INFLUENCE OF AN ERGOLINE BICYCLE ERGOMETER ON BODY SEGMENT KINEMATICS AND POSTURE

INTRODUCTION Bicycle erogmeters have been the most used modality in the investigation of physiological and biomechanical parameters in cycling, for their ease of calibration and adaptation to various body size. In addition, the possibility to apply rackg type saddles, handlebars, and pedals allows the athlete to more closely replicates road racing condition in laboratory. There is, however, very little information about the effects of these devices on body kinematics. By a simultaneous right and left 3-D kinematic analysis, the purpose of this study was to compare body segment kinematics and posture of five experienced cyclists while pedaling on their own racing bicycle and on a widely used bicycle ergometer. METHODS Five experienced road cyclists were the subjects of this study. Each athlete first pedaled on his own bicycle mounted on rollers fitted with a variable-load device and then, performed on an electronically braked cycle erogmeter (Ergoline, Germany) which was mechanically modified to allow the athletes to correctly adjust the seat and handlebar, and to use their nonnal cycling shoes and cleats. Using the ELm system motion analyzer (four 100 Hz-TV cameras), the 3-D coordinates of small retoreflective markers glued onto 19 anatomical repere points were recorded with the subjects pedaling at 90-95 rpm. RESULTS As it can be seen in the table, considering lower limb joint motion in the sagittal plane, sigdcant differences between the two pedaling conditions were found in the ankle range of motion (ROM) and in maximum (MAX) and minimum (MIN) angular hip flexion. Others relevant differences were evident examining joint rotation center trajectories in the frontal plane, with the foot and shank performing farther from the bicycle frame using the Ergoline. In most of the subjects this resulted in an excessive transverse/frontal knee motion. The pelvis is significantly less anteroversed on the bicycle ergometer with more pelvic tilt in the frontal and horizontal plane. CONCLUSION The use of the examined ergometer significantly altered lower limb and pelvis kinematics in the frontal plane compared to standard bicycle. This must be considered when this device is used for training andlor to collect physiological and biomechanical data

FATIGUE EFFECTS ON SHOOTING ARCHERY PERFORMANCE

As archery competitions normally last many hours requiring a great deal of shoots, the athletes are usually subjected to a deterioration of muscle performance Deterioration of mechanical performance of one or more muscles, which are not able to maintain longer the desired force level, may be related to technique and motor strategy changes Although these modification are probably very subtle, their effect may produce undesirable impact on arrow scores It was the purpose of this study to analyse the possible effect of muscular fatigue on strategy used by athletes to accomplish the task. An additional objective was to determine whether or not fatigue effects are somewhat dependent on skill level of athletes. Twelve archers of Italian Archery Federation were the subjects of this study. According to their FITA scores they were classified as intermediate (n = 7; FITA scores ranging from 1.180 to 1300) and top level archers (n = 5; FITA scores > 1300). 15 shoots for each archer were recorded and analysed at firstly. After these measurements a fatigue protocol was performed. The athletes come to a full drawing position and remained in the aiming phase for 20 s. Each athlete performed six series of ten repetition with rest interval of 20 s. between the sets. Immediately following the fatigue protocol, the subjects performed other 15 shoots. EMG, kinematics and force platform data were acquired and processed using the ELITE motion analysis system An electrical device attached to the bow was used to detect the moment of clicker closure, arrow release. and contact-loss of the arrow with the bowstring Surface EMG was collected from the finger flexor muscles and biceps of the drawing arm and from upper and lower back muscles, with a sampling rate of 1000 Hz. Markers were placed on. the temporal bone and the mandibular joint to mark the head: the shoulders. elbows. wrists and hands to mark the arms; the iliac crests, knees. ankles, and third metatarsal heads to mark the lower limbs. In addition. three markers were placed on the backbone and other three were attached to the bow. Ground reaction forces and centre of pressure displacements were measured with a Kistler force platform at a sampling rate of I000 Hz. In each subject no significant variation in performance scores was evident. In all the subjects a significant increase in bow lateral sway were observed after the fatigue protocol. The increase was much more evident in less skilled subjects. Furthermore, the results showed that less skilled subjects displayed longer aiming phase duration after fatigue protocol

