DAΦNE operation with electron-cloud-clearing electrodes.

The effects of an electron cloud (e-cloud) on beam dynamics are one of the major factors limiting performances of high intensity positron, proton, and ion storage rings. In the electron-positron collider DAΦNE, namely, a horizontal beam instability due to the electron-cloud effect has been identified as one of the main limitations on the maximum stored positron beam current and as a source of beam quality deterioration. During the last machine shutdown in order to mitigate such instability, special electrodes have been inserted in all dipole and wiggler magnets of the positron ring. It has been the first installation all over the world of this type since long metallic electrodes have been installed in all arcs of the collider positron ring and are currently used during the machine operation in collision. This has allowed a number of unprecedented measurements (e-cloud instabilities growth rate, transverse beam size variation, tune shifts along the bunch train) where the e-cloud contribution is clearly evidenced by turning the electrodes on and off. In this Letter we briefly describe a novel design of the electrodes, while the main focus is on experimental measurements. Here we report all results that clearly indicate the effectiveness of the electrodes for e-cloud suppression.

Currents connecting communities: nearshore community similarity and ocean circulation.

Understanding the mechanisms that create spatial heterogeneity in species distributions is fundamental to ecology. For nearshore marine systems, most species have a pelagic larval stage where dispersal is strongly influenced by patterns of ocean circulation. Concomitantly, nearshore habitats and the local environment are also influenced by ocean circulation. Because of the shared dependence on the seascape, distinguishing the relative importance of the local environment from regional patterns of dispersal for community structure remains a challenge. Here, we quantify the "oceanographic distance" and "oceanographic asymmetry" between nearshore sites using ocean circulation modeling results. These novel metrics quantify spatial separation based on realistic patterns of ocean circulation, and we explore their explanatory power for intertidal and subtidal community similarity in the Southern California Bight. We find that these metrics show significant correspondence with patterns of community similarity and that their combined explanatory power exceeds that of the thermal structure of the domain. Our approach identifies the unique influence of ocean circulation on community structure and provides evidence for oceanographically mediated dispersal limitation in nearshore marine communities.

Test of "crab-waist" collisions at the DAPhiNE Phi factory.

The electron-positron collider DAPhiNE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.

Models with environmental drivers offer a plausible mechanism for the rapid spread of infectious disease outbreaks in marine organisms.

The first signs of sea star wasting disease (SSWD) epidemic occurred in just few months in 2013 along the entire North American Pacific coast. Disease dynamics did not manifest as the typical travelling wave of reaction-diffusion epidemiological model, suggesting that other environmental factors might have played some role. To help explore how external factors might trigger disease, we built a coupled oceanographic-epidemiological model and contrasted three hypotheses on the influence of temperature on disease transmission and pathogenicity. Models that linked mortality to sea surface temperature gave patterns more consistent with observed data on sea star wasting disease, which suggests that environmental stress could explain why some marine diseases seem to spread so fast and have region-wide impacts on host populations.

[Occupational backache: crossover study]. / Rachialgie occupazionali: studio trasversale.

The authors briefly review the risk factors for the spine involved in working activities. Three hundred workers doing different jobs were studied for their general physical condition, job-related postures, the site of any back pain, and motor activity practiced. In line with other studies, data confirm that no worker category is immune from back problems, but highlight the positive role of motor activity in pain perception.

Major shifts at the range edge of marine forests: the combined effects of climate changes and limited dispersal.

Global climate change is likely to constrain low latitude range edges across many taxa and habitats. Such is the case for NE Atlantic marine macroalgal forests, important ecosystems whose main structuring species is the annual kelp Saccorhiza polyschides. We coupled ecological niche modelling with simulations of potential dispersal and delayed development stages to infer the major forces shaping range edges and to predict their dynamics. Models indicated that the southern limit is set by high winter temperatures above the physiological tolerance of overwintering microscopic stages and reduced upwelling during recruitment. The best range predictions were achieved assuming low spatial dispersal (5 km) and delayed stages up to two years (temporal dispersal). Reconstructing distributions through time indicated losses of ~30% from 1986 to 2014, restricting S. polyschides to upwelling regions at the southern edge. Future predictions further restrict populations to a unique refugium in northwestern Iberia. Losses were dependent on the emissions scenario, with the most drastic one shifting ~38% of the current distribution by 2100. Such distributional changes might not be rescued by dispersal in space or time (as shown for the recent past) and are expected to drive major biodiversity loss and changes in ecosystem functioning.

