1,332 research outputs found

    A new species of Hexacladia Ashmead (Hymenoptera, Encyrtidae) and new record of Hexacladia smithii Ashmead as parasitoids of Dichelops furcatus (Fabricius) (Hemiptera, Pentatomidae) in Argentina

    Get PDF
    Pentatomid adults of the species Dichelops furcatus (F.), collected on stubble of soybean, Glycine max (Linnaeus) Merril, in Santa Fe province of Argentina, were found parasitized by two encyrtid wasp species (Hymenoptera: Encyrtidae). One of the encyrtids is described as Hexacladia dichelopsis Torréns & Fidalgo, sp. n., from both sexes, and the other species H. smithii Ashmead, is recorded for the first time from D. furcatus in Argentina. Both species are gregarious endoparasitoids which carry out the whole development (larval and pupal) in their living hosts; they emerge as imagoes, by cutting their way out through the dorsal wall of the abdomen. Including the newly described H. dichelopsis, seven species of the genus are recorded from South America, and an identification key to separate them is presented. Copyright Javier Torréns et al.Fil: Torrens, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Fidalgo, Alberto Antonio P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Fernández, Celina Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Punschke, Eduardo. Universidad Nacional de Rosario; Argentin

    The oogenic cycle of Nereis diversicolor (O. F. Müller, 1776) (Annelida: Polychaeta) in shallow water environments in southwestern Portugal

    Get PDF
    This study presents data on the oogenesis and sex ratio of Nereis diversicolor (O. F. Müller, 1776) from April 1993 to May 1994 on the southwestern coast of Portugal: Odeceixe (ODX), Aljezur (ALZ) and Carrapateira (CAR). The results obtained showed that N. diversicolor presented, during the entire period of study, adults with gametes as well as a constant presence of juveniles. The average (±SD) oocyte diameter were, respectively, 136 ± 39 μm ODX, 140 ± 37 μm for ALZ, and 130 ± 49 μm for CAR. The sex ratio was always favourable to females, being 1: 2,9 for ODX, 1: 3,1 for ALZ and 1: 4,1 for CAR. In the warmer waters of CAR, accelerated maturation, reduced size, and a strong female-biased sex ratio were observed.En este estudio se presentan datos sobre oogénesis y proporción de sexos de Nereis diversicolor (O. F. Müller, 1776) durante los meses de abril 1993 a mayo 1994 en la costa suroeste de Portugal: Odeceixe (ODX), Aljezur (ALZ) y Carrapateira (CAR). Los resultados obtenidos demuestran que N. diversicolor presenta adultos con gametos a lo largo del periodo de estudio, y también una constante presencia de juveniles. Las medias (± el error estándar) del diámetro de los oocitos fueron, respectivamente: 136 ± 39 μm para ODX; 140 ± 37 μm para ALZ; y 130 ± 49 μm para CAR. La proporción de sexos siempre fue favorable para las hembras, siendo de 1: 2,9 para ODX, 1: 3,1 para ALZ y 1: 4,1 para CAR. En las aguas más calientes de CAR se observó maduración más rápida, tamaño reducido de los individuos y proporción de sexos fuertemente desviada hacia las hembras.Instituto Español de Oceanografí

    Reproduction and growth in captivity of the polychaete Nereis diversicolor O. F. Müller, 1776, using two different kinds of sediment: Preliminary assays

