89 research outputs found
Adams and Eves: High school math and the gender gap in Economics majors
Why so few women graduate in Economics? We investigate the gender gap among Italian university graduates in Economics between 2010 and 2019. With women's probability of graduating in Economics being 27% lower than men's, the gap is larger than in Business and even STEM. The association between the gender gap and the mathematical content of high school curricula is especially strong in Economics. A triple difference analysis shows that a reform raising the mathematical content of traditionally low math curricula caused an increase in the gender gap, with women's probability of graduating in Economics decreasing by 12 percentage points
Shaft-hub press fit subjected to couples and radial forces: analytical evaluation of the shaft-hub detachment loading
A shaft-hub press fit subjected to two non-axisymmetric loading conditions is examined and the situation
of incipient detachment between the shaft and the hub is determined. The first condition consists of a
central radial load P applied to the hub, balanced by two lateral forces P=2 applied to the shaft at a
distance d from the hub lateral walls. In the second condition, a central couple C is applied to the hub,
and it is balanced by two lateral opposite loads withstood by the shaft at a distance d from the hub
lateral walls. The shaft-hub contact is modelled in terms of two elastic Timoshenko beams connected by
distributed elastic springs (Winkler foundation), whose constant is analytically evaluated. Based upon
this enhanced beam-like modelling, the loading inducing an undesired shaft-hub incipient detachment
is theoretically determined in terms of the shaft-hub geometry, of the initial shaft-hub interference, and
of the elastic constants. Finite element forecasts are presented to quantify the error of this beam-like
approximate analytical approach
ANALYSIS OF THE LUBRICATION REGIMES AT THE SMALL END AND BIG END OF A CONNECTING ROD OF A HIGH PERFORMANCE MOTORBIKE ENGINE
ABSTRACT In the present paper, the algorithm proposed by Giacopini et. al. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account
Identifying reliable predictors of protein-energy malnutrition in hospitalized frail older adults. A prospective longitudinal study
BACKGROUND:
Decreased food intake is a risk factor for relevant complications (e.g. infections, pressure ulcers), longer hospital stays, higher readmission rates, greater health care costs and increased patient mortality, particularly in frail hospitalized older adults who are malnourished or at risk of malnutrition. Nurses are called to improve this criticality, starting from accurately identify patients for malnutrition at hospital admission and effectively monitoring their food intake.
OBJECTIVES:
The primary aim was to identify reliable predictive indicators of reduced food intake at hospital admission. The secondary aims were to assess the adequacy of daily energy and protein intake and the impact of nutrient intake on patient outcomes.
DESIGN:
Prospective observational longitudinal study.
SETTING:
Internal Medicine Ward of an Academic Teaching University Hospital.
PARTICIPANTS:
Acute older adults who were malnourished or at risk of malnutrition (Nutritional Risk Score-2002\u202f 65\u202f3, middle-upper arm circumference\u2009<23.5\u202fcm or impaired self-feeding ability) at admission.
METHODS:
The effective energy and protein intake was monitored during the first 5\u202fdays of hospital stay by a photographic method and compared to the daily energy and protein requirement calculated by specific equations. Data on anthropometry, inflammation/malnutrition laboratory data and body composition (phase\u202fangle calculated using bioelectrical impedance analysis) were collected.
RESULTS:
Eighty-one subjects (age 81.5\u202f\ub1\u202f11.5\u202fyears) were enrolled. Mean energy intake was 669.0\u202f\ub1\u202f573.9\u202fkcal/day, and mean protein intake was 30.7\u202f\ub1\u202f25.8\u202fg/day. Over 60% of patients ingested\u2009 6450% of their calculated energy and protein requirements: these patients were older (p\u202f=\u202f0.026), had a lower middle-upper arm circumference (p\u202f=\u202f0.022) and total arm area (p\u202f=\u202f0.038), a higher C-reactive protein/albumin ratio and Instant Nutritional Assessment score (p\u202f<\u202f0.01), and experienced longer hospital stays (p\u202f 64\u202f0.04) and higher in-hospital and 30-day post-discharge mortality (p\u202f<\u202f0.001). In the multivariate analysis, lower middle-upper arm circumference, higher C-reactive protein/albumin ratio, and impaired self-feeding at admission were independently associated with critically reduced energy and protein intake.
