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ENCODE projects exist for many eukaryotes, including humans, but as of yet no defined project exists for plants. A plant ENCODE would be invaluable to the research community and could be more readily produced than its metazoan equivalents by capitalizing on the preexisting infrastructure provided from similar projects. Collecting and normalizing plant epigenomic data for a range of species will facilitate hypothesis generation, cross-species comparisons, annotation of genomes, and an understanding of epigenomic functions throughout plant evolution. Here, we discuss the need for such a project, outline the challenges it faces, and suggest ways forward to build a plant ENCODE.
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Bases de Datos Genéticas , Epigenómica , Plantas/genética , Metilación de ADN/genética , Genoma Humano , Genoma de Planta , Humanos , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Orb-web weaving spiders and their relatives use multiple types of task-specific silks. The majority of spider silk studies have focused on the ultra-tough dragline silk synthesized in major ampullate glands, but other silk types have impressive material properties. For instance, minor ampullate silks of orb-web weaving spiders are as tough as draglines, due to their higher extensibility despite lower strength. Differences in material properties between silk types result from differences in their component proteins, particularly members of the spidroin (spider fibroin) gene family. However, the extent to which variation in material properties within a single silk type can be explained by variation in spidroin sequences is unknown. Here, we compare the minor ampullate spidroins (MiSp) of orb-weavers and cobweb weavers. Orb-web weavers use minor ampullate silk to form the auxiliary spiral of the orb-web while cobweb weavers use it to wrap prey, suggesting that selection pressures on minor ampullate spidroins (MiSp) may differ between the two groups. RESULTS: We report complete or nearly complete MiSp sequences from five cobweb weaving spider species and measure material properties of minor ampullate silks in a subset of these species. We also compare MiSp sequences and silk properties of our cobweb weavers to published data for orb-web weavers. We demonstrate that all our cobweb weavers possess multiple MiSp loci and that one locus is more highly expressed in at least two species. We also find that the proportion of ß-spiral-forming amino acid motifs in MiSp positively correlates with minor ampullate silk extensibility across orb-web and cobweb weavers. CONCLUSIONS: MiSp sequences vary dramatically within and among spider species, and have likely been subject to multiple rounds of gene duplication and concerted evolution, which have contributed to the diverse material properties of minor ampullate silks. Our sequences also provide templates for recombinant silk proteins with tailored properties.
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Evolución Molecular , Seda/genética , Arañas/genética , Sustitución de Aminoácidos , Animales , Fibroínas/genética , Duplicación de Gen , Filogenia , Arañas/clasificaciónRESUMEN
To date, biomechanical analyses of soccer kicking have focused predominantly on lower-extremity motions, with little emphasis on the trunk and upper body. The purpose of this study was to evaluate differences in trunk axial kinematics between novice (n = 10) and skilled (n = 10) participants, as well as to establish the relationship of trunk axial motion and sagittal plane thigh rotation to poststrike ball velocity. Three-dimensional body segmental motion data were captured using high-resolution motion analysis (120 Hz) while each participant completed 5 maximal instep soccer-style kicks. The results demonstrate that skilled participants use 53% greater axial trunk range of motion compared with novice participants (P < .01), as well as 62% greater peak trunk rotation velocity (P < .01). The results also show a moderate, positive correlation of peak trunk rotation velocity with poststrike ball velocity (r = .57; P < .01), and peak hip flexion velocity with poststrike ball velocity (r = .63; P < .01). The current study highlights the potential for trunk rotation-specific training to improve maximum instep kick velocity in developing soccer athletes.
