Origins and nature of vessels in monocotyledons. 9. Sansevieria

AbstractSections of fixed material of four collections of three species of Sansevieria were studied by means of scanning electron microscopy (SEM) to initiate study of distribution of vessel elements and the ultrastructural nature of tracheary elements in the genus. Roots of Sansevieria have scalariform perforation plates in vessels; only tracheids are present in stems (=rhizomes) and leaves. This distribution is similar to that of genera of Asparagales claimed in recent molecular phylogenies to be close to Sansevieria: Dracaena, Ophiopogon, and Ruscus. Also similar in tracheary element types is Orchidaceae, now considered a member of Asparagales. Ultrastructural study of Sansevieria tracheary elements reveals intermediacy between vessel elements and tracheids because porose pit membranes extend across entire end walls of tracheids, and portions of scalariform perforation plates of vessel elements. This correlates with longevity of roots in Sansevieria, and probable moderate transpiration rates in leaves. In Sansevieria, as in other monocotyledons, vessel type occurrence, organographic distribution, and tracheary element ultrastructure relate primarily to ecology, although molecular-based trees, in fact, help understand the patterns of shift in ecological adaptation with attendant change in tracheary element structure

Computer-Assisted Proofs of Some Identities for Bessel Functions of Fractional Order

We employ computer algebra algorithms to prove a collection of identities involving Bessel functions with half-integer orders and other special functions. These identities appear in the famous Handbook of Mathematical Functions, as well as in its successor, the DLMF, but their proofs were lost. We use generating functions and symbolic summation techniques to produce new proofs for them.Comment: Final version, some typos were corrected. 21 pages, uses svmult.cl

Physical and chemical properties of the groundwater of the Santo Domingo-Salinas ranges, South Central Pyrenees

The Santo Domingo-Salinas ranges represent a unique Natural Area in the south-central Pyrenees, and they were declarationas a Protected Landscape in 2015. Available biological and geological knowledge is extensive but lacks of information on groundwater quality. In this work we provide new hydrogeological results and integrate them with previously available hydrogeological data. To do so, we have: (i) compiled existing hydrogeological information, (ii) exhaustively developed an inventory of water points, (iii) sampled, analyzed and interpreted the hydrochemical facies detected, and (iv) developed a preliminary conceptual model for the hydrogeological functioning of the area. These information has been integrated in an map that displays the chemical analyses of the two new campaigns (Stiff diagrams), the flow rates and the three aquifer systems defined. This new information improves and synthetizes the knowledge of the hidrogeology of the Santo Domingo-Salinas ranges Protected Landscape and it will help in its future management and planning

How does flow in a pipe become turbulent?

The transition to turbulence in pipe flow does not follow the scenario familiar from Rayleigh-Benard or Taylor-Couette flow since the laminar profile is stable against infinitesimal perturbations for all Reynolds numbers. Moreover, even when the flow speed is high enough and the perturbation sufficiently strong such that turbulent flow is established, it can return to the laminar state without any indication of the imminent decay. In this parameter range, the lifetimes of perturbations show a sensitive dependence on initial conditions and an exponential distribution. The turbulence seems to be supported by three-dimensional travelling waves which appear transiently in the flow field. The boundary between laminar and turbulent dynamics is formed by the stable manifold of an invariant chaotic state. We will also discuss the relation between observations in short, periodically continued domains, and the dynamics in fully extended puffs.Comment: for the proceedings of statphys 2

Dilepton production in heavy ion collisions at intermediate energies

We present a unified description of the vector meson and dilepton production in elementary and in heavy ion reactions. The production of vector mesons ($\rho,\omega$) is described via the excitation of nuclear resonances ($R$). The theoretical framework is an extended vector meson dominance model (eVMD). The treatment of the resonance decays $R\longmapsto NV$ with arbitrary spin is covariant and kinematically complete. The eVMD includes thereby excited vector meson states in the transition form factors. This ensures correct asymptotics and provides a unified description of photonic and mesonic decays. The resonance model is successfully applied to the $\omega$ production in $p+p$ reactions. The same model is applied to the dilepton production in elementary reactions ($p+p, p+d$). Corresponding data are well reproduced. However, when the model is applied to heavy ion reactions in the BEVALAC/SIS energy range the experimental dilepton spectra measured by the DLS Collaboration are significantly underestimated at small invariant masses. As a possible solution of this problem the destruction of quantum interference in a dense medium is discussed. A decoherent emission through vector mesons decays enhances the corresponding dilepton yield in heavy ion reactions. In the vicinity of the $\rho/\omega$-peak the reproduction of the data requires further a substantial collisional broadening of the $\rho$ and in particular of the $\omega$ meson.Comment: 32 pages revtex, 19 figures, to appear in PR

