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1.
Sci Rep ; 10(1): 5975, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32249775

RESUMO

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.


Assuntos
Doenças dos Animais/transmissão , Organismos Aquáticos , Doenças Transmissíveis/veterinária , Modelos Teóricos , Doenças dos Animais/epidemiologia , Animais , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/transmissão , Surtos de Doenças , Oceanografia , Temperatura
2.
Sci Rep ; 7: 44348, 2017 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-28276501

RESUMO

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.


Assuntos
Kelp/fisiologia , Modelos Estatísticos , Phaeophyceae/fisiologia , Dispersão Vegetal/fisiologia , Oceano Atlântico , Biodiversidade , Mudança Climática , Ecossistema , Estações do Ano
3.
Phys Rev Lett ; 110(12): 124801, 2013 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-25166811

RESUMO

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.

4.
Ecology ; 92(6): 1193-200, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21797147

RESUMO

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.


Assuntos
Organismos Aquáticos , Biota , Modelos Estatísticos , Temperatura , Movimentos da Água , Animais , California , Larva , Oceano Pacífico , Dinâmica Populacional
5.
Phys Rev Lett ; 104(17): 174801, 2010 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-20482112

RESUMO

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.

7.
G Ital Med Lav Ergon ; 29(4): 927-31, 2007.
Artigo em Italiano | MEDLINE | ID: mdl-18409265

RESUMO

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.


Assuntos
Dor nas Costas , Doenças Profissionais , Adulto , Idoso , Dor nas Costas/diagnóstico , Dor nas Costas/etiologia , Estudos Cross-Over , Interpretação Estatística de Dados , Feminino , Humanos , Dor Lombar/diagnóstico , Dor Lombar/etiologia , Masculino , Pessoa de Meia-Idade , Atividade Motora , Doenças Profissionais/diagnóstico , Doenças Profissionais/etiologia , Ocupações , Medição da Dor , Percepção , Postura , Fatores de Risco
8.
J Neurosurg Sci ; 50(2): 45-8, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16841027

RESUMO

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.


Assuntos
Plexo Braquial/lesões , Plexo Braquial/cirurgia , Transferência de Nervo/métodos , Neurofibroma/cirurgia , Neoplasias do Sistema Nervoso Periférico/cirurgia , Adulto , Plexo Braquial/patologia , Vértebras Cervicais/cirurgia , Feminino , Humanos , Neurofibroma/diagnóstico , Neoplasias do Sistema Nervoso Periférico/diagnóstico , Neoplasias do Sistema Nervoso Periférico/patologia
9.
G Ital Med Lav Ergon ; 26(3): 180-2, 2004.
Artigo em Italiano | MEDLINE | ID: mdl-15551946

RESUMO

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.


Assuntos
Medicina Aeroespacial , Aeronaves , Condução de Veículo , Dor nas Costas/etiologia , Doenças Profissionais/etiologia , Vibração/efeitos adversos , Adolescente , Adulto , Fatores Etários , Dor nas Costas/epidemiologia , Dor nas Costas/prevenção & controle , Distribuição de Qui-Quadrado , Estudos Transversais , Exercício Físico , Humanos , Pessoa de Meia-Idade , Ocupações , Fatores de Risco , Esportes , Fatores de Tempo
10.
Phys Rev Lett ; 90(20): 205002, 2003 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-12785902

RESUMO

We report on the first study of the dynamic transverse forces imparted to an ultrarelativistic positron beam by a long plasma in the underdense regime. Focusing of the 28.5 GeV beam is observed from time-resolved beam profiles after the 1.4 m plasma. The strength of the imparted force varies along the approximately 12 ps full length of the bunch as well as with plasma density. Computer simulations substantiate the longitudinal aberration seen in the data and reveal mechanisms for emittance degradation.

11.
Phys Rev Lett ; 88(13): 135004, 2002 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11955106

RESUMO

The successful utilization of an ion channel in a plasma to wiggle a 28.5-GeV electron beam to obtain broadband x-ray radiation is reported. The ion channel is induced by the electron bunch as it propagates through an underdense 1.4-meter-long lithium plasma. The quadratic density dependence of the spontaneously emitted betatron x-ray radiation and the divergence angle of approximately (1-3)x10(-4) radian of the forward-emitted x-rays as a consequence of betatron motion in the ion channel are in good agreement with theory. The absolute photon yield and the peak spectral brightness at 14.2-keV photon energy are estimated.