EFFECTS OF PLANTAR ORTHOSIS ON DYNAMIC PLANTAR PRESSURE MEASUREMENTS IN RUNNERS

During the past years, the use of custom-made plantar orthoses (POs) has been sharply increased among athletes. Concurrently, a great effort has been dedicated by orthotic designers and manufacturers to improve the quality of their products. Only recently, however, systems that allow dynamic plantar pressure measurements within shoes have become available. Data and information provided by these devices can potentially reveal information about both the structure and the function of the foot and may also be used to evaluate the effectiveness of specifically designed POs on plantar foot pressure. By analyzing the pressure distribution in different plantar areas and the centre of force path as well, the aim of this work was to examine the efficacy of specific custom-made POs in athletes wearing their own running shoes. For this purpose, eleven runners were randomly selected among a population of competitive athletes wearing POs. The orthosis had been made by different laboratories using different casting methods. Each subject performed two separate running trials at 12 km/h on a motorized treadmill: one trial wearing his own custom-orthotics in the shoes, and one trial without. In the two experimental conditions, data for at least six strides for each foot was collected. The Fscan inshoe pressure measurement system was used to measure piantar pressure during all trials. The system used an ultra-thin flexible and trimmable sensor with 960sensing locations distributed evenly across the entire plantar surface. These food sensors can be customized to the individual needs and sizing of each subject. According to previous studies, the results of trials with and without orthosis appeared to show a sensitivity to this change in condition. In many ofthe examined parameters, significant changes have been found between the two experimental conditions. However, in three cases, although inserts are thoughtto redistribute and decrease local plantar pressure beneath the foot, Pos significantly increased pressure in particular areas of the metatarsal region. Furthermore, in two subjects, a dramatic pressure increase had been found in the lateral portion of the midfoot suggesting an overcorrection of the medial arch support. In four subjects the effect of POs was not significant in each of the examined parameters. In only three subjects, the centre of force path was found to deviate significantly with POs

IN-SHOE PRESSURE DISTRIBUTION DURING FENCING LUNGE

Fencing is a sport involving sharp backward and forward movements interspersed with several slower gliding steps in which lower limb agility is crucial to good movements and correct body positioning. Thus, while the upper extremity uses the weapon, the legs and feet work to get the fencer in position to it. From a biomechanical point of view, particularly stressed are the feet. Incidence of foot injury in fencing is high, and there have been many cases reported of metatarsal stress fractures, capsulitis, plantar fasciitis, and interdigital neuromas. Although it would be useful to accurately evaluate the high pressure points so that overall lower limb salvage may be improved, to our knowledge, no information about the force and pressure distribution beneath the foot of fencers performing technical actions is available. The purpose of this study was, therefore, to evaluate dynamic in-shoe plantar pressure during fencing lunge. Six right-handed foilists of national level (age: 24k5.5) were the subjects of this study. Each athlete was asked to perform the following technical actions: simple lunge; step forward-lunge; step backward-lunge; jump forward-lunge. Data for at least six trials per condition was collected. The Fscan in-shoe pressure measurement system was used to measure plantar pressure during all trials. The system uses an ultra-thin flexible and trimmable sensor with 960sensing locations distributed evenly across the entire plantar surface. These footsensors can be customized to the individual needs and sizing of each subject. The parameters examined included the centre of pressure path, time-pressure relationships, and the force and pressure in three regions of the foot (rear, mid, and forepart).Despite the apparent intersubject similarities in performing the actions, clear differences were observed in most of the examined parameters. In contrast to the above finding, the variability within-subject was low indicating a high consistency in movement execution, As expected, in all the technical actions, an asymmetrical load was placed on the lower extremities, with the right foot of the athletes particularly subjected to stress in the forward actions. The results showed that the majority of the right foot pressure was localized in the forefoot and especially over the head of the first and second metatarsal and hallux. High pressure levels, as those found here, applied too often and over a long periods of time can cause structural damage to the foot. Shoe and plantar orthosis designers should attempt to reduce such risks designing sager footwear and proper shoe inserts

The primordial environment of super massive black holes: large scale galaxy overdensities around z∼6z\sim6 QSOs with LBT

