Specific Heat Discontinuity, deltaC, at Tc in BaFe2(As0.7P0.3)2 - Consistent with Unconventional Superconductivity

We report the specific heat discontinuity, deltaC/Tc, at Tc = 28.2 K of a collage of single crystals of BaFe2(As0.7P0.3)2 and compare the measured value of 38.5 mJ/molK**2 with other iron pnictide and iron chalcogenide (FePn/Ch) superconductors. This value agrees well with the trend established by Bud'ko, Ni and Canfield who found that deltaC/Tc ~ a*Tc**2 for 14 examples of doped Ba1-xKxFe2As2 and BaFe2-xTMxAs2, where the transition metal TM=Co and Ni. We extend their analysis to include all the FePn/Ch superconductors for which deltaC/Tc is currently known and find deltaC/Tc ~ a*Tc**1.9 and a=0.083 mJ/molK**4. A comparison with the elemental superconductors with Tc>1 K and with A-15 superconductors shows that, contrary to the FePn/Ch superconductors, electron-phonon-coupled conventional superconductors exhibit a significantly different dependence of deltaC on Tc, namely deltaC/Tc ~ Tc**0.9. However deltaC/gamma*Tc appears to be comparable in all three classes (FePn/Ch, elemental and A-15) of superconductors with, e. g., deltaC/gamma*Tc=2.4 for BaFe2(As0.7P0.3)2. A discussion of the possible implications of these phenomenological comparisons for the unconventional superconductivity believed to exist in the FePn/Ch is given.Comment: some disagreement in reference and footnote numbering with the published versio

Selective Serotonin Reuptake Inhibitor Use Is Associated with Right Ventricular Structure and Function: The MESA-Right Ventricle Study

PURPOSE:Serotonin and the serotonin transporter have been implicated in the development of pulmonary hypertension (PH). Selective serotonin reuptake inhibitors (SSRIs) may have a role in PH treatment, but the effects of SSRI use on right ventricular (RV) structure and function are unknown. We hypothesized that SSRI use would be associated with RV morphology in a large cohort without cardiovascular disease (N = 4114). METHODS:SSRI use was determined by medication inventory during the Multi-Ethnic Study of Atherosclerosis baseline examination. RV measures were assessed via cardiac magnetic resonance imaging. The cross-sectional relationship between SSRI use and each RV measure was assessed using multivariable linear regression; analyses for RV mass and end-diastolic volume (RVEDV) were stratified by sex. RESULTS:After adjustment for multiple covariates including depression and left ventricular measures, SSRI use was associated with larger RV stroke volume (RVSV) (2.75 mL, 95% confidence interval [CI] 0.48-5.02 mL, p = 0.02). Among men only, SSRI use was associated with greater RV mass (1.08 g, 95% CI 0.19-1.97 g, p = 0.02) and larger RVEDV (7.71 mL, 95% 3.02-12.40 mL, p = 0.001). SSRI use may have been associated with larger RVEDV among women and larger RV end-systolic volume in both sexes. CONCLUSIONS:SSRI use was associated with higher RVSV in cardiovascular disease-free individuals and, among men, greater RV mass and larger RVEDV. The effects of SSRI use in patients with (or at risk for) RV dysfunction and the role of sex in modifying this relationship warrant further study

Collection description and finding aid

Collection description and finding aid for The Howard P. Willens Collection. To view items in the physical collection, it is necessary to fill out a manuscript request form in the library. Some materials may not be immediately available for use

Agricultural practise and water quality in the Netherlands. Background information for the 1992-1997 period for the country report EU Nitrate Directive

This overview documents agricultural practice, and groundwater and surface water quality, in the Netherlands, mainly for the period from 1992 to 1997. It is intended to provide the Dutch authorities with basic information for reporting on the results of monitoring programmes to asses the effectiveness of the Dutch Action programme. A start was made in the 1992-1997 reporting period with the implementation of the Code of Good Practice in the Netherlands. In part, this concerned accentuation of measures taken in the 1987-1992 period. Nitrogen present in agriculture via chemical fertilisers and manure decreased slightly in 1992-1997. The nitrogen surplus in agriculture has not changed as a result of lower crop yields. Nitrate concentrations in groundwater under agricultural land showed no trend in the reporting period, in which fluctuations in precipitation surplus were accounted for. The nitrate concentration in groundwater and the frequency of exceeding the European reference value not only depends on human activities but also on soil type, the local hydrological conditions and sampling depths. The annual average nitrate concentrations in fresh surface waters influenced by agriculture and other fresh waters decreased in the reporting period. Maximum concentrations showed, on the contrary, an increase. The reason for this is unknown. Nitrate concentrations at monitoring locations in marine waters decreased or did not change. This holds for both average and maximum concentrations. Eutrophication expressed as the concentration of chorophyll-a showed no clear trend in both fresh and marine surface waters in the 1992-1997 period. If the period before 1992 is taken into account (from 1986 onwards), a decrease in eutrophication is observed in fresh waters. It is too early to determine effects of the Dutch Action programme, implemented in 1996; this applies especially to nitrate concentrations in surface and groundwater.Het rapport geeft een overzicht van de landbouwpraktijk en de grond- en oppervlaktewaterkwaliteit in Nederland in met name de periode 1992-1997. Het levert het basismateriaal voor het onderdeel 'resultaten controleprogramma's' in de rapportage die de Nederlandse overheid medio 2000 aan de Europese Commissie dient toe te sturen in het kader van de Nitraatrichtlijn. De resultaten van de controleprogramma's moeten een indruk geven van de effectiviteit van het Nederlandse actieprogramma ter uitvoering van de EU-nitraatrichtlijn. de invoering van de in de code voor Goede Landbouwpraktijk uit 1993 genoemde maatregelen. Deels betreft het hier een gefaseerde aanscherping van maatregelen die reeds in 1987 een aanvang hebben genomen. De stikstofaanvoer naar de bodem via meststoffen in de landbouw is in de verslagperiode licht afgenomen. Het stikstofoverschot van de Nederlandse landbouw is niet verminderd als gevolg van lagere gewasopbrengsten. De nitraatconcentratie in het grondwater onder landbouwgrond laat geen trendmatige verandering zijn in de verslagperiode als gecorrigeerd wordt voor weersinvloeden. Het effect van droge en natte jaren is met name in het bovenste grondwater groot. De gemeten nitraatconcentratie in het grondwater is m.n. afhankelijk van de hydrologische omstandigheden, het bodemtype en de diepte van bemonsteren. De jaargemiddelde nitraatconcentraties in de zoete oppervlaktewateren nemen in de verslagperiode af. De maximum nitraatconcentraties daarentegen vertonen geen duidelijke trend. De nitraatconcentraties in de zoute wateren blijven gelijk of dalen, dit geldt voor zowel de gemiddelde als de maximale waarden. De eutrofiering uitgedrukt als de concentratie aan chlorofyl-a vertoont in de periode 1992-1997 in de zoete oppervlaktewateren en in het kustwater geen duidelijke trend. Over een langere periode gezien (vanaf 1986), is in de rijkswateren en de regionale wateren wel sprake van een daling. Het is nog te vroeg om effecten van het Nederlandse actieprogramma, dat vanaf 1996 van start is gegaan, te kunnen vaststellen, met name als het gaat om de grond- en oppervlaktewaterkwaliteit