1,845,703 research outputs found

    Review of the West Indian species of Efferia Coquillett (Diptera: Asilidae): Part 1. Bahamas, Cayman Islands, Cuba, and Jamaica

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    The genus Efferia Coquillett from the Bahamas, Cayman Islands, Cuba, and Jamaica is reviewed. The fauna now totals 16 species with 6 new species described (Ef. bellardii n. sp., Ef. bromleyi n. sp., Ef. hinei n. sp., Ef. insula n. sp., Ef. pina n. sp., and Ef. vinalensis n. sp.). Cuba has the greatest diversity with 10 species, Jamaica 3, the Bahamas 2, and the Cayman Islands 1. Efferia stylata (Fabricius) is removed from the species list of these West Indian islands. The wings of Ef. caymanensis Scarbrough and Ef. bromleyi, spermathecae of Ef. bromleyi, Ef. cubensis (Bromley), Ef. insula, Ef. nigritarsis (Hine), and terminalia of all species are illustrated. Keys for the identification of the species are provided. Specimens of two additional species from Cuba are in too poor a condition to be described but their terminalia are illustrated and the species are included in the key to the males

    Is low cardiac ejection fraction a risk factor for stroke?

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    Background and Purpose: Reduced ejection fraction (EF) ?35% has been suggested as a criterion for anticoagulation in persons with heart failure in sinus rhythm, but the literature supporting EF as an independent stroke risk factor is conflicting. We here review the status of reduced EF as a stroke risk factor. Methods: We performed a Medline search combining terms for stroke and heart failure (HF) or cardiac left ventricular systolic dysfunction and reviewed evidence that reduced EF increases the risk of stroke. We also reviewed clinical and epidemiological HF studies that included data on stroke and EF. Results: Two of three longitudinal cohort studies found reduced EF (<50%) to be a stroke risk factor but did not find an inverse relationship between EF level and degree of stroke risk. Exploratory analyses of three clinical studies found an inverse relationship between EF level and degree of stroke risk but only in specific subgroups and vascular risk factors appeared to attenuate this relationship. Three analyses suggested an increased stroke risk with EF ?20%. Conclusion: Reduced EF (<50%) probably increases stroke risk but this is not consistently demonstrated in all populations studied. Reduced EF of any degree may be a surrogate for atherosclerotic cerebrovascular disease and in these patients traditional vascular risk factors may be more important for stroke risk than EF. There is no evidence to support EF ?35% as a specific stroke risk factor. Research is needed to determine if very reduced EF (?20%) is a specific stroke risk factor.peer-reviewe

    A strategic evaluation of the introduction of the East Friesian sheep breed on a North Island hill country farm : a thesis submitted in partial fulfilment of the requirements for the degree of Masters in Applied Science in Agricultural Systems and Management at Massey University

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    New Zealand sheep fanning has changed dramatically over the past 20 years as it has adjusted to a market-led and unsubsidised economy. Despite this, new technology and management practices such as cross breeding offer exciting opportunities for improving sheep industry profitability. The introduction of new genetic material into the sheep flock can provide benefits through improved productivity and product attributes but it may also have negative consequences for industry growth if used incorrectly. The advantages of introducing a new sheep breed to a farm are usually widely published but not necessarily well researched. The East Friesian (EF) was made available to farmers in autumn 1996. It has a reputation for being highly fertile, a good milk producer and heavy-weight-lamb producer. However, no research has been published on how to develop a profitable management strategy for adopting EF's onto a hill country property. The purpose of this study was to test the hypothesis that the EF would improve the productivity and profitability of a lower North Island hill country farm. A case farm analysis using the STOCKPOL farm simulation model was used to compare the productivity and profitability of the current Romney (Rn x Rn) flock with either an East Friesian (EF) x Rn crossbred flock or a purebred EF x EF flock. The STOCKPOL model was calibrated to simulate the existing sheep and beef cattle policy for the 324 ha hill country farm, Tuapaka. Pasture growth rate data were adjusted to sustain the reordered levels of animal production and establish a basis against which the EF x Rn and EF x EF flocks could be compared. The cattle policy was fixed for all options. Ewe numbers, with a 20 % replacement rate, were adjusted for the live weight profiles and production levels of the EF x Rn (67 kg at mating; 148 lambs born: 100 ewes mated) and EF x EF (80 kg at mating; 230 lambs born: 100 ewes mated) breeds until the farm system was just biologically feasible. This indicated 1315 EF x Rn sheep or 909 EF x EF could be farmed compared to 1930 Romneys (52 kg; 117 lambs born: 100 ewes mated). In stock unit terms (SU) the EF x Rn was 1.25 and the EF x EF 1.54 compared to the Rn x Rn ewe (1.00) which consumed 526 kgDM per year. The STOCKPOL outputs were copied into an enterprise margin (EM) format and the profitability of the sheep breeds calculated after adjusting for the cost of capital (CoC) of sheep wintered. The EM's (per ha) were 324,324, 340 and 351fortheRnxRn,EFxRnandEFxEFbreeds,respectively.TheEFxEFwasthepreferredoptionforallriskpreferences.AsheepagestructuremodelwasdevelopedtosimulatedthetransitiontoanEFxRncrossbredflock.Thistooksixyears.Theadditionalnetpresentvalue(NPV)in1998dollarsoftheEFxRnvs.theRnxRnwas351 for the Rn x Rn, EF x Rn and EF x EF breeds, respectively. The EF x EF was the preferred option for all risk preferences. A sheep age structure model was developed to simulated the transition to an EF x Rn crossbred flock. This took six years. The additional net present value (NPV) in 1998 dollars of the EF x Rn vs. the Rn x Rn was 92,133. The transition to a purebred EF flock would take 24 years if a grading up strategy were adopted. An important finding was the breed x pasture production interaction. Annual pasture consumption was 869 t DM for the Rn x Rn flock, 780 t DM for the EF x Rn policy and 647 t DM for the EF x EF flock. Reduced pasture production occurred because of the higher lamb:ewe ratio of the EF sheep contributed to increased pasture senescence and decay in the summer and autumn. Ways to prevent this occurring need to be explored through further modelling studies using STOCKPOL and by evaluating the experience of famers who have adopted EF's. The study confirmed the hypothesis: EF sheep would improve production and profit on the hill country case farm. Recent farmer experience with the East Friesian should now be evaluated against this result. Title: A strategic evaluation of the introduction of the East Friesian sheep breed on a North Island hill country farm. Author: Jesus Romero Martinez Year: 1998 Degree: MApplSc (Agricultural Systems and Management)

