Diet segregation in American bison (Bison bison) of Yellowstone National Park (Wyoming, USA)

Abstract Background Body size is a major factor in the nutritional ecology of ruminant mammals. Females, due to their smaller size and smaller rumen, have more rapid food-passage times than males and thereby require higher quality forage. Males are more efficient at converting high-fiber forage into usable energy and thus, are more concerned with quantity. American bison are sexually dimorphic and sexually segregate for the majority of their adult lives, and in Yellowstone National Park, they occur in two distinct subpopulations within the Northern and Central ranges. We used fecal nitrogen and stable isotopes of carbon and nitrogen from American bison to investigate sex-specific differences in diet composition, diet quality, and dietary breadth between the mating season and a time period spanning multiple years, and compared diet indicators for these different time periods between the Northern and Central ranges. Results During mating season, diet composition of male and female American bison differed significantly; females had higher quality diets, and males had greater dietary breadth. Over the multi-year period, females had higher quality diets and males, greater dietary breadth. Diet segregation for bison in the Central Range was more pronounced during the mating season than for the multi-year period and females had higher quality diets than males. Finally, diet segregation in the Northern Range was more pronounced during the multi-year period than during the mating season, and males had greater dietary breadth. Conclusions Female bison in Yellowstone National Park have higher quality diets than males, whereas males ingest a greater diversity of plants or plants parts, and bison from different ranges exhibited more pronounced diet segregation during different times. Collectively, our results suggest that diet segregation in bison of Yellowstone National Park is associated with sex-specific differences in nutritional demands. Altogether, our results highlight the importance of accounting for spatial and temporal heterogeneity when conducting dietary studies on wild ungulates.https://deepblue.lib.umich.edu/bitstream/2027.42/137700/1/12898_2017_Article_137.pd

Strain improvement and strain maintenance revisited. The use of actinoplanes teichomyceticus atcc 31121 protoplasts in the identification of candidates for enhanced teicoplanin production

Multicellular cooperation in actinomycetes is a division of labor-based beneficial trait where phenotypically specialized clonal subpopulations, or genetically distinct lineages, perform complementary tasks. The division of labor improves the access to nutrients and optimizes reproductive and vegetative tasks while reducing the costly production of secondary metabolites and/or of secreted enzymes. In this study, we took advantage of the possibility to isolate genetically distinct lineages deriving from the division of labor, for the isolation of heterogeneous teicoplanin producer phenotypes from Actinoplanes teichomyceticus ATCC 31121. In order to efficiently separate phenotypes and associated genomes, we produced and regenerated protoplasts. This approach turned out to be a rapid and effective strain improvement method, as it allowed the identification of those phenotypes in the population that produced higher teicoplanin amounts. Interestingly, a heterogeneous teicoplanin complex productivity pattern was also identified among the clones. This study suggests that strain improvement and strain maintenance should be integrated with the use of protoplasts as a strategy to unravel the hidden industrial potential of vegetative mycelium

Channel plasmon-polaritons: modal shape, dispersion, and losses

We theoretically study channel plasmon-polaritons (CPPs) with a geometry similar to that in recent experiments at telecom wavelengths (Bozhevolnyi et al., Nature 440, 508 (2006)). The CPP modal shape, dispersion relation, and losses are simulated using the multiple multipole method and the finite difference time domain technique. It is shown that, with the increase of the wavelength, the fundamental CPP mode shifts progressively towards the groove opening, ceasing to be guided at the groove bottom and becoming hybridized with wedge plasmon-polaritons running along the groove edges.Comment: 4 pages, 4 figure

El surco de desarrollo radicular como causa de fracaso endodóncico: a propósito de un caso

El surco de desarrollo radicular es una anomalía dentaria de origen embriológico presente en el 8,5% de la población que se localiza principalmente en la cara palatina de los incisivos laterales superiores. Este surco se origina en la fosa central y atravesando el cíngulo se dirige hacia el ápice, siendo su longitud variable. A través de él, los microorganismos penetran en el ligamento periodontal, causando una destrucción ósea localizada. Clínicamente los dientes afectados por esta anomalía pueden ser asintomáticos o bien presentar patología periodontal, pulpitis o necrosis pulpar por afectación secundaria de la pulpa. Presentamos el caso de una paciente que acudió a nuestro Servicio para realizarse la cirugía periapical del 1.2

Study of two MTA cements

Introduction: To determine and compare the pH, conductivity and calcium release of an experimental Portland cement (PE) consisting of trioxid mineral aggregate and a comercially available modified Portland cement (C.P.M.) after 1, 2, 3, 4, 8, 10, 15 and 30 days. Material and Methods: Cements were mixed following the manufacturer's instructions, with a powder: liquid ratio of 3:1. Each cement was placed in 12 PVC tubes 1 mm in diameter and 10 mm in length and allowed to set. Four empty tubes were used as negative controls. Tubes were submerged in plastic flasks containing 10 ml deionized water and stored at 37ºC and 100% humidity. After 1, 2, 3, 4, 8, 10, 15 and 30 days tubes were removed from the flasks and these were refilled with deionized water. We measured pH, conductivity and calcium content of the recovered solution. Data were analyzed using repeated measures ANOVA. Results: pH was 0.3 units more alkaline with PE cement (p=0.023). pH experienced a slight decrease with time (p0.05). Conductivity of PE and CPM cements diminished at 4 days and almost recovered at 30 days (p0.05). Conclusions: PE cement raised pH slightly more and had higher conductivity than CPM. Calcium release diminished after the first day and recovered at 30 days, similarly for both cements