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Rendimiento Atlético/fisiología , Extremidad Inferior/fisiología , Fútbol/fisiología , Tórax/fisiología , Aceleración , Fenómenos Biomecánicos , Humanos , Imagenología Tridimensional , Masculino , Rango del Movimiento Articular/fisiología , Rotación , Adulto JovenRESUMEN
BACKGROUND AND CONTEXT: Copper deficiency myelopathy (CDM) is a rare disease that can present with spastic quadriparesis and sensory ataxia. As a result, it can precisely mimic cervical spondylitic myelopathy (CSM). Copper deficiency may be seen following gastric bypass surgery, malabsorption syndromes such as celiac disease, and with excessive exogenous zinc intake. We present a systematic review of the literature for CDM and an illustrative case. PURPOSE: Provide a systematic review of CDM to highlight the importance of recognizing the consideration of CDM in patients presenting to a spine surgeon with myelopathy that progress despite adequate surgical decompression, or myelopathy concomitant with cytopenia, thus requiring further workup. STUDY DESIGN/SETTING: Retrospective medical record review and systematic review of the literature PATIENT SAMPLE: PubMed and Ovid-Embase database search was conducted in July 2022 OUTCOME MEASURES: Self-reported measures include PRISMA flow diagram for retrospective review; Physiological measures include retrospective review of MRI imaging of cervical spine; alternate demographic and laboratory value data extracted via literature review METHODS: A PubMed and Ovid-Embase database search was conducted in July 2022 searching for "copper deficiency myelopathy (MeSH)" from 2000 to 2022 via PRISMA guidelines. Following title and abstract review, the following data was extracted from full text: age, sex, etiology, hematological values upon presentation (mean corpuscular volume, white blood count, platelet count, and hemoglobin level), metal serum studies (serum copper, ceruloplasmin, and zinc), 24-hour collection of copper and zinc, and distinct radiographic findings on MRI. RESULTS: A total of 116 studies were included in this review which contained 198 cases of copper deficiency myelopathy. The mean age was 53.57 ± 14.14 years, with the majority being females (63.8%). The most common etiology was prior gastric surgery (n=55, 36.2 %) followed by excessive zinc consumption from the use of zinc denture cream (n=39, 19.9%). The mean serum copper was 15.67 ± 17.84 (normal=80.0-155.0) mcg/dL and mean ceruloplasmin was 6.43 ± 5.25 (normal=16-45) mg/dL. In spite of appropriate treatment with copper supplementation, only 47 cases (24%) reported improvement in neurological status, and only 10 (5.1%) recovered to baseline. A hyperintense T2 signal abnormality resembling an inverted "v" in the dorsal columns was the most common radiographic abnormality. CONCLUSION: Pertinent risk factors for copper deficiency myelopathy include prior upper gastrointestinal surgery, zinc excess, and malabsorption. Characteristic laboratory and imaging findings include cytopenia, low serum copper and ceruloplasmin, and distinct inverted "v" T2 signal hyperintensity in the dorsal columns. The neurologic deterioration with copper deficiency will progress in spite of decompressive surgery, and can be devastating and irreversible even with copper supplementation, reinforcing the importance of early detection. We thus recommend patients with myelopathy presenting with a history of gastric bypass, malabsorption syndromes, excessive zinc exposure, cytopenia, or imaging resembling an inverted "v" shaped hyperintense T2 MRI signal in the dorsal columns, should first undergo blood tests for copper, ceruloplasmin, and B12 levels prior to surgical consideration.
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BACKGROUND: Orb-web and cob-web weaving spiders spin dragline silk fibers that are among the strongest materials known. Draglines are primarily composed of MaSp1 and MaSp2, two spidroins (spider fibrous proteins) expressed in the major ampullate (MA) silk glands. Prior genetic studies of dragline silk have focused mostly on determining the sequence of these spidroins, leaving other genetic aspects of silk synthesis largely uncharacterized. RESULTS: Here, we used deep sequencing to profile gene expression patterns in the Western black widow, Latrodectus hesperus. We sequenced millions of 3'-anchored "tags" of cDNAs derived either from MA glands or control tissue (cephalothorax) mRNAs, then associated the tags with genes by compiling a reference database from our newly constructed normalized L. hesperus cDNA library and published L. hesperus sequences. We were able to determine transcript abundance and alternative polyadenylation of each of three loci encoding MaSp1. The ratio of MaSp1:MaSp2 transcripts varied between individuals, but on average was similar to the estimated ratio of MaSp1:MaSp2 in dragline fibers. We also identified transcription of TuSp1 in MA glands, another spidroin family member that encodes the primary component of egg-sac silk, synthesized in tubuliform glands. In addition to the spidroin paralogs, we identified 30 genes that are more abundantly represented in MA glands than cephalothoraxes and represent new candidates for involvement in spider silk synthesis. CONCLUSIONS: Modulating expression rates of MaSp1 variants as well as MaSp2 and TuSp1 could lead to differences in mechanical properties of dragline fibers. Many of the newly identified candidate genes likely encode secreted proteins, suggesting they could be incorporated into dragline fibers or assist in protein processing and fiber assembly. Our results demonstrate previously unrecognized transcript complexity in spider silk glands.
