We investigated the effect of climatic, demographic factors and intra-country geographical variations on the incidence of invasive meningococcal disease (IMD) in Italy. For this purpose, incidence rates of IMD cases reported in Italy between 1994 and 2012 were calculated, and a cluster analysis was performed. A geographical gradient was determined, with lower incidence rates in central and southern Italy, compared to the northern parts, where most clusters were observed. IMD rates were higher in medium-sized towns than in villages. Adults were at lower risk of IMD than children aged ⩽4 years. IMD incidence tended to decrease with increasing monthly mean temperatures (incidence rate ratio 0·94, 95% confidence interval 0·90–0·99). In conclusion, geographical variations in IMD incidence were found, where age and temperature were associated with disease occurrence. Whether geographical variations should be considered in national intervention plans is still a matter for discussion.

We analyze the trajectory of near-Earth asteroid 2009~BD, which is a candidate target of the NASA Asteroid Redirect Mission. The small size of 2009 BD and its Earth-like orbit pose challenges to understanding the dynamical properties of 2009 BD. In particular, nongravitational perturbations, such as solar radiation pressure and the Yarkovsky effect, are essential to match observational data and provide reliable predictions. By using Spitzer Space Telescope IRAC observations and our model for the thermophysical properties and the nongravitational forces acting on 2009 BD we obtain probabilistic derivations of the physical properties of this object. We find two physically possible solutions. The first solution shows 2009 BD as a 2.9 ± 0.3 m diameter rocky body with an extremely high albedo that is covered with regolith-like material, causing it to exhibit a low thermal inertia. The second solution suggests 2009 BD to be a 4 ± 1 m diameter asteroid with albedo 0.45 ± 0.35 that consists of a collection of individual bare rock slabs. We are unable to rule out either solution based on physical reasoning. 2009 BD is the smallest asteroid for which physical properties have been constrained, providing unique information on the physical properties of objects in the size range smaller than 10 m.

In this study we assessed the seroprevalence of hepatitis E virus (HEV) infection in both the Italian population and immigrants from developing countries in Foggia (Apulia, Southern Italy). The seroprevalence of HEV was determined in 1217 subjects [412 (34%) immigrants and 805 Italian subjects (blood donors, general population, HIV-positive, haemodialysis patients)]. Serum samples were tested for anti-HEV and confirmed by Western blot assay; in positive patients HEV RNA and genotype were also determined. There were 8·8% of patients that were positive to anti-HEV, confirmed by Western blot. The prevalence in immigrants was 19·7%, and in Italians 3·9% (blood donors 1·3%, general population 2·7%, HIV-positive patients 2·0%, haemodialysis patients 9·6%). Anti-HEV IgM was found in 38/107 (35·5%) of the anti-HEV-positive serum samples (34 immigrants, four Italians). This study indicates a higher circulation of HEV in immigrants and Italian haemodialysis patients, whereas a low prevalence of HEV antibodies was seen in the remaining Italian population.

The parasitic nematode Anguillicola crassus was recently introduced into populations of the European eel, Anguilla anguilla. We investigated, under experimental conditions, the regulation of A. crassus infrapopulations. We tested the effects of (1) the resource-limited habitat of the parasite and (2) the coexistence of several developmental stages in its niche (the swim-bladder) on the composition of the infrapopulations. The results revealed that the respective effects of these factors differed substantially during the course of the infection. Third-stage larvae (L3s) establishment would not be constrained by the size of the swim-bladder. Their moult to fourth-stage larvae (L4s) would be accelerated as the number of L3s increased. The moulting time of L4s to adults would be reduced by males and would be constrained by the size of the swim-bladder. However, the moult of L4s to adults and their further development would be synchronized with those of the opposite sex. At the time of mating, the number of males and the body weight of adults would depend on the size of the swim-bladder. Soon after the laying of eggs, the developmental constraint on the late L3s would decrease. When adults die, constraints would cease and late larval stages would moult to become adults.

Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate the presence of seasonal variations of daily activity rhythms. Athletic Thoroughbred horses were kept in individual boxes with paddock. Digitally integrated measure of total activity of each mare was continuously recorded by actigraphy-based data loggers. Horse total activities were not evenly distributed over the day, but they were mainly diurnal during the year. Daily activity rhythms showed clear seasonal variations, with the highest daily amount of activity during the vernal equinox and the lowest during the winter solstice. Interestingly, the amount of activity during either photophase or scotophase changed significantly throughout the year. Circadian analysis of horse activities showed that the acrophase, the estimated time at which the peak of the rhythm occurs, did not change during the year, it always occurred in the middle of the photoperiod. Analysing the time structure of long-term and continuously measured activity and feeding could be a useful method to critically evaluate athletic horse management systems in which spontaneous locomotor activity and feeding are severely limited. Circadian rhythms are present in several elements of sensory motor and psychomotor functions and these would be taken into consideration to plan the training schedules and competitions in athletic horses.

The Triangulum Spiral Galaxy Messier 33 offers unique insights into the building of a galactic disk. We identify spectacular arcs of intermediate age (0.6 Gyr − 2 Gyr) stars in the low-metallicity outer disk. The northern arc spans ~120 degrees in azimuth and up to 5 arcmin in width. The arcs are located 2-3 disk scale lengths from the galaxy centre (where 1 disk scale length is equivalent to 0.1 degrees in the V-band) and lie precisely where there is a warp in the HI profile of M33. Warps and infall are inextricably linked (Binney, 1992). We present spectroscopy of candidate stars in the outer northern arc, secured using the Keck I telescope in Hawaii. The target stars have estimated visual magnitudes as faint as V~ 25m. Absorption bands of CN are seen in all spectra reported in this review talk, confirming their carbon star status. Also presented are PAH emissivity radial profiles generated from IRAC observations of M33 using the Spitzer Space Telescope. A dramatic change of phase in the m = 2 Fourier component is detected at the domain of the arcs. M33 serves as an excellent example how the disks of spiral galaxies in our Universe are built: as dynamically open systems, growing from the inward, outward.

We are conducting a survey of several regions of high-mass star formation to assess their content and structure. The observations include spitzer observations, ground-based optical and near-IR imaging surveys, and optical and IR spectra of objects and locations in the molecular clouds. The goal of the survey is to gain a better understanding of the processes involved in high mass star formation by determining the characteristics of the stars detected in these regions and investigating the properties of the interstellar medium (ISM) environment in which these stars form. In this contribution, we present results on the identification and spatial analysis of young stars in three clusters, W5/AFGL 4029, S255, and S235. First we show how the IRAC data are used to roughly segregate young stars according to their mid-infrared colors, into two groups corresponding the SED class I and class II young stellar objects. Then using the IRAC data in combination with 2MASS, we show how more young stars can be identified. Finally, we examine the spatial distributions of young stars in these clusters and find a range of morphologies and of peak surface densities.

We present initial results from a survey of the Orion A and B molecular clouds made with the InfraRed Array Camera (IRAC) onboard the Spitzer Space Telescope. This survey encompasses a total of 5.6 square degrees with the sensitivity to detect objects below the hydrogen burning limit at an age of 1 Myr. These observations cover a number of known star forming regions, from the massive star forming clusters in the Orion Nebula and NGC 2024, to small groups of low mass stars in the L1641. We combine the IRAC photometry with photometry from the 2MASS point source catalog and use the resulting seven band data to identify stars with infrared excesses due to dusty disks and envelopes. Using the presence of an infrared excess as an indicator of youth, we show the distribution of young stars and protostars in the two molecular clouds. We find that roughly half of the stars are found in dense clusters surrounding the two regions of recent massive star formation in the Orion clouds, NGC 2024 and the Orion Nebula.

The reporting period has shown that Space has become a firmly established domain in observational Astrophysics, also in the low energy astrophysics area. The launching of new spacecraft is always an important addition to the capabilities of the Astronomers, but the availability of space observatories is strongly affected by the fact that they disappear as their subsystems become damaged or, for other reasons, become inoperable. The relatively short life of astronomical space facilities has generated new dynamic in the life cycle of observational tools for the astronomer, rather different from that for ground facilities. Launch failures or the final in-orbit functionality verification can also very strongly affect the availability of observational capabilities in space astrophysics. The only spacecraft designed without this built-in life time restriction, is the Hubble Space Telescope, which can be serviced by the Space Shuttle.