We investigated the presence of galaxy overdensities around four $z\sim6$ QSOs, namely SDSS J1030+0524 (z = 6.28), SDSS J1148+5251 (z = 6.41), SDSS J1048+4637 (z = 6.20) and SDSS J1411+1217 (z = 5.95), through deep $r$-, $i$- and $z$- band imaging obtained with the wide-field ($\sim23'\times25'$) Large Binocular Camera (LBC) at the Large Binocular Telescope (LBT). We adopted color-color selections within the $i-z$ vs $r-z$ plane to identify samples of $i$-band dropouts at the QSO redshift and measure their relative abundance and spatial distribution in the four LBC fields, each covering $\sim8\times8$ physical Mpc at $z\sim6$. The same selection criteria were then applied to $z$-band selected sources in the $\sim$1 deg$^2$ Subaru-XMM Newton Deep Survey to derive the expected number of dropouts over a blank LBC-sized field ($\sim$0.14 deg$^2$). The four observed QSO fields host a number of candidates larger than what is expected in a blank field. By defining as $i$-band dropouts objects with $z_{AB}1.4$ and undetected in the $r$-band, we found 16, 10, 9, 12 dropouts in SDSS J1030+0524, SDSS J1148+5251, SDSS J1048+4637, and SDSS J1411+1217, respectively, whereas only 4.3 such objects are expected over a 0.14 deg$^2$ blank field. This corresponds to overdensity significances of 3.3, 1.9, 1.7, 2.5$\sigma$, respectively. By considering the total number of dropouts in the four LBC fields and comparing it with what is expected in four blank fields of 0.14 deg$^2$ each, we find that high-z QSOs reside in overdense environments at the $3.7\sigma$ level. This is the first direct and unambiguous measurement of the large scale structures around $z\sim6$ QSOs. [shortened]Comment: 12 pages, 8 figures. Accepted for publication in A&

ASTRI SST-2M prototype and mini-array simulation chain, data reduction software, and archive in the framework of the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) is a worldwide project aimed at building the next-generation ground-based gamma-ray observatory. Within the CTA project, the Italian National Institute for Astrophysics (INAF) is developing an end-to-end prototype of the CTA Small-Size Telescopes with a dual-mirror (SST-2M) Schwarzschild-Couder configuration. The prototype, named ASTRI SST-2M, is located at the INAF "M.C. Fracastoro" observing station in Serra La Nave (Mt. Etna, Sicily) and is currently in the scientific and performance validation phase. A mini-array of (at least) nine ASTRI telescopes has been then proposed to be deployed at the Southern CTA site, by means of a collaborative effort carried out by institutes from Italy, Brazil, and South-Africa. The CTA/ASTRI team is developing an end-to-end software package for the reduction of the raw data acquired with both ASTRI SST-2M prototype and mini-array, with the aim of actively contributing to the global ongoing activities for the official data handling system of the CTA observatory. The group is also undertaking a massive Monte Carlo simulation data production using the detector Monte Carlo software adopted by the CTA consortium. Simulated data are being used to validate the simulation chain and evaluate the ASTRI SST-2M prototype and mini-array performance. Both activities are also carried out in the framework of the European H2020-ASTERICS (Astronomy ESFRI and Research Infrastructure Cluster) project. A data archiving system, for both ASTRI SST-2M prototype and mini-array, has been also developed by the CTA/ASTRI team, as a testbed for the scientific archive of CTA. In this contribution, we present the main components of the ASTRI data handling systems and report the status of their development.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC 2017), Bexco, Busan, Korea. All CTA contributions at arXiv:1709.0348

The GOODS-MUSIC sample: a multicolour catalog of near-IR selected galaxies in the GOODS-South field

We present a high quality multiwavelength (from 0.3 to 8.0 micron) catalog of the large and deep area in the GOODS Southern Field covered by the deep near-IR observations obtained with the ESO VLT. The catalog is entirely based on public data: in our analysis, we have included the F435W, F606W, F775W and F850LP ACS images, the JHKs VLT data, the Spitzer data provided by IRAC instrument (3.6, 4.5, 5.8 and 8.0 micron), and publicly available U-band data from the 2.2ESO and VLT-VIMOS. We describe in detail the procedures adopted to obtain this multiwavelength catalog. In particular, we developed a specific software for the accurate "PSF-matching" of space and ground-based images of different resolution and depth (ConvPhot), of which we analyse performances and limitations. We have included both z-selected, as well as Ks-selected objects, yielding a unique, self-consistent catalog. The largest fraction of the sample is 90% complete at z~26 or Ks~23.8 (AB scale). Finally, we cross-correlated our data with all the spectroscopic catalogs available to date, assigning a spectroscopic redshift to more than 1000 sources. The final catalog is made up of 14847 objects, at least 72 of which are known stars, 68 are AGNs, and 928 galaxies with spectroscopic redshift (668 galaxies with reliable redshift determination). We applied our photometric redshift code to this data set, and the comparison with the spectroscopic sample shows that the quality of the resulting photometric redshifts is excellent, with an average scatter of only 0.06. The full catalog, which we named GOODS-MUSIC (MUltiwavelength Southern Infrared Catalog), including the spectroscopic information, is made publicly available, together with the software specifically designed to this end.Comment: Accepted for publication in Astronomy and Astrophysics, uses aa.cls, 20 pages, 16 figures. Further information at http://lbc.oa-roma.inaf.it/good