CONCLUSIONS:
Middle-upper arm circumference, C-reactive protein/albumin ratio, and impaired self-feeding are easily obtainable indicators of impaired energy and protein intake and poor clinical outcomes. Such parameters should be adopted as screening criteria to assess the risk for critically reduced energy/protein intake in hospitalized older adults. These findings are relevant to improve clinical practice through the implementation of multidisciplinary strategies, given the adverse clinical outcomes related to hospital malnutrition
Palliative care training addressed to hospital healthcare professionals by palliative care specialists: a mixed-method evaluation
Despite the great advances in the concept of palliative care (PC) and its benefits, its application seems to be delayed, leaving unfulfilled the many needs of patients and family members. One way to overcome this difficulty could be to develop a new training programme by palliative care specialists to improve PC primary skills in healthcare professionals. The aim of this study was to evaluate the training's impact on trainees within a hospital setting using Kirkpatrick's and Moore's models
Exploring mobile network data for tourism statistics: the collaboration between Istat and Vodafone Business Italia
The paper describes the collaboration between Istat and Vodafone Business Italia
to innovate and enhance tourism statistics. The common goal is to evaluate the
potential uses of mobile phone data in current surveys and to investigate new outputs
for official statistics, such as visiting routes and means of transport. The analysis
concerned inbound tourism (foreigners in Italy), domestic tourism (Italians in Italy),
and outbound tourism (Italians abroad). The work presents analyses and results for
the Province of Rimini and the Municipality of Roma, referred to August 2019/2020
and April 2020, and a trial of the use of the “Welcome SMS” for the estimate of
the residents in Italy who travel to foreign countries. Phone data required specific
treatments to meet the definitions of official statistics. Some aspects related to the
location and definition of overnight stays will require further investigation
Exploring mobile network data for tourism statistics: the collaboration between Istat and Vodafone Business Italia
The paper describes the collaboration between Istat and Vodafone Business Italia
to innovate and enhance tourism statistics. The common goal is to evaluate the
potential uses of mobile phone data in current surveys and to investigate new outputs
for official statistics, such as visiting routes and means of transport. The analysis
concerned inbound tourism (foreigners in Italy), domestic tourism (Italians in Italy),
and outbound tourism (Italians abroad). The work presents analyses and results for
the Province of Rimini and the Municipality of Roma, referred to August 2019/2020
and April 2020, and a trial of the use of the “Welcome SMS” for the estimate of
the residents in Italy who travel to foreign countries. Phone data required specific
treatments to meet the definitions of official statistics. Some aspects related to the
location and definition of overnight stays will require further investigation
Health risks related to illegal and on-line sale of drugs and food supplements: results of a survey on marketed products in Italy from 2011 to 2013
Objectives. The increasing illegal and on-line market of medicines and food supplements is helping the widespread diffusion of harmful counterfeit and forbidden products among consumers of developed countries. The objectives of this survey were the description of the main frauds recognized by public officers and the detection of illegal or counterfeit drugs and food supplements.Methods. Medicines and food supplements found by Police forces on the illegal market or resulting from seizures made by Italian Customs authorities were visually inspected and analysed to evaluate their quality and the presence of other undeclared substances.Results. The visual inspection and the chemical analysis revealed unsuitable packaging (mostly lacking of adequate information for consumers), absence of the declared active substances and presence of undeclared active substances. Products containing doping agents, illegal substances and active ingredients requiring medical supervision were found.Conclusion. The present work confirmed the health risk associated with assumption of medicines purchased on the Internet and from the illegal supply chain and evidenced a new threat to consumer safety related to the presence of pharmaceutical active ingredients in food supplements claiming to contain only “natural ingredients”.
