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1.
J Comp Pathol ; 200: 1-11, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36587440

RESUMEN

This study catalogued ocular pathology in fish histopathology submissions to a specialist diagnostic service and investigated associations with species and systemic disease, with a focus on species of conservation interest. Cross-tabulations and Fisher's exact tests were used to identify associations among the variables and results are reported as prevalence ratios (PRs) with 95% confidence intervals (CI). Of 12,488 reports reviewed, ocular histology examination was available for 4,572 submissions, in which histopathological ocular lesions were identified in 18% (813/4572). Most diagnoses (701/813; 87%) were in marine fish. Inflammatory conditions were most common (608/813; 75%), with identification of a bacterial aetiology in 42% (255/608) and a parasitic aetiology in 30% (183/608). Most bacterial infections were due to mycobacteriosis (153/255; 60%) and most parasitic infections were due to scuticociliatosis (114/184; 62%). The Syngnathidae, Centriscidae and Cichlidae families were each more likely than all other families combined to be diagnosed with ocular manifestations of mycobacteriosis (PRs = 2.6, 4.4 and 2.9, respectively, P <0.0001 for each). The Syngnathidae were also more likely to be diagnosed with ocular scuticociliatosis (PR = 1.9, P <0.0001). Fifty-four percent (39/72) of ocular mycobacteriosis and 38% (9/24) of gas bubble disease cases affected threatened or near threatened Syngnathidae species. The Apogonidae were more likely than any other family to have ocular iridovirus (PR = 10.3, 95% CI = 5.5-19.4, P <0.0001) and neoplasia (PR = 8.2, 95% CI = 4.2-16.3, P <0.0001). The endangered Banggai cardinalfish (Pterapogon kauderni) accounted for 13/15 ocular iridovirus and 16/18 mycobacteriosis cases in this family. All cases of neoplasia in the Apogonidae occurred in pajama cardinalfish (Sphaeramia nematoptera). These results should inform clinical diagnosis of ocular disease in aquarium fish and influence training for aquarists, highlighting ocular pathology as a potential early warning of systemic disease. The findings also have direct/indirect consequences for the welfare and conservation of some of these popular flagship fish species.


Asunto(s)
Infecciones Bacterianas , Enfermedades de los Peces , Animales , Infecciones Bacterianas/veterinaria , Enfermedades de los Peces/patología
2.
Phys Rev Lett ; 125(4): 044803, 2020 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-32794783

RESUMEN

Energy recovery has been achieved in a multipass linear accelerator, demonstrating a technology for more compact particle accelerators operating at higher currents and reduced energy consumption. Energy delivered to the beam during the first four passes through the accelerating structure was recovered during four subsequent decelerating passes. High-energy efficiency was achieved by the use of superconducting accelerating cavities and permanent magnets. The fixed-field alternating-gradient optical system used for the return loop successfully transported electron bunches of 42, 78, 114, and 150 MeV in a common vacuum chamber. This new kind of accelerator, an eight-pass energy recovery linac, has the potential to accelerate much higher current than existing linear accelerators while maintaining small beam dimensions and consuming much less energy per electron.

3.
Phys Rev Lett ; 124(24): 244801, 2020 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-32639812

RESUMEN

Continuous-wave photoinjectors operating at high accelerating gradients promise to revolutionize many areas of science and applications. They can establish the basis for a new generation of monochromatic x-ray free electron lasers, high-brightness hadron beams, or a new generation of microchip production. In this Letter we report on the record-performing superconducting rf electron gun with CsK_{2}Sb photocathode. The gun is generating high charge electron bunches (up to 10 nC/bunch) and low transverse emittances, while operating for months with a single photocathode. This achievement opens a new era in generating high-power beams with a very high average brightness.

4.
Phys Rev Lett ; 124(8): 084801, 2020 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-32167359

RESUMEN

Cooling of beams of gold ions using electron bunches accelerated with radio-frequency systems was recently experimentally demonstrated in the Relativistic Heavy Ion Collider at Brookhaven National Laboratory. Such an approach is new and opens the possibility of using this technique at higher energies than possible with electrostatic acceleration of electron beams. The challenges of this approach include generation of electron beams suitable for cooling, delivery of electron bunches of the required quality to the cooling sections without degradation of beam angular divergence and energy spread, achieving the required small angles between electron and ion trajectories in the cooling sections, precise velocity matching between the two beams, high-current operation of the electron accelerator, as well as several physics effects related to bunched-beam cooling. Here we report on the first demonstration of cooling hadron beams using this new approach.

