consists of forward peristalsis interrupted by episodes of pausing, turning and exploratory behavior (head swinging. This behavior can be regulated by visual input as seen by light-induced increase in pausing, head swinging and direction change as well as reduction of linear speed that characterizes the larval photophobic response. During 3rd instar stage, Drosophila larvae gradually cease to be repelled by light and are photoneutral by the time they wander in search for a place to undergo metamorphosis. Thus, Drosophila larval photobehavior can be used to study control of locomotion. Results We used targeted neuronal silencing to assess the role of candidate neurons in the regulation of larval photobehavior. Inactivation of DOPA decarboxylase (Ddc neurons increases the response to light throughout larval development, including during the later stages of the 3rd instar characterized by photoneutral response. Increased response to light is characterized by increase in light-induced direction change and associated pause, and reduction of linear movement. Amongst Ddc neurons, suppression of the activity of corazonergic and serotonergic but not dopaminergic neurons increases the photophobic response observed during 3rd instar stage. Silencing of serotonergic neurons does not disrupt larval locomotion or the response to mechanical stimuli. Reduced serotonin (5-hydroxytryptamine, 5-HT signaling within serotonergic neurons recapitulates the results obtained with targeted neuronal silencing. Ablation of serotonergic cells in the ventral nerve cord (VNC does not affect the larval response to light. Similarly, disruption of serotonergic projections that contact the photoreceptor termini in the brain hemispheres does not impact the larval response to light. Finally, pan-neural over-expression of 5-HT1ADro receptors, but not of any other 5-HT receptor subtype, causes a significant decrease in the response to

Effect of Larval Density on Food Utilization Efficiency of Tenebrio molitor (Coleoptera: Tenebrionidae).

Science.gov (United States)

Morales-Ramos, Juan A; Rojas, M Guadalupe

2015-10-01

Crowding conditions of larvae may have a significant impact on commercial production efficiency of some insects, such as Tenebrio molitor L. (Coleoptera: Tenebrionidae). Although larval densities are known to affect developmental time and growth in T. molitor, no reports were found on the effects of crowding on food utilization. The effect of larval density on food utilization efficiency of T. molitor larvae was studied by measuring efficiency of ingested food conversion (ECI), efficiency of digested food conversion (EDC), and mg of larval weight gain per gram of food consumed (LWGpFC) at increasing larval densities (12, 24, 36, 48, 50, 62, 74, and 96 larvae per dm(2)) over four consecutive 3-wk periods. Individual larval weight gain and food consumption were negatively impacted by larval density. Similarly, ECI, ECD, and LWGpFC were negatively impacted by larval density. Larval ageing, measured as four consecutive 3-wk periods, significantly and independently impacted ECI, ECD, and LWGpFC in a negative way. General linear model analysis showed that age had a higher impact than density on food utilization parameters of T. molitor larvae. Larval growth was determined to be responsible for the age effects, as measurements of larval mass density (in grams of larvae per dm(2)) had a significant impact on food utilization parameters across ages and density treatments (in number of larvae per dm(2)). The importance of mass versus numbers per unit of area as measurements of larval density and the implications of negative effects of density on food utilization for insect biomass production are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

'Peer pressure' in larval Drosophila?

Science.gov (United States)

Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

2014-06-06

Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. © 2014. Published by The Company of Biologists Ltd.

Descriptions of four larval forms of Nilodosis Kieffer from East Asia

Directory of Open Access Journals (Sweden)

Hongqu Tang

2012-10-01

Full Text Available Larval material putatively assigned to the genus Nilodosis Kieffer from Korea, China and Japan has been compared. The results show that the Japanese larval form has the club- to balloon-shaped cephalic setae S7 and S9 in common with the Korean larval form, but it can be separated from the latter by the shape of the inner mandibular teeth and the premandibular teeth. The larval forms from China (Guangdong and Yunnan apparently consist of two independent species. It is most likely that there will be more species in this genus found in Asia. Larvae are mud-sandy bottom-dwellers that can occur in the littoral of lakes and the potamal of larger rivers, up to a maximum depth of 5 meters. The specific larval characters show that it probably is a semi-psammorheophilic predator. doi: 10.5324/fn.v31i0.1406.Published online: 17 October 2012. 

Proteomics Insights: Proteins related to Larval Attachment and Metamorphosis of Marine Invertebrates

Directory of Open Access Journals (Sweden)

KONDETHIMMANAHALLI eCHANDRAMOULI

2014-10-01

Full Text Available The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTM are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

Proteomics insights: proteins related to larval attachment and metamorphosis of marine invertebrates

KAUST Repository

Chandramouli, Kondethimmanahalli

2014-10-31

The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTMs) are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

Proteomics insights: proteins related to larval attachment and metamorphosis of marine invertebrates

KAUST Repository

Chandramouli, Kondethimmanahalli; Qian, Pei-Yuan; Ravasi, Timothy

2014-01-01

The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTMs) are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

Vertical binocular disparity is encoded implicitly within a model neuronal population tuned to horizontal disparity and orientation.

Directory of Open Access Journals (Sweden)

Jenny C A Read

2010-04-01

Full Text Available Primary visual cortex is often viewed as a "cyclopean retina", performing the initial encoding of binocular disparities between left and right images. Because the eyes are set apart horizontally in the head, binocular disparities are predominantly horizontal. Yet, especially in the visual periphery, a range of non-zero vertical disparities do occur and can influence perception. It has therefore been assumed that primary visual cortex must contain neurons tuned to a range of vertical disparities. Here, I show that this is not necessarily the case. Many disparity-selective neurons are most sensitive to changes in disparity orthogonal to their preferred orientation. That is, the disparity tuning surfaces, mapping their response to different two-dimensional (2D disparities, are elongated along the cell's preferred orientation. Because of this, even if a neuron's optimal 2D disparity has zero vertical component, the neuron will still respond best to a non-zero vertical disparity when probed with a sub-optimal horizontal disparity. This property can be used to decode 2D disparity, even allowing for realistic levels of neuronal noise. Even if all V1 neurons at a particular retinotopic location are tuned to the expected vertical disparity there (for example, zero at the fovea, the brain could still decode the magnitude and sign of departures from that expected value. This provides an intriguing counter-example to the common wisdom that, in order for a neuronal population to encode a quantity, its members must be tuned to a range of values of that quantity. It demonstrates that populations of disparity-selective neurons encode much richer information than previously appreciated. It suggests a possible strategy for the brain to extract rarely-occurring stimulus values, while concentrating neuronal resources on the most commonly-occurring situations.

Age-Dependent Developmental Response to Temperature: An Examination of the Rarely Tested Phenomenon in Two Species (Gypsy Moth (Lymantria dispar and Winter Moth (Operophtera brumata

Directory of Open Access Journals (Sweden)

David R. Gray

2018-04-01

Full Text Available The pervading paradigm in insect phenology models is that the response to a given temperature does not vary within a life stage. The developmental rate functions that have been developed for general use, or for specific insects, have for the most part been temperature-dependent but not age-dependent, except where age is an ordinal variable designating the larval instar. Age dependence, where age is a continuous variable, is not often reported (or investigated, and is rarely included in phenology models. I provide a short review of the seldom-investigated phenomenon of age dependence in developmental response to temperature, and compare the derivation of the winter moth egg phenology model by Salis et al. to the derivation of another egg phenology model with age-dependent responses to temperature I discuss some probable reasons for the discrepancies (acknowledged by Salis et al. between modelled and observed developmental rates of the winter moth, and discuss the contribution that geographically robust phenology models can make to estimates of species distributions.

Conjunctions between motion and disparity are encoded with the same spatial resolution as disparity alone.

Science.gov (United States)

Allenmark, Fredrik; Read, Jenny C A

2012-10-10

Neurons in cortical area MT respond well to transparent streaming motion in distinct depth planes, such as caused by observer self-motion, but do not contain subregions excited by opposite directions of motion. We therefore predicted that spatial resolution for transparent motion/disparity conjunctions would be limited by the size of MT receptive fields, just as spatial resolution for disparity is limited by the much smaller receptive fields found in primary visual cortex, V1. We measured this using a novel "joint motion/disparity grating," on which human observers detected motion/disparity conjunctions in transparent random-dot patterns containing dots streaming in opposite directions on two depth planes. Surprisingly, observers showed the same spatial resolution for these as for pure disparity gratings. We estimate the limiting receptive field diameter at 11 arcmin, similar to V1 and much smaller than MT. Higher internal noise for detecting joint motion/disparity produces a slightly lower high-frequency cutoff of 2.5 cycles per degree (cpd) versus 3.3 cpd for disparity. This suggests that information on motion/disparity conjunctions is available in the population activity of V1 and that this information can be decoded for perception even when it is invisible to neurons in MT.

File list: InP.Lar.10.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

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File list: InP.Lar.50.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.50.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.50.AllAg.Larval_brain.bed ...

File list: InP.Lar.05.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.05.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.05.AllAg.Larval_brain.bed ...

File list: InP.Lar.20.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.20.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.20.AllAg.Larval_brain.bed ...

Reduced larval feeding rate is a strong evolutionary correlate of ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics; Volume 85; Issue 3. Reduced larval feeding rate is a strong evolutionary correlate of rapid development in Drosophila melanogaster. M. Rajamani N. Raghavendra ... Keywords. life-history evolution; development time; larval feeding rate; competition; tradeoffs; Drosophila melanogaster.

Effects of two stressors on amphibian larval development.

Science.gov (United States)

Stark, Karolina; Scott, David E; Tsyusko, Olga; Coughlin, Daniel P; Hinton, Thomas G

2012-05-01

In parallel with a renewed interest in nuclear power and its possible environmental impacts, a new environmental radiation protection system calls for environmental indicators of radiological stress. However, because environmental stressors seldom occur alone, this study investigated the combined effects of an ecological stressor (larval density) and an anthropogenic stressor (ionizing radiation) on amphibians. Scaphiopus holbrookii tadpoles reared at different larval densities were exposed to four low irradiation dose rates (0.13, 2.4, 21, and 222 mGy d(-1)) from (137)Cs during the sensitive period prior to and throughout metamorphosis. Body size at metamorphosis and development rate served as fitness correlates related to population dynamics. Results showed that increased larval density decreased body size but did not affect development rate. Low dose rate radiation had no impact on either endpoint. Copyright © 2012 Elsevier Inc. All rights reserved.

Healthcare disparities in critical illness.

Science.gov (United States)

Soto, Graciela J; Martin, Greg S; Gong, Michelle Ng

2013-12-01

To summarize the current literature on racial and gender disparities in critical care and the mechanisms underlying these disparities in the course of acute critical illness. MEDLINE search on the published literature addressing racial, ethnic, or gender disparities in acute critical illness, such as sepsis, acute lung injury, pneumonia, venous thromboembolism, and cardiac arrest. Clinical studies that evaluated general critically ill patient populations in the United States as well as specific critical care conditions were reviewed with a focus on studies evaluating factors and contributors to health disparities. Study findings are presented according to their association with the prevalence, clinical presentation, management, and outcomes in acute critical illness. This review presents potential contributors for racial and gender disparities related to genetic susceptibility, comorbidities, preventive health services, socioeconomic factors, cultural differences, and access to care. The data are organized along the course of acute critical illness. The literature to date shows that disparities in critical care are most likely multifactorial involving individual, community, and hospital-level factors at several points in the continuum of acute critical illness. The data presented identify potential targets as interventions to reduce disparities in critical care and future avenues for research.

What Are Cancer Disparities?

Science.gov (United States)

This infographic shows the factors associated with cancer disparities, examples of how the cancer burden differs across certain population groups, and NCI actions to understand and reduce cancer disparities.

Contributions for larval development optimization of Homarus gammarus

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Pedro Tiago Fonseca Sá

2014-06-01

The seawater rising temperature resulted in a decrease of intermoult period in all larval development stages and at all tested temperatures, ranging from 4.77 (Z1 to 16.5 days (Z3 at 16°C, whereas at 23°C, ranged from 3:02 (Z1 and 9.75 days (Z3. The results obtained are an extremely useful guide for future optimization of protocols on larval development of H. gammarus.

Fitness consequences of larval exposure to Beauveria bassiana on adults of the malaria vector Anopheles stephensi.

Science.gov (United States)

Vogels, Chantal B F; Bukhari, Tullu; Koenraadt, Constantianus J M

2014-06-01

Entomopathogenic fungi have shown to be effective in biological control of both larval and adult stages of malaria mosquitoes. However, a small fraction of mosquitoes is still able to emerge after treatment with fungus during the larval stage. It remains unclear whether fitness of these adults is affected by the treatment during the larval stage and whether they are still susceptible for another treatment during the adult stage. Therefore, we tested the effects of larval exposure to the entomopathogenic fungus Beauveria bassiana on fitness of surviving Anopheles stephensi females. Furthermore, we tested whether larval exposed females were still susceptible to re-exposure to the fungus during the adult stage. Sex ratio, survival and reproductive success were compared between non-exposed and larval exposed A. stephensi. Comparisons were also made between survival of non-exposed and larval exposed females that were re-exposed to B. bassiana during the adult stage. Larval treatment did not affect sex ratio of emerging mosquitoes. Larval exposed females that were infected died significantly faster and laid equal numbers of eggs from which equal numbers of larvae hatched, compared to non-exposed females. Larval exposed females that were uninfected had equal survival, but laid a significantly larger number of eggs from which a significantly higher number of larvae hatched, compared to non-exposed females. Larval exposed females which were re-exposed to B. bassiana during the adult stage had equal survival as females exposed only during the adult stage. Our results suggest that individual consequences for fitness of larval exposed females depended on whether a fungal infection was acquired during the larval stage. Larval exposed females remained susceptible to re-exposure with B. bassiana during the adult stage, indicating that larval and adult control of malaria mosquitoes with EF are compatible. Copyright © 2014. Published by Elsevier Inc.

The moral problem of health disparities.

Science.gov (United States)

Jones, Cynthia M

2010-04-01

Health disparities exist along lines of race/ethnicity and socioeconomic class in US society. I argue that we should work to eliminate these health disparities because their existence is a moral wrong that needs to be addressed. Health disparities are morally wrong because they exemplify historical injustices. Contractarian ethics, Kantian ethics, and utilitarian ethics all provide theoretical justification for viewing health disparities as a moral wrong, as do several ethical principles of primary importance in bioethics. The moral consequences of health disparities are also troubling and further support the claim that these disparities are a moral wrong. The Universal Declaration of Human Rights provides additional support that health disparities are a moral wrong, as does an analogy with the generally accepted duty to provide equal access to education. In this article, I also consider and respond to 3 objections to my thesis.

Granulomatous responses in larval taeniid infections.

Science.gov (United States)

Díaz, Á; Sagasti, C; Casaravilla, C

2018-05-01

Granulomas are responses to persistent nonliving bodies or pathogens, centrally featuring specialized macrophage forms called epithelioid and multinucleated giant cells. The larval stages of the cestode parasites of the Taeniidae family (Taenia, Echinococcus) develop for years in fixed tissue sites in mammals. In consequence, they are targets of granulomatous responses. The information on tissue responses to larval taeniids is fragmented among host and parasite species and scattered over many decades. We attempt to draw an integrated picture of these responses in solid tissues. The intensity of inflammation around live parasites spans a spectrum from minimal to high, parasite vitality correlating with low inflammation. The low end of the inflammatory spectrum features collagen capsules proximal to the parasites and moderate distal infiltration. The middle of the spectrum is dominated by classical granulomatous responses, whereas the high end features massive eosinophil invasions. Across the range of parasite species, much observational evidence suggests that eosinophils are highly effective at killing larval taeniids in solid tissues, before and during chronic granulomatous responses. The evidence available also suggests that these parasites are adapted to inhibit host granulomatous responses, in part through the exacerbation of host regulatory mechanisms including regulatory T cells and TGF-β. © 2018 John Wiley & Sons Ltd.

Mapping Medicare Disparities Tool

Data.gov (United States)

U.S. Department of Health & Human Services — The CMS Office of Minority Health has designed an interactive map, the Mapping Medicare Disparities Tool, to identify areas of disparities between subgroups of...

Effects of beach morphology and waves on onshore larval transport

Science.gov (United States)

Fujimura, A.; Reniers, A.; Paris, C. B.; Shanks, A.; MacMahan, J.; Morgan, S.

2015-12-01

Larvae of intertidal species grow offshore, and migrate back to the shore when they are ready to settle on their adult substrates. In order to reach the habitat, they must cross the surf zone, which is characterized as a semi-permeable barrier. This is accomplished through physical forcing (i.e., waves and current) as well as their own behavior. Two possible scenarios of onshore larval transport are proposed: Negatively buoyant larvae stay in the bottom boundary layer because of turbulence-dependent sinking behavior, and are carried toward the shore by streaming of the bottom boundary layer; positively buoyant larvae move to the shore during onshore wind events, and sink to the bottom once they encounter high turbulence (i.e., surf zone edge), where they are carried by the bottom current toward the shore (Fujimura et al. 2014). Our biophysical Lagrangian particle tracking model helps to explain how beach morphology and wave conditions affect larval distribution patterns and abundance. Model results and field observations show that larval abundance in the surf zone is higher at mildly sloped, rip-channeled beaches than at steep pocket beaches. Beach attributes are broken up to examine which and how beach configuration factors affect larval abundance. Modeling with alongshore uniform beaches with variable slopes reveal that larval populations in the surf zone are negatively correlated with beach steepness. Alongshore variability enhances onshore larval transport because of increased cross-shore water exchange by rip currents. Wave groups produce transient rip currents and enhance cross-shore exchange. Effects of other wave components, such as wave height and breaking wave rollers are also considered.

First feeding of larval herring

DEFF Research Database (Denmark)

Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

1985-01-01

The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

Remotely Sensing Larval Population Dynamics of Rice Field Anophelines

Science.gov (United States)

Beck, Louisa R.; Dister, Sheri W.; Wood, Byron L.; Washino, Robert K.

1997-01-01

The primary objective of both studies was to determine if RS and GIS techniques could be used to distinguish between high and low larval-producing rice fields in California. Results of the first study suggested that early-season green-up and proximity to livestock pastures were positively correlated with high larval abundance. Based on the early-season spectral differences between high and low larval-producing fields, it appeared that canopy development and tillering influenced mosquito habitat quality. At that time, rice fields consisted of a mixture of plants and water, a combination that allowed An. freeborni females to lay eggs in partial sunlight, protected from both predators and wind. This established a population earlier in the season than in other, 'less-green' fields where tillering and plant emergence was too minimal for ovipositioning. The study also indicated the importance of the distance that a mosquito would have to fly in order to take a bloodmeal prior to ovipositing. These associations were fully explored in an expanded study two years later. The second study confirmed the positive relationship between early season canopy development and larval abundance, and also demonstrated the relationship between abundance and distance-to-pasture. The association between greenness (as measured using NDVI), distance-to-pasture, and abundance is illustrated. The second study also indicated the siginificance of the landscape context of rice fields for larval production. Fields that included opportunities for feeding and resting within the flight range of the mosquito had higher abundances than did fields that were in a homogeneous rice area.

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

Directory of Open Access Journals (Sweden)

Takken Willem

2010-01-01

Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

Vegetative substrates used by larval northern pike in Rainy and Kabetogama Lakes, Minnesota

Science.gov (United States)

Anne L. Timm; Rodney B. Pierce

2015-01-01

Our objective was to identify characteristics of aquatic vegetative communities used as larval northern pike nursery habitat in Rainy and Kabetogama lakes, glacial shield reservoirs in northern Minnesota. Quatrefoil light traps fished at night were used to sample larval northern pike in 11 potential nursery areas. Larval northern pike were most commonly sampled among...

Evolution of increased adult longevity in Drosophila melanogaster populations selected for adaptation to larval crowding.

Science.gov (United States)

Shenoi, V N; Ali, S Z; Prasad, N G

2016-02-01

In holometabolous animals such as Drosophila melanogaster, larval crowding can affect a wide range of larval and adult traits. Adults emerging from high larval density cultures have smaller body size and increased mean life span compared to flies emerging from low larval density cultures. Therefore, adaptation to larval crowding could potentially affect adult longevity as a correlated response. We addressed this issue by studying a set of large, outbred populations of D. melanogaster, experimentally evolved for adaptation to larval crowding for 83 generations. We assayed longevity of adult flies from both selected (MCUs) and control populations (MBs) after growing them at different larval densities. We found that MCUs have evolved increased mean longevity compared to MBs at all larval densities. The interaction between selection regime and larval density was not significant, indicating that the density dependence of mean longevity had not evolved in the MCU populations. The increase in longevity in MCUs can be partially attributed to their lower rates of ageing. It is also noteworthy that reaction norm of dry body weight, a trait probably under direct selection in our populations, has indeed evolved in MCU populations. To the best of our knowledge, this is the first report of the evolution of adult longevity as a correlated response of adaptation to larval crowding. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Kauri seeds and larval somersaults

DEFF Research Database (Denmark)

Dupont, Steen Thorleif

2012-01-01

The trunk morphology of the larvae of the kauri pine (Agathis) seed infesting moth Agathiphaga is described using conventional, polarization, and scanning electron microscopy. The pine seed chamber formed by the larva is also described and commented on. The simple larval chaetotaxy includes more ...

Penaeid prawns in the St Lucia Lake System: Post-larval recruitment ...

African Journals Online (AJOL)

Penaeid prawns in the St Lucia Lake System: Post-larval recruitment and the bait fishery. ... Recruitment of post-larval penaeid prawns and the bait prawn fishery in the St Lucia Lake System were monitored for ... AJOL African Journals Online.

Immunocytochemistry and metamorphic fate of the larval nervous system of Triphyllozoon mucronatum (Ectoprocta: Gymnolaemata: Cheilostomata)

DEFF Research Database (Denmark)

Wanninger, Andreas; Koop, Demian; Degnan, Bernard M.

2005-01-01

The development of gymnolaemate Ectoprocta includes a larval stage of either the coronate or the cyphonautes type. Herein, we provide the first description of the larval neural anatomy of a coronate larva using immunocytochemical methods. We used antibodies against the neurotransmitters serotonin...... that the larval neuroanatomy and the processes that underlie the reorganization of larval organ systems during metamorphosis may vary much more among lophotrochozoan taxa than previously thought....... and FMRFamide and followed the fate of immunoreactive cells through metamorphosis. The larval serotonergic nervous system of Triphyllozoon mucronatum consists of an apical commissure, one pair of lateral axons, a coronate nerve net, an internal nerve mesh, and one pair of axons innervating the frontal organ....... FMRFamide is only found in the larval commissure and in the lateral axons. The entire serotonergic and FMRFamidergic nervous system is lost during metamorphosis and the adult neural structures form independent of the larval ones. In the postlarval zooid, both neurotransmitters are detected in the cerebral...

The larval development of the red mangrove crab Sesarma meinerti ...

African Journals Online (AJOL)

The larval stages of the red mangrove crab Sesarma meinerti de Man were reared in the laboratory. Larval development consists of five zoeal stages and one megalopa. Zoeal development lasts an average of 25 days at 25°C. The external morphology of larvae is described in detail and their relationship with larvae of.

Larval helminths in intermediate hosts

DEFF Research Database (Denmark)

Fredensborg, Brian Lund; Poulin, R

2005-01-01

Density-dependent effects on parasite fitness have been documented from adult helminths in their definitive hosts. There have, however, been no studies on the cost of sharing an intermediate host with other parasites in terms of reduced adult parasite fecundity. Even if larval parasites suffer a ...

Observations on the reproductive and larval biology of Blennius pavo (Pisces: Teleostei)

Science.gov (United States)

Westernhagen, H.

1983-09-01

Social behaviour and spawning of adult Blennius pavo kept in the laboratory are described. Eggs are deposited in batches on the walls of artificial spawning places (PVC pipes). One male guards and tends the eggs of different females in one spawning place. Larval hatching occurs in groups according to oviposition. Minimum incubation temperature is around 14 15°C. Larval survival in 1-1 rearing jars is not related to larval total length but to density of larval stock. An experimental population of laboratory reared juvenile and adolescent B. pavo displays a male to female ratio of 1:1.4. Factors possibly influencing the sex ratio of this littoral fish are discussed in view of the situation in its natural environment.

Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

Science.gov (United States)

Heap, Lucy A.; Vanwalleghem, Gilles C.; Thompson, Andrew W.; Favre-Bulle, Itia; Rubinsztein-Dunlop, Halina; Scott, Ethan K.

2018-01-01

The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH) to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC)/stratum griseum periventriculare (SPV), and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil. PMID:29403362

Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

Directory of Open Access Journals (Sweden)

Lucy A. Heap

2018-01-01

Full Text Available The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC/stratum griseum periventriculare (SPV, and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil.

Measuring larval nematode contamination on cattle pastures: Comparing two herbage sampling methods.

Science.gov (United States)

Verschave, S H; Levecke, B; Duchateau, L; Vercruysse, J; Charlier, J

2015-06-15

Assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. Direct quantification of infective larvae (L3) on herbage is the most applied method to measure pasture larval contamination. However, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. The aim of this study was (1) to compare two different sampling methods in terms of pasture larval count results and time required to sample, (2) to assess the amount of variation in larval counts at the level of sample plot, pasture and season, respectively and (3) to calculate the required sample size to assess pasture larval contamination with a predefined precision using random plots across pasture. Eight young stock pastures of different commercial dairy herds were sampled in three consecutive seasons during the grazing season (spring, summer and autumn). On each pasture, herbage samples were collected through both a double-crossed W-transect with samples taken every 10 steps (method 1) and four random located plots of 0.16 m(2) with collection of all herbage within the plot (method 2). The average (± standard deviation (SD)) pasture larval contamination using sampling methods 1 and 2 was 325 (± 479) and 305 (± 444)L3/kg dry herbage (DH), respectively. Large discrepancies in pasture larval counts of the same pasture and season were often seen between methods, but no significant difference (P = 0.38) in larval counts between methods was found. Less time was required to collect samples with method 2. This difference in collection time between methods was most pronounced for pastures with a surface area larger than 1 ha. The variation in pasture larval counts from samples generated by random plot sampling was mainly due to the repeated measurements on the same pasture in the same season (residual variance

Experimental studies on the larval development of the shrimps Crangon crangon and C. allmanni

Science.gov (United States)

Criales, M. M.; Anger, K.

1986-09-01

Larvae of the shrimps Crangon crangon L. and C. allmanni Kinahan were reared in the laboratory from hatching through metamorphosis. Effects of rearing methods (larval density, application of streptomycin, food) and of salinity on larval development were tested only in C. crangon, influence of temperature was studied in both species. Best results were obtained when larvae were reared individually, with a mixture of Artemia sp. and the rotifer Brachionus plicatilis as food. Streptomycin had partly negative effects and was thus not adopted for standard rearing techniques. All factors tested in this study influenced not only the rates of larval survival and moulting, but also morphogenesis. In both species, in particular in C. crangon, a high degree of variability in larval morphology and in developmental pathways was observed. Unsuitable conditions, e.g. crowding in mass culture, application of antibiotics, unsuitable food (rotifers, phytoplankton), extreme temperatures and salinities, tend to increase the number of larval instars and of morphological forms. The frequency of moulting is controlled mainly by temperature. Regression equations describing the relations between the durations of larval instars and temperature are given for both Crangon species. The number of moults is a linear function of larval age and a power function of temperature. There is high variation in growth (measured as carapace length), moulting frequency, morphogenesis, and survival among hatches originating from different females. The interrelations between these different measures of larval development in shrimps and prawns are discussed.

Effect of massing on larval growth rate.

Science.gov (United States)

Johnson, Aidan P; Wallman, James F

2014-08-01

Estimation of minimum postmortem interval commonly relies on predicting the age of blowfly larvae based on their size and an estimate of the temperatures to which they have been exposed throughout their development. The majority of larval growth rate data have been developed using small larval masses in order to avoid excess heat generation. The current study collected growth rate data for larvae at different mass volumes, and assessed the temperature production of these masses, for two forensically important blow fly species, Chrysomya rufifacies and Calliphora vicina. The growth rate of larvae in a small mass, exposed to the higher temperatures equivalent to those experienced by large masses, was also assessed to determine if observed differences were due to the known temperature effects of maggot masses. The results showed that temperature production increased with increasing mass volume, with temperature increases of 11 °C observed in the large Ch. rufifacies masses and increases of 5 °C in the large C. vicina masses. Similarly, the growth rate of the larvae was affected by mass size. The larvae from small masses grown at the higher temperatures experienced by large masses displayed an initial delay in growth, but then grew at a similar rate to those larvae at a constant 23 °C. Since these larvae from masses of equivalent sizes displayed similar patterns of growth rate, despite differing temperatures, and these growth rates differed from larger masses exposed to the same temperatures, it can be concluded that larval growth rate within a mass may be affected by additional factors other than temperature. Overall, this study highlights the importance of understanding the role of massing in larval development and provides initial developmental data for mass sizes of two forensically important blowfly species commonly encountered in Australian forensic casework. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Disparities in Gynecological Malignancies

Directory of Open Access Journals (Sweden)

Sudeshna eChatterjee

2016-02-01

Full Text Available Objectives: Health disparities and inequalities in access to care among different socioeconomic, ethnic, and racial groups have been well documented in the U.S. healthcare system. In this review, we aimed to provide an overview of barriers to care contributing to health disparities in gynecological oncology management and to describe site-specific disparities in gynecologic care for endometrial, ovarian, and cervical cancer. Methods: We performed a literature review of peer-reviewed academic and governmental publications focusing on disparities in gynecological care in the United States by searching PubMed and Google Scholar electronic databases. Results: There are multiple important underlying issues that may contribute to the disparities in gynecological oncology management in the United States, namely geographic access and hospital based-discrepancies, research-based discrepancies, influence of socioeconomic and health insurance status, and finally the influence of race and biological factors. Despite the reduction in overall cancer-related deaths since the 1990s, the 5-year survival for Black women is significantly lower than for White women for each gynecologic cancer type and each stage of diagnosis. For ovarian and endometrial cancer, black patients are less likely to receive treatment consistent with evidence-based guidelines and have worse survival outcomes even after accounting for stage and comorbidities. For cervical and endometrial cancer, the mortality rate for black women remains twice that of White women. Conclusions: Health care disparities in the incidence and outcome of gynecologic cancers are complex and involve biologic factors as well as racial, socioeconomic and geographic barriers that influence treatment and survival. These barriers must be addressed to provide optimal care to women in the U.S. with gynecologic cancer.

Changes in Lymantria dispar protocerebral neurosecretory neurons after exposure to cadmium

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Ilijin Larisa

2011-01-01

Full Text Available Gypsy moth 4th instar caterpillars were fed for 3 days with an artificial diet supplemented with increasing cadmium (Cd concentrations (0, 10, 30, 100 and 250 μg⁄g of dry food weight. Changes in the morphometric characteristics of A1’ dorso-medial and L2 dorso-lateral neurosecretory neurons (nsn were analyzed. In the A1’ nsn, Cd supplements led to an enhanced nuclear size, except in the group treated with 250 μg Cd⁄g in the form of dry food. The size of L2 type nsn was increased in the groups provided with 30 and 100 μg Cd⁄g, while no differences in the size of nuclei was detected in L2 neurons among the experimental groups.

Processing vertical size disparities in distinct depth planes.

Science.gov (United States)

Duke, Philip A; Howard, Ian P

2012-08-17

A textured surface appears slanted about a vertical axis when the image in one eye is horizontally enlarged relative to the image in the other eye. The surface appears slanted in the opposite direction when the same image is vertically enlarged. Two superimposed textured surfaces with different horizontal size disparities appear as two surfaces that differ in slant. Superimposed textured surfaces with equal and opposite vertical size disparities appear as a single frontal surface. The vertical disparities are averaged. We investigated whether vertical size disparities are averaged across two superimposed textured surfaces in different depth planes or whether they induce distinct slants in the two depth planes. In Experiment 1, two superimposed textured surfaces with different vertical size disparities were presented in two depth planes defined by horizontal disparity. The surfaces induced distinct slants when the horizontal disparity was more than ±5 arcmin. Thus, vertical size disparities are not averaged over surfaces with different horizontal disparities. In Experiment 2 we confirmed that vertical size disparities are processed in surfaces away from the horopter, so the results of Experiment 1 cannot be explained by the processing of vertical size disparities in a fixated surface only. Together, these results show that vertical size disparities are processed separately in distinct depth planes. The results also suggest that vertical size disparities are not used to register slant globally by their effect on the registration of binocular direction of gaze.

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

NARCIS (Netherlands)

Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

2010-01-01

Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

Minority Health and Health Disparities

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... ik People" People Awakening Resilience Project (PARP), Cuqyun "Measuring" Treatment and Health Services Research Alcohol Treatment and ... addressing Health Disparities . 1 2009-2013 Health Disparities Strategic Plan, p.4 2 Ibid, p.4 3 ...

Passive larval transport explains recent gene flow in a Mediterranean gorgonian

Science.gov (United States)

Padrón, Mariana; Costantini, Federica; Baksay, Sandra; Bramanti, Lorenzo; Guizien, Katell

2018-06-01

Understanding the patterns of connectivity is required by the Strategic Plan for Biodiversity 2011-2020 and will be used to guide the extension of marine protection measures. Despite the increasing accuracy of ocean circulation modelling, the capacity to model the population connectivity of sessile benthic species with dispersal larval stages can be limited due to the potential effect of filters acting before or after dispersal, which modulates offspring release or settlement, respectively. We applied an interdisciplinary approach that combined demographic surveys, genetic methods (assignment tests and coalescent-based analyses) and larval transport simulations to test the relative importance of demographics and ocean currents in shaping the recent patterns of gene flow among populations of a Mediterranean gorgonian ( Eunicella singularis) in a fragmented rocky habitat (Gulf of Lion, NW Mediterranean Sea). We show that larval transport is a dominant driver of recent gene flow among the populations, and significant correlations were found between recent gene flow and larval transport during an average single dispersal event when the pelagic larval durations (PLDs) ranged from 7 to 14 d. Our results suggest that PLDs that efficiently connect populations distributed over a fragmented habitat are filtered by the habitat layout within the species competency period. Moreover, a PLD ranging from 7 to 14 d is sufficient to connect the fragmented rocky substrate of the Gulf of Lion. The rocky areas located in the centre of the Gulf of Lion, which are currently not protected, were identified as essential hubs for the distribution of migrants in the region. We encourage the use of a range of PLDs instead of a single value when estimating larval transport with biophysical models to identify potential connectivity patterns among a network of Marine Protected Areas or even solely a seascape.

Larval outbreaks in West Greenland

DEFF Research Database (Denmark)

Lund, Magnus; Raundrup, Katrine; Westergaard-Nielsen, Andreas

2017-01-01

effects of a larval outbreak in 2011 on vegetation productivity and CO2 exchange. We estimate a decreased carbon (C) sink strength in the order of 118–143 g C m−2, corresponding to 1210–1470 tonnes C at the Kobbefjord catchment scale. The decreased C sink was, however, counteracted the following years...

How Metamorphosis Is Different in Plethodontids: Larval Life History Perspectives on Life-Cycle Evolution

Science.gov (United States)

Beachy, Christopher K.; Ryan, Travis J.; Bonett, Ronald M.

2017-01-01

Plethodontid salamanders exhibit biphasic, larval form paedomorphic, and direct developing life cycles. This diversity of developmental strategies exceeds that of any other family of terrestrial vertebrate. Here we compare patterns of larval development among the three divergent lineages of biphasic plethodontids and other salamanders. We discuss how patterns of life-cycle evolution and larval ecology might have produced a wide array of larval life histories. Compared with many other salamanders, most larval plethodontids have relatively slow growth rates and sometimes exceptionally long larval periods (up to 60 mo). Recent phylogenetic analyses of life-cycle evolution indicate that ancestral plethodontids were likely direct developers. If true, then biphasic and paedomorphic lineages might have been independently derived through different developmental mechanisms. Furthermore, biphasic plethodontids largely colonized stream habitats, which tend to have lower productivity than seasonally ephemeral ponds. Consistent with this, plethodontid larvae grow very slowly, and metamorphic timing does not appear to be strongly affected by growth history. On the basis of this, we speculate that feeding schedules and stress hormones might play a comparatively reduced role in governing the timing of metamorphosis of stream-dwelling salamanders, particularly plethodontids. PMID:29269959

The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

Energy Technology Data Exchange (ETDEWEB)

Cioni, C.; De Palma, F.; De Vito, L.; Stefanelli, A. [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell`Uomo

1997-12-31

In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

Energy Technology Data Exchange (ETDEWEB)

Cioni, C; De Palma, F; De Vito, L; Stefanelli, A [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell` Uomo

1998-12-31

In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

Adaptive locomotor behavior in larval zebrafish.

Science.gov (United States)

Portugues, Ruben; Engert, Florian

2011-01-01

In this study we report that larval zebrafish display adaptive locomotor output that can be driven by unexpected visual feedback. We develop a new assay that addresses visuomotor integration in restrained larval zebrafish. The assay involves a closed-loop environment in which the visual feedback a larva receives depends on its own motor output in a way that resembles freely swimming conditions. The experimenter can control the gain of this closed feedback loop, so that following a given motor output the larva experiences more or less visual feedback depending on whether the gain is high or low. We show that increases and decreases in this gain setting result in adaptive changes in behavior that lead to a generalized decrease or increase of motor output, respectively. Our behavioral analysis shows that both the duration and tail beat frequency of individual swim bouts can be modified, as well as the frequency with which bouts are elicited. These changes can be implemented rapidly, following an exposure to a new gain of just 175 ms. In addition, modifications in some behavioral parameters accumulate over tens of seconds and effects last for at least 30 s from trial to trial. These results suggest that larvae establish an internal representation of the visual feedback expected from a given motor output and that the behavioral modifications are driven by an error signal that arises from the discrepancy between this expectation and the actual visual feedback. The assay we develop presents a unique possibility for studying visuomotor integration using imaging techniques available in the larval zebrafish.

Effect of corticosterone on larval growth, antipredator behaviour and metamorphosis of Hylarana indica.

Science.gov (United States)

Kulkarni, P S; Gramapurohit, N P

2017-09-15

Corticosterone (CORT), a principal glucocorticoid in amphibians, is known to regulate diverse physiological processes including growth and metamorphosis of anuran tadpoles. Environmental stressors activate the neuroendocrine stress axis (hypothalamus-pituitary-interrenal axis, HPI) leading to an acute increase in CORT, which in turn, helps in coping with particular stress. However, chronic increase in CORT can negatively affect other physiological processes such as growth and metamorphosis. Herein, we studied the effect of exogenous CORT on larval growth, antipredator behaviour and metamorphic traits of Hylarana indica. Embryonic exposure to 5 or 20μg/L CORT did not affect their development, hatching duration as well as larval growth and metamorphosis. Exposure of tadpoles to 10 or 20μg/L CORT throughout larval development caused slower growth and development leading to increased body mass at stage 37. However, body and tail morphology of tadpoles was not affected. Interestingly, larval exposure to 5, 10 or 20μg/L CORT enhanced their antipredator response against kairomones in a concentration-dependent manner. Further, larval exposure to increasing concentrations of CORT resulted in the emergence of heavier froglets at 10 and 20μg/L while, delaying metamorphosis at all concentrations. Interestingly, the heavier froglets had shorter hindlimbs and consequently shorter jump distances. Tadpoles exposed to 20μg/L CORT during early, mid or late larval stages grew and developed slowly but tadpole morphology was not altered. Interestingly, exposure during early or mid-larval stages resulted in an enhanced antipredator response. These individuals metamorphosed later but at higher body mass while SVL was unaffected. Copyright © 2016 Elsevier Inc. All rights reserved.

Larval diet affects mosquito development and permissiveness to Plasmodium infection.

Science.gov (United States)

Linenberg, Inbar; Christophides, George K; Gendrin, Mathilde

2016-12-02

The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii. We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clarke's Pool Pellets and Nishikoi Fish Pellets, and one flaked diet, Tetramin Fish-Flakes. Larvae grow and develop faster and produce bigger adults when feeding on both types of pellets compared with flakes. This correlates with a higher microbiota load in pellet-fed larvae, in agreement with the known positive effect of the microbiota on mosquito development. Larval diet also significantly influences the prevalence and intensity of Plasmodium berghei infection in adults, whereby Nishikoi Fish Pellets-fed larvae develop into adults that are highly permissive to parasites and survive longer after infection. This correlates with a lower amount of Enterobacteriaceae in the midgut microbiota. Together, our results shed light on the influence of larval feeding on mosquito development, microbiota and vector competence; they also provide useful data for mosquito rearing.

Larval settlement and metamorphosis of the mussel Mytilus coruscus in response to monospecific bacterial biofilms.

Science.gov (United States)

Yang, Jin-Long; Shen, Pei-Jing; Liang, Xiao; Li, Yi-Feng; Bao, Wei-Yang; Li, Jia-Le

2013-01-01

The effects of bacterial biofilms (BFs) on larval settlement and metamorphosis of the mussel, Mytilus coruscus, were investigated in the laboratory. Of nine different isolates, Shewanella sp.1 BF induced the highest percentage of larval settlement and metamorphosis, whereas seven other isolates had a moderate inducing activity and one isolate, Pseudoalteromonas sp. 4, had a no inducing activity. The inducing activity of individual bacterial isolates was not correlated either with their phylogenetic relationship or with the surfaces from which they were isolated. Among the eight bacterial species that demonstrated inducing activity, bacterial density was significantly correlated with the inducing activity for each strain, with the exception of Vibrio sp. 1. The Shewanella sp. 1 BF cue that was responsible for inducing larval settlement and metamorphosis was further investigated. Treatment of the BFs with formalin, antibiotics, ultraviolet irradiation, heat, and ethanol resulted in a significant decrease in their inducing activities and cell survival. BF-conditioned water (CW) did not induce larval metamorphosis, but it triggered larval settlement behavior. A synergistic effect of CW with formalin-fixed Shewanella sp. 1 BF significantly promoted larval metamorphosis. Thus, a cocktail of chemical cues derived from bacteria may be necessary to stimulate larval settlement and metamorphosis in this species.

The role of individual variation in marine larval dispersal

KAUST Repository

Nanninga, Gerrit B.

2014-12-08

The exchange of individuals among patchy habitats plays a central role in spatial ecology and metapopulation dynamics. Dispersal is frequently observed to vary non-randomly within populations (e.g., short vs. long), indicating that variability among individuals may shape heterogeneity in patterns of connectivity. The concept of context- and condition-dependent dispersal describes the balance between the costs and benefits of dispersal that arises from the interaction of temporal and spatial landscape heterogeneity (the context) with phenotypic variability among individuals (the condition). While this hypothesis is widely accepted in terrestrial theory, it remains questionable to what extent the concept of adaptive dispersal strategies may apply to marine larval dispersal, a process that is largely determined by stochastic forces. Yet, larvae of many taxa exhibit strong navigational capabilities and there is mounting evidence of widespread intra-specific variability in biological traits that are potentially correlated with dispersal potential. While so far there are few known examples of real larval dispersal polymorphisms, intra-specifically variable dispersal strategies may be common in marine systems. Whether adaptive or not, it is becoming apparent that inter-individual heterogeneity in morphology, behavior, condition, and life history traits may have critical effects on population-level heterogeneity in dispersal. Here, we explore the eco-evolutionary causes and consequences of intrinsic and extrinsic variability on larval dispersal by synthesizing the existing literature and drawing conceptual parallels from terrestrial theory. We emphasize the potential importance of larval dispersal polymorphisms in marine population dynamics.

Embryogenesis and larval biology of the cold-water coral Lophelia pertusa.

Directory of Open Access Journals (Sweden)

Ann I Larsson

Full Text Available Cold-water coral reefs form spectacular and highly diverse ecosystems in the deep sea but little is known about reproduction, and virtually nothing about the larval biology in these corals. This study is based on data from two locations of the North East Atlantic and documents the first observations of embryogenesis and larval development in Lophelia pertusa, the most common framework-building cold-water scleractinian. Embryos developed in a more or less organized radial cleavage pattern from ∼ 160 µm large neutral or negatively buoyant eggs, to 120-270 µm long ciliated planulae. Embryogenesis was slow with cleavage occurring at intervals of 6-8 hours up to the 64-cell stage. Genetically characterized larvae were sexually derived, with maternal and paternal alleles present. Larvae were active swimmers (0.5 mm s(-1 initially residing in the upper part of the water column, with bottom probing behavior starting 3-5 weeks after fertilization. Nematocysts had developed by day 30, coinciding with peak bottom-probing behavior, and possibly an indication that larvae are fully competent to settle at this time. Planulae survived for eight weeks under laboratory conditions, and preliminary results indicate that these planulae are planktotrophic. The late onset of competency and larval longevity suggests a high dispersal potential. Understanding larval biology and behavior is of paramount importance for biophysical modeling of larval dispersal, which forms the basis for predictions of connectivity among populations.

Counties eliminating racial disparities in colorectal cancer mortality.

Science.gov (United States)

Rust, George; Zhang, Shun; Yu, Zhongyuan; Caplan, Lee; Jain, Sanjay; Ayer, Turgay; McRoy, Luceta; Levine, Robert S

2016-06-01

Although colorectal cancer (CRC) mortality rates are declining, racial-ethnic disparities in CRC mortality nationally are widening. Herein, the authors attempted to identify county-level variations in this pattern, and to characterize counties with improving disparity trends. The authors examined 20-year trends in US county-level black-white disparities in CRC age-adjusted mortality rates during the study period between 1989 and 2010. Using a mixed linear model, counties were grouped into mutually exclusive patterns of black-white racial disparity trends in age-adjusted CRC mortality across 20 three-year rolling average data points. County-level characteristics from census data and from the Area Health Resources File were normalized and entered into a principal component analysis. Multinomial logistic regression models were used to test the relation between these factors (clusters of related contextual variables) and the disparity trend pattern group for each county. Counties were grouped into 4 disparity trend pattern groups: 1) persistent disparity (parallel black and white trend lines); 2) diverging (widening disparity); 3) sustained equality; and 4) converging (moving from disparate outcomes toward equality). The initial principal component analysis clustered the 82 independent variables into a smaller number of components, 6 of which explained 47% of the county-level variation in disparity trend patterns. County-level variation in social determinants, health care workforce, and health systems all were found to contribute to variations in cancer mortality disparity trend patterns from 1990 through 2010. Counties sustaining equality over time or moving from disparities to equality in cancer mortality suggest that disparities are not inevitable, and provide hope that more communities can achieve optimal and equitable cancer outcomes for all. Cancer 2016;122:1735-48. © 2016 American Cancer Society. © 2016 American Cancer Society.