Transarticular repair of the brachial plexus. Case report.

This paper illustrates the repair of a complex and unusually placed iatrogenic injury of the brachial plexus. The authors present the case of a 36-year old woman, musician (piano solista), with a dumbbell tumour of the brachial plexus. A general surgeon performed a gross total removal of the tumour, cutting it flush with the exit of the neuroforamen and this resulted in a severe upper brachial plexus injury. Four months later, the brachial plexus was repaired with a nerve graft, using a double extraforaminal and preforaminal approach via the transarticular route. The surgical procedure proved to be effective and without significant consequences for the patient.

D-dimer plasma concentration in various clinical conditions: implication for the use of this test in the diagnostic approach of venous thromboembolism.

Plasma measurement of D-Dimer (DD) represents a definite aid in the diagnostic approach of outpatients with suspected venous thromboembolism (VTE). However, the high sensitivity (about 95%) of the test which allows to rule out VTE when concentrations are below a given cutoff (500 micrograms/L as measured by the ELISA technique) is counterbalanced by a poor specificity (about 40%). Because the specificity might even be lower in patients who are hospitalized we determined the DD plasma concentration in 255 patients who were consecutively admitted in general internal medicine wards with various pathological conditions. The proportion of patients who had DD levels below the cutoff of 500 micrograms/L was 6% (1/18) in patients with VTE and 22% (52/237) in hospitalized patients without VTE: the figure was 21% in patients with pulmonary infections, 14% in patients with other infections, 11% in patients with neoplastic diseases, 34% in patients with coronary or cerebrovascular disease, 19% in patients with cardiac failure, 69% in patients with rheumatologic disease and in 16% in subjects with miscellaneous clinical conditions. The high rate of elevated plasma DD in hospitalized patients questions the usefulness of this test in the diagnostic approach of VTE in aged patients who present with concomitant disease like infections, neoplasia, cardiac failure and many other pathological conditions, except rheumatologic affections and coronary or cerebrovascular diseases.

Desiccation, predation, and mussel-barnacle interactions in the northern Gulf of California.

Field experiments were conducted in order to determine the potential for desiccation and predation to mediate the effect of mussels (Brachidontes semilaevis) on barnacles (Chthamalus anisopoma) in the highly seasonal northern Gulf of California. We did this by removing both mussels and a common mussel predator (Morula ferruginosa: Gastropoda) and by spraying selected sites with sea water during summertime spring low tides. We also determined the effect of crowding on resistance to desiccation in barnacles, and the effect of barnacles on colonization by mussels. The mussel-barnacle community was not affected by keeping experimental quadrats damp during daytime low tides throughout the summer. Exposure to summertime low tides, however, did affect the survivorship of isolated, but not crowded, barnacles; and barnacle clumps enhanced the recruitment of mussels. Hence crowding in barnacles had a positive effect on both barnacle survivorship and mussel recruitment. Morula had a negative effect on mussel density, and mussels had a negative effect on barnacle density. The effect of Morula on barnacle density was positive, presumably due to its selective removal of mussels. These results suggest an indirect mutualism between barnacles and the gastropod predator, because barnacles attract settlement or enhance the survival of mussels, and the predator reduces the competitive effect of mussels on barnacles.

Reverse dorsal digital island flap.

The anatomic and clinical bases for a reliable and versatile homodigital flap for covering difficult distal dorsal and dorsolateral wounds of the long fingers are presented. This one-step procedure, which uses the dorsal skin of the first or second phalanx transposed as a reverse island flap, preserving the collateral nerve and artery to the fingertip, has proved valuable in salvaging the severely injured digits of nine patients (for a total of 12 flaps). It would seem to be a relatively simple way of achieving early recovery because it does not require distant flap reconstruction, the immobilization of adjacent digits, or homodigital flaps that might jeopardize an already injured finger. Furthermore, it reduces the time of hospitalization and improves patient welfare.

Replantation of large segments in children.