5.
Phys Rev Lett ; 122(20): 204803, 2019 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-31172775

RESUMEN

This Letter reports the first spin tune measurement at high energies (24 and 255 GeV) with a driven coherent spin motion. To maintain polarization in a polarized proton collider, it is important to know the spin tune of the polarized proton beam, which is defined as the number of full spin precessions per revolution. A nine-magnet spin flipper has demonstrated high spin-flip efficiency in the presence of two Siberian snakes [H. Huang et al., Phys. Rev. Lett. 120, 264804 (2018).10.1103/PhysRevLett.120.264804]. The spin flipper drives a spin resonance with a given frequency (or tune) and strength. When the drive tune is close to the spin tune, the proton spin direction is not vertical anymore, but precesses around the vertical direction. By measuring the precession frequency of the horizontal component, the spin tune can be precisely measured. A driven coherent spin motion and fast turn-by-turn polarization measurement are keys to the measurement. The vertical spin direction is restored after turning the spin flipper off and the polarization value is not affected by the measurement. The fact that this manipulation preserves the polarization makes it possible to measure the spin tune during the operation of a high energy accelerator.

6.
Phys Rev Lett ; 120(26): 264804, 2018 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-30004736

RESUMEN

In polarized proton collision experiments, it is highly advantageous to flip the spin of each bunch of protons during the stores to reduce the systematic errors. Experiments done at energies less than 2 GeV have demonstrated a spin-flip efficiency over 99%. At high energy colliders with Siberian snakes, a single magnet spin flipper does not work because of the large spin tune spread and the generation of multiple, overlapping resonances. A more sophisticated spin flipper, constructed of nine-dipole magnets, was used to flip the spin in the BNL Relativistic Heavy Ion Collider. A special optics choice was also used to make the spin tune spread very small. A 97% spin-flip efficiency was measured at both 24 and 255 GeV. These results show that efficient spin flipping can be achieved at high energies using a nine-magnet spin flipper.

7.
Nervenarzt ; 88(12): 1385-1394, 2017 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-28932874

RESUMEN

BACKGROUND: Recent advances in the field of epilepsy genetics have led to an increased fraction of patients with epilepsies where the etiology of the disease could be identified. Nevertheless, there is some criticism regarding the use of epilepsy genetics because in many cases the identification of a pathogenetic mutation does not lead to an adaptation of therapy or to an improved prognosis. In addition, the interpretation of genetic results might be complicated due to the considerable numbers of variants of unclear significance. OBJECTIVE: This publication presents the arguments in favour of a broad use of genetic investigations for children with epilepsies. Several diseases where a genetic diagnosis does in fact have direct therapeutic consequences are mentioned. In addition, the indirect impact of an established etiology, encompassing the avoidance of unnecessary diagnostic measures, possibility of genetic counselling, and the easing of the psychologic burden for the caregivers, should not be underestimated. CONCLUSION: The arguments in favour of broad genetic diagnostics prevail notwithstanding the lack of relevant new developments regarding the therapy.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Epilepsia/diagnóstico , Epilepsia/genética , Anticonvulsivantes/efectos adversos , Niño , Análisis Mutacional de ADN , Quimioterapia Combinada , Epilepsia/terapia , Pruebas Genéticas , Humanos , Pronóstico , Síndrome , Resultado del Tratamiento
8.
Neuropediatrics ; 43(6): 339-45, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23129438

RESUMEN

INTRODUCTION: A total of 83% of children report headache during a 6-month period. The estimated 1-year prevalence of chronic daily headache (CDH) in children is at least 1 to 2%. Muscle pain is associated with headache severity and chronicity. Muscle pain can be associated with active muscular trigger points, a functional concept still remaining a controversy. An integrated approach including bio-behavioral management is accepted as standard treatment but does not provide sufficient pain relief in all patients. OBJECTIVE: We report the individual clinical course of five adolescents with treatment-refractory CDH associated with focal muscle pain. We describe a concept of short-term integrative intervention including botulinum toxin (StiBo) in a personalized "follow the referred pain pattern" injection regimen with the focus on long-term follow-up. RESULTS: StiBo showed short-term efficacy on headache frequency and severity. In the long-term follow-up, CDH was not existent in any of the patients. CONCLUSION: The treatment may have enabled the patients to draw attention away from a repeated circle of muscle-triggered pain and withdrawal of daily activities toward self-driven activities, thereby potentially preventing the development of further chronification. To prove this hypothesis, a prospective, placebo-controlled study in young adolescents with CDH should be initiated including objective outcome parameters on muscular level.


Asunto(s)
Toxinas Botulínicas/uso terapéutico , Trastornos de Cefalalgia/tratamiento farmacológico , Dolor Musculoesquelético/tratamiento farmacológico , Adolescente , Niño , Estudios de Seguimiento , Trastornos de Cefalalgia/complicaciones , Humanos , Dolor Musculoesquelético/complicaciones , Dimensión del Dolor , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
9.
Phys Rev Lett ; 99(15): 154801, 2007 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-17995173

RESUMEN

Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

10.
Phys Rev Lett ; 96(17): 174801, 2006 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-16712305

RESUMEN

The Brookhaven Relativistic Heavy Ion Collider (RHIC) has been providing collisions of polarized protons at a beam energy of 100 GeV since 2001. Equipped with two full Siberian snakes in each ring, polarization is preserved during acceleration from injection to 100 GeV. However, the intrinsic spin resonances beyond 100 GeV are about a factor of 2 stronger than those below 100 GeV making it important to examine the impact of these strong intrinsic spin resonances on polarization survival and the tolerance for vertical orbit distortions. Polarized protons were first accelerated to the record energy of 205 GeV in RHIC with a significant polarization measured at top energy in 2005. This Letter presents the results and discusses the sensitivity of the polarization survival to orbit distortions.

