952 research outputs found
Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus) – implications for incipient speciation in island freshwater fish species
No full textBackground: Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory) taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species.
Results: Microchemical analyses of otolith isotopes (Sr-88, Ba-137 and Ca-43) differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae). Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP) fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices) provide a prezygotic reproductive isolation mechanism between the two ecotypes.
Conclusion: This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith microchemistry, morphology, spawning timing, population genetics) yield congruent results, and provide clear and independent evidence for the existence of distinct migratory and non-migratory ecotypes within a river in a geographically confined range. The morphological changes within the non-migratory populations parallel interspecific patterns observed in all non-migratory New Zealand endemic Gobiomorphus species and other derived gobiid taxa, a pattern suggesting parallel evolution. This study indicates, for the first time, that distinct ecotypes of island freshwater fish species may be formed as a consequence of loss of migration and subsequent diversification. Therefore, if reproductive isolation persists, these processes may provide a mechanism to facilitate speciation
Inequalities, Agency, and Well-being: Conceptual Linkages and Measurement Challenges in Development
No full textdevelopment, inequality, gender, well-being, agency, capability, distribution, Sen
What Do Quarterly Workforce Dynamics Tell Us About Wal-Mart? Evidence from New Stores in Pennsylvania
No full textIn this paper I seek to better inform debate regarding Wal-Mart’s local impact on wages, and employment dynamics by combining data on Wal-Mart stores with the recently release Quarterly Workforce Indicators provided by the US Census. Use a panel of Pennsylvania counties, who saw entrance of a Wal-Mart in 2002, I find a new store has no effect on existing employee wages in the retail sector. However, new retail sector hires experience a roughly 1,500 purchases of diapers annual since 1999 I have no financial relationship with Wal-Mart or any affiliate that I am aware of.Wal-Mart, Pennsylvania, Quarterly Workforce Indicators
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Positron emission tomography changes management, improves prognostic stratification and is superior to gallium scintigraphy in patients with low-grade lymphoma: results of a multicentre prospective study
No full text© Springer-Verlag 2008Purpose: Positron emission tomography (PET) was evaluated in low-grade non-Hodgkin lymphoma (NHL) to determine its impact on staging and management and to compare PET and gallium scans. Methods: PET resulted in management plan changes in 74 patients with untreated low-grade NHL stages I to III. Patient outcomes to 12 months were documented. Results: PET identified additional lesions in 50% of patients, led to a change in stage in 32%, and had a significant impact on management in 34%. Inferior progression-free survival was noted in patients with additional lesions detected by PET (p=0.001) and in the 28% of patients upstaged by PET to stage III or IV (p=0.024). In a subset of 16 patients undergoing both PET and gallium scans, PET was found to be superior. Conclusion: PET has a major role in the management of low-grade NHL in addition to its proven role in aggressive lymphoma.Andrew M. Scott, Dishan H. Gunawardana, Joseph Wong, Ian Kirkwood, Rodney J. Hicks, Ivan Ho Shon, Jayne E. Ramshaw and Peter Robin
Dichloropropenes
No full textPrepared by Syracuse Research Corporation ; prepared for U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry."Chemical manager(s)/author(s): Annette Ashizawa, Sharon Wilbur, Heraline Hicks, ATSDR, Division of Toxicology and Environmental Medicine, Atlanta, GA; Julie M. Klotzbach, Daniel J. Plewak, Syracuse Research Corporation, North Syracuse, NY." - P. ix."A Toxicological Profile for 1,3-Dichloropropene, Draft for Public Comment, was released in 2006. This edition supersedes any previously released draft or final profile"--P. iii.Includes bibliographical references (p. 247-270) and index
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
No full textThis Letter reports a measurement of the CP violation observables SJ/ψK0S and CJ/ψK0S in the decay channel B0→J/ψK0S performed with 1.0 fb−1 of pp collisions at s√=7 TeV collected by the LHCb experiment. The fit to the data yields SJ/ψK0S=0.73±0.07(stat)±0.04(syst) and CJ/ψK0S=0.03±0.09(stat)±0.01(syst). Both values are consistent with the current world averages and within
expectations from the Standard Model
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
The Green Papyri and the Museum of the Bible
No full textThrough the discussion of the birth and development of the Green papyrus collection and its partial inclusion in the Museum of the Bible of Washington DC, this chapter addresses for the first time questions related to the development of papyrus collecting and publishing and their colonial roots. It shows that many collectors and academics are still following methods and practices embedded into the colonial past, and this constitutes a threat to the preservation of ancient manuscripts from Egypt. In conclusion, the author suggests how to move towards more responsible collecting and publishing
Prediction of outcome after revascularization in patients with poor left ventricular function
No full text© 1996 by The Society of Thoracic SurgeonsBackground. In patients with poor left ventricular function, the determinants of outcome after revascularization are unknown. Methods. We studied prospectively 57 patients with stable coronary artery disease and poor left ventricular function (left ventricular ejection fraction 0.28 ± 0.04) who underwent coronary artery bypass grafting. Clinical variables were assessed as predictors of outcome in all patients, and peoperative stress thallium-201 scintigraphic data were analysed in 37 patients. Results. The operative mortality was 1.7%. At 12 months after operation, 46 of the 49 survivors were angina-free and 35 had fewer heart failure symptoms, but postoperative left ventricular ejection fraction (0.30 ± 0.09) did not change significantly. Eighteen survivors had left ventricular ejection fraction improved by 0.05 or more (0.30 ± 0.03 preoperatively, 0.40 ± 0.05 postopertively; p = 0.0001). The adjusted odds ratio of large reversible thallium-201 defects in predicting such outcome was 15 (95% confidence interval, 1.6 to 140), whereas othe clinical variables had no predictive value. The transplantation-free 5-year survival was 73%. Conclusions. In patients with poor left ventricular function, surgical revascularization can be performed safely, with good symptomatic relief and long-term survival. One-year survival and improvement in left ventricular function is better in patients with large reversible defects on preoperative stress thallium-201 scintigraphy.Robert K. M. Chan, Jai Raman, Kenneth J. Lee, Alexander Rosalion, Rodney J. Hicks, Sampanth Pornvilawan, Benjamin S. T. Sia, John D. Horowitz, Andrew M. Tonkin and Brian F. Buxto
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