Tralokinumab provides clinically meaningful responses at week 16 in adults with moderate-to-severe atopic dermatitis who do not achieve IGA 0/1

Background and Objective: Investigator’s Global Assessment of clear/almost clear skin (IGA 0/1) is a difficult endpoint to achieve after short-term treatment of chronic moderate-to-severe atopic dermatitis, and does not fully reflect clinically meaningful changes in other parameters. We assessed the impact of tralokinumab versus placebo on other clinically meaningful parameters in patients not achieving IGA 0/1 at week 16 using pooled data from two monotherapy phase III trials, ECZTRA 1 and 2. Methods: This post hoc analysis included patients (n = 1328) from ECZTRA 1 and 2 who did not achieve the co-primary endpoint, IGA 0/1 at week 16 without rescue medication. Endpoints evaluating atopic dermatitis extent and severity included proportions of patients achieving IGA 0/1, 50%, 75%, and 90% improvement in Eczema Area and Severity Index (EASI-50/75/90); endpoints evaluating patient-reported outcomes included a ≥ 3-point improvement in worst daily pruritus Numerical Rating Scale (NRS), a ≥ 3-point improvement in eczema-related sleep interference (sleep) NRS, a ≥ 4-point improvement in Dermatology Life Quality Index (DLQI), and DLQI ≤ 5. Specifically, clinically meaningful responses were defined as EASI-50, a ≥ 3-point improvement in itch NRS, or a ≥ 4-point improvement in DLQI at week 16. Results: Among ECZTRA 1 and 2 patients who did not achieve IGA 0/1 at week 16 without rescue medication, a significantly greater proportion of patients receiving tralokinumab versus placebo achieved EASI-50 (33.0% vs 13.0%), a ≥ 3-point improvement in itch NRS (22.6% vs 9.4%), or a ≥ 4-point improvement in DLQI (41.2% vs 24.5%) at week 16. In addition, compared with placebo, a numerically greater proportion of tralokinumab-treated patients achieved all three measures of clinically meaningful response (30% vs 18%) or a clinically meaningful change in at least one outcome (48.8% vs 28.5%). Significantly greater proportions of patients receiving tralokinumab versus placebo achieved additional clinician-reported and patient-reported outcomes, such as EASI-75 (13.5% vs 4.1%), EASI-90 (3.5% vs 1.1%), DLQI ≤ 5 (22.5% vs 12.5%), and a ≥ 3-point improvement in sleep NRS (24.5% vs 11.5%). Conclusions: Tralokinumab provided clinically meaningful responses in patients with moderate-to-severe atopic dermatitis who did not achieve IGA 0/1 at week 16 and/or used rescue medication. Using multiple validated outcome measures of both efficacy and quality of life, alongside IGA scores, can better characterize tralokinumab treatment responses in patients with moderate-to-severe atopic dermatitis. [Video abstract available] Clinical Trial Registration: NCT03131648 (ECZTRA 1); study start date: 30 May, 2017; primary completion date: 7 August, 2018; study completion date: 10 October, 2019. NCT03160885 (ECZTRA 2); study start date: 12 June, 2017; primary completion date: 4 September, 2019; study completion date: 14 August, 2019. [MediaObject not available: see fulltext.]

Association between white matter hyperintensities, cortical volumes, and late-onset epilepsy

ObjectiveTo identify the association between brain vascular changes and cortical volumes on MRI and late-onset epilepsy.MethodsIn 1993-1995, 1,920 participants (median age 62.7, 59.9% female) in the community-based Atherosclerosis Risk in Communities (ARIC) Study underwent MRI, and white matter hyperintensities were measured. In addition, in 2011-2013, 1,964 ARIC participants (median age 72.4, 61.1% female) underwent MRI, and cortical volumes and white matter hyperintensities were measured. We identified cases of late-onset epilepsy (starting at age 60 or later) from ARIC hospitalization records and Medicare claims data. Using the 1993-1995 MRI, we evaluated the association between white matter hyperintensities and subsequent epilepsy using survival analysis. We used the 2011-2013 MRI to conduct cross-sectional logistic regression to examine the association of cortical volumes and white matter hyperintensities with late-onset epilepsy. All models were adjusted for demographics, hypertension, diabetes, smoking, and APOE ϵ4 allele status.ResultsNinety-seven ARIC participants developed epilepsy after having an MRI in 1993-1995 (incidence 3.34 per 1,000 person-years). The degree of white matter hyperintensities measured at ages 49-72 years was associated with the risk of late-onset epilepsy (hazard ratio 1.27 per age-adjusted SD, 95% confidence interval [CI] 1.06-1.54). Lower cortical volume scores were associated cross-sectionally with higher odds of late-onset epilepsy (odds ratio 1.87, 95% CI 1.16-3.02) per age-adjusted SD.ConclusionsThis study demonstrates associations between earlier-life white matter hyperintensities on MRI and later-life incident epilepsy, and between cortical volumes measured later in life and late-onset epilepsy. These findings may help illuminate the causes of late-onset epilepsy