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Araña Viuda Negra/genética , Fibroínas/genética , Perfilación de la Expresión Génica/métodos , Animales , Fibroínas/biosíntesis , Biblioteca de Genes , Análisis de Secuencia de ADNRESUMEN
Viscosity represents a key product quality indicator but has been difficult to measure in-process in real-time. This is particularly true if the process involves complex mixing phenomena operated at dynamic conditions. To address this challenge, in this study, we developed an innovative soft sensor by integrating advanced artificial neural networks. The soft sensor first employs a deep learning autoencoder to extract information-rich process features by compressing high-dimensional industrial data and then adopts a heteroscedastic noise neural network to simultaneously predict product viscosity and associated uncertainty. To evaluate its performance, predictions of product viscosity were made for a number of industrial batches operated over different seasons. Furthermore, probabilistic machine learning techniques, including the Gaussian process and the Bayesian neural network, were selected to benchmark against the heteroscedastic noise neural network. Through comparison, it is found that the proposed soft-sensor has both high accuracy and high reliability, indicating its potential for process monitoring and quality control.
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Higher rates of dispersal in one sex than the other are widespread, and often attributed to the genetic advantages of reduced inbreeding. The direction of sex-biased dispersal shows strong phylogenetic conservatism (e.g. males disperse more than females in most mammals, but the reverse is true in most birds). By contrast, our genetic data reveal strong inter-population variation in the relative dispersal rates of two species of sea snakes (Laticauda saintgironsi and L. laticaudata) in the Noumea Lagoon of New Caledonia. Assignment methods using microsatellite data identified parallel variation in sex-specific dispersal in both species: dispersal was female-biased in the north-west of the sampling area (in islands far from the main island), but male-biased in the south-east (in islands closer to the main island). This flexibility may reflect sex differences in diets, with spatial variation in sex-specific resources generating spatial variation in sex-specific dispersal distances.
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Migración Animal , Elapidae/genética , Animales , Femenino , Variación Genética , Masculino , Repeticiones de Microsatélite/genética , Nueva Caledonia , Dinámica Poblacional , Conducta Sexual AnimalRESUMEN
The sea snake subfamily Laticaudinae consists of a single genus with eight named species, based on morphological characters. We used microsatellite and mitochondrial DNA (mtDNA) data to clarify the adaptive radiation of these oviparous sea snakes in the South Pacific, with special reference to New Caledonia and Vanuatu. A mitochondrial DNA data set (ND4 gene 793 bp) was obtained from 345 individuals of the five species of Laticauda sp. sea snakes endemic to the region. Maximum likelihood and Bayesian approaches yielded the same optimal tree topology, identifying two major clades (yellow-banded and blue-banded sea snakes). Although all laticaudine sea snakes rely on small islands as oviposition sites, the two lineages differ in their use of marine vs. terrestrial habitats. A highly aquatic species (Laticauda laticaudata) shows a strong pattern of genetic isolation by distance, implying that the patchy distribution of terrestrial habitats has had little impact on gene flow. The more terrestrial clade (Laticauda colubrina, Laticauda frontalis, Laticauda guineai, Laticauda saintgironsi) shows stronger geographic differentiation in allelic frequencies, associated with island groups rather than with geographic distance. Microsatellites and mtDNA suggest that L. frontalis (restricted to Vanuatu) represents a recent founder-induced speciation event, from allopatric migrants of the New Caledonian taxon L. saintgironsi. A major divergence in speciation patterns between the two major clades of laticaudine snakes thus correlates with (and perhaps, is driven by) differences in the importance of terrestrial habitats in the species' ecology.
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Elapidae/genética , Animales , ADN Mitocondrial/genética , Elapidae/clasificación , Datos de Secuencia Molecular , FilogeniaRESUMEN
MPO (myeloperoxidase) catalyses the oxidation of chloride, bromide and thiocyanate by hydrogen peroxide to HOCl (hypochlorous acid), HOBr (hypobromous acid) and HOSCN (hypothiocyanous acid) respectively. Specificity constants indicate that SCN- is a major substrate for MPO. HOSCN is also a major oxidant generated by other peroxidases including salivary, gastric and eosinophil peroxidases. While HOCl and HOBr are powerful oxidizing agents, HOSCN is a less reactive, but more specific, oxidant which targets thiols and especially low pKa species. In the present study we show that HOSCN targets cysteine residues present in PTPs (protein tyrosine phosphatases) with this resulting in a loss of PTP activity for the isolated enzyme, in cell lysates and intact J774A.1 macrophage-like cells. Inhibition also occurs with MPO-generated HOCl and HOBr, but is more marked with MPO-generated HOSCN, particularly at longer incubation times. This inhibition is reversed by dithiothreitol, particularly at early time points, consistent with the reversible oxidation of the active site cysteine residue to give either a cysteine-SCN adduct or a sulfenic acid. Inhibition of PTP activity is associated with increased phosphorylation of p38a and ERK2 (extracellular-signal-regulated kinase 2) as detected by Western blot analysis and phosphoprotein arrays, and results in altered MAPK (mitogen-activated protein kinase) signalling. These data indicate that the highly selective targeting of some protein thiols by HOSCN can result in perturbation of cellular phosphorylation and altered cell signalling. These changes occur with (patho)physiological concentrations of SCN- ions, and implicate HOSCN as an important mediator of inflammation-induced oxidative damage, particularly in smokers who have elevated plasma levels of SCN-.
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Antioxidantes/metabolismo , Sistema de Señalización de MAP Quinasas , Macrófagos/efectos de los fármacos , Peroxidasa/metabolismo , Proteínas Tirosina Fosfatasas/antagonistas & inhibidores , Tiocianatos/metabolismo , Animales , Antioxidantes/farmacología , Apoptosis , Línea Celular , Macrófagos/metabolismo , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 1/antagonistas & inhibidores , Tiocianatos/farmacología , Factores de Transcripción/biosíntesisRESUMEN
There is widespread agreement that biodiversity loss must be reduced, yet to alleviate threats to plant and animal species, the forces driving these losses need to be better understood. We searched for explanatory variables for threatened-species data at the country level through land-use information instead of previously used socioeconomic and demographic variables. To explain the number of threatened species in one country, we used information on land-use patterns in all neighboring countries and on the extent of the country's sea border. We carried out multiple regressions of the numbers of threatened species as a function of land-use patterns, and we tested various specifications of this function, including spatial autocorrelation. Most cross-border land-use patterns had a significant influence on the number of threatened species, and land-use patterns explained the number of threatened species better than less proximate socioeconomic variables. More specifically, our overall results showed a highly adverse influence of plantations and permanent cropland, a weaker negative influence of permanent pasture, and, for the most part, a beneficial influence of nonarable lands and natural forest. Surprisingly, built-up land also showed a conserving influence on threatened species. The adverse influences extended to distances between about 250 km (plants) and 2000 km (birds and mammals) away from where the species threat was recorded, depending on the species. Our results highlight that legislation affecting biodiversity should look beyond national boundaries.
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Conservación de los Recursos Naturales , Ecosistema , Extinción Biológica , Actividades Humanas , Animales , Aves , Demografía , Cooperación Internacional , Mamíferos , Modelos Biológicos , Plantas , Factores SocioeconómicosRESUMEN
Objective: In this study, we evaluated the afterschool PAWS (Peer-education About Weight Steadiness) Club program delivered by peer or adult educators to improve food choices, physical activity, and psychosocial variables related to healthy eating. Methods: We had 109 adolescents (53 in adult-led group; 56 in peer-led group) participate in a cluster randomized controlled intervention. The 12-session curriculum framed within Social Cognitive Theory (SCT) and Stages of Change addressed mediators of behavior change related to cooking skills, food intake, and physical activity. Anthropometric, dietary intake, physical activity, and SCT mediators were assessed at baseline, post-intervention, and 6-months post-intervention. Results: Adolescents in the peer-led group significantly improved whole grain intake at post-intervention (p = .017) and 6-months post-intervention (p = .014). Both peer-led and adult-led groups had significant reductions in caloric intake at 6-months post-intervention (p = .047). Only the adult-led group improved self-efficacy (SE) and social/family support (SS) for healthy eating at post-intervention [p = .019 (SE); p = .048 (SS)] and 6-months post-intervention [p = .036 (SE); p = .022 (SS)]. Conclusions: The PAWS Club program promoted lower caloric intake by adolescents. Peer educators were effective at increasing whole grains in adolescents, and adult educators contributed to positive changes in SE and SS related to healthy eating.
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Culinaria , Dieta Saludable , Ejercicio Físico , Promoción de la Salud , Niño , Análisis por Conglomerados , Conducta Alimentaria , Femenino , Preferencias Alimentarias , Humanos , Actividades Recreativas , Masculino , Grupo ParitarioRESUMEN
The horizontal transfer of the bacterium Wolbachia pipientis between invertebrate hosts hinges on the ability of Wolbachia to adapt to new intracellular environments. The experimental transfer of Wolbachia between distantly related host species often results in the loss of infection, presumably due to an inability of Wolbachia to adapt quickly to the new host. To examine the process of adaptation to a novel host, we transferred a life-shortening Wolbachia strain, wMelPop, from the fruit fly Drosophila melanogaster into a cell line derived from the mosquito Aedes albopictus. After long-term serial passage in this cell line, we transferred the mosquito-adapted wMelPop into cell lines derived from two other mosquito species, Aedes aegypti and Anopheles gambiae. After a prolonged period of serial passage in mosquito cell lines, wMelPop was reintroduced into its native host, D. melanogaster, by embryonic microinjection. The cell line-adapted wMelPop strains were characterized by a loss of infectivity when reintroduced into the original host, grew to decreased densities, and had reduced abilities to cause life-shortening infection and cytoplasmic incompatibility compared to the original strain. We interpret these shifts in phenotype as evidence for genetic adaptation to the mosquito intracellular environment. The use of cell lines to preadapt Wolbachia to novel hosts is suggested as a possible strategy to improve the success of transinfection in novel target insect species.
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Adaptación Biológica , Pase Seriado , Wolbachia/fisiología , Aedes , Animales , Anopheles , Línea Celular , Drosophila melanogaster/microbiología , Femenino , Infecciones por Bacterias Gramnegativas/microbiología , Masculino , Virulencia , Wolbachia/patogenicidadRESUMEN
BACKGROUND AND PURPOSE: Falls are a common problem for older adults, often resulting in injury, fear of falling, and decreased quality of life. Fall risk can be decreased by modifying risk factors. Because many of the modifiable risk factors involve physical function, physical therapists play a key role in both risk factor assessment and intervention. The purpose of this study was to determine home health physical therapists' (1) knowledge of fall risk factors and interventions, and (2) practice patterns regarding assessment of fall risk. METHODS: A survey was developed and pilot tested for content validity and ease of use. Physical therapists working in home health were selected as participants because many of their patients are older adults at risk for falling. A list of home health agencies was obtained through the Alabama Department of Public Health website and agencies were contacted to determine the number of therapists working in each facility. One hundred and twenty three surveys were sent to 47 agencies. Forty seven surveys were returned for a response rate of 40%. RESULTS: Most home health physical therapists assess older adults for fall risk and provide interventions to decrease risk. However, slightly less than half of the surveyed therapists did not link interventions with specific risk factors. In addition, less than half of the therapists routinely refer patients to other health care providers to address fall risk factors. In order of importance, the highest ranked risk factors were environmental hazards, postural hypotension, and polypharmacy with muscle weakness the lowest ranked risk factor. Approximately 80% of the therapists listed balance training and strengthening exercises as interventions, whereas footwear and referral to other health professionals were listed only by 13% and 25% of the therapists, respectively. CONCLUSION: Home health physical therapists are knowledgeable concerning fall risk assessment and intervention strategies. However, these therapists are less likely to refer to other health care professionals to address fall risk.
