Convergence of large deviation estimators

We study the convergence of statistical estimators used in the estimation of large deviation functions describing the fluctuations of equilibrium, nonequilibrium, and manmade stochastic systems. We give conditions for the convergence of these estimators with sample size, based on the boundedness or unboundedness of the quantity sampled, and discuss how statistical errors should be defined in different parts of the convergence region. Our results shed light on previous reports of 'phase transitions' in the statistics of free energy estimators and establish a general framework for reliably estimating large deviation functions from simulation and experimental data and identifying parameter regions where this estimation converges.Comment: 13 pages, 6 figures. v2: corrections focusing the paper on large deviations; v3: minor corrections, close to published versio

Managing rare and undetectable events in risk assessment: the case of a satellite system launch project

Assessing the wide diversity of risk types in large and complex projects using the traditional hyperbolic iso-risks curves may seem a simplistic and reductive approach, and evaluating the risk factor through the multiplication of likelihood and severity parameters results in defining as dangerous those risks that are associated either with rare but devastating consequences or with probable but minor effects. In this work, the authors aimed at focusing on those risks that, despite their low occurrence probability, may significantly compromise a project result. To this extent, a different formula has been used to compute the risk factor, keeping into account risk detectability and evaluating the potential consequences in four different domains (cost, time, performance, reputation). This approach has been validated on the case of a large industrial project related to the launch of an innovative mobile telecommunications system, collecting the experts' opinions in a primary Italian firm in aerospace industry

Olfactory evaluation in obstructive sleep apnoea patients

The sense of smell has a high impact on the quality of life. The aim of the present study was to investigate olfactory dysfunction in patients with obstructive sleep apnoea syndrome (OSAS) and correlate the severity of disease with olfactory dysfunction. The relationships between nasal obstruction, nasal mucociliary cleareance and olfactory tests were also evaluated. Sixty patients with a diagnosis of OSAS were enrolled and underwent olfactory function evaluation. In all patients olfactory performance was tested with the Sniffin’ Sticks method. Mucociliary transport times and anterior rhinomanometry were performed to identify eventual nasal obstruction and deficits in nasal mucociliary clearance. Olfactory dysfunction was present in 22 (36.6%) patients of the study group: of these, hyposmia was present in 19 (86.4%) and anosmia in 3 (13.6%). The mean TDI score in the study group was 30. A strong correlation between the olfactory dysfunction and severity of sleep apnoea measured using the AHI was found. Patients with OSA would seem to have a high incidence of olfactory dysfunction. The degree of olfactory dysfunction appears to be related to the severity of disease. However, other co-factors such as nasal obstruction and reduced mucociliary clearance might also play a role in of the aetiology of this condition

New Records of a Stranding Humpback Whale (Megaptera novaeangliae) in Argentine Sea and Notes on its Epibionts.

Se analizó el caso de una ballena jorobada (Megaptera novaeangliae) varada en Playa Baterías (38°58?60?S, 61°48?0?O), provincia de Buenos Aires, Argentina. El individuo era un macho juvenil de 12 metros de largo y constituye el primer ejemplar hallado completo en las costas del sudoeste bonaerense. Se tomaron medidas corporales e identificaron las especies de epibiontes asociados al ejemplar. Son escasos los registros de ballenas jorobadas provenientes del Mar Argentino, por lo estos casos son importantes para obtener datos y material de investigación que permita comprender la incidencia de los varamientos en nuestro país.We analyzed the case of a young humpback whale (Megaptera novaeangliae) which was stranded on Playa Baterías (38°58'60"S; 61°48'0"W), Buenos Aires province, Argentina. The animal was a juvenile male of 12 meters long and it is the first one found whole on the coast of southeast Buenos Aires. We took measures of the animal body and samples of epibionts. The records of humpback whales from Argentine Sea are scarce, which makes this case important to get material and information to increase our knowledge of strandings in our country.Fil: Angeletti, Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Cervellini, Patricia M.. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Massola, Victoria. Fundación para la Recepción y Asistencia de Animales Marinos; Argentina. Reserva Natural Provincial Bahía Blanca; Argentin

Meiobenthos and nematode assemblages from different deep-sea habitats of the Strait of Sicily (Central Mediterranean Sea)