Association of Head Injury with Late-Onset Epilepsy: Results from the Atherosclerosis Risk in Communities Cohort

Background and Objectives Late-onset epilepsy (LOE; i.e., epilepsy starting in later adulthood) affects a significant number of individuals. Head injury is also a risk factor for acquired epilepsy, but the degree to which prior head injury may contribute to LOE is less well understood. Our objective was to determine the association between head injury and subsequent development of LOE. Methods Included were 8,872 participants enrolled in the Atherosclerosis Risk in Communities (ARIC) study with continuous Centers for Medicare Services fee-for-service (FFS) coverage (55.1% women, 21.6% Black). We identified head injuries through 2018 from linked Medicare fee for service claims for inpatient/emergency department care, active surveillance of hospitalizations, and participant self-report. LOE cases through 2018 were identified from linked Medicare FFS claims. We used Cox proportional hazards models to evaluate associations of head injury with LOE, adjusting for demographic, cardiovascular, and lifestyle factors. Results The adjusted hazard ratio (HR) for developing LOE after a history of head injury was 1.88 (95% confidence interval [CI] 1.44-2.43). There was evidence for dose-response associations with greater risk for LOE with increasing number of prior head injuries (HR 1.37, 95% CI 1.01-1.88 for 1 prior head injury and HR 3.55, 95% CI 2.51-5.02 for 2+ prior head injuries, compared to no head injuries) and with more severe head injury (HR 2.53, 95% CI 1.83-3.49 for mild injury and HR 4.90, 95% CI 3.15-7.64 for moderate/severe injury, compared to no head injuries). Associations with LOE were significant for head injuries sustained at older age (age ≥67 years: HR 4.01, 95% CI 2.91-5.54), but not for head injuries sustained at younger age (age < 67 years: HR 0.98, 95% CI 0.68-1.41). Discussion Head injury was associated with increased risk of developing LOE, particularly when head injuries were sustained at an older age, and there was evidence for higher risk for LOE after a greater number of prior head injuries and after more severe head injuries. Classification of Evidence This study provides Class I evidence that an increased risk of late-onset epilepsy is associated with head injury and that this risk increases further with multiple and more severe head injuries

Assessment of hydropyrolysis as a method for the quantification of black carbon using standard reference materials

A wide selection of thermal, chemical and optical methods have been proposed for the quantification of black carbon (BC) in environmental matrices, and the results to date differ markedly depending upon the method used. A new approach is hydropyrolysis (hypy), where pyrolysis assisted by high hydrogen pressures (150 bar) facilitates the complete reductive removal of labile organic matter, so isolating a highly stable portion of the BC continuum (defined as BChypy). Here, the potential of hypy for the isolation and quantification of BC is evaluated using the 12 reference materials from the International BC Ring Trial, comprising BC-rich samples, BC-containing environmental matrices and BC-free potentially interfering materials. By varying the hypy operating conditions, it is demonstrated that lignocellulosic, humic and other labile organic carbon material (defined as non-BChypy) is fully removed by 550 °C, with hydrogasification of the remaining BChypy not commencing until over 575 °C. The resulting plateau in sample mass and carbon loss is apparent in all of the environmental samples, facilitating BC quantification in a wide range of materials. The BChypy contents for all 12 ring trial samples fall within the range reported in the BC inter-comparison study, and systematic differences with other methods are rationalised. All methods for BC isolation, including hypy are limited by the fact that BC cannot be distinguished from extremely thermally mature organic matter; for example in high rank coals. However, the data reported here indicates that BChypy has an atomic H/C ratio of less than 0.5 and therefore comprises a chemically well-defined polyaromatic structure in terms of the average size of peri-condensed aromatic clusters of &gt;7 rings (24 carbon atoms), that is consistent across different sample matrices. This, together with the sound underlying rationale for the reductive removal of labile organic matter, makes hypy an ideal approach for matrix independent BC quantification. The hypy results are extremely reproducible, with BChypy determinations from triplicate analyses typically within ±2% across all samples, limited mainly by the precision of the elemental analyser