Dynamics of Nanosecond Laser Pulse Propagation and of Associated Instabilities in a Magnetized Underdense Plasma.

The propagation and energy coupling of intense laser beams in plasmas are critical issues in inertial confinement fusion. Applying magnetic fields to such a setup has been shown to enhance fuel confinement and heating. Here we report on experimental measurements demonstrating improved transmission and increased smoothing of a high-power laser beam propagating in a magnetized underdense plasma. We also measure enhanced backscattering, which our kinetic simulations show is due to magnetic confinement of hot electrons, thus leading to reduced target preheating.

Survival probability during one-year follow-up after index hospitalization for heart failure: an Italian retrospective study.

Background: Heart failure affects about 64 million people worldwide, and despite the economic resources employed to improve its prognosis, mortality is still alarming. The aim of this study was to investigate the impact of patients' characteristics on survival probability during one-year follow-up after an index hospitalization for heart failure. Study design: A three-year retrospective study was conducted on the records of the Hospitals belonging the Local Health Unit of L'Aquila, a Healthcare Facility located in the centre of Italy. Methods: Patients admitted to hospital with a heart failure event as main diagnosis were selected and followed up for one year after their discharge to obtain data for survival analysis. Results: During the observational period for 1,929 patients hospitalized with a Heart failure index event, 1,655 (85.8%) of them were discharged alive and followed up for one year after the discharge. Fourteen percent of patients (n = 232) died for reasons related to Heart failure during the follow-up period. Fifty percent of them (n = 116), died within three months from the index hospitalization discharge. Age ≥75 years (HR 3.192, 95% CI 1.964-5.188), discharging to home (HR 0.399, 95% CI 0.297-0.536), length of stay ≥8 days during the index hospitalization (HR 1.533, 95% CI 1.163-2.019), and high education level (HR 0.517, 95% CI 0.273-0.977), were found to be associated with the survival probability. Conclusion: Study results indicate that older patients, especially those with a low educational level, those with longer index hospitalization, and those not sent directly to home, deserve more care and attention after discharge.

Sociocultural overview and predisposing factors of body art in a health promotion perspective: survey on a sample of Italian young adults.

Background: The body art (tattoos, body piercing and other aesthetic practices) is increasing at global level and involves different aspects of public health, from epidemiological feature to cultural and psychosocial determinants and regulatory issues. The study is aimed at estimating the prevalence of tattooed and pierced in youth, focusing on emerging profiles. Study design: A cross-sectional study has been conducted on 575 students at the first year of degree courses of an Italian University. Methods: Students were asked to fill an online questionnaire. Logistic regression models were evaluated in order to identify predictive factors and determinants of practice (tattoos, piercing, body art). Results: The 41.9% of participants underwent at least one body art intervention, with a higher prevalence in females. Multivariate logistic regression suggested an association of body art practice with type of school and university course, as well as lifestyle characteristics (smoking, alcohol abuse). In addition, the intention to undergo to body art intervention in the future appeared significantly higher in women and more frequent in apparently 'protected' categories such as medical students and non-problematic alcohol users. Conclusions: The study confirmed the importance of the surveillance and social and behavioural research on body art practice and suggested different health promotion perspectives, such as early intervention towards adolescents and late intervention towards young adults belonging to lesser risky population groups.

Analysing spectral changes over time to identify articulatory impairments in dysarthria.

Identifying characteristics of articulatory impairment in speech motor disorders is complicated due to the time-consuming nature of kinematic measures. The goal is to explore whether analysing the acoustic signal in terms of total squared changes of Mel-Frequency Cepstral Coefficients (TSC_MFCC) and its pattern over time provides sufficient spectral information to distinguish mild and moderate dysarthric French speakers with Amyotrophic Lateral Sclerosis (ALS) and Parkinson's Disease (PD) from each other and from healthy speakers. Participants produced the vowel-glide sequences /ajajaj/, /ujujuj/, and /wiwiwi/. From the time course of TSC_MFCCs, event-related and global measures were extracted to capture the degree of acoustic change and its variability. In addition, durational measures were obtained. For both mild and moderately impaired PD and ALS speakers, the degree of acoustic change and its variability, averaged over the complete contour, separated PD and ALS speakers from each other and from healthy speakers, especially when producing the sequences /ujujuj/ and /wiwiwi/. Durational measures separated the moderate ALS from healthy and moderate PD speakers. Using the approach on repetitive sequences targeting the lingual and labial articulators to characterize articulatory impairment in speech motor disorders is promising. Findings are discussed against prior findings of articulatory impairment in the populations studied.

Laser-Plasma Interaction Experiment for Solar Burst Studies.

A new experimental platform based on laser-plasma interaction is proposed to explore the fundamental processes of wave coupling at the origin of interplanetary radio emissions. It is applied to the study of electromagnetic (EM) emission at twice the plasma frequency (2ω_{p}) observed during solar bursts and thought to result from the coalescence of two Langmuir waves (LWs). In the interplanetary medium, the first LW is excited by electron beams, while the second is generated by electrostatic decay of Langmuir waves. In the present experiment, instead of an electron beam, an energetic laser propagating through a plasma excites the primary LW, with characteristics close to those at near-Earth orbit. The EM radiation at 2ω_{p} is observed at different angles. Its intensity, spectral evolution, and polarization confirm the LW-coalescence scenario.

Nurses' and physicians' opinions on end-of-life: a secondary analysis from an Italian cross-sectional study.

BACKGROUND: In daily clinical practice, healthcare workers face end-of-life issues, such as futility, which is generally defined as the provision of treatments that do not produce any meaningful benefit for patients. STUDY DESIGN: To investigate the end-of-life issues according to Italian nurses' and physicians' opinions and to detect any differences between them, a secondary analysis of existing data from a cross-sectional study was conducted. METHODS: A validated questionnaire was used involving 351 nurses and 128 physicians from four hospitals in Central Italy. RESULTS: Regarding the definition of futility, nurses mainly focused on agony, suffering, and risks, while physicians paid more attention to the hope of healing. Nevertheless, both were distressed by different aspects of the treatments; in particular, nurses by the 'invasiveness of the treatments' and physicians by the 'over-medicalization of death'. Instead, nurses and physicians similarly recognized patients' right to seek to anticipate the end of life when they are terminally-ill and to express freely their desire not to be revived. CONCLUSIONS: The description of experiences and opinions of health professionals could represent a valid basis to develop a 'regulatory system' aimed to guide and support daily clinical and nursing activities.

Dynamics of the Electromagnetic Fields Induced by Fast Electron Propagation in Near-Solid-Density Media.

The propagation of fast electron currents in near solid-density media was investigated via proton probing. Fast currents were generated inside dielectric foams via irradiation with a short (∼0.6 ps) laser pulse focused at relativistic intensities (Iλ^{2}∼4×10^{19} W cm^{-2} µm^{2}). Proton probing provided a spatially and temporally resolved characterization of the evolution of the electromagnetic fields and of the associated net currents directly inside the target. The progressive growth of beam filamentation was temporally resolved and information on the divergence of the fast electron beam was obtained. Hybrid simulations of electron propagation in dense media indicate that resistive effects provide a major contribution to field generation and explain well the topology, magnitude, and temporal growth of the fields observed in the experiment. Estimations of the growth rates for different types of instabilities pinpoints the resistive instability as the most likely dominant mechanism of beam filamentation.

Evaluation of the perception of clinical competencies by nursing students in the different clinical settings: an observational study.

INTRODUCTION: The university educational sphere has many dilemmas. The question of sufficient knowledge and skills for students to acquire abilities to provide care in different clinical setting is one important dilemma. AIM: To measure the level of competencies by nursing students and its application in different clinical environments. METHODS: Nursing students of two Italian universities participated in the research. Data collection took place April to July 2015 using the Nurse Competence Scale. The Strengthening Reporting of Observational Studies in Epidemiology Guidelines was used to describe the study. Pearson's chi-square test, Student's t test, and regression tests were used for statistical analysis. RESULTS: The questionnaire response rate was 87.27% (n = 698). Most of the nursing students assessed their level of competency as 'good' and evaluated themselves as more competent than their actual nursing role. Students also appraised themselves as competent either via their clinical practices accomplished or in the therapeutic interventions. CONCLUSION: This study shows that the self-evaluation of the competencies acquired by nursing students in clinical settings in Latium and Abruzzo is of a good standard. This study also affirms that NCS is a valuable and reliable tool to measure clinical competencies in different clinical settings.

Nurse Competence Scale: psychometric assessment in the Italian context.

INTRODUCTION: The Nurse Competence Scale is a tool for evaluating nursing clinical competence. This tool has been used and psychometrically validated previously in different countries but never in Italy. Assessing the validity and reliability of the Nurse Competence Scale in the Italian context has been a strong necessity for many years. AIM: To test the psychometric properties and evaluate the internal construct validity of the Italian version of the Nurse Competence Scale. METHODS: This study is a secondary analysis on a database of 698 bachelor nursing students who were trained in different clinical settings at two Italian universities. Internal consistency was examined with Cronbach's alpha coefficients and inter-item analysis, and construct validity was evaluated by Exploratory Factor Analysis with Oblimin rotation with Kaiser normalization, and eventually Confirmatory Factor Analysis. RESULTS: The results highlighted the necessity for refinements of the Nurse Competence Scale in the Italian Context. The original model of the Nurse Competence Scale (73 items) was not confirmed. The confirmatory factor analysis presented significant values of Chi-squared test = 10942.766, with degrees of freedom being 2.534 and a ratio of χ²/df = 4.318. The Comparative Fit Index value was significant 0.809 and the Normed Fit Index 0.765 was noteworthy too. The value of Root Mean Square Error of Approximation was significant 0.069. The Cronbach's α coefficient for the new scale was excellent (0.922). The exploratory factor analysis resulted in the Italian Nurse Competence Scale composed of 58 items divided into seven dimensions: using the research, professional awareness, ethical values, tutorial functions, professional leadership, educational interventions, and management of care processes. CONCLUSIONS: The Italian version of the Nurse Competence Scale with 7 dimension and 58 items is an appropriate tool for describing and comparing self-assessed competencies by nurses. Such evaluations could constitute an important contribution to have better educational environments. Self-assessment of competencies can also raise a stronger awareness of individual educational needs.

Experimental Evidence of Backward Raman Scattering Driven Cooperatively by Two Picosecond Laser Pulses Propagating Side by Side.

This Letter investigates experimentally the backward stimulated Raman scattering (SRS) of two copropagating, 1-µm wavelength, 1.5-ps duration laser pulses focused side by side, but not simultaneously, in a preformed underdense plasma. When the two lasers do not interact, one of the pulses (so-called strong) yields a large SRS reflectivity, while the other weak pulse is essentially ineffective as regards SRS. By contrast, the weak pulse shows significant SRS activity if it is launched in the plasma slightly after the strong one, and for time delays as large as about 15 ps. For crossed polarizations and a lateral distance of 80-90 µm, the time delay has to be larger than 3-4 ps for the weak pulse to be active, while it has just to be positive when the polarizations are parallel. The experimental results are discussed with the help of large-scale particle-in-cell simulations.

Signatures of the Self-Similar Regime of Strongly Coupled Stimulated Brillouin Scattering for Efficient Short Laser Pulse Amplification.

Plasma-based laser amplification is considered as a possible way to overcome the technological limits of present day laser systems and achieve exawatt laser pulses. Efficient amplification of a picosecond laser pulse by stimulated Brillouin scattering (SBS) of a pump pulse in a plasma requires to reach the self-similar regime of the strongly coupled (SC) SBS. In this Letter, we report on the first observation of the signatures of the transition from linear to self-similar regimes of SC-SBS, so far only predicted by theory and simulations. With a new fully head-on collision geometry, subpicosecond pulses are amplified by a factor of 5 with energy transfers of few tens of mJ. We observe pulse shortening, frequency spectrum broadening, and down-shifting for increasing gain, signatures of SC-SBS amplification entering the self-similar regime. This is also confirmed by the power law dependence of the gain on the amplification length: doubling the interaction length increases the gain by a factor 1.4. Pump backward Raman scattering (BRS) on SC-SBS amplification has been measured for the first time, showing a strong decrease of the BRS amplitude and frequency bandwidth when SBS seed amplification occurs.

Nurses' Job satisfaction: an Italian study.

BACKGROUND: The aim of the work presented was to assess job satisfaction of a number of nurses from different departments working in public hospitals in Italy. The assessment was carried out through the combined use of questionnaires, which measured different aspects of job satisfaction, such as coping abilities, stress level and optimism/pessimism. The literature supports the fact that nurses' job dissatisfaction is closely connected with high levels of stress, burnout and physical and mental exhaustion, together with high workload levels and the complexity of care. The growing interest in measuring the levels of nurses' job satisfaction is attributable to a number of problems that have been raised worldwide, two of which are becoming ever so important: turnover and shortage of nurses. The research question is: Which are the main motivating factors of Italian nurses' job satisfaction/dissatisfaction? METHODS: The study used a convenience (non probability) sample of 1,304 nurses from 15 different wards working in Italian public hospitals from a number of cities in northern, central and southern Italy. The survey instrument was a questionnaire consisting of 205 items which included 5 different questionnaires combined together. RESULTS: The results show a low level of job satisfaction (IWS= 11.5, JSS=126.4). However, the participants were overall happy about their job and considered autonomy and salary important factors for job satisfaction. CONCLUSION: Research has shown that the nurses' level of satisfaction in Italian hospitals is low. The results revealed dissatisfaction with task requirements, organizational policies and advance in career. Nurses interviewed did not feel stressed and showed to be optimistic overall. New research on the subject should be conducted by focusing on ward differences, North and South of Italy and on gender differences.

Topology of megagauss magnetic fields and of heat-carrying electrons produced in a high-power laser-solid interaction.

The intricate spatial and energy distribution of magnetic fields, self-generated during high power laser irradiation (at Iλ^{2}∼10^{13}-10^{14} W.cm^{-2}.µm^{2}) of a solid target, and of the heat-carrying electron currents, is studied in inertial confinement fusion (ICF) relevant conditions. This is done by comparing proton radiography measurements of the fields to an improved magnetohydrodynamic description that fully takes into account the nonlocality of the heat transport. We show that, in these conditions, magnetic fields are rapidly advected radially along the target surface and compressed over long time scales into the dense parts of the target. As a consequence, the electrons are weakly magnetized in most parts of the plasma flow, and we observe a reemergence of nonlocality which is a crucial effect for a correct description of the energetics of ICF experiments.

Complexity of care: a concept analysis.

BACKGROUND: In spite of the high number of tools designed to measure the complexity of care, there is still great diversity in the meaning of this concept. METHODS: The study was carried out using the concept analysis method as described by Beth Rodgers; 27 international papers were selected using PubMed, Web of Science and CINAHL data sets, without any time constraints. RESULTS: A number of similar concepts relating to multiplicity, intensity of care and workload were selected. The antecedents were classified according to personal and clinical features of patients, the characteristics of care, the social and organizational features; the tools that emerged measure the risk of complexity of care. Among the consequences, those that emerged were related to patients, operators and organization. The two attributes of complexity of care are connected with measurement, on the one side, and uncertainly, on the other. CONCLUSIONS: As difficult as it is to define complexity of care, the analysis states that its classification should be targeted at redefining hospital organization.

Amplification of ultrashort laser pulses by brillouin backscattering in plasmas.

Plasma media, by exciting Raman (electron) or Brillouin (ion) waves, have been used to transfer energy from moderately long, high-energy light pulses to short ones. Using multidimensional kinetic simulations, we define here the optimum window in which a Brillouin scheme can be exploited for amplification and compression of short laser pulses over short distances to very high power. We also show that shaping the plasma allows for increasing the efficiency of the process while minimizing other unwanted plasma processes. Moreover, we show that, contrary to what was traditionally thought (i.e., using Brillouin in gases for nanosecond pulse compression), this scheme is able to amplify pulses of extremely short duration.

Request for ethics support in healthcare practices. Reasons and characteristics of Ethics Consultation Service users.

BACKGROUND: Ethical problems in healthcare practices are increasing. Therefore, healthcare professionals encounter difficult ethical problems more frequently in their professional activities. For this reason, in several countries Ethics Consultation Services have been created, and a debate concerning their role and organization model has developed. Despite the great interest of healthcare professionals in ethics support, Ethics Consultation Services are scarcely diffused in Italy. METHODS: A survey was conducted to identify the levels of the nurses' experience and knowledge in the field of ethics and to assess their willingness to use a consultation service to approach ethical issues in healthcare. A questionnaire was administered and completed personally by 374 nurses appropriately instructed beforehand on its use. They were recruited from post-basic training courses at the Faculty of Medicine and Surgery of the University of L'Aquila. RESULTS: The willingness to recur to an ethical consultation, indicated by 90.3% of respondents, would confirm the hypothesis that the increasing ethical difficulties encountered in healthcare activities determined a greater interest towards this kind of service. The results of the study underline both the need and expectations the nurses have for ethics consultation and support to face ethical difficulties in patient care, and describe the characteristics of potential users. CONCLUSION: In our country the delay in approaching such problems is in contrast with the marked interest the healthcare professionals have for a possible request for support to face ethical problems in patient care. The study shows the respondents' high degree of appreciation of the contents of an ethics consultation activity and, consequently, it is desirable that the creation of an Ethics Consultation Service takes into consideration the indications given by the potential users, in addition to the experiences coming from other countries.

Absolute calibration up to 20 MeV of an online readout CMOS system suitable to detect high-power lasers accelerated protons.

We present the design and absolute calibration of a charged particle online readout CMOS system tailored for high-power laser experiments. This system equips a Thomson parabola spectrometer, which is used at the Apollon petawatt scale laser facility to measure the spectra of protons produced by high-intensity laser-target interactions. The RadEye1 CMOS matrices array detectors are paired with a custom triggering system for image grabbing. This allows us to register the proton and ion signals remotely. The repetition rate is presently 1 shot/min, but the frame grabbing enables the system to be compatible with modern high-power lasers running, e.g., at 1 Hz. We detail here the implementation, in the harsh electromagnetic environment of such interactions, of the system, and its absolute calibration, which was performed for proton energies from 4 to 20 MeV.

Weibel-induced filamentation during an ultrafast laser-driven plasma expansion.

The development of current instabilities behind the front of a cylindrically expanding plasma has been investigated experimentally via proton probing techniques. A multitude of tubelike filamentary structures is observed to form behind the front of a plasma created by irradiating solid-density wire targets with a high-intensity (I ~ 10(19) W/cm(2)), picosecond-duration laser pulse. These filaments exhibit a remarkable degree of stability, persisting for several tens of picoseconds, and appear to be magnetized over a filament length corresponding to several filament radii. Particle-in-cell simulations indicate that their formation can be attributed to a Weibel instability driven by a thermal anisotropy of the electron population. We suggest that these results may have implications in astrophysical scenarios, particularly concerning the problem of the generation of strong, spatially extended and sustained magnetic fields in astrophysical jets.

Experimental evidence of short light pulse amplification using strong-coupling stimulated brillouin scattering in the pump depletion regime.

The energy transfer from a long (3.5 ps) pump pulse to a short (400 fs) seed pulse due to stimulated Brillouin backscattering in the strong-coupling regime is investigated. The two pulses, both at the same wavelength of 1.057 microm are quasicounterpropagating in a preformed underdense plasma. Relative amplification factors for the seed pulse of up to 32 are obtained. The maximum obtained amplified energy is 60 mJ. Simulations are in agreement with the experimental results and suggest paths for further improvement of the amplification scheme.

Development of gas jet targets for laser-plasma experiments at near-critical density.

Computational fluid dynamics simulations are performed to design gas nozzles, associated with a 1000 bars backing pressure system, capable of generating supersonic gas jet targets with densities close to the critical density for 1053 nm laser radiation (1021 cm-3). Such targets should be suitable for laser-driven ion acceleration at a high repetition rate. The simulation results are compared to the density profiles measured by interferometry, and characterization of the gas jet dynamics is performed using strioscopy. Proton beams with maximum energies up to 2 MeV have been produced from diatomic hydrogen gas jet targets in a first experiment.