Larval diet affects mosquito development and permissiveness to Plasmodium infection

OpenAIRE

Gendrin, MEM; Christophides; Linenberg, Inbar

2016-01-01

The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii . We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clar...

Organogénesis durante el periodo larval en peces

OpenAIRE

Zavala-Leal, I; Dumas, Silvie; Peña Martínez, Renato

2011-01-01

La presencia de un periodo larval caracteriza a los peces con ontogenia indirecta. Este periodo de desarrollo implica una serie de transformaciones encaminadas a la adquisición de las características biológicas y ecológicas propias de la especie; y en muchos casos culmina con cambios de distribución y hábitos alimenticios. El periodo larval incluye cuatro estadios de desarrollo: larva vitelina, larva pre-flexión, larva flexión y larva post-flexión. Cada estadio de desarrollo presenta caracter...

Does white clover (Trifolium repens abundance in temperate pastures determine Sitona obsoletus (Coleoptera: Curculionidae larval populations?

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Mark Richard McNeill

2016-09-01

Full Text Available To determine if host plant abundance determined the size of clover root weevil (CRW Sitona obsoletus larval populations, a study was conducted over four years in plots sown in ryegrass (Lolium perenne (cv. Nui sown at either 6 or 30 kg/ha and white clover (Trifolium repens sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand with % clover measured in autumn (April and spring (September of each year. Overall, mean larval densities measured in spring 2012, 2013, 2014 and 2015 were 310, 38, 59 and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3 and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October larval populations to % white clover measured in each plot in autumn (April found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted

Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

Science.gov (United States)

McNeill, Mark R; van Koten, Chikako; Cave, Vanessa M; Chapman, David; Hodgson, Hamish

2016-01-01

To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass ( Lolium perenne ) (cv. Nui) sown at either 6 or 30 kg/ha and white clover ( Trifolium repens ) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012-2015 were 310, 38, 59, and 31 larvae m -2 , respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3, and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted, but the numbers

Domestic Larval Control Practices and Malaria Prevalence among Under-Five Children in Burkina Faso.

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Souleymane Diabaté

Full Text Available Larval source management has contributed to malaria decline over the past years. However, little is known about the impact of larval control practices undertaken at the household level on malaria transmission.The study was conducted in Kaya health district after the 2010 mass distribution of insecticide treated-nets and the initiation of malaria awareness campaigns in Burkina Faso. The aim was to (i estimate the level of domestic larval control practices (cleaning of the house and its surroundings, eradication of larval sources, and elimination of hollow objects that might collect water; (ii identify key determinants; and (iii explore the structural relationships between these practices, participation in awareness-raising activities and mothers' knowledge/attitudes/practices, and malaria prevalence among under-five children.Overall, 2004 households were surveyed and 1,705 under-five children were examined. Half of the mothers undertook at least one action to control larval proliferation. Mothers who had gone to school had better knowledge about malaria and were more likely to undertake domestic larval control practices. Living in highly exposed rural areas significantly decreased the odds of undertaking larval control actions. Mothers' participation in malaria information sessions increased the adoption of vector control actions and bednet use. Malaria prevalence was statistically lower among children in households where mothers had undertaken at least one vector control action or used bed-nets. There was a 0.16 standard deviation decrease in malaria prevalence for every standard deviation increase in vector control practices. The effect of bednet use on malaria prevalence was of the same magnitude.Cleaning the house and its surroundings, eradicating breeding sites, and eliminating hollow objects that might collect water play a substantial role in preventing malaria among under-five. There is a need for national malaria control programs to

Isolation and culture of larval cells from C. elegans.

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Sihui Zhang

Full Text Available Cell culture is an essential tool to study cell function. In C. elegans the ability to isolate and culture cells has been limited to embryonically derived cells. However, cells or blastomeres isolated from mixed stage embryos terminally differentiate within 24 hours of culture, thus precluding post-embryonic stage cell culture. We have developed an efficient and technically simple method for large-scale isolation and primary culture of larval-stage cells. We have optimized the treatment to maximize cell number and minimize cell death for each of the four larval stages. We obtained up to 7.8×10(4 cells per microliter of packed larvae, and up to 97% of adherent cells isolated by this method were viable for at least 16 hours. Cultured larval cells showed stage-specific increases in both cell size and multinuclearity and expressed lineage- and cell type-specific reporters. The majority (81% of larval cells isolated by our method were muscle cells that exhibited stage-specific phenotypes. L1 muscle cells developed 1 to 2 wide cytoplasmic processes, while L4 muscle cells developed 4 to 14 processes of various thicknesses. L4 muscle cells developed bands of myosin heavy chain A thick filaments at the cell center and spontaneously contracted ex vivo. Neurons constituted less than 10% of the isolated cells and the majority of neurons developed one or more long, microtubule-rich protrusions that terminated in actin-rich growth cones. In addition to cells such as muscle and neuron that are high abundance in vivo, we were also able to isolate M-lineage cells that constitute less than 0.2% of cells in vivo. Our novel method of cell isolation extends C. elegans cell culture to larval developmental stages, and allows use of the wealth of cell culture tools, such as cell sorting, electrophysiology, co-culture, and high-resolution imaging of subcellular dynamics, in investigation of post-embryonic development and physiology.

Redescription of the early larval stages of the pandalid shrimp Chlorotocus crassicornis (Decapoda: Caridea: Pandalidae).

Science.gov (United States)

Landeira, Jose M; Jiang, Guo-Chen; Chan, Tin-Yam; Shih, Tung-Wei; Gozález-Gordillo, J Ignacio

2015-09-07

The first four larval stages of the pandalid shrimp Chlorotocus crassicornis (A. Costa, 1871) are described and illustrated from laboratory-reared material obtained from ovigerous females collected in the southwestern Spain and south Taiwan. The second to fourth larval stages of this species are reported for the first time to science. Detailed examination of the first larval stages reveals that previous description misidentified some key larval characters which have prevented its identification in plankton samples. It is found that the zoeal morphology of Chlorotocus is not very different from other pandalid larvae, and in fact closely resembles Plesionika and Heterocarpus.

Rapid effects of marine reserves via larval dispersal.

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Richard Cudney-Bueno

Full Text Available Marine reserves have been advocated worldwide as conservation and fishery management tools. It is argued that they can protect ecosystems and also benefit fisheries via density-dependent spillover of adults and enhanced larval dispersal into fishing areas. However, while evidence has shown that marine reserves can meet conservation targets, their effects on fisheries are less understood. In particular, the basic question of if and over what temporal and spatial scales reserves can benefit fished populations via larval dispersal remains unanswered. We tested predictions of a larval transport model for a marine reserve network in the Gulf of California, Mexico, via field oceanography and repeated density counts of recently settled juvenile commercial mollusks before and after reserve establishment. We show that local retention of larvae within a reserve network can take place with enhanced, but spatially-explicit, recruitment to local fisheries. Enhancement occurred rapidly (2 yrs, with up to a three-fold increase in density of juveniles found in fished areas at the downstream edge of the reserve network, but other fishing areas within the network were unaffected. These findings were consistent with our model predictions. Our findings underscore the potential benefits of protecting larval sources and show that enhancement in recruitment can be manifested rapidly. However, benefits can be markedly variable within a local seascape. Hence, effects of marine reserve networks, positive or negative, may be overlooked when only focusing on overall responses and not considering finer spatially-explicit responses within a reserve network and its adjacent fishing grounds. Our results therefore call for future research on marine reserves that addresses this variability in order to help frame appropriate scenarios for the spatial management scales of interest.

Expression of Calmodulin and Myosin Light Chain Kinase during Larval Settlement of the Barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan; Wang, Hao; Matsumura, Kiyotaka; Qian, Pei-Yuan

2012-01-01

Barnacles are one of the most common organisms in intertidal areas. Their life cycle includes seven free-swimming larval stages and sessile juvenile and adult stages. The transition from the swimming to the sessile stages, referred to as larval settlement, is crucial for their survivor success and subsequent population distribution. In this study, we focused on the involvement of calmodulin (CaM) and its binding proteins in the larval settlement of the barnacle, Balanus (= Amphibalanus) amphitrite. The full length of CaM gene was cloned from stage II nauplii of B. amphitrite (referred to as Ba-CaM), encoding 149 amino acid residues that share a high similarity with published CaMs in other organisms. Quantitative real-time PCR showed that Ba-CaM was highly expressed in cyprids, the stage at which swimming larvae are competent to attach and undergo metamorphosis. In situ hybridization revealed that the expressed Ba-CaM gene was localized in compound eyes, posterior ganglion and cement glands, all of which may have essential functions during larval settlement. Larval settlement assays showed that both the CaM inhibitor compound 48/80 and the CaM-dependent myosin light chain kinase (MLCK) inhibitor ML-7 effectively blocked barnacle larval settlement, whereas Ca 2+/CaM-dependent kinase II (CaMKII) inhibitors did not show any clear effects. The subsequent real-time PCR assay showed a higher expression level of Ba-MLCK gene in larval stages than in adults, suggesting an important role of Ba-MLCK gene in larval development and competency. Overall, the results suggest that CaM and CaM-dependent MLCK function during larval settlement of B. amphitrite. © 2012 Chen et al.

Expression of Calmodulin and Myosin Light Chain Kinase during Larval Settlement of the Barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan

2012-02-13

Barnacles are one of the most common organisms in intertidal areas. Their life cycle includes seven free-swimming larval stages and sessile juvenile and adult stages. The transition from the swimming to the sessile stages, referred to as larval settlement, is crucial for their survivor success and subsequent population distribution. In this study, we focused on the involvement of calmodulin (CaM) and its binding proteins in the larval settlement of the barnacle, Balanus (= Amphibalanus) amphitrite. The full length of CaM gene was cloned from stage II nauplii of B. amphitrite (referred to as Ba-CaM), encoding 149 amino acid residues that share a high similarity with published CaMs in other organisms. Quantitative real-time PCR showed that Ba-CaM was highly expressed in cyprids, the stage at which swimming larvae are competent to attach and undergo metamorphosis. In situ hybridization revealed that the expressed Ba-CaM gene was localized in compound eyes, posterior ganglion and cement glands, all of which may have essential functions during larval settlement. Larval settlement assays showed that both the CaM inhibitor compound 48/80 and the CaM-dependent myosin light chain kinase (MLCK) inhibitor ML-7 effectively blocked barnacle larval settlement, whereas Ca 2+/CaM-dependent kinase II (CaMKII) inhibitors did not show any clear effects. The subsequent real-time PCR assay showed a higher expression level of Ba-MLCK gene in larval stages than in adults, suggesting an important role of Ba-MLCK gene in larval development and competency. Overall, the results suggest that CaM and CaM-dependent MLCK function during larval settlement of B. amphitrite. © 2012 Chen et al.

Contributions of Anopheles larval control to malaria suppression in tropical Africa: review of achievements and potential.

Science.gov (United States)

Walker, K; Lynch, M

2007-03-01

Malaria vector control targeting the larval stages of mosquitoes was applied successfully against many species of Anopheles (Diptera: Culicidae) in malarious countries until the mid-20th Century. Since the introduction of DDT in the 1940s and the associated development of indoor residual spraying (IRS), which usually has a more powerful impact than larval control on vectorial capacity, the focus of malaria prevention programmes has shifted to the control of adult vectors. In the Afrotropical Region, where malaria is transmitted mainly by Anopheles funestus Giles and members of the Anopheles gambiae Giles complex, gaps in information on larval ecology and the ability of An. gambiae sensu lato to exploit a wide variety of larval habitats have discouraged efforts to develop and implement larval control strategies. Opportunities to complement adulticiding with other components of integrated vector management, along with concerns about insecticide resistance, environmental impacts, rising costs of IRS and logistical constraints, have stimulated renewed interest in larval control of malaria vectors. Techniques include environmental management, involving the temporary or permanent removal of anopheline larval habitats, as well as larviciding with chemical or biological agents. This present review covers large-scale trials of anopheline larval control methods, focusing on field studies in Africa conducted within the past 15 years. Although such studies are limited in number and scope, their results suggest that targeting larvae, particularly in human-made habitats, can significantly reduce malaria transmission in appropriate settings. These approaches are especially suitable for urban areas, where larval habitats are limited, particularly when applied in conjunction with IRS and other adulticidal measures, such as the use of insecticide treated bednets.

Social coercion of larval development in an ant species.

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Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

2016-04-01

Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

Social coercion of larval development in an ant species

Science.gov (United States)

Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

2016-04-01

Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

Larval traits carry over to affect post-settlement behaviour in a common coral reef fish.

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Dingeldein, Andrea L; White, J Wilson

2016-07-01

Most reef fishes begin life as planktonic larvae before settling to the reef, metamorphosing and entering the benthic adult population. Different selective forces determine survival in the planktonic and benthic life stages, but traits established in the larval stage may carry over to affect post-settlement performance. We tested the hypothesis that larval traits affect two key post-settlement fish behaviours: social group-joining and foraging. Certain larval traits of reef fishes are permanently recorded in the rings in their otoliths. In the bluehead wrasse (Thalassoma bifasciatum), prior work has shown that key larval traits recorded in otoliths (growth rate, energetic condition at settlement) carry over to affect post-settlement survival on the reef, with higher-larval-condition fish experiencing less post-settlement mortality. We hypothesized that this selective mortality is mediated by carry-over effects on post-settlement antipredator behaviours. We predicted that better-condition fish would forage less and be more likely to join groups, both behaviours that would reduce predation risk. We collected 550 recently settled bluehead wrasse (Thalassoma bifasciatum) from three reef sites off St. Croix (USVI) and performed two analyses. First, we compared each settler's larval traits to the size of its social group to determine whether larval traits influenced group-joining behaviour. Secondly, we observed foraging behaviour in a subset of grouped and solitary fish (n = 14) for 1-4 days post-settlement. We then collected the fish and tested whether larval traits influenced the proportion of time spent foraging. Body length at settlement, but not condition, affected group-joining behaviour; smaller fish were more likely to remain solitary or in smaller groups. However, both greater length and better condition were associated with greater proportions of time spent foraging over four consecutive days post-settlement. Larval traits carry over to affect post

Circatrigintan instead of lunar periodicity of larval release in a brooding coral species.

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Linden, Bart; Huisman, Jef; Rinkevich, Baruch

2018-04-04

Larval release by brooding corals is often assumed to display lunar periodicity. Here, we show that larval release of individual Stylophora pistillata colonies does not comply with the assumed tight entrainment by the lunar cycle, and can better be classified as a circatrigintan pattern. The colonies exhibited three distinct reproductive patterns, characterized by short intervals, long intervals and no periodicity between reproductive peaks, respectively. Cross correlation between the lunar cycle and larval release of the periodic colonies revealed an approximately 30-day periodicity with a variable lag of 5 to 10 days after full moon. The observed variability indicates that the lunar cycle does not provide a strict zeitgeber. Other factors such as water temperature and solar radiation did not correlate significantly with the larval release. The circatrigintan patterns displayed by S. pistillata supports the plasticity of corals and sheds new light on discussions on the fecundity of brooding coral species.

Diel variation of larval fish abundance in the Amazon and Rio Negro

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ARAUJO-LIMA C. A. R. M.

2001-01-01

Full Text Available Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling.

Diel variation of larval fish abundance in the Amazon and Rio Negro

Directory of Open Access Journals (Sweden)

C. A. R. M. ARAUJO-LIMA

Full Text Available Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling.

A review of postfeeding larval dispersal in blowflies: implications for forensic entomology

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Gomes, Leonardo; Godoy, Wesley Augusto Conde; von Zuben, Claudio José

2006-05-01

Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.

Short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish (Danio rerio).

Science.gov (United States)

Cao, Fangjie; Wu, Peizhuo; Huang, Lan; Li, Hui; Qian, Le; Pang, Sen; Qiu, Lihong

2018-05-01

Previous study indicated that azoxystrobin had high acute toxicity to zebrafish, and larval zebrafish were more sensitive to azoxystrobin than adult zebrafish. The objective of the present study was to investigate short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish. After zebrafish embryos and adults were exposed to 0.01, 0.05 and 0.20 mg/L azoxystrobin (equal to 25, 124 and 496 nM azoxystrobin, respectively) for 8 days, the lethal effect, physiological responses, liver histology, mitochondrial ultrastructure, and expression alteration of genes related to mitochondrial respiration, oxidative stress, cell apoptosis and innate immune response were determined. The results showed that there was no significant effect on larval and adult zebrafish after exposure to 0.01 mg/L azoxystrobin. However, increased ROS, MDA concentration and il1b in larval zebrafish, as well as increased il1b, il8 and cxcl-c1c in adult zebrafish were induced after exposure to 0.05 mg/L azoxystrobin. Reduced mitochondrial complex III activity and ATP concentration, increased SOD activity, ROS and MDA concentration, decreased cytb, as well as increased sod1, sod2, cat, il1b, il8 and cxcl-c1c were observed both in larval and adult zebrafish after exposure to 0.20 mg/L azoxystrobin; meanwhile, increased p53, bax, apaf1 and casp9, alteration of liver histology and mitochondrial ultrastructure in larval zebrafish, and alteration of mitochondrial ultrastructure in adult zebrafish were also induced. The results demonstrated that azoxytrobin induced short-term developmental effects on larval zebrafish and adult zebrafish, including mitochondrial dysfunction, oxidative stress, cell apoptosis and innate immune response. Statistical analysis indicated that azoxystrobin induced more negative effects on larval zebrafish, which might be the reason for the differences of developmental toxicity between larval and adult zebrafish caused by

Acondicionamiento de reproductores, desove y cultivo larval de Graus nigra (Philippi, 1887 (Kyphosidae: Girellinae Broodstock conditioning, spawning and larval culture of Graus nigra (Philippi, 1887 (Kyphosidae: Girellinae

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Avelino Muñoz

2012-09-01

Full Text Available Se describen resultados sobre acondicionamiento reproductivo, desove y cultivo larval de Graus nigra ("vieja negra", "mulata". Peces adultos silvestres se recolectaron y se utilizaron como reproductores, los que al final del período de acondicionamiento alcanzaron el estado de maduración gonadal y desovaron en forma natural y espontánea. Los huevos fueron recolectados y después de 36 h de incubación eclosionaron, con una tasa de eclosión promedio de 60%. Las larvas recién eclosionadas midieron 2,9 ± 0,23 mm y alcanzaron el día 50 post-eclosión (PE una longitud total de 12,6 ± 0,37 mm. La sobrevivencia larval posterior a la eclosión fue entre 50,9 y 79,1% y al día 30 PE fue de 12,1%. El cultivo larval se desarrolló en estanques con suministro de agua de mar filtrada y esterilizada. Después de la reabsorción del saco vitelino se produjo el desarrollo del tracto digestivo y las larvas se alimentaron con dieta viva enriquecida con emulsión de ácidos grasos altamente insaturados. A los 35 días de cultivo se ofreció alimento artificial a las larvas cuyo tamano fue aumentando progresivamente a medida que progresó su desarrollo ontogénico. Se describe la evolución anatómica de las larvas y las relaciones morfométricas que representan su desarrollo; se caracteriza el patrón de crecimiento de las larvas hasta los 50 días post-eclosión y se discuten aspectos relacionados con la sobrevivencia larval y la introducción de mejoras para optimizar la producción de larvas y juveniles.In this study results related to reproductive conditioning, spawning and larval culture of Graus nigra ("vieja negra", "mulata" are given. Wild adult fishes were collected and used as brooders which at the end of the conditioning period reached gonadal maturation state and spawned naturally and spontaneously. Eggs were collected and after 36 hours of incubation they hatched at average rate of 60%. The hatched larvae measured 2.9 ± 0.23 mm and at day 50

Disseminating Health Disparities Education Through Tele-Learning

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LaSonya Knowles

2008-08-01

Full Text Available Twenty years of research demonstrate that there are wide disparities in health throughout America. Health disparities are differences in the incidence, prevalence, mortality, and burden of diseases and other adverse health conditions that exist when specific population subgroups are compared. Health Disparities in America: Working Toward Social Justice is a course instructed every fall by Dr. Lovell Jones, director of The Center for Research on Minority Health (CRMH at UT M.D. Anderson Cancer Center. The CRMH has created a course that examines the social and societal factors that are fundamental in creating disparities in health. Students from 10 different academic programs and institutions participate in this course. The course is unique in the aspect that various, diverse speakers whom are experts in their field of study instruct each class. This health disparities course is conducted at one of three different academic institutions in the Houston area and broadcast via satellite to various academic institutions by means of teleeducation. Tele-education is defined as a mode of instruction utilizing different forms of media such as video, audio technology tools and computers. Video and audio technologies involve the transmission of interface between learners and instructors, either interactive or non-interactive. Tele-education technologies have an important role to play in addressing the dissemination of health disparities education. The purpose of this program is to determine the feasibility of tele-education as a mode of instruction to introduce the multi-disciplinary components of health disparities. Our findings suggest that tele-education is a useful tool in imparting health disparities education.

Linking larval history to juvenile demography in the bicolor damselfish Stegastes partitus (Perciformes:Pomacentridae

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Richard S Nemeth

2005-05-01

Full Text Available Otolith-based reconstructions of daily larval growth increments were used to examine the effect of variation in larval growth on size and age at settlement and post-settlement growth,survival and habitat preferences of juvenile bicolor damselfish (Stegastes partitus Poey.During August 1992 and 1994,newly settled S. partitus were collected from Montastraea coral heads and Porites rubble piles in Tague Bay,St.Croix,U.S. Virgin Islands (17 °45 ’ N,64 °42 ’ W.Daily lapillar otolith increments from each fish were counted and measured with Optimas image analysis software.S.partitus pelagic larval duration was 23.7 d in 1992 (n =70and 24.6 d in 1994 (n =38and larval age at settlement averaged 13.0 mm total length both years.Analysis of daily otolith increments demonstrated that variation in larval growth rates and size and age at settlement had no detectable effect on post-settlement survivorship but that larger larvae showed a preference for Montastraea coral at settlement.Late larval and early juvenile growth rates showed a significant positive relationship indicating that growth patterns established during the planktonic stage can span metamorphosis and continue into the benthic juvenile phase.Larval growth rates during the first two weeks post-hatching also had a strong effect on age to developmental competence (ability to undergo metamorphosisin both 1992 and 1994 with the fastest growing larvae being 8 d younger and 0.8 mm smaller at settlement than the slowest growing larvae.These differential growth rates in early stage larvae established trajectories toward larval developmental competence and may prove important in biogeographical studies of larval dispersal.Reconstruyendo aumentos diarios de otolitos se compará la variación en crecimiento larval sobre el tamaño y la edad de asentamiento,y el crecimiento post-acentamiento, sobrevivencia y preferencia de hábitat,del pez damisela bicolor (Stegastes partitus Poeyjoven.En agosto de 1992

Toward an understanding of the molecular mechanisms of barnacle larval settlement: A comparative transcriptomic approach

KAUST Repository

Chen, Zhang-Fan

2011-07-29

Background: The barnacle Balanus amphitrite is a globally distributed biofouler and a model species in intertidal ecology and larval settlement studies. However, a lack of genomic information has hindered the comprehensive elucidation of the molecular mechanisms coordinating its larval settlement. The pyrosequencing-based transcriptomic approach is thought to be useful to identify key molecular changes during larval settlement. Methodology and Principal Findings: Using 454 pyrosequencing, we collected totally 630,845 reads including 215,308 from the larval stages and 415,537 from the adults; 23,451 contigs were generated while 77,785 remained as singletons. We annotated 31,720 of the 92,322 predicted open reading frames, which matched hits in the NCBI NR database, and identified 7,954 putative genes that were differentially expressed between the larval and adult stages. Of these, several genes were further characterized with quantitative real-time PCR and in situ hybridization, revealing some key findings: 1) vitellogenin was uniquely expressed in late nauplius stage, suggesting it may be an energy source for the subsequent non-feeding cyprid stage; 2) the locations of mannose receptors suggested they may be involved in the sensory system of cyprids; 3) 20 kDa-cement protein homologues were expressed in the cyprid cement gland and probably function during attachment; and 4) receptor tyrosine kinases were expressed higher in cyprid stage and may be involved in signal perception during larval settlement. Conclusions: Our results provide not only the basis of several new hypotheses about gene functions during larval settlement, but also the availability of this large transcriptome dataset in B. amphitrite for further exploration of larval settlement and developmental pathways in this important marine species. © 2011 Chen et al.

Live Cell Imaging of Butterfly Pupal and Larval Wings In Vivo.

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Ohno, Yoshikazu; Otaki, Joji M

2015-01-01

Butterfly wing color patterns are determined during the late larval and early pupal stages. Characterization of wing epithelial cells at these stages is thus critical to understand how wing structures, including color patterns, are determined. Previously, we successfully recorded real-time in vivo images of developing butterfly wings over time at the tissue level. In this study, we employed similar in vivo fluorescent imaging techniques to visualize developing wing epithelial cells in the late larval and early pupal stages 1 hour post-pupation. Both larval and pupal epithelial cells were rich in mitochondria and intracellular networks of endoplasmic reticulum, suggesting high metabolic activities, likely in preparation for cellular division, polyploidization, and differentiation. Larval epithelial cells in the wing imaginal disk were relatively large horizontally and tightly packed, whereas pupal epithelial cells were smaller and relatively loosely packed. Furthermore, larval cells were flat, whereas pupal cells were vertically elongated as deep as 130 μm. In pupal cells, many endosome-like or autophagosome-like structures were present in the cellular periphery down to approximately 10 μm in depth, and extensive epidermal feet or filopodia-like processes were observed a few micrometers deep from the cellular surface. Cells were clustered or bundled from approximately 50 μm in depth to deeper levels. From 60 μm to 80 μm in depth, horizontal connections between these clusters were observed. The prospective eyespot and marginal focus areas were resistant to fluorescent dyes, likely because of their non-flat cone-like structures with a relatively thick cuticle. These in vivo images provide important information with which to understand processes of epithelial cell differentiation and color pattern determination in butterfly wings.

Larval settlement: the role of surface topography for sessile coral reef invertebrates.

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Whalan, Steve; Wahab, Muhammad A Abdul; Sprungala, Susanne; Poole, Andrew J; de Nys, Rocky

2015-01-01

For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates.

Quantitative proteomics study of larval settlement in the barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan; Zhang, Huoming; Wang, Hao; Matsumura, Kiyotaka; Wong, Yue Him; Ravasi, Timothy; Qian, Pei-Yuan

2014-01-01

Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. © 2014 Chen et al.

Quantitative proteomics study of larval settlement in the barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan

2014-02-13

Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. © 2014 Chen et al.

Microbial gut diversity of Africanized and European honey bee larval instars.

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Svjetlana Vojvodic

Full Text Available The first step in understanding gut microbial ecology is determining the presence and potential niche breadth of associated microbes. While the core gut bacteria of adult honey bees is becoming increasingly apparent, there is very little and inconsistent information concerning symbiotic bacterial communities in honey bee larvae. The larval gut is the target of highly pathogenic bacteria and fungi, highlighting the need to understand interactions between typical larval gut flora, nutrition and disease progression. Here we show that the larval gut is colonized by a handful of bacterial groups previously described from guts of adult honey bees or other pollinators. First and second larval instars contained almost exclusively Alpha 2.2, a core Acetobacteraceae, while later instars were dominated by one of two very different Lactobacillus spp., depending on the sampled site. Royal jelly inhibition assays revealed that of seven bacteria occurring in larvae, only one Neisseriaceae and one Lactobacillus sp. were inhibited. We found both core and environmentally vectored bacteria with putatively beneficial functions. Our results suggest that early inoculation by Acetobacteraceae may be important for microbial succession in larvae. This assay is a starting point for more sophisticated in vitro models of nutrition and disease resistance in honey bee larvae.

Caterpillar hairs as an anti-parasitoid defence.

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Kageyama, Azusa; Sugiura, Shinji

2016-10-01

Caterpillar hairs are thought to act as a physical barrier against natural enemies, including parasitoids. However, very few studies have experimentally demonstrated how hairs protect caterpillars from parasitoid oviposition. To clarify the importance of caterpillar hairs as an anti-parasitoid defence, we observed the generalist endoparasitoid Meteorus pulchricornis (Hymenoptera: Braconidae) attacking both smooth and hairy caterpillars under laboratory conditions. A female Meteorus pulchricornis uses its ovipositor to inject venom and lay a single egg inside host larvae. We placed a smooth Spodoptera litura (Lepidoptera: Noctuidae) caterpillar or a hairy Lymantria dispar japonica (Lepidoptera: Erebidae) caterpillar in front of parasitoid females. We observed that 100 % and 84 % of the parasitoids could successfully stab their ovipositors into the smooth larvae of S. litura and first instars of the hairy caterpillar L. dispar japonica, respectively. However, only 24 % of parasitoids could successfully stab their ovipositors into second-instar L. dispar japonica. A higher rate of successful stabs (94 %) by parasitoids was obtained by cutting the hairs of second instar L. dispar japonica much shorter than the parasitoid ovipositor. The results demonstrate that the long, thick hairs of second and later instars of L. dispar japonica function as a physical barrier against parasitoid oviposition.

Larval connectivity of pearl oyster through biophysical modelling; evidence of food limitation and broodstock effect

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Thomas, Yoann; Dumas, Franck; Andréfouët, Serge

2016-12-01

The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia atoll lagoons. This aquaculture relies on spat collection, a process that experiences spatial and temporal variability and needs to be optimized by understanding which factors influence recruitment. Here, we investigate the sensitivity of P. margaritifera larval dispersal to both physical and biological factors in the lagoon of Ahe atoll. Coupling a validated 3D larval dispersal model, a bioenergetics larval growth model following the Dynamic Energy Budget (DEB) theory, and a population dynamics model, the variability of lagoon-scale connectivity patterns and recruitment potential is investigated. The relative contribution of reared and wild broodstock to the lagoon-scale recruitment potential is also investigated. Sensitivity analyses pointed out the major effect of the broodstock population structure as well as the sensitivity to larval mortality rate and inter-individual growth variability to larval supply and to the subsequent settlement potential. The application of the growth model clarifies how trophic conditions determine the larval supply and connectivity patterns. These results provide new cues to understand the dynamics of bottom-dwelling populations in atoll lagoons, their recruitment, and discuss how to take advantage of these findings and numerical models for pearl oyster management.

Larval biology of the crab Rhithropanopeus harrisii (Gould): a synthesis.

Science.gov (United States)

Forward, Richard B

2009-06-01

This synthesis reviews the physiological ecology and behavior of larvae of the benthic crab Rhithropanopeus harrisii, which occurs in low-salinity areas of estuaries. Larvae are released rhythmically around the time of high tide in tidal estuaries and in the 2-h interval after sunset in nontidal estuaries. As in most subtidal crustaceans, the timing of larval release is controlled by the developing embryos, which release peptide pheromones that stimulate larval release behavior by the female to synchronize the time of egg hatching. Larvae pass through four zoeal stages and a postlarval or megalopal stage that are planktonic before metamorphosis. They are retained near the adult population by means of an endogenous tidal rhythm in vertical migration. Larvae have several safeguards against predation: they undergo nocturnal diel vertical migration (DVM) and have a shadow response to avoid encountering predators, and they bear long spines as a deterrent. Photoresponses during DVM and the shadow response are enhanced by exposure to chemical cues from the mucus of predator fishes and ctenophores. The primary visual pigment has a spectral sensitivity maximum at about 500 nm, which is typical for zooplankton and matches the ambient spectrum at twilight. Larvae can detect vertical gradients in temperature, salinity, and hydrostatic pressure, which are used for depth regulation and avoidance of adverse environmental conditions. Characteristics that are related to the larval habitat and are common to other crab larval species are considered.

Health disparities through a psychological lens.

Science.gov (United States)

Adler, Nancy E

2009-11-01

There is growing concern in the United States about avoidable, unjust differences in health associated with sociodemographic characteristics, such as socioeconomic status and race/ethnicity. This concern has sparked research to identify how disparities develop and how they can be reduced. Studies showing that disparities occur at all levels of socioeconomic status, not simply at the very bottom, suggest that psychosocial factors play an important role. The author discusses both content and process issues in psychological research on disparities. Copyright 2009 by the American Psychological Association

Toxicity of organophosphorus pesticide sumithion on larval stages of stinging catfish Heteropneustes fossilis

NARCIS (Netherlands)

Shahjahan, M.; Kabir, M.F.; Sumon, Kizar Ahmed; Bhowmik, Lipi Rani; Rashid, Harunur

2017-01-01

Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations (150 and 250

Muscle organizers in Drosophila: the role of persistent larval fibers in adult flight muscle development

Science.gov (United States)

Farrell, E. R.; Fernandes, J.; Keshishian, H.

1996-01-01

In many organisms muscle formation depends on specialized cells that prefigure the pattern of the musculature and serve as templates for myoblast organization and fusion. These include muscle pioneers in insects and muscle organizing cells in leech. In Drosophila, muscle founder cells have been proposed to play a similar role in organizing larval muscle development during embryogenesis. During metamorphosis in Drosophila, following histolysis of most of the larval musculature, there is a second round of myogenesis that gives rise to the adult muscles. It is not known whether muscle founder cells organize the development of these muscles. However, in the thorax specific larval muscle fibers do not histolyze at the onset of metamorphosis, but instead serve as templates for the formation of a subset of adult muscles, the dorsal longitudinal flight muscles (DLMs). Because these persistent larval muscle fibers appear to be functioning in many respects like muscle founder cells, we investigated whether they were necessary for DLM development by using a microbeam laser to ablate them singly and in combination. We found that, in the absence of the larval muscle fibers, DLMs nonetheless develop. Our results show that the persistent larval muscle fibers are not required to initiate myoblast fusion, to determine DLM identity, to locate the DLMs in the thorax, or to specify the total DLM fiber volume. However, they are required to regulate the number of DLM fibers generated. Thus, while the persistent larval muscle fibers are not obligatory for DLM fiber formation and differentiation, they are necessary to ensure the development of the correct number of fibers.

The neural basis of visual behaviors in the larval zebrafish.

Science.gov (United States)

Portugues, Ruben; Engert, Florian

2009-12-01

We review visually guided behaviors in larval zebrafish and summarise what is known about the neural processing that results in these behaviors, paying particular attention to the progress made in the last 2 years. Using the examples of the optokinetic reflex, the optomotor response, prey tracking and the visual startle response, we illustrate how the larval zebrafish presents us with a very promising model vertebrate system that allows neurocientists to integrate functional and behavioral studies and from which we can expect illuminating insights in the near future. Copyright 2009 Elsevier Ltd. All rights reserved.

Do wealth disparities contribute to health disparities within racial/ethnic groups?

Science.gov (United States)

Pollack, Craig Evan; Cubbin, Catherine; Sania, Ayesha; Hayward, Mark; Vallone, Donna; Flaherty, Brian; Braveman, Paula A

2013-05-01

Though wide disparities in wealth have been documented across racial/ethnic groups, it is largely unknown whether differences in wealth are associated with health disparities within racial/ethnic groups. Data from the Survey of Consumer Finances (2004, ages 25-64) and the Health and Retirement Survey (2004, ages 50+), containing a wide range of assets and debts variables, were used to calculate net worth (a standard measure of wealth). Among non-Hispanic black, Hispanic and non-Hispanic white populations, we tested whether wealth was associated with self-reported poor/fair health status after accounting for income and education. Except among the younger Hispanic population, net worth was significantly associated with poor/fair health status within each racial/ethnic group in both data sets. Adding net worth attenuated the association between education and poor/fair health (in all racial/ethnic groups) and between income and poor/fair health (except among older Hispanics). The results add to the literature indicating the importance of including measures of wealth in health research for what they may reveal about disparities not only between but also within different racial/ethnic groups.

Interactive effects of maternal and environmental exposure to coal combustion wastes decrease survival of larval southern toads (Bufo terrestris)

International Nuclear Information System (INIS)

Metts, Brian S.; Buhlmann, Kurt A.; Scott, David E.; Tuberville, Tracey D.; Hopkins, William A.

2012-01-01

We conducted a mesocosm study to assess the individual and interactive effects of previous maternal exposure and larval exposure to trace element-laden sediments on southern toads (Bufo terrestris). Previous maternal exposure to coal combustion wastes (CCW) reduced larval survival to metamorphosis up to 57% compared to larvae of unexposed females. Larvae reared on CCW accumulated significant concentrations of trace elements resulting in extended larval periods, reduced growth rates, and reduced mass at metamorphosis. However, the effects were dependent on age of sediments, suggesting the effects of contaminants from CCW may be partially ameliorated over time through the reduced bioavailability of trace elements in aged CCW. Most importantly, maternal exposure to contaminants coupled with larval exposure to fresh CCW interacted to reduce survival to metamorphosis by 85% compared to reference conditions. Our study yields further evidence that disposal of CCW in aquatic basins potentially creates ecological traps for some amphibian populations. - Highlights: ► The interaction of maternal exposure and larval exposure to CCW reduced survival. ► Previous maternal exposure to CCW had a latent effect on survival to metamorphosis. ► Larval southern toads exposed to CCW experienced prolonged larval periods. ► Larval southern toads exposed to CCW had reduced growth rates. ► Larval southern toads exposed to CCW had reduced mass at metamorphosis. - Maternal and environmental exposure to coal combustion wastes interact to decrease survival in larval amphibians.

Ovarian development and early larval survival of Stenopus zanzibaricus (Bruce, 1976

Directory of Open Access Journals (Sweden)

Daniel Marques

2014-06-01

Full Text Available Despite economically valuable, ornamental shrimps are poorly studied and there is a lack of protocols for their captive breeding. Stenopus is one of the most important genera of ornamental shrimps, being Stenopus zanzibaricus one of the species with less information about captive breeding and larviculture. For a better knowledge of its reproductive cycle, we evaluated morphological and color changes during ovarian development of adult females through daily photographs taken during all the cycle. The effect of three diets (Brachionus plicatilis + Tetraselmis chuii; newly artemia nauplii + Tetraselmis chuii; newly artemia nauplii and two different temperatures (25ºC and 27ºC on early larval development were also evaluated. With this study, it was expected to obtain some insight about Stenopus zanzibaricus reproductive cycle and early larval development, in order to develop captive breeding and larval rearing protocols for this economic valuable species.

Philanthropy and disparities: progress, challenges, and unfinished business.

Science.gov (United States)

Mitchell, Faith; Sessions, Kathryn

2011-10-01

Philanthropy has invested millions of dollars to reduce disparities in health care and improve minority health. Grants to strengthen providers' cultural competence, diversify health professions, and collect data have improved understanding of and spurred action on disparities. The persistence of disparities in spite of these advances has shifted philanthropic attention toward strategies to change social, economic, and environmental conditions. We argue that these evolving perspectives, along with earlier groundwork, present new opportunities for funders, especially in combination with progress toward universal health coverage. This article looks at how philanthropy has addressed health disparities over the past decade, with a focus on accomplishments, the work remaining to be done, and how funders can help advance the disparities agenda.

A strain of Serratia marcescens pathogenic for larvae of Lymantria dispar: Characterization

Science.gov (United States)

J.D. Podgwaite; B.J. Cosenza

1976-01-01

A gram-negative bacillus, pathogenic for gypsy moth larvae, was characterized culturally, morphologically, and physiologically as a member of the Serratia group of the family Enterobacteriaceae. The microorganism lacked the pigmentation characteristic of the group but was generally distinguished from closely related members of the family by its...

Live Cell Imaging of Butterfly Pupal and Larval Wings In Vivo.

Directory of Open Access Journals (Sweden)

Yoshikazu Ohno

Full Text Available Butterfly wing color patterns are determined during the late larval and early pupal stages. Characterization of wing epithelial cells at these stages is thus critical to understand how wing structures, including color patterns, are determined. Previously, we successfully recorded real-time in vivo images of developing butterfly wings over time at the tissue level. In this study, we employed similar in vivo fluorescent imaging techniques to visualize developing wing epithelial cells in the late larval and early pupal stages 1 hour post-pupation. Both larval and pupal epithelial cells were rich in mitochondria and intracellular networks of endoplasmic reticulum, suggesting high metabolic activities, likely in preparation for cellular division, polyploidization, and differentiation. Larval epithelial cells in the wing imaginal disk were relatively large horizontally and tightly packed, whereas pupal epithelial cells were smaller and relatively loosely packed. Furthermore, larval cells were flat, whereas pupal cells were vertically elongated as deep as 130 μm. In pupal cells, many endosome-like or autophagosome-like structures were present in the cellular periphery down to approximately 10 μm in depth, and extensive epidermal feet or filopodia-like processes were observed a few micrometers deep from the cellular surface. Cells were clustered or bundled from approximately 50 μm in depth to deeper levels. From 60 μm to 80 μm in depth, horizontal connections between these clusters were observed. The prospective eyespot and marginal focus areas were resistant to fluorescent dyes, likely because of their non-flat cone-like structures with a relatively thick cuticle. These in vivo images provide important information with which to understand processes of epithelial cell differentiation and color pattern determination in butterfly wings.

Environmental Health Disparities in Housing

Science.gov (United States)

2011-01-01

The physical infrastructure and housing make human interaction possible and provide shelter. How well that infrastructure performs and which groups it serves have important implications for social equity and health. Populations in inadequate housing are more likely to have environmental diseases and injuries. Substantial disparities in housing have remained largely unchanged. Approximately 2.6 million (7.5%) non-Hispanic Blacks and 5.9 million Whites (2.8%) live in substandard housing. Segregation, lack of housing mobility, and homelessness are all associated with adverse health outcomes. Yet the experience with childhood lead poisoning in the United States has shown that housing-related disparities can be reduced. Effective interventions should be implemented to reduce environmental health disparities related to housing. PMID:21551378

Disparity in cancer care: a Canadian perspective

OpenAIRE

Ahmed, S.; Shahid, R.K.

2012-01-01

Canada is facing cancer crisis. Cancer has become the leading cause of death in Canada. Despite recent advances in cancer management and research, growing disparities in cancer care have been noticed, especially in socio-economically disadvantaged groups and under-served communities. With the rising incidence of cancer and the increasing numbers of minorities and of social disparities in general, and without appropriate interventions, cancer care disparities will become only more pronounced. ...

REGIONAL DISPARITIES – HISTORICAL CULTURAL INFLUENCES AND

Directory of Open Access Journals (Sweden)

MARIA OŢIL

2015-08-01

Full Text Available In recent decades, the issue of regional disparities has become a highly debated topic, knowledge regarding regional disparities being a matter of political priority as their persistence hinders the appropriate integration process. On the other hand, emphasis was put on integration through the process of EU enlargement, thus highlighting other issues related to the nature and size of disparities. Regional disparities regarding development and the living standards of the population have long been the concern of all Member States. In the case of Romania, recently admitted into the European structures, registering large backlogs to economically developed countries, the intense mobilization of internal and external factors of economic growth in order to reduce and eliminate disparities compared to other countries, represents a clear necessity. The "European Union" (EU project is of an unprecedented complexity and scale because it involves a plurality of states, which are culturally and economically heterogeneous. Moreover, these economic and cultural differences exist even within the states. Hence, there is also the central idea of the Union, regarding unity in diversity. In Romania the local, regional communities have a strong identity, but still evolving. Taking into account Romania's objective of successfully integrating into European structures, and the principles of democratic decision-making requires that regional development should aim at reducing economic and social disparities based on a notable involvement of the local, regional communities. Based on these facts, the paper aims to present the current regional (and intra-regional disparities in Romania with regard to a number of synthetic indicators of capital, of labor and of outcomes. The persistence in time of these economic disparities can be explained by considering the cultural legacies – represented by norms, values, institutions, that impact on how people interact, communicate

Rural Urban Disparity in and around Surabaya Region, Indonesia

Directory of Open Access Journals (Sweden)

Vely Kukinul Siswanto

2014-12-01

Full Text Available A shift in development towards the outskirts of urban areas changes the characteristics of the region and can ultimately lead to urban disparities in economic and social terms. The current study has tried to divide the study area covers the areas of surrounding Surabaya as urban, peri urban and rural areas with reference to three time periods (2008, 2009 and 2010 and shows that the typology in the study area changes each year. Furthermore, based on the theil index analysis, using a number of pre-prosperous household for social disparity and per capita GDP (Gross Domestic Product for economic disparity shows that urban and peri urban areas have medium and high level of social and economic disparity compare with rural area which have low levels of disparity. Through multivariate correlation analysis can be seen that the health center distance, electricity and water users effecting the social disparity. Moreover, the financial, industrial, electricity, trade, construction, transportation, agriculture, and mining sector's productivity have a significant relationship with the economic disparity. Health facilities, water and electricity improvement strategies to be followed for reducing the social disparity. Electricity improvement, water, services sector, transportation infrastructure, and industrial development to reduce the economic disparity.

Global stereo matching algorithm based on disparity range estimation

Science.gov (United States)

Li, Jing; Zhao, Hong; Gu, Feifei

2017-09-01

The global stereo matching algorithms are of high accuracy for the estimation of disparity map, but the time-consuming in the optimization process still faces a curse, especially for the image pairs with high resolution and large baseline setting. To improve the computational efficiency of the global algorithms, a disparity range estimation scheme for the global stereo matching is proposed to estimate the disparity map of rectified stereo images in this paper. The projective geometry in a parallel binocular stereo vision is investigated to reveal a relationship between two disparities at each pixel in the rectified stereo images with different baselines, which can be used to quickly obtain a predicted disparity map in a long baseline setting estimated by that in the small one. Then, the drastically reduced disparity ranges at each pixel under a long baseline setting can be determined by the predicted disparity map. Furthermore, the disparity range estimation scheme is introduced into the graph cuts with expansion moves to estimate the precise disparity map, which can greatly save the cost of computing without loss of accuracy in the stereo matching, especially for the dense global stereo matching, compared to the traditional algorithm. Experimental results with the Middlebury stereo datasets are presented to demonstrate the validity and efficiency of the proposed algorithm.

Efficiency of two larval diets for mass-rearing of the mosquito Aedes aegypti.