The Blue Straggler population in the globular cluster M53 (NGC5024): a combined HST, LBT, CFHT study

We used a proper combination of multiband high-resolution and wide field multi-wavelength observations collected at three different telescopes (HST, LBT and CFHT) to probe Blue Straggler Star (BSS) populations in the globular cluster M53. Almost 200 BSS have been identified over the entire cluster extension. The radial distribution of these stars has been found to be bimodal (similarly to that of several other clusters) with a prominent dip at ~60'' (~2 r_c) from the cluster center. This value turns out to be a factor of two smaller than the radius of avoidance (r_avoid, the radius within which all the stars of ~1.2 M_sun have sunk to the core because of dynamical friction effects in an Hubble time). While in most of the clusters with a bimodal BSS radial distribution, r_avoid has been found to be located in the region of the observed minimum, this is the second case (after NGC6388) where this discrepancy is noted. This evidence suggests that in a few clusters the dynamical friction seems to be somehow less efficient than expected. We have also used this data base to construct the radial star density profile of the cluster: this is the most extended and accurate radial profile ever published for this cluster, including detailed star counts in the very inner region. The star density profile is reproduced by a standard King Model with an extended core (~25'') and a modest value of the concentration parameter (c=1.58). A deviation from the model is noted in the most external region of the cluster (at r>6.5' from the center). This feature needs to be further investigated in order to address the possible presence of a tidal tail in this cluster.Comment: 25 pages, 9 figures, accepted for publication on Ap

Physical properties of z~4 LBGs: differences between galaxies with and without Ly-alpha emission

We have analysed the physical properties of z~4 Lyman Break Galaxies observed in the GOODS-S survey, in order to investigate the possible differences between galaxies where the Ly-alpha is present in emission, and those where the line is absent or in absorption. The objects have been selected from their optical color and then spectroscopically confirmed by Vanzella et al. (2005). From the public spectra we assessed the nature of the Ly-alpha emission and divided the sample into galaxies with Ly-alpha in emission and objects without Ly-alpha line (i.e. either absent or in absorption). We have then used the complete photometry, from U band to mid infrared from the GOODS-MUSIC database, to study the observational properties of the galaxies, such as UV spectral slopes and optical to mid-infrared colors, and the possible differences between the two samples. Finally through standard spectral fitting tecniques we have determined the physical properties of the galaxies, such as total stellar mass, stellar ages and so on, and again we have studied the possible differences between the two samples. Our results indicate that LBG with Ly-alpha in emission are on average a much younger and less massive population than the LBGs without Ly-alpha emission. Both populations are forming stars very actively and are relatively dust free, although those with line emission seem to be even less dusty on average. We briefly discuss these results in the context of recent models for the evolution of Lyman break galaxies and Ly-alpha emitters.Comment: Accepted for publication in A&A. Uses aa.cls, 6 pages, 3 figure

LBT Discovery of a Yellow Supergiant Eclipsing Binary in the Dwarf Galaxy Holmberg IX

In a variability survey of M81 using the Large Binocular Telescope we have discovered a peculiar eclipsing binary (MV ~ -7.1) in the field of the dwarf galaxy Holmberg IX. It has a period of 272 days and the light curve is well-fit by an overcontact model in which both stars are overflowing their Roche lobes. It is composed by two yellow supergiants (V-I ~ 1 mag, T_eff = 4800 K), rather than the far more common red or blue supergiants. Such systems must be rare. While we failed to find any similar systems in the literature, we did, however note a second example. The SMC F0 supergiant R47 is a bright (MV ~ -7.5) periodic variable whose All Sky Automated Survey (ASAS) light curve is well-fit as a contact binary with a 181 day period. We propose that these systems are the progenitors of supernovae like SN 2004et and SN 2006ov, which appeared to have yellow progenitors. The binary interactions (mass transfer, mass loss) limit the size of the supergiant to give it a higher surface temperature than an isolated star at the same core evolutionary stage. We also discuss the possibility of this variable being a long-period Cepheid.Comment: ApJ Letters, accepted, 15 pages, 4 figures, 1 table, and 1 photometry fil