    Get PDF
    The polychaetes used as bait for sport and commercial fishing are a natural resource exploited in a large number of estuaries. One of the most common species captured is the ragworm Nereis diversicolor O. F. Müller (1776). This species is also used in aquaculture, mainly because of its easy availability to local dealers, and plays an important role as a nutrient stimulating gonad maturation and spawning in hatcheries. The high economic value of these worms, and the size of their catch in the main Portuguese estuaries, have led to their intense exploitation as commercial bait. Accordingly, a small-scale reproduction study of this species was carried out under controlled conditions (temperature, salinity and luminosity) in two different sediments (sand and mud), following its development from the larval to the adult stages. Such elucidation of certain aspects of its life cycle is instrumental for the species's future culture in artificial systems. The present study represents the starting point of large-scale production that will reduce the anthropogenic disturbance to biological estuary communities. The main objective of this study was to obtain preliminary results that would enable us to understand the period of growth necessary to reach a commercially valuable size. Such growth was rapid in both types of sediment, taking only a few months.Los gusanos de mar utilizados como cebo, tanto en la pesca profesional como en la deportiva, constituyen un recurso que es explotado en un gran número de estuarios. Uno de los gusanos más usados con esta finalidad es el nereido Nereis diversicolor O. F. Müller, 1776. Además de ser normalmente utilizada como cebo fresco, es una especie cada vez más empleada en acuicultura debido, por un lado, a la facilidad de su obtención en el mercado y, por otro, al importante papel que parece desempeñar en la maduración de las gónadas e inducción de las puestas en especies cultivadas. El elevado valor económico asociado a la captura de estos nereidos en los principales estuarios portugueses ha provocado la intensificación de su extracción con fines comerciales. En este ámbito se inició el estudio de la reproducción de esta especie a pequeña escala bajo condiciones controladas (temperatura, salinidad y luminosidad) en dos tipos de substrato (arena y fango). Se estudió el desarrollo de la especie desde su fase larvaria hasta su estadio adulto, con la finalidad de conocer aquellos aspectos de su ciclo de vida que posibiliten su cultivo futuro en sistemas artificiales. Estos resultados constituyen el embrión para una posible producción a gran escala de este gusano, que posibilitaría, por otro lado, la reducción de la perturbación sobre las comunidades biológicas estuarinas. En este trabajo se presentan los resultados preliminares de este estudio. Los datos obtenidos permiten inferir que el crecimiento es muy rápido en ambos tipos de sedimento, alcanzándose en pocos meses las tallas comerciales.Instituto Español de Oceanografí

    Sweet's Syndrome and Relapsing Polychondritis Signal Myelodysplastic Syndrome

    Get PDF
    Certas dermatoses, pertencentes ao grupo das síndromes paraneoplásicas mucocutâneas, podem ser o prenúncio de uma neoplasia previamente não conhecida. Tanto a síndrome de Sweet como a policondrite recidivante incluem-se neste grupo. A síndrome de Sweet e a PR são raramente encontradas em um mesmo paciente. A presença de policondrite recidivante e síndrome de Sweet em um mesmo paciente tem se revelado mais frequente em pacientes com neoplasias associadas, sobretudo hematológicas. Relata-se o caso de paciente do sexo masculino, 79 anos, com síndrome de Sweet e policondrite recidivante, em quem, subsequentemente, foi diagnosticada uma síndrome mielodisplásica. Palavras-chave: Policondrite recidivante; Síndrome de Sweet; Síndromes paraneoplásica

    Do sixth-grade writers need process strategies?

    Get PDF
    Background: Strategy-focussed writing instruction trains students both to set explicit product goals and to adopt specific procedural strategies, particularly for planning text. A number of studies have demonstrated that strategy-focussed writing instruction is effective in developing writing performance. Aim: The present study aimed to determine whether teaching process strategies provides additional benefit over teaching students to set product goals. Sample: 94 typically developing Spanish sixth-grade (upper primary) students. Method: Students received 10 hours of instruction in one of three conditions: Strategy-focussed training in setting product goals and in writing procedures (planning and revision; Product-and-Process), strategy-focussed training in setting product goals (Product-Only), and product-focussed instruction (Control). Students' writing performance was assessed before, during, and after intervention with process measures based on probed self-report and holistic and text-analytic measures of text quality. Results: Training that included process instruction was successful in changing students' writing processes, with no equivalent process changes in the Product-Only or control conditions. Both Process-and-Product and Product-Only conditions resulted in substantial improvements in the quality of students' texts relative to controls, but with no evidence of benefits of process instruction over those provided by the Product-Only condition. Teaching process substantially increased time-on-task. Conclusions: Our findings confirm the value of strategy-focussed writing instruction, but question the value of training specific process strategies

    Parasitism of Eucharitidae (Hymenoptera: Chalcidoidea) on Ectatomma brunneum (Formicidae: Ectatomminae) in Argentina: review of biological aspects

    Get PDF
    En este trabajo se hace una revisión de la biología de los eucarítidos parasitoides de Ectatomma brunneum. Se dá a conocer un nuevo registro de parasitoidismo para Kapala sp., y una nueva planta hospedadora para Dicoelothorax platycerus.A review of the biology of eucharitids parasitoids of Ectatomma brunneum is provided. A new record of parasitism for Kapala sp., and a new host plant for Dicoelothorax platycerus are included.Fil: Torrens, Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; ArgentinaFil: Fidalgo, Alberto Antonio P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; Argentin

    Role of advanced technology in the detection of sight-threatening eye disease in a UK community setting.

