4,330 research outputs found
Likelihood Analysis of Cosmic Shear on Simulated and VIRMOS-DESCART Data
We present a maximum likelihood analysis of cosmological parameters from
measurements of the aperture mass up to 35 arcmin, using simulated and real
cosmic shear data. A four-dimensional parameter space is explored which
examines the mean density \Omega_M, the mass power spectrum normalization
\sigma_8, the shape parameter \Gamma and the redshift of the sources z_s.
Constraints on \Omega_M and \sigma_8 (resp. \Gamma and z_s) are then given by
marginalizing over \Gamma and z_s (resp. \Omega_M and \sigma_8). For a flat
LCDM cosmologies, using a photometric redshift prior for the sources and \Gamma
\in [0.1,0.4], we find \sigma_8=(0.57\pm0.04) \Omega_M^{(0.24\mp 0.18)
\Omega_M-0.49} at the 68% confidence level (the error budget includes
statistical noise, full cosmic variance and residual systematic). The estimate
of \Gamma, marginalized over \Omega_M \in [0.1,0.4], \sigma_8 \in [0.7,1.3] and
z_s constrained by photometric redshifts, gives \Gamma=0.25\pm 0.13 at 68%
confidence. Adopting h=0.7, a flat universe, \Gamma=0.2 and \Omega_m=0.3 we
find \sigma_8=0.98 \pm0.06 . Combined with CMB, our results suggest a non-zero
cosmological constant and provide tight constraints on \Omega_M and \sigma_8.
We finaly compare our results to the cluster abundance ones, and discuss the
possible discrepancy with the latest determinations of the cluster method. In
particular we point out the actual limitations of the mass power spectrum
prediction in the non-linear regime, and the importance for its improvement.Comment: 11 pages, submitted to A&
Ecología y comportamiento reproductivo de Eleutherodactylus aureolineatus (Anura, Brachycephalidae) del dosel de la cuenca del Amazonas Superior, Ecuador
Exploration and investigation of the anuran fauna in the canopies of the Upper Amazon Basin has led to the recent discoveries of new species of the genus Eleutherodactylus utilizing the microhabitat within bromeliads. Detailed information on the ecology and natural history of these communities are scarce due, in part, to the difficulty of accessing their habitat. New sampling methods for rainforest canopies have allowed for the collection and observation of the herpetofauna utilizing this habitat. Sexual size dimorphism in Eleutherodactylus aureolineatus, confirms placement in the E. unistrigatus species group and E. lacrimosus assemblage. The described microhabitat, vocalization characteristics, reproductive behavior and egg deposition of E. aureolineatus provides significant ecological background on this poorly documented group of frogs and their important "wetlands in the sky". The data and observations herein contribute to the overall understanding of the characters and ecological factors which define the E. lacrimosus assemblage.La exploración y la investigación de la fauna de anuros en el estrato del dosel de la cuenca del Amazonas Superior ha llevado a descubrimientos recientes de nuevas especies del genero Eleutherodactylus que utilizan el interior de las bromelidas como micro-hábitat. La información detallada en la ecología y la historia natural de estas comunidades es escasa debido en parte a la dificultad de acceso de su hábitat. Nuevos métodos de muestreo para doseles de selvas pluviales han tomado en cuenta la colecta y la observación de la herpetofauna que utiliza este hábitat. El dimorfismo sexual de tamaño en Eleutherodactylus aureolineatus confirma su posición dentro del grupo de especies de E. unistrigatus y la colección de E. lacrimosus. La descripción del micro-hábitat, características de vocalización, comportamiento reproductivo y el sitio de deposición de huevo de E. aureolineatus provee antecedentes ecológicos importantes para este grupo de ranas pobremente documentadas y sus importantes "pantanos en el cielo". Los datos y las observaciones que aquí se presentan, contribuyen a la comprensión general de los caracteres y los factores ecológicos que definen la colección de E. lacrimosus
A new species of the Eleutherodactylus lacrimosus assemblage (Anura, Brachycephalidae) from the lowland rainforest canopy of Yasuni National Park, Amazonian Ecuador
A new species of Eleutherodactylus from the lowland rainforest canopy in northeastern Amazonian Ecuador is described. It is placed in the Eleutherodactylus lacrimosus assemblage of the greater unistrigatus group. It is most similar to the sympatric species Eleutherodactylus lacrimosus, but differs by the lack of a papilla at the tip of the snout, tubercles on upper eyelids, tubercles on dorsum, dorsal markings, and larger body size, and the presence of lateral fringes on the fingers and a tarsal fold. The new species inhabits tank bromeliads in the upper strata of the rainforest canopy at heights of 23.5-38.0 m. The effects of implementation of canopy surveys on biological diversity are briefly discussed
Beyond Diagnosis: Evolving Prostate Biopsy in the Era of Focal Therapy
Despite decades of use as the “gold standard” in the detection of prostate cancer, the optimal biopsy regimen is still not universally agreed upon. While important aspects such as the need for laterally placed biopsies and the importance of apical cancer are known, repeated studies have shown significant patients with cancer on subsequent biopsy when the original biopsy was negative and an ongoing suspicion of cancer remained. Attempts to maximise the effectiveness of repeat biopsies have given rise to the alternate approaches of saturation biopsy and the transperineal approach. Recent interest in focal treatment of prostate cancer has further highlighted the need for accurate detection of prostate cancer, and in response, the introduction of transperineal template-guided biopsy. While the saturation biopsy approach and the transperineal template approach increase the detection rate of cancer in men with a previous negative biopsy and appear to have acceptable morbidity, there is a lack of clinical trials evaluating the different biopsy strategies. This paper reviews the evolution of prostatic biopsy and current controversies
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