Directory of Open Access Journals (Sweden)

J G Bond

Full Text Available Aedes aegypti is a major vector of arboviruses that may be controlled on an area-wide basis using the sterile insect technique (SIT. Larval diet is a major factor in mass-rearing for SIT programs. We compared dietary effects on immature development and adult fitness-related characteristics for an International Atomic Energy Agency (IAEA diet, developed for rearing Ae. albopictus, and a standardized laboratory rodent diet (LRD, under a 14:10 h (light:dark photoperiod ("light" treatment or continuous darkness during larval rearing. Larval development was generally fastest in the IAEA diet, likely reflecting the high protein and lipid content of this diet. The proportion of larvae that survived to pupation or to adult emergence did not differ significantly between diets or light treatments. Insects from the LRD-dark treatment produced the highest proportion of male pupae (93% at 24 h after the beginning of pupation whereas adult sex ratio from the IAEA diet tended to be more male-biased than that of the LRD diet. Adult longevity did not differ significantly with larval diet or light conditions, irrespective of sex. In other aspects the LRD diet generally performed best. Adult males from the LRD diet were significantly larger than those from the IAEA diet, irrespective of light treatment. Females from the LRD diet had ~25% higher fecundity and ~8% higher egg fertility compared to those from the IAEA diet. Adult flight ability did not differ between larval diets, and males had a similar number of copulations with wild females, irrespective of larval diet. The LRD diet had lower protein and fat content but a higher carbohydrate and energetic content than the IAEA diet. We conclude that the LRD diet is a low-cost standardized diet that is likely to be suitable for mass-rearing of Ae. aegypti for area-wide SIT-based vector control.

Allometric disparity in rodent evolution

OpenAIRE

Wilson LAB

2013-01-01

In this study, allometric trajectories for 51 rodent species, comprising equal representatives from each of the major clades (Ctenohystrica, Muroidea, Sciuridae), are compared in a multivariate morphospace (=allometric space) to quantify magnitudes of disparity in cranial growth. Variability in allometric trajectory patterns was compared to measures of adult disparity in each clade, and dietary habit among the examined species, which together encapsulated an ecomorphological breadth. Results ...

Determination of the efficiency of diets for larval development in mass rearing Aedes aegypti (Diptera: Culicidae).

Science.gov (United States)

Gunathilaka, P A D H N; Uduwawala, U M H U; Udayanga, N W B A L; Ranathunge, R M T B; Amarasinghe, L D; Abeyewickreme, W

2017-11-23

Larval diet quality and rearing conditions have a direct and irreversible effect on adult traits. Therefore, the current study was carried out to optimize the larval diet for mass rearing of Aedes aegypti, for Sterile Insect Technique (SIT)-based applications in Sri Lanka. Five batches of 750 first instar larvae (L 1) of Ae. aegypti were exposed to five different concentrations (2-10%) of International Atomic Energy Agency (IAEA) recommended the larval diet. Morphological development parameters of larva, pupa, and adult were detected at 24 h intervals along with selected growth parameters. Each experiment was replicated five times. General Linear Modeling along with Pearson's correlation analysis were used for statistical treatments. Significant differences (P rate and success, sex ratio, adult success, fecundity and hatching rate of Ae. aegypti. The best quality adults can be produced at larval diet concentration of 10%. However, the 8% larval diet concentration was most suitable for adult male survival.

Health Disparities Calculator (HD*Calc) - SEER Software

Science.gov (United States)

Statistical software that generates summary measures to evaluate and monitor health disparities. Users can import SEER data or other population-based health data to calculate 11 disparity measurements.

Energy price disparity and public welfare

International Nuclear Information System (INIS)

Templet, P.H.

2001-01-01

The differences in the price of energy to economic sectors are linked to a number of system parameters and to public welfare. There are large disparities in energy prices within states when comparing residential and industrial prices although neoclassical economics predicts one price in markets. The large disparities between the two sectors across states negatively affects the efficiency of resource allocation, creates subsidies for those getting the cheap energy and results in unequal access to energy. These in turn lead to inefficient partitioning of energy between products and waste, higher pollution, leakage of wealth and poorer energy use efficiency, i.e. high energy intensity. States with large energy price disparities between sectors have statistically higher poverty, lower incomes, more pollution and use more energy but with less efficiency. Higher energy price disparities also result in higher throughput per unit of output thus reducing the chances for sustainability and lower public welfare. 31 refs

Luminance, Colour, Viewpoint and Border Enhanced Disparity Energy Model.

Directory of Open Access Journals (Sweden)

Jaime A Martins

Full Text Available The visual cortex is able to extract disparity information through the use of binocular cells. This process is reflected by the Disparity Energy Model, which describes the role and functioning of simple and complex binocular neuron populations, and how they are able to extract disparity. This model uses explicit cell parameters to mathematically determine preferred cell disparities, like spatial frequencies, orientations, binocular phases and receptive field positions. However, the brain cannot access such explicit cell parameters; it must rely on cell responses. In this article, we implemented a trained binocular neuronal population, which encodes disparity information implicitly. This allows the population to learn how to decode disparities, in a similar way to how our visual system could have developed this ability during evolution. At the same time, responses of monocular simple and complex cells can also encode line and edge information, which is useful for refining disparities at object borders. The brain should then be able, starting from a low-level disparity draft, to integrate all information, including colour and viewpoint perspective, in order to propagate better estimates to higher cortical areas.

Health Disparities in Veterans: A Map of the Evidence.

Science.gov (United States)

Kondo, Karli; Low, Allison; Everson, Teresa; Gordon, Christine D; Veazie, Stephanie; Lozier, Crystal C; Freeman, Michele; Motu'apuaka, Makalapua; Mendelson, Aaron; Friesen, Mark; Paynter, Robin; Friesen, Caroline; Anderson, Johanna; Boundy, Erin; Saha, Somnath; Quiñones, Ana; Kansagara, Devan

2017-09-01

Goals for improving the quality of care for all Veterans and eliminating health disparities are outlined in the Veterans Health Administration Blueprint for Excellence, but the degree to which disparities in utilization, health outcomes, and quality of care affect Veterans is not well understood. To characterize the research on health care disparities in the Veterans Health Administration by means of a map of the evidence. We conducted a systematic search for research studies published from 2006 to February 2016 in MEDLINE and other data sources. We included studies of Veteran populations that examined disparities in 3 outcome categories: utilization, quality of health care, and patient health. We abstracted data on study design, setting, population, clinical area, outcomes, mediators, and presence of disparity for each outcome category. We grouped the data by population characteristics including race, disability status, mental illness, demographics (age, era of service, rural location, and distance from care), sex identity, socioeconomic status, and homelessness, and created maps illustrating the evidence. We reviewed 4249 citations and abstracted data from 351 studies which met inclusion criteria. Studies examining disparities by race/ethnicity comprised by far the vast majority of the literature, followed by studies examining disparities by sex, and mental health condition. Very few studies examined disparities related to lesbian, gay, bisexual, or transgender identity or homelessness. Disparities findings vary widely by population and outcome. Our evidence maps provide a "lay of the land" and identify important gaps in knowledge about health disparities experienced by different Veteran populations.

Disparity modifications and the emotional effects of stereoscopic images

Science.gov (United States)

Kawai, Takashi; Atsuta, Daiki; Tomiyama, Yuya; Kim, Sanghyun; Morikawa, Hiroyuki; Mitsuya, Reiko; Häkkinen, Jukka

2014-03-01

This paper describes a study that focuses on disparity changes in emotional scenes of stereoscopic (3D) images, in which an examination of the effects on pleasant and arousal was carried out by adding binocular disparity to 2D images that evoke specific emotions, and applying disparity modification based on the disparity analysis of famous 3D movies. From the results of the experiment, for pleasant, a significant difference was found only for the main effect of the emotions. On the other hand, for arousal, there was a trend of increasing the evaluation values in the order 2D condition, 3D condition and 3D condition applied the disparity modification for happiness, surprise, and fear. This suggests the possibility that binocular disparity and the modification affect arousal.

Turbulence, larval fish ecology and fisheries recruitment : a review of field studies

DEFF Research Database (Denmark)

MacKenzie, Brian

2000-01-01

, and recruitment in entire populations. One of the main findings is that field studies show contrasting effects of turbulence on feeding, growth and mortality rates in nature and on recruitment. Coincident and multiple variations in ecosystem processes, lack of understanding of how some of these processes (e......Fish recruitment varies widely between years but much of this variability cannot be explained by most models of fish population dynamics. In this review, I examine the role of environmental variability on fish recruitment, and ill particular how turbulence affects feeding and growth of larval fish.......g. larval diet composition, feeding behaviour, growth rates, prey patchiness) respond to turbulence, and unavoidable sampling artifacts are mainly responsible for this result. Upwelling as well as frontal processes appear important for larval fish growth and survival, and turbulence levels vary both within...

Larval developmental rate, metabolic rate and future growth performance in Atlantic salmon

DEFF Research Database (Denmark)

Serrano, Jonathan Vaz; Åberg, Madelene; Gjoen, Hans Magnus

2009-01-01

, quantified as time to first feeding, and growth in later stages was demonstrated in Atlantic salmon (Salmo salar L.). The observed relationship between future growth and larval developmental rate suggests that sorting larvae by time to first feeding can be a potential tool to optimize feeding strategies...... and growth in commercial rearing of Atlantic salmon. Furthermore, the link between larval standard metabolic rate and developmental rate and future growth is discussed in the present study....

The intersection of disability and healthcare disparities: a conceptual framework.

Science.gov (United States)

Meade, Michelle A; Mahmoudi, Elham; Lee, Shoou-Yih

2015-01-01

This article provides a conceptual framework for understanding healthcare disparities experienced by individuals with disabilities. While health disparities are the result of factors deeply rooted in culture, life style, socioeconomic status, and accessibility of resources, healthcare disparities are a subset of health disparities that reflect differences in access to and quality of healthcare and can be viewed as the inability of the healthcare system to adequately address the needs of specific population groups. This article uses a narrative method to identify and critique the main conceptual frameworks that have been used in analyzing disparities in healthcare access and quality, and evaluating those frameworks in the context of healthcare for individuals with disabilities. Specific models that are examined include the Aday and Anderson Model, the Grossman Utility Model, the Institute of Medicine (IOM)'s models of Access to Healthcare Services and Healthcare Disparities, and the Cultural Competency model. While existing frameworks advance understandings of disparities in healthcare access and quality, they fall short when applied to individuals with disabilities. Specific deficits include a lack of attention to cultural and contextual factors (Aday and Andersen framework), unrealistic assumptions regarding equal access to resources (Grossman's utility model), lack of recognition or inclusion of concepts of structural accessibility (IOM model of Healthcare Disparities) and exclusive emphasis on supply side of the healthcare equation to improve healthcare disparities (Cultural Competency model). In response to identified gaps in the literature and short-comings of current conceptualizations, an integrated model of disability and healthcare disparities is put forth. We analyzed models of access to care and disparities in healthcare to be able to have an integrated and cohesive conceptual framework that could potentially address issues related to access to

Diatom production in the marine environment : implications for larval fish growth and condition

DEFF Research Database (Denmark)

St. John, Michael; Clemmesen, C.; Lund, T.

2001-01-01

To test the effects of diatom production on larval fish growth and condition. laboratory experiments were performed with larval North Sea cod reared on different algal food chains. These food chains were based on cultures of (a) the diatoms Skeletonema costatum and Thalassiosira weissflogii: (b....../omega6 fatty acids in the algal source had no significant effect. The highest and lowest growth rates were observed in food chains based on H. triquetra and T. weissflogii. respectively (means for days 14-16 of 4.0 and - 4.7). The mixed diatom/dinoflagellate diet resulted in inter- mediate growth rates...... and condition. Regressions of growth rates against EPA and DHA content indicated no inhibitory effect of diatom production on growth in larval cod...

Eggshells as an index of aedine mosquito production. 2: Relationship of Aedes taeniorhynchus eggshell density to larval production.

Science.gov (United States)

Addison, D S; Ritchie, S A; Webber, L A; Van Essen, F

1992-03-01

To test if eggshell density could be used as an index of aedine mosquito production, we compared eggshell density with the larval production of Aedes taeniorhynchus in Florida mangrove basin forests. Quantitative (n = 7) and categorical (n = 34) estimates of annual larval production were regressed against the number of eggshells per cc of soil. Significant regressions were obtained in both instances. Larval production was concentrated in zones with the highest eggshell density. We suggest that eggshell density and distribution can be used to identify oviposition sites and the sequence of larval appearance.

Effects of elevated CO2 leaf diets on gypsy moth (Lepidoptera: Lymantriidae) respiration rates.

Science.gov (United States)

Foss, Anita R; Mattson, William J; Trier, Terry M

2013-06-01

Elevated levels of CO2 affect plant growth and leaf chemistry, which in turn can alter host plant suitability for insect herbivores. We examined the suitability of foliage from trees grown from seedlings since 1997 at Aspen FACE as diet for the gypsy moth (Lymantria dispar L.) Lepidoptera: Lymantriidae: paper birch (Betula papyrifera Marshall) in 2004-2005, and trembling aspen (Populus tremuloides Michaux) in 2006-2007, and measured consequent effects on larval respiration. Leaves were collected for diet and leaf chemistry (nutritional and secondary compound proxies) from trees grown under ambient (average 380 ppm) and elevated CO2 (average 560 ppm) conditions. Elevated CO2 did not significantly alter birch or aspen leaf chemistry compared with ambient levels with the exception that birch percent carbon in 2004 and aspen moisture content in 2006 were significantly lowered. Respiration rates were significantly higher (15-59%) for larvae reared on birch grown under elevated CO2 compared with ambient conditions, but were not different on two aspen clones, until larvae reached the fifth instar, when those consuming elevated CO2 leaves on clone 271 had lower (26%) respiration rates, and those consuming elevated CO2 leaves on clone 216 had higher (36%) respiration rates. However, elevated CO2 had no apparent effect on the respiration rates of pupae derived from larvae fed either birch or aspen leaves. Higher respiration rates for larvae fed diets grown under ambient or elevated CO2 demonstrates their lower efficiency of converting chemical energy of digested food stuffs extracted from such leaves into their biosynthetic processes.

Proteolytic activity regarding Sarconesiopsis magellanica (Diptera: Calliphoridae) larval excretions and secretions.

Science.gov (United States)

Pinilla, Yudi T; Moreno-Pérez, Darwin A; Patarroyo, Manuel A; Bello, Felio J

2013-12-01

Sarconesiopsis magellanica (Diptera: Calliphoridae) is a medically important necrophagous fly which is used for establishing the post-mortem interval. Diptera maggots release proteolytic enzymes contained in larval excretion and secretion (ES) products playing a key role in digestion. Special interest in proteolytic enzymes has also been aroused regarding understanding their role in wound healing since they degrade necrotic tissue during larval therapy. This study was thus aimed at identifying and characterising S. magellanica proteolytic enzyme ES products for the first time. These products were obtained from first-, second- and third-instar larvae taken from a previously-established colony. ES proteins were separated by SDS-PAGE and their proteolytic activity was characterised by zymograms and inhibition assays involving BAPNA (Nα-benzoyl-dl-Arg-p-nitroanilide) and SAPNA substrates, using synthetic inhibitors. The protein profile ranged from ∼69kDa to ∼23kDa; several of them coincided with the Lucilia sericata ES protein profile. Serine-protease hydrolysis activity (measured by zymogram) was confirmed when a ∼25kDa band disappeared upon ES incubation with PMSF inhibitor at pH 7.8. Analysis of larval ES proteolytic activity on BAPNA and SAPNA substrates (determined by using TLCK and TPCK specific inhibitors) suggested a greater amount of trypsin-like protease. These results support the need for further experiments aimed at validating S. magellanica use in larval therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

Regional and seasonal differences in growth of larval North Sea herring (clupea harengus L.) estimated by otolith microstructure analysis

DEFF Research Database (Denmark)

Munk, Peter; Heath, Mike; Skaarup, Bo

1991-01-01

The ecology processes of the larval life of autumn-spawned North Sea herring have been studied in a multidisciplinary and internationally coordinated research programme (ACE). The programme focused on larval advection and the importance of the autumn/winter circulation in determining larval distr...

Larval connectivity studies in the Western Iberian Peninsula

Science.gov (United States)

Dubert, Jesus; Nolasco, Rita; Queiroga, Henrique

2010-05-01

The study of the connectivity between populations is one of the 'hot' applications of numerical models of the ocean circulation. An IBM (Individual Based model) was developed, using Carcinus manenas larvae crab as a model. A set of particles was used as a representation of larvae, in order to study their larval life cycle, including the larval growth, larval mortality (both depending on temperature and salinity), larval dispersal by currents, diel vertical migration, and larval recruitment. The life cycle of every larvae in the ocean, was modeled from zoeae 1 stage to megalopae stage, during typical periods of 30-50 days. Larvae were initialized in 14 estuarine systems of the Atlantic Western Iberian Peninsula, from January to July. In every period, a number of 225 larvae are initialized in everyone of the 14 considered estuaries, with fortynighly periodicity. The larvae evolves during the (variable, depending mainly on temperature) period of growth in the ocean, and when a larvae reach the age for recruit, if it is located in the neighborhood of the considered estuarine systems, the larvae is accounted as a recruited larvae in that place. With this methodology, a connectivity matrix can be computed, acconting for the 225 larvae emitted in every estuary, the number of larvae that reaches the every place. The connectivity matrix depends strongly on the current regime along the Atlantic coast of Iberian Peninsula, and has been calculated for the present circulation, for the period 2001 to 2009, for runs with realistic forcing with NCEP2 and Quikscat (for winds) forcing. The connectivity matrix, have also been calculated for climatological runs. For the present climatological conditions, it is observed the prevalence of southward transport for the period January-July, because the prevalence of Northerly winds along the west coast of IP in the COADS present time climatology. Strong dispersal is observed at the Northern estuaries, during winter with strong loss of

Why the WTA - WTP disparity matters

Science.gov (United States)

Brown Thomas C.; Gregory R.

1999-01-01

The disparity between willingness to pay (WTP) and willingness to accept compensation (WTA) has been demonstrated repeatedly. Because using WTP estimates of value where a WTA estimate is appropriate tends to undervalue environmental assets, this issue is important to environmental managers. We summarize reasons for the disparity and then discuss some of the...

34 CFR 222.162 - What disparity standard must a State meet in order to be certified and how are disparities in...

Science.gov (United States)

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false What disparity standard must a State meet in order to be certified and how are disparities in current expenditures or revenues per pupil measured? 222.162... of the Act § 222.162 What disparity standard must a State meet in order to be certified and how are...

Offshore-onshore linkages in the larval life history of sole in the Gulf of Lions (NW-Mediterranean)

Science.gov (United States)

Morat, Fabien; Letourneur, Yves; Blamart, Dominique; Pécheyran, Christophe; Darnaude, Audrey M.; Harmelin-Vivien, Mireille

2014-08-01

Understanding individual dispersion from offshore natal areas to coastal nurseries during pelagic larval life is especially important for the sustainable management of exploited marine fish species. For several years, the hatching period, the larval life duration, the average growth rate and the otolith chemical composition (δ13C, δ18O, Sr:Ca and Ba:Ca) during the larval life were studied for young of the year (YOY) of sole collected in three main nurseries of the Gulf of Lions (GoL) (Thau, Mauguio and Berre). We investigated the spatial variation in the origin of the sole larvae which colonised the nurseries around the GoL, and whether temporal differences in environmental conditions during this life stage affected growth and larval life duration. The hatching period ranges from October to March, depending on year and site. Average ages at metamorphosis varied between 43 and 50 days, with the lowest and highest values consistently found for Mauguio and Berre, respectively. Otolith growth rates ranged between 2.7 and 3.2 μm d-1, with the lowest values in Thau and Mauguio and the highest in Berre. Otolith chemical composition during the larval life also varied, suggesting contrasted larval environmental histories in YOY among nurseries. In fishes from Berre and Mauguio, larval life was more influenced by the Rhône River, showing consistently higher larval Ba:Ca ratios (10/23 μmol mol-1) and lower δ13C (-6.5/-6.1‰) and δ18O values (-1.6/0.1‰) than for Thau (with Ba:Ca ratios < 8 μmol mol-1, δ13C ˜-2.3‰ and δ18O ˜1.5‰). Differences in larval otolith composition were observed for 2004, with higher Ba:Ca and lower δ13C and δ18O values than in the two other years. These differences were explained by changes in composition and chemical signatures of water masses after an exceptional flooding event of the Rhône River in late 2003.

Process-based models of feeding and prey selection in larval fish

DEFF Research Database (Denmark)

Fiksen, O.; MacKenzie, Brian

2002-01-01

believed to be important to prey selectivity and environmental regulation of feeding in fish. We include the sensitivity of prey to the hydrodynamic signal generated by approaching larval fish and a simple model of the potential loss of prey due to turbulence whereby prey is lost if it leaves...... jig dry wt l(-1). The spatio-temporal fluctuation of turbulence (tidal cycle) and light (sun height) over the bank generates complex structure in the patterns of food intake of larval fish, with different patterns emerging for small and large larvae....

Reduced Disparities in Birth Rates Among Teens

Science.gov (United States)

... Teens Winnable Battles Social Media at CDC Reduced Disparities in Birth Rates among Teens Aged 15–19 ... Pregnancy Prevention Community-Wide Initiative. National Rates and Disparities Nationally, the teen birth rate (number of births ...

Larval Performance in the Context of Ecological Diversification and Speciation in Lycaeides Butterflies

Directory of Open Access Journals (Sweden)

Cynthia F. Scholl

2012-01-01

Full Text Available The role of ecology in diversification has been widely investigated, though few groups have been studied in enough detail to allow comparisons of different ecological traits that potentially contribute to reproductive isolation. We investigated larval performance within a species complex of Lycaeides butterflies. Caterpillars from seven populations were reared on five host plants, asking if host-specific, adaptive larval traits exist. We found large differences in performance across plants and fewer differences among populations. The patterns of performance are complex and suggest both conserved traits (i.e., plant effects across populations and more recent dynamics of local adaptation, in particular for L. melissa that has colonized an exotic host. We did not find a relationship between oviposition preference and larval performance, suggesting that preference did not evolve to match performance. Finally, we put larval performance within the context of several other traits that might contribute to ecologically based reproductive isolation in the Lycaeides complex. This larger context, involving multiple ecological and behavioral traits, highlights the complexity of ecological diversification and emphasizes the need for detailed studies on the strength of putative barriers to gene flow in order to fully understand the process of ecological speciation.

Polycystic echinococcosis in Colombia: the larval cestodes in infected rodents.

Science.gov (United States)

Morales, G A; Guzman, V H; Wells, E A; Angel, D

1979-07-01

Described are the characteristics of the polycystic larval cestodes found in an endemic area of echinococcosis in the Easter Plains of Colombia and the tissue reaction evoked in infected rodents. Of 848 free-ranging animals examined, polycystic hydatids were found in 44/93 Cuniculus paca and 1/369 Proechimys sp. None of 20 Dasyprocta fuliginosa examined was infected, but hunters provided a heart with hydatid cysts and information about two additional animals with infected livers. Recognition of an endemic area of polycystic echinococcosis provides a means to investigate the life cycle of the parasites and to study the histogenesis of the larval cestodes in susceptible laboratory animals.

Predator-induced larval cloning in the sand dollar Dendraster excentricus: might mothers matter?

Science.gov (United States)

Vaughn, Dawn

2009-10-01

Predator-induced cloning in echinoid larvae, with reduced size a consequence of cloning, is a dramatic modification of development and a novel response to risks associated with prolonged planktonic development. Recent laboratory studies demonstrate that exposure to stimuli from predators (i.e., fish mucus) induces cloning in the pluteus larvae (plutei) of Dendraster excentricus. However, the timing and incidence of cloning and size reduction of unrelated conspecific plutei differed across experiments. A variable cloning response suggests the effects of such factors as cue quality, egg provisioning, maternal experience, and genetic background, indicating that the potential advantages of cloning as an adaptive response to predators are not available to all larvae. This study tested the hypothesis that cloning in D. excentricus plutei is maternally influenced. Plutei from three half-sibling larval families (different mothers, same father) were exposed to fish mucus for 9 days during early development. Cloning was inferred in a percentage of plutei from each family; however, the rate and success of cloning differed significantly among the larval half-siblings. Unexpectedly, all mucus-treated plutei were smaller and developmentally delayed when compared to all plutei reared in the absence of a mucus stimulus. Thus, while the results from this study support the hypothesis of an influence of mothers on cloning of larval offspring, reduced larval size was a uniform response to fish mucus and did not indicate an effect of mothers. Hypotheses of the developmental effects of fish mucus on larval size with or without successful cloning are discussed.

Habitat use by larval fishes in a temperate South African surf zone

Science.gov (United States)

Watt-Pringle, Peter; Strydom, Nadine A.

2003-12-01

Larval fishes were sampled in the Kwaaihoek surf zone on the south east coast of South Africa. On six occasions between February and May 2002, larval fishes were collected in two habitat types identified in the inner surf zone using a modified beach-seine net. The surf zone habitats were classified as either sheltered trough areas or adjacent exposed surf areas. Temperature, depth and current measurements were taken at all sites. Trough habitats consisted of a depression in surf topography characterised by reduced current velocities and greater average depth than adjacent surf areas. In total, 325 larval fishes were collected. Of these, 229 were collected in trough and 96 in surf habitats. At least 22 families and 37 species were represented in the catch. Dominant families were the Mugilidae, Sparidae, Atherinidae, and Engraulidae. Dominant species included Liza tricuspidens and Liza richardsonii (Mugilidae), Rhabdosargus holubi and Sarpa salpa (Sparidae), Atherina breviceps (Atherinidae) and Engraulis japonicus (Engraulide). Mean CPUE of postflexion larvae of estuary-dependent species was significantly greater in trough areas. The proportion of postflexion larval fishes in trough habitat was significantly greater than that of preflexion stages, a result that was not apparent in surf habitat sampled. CPUE of postflexion larvae of estuary-dependent fishes was negatively correlated with current magnitude and positively correlated with habitat depth. Mean body length of larval fishes was significantly greater in trough than in surf habitats. These results provide evidence that the CPUE of postflexion larvae of estuary-dependent fishes is higher in trough habitat in the surf zone and this may be indicative of active habitat selection for areas of reduced current velocity/wave action. The implications of this behaviour for estuarine recruitment processes are discussed.

Assessing the toxicity of sediments using the medaka embryo-larval assay and 2 other bioassays.

Science.gov (United States)

Barhoumi, Badreddine; Clérandeau, Christelle; Landi, Laure; Pichon, Anaïk; Le Bihanic, Florane; Poirier, Dominique; Anschutz, Pierre; Budzinski, Hélène; Driss, Mohamed Ridha; Cachot, Jérôme

2016-09-01

Sediments are sinks for aquatic pollutants, and analyzing toxicity in such complex matrices is still challenging. To evaluate the toxicity of bioavailable pollutants accumulated in sediments from the Bizerte lagoon (Tunisia), a novel assay, the medaka embryo-larval assay by sediment contact, was applied. Japanese medaka (Oryzias latipes) embryos were incubated in direct contact with sediment samples up to hatching. Lethal and sublethal adverse effects were recorded in embryos and larvae up to 20 d postfertilization. Results from medaka embryo-larval assay were compared with cytotoxicity (Microtox®), genotoxicity (SOS chromotest), and pollutant content of sediments. The results highlight differences in the contamination profile and toxicity pattern between the different studied sediments. A significant correlation was shown between medaka embryo-larval assay by sediment contact and SOS chromotest responses and concentrations of most organic pollutants studied. No correlation was shown between pollutant levels and Microtox. According to the number of sediment samples detected as toxic, medaka embryo-larval assay by sediment contact was more sensitive than Microtox, which in turn was more sensitive than the SOS chromotest; and medaka embryo-larval assay by sediment contact allowed sediment toxicity assessment of moderately polluted sediments without pollutant extraction and using an ecologically realistic exposure scenario. Although medaka embryo-larval assay by sediment contact should be tested on a larger sample set, the results show that it is sensitive and convenient enough to monitor the toxicity of natural sediments. Environ Toxicol Chem 2016;35:2270-2280. © 2016 SETAC. © 2016 SETAC.

Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

KAUST Repository

Williamson, David H.; Harrison, Hugo B.; Almany, Glenn R.; Berumen, Michael L.; Bode, Michael; Bonin, Mary C.; Choukroun, Severine; Doherty, Peter J.; Frisch, Ashley J.; Saenz-Agudelo, Pablo; Jones, Geoffrey P.

2016-01-01

Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

KAUST Repository

Williamson, David H.

2016-11-15

Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

Identifying health disparities across the tobacco continuum.

Science.gov (United States)

Fagan, Pebbles; Moolchan, Eric T; Lawrence, Deirdre; Fernander, Anita; Ponder, Paris K

2007-10-01

Few frameworks have addressed work-force diversity, inequities and inequalities as part of a comprehensive approach to eliminating tobacco-related health disparities. This paper summarizes the literature and describes the known disparities that exist along the tobacco disease continuum for minority racial and ethnic groups, those living in poverty, those with low education and blue-collar and service workers. The paper also discusses how work-force diversity, inequities in research practice and knowledge allocation and inequalities in access to and quality of health care are fundamental to addressing disparities in health. We examined the available scientific literature and existing public health reports to identify disparities across the tobacco disease continuum by minority racial/ethnic group, poverty status, education level and occupation. Results indicate that differences in risk indicators along the tobacco disease continuum do not explain fully tobacco-related cancer consequences among some minority racial/ethnic groups, particularly among the aggregate groups, blacks/African Americans and American Indians/Alaska Natives. The lack of within-race/ethnic group data and its interactions with socio-economic factors across the life-span contribute to the inconsistency we observe in the disease causal paradigm. More comprehensive models are needed to understand the relationships among disparities, social context, diversity, inequalities and inequities. A systematic approach will also help researchers, practitioners, advocates and policy makers determine critical points for interventions, the types of studies and programs needed and integrative approaches needed to eliminate tobacco-related disparities.

Tethered by Self-Generated Flow: Mucus String Augmented Feeding Current Generation in Larval Oysters

Science.gov (United States)

Jiang, H.; Wheeler, J.; Anderson, E.

2016-02-01

Marine zooplankton live in a nutritionally dilute environment. To survive, they must process an enormous volume of water relative to their own body volume for food. To achieve this, many zooplankters including copepods, invertebrate larvae, and protists create a feeding current to concentrate and transport food items to their food gathering structures. To enhance the efficiency of the feeding current, these zooplankters often rely on certain "tethering" mechanisms to retard their translational motion for producing a strong feeding current. The tethering force may include excess weight due to gravity, force from attachment to solid surfaces, and drag experienced by strategically placed morphological structures. Larval oysters are known from previous studies to release mucus strings during feeding, presumably for supplying a tethering force to enhance their feeding-current efficiency. But the underlying mechanism is unclear. In this study, we used a high-speed microscale imaging system (HSMIS) to observe the behavior of freely swimming and feeding larval oysters. We also used HSMIS to measure larval imposed feeding currents via a micro-particle image velocimetry (µPIV) technique. HSMIS allows observations along a vertically oriented focal plane in a relatively large water vessel with unprecedented spatial and temporal resolutions. Our high-speed videos show that a feeding larval oyster continuously released a long mucus string into its feeding current that flows downward; the feeding current subsequently dragged the mucus string downward. Analysis of our µPIV data combined with a hydrodynamic model further suggests that the drag force experienced by the mucus string in the feeding current contributes significantly to the tethering force required to generate the feeding current. Thus, mucus strings in larval oysters act as "anchors" in larval self-generated flow to actively tether the feeding larvae.

Disparities at the intersection of marginalized groups

Science.gov (United States)

Jackson, John W.; Williams, David R.; VanderWeele, Tyler J.

2016-01-01

Mental health disparities exist across several dimensions of social inequality, including race/ethnicity, socioeconomic status and gender. Most investigations of health disparities focus on one dimension. Recent calls by researchers argue for studying persons who are marginalized in multiple ways, often from the perspective of intersectionality, a theoretical framework applied to qualitative studies in law, sociology, and psychology. Quantitative adaptations are emerging but there is little guidance as to what measures or methods are helpful. Here, we consider the concept of a joint disparity and its composition, show that this approach can illuminate how outcomes are patterned for social groups that are marginalized across multiple axes of social inequality, and compare the insights gained with that of other measures of additive interaction. We apply these methods to a cohort of males from the National Longitudinal Survey of Youth, examining disparities for black males with low early life SES vs. white males with high early life SES across several outcomes that predict mental health, including unemployment, wages, and incarceration. We report striking disparities in each outcome, but show that the contribution of race, SES, and their intersection varies. PMID:27531592

Social determinants and sexually transmitted disease disparities.

Science.gov (United States)

Hogben, Matthew; Leichliter, Jami S

2008-12-01

Social determinants of health play an important role in sexually transmitted disease (STD) transmission and acquisition; consequently, racial and ethnic disparities among social determinants are influences upon disparities in STD rates. In this narrative review, we outline a general model showing the relationship between social determinants and STD outcomes, mediated by epidemiologic context. We then review 4 specific social determinants relevant to STD disparities: segregation, health care, socioeconomics and correctional experiences, followed by 2 facets of the resultant epidemiologic context: core areas and sexual networks. This review shows that disparities exist among the social determinants and that they are related to each other, as well as to core areas, sexual networks, and STD rates. Finally, we discuss the implications of our review for STD prevention and control with particular attention to STD program collaboration and service integration.

Depletion of juvenile hormone esterase extends larval growth in Bombyx mori.

Science.gov (United States)

Zhang, Zhongjie; Liu, Xiaojing; Shiotsuki, Takahiro; Wang, Zhisheng; Xu, Xia; Huang, Yongping; Li, Muwang; Li, Kai; Tan, Anjiang

2017-02-01

Two major hormones, juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulate insect growth and development according to their precisely coordinated titres, which are controlled by both biosynthesis and degradation pathways. Juvenile hormone esterase (JHE) is the primary JH-specific degradation enzyme that plays a key role in regulating JH titers, along with JH epoxide hydrolase (JHEH) and JH diol kinase (JHDK). In the current study, a loss-of-function analysis of JHE in the silkworm, Bombyx mori, was performed by targeted gene disruption using the transgenic CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/RNA-guided Cas9 nucleases) system. Depletion of B. mori JHE (BmJHE) resulted in the extension of larval stages, especially the penultimate and ultimate larval stages, without deleterious effects to silkworm physiology. The expression of JHEH and JHDK was upregulated in mutant animals, indicating the existence of complementary routes in the JH metabolism pathway in which inactivation of one enzyme will activate other enzymes. RNA-Seq analysis of mutant animals revealed that genes involved in protein processing in the endoplasmic reticulum and in amino acid metabolism were affected by BmJHE depletion. Depletion of JHE and subsequent delayed JH metabolism activated genes in the TOR pathway, which are ultimately responsible for extending larval growth. The transgenic Cas9 system used in the current study provides a promising approach for analysing the actions of JH, especially in nondrosophilid insects. Furthermore, prolonging larval stages produced larger larvae and cocoons, which is greatly beneficial to silk production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transcriptome and quantitative proteome analysis reveals molecular processes associated with larval metamorphosis in the polychaete pseudopolydora vexillosa

KAUST Repository

Chandramouli, Kondethimmanahalli

2013-03-01

Larval growth of the polychaete worm Pseudopolydora vexillosa involves the formation of segment-specific structures. When larvae attain competency to settle, they discard swimming chaetae and secrete mucus. The larvae build tubes around themselves and metamorphose into benthic juveniles. Understanding the molecular processes, which regulate this complex and unique transition, remains a major challenge because of the limited molecular information available. To improve this situation, we conducted high-throughput RNA sequencing and quantitative proteome analysis of the larval stages of P. vexillosa. Based on gene ontology (GO) analysis, transcripts related to cellular and metabolic processes, binding, and catalytic activities were highly represented during larval-adult transition. Mitogen-activated protein kinase (MAPK), calcium-signaling, Wnt/β-catenin, and notch signaling metabolic pathways were enriched in transcriptome data. Quantitative proteomics identified 107 differentially expressed proteins in three distinct larval stages. Fourteen and 53 proteins exhibited specific differential expression during competency and metamorphosis, respectively. Dramatic up-regulation of proteins involved in signaling, metabolism, and cytoskeleton functions were found during the larval-juvenile transition. Several proteins involved in cell signaling, cytoskeleton and metabolism were up-regulated, whereas proteins related to transcription and oxidative phosphorylation were down-regulated during competency. The integration of high-throughput RNA sequencing and quantitative proteomics allowed a global scale analysis of larval transcripts/proteins associated molecular processes in the metamorphosis of polychaete worms. Further, transcriptomic and proteomic insights provide a new direction to understand the fundamental mechanisms that regulate larval metamorphosis in polychaetes. © 2013 American Chemical Society.

Transcriptome and quantitative proteome analysis reveals molecular processes associated with larval metamorphosis in the polychaete pseudopolydora vexillosa

KAUST Repository

Chandramouli, Kondethimmanahalli; Sun, Jin; Mok, FloraSy; Liu, Lingli; Qiu, Jianwen; Ravasi, Timothy; Qian, Peiyuan

2013-01-01

Larval growth of the polychaete worm Pseudopolydora vexillosa involves the formation of segment-specific structures. When larvae attain competency to settle, they discard swimming chaetae and secrete mucus. The larvae build tubes around themselves and metamorphose into benthic juveniles. Understanding the molecular processes, which regulate this complex and unique transition, remains a major challenge because of the limited molecular information available. To improve this situation, we conducted high-throughput RNA sequencing and quantitative proteome analysis of the larval stages of P. vexillosa. Based on gene ontology (GO) analysis, transcripts related to cellular and metabolic processes, binding, and catalytic activities were highly represented during larval-adult transition. Mitogen-activated protein kinase (MAPK), calcium-signaling, Wnt/β-catenin, and notch signaling metabolic pathways were enriched in transcriptome data. Quantitative proteomics identified 107 differentially expressed proteins in three distinct larval stages. Fourteen and 53 proteins exhibited specific differential expression during competency and metamorphosis, respectively. Dramatic up-regulation of proteins involved in signaling, metabolism, and cytoskeleton functions were found during the larval-juvenile transition. Several proteins involved in cell signaling, cytoskeleton and metabolism were up-regulated, whereas proteins related to transcription and oxidative phosphorylation were down-regulated during competency. The integration of high-throughput RNA sequencing and quantitative proteomics allowed a global scale analysis of larval transcripts/proteins associated molecular processes in the metamorphosis of polychaete worms. Further, transcriptomic and proteomic insights provide a new direction to understand the fundamental mechanisms that regulate larval metamorphosis in polychaetes. © 2013 American Chemical Society.

Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities

Science.gov (United States)

Abesamis, Rene A.; Saenz-Agudelo, Pablo; Berumen, Michael L.; Bode, Michael; Jadloc, Claro Renato L.; Solera, Leilani A.; Villanoy, Cesar L.; Bernardo, Lawrence Patrick C.; Alcala, Angel C.; Russ, Garry R.

2017-09-01

Networks of no-take marine reserves (NTMRs) are a widely advocated strategy for managing coral reefs. However, uncertainty about the strength of population connectivity between individual reefs and NTMRs through larval dispersal remains a major obstacle to effective network design. In this study, larval dispersal among NTMRs and fishing grounds in the Philippines was inferred by conducting genetic parentage analysis on a coral-reef fish ( Chaetodon vagabundus). Adult and juvenile fish were sampled intensively in an area encompassing approximately 90 km of coastline. Thirty-seven true parent-offspring pairs were accepted after screening 1978 juveniles against 1387 adults. The data showed all types of dispersal connections that may occur in NTMR networks, with assignments suggesting connectivity among NTMRs and fishing grounds ( n = 35) far outnumbering those indicating self-recruitment ( n = 2). Critically, half (51%) of the inferred occurrences of larval dispersal linked reefs managed by separate, independent municipalities and constituent villages, emphasising the need for nested collaborative management arrangements across management units to sustain NTMR networks. Larval dispersal appeared to be influenced by wind-driven seasonal reversals in the direction of surface currents. The best-fit larval dispersal kernel estimated from the parentage data predicted that 50% of larvae originating from a population would attempt to settle within 33 km, and 95% within 83 km. Mean larval dispersal distance was estimated to be 36.5 km. These results suggest that creating a network of closely spaced (less than a few tens of km apart) NTMRs can enhance recruitment for protected and fished populations throughout the NTMR network. The findings underscore major challenges for regional coral-reef management initiatives that must be addressed with priority: (1) strengthening management of NTMR networks across political or customary boundaries; and (2) achieving adequate population

Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities

KAUST Repository

Abesamis, Rene A.

2017-03-24

Networks of no-take marine reserves (NTMRs) are a widely advocated strategy for managing coral reefs. However, uncertainty about the strength of population connectivity between individual reefs and NTMRs through larval dispersal remains a major obstacle to effective network design. In this study, larval dispersal among NTMRs and fishing grounds in the Philippines was inferred by conducting genetic parentage analysis on a coral-reef fish (Chaetodon vagabundus). Adult and juvenile fish were sampled intensively in an area encompassing approximately 90 km of coastline. Thirty-seven true parent-offspring pairs were accepted after screening 1978 juveniles against 1387 adults. The data showed all types of dispersal connections that may occur in NTMR networks, with assignments suggesting connectivity among NTMRs and fishing grounds (n = 35) far outnumbering those indicating self-recruitment (n = 2). Critically, half (51%) of the inferred occurrences of larval dispersal linked reefs managed by separate, independent municipalities and constituent villages, emphasising the need for nested collaborative management arrangements across management units to sustain NTMR networks. Larval dispersal appeared to be influenced by wind-driven seasonal reversals in the direction of surface currents. The best-fit larval dispersal kernel estimated from the parentage data predicted that 50% of larvae originating from a population would attempt to settle within 33 km, and 95% within 83 km. Mean larval dispersal distance was estimated to be 36.5 km. These results suggest that creating a network of closely spaced (less than a few tens of km apart) NTMRs can enhance recruitment for protected and fished populations throughout the NTMR network. The findings underscore major challenges for regional coral-reef management initiatives that must be addressed with priority: (1) strengthening management of NTMR networks across political or customary boundaries; and (2) achieving adequate population

Is the Schwabe Organ a Retained Larval Eye? Anatomical and Behavioural Studies of a Novel Sense Organ in Adult Leptochiton asellus (Mollusca, Polyplacophora Indicate Links to Larval Photoreceptors.

Directory of Open Access Journals (Sweden)

Lauren H Sumner-Rooney

Full Text Available The discovery of a sensory organ, the Schwabe organ, was recently reported as a unifying feature of chitons in the order Lepidopleurida. It is a patch of pigmented tissue located on the roof of the pallial cavity, beneath the velum on either side of the mouth. The epithelium is densely innervated and contains two types of potential sensory cells. As the function of the Schwabe organ remains unknown, we have taken a cross-disciplinary approach, using anatomical, histological and behavioural techniques to understand it. In general, the pigmentation that characterises this sensory structure gradually fades after death; however, one particular concentrated pigment dot persists. This dot is positionally homologous to the larval eye in chiton trochophores, found in the same neuroanatomical location, and furthermore the metamorphic migration of the larval eye is ventral in species known to possess Schwabe organs. Here we report the presence of a discrete subsurface epithelial structure in the region of the Schwabe organ in Leptochiton asellus that histologically resembles the chiton larval eye. Behavioural experiments demonstrate that Leptochiton asellus with intact Schwabe organs actively avoid an upwelling light source, while Leptochiton asellus with surgically ablated Schwabe organs and a control species lacking the organ (members of the other extant order, Chitonida do not (Kruskal-Wallis, H = 24.82, df = 3, p < 0.0001. We propose that the Schwabe organ represents the adult expression of the chiton larval eye, being retained and elaborated in adult lepidopleurans.

Health Psychology special series on health disparities

NARCIS (Netherlands)

Kazak, A.E.; Bosch, J.; Klonoff, E.A.

2012-01-01

With the initiation of this new ongoing special series in Health Psychology on health disparities, we will publish articles that highlight ways in which health psychology can contribute to understanding and ameliorating these disparities. We welcome articles for this new special series and

Bioenergetics models to estimate numbers of larval lampreys consumed by smallmouth bass in Elk Creek, Oregon

Science.gov (United States)

Schultz, Luke; Heck, Michael; Kowalski, Brandon M; Eagles-Smith, Collin A.; Coates, Kelly C.; Dunham, Jason B.

2017-01-01

Nonnative fishes have been increasingly implicated in the decline of native fishes in the Pacific Northwest. Smallmouth Bass Micropterus dolomieu were introduced into the Umpqua River in southwest Oregon in the early 1960s. The spread of Smallmouth Bass throughout the basin coincided with a decline in counts of upstream-migrating Pacific Lampreys Entosphenus tridentatus. This suggested the potential for ecological interactions between Smallmouth Bass and Pacific Lampreys, as well as freshwater-resident Western Brook Lampreys Lampetra richardsoni. To evaluate the potential effects of Smallmouth Bass on lampreys, we sampled diets of Smallmouth Bass and used bioenergetics models to estimate consumption of larval lampreys in a segment of Elk Creek, a tributary to the lower Umpqua River. We captured 303 unique Smallmouth Bass (mean: 197 mm and 136 g) via angling in July and September. We combined information on Smallmouth Bass diet and energy density with other variables (temperature, body size, growth, prey energy density) in a bioenergetics model to estimate consumption of larval lampreys. Larval lampreys were found in 6.2% of diet samples, and model estimates indicated that the Smallmouth Bass we captured consumed 925 larval lampreys in this 2-month study period. When extrapolated to a population estimate of Smallmouth Bass in this segment, we estimated 1,911 larval lampreys were consumed between July and September. Although the precision of these estimates was low, this magnitude of consumption suggests that Smallmouth Bass may negatively affect larval lamprey populations.

Larval dispersal modeling of pearl oyster Pinctada margaritifera following realistic environmental and biological forcing in Ahe atoll lagoon.

Directory of Open Access Journals (Sweden)

Yoann Thomas

Full Text Available Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination location, vertical swimming behavior and pelagic larval duration (PLD factors. The potential connectivity was spatially weighted according to both the natural and cultivated broodstock densities to provide a realistic view of connectivity. We found that the mean pattern of potential connectivity was driven by the southwest and northeast main barotropic circulation structures, with high retention levels in both. Destination locations, spawning sites and PLD were the main drivers of potential connectivity, explaining respectively 26%, 59% and 5% of the variance. Differences between potential and realistic connectivity showed the significant contribution of the pearl oyster broodstock location to its own dynamics. Realistic connectivity showed larger larval supply in the western destination locations, which are preferentially used by farmers for spat collection. In addition, larval supply in the same sectors was enhanced during summer wind conditions. These results provide new cues to understanding the dynamics of bottom-dwelling populations in atoll lagoons, and show how to take advantage of numerical models for pearl oyster management.