11.
Phys Rev Lett ; 91(3): 034801, 2003 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-12906421

RESUMEN

Higher-order and coupled snake resonances were observed during the 2002 polarized proton run in RHIC. Strong depolarization was observed when the fractional part of the vertical betatron tune approached 1/4, and when the fractional part of the horizontal tune approached 3/14. Because of the closed orbit error, each snake resonance splits into two. From the width of the observed snake resonances, we can derive the strength of the imperfection spin resonance. Our results appear consistent with the measured closed orbit error.

12.
Phys Rev Lett ; 89(5): 052302, 2002 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-12144435

RESUMEN

The analyzing power for proton-carbon elastic scattering in the Coulomb-nuclear interference region of momentum transfer, 9.0x10(-3)<-t<4.1x10(-2) (GeV/c)(2), was measured with a 21.7 GeV/c polarized proton beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory. The ratio of hadronic spin-flip to nonflip amplitude, r(5), was obtained from the analyzing power to be Rer(5)=0.088+/-0.058 and Imr(5)=-0.161+/-0.226.

13.
Phys Rev Lett ; 84(6): 1184-7, 2000 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-11017474

RESUMEN

A new type of spin depolarization resonance has been observed at the Brookhaven Alternating Gradient Synchrotron (AGS). This spin resonance is identified as a strong closed-orbit sideband around the dominant intrinsic spin resonance. The strength of the resonance was proportional to the 9th harmonic component of the horizontal closed orbit and proportional to the vertical betatron oscillation amplitude. This "hybrid" spin resonance cannot be overcome by the partial snake at the AGS, but it can be corrected by the harmonic orbit correctors.

14.
J Neurosci ; 20(21): 8031-41, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11050124

RESUMEN

In lower vertebrates, retinal ganglion cells (RGCs) can regenerate their axons and reestablish functional connections after optic nerve injury. We show here that in goldfish RGCs, the effects of several trophic factors converge on a purine-sensitive signaling mechanism that controls axonal outgrowth and the expression of multiple growth-associated proteins. In culture, goldfish RGCs regenerate their axons in response to two molecules secreted by optic nerve glia, axogenesis factor-1 (AF-1) and AF-2, along with ciliary neurotrophic factor. The purine analog 6-thioguanine (6-TG) blocked outgrowth induced by each of these factors. Previous studies in PC12 cells have shown that the effects of 6-TG on neurite outgrowth may be mediated via inhibition of a 47 kDa protein kinase. Growth factor-induced axogenesis in RGCs was accompanied by many of the molecular changes that characterize regenerative growth in vivo, e.g. , increased expression of GAP-43 and certain cell surface glycoproteins. 6-TG inhibited all of these changes but not those associated with axotomy per se, e.g., induction of jun family transcription factors, nor did it affect cell survival. Additional studies using RGCs from transgenic zebrafish showed that expression of Talpha-1 tubulin is likewise stimulated by AF-1 and blocked by 6-TG. The purine nucleoside inosine had effects opposite to those of 6-TG. Inosine stimulated outgrowth and the characteristic pattern of molecular changes in RGCs and competitively reversed the inhibitory effects of 6-TG. We conclude that axon regeneration and the underlying program of gene expression in goldfish RGCs are mediated via a common, purine-sensitive pathway.


Asunto(s)
Axones/metabolismo , Proteínas de Peces , Regeneración Nerviosa/genética , Purinas/metabolismo , Células Ganglionares de la Retina/metabolismo , Transducción de Señal/fisiología , Molécula de Adhesión Celular del Leucocito Activado/biosíntesis , Animales , Antígenos de Superficie , Axones/efectos de los fármacos , Unión Competitiva/efectos de los fármacos , Moléculas de Adhesión Celular Neuronal/biosíntesis , Células Cultivadas , Factor Neurotrófico Ciliar/metabolismo , Factor Neurotrófico Ciliar/farmacología , Proteína GAP-43/biosíntesis , Expresión Génica/efectos de los fármacos , Carpa Dorada , Sustancias de Crecimiento/metabolismo , Sustancias de Crecimiento/farmacología , Nucleótidos de Guanina/farmacología , Inosina/metabolismo , Inosina/farmacología , Proteínas de la Membrana/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuritas/efectos de los fármacos , Neuritas/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Purinas/farmacología , Células Ganglionares de la Retina/citología , Células Ganglionares de la Retina/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Tionucleótidos/farmacología , Tubulina (Proteína)/biosíntesis
20.
Phys Rev Lett ; 64(22): 2627-2629, 1990 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-10041768
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