386 research outputs found
Teams in New Ventures: Gender, Human Capital and Motivation
Purpose- This paper dismantles the idea that sex per se explains entrepreneurial outcomes and demonstrates the influence of a gendered motivation on forging and shaping new venture teams, which is a disruptive choice affecting the future of start-ups.
Methods- A two-level research model is validated on data from the PSED II, with a system of simultaneous equations. Firstly, we test if team features affect the performance of new ventures; then, we investigate determinants of team features with a focus on sex and motivation of nascent entrepreneurs.
Findings- Human capital (HC) in terms of education and experience of team members consistently explains
venture evolution only when considering the larger team of affiliates. The HC gathered by nascent
entrepreneurs is not due to the simplistic sex condition, but rather to a gendered motivation related to the
inferior need of achievement of women.
Research limitations- Limitations of discretionary scoring assigned to items of the PSED II survey are
present, but unavoidable when processing qualitative data.
Social and Practical implications- Women need to be (culturally) educated on how to re-balance their
personal motivation towards entrepreneurship by fostering their incentives for achievement. Political and
educational programs could trigger success in the creation of new businesses led by women.
Originality/value- This paper contributes to the literature on nascent entrepreneurship, focusing on the
entrepreneurial teams in the initial phase of business creation, and provides the basis for further studies
aimed at eradicating the stereotypes of gender roles that lead women to self-exclusion and organizational
errors
A Resilience and Robustness Oriented Design of Base-Isolated Structures: The New Camerino University Research Center
This paper analyses the new Research Centre designed for the University of Camerino and entirely financed by the national Civil Protection Department (DPC), following the seismic events in Central Italy in 2016. The building has been designed to guarantee speed of execution as well as a high level of safety, especially regarding seismic actions. The structural solution was to create an isolated system with a steel braced super-structure with pinned joints and r.c. sub-structures able to adapt to the complex morphology of the area. As described in the first part of the paper, design choices have been made to achieve a high level of resilience and robustness, i.e., to limit damage to structural and non-structural components and equipment under moderate and design seismic actions and to avoid disproportionate consequences in the event of extreme actions, larger than the design ones. In the second part of the paper, specific risk analyses have been carried out to evaluate the real performance of the building under increasing intensity levels, with reference to both serviceability and ultimate conditions. To this purpose a site-specific hazard study was first conducted, then non-linear analyses were performed using a hazard-consistent set of records with return periods ranging from TR = 60 years to TR = 10000 years. The main demand parameters of both the isolation system and the super-structure were recorded and capacity values corresponding to different ultimate and damage limit conditions were defined. The results obtained in terms of demand hazard curves show that the building performances in terms of robustness and resilience are very high, confirming the efficacy of the strategies adopted in the design
A new indirect measurement method of the electron temperature for the Protosphera's pinch plasma
This article presents a new method for estimating the electron temperature of
the Protosphera's screw pinch. The temperature radial profile is obtained by a
self-consistent modeling of a 1D MHD equilibrium along with a 0D power balance
of the plasma column, given measurements and estimates of the axial pinch
plasma current, of the plasma rotational frequency and, at the equatorial
plane, of the electron density radial profile, of the edge poloidal magnetic
field, of the edge electron temperature and of the neutrals pressure in the
vacuum vessel. The plasma is considered in equilibrium with its neutral phase
and in constant rotation. A MATLAB code has been developed with the aim of
estimating the MHD radial equilibrium profiles, the thermodynamic plasma state
and the neutrals profile. The numerical estimates are compared with available
experimental data showing a good agreement.Comment: 4 pages, 6 figures, 1 table, research presented to the "6th ICFDT