    Asymmetrical hybridization and gene flow between Eisenia andrei and E. fetida lumbricid earthworms

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    Uniformly pigmented Eisenia andrei (Ea) and striped E. fetida (Ef) lumbricid earthworms are hermaphrodites capable of self-fertilization, cross-fertilization, and asymmetrical hybridization. The latter was detected by genotyping of F1 and F2 progeny of the controlled Ea+Ef pairs by species-specific sequences of maternal mitochondrial COI genes and maternal/paternal nuclear S28 rRNA genes. Among F1offspring there were self-fertilized Ea (aAA), Ef (fFF), and cross-fertilized fertile Ea-derived hybrids (aAF); the latter mated with Ea and gave new generation of Ea and hybrids, while mated with Ef gave Ea, Ef, Ea-derived hybrids and sterile Ef-derived hybrids (fFA). Coelomic fluid of Ea exhibits unique fluorescence spectra called here the M-fluorescence considered as a molecular biomarker of this species. Since similar fluorescence was detected also in some Ef (hypothetical hybrids?), the aim of present investigations was to identify the M-positive earthworms among families genotyped previously. It was assumed that factor/s responsible for metabolic pathways leading to production of undefined yet M-fluorophore might be encoded/controlled by alleles of hypothetical nuclear gene of Eisenia sp. segregating independently from species-specific S28 rRNA nuclear genes, where 'MM' or 'Mm' alleles determine M-positivity while 'mm' alleles determine M-negative phenotypes. Spectra of M-fluorescence were detected in all 10 Ea (aAAMM) and 19 Ea-derived hybrids (aAFMm), three of four Ef-derived hybrids (fFAMm) and one 'atypical' Ef (fFFMm) among 13 Ef earthworms. Among progeny of 'atypical' M-positive Ef (fFFMm) reappeared 'typical' M-negative Ef (fFFmm), confirming such hypothesis. Alternatively, the M-fluorescence might be dependent on unknown gene products of vertically-transmitted Ea-specific symbiotic bacteria sexually transferred to the Ef partner. Hypotheses of intrinsic and external origin of M-fluorescence might complement each other. The presence/absence of M-fluorophore does not correspond with body pigmentation patterns; Ef-characteristic banding appeared in posterior parts of hybrids body. In conclusion, Ea/Ef hybridization may serve for further studies on bi-directional gene flow

    Estimation of ejection fraction with ventriculography versus echocardiography in patients referred for cardiac surgery

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    Abstract: Aim: The aim of this study was to compare the estimation of ejection fraction (EF) by ventricuography (VG) and echocardiography (ECHO) in patients referred for surgery and to validate the results by comparison with other published data. Methods: One hundred patients who underwent VG prior to surgery were subjected to a trans-thoracic ECHO. Radiographers calculated the EF by tracing the outer border of the ventriculogram during systole and diastole. A single cardiologist, who was blinded to the angiogram result, measured EF during trans-thoracic ECHO using the biplane Simpsonā€™s method. Results: EF was significantly higher by VG versus ECHO for the whole group (67.9Ā±13.2 vs 55.7Ā±8.5, p=0.000). In 81 patients the EF estimated at VG was higher than that calculated at ECHO (71.7Ā±10.2 vs 55.9Ā±7.2, p=0.000). In 19 patients the EF estimated at VG was lower than that calculated at ECHO, but the difference was not significant (51.8Ā±12.9 by VG vs 55.4Ā±12.8, p=0.387). In 13 patients, with an EF less than 50% on VG, the correlation with ECHO was very good (42.0Ā±9.0 vs 42.0Ā±8.3, p=0.995). Two patients with an EF fraction under 30% had similar measurements by VG and ECHO. The EF range as measured by ECHO was consistent with published data. Conclusion: Ventriculography overestimates EF when compared with ECHO. When EF is less than 50% on VG, ECHO findings were similar. The value of ventriculography in patients referred for cardiac surgery is now being brought into question when ECHO, a better and less invasive test that measures EF, is available.peer-reviewe

