137 research outputs found
Analysis of the energy consumption of a rotary harrow
This paper shows the development and study of a FEM model of a rotary harrow. A proper use of a
rotary harrow depends on its geometry and on the working parameters, such as: drag speed and
angular speed. The aim of this work is to develop a rotary harrow model in the ANSYS environment
in order to analyze and to optimize its geometric parameters. The model, validated through
comparison with some experimental data, was then used to analyze the forces exchanged between the
tines and the soil as a function of the drag speed, the angular speed and the working depth. Different
tine orientations and three different types of terrain were considere
Self-Other Positioning in Obesity: A Pilot Study Using Repertory Grid Technique
Self-other positioning was investigated in a group of obese youths in order to empirically test the clinical hy-pothesis – based on the constructionist theory
of Family Semantic Polarities – that obese people are affected by a negative
self-perception and low self-esteem. Repertory grid technique was used with 30
participants (15 obese-overweight and 15 control) to elicit and compare their personal constructs and assess, via ad hoc measurement indices, the positions they as-
signed to the self and significant others in relation to these constructs. The results confirmed
the research hypotheses, with obese subjects displaying a tendency to pos
ition both self and others at the negative pole of bipolar constructs and reporting greater self-ideal discrepancy. These findings and their limitations are discussed in relation to their clinical applications and in light of the methodologi cal issues arising from the study
Comparison of source apportionment approaches and analysis of non-linearity in a real case model application
Abstract. The response of particulate matter (PM) concentrations to emission reductions was analysed by assessing the results obtained with two different source apportionment approaches. The brute force (BF) method source impacts, computed at various emission reduction levels using two chemical transport models (CAMx and FARM), were compared with the contributions obtained with the tagged species (TS) approach (CAMx with the PSAT module). The study focused on the main sources of secondary inorganic aerosol precursors in the Po Valley (northern Italy): agriculture, road transport, industry and residential combustion. The interaction terms between different sources obtained from a factor decomposition analysis were used as indicators of non-linear PM10 concentration responses to individual source emission reductions. Moreover, such interaction terms were analysed in light of the free ammonia / total nitrate gas ratio to determine the relationships between the chemical regime and the non-linearity at selected sites. The impacts of the different sources were not proportional to the emission reductions, and such non-linearity was most relevant for 100 % emission reduction levels compared with smaller reduction levels (50 % and 20 %). Such differences between emission reduction levels were connected to the extent to which they modify the chemical regime in the base case. Non-linearity was mainly associated with agriculture and the interaction of this source with road transport and, to a lesser extent, with industry. Actually, the mass concentrations of PM10 allocated to agriculture by the TS and BF approaches were significantly different when a 100 % emission reduction was applied. However, in many situations the non-linearity in PM10 annual average source allocation was negligible, and the TS and BF approaches provided comparable results. PM mass concentrations attributed to the same sources by TS and BF were highly comparable in terms of spatial patterns and quantification of the source allocation for industry, transport and residential combustion. The conclusions obtained in this study for PM10 are also applicable to PM2.5
A web-based health technology assessment in tele-echocardiography: the experience within an Italian project
Due to major advances in the information technology, telemedicine applications are ready for a widespread use. Nonetheless, to allow their diffusion in National Health Care Systems (NHCSs) specific methodologies of health technology assessment (HTA ) should be used to assess the standardization, the overall quality, the interoperability, the addressing to legal, economic and cost benefit aspects. One of the limits to the diffusion of the digital tele-echocardiography (T-E) applications in the NHCS lacking of a specific methodology for the HTA . In the present study, a solution offering a structured HTA of T-E products was designed. The methodology assured also the definition of standardized quality levels for the application. The first level represents the minimum level of acceptance; the other levels are accessory levels useful for a more accurate assessment of the product. The methodology showed to be useful to rationalize the process of standardization and has received a high degree of acceptance by the subjects involved