Much attention is currently devoted at upgrading our knowledge on biodiversity and functioning of deep water ecosystems. Information is constantly enriched by researchers, even from basins as the long-studied Mediterranean Sea. In such a perspective, we studied meiobenthic and nematode communities inhabiting muddy sediments from three different habitats at bathyal depths in the Strait of Sicily: a cold-water coral site (CS) in the Maltese Coral Province, a muddy bottom in the same area (MS), and a hydrocarbon imprinted pockmark site (PS) in the Gela Basin. The average meiofauna density at CS (1343 ind/10 cm2) and MS (1804 ind/10 cm2) is much higher than that reported in literature for similar habitats; it is also markedly more elevated than that recorded at PS (224 ind/10 cm2). Although nematodes of the three sites show different abundances, they share similar assemblage structure. Nematodes (avg. 86%) and copepods (avg. 9.3%) were the most abundant meiofaunal taxa at all sites followed by annelids, kinorhynchs and turbellarians. Nematodes were composed by 21 families and 46 genera, with Terschellingia, as most abundant genus (12.4%), followed by Microlaimus (11%), Daptonema (11%), Thalassomonhystera (10.8%), Acantholaimus (9.5%) and Sabatieria (8.7%). The genera Thalassomonhystera, Terschellingia, Microlaimus, Daptonema, Chromadorita, Sabatieria, and Anticoma display a dominance in at least one station. The taxonomic structure of meiofaunal communities of the studied sites is rather similar but differences in relative abundance are evident

The Yellow Coral Dendrophyllia cornigera in a Warming Ocean

Ocean warming is expected to impinge detrimentally on marine ecosystems worldwide up to impose extreme environmental conditions capable to potentially jeopardize the good ecological status of scleractinian coral reefs at shallow and bathyal depths. The integration of literature records with newly acquired remotely operated vehicle (ROV) data provides an overview of the geographic distribution of the temperate coral Dendrophyllia cornigera spanning the eastern Atlantic Ocean to the whole Mediterranean Sea. In addition, we extracted temperature values at each occurrence site to define the natural range of this coral, known to maintain its physiological processes at 16\ub0C. Our results document a living temperature range between 3c7\ub0C and 17\ub0C, suggesting that the natural thermal tolerance of this eurybathic coral may represent an advantage for its survival in a progressively warming ocean

Instruções técnicas para o cultivo comercial de hortaliças em Rondônia.

Instrucoes tecnicas dirigidas a extensionistas, baseadas em trabalhos de pesquisa e unidades de observacoes, conduzidas no periodo de 1984/86, pela EMBRAPA-UEPAE Porto Velho, em varios locais do Estado. Apresentam-se meios de superar algumas limitacoes tecnicas e contribui com o crescimento da atividade olericola e Rondonia. Inclui informacoes sobre propagacao, epoca de plantio e regioes aptas para o cultivo, preparo do solo, calagem, adubacao e adubacao organica, doencas e pragas, nematoides e rotacao de culturas.bitstream/item/55039/1/Circ.Tec.110001.pd

On The Age Estimation of LBDS 53W091

The recent spectral analysis of LBDS 53W091 by Spinrad and his collaborators has suggested that this red galaxy at z=1.55 is at least 3.5 Gyr old. This imposes an important constraint on cosmology, suggesting that this galaxy formed at z > 6.5, assuming recent estimates of cosmological parameters. We have performed chi^2 tests to the continuum of this galaxy using its UV spectrum and photometric data (RJHK). We have used the updated Yi models that are based on the Yale tracks. We find it extremely difficult to reproduce such large age estimates, under the assumption of the most probable input parameters. Using the same configuration as in Spinrad et al. (solar abundance models), our analysis suggests an age of approximately 1.4 -- 1.8 Gyr. The discrepancy between Spinrad et al.'s age estimate (based on the 1997 Jimenez models) and ours originates from the large difference in the model integrated spectrum: the Jimenez models are much bluer than the Yi models and the Bruzual \& Charlot (BC) models. Preliminary tests favor the Yi and BC models. The updated age estimate of LBDS 53W091 would suggest that this galaxy formed approximately at z=2-3.Comment: LaTeX, 18 eps files Accepted for publication in ApJ (Feb 10, 2000, vol 530), uses emulateapj.st

Facility for validating technologies for the autonomous space rendezvous and docking to uncooperative targets

We present the latest advancements in the air-bearing facility installed at La Sapienza’s GN Lab in the School of Aerospace Engineering. This facility has been utilized in recent times to validate robust control laws for simultaneous attitude control and vibration active damping. The instrumentation and testbed have been restructured and enhanced to enable simulations of close proximity operations. Relative pose determination, accomplished through visual navigation as either an auxiliary or standalone system, is the first building block. Leveraging the acquired knowledge, optimal guidance and control algorithms can be tested for contactless operations (e.g. on-orbit inspection), as well as berthing and docking tasks