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Accidentes por Caídas/prevención & control , Accidentes Domésticos/prevención & control , Evaluación Geriátrica/métodos , Conocimientos, Actitudes y Práctica en Salud , Especialidad de Fisioterapia , Medición de Riesgo/métodos , Anciano , Femenino , Servicios de Atención de Salud a Domicilio , Humanos , Masculino , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
Devil Facial Tumour Disease (DFTD), a highly contagious cancer, has decimated Tasmanian devil (Sarcophilus harrisii) numbers in the wild. To ensure its long-term survival, a captive breeding program was implemented but has not been as successful as envisaged at its launch in 2005. We therefore investigated the reproductive success of 65 captive devil pair combinations, of which 35 produced offspring (successful pairs) whereas the remaining 30 pairs, despite being observed mating, produced no offspring (unsuccessful pairs). The devils were screened at six MHC Class I-linked microsatellite loci. Our analyses revealed that younger females had a higher probability of being successful than older females. In the successful pairs we also observed a higher difference in total number of heterozygous loci, i.e. when one devil had a high total number of heterozygous loci, its partner had low numbers. Our results therefore suggest that devil reproductive success is subject to disruptive MHC selection, which to our knowledge has never been recorded in any vertebrate. In order to enhance the success of the captive breeding program the results from the present study show the importance of using young (2-year old) females as well as subjecting the devils to MHC genotyping.
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Enfermedades de los Animales , Especies en Peligro de Extinción , Genes MHC Clase I/inmunología , Marsupiales , Repeticiones de Microsatélite/inmunología , Neoplasias , Envejecimiento/genética , Envejecimiento/inmunología , Enfermedades de los Animales/genética , Enfermedades de los Animales/inmunología , Animales , Australia , Femenino , Marsupiales/genética , Marsupiales/inmunología , Neoplasias/genética , Neoplasias/inmunologíaRESUMEN
BACKGROUND: Colleges have been experiencing reduced resource allocations, shifting student expectations, and organizational change. These changes increase employee stress at all levels. Ensuring that employee needs are being met and promoting a healthy and productive workforce has never been more important. OBJECTIVE: To investigate employees' current perceptions of their work environments using the Work Environment Impact Scale-Self Rating (WEIS-SR). METHODS: Full and part time employees on a small college campus in the United States were surveyed using the WEIS-SR through an online survey program to protect their anonymity. RESULTS: Perception of staffing levels, workplace support for a healthy lifestyle, number of supervisors, and personal health ratings contributed to employee perceptions of their work environment. There were also differences between staff, administration, and tenured and non-tenured faculty. CONCLUSIONS: From an occupational performance perspective, valuable information on employees' levels of volition, performance capacity and habituation, and perceptions of their physical and social environment in relation to their work environments was obtained. Further support for the use of the WEIS-SR and psychometric properties of the instrument (reliability and validity) was obtained.
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Estrés Psicológico/etiología , Universidades , Lugar de Trabajo/psicología , Adolescente , Adulto , Anciano , Eficiencia , Femenino , Estado de Salud , Humanos , Satisfacción en el Trabajo , Masculino , Persona de Mediana Edad , Percepción , Admisión y Programación de Personal , Apoyo Social , Universidades/organización & administración , Equilibrio entre Vida Personal y Laboral , Adulto JovenRESUMEN
A spotted fever-like rickettsia was identified in a Hemaphysalis tick by polymerase chain reaction (PCR) amplification and sequencing of the 16S rDNA, ompA, and ompB genes. A comparison of these nucleotide sequences with those of other spotted fever group (SFG) rickettsiae revealed that the Hemaphysalis tick rickettsia ia was distinct from other previously reported strains. Phylogenetic analysis based on both ompA and ompB also indicates that the strain's closest relatives are the agents of Thai tick typhus (Rickettsia honei strain TT-118) and Flinders Island spotted fever (R. honei). This study represents the first report of an R. honei-like agent from a Hemaphysalis tick in Australia and of a spotted fever group rickettsia from Cape York Peninsula, Queensland.