in the study.Grazie ai grandi progressi nell\u27information technology le applicazioni di telemedicina sono mature per un uso diffuso. Tuttavia per permettere la loro introduzione nel sistema sanitario nazionale devono essere utilizzate specifiche metodologie di health technology assessment (HTA ) per valutare il grado di standardizzazione, la qualit? totale, l\u27interoperabilit?, il rispetto dei requisiti legali ed economici e il rapporto costo-beneficio. Con riferimento alla tele-ecocardiografia digitale uno dei limiti ? la mancanza di una specifica metodologia di HTA . Nel presente studio, ? stata proposta una soluzione che offre un HTA strutturato di prodotti di tele-ecocardiografia (T-E) digitale. La metodologia ha assicurato anche la definizione di livelli standardizzati di qualit? per l\u27applicazione. Il primo livello rappresenta il livello minimo di accettazione; gli altri livelli riguardano aspetti accessori e sono utili per una pi? accurata valutazione del prodotto. La metodologia si ? mostrata di utilit? per razionalizzare il processo di standardizzazione ed ha ricevuto un elevato grado di accettazione dei soggetti coinvolti
Procedure di record linkage in epidemiologia: uno studio multicentrico italiano, Record-linkage procedures in epidemiology: an italian multicentre study
Abstract Objective: to compare record linkage (RL) procedures adopted in several Italian settings and a standard probabilistic RL procedure for matching data from electronic health care databases. Design: two health care archives are matched: the hospital discharges (HD) archive and the population registry of four Italian areas. Exact deterministic, stepwise deterministic techniques and a standard probabilistic RL procedure are applied to match HD for acute myocardial infarction (AMI) and diabetes mellitus. Sensitivity and specificity for RL procedures are estimated after manual review. Age and gender standardized annual hospitalization rates for AMI and diabetes are computed using different RL procedures and compared
An Italian Multicenter Perspective Harmonization Trial for the Assessment of MET Exon 14 Skipping Mutations in Standard Reference Samples
Lung cancer remains the leading cause of cancer deaths worldwide. International societies have promoted the molecular analysis of MET proto-oncogene, receptor tyrosine kinase (MET) exon 14 skipping for the clinical stratification of non-small cell lung cancer (NSCLC) patients. Different technical approaches are available to detect MET exon 14 skipping in routine practice. Here, the technical performance and reproducibility of testing strategies for MET exon 14 skipping carried out in various centers were evaluated. In this retrospective study, each institution received a set (n = 10) of a customized artificial formalin-fixed paraffin-embedded (FFPE) cell line (Custom METex14 skipping FFPE block) that harbored the MET exon 14 skipping mutation (Seracare Life Sciences, Milford, MA, USA), which was previously validated by the Predictive Molecular Pathology Laboratory at the University of Naples Federico II. Each participating institution managed the reference slides according to their internal routine workflow. MET exon 14 skipping was successfully detected by all participating institutions. Molecular analysis highlighted a median Cq cut off of 29.3 (ranging from 27.1 to 30.7) and 2514 (ranging from 160 to 7526) read counts for real-time polymerase chain reaction (RT-PCR) and NGS-based analyses, respectively. Artificial reference slides were a valid tool to harmonize technical workflows in the evaluation of MET exon 14 skipping molecular alterations in routine practice
Role of DNA repair machinery and p53 in the testicular germ cell cancer: a review
Notwithstanding the peculiar sensitivity to cisplatin-based treatment, resulting in a very high percentage of cures even in advanced stages of the disease, still we do not know the biological mechanisms that make Testicular Germ Cell Tumor (TGCT) "unique" in the oncology scene. p53 and MDM2 seem to play a pivotal role, according to several in vitro observations, but no correlation has been found between their mutational or expression status in tissue samples and patients clinical outcome. Furthermore, other players seem to be on stage: DNA Damage Repair Machinery (DDR) , especially Homologous Recombination (HR) proteins, above all Ataxia Telangiectasia Mutated (ATM), cooperates with p53 in response to DNA damage, activating apoptotic cascade and contributing to cell "fate". Homologous Recombination deficiency has been assumed to be a Germ Cell Tumor characteristic underlying platinum-sensitivity, whereby Poly(ADP-ribose) polymerase (PARP), an enzyme involved in HR DNA repair, is an intriguing target: PARP inhibitors have already entered in clinical practice of other malignancies and trials are recruiting TGCT patients in order to validate their role in this disease. This paper aims to summarize evidence, trying to outline an overview of DDR implications not only in TGCT curability, but also in resistance to chemotherapy
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
- …