COVID-19 in patients with hematologic disorders undergoing therapy: perspective of a large referral hematology center in Rome
Introduction: Patients with cancer may be more susceptible to and have higher morbidity and mortality rates from COVID-19 than the general population, while epidemiologic data specifically addressed to hematologic patients are limited. To investigate whether patients with hematologic diseases undergoing therapy are at increased risk for acquiring SARS CoV-2 infection compared to the general population, a retrospective study was carried out at a referral hematologic center in Rome, Italy, during the period of the greatest epidemic spread (March 8 to May 14, 2020). Methods: All adult and pediatric patients with a diagnosis of a neoplastic or a nonneoplastic hematologic disease who underwent treatment (chemotherapy or immunosuppressive or supportive therapy) during the study period or in the previous 6 months were considered. The prevalence of COVID-19 in the overall outpatient and inpatient population undergoing hematologic treatment compared to that of the general population was analyzed. The measures taken to manage patients during the epidemic period are described. Results: Overall, 2,513 patients with hematological diseases were considered. Out of 243 (9.7%) patients who were screened for SARS CoV-2, three of 119 (2.5%) outpatients with fever or respiratory symptoms and none of 124 asymptomatic patients were diagnosed with COVID-19. Three further patients were diagnosed with COVID-19 and managed in other hospitals in Rome. As of May 14, 2020, the prevalence of COVID-19 in our hematologic population accounted for 0.24% (95% CI 0.23-0.25; 6 of 2,513 patients: 1 case in every 419 patients) as compared to 0.12% (7,280 of 5,879,082 residents; 1 case in every 807 residents) in the general population (p = 0.14). Three of 6 patients diagnosed with COVID-19 required critical care and 2 died while still positive for SARS CoV-2. Out of 225 healthcare providers on duty at our Institution during the study period, 2 (0.9%) symptomatic cases were diagnosed with COVID-19. Conclusion: In our experience, the prevalence of COVID-19 in hematologic patients, mainly affected by malignancies, was not significantly higher compared to that of the general population. Definition of adapted strategies for healthcare services, while continuing to administer the standard hematologic treatments, represents the crucial challenge for the management of hematologic diseases in the COVID-19 era
Aerodynamic investigations of ventilated brake discs.
The heat dissipation and performance of a ventilated brake disc strongly depends
on the aerodynamic characteristics of the flow through the rotor passages. The
aim of this investigation was to provide an improved understanding of ventilated
brake rotor flow phenomena, with a view to improving heat dissipation, as well
as providing a measurement data set for validation of computational fluid
dynamics methods. The flow fields at the exit of four different brake rotor
geometries, rotated in free air, were measured using a five-hole pressure probe
and a hot-wire anemometry system. The principal measurements were taken using
two-component hot-wire techniques and were used to determine mean and unsteady
flow characteristics at the exit of the brake rotors. Using phase-locked data
processing, it was possible to reveal the spatial and temporal flow variation
within individual rotor passages. The effects of disc geometry and rotational
speed on the mean flow, passage turbulence intensity, and mass flow were
determined. The rotor exit jet and wake flow were clearly observed as
characterized by the passage geometry as well as definite regions of high and
low turbulence. The aerodynamic flow characteristics were found to be reasonably
independent of rotational speed but highly dependent upon rotor geometry
Levofloxacin to prevent bacterial infection in patients with cancer and neutropenia.
BACKGROUND:
The prophylactic use of fluoroquinolones in patients with cancer and neutropenia is controversial and is not a recommended intervention.
METHODS:
We randomly assigned 760 consecutive adult patients with cancer in whom chemotherapy-induced neutropenia (<1000 neutrophils per cubic millimeter) was expected to occur for more than seven days to receive either oral levofloxacin (500 mg daily) or placebo from the start of chemotherapy until the resolution of neutropenia. Patients were stratified according to their underlying disease (acute leukemia vs. solid tumor or lymphoma).