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Ixodidae/microbiología , Filogenia , Rickettsia/genética , Animales , Proteínas de la Membrana Bacteriana Externa/genética , Secuencia de Bases , Análisis por Conglomerados , Cartilla de ADN , Modelos Genéticos , Datos de Secuencia Molecular , Queensland , ARN Ribosómico 16S/genética , Rickettsia/clasificación , Análisis de Secuencia de ADNRESUMEN
Most strains of the widespread endosymbiotic bacterium Wolbachia pipientis are benign or behave as reproductive parasites. The pathogenic strain wMelPop is a striking exception, however: it overreplicates in its insect hosts and causes severe life shortening. The mechanism of this pathogenesis is currently unknown. We have sequenced the genomes of three variants of wMelPop and of the closely related nonpathogenic strain wMelCS. We show that the genomes of wMelCS and wMelPop appear to be identical in the nonrepeat regions of the genome and differ detectably only by the triplication of a 19-kb region that is unlikely to be associated with life shortening, demonstrating that dramatic differences in the host phenotype caused by this endosymbiont may be the result of only minor genetic changes. We also compare the genomes of the original wMelPop strain from Drosophila melanogaster and two sequential derivatives, wMelPop-CLA and wMelPop-PGYP. To develop wMelPop as a novel biocontrol agent, it was first transinfected into and passaged in mosquito cell lines for approximately 3.5 years, generating wMelPop-CLA. This cell line-passaged strain was then transinfected into Aedes aegypti mosquitoes, creating wMelPop-PGYP, which was sequenced after 4 years in the insect host. We observe a rapid burst of genomic changes during cell line passaging, but no further mutations were detected after transinfection into mosquitoes, indicating either that host preadaptation had occurred in cell lines, that cell lines are a more selectively permissive environment than animal hosts, or both. Our results provide valuable data on the rates of genomic and phenotypic change in Wolbachia associated with host shifts over short time scales.
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Evolución Molecular , Genoma Bacteriano , Wolbachia/genética , Aedes/microbiología , Animales , Secuencia de Bases , Línea Celular , Drosophila melanogaster/microbiología , Duplicación de Gen , Datos de Secuencia Molecular , Mutación , Selección Genética , Virulencia/genética , Wolbachia/patogenicidadRESUMEN
Sex-biased dispersal is widespread in the animal kingdom and is affected by numerous factors including mating system, social factors and environmental conditions. Unlike birds and mammals, there is no common trend in amphibians and explaining the direction and degree of sex-biased dispersal in species-specific cases is difficult. We conducted a study on dispersal of the Chinese piebald odorous frog (Odorrana schmackeri) in a fragmented landscape associated with dam construction. Ten microsatellite loci were used to analyze 382 samples sourced from 14 fragmented 'islands'. Assignment tests indicated a significant pattern of female-biased dispersal on one island with inconsistencies in the strength and direction of this pattern between nearby islands. The effects of four island attributes and two potential impact factors on the pattern of sex-biased dispersal were examined. We found that the extent of isolation from the mainland and the number of breeding sites both showed a negative correlation with female biased dispersal, such that the closer an island is to the mainland the more likely it is to display female biased dispersal, and the more breeding sites on an island the more male immigrants. Based on these results, we conclude that geographic isolation and limited breeding resources are the most likely explanation for the patterns of dispersal observed in this fragmented population of amphibians.
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Migración Animal , Ranidae/genética , Aislamiento Reproductivo , Razón de Masculinidad , Animales , Cruzamiento , China , Ecosistema , Femenino , Sitios Genéticos , Variación Genética , Islas , Masculino , Repeticiones de Microsatélite , Dinámica Poblacional , Conducta Sexual AnimalRESUMEN
BACKGROUND: This study investigates secular trends in ischaemic heart disease (IHD) and stroke mortality by socioeconomic status (SES) in Australia to determine if absolute and relative differences between low and high SES areas have changed over time. METHODS: IHD and stroke mortality data for adults aged 35-74 years and corresponding population data from Australian censuses for 1979-2006 were stratified into quintiles using an area-based measure of SES and analysed by quinquennia (and 2004-06). IHD and stroke (rates per 100,000) adjusted for age, country of birth, and rurality were compared across SES strata (separately by sex) using Poisson regression. RESULTS: Mortality declined monotonically over the study period in all SES groups and both sexes. Absolute differences between low and high SES groups narrowed for IHD in females (27 to 23 per 100,000) and stroke in males and females (16 to 13, and 13 to 7 per 100,000, respectively), although absolute differences widened for IHD in males (52 to 63 per 100,000). Relative declines were greater in high compared to low SES groups for IHD (28% average quinquennial decline in high SES; compared with 21% in low SES for males; 30% and 21% for females), and for stroke (25% average quinquennial decline in high SES; 21% in low SES for males; 26% and 23% for females). CONCLUSION: Differences in mortality rates between lower and higher SES groups narrowed for both IHD (in females) and stroke (in males and females) from 1979-2006, indicating that the epidemic decline is now at a late stage when low SES groups are benefiting more, in absolute terms, than high SES groups. However males in the lower SES groups are still at an earlier stage of the epidemic decline in IHD mortality.