    EF+EX Forest Algebras

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    We examine languages of unranked forests definable using the temporal operators EF and EX. We characterize the languages definable in this logic, and various fragments thereof, using the syntactic forest algebras introduced by Bojanczyk and Walukiewicz. Our algebraic characterizations yield efficient algorithms for deciding when a given language of forests is definable in this logic. The proofs are based on understanding the wreath product closures of a few small algebras, for which we introduce a general ideal theory for forest algebras. This combines ideas from the work of Bojanczyk and Walukiewicz for the analogous logics on binary trees and from early work of Stiffler on wreath product of finite semigroups

    Which executive functioning deficits are associated with AD/HD, ODD/CD and comorbid AD/HD+ODD/CD?

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    Item does not contain fulltextThis study investigated (1) whether attention deficit/hyperactivity disorder (AD/HD) is associated with executive functioning (EF) deficits while controlling for oppositional defiant disorder/conduct disorder (ODD/CD), (2) whether ODD/CD is associated with EF deficits while controlling for AD/HD, and (3)~whether a combination of AD/HD and ODD/CD is associated with EF deficits (and the possibility that there is no association between EF deficits and AD/HD or ODD/CD in isolation). Subjects were 99~children ages 6ā€“12 years. Three putative domains of EF were investigated using well-validated tests: verbal fluency, working memory, and planning. Independent of ODD/CD, AD/HD was associated with deficits in planning and working memory, but not in verbal fluency. Only teacher rated AD/HD, but not parent rated AD/HD, significantly contributed to the prediction of EF task performance. No EF deficits were associated with ODD/CD. The presence of comorbid AD/HD accounts for the EF deficits in children with comorbid AD/HD+ODD/CD. These results suggest that EF deficits are unique to AD/HD and support the model proposed by R. A. Barkley (1997).17 p

    Developmental differences in the structure of executive function in middle childhood and adolescence

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    Although it has been argued that the structure of executive function (EF) may change developmentally, there is little empirical research to examine this view in middle childhood and adolescence. The main objective of this study was to examine developmental changes in the component structure of EF in a large sample (N = 457) of 7ā€“15 year olds. Participants completed batteries of tasks that measured three components of EF: updating working memory (UWM), inhibition, and shifting. Confirmatory factor analysis (CFA) was used to test five alternative models in 7ā€“9 year olds, 10ā€“12 year olds, and 13ā€“15 year olds. The results of CFA showed that a single-factor EF model best explained EF performance in 7ā€“9-year-old and 10ā€“12-year-old groups, namely unitary EF, though this single factor explained different amounts of variance at these two ages. In contrast, a three-factor model that included UWM, inhibition, and shifting best accounted for the data from 13ā€“15 year olds, namely diverse EF. In sum, during middle childhood, putative measures of UWM, inhibition, and shifting may rely on similar underlying cognitive processes. Importantly, our findings suggest that developmental dissociations in these three EF components do not emerge until children transition into adolescence. These findings provided empirical evidence for the development of EF structure which progressed from unity to diversity during middle childhood and adolescence

    Mid-Infrared Emission Features in the ISM: Feature-to-Feature Flux Ratios

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    Using a limited, but representative sample of sources in the ISM of our Galaxy with published spectra from the Infrared Space Observatory, we analyze flux ratios between the major mid-IR emission features (EFs) centered around 6.2, 7.7, 8.6 and 11.3 microns, respectively. In a flux ratio-to-flux ratio plot of EF(6.2)/EF(7.7) as a function of EF(11.3)/EF(7.7), the sample sources form roughly a Ī›\Lambda-shaped locus which appear to trace, on an overall basis, the hardness of a local heating radiation field. But some driving parameters other than the radiation field may also be required for a full interpretation of this trend. On the other hand, the flux ratio of EF(8.6)/EF(7.7) shows little variation over the sample sources, except for two HII regions which have much higher values for this ratio due to an ``EF(8.6\um) anomaly,'' a phenomenon clearly associated with environments of an intense far-UV radiation field. If further confirmed on a larger database, these trends should provide crucial information on how the EF carriers collectively respond to a changing environment.Comment: 16 pages, 1 figure, 1 table; accepted for publication in ApJ Letter
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