If one looks at the final results obtained in children, one should conclude that replantation of large segments is more often indicated in children than in adult patients. Nevertheless, the more common components of crush or avulsion and the frequent severe associated lesions must restrain the surgeon's enthusiasm when indicating replantation of a large segment in children. The possible dramatic consequences of a late revascularization syndrome can be easily foreseen as an outcome of replantation of a large segment in children. Moreover, the problem of growth must be faced from the start, programming secondary surgery either for soft tissue assessment (skin retraction treatments, tendon lengthening, muscle sliding) or for bone lengthening. The final outcome being a functional arm, special care has to be taken in nerve repair integrated with possible secondary tendon transfers to compensate the functional deficit. With all these limitations in indications, care in emergency, and correct timing and planning for secondary surgery, the final functional results of macroreplantations in children will certainly be improved.

[Vibration, back pain and physical exercise in high-risk professionals: a cross-sectional study]. / Vibrazione, dolore rachideo e attività motoria in categorie professionali a rischio: studio trasversale.

Repeated loads and vibration stress in professional settings are relevant risk factors for back pain. Aim of this cross-sectional study was to estimate: a) the prevalence of back pain in two high-risk professional samples (helicopter pilots and bus drivers); b) the association between physical/sports exercise and back pain subjective perception across age. Prevalence of back pain is 94% in helicopter pilots and 74% in bus drivers; prevalence of back pain significantly increases with age. The positive effect of regular physical/sports exercise on subjective back pain significantly decreases with age. Physical or sports exercise adapted to structural characteristic of patients can result effective in diminishing personal impairment in subjects at professional risk.

Adult Plasticity and Rapid Larval Evolution in a Recently Isolated Barnacle Population.

Balanus amphitrite, a common barnacle species, was introduced into the landlocked Salton Sea in 1943 or 1944. In 1949, Balanus amphitrite from the Salton Sea was classified as the subspecies, Balanus amphitrite saltonensis, based upon morphological differences between Salton Sea and coastal individuals. This classification was maintained following an investigation of the Balanus amphitrite complex in 1975. Such a designation implies that the morphological divergence is underlain by genetic differences. Using field and laboratory transplantations, I tested the alternative hypothesis that the observed morphological divergence in the adult stage of Balanus amphitrite was the result of phenotypic plasticity. The results show that the divergence in the examined adult characters is in fact due to environmentally induced phenotypic plasticity. There were also phenotypic differences between larvae from the Salton Sea and those from coastal habitats that only became apparent during experimentation with the adult stage. Here, however, experimental results suggest that the divergence was due to an evolutionary process, probably selection. These results also provide the basis for two slightly precautionary conclusions: (1) the observation that individuals living in typical and novel habitats differ cannot even weakly indicate a cause for the difference, and (2) a consideration of the divergence of populations is incomplete if all of the life history stages of the organism are not studied.

Novel final focus design for future linear colliders.

The length, complexity, and cost of the present final focus designs for linear colliders grow very quickly with the beam energy. In this Letter, a novel final focus system is presented and compared with the one proposed for the Next Linear Collider (NLC Zeroth-Order Design Report, edited by T. O. Raubenheimer, SLAC Report No. 474, 1996). This new design has fewer optical elements and is much shorter, nonetheless achieving better chromatic properties. Moreover, the new system is more suitable for operation over a larger energy range.

Meralgia paraesthetica following weight loss. Case report.

The authors report on a case of persistent meralgia paraesthetica of the left side, following a weight loss of 8 kg in one month. Not only volumetric changes of the panniculus adiposus in the inguinal region but also a slight arrangement of the inguinal ligament and a state of undernourishment contribute to the compression of the lateral femoral cutaneous nerve. By microsurgical epineurectomy and interfascicular neurolysis the disappearance of the meralgia and preservation of the sensation on the antero-lateral aspect of the thigh are obtained.

Axillary nerve injuries--21 cases treated by nerve graft and neurolysis.

This report describes 21 cases of isolated paralysis of the axillary nerve. Six patients, in whom the nerve was in continuity, were treated by neurolysis. Fifteen patients with transections required nerve grafts, as direct suture was impossible. The anatomy and operative approach are presented and the results shown. The quality of recovery underscores the value of treatment in such injuries.