The results presented here are from an ongoing mid-infrared imaging study of PPNe and PNe, using MIRAC2 the UA/SAO mid-IR camera. Our 8-21 μm observations have a spatial resolution of about 0.7″ to 1.5″, and a pixel scale of 0.25″/pixel (at UKIRT) or 0.34″/pixel (at IRTF). The high S/N and good spatial sampling in our images of IRAS 22272+5435 and IRAS 07134+1005 allow us to construct temperature and optical depth maps. Using our 11.7μm and 20.6μm images we also construct maps which isolate the 11.3μm (UIR) and 21μm emission features (Justannont et al. 1995). As a second part of this project, we are modelling the dust emission from PPNe and young PNe, using a axisymmetrical radiative transfer code.

Over the past ten years a technological revolution has occurred in the development of two-dimensional infrared array detectors for astronomical observations. The wide application of these arrays for both ground-based and space observations has resulted in a profound change in the capabilities and perspective for infrared astronomy, resulting in new views of the infrared sky. A review will be presented describing these detectors, the numerous advantages they provide for astronomical observations, the present state of array technology, and the potential for future growth.

Infrared images (1.65 μm) of the eclipsed Sim were taken atop Mauna Kea, Hawaii, during the July 11, 1991 total eclipse with an Amber Engineering 128 × 128 InSb array camera. The camera, mounted on a portable solar tracker, had a 3.8-cm, f/2 objective that produced a 4.9° field of view. The primary objective of the experiment was to search for dust or rocky rings around the Sun, previously detected at about 4 R ⊙. High thin clouds, atmospheric dust and aerosols from the June 1991 explosion of Mount Pinatubo in the Philippines, and the overall brightness of the solar corona resulted in a very high infrared background. Despite this, high signal-to-noise radial infrared intensity profiles were obtained of the solar corona from the Moon's limb out to about 10 R ⊙. Preliminary analysis shows some evidence for an enhanced surface brightness between 3 to 4 R ⊙ along the east-west direction, but much fainter than seen in previous solar eclipses. The transition region between the K-corona and the F-corona clearly shows at 2.5 R ⊙, and the surface brightness of the F-corona as a function of radius (from about 2 to 10 R ⊙) can be fit by a simple power law.

Electrochemical anodization in the transition regime, between porous silicon formation region and electropolishing region, of monocrystalline silicon was investigated. Using this process bright and stable photoluminescence could be obtained on a very large range of substrate resistivities: p=12-0.005 Ωcm for p-type silicon and p = 20-0.001 Ωcm for n-type substrates.

Photoluminescence spectra, Fourier Transform IR (FTIR) absorbance and X-Ray Diffraction (XRD) measurements are reported. Investigations showed that anodic silicon suboxide was formed on the surface. The porous structure obtained in the transition regime is suggested to consist of silicon crystallites built inside an anodic oxide.

The carbon-rich PPN M 2–9 and IRAS 21282+5050 are known to exhibit UIR feature emission at 7.7, 8.6, and 11.22 μm. The two nebulae have been imaged in the mid-IR with the UA/SAO/NRL Mid-Infrared Array Camera (MIRAC) in bandpasses which include UIR feature emission (8.8 and 11.22 μm). Near-infrared images of the nebulae have also been taken with the NICMOS 3 Hg:Cd:Te array camera at J, H, and K for M 2–9 and at K for IRAS 21282+5050.

We present high-resolution near- and mid-infrared images of the planetary nebula IC 418 at 1.2 (J), 1.6 (H), 2.2 (K), 9.8, and 11.7 μm. The near-IR images were obtained with a 64×64 pixel Hg:Cd:Te array camera, and the mid-IR images were obtained using the new 20×64 pixel Mid-Infrared Array Camera (MIRAC). The size of IC 418 in the near-IR is seen to vary with wavelength, being largest at K and smallest at J. Differences in the morphology of the nebula are seen between the J and K images. There is excess near-IR emission in the center of the nebula, after subtracting out the emission from the central star. Faint halo emission is detected at H and K, extending to a total diameter of approximately 40″. The 9.8 μm emission is distributed nonsymmetrically, with the peak in the NE lobe.