Robust plasmon waveguides in strongly-interacting nanowire arrays

Arrays of parallel metallic nanowires are shown to provide a tunable, robust, and versatile platform for plasmon interconnects, including high-curvature turns with minimum signal loss. The proposed guiding mechanism relies on gap plasmons existing in the region between adjacent nanowires of dimers and multi-wire arrays. We focus on square and circular silver nanowires in silica, for which excellent agreement between both boundary element method and multiple multipolar expansion calculations is obtained. Our work provides the tools for designing plasmon-based interconnects and achieving high degree of integration with minimum cross talk between adjacent plasmon guides.Comment: 4 pages, 5 figure

Surface plasmon enhanced photodetectors based on internal photoemission

Surface plasmon photodetectors are of broad interest. They are promising for several applications including telecommunications, photovoltaic solar cells, photocatalysis, color-sensitive detection, and sensing, as they can provide highly enhanced fields and strong confinement (to subwavelength scales). Such photodetectors typically combine a nanometallic structure that supports surface plasmons with a photodetection structure based on internal photoemission or electron-hole pair creation. Photodetector architectures are highly varied, including waveguides, gratings, nanoparticles, nanoislands, or nanoantennas. We review the operating principles behind surface plasmon photodetectors based on the internal photoelectric effect, and we survey and compare the most recent and leading edge concepts reported in the literature

Quiste globulomaxilar: presentación de seis casos

Se presentan seis casos de quiste globulomaxilar, cinco de los cuales se diagnosticaron de modo casual y el sexto por dolor y tumefacción causados por sobreinfección. Se practicó extirpación en todos los casos y el resultado fue satisfactorio. No aparecieron recidivas después de un año de la intervención quirúrgica. Se revisa la anatomía patológica, la clinica, el diagnóstico diferencial y el tratamiento del quiste globulomaxilar

Growth hormone therapy and respiratory disorders: Long-term follow-up in PWS children

Context: Adenotonsillar tissue hypertrophy and obstructive sleep apnea have been reported during short-term GH treatment in children with Prader-Willi syndrome (PWS). Objective: We conducted an observational study to evaluate the effects of long-term GH therapy on sleep-disordered breathing and adenotonsillar hypertrophy in children with PWS. Design: This was a longitudinal observational study. PatientsandMethods:Weevaluated 75 children with genetically confirmedPWS,ofwhom50 fulfilled the criteria and were admitted to our study. The patients were evaluated before treatment (t0), after 6 weeks (t1), after 6 months (t2), after 12 months (t3), and yearly (t4-t6) thereafter, for up to 4 years of GH therapy. The central apnea index, obstructive apnea hypopnea index (OAHI), respiratory disturbance index, and minimal blood oxygen saturation were evaluated overnight using polysomnography. We evaluated the adenotonsillar size using a flexible fiberoptic endoscope. Results: The percentage of patients with an OAHI of 1 increased from 3 to 22, 36, and 38 at t1, t4, and t6, respectively (2 12.2; P .05). We observed a decrease in the respiratory disturbance indexfrom1.4 (t0) to 0.8 (t3) (P.05)andthe centralapneaindexfrom1.2 (t0) to 0.1 (t4) (P.0001). We had to temporarily suspend treatment for 3 patients at t1, t4, and t5 because of severe obstructive sleep apnea. The percentage of patients with severe adenotonsillar hypertrophy was significantly higher at t4 and t5 than at t0. The OAHI directly correlated with the adenoid size (adjusted for age) (P .01) but not with the tonsil size and IGF-1 levels. Conclusion: Long-termGHtreatment in patients withPWSis safe; however,werecommend annual polysomnography and adenotonsillar evaluation

Prevalence of HIV and other sexually transmitted infections among female commercial sex workers in Argentina

Sexually transmitted infections (STIs) have shown to enhance the transmission of human immunodeficiency virus (HIV) and to be more common among female commercial sex workers (FSWs). A cross-sectional study was conducted among 625 FSWs in six cities of Argentina in 2000-2002. The seroprevalence of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphotropic virus type I/II, and syphilis was 3.2%, 14.4%, 4.3%, 1.6%, and 45.7%, respectively. Syphilis was associated with older age (≥ 30 years, adjusted odds ratio [AOR] = 2.6 to 4.9), ≥ 10 years in sex work (AOR = 2.2), use of illegal drugs (AOR = 2.1), and a prior history of an STI (AOR = 3.0). HBV and syphilis was the most common co-infection in 44 (7.5%) subjects. FSWs in Argentina are exposed to HIV and other STIs due to high-risk sexual and illegal drug use behavior. Renewed efforts are necessary to intervene effectively in this high-risk population.Fil: Pando, María de los Ángeles. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Berini, Carolina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; ArgentinaFil: Bibini, Mariel. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; ArgentinaFil: Fernández, Mauro. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Reinaga, Elena. Asociación de Mujeres Meretrices de Argentina; ArgentinaFil: Maulen, Sergio. Nexo Asociación Civil; ArgentinaFil: Marone, Rubén. Nexo Asociación Civil; ArgentinaFil: Biglione, Mirna Marcela. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Montano, Silvia M.. Naval Medical Research Unit No. 6; PerúFil: Bautista, Christian T.. Henry M. Jackson Foundation; Estados UnidosFil: Weissenbacher, Mercedes Crecencia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Sanchez, José L.. Henry M. Jackson Foundation; Estados UnidosFil: Ávila, María Mercedes. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin