Paediatric wheezy admissions at and around school holiday periods

Objective: To study the influence of school holidays on paediatric admissions with wheezing. Design, setting and patients: Retrospective analysis of all admissions due to wheeze in the paediatric age group. Regional hospital catering for all such admissions, subdivided by age group. Outcome measures: Comparison of hospitalisations due to wheezing before, during and after school holiday periods. Results: Summated admissions showed an increase in admissions over the Christmas period for preschool children, and a decrease for school age children. In Easter and at the start of the summer holidays, admissions decreased in all age groups, except for the late school age group which showed increased admissions in April-May. After the summer holidays, a rise in admissions was noted for all ages. Conclusions: Our findings support the multiphenotypic theory for the precipitation of wheezy attacks, with a changeover from a predominantly viral respiratory trigger to a more atopic form of the disease at around 10 years of age. Prophylaxis during school periods is especially important, and advice leading to prophylaxis dose reduction in the benign summer months should be accompanied by advice to restart adequate prophylaxis medication prior to restarting school.peer-reviewe

Activity cycles in members of young loose stellar associations

Magnetic cycles have been detected in tens of solar-like stars. The relationship between the cycle properties and global stellar parameters is not fully understood yet. We searched for activity cycles in 90 solar-like stars with ages between 4 and 95 Myr aiming to investigate the properties of activity cycles in this age range. We measured the length $P_{ cyc}$ of a given cycle by analyzing the long-term time-series of three activity indexes. For each star, we computed also the global magnetic activity index that is proportional to the amplitude of the rotational modulation and is a proxy of the mean level of the surface magnetic activity. We detected activity cycles in 67 stars. Secondary cycles were also detected in 32 stars. The lack of correlation between $P_{ cyc}$ and $P_{ rot}$ suggest that these stars belong to the Transitional Branch and that the dynamo acting in these stars is different from the solar one. This statement is also supported by the analysis of the butterfly diagrams. We computed the Spearman correlation coefficient $r_{ S}$ between $P_{ cyc}$, and different stellar parameters. We found that $P_{ cyc}$ is uncorrelated with all the investigated parameters. The index is positively correlated with the convective turn-over time-scale, the magnetic diffusivity time-scale $\tau_{ diff}$, and the dynamo number $D_{ N}$, whereas it is anti-correlated with the effective temperature $T_{ eff}$, the photometric shear $\Delta\Omega_{\rm phot}$ and the radius $R_{ C}$ at which the convective zone is located. We found that $P_{ cyc}$ is about constant and that decreases with the stellare age in the range 4-95 Myr. We investigated the magnetic activity of AB Dor A by merging ASAS time-series with previous long-term photometric data. We estimated the length of the AB Dor A primary cycle as $P_{ cyc} = 16.78 \pm 2 \rm yr$.Comment: 19 pages , 15 figures, accepte

Lower limit for differential rotation in members of young loose stellar associations

Surface differential rotation (SDR) plays a key role in dynamo models. SDR estimates are therefore essential for constraining theoretical models. We measure a lower limit to SDR in a sample of solar-like stars belonging to young associations with the aim of investigating how SDR depends on global stellar parameters in the age range (4-95 Myr). The rotation period of a solar-like star can be recovered by analyzing the flux modulation caused by dark spots and stellar rotation. The SDR and the latitude migration of dark-spots induce a modulation of the detected rotation period. We employ long-term photometry to measure the amplitude of such a modulation and to compute the quantity DeltaOmega_phot =2p/P_min -2pi/P_max that is a lower limit to SDR. We find that DeltaOmega_phot increases with the stellar effective temperature and with the global convective turn-over time-scale tau_c. We find that DeltaOmega_phot is proportional to Teff^2.18pm 0.65 in stars recently settled on the ZAMS. This power law is less steep than those found by previous authors, but closest to recent theoretical models. We find that DeltaOmega_phot steeply increases between 4 and 30 Myr and that itis almost constant between 30 and 95 Myr in a 1 M_sun star. We find also that the relative shear increases with the Rossby number Ro. Although our results are qualitatively in agreement with hydrodynamical mean-field models, our measurements are systematically higher than the values predicted by these models. The discrepancy between DeltaOmega_phot measurements and theoretical models is particularly large in stars with periods between 0.7 and 2 d. Such a discrepancy, together with the anomalous SDR measured by other authors for HD 171488 (rotating in 1.31 d), suggests that the rotation period could influence SDR more than predicted by the models.Comment: 23 pages, 15 figures, 5 tables,accepted by Astronomy and Astrophysic

Neutrino flux predictions for known Galactic microquasars

It has been proposed recently that Galactic microquasars may be prodigious emitters of TeV neutrinos that can be detected by upcoming km^2 neutrino telescopes. In this paper we consider a sample of identified microquasars and microquasar candiates, for which available data enables rough determination of the jet parameters. By employing the parameters inferred from radio observations of various jet ejection events, we determine the neutrino fluxes that should have been produced during these events by photopion production in the jet. Despite the large uncertainties in our analysis, we demonstrate that in several of the sources considered, the neutrino flux at Earth, produced in events similar to those observed, would exceed the detection threshold of a km^2 neutrino detector. The class of microquasars may contain also sources with bulk Lorentz factors larger than those characteristic of the sample considered here, directed along our line of sight. Such sources, which may be very difficult to resolve at radio wavelengths and hence may be difficult to identify as microqusar candidates, may emit neutrinos with fluxes significantly larger than typically obtained in the present analysis. These sources may eventually be identified through their neutrino and gamma-ray emission.Comment: 17 pages. Submitted to Ap

Does poverty rate increase terrorism in a country?: An analysis from 1970-2019 ★

While terrorism has been a constant product of society, its determinants have been sporadic at best and inconclusive at worst. With the scientific community failing to arrive at a common consensus in reference to poverty as defined by GDP per capita, I hope to find a concrete conclusion by taking a different approach and examining the relationship between poverty rate and terrorism. In order to define the impact of poverty rate on terrorism, I utilized the Quality of Government Index Standard Time Series Dataset and the Global Terrorism Database. Further analysis was conducted by performing an OLS regression on the data via the negative binomial regression and Prais-Winsten models. This study deviates from the general consensus on poverty and terror by concluding that a negative relationship exists between poverty rate and terrorism; although, it does not retain significance when more impactful variables are compared. The findings suggest GDP per capita, state fragility, unemployment rate, and linguistic fractionalization as alternative, significant, determinants of terror. Of these, the most intriguing relationship exists between GDP and terrorism. In the presence of increased security measures after 2005, a positive relationship forms and alludes to wealthier countries being more susceptible to terror attacks despite funding counter measures. This provides an explanation to the increase in terrorism seen in the early 21st century, while suggesting that poverty rate exerts influence over terrorism rates. However, when the additional security precautions are considered, state fragility or unemployment overshadow poverty rate as variables of significance

Detection potential to point-like neutrino sources with the NEMO-km3 telescope

The NEMO Collaboration is conducting an R&D activity towards the construction of a Mediterranean km3 neutrino telescope. In this work, we present the results of Monte Carlo simulation studies on the capability of the proposed NEMO telescope to detect and identify point-like sources of high energy muon neutrinos.Comment: To be published on BCN06 proceedings (Barcelona, July 4-7, 2006

Chandra Studies of the X-ray Point Source Luminosity Functions of M31

Three different M31 disk fields, spanning a range of stellar populations, were observed by Chandra. We report the X-ray point source luminosity function (LF) of each region, and the LF of M31's globular clusters, and compare these with each other and with the LF of the galaxy's bulge. To interpret the results we also consider tracers of the stellar population, such as OB associations and supernova remnants. We find differences in the LFs among the fields, but cannot definitively relate them to the stellar content of the fields. We find that stellar population information, average and maximum source luminosities, X-ray source densities, and slopes of the LF are useful in combination.Comment: 7 pages, 3 figures, accepted for publication in ApJ. Higher-resolution figures available on reques