    Get PDF
    Background/aims: To determine the performance of combinations of structural and functional screening tests in detecting sight-threatening eye disease in a cohort of elderly subjects recruited from primary care. Methods: 505 subjects aged ≥60 years underwent frequency doubling technology (FDT) perimetry, iVue optical coherence tomography (iWellness and peripapillary retinal nerve fibre layer (RNFL) scans) and intraocular pressure with the Ocular Response Analyzer, all performed by an ophthalmic technician. The reference standard was a full ophthalmic examination by an experienced clinician who was masked to the index test results. Subjects were classified as presence or absence of sight-threatening eye disease (clinically significant cataract, primary open-angle glaucoma, intermediate or advanced age-related macular degeneration and significant diabetic retinopathy). Univariate and multivariate logistic regression analyses were used to determine the association between abnormal screening test results and the presence of sight-threatening eye disease. Results: 171 subjects (33.8%) had one or more sight-threatening eye diseases. The multivariate analysis found significant associations with any of the target conditions for visual acuity of <6/12, an abnormal FDT and peripapillary RNFL thickness outside the 99% normal limit. The sensitivity of this optimised screening panel was 61.3% (95% CI 53.5 to 68.7), with a specificity of 78.8% (95% CI 74.0 to 83.1), a positive predictive value of 59.5% (95% CI 53.7 to 65.2) and an overall diagnostic accuracy of 72.9% (95% CI 68.8 to 76.8). Conclusions: A subset of screening tests may provide an accurate and efficient means of population screening for significant eye disease in the elderly. This study provides useful preliminary data to inform the development of further larger, multicentre screening studies to validate this screening panel

    Authentic leadership’s effect on customer orientation and turnover intention among Portuguese hospitality employees: the mediating role of affective commitment

    Get PDF
    Purpose: Hospitality employees’ attitudes and behaviors play a crucial role in enhancing customer satisfaction and service quality and ultimately firms’ success; therefore, organizations must have skilled, customer-oriented staff. More research is required to help hospitality managers gain insights into the best strategies to promote and retain customer-oriented employees. This study specifically sought to provide a more comprehensive understanding of the ways that authentic leadership (AL) can affect employees’ customer orientation and turnover intention, including exploring affective commitment’s (AC) potential mediating role. Design/methodology/approach: The sample included 350 employees from different hospitality organizations in Portugal. Data were collected using anonymously completed structured questionnaires available online or in a paper-and-pencil format. Findings: The results demonstrate that AL has a positive effect on customer orientation and a negative effect on turnover intention. Moreover, they indicate that AC mediates the relationships between AL and both customer orientation and turnover intention. All hypotheses received empirical support. Practical implications: Hotel managers can increase employees’ AC and customer orientation by engaging in AL behaviors. Similarly, management can avoid having employees voluntarily leave their jobs using more AL styles and strengthening employees’ affective bonds to their organization. Originality/value: Prior hospitality studies have rarely focused on AL. This study is the first to analyze AL’s effect on customer orientation and AC’s role as a mediator variable in the relationships between AL and customer orientation and turnover intention, thus integrating all these variables into a single research model.info:eu-repo/semantics/acceptedVersio

    Effects of direct instruction and strategy modelling on upper-primary students' writing development

    Get PDF
    Strategy-focused instruction is one of the most effective approaches to improve writing skills. It aims to teach developing writers strategies that give them executive control over their writing processes. Programs under this kind of instruction tend to have multiple components that include direct instruction, modeling and scaffolded practice. This multi-component nature has two drawbacks: it makes implementation challenging due to the amount of time and training required to perform each stage, and it is difficult to determine the underlying mechanisms that contribute to its effectiveness. To unpack why strategy-focused instruction is effective, we explored the specific effects of two key components: direct teaching of writing strategies and modeling of strategy use. Six classes (133 students) of upper-primary education were randomly assigned to one of the two experimental conditions, in which students received instruction aimed at developing effective strategies for planning and drafting, or control group with no strategy instruction: Direct Instruction (N = 46), Modeling (N = 45), and Control (N = 42). Writing performance was assessed before the intervention and immediately after the intervention with two tasks, one collaborative and the other one individual to explore whether differential effects resulted from students writing alone or in pairs. Writing performance was assessed through reader-based and text-based measures of text quality. Results at post-test showed similar improvement in both intervention conditions, relatively to controls, in all measures and in both the collaborative and the individual task. No statistically significant differences were observed between experimental conditions. These findings suggest that both components, direct teaching and modeling, are equally effective in improving writing skills in upper primary students, and these effects are present even after a short training
    • …
    corecore