Population dynamics and management implications of larval dispersal

African Journals Online (AJOL)

caused by the identified mechanism provides: (1) the basis for spatially explicit management, and (2) an explanation for the observed spatial variability in the degree of overfishing. Research on larval dispersal is also providing the information necessary to design spatially explicit management strategies involving either ...

Rural Health Disparities

Science.gov (United States)

... in the Delta Region for specific data. U.S. – Mexico Border While life expectancy in many counties of ... documents the successes, challenges, and relevant information for planning. ... on rural/urban disparities see What sources cover health behaviors and ...

Challenges for Multilevel Health Disparities Research in a Transdisciplinary Environment

Science.gov (United States)

Holmes, John H.; Lehman, Amy; Hade, Erinn; Ferketich, Amy K.; Sarah, Gehlert; Rauscher, Garth H.; Abrams, Judith; Bird, Chloe E.

2008-01-01

Numerous factors play a part in health disparities. Although health disparities are manifested at the level of the individual, other contexts should be considered when investigating the associations of disparities with clinical outcomes. These contexts include families, neighborhoods, social organizations, and healthcare facilities. This paper reports on health disparities research as a multilevel research domain from the perspective of a large national initiative. The Centers for Population Health and Health Disparities (CPHHD) program was established by the NIH to examine the highly dimensional, complex nature of disparities and their effects on health. Because of its inherently transdisciplinary nature, the CPHHD program provides a unique environment in which to perform multilevel health disparities research. During the course of the program, the CPHHD centers have experienced challenges specific to this type of research. The challenges were categorized along three axes: sources of subjects and data, data characteristics, and multilevel analysis and interpretation. The CPHHDs collectively offer a unique example of how these challenges are met; just as importantly, they reveal a broad range of issues that health disparities researchers should consider as they pursue transdisciplinary investigations in this domain, particularly in the context of a large team science initiative. PMID:18619398

Perspectives of Orthopedic Surgeons on Racial/Ethnic Disparities in Care.

Science.gov (United States)

Adelani, Muyibat A; O'Connor, Mary I

2017-08-01

Racial/ethnic disparities in healthcare, including orthopedics, have been extensively documented. However, the level of knowledge among orthopedic surgeons regarding racial/ethnic disparities is unknown. The purpose of this study is to determine the views of orthopedic surgeons on (1) the extent of racial/ethnic disparities in orthopedic care, (2) patient and system factors that may contribute, and (3) the potential role of orthopedic surgeons in the reduction of disparities. Three hundred five members of the American Orthopaedic Association completed a survey to assess their knowledge of racial/ethnic disparities and their perceptions about the underlying causes. Twelve percent of respondents believe that patients often receive different care based on race/ethnicity in healthcare in general, while 9 % believe that differences exist in orthopedic care in general, 3 % believe that differences exist within their hospitals/clinics, and 1 % reported differences in their own practices. Despite this, 68 % acknowledge that there is evidence of disparities in orthopedic care. Fifty-one percent believe that a lack of insurance significantly contributes to disparities. Thirty-five percent believe that diversification of the orthopedic workforce would be a "very effective" strategy in addressing disparities, while 25 % percent believe that research would be "very effective" and 24 % believe that surgeon education would be "very effective." Awareness regarding racial/ethnic disparities in musculoskeletal care is low among orthopedic surgeons. Additionally, respondents were more likely to acknowledge disparities within the practices of others than their own. Increased diversity, research, and education may help improve knowledge of this problem.

Global health disparities: crisis in the diaspora.

Science.gov (United States)

Cox, Raymond L.

2004-01-01

The United States spends more than the rest of the world on healthcare. In 2000, the U.S. health bill was 1.3 trillion dollars, 14.5% of its gross domestic product. Yet, according to the WHO World Health Report 2000, the United States ranked 37th of 191 member nations in overall health system performance. Racial/ethnic disparities in health outcomes are the most obvious examples of an unbalanced healthcare system. This presentation will examine health disparities in the United States and reveal how health disparities among and within countries affect the health and well-being of the African Diaspora. PMID:15101675

Gender and regional disparities of tuberculosis in Hunan, China.

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Chen, Mengshi; Kwaku, Abuaku Benjamin; Chen, Youfang; Huang, Xin; Tan, Hongzhuan; Wen, Shi Wu

2014-04-27

Major efforts have been made to improve the health care system in Hunan province, China. The aims of this study were to assess whether and to what extent these efforts have impacted on gender and regional disparities of Tuberculosis (TB) incidence in recent years, especially for less developed areas. We obtained data from the 2005-2009 China Information System for Disease Control and Prevention (CISDCP)to conduct this study in Hunan province. Counties within the province were divided into four regions according to quartiles based on the 2007 per capita GDP. Index of Disparity (ID) and Relative Index of Inequality (RII) were used to measure the disparities of TB incidence in relation to gender and region. Bootstrap technique was used to increase the precision. The average annual incidence of TB was 111.75 per 100,000 in males and 43.44 per 100 000 in females in Hunan. The gender disparity was stable, with ID from 42.34 in 2005 to 43.92 in 2009. For regional disparity, ID, RII (mean) and RII (ratio) decreased significantly from 2005 to 2009 in males (P China, regional disparity in relation to incidence of TB decreased significantly, but the gender disparity remains in the Hunan province.

Stigma and Racial/Ethnic HIV Disparities: Moving toward Resilience

Science.gov (United States)

Earnshaw, Valerie A.; Bogart, Laura M.; Dovidio, John F.; Williams, David R.

2013-01-01

Prior research suggests that stigma plays a role in racial/ethnic health disparities. However, there is limited understanding about the mechanisms by which stigma contributes to HIV-related disparities in risk, incidence and screening, treatment, and survival and what can be done to reduce the impact of stigma on these disparities. We introduce…

Larval gizzard shad characteristics in Lake Oahe, South Dakota: A species at the northern edge of its range

Science.gov (United States)

Fincel, Mark J.; Chipps, Steven R.; Graeb, Brian D. S.; Edwards, Kris R.

2013-01-01

Gizzard shad, Dorosoma cepedianum, have generally been restricted to the lower Missouri River impoundments in South Dakota. In recent years, gizzard shad numbers have increased in Lake Oahe, marking the northern-most natural population. These increases could potentially affect recreational fishes. Specifically, questions arise about larval gizzard shad growth dynamics and if age-0 gizzard shad in Lake Oahe will exhibit fast or slow growth, both of which can have profound effects on piscivore populations in this reservoir. In this study, we evaluated larval gizzard shad hatch timing, growth, and density in Lake Oahe. We collected larval gizzard shad from six sites from May to July 2008 and used sagittal otoliths to estimate the growth and back-calculate the hatch date. We found that larval gizzard shad hatched earlier in the upper part of the reservoir compared to the lower portion and that hatch date appeared to correspond to warming water temperatures. The peak larval gizzard shad density ranged from 0.6 to 33.6 (#/100 m3) and varied significantly among reservoir sites. Larval gizzard shad growth ranged from 0.24 to 0.57 (mm/d) and differed spatially within the reservoir. We found no relationship between the larval gizzard shad growth or density and small- or large-bodied zooplankton density (p > 0.05). As this population exhibits slow growth and low densities, gizzard shad should remain a suitable forage option for recreational fishes in Lake Oahe.

Sampling uncharted waters: Examining rearing habitat of larval Longfin Smelt (Spirinchus thaleichthys) in the upper San Francisco Estuary

Science.gov (United States)

Grimaldo, Lenny; Feyrer, Frederick; Burns, Jillian; Maniscalco, Donna

2017-01-01

The southern-most reproducing Longfin Smelt population occurs in the San Francisco Estuary, California, USA. Long-term monitoring of estuarine habitat for this species has generally only considered deep channels, with little known of the role shallow waters play in supporting their early life stage. To address the need for focused research on shallow-water habitat, a targeted study of Longfin Smelt larvae in littoral habitat was conducted to identify potential rearing habitats during 2013 and 2014. Our study objectives were to (1) determine if larval densities vary between littoral habitats (tidal slough vs. open-water shoal), (2) determine how larval densities in littoral habitats vary with physicochemical and biological attributes, (3) determine if larval densities vary between littoral habitats and long-term monitoring channel collections, and (4) determine what factors predict larval rearing distributions from the long-term monitoring channel collections. Larval densities did not vary between littoral habitats but they did vary between years. Water temperature, salinity, and chlorophyll a were found important in predicting larval densities in littoral habitats. Larval densities do not vary between littoral and channel surveys; however, the analysis based on channel data suggests that Longfin Smelt are hatching and rearing in a much broader region and under higher salinities (∼2–12 psu) than previously recognized. Results of this study indicate that conservation efforts should consider how freshwater flow, habitat, climate, and food webs interact as mechanisms that influence Longfin Smelt recruitment in estuarine environments.

The larval development and population dynamics of Derocheilocaris ...

African Journals Online (AJOL)

Seven larval stages of Derocheilocaris algoensis have been described and appear to be identical with those of D. typica from North America. This stresses the remarkable conservativeness of this subclass of Crustacea. The population biology of D. algoensis has been studied over 16 months and reproduction has been ...

Measurements and Counts for Larval and Juvenile Beryx Specimens

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Larval alfonsin (Beryx species) were collected in the vicinity of the Southeast Hancock Seamount. A three-net Tucker trawl (I m2 effective mouth opening and 0.333 mm...

Scanning electron microscopy of the four larval instars of the Dengue fever vector Aedes aegypti (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Stefan Schaper

2006-09-01

Full Text Available Aedes aegypti is the main insect vector of Dengue fever and dengue hemorrhagic fever/dengue shock syndrome and represents the only vulnerable element in the control of this disease. Therefore, the identification and quantification of this mosquito is an important task; however, the majority of taxonomic keys are based on the 4th larval instar. For that reason, this study describes the four larval instars of A. aegypti using scanning electron microscopy. Morphological changes during larval development were observed at the pecten, comb scales and the ventral brush of the abdominal segment X; however, the 3rd and 4th instars showed similar structures with only a slight variation. The structures described in this study will be helpful in the identification of the four instars of A. aegypti, a fundamental task for comprehending the natural history of dengue mainly in new territories affected. Rev. Biol. Trop. 54 (3: 847-852. Epub 2006 Sept. 29.Aedes aegypti es el principal insecto vector de la fiebre del dengue y del dengue hemorrágico/síndrome del choque por dengue y es el único elemento atacable para el control de esta virosis. La identificación y cuantificación de éste es una tarea importante; no obstante, la mayoría de las llaves taxonómicas se basan en el cuarto estadio larval. Por esta razón, en este trabajo se describen los cuatro estadios larvales de A. aegypti los cuales fueron examinados mediante microscopia electrónica de rastreo. Los cambios morfológicos ocurridos durante el desarrollo larval fueron observados en el pecten, las escamas del peine, el cepillo ventral del décimo segmento. El 3ero y 4to estadios larvales mostraron estructuras similares con sólo ligeras variaciones. Las estructuras descritas en este artículo permiten identificar cualquiera de los cuatro estadios larvales de A. aegypti, lo cual representa una tarea importante en la comprensión de la historia natural del dengue en los nuevos territorios afectados.

A quantitative measurement of binocular color fusion limit for different disparities

Science.gov (United States)

Chen, Zaiqing; Shi, Junsheng; Tai, Yonghan; Huang, Xiaoqiao; Yun, Lijun; Zhang, Chao

2018-01-01

Color asymmetry is a common phenomenon in stereoscopic display system, which can cause visual fatigue or visual discomfort. When the color difference between the left and right eyes exceeds a threshold value, named binocular color fusion limit, color rivalry is said to occur. The most important information brought by stereoscopic displays is the depth perception produced by the disparity. As the stereo pair stimuli are presented separately to both eyes with disparities and those two monocular stimuli differ in color but share an iso-luminance polarity, it is possible for stereopsis and color rivalry to coexist. In this paper, we conducted an experiment to measure the color fusion limit for different disparity levels. In particular, it examines how the magnitude and sign of disparity affect the binocular color fusion limit that yields a fused, stable stereoscopic percept. The binocular color fusion limit was measured at five levels of disparities: 0, +/-60, +/-120 arc minutes for a sample color point which was selected from the 1976 CIE u'v' chromaticity diagram. The experimental results showed that fusion limit for the sample point varied with the level and sign of disparity. It was an interesting result that the fusion limit increased as the disparity decreases at crossed disparity direction (sign -), but there is almost no big change at uncrossed disparity direction (sign +). We found that color fusion was more difficult to achieve at the crossed disparity direction than at the uncrossed disparity direction.

Properties of the Visible Light Phototaxis and UV Avoidance Behaviors in the Larval Zebrafish.

Science.gov (United States)

Guggiana-Nilo, Drago A; Engert, Florian

2016-01-01

For many organisms, color is an essential source of information from visual scenes. The larval zebrafish has the potential to be a model for the study of this topic, given its tetrachromatic retina and high dependence on vision. In this study we took a step toward understanding how the larval zebrafish might use color sensing. To this end, we used a projector-based paradigm to force a choice of a color stimulus at every turn of the larva. The stimuli used spanned most of the larval spectral range, including activation of its Ultraviolet (UV) cone, which has not been described behaviorally before. We found that zebrafish larvae swim toward visible wavelengths (>400 nm) when choosing between them and darkness, as has been reported with white light. However, when presented with UV light and darkness zebrafish show an intensity dependent avoidance behavior. This UV avoidance does not interact cooperatively with phototaxis toward longer wavelengths, but can compete against it in an intensity dependent manner. Finally, we show that the avoidance behavior depends on the presence of eyes with functional UV cones. These findings open future avenues for studying the neural circuits that underlie color sensing in the larval zebrafish.

Racial/Ethnic Disparities in Mental Health Care Utilization among U.S. College Students: Applying the Institution of Medicine Definition of Health Care Disparities.

Science.gov (United States)

Hunt, Justin B; Eisenberg, Daniel; Lu, Liya; Gathright, Molly

2015-10-01

The authors apply the Institute of Medicine's definition of health care disparities to college students. The analysis pools data from the first two waves of the Healthy Minds Study, a multicampus survey of students' mental health (N = 13,028). A probit model was used for any past-year service utilization, and group differences in health status were adjusted by transforming the entire distribution for each minority population to approximate the white distribution. Disparities existed between whites and all minority groups. Compared to other approaches, the predicted service disparities were greater because this method included the effects of mediating SES variables. Health care disparities persist in the college setting despite improved access and nearly universal insurance coverage. Our findings emphasize the importance of investigating potential sources of disparities beyond geography and coverage.

Occurrence of Terranova larval types (Nematoda: Anisakidae in Australian marine fish with comments on their specific identities

Directory of Open Access Journals (Sweden)

Shokoofeh Shamsi

2016-03-01

Full Text Available Pseudoterranovosis is a well-known human disease caused by anisakid larvae belonging to the genus Pseudoterranova. Human infection occurs after consuming infected fish. Hence the presence of Pseudoterranova larvae in the flesh of the fish can cause serious losses and problems for the seafood, fishing and fisheries industries. The accurate identification of Pseudoterranova larvae in fish is important, but challenging because the larval stages of a number of different genera, including Pseudoterranova, Terranova and Pulchrascaris, look similar and cannot be differentiated from each other using morphological criteria, hence they are all referred to as Terranova larval type. Given that Terranova larval types in seafood are not necessarily Pseudoterranova and may not be dangerous, the aim of the present study was to investigate the occurrence of Terranova larval types in Australian marine fish and to determine their specific identity. A total of 137 fish belonging to 45 species were examined. Terranova larval types were found in 13 species, some of which were popular edible fish in Australia. The sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2 respectively of the Terranova larvae in the present study showed a high degree of similarity suggesting that they all belong to the same species. Due to the lack of a comparable sequence data of a well identified adult in the GenBank database the specific identity of Terranova larval type in the present study remains unknown. The sequence of the ITS regions of the Terranova larval type in the present study and those of Pseudoterranova spp. available in GenBank are significantly different, suggesting that larvae found in the present study do not belong to the genus Pseudoterranova, which is zoonotic. This study does not rule out the presence of Pseudoterranova larvae in Australian fish as Pseudoterranova decipiens E has been reported in adult form from seals in Antarctica and it

Decomposing Racial/Ethnic Disparities in Influenza Vaccination among the Elderly

Science.gov (United States)

Yoo, Byung-Kwang; Hasebe, Takuya; Szilagyi, Peter G.

2015-01-01

While persistent racial/ethnic disparities in influenza vaccination have been reported among the elderly, characteristics contributing to disparities are poorly understood. This study aimed to assess characteristics associated with racial/ethnic disparities in influenza vaccination using a nonlinear Oaxaca-Blinder decomposition method. We performed cross-sectional multivariable logistic regression analyses for which the dependent variable was self-reported receipt of influenza vaccine during the 2010–2011 season among community dwelling non-Hispanic African-American (AA), non-Hispanic White (W), English-speaking Hispanic (EH) and Spanish-speaking Hispanic (SH) elderly, enrolled in the 2011 Medicare Current Beneficiary Survey (MCBS) (un-weighted/weighted N= 6,095/19.2million). Using the nonlinear Oaxaca-Blinder decomposition method, we assessed the relative contribution of seventeen covariates—including socio-demographic characteristics, health status, insurance, access, preference regarding healthcare, and geographic regions —to disparities in influenza vaccination. Unadjusted racial/ethnic disparities in influenza vaccination were 14.1 percentage points (pp) (W-AA disparity, p.8). The Oaxaca-Blinder decomposition method estimated that the unadjusted W-AA and W-SH disparities in vaccination could be reduced by only 45% even if AA and SH groups become equivalent to Whites in all covariates in multivariable regression models. The remaining 55% of disparities were attributed to (a) racial/ethnic differences in the estimated coefficients (e.g., odds ratios) in the regression models and (b) characteristics not included in the regression models. Our analysis found that only about 45% of racial/ethnic disparities in influenza vaccination among the elderly could be reduced by equalizing recognized characteristics among racial/ethnic groups. Future studies are needed to identify additional modifiable characteristics causing disparities in influenza vaccination. PMID

Egg-larval mortality of Pacific herring in Prince William Sound, Alaska, after the Exxon Valdez oil spill

International Nuclear Information System (INIS)

McGurk, M. D.; Brown, E. D.

1996-01-01

Experiments were carried out to test the hypothesis that instantaneous daily rates of egg-larval mortality of Pacific herring were higher at two oil-exposed sites than at two other sites not so exposed. Results showed that egg-larval mortality was twice as great in the oil-exposed areas as in the two non-oiled areas. Larval growth rates were also severely affected; they were about half of those measured in populations from other areas of the north Pacific Ocean. A cautionary note was introduced to the effect that the differences in the egg-larval mortality between oiled and control sites may have been influenced by differences in egg dessication, predation, and wave scouring, hence these results should not be construed as conclusive evidence of oil spill damage. 40 refs., 6 figs

Variability in growth rates of larval haddock in the northern North Sea

DEFF Research Database (Denmark)

Gallego, A.; Heath, M.R.; Basford, D.J.

1999-01-01

of the spring plankton production bloom, and a likely explanation for the absence of environmental effects on larval growth was high food availability and larval feeding rates. Nevertheless, differences in growth were observed between cohorts, with larvae hatched later in the spring displaying higher growth...... at age than those hatched earlier. Particle-tracking modelling suggested that differences in temperature history between cohorts, on their own or compounded by a potential interaction between temperature and the development of plankton production, may explain the higher growth rate of the larvae hatched...

Epidemiology, Policy, and Racial/Ethnic Minority Health Disparities

Science.gov (United States)

Carter-Pokras, Olivia; Offutt-Powell, Tabatha; Kaufman, Jay S.; Giles, Wayne; Mays, Vickie

2013-01-01

Purpose Epidemiologists have long contributed to policy efforts to address health disparities. Three examples illustrate how epidemiologists have addressed health disparities in the U.S. and abroad through a “social determinants of health” lens. Methods To identify examples of how epidemiologic research has been applied to reduce health disparities, we queried epidemiologists engaged in disparities research in the U.S., Canada, and New Zealand, and drew upon the scientific literature. Results Resulting examples covered a wide range of topic areas. Three areas selected for their contributions to policy were: 1) epidemiology's role in definition and measurement, 2) the study of housing and asthma, and 3) the study of food policy strategies to reduce health disparities. While epidemiologic research has done much to define and quantify health inequalities, it has generally been less successful at producing evidence that would identify targets for health equity intervention. Epidemiologists have a role to play in measurement and basic surveillance, etiologic research, intervention research, and evaluation research. However, our training and funding sources generally place greatest emphasis on surveillance and etiologic research. Conclusions: The complexity of health disparities requires better training for epidemiologists to effectively work in multidisciplinary teams. Together we can evaluate contextual and multilevel contributions to disease and study intervention programs in order to gain better insights into evidenced-based health equity strategies. PMID:22626003

Stretch-activated cation channel from larval bullfrog skin

DEFF Research Database (Denmark)

Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

2010-01-01

Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed ...

A developmental and energetic basis linking larval oyster shell formation to acidification sensitivity

Science.gov (United States)

Waldbusser, George G.; Brunner, Elizabeth L.; Haley, Brian A.; Hales, Burke; Langdon, Christopher J.; Prahl, Frederick G.

2013-05-01

Acidified waters are impacting commercial oyster production in the U.S. Pacific Northwest, and favorable carbonate chemistry conditions are predicted to become less frequent. Within 48 h of fertilization, unshelled Pacific oyster (Crassostrea gigas) larvae precipitate roughly 90% of their body weight as calcium carbonate. We measured stable carbon isotopes in larval shell and tissue and in algal food and seawater dissolved inorganic carbon in a longitudinal study of larval development and growth. Using these data and measured biochemical composition of larvae, we show that sensitivity of initial shell formation to ocean acidification results from diminished ability to isolate calcifying fluid from surrounding seawater, a limited energy budget and a strong kinetic demand for calcium carbonate precipitation. Our results highlight an important link between organism physiology and mineral kinetics in larval bivalves and suggest the consideration of mineral kinetics may improve understanding winners and losers in a high CO2 world.

Racial Disparities in Palliative Care for Prostate Cancer

Science.gov (United States)

2016-01-01

1 | P a g e Award Number: W81XWH-10-1-0802 TITLE: " Racial Disparities in Palliative Care for Prostate Cancer." PRINCIPAL INVESTIGATOR: Alfred I...CONTRACT NUMBER W81XWH-10-1-0802 " Racial Disparities in Palliative Care for Prostate Cancer." 5b. GRANT NUMBER PC094372 5c. PROGRAM ELEMENT NUMBER...developed the tools/methods for working with SEER-Medicare. We plan to use analytic approaches and methods to explore racial disparities in the use of

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

KAUST Repository

He, Li-Sheng

2012-10-24

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts.

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

KAUST Repository

He, Li-Sheng; Xu, Ying; Matsumura, Kiyotaka; Zhang, Yu; Zhang, Gen; Qi, Shu-Hua; Qian, Pei-Yuan

2012-01-01

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts.

Composition and temporal patterns of larval fish communities in Chesapeake and Delaware Bays

Directory of Open Access Journals (Sweden)

Filipe Ribeiro

2015-11-01

Full Text Available Comparing larval fish assemblages in different estuaries provides insights about the coastal distribution of larval populations, larval transport, and adult spawning locations (Ribeiro et al. 2015. We simultaneously compared the larval fish assemblages entering two Middle Atlantic Bight (MAB estuaries (Delaware Bay and Chesapeake Bay, USA through weekly sampling from 2007 to 2009. In total, 43 taxa (32 families and 36 taxa (24 families were collected in Delaware and Chesapeake Bays, respectively. Mean taxonomic diversity, mean richness, and evenness were generally lower in Delaware Bay. Communities of both bays were dominated by Anchoa spp., Gobiosoma spp., Micropogonias undulatus, and Brevoortia tyrannus; Paralichthys spp. was more abundant in Delaware Bay and Microgobius thalassinus was more abundant in Chesapeake Bay. Inter-annual variation in the larval fish communities was low at both sites, with a relatively consistent composition across years, but strong seasonal (intra-annual variation in species composition occurred in both bays. Two groups were identified in Chesapeake Bay: a ‘winter’ group dominated by shelf-spawned species (e.g. M. undulatus and a ‘summer’ group comprising obligate estuarine species and coastal species (e.g. Gobiosoma spp. and Cynoscion regalis, respectively. In Delaware Bay, 4 groups were identified: a ‘summer’ group of mainly obligate estuarine fishes (e.g. Menidia sp. being replaced by a ‘fall’ group (e.g. Ctenogobius boleosoma and Gobionellus oceanicus; ‘winter’ and ‘spring’ groups were dominated by shelf-spawned (e.g. M. undulatus and Paralichthys spp. and obligate estuarine species (e.g. Leiostomus xanthurus and Pseudopleuronectes americanus, respectively. This study demonstrates that inexpensive and simultaneous sampling in different estuaries provides important insights into the variability in community structure of fish assemblages at large spatial scales.

[Canine peritoneal larval cestodosis caused by Mesocestoides spp. larval stages].

Science.gov (United States)

Häußler, T C; Peppler, C; Schmitz, S; Bauer, C; Hirzmann, J; Kramer, M

2016-01-01

In a female dog with unspecific clinical symptoms, sonography detected a hyperechoic mass in the middle abdomen and blood analysis a middle grade systemic inflammatory reaction. Laparotomy revealed a peritoneal larval cestodosis (PLC). The diagnosis of an infection with tetrathyridia of Mesocestoides spp. was confirmed by parasitological examination and molecularbiological analysis. Reduction of the intra-abdominal parasitic load as well as a high dose administration of fenbendazole over 3 months led to a successful treatment which could be documented sonographically and by decreased concentrations of C-reactive protein (CRP). Seven months after discontinuation of fenbendazole administration, PLC recurred, pre-empted by an elevation of serum CRP values. According to the literature a life-long fenbendazole treatment was initiated. In cases of unclear chronic granulomatous inflammations in the abdominal cavity in dogs, PLC should be considered. CRP concentration and sonographic examinations are suitable to control for treatment success and a possibly occurring relapse.

Disparities in Disability by Educational Attainment Across US States.

Science.gov (United States)

Montez, Jennifer Karas; Zajacova, Anna; Hayward, Mark D

2017-07-01

To examine how disparities in adult disability by educational attainment vary across US states. We used the nationally representative data of more than 6 million adults aged 45 to 89 years in the 2010-2014 American Community Survey. We defined disability as difficulty with activities of daily living. We categorized education as low (less than high school), mid (high school or some college), or high (bachelor's or higher). We estimated age-standardized disability prevalence by educational attainment and state. We assessed whether the variation in disability across states occurs primarily among low-educated adults and whether it reflects the socioeconomic resources of low-educated adults and their surrounding contexts. Disparities in disability by education vary markedly across states-from a 20 percentage point disparity in Massachusetts to a 12-point disparity in Wyoming. Disparities vary across states mainly because the prevalence of disability among low-educated adults varies across states. Personal and contextual socioeconomic resources of low-educated adults account for 29% of the variation. Efforts to reduce disparities in disability by education should consider state and local strategies that reduce poverty among low-educated adults and their surrounding contexts.

Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya

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Mwangangi Joseph M

2010-08-01

Full Text Available Abstract Background The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru, unplanned rice cultivation (Kiamachiri and non-irrigated (Murinduko agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. Results Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252, respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval

Larval habitats of Anopheles gambiae s.s. (Diptera: Culicidae influences vector competence to Plasmodium falciparum parasites

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Gouagna Louis C

2007-04-01

Full Text Available Abstract Background The origin of highly competent malaria vectors has been linked to productive larval habitats in the field, but there isn't solid quantitative or qualitative data to support it. To test this, the effect of larval habitat soil substrates on larval development time, pupation rates and vector competence of Anopheles gambiae to Plasmodium falciparum were examined. Methods Soils were collected from active larval habitats with sandy and clay substrates from field sites and their total organic matter estimated. An. gambiae larvae were reared on these soil substrates and the larval development time and pupation rates monitored. The emerging adult mosquitoes were then artificially fed blood with infectious P. falciparum gametocytes from human volunteers and their midguts examined for oocyst infection after seven days. The wing sizes of the mosquitoes were also measured. The effect of autoclaving the soil substrates was also evaluated. Results The total organic matter was significantly different between clay and sandy soils after autoclaving (P = 0.022. A generalized liner model (GLM analysis identified habitat type (clay soil, sandy soil, or lake water and autoclaving (that reduces presence of microbes as significant factors affecting larval development time and oocyst infection intensities in adults. Autoclaving the soils resulted in the production of significantly smaller sized mosquitoes (P = 0.008. Autoclaving clay soils resulted in a significant reduction in Plasmodium falciparum oocyst intensities (P = 0.041 in clay soils (unautoclaved clay soils (4.28 ± 0.18 oocysts/midgut; autoclaved clay soils = 1.17 ± 0.55 oocysts/midgut although no difference (P = 0.480 in infection rates was observed between clay soils (10.4%, sandy soils (5.3% or lake water (7.9%. Conclusion This study suggests an important nutritional role for organic matter and microbial fauna on mosquito fitness and vector competence. It shows that the quality of

The ecology, geopolitics, and economics of managing Lymantria dispar in the United States

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Patrick C. Tobin; Barry B. Bai; Donald A. Eggen; Donna S. Leonard

2012-01-01

Increases in global trade and travel have resulted in a number of species being inadvertently (or, in a few cases, deliberately) introduced into new geographical locations. In most cases, there is generally a lack of information regarding a species' biology and ecology, and its potential to cause environmental and economic harm. Regardless, management decisions...

Explaining Racial Disparities in Infant Health in Brazil

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Nyarko, Kwame A.; Lopez-Camelo, Jorge; Castilla, Eduardo E.

2015-01-01

Objectives. We sought to quantify how socioeconomic, health care, demographic, and geographic effects explain racial disparities in low birth weight (LBW) and preterm birth (PTB) rates in Brazil. Methods. We employed a sample of 8949 infants born between 1995 and 2009 in 15 cities and 7 provinces in Brazil. We focused on disparities in LBW (Public policies to improve children’s health should target prenatal care and geographic location differences to reduce health disparities between infants of African and European ancestries in Brazil. PMID:26313046

An Approach to Integrating Health Disparities within Undergraduate Biomedical Engineering Education.

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Vazquez, Maribel; Marte, Otto; Barba, Joseph; Hubbard, Karen

2017-11-01

Health disparities are preventable differences in the incidence, prevalence and burden of disease among communities targeted by gender, geographic location, ethnicity and/or socio-economic status. While biomedical research has identified partial origin(s) of divergent burden and impact of disease, the innovation needed to eradicate health disparities in the United States requires unique engagement from biomedical engineers. Increasing awareness of the prevalence and consequences of health disparities is particularly attractive to today's undergraduates, who have undauntedly challenged paradigms believed to foster inequality. Here, the Department of Biomedical Engineering at The City College of New York (CCNY) has leveraged its historical mission of access-and-excellence to integrate the study of health disparities into undergraduate BME curricula. This article describes our novel approach in a multiyear study that: (i) Integrated health disparities modules at all levels of the required undergraduate BME curriculum; (ii) Developed opportunities to include impacts of health disparities into undergraduate BME research projects and mentored High School summer STEM training; and (iii) Established health disparities-based challenges as BME capstone design and/or independent entrepreneurship projects. Results illustrate the rising awareness of health disparities among the youngest BMEs-to-be, as well as abundant undergraduate desire to integrate health disparities within BME education and training.

Cloning of aquaporin-1 of the blue crab, Callinectes sapidus: its expression during the larval development in hyposalinity.

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Chung, J Sook; Maurer, Leah; Bratcher, Meagan; Pitula, Joseph S; Ogburn, Matthew B

2012-09-03

Ontogenetic variation in salinity adaptation has been noted for the blue crab, Callinectes sapidus, which uses the export strategy for larval development: females migrate from the estuaries to the coast to spawn, larvae develop in the ocean, and postlarvae (megalopae) colonize estuarine areas. We hypothesized that C. sapidus larvae may be stenohaline and have limited osmoregulatory capacity which compromises their ability to survive in lower salinity waters. We tested this hypothesis using hatchery-raised larvae that were traceable to specific life stages. In addition, we aimed to understand the possible involvement of AQP-1 in salinity adaptation during larval development and during exposure to hyposalinity. A full-length cDNA sequence of aquaporin (GenBank JQ970426) was isolated from the hypodermis of the blue crab, C. sapidus, using PCR with degenerate primers and 5' and 3' RACE. The open reading frame of CasAQP-1 consists of 238 amino acids containing six helical structures and two NPA motifs for the water pore. The expression pattern of CasAQP-1 was ubiquitous in cDNAs from all tissues examined, although higher in the hepatopancreas, thoracic ganglia, abdominal muscle, and hypodermis and lower in the antennal gland, heart, hemocytes, ovary, eyestalk, brain, hindgut, Y-organs, and gill. Callinectes larvae differed in their capacity to molt in hyposalinity, as those at earlier stages from Zoea (Z) 1 to Z4 had lower molting rates than those from Z5 onwards, as compared to controls kept in 30 ppt water. No difference was found in the survival of larvae held at 15 and 30 ppt. CasAQP-1 expression differed with ontogeny during larval development, with significantly higher expression at Z1-2, compared to other larval stages. The exposure to 15 ppt affected larval-stage dependent CasAQP-1 expression which was significantly higher in Z2- 6 stages than the other larval stages. We report the ontogenetic variation in CasAQP-1 expression during the larval development

Biochemical changes during larval development in the short neck clam, Paphia malabarica Chemnitz

Digital Repository Service at National Institute of Oceanography (India)

Gireesh, R.; Biju, A.; Muthiah, P.

larvae through feeding on organic particles and are subsequently used for supporting metamorphosis. (Rodriguez, Sedano, Garcia- Martin, Perez-Camacho & Sanchez 1990; Haws, DiMichele & Hand1993). During this stage, larval velum disap- pears, and larvae... on lipid class composition. Part II: larval rearing, competency and settlement. Journal of Shell¢sh Research 22, 377^388. RodriguezJ.L., SedanoF.J., Garcia-Martin L.O., Perez-Cama- choA. & SanchezJ.L. (1990) Energy metabolism of newly settled Ostrea edulis...

A reaction-diffusion model to capture disparity selectivity in primary visual cortex.

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Mohammed Sultan Mohiuddin Siddiqui

Full Text Available Decades of experimental studies are available on disparity selective cells in visual cortex of macaque and cat. Recently, local disparity map for iso-orientation sites for near-vertical edge preference is reported in area 18 of cat visual cortex. No experiment is yet reported on complete disparity map in V1. Disparity map for layer IV in V1 can provide insight into how disparity selective complex cell receptive field is organized from simple cell subunits. Though substantial amounts of experimental data on disparity selective cells is available, no model on receptive field development of such cells or disparity map development exists in literature. We model disparity selectivity in layer IV of cat V1 using a reaction-diffusion two-eye paradigm. In this model, the wiring between LGN and cortical layer IV is determined by resource an LGN cell has for supporting connections to cortical cells and competition for target space in layer IV. While competing for target space, the same type of LGN cells, irrespective of whether it belongs to left-eye-specific or right-eye-specific LGN layer, cooperate with each other while trying to push off the other type. Our model captures realistic 2D disparity selective simple cell receptive fields, their response properties and disparity map along with orientation and ocular dominance maps. There is lack of correlation between ocular dominance and disparity selectivity at the cell population level. At the map level, disparity selectivity topography is not random but weakly clustered for similar preferred disparities. This is similar to the experimental result reported for macaque. The details of weakly clustered disparity selectivity map in V1 indicate two types of complex cell receptive field organization.

Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus.

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Peter W Alderks

Full Text Available The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r(2 = 0.92. The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥ 1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or -15.2 dB re 1 g (z-axis. Lowest AEBR thresholds were 140-150 dB re 1 µPa or -33 to -23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9-2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.

Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus.

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Alderks, Peter W; Sisneros, Joseph A

2013-01-01

The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR) in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r(2) = 0.92). The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥ 1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or -15.2 dB re 1 g (z-axis). Lowest AEBR thresholds were 140-150 dB re 1 µPa or -33 to -23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9-2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.

Larval fish dispersal in a coral-reef seascape

KAUST Repository

Almany, Glenn R.; Planes, Serge; Thorrold, Simon R.; Berumen, Michael L.; Bode, Michael; Saenz Agudelo, Pablo; Bonin, Mary C.; Frisch, Ashley J.; Harrison, Hugo B.; Messmer, Vanessa; Nanninga, Gerrit B.; Priest, Mark; Srinivasan, Maya; Sinclair-Taylor, Tane; Williamson, David H.; Jones, Geoffrey P.

2017-01-01

Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km2) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13–19 km, with 90% of settlement occurring within 31–43 km. Mean dispersal distances were considerably greater (43–64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

Larval fish dispersal in a coral-reef seascape

KAUST Repository

Almany, Glenn R.

2017-05-23

Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km2) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13–19 km, with 90% of settlement occurring within 31–43 km. Mean dispersal distances were considerably greater (43–64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

Estimation of larval density of Liriomyza sativae Blanchard (Diptera ...

African Journals Online (AJOL)

This study was conducted to develop sequential sampling plans to estimate larval density of Liriomyza sativae Blanchard (Diptera: Agromyzidae) at three precision levels in cucumber greenhouse. The within- greenhouse spatial patterns of larvae were aggregated. The slopes and intercepts of both Iwao's patchiness ...

Fruit Fly Liquid Larval Diet Technology Transfer and Update

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Since October 2006, USDA-ARS has been implementing a fruit fly liquid larval diet technology transfer, which has proceeded according to the following steps: (1) Recruitment of interested groups through request; (2) Establishment of the Material Transfer Agreement (MTA) with ARS; (3) Fruit fly liquid...

Patterning Muscles Using Organizers: Larval Muscle Templates and Adult Myoblasts Actively Interact to Pattern the Dorsal Longitudinal Flight Muscles of Drosophila

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Roy, Sudipto; VijayRaghavan, K.

1998-01-01

Pattern formation in muscle development is often mediated by special cells called muscle organizers. During metamorphosis in Drosophila, a set of larval muscles function as organizers and provide scaffolding for the development of the dorsal longitudinal flight muscles. These organizers undergo defined morphological changes and dramatically split into templates as adult fibers differentiate during pupation. We have investigated the cellular mechanisms involved in the use of larval fibers as templates. Using molecular markers that label myoblasts and the larval muscles themselves, we show that splitting of the larval muscles is concomitant with invasion by imaginal myoblasts and the onset of differentiation. We show that the Erect wing protein, an early marker of muscle differentiation, is not only expressed in myoblasts just before and after fusion, but also in remnant larval nuclei during muscle differentiation. We also show that interaction between imaginal myoblasts and larval muscles is necessary for transformation of the larval fibers. In the absence of imaginal myoblasts, the earliest steps in metamorphosis, such as the escape of larval muscles from histolysis and changes in their innervation, are normal. However, subsequent events, such as the splitting of these muscles, fail to progress. Finally, we show that in a mutant combination, null for Erect wing function in the mesoderm, the splitting of the larval muscles is aborted. These studies provide a genetic and molecular handle for the understanding of mechanisms underlying the use of muscle organizers in muscle patterning. Since the use of such organizers is a common theme in myogenesis in several organisms, it is likely that many of the processes that we describe are conserved. PMID:9606206

Racial and ethnic disparities in antidepressant drug use.

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Chen, Jie; Rizzo, John A

2008-12-01

Little is known about racial and ethnic disparities in health care utilization, expenditures and drug choice in the antidepressant market. This study investigates factors associated with the racial and ethnic disparities in antidepressant drug use. We seek to determine the extent to which disparities reflect differences in observable population characteristics versus heterogeneity across racial and ethnic groups. Among the population characteristics, we are interested in identifying which factors are most important in accounting for racial and ethnic disparities in antidepressant drug use. Using Medical Expenditure Panel Survey (MEPS) data from 1996-2003, we have an available sample of 10,416 Caucasian, 1,089 African American and 1,539 Hispanic antidepressant drug users aged 18 to 64 years. We estimate individual out-of-pocket payments, total prescription drug expenditures, drug utilization, the probability of taking generic versus brand name antidepressants, and the share of drugs that are older types of antidepressants (e.g., TCAs and MAOIs) for these individuals during a calendar year. Blinder-Oaxaca decomposition techniques are employed to determine the extent to which disparities reflect differences in observable population characteristics versus unobserved heterogeneity across racial and ethnic groups. Caucasians have the highest antidepressant drug expenditures and utilization. African-Americans have the lowest drug expenditures and Hispanics have the lowest drug utilization. Relative to Caucasians and Hispanics, African-Americans are more likely to purchase generics and use a higher share of older drugs (e.g., TCAs and MAOIs). Differences in observable characteristics explain most of the racial/ethnic differences in these outcomes, with the exception of drug utilization. Differences in health insurance and education levels are particularly important factors in explaining disparities. In contrast, differences in drug utilization largely reflect unobserved

Gene expression patterns during the larval development of European sea bass (dicentrarchus labrax) by microarray analysis.

Science.gov (United States)

Darias, M J; Zambonino-Infante, J L; Hugot, K; Cahu, C L; Mazurais, D

2008-01-01

During the larval period, marine teleosts undergo very fast growth and dramatic changes in morphology, metabolism, and behavior to accomplish their metamorphosis into juvenile fish. Regulation of gene expression is widely thought to be a key mechanism underlying the management of the biological processes required for harmonious development over this phase of life. To provide an overall analysis of gene expression in the whole body during sea bass larval development, we monitored the expression of 6,626 distinct genes at 10 different points in time between 7 and 43 days post-hatching (dph) by using heterologous hybridization of a rainbow trout cDNA microarray. The differentially expressed genes (n = 485) could be grouped into two categories: genes that were generally up-expressed early, between 7 and 23 dph, and genes up-expressed between 25 and 43 dph. Interestingly, among the genes regulated during the larval period, those related to organogenesis, energy pathways, biosynthesis, and digestion were over-represented compared with total set of analyzed genes. We discuss the quantitative regulation of whole-body contents of these specific transcripts with regard to the ontogenesis and maturation of essential functions that take place over larval development. Our study is the first utilization of a transcriptomic approach in sea bass and reveals dynamic changes in gene expression patterns in relation to marine finfish larval development.

Characterization and expression of calmodulin gene during larval settlement and metamorphosis of the polychaete Hydroides elegans

KAUST Repository

Chen, Zhangfan

2012-08-01

The polychaete . Hydroides elegans (Serpulidae, Lophotrochozoa) is a problematic marine fouling organism in most tropical and subtropical coastal environment. Competent larvae of . H. elegans undergo the transition from the swimming larval stage to the sessile juvenile stage with substantial morphological, physiological, and behavior changes. This transition is often referred to as larval settlement and metamorphosis. In this study, we examined the possible involvement of calmodulin (CaM) - a multifunctional calcium metabolism regulator, in the larval settlement and metamorphosis of . H. elegans. A full-length . CaM cDNA was successfully cloned from . H. elegans (. He-CaM) and it contained an open reading frame of 450. bp, encoding 149 amino acid residues. It was highly expressed in 12. h post-metamorphic juveniles, and remained high in adults. . In situ hybridization conducted in competent larvae and juveniles revealed that . He-CaM gene was continuously expressed in the putative growth zones, branchial rudiments, and collar region, suggesting that . He-CaM might be involved in tissue differentiation and development. Our subsequent bioassay revealed that the CaM inhibitor W7 could effectively inhibit larval settlement and metamorphosis, and cause some morphological defects of unsettled larvae. In conclusion, our results revealed that CaM has important functions in the larval settlement and metamorphosis of . H. elegans. © 2012 Elsevier Inc..

Vector disparity sensor with vergence control for active vision systems.

Science.gov (United States)

Barranco, Francisco; Diaz, Javier; Gibaldi, Agostino; Sabatini, Silvio P; Ros, Eduardo

2012-01-01

This paper presents an architecture for computing vector disparity for active vision systems as used on robotics applications. The control of the vergence angle of a binocular system allows us to efficiently explore dynamic environments, but requires a generalization of the disparity computation with respect to a static camera setup, where the disparity is strictly 1-D after the image rectification. The interaction between vision and motor control allows us to develop an active sensor that achieves high accuracy of the disparity computation around the fixation point, and fast reaction time for the vergence control. In this contribution, we address the development of a real-time architecture for vector disparity computation using an FPGA device. We implement the disparity unit and the control module for vergence, version, and tilt to determine the fixation point. In addition, two on-chip different alternatives for the vector disparity engines are discussed based on the luminance (gradient-based) and phase information of the binocular images. The multiscale versions of these engines are able to estimate the vector disparity up to 32 fps on VGA resolution images with very good accuracy as shown using benchmark sequences with known ground-truth. The performances in terms of frame-rate, resource utilization, and accuracy of the presented approaches are discussed. On the basis of these results, our study indicates that the gradient-based approach leads to the best trade-off choice for the integration with the active vision system.

Temporal Integration of Auditory Stimulation and Binocular Disparity Signals

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Marina Zannoli

2011-10-01

Full Text Available Several studies using visual objects defined by luminance have reported that the auditory event must be presented 30 to 40 ms after the visual stimulus to perceive audiovisual synchrony. In the present study, we used visual objects defined only by their binocular disparity. We measured the optimal latency between visual and auditory stimuli for the perception of synchrony using a method introduced by Moutoussis & Zeki (1997. Visual stimuli were defined either by luminance and disparity or by disparity only. They moved either back and forth between 6 and 12 arcmin or from left to right at a constant disparity of 9 arcmin. This visual modulation was presented together with an amplitude-modulated 500 Hz tone. Both modulations were sinusoidal (frequency: 0.7 Hz. We found no difference between 2D and 3D motion for luminance stimuli: a 40 ms auditory lag was necessary for perceived synchrony. Surprisingly, even though stereopsis is often thought to be slow, we found a similar optimal latency in the disparity 3D motion condition (55 ms. However, when participants had to judge simultaneity for disparity 2D motion stimuli, it led to larger latencies (170 ms, suggesting that stereo motion detectors are poorly suited to track 2D motion.

Why should we investigate the morphological disparity of plant clades?