A computational framework for testing hypotheses of the minimal mechanical requirements for cell aggregation using early annual killifish embryogenesis as a model
Introduction: Deciphering the biological and physical requirements for the outset of multicellularity is limited to few experimental models. The early embryonic development of annual killifish represents an almost unique opportunity to investigate de novo cellular aggregation in a vertebrate model. As an adaptation to seasonal drought, annual killifish employs a unique developmental pattern in which embryogenesis occurs only after undifferentiated embryonic cells have completed epiboly and dispersed in low density on the egg surface. Therefore, the first stage of embryogenesis requires the congregation of embryonic cells at one pole of the egg to form a single aggregate that later gives rise to the embryo proper. This unique process presents an opportunity to dissect the self-organizing principles involved in early organization of embryonic stem cells. Indeed, the physical and biological processes required to form the aggregate of embryonic cells are currently unknown.Methods: Here, we developed an in silico, agent-based biophysical model that allows testing how cell-specific and environmental properties could determine the aggregation dynamics of early Killifish embryogenesis. In a forward engineering approach, we then proceeded to test two hypotheses for cell aggregation (cell-autonomous and a simple taxis model) as a proof of concept of modeling feasibility. In a first approach (cell autonomous system), we considered how intrinsic biophysical properties of the cells such as motility, polarity, density, and the interplay between cell adhesion and contact inhibition of locomotion drive cell aggregation into self-organized clusters. Second, we included guidance of cell migration through a simple taxis mechanism to resemble the activity of an organizing center found in several developmental models.Results: Our numerical simulations showed that random migration combined with low cell-cell adhesion is sufficient to maintain cells in dispersion and that aggregation can indeed arise spontaneously under a limited set of conditions, but, without environmental guidance, the dynamics and resulting structures do not recapitulate in vivo observations.Discussion: Thus, an environmental guidance cue seems to be required for correct execution of early aggregation in early killifish development. However, the nature of this cue (e.g., chemical or mechanical) can only be determined experimentally. Our model provides a predictive tool that could be used to better characterize the process and, importantly, to design informed experimental strategies
Three-row versus two-row circular staplers for left-sided colorectal anastomosis: a propensity score-matched analysis of the iCral 2 and 3 prospective cohorts
Background: Since most anastomoses after left-sided colorectal resections are performed with a circular stapler, any technological change in stapling devices may influence the incidence of anastomotic adverse events. The aim of the present study was to analyze the effect of a three-row circular stapler on anastomotic leakage and related morbidity after left-sided colorectal resections. Materials and methods: A circular stapled anastomosis was performed in 4255 (50.9%) out of 8359 patients enrolled in two prospective multicenter studies in Italy, and, after exclusion criteria to reduce heterogeneity, 2799 (65.8%) cases were retrospectively analyzed through a 1:1 propensity score-matching model including 20 covariates relative to patient characteristics, to surgery and to perioperative management. Two well-balanced groups of 425 patients each were obtained: group (A) – true population of interest, anastomosis performed with a three-row circular stapler; group (B) – control population, anastomosis performed with a two-row circular stapler. The target of inferences was the average treatment effect in the treated (ATT). The primary endpoints were overall and major anastomotic leakage and overall anastomotic bleeding; the secondary endpoints were overall and major morbidity and mortality rates. The results of multiple logistic regression analyses for the outcomes, including the 20 covariates selected for matching, were presented as odds ratios (OR) and 95% confidence intervals (95% CI). Results: Group A versus group B showed a significantly lower risk of overall anastomotic leakage (2.1 vs. 6.1%; OR 0.33; 95% CI 0.15–0.73; P = 0.006), major anastomotic leakage (2.1 vs. 5.2%; OR 0.39; 95% CI 0.17–0.87; P = 0.022), and major morbidity (3.5 vs. 6.6% events; OR 0.47; 95% CI 0.24–0.91; P = 0.026). Conclusion: The use of three-row circular staplers independently reduced the risk of anastomotic leakage and related morbidity after left-sided colorectal resection. Twenty-five patients were required to avoid one leakage
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