Notas sobre la historia natural de las oropéndolas Psarocolius yuracares y P. Angustifrons Alfredi en la provincia Chapare, Cochabamba, Bolivia

Se aportan datos de historia natural para dos oropéndolas o tojos (Psarocolius yuracares y P. angustifrons alfredi) poco estudiadas de la provincia Chapare, Departamento Cochabamba, Bolivia. P. yuracares resultó ser la más escasa, y se la encontró, generalmente desplazándose en bandadas monoespecíficas, hasta los 900 m s.n.m. Se encontraron tres colonias de nidificación, dos pequeñas de 5-6 nidos en palmas Socratea en la selva (Agosto y Noviembre), y una colonia mayor (Octubre), cerca de plantaciones, con más de 30 nidos activos en un gran árbol leguminoso de unos 35 m. Esta fue un colonia mixta con nidos de otra oropéndola (P. decumanus). Los nidos de P. yuracares, más cilíndricos y de tejido más tosco que los de P. decumanus, estaban agrupados en dos núcleos (clusters), cada uno con un macho que cantaba y efectuaba despliegues, los cuales no colaboraban ni con la construcción ni con la alimentación de pichones, pero sí en alejar al Tordo Gigante (Molothrus oryzivorus). P. angustifrons alfredi resultó la oropéndola más abundante del Chapare, y se encontró en abundancia en plantaciones, pueblos y aldeas, donde nidifica a partir de Julio. No encontramos sus nidos arriba de los 700 m s.n.m. De 15 colonias, nueve fueron construidas en la palma tembe (Bactris gasipaes), nativa y cultivada en el Chapare. Las colonias nunca excedieron los 14 nidos, dando un promedio de 6,7 nidos simultáneamente activos por colonia. Los nidos, de tejido tosco, estaban bien espaciados y nunca encimados. Esta oropéndola expulsó agresivamente de sus colonias a Psarocolius yuracares y al Tojito (Cacicus cela). Se observaron desde uno a cuatro machos en las colonias, en un caso dos de éstos alternando en despliegues y cantos. Sólo las hembras efectuaron todas las actividades de nidificación. Pichones dependientes se observaron junto con hembras hasta el comienzo de la temporada de cría siguiente. No se detectó parasitismo por el Tordo Gigante.-We present natural history data for the little-known Olive (Psarocolius yuracares) and Yellowbilled (P. angustifrons alfredi) oropendolas from Chapare Province, Cochabamba department, Bolivia. The Olive was the scarcest oropendola, usually traveling in monospecific flocks up to 900 m a.s.l. We found only three nesting colonies, two with 5–6 nests in Socratea palms in dense forest (August and November), and one with about 30 active nests (October), close to plantations, in an emergent, 35-m high legume tree. This last colony was mixed, having active nests of Crested Oropendolas (P. decumanus). Nests of Olive Oropendolas were located in two separate, dense clusters, and were more cylindrical and coarsely woven than those of Crested Oropendolas. One singing and displaying male was present at each cluster, which did not participate in nesting activities, but helped to expel Giant Cowbirds (Molothrus oryzivorus) from the colony. The Yellow-billed was the most abundant oropendola in the Chapare, visiting and nesting in plantations, villages and towns, from July onwards. No nests were observed above 700 m a.s.l. Nine of 15 colonies were built in peach palms (Bactris gasipaes), a native species cultivated in Chapare. Colonies did not exceed 14 nests, and had a mean of 6.7 simultaneously active nests. Nests were coarsely woven, well spaced and never clustered. This oropendola agressively expelled Olive Oropendolas and Yellow-rumped Caciques (Cacicus cela) from their nesting trees. One to four males visited the colonies and, in one case, two males alternated in songs and displays. All nesting activities were carried out by females. Dependent chicks may remain with females up to the start of the following breeding season. We did not detect parasitism by Giant Cowbirds on this speciesFil: Fraga, Rosendo Manuel. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Kreft, Stefan. University of Applied Sciences Eberswalde; Alemani

Altitudinalbewegungen von Vögeln in den Anden:mit einer Feldstudie im Nationalpark Carrasco (Bolivien)

Diese Schrift widmet sich den Bewegungen der Vögel der Anden entlang des Höhengradienten (Altitudinalwanderungen) und ihrer öko-ethologischen Steuerung. Daneben leistet sie einen Beitrag zum Naturschutz tropischer Bergwald-Ökosysteme. Umfassende Literaturauswertungen zeigen Forschungs- und Wissensdefizite auf. Eigene ornithologische Felderhebungen im Nationalpark Carrasco und seinem Umland in Bolivien erfolgten in den Jahren 2000-2003 entlang eines Höhentransekts durch tropischen Feuchtwald vom Tiefland zur Waldgrenze. Es wurde unterschieden zwischen altitudinalen jahreszeitlichen Zugvögeln, Vögeln mit kürzerfristigen Pendelbewegungen und dem isolierten Auftreten von Individuen außerhalb des Areals (Vagranten). Altitudinalwanderungen von Vögeln erweisen sich als artspezifisch, orts- und zeitspezifisch. Diese Studie ist ein Beitrag zum Verständnis der Idiosynkrasien und Komplexität der Altitudinalwanderungen von Vögeln in den Anden – und damit des artenreichsten Vogelzugsystems der Erde.The present study investigates the movements of Andean birds along the altitudinal gradient and the eco-ethological control of these movements. In addition, it aims at increasing the effectiveness of conservation of tropical forest ecosystems. A comprehensive literature review reveals considerable gaps in research and knowledge. An ornithological field study was carried out in Carrasco National Park and its surroundings in Bolivia from 2000 to 2003, covering a humid tropical forest transect from the lowlands to timberline. It differentiates between seasonal altitudinal migrant birds, relatively short-term commuters and isolated appearances of individuals outside their range (vagrants). Altitudinal bird movements are shown to be species-specific, but also specific to the spatio-temporal situation. This study contributes to the understanding of the idiosyncracies and complexities of altitudinal movements of Andean birds – and thus of the most bird species-rich migratory system on Earth

Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration

Hydration influences blood volume, blood viscosity, and water content in soft tissues - variables that determine the biophysical properties of biological tissues including their stiffness. In the brain, the relationship between hydration and stiffness is largely unknown despite the increasing importance of stiffness as a quantitative imaging marker. In this study, we investigated cerebral stiffness (CS) in 12 healthy volunteers using ultrasound time-harmonic elastography (THE) in different hydration states: (i) during normal hydration, (ii) after overnight fasting, and (iii) within 1 h of drinking 12 ml of water per kg body weight. In addition, we correlated shear wave speed (SWS) with urine osmolality and hematocrit. SWS at normal hydration was 1.64 ± 0.02 m/s and decreased to 1.57 ± 0.04 m/s (p < 0.001) after overnight fasting. SWS increased again to 1.63 ± 0.01 m/s within 30 min of water drinking, returning to values measured during normal hydration (p = 0.85). Urine osmolality at normal hydration (324 ± 148 mOsm/kg) increased to 784 ± 107 mOsm/kg (p < 0.001) after fasting and returned to normal (288 ± 128 mOsm/kg, p = 0.83) after water drinking. SWS and urine osmolality correlated linearly (r = -0.68, p < 0.001), while SWS and hematocrit did not correlate (p = 0.31). Our results suggest that mild dehydration in the range of diurnal fluctuations is associated with significant softening of brain tissue, possibly due to reduced cerebral perfusion. To ensure consistency of results, it is important that cerebral elastography with a standardized protocol is performed during normal hydration

Cerebral tomoelastography based on multifrequency MR elastography in two and three dimensions

Magnetic resonance elastography (MRE) generates quantitative maps of the mechanical properties of biological soft tissues. However, published values obtained by brain MRE vary largely and lack detail resolution, due to either true biological effects or technical challenges. We here introduce cerebral tomoelastography in two and three dimensions for improved data consistency and detail resolution while considering aging, brain parenchymal fraction (BPF), systolic blood pressure, and body-mass-index. Multifrequency MRE with 2D- and 3D-tomoelastography postprocessing was applied to the brains of 31 volunteers (age range: 22-61 years) for analyzing the coefficient of variation (CV) and effects of biological factors. Eleven volunteers were rescanned after one day and one year to determine intraclass correlation coefficient (ICC) and identify possible long-term changes. White matter shear-wave-speed (SWS) was slightly higher in 2D-MRE (1.28±0.02m/s) than 3D-MRE (1.22±0.05m/s, p<0.0001), with less variation after one day in 2D (0.33±0.32%) than in 3D (0.96±0.66%, p=0.004), which was also reflected in a slightly lower CV and higher ICC in 2D (1.84%, 0.97 [0.88-0.99]) than in 3D (3.89%, 0.95 [0.76-0.99]). Remarkably, 3D-MRE was sensitive to a decrease in white matter SWS within only one year, whereas no change in white matter volume was observed during this follow-up period. Across volunteers, stiffness correlated with age and BPF, but not with blood pressure and body-mass-index. Cerebral tomoelastography provides high-resolution viscoelasticity maps with excellent consistency. Brain MRE in 2D shows less variation across volunteers in shorter scan times than 3D-MRE, while 3D-MRE appears to be more sensitive to subtle biological effects such as aging

Functional losses in ground spider communities due to habitat structure degradation under tropical land-use change

Deforestation and land‐use change in tropical regions result in habitat loss and extinction of species that are unable to adapt to the conditions in agricultural landscapes. If the associated loss of functional diversity is not compensated by species colonizing the converted habitats, extinctions might be followed by a reduction or loss of ecosystem functions including biological control. To date, little is known about how land‐use change in the tropics alters the functional diversity of invertebrate predators and which key environmental factors may mitigate the decline in functional diversity and predation in litter and soil communities. We applied litter sieving and heat extraction to study ground spider communities and assessed structural characteristics of vegetation and parameters of litter in rainforest and agricultural land‐use systems (jungle rubber, rubber, and oil palm monocultures) in a Southeast Asian hotspot of rainforest conversion: Sumatra, Indonesia. We found that (1) spider density, species richness, functional diversity, and community predation (energy flux to spiders) were reduced by 57–98% from rainforest to oil palm monoculture; (2) jungle rubber and rubber monoculture sustained relatively high diversity and predation in ground spiders, but small cryptic spider species strongly declined; (3) high species turnover compensated losses of some functional trait combinations, but did not compensate for the overall loss of functional diversity and predation per unit area; (4) spider diversity was related to habitat structure such as amount of litter, understory density, and understory height, while spider predation was better explained by plant diversity. Management practices that increase habitat‐structural complexity and plant diversity such as mulching, reduced weeding, and intercropping monocultures with other plants may contribute to maintaining functional diversity of and predation services provided by ground invertebrate communities in plantations

Chemical and structural investigations on uranium oxide-based microparticles as reference materials for analytical measurements

The analysis of individual micrometre- and submicrometre-sized particles collected by IAEA’s safeguards inspectors on swipe samples during in-field verification activities requires the implementation of a sustainable quality control system such as suitable microparticulate reference materials. To this end, pure and neodymium-doped uranium oxide-based microparticles utilising an aerosol-based particle production process were prepared. SEM/EDX measurements confirmed the monodispersity of the produced microspheres as well as the incorporation of 15 mol% Nd into the compound particles. The timeline of structural investigations mirror the ongoing alteration of particles being stored under laboratory atmosphere. While results from in-SEM Raman (CEA, DAM) on microparticles after two years storage time point to the formation of U3O8 and a minor fraction of schoepite phase (hydrated UO3), in U L3-edge XAFS after four months storage time and U M4-edge HR-XANES after ten months storage time spectra (INE-Beamline and ACT station @ KIT synchrotron radiation source) mainly U(IV) and U(V), respectively, was observed. These results provide new insight into ageing mechanism of the microparticles after preparation. From these results important conclusions with respect to storage conditions and shelf life of the reference particles can be drawn. The first batch of pure U-oxide microparticles produced in Juelich was successfully certified regarding the isotopic composition and the U amount per particle and applied in an international laboratory exercise NUSIMEP-9

Clinical implications of AGR2 in primary prostate cancer: Results from a large-scale study

Human anterior gradient-2 (AGR2) has been implicated in carcinogenesis of various solid tumours, but the expression data in prostate cancer are contradictory regarding its prognostic value. The objective of this study is to evaluate the expression of AGR2 in a large prostate cancer cohort and to correlate it with clinicopathological data. AGR2 protein expression was analysed immunohistochemically in 1023 well-characterized prostate cancer samples with a validated antibody. AGR2 expression levels in carcinomas were compared with matched tissue samples of adjacent normal glands. AGR2 expression levels were dichotomized and tested for statistical significance. Increased AGR2 expression was found in 93.5% of prostate cancer cases. AGR2 levels were significantly higher in prostate cancer compared with normal prostate tissue. A gradual loss of AGR2 expression was associated with increasing tumour grade (ISUP), and AGR2 expression is inversely related to patient survival, however, multivariable significance is not achieved. AGR2 is clearly upregulated in the majority of prostate cancer cases, yet a true diagnostic value appears unlikely. In spite of the negative correlation of AGR2 expression with increasing tumour grade, no independent prognostic significance was found in this large-scale study