Science.gov (United States)

Oyston, Jack W; Hughes, Martin; Gerber, Sylvain; Wills, Matthew A

2016-04-01

Disparity refers to the morphological variation in a sample of taxa, and is distinct from diversity or taxonomic richness. Diversity and disparity are fundamentally decoupled; many groups attain high levels of disparity early in their evolution, while diversity is still comparatively low. Diversity may subsequently increase even in the face of static or declining disparity by increasingly fine sub-division of morphological 'design' space (morphospace). Many animal clades reached high levels of disparity early in their evolution, but there have been few comparable studies of plant clades, despite their profound ecological and evolutionary importance. This study offers a prospective and some preliminary macroevolutionary analyses. Classical morphometric methods are most suitable when there is reasonable conservation of form, but lose traction where morphological differences become greater (e.g. in comparisons across higher taxa). Discrete character matrices offer one means to compare a greater diversity of forms. This study explores morphospaces derived from eight discrete data sets for major plant clades, and discusses their macroevolutionary implications. Most of the plant clades in this study show initial, high levels of disparity that approach or attain the maximum levels reached subsequently. These plant clades are characterized by an initial phase of evolution during which most regions of their empirical morphospaces are colonized. Angiosperms, palms, pines and ferns show remarkably little variation in disparity through time. Conifers furnish the most marked exception, appearing at relatively low disparity in the latest Carboniferous, before expanding incrementally with the radiation of successive, tightly clustered constituent sub-clades. Many cladistic data sets can be repurposed for investigating the morphological disparity of plant clades through time, and offer insights that are complementary to more focused morphometric studies. The unique structural and

Larval food quantity affects development time, survival and adult biological traits that influence the vectorial capacity of Anopheles darlingi under laboratory conditions.

Science.gov (United States)

Araújo, Maisa da-Silva; Gil, Luiz Herman S; e-Silva, Alexandre de-Almeida

2012-08-02

The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology. However, in order develop effective control strategies and laboratory breeding conditions for this species, more data on the factors affecting vector biology is needed. The aim of the present study is to assess the effects of larval food quantity on the vectorial capacity of An. darling under laboratory conditions. Anopheles darlingi was maintained at 28°C, 80% humidity and exposed to a daily photoperiod of 12 h. Larvae were divided into three experimental groups that were fed either a low, medium, or high food supply (based on the food amounts consumed by other species of culicids). Each experiment was replicated for six times. A cohort of adults were also exposed to each type of diet and assessed for several biological characteristics (e.g. longevity, bite frequency and survivorship), which were used to estimate the vectorial capacity of each experimental group. The group supplied with higher food amounts observed a reduction in development time while larval survival increased. In addition to enhanced longevity, increasing larval food quantity was positively correlated with increasing frequency of bites, longer blood meal duration and wing length, resulting in greater vectorial capacity. However, females had greater longevity than males despite having smaller wings. Overall, several larval and adult biological traits were significantly affected by larval food availability. Greater larval food supply

A larval hunger signal in the bumblebee Bombus terrestris

DEFF Research Database (Denmark)

Den Boer, Susanne Petronella A; Duchateau, Marie-Jose

2006-01-01

Larvae of Bombus terrestris, a pollen-storing bumblebee, are dependent on progressive provisioning by workers. We test the hypothesis that larval cuticular chemicals can act as a hunger signal. We first show with a new classical conditioning experiment, using a Y-shaped tube, that workers can...

Basolateral Cl- channels in the larval bullfrog skin epithelium

DEFF Research Database (Denmark)

Hillyard, Stanley D.; Rios, K.; Larsen, Erik Hviid

2002-01-01

The addition of 150 U/ml nystatin to the mucosal surface of isolated skin from larval bullfrogs increases apical membrane permeability and allows a voltage clamp to be applied to the basolateral membrane. With identical Ringer's solutions bathing either side of the tissue the short-circuit curren...

78 FR 35837 - National Institute on Minority Health and Health Disparities Research Endowments

Science.gov (United States)

2013-06-14

... disparities research to close the disparity gap in the burden of illness and death experienced by racial and... Number NIH-2007-0931] RIN 0925-AA61 National Institute on Minority Health and Health Disparities Research... disparities research and other health disparities research. DATES: Comments must be received on or before...

Numerical simulations of barnacle larval dispersion coupled with field observations on larval abundance, settlement and recruitment in a tropical monsoon influenced coastal marine environment

Digital Repository Service at National Institute of Oceanography (India)

Gaonkar, C.A.; Samiksha S.V.; George, G.; Aboobacker V.M.; Vethamony, P.; Anil, A.C.

Observations were carried out to monitor the larval abundance, settlement and recruitment of barnacles on a regular basis for a period of two years. The results were then compared with the numerical modelling studies carried out along the west coast...

Recurrent connectivity can account for the dynamics of disparity processing in V1

Science.gov (United States)

Samonds, Jason M.; Potetz, Brian R.; Tyler, Christopher W.; Lee, Tai Sing

2013-01-01

Disparity tuning measured in the primary visual cortex (V1) is described well by the disparity energy model, but not all aspects of disparity tuning are fully explained by the model. Such deviations from the disparity energy model provide us with insight into how network interactions may play a role in disparity processing and help to solve the stereo correspondence problem. Here, we propose a neuronal circuit model with recurrent connections that provides a simple account of the observed deviations. The model is based on recurrent connections inferred from neurophysiological observations on spike timing correlations, and is in good accord with existing data on disparity tuning dynamics. We further performed two additional experiments to test predictions of the model. First, we increased the size of stimuli to drive more neurons and provide a stronger recurrent input. Our model predicted sharper disparity tuning for larger stimuli. Second, we displayed anti-correlated stereograms, where dots of opposite luminance polarity are matched between the left- and right-eye images and result in inverted disparity tuning in the disparity energy model. In this case, our model predicted reduced sharpening and strength of inverted disparity tuning. For both experiments, the dynamics of disparity tuning observed from the neurophysiological recordings in macaque V1 matched model simulation predictions. Overall, the results of this study support the notion that, while the disparity energy model provides a primary account of disparity tuning in V1 neurons, neural disparity processing in V1 neurons is refined by recurrent interactions among elements in the neural circuit. PMID:23407952

The influence of substrate material on ascidian larval settlement.

Science.gov (United States)

Chase, Anna L; Dijkstra, Jennifer A; Harris, Larry G

2016-05-15

Submerged man-made structures present novel habitat for marine organisms and often host communities that differ from those on natural substrates. Although many factors are known to contribute to these differences, few studies have directly examined the influence of substrate material on organism settlement. We quantified larval substrate preferences of two species of ascidians, Ciona intestinalis (cryptogenic, formerly C. intestinalis type B) and Botrylloides violaceus (non-native), on commonly occurring natural (granite) and man-made (concrete, high-density polyethylene, PVC) marine materials in laboratory trials. Larvae exhibited species-specific settlement preferences, but generally settled more often than expected by chance on concrete and HDPE. Variation in settlement between materials may reflect preferences for rougher substrates, or may result from the influence of leached chemicals on ascidian settlement. These findings indicate that an experimental plate material can influence larval behavior and may help us understand how substrate features may contribute to differences in settlement in the field. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integrating intersectionality and biomedicine in health disparities research.

Science.gov (United States)

Kelly, Ursula A

2009-01-01

Persisting health disparities have lead to calls for an increase in health research to address them. Biomedical scientists call for research that stratifies individual indicators associated with health disparities, for example, ethnicity. Feminist social scientists recommend feminist intersectionality research. Intersectionality is the multiplicative effect of inequalities experienced by nondominant marginalized groups, for example, ethnic minorities, women, and the poor. The elimination of health disparities necessitates integration of both paradigms in health research. This study provides a practical application of the integration of biomedical and feminist intersectionality paradigms in nursing research, using a psychiatric intervention study with battered Latino women as an example.

Intra-instar larval cannibalism in Anopheles gambiae (s.s.) and Anopheles stephensi (Diptera: Culicidae).

Science.gov (United States)

Porretta, Daniele; Mastrantonio, Valentina; Crasta, Graziano; Bellini, Romeo; Comandatore, Francesco; Rossi, Paolo; Favia, Guido; Bandi, Claudio; Urbanelli, Sandra

2016-11-02

Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1) has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4) of Anopheles gambiae (s.s.) and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size) on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s.) than in An. stephensi. In both species the total number of cannibalistic events increased from 0-24 to 0-48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s.) and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of

Intra-instar larval cannibalism in Anopheles gambiae (s.s. and Anopheles stephensi (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Daniele Porretta

2016-11-01

Full Text Available Abstract Background Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1 has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4 of Anopheles gambiae (s.s. and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Results Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s. than in An. stephensi. In both species the total number of cannibalistic events increased from 0–24 to 0–48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. Conclusions The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s. and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior

Larval growth in the dominant polychaete Polydora ciliata is food-limited in a eutrophic Danish estuary (Isefjord)

DEFF Research Database (Denmark)

Pedersen, Troels Møller; Almeda, Rodrigo; Fotel, Frank Lech

2010-01-01

Food limitation in larval growth of the spionid polychaete Polydora ciliata was examined in a typical eutrophic estuary, Isefjord, in Denmark. In the field, food availability and the energetic requirements of the P. ciliata larval population were measured during 2 different periods in 2004 and 20...

Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

Directory of Open Access Journals (Sweden)

Harvey J Walsh

Full Text Available Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf. Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf

Mosquito larval source management for controlling malaria

Science.gov (United States)

Tusting, Lucy S; Thwing, Julie; Sinclair, David; Fillinger, Ulrike; Gimnig, John; Bonner, Kimberly E; Bottomley, Christian; Lindsay, Steven W

2015-01-01

Background Malaria is an important cause of illness and death in people living in many parts of the world, especially sub-Saharan Africa. Long-lasting insecticide treated bed nets (LLINs) and indoor residual spraying (IRS) reduce malaria transmission by targeting the adult mosquito vector and are key components of malaria control programmes. However, mosquito numbers may also be reduced by larval source management (LSM), which targets mosquito larvae as they mature in aquatic habitats. This is conducted by permanently or temporarily reducing the availability of larval habitats (habitat modification and habitat manipulation), or by adding substances to standing water that either kill or inhibit the development of larvae (larviciding). Objectives To evaluate the effectiveness of mosquito LSM for preventing malaria. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CABS Abstracts; and LILACS up to 24 October 2012. We handsearched the Tropical Diseases Bulletin from 1900 to 2010, the archives of the World Health Organization (up to 11 February 2011), and the literature database of the Armed Forces Pest Management Board (up to 2 March 2011). We also contacted colleagues in the field for relevant articles. Selection criteria We included cluster randomized controlled trials (cluster-RCTs), controlled before-and-after trials with at least one year of baseline data, and randomized cross-over trials that compared LSM with no LSM for malaria control. We excluded trials that evaluated biological control of anopheline mosquitoes with larvivorous fish. Data collection and analysis At least two authors assessed each trial for eligibility. We extracted data and at least two authors independently determined the risk of bias in the included studies. We resolved all disagreements through discussion with a third author. We analyzed the data using Review Manager 5 software

Stereo Disparity through Cost Aggregation with Guided Filter

Directory of Open Access Journals (Sweden)

Pauline Tan

2014-10-01

Full Text Available Estimating the depth, or equivalently the disparity, of a stereo scene is a challenging problem in computer vision. The method proposed by Rhemann et al. in 2011 is based on a filtering of the cost volume, which gives for each pixel and for each hypothesized disparity a cost derived from pixel-by-pixel comparison. The filtering is performed by the guided filter proposed by He et al. in 2010. It computes a weighted local average of the costs. The weights are such that similar pixels tend to have similar costs. Eventually, a winner-take-all strategy selects the disparity with the minimal cost for each pixel. Non-consistent labels according to left-right consistency are rejected; a densification step can then be launched to fill the disparity map. The method can be used to solve other labeling problems (optical flow, segmentation but this article focuses on the stereo matching problem.

Disparity Disambiguation by Fusion of Signal and Symbolic-Level Information

DEFF Research Database (Denmark)

Ralli, J.; Diaz, J.; Ros, E.

2012-01-01

We describe a method for resolving ambiguities in low-level disparity calculations in a stereo-vision scheme by using a recurrent mechanism that we call signal-symbol loop. Due to the local nature of low-level processing it is not always possible to estimate the correct disparity values produced...... at this level. Symbolic abstraction of the signal produces robust, high confidence, multimodal image features which can be used to interpret the scene more accurately and therefore disambiguate low-level interpretations by biasing the correct disparity. The fusion process is capable of producing more accurate...... dense disparity maps than the low- and symbolic-level algorithms can produce independently. Therefore we describe an efficient fusion scheme that allows symbolic- and low-level cues to complement each other, resulting in a more accurate and dense disparity representation of the scene....

A Marriage Of Larval Modeling And Empirical Data: Linking Adult, Larval And Juvenile Scallops In An Estuary

Science.gov (United States)

Bayer, S.; Wahle, R.; Brooks, D. A.; Brady, D. C.

2016-02-01

The giant sea scallop, Placopecten magellanicus, is a commercially valuable sedentary broadcast spawner that occupies offshore banks and coastal bays and estuaries in the Northwest Atlantic. Although area closures have helped repopulate depleted scallop populations, little is known about whether populations at densities that yield larvae supply local or distant populations. Surveying scallop populations in the Damariscotta River estuary in Maine during the 2013 and 2014 spawning seasons, and settling out spat bags to collect settling larvae along the gradient of the estuary, we were able to compare adult densities to newly settled juvenile (`spat') abundance. Using the location where we found a high density of adults, we incorporated previously published behavior, pelagic larval duration, wind and current data into a particle dispersal model within the estuary to determine likely sinks for larvae from the 2013 and 2014 spawning seasons. Preliminary model simulations demonstrate where in the estuary swimming is effective in affecting water column position for larvae, and that most larvae are retained much closer to the mouth of the estuary than previously expected. Combining larval dispersal modeling with empirical data on adult densities and spat settlement on the scale of an embayment or estuary may be helpful in determining sources, sinks and areas that are both sources and sinks for shellfish species that are endangered or economically critical. This may aid in determining small area closures or Marine Protected Areas along coastal regions in the Gulf of Maine and beyond.

Influence of larval and pupal products on the oviposition behavior of Aedes Fluviatilis (Lutz (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Rotraut A. G. B. Consoli

1988-06-01

Full Text Available Several larval and pupal products of Aedes fluviatilis (Lutz were tested for their influence on the oviposition behaviour of females of the same species. Significant (alfa = 0,05 atractiveness was shown by: larval water, previously containing 5 to 15 larvae/1,5 ml; larval water, preserved up to 38 days; evaporate and reconstructed larval water extracts up to 2 years after production and water filtered through fresh or dried ground larvae. hexanic larval water extracts and water filtered through fresh or dired ground pupae did not influence oviposition.Estudou-se a influência sobre o comportamento de oviposição das fêmeas de Aedes fluviatilis (Lutz de produtos derivados das formas imaturas da mesma espécie. As fêmeas foram atraídas significativamente (x=0,05 por ocasião da ovoposição por: água destilada que contivera 5 ou 15 larvas/1,5 ml, a mesma água (5 larvas/1,5 mlapós sua preservação por 38 dias; extratos evaporados e reconstituídos de água que conteve larvas, por até dois anos a sua produção, e filtrados de macerados frescos e secos de larvas. Extratos hexânicos de água que conteve larvas e filtrados de macerados descos e secos de pupas não atraíram a ovoposição das fêmeas.

Literacy and Health Disparities

Science.gov (United States)

Prins, Esther; Mooney, Angela

2014-01-01

This chapter explores the relationship between literacy and health disparities, focusing on the concept of health literacy. Recommendations are provided for ways to bridge the health literacy gap for learners in adult basic education and family literacy programs.

The association between racial disparity in income and reported sexually transmitted infections.

Science.gov (United States)

Owusu-Edusei, Kwame; Chesson, Harrell W; Leichliter, Jami S; Kent, Charlotte K; Aral, Sevgi O

2013-05-01

We examined the association between racial disparity in income and reported race-specific county-level bacterial sexually transmitted infections (STIs) in the United States focusing on disparities between Blacks and Whites. Data are from the US 2000 decennial census. We defined 2 race-income county groups (high and low race-income disparity) on the basis of the difference between Black and White median household incomes. We used 2 approaches to examine disparities in STI rates across the groups. In the first approach, we computed and compared race-specific STI rates for the groups. In the second approach, we used spatial regression analyses to control for potential confounders. Consistent with the STI literature, chlamydia, gonorrhea, and syphilis rates for Blacks were substantially higher than were those for Whites. We also found that racial disparities in income were associated with racial disparities in chlamydia and gonorrhea rates and, to a lesser degree, syphilis rates. Racial disparities in household income may be a more important determinant of racial disparities in reported STI morbidity than are absolute levels of household income.

Foraging and predation risk for larval cisco (Coregonus artedi) in Lake Superior: a modelling synthesis of empirical survey data

Science.gov (United States)

Myers, Jared T.; Yule, Daniel L.; Jones, Michael L.; Quinlan, Henry R.; Berglund, Eric K.

2014-01-01

The relative importance of predation and food availability as contributors to larval cisco (Coregonus artedi) mortality in Lake Superior were investigated using a visual foraging model to evaluate potential predation pressure by rainbow smelt (Osmerus mordax) and a bioenergetic model to evaluate potential starvation risk. The models were informed by observations of rainbow smelt, larval cisco, and zooplankton abundance at three Lake Superior locations during the period of spring larval cisco emergence and surface-oriented foraging. Predation risk was highest at Black Bay, ON, where average rainbow smelt densities in the uppermost 10 m of the water column were >1000 ha−1. Turbid conditions at the Twin Ports, WI-MN, affected larval cisco predation risk because rainbow smelt remained suspended in the upper water column during daylight, placing them alongside larval cisco during both day and night hours. Predation risk was low at Cornucopia, WI, owing to low smelt densities (cisco survival at Black Bay and to a lesser extent at Twin Ports, and that starvation may be a major source of mortality at all three locations. The framework we describe has the potential to further our understanding of the relative importance of starvation and predation on larval fish survivorship, provided information on prey resources available to larvae are measured at sufficiently fine spatial scales and the models provide a realistic depiction of the dynamic processes that the larvae experience.

CDC Health Disparities and Inequalities Report--U.S. 2013

Science.gov (United States)

... Women's Health Health Literacy Health Equity CDC Health Disparities & Inequalities Report (CHDIR) Recommend on Facebook Tweet Share ... 2011 Report More Information CDC Releases Second Health Disparities & Inequalities Report - United States, 2013 CDC and its ...

Molecular phylogeny and larval morphological diversity of the lanternfish genus Hygophum (Teleostei: Myctophidae).

Science.gov (United States)

Yamaguchi, M; Miya, M; Okiyama, M; Nishida, M

2000-04-01

Larvae of the deep-sea lanternfish genus Hygophum (Myctophidae) exhibit a remarkable morphological diversity that is quite unexpected, considering their homogeneous adult morphology. In an attempt to elucidate the evolutionary patterns of such larval morphological diversity, nucleotide sequences of a portion of the mitochondrially encoded 16S ribosomal RNA gene were determined for seven Hygophum species and three outgroup taxa. Secondary structure-based alignment resulted in a character matrix consisting of 1172 bp of unambiguously aligned sequences, which were subjected to phylogenetic analyses using maximum-parsimony, maximum-likelihood, and neighbor-joining methods. The resultant tree topologies from the three methods were congruent, with most nodes, including that of the genus Hygophum, being strongly supported by various tree statistics. The most parsimonious reconstruction of the three previously recognized, distinct larval morphs onto the molecular phylogeny revealed that one of the morphs had originated as the common ancestor of the genus, the other two having diversified separately in two subsequent major clades. The patterns of such diversification are discussed in terms of the unusual larval eye morphology and geographic distribution. Copyright 2000 Academic Press.

Silk formation mechanisms in the larval salivary glands of Apis ...

Indian Academy of Sciences (India)

Unknown

The mechanism of silk formation in Apis mellifera salivary glands, during the 5th instar, was studied. Larval salivary glands .... be used in the silk-manufacture industry. This paper analyses .... (figure 3C); and are highly birefringent (figure 3D).

Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

Directory of Open Access Journals (Sweden)

Ori Segev

Full Text Available Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail on Near Eastern fire salamander (Salamandra infraimmaculata larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

Mosquito larval habitats and public health implications in Abeokuta ...

African Journals Online (AJOL)

The larval habitats of mosquitoes were investigated in Abeokuta, Nigeria in order to determine the breeding sites of the existing mosquito fauna and its possible public health implications on the residents of the City. The habitats were sampled between August 2005 and July 2006 using plastic dippers and a pipette.

Gender Disparity in Education Enrollment in Pakistan

OpenAIRE

Shakil Quayes; Richard David Ramsey

2015-01-01

The paper examines the determinants of school enrollment in Pakistan. The likelihood of school enrollment is estimated using separate logistic regression models for three different age groups. The empirical results indicate severe gender disparity in school enrollment across all age groups, particularly among the older age groups. Although the rate of school enrollment is positively associated with household income, the gender disparity actually deteriorates with an increase in household inco...

Copper affects biofilm inductiveness to larval settlement of the serpulid polychaete Hydroides elegans (Haswell)

KAUST Repository

Bao, Wei Yang; Lee, On On; Chung, Hong Chun; Li, Mu; Qian, Pei Yuan

2010-01-01

Copper (Cu) contamination is a potential threat to the marine environment due to the use of Cu-based antifouling paints. Cu stress on larval settlement of the polychaete Hydroides elegans was investigated, and this was linked to Cu stress on biofilms and on the biofilm development process. The inductiveness of young biofilms was more easily altered by Cu stress than that of old biofilms, indicating the relative vulnerability of young biofilms. This might result from changes in bacterial survival, the bacterial community composition and the chemical profiles of young biofilms. Cu also affected biofilm development and the chemical high performance liquid chromatograph fingerprint profile. The results indicate that Cu affected larval settlement mainly through its effect on the process of biofilm development in the marine environment, and the chemical profile was crucial to biofilm inductiveness. It is strongly recommended that the effects of environmentally toxic substances on biofilms are evaluated in ecotoxicity bioassays using larval settlement of invertebrates as the end point. © 2010 Taylor & Francis.

Mind the gap: race/ethnic and socioeconomic disparities in obesity.

Science.gov (United States)

Krueger, Patrick M; Reither, Eric N

2015-11-01

Race/ethnic and socioeconomic status (SES) disparities in obesity are substantial and may widen in the future. We review nine potential mechanisms that recent research has used to explain obesity disparities. Those nine mechanisms fall into three broad groups-health behaviors, biological factors, and the social environment-which incorporate both proximate and upstream determinants of obesity disparities. Efforts to reduce the prevalence of obesity in the US population and to close race/ethnic and SES disparities in obesity will likely require the use of multifaceted interventions that target multiple mechanisms simultaneously. Unfortunately, relatively few of the mechanisms reviewed herein have been tested in an intervention framework.

Patterns and persistence of larval retention and connectivity in a marine fish metapopulation

KAUST Repository

Saenz Agudelo, Pablo

2012-08-14

Connectivity, the demographic linking of local populations through the dispersal of individuals, is one of the most poorly understood processes in population dynamics, yet has profound implications for conservation and harvest strategies. For marine species with pelagic larvae, direct estimation of connectivity remains logistically challenging and has mostly been limited to single snapshots in time. Here, we document seasonal and interannual patterns of larval dispersal in a metapopulation of the coral reef fish Amphiprion polymnus. A 3-year record of larval trajectories within and among nine discrete local populations from an area of approximately 35 km was established by determining the natal origin of settled juveniles through DNA parentage analysis. We found that spatial patterns of both self-recruitment and connectivity were remarkably consistent over time, with a low level of self-recruitment at the scale of individual sites. Connectivity among sites was common and multidirectional in all years and was not significantly influenced by seasonal variability of predominant surface current directions. However, approximately 75% of the sampled juveniles could not be assigned to parents within the study area, indicating high levels of immigrations from sources outside the study area. The data support predictions that the magnitude and temporal stability of larval connectivity decreases significantly with increasing distance between subpopulations, but increases with the size of subpopulations. Given the considerable effort needed to directly measure larval exchange, the consistent patterns suggest snapshot parentage analyses can provide useful dispersal estimates to inform spatial management decisions. © 2012 Blackwell Publishing Ltd.

Geographic disparity in kidney transplantation under KAS.

Science.gov (United States)

Zhou, Sheng; Massie, Allan B; Luo, Xun; Ruck, Jessica M; Chow, Eric K H; Bowring, Mary G; Bae, Sunjae; Segev, Dorry L; Gentry, Sommer E

2017-12-12

The Kidney Allocation System fundamentally altered kidney allocation, causing a substantial increase in regional and national sharing that we hypothesized might impact geographic disparities. We measured geographic disparity in deceased donor kidney transplant (DDKT) rate under KAS (6/1/2015-12/1/2016), and compared that with pre-KAS (6/1/2013-12/3/2014). We modeled DSA-level DDKT rates with multilevel Poisson regression, adjusting for allocation factors under KAS. Using the model we calculated a novel, improved metric of geographic disparity: the median incidence rate ratio (MIRR) of transplant rate, a measure of DSA-level variation that accounts for patient casemix and is robust to outlier values. Under KAS, MIRR was 1.75 1.81 1.86 for adults, meaning that similar candidates across different DSAs have a median 1.81-fold difference in DDKT rate. The impact of geography was greater than the impact of factors emphasized by KAS: having an EPTS score ≤20% was associated with a 1.40-fold increase (IRR =  1.35 1.40 1.45 , P geographic disparities with KAS (P = .3). Despite extensive changes to kidney allocation under KAS, geography remains a primary determinant of access to DDKT. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Determinants of health disparities between Italian regions

Directory of Open Access Journals (Sweden)

Giannoni Margherita

2010-06-01

Full Text Available Abstract Background Among European countries, Italy is one of the countries where regional health disparities contribute substantially to socioeconomic health disparities. In this paper, we report on regional differences in self-reported poor health and explore possible determinants at the individual and regional levels in Italy. Methods We use data from the "Indagine Multiscopo sulle Famiglie", a survey of aspects of everyday life in the Italian population, to estimate multilevel logistic regressions that model poor self-reported health as a function of individual and regional socioeconomic factors. Next we use the causal step approach to test if living conditions, healthcare characteristics, social isolation, and health behaviors at the regional level mediate the relationship between regional socioeconomic factors and self-rated health. Results We find that residents living in regions with more poverty, more unemployment, and more income inequality are more likely to report poor health and that poor living conditions and private share of healthcare expenditures at the regional level mediate socioeconomic disparities in self-rated health among Italian regions. Conclusion The implications are that regional contexts matter and that regional policies in Italy have the potential to reduce health disparities by implementing interventions aimed at improving living conditions and access to quality healthcare.

Controlling disease and creating disparities: a fundamental cause perspective.

Science.gov (United States)

Phelan, Jo C; Link, Bruce G

2005-10-01

The United States and other developed countries experienced enormous improvements in population health during the 20th century. In the context of this dramatic positive change, health disparities by race and socioeconomic status emerged for several potent killers. Any explanation for current health disparities must take these changing patterns into account. Any explanation that ignores large improvements in population health and fails to account for the emergence of disparities for specific diseases is an inadequate explanation of current disparities. We argue that genetic explanations and some prominent social causation explanations are incompatible with these facts. We propose that the theory of "fundamental causes" can account for both vast improvements in population health and the creation of large socioeconomic and racial disparities in mortality for specific causes of death over time. Specifically, we argue that it is our enormously expanded capacity to control disease and death in combination with existing social and economic inequalities that create health disparities by race and socioeconomic status: When we develop the ability to control disease and death, the benefits of this new-found ability are distributed according to resources of knowledge, money, power, prestige, and beneficial social connections. We present data on changing mortality patterns by race and socioeconomic status for two types of diseases: those for which our capacity to prevent death has increased significantly and those for which we remain largely unable to prevent death. Time trends in mortality patterns are consistent with the fundamental cause explanation.

Employment and Wage Disparities for Nurses With Activity Limitations.

Science.gov (United States)

Wilson, Barbara L; Butler, Richard J; Butler, Matthew J

2016-11-01

No studies quantify the labor market disparities between nurses with and without activity difficulties (physical impairment or disability). We explore disparate treatment of nurses with activity difficulties at three margins of the labor market: the ability to get a job, the relative wage rate offered once a nurse has a job, and the annual hours of work given that wage rate. Key variables from the American Community Survey (ACS) were analyzed, including basic demographic information, wages, hours of work, and employment status of registered nurses from 2006 to 2014. Although there is relatively little disparity in hourly wages, there is enormous disparity in the disabled's employment and hours of work opportunities, and hence a moderate amount of disparity in annual wages. This has significant implications for the nursing labor force, particularly as the nursing workforce continues to age and physical limitations or disabilities increase by 15-fold from 25 to 65 years of age.  Physical or psychological difficulties increase sharply over the course of a nurse's career, and employers must heighten efforts to facilitate an aging workforce and provide appropriate job accommodations for nurses with activity limitations. © 2016 Sigma Theta Tau International.

Development tendencies of regional disparities in the Slovak Republic

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Klamár Radoslav

2016-01-01

Full Text Available Presented paper deals with the issues of regional development and regional disparities in Slovakia in the years 2001-2014. Levelling respectively increase of regional disparities was evaluated through a set of 13 socio-economic indicators (gross birth rate, average monthly wage, monthly labour costs per employee, employment rate, unemployment rate, net monthly income and expenses per capita, completed dwellings, creation of GDP, labour productivity per employee in industry and construction, number of organizations focused on generating profit and number of freelancers which were used in the territorial units at the level of self-governing regions of the Slovak Republic (NUTS III level. In terms of the evaluation and comparison of regional disparities were used the Gini coefficient and the coefficient of variation for mutual comparison and validation of divergent or convergent tendencies of regional disparities in Slovakia.

Exploring the larval fish community of the central Red Sea with an integrated morphological and molecular approach

KAUST Repository

Isari, Stamatina

2017-08-03

An important aspect of population dynamics for coral reef fishes is the input of new individuals from the pelagic larval pool. However, the high biodiversity and the difficulty of identifying larvae of closely related species represent obstacles to more fully understanding these populations. In this study, we combined morphology and genetic barcoding (Cytochrome Oxidase I gene) to characterize the seasonal patterns of the larval fish community at two sites in close proximity to coral reefs in the central-north Red Sea: one shallower inshore location (50 m depth) and a nearby site located in deeper and more offshore waters (~ 500 m depth). Fish larvae were collected using oblique tows of a 60 cm-bongo net (500 μm mesh size) every month for one year (2013). During the warmer period of the year (June-November), the larval fish stock was comparable between sampling sites. However, during the colder months, abundances were higher in the inshore than in the offshore waters. Taxonomic composition and temporal variation of community structure differed notably between sites, potentially reflecting habitat differences, reproductive patterns of adults, and/or advective processes in the area. Eleven out of a total of 62 recorded families comprised 69–94% of the fish larval community, depending on sampling site and month. Richness of taxa was notably higher in the inshore station compared to the offshore, particularly during the colder period of the year and especially for the gobiids and apogonids. Two mesopelagic taxa (Vinciguerria sp. and Benthosema spp.) comprised an important component of the larval community at the deeper site with only a small and sporadic occurrence in the shallower inshore waters. Our data provide an important baseline reference for the larval fish communities of the central Red Sea, representing the first such study from Saudi Arabian waters.

Ocean acidification alters temperature and salinity preferences in larval fish.

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Pistevos, Jennifer C A; Nagelkerken, Ivan; Rossi, Tullio; Connell, Sean D

2017-02-01

Ocean acidification alters the way in which animals perceive and respond to their world by affecting a variety of senses such as audition, olfaction, vision and pH sensing. Marine species rely on other senses as well, but we know little of how these might be affected by ocean acidification. We tested whether ocean acidification can alter the preference for physicochemical cues used for dispersal between ocean and estuarine environments. We experimentally assessed the behavioural response of a larval fish (Lates calcarifer) to elevated temperature and reduced salinity, including estuarine water of multiple cues for detecting settlement habitat. Larval fish raised under elevated CO 2 concentrations were attracted by warmer water, but temperature had no effect on fish raised in contemporary CO 2 concentrations. In contrast, contemporary larvae were deterred by lower salinity water, where CO 2 -treated fish showed no such response. Natural estuarine water-of higher temperature, lower salinity, and containing estuarine olfactory cues-was only preferred by fish treated under forecasted high CO 2 conditions. We show for the first time that attraction by larval fish towards physicochemical cues can be altered by ocean acidification. Such alterations to perception and evaluation of environmental cues during the critical process of dispersal can potentially have implications for ensuing recruitment and population replenishment. Our study not only shows that freshwater species that spend part of their life cycle in the ocean might also be affected by ocean acidification, but that behavioural responses towards key physicochemical cues can also be negated through elevated CO 2 from human emissions.

Global mismatch between fishing dependency and larval supply from marine reserves

Science.gov (United States)

Andrello, Marco; Guilhaumon, François; Albouy, Camille; Parravicini, Valeriano; Scholtens, Joeri; Verley, Philippe; Barange, Manuel; Sumaila, U. Rashid; Manel, Stéphanie; Mouillot, David

2017-07-01

Marine reserves are viewed as flagship tools to protect exploited species and to contribute to the effective management of coastal fisheries. Yet, the extent to which marine reserves are globally interconnected and able to effectively seed areas, where fisheries are most critical for food and livelihood security is largely unknown. Using a hydrodynamic model of larval dispersal, we predict that most marine reserves are not interconnected by currents and that their potential benefits to fishing areas are presently limited, since countries with high dependency on coastal fisheries receive very little larval supply from marine reserves. This global mismatch could be reversed, however, by placing new marine reserves in areas sufficiently remote to minimize social and economic costs but sufficiently connected through sea currents to seed the most exploited fisheries and endangered ecosystems.

Functional genomics identifies regulators of the phototransduction machinery in the Drosophila larval eye and adult ocelli.

Science.gov (United States)

Mishra, Abhishek Kumar; Bargmann, Bastiaan O R; Tsachaki, Maria; Fritsch, Cornelia; Sprecher, Simon G

2016-02-15

Sensory perception of light is mediated by specialized Photoreceptor neurons (PRs) in the eye. During development all PRs are genetically determined to express a specific Rhodopsin (Rh) gene and genes mediating a functional phototransduction pathway. While the genetic and molecular mechanisms of PR development is well described in the adult compound eye, it remains unclear how the expression of Rhodopsins and the phototransduction cascade is regulated in other visual organs in Drosophila, such as the larval eye and adult ocelli. Using transcriptome analysis of larval PR-subtypes and ocellar PRs we identify and study new regulators required during PR differentiation or necessary for the expression of specific signaling molecules of the functional phototransduction pathway. We found that the transcription factor Krüppel (Kr) is enriched in the larval eye and controls PR differentiation by promoting Rh5 and Rh6 expression. We also identified Camta, Lola, Dve and Hazy as key genes acting during ocellar PR differentiation. Further we show that these transcriptional regulators control gene expression of the phototransduction cascade in both larval eye and adult ocelli. Our results show that PR cell type-specific transcriptome profiling is a powerful tool to identify key transcriptional regulators involved during several aspects of PR development and differentiation. Our findings greatly contribute to the understanding of how combinatorial action of key transcriptional regulators control PR development and the regulation of a functional phototransduction pathway in both larval eye and adult ocelli. Copyright © 2015 Elsevier Inc. All rights reserved.

Batch fertility and larval parameters of the jaguar cichlid (Cichlasoma managuense spawned in the laboratory (ESP

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Jorge Günther Nonell

2016-03-01

Full Text Available Batch fertility and larval parameters of 32 spawns of the jaguar guapote (Cichlasoma managuense in the laboratory were analyzed. Batch fertility was positively correlated with the female weight with spawns between about 3000 to 6000 larvae for females between 100 and 500 g wet weight. No significant correlation was found between larval parameters (fresh weight and % dry weight and female weight.

Fisheries Closed Areas Strengthen Scallop Larval Settlement and Connectivity Among Closed Areas and Across International Open Fishing Grounds: A Model Study

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Davies, Kimberley T. A.; Gentleman, W. C.; DiBacco, C.; Johnson, C. L.

2015-09-01

This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.

Black-white preterm birth disparity: a marker of inequality

Science.gov (United States)

Purpose. The racial disparity in preterrn birth (PTB) is a persistent feature of perinatal epidemiology, inconsistently modeled in the literature. Rather than include race as an explanatory variable, or employ race-stratified models, we sought to directly model the PTB disparity ...

Study on Silkworm Bed Cleaning Frequency during Larval Growth ...

African Journals Online (AJOL)

Study on Silkworm Bed Cleaning Frequency during Larval Growth Period. Abiy Tilahun, Kedir Shifa, Ahmed Ibrahim, Metasebia Terefe. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/star.v4i2.5 · AJOL African ...

Variations in the drift of larval cod ( Gadus morhua L.) in the Baltic Sea : combining field observations and modelling

DEFF Research Database (Denmark)

Voss, R.; Hinrichsen, H.H.; St. John, Michael

1999-01-01

Coupled three-dimensional (3-D) physical oceanographic modelling and field sampling programmes were carried out in May 1988 and August 1991 to investigate the potential drift of larval cod (Gadus morhua L.) in the Bornholm Basin of the Baltic Sea. The goals were to predict the transport of cod...... larvae, thus aiding the identification of physical processes influencing larval retention/dispersal. Numerical simulations were performed using a 3-D eddy-resolving baroclinic model based on the Bryan-Cox-Semtner code adapted for the Baltic Sea. Within the Bornholm Basin, the model was initialized...... for the time periods considered. Larval drift was simulated either by incorporation of passive drifters, or as the initial horizontal distribution of larvae implemented into the model. Drift model simulations of larval transport agreed relatively well with field observations. The influence of variations...

Neuroendocrine control of Drosophila larval light preference

DEFF Research Database (Denmark)

Yamanaka, Naoki; Romero, Nuria M.; Martin, Francisco A.

2013-01-01

melanogaster larvae. PTTH, through its receptor Torso, acts on two light sensors???the Bolwig???s organ and the peripheral class IV dendritic arborization neurons???to regulate light avoidance. We found that PTTH concomitantly promotes steroidogenesis and light avoidance at the end of larval stage, driving...

The post-larval and juvenile fish assemblage in the Sukhothai floodplain, Thailand

Science.gov (United States)

Siriwan, Suksri; Boonsatien, Boonsoong

2017-06-01

This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae (47.27%), Cobitidae (7.88%), Siluridae (6.67%), Bagridae (6.06%) and Mastacembelidae (3.33%) families. The most-abundant larval species were the Striped flying barb Esomus metallicus (16.90%), the Siamese mud carp Henicorhynchus siamensis (8.48%) and the Sumatran river sprat Clupeichthys goniognathus (8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid Rasbora species.

Larval competition of Chrysomya megacephala and Chrysomya rufifacies (Diptera: Calliphoridae): behavior and ecological studies of two blow fly species of forensic significance.

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Shiao, Shiuh-Feng; Yeh, Ta-Chuan

2008-07-01

Chrysomya megacephala and Chrysomya rufifacies are two predominant necrophagous species in Taiwan. Larvae of the latter can prey on other maggots, including that of their own species as facultative food. This facultative characteristic of C. rufifacies may enhance its competitive advantage over other maggots and could also change the situation of other coexisting colonies. In this study, these two species were colonized in the laboratory, and the main objective was to try to understand the effect of competition on larval development. According to our results, intraspecific competition mostly occurred as competition for food; when the rearing density was increased, larvae pupated earlier, resulting in a lighter adult dry weight. The tendencies were similar in both species, but C. megacephala developed smaller viable adults and had higher survivorship at high densities. Although C. rufifacies could use the food resource of cannibalism, its survivorship was still low. Our results also showed there were significant interactions between intraspecific competition and the density factor. However, with interspecific competition, the first-instar larvae of C. rufifacies invaded maggot masses of C. megacephala to feed together. The third instars of C. rufifacies were able to expel C. megacephala larvae from food by using a fleshy protrusion on their body surface; C. megacephala was usually forced to pupate earlier by shortening its larval stages. The results indicated that a temporary competitive advantage could only be obtained by C. rufifacies under a proper larval density. In addition, the effects on different larval stages, the responses to different competition intensities, and the temperature-dependent effects on interspecific competition are also discussed. In general, under mixed-species rearing at different temperatures and densities, larval duration, adult dry weight, and survivorship of both species decreased. However, our results did not completely agree with

Gender disparities in health care.

Science.gov (United States)

Kent, Jennifer A; Patel, Vinisha; Varela, Natalie A

2012-01-01

The existence of disparities in delivery of health care has been the subject of increased empirical study in recent years. Some studies have suggested that disparities between men and women exist in the diagnoses and treatment of health conditions, and as a result measures have been taken to identify these differences. This article uses several examples to illustrate health care gender bias in medicine. These examples include surgery, peripheral artery disease, cardiovascular disease, critical care, and cardiovascular risk factors. Additionally, we discuss reasons why these issues still occur, trends in health care that may address these issues, and the need for acknowledgement of the current system's inequities in order to provide unbiased care for women in the future. © 2012 Mount Sinai School of Medicine.

Mind the Gap: Race\\Ethnic and Socioeconomic Disparities in Obesity

OpenAIRE

Krueger, Patrick M.; Reither, Eric N.

2015-01-01

Race/ethnic and socioeconomic status (SES) disparities in obesity are substantial and may widen in the future. We review seven potential mechanisms that recent research has used to explain obesity disparities. Those seven mechanisms fall into three broad groups—health behaviors, biological and developmental factors, and the social environment—which incorporate both proximate and upstream determinants of obesity disparities. Efforts to reduce the prevalence of obesity in the U.S. population an...

Examining the Gap: Compensation Disparities between Male and Female Physician Assistants.

Science.gov (United States)

Smith, Noël; Cawley, James F; McCall, Timothy C

Compensation disparities between men and women have been problematic for decades, and there is considerable evidence that the gap cannot be entirely explained by nongender factors. The current study examined the compensation gap in the physician assistant (PA) profession. Compensation data from 2014 was collected by the American Academy of PAs in 2015. Practice variables, including experience, specialty, and hours worked, were controlled for in an ordinary least-squares sequential regression model to examine whether there remained a disparity in total compensation. In addition, the absolute disparity in compensation was compared with historical data collected by American Academy of PAs over the previous 1.5 decades. Without controlling for practice variables, a total compensation disparity of $16,052 existed between men and women in the PA profession. Even after PA practice variables were controlled for, a total compensation disparity of $9,695 remained between men and women (95% confidence interval, $8,438-$10,952). A 17-year trend indicates the absolute disparity between men and women has not lessened, although the disparity as a percent of male compensation has decreased in recent years. There remain challenges to ensuring pay equality in the PA profession. Even when compensation-relevant factors such as experience, hours worked, specialty, postgraduate training, region, and call are controlled for, there is still a substantial gender disparity in PA compensation. Remedies that may address this pay inequality include raising awareness of compensation disparities, teaching effective negotiation skills, assisting employers as they develop equitable compensation plans, having less reliance on past salary in position negotiation, and professional associations advocating for policies that support equal wages and opportunities, regardless of personal characteristics. Copyright © 2017 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Rate-distortion analysis of steganography for conveying stereovision disparity maps

Science.gov (United States)

Umeda, Toshiyuki; Batolomeu, Ana B. D. T.; Francob, Filipe A. L.; Delannay, Damien; Macq, Benoit M. M.

2004-06-01

3-D images transmission in a way which is compliant with traditional 2-D representations can be done through the embedding of disparity maps within the 2-D signal. This approach enables the transmission of stereoscopic video sequences or images on traditional analogue TV channels (PAL or NTSC) or printed photographic images. The aim of this work is to study the achievable performances of such a technique. The embedding of disparity maps has to be seen as a global rate-distortion problem. The embedding capacity through steganography is determined by the transmission channel noise and by the bearable distortion on the watermarked image. The distortion of the 3-D image displayed as two stereo views depends on the rate allocated to the complementary information required to build those two views from one reference 2-D image. Results from the works on the scalar Costa scheme are used to optimize the embedding of the disparity map compressed bit stream into the reference image. A method for computing the optimal trade off between the disparity map distortion and embedding distortion as a function of the channel impairments is proposed. The goal is to get a similar distortion on the left (the reference image) and the right (the disparity compensated image) images. We show that in typical situations the embedding of 2 bits/pixels in the left image, while the disparity map is compressed at 1 bit per pixel leads to a good trade-off. The disparity map is encoded with a strong error correcting code, including synchronisation bits.

Partnering health disparities research with quality improvement science in pediatrics.

Science.gov (United States)

Lion, K Casey; Raphael, Jean L

2015-02-01

Disparities in pediatric health care quality are well described in the literature, yet practical approaches to decreasing them remain elusive. Quality improvement (QI) approaches are appealing for addressing disparities because they offer a set of strategies by which to target modifiable aspects of care delivery and a method for tailoring or changing an intervention over time based on data monitoring. However, few examples in the literature exist of QI interventions successfully decreasing disparities, particularly in pediatrics, due to well-described challenges in developing, implementing, and studying QI with vulnerable populations or in underresourced settings. In addition, QI interventions aimed at improving quality overall may not improve disparities, and in some cases, may worsen them if there is greater uptake or effectiveness of the intervention among the population with better outcomes at baseline. In this article, the authors review some of the challenges faced by researchers and frontline clinicians seeking to use QI to address health disparities and propose an agenda for moving the field forward. Specifically, they propose that those designing and implementing disparities-focused QI interventions reconsider comparator groups, use more rigorous evaluation methods, carefully consider the evidence for particular interventions and the context in which they were developed, directly engage the social determinants of health, and leverage community resources to build collaborative networks and engage community members. Ultimately, new partnerships between communities, providers serving vulnerable populations, and QI researchers will be required for QI interventions to achieve their potential related to health care disparity reduction. Copyright © 2015 by the American Academy of Pediatrics.

Psychiatrists' attitudes toward and awareness about racial disparities in mental health care.

Science.gov (United States)

Mallinger, Julie B; Lamberti, J Steven

2010-02-01

Psychiatrists may perpetuate racial-ethnic disparities in health care through racially biased, albeit unconscious, behaviors. Changing these behaviors requires that physicians accept that racial-ethnic disparities exist and accept their own contributions to disparities. The purposes of this study were to assess psychiatrists' awareness of racial disparities in mental health care, to evaluate the extent to which psychiatrists believe they contribute to disparities, and to determine psychiatrists' interest in participating in disparities-reduction programs. A random sample of psychiatrists, identified through the American Psychiatric Association's member directory, was invited to complete the online survey. The survey was also distributed to psychiatrists at a national professional conference. Of the 374 respondents, most said they were not familiar or only a little familiar with the literature on racial disparities. Respondents tended to believe that race has a moderate influence on quality of psychiatric care but that race is more influential in others' practices than in their own practices. One-fourth had participated in any type of disparities-reduction program within the past year, and approximately one-half were interested in participating in such a program. Psychiatrists may not recognize the pervasiveness of racial inequality in psychiatric care, and they may attribute racially biased thinking to others but not to themselves. Interventions to eliminate racial-ethnic disparities should focus on revealing and modifying unconscious biases. Lack of physician interest may be one barrier to such interventions.

Race-Based Health Disparities and the Digital Divide: Implications for Nursing Practice.

Science.gov (United States)

Price, Zula

2015-12-01

Knowledge of the sources of race-based health disparities could improve nursing practice and education in minority underserved communities. This purpose of this paper was to consider if Black-nonBlack health disparities were at least in part explained by Black-nonBlack disparities in access to Internet-based health information. With data on the U.S. adult population from the 2012 General Social Survey, the parameters of a health production function in which computer usage as an input was estimated. It was found that while there are Black-nonBlack disparities in health, once computer usage was accounted for, Black-nonBlack health disparities disappeared. This suggests nursing and health interventions that improve Internet access for Black patients in underserved communities could improve the health of Black Americans and close the racial health disparities gap. These findings complement recent nursing researchfindings that suggest closing Black-nonBlack disparities in computer access, the "digital divide," can render nursing practice more effective in providing care to minority and underserved communities.

Exposure to waterborne Cu inhibits cutaneous Na⁺ uptake in post-hatch larval rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Zimmer, Alex M; Brauner, Colin J; Wood, Chris M

2014-05-01

In freshwater rainbow trout (Oncorhynchus mykiss), two common responses to acute waterborne copper (Cu) exposure are reductions in ammonia excretion and Na(+) uptake at the gills, with the latter representing the likely lethal mechanism of action for Cu in adult fish. Larval fish, however, lack a functional gill following hatch and rely predominantly on cutaneous exchange, yet represent the most Cu-sensitive life stage. It is not known if Cu toxicity in larval fish occurs via the skin or gills. The present study utilized divided chambers to assess cutaneous and branchial Cu toxicity over larval development, using disruptions in ammonia excretion (Jamm) and Na(+) uptake (Jin(Na)) as toxicological endpoints. Early in development (early; 3 days post-hatch; dph), approximately 95% of Jamm and 78% of Jin(Na) occurred cutaneously, while in the late developmental stage (late; 25 dph), the gills were the dominant site of exchange (83 and 87% of Jamm and Jin(Na), respectively). Exposure to 50 μg/l Cu led to a 49% inhibition of Jamm in the late developmental stage only, while in the early and middle developmental (mid; 17 dph) stages, Cu had no effect on Jamm. Jin(Na), however, was significantly inhibited by Cu exposure at the early (53% reduction) and late (47% reduction) stages. Inhibition at the early stage of development was mediated by a reduction in cutaneous uptake, representing the first evidence of cutaneous metal toxicity in an intact aquatic organism. The inhibitions of both Jamm and Jin(Na) in the late developmental stage occurred via a reduction in branchial exchange only. The differential responses of the skin and gills to Cu exposure suggest that the mechanisms of Jamm and Jin(Na) and/or Cu toxicity differ between these tissues. Exposure to 20μg/l Cu revealed that Jamm is the more Cu-sensitive process. The results presented here have important implications in predicting metal toxicity in larval fish. The Biotic Ligand Model (BLM) is currently used to predict

The implications of temperature-mediated plasticity in larval instar number for development within a marine invertebrate, the shrimp Palaemonetes varians.

Directory of Open Access Journals (Sweden)

Andrew Oliphant

Full Text Available Variations in larval instar number are common among arthropods. Here, we assess the implications of temperature-mediated variations in larval instar number for larval development time, larval growth rates, and juvenile dry weight within the palaemonid shrimp, Palaemonetes varians. In contrast with previous literature, which focuses on terrestrial arthropods, particularly model and pest species often of laboratory lines, we use wild shrimp, which differ in their life history from previous models. Newly-hatched P. varians larvae were first reared at 5, 10, 17, 25, and 30 °C to assess their thermal scope for development. Larvae developed at 17, 25, and 30 °C. At higher temperatures, larvae developed through fewer larval instars. Two dominant developmental pathways were observed; a short pathway of four instars and a long pathway of five instars. Longer developmental pathways of six to seven instars were rarely observed (mostly at lower temperatures and consisted of additional instars as 'repeat' instars; i.e. little developmental advance over the preceding instar. To assess the implications of temperature-mediated variation in larval instar number, newly-hatched larvae were then reared at 15, 20, and 25 °C. Again, the proportion of larvae developing through four instars increased with temperature. At all temperatures, larval development time and juvenile dry weight were greater for larvae developing through five instars. Importantly, because of the increasing proportion of larvae developing through four instars with increasing temperature, larval traits associated with this pathway (reduced development time and juvenile dry weight became more dominant. As a consequence of increasing growth rate with temperature, and the shift in the proportion of larvae developing through four instars, juvenile dry weight was greatest at intermediate temperatures (20 °C. We conclude that at settlement P. varians juveniles do not follow the temperature-size rule

The implications of temperature-mediated plasticity in larval instar number for development within a marine invertebrate, the shrimp Palaemonetes varians.

Science.gov (United States)

Oliphant, Andrew; Hauton, Chris; Thatje, Sven

2013-01-01

Variations in larval instar number are common among arthropods. Here, we assess the implications of temperature-mediated variations in larval instar number for larval development time, larval growth rates, and juvenile dry weight within the palaemonid shrimp, Palaemonetes varians. In contrast with previous literature, which focuses on terrestrial arthropods, particularly model and pest species often of laboratory lines, we use wild shrimp, which differ in their life history from previous models. Newly-hatched P. varians larvae were first reared at 5, 10, 17, 25, and 30 °C to assess their thermal scope for development. Larvae developed at 17, 25, and 30 °C. At higher temperatures, larvae developed through fewer larval instars. Two dominant developmental pathways were observed; a short pathway of four instars and a long pathway of five instars. Longer developmental pathways of six to seven instars were rarely observed (mostly at lower temperatures) and consisted of additional instars as 'repeat' instars; i.e. little developmental advance over the preceding instar. To assess the implications of temperature-mediated variation in larval instar number, newly-hatched larvae were then reared at 15, 20, and 25 °C. Again, the proportion of larvae developing through four instars increased with temperature. At all temperatures, larval development time and juvenile dry weight were greater for larvae developing through five instars. Importantly, because of the increasing proportion of larvae developing through four instars with increasing temperature, larval traits associated with this pathway (reduced development time and juvenile dry weight) became more dominant. As a consequence of increasing growth rate with temperature, and the shift in the proportion of larvae developing through four instars, juvenile dry weight was greatest at intermediate temperatures (20 °C). We conclude that at settlement P. varians juveniles do not follow the temperature-size rule; this is of

Diel and Lunar Variations in Larval Fish Supply in Malindi Marine ...

African Journals Online (AJOL)

2Department of Fisheries and Aquatic Sciences, University of Eldoret, PO Box 1125, Eldoret, Kenya; ... in fish larval occurrence was thus studied in Malindi Marine Park, Kenya, to assess diel and lunar ..... New South Wales University Press,.

Lossless Compression of Stereo Disparity Maps for 3D

DEFF Research Database (Denmark)

Zamarin, Marco; Forchhammer, Søren

2012-01-01

Efficient compression of disparity data is important for accurate view synthesis purposes in multi-view communication systems based on the “texture plus depth” format, including the stereo case. In this paper a novel technique for lossless compression of stereo disparity images is presented...

Using temporal seeding to constrain the disparity search range in stereo matching

CSIR Research Space (South Africa)

Ndhlovu, T

2011-11-01

Full Text Available for reusing computed disparity estimates on features in a stereo image sequence to constrain the disparity search range. Features are detected on a left image and their disparity estimates are computed using a local-matching algorithm. The features...

Plant microRNAs in larval food regulate honeybee caste development.

Science.gov (United States)

Zhu, Kegan; Liu, Minghui; Fu, Zheng; Zhou, Zhen; Kong, Yan; Liang, Hongwei; Lin, Zheguang; Luo, Jun; Zheng, Huoqing; Wan, Ping; Zhang, Junfeng; Zen, Ke; Chen, Jiong; Hu, Fuliang; Zhang, Chen-Yu; Ren, Jie; Chen, Xi

2017-08-01

The major environmental determinants of honeybee caste development come from larval nutrients: royal jelly stimulates the differentiation of larvae into queens, whereas beebread leads to worker bee fate. However, these determinants are not fully characterized. Here we report that plant RNAs, particularly miRNAs, which are more enriched in beebread than in royal jelly, delay development and decrease body and ovary size in honeybees, thereby preventing larval differentiation into queens and inducing development into worker bees. Mechanistic studies reveal that amTOR, a stimulatory gene in caste differentiation, is the direct target of miR162a. Interestingly, the same effect also exists in non-social Drosophila. When such plant RNAs and miRNAs are fed to Drosophila larvae, they cause extended developmental times and reductions in body weight and length, ovary size and fecundity. This study identifies an uncharacterized function of plant miRNAs that fine-tunes honeybee caste development, offering hints for understanding cross-kingdom interaction and co-evolution.

Foreword: Big Data and Its Application in Health Disparities Research.

Science.gov (United States)

Onukwugha, Eberechukwu; Duru, O Kenrik; Peprah, Emmanuel

2017-01-01

The articles presented in this special issue advance the conversation by describing the current efforts, findings and concerns related to Big Data and health disparities. They offer important recommendations and perspectives to consider when designing systems that can usefully leverage Big Data to reduce health disparities. We hope that ongoing Big Data efforts can build on these contributions to advance the conversation, address our embedded assumptions, and identify levers for action to reduce health care disparities.

Comparative evaluation of sea-urchin larval stage sensitivity to ocean acidification.

Science.gov (United States)

Passarelli, M C; Cesar, A; Riba, I; DelValls, T A

2017-10-01

Changes in the marine carbonate system may affect various calcifying organisms. This study is aimed to compare the sensitivity of embryo-larval development of two species of sea urchins (Paracentrutos lividus and Lytechinus variegatus) collected and exposed to samples from different coastal zone (Spain and Brazil) to ocean acidification. The results showed that the larval stages are very sensitive to small changes in the seawater's pH. The larvae from P. lividus species showed to be more sensitive to acidified elutriate sediments than larvae from L. variegatus sea urchin. Furthermore, this study has demonstrated that the CO 2 enrichment in aquatic ecosystems cause changes on the mobility of the metals: Zn, Cu, Fe, Al and As, which was presented different behavior among them. Although an increase on the mobility of metals was found, the results using the principal component analysis showed that the pH reduction show the highest correlations with the toxicity and is the main cause of embryo-larval development inhibition. In this comparative study it is demonstrated that both species are able to assess potential effects of the ocean acidification related to CO 2 enrichment by both near future scenarios and the risk associated with CO 2 leakages in the Carbon Capture and Storage (CCS) process, and the importance of comparative studies in different zones to improve the understanding of the impacts caused by ocean acidification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

Science.gov (United States)

Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

2014-04-01

The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability. © 2013 John Wiley & Sons Ltd.

2D Gel-Based Multiplexed Proteomic Analysis during Larval Development and Metamorphosis of the Biofouling Polychaete Tubeworm Hydroides elegans

KAUST Repository

Zhang, Yu; Sun, Jin; Xiao, Kang; Arellano, Shawn M.; Thiyagarajan, Vengatesen; Qian, Pei Yuan

2010-01-01

Larval settlement and metamorphosis of a common biofouling polychaete worm, Hydroides elegans, involve remarkable structural and physiological changes during this pelagic to sessile habitat shift. The endogenous protein molecules and post-translational modifications that drive this larval transition process are not only of interest to ecologists but also to the antifouling paint industry, which aims to control the settlement of this biofouling species on man-made structures (e.g., ship hulls). On the basis of our recent proteomic studies, we hypothesize that rapid larval settlement of H. elegans could be mediated through changes in phosphorylation status of proteins rather than extensive de novo synthesis of proteins. To test this hypothesis, 2D gel-based multiplexed proteomics technology was used to monitor the changes in protein expression and phosphorylation status during larval development and metamorphosis of H. elegans. The protein expression profiles of larvae before and after they reached competency to attach and metamorphose were similar in terms of major proteins, but the percentage of phosphorylated proteins increased from 41% to 49% after competency. Notably, both the protein and phosphoprotein profiles of the metamorphosed individuals (adult) were distinctly different from that of the larvae, with only 40% of the proteins phosphorylated in the adult stage. The intensity ratio of all phosphoprotein spots to all total protein spots was also the highest in the competent larval stage. Overall, our results indicated that the level of protein phosphorylation might play a crucial role in the initiation of larval settlement and metamorphosis. © 2010 American Chemical Society.

2D Gel-Based Multiplexed Proteomic Analysis during Larval Development and Metamorphosis of the Biofouling Polychaete Tubeworm Hydroides elegans

KAUST Repository

Zhang, Yu

2010-09-03

Larval settlement and metamorphosis of a common biofouling polychaete worm, Hydroides elegans, involve remarkable structural and physiological changes during this pelagic to sessile habitat shift. The endogenous protein molecules and post-translational modifications that drive this larval transition process are not only of interest to ecologists but also to the antifouling paint industry, which aims to control the settlement of this biofouling species on man-made structures (e.g., ship hulls). On the basis of our recent proteomic studies, we hypothesize that rapid larval settlement of H. elegans could be mediated through changes in phosphorylation status of proteins rather than extensive de novo synthesis of proteins. To test this hypothesis, 2D gel-based multiplexed proteomics technology was used to monitor the changes in protein expression and phosphorylation status during larval development and metamorphosis of H. elegans. The protein expression profiles of larvae before and after they reached competency to attach and metamorphose were similar in terms of major proteins, but the percentage of phosphorylated proteins increased from 41% to 49% after competency. Notably, both the protein and phosphoprotein profiles of the metamorphosed individuals (adult) were distinctly different from that of the larvae, with only 40% of the proteins phosphorylated in the adult stage. The intensity ratio of all phosphoprotein spots to all total protein spots was also the highest in the competent larval stage. Overall, our results indicated that the level of protein phosphorylation might play a crucial role in the initiation of larval settlement and metamorphosis. © 2010 American Chemical Society.

Modeling the effects of integrating larval habitat source reduction and insecticide treated nets for malaria control.

Directory of Open Access Journals (Sweden)

Laith Yakob

Full Text Available Integrated vector management for malaria control has received a lot of recent interest. Attacking multiple points in the transmission cycle is hoped to act synergistically and improve upon current single-tool interventions based on the use of insecticide-treated bed nets (ITNs. In the present study, we theoretically examined the application of larval habitat source reduction with ITNs in reducing malaria transmission. We selected this type of environmental management to complement ITNs because of a potential secondary mode of action that both control strategies share. In addition to increasing vector mortality, ITNs reduce the rate at which female mosquitoes locate human hosts for blood feeding, thereby extending their gonotrophic cycle. Similarly, while reducing adult vector emergence and abundance, source reduction of larval habitats may prolong the cycle duration by extending delays in locating oviposition sites. We found, however, that source reduction of larval habitats only operates through this secondary mode of action when habitat density is below a critical threshold. Hence, we illustrate how this strategy becomes increasingly effective when larval habitats are limited. We also demonstrate that habitat source reduction is better suited to human populations of higher density and in the presence of insecticide resistance or when the insecticidal properties of ITNs are depleted.

Composition and diversity of larval fish in the mangrove estuarine area of Marudu Bay, Sabah, Malaysia.

Science.gov (United States)

Rezagholinejad, Sadaf; Arshad, Aziz; Amin, S M Nurul; Ara, Roushon

2016-07-01

The composition of fish larvae and their diversity in different habitats are very important for fisheries management. Larval fishes were investigated in a mangrove estuary of Marudu Bay, Sabah, Malaysia from October 2012 to September 2013 at five different sites. Monthly samples of fish larvae were collected at five sampling sites by a plankton net with a mouth opening of 40.5 cm in diameter. In total, 3879 larval fish were caught in the investigated area. The mean density of ichthyoplankton at this area was 118 larvae/100 m(3). The fish larval assemblage comprised of 20 families whereas 13 families occurred at St1, 16 at St2, 16 at St3, 12 at St4 and 16 at St5. The top major families were Sillaginidae, Engraulidae, Mugilidae and Sparidae with Sillaginidae consisted 44% of total larval composition. St3 with 143 larvae/100 m(3) had the highest density amongst the stations which was due to higher abundance of Sillaginidae. Shannon-Wiener diversity index represented significant variation during monsoon and inter-monsoon seasons, peaking in the months December-January and May-June. However, Shannon-Wiener index, evenness and family richness showed significant differences among stations and months (p < 0.05).

Larval dispersion of the estuarine crab Neohelice granulata in coastal marine waters of the Southwest Atlantic

Science.gov (United States)

Bas, Claudia; Luppi, Tomás; Spivak, Eduardo; Schejter, Laura

2009-08-01

The estuarine brachyuran crab Neohelice granulata export their larvae from the parental intertidal population of the Mar Chiquita coastal lagoon, and probably other populations, to marine waters. The degree of larval dispersion or self-recruitment of populations is unknown. We evaluated the presence of all larval stages of N. granulata in coastal waters of Argentina between 37.9° and 35.8° S, at two different spatial scales: a broad scale of tens to hundreds of kilometers from the Río de la Plata estuary in the north, to Mar Chiquita lagoon in the south, and a small scale of hundreds of meters to some kilometers around the mouth of Mar Chiquita, during spring and summer. Additionally, we registered the larval composition and density at San Clemente creek population, in Samborombon Bay (Río de la Plata estuary), every 3 h along a 30-hour period. Evidence indicates that larval release of N. granulata is temporally synchronized with nocturnal ebb tides and all development from Zoea I to Zoea IV occur in areas close to the parental population, even with very different oceanographic characteristics. A possible mechanism based on salinity selection and wind-driven transport is proposed for such behavior, and some considerations related to the connectivity of present populations are made.

Body shape, burst speed and escape behavior of larval anurans

Science.gov (United States)

Gage H. Dayton; Daniel Saenz; Kristen A. Baum; R. Brian Langerhans; Thomas J. DeWitt

2005-01-01

Variation in behavior, morphology and life history traits of larval anurans across predator gradients, and consequences of that variation, have been abundantly studied. Yet the functional link between morphology and burst-swimming speed is largely unknown. We conducted experiments with two divergent species of anurans, Scaphiopus holbrookii and

Unequal before the Law : Measuring Legal Gender Disparities across the World

OpenAIRE

Iqbal, Sarah; Islam, Asif; Ramalho, Rita; Sakhonchik, Alena

2016-01-01

Several economies have laws that treat women differently from men. This study explores the degree of such legal gender disparities across 167 economies around the world. This is achieved by constructing a simple measure of legal gender disparities to evaluate how countries perform. The average number of overall legal gender disparities across 167 economies is 17, ranging from a minimum of ...

Racial/ethnic disparity in obesity among US youth, 1999-2013.

Science.gov (United States)

An, Ruopeng

2015-11-04

One fundamental goal in the Healthy People 2020 is to achieve health equity and eliminate disparities. To examine the annual trends in racial/ethnic disparity in obesity among US youth from 1999 to 2013. Nationally representative sample of 108,811 students in grades 9th-12th from the Youth Risk Behavior Surveillance System (YRBSS) 1999-2013 surveys. Body mass index (BMI) was calculated based on self-reported height and weight. Obesity in youth is defined as BMI at or above 95th sex- and age-specific percentile of the 2000 Centers for Disease Control and Prevention growth charts. Multiple logistic regressions were conducted to estimate the annual prevalence of obesity by race/ethnicity, adjusted for gender and age group and accounted for the YRBSS survey design. Between-group variance (BGV) was used to measure absolute racial/ethnic disparity in obesity, and the mean log deviation (MLD) and the Theil Index (T) were used to measure relative racial/ethnic disparity in obesity, weighted by corresponding racial/ethnic population size. The obesity prevalence among non-Hispanic Whites, non-Hispanic African Americans, non-Hispanic other race or multi-race, and Hispanic increased from 10.05%, 12.31%, 10.25%, and 13.24% in 1999 to 13.14%, 15.76%, 10.87%, and 15.20% in 2013, respectively. Both absolute and relative racial/ethnic disparity in obesity increased initially since 1999 but then steadily declined starting from mid-2000s back to around its original level by 2013. The obesity epidemic in youth is marked by salient and persistent disparity pertaining to race/ethnicity. No improvement on racial/ethnic disparity in obesity among American youth was observed during 1999-2013.

Male/Female Salary Disparity for Professors of Educational Administration.

Science.gov (United States)

Pounder, Diana G.

The earnings gap between male and female workers across all occupational groups has been well documented; full-time women workers earn, on average, approximately 65 percent of men's salaries. Although male/female salary disparity is largest across occupational groups, salary disparity within occupational groups still prevails. For example, the…

Objective quality assessment of stereoscopic images with vertical disparity using EEG

Science.gov (United States)

Shahbazi Avarvand, Forooz; Bosse, Sebastian; Müller, Klaus-Robert; Schäfer, Ralf; Nolte, Guido; Wiegand, Thomas; Curio, Gabriel; Samek, Wojciech

2017-08-01

Objective. Neurophysiological correlates of vertical disparity in 3D images are studied in an objective approach using EEG technique. These disparities are known to negatively affect the quality of experience and to cause visual discomfort in stereoscopic visualizations. Approach. We have presented four conditions to subjects: one in 2D and three conditions in 3D, one without vertical disparity and two with different vertical disparity levels. Event related potentials (ERPs) are measured for each condition and the differences between ERP components are studied. Analysis is also performed on the induced potentials in the time frequency domain. Main results. Results show that there is a significant increase in the amplitude of P1 components in 3D conditions in comparison to 2D. These results are consistent with previous studies which have shown that P1 amplitude increases due to the depth perception in 3D compared to 2D. However the amplitude is significantly smaller for maximum vertical disparity (3D-3) in comparison to 3D with no vertical disparity. Our results therefore suggest that the vertical disparity in 3D-3 condition decreases the perception of depth compared to other 3D conditions and the amplitude of P1 component can be used as a discriminative feature. Significance. The results show that the P1 component increases in amplitude due to the depth perception in the 3D stimuli compared to the 2D stimulus. On the other hand the vertical disparity in the stereoscopic images is studied here. We suggest that the amplitude of P1 component is modulated with this parameter and decreases due to the decrease in the perception of depth.

75 FR 29357 - National Center on Minority and Health Disparities; Notice of Closed Meeting

Science.gov (United States)

2010-05-25

... and Health Disparities; Notice of Closed Meeting Pursuant to section 10(d) of the Federal Advisory... and Health Disparities Special NCMHD Health Disparities Research on Minority and Underserved... Health and Health Disparities, 6707 Democracy Boulevard, Suite 800, Bethesda, MD 20892. (301) 594-8696...

Proteomic analysis of Oesophagostomum dentatum (Nematoda during larval transition, and the effects of hydrolase inhibitors on development.

Directory of Open Access Journals (Sweden)

Martina Ondrovics

Full Text Available In this study, in vitro drug testing was combined with proteomic and bioinformatic analyses to identify and characterize proteins involved in larval development of Oesophagostomum dentatum, an economically important parasitic nematode. Four hydrolase inhibitors ο-phenanthroline, sodium fluoride, iodoacetamide and 1,2-epoxy-3-(pnitrophenoxy-propane (EPNP significantly inhibited (≥90% larval development. Comparison of the proteomic profiles of the development-inhibited larvae with those of uninhibited control larvae using two-dimensional gel electrophoresis, and subsequent MALDI-TOF mass spectrometric analysis identified a down-regulation of 12 proteins inferred to be involved in various larval developmental processes, including post-embryonic development and growth. Furthermore, three proteins (i.e. intermediate filament protein B, tropomyosin and peptidyl-prolyl cis-trans isomerase inferred to be involved in the moulting process were down-regulated in moulting- and development-inhibited O. dentatum larvae. This first proteomic map of O. dentatum larvae provides insights in the protein profile of larval development in this parasitic nematode, and significantly improves our understanding of the fundamental biology of its development. The results and the approach used might assist in developing new interventions against parasitic nematodes by blocking or disrupting their key biological pathways.

A Study of the Pelagic Larval Duration of Acropora humilis, Coral Recruitment and Connectivity in the Saudi Arabian Red Sea

KAUST Repository

Khalil, Maha

2011-01-01

Combined knowledge of the pelagic larval duration of coral species and coral recruitment patterns can provide evidence of inter-reef connectivity and indicate a reef’s ability to recover. We attempted to determine the maximum pelagic larval duration

The Role of Binocular Disparity in Rapid Scene and Pattern Recognition

Directory of Open Access Journals (Sweden)

Matteo Valsecchi

2013-04-01

Full Text Available We investigated the contribution of binocular disparity to the rapid recognition of scenes and simpler spatial patterns using a paradigm combining backward masked stimulus presentation and short-term match-to-sample recognition. First, we showed that binocular disparity did not contribute significantly to the recognition of briefly presented natural and artificial scenes, even when the availability of monocular cues was reduced. Subsequently, using dense random dot stereograms as stimuli, we showed that observers were in principle able to extract spatial patterns defined only by disparity under brief, masked presentations. Comparing our results with the predictions from a cue-summation model, we showed that combining disparity with luminance did not per se disrupt the processing of disparity. Our results suggest that the rapid recognition of scenes is mediated mostly by a monocular comparison of the images, although we can rely on stereo in fast pattern recognition.

Survival and larval development of Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) on alternatives host; Sobrevivencia e desenvolvimento larval de Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) em hospedeiros alternativos

Energy Technology Data Exchange (ETDEWEB)

Sa, Verissimo G.M. de [Universidade Federal de Minas Gerais (UFMG), Montes Claros, MG (Brazil). Dept. de Agronomia; Fonseca, Bernardo V.C. [Universidade FUMEC, Belo Horizonte, MG (Brazil); Boregas, Katia G.B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Ecologia; Waquil, Jose M. [EMBRAPA Milho e Sorgo, Sete Lagoas, MG (Brazil)]. E-mail: aaquil@cnpms.embrapa.br

2009-01-15

Two bioassays were conducted to evaluate the suitability of host plants of fall armyworm (FAW), Spodoptera frugiperda (J E Smith), in the Brazilian agro-ecosystem. Larval development and survival were analyzed by infesting leaves of maize, grain sorghum, Johnson grass, soybean, Brachiaria and tobacco with FAW newly hatched larvae in a no choice test. No significant differences of survival were observed among insects reared on different hosts, except for tobacco, where no survivors were recorded. Larvae fed on soybean and artificial diet grew larger than those fed on the other hosts. The heaviest pupa was observed from larva fed on artificial diet and the lighter from larva fed on Brachiaria grass. No significant differences were reported on larval development time on natural hosts, but it was longer for larvae reared on artificial diet. Three classes of larval development time were observed on maize, four on sorghum, Brachiaria and soybean, and five on artificial diet. Nearly 85% of FAW larvae completed development within 12 d on maize; 77% on grain sorghum, 80% on Johnson grass, 68% on Brachiaria and 83% on soybean within 14 d and 69% on artificial diet within 17 d. The host suitability to FAW decreases from maize to sorghum, soybean and Brachiaria. (author)

Nontarget lepidoptera species found in the pheromone traps for selected Tortricid species in 2002 and 2003 years

Directory of Open Access Journals (Sweden)

Eva Hrudová

2005-01-01

Full Text Available Pheromone traps were used to monitor the following tortricid moths, i.e. Adoxophyes orana, Archips podanus, A. rosanus, Hedya nubiferana, Pandemis heparana, Spilonota ocellana, Cydia pomonella, Cydia funebrana and Cydia molesta in the localities Brno-Tuřany (Brno-město, Nebovidy (Brno-venkov and Prakšice (Uherské Hradiště. Other Lepidoptera non-target species were present in these target-species pheromone traps, i.e. Adoxophyes orana, Agrotis segetum, Amphipoea oculaea, Archips rosanus, Celypha striana, Cydia coronillana, Enarmonia formosana, Epiblema scutulanum, Epinotia huebneriana, Eucosma fervidana, Euxoa tritici, Hedya pruniana, H. nubiferana, Lymantria dispar, Noctua pronuba, Notocelia rosaecolana, N. roborana, Pammene albuginana, P. suspectana, Pandemis cerasana, Pyrausta rectefascialis, P. aurata, Spilonota ocellana, Yponomeuta malinellus and Zygaena purpuralis.

76 FR 63310 - National Center On Minority and Health Disparities Notice of Closed Meetings

Science.gov (United States)

2011-10-12

... and Health Disparities Notice of Closed Meetings Pursuant to section 10(d) of the Federal Advisory... and Health Disparities Special Emphasis Panel; NIMHD Health Disparities Research (R01). Date: November... Disparities, National Institutes of Health, 6707 Democracy Blvd., MSC. 5465, Suite 800, Bethesda, MD 20892...

Larval dispersal in three coral reef decapod species: Influence of larval duration on the metapopulation structure

Science.gov (United States)

Zavala-Hidalgo, Jorge; Allende-Arandía, Eugenia; Hermoso-Salazar, Margarita

2018-01-01

Most coral-associated decapod species have non-migratory adult populations and depend on their planktonic larvae for dispersal. This study examined the metapopulation structure of three decapod species with different pelagic larval duration (PLD) from twelve coral reef complexes of the Gulf of Mexico. The dispersion of larvae was analyzed through the use of a realistic numerical simulation of the Gulf of Mexico with the Hybrid Coordinate Ocean Model. To study the transport and dispersion of particles in near-surface waters, a particle-tracking subroutine was run using as input the currents from the model. The simulation consisted of the launch of 100 passive particles (virtual larvae) every 24 hours from each reef throughout five years, and tracked for as long as 210 days. Results indicated that species with a short PLD, Mithraculus sculptus (PLD 8‒13 days), had a weak connection among the reefs, but higher self-recruitment, especially on the narrow western shelf. The species with a longer PLD, Dromia erythropus (28‒30 days), had a stronger connection among neighboring reefs (< 300 km). Finally, the species with an even longer PLD, Stenopus hispidus (123‒210 days), had a wider potential distribution than the other species. Circulation on synoptic, seasonal and interannual scales had differential effects on the larval dispersal of each species. The metapopulation structure of M. sculptus and D. erythropus seemed to combine features of the non-equilibrium and the patchy models, whereas that of S. hispidus presumably fit to a patchy model. These findings support previous observations that indicate that species with longer PLD tend to occupy larger areas than species with short PLD, although recruitment of juveniles to the adult populations will also depend on other factors, such as the availability of suitable habitats and the ability to colonize them. PMID:29558478

Influence of swimming behavior of copepod nauplii on feeding of larval turbot (Scophthalmus maximus)

DEFF Research Database (Denmark)

Bruno, Eleonora; Højgaard, Jacob Kring; Hansen, Benni Winding

2018-01-01

Feeding in larval fish is influenced by a range of factors and among these are the morphological and behavioral characteristics of their prey. We investigated the influence of the swimming behavior of two species of calanoid copepods, Acartia tonsa and Temora longicornis, on larval turbot feeding....... The nauplii of these species represent two contrasting swimming behaviors: A. tonsa is a jump-sink type swimmer, while T. longicornis is a cruise swimming type. Three replicates of ten larvae aged 7 and 9 days post hatch (DPH) were observed feeding on one of the two copepod species using a 2-dimensional video...

A single GABAergic neuron mediates feedback of odor-evoked signals in the mushroom body of larval Drosophila

Directory of Open Access Journals (Sweden)

Liria Monica Masuda-Nakagawa

2014-04-01

Full Text Available Inhibition has a central role in defining the selectivity of the responses of higher order neurons to sensory stimuli. However, the circuit mechanisms of regulation of these responses by inhibitory neurons are still unclear. In Drosophila, the mushroom bodies (MBs are necessary for olfactory memory, and by implication for the selectivity of learned responses to specific odors. To understand the circuitry of inhibition in the calyx (the input dendritic region of the MBs, and its relationship with MB excitatory activity, we used the simple anatomy of the Drosophila larval olfactory system to identify any inhibitory inputs that could contribute to the selectivity of MB odor responses. We found that a single neuron accounts for all detectable GABA innervation in the calyx of the MBs, and that this neuron has presynaptic terminals in the calyx and postsynaptic branches in the MB lobes (output axonal area. We call this neuron the larval anterior paired lateral (APL neuron, because of its similarity to the previously described adult APL neuron. Reconstitution of GFP partners (GRASP suggests that the larval APL makes extensive contacts with the MB intrinsic neurons, Kenyon Cells (KCs, but few contacts with incoming projection neurons. Using calcium imaging of neuronal activity in live larvae, we show that the larval APL responds to odors, in a mannner that requires output from KCs. Our data suggest that the larval APL is the sole GABAergic neuron that innervates the MB input region and carries inhibitory feedback from the MB output region, consistent with a role in modulating the olfactory selectivity of MB neurons.

Disparities in abortion experience and access to safe abortion ...

African Journals Online (AJOL)

In Ghana, abortion mortality constitutes 11% of maternal mortality. Empirical studies on possible disparities in abortion experience and access to safe abortion services are however lacking. Based on a retrospective survey of 1,370 women aged 15-49 years in two districts in Ghana, this paper examines disparities in ...

Examples of Cancer Health Disparities

Science.gov (United States)

... and the bacterium H. pylori (stomach cancer) in immigrant countries of origin contributes to these disparities. ( ACS ) ... Cancer.gov en español Multimedia Publications Site Map Digital Standards for NCI Websites POLICIES Accessibility Comment Policy ...

Socio-economic disparities in health system responsiveness in India.

Science.gov (United States)

Malhotra, Chetna; Do, Young Kyung

2013-03-01

To assess the magnitude of socio-economic disparities in health system responsiveness in India after correcting for potential reporting heterogeneity by socio-economic characteristics (education and wealth). Data from Wave 1 of the Study on Global Ageing and Adult Health (2007-2008) involving six Indian states were used. Seven health system responsiveness domains were considered for a respondent's last visit to an outpatient service in 12 months: prompt attention, dignity, clarity of information, autonomy, confidentiality, choice and quality of basic amenities. Hierarchical ordered probit models (correcting for reporting heterogeneity through anchoring vignettes) were used to assess the association of socio-economic characteristics with the seven responsiveness domains, controlling for age, gender and area of residence. Stratified analysis was also conducted among users of public and private health facilities. Our statistical models accounting for reporting heterogeneity revealed socio-economic disparities in all health system responsiveness domains. Estimates suggested that individuals from the lowest wealth group, for example, were less likely than individuals from the highest wealth group to report 'very good' on the dignity domain by 8% points (10% vs 18%). Stratified analysis showed that such disparities existed among users of both public and private health facilities. Socio-economic disparities exist in health system responsiveness in India, irrespective of the type of health facility used. Policy efforts to monitor and improve these disparities are required at the health system level.

Racial and ethnic disparities in U.S. cancer screening rates

Science.gov (United States)

The percentage of U.S. citizens screened for cancer remains below national targets, with significant disparities among racial and ethnic populations, according to the first federal study to identify cancer screening disparities among Asian and Hispanic gr

Response of larval sea lampreys (Petromyzon marinus) to pulsed DC electrical stimuli in laboratory experiments

Science.gov (United States)

Bowen, Anjanette K.; Weisser, John W.; Bergstedt, Roger A.; Famoye, Felix

2003-01-01

Four electrical factors that are used in pulsed DC electrofishing for larval sea lampreys (Petromyzon marinus) were evaluated in two laboratory studies to determine the optimal values to induce larval emergence over a range of water temperatures and conductivities. Burrowed larvae were exposed to combinations of pulsed DC electrical factors including five pulse frequencies, three pulse patterns, and two levels of duty cycle over a range of seven voltage gradients in two separate studies conducted at water temperatures of 10, 15, and 20°C and water conductivities of 25, 200, and 900 μS/cm. A four-way analysis of variance was used to determine significant (α = 0.05) influences of each electrical factor on larval emergence. Multiple comparison tests with Bonferroni adjustments were used to determine which values of each factor resulted in significantly higher emergence at each temperature and conductivity. Voltage gradient and pulse frequency significantly affected emergence according to the ANOVA model at each temperature and conductivity tested. Duty cycle and pulse pattern generally did not significantly influence the model. Findings suggest that a setting of 2.0 V/cm, 3 pulses/sec, 10% duty, and 2:2 pulse pattern seems the most promising in waters of medium conductivity and across a variety of temperatures. This information provides a basis for understanding larval response to pulsed DC electrofishing gear factors and identifies electrofisher settings that show promise to increase the efficiency of the gear during assessments for burrowed sea lamprey larvae.

Age- and Wavelength-Dependency of Drosophila Larval Phototaxis and Behavioral Responses to Natural Lighting Conditions

Directory of Open Access Journals (Sweden)

Simon G. Sprecher

2017-04-01

Full Text Available Animals use various environmental cues as key determinant for their behavioral decisions. Visual systems are hereby responsible to translate light-dependent stimuli into neuronal encoded information. Even though the larval eyes of the fruit fly Drosophila melanogaster are comparably simple, they comprise two types of photoreceptor neurons (PRs, defined by different Rhodopsin genes expressed. Recent findings support that for light avoidance Rhodopsin5 (Rh5 expressing photoreceptors are crucial, while Rhodopsin6 (Rh6 expressing photoreceptors are dispensable under laboratory conditions. However, it remains debated how animals change light preference during larval live. We show that larval negative phototaxis is age-independent as it persists in larvae from foraging to wandering developmental stages. Moreover, if spectrally different Rhodopsins are employed for the detection of different wavelength of light remains unexplored. We found that negative phototaxis can be elicit by light with wavelengths ranging from ultraviolet (UV to green. This behavior is uniquely mediated by Rh5 expressing photoreceptors, and therefore suggest that this photoreceptor-type is able to perceive UV up to green light. In contrast to laboratory our field experiments revealed that Drosophila larvae uses both types of photoreceptors under natural lighting conditions. All our results, demonstrate that Drosophila larval eyes mediate avoidance of light stimuli with a wide, ecological relevant range of quantity (intensities and quality (wavelengths. Thus, the two photoreceptor-types appear more likely to play a role in different aspects of phototaxis under natural lighting conditions, rather than color discrimination.

January Monthly Spotlight: Cervical Health and Cervical Cancer Disparities

Science.gov (United States)

In January, CRCHD joins the nation in raising awareness for Cervical Health and Cervical Cancer Disparities. This month we share a special focus on NCI/CRCHD research programs that are trying to reduce cervical cancer disparities in underserved communities and the people who are spreading the word about the importance of early detection.

Recruitment decline in North Sea herring is accompanied by reduced larval growth rates

DEFF Research Database (Denmark)

Payne, Mark; Ross, Stine Dalmann; Worsøe Clausen, Lotte

2013-01-01

The stock of North Sea autumn spawning herring (Clupea harengus L.) has shown an unprecedented sequence of ten years of sharply reduced recruitment, in spite of a high spawning biomass. Recent work has identified this below-expected recruitment as being determined during the larval phase: however...... rate of 8%, concurrent with the reduced larval survival and recruitment, was identified: after correcting for the effect of other explanatory variables (e.g. temperature changes), the gross reduction was found to be 12%. This reduction is most probably due to changes in either the amount or quality...... and larvae survival, thereby narrowing the range of potential mechanisms underlying the observed reduction in the recruitment of North Sea autumn spawning herring...

Small nonnative fishes as predators of larval razorback suckers

Science.gov (United States)

Carpenter, J.; Mueller, G.A.

2008-01-01

The razorback sucker (Xyrauchen texanus), an endangered big-river fish of the Colorado River basin, has demonstrated no sustainable recruitment in 4 decades, despite presence of spawning adults and larvae. Lack of adequate recruitment has been attributed to several factors, including predation by nonnative fishes. Substantial funding and effort has been expended on mechanically removing nonnative game fishes, typically targeting large predators. As a result, abundance of larger predators has declined, but the abundance of small nonnative fishes has increased in some areas. We conducted laboratory experiments to determine if small nonnative fishes would consume larval razorback suckers. We tested adults of three small species (threadfin shad, Dorosoma petenense; red shiner, Cyprinella lutrensis; fathead minnow, Pimephales promelas) and juveniles of six larger species (common carp, Cyprinus carpio; yellow bullhead, Ameiurus natalis; channel catfish, Ictalurus punctatus; rainbow trout, Oncorhynchus mykiss; green sunfish, Lepomis cyanellus; bluegill, L. macrochirus). These nonnative fishes span a broad ecological range and are abundant within the historical range of the razorback sucker. All nine species fed on larval razorback suckers (total length, 9-16 mm). Our results suggest that predation by small nonnative fishes could be responsible for limiting recovery of this endangered species.

Larval nematodes in stomach wall granulomas of smelt Osmerus eperlanus from the German North Sea coast

OpenAIRE

Obiekezie, A. I.; Lick, Roland R.; Kerstan, Susanne L.; Möller, Heino

1992-01-01

Occurrence of stomach wall granulomas in European smelt was studled at 6 locations along the German North Sea coast. Identification of larval nematodes inhabiting these granulomas is provided for the first time. Three species, isolated by pepsin-HC1 digestion, are involved: Hysterothylacium cf. cornutum, Cosmocephalus obvelatus and Paracuaria tridentata. 72% of all stomachs examined were affected. The ratio of number of granulomas to number of the 3 larval species free in the mesentery was 1:...

Large wood and in-stream habitat for juvenile coho salmon and larval lampreys in a Pacific Northwest stream

Science.gov (United States)

Gonzalez, Rosalinda; Dunham, Jason B.; Lightcap, Scott W.; McEnroe, Jeffery R.

2017-01-01

The influences of large wood on Pacific salmon are well-studied, but studies of nonsalmonid species such as lampreys are uncommon. To address this need, we evaluated the potential effects of large wood on larval lampreys (Pacific Lamprey, Entosphenus tridentatus; and potentially Western Brook Lamprey Lampetra richardsoni), as well as juvenile Coho Salmon Oncorhynchus kisutch, in a small coastal Oregon stream. Our objectives were to 1) identify in-stream habitat characteristics associated with the presence of larval lampreys and abundance of juvenile Coho Salmon; and 2) evaluate how these characteristics were associated with in-stream wood. To address habitat use, we quantified presence of larval lampreys in 92 pools and abundance of juvenile Coho Salmon in 44 pools during summer low flows. We focused on a study reach where large wood was introduced into the stream between 2008 and 2009. Results indicated that presence of larval lampreys was significantly associated with availability of fine sediment and deeper substrate. The abundance of juvenile Coho Salmon (fish/pool) was strongly associated with pool surface area and to a weaker extent with the proportion of cobble and boulder substrates in pools. Pools with wood, regardless of whether they were formed by wood, had significantly greater coverage of fine sediment, deeper substrate, and greater pool surface area. Taken together, these results suggest that in-stream wood can provide habitat associated with presence of larval lampreys and greater abundance of juvenile Coho Salmon.

Mutation of a cuticular protein, BmorCPR2, alters larval body shape and adaptability in silkworm, Bombyx mori.

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Qiao, Liang; Xiong, Gao; Wang, Ri-xin; He, Song-zhen; Chen, Jie; Tong, Xiao-ling; Hu, Hai; Li, Chun-lin; Gai, Ting-ting; Xin, Ya-qun; Liu, Xiao-fan; Chen, Bin; Xiang, Zhong-huai; Lu, Cheng; Dai, Fang-yin

2014-04-01

Cuticular proteins (CPs) are crucial components of the insect cuticle. Although numerous genes encoding cuticular proteins have been identified in known insect genomes to date, their functions in maintaining insect body shape and adaptability remain largely unknown. In the current study, positional cloning led to the identification of a gene encoding an RR1-type cuticular protein, BmorCPR2, highly expressed in larval chitin-rich tissues and at the mulberry leaf-eating stages, which is responsible for the silkworm stony mutant. In the Dazao-stony strain, the BmorCPR2 allele is a deletion mutation with significantly lower expression, compared to the wild-type Dazao strain. Dysfunctional BmorCPR2 in the stony mutant lost chitin binding ability, leading to reduced chitin content in larval cuticle, limitation of cuticle extension, abatement of cuticle tensile properties, and aberrant ratio between internodes and intersegmental folds. These variations induce a significant decrease in cuticle capacity to hold the growing internal organs in the larval development process, resulting in whole-body stiffness, tightness, and hardness, bulging intersegmental folds, and serious defects in larval adaptability. To our knowledge, this is the first study to report the corresponding phenotype of stony in insects caused by mutation of RR1-type cuticular protein. Our findings collectively shed light on the specific role of cuticular proteins in maintaining normal larval body shape and will aid in the development of pest control strategies for the management of Lepidoptera.

The Effects of Hurricane Katrina on Food Access Disparities in New Orleans

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Bodor, J. Nicholas; Rice, Janet C.; Swalm, Chris M.; Hutchinson, Paul L.

2011-01-01

Disparities in neighborhood food access are well documented, but little research exists on how shocks influence such disparities. We examined neighborhood food access in New Orleans at 3 time points: before Hurricane Katrina (2004–2005), in 2007, and in 2009. We combined existing directories with on-the-ground verification and geographic information system mapping to assess supermarket counts in the entire city. Existing disparities for African American neighborhoods worsened after the storm. Although improvements have been made, by 2009 disparities were no better than prestorm levels. PMID:21233432

Ontogenetic changes in larval swimming and orientation of pre-competent sea urchin Arbacia punctulata in turbulence

Science.gov (United States)

Wheeler, Jeanette D.; Chan, Kit Yu Karen; Anderson, Erik J.; Mullineaux, Lauren S.

2016-01-01

ABSTRACT Many marine organisms have complex life histories, having sessile adults and relying on the planktonic larvae for dispersal. Larvae swim and disperse in a complex fluid environment and the effect of ambient flow on larval behavior could in turn impact their survival and transport. However, to date, most studies on larvae–flow interactions have focused on competent larvae near settlement. We examined the importance of flow on early larval stages by studying how local flow and ontogeny influence swimming behavior in pre-competent larval sea urchins, Arbacia punctulata. We exposed larval urchins to grid-stirred turbulence and recorded their behavior at two stages (4- and 6-armed plutei) in three turbulence regimes. Using particle image velocimetry to quantify and subtract local flow, we tested the hypothesis that larvae respond to turbulence by increasing swimming speed, and that the increase varies with ontogeny. Swimming speed increased with turbulence for both 4- and 6-armed larvae, but their responses differed in terms of vertical swimming velocity. 4-Armed larvae swam most strongly upward in the unforced flow regime, while 6-armed larvae swam most strongly upward in weakly forced flow. Increased turbulence intensity also decreased the relative time that larvae spent in their typical upright orientation. 6-Armed larvae were tilted more frequently in turbulence compared with 4-armed larvae. This observation suggests that as larvae increase in size and add pairs of arms, they are more likely to be passively re-oriented by moving water, rather than being stabilized (by mechanisms associated with increased mass), potentially leading to differential transport. The positive relationship between swimming speed and larval orientation angle suggests that there was also an active response to tilting in turbulence. Our results highlight the importance of turbulence to planktonic larvae, not just during settlement but also in earlier stages through morphology�

Modelling larval transport in a axial convergence front

Science.gov (United States)

Robins, P.

2010-12-01

Marine larvae exhibit different vertical swimming behaviours, synchronised by factors such as tidal currents and daylight, in order to aid retention near the parent populations and hence promote production, avoid predation, or to stimulate digestion. This paper explores two types of larval migration in an estuarine axial convergent front which is an important circulatory mechanism in many coastal regions where larvae are concentrated. A parallelised, three-dimensional, ocean model was applied to an idealised estuarine channel which was parameterised from observations of an axial convergent front which occurs in the Conwy Estuary, U.K. (Nunes and Simpson, 1985). The model successfully simulates the bilateral cross-sectional recirculation of an axial convergent front, which has been attributed to lateral density gradients established by the interaction of the lateral shear of the longitudinal currents with the axial salinity gradients. On the flood tide, there is surface axial convergence whereas on the ebb tide, there is (weaker) surface divergence. Further simulations with increased/decreased tidal velocities and with stronger/weaker axial salinity gradients are planned so that the effects of a changing climate on the secondary flow can be understood. Three-dimensional Lagrangian Particle Tracking Models (PTMs) have been developed which use the simulated velocity fields to track larvae in the estuarine channel. The PTMs take into account the vertical migrations of two shellfish species that are commonly found in the Conwy Estuary: (i) tidal migration of the common shore crab (Carcinus maenas) and (ii), diel (daily) migration of the Great scallop (Pecten maximus). These migration behaviours are perhaps the most widespread amongst shellfish larvae and have been compared with passive (drifting) particles in order to assess their relative importance in terms of larval transport. Preliminary results suggest that the net along-estuary dispersal over a typical larval

Effect of Medicaid Managed Care on racial disparities in health care access.

Science.gov (United States)

Cook, Benjamin Lê

2007-02-01

To evaluate the impact of Medicaid Managed Care (MMC) on racial disparities in access to care consistent with the Institute of Medicine (IOM) definition of racial disparity, which excludes differences stemming from health status but includes socioeconomic status (SES)-mediated differences. Secondary data from the Adult Samples of the 1997-2001 National Health Interview Survey, metropolitan statistical area (MSA)-level Medicaid Health Maintenance Organization (MHMO) market share from the 1997 to 2001 InterStudy MSA Trend Dataset, and MSA characteristics from the 1997 to 2001 Area Resource File. I estimate multivariate regression models to compare racial disparities in doctor visits, emergency room (ER) use, and having a usual source of care between enrollees in MMC and Medicaid Fee-for-Service (FFS) plans. To contend with potential selection bias, I use a difference-in-difference analytical strategy and assess the impact of greater MHMO market share at the MSA level on Medicaid enrollees' access measures. To implement the IOM definition of racial disparity, I adjust for health status but not SES factors using a novel method to transform the distribution of health status for minority populations to approximate the white health status distribution. MMC enrollment is associated with lowered disparities in having any doctor visit in the last year for blacks, and in having any usual source of care for both blacks and Hispanics. Increasing Medicaid HMO market share lowered disparities in having any doctor visits in the last year for both blacks and Hispanics. Although disparities in most other measures were not much affected, black-white ER use disparities exist among MMC enrollees and in areas of high MHMO market share. MMC programs' reduction of some disparities suggests that recent shifts in Medicaid policy toward managed care plans have benefited minority enrollees. Future research should investigate whether black-white disparities in ER use within MMC groups

Prioritizing health disparities in medical education to improve care

Science.gov (United States)

Awosogba, Temitope; Betancourt, Joseph R.; Conyers, F. Garrett; Estapé, Estela S.; Francois, Fritz; Gard, Sabrina J.; Kaufman, Arthur; Lunn, Mitchell R.; Nivet, Marc A.; Oppenheim, Joel D.; Pomeroy, Claire; Yeung, Howa

2015-01-01

Despite yearly advances in life-saving and preventive medicine, as well as strategic approaches by governmental and social agencies and groups, significant disparities remain in health, health quality, and access to health care within the United States. The determinants of these disparities include baseline health status, race and ethnicity, culture, gender identity and expression, socioeconomic status, region or geography, sexual orientation, and age. In order to renew the commitment of the medical community to address health disparities, particularly at the medical school level, we must remind ourselves of the roles of doctors and medical schools as the gatekeepers and the value setters for medicine. Within those roles are responsibilities toward the social mission of working to eliminate health disparities. This effort will require partnerships with communities as well as with academic centers to actively develop and to implement diversity and inclusion strategies. Besides improving the diversity of trainees in the pipeline, access to health care can be improved, and awareness can be raised regarding population-based health inequalities. PMID:23659676

Prioritizing health disparities in medical education to improve care.

Science.gov (United States)

Awosogba, Temitope; Betancourt, Joseph R; Conyers, F Garrett; Estapé, Estela S; Francois, Fritz; Gard, Sabrina J; Kaufman, Arthur; Lunn, Mitchell R; Nivet, Marc A; Oppenheim, Joel D; Pomeroy, Claire; Yeung, Howa

2013-05-01

Despite yearly advances in life-saving and preventive medicine, as well as strategic approaches by governmental and social agencies and groups, significant disparities remain in health, health quality, and access to health care within the United States. The determinants of these disparities include baseline health status, race and ethnicity, culture, gender identity and expression, socioeconomic status, region or geography, sexual orientation, and age. In order to renew the commitment of the medical community to address health disparities, particularly at the medical school level, we must remind ourselves of the roles of doctors and medical schools as the gatekeepers and the value setters for medicine. Within those roles are responsibilities toward the social mission of working to eliminate health disparities. This effort will require partnerships with communities as well as with academic centers to actively develop and to implement diversity and inclusion strategies. Besides improving the diversity of trainees in the pipeline, access to health care can be improved, and awareness can be raised regarding population-based health inequalities. © 2013 New York Academy of Sciences.

Climate change and larval transport in the ocean: fractional effects from physical and physiological factors.

Science.gov (United States)

Kendall, Matthew S; Poti, Matt; Karnauskas, Kristopher B

2016-04-01

Changes in larval import, export, and self-seeding will affect the resilience of coral reef ecosystems. Climate change will alter the ocean currents that transport larvae and also increase sea surface temperatures (SST), hastening development, and shortening larval durations. Here, we use transport simulations to estimate future larval connectivity due to: (1) physical transport of larvae from altered circulation alone, and (2) the combined effects of altered currents plus physiological response to warming. Virtual larvae from islands throughout Micronesia were moved according to present-day and future ocean circulation models. The Hybrid Coordinate Ocean Model (HYCOM) spanning 2004-2012 represented present-day currents. For future currents, we altered HYCOM using analysis from the National Center for Atmospheric Research Community Earth System Model, version 1-Biogeochemistry, Representative Concentration Pathway 8.5 experiment. Based on the NCAR model, regional SST is estimated to rise 2.74 °C which corresponds to a ~17% decline in larval duration for some taxa. This reduction was the basis for a separate set of simulations. Results predict an increase in self-seeding in 100 years such that 62-76% of islands experienced increased self-seeding, there was an average domainwide increase of ~1-3% points in self-seeding, and increases of up to 25% points for several individual islands. When changed currents alone were considered, approximately half (i.e., random) of all island pairs experienced decreased connectivity but when reduced PLD was added as an effect, ~65% of connections were weakened. Orientation of archipelagos relative to currents determined the directional bias in connectivity changes. There was no universal relationship between climate change and connectivity applicable to all taxa and settings. Islands that presently export large numbers of larvae but that also maintain or enhance this role into the future should be the focus of conservation

Interactive Effects of Endogenous and Exogenous Nutrition on Larval Development for Crown-Of-Thorns Starfish

Directory of Open Access Journals (Sweden)

Ciemon Frank Caballes

2017-03-01

Full Text Available Outbreaks of crown-of-thorns starfish are often attributed to step-changes in larval survivorship following anomalous increases in nutrients and food availability. However, larval growth and development is also influenced by the nutritional condition of spawning females, such that maternal provisioning may offset limitations imposed by limited access to exogenous sources of nutrients during the formative stages of larval development. This study examined the individual, additive, and interactive effects of endogenous (maternal diet: Acropora, Porites, mixed, and starved and exogenous (larval diet: high concentration at 104 cells·mL−1, low concentration at 103 algal cells·mL−1, and starved nutrition on the survival, growth, morphology, and development of larvae of the crown-of-thorns starfish. Female starfish on Acropora and mixed diet produced bigger oocytes compared to Porites-fed and starved treatments. Using oocyte size as a proxy for maternal provisioning, endogenous reserves in the oocyte had a strong influence on initial larval survival and development. This suggests that maternal reserves can delay the onset of obligate exogenous food acquisition and allow larvae to endure prolonged periods of poor environmental nutritive conditions or starvation. The influence of exogenous nutrition became more prominent in later stages, whereby none of the starved larvae reached the mid-to-late brachiolaria stage 16 days after the onset of the ability to feed. There was no significant difference in the survival, development, and competency of larvae between high and low food treatments. Under low algal food conditions, larvae compensate by increasing the length of ciliated feeding bands in relation to the maximum length and width, which improve food capture and feeding efficiency. However, the effects of endogenous nutrition persisted in the later developmental stages, as larvae from starved females were unable to develop larger feeding structures

Calcified aquatic insect larval constructions in the Pleistocene tufa of Jebel El Mida, Gafsa, southern Tunisia: Recognition and paleoenvironmental significance

Science.gov (United States)

Ben Ahmed, Walid; Henchiri, Mohsen; Mastouri, Amna; Slim S'himi, Najet

2018-04-01

Calcified aquatic larval cases were recognized and identified in the Pleistocene tufa masses of Jebel El Mida, Gafsa, southern Tunisia. These larval constructions belong to three main insect families: caddisflies (Trichoptera, Hydropsychidae), midges (Diptera, Chironomidae) and aquatic moths (Lepidoptera, Pyralidae) that inhabited tubes in the tufa and spun nets. Each insect community has its distinctive characteristics of larval constructions that allow their recognition. The larval constructions recognized comprise fixed and portable (for caddisflies) dwelling cases and silken retreats and feeding capture nets. These last-mentioned are almost completely eroded and only remnants are preserved. The spatial distribution of these larval cases within the tufa is not random but, rather imposed by some specific paleohydraulic conditions. It's the reason why aquatic insect larval constructions are considered as prominent tool for the reconstruction of tufa and travertine depositional environments. Chironomid fixed dwelling cases (diameters range from 0.6 mm for clustered tubes to 3 mm) indicate the deposition of tufa under lotic (flowing) or lentic (standing) water conditions. The later hydraulic condition is shared with hydropsychids with fixed retreats (0.2-4 mm in diameter). Portable case-building caddisflies (case length ranging from 5 to 20 mm, and diameter from 3 to 5 mm at the cephalic end) prefer lentic conditions and are almost completely missing in high-energy flowing water locations that are preferred by pyralids (tubes are between 5 and 10 mm long and 3 mm in diameter). These insect families benefit from inhabiting the tufa by the availability of construction materials of their cases and the necessary space for their development.

Morphological analysis of Drosophila larval peripheral sensory neuron dendrites and axons using genetic mosaics.

Science.gov (United States)

Karim, M Rezaul; Moore, Adrian W

2011-11-07

Nervous system development requires the correct specification of neuron position and identity, followed by accurate neuron class-specific dendritic development and axonal wiring. Recently the dendritic arborization (DA) sensory neurons of the Drosophila larval peripheral nervous system (PNS) have become powerful genetic models in which to elucidate both general and class-specific mechanisms of neuron differentiation. There are four main DA neuron classes (I-IV)(1). They are named in order of increasing dendrite arbor complexity, and have class-specific differences in the genetic control of their differentiation(2-10). The DA sensory system is a practical model to investigate the molecular mechanisms behind the control of dendritic morphology(11-13) because: 1) it can take advantage of the powerful genetic tools available in the fruit fly, 2) the DA neuron dendrite arbor spreads out in only 2 dimensions beneath an optically clear larval cuticle making it easy to visualize with high resolution in vivo, 3) the class-specific diversity in dendritic morphology facilitates a comparative analysis to find key elements controlling the formation of simple vs. highly branched dendritic trees, and 4) dendritic arbor stereotypical shapes of different DA neurons facilitate morphometric statistical analyses. DA neuron activity modifies the output of a larval locomotion central pattern generator(14-16). The different DA neuron classes have distinct sensory modalities, and their activation elicits different behavioral responses(14,16-20). Furthermore different classes send axonal projections stereotypically into the Drosophila larval central nervous system in the ventral nerve cord (VNC)(21). These projections terminate with topographic representations of both DA neuron sensory modality and the position in the body wall of the dendritic field(7,22,23). Hence examination of DA axonal projections can be used to elucidate mechanisms underlying topographic mapping(7,22,23), as well as

Do effects of mercury in larval amphibians persist after metamorphosis?

Science.gov (United States)

Todd, Brian D; Willson, John D; Bergeron, Christine M; Hopkins, William A

2012-01-01

Despite widespread concern about the role of environmental contaminants in global amphibian declines, and evidence that post-metamorphic life stages contribute disproportionately to amphibian population dynamics, most studies in amphibian ecotoxicology focus on larval life stages. Studies that focus solely on early life stages may miss important effects of contaminant exposure, such as latent effects that manifest some time after previous exposure. Moreover, it is often assumed that effects observed in amphibian larvae will persist to affect survival or reproduction later in life. We used terrestrial enclosures to determine whether exposure to mercury (Hg) through maternal transfer and/or larval diet had any adverse effects in post-metamorphic American toads (Bufo americanus). We found a 5% difference in size at metamorphosis that was attributed to maternal Hg exposure persisted for 1 year in the terrestrial environment, resulting in a 7% difference at the conclusion of the study. Although patterns of survival differed among treatments through time, we found no overall difference in survival after 1 year. We also found no evidence of emergent latent effects in the terrestrial toads that could be attributed to earlier exposure. Our results indicate that adverse effects of maternal Hg exposure that were observed in larval amphibians may persist to affect later terrestrial life stages but that no novel adverse effects developed when animals were raised in a semi-natural environment. Moreover, we found no evidence of persistent effects of dietary Hg exposure in larvae, highlighting a need for greater focus on maternal effects in amphibian ecotoxicology. Finally, we suggest an increase in the use of longitudinal studies to better understand contaminant impacts to amphibian populations via effects in both aquatic and terrestrial life stages.

Sampling little fish in big rivers: Larval fish detection probabilities in two Lake Erie tributaries and implications for sampling effort and abundance indices

Science.gov (United States)

Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Roseman, Edward F.; DeBruyne, Robin L.

2014-01-01

Larval fish are frequently sampled in coastal tributaries to determine factors affecting recruitment, evaluate spawning success, and estimate production from spawning habitats. Imperfect detection of larvae is common, because larval fish are small and unevenly distributed in space and time, and coastal tributaries are often large and heterogeneous. We estimated detection probabilities of larval fish from several taxa in the Maumee and Detroit rivers, the two largest tributaries of Lake Erie. We then demonstrated how accounting for imperfect detection influenced (1) the probability of observing taxa as present relative to sampling effort and (2) abundance indices for larval fish of two Detroit River species. We found that detection probabilities ranged from 0.09 to 0.91 but were always less than 1.0, indicating that imperfect detection is common among taxa and between systems. In general, taxa with high fecundities, small larval length at hatching, and no nesting behaviors had the highest detection probabilities. Also, detection probabilities were higher in the Maumee River than in the Detroit River. Accounting for imperfect detection produced up to fourfold increases in abundance indices for Lake Whitefish Coregonus clupeaformis and Gizzard Shad Dorosoma cepedianum. The effect of accounting for imperfect detection in abundance indices was greatest during periods of low abundance for both species. Detection information can be used to determine the appropriate level of sampling effort for larval fishes and may improve management and conservation decisions based on larval fish data.

Racial Disparities in Access to Care Under Conditions of Universal Coverage.

Science.gov (United States)

Siddiqi, Arjumand A; Wang, Susan; Quinn, Kelly; Nguyen, Quynh C; Christy, Antony Dennis

2016-02-01

Racial disparities in access to regular health care have been reported in the U.S., but little is known about the extent of disparities in societies with universal coverage. To investigate the extent of racial disparities in access to care under conditions of universal coverage by observing the association between race and regular access to a doctor in Canada. Racial disparities in access to a regular doctor were calculated using the largest available source of nationally representative data in Canada--the Canadian Community Health Survey. Surveys from 2000-2010 were analyzed in 2014. Multinomial regression analyses predicted odds of having a regular doctor for each racial group compared to whites. Analyses were stratified by immigrant status--Canadian-born versus shorter-term immigrant versus longer-term immigrants--and controlled for sociodemographics and self-rated health. Racial disparities in Canada, a country with universal coverage, were far more muted than those previously reported in the U.S. Only among longer-term Latin American immigrants (OR=1.90, 95% CI=1.45, 2.08) and Canadian-born Aboriginals (OR=1.34, 95% CI=1.22, 1.47) were significant disparities noted. Among shorter-term immigrants, all Asians were more likely than whites, and among longer-term immigrants, South Asians were more like than whites, to have a regular doctor. Universal coverage may have a major impact on reducing racial disparities in access to health care, although among some subgroups, other factors may also play a role above and beyond health insurance. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Silk formation mechanisms in the larval salivary glands of Apis ...

Indian Academy of Sciences (India)

Unknown

The mechanism of silk formation in Apis mellifera salivary glands, during the 5th instar, was studied. Larval salivary glands were dissected and prepared for light and polarized light microscopy, as well as for scanning and transmission electron microscopy. The results showed that silk formation starts at the middle of the 5th ...

Diatom diet selectivity by early post-larval abalone Haliotis diversicolor supertexta under hatchery conditions

Science.gov (United States)

Zhang, Yuyu; Gao, Yahui; Liang, Junrong; Chen, Changping; Zhao, Donghai; Li, Xuesong; Li, Yang; Wu, Wenzhong

2010-11-01

Benthic diatoms constitute the primary diet of abalone during their early stages of development. To evaluate the dietary preferences of early post-larval abalone, Haliotis diversicolor supertexta, we analyzed the gut contents of post-larvae that settled on diatom films. We compared the abundance and species diversity of diatom assemblages in the gut to those of the epiphytic diatom assemblages on the attachment films, and identified 40 benthic diatom species in the gut contents of post-larvae 12 to 24 d after settlement. The most abundant taxa in the gut contents were Navicula spp., Amphora copulate, and Amphora coffeaeformis. Navicula spp. accounted for 64.0% of the cell density. In the attachment films, we identified 110 diatom species belonging to 38 genera. Pennate diatoms were the dominant members including the species Amphiprora alata, Cocconeis placentula var. euglypta, Cylindrotheca closterium, Navicula sp. 2, and A. coffeaeformis. Nano-diatoms (abalone seed. The difference of the composition and abundance of diatoms between in the guts and on the biofilms suggests that early post-larval grazing was selective. An early post-larval abalone preferred nano-diatoms and the genera Navicula and Amphora during the month after settlement.

Explaining variation in adult Anopheles indoor resting abundance: the relative effects of larval habitat proximity and insecticide-treated bed net use.

Science.gov (United States)

McCann, Robert S; Messina, Joseph P; MacFarlane, David W; Bayoh, M Nabie; Gimnig, John E; Giorgi, Emanuele; Walker, Edward D

2017-07-17

Spatial determinants of malaria risk within communities are associated with heterogeneity of exposure to vector mosquitoes. The abundance of adult malaria vectors inside people's houses, where most transmission takes place, should be associated with several factors: proximity of houses to larval habitats, structural characteristics of houses, indoor use of vector control tools containing insecticides, and human behavioural and environmental factors in and near houses. While most previous studies have assessed the association of larval habitat proximity in landscapes with relatively low densities of larval habitats, in this study these relationships were analysed in a region of rural, lowland western Kenya with high larval habitat density. 525 houses were sampled for indoor-resting mosquitoes across an 8 by 8 km study area using the pyrethrum spray catch method. A predictive model of larval habitat location in this landscape, previously verified, provided derivations of indices of larval habitat proximity to houses. Using geostatistical regression models, the association of larval habitat proximity, long-lasting insecticidal nets (LLIN) use, house structural characteristics (wall type, roof type), and peridomestic variables (cooking in the house, cattle near the house, number of people sleeping in the house) with mosquito abundance in houses was quantified. Vector abundance was low (mean, 1.1 adult Anopheles per house). Proximity of larval habitats was a strong predictor of Anopheles abundance. Houses without an LLIN had more female Anopheles gambiae s.s., Anopheles arabiensis and Anopheles funestus than houses where some people used an LLIN (rate ratios, 95% CI 0.87, 0.85-0.89; 0.84, 0.82-0.86; 0.38, 0.37-0.40) and houses where everyone used an LLIN (RR, 95% CI 0.49, 0.48-0.50; 0.39, 0.39-0.40; 0.60, 0.58-0.61). Cooking in the house also reduced Anopheles abundance across all species. The number of people sleeping in the house, presence of cattle near the house

The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees

Directory of Open Access Journals (Sweden)

Bryan R. Helm

2017-06-01

Full Text Available In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee, Apis mellifera, nurse bees provision food to developing larvae, directly moderating growth rates and caste development. However, the eusocial nature of honey bees makes nutritional studies challenging, because diet components cannot be systematically manipulated in the hive. Using in vitro rearing, we investigated the roles and interactions between carbohydrate and protein content on larval survival, growth, and development in A. mellifera. We applied a geometric framework to determine how these two nutritional components interact across nine artificial diets. Honey bees successfully completed larval development under a wide range of protein and carbohydrate contents, with the medium protein (∼5% diet having the highest survival. Protein and carbohydrate both had significant and non-linear effects on growth rate, with the highest growth rates observed on a medium-protein, low-carbohydrate diet. Diet composition did not have a statistically significant effect on development time. These results confirm previous findings that protein and carbohydrate content affect the growth of A. mellifera larvae. However, this study identified an interaction between carbohydrate and protein content that indicates a low-protein, high-carb diet has a negative effect on larval growth and survival. These results imply that worker recruitment in the hive would decline under low protein conditions, even when nectar abundance or honey stores are sufficient.

Seasonal variations in larval biomass and biochemical composition of brown shrimp, Crangon crangon (Decapoda, Caridea), at hatching

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Urzúa, Ángel; Anger, Klaus

2013-06-01

The "brown shrimp", Crangon crangon (Linnaeus 1758), is a benthic key species in the North Sea ecosystem, supporting an intense commercial fishery. Its reproductive pattern is characterized by a continuous spawning season from mid-winter to early autumn. During this extended period, C. crangon shows significant seasonal variations in egg size and embryonic biomass, which may influence larval quality at hatching. In the present study, we quantified seasonal changes in dry weight (W) and chemical composition (CHN, protein and lipid) of newly hatched larvae of C. crangon. Our data revealed significant variations, with maximum biomass values at the beginning of the hatching season (February-March), a decrease throughout spring (April-May) and a minimum in summer (June-September). While all absolute values of biomass and biochemical constituents per larva showed highly significant differences between months ( P larvae" hatching from larger "winter eggs" showed higher initial values of biomass compared to "summer larvae" originating from smaller "summer eggs". This indicates carry-over effects persisting from the embryonic to the larval phase. Since "winter larvae" are more likely exposed to poor nutritional conditions, intraspecific variability in larval biomass at hatching is interpreted as part of an adaptive reproductive strategy compensating for strong seasonality in plankton production and transitory periods of larval food limitation.

Olfactory memories are intensity specific in larval Drosophila.

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Mishra, Dushyant; Chen, Yi-Chun; Yarali, Ayse; Oguz, Tuba; Gerber, Bertram

2013-05-01

Learning can rely on stimulus quality, stimulus intensity, or a combination of these. Regarding olfaction, the coding of odour quality is often proposed to be combinatorial along the olfactory pathway, and working hypotheses are available concerning short-term associative memory trace formation of odour quality. However, it is less clear how odour intensity is coded, and whether olfactory memory traces include information about the intensity of the learnt odour. Using odour-sugar associative conditioning in larval Drosophila, we first describe the dose-effect curves of learnability across odour intensities for four different odours (n-amyl acetate, 3-octanol, 1-octen-3-ol and benzaldehyde). We then chose odour intensities such that larvae were trained at an intermediate odour intensity, but were tested for retention with either that trained intermediate odour intensity, or with respectively higher or lower intensities. We observed a specificity of retention for the trained intensity for all four odours used. This adds to the appreciation of the richness in 'content' of olfactory short-term memory traces, even in a system as simple as larval Drosophila, and to define the demands on computational models of associative olfactory memory trace formation. We suggest two kinds of circuit architecture that have the potential to accommodate intensity learning, and discuss how they may be implemented in the insect brain.

Relevance of biofilm bacteria in modulating the larval metamorphosis of Balanus amphitrite

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.; Anil, A.C.; Raghukumar, S.

Balanus amphitrite, on its larval metamorphosis. The effect of multispecies bacterial film was also assessed. The production of different molecules by the bacteria was influenced by the nutrient media under which they were grown. It was observed...

Larval development of Dagetichthys marginatus (Soleidae obtained from hormone-induced spawning under artificial rearing conditions

Directory of Open Access Journals (Sweden)

Ernst F. Thompson

2007-09-01

Full Text Available Dagetichthys marginatus (formerly Synaptura marginata larvae were laboratory-reared from wild caught adult broodstock as part of an aquaculture research project in temperate South Africa. A larval description for the species is provided in this paper. This work also represents the first larval description for the genus Dagetichthys, which is represented by five species, three of which occur in the western Indian Ocean. Larval development in D. marginatus is typical of Soleidae. Dagetichthys marginatus larvae are heavily pigmented, with four characteristic melanophore “blotches” on the finfold. These larvae are easily distinguished from other soleid larvae commonly encountered in temperate South Africa based on the large size at flexion (5-7.06 mm BL and the heavily pigmented body. Laboratory-reared postflexion larvae in this study showed similar meristic counts to those of wild caught adult fish. Despite the common occurrence of mature adults of this species in shallow marine waters off temperate South Africa, larvae are absent from nearshore ichthyoplankton catches. As yet, the spawning strategy of the species is unknown.

Of tests, trochs, shells, and spicules: Development of the basal mollusk Wirenia argentea (Solenogastres) and its bearing on the evolution of trochozoan larval key features

DEFF Research Database (Denmark)

Todt, Christiane; Wanninger, Andreas

2010-01-01

) to be derived. Larval characters are central in these discussions, specifically the larval test (calymma, apical cap), the ontogeny of the epidermal scleritome, and the proposed absence of larval protonephridia. To date, developmental data are available for five solenogaster species, but most reports...... a fully developed foregut, but the midgut and hindgut are not yet interconnected. CONCLUSIONS: Solenogastres develop via a trochophore-like lecitotrophic larva with a preoral apical cap that at least partly represents an enlarged prototrochal area. Homology of this larval type (pericalymma larva) to test...

Growth pattern and growth dependent mortality of larval and pelagic juvenile North Sea cod Gadus morhua

DEFF Research Database (Denmark)

Nielsen, Rune; Munk, Peter

2004-01-01

and May 2001), and larval/juvenile growth history from each of the sampling sequences was outlined. Growth rate was estimated by fitting a Laird-Gompertz equation to lengths-at-age, and we found the mean specific growth rate in length at age 20 d was 3.2% d(-1), declining to 1.9% d(-1) at an age of 90 d....... Otolith radius and larval standard length were highly correlated, and otolith growth was used as a measure of larval somatic growth. The larvae were divided into 3 groups dependent on their hatch-date, and for each hatch group, the same period of past growth was compared between fish sampled in April...... and May. A 2-way repeated-measurement ANOVA revealed a significant higher past growth of fish sampled in May in 2 of the 3 hatch-groups, implying a higher mortality of the slow growing larvae. Additionally, otolith size at age differed significantly between the April and May sampling of the oldest larvae...

Gender disparities in completing school education in India: Analyzing regional variations

OpenAIRE

Husain, Zakir

2010-01-01

Is gender disparity greater in North India? This paper seeks to answer this question by examining gender differences in probability of completing school education across regions in India. A Gender Disparity Index is calculated using National Sample Survey Organization unit level data from the 61st Round and regional variations in this index analyzed to examine the hypothesis that gender disparity is greater in the North, comparative to the rest of India. This is followed by an econometric exe...

Contribution of screening and survival differences to racial disparities in colorectal cancer rates

Science.gov (United States)

Lansdorp-Vogelaar, Iris; Kuntz, Karen M.; Knudsen, Amy B.; van Ballegooijen, Marjolein; Zauber, Ann G.; Jemal, Ahmedin

2012-01-01

Background Considerable disparities exist in colorectal cancer (CRC) incidence and mortality rates between blacks and whites in the US. We estimated how much of these disparities could be explained by differences in CRC screening and stage-specific relative CRC survival. Methods We used the MISCAN-Colon microsimulation model to estimate CRC incidence and mortality rates in blacks aged 50 years and older from 1975 to 2007 assuming they had: 1) the same trends in screening rates as whites instead of observed screening rates (incidence and mortality); and 2) the same trends in stage-specific relative CRC survival rates as whites instead of observed (mortality only); and 3) a combination of both. The racial disparities in CRC incidence and mortality rates attributable to differences in screening and/or stage-specific relative CRC survival were then calculated by comparing rates from these scenarios to the observed black rates. Results Differences in screening account for 42% of disparity in CRC incidence and 19% of disparity in CRC mortality between blacks and whites. 36% of the disparity in CRC mortality could be attributed to differences in stage-specific relative CRC survival. Together screening and survival explained a little over 50% of the disparity in CRC mortality between blacks and whites. Conclusion Differences in screening and relative CRC survival are responsible for a considerable proportion of the observed disparities in CRC incidence and mortality rates between blacks and whites. Impact Enabling blacks to achieve equal access to care as whites could substantially reduce the racial disparities in CRC burden. PMID:22514249

GROWTH AND BEHAVIOR OF LARVAL ZEBRAFISH Danio ...

Science.gov (United States)

Because Zebrafish (Danio rerio) have become a popular and important model for scientific research, the capability to rear larval zebrafish to adulthood is of great importance. Recently research examining the effects of diet (live versus processed) have been published. In the current study we examined whether the larvae can be reared on a processed diet alone, live food alone, or the combination while maintaining normal locomotor behavior, and acceptable survival, length and weight at 14 dpf in a static system. A 14 day feeding trial was conducted in glass crystallizing dishes containing 500 ml of 4 ppt Instant Ocean. On day 0 pdf 450 embryos were selected as potential study subjects and placed in a 26○C incubator on a 14:10 (light:dark) light cycle. At 4 dpf 120 normally developing embryos were selected per treatment and divided into 3 bowls of 40 embryos (for an n=3 per treatment; 9 bowls total). Treatment groups were: G (Gemma Micro 75 only), R (L-type marine rotifers (Brachionus plicatilis) only) or B (Gemma and rotifers). Growth (length), survival, water quality and rotifer density were monitored on days 5-14. On day 14, weight of larva in each bowl was measured and 8 larva per bowl were selected for use in locomotor testing. This behavior paradigm tests individual larval zebrafish under both light and dark conditions in a 24-well plate.After 14 dpf, survival among the groups was not different (92-98%). By days 7 -14 R and B larvae were ~2X longer

Variable disparity-motion estimation based fast three-view video coding

Science.gov (United States)

Bae, Kyung-Hoon; Kim, Seung-Cheol; Hwang, Yong Seok; Kim, Eun-Soo

2009-02-01

In this paper, variable disparity-motion estimation (VDME) based 3-view video coding is proposed. In the encoding, key-frame coding (KFC) based motion estimation and variable disparity estimation (VDE) for effectively fast three-view video encoding are processed. These proposed algorithms enhance the performance of 3-D video encoding/decoding system in terms of accuracy of disparity estimation and computational overhead. From some experiments, stereo sequences of 'Pot Plant' and 'IVO', it is shown that the proposed algorithm's PSNRs is 37.66 and 40.55 dB, and the processing time is 0.139 and 0.124 sec/frame, respectively.

Larval abundance and its relation to macrofouling settlement pattern in the coastal waters of Kalpakkam, southeastern part of India.

Science.gov (United States)

Sahu, Gouri; Satpathy, K K; Mohanty, A K; Biswas, Sudeepta; Achary, M Smita; Sarkar, S K

2013-02-01

The present work revealed that salinity, water temperature, and food availability were the most crucial factors affecting the abundance of larvae and their settlement as macrofouling community in the coastal waters of Kalpakkam. Quantitative as well as qualitative results showed that late post-monsoon (April-May) and pre-monsoon (June-September) periods were found to be suitable periods for larval growth, development, and survival to adult stages for most of the organisms. Clustering of physico-chemical and biological (including larval and adult availability) data yielded two major clusters; one formed by northeast (NE) monsoon months (October-January) and the other by post-monsoon/summer (February-May) months, whereas; pre-monsoon months (June-September) were distributed between these two clusters. Among all the major macrofouler groups, only bivalves established a successful relationship between its larval abundance and adult settlement. Principal component analysis indicated good associations of bivalve larvae with polychaete larvae and adult bivalves with adult barnacles. However, biotic relation between ascidians and bryozoans was observed both in the larval as well as adult community.

75 FR 66114 - National Center on Minority Health and Health Disparities; Notice of Closed Meeting

Science.gov (United States)

2010-10-27

... Health and Health Disparities; Notice of Closed Meeting Pursuant to section 10(d) of the Federal Advisory... and Health Disparities Special Emphasis Panel; NCMHD Health Disparities Research on Minority and... Review Officer, National Institute on Minority Health and Health Disparities, 6707 Democracy Boulevard...

75 FR 12766 - National Center on Minority Health and Health Disparities; Notice of Closed Meetings

Science.gov (United States)

2010-03-17

... Health and Health Disparities; Notice of Closed Meetings Pursuant to section 10(d) of the Federal... and Health Disparities Special Emphasis Panel Loan Repayment Program for Health Disparities Research... Review, National Center on Minority Health and Health Disparities, 6707 Democracy Boulevard, Suite 800...

Larval development of hoplias cf. Lacerdae (Pisces: Erythrinidae and delayed initial feeding effects

Directory of Open Access Journals (Sweden)

Rodolfo N. Sirol

1998-06-01

Full Text Available Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days. Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15, were separeted, and fed with Artemia nauplii for 10 days. The point-of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding, was not apparent in this species.

Safety of methionine, a novel biopesticide, to adult and larval honey bees (Apis mellifera L.).

Science.gov (United States)

Weeks, Emma N I; Schmehl, Daniel R; Baniszewski, Julie; Tomé, Hudson V V; Cuda, James P; Ellis, James D; Stevens, Bruce R

2018-03-01

Methionine is an essential/indispensible amino acid nutrient required by adult and larval honey bees (Apis mellifera L. [Hymenoptera: Apidae]). Bees are unable to rear broods on pollen deficient in methionine, and reportedly behaviorally avoid collecting pollen or nectar from florets deficient in methioinine. In contrast, it has been demonstrated that methionine is toxic to certain pest insects; thus it has been proposed as an effective biopesticide. As an ecofriendly integrated pest management agent, methionine boasts a novel mode of action differentiating it from conventional pesticides, while providing non-target safety. Pesticides that minimize collateral effects on bees are desirable, given the economic and ecological concerns about honey bee health. The aim of the present study was to assess the potential impact of the biopesticide methionine on non-target adult and larval honey bees. Acute contact adult toxicology bioassays, oral adult assessments and chronic larval toxicity assessments were performed as per U.S. Environmental Protection Agency (EPA) requirements. Our results demonstrated that methionine fits the U.S. EPA category of practically nontoxic (i.e. lethal dose to 50% mortality or LD 50 > 11µg/bee) to adult honey bees. The contact LD 50 was > 25µg/bee and the oral LD 50 was > 100µg/bee. Mortality was observed in larval bees that ingested DL-methionine (effective concentration to 50% mortality or EC 50 560µg/bee). Therefore, we conclude that methionine poses little threat to the health of the honey bee, due to unlikely exposure at concentrations shown to elicit toxic effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Disparities in criminal court referrals to drug treatment and prison for minority men.

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Nicosia, Nancy; Macdonald, John M; Arkes, Jeremy

2013-06-01

We investigated the extent to which racial/ethnic disparities in prison and diversion to drug treatment were explained by current arrest and criminal history characteristics among drug-involved offenders, and whether those disparities decreased after California's Proposition 36, which mandated first- and second-time nonviolent drug offenders drug treatment instead of prison. We analyzed administrative data on approximately 170,000 drug-involved arrests in California between 1995 and 2005. We examined odds ratios from logistic regressions for prison and diversion across racial/ethnic groups before and after Proposition 36. We found significant disparities in prison and diversion for Blacks and Hispanics relative to Whites. These disparities decreased after controlling for current arrest and criminal history characteristics for Blacks. Proposition 36 was also associated with a reduction in disparities, but more so for Hispanics than Blacks. Disparities in prison and diversion to drug treatment among drug-involved offenders affect hundreds of thousands of citizens and might reinforce imbalances in criminal justice and health outcomes. Our study indicated that standardized criminal justice policies that improved access to drug treatment might contribute to alleviating some share of these disparities.

Feminist intersectionality: bringing social justice to health disparities research.

Science.gov (United States)

Rogers, Jamie; Kelly, Ursula A

2011-05-01

The principles of autonomy, beneficence, non-maleficence, and justice are well established ethical principles in health research. Of these principles, justice has received less attention by health researchers. The purpose of this article is to broaden the discussion of health research ethics, particularly the ethical principle of justice, to include societal considerations--who and what are studied and why?--and to critique current applications of ethical principles within this broader view. We will use a feminist intersectional approach in the context of health disparities research to firmly establish inseparable links between health research ethics, social action, and social justice. The aim is to provide an ethical approach to health disparities research that simultaneously describes and seeks to eliminate health disparities. © The Author(s) 2011

75 FR 9421 - National Center on Minority Health and Health Disparities; Notice of Closed Meeting

Science.gov (United States)

2010-03-02

... Health and Health Disparities; Notice of Closed Meeting Pursuant to section 10(d) of the Federal Advisory... and Health Disparities Special Emphasis Panel; Loan Repayment Program for Health Disparities Research..., National Center on Minority Health and Health Disparities, 6707 Democracy Boulevard, Suite 800, Bethesda...

Solving Disparities Through Payment And Delivery System Reform: A Program To Achieve Health Equity.

Science.gov (United States)

DeMeester, Rachel H; Xu, Lucy J; Nocon, Robert S; Cook, Scott C; Ducas, Andrea M; Chin, Marshall H

2017-06-01

Payment systems generally do not directly encourage or support the reduction of health disparities. In 2013 the Finding Answers: Solving Disparities through Payment and Delivery System Reform program of the Robert Wood Johnson Foundation sought to understand how alternative payment models might intentionally incorporate a disparities-reduction component to promote health equity. A qualitative analysis of forty proposals to the program revealed that applicants generally did not link payment reform tightly to disparities reduction. Most proposed general pay-for-performance, global payment, or shared savings plans, combined with multicomponent system interventions. None of the applicants proposed making any financial payments contingent on having successfully reduced disparities. Most applicants did not address how they would optimize providers' intrinsic and extrinsic motivation to reduce disparities. A better understanding of how payment and care delivery models might be designed and implemented to reduce health disparities is essential. Project HOPE—The People-to-People Health Foundation, Inc.

Disparities in Birth Weight and Gestational Age by Ethnic Ancestry in South American countries

Science.gov (United States)

Wehby, George L.; Gili, Juan A.; Pawluk, Mariela; Castilla, Eduardo E.; López-Camelo, Jorge S.

2015-01-01

Objective We examine disparities in birth weight and gestational age by ethnic ancestry in 2000–2011 in eight South American countries. Methods The sample included 60480 singleton live-births. Regression models were estimated to evaluate differences in birth outcomes by ethnic ancestry controlling for time trends. Results Significant disparities were found in seven countries. In four countries – Brazil, Ecuador, Uruguay, and Venezuela – we found significant disparities in both low birth weight and preterm birth. Disparities in preterm birth alone were observed in Argentina, Bolivia, and Colombia. Several differences in continuous birth weight, gestational age, and fetal growth rate were also observed. There were no systematic patterns of disparities between the evaluated ethnic ancestry groups across the study countries, in that no racial/ethnic group consistently had the best or worst outcomes in all countries. Conclusions Racial/ethnic disparities in infant health are common in several South American countries. Differences across countries suggest that racial/ethnic disparities are driven by social and economic mechanisms. Researchers and policymakers should acknowledge these disparities and develop research and policy programs to effectively target them. PMID:25542227

Variability in transport of fish eggs and larvae. IV. Interannual variability in larval stage duration of immigrating plaice in the Dutch Wadden Sea

OpenAIRE

van der Veer, Henk; Bolle, Loes J.; Geffen, Audrey J.; Witte, Johannes IJ.

2009-01-01

Larval immigration of plaice Pleuronectes platessa L. into the western Wadden Sea in spring was followed biweekly from 1993 to 2002. For each year (1993 excluded), 150 settling individuals were selected and used for reconstruction of larval stage duration based on otolith daily ring counts. In addition, prevailing water temperature conditions during drift as revealed from NOAA satellite images were determined. Mean larval stage duration varied between about 40 and 60 d, without...

The first 50Myr of dinosaur evolution: macroevolutionary pattern and morphological disparity.

Science.gov (United States)

Brusatte, Stephen L; Benton, Michael J; Ruta, Marcello; Lloyd, Graeme T

2008-12-23

The evolutionary radiation of dinosaurs in the Late Triassic and Early Jurassic was a pivotal event in the Earth's history but is poorly understood, as previous studies have focused on vague driving mechanisms and have not untangled different macroevolutionary components (origination, diversity, abundance and disparity). We calculate the morphological disparity (morphospace occupation) of dinosaurs throughout the Late Triassic and Early Jurassic and present new measures of taxonomic diversity. Crurotarsan archosaurs, the primary dinosaur 'competitors', were significantly more disparate than dinosaurs throughout the Triassic, but underwent a devastating extinction at the Triassic-Jurassic boundary. However, dinosaur disparity showed only a slight non-significant increase after this event, arguing against the hypothesis of ecological release-driven morphospace expansion in the Early Jurassic. Instead, the main jump in dinosaur disparity occurred between the Carnian and Norian stages of the Triassic. Conversely, dinosaur diversity shows a steady increase over this time, and measures of diversification and faunal abundance indicate that the Early Jurassic was a key episode in dinosaur evolution. Thus, different aspects of the dinosaur radiation (diversity, disparity and abundance) were decoupled, and the overall macroevolutionary pattern of the first 50Myr of dinosaur evolution is more complex than often considered.

Larval trophodynamics, turbulence, and drift on Georges Bank : A sensitivity analysis of cod and haddock

DEFF Research Database (Denmark)

Werner, F.E.; MacKenzie, Brian; Perry, R.I.

2001-01-01

Using an individual-based model approach we consider trophodynamic effects on the growth and survival of larval cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) on Georges Bank during late winter/early spring. These studies represent an extension of results described in Werner et al. (1996...... be an important input to larval growth and survival models. The inclusion of turbulence in determining the position of passive larvae in the water column allows the larvae to sample the entire water column, contributing to a decrease in the variance of the size of the larvae over time. The ability of larvae...

Translating Research into Policy: Reducing Breast Cancer Disparities in Illinois

Science.gov (United States)

Dr. Carol Ferrans is internationally recognized for her work in disparities in health care and quality of life outcomes. She has a distinguished record of research that includes major grants funded by three institutes of the National Institutes of Health (National Cancer Institute, National Institute for Minority Health and Health Disparities, and National Institute for Nursing Research).    Dr. Ferrans’ work has been instrumental in reducing the disparity in breast cancer mortality Chicago, which at its peak was among the worst in the nation.  Efforts led by Dr. Ferrans and colleagues led directly to statewide legislation, to address the multifaceted causes of black/white disparity in deaths from breast cancer.  She was one of the founders of the Metropolitan Chicago Breast Cancer Task Force (MCBCTF), leading the team focusing on barriers to mammography screening, to identify reasons for the growing disparity in breast cancer mortality. Their findings (citing Ferrans’ research and others) and recommendations for action were translated directly into the Illinois Reducing Breast Cancer Disparities Act and two additional laws strengthening the Act.  These laws and other statewide efforts have improved access to screening and quality of mammography throughout the Illinois. In addition, Dr. Ferrans and her team identified cultural beliefs contributing to later stage diagnosis of breast cancer in African American and Latino women in Chicago, and most importantly, showed that these beliefs can be changed.  They reached more than 8,000 African American women in Chicago with a short film on DVD, which was effective in changing beliefs and promoting screening.  Her team’s published findings were cited by the American Cancer Society in their guidelines for breast cancer screening.  The Chicago black/white disparity in breast cancer deaths has decreased by 35% since the MCBCTF first released its report, according to data from the Illinois Department of Public

Effect of different diets and rearing tanks on the development and larval survival of Lysmata amboinensis (De Mann, 1888

Directory of Open Access Journals (Sweden)

Daniel Marques

2014-06-01

Full Text Available The optimization of rearing tanks and identification of rich nutritional diets for the larval development of ornamental decapods are two key factors in defining suitable protocols for larval rearing. The main objective of this study was to evaluate the effect of two rearing tanks (spheroconical and planktonkreisel and three different diets (diet 1: newly hatched Artemia nauplii on a density of 5 nauplii/ml, diet 2: newly hatched Artemia nauplii and harpacticoid copepods on a proportion of 3 artemia nauplii and 2 copepods/ml, Diet 3: Tetraselmis chuii for the first 24h, followed by Artemia nauplii at a density of 5 nauplii/ml on the survival rate and larval development time of Lysmata amboinensis. The results here obtained indicated that the survival rate at 10 days after hatching on kreisel tanks (48.9 ± 3.60% was significantly higher than spheroconical tanks (16.2 ± 2.80% (PTetraselmis chuii was used as a first food (76.7 ± 6.67%. The development time from Zoea I to Zoea IV of L. amboinensis was faster when subject to diet 1 (7.5 ± 0.01 days. In contrast, diet 3 was revealed a longer development period (8.2 ± 0.01 days. The use of copepods diet on the larval rearing of L. amboinensis larvae although not displaying the highest survival, revealed to be extremely promising, needing to adjust the size of the prey throughout the larval development of L. amboinensis.