12.
Phys Rev Lett ; 88(15): 154801, 2002 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11955201

RESUMO

The transverse dynamics of a 28.5-GeV electron beam propagating in a 1.4 m long, (0-2)x10(14) cm(-3) plasma are studied experimentally in the underdense or blowout regime. The transverse component of the wake field excited by the short electron bunch focuses the bunch, which experiences multiple betatron oscillations as the plasma density is increased. The spot-size variations are observed using optical transition radiation and Cherenkov radiation. In this regime, the behavior of the spot size as a function of the plasma density is well described by a simple beam-envelope model. Dynamic changes of the beam envelope are observed by time resolving the Cherenkov light.

13.
Phys Rev Lett ; 87(24): 244801, 2001 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-11736507

RESUMO

The observation of plasma focusing of a 28.5 GeV positron beam is reported. The plasma was formed by ionizing a nitrogen jet only 3 mm thick. Simultaneous focusing in both transverse dimensions was observed with effective focusing strengths of order tesla per micron. The minimum area of the beam spot was reduced by a factor of 2.0+/-0.3 by the plasma. The longitudinal beam envelope was measured and compared with numerical calculations.

15.
Phys Rev Lett ; 86(17): 3779-82, 2001 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-11329322

RESUMO

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.

16.
Hand Clin ; 16(4): 547-61, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11117046

RESUMO

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.


Assuntos
Amputação Traumática/cirurgia , Traumatismos do Braço/cirurgia , Reimplante/métodos , Braço/crescimento & desenvolvimento , Traumatismos do Braço/fisiopatologia , Criança , Pré-Escolar , Feminino , Humanos , Reimplante/efeitos adversos , Retalhos Cirúrgicos , Técnicas de Sutura , Tendões/cirurgia
18.
Plast Reconstr Surg ; 93(3): 552-7, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8115510

RESUMO

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.


Assuntos
Traumatismos dos Dedos/cirurgia , Dedos/cirurgia , Retalhos Cirúrgicos/métodos , Adulto , Artérias , Criança , Dedos/irrigação sanguínea , Dedos/inervação , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Transplante de Pele/métodos , Retalhos Cirúrgicos/patologia , Resultado do Tratamento
19.
Biol Bull ; 186(2): 172-181, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29281367

RESUMO

Larvae of the scleractinian coral Agaricia humilis settle and metamorphose in response to chemosensory recognition of a morphogen on the surfaces of Hydrolithon boergesenii and certain other crustose coralline red algae. The requirement of the larva for this inducer apparently helps to determine the spatial pattern of recruitment in the natural environment. Previous research showed that the inducer is associated with the insoluble cell wall fraction of the recruiting algae or their microbial epibionts, and that a soluble but unstable fragment of the inducing molecule can be liberated by limited hydrolysis, either with alkali or with enzymes specific for cell wall polysaccharides. We now show that the parent morphogen can be solubilized by gentle decalcification of the algal cell walls with the chelators EGTA or EDTA, suggesting that the morphogen may be a component of the calcified recruiting alga itself, rather than a product of any noncalcified microbial epibionts. The solubilized inducer is subsequently purified by hydrophobic-interaction and DEAE chromatography. The purified, amphipathic morphogen retains activity when tightly bound to beads of a hydrophobic-interaction chromatography resin, and this activity (tested with laboratory-reared larvae) is identical in the ocean and the laboratory. We have attached the purified, resin-bound inducer to surfaces coated with a silicone adhesive and thus produced a potent artificial recruiting substratum--i.e., a morphogen-based chemical "flypaper" for A. humilis larvae. This material should prove useful in resolving the role of chemosensory recognition of morphogens in the control of substratum-specific settlement, metamorphosis, and recruitment and in the maintenance of species isolation mechanisms in the natural environment.

20.
Thromb Res ; 69(1): 125-30, 1993 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-8465271

RESUMO

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.


Assuntos
Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Tromboembolia/sangue , Idoso , Envelhecimento , Biomarcadores/sangue , Reações Falso-Positivas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
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