Study of the B^0 Semileptonic Decay Spectrum at the Upsilon(4S) Resonance

We have made a first measurement of the lepton momentum spectrum in a sample of events enriched in neutral B's through a partial reconstruction of B0 --> D*- l+ nu. This spectrum, measured with 2.38 fb**-1 of data collected at the Upsilon(4S) resonance by the CLEO II detector, is compared directly to the inclusive lepton spectrum from all Upsilon(4S) events in the same data set. These two spectra are consistent with having the same shape above 1.5 GeV/c. From the two spectra and two other CLEO measurements, we obtain the B0 and B+ semileptonic branching fractions, b0 and b+, their ratio, and the production ratio f+-/f00 of B+ and B0 pairs at the Upsilon(4S). We report b+/b0=0.950 (+0.117-0.080) +- 0.091, b0 = (10.78 +- 0.60 +- 0.69)%, and b+ = (10.25 +- 0.57 +- 0.65)%. b+/b0 is equivalent to the ratio of charged to neutral B lifetimes, tau+/tau0.Comment: 14 page, postscript file also available at http://w4.lns.cornell.edu/public/CLN

Studies of the Cabbibo-Suppressed Decays D+→π0ℓ+νD^+ \to \pi^0 \ell^+ \nu and D+→ηe+νeD^+ \to \eta e^+ \nu_e

Using 4.8 fb$^{-1}$ of data taken with the CLEO II detector, the branching fraction for the Cabibbo-suppressed decay $D^+\to\pi^0\ell^+\nu$ measured relative to the Cabibbo favored decay $D^+\to\bar{K^0}\ell^+\nu$ is found to be $0.046\pm 0.014\pm 0.017$. Using $V_{cs}$ and $V_{cd}$ from unitarity constraints, we determine $| f_+^{\pi}(0)/f_+^K(0)|^2=0.9\pm 0.3\pm 0.3$ We also present a 90% confidence level upper limit for the branching ratio of the decay $D^+ \to \eta e^+\nu_e$ relative to that for $D^+ \to \pi^0 e^+\nu_e$ of 1.5.Comment: 10 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Curious bivalves: Systematic utility and unusual properties of anomalodesmatan mitochondrial genomes

publisher: Elsevier articletitle: Curious bivalves: Systematic utility and unusual properties of anomalodesmatan mitochondrial genomes journaltitle: Molecular Phylogenetics and Evolution articlelink: http://dx.doi.org/10.1016/j.ympev.2017.03.004 content_type: article copyright: Crown Copyright © 2017 Published by Elsevier Inc. All rights reserved.The file attached is the final draft version of the article

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Glacial meltwater and groundwater interactions : evidence from the Virkisjokull observatory in Iceland

There is growing recognition of the important role that groundwater may have in buffering changes in river discharge due to increased melting of glaciers. Glacial deposits, particularly proglacial deposits and outwash plains can form significant aquifers and contain groundwater stores that are rarely quantified. In addition, interaction of basal melting of glaciers with groundwater can help to sustain flow through prolonged cold winters. The multidisciplinary BGS observatory at Virkisjökull in Iceland provides an excellent opportunity to characterise and quantify glacial meltwaters and groundwater. Glacier meltwater has been measured since September 2011, and precipitation and temperature from weather stations at varying altitudes since September 2009. Meltwaters and groundwater in the proglacial environment have been sampled periodically and analysed for inorganic chemistry, CFC, SF6 and stable isotopes to help understand the origin and flow paths of meltwaters and groundwater. The proglacial deposits have been mapped and the permeability of targeted deposits characterised. Initial findings show that the outwash plain provides a significant highly permeable aquifer, and is recharged locally from precipitation, with a growing influence of meltwater close to the meltwater channel. Shallow groundwater from snow melt within the catchment provides significant flow to the meltwater channels in spring, but in the prolonged winter, basal meltwater, possibly linked with sub glacial groundwater, helps to sustain flow in the meltwater channels. This initial study has led to the design of a more detailed experiment in the summer of 2012 involving the drilling and instrumentation of a targeted network of piezometers across the sandur and proglacial area

Unsaturated flow and solute transport through the chalk : tracer test and dual permeability modelling