3D Finite Element Electrical Model of Larval Zebrafish ECG Signals

Science.gov (United States)

Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

2016-01-01

Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace’s equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions. PMID:27824910

Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

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Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

2015-10-01

Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. © 2015 SETAC.

Pheromone modulates two phenotypically plastic traits - adult reproduction and larval diapause - in the nematode Caenorhabditis elegans.

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Wharam, Barney; Weldon, Laura; Viney, Mark

2017-08-22

Animals use information from their environment to make decisions, ultimately to maximize their fitness. The nematode C. elegans has a pheromone signalling system, which hitherto has principally been thought to be used by worms in deciding whether or not to arrest their development as larvae. Recent studies have suggested that this pheromone can have other roles in the C. elegans life cycle. Here we demonstrate a new role for the C. elegans pheromone, showing that it accelerates hermaphrodites' reproductive rate, a phenomenon which we call pheromone-dependent reproductive plasticity (PDRP). We also find that pheromone accelerates larval growth rates, but this depends on a live bacterial food source, while PDRP does not. Different C. elegans strains all show PDRP, though the magnitude of these effects differ among the strains, which is analogous to the diversity of arrested larval phenotypes that this pheromone also induces. Using a selection experiment we also show that selection for PDRP or for larval arrest affects both the target and the non-target trait, suggesting that there is cross-talk between these two pheromone-dependent traits. Together, these results show that C. elegans' pheromone is a signal that acts at two key life cycle points, controlling alternative larval fates and affecting adult hermaphrodites' reproduction. More broadly, these results suggest that to properly understand and interpret the biology of pheromone signalling in C. elegans and other nematodes, the life-history biology of these organisms in their natural environment needs to be considered.

Purification and analyses of the specificity of two putative diagnostic antigens for larval cyathostomin infection in horses.

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Dowdall, S M J; Proudman, C J; Love, S; Klei, T R; Matthews, J B

2003-12-01

Cyathostomins are important equine gastrointestinal parasites. Mass emergence of mucosal stage larvae causes a potentially fatal colitis. Mucosal stages are undetectable non-invasively. An assay that would estimate mucosal larval stage infection would greatly assist in treatment, control and prognosis. Previously, we identified two putative diagnostic antigens (20 and 25 kDa) in somatic larval preparations. Here, we describe their purification and antigen-specific IgG(T) responses to them. Western blots confirmed the purity of the antigens and showed that epitopes in the 20 kDa complex were specific to larval cyathostomins. No cross-reactive antigens appeared to be present in Parascaris equorum or Strongyloides westeri species. Low levels of cross-reactivity were observed in Strongylus edentatus and Strongylus vulgaris species. Use of purified antigens greatly reduced background binding in equine sera. These results indicate that both antigen complexes may be of use in a diagnostic assay.

Diet of larval albacore Thunnus alalunga (Bonnaterre, 1788 off Mallorca Island (NW Mediterranean

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Ignacio Alberto Catalán

2007-06-01

Full Text Available These are the first data on the feeding of larval albacore (Thunnus alalunga Bonnaterre, 1788 in the Mediterranean. Specimens were gathered from day-time bongo-hauls conducted over the SW Mallorcan (Balearic Islands shelf-slope. Ninety eight percent of 101 individuals ranging from 2.65 to 9.4 mm standard length (SL contained 1 to 15 prey items per gut. Mean number of prey/gut was 3.55 ± 2.19 (SD. A positive correlation was found between larval SL and the number of prey/gut. The analysis of frequency of occurrence (F, numerical frequency (N, weight frequency (W and the Index of Relative Importance (IRI showed a dominance of copepodites and nauplii in the smallest size-class. As larvae grew, cladocerans and Calanoida copepodites dominated the diet, and cladocerans and copepodites were important in F, N and W. Piscivory was observed after notochord flexion and was important in terms of W. A positive correlation between mean prey size and both SL and lower jaw length (LJL was observed. The niche breadth (S did not vary with LJL, but the raw prey size range did. Larger copepodites, the absence of nauplii and the incorporation of fish larvae and a larger number of cladocerans in the diet accounted for the increase in mean prey size through increased larval size.

Analysis of synaptic growth and function in Drosophila with an extended larval stage.

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Miller, Daniel L; Ballard, Shannon L; Ganetzky, Barry

2012-10-03

The Drosophila larval neuromuscular junction (NMJ) is a powerful system for the genetic and molecular analysis of neuronal excitability, synaptic transmission, and synaptic development. However, its use for studying age-dependent processes, such as maintenance of neuronal viability and synaptic stability, are temporally limited by the onset of pupariation and metamorphosis. Here we characterize larval NMJ growth, growth regulation, structure, and function in a developmental variant with an extended third instar (ETI). RNAi-knockdown of the prothoracicotropic hormone receptor, torso, in the ring gland of developing larvae leaves the timing of first and second instar molts largely unchanged, but triples duration of the third instar from 3 to 9.5 d (McBrayer et al., 2007; Rewitz et al., 2009). During this ETI period, NMJs undergo additional growth (adding >50 boutons/NMJ), and this growth remains under the control of the canonical regulators Highwire and the TGFβ/BMP pathway. NMJ growth during the ETI period occurs via addition of new branches, satellite boutons, and interstitial boutons, and continues even after muscle growth levels off. Throughout the ETI, organization of synapses and active zones remains normal, and synaptic transmission is unchanged. These results establish the ETI larval system as a viable model for studying motor neuron diseases and for investigating time-dependent effects of perturbations that impair mechanisms of neuroprotection, synaptic maintenance, and response to neural injury.

Feeding, growth, and survival of post-larval abalone Haliotis asinina on different benthic diatoms

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Emmanuel C. Capinpin, Jr.

2007-12-01

Full Text Available The feeding behavior, digestive efficiency, growth, and survival of post-larval abalone Haliotis asininafed with 5 species of locally isolated benthic diatom strains (Navicula mollis, N. ramosissima, Stauroneissp., Pleurosigma sp., and Cocconeis sp. were examined in the laboratory. Two 15-day feeding trialsusing 1 mm post-larvae were conducted. No significant differences were observed in sizes of post-larvalabalone after 15 days in all diatom treatments (P>0.05. However, in both trials, Cocconeis sp. resulted inhigh survival rates (88.9±5.6% and 80.0±20.0% for Trials 1 and 2, respectively. Cocconeis sp. wasefficiently digested by post-larval abalone, with most of the cells being ruptured during ingestion and/orpassage through the gut. One diatom strain, Pleurosigma sp., resulted to a high survival but producedthe slowest growth rate (<10 ìm.d-1 SL. It was probably not ingested easily during the experiment due toits large size or mobility. For the other diatom strains, N. mollis and N. ramosissima, most cells passedthrough the gut with the cells left intact. Stauroneis sp. is highly digestible, but did not result to highsurvival, although the remaining live post-larval abalone fed on this diatom as well as on N. mollis grewfaster during the second week of both feeding trials. N. ramosissima resulted to poorest survival rate(<10% due to its poor digestibility. Only Cocconeis sp. showed a fairly high growth rate, digestionefficiency, and survival rate. N. mollis which gave a fairly high survival rate and Stauroneis may be addedtowards the later stages of post-larval rearing as well as other large diatoms. The digestion efficiency ofdiatom strains is considered an important factor determining its dietary value, but other factors may alsobe important such as volume contents, biochemical composition, and other physical characteristics.

Can universal coverage eliminate health disparities? Reversal of disparate injury outcomes in elderly insured minorities.

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Ramirez, Michelle; Chang, David C; Rogers, Selwyn O; Yu, Peter T; Easterlin, Molly; Coimbra, Raul; Kobayashi, Leslie

2013-06-15

Health outcome disparities in racial minorities are well documented. However, it is unknown whether such disparities exist among elderly injured patients. We hypothesized that such disparities might be reduced in the elderly owing to insurance coverage under Medicare. We investigated this issue by comparing the trauma outcomes in young and elderly patients in California. A retrospective analysis of the California Office of Statewide Health Planning and Development hospital discharge database was performed for all publicly available years from 1995 to 2008. Trauma admissions were identified by International Classification of Disease, Ninth Revision, primary diagnosis codes from 800 to 959, with certain exclusions. Multivariate analysis examined the adjusted risk of in-hospital mortality in young (<65 y) and elderly (≥65 y) patients, controlling for age, gender, injury severity as measured by the survival risk ratio, Charlson comorbidity index, insurance status, calendar year, and teaching hospital status. A total of 1,577,323 trauma patients were identified. Among the young patients, the adjusted odds ratio of death relative to non-Hispanic whites for blacks, Hispanics, Asians, and Native Americans/others was 1.2, 1.2, 0.90, and 0.78, respectively. The corresponding adjusted odds ratios of death for elderly patients were 0.78, 0.87, 0.92, and 0.61. Young black and Hispanic trauma patients had greater mortality risks relative to non-Hispanic white patients. Interestingly, elderly black and Hispanic patients had lower mortality risks compared with non-Hispanic whites. Copyright © 2013 Elsevier Inc. All rights reserved.

Trust in physicians and racial disparities in HIV care.

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Saha, Somnath; Jacobs, Elizabeth A; Moore, Richard D; Beach, Mary Catherine

2010-07-01

Mistrust among African Americans is often considered a potential source of racial disparities in HIV care. We sought to determine whether greater trust in one's provider among African-American patients mitigates racial disparities. We analyzed data from 1,104 African-American and 201 white patients participating in a cohort study at an urban, academic HIV clinic between 2005 and 2008. African Americans expressed lower levels of trust in their providers than did white patients (8.9 vs. 9.4 on a 0-10 scale; p African Americans were also less likely than whites to be receiving antiretroviral therapy (ART) when eligible (85% vs. 92%; p = 0.02), to report complete ART adherence over the prior 3 days (83% vs. 89%; p = 0.005), and to have a suppressed viral load (40% vs. 47%; p = 0.04). Trust in one's provider was not associated with receiving ART or with viral suppression but was significantly associated with adherence. African Americans who expressed less than complete trust in their providers (0-9 of 10) had lower ART adherence than did whites (adjusted OR, 0.40; 95% CI, 0.25-0.66). For African Americans who expressed complete trust in their providers (10 of 10), the racial disparity in adherence was less prominent but still substantial (adjusted OR, 0.59; 95% CI, 0.36-0.95). Trust did not affect disparities in receipt of ART or viral suppression. Our findings suggest that enhancing trust in patient-provider relationships for African-American patients may help reduce disparities in ART adherence and the outcomes associated with improved adherence.

Age-Related Racial Disparity in Suicide Rates Among U.S. Youth

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... May 30, 2018 Age-Related Racial Disparity in Youth Suicide Rates May 21, 2018 News by Year 2018 ... May 30, 2018 Age-Related Racial Disparity in Youth Suicide Rates May 21, 2018 News by Year 2018 ...

Friend Effects and Racial Disparities in Academic Achievement

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Jennifer Flashman

2014-07-01

Full Text Available Racial disparities in achievement are a persistent fact of the US educational system. An often cited but rarely directly studied explanation for these disparities is that adolescents from different racial and ethnic backgrounds are exposed to different peers and have different friends. In this article I identify the impact of friends on racial and ethnic achievement disparities. Using data from Add Health and an instrumental variable approach, I show that the achievement characteristics of youths’ friends drive friend effects; adolescents with friends with higher grades are more likely to increase their grades compared to those with lower-achieving friends. Although these effects do not differ across race/ethnicity, given differences in friendship patterns, if black and Latino adolescents had friends with the achievement characteristics of white students, the GPA gap would be 17 to 19 percent smaller. Although modest, this effect represents an important and often overlooked source of difference among black and Latino youth.

Phenotypic plasticity in sperm traits in scorpionflies (Mecoptera : Panorpidae): Consequences of larval history and seasonality on sperm length and sperm transfer

NARCIS (Netherlands)

Vermeulen, Andreas; Engels, Sierk; Engqvist, Leif; Sauer, Klaus Peter

2009-01-01

We examined effects of seasonality, larval food availability and larval rearing density on sperm length, sperm transfer rates and body size in the bivoltine scorpionfly Panorpa vulgaris. Males of the first annual generation were larger and had larger sperm. Comparing individuals of two summer

Longfin yellowtail (SEriola rivoliana) larval rearing: skeletal development and effects of increasing dietary DHA levels at weaning phase

OpenAIRE

Mesa-Rodríguez, Antonio

2017-01-01

Programa de doctorado: Acuicultura: producción controlada de animales acuáticos [EN] Seriola rivoliana is considered as relevant species for aquaculture diversification and the information available is limited. The main objective of the present Thesis was to improve longfin yellowtail (S. rivoliana) larval production. In this sense, three specific objectives were established, in order to evaluate the most appropriate larval rearing technique, the obtention of bone development information a...

Asthma Management Disparities: A Photovoice Investigation with African American Youth

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Evans-Agnew, Robin

2016-01-01

Disparities in asthma management are a burden on African American youth. The objective of this study is to describe and compare the discourses of asthma management disparities (AMDs) in African American adolescents in Seattle to existing youth-related asthma policies in Washington State. Adolescents participated in a three-session photovoice…

Social justice, health disparities, and culture in the care of the elderly.

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Dilworth-Anderson, Peggye; Pierre, Geraldine; Hilliard, Tandrea S

2012-01-01

Older minority Americans experience worse health outcomes than their white counterparts, exhibiting the need for social justice in all areas of their health care. Justice, fairness, and equity are crucial to minimizing conditions that adversely affect the health of individuals and communities. In this paper, Alzheimer's disease (AD) is used as an example of a health care disparity among elderly Americans that requires social justice interventions. Cultural factors play a crucial role in AD screening, diagnosis, and access to care, and are often a barrier to support and equality for minority communities. The "conundrum of health disparities" refers to the interplay between disparity, social justice, and cultural interpretation, and encourages researchers to understand both (1) disparity caused by economic and structural barriers to access, treatment, and diagnosis, and (2) disparity due to cultural interpretation of disease, in order to effectively address health care issues and concerns among elderly Americans. © 2012 American Society of Law, Medicine & Ethics, Inc.

Organizational Change Management For Health Equity: Perspectives From The Disparities Leadership Program.

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Betancourt, Joseph R; Tan-McGrory, Aswita; Kenst, Karey S; Phan, Thuy Hoai; Lopez, Lenny

2017-06-01

Leaders of health care organizations need to be prepared to improve quality and achieve equity in today's health care environment characterized by a focus on achieving value and addressing disparities in a diverse population. To help address this need, the Disparities Solutions Center at Massachusetts General Hospital launched the Disparities Leadership Program in 2007. The leadership program is an ongoing, year-long, executive education initiative that trains leaders from hospitals, health plans, and health centers to improve quality and eliminate racial and ethnic disparities in health care. Feedback from participating organizations demonstrates that health care leaders seem to possess knowledge about what disparities are and about what should be done to eliminate them. Data collection, performance measurement, and multifaceted interventions remain the tools of the trade. However, the barriers to success are lack of leadership buy-in, organizational prioritization, energy, and execution, which can be addressed through organizational change management strategies. Project HOPE—The People-to-People Health Foundation, Inc.

Linking Diversity and Disparity Measures

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Sahadeb Sarkar

2012-07-01

Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} The purpose of this paper is to examine links between the diversity measures (Patil and Taillie 1982 and the disparity measures (Lindsay 1994, quantities apparently developed for somewhat different purposes. We demonstrate that numerous diversity measures satisfying all the desirable criteria mentioned by Patil and Taillie can be defined by the generating functions of certain disparities and the associated residual adjustment functions. This provides the statistician and the ecologist a wide class of flexible indices for the statistical measurement of diversity.

Socioeconomic Disparities and Health: Impacts and Pathways

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Kondo, Naoki

2012-01-01

Growing socioeconomic disparity is a global concern, as it could affect population health. The author and colleagues have investigated the health impacts of socioeconomic disparities as well as the pathways that underlie those disparities. Our meta-analysis found that a large population has risks of mortality and poor self-rated health that are attributable to income inequality. The study results also suggested the existence of threshold effects (ie, a threshold of income inequality over which the adverse impacts on health increase), period effects (ie, the potential for larger impacts in later years, specifically after the 1990s), and lag effects between income inequality and health outcomes. Our other studies using Japanese national representative survey data and a large-scale cohort study of Japanese older adults (AGES cohort) support the relative deprivation hypothesis, namely, that invidious social comparisons arising from relative deprivation in an unequal society adversely affect health. A study with a natural experiment design found that the socioeconomic gradient in self-rated health might actually have become shallower after the 1997–98 economic crisis in Japan, due to smaller health improvements among middle-class white-collar workers and middle/upper-income workers. In conclusion, income inequality might have adverse impacts on individual health, and psychosocial stress due to relative deprivation may partially explain those impacts. Any study of the effects of macroeconomic fluctuations on health disparities should also consider multiple potential pathways, including expanding income inequality, changes in the labor market, and erosion of social capital. Further studies are needed to attain a better understanding of the social determinants of health in a rapidly changing society. PMID:22156290

Socioeconomic disparities and health: impacts and pathways.

Science.gov (United States)

Kondo, Naoki

2012-01-01

Growing socioeconomic disparity is a global concern, as it could affect population health. The author and colleagues have investigated the health impacts of socioeconomic disparities as well as the pathways that underlie those disparities. Our meta-analysis found that a large population has risks of mortality and poor self-rated health that are attributable to income inequality. The study results also suggested the existence of threshold effects (ie, a threshold of income inequality over which the adverse impacts on health increase), period effects (ie, the potential for larger impacts in later years, specifically after the 1990s), and lag effects between income inequality and health outcomes. Our other studies using Japanese national representative survey data and a large-scale cohort study of Japanese older adults (AGES cohort) support the relative deprivation hypothesis, namely, that invidious social comparisons arising from relative deprivation in an unequal society adversely affect health. A study with a natural experiment design found that the socioeconomic gradient in self-rated health might actually have become shallower after the 1997-98 economic crisis in Japan, due to smaller health improvements among middle-class white-collar workers and middle/upper-income workers. In conclusion, income inequality might have adverse impacts on individual health, and psychosocial stress due to relative deprivation may partially explain those impacts. Any study of the effects of macroeconomic fluctuations on health disparities should also consider multiple potential pathways, including expanding income inequality, changes in the labor market, and erosion of social capital. Further studies are needed to attain a better understanding of the social determinants of health in a rapidly changing society.

Morphology of First Zoeal Stage of Four Genera of Alvinocaridid Shrimps from Hydrothermal Vents and Cold Seeps: Implications for Ecology, Larval Biology and Phylogeny.

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Iván Hernández-Ávila

Full Text Available Alvinocaridid shrimps are endemic species inhabiting hydrothermal vents and/or cold seeps. Although indirect evidences (genetic and lipid markers suggest that their larval stages disperse widely and support large scale connectivity, larval life and mechanisms underlying dispersal are unknown in alvinocaridids. Here we provide for the first time detailed descriptions of the first larval stage (zoea I of four alvinocaridid species: Rimicaris exoculata and Mirocaris fortunata from the Mid-Atlantic Ridge, Alvinocaris muricola from the Congo Basin and Nautilocaris saintlaurentae from the Western Pacific. The larvae were obtained from onboard hatching of brooding females (either at atmospheric pressure or at habitat pressure in hyperbaric chambers and from the water column near adult habitats, sampled with plankton pumps or sediment traps. Major characteristics of the alvinocaridid larvae include undeveloped mandible and almost complete absence of setation in the inner margin of the mouth parts and maxillipeds. Although the larvae are very similar between the four species studied, some morphological features could be used for species identification. In addition, undeveloped mouthparts and the large amount of lipid reserves strongly support the occurrence of primary lecithotrophy in the early stage of alvinocaridids. Although lecithotrophy in decapod crustaceans is usually associated with abbreviated larval development, as a mechanism of larval retention, morphological and physiological evidences suggest the occurrence of an extended and lecithotrophic larval stage in the Alvinocarididae. These traits permit the colonization of widely dispersed and fragmented environments of hydrothermal vents and cold seeps. Distribution of larval traits along the phylogenetic reconstruction of the Alvinocarididae and related families suggest that lecithotrophy/planktotrophy and extended/abbreviated development have evolved independently along related families in all

Racial/Ethnic Disparities in Nursing Home Quality of Life Deficiencies, 2001 to 2011

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Lauren J. Campbell MA

2016-06-01

Full Text Available Objectives: Racial/ethnic disparities in nursing homes (NHs are associated with lower quality of care, and state Medicaid payment policies may influence NH quality. However, no studies analyzing disparities in NH quality of life (QoL exist. Therefore, this study aims to estimate associations at the NH level between average number of QoL deficiencies and concentrations of racial/ethnic minority residents, and to identify effects of state Medicaid payment policies on racial/ethnic disparities. Method: Multivariable Poisson regression with NH random effects was used to determine the association between NH minority concentration in 2000 to 2010 and average number of QoL deficiencies in 2001 to 2011 at the NH level, and the effect of state NH payment policies on QoL deficiencies and racial/ethnic disparities in QoL deficiencies across NH minority concentrations. Results: Racial/ethnic disparities in QoL between high and low minority concentration NHs decrease over time, but are not eliminated. Case mix payment was associated with an increased disparity between high and low minority concentration NHs in QoL deficiencies. Discussion: NH managers and policy makers should consider initiatives targeting minority residents or low-performing NHs with higher minority concentrations for improvement to reduce disparities and address QoL deficiencies.

The role of health-related behaviors in the socioeconomic disparities in oral health.

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Sabbah, Wael; Tsakos, Georgios; Sheiham, Aubrey; Watt, Richard G

2009-01-01

This study aimed to examine the socioeconomic disparities in health-related behaviors and to assess if behaviors eliminate socioeconomic disparities in oral health in a nationally representative sample of adult Americans. Data are from the US Third National Health and Nutrition Examination Survey (1988-1994). Behaviors were indicated by smoking, dental visits, frequency of eating fresh fruits and vegetables and extent of calculus, used as a marker for oral hygiene. Oral health outcomes were gingival bleeding, loss of periodontal attachment, tooth loss and perceived oral health. Education and income indicated socioeconomic position. Sex, age, ethnicity, dental insurance and diabetes were adjusted for in the regression analysis. Regression analysis was used to assess socioeconomic disparities in behaviors. Regression models adjusting and not adjusting for behaviors were compared to assess the change in socioeconomic disparities in oral health. The results showed clear socioeconomic disparities in all behaviors. After adjusting for behaviors, the association between oral health and socioeconomic indicators attenuated but did not disappear. These findings imply that improvement in health-related behaviors may lessen, but not eliminate socioeconomic disparities in oral health, and suggest the presence of more complex determinants of these disparities which should be addressed by oral health preventive policies.

Butterfly Larval Host Plant use in a Tropical Urban Context: Life History Associations, Herbivory, and Landscape Factors

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Tiple, Ashish D.; Khurad, Arun M.; Dennis, Roger L. H.

2011-01-01

This study examines butterfly larval host plants, herbivory and related life history attributes within Nagpur City, India. The larval host plants of 120 butterfly species are identified and their host specificity, life form, biotope, abundance and perennation recorded; of the 126 larval host plants, most are trees (49), with fewer herbs (43), shrubs (22), climbers (7) and stem parasites (2). They include 89 wild, 23 cultivated, 11 wild/cultivated and 3 exotic plant species; 78 are perennials, 43 annuals and 5 biannuals. Plants belonging to Poaceae and Fabaceae are most widely used by butterfly larvae. In addition to distinctions in host plant family affiliation, a number of significant differences between butterfly families have been identified in host use patterns: for life forms, biotopes, landforms, perennation, host specificity, egg batch size and ant associations. These differences arising from the development of a butterfly resource database have important implications for conserving butterfly species within the city area. Differences in overall butterfly population sizes within the city relate mainly to the number of host plants used, but other influences, including egg batch size and host specificity are identified. Much of the variation in population size is unaccounted for and points to the need to investigate larval host plant life history and strategies as population size is not simply dependent on host plant abundance. PMID:21864159

Larval Population Density Alters Adult Sleep in Wild-Type Drosophila melanogaster but Not in Amnesiac Mutant Flies

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Michael W. Chi

2014-08-01

Full Text Available Sleep has many important biological functions, but how sleep is regulated remains poorly understood. In humans, social isolation and other stressors early in life can disrupt adult sleep. In fruit flies housed at different population densities during early adulthood, social enrichment was shown to increase subsequent sleep, but it is unknown if population density during early development can also influence adult sleep. To answer this question, we maintained Drosophila larvae at a range of population densities throughout larval development, kept them isolated during early adulthood, and then tested their sleep patterns. Our findings reveal that flies that had been isolated as larvae had more fragmented sleep than those that had been raised at higher population densities. This effect was more prominent in females than in males. Larval population density did not affect sleep in female flies that were mutant for amnesiac, which has been shown to be required for normal memory consolidation, adult sleep regulation, and brain development. In contrast, larval population density effects on sleep persisted in female flies lacking the olfactory receptor or83b, suggesting that olfactory signals are not required for the effects of larval population density on adult sleep. These findings show that population density during early development can alter sleep behavior in adulthood, suggesting that genetic and/or structural changes are induced by this developmental manipulation that persist through metamorphosis.

Examining Sexual Orientation Disparities in Unmet Medical Needs among Men and Women

OpenAIRE

Everett, Bethany G.; Mollborn, Stefanie

2013-01-01

Using the National Longitudinal Study of Adolescent Health (N = 13,810), this study examines disparities in unmet medical needs by sexual orientation identity during young adulthood. We use binary logistic regression and expand Andersen’s health care utilization framework to identify factors that shape disparities in unmet medical needs by sexual orientation. We also investigate whether the well-established gender disparity in health-seeking behaviors among heterosexual persons holds for sexu...

Gender Disparity at Elementary Education Level in Jammu and Kashmir: An Exploratory Study

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Gul, Showkeen Bilal Ahmad; Khan, Zebun Nisa

2014-01-01

This paper is based on a study to explore gender disparity at elementary education level in Jammu and Kashmir. Gender disparity in education refers to differences in outcomes observed between two sexes. Education disparities can be seen in different enrolment rates, dropout rates, and survival rates among the sexes. The central government and…

The influence of health disparities on targeting cancer prevention efforts.

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Zonderman, Alan B; Ejiogu, Ngozi; Norbeck, Jennifer; Evans, Michele K

2014-03-01

Despite the advances in cancer medicine and the resultant 20% decline in cancer death rates for Americans since 1991, there remain distinct cancer health disparities among African Americans, Hispanics, Native Americans, and the those living in poverty. Minorities and the poor continue to bear the disproportionate burden of cancer, especially in terms of stage at diagnosis, incidence, and mortality. Cancer health disparities are persistent reminders that state-of-the-art cancer prevention, diagnosis, and treatment are not equally effective for and accessible to all Americans. The cancer prevention model must take into account the phenotype of accelerated aging associated with health disparities as well as the important interplay of biological and sociocultural factors that lead to disparate health outcomes. The building blocks of this prevention model will include interdisciplinary prevention modalities that encourage partnerships across medical and nonmedical entities, community-based participatory research, development of ethnically and racially diverse research cohorts, and full actualization of the prevention benefits outlined in the 2010 Patient Protection and Affordable Care Act. However, the most essential facet should be a thoughtful integration of cancer prevention and screening into prevention, screening, and disease management activities for hypertension and diabetes mellitus because these chronic medical illnesses have a substantial prevalence in populations at risk for cancer disparities and cause considerable comorbidity and likely complicate effective treatment and contribute to disproportionate cancer death rates. Published by Elsevier Inc.

Trends in racial disparities for asthma outcomes among children 0 to 17 years, 2001-2010.

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Akinbami, Lara J; Moorman, Jeanne E; Simon, Alan E; Schoendorf, Kenneth C

2014-09-01

Racial disparities in childhood asthma have been a long-standing target for intervention, especially disparities in hospitalization and mortality. Describe trends in racial disparities in asthma outcomes using both traditional population-based rates and at-risk rates (based on the estimated number of children with asthma) to account for prevalence differences between race groups. Estimates of asthma prevalence and outcomes (emergency department [ED] visits, hospitalizations, and deaths) were calculated from national data for 2001 to 2010 for black and white children. Trends were calculated using weighted loglinear regression, and changes in racial disparities over time were assessed using Joinpoint. Disparities in asthma prevalence between black and white children increased from 2001 to 2010; at the end of this period, black children were twice as likely as white children to have asthma. Population-based rates showed that disparities in asthma outcomes remained stable (ED visits and hospitalizations) or increased (asthma attack prevalence, deaths). In contrast, analysis with at-risk rates, which account for differences in asthma prevalence, showed that disparities in asthma outcomes remained stable (deaths), decreased (ED visits, hospitalizations), or did not exist (asthma attack prevalence). Using at-risk rates to assess racial disparities in asthma outcomes accounts for prevalence differences between black and white children, and adds another perspective to the population-based examination of asthma disparities. An at-risk rate analysis shows that among children with asthma, there is no disparity for asthma attack prevalence and that progress has been made in decreasing disparities in asthma ED visit and hospitalization rates. Published by Elsevier Inc.

Implementing the Institute of Medicine definition of disparities: an application to mental health care.

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McGuire, Thomas G; Alegria, Margarita; Cook, Benjamin L; Wells, Kenneth B; Zaslavsky, Alan M

2006-10-01

In a recent report, the Institute of Medicine (IOM) defines a health service disparity between population groups to be the difference in treatment or access not justified by the differences in health status or preferences of the groups. This paper proposes an implementation of this definition, and applies it to disparities in outpatient mental health care. Health Care for Communities (HCC) reinterviewed 9,585 respondents from the Community Tracking Study in 1997-1998, oversampling individuals with psychological distress, alcohol abuse, drug abuse, or mental health treatment. The HCC is designed to make national estimates of service use. Expenditures are modeled using generalized linear models with a log link for quantity and a probit model for any utilization. We adjust for group differences in health status by transforming the entire distribution of health status for minority populations to approximate the white distribution. We compare disparities according to the IOM definition to other methods commonly used to assess health services disparities. Our method finds significant service disparities between whites and both blacks and Latinos. Estimated disparities from this method exceed those for competing approaches, because of the inclusion of effects of mediating factors (such as income) in the IOM approach. A rigorous definition of disparities is needed to monitor progress against disparities and to compare their magnitude across studies. With such a definition, disparities can be estimated by adjusting for group differences in models for expenditures and access to mental health services.

Effects of fenoxycarb exposure on complete larval development of the xanthid crab, Rhithropanopeus harrisii

International Nuclear Information System (INIS)

Cripe, G.M.; McKenney, C.L.; Hoglund, M.D.; Harris, P.S.

2003-01-01

The pest control agent fenoxycarb reduced survival and extended duration of developing larval stages in the xanthid crab, Rhithropanopeus harrisii. - Pest control agents, such as juvenile hormone analogues (JHA), have been developed to limit effects on non-target organisms that co-inhabit insect pest habitats. Rhithropanopeus harrisii, an estuarine xanthid crab, was used to observe the impacts of the JHA, fenoxycarb, on the pattern of complete larval development as well as survival of larvae and successful metamorphosis to first crab stage. Significant mortality occurred in the first of four zoeal stages (after 2-3 days of exposure) at the highest treatment of 240 μg fenoxycarb/l and in megalopae exposed to 48 μg fenoxycarb/l. The time required to metamorphose to the first crab stage was significantly increased for megalopae in all treatments ≥48 μg/l. This delay in development was sufficient to significantly prolong the entire developmental period from zoea to crabs. Unexposed larvae developed to crabs in an average of 16 days; larvae exposed to ≥48 μg/l required 19-20 days. Reduced survival and extended duration of developing larval stages in the life history of a benthic invertebrate may alter the population dynamics of these organisms in the estuary

Effects of fenoxycarb exposure on complete larval development of the xanthid crab, Rhithropanopeus harrisii

Energy Technology Data Exchange (ETDEWEB)

Cripe, G.M.; McKenney, C.L.; Hoglund, M.D.; Harris, P.S

2003-09-01

The pest control agent fenoxycarb reduced survival and extended duration of developing larval stages in the xanthid crab, Rhithropanopeus harrisii. - Pest control agents, such as juvenile hormone analogues (JHA), have been developed to limit effects on non-target organisms that co-inhabit insect pest habitats. Rhithropanopeus harrisii, an estuarine xanthid crab, was used to observe the impacts of the JHA, fenoxycarb, on the pattern of complete larval development as well as survival of larvae and successful metamorphosis to first crab stage. Significant mortality occurred in the first of four zoeal stages (after 2-3 days of exposure) at the highest treatment of 240 {mu}g fenoxycarb/l and in megalopae exposed to 48 {mu}g fenoxycarb/l. The time required to metamorphose to the first crab stage was significantly increased for megalopae in all treatments {>=}48 {mu}g/l. This delay in development was sufficient to significantly prolong the entire developmental period from zoea to crabs. Unexposed larvae developed to crabs in an average of 16 days; larvae exposed to {>=}48 {mu}g/l required 19-20 days. Reduced survival and extended duration of developing larval stages in the life history of a benthic invertebrate may alter the population dynamics of these organisms in the estuary.

Clinical cultural competency and knowledge of health disparities among pharmacy students.

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Okoro, Olihe N; Odedina, Folakemi T; Reams, Romonia R; Smith, W Thomas

2012-04-10

To evaluate the level of competency and knowledge about health disparities among third-year doctor of pharmacy (PharmD) students at 2 Florida public colleges of pharmacy and to explore the demographic correlates of these variables. A cross-sectional survey study design was used to collect data from participants. The students had low health-disparities knowledge and moderate skills in dealing with sociocultural issues and cross-cultural encounters. Speaking a language(s) other than English and having exposure to cultural-competency instruction were the demographic variables found to be most significantly associated with clinical cultural competency and/or knowledge of health disparities. Clinical cultural competency and health-disparities instruction may not be adequately incorporated into the pharmacy school curricula in the institutions studied. Relevant education and training are necessary to enhance cultural competency among pharmacy students.

Area-socioeconomic disparities in mental health service use among children involved in the child welfare system.

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Kim, Minseop; Garcia, Antonio R; Yang, Shuyan; Jung, Nahri

2018-06-01

Relying on data from a nationally representative sample of youth involved in the child welfare system (CWS) in 1999-2000 (the National Survey of Child and Adolescent Well-Being, Cohort 1) and 2008-2009 (Cohort 2), this study implemented a diverse set of disparity indicators to estimate area-socioeconomic disparities in mental health (MH) services use and changes in area-socioeconomic disparities between the two cohorts. Our study found that there are area-socioeconomic disparities in MH service use, indicating that the rates of MH service use among youth referred to the CWS differ by area-socioeconomic positions defined by county-level poverty rates. We also found that area-socioeconomic disparities increased over time. However, the magnitude of the increase varied widely across disparity measures, suggesting that there are different conclusions about the trend and magnitude of area-socioeconomic disparities, depending upon which disparity measures are implemented. A greater understanding of the methodological differences among disparity measures is warranted, which will in turn impact how interventions are designed to reduce socioeconomic disparities among children in the CWS. Copyright © 2018. Published by Elsevier Ltd.

Impact of viral enhancin genes on potency of Lymantria dispar multiple nucleopolyhedrovirus in L. dispar following disruption of the peritrophic matrix

Science.gov (United States)

Kelli Hoover; Merideth A. Humphries; Alyssa R. Genfron; James M. Slavicek

2010-01-01

Enhancins are metalloproteases found in many betabaculoviruses and several alphabaculoviruses, which enhance alphabaculovirus potency by degrading a protein component of the peritrophic matrix (PM), facilitating passage of virions through this structure. Earlier studies on betabaculovirus enhancins within heterologous systems suggested that enhancins facilitate virion...

Larval development and shape variation of the kelpfish Myxodes viridis (Teleostei: Clinidae

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Francisca Zavala-Muñoz

2016-03-01

Full Text Available Larval development and shape ontogeny of the kelpfish Myxodes viridis (Clinidae are described for the first time. A total of 214 individuals ranging between 3.51 and 23.09 mm standard length collected off central Chile were assessed employing classic and geometric morphometrics, illustration with camera lucida and a double-staining technique for cartilaginous and bone structure observation. Based on characteristics such as yolk sac presence and fin formation, six stages of larval development were differentiated: yolk sac, preflexion, flexion, early postflexion, late postflexion and juvenile. Shape changes during development are subtle and occur smoothly, being more significant in the head and preanal length, and ontogenetic allometry accounts for almost 15%. Cartilage formation takes place first at the branchial arches and cranium; then hypural, haemal and neural arches are consecutively formed. Bony structure ossification occurs late in the development. Vertebral centra ossify directly, without cartilaginous matrix replacement.

larvalign: Aligning Gene Expression Patterns from the Larval Brain of Drosophila melanogaster.

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Muenzing, Sascha E A; Strauch, Martin; Truman, James W; Bühler, Katja; Thum, Andreas S; Merhof, Dorit

2018-01-01

The larval brain of the fruit fly Drosophila melanogaster is a small, tractable model system for neuroscience. Genes for fluorescent marker proteins can be expressed in defined, spatially restricted neuron populations. Here, we introduce the methods for 1) generating a standard template of the larval central nervous system (CNS), 2) spatial mapping of expression patterns from different larvae into a reference space defined by the standard template. We provide a manually annotated gold standard that serves for evaluation of the registration framework involved in template generation and mapping. A method for registration quality assessment enables the automatic detection of registration errors, and a semi-automatic registration method allows one to correct registrations, which is a prerequisite for a high-quality, curated database of expression patterns. All computational methods are available within the larvalign software package: https://github.com/larvalign/larvalign/releases/tag/v1.0.

Environmental calcium and variation in yolk sac size influence swimming performance in larval lake sturgeon (Acipenser fulvescens)

DEFF Research Database (Denmark)

Deslauriers, David; Svendsen, Jon Christian; Genz, Janet

2018-01-01

, because the yolk sac is likely to affect drag forces during swimming. Testing swimming performance of larval A. fulvescens reared in four different calcium treatments spanning the range of 4-132 mg l-1 [Ca2+], this study found no treatment effects on the sprint swimming speed. A novel test of volitional...... reduced swimming performance and could be more susceptible to predation or premature downstream drift. Our study reveals how environmental factors and phenotypic variation influence locomotor performance in a larval fish....

Disparities in Intratumoral Steroidogenesis

Science.gov (United States)

2017-12-01

cancer. The reasons for this racial disparity in prostate cancer incidence and mortality are unknown but may stem from economic , social, psychological...them are elevated in the prostate tumors of African American men. We further hypothesize that elevated cholesterol, which is an essential component of...cancer promotional effects of high cholesterol. Essentially , we anticipate the level of cholesterol reduction needed to protect the prostate will be

Effects of larval population density on rates of development and interactions between two species of Chrysomya (Diptera: Calliphoridae) in laboratory culture.

Science.gov (United States)

Goodbrod, J R; Goff, M L

1990-05-01

Rearing of Chrysomya megacephala (F.) and Chrysomya rufifacies (Macquart) in pure cultures at seven different population densities (larvae per gram of liver) demonstrated an inverse relationship between density and the duration of the larval stage. In pure cultures, larval mortality rates decreased with increasing density until an optimum density was reached (8 larvae/g liver for C. megacephala and 10 larvae/g liver for C. rufifacies), then decreased directly with density. Puparial and adult weights varied inversely with density for both species in pure cultures. Internal feeding mass temperatures were above ambient temperatures for all cultures, with maximum temperatures recorded in cultures with 20 and 40 larvae/g liver for G. rufifacies and C. megacephala, respectively. In paired encounters, larvae of C. rufifacies were cannibalistic and predatory on C. megacephala larvae after the first instar. In mixed cultures of these two species, the larval mortality of C. rufifacies remained relatively stable, whereas the larval mortality of C. megacephala increased directly with population density.

Larval habitat for the avian malaria vector culex quinquefasciatus (Diptera: Culicidae) in altered mid-elevation mesic-dry forests in Hawai'i

Science.gov (United States)

Reiter, M.E.; Lapointe, D.A.

2009-01-01

Effective management of avian malaria (Plasmodium relictum) in Hawai'i's endemic honeycreepers (Drepanidinae) requires the identification and subsequent reduction or treatment of larval habitat for the mosquito vector, Culex quinquefasciatus (Diptera: Culicidae). We conducted ground surveys, treehole surveys, and helicopter aerial surveys from 20012003 to identify all potential larval mosquito habitat within two 100+ ha mesic-dry forest study sites in Hawai'i Volcanoes National Park, Hawai'i; 'Ainahou Ranch and Mauna Loa Strip Road. At 'Ainahou Ranch, anthropogenic sites (43%) were more likely to contain mosquitoes than naturally occurring (8%) sites. Larvae of Cx. quinquefasciatus were predominately found in anthropogenic sites while Aedes albopictus larvae occurred less frequently in both anthropogenic sites and naturally-occurring sites. Additionally, moderate-size (???20-22,000 liters) anthropogenic potential larval habitat had >50% probability of mosquito presence compared to larger- and smaller-volume habitat (malaria, may be controlled by larval habitat reduction in the mesic-dry landscapes of Hawai'i where anthropogenic sources predominate.

EFFECTS OF THALLIUM ON THE LARVAL DEVELOPMENT OF LUCILIA SERICATA MEIGEN 1826 AND PMI ESTIMATION

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Arif Gökhan BAŞARAN

2011-08-01

Full Text Available Determination of larval growth rate of and forensic analysis of the age of Calliphoridae larvae on a corpse are useful evidence in legal investigations for the estimation of exact death time and time duration after death; post mortem interval. However many factors, such as temperature, tissue type and contamination of drugs and toxins, effect larval development of blow fly larvae and consequently theestimation of post mortem interval. The present study examined the larval growth rate of a forensically important blow fly species, Lucilia sericata Meigen 1826 in different concentrations (0,12; 0,25; 0,50; 1 and 2 μg/g of toxic heavy metal Thallium under controlled laboratory conditions. Body length and weight, death ratio of larvae and pupa between experimental and control groups were compared. Results demonstrated that the development rate of larvae between uncontaminated and contaminated diets varies significantly. In short, they molted later, reached maximum length more slowly and sometimesproduced significantly smaller pupae in contaminated food source. These results emphasized that the importance of determining the contamination rate of toxins in tissue for the forensic entomologist,while using development rates from standard curves based on larvae fed non-contaminated mediums.

O efeito da salinidade no desenvolvimento larval do caranguejo - uçá, Ucides cordatus (Linnaeus, 1763 (Decapoda: Ocypodidae no Norte do Brasil The effect of salinity on the larval development of the uçá-crab, Ucides cordatus (Linnaeus, 1763 (Decapoda: Ocypodidae in Northern Brazil

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Darlan de Jesus de Brito Simith

2008-01-01

Full Text Available O presente trabalho estudou o efeito da salinidade na sobrevivência e na duração do desenvolvimento larval do caranguejo-uçá, Ucides cordatus (do estuário do Rio Caeté, Norte do Brasil, até a fase de megalopa em sete tratamentos de salinidade (0, 5, 10, 15, 20, 25 e 30. A salinidade afetou significativamente a sobrevivência das larvas zoea, no entanto não afetou a duração do desenvolvimento larval (20,77 ± 1,56 dias. Nas salinidades 0, 5 e 10 houve total mortalidade das larvas zoea. Somente a partir da salinidade 15 observou-se um desenvolvimento completo até a fase de megalopa. A taxa de sobrevivência foi maior em salinidade 30 (72% e menor em 15 (16%. A reduzida taxa de sobrevivência das larvas zoea de U. cordatus, em salinidades baixas, indica a necessidade de dispersão larval do estuário para as águas costeiras onde as condições de salinidade para o desenvolvimento larval são mais favoráveis. Caso contrário se não houvesse a dispersão, a reduzida salinidade das águas estuarinas no período chuvoso, causaria uma elevada mortalidade, afetando desta forma o recrutamento, a manutenção e o crescimento da população de U. cordatus nos manguezais.The present work studied the effect of salinity on the survival and duration of larval development of the mangrove crab, Ucides cordatus (from the Caeté River estuary, North of Brazil until the megalopal phase in seven salinity treatments (0, 5, 10, 15, 20, 25 e 30. Salinity significantly affected the survival of the zoea larvae, however it did not affect the duration of the larval development (20.77 ± 1.56 days. In salinity 0, 5 and 10 all zoea larvae died. Only from off salinity 15, complete development until the megalopal phase occurred. The survival rate was highest in salinity 30 (72% and lowest in 15 (16%. The reduced survival rate of the U. cordatus zoea larvae, in low salinities, indicates the necessity of larval dispersion from the estuary to coastal waters, where

Ant-Related Oviposition and Larval Performance in a Myrmecophilous Lycaenid

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Matthew D. Trager

2013-01-01

Full Text Available We experimentally assessed ant-related oviposition and larval performance in the Miami blue butterfly (Cyclargus thomasi bethunebakeri. Ant tending had sex-dependent effects on most measures of larval growth: female larvae generally benefitted from increased tending frequency whereas male larvae were usually unaffected. The larger size of female larvae tended by ants resulted in a substantial predicted increase in lifetime egg production. Oviposition by adult females that were tended by C. floridanus ants as larvae was similar between host plants with or without ants. However, they laid relatively more eggs on plants with ants than did females raised without ants, which laid less than a third of their eggs on plants with ants present. In summary, we found conditional benefits for larvae tended by ants that were not accompanied by oviposition preference for plants with ants present, which is a reasonable result for a system in which ant presence at the time of oviposition is not a reliable indicator of future ant presence. More broadly, our results emphasize the importance of considering the consequences of variation in interspecific interactions, life history traits, and multiple measures of performance when evaluating the costs and benefits of mutualistic relationships.

Gender-Based Pay Disparities in Intercollegiate Coaching: The Legal Issues.