RESULTS:
An intention-to-treat analysis showed that fever was present for the duration of neutropenia in 65 percent of patients who received levofloxacin prophylaxis, as compared with 85 percent of those receiving placebo (243 of 375 vs. 308 of 363; relative risk, 0.76; absolute difference in risk, -20 percent; 95 percent confidence interval, -26 to -14 percent; P=0.001). The levofloxacin group had a lower rate of microbiologically documented infections (absolute difference in risk, -17 percent; 95 percent confidence interval, -24 to -10 percent; P<0.001), bacteremias (difference in risk, -16 percent; 95 percent confidence interval, -22 to -9 percent; P<0.001), and single-agent gram-negative bacteremias (difference in risk, -7 percent; 95 percent confidence interval, -10 to -2 percent; P<0.01) than did the placebo group. Mortality and tolerability were similar in the two groups. The effects of prophylaxis were also similar between patients with acute leukemia and those with solid tumors or lymphoma.
CONCLUSIONS:
Prophylactic treatment with levofloxacin is an effective and well-tolerated way of preventing febrile episodes and other relevant infection-related outcomes in patients with cancer and profound and protracted neutropenia. The long-term effect of this intervention on microbial resistance in the community is not known
Current drive at plasma densities required for thermonuclear reactors
Progress in thermonuclear fusion energy research based on deuterium plasmas magnetically confined in toroidal tokamak devices requires the development of efficient current drive methods. Previous experiments have shown that plasma current can be driven effectively by externally launched radio frequency power coupled to lower hybrid plasma waves. However, at the high plasma densities required for fusion power plants, the coupled radio frequency power does not penetrate into the plasma core, possibly because of strong wave interactions with the plasma edge. Here we show experiments performed on FTU (Frascati Tokamak Upgrade) based on theoretical predictions that nonlinear interactions diminish when the peripheral plasma electron temperature is high, allowing significant wave penetration at high density. The results show that the coupled radio frequency power can penetrate into high-density plasmas due to weaker plasma edge effects, thus extending the effective range of lower hybrid current drive towards the domain relevant for fusion reactors
Corrigendum: Current drive at plasma densities required for thermonuclear reactors
Nature Communications 1: Article number: 55 (2010); Published: 10 August 2010; Updated:19 September 2013. In Fig. 3 of this Article, the colours of the blue and green curves were accidentally interchanged while the manuscript was being revised. In addition, the x axis labels on Fig. 4 should have read 'Frequency (MHz)'
Predicting hemoglobin levels in whole blood donors using transition models and mixed effects models
Invasive fungal infections in neutropenic enterocolitis: A systematic analysis of pathogens, incidence, treatment and mortality in adult patients
BACKGROUND: Neutropenic enterocolitis is a life-threatening complication most frequently occurring after intensive chemotherapy in acute leukaemias. Gramnegative bacteria constitute the most important group of causative pathogens. Fungi have also been reported, but their practical relevance remains unclear. The guidelines do not address concrete treatment recommendations for fungal neutropenic enterocolitis. METHODS: Here, we conducted a metaanalysis to answer the questions: What are frequency and mortality of fungal neutropenic enterocolitis? Do frequencies and microbiological distribution of causative fungi support empirical antimycotic therapy? Do reported results of antimycotic therapy in documented fungal neutropenic enterocolitis help with the selection of appropriate drugs? Following a systematic search, we extracted and summarised all detail data from the complete literature. RESULTS: Among 186 articles describing patients with neutropenic enterocolitis, we found 29 reports describing 53 patients with causative fungal pathogens. We found no randomised controlled trial, no good quality cohort study and no good quality case control study on the role of antifungal treatment. The pooled frequency of fungal neutropenic enterocolitis was 6.2% calculated from all 860 reported patients and 3.4% calculated from selected representative studies only. In 94% of the patients, Candida spp. were involved. The pooled mortality rate was 81.8%. Most authors did not report or perform antifungal therapy. CONCLUSION: In patients with neutropenic enterocolitis, fungal pathogens play a relevant, but secondary role compared to bacteria. Evidence concerning therapy is very poor, but epidemiological data from this study may provide helpful clues to select empiric antifungal therapy in neutropenic enterocolitis
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