Physiological and driving behaviour changes associated to different road intersections

Road traffic injuries claim more than 1.2 million lives each year in the world and have a huge impact on health and development. It is commonly acknowledged that the human factor and the interaction between the human factor and the road environment are among the most common causes of road accidents. Intersections are among the most complex road environments: their geometric and traffic characteristics weigh the driver workload, affecting the driving behaviour and consequently the risk of accident. This study intends therefore to contribute for a better understanding of the relationship between different types of intersection and the human factor. The ultimate aim is to understand how at grade intersections affect the driving behaviour by comparing the drivers’ stress level for roundabouts and standard intersections. Electrodermal activity can provide a real-time assessment of the driver's stress level. Electrodermal activity was therefore collected continuously during a driving study which took place on a test environment based at Cranfield University and surrounding roads. Twenty participants were involved within the study. The analysis focused on four crossing manoeuvres on three at grade intersections (two T-junctions and a roundabout) situated on the study location. Results showed that the number of SCR peaks as well as the amplitude of the peaks are overall higher for the two manoeuvres on the roundabout. The stress level induced by each type of intersection was evaluated through an Electrodermal Impact Index which takes into account both the number and the amplitude of SCR peaks. Results suggested that the stress level induced by roundabouts is more than double that induced by standard intersections

Seismic potential in the Italian Peninsula from integration and comparison of seismic and geodetic strain rates.

Seismological and geodetic data provide key information about the kinematics and active tectonics of plate margins. Focal solutions enable determining the directions in which the current tectonic stress acts when fault rupturing occurs; GPS measurements provide information on the crustal velocity field and on current interseismic strain rates. The comparison of the strain rates resulting from the two datasets provides further insight into how large an area is affected by aseismic deformation, which is a valuable indicator for seismic hazard mitigation and estimating the seismic potential. In this work, we investigate both seismic and geodetic strain rates and the combined field resulting from the joint inversion of the geodetic and seismic datasets, providing a picture of the overall deformation field and its variation during the last decades. In this way, we seek to give an overview of the seismic potential distribution across the Apennines and southern Italy, as a qualitative analysis of space-time variations in the released seismic strain rate, compared to the space-time distribution of the cumulated geodetic strain rate. The results show a variable distribution of the seismic efficiency over the peninsula. The Southern Apennines shows the greatest seismic potential, highlighting a significantly lower seismicity in the last two decades over an area affected by the highest total strain rates. The Messina Straits and eastern Sicily have a significant seismic potential, together with the Calabrian arc (from the Tindari-Letojanni and central Aeolian islands to the Mt. Pollino area), as a result of seismic gaps with respect to the combined strain rates in the investigated period. This long gap highlights the longer recurrence periods for the strongest earthquakes on this area. The central-northern Apennines and off-shore northern Sicily, show a lower seismic potential than central-southern Apennines, probably due to the more recent seismicity affecting these areas

Smoking ban : a long-term analysis of the Malta paradox in a population of over 400,000 subjects

Objectives: The introduction of laws that make indoor public areas and workplaces smoke-free has resulted in a significant reduction in the incidence of acute coronary syndromes (ACS). Malta was the second European country to introduce the smoking ban legislation in April 2004. The purpose of the study was to investigate the impact of the smoking ban in Malta on ACS morbidity and mortality. Methods: The number of ACS hospital admissions and the number of cardiovascular deaths were retrospectively analysed. The annual data for 5 years prior to and following the introduction of the Tobacco Act were obtained according to age-groups for both genders. Poisson regression analyses were performed to assess for decline in ACS admission and cardiovascular death. Results: The ACS admission rate increased throughout the 5 years following the introduction of the smoking ban. There was no change in mortality rate in the 5 years following the legislation, except in 2007 when a small but significant decline was noted. Conclusions: The Malta smoking ban did not have a significant impact on cardiovascular mortality and ACS admissions rates, indicating the need for proper enforcement of the public smoking ban and increase in public awareness regarding the adverse effects of smoking.peer-reviewe