The systematic position of Plagiochila moritziana, P. trichostoma and P. deflexa based on ITS sequence variation of nuclear ribosomal DNA, morphology, and lipophilic secondary metabolites

According to phylogenetic analyses of nrDNA ITS1 and ITS2 sequences (including the 5.8S unit) the Neotropical Plagiochila moritziana, P. rutilans var. rutilans, P. rutilans var. standleyi, P. trichostoma (= P. permista, syn. nov.), and P. subtrinitensis form a monophyletic lineage and are placed in P. sect. Rutilantes; all five taxa lack a ca 20 base pair sequence that is present in all the taxa of the other Plagiochila sections investigated. The Central American P. subtrinitensis is treated as a synonym of the Hawaiian endemic P. deflexa. Plagiochila moritziana is excluded from sect. Fuscoluteae and reduced to a variety of P. rutilans; P. sect. Permistae is treated as a synonym of P. sect. Rutilantes. The sporophytes of P. trichostoma and P. deflexa are described for the first time. Fresh material of P. rutilans var. moritziana exhibits a distinct odor of peppermint caused by the presence of several menthane monoterpenoids, principally pulegone. The Central American P. rutilans var. standleyi is reported from Ecuador, new to South America. Lectotypes are designated for P. rutilans var. moritziana, P. subtrinitensis, and P. trichostoma

Plagiochila rutilans (Hepaticae): A poorly known species from tropical America

The neotropical liverwort, Plagiochila rutilans Lindenb., is conspecific with P. remotifolia Hampe and Gottsche, P. farlowii Steph., P. harrisana Steph, and P. organensis Herzog. Plagiochila standleyi Carl is reduced to a variety of P. rutilans. Plagiochila gymnocalycina (Lehm. and Lindenb.) Mont. and P. portoricensis Hampe and Gottsche (= P. simplex (Sw.) Lindenb.) are excluded from the synonymy of P. rutilans. Plagiochila rutilans var. liebmanniana Gottsche is a synonym of P. crispabilis Lindenb.; P. rutilans var. laxa Lindenb. and var. angustifolia Herzog are conspecific with P. gymnocalycina. Sporophytes of P. rutilans are described for the first time. Fresh material of P. rutilans exhibits a distinct odor of peppermint caused by the presence of several menthane monoterpenoids, principally pulegone. NMR (nuclear magnetic resonance) fingerprints and GC-MS data indicate that the lipophilic secondary metabolite profiles are distinct for the two varieties accepted in this study

Analysis of historical changes in soil fertility and organic matter levels of the North American Great Plains

Non-Peer Reviewe

Thickness uniformity measurements and damage threshold tests of large-area GaAs/AlGaAs crystalline coatings for precision interferometry

Precision interferometry is the leading method for extremely sensitive measurements in gravitational wave astronomy. Thermal noise of dielectric coatings poses a limitation to the sensitivity of these interferometers. To decrease coating thermal noise, new crystalline GaAs/AlGaAs multilayer mirrors have been developed. To date, the surface figure and thickness uniformity of these alternative low-loss coatings has not been investigated. Surface figure errors, for example, cause small angle scattering and thereby limit the sensitivity of an interferometer. Here we measure the surface figure of highly reflective, substrate-transferred, crystalline GaAs/AlGaAs coatings with a custom scanning reflectance system. We exploit the fact that the reflectivity varies with the thickness of the coating. To increase penetration into the coating, we used a 1550 nm laser on a highly reflective coating designed for a center wavelength of 1064 nm. The RMS thickness variation of a two inch optic was measured to be 0.41 ± 0.05 nm. This result is within 10% of the thickness uniformity, of 0.37 nm RMS, achieved with ion-beam sputtered coatings for the aLIGO detector. We additionally measured a lower limit of the laser induced damage threshold of 64 MW/cm2 for GaAs/AlGaAs coatings at a wavelength of 1064 nm. © 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Compound retention in care and all-cause mortality among persons living with human immunodeficiency virus

Background: To obtain optimal health outcomes, persons living with human immunodeficiency virus (HIV) must be retained in clinical care. We examined the relationships between 4 possible combinations of 2 separate retention measures (missed visits and the Institute of Medicine [IOM] indicator) and all-cause mortality. Methods: The sample included 4162 antiretroviral therapy (ART)–naive patients who started ART between January 2000 and July 2010 at any of 5 US sites of the Center for AIDS Research Network of Integrated Clinical Systems. The independent variable of interest was retention, captured over the 12-month period after the initiation of ART. The study outcome, all-cause mortality 1 year after ART initiation, was determined by querying the Social Security Death Index or the National Death Index. We evaluated the associations of the 4 categories of retention with all-cause mortality, using the Cox proportional hazards models. Results: Ten percent of patients did not meet retention standards for either measure (hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.59–3.21). Patients retained by the IOM but not the missed-visits measure (42%) had a higher HR for mortality (1.72; 95% CI, 1.33–2.21) than patients retained by both measures (41%). Patients retained by the missed-visits but not the IOM measure (6%) had the same mortality hazards as patients retained by both measures (HR, 1.01; 95% CI, .54–1.87). Conclusions: Missed visits within the first 12 months of ART initiation are a major risk factor for subsequent death. Incorporating missed visits in clinical and public health retention and viral suppression programming is advised

Thermal Resonance in Signal Transmission

We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance observed in arrays of bistable systems.Comment: To appear in Phys. Rev.

The glassy response of solid He-4 to torsional oscillations

We calculated the glassy response of solid He-4 to torsional oscillations assuming a phenomenological glass model. Making only a few assumptions about the distribution of glassy relaxation times in a small subsystem of otherwise rigid solid He-4, we can account for the magnitude of the observed period shift and concomitant dissipation peak in several torsion oscillator experiments. The implications of the glass model for solid He-4 are threefold: (1) The dynamics of solid He-4 is governed by glassy relaxation processes. (2) The distribution of relaxation times varies significantly between different torsion oscillator experiments. (3) The mechanical response of a torsion oscillator does not require a supersolid component to account for the observed anomaly at low temperatures, though we cannot rule out its existence.Comment: 9 pages, 4 figures, presented at QFS200