A tracer test was carried out in the unsaturated Chalk at the Fleam Dyke research site in Cambridgeshire, UK, to investigate the role of the Chalk fractures and matrix in unsaturated flow and solute transport. The experiment, under natural rainfall conditions, involved distributing deuterated water on a grass-covered lysimeter (a cube of volume 125 m3) and on an adjacent 4 m × 4 m field plot. Tracer migration was monitored through regular core sampling and collection of lysimeter drainage water. The presence of occasional secondary peaks in sampling of the vertical tracer profile suggested the occurrence of fracture flow, allowing some tracer to bypass the Chalk matrix. However, in the 15 months following application, none of the tracer was detected in the lysimeter drainage at 5 m depth. Modelling of the tracer results was undertaken with the 1-D numerical transient dual permeability model MACRO 5.0, initially developed for macroporous soils. Modelling results showed that MACRO 5.0 could reliably simulate transient recharge through the Chalk. The simulations suggested that fracture flow is important at the site, but that it is only initiated at 1 m depth or deeper. The extent of fracture flow appeared to be highly variable in different layers of the profile, varying between 40% and 85% of the cumulative flux, mainly depending on the saturated hydraulic conductivity of the matrix. Diffusion between the fractures and the matrix tended to equalize solute concentrations in both flow domains, although solute bypass through the fractures occurred in some Chalk strata. Besides diffusive exchange, the modelling stressed the importance of advective exchange of solutes. The results suggest that the Chalk aquifer at the Fleam Dyke site is only moderately vulnerable to pollution, even though for moderate rainfall conditions some bypass flow was possible

Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger and Brasilicereus Backeberg Anatomia de espécies brasileiras pertencentes à tribo Cereeae (subfamília Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger and Brasilicereus Backeberg

(Anatomy of Brazilian Cereeae (subfamily Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger wâBrasilicereus Backeberg). Arrojadoa, Stephanocereus and Brasilicereus are endemic Brazilian Cereeae, occurring along the Espinhaço Range, in the campos rupestres, cerrados and caatingas, from northern Minas Gerais to southern Bahia. The genera are columnar, erect to semi-erect cacti, except for one species, A bahiensis, which is globose. This study describes the anatomy of dermal, fundamental and vascular systems, aiming to find diagnostic characters for the genera and species. Basal portions of stems were sectioned transversely and longitudinally, and stained with Astrablue and Safranin. The species share a uniseriate epidermis, with thick cuticle; well developed collenchymatic hypodermis, containing prismatic crystals; cortex with numerous mucilage cells, druses and vascular bundles; outside cortex as a palisade parenchyma; periderm composed of lignified cork cells alternating with suberized cells; pheloderm consisting of a few layers of thin-walled cells; phloem composed of solitary or multiple of two to three sieve tube elements, companion cells, axial and radial parenchyma; secondary xylem with solitary to multiple vessels, with simple perforation plates and alternate bordered to semi-bordered pits; axial parenchyma scanty vasicentric to incomplete; libriform septate fibres; large rays. Unlignified parenchyma is seen in the secondary xylem, varying from a few cells to bands among axial and radial elements. The following are considered diagnostic characters: the shape of lignified phellem cells, cubic to radially elongate, which individualizes S. leucostele; an underdeveloped hypodermis and the occurrence of sclereids in the cortex are exclusive to Brasilicereus markgrqfii.<br>(Anatomia de espécies brasileiras pertencentes à tribo Cereeae (subfamília Cactoideae, Cactaceae): Arrojadoa Britton & Rose, Stephanocereus A. Berger andBrasilicereus Backeberg). Arrojadoa, Stephanocereus e Brasilicereus são gêneros endêmicos à Serra do Espinhaço, ocorrendo ao norte de Minas Gerais, e na Chapada Diamantina, ao sul da Bahia, associados aos campos rupestres, cerrados e caatingas. Os gêneros, pertencentes à subfamília Cactoideae, tribo Cereeae, são colunares, eretos ou cespitosos, com exceção da espécie A. bahiensis, que é globosa. Este trabalho descreve a anatomia dos tecidos de revestimento, fundamental e vascular das espécies, com o objetivo de buscar caracteres diagnósticos para os gêneros e as espécies. Porções basais dos caules de cada indivíduo foram secionadas transversal e longitudinalmente, e coradas com azul de astra e safranina. Dentre as várias características compartilhadas, citam-se epiderme unisseriada, coberta por espesso estrato cuticular; hipoderme colenquimática bem desenvolvida, contendo cristais prismáticos; córtex diferenciado numa paliçada em sua porção mais externa; periderme com súber constituído por camadas de células lignificadas alternadas com camadas de células suberizadas; feloderme com poucas camadas de células de paredes delgadas; floema secundário composto por elementos de tubo crivado, células companheiras, parênquima axial e radial; xilema secundário com vasos solitários a múltiplos, com placa de perfuração simples, pontoações areoladas a semi-areoladas; parênquima axial vasicêntrico escasso a incompleto; fibras libriformes; raios altos e largos. A ocorrência de parênquima não lignificado no xilema secundário é observada, variando de umas poucas células a faixas contínuas nas espécies. Os caracteres de valor diagnóstico encontrados são: a forma das células lignificadas do súber, cúbicas ou alongadas, que individualizam a espécie S. leucostele; hipoderme pouco desenvolvida e a ocorrência de esclereídes no córtex, exclusivos deB. markgraaffii