Transverse oscillations of a multi-stranded loop

We investigate the transverse oscillations of a line-tied multi-stranded coronal loop composed of several parallel cylindrical strands. First, the collective fast normal modes of the loop are found with the T-matrix theory. There is a huge quantity of normal modes with very different frequencies and a complex structure of the associated magnetic pressure perturbation and velocity field. The modes can be classified as bottom, middle, and top according to their frequencies and spatial structure. Second, the temporal evolution of the velocity and magnetic pressure perturbation after an initial disturbance are analyzed. We find complex motions of the strands. The frequency analysis reveals that these motions are a combination of low and high frequency modes. The complexity of the strand motions produces a strong modulation of the whole tube movement. We conclude that the presumed internal fine structure of a loop influences its transverse oscillations and so its transverse dynamics cannot be properly described by those of an equivalent monolithic loop.Comment: Accepted in Ap

Early suppression of lymphoproliferative response in dogs with natural infection by Leishmania infantum.

Dogs are the domestic reservoirs of zoonotic visceral leishmaniasis caused by Leishmania infantum. Early detection of canine infections evolving to clinically patent disease may be important to leishmaniasis control. In this study we firstly investigated the peripheral blood mononuclear cell (PBMC) response to leishmanial antigens and to polyclonal activators concanavalin A, phytohemagglutinin and pokeweed mitogen, of mixed-breed dogs with natural L. infantum infection, either in presymptomatic or in patent disease condition, compared to healthy animals. Leishmania antigens did not induce a clear proliferative response in any of the animals examined. Furthermore, mitogen-induced lymphocyte proliferation was found strongly reduced not only in symptomatic, but also in presymptomatic dogs suggesting that the cell-mediated immunity is suppressed in progressive canine leishmaniasis. To test this finding, naive Beagle dogs were exposed to natural L. infantum infection in a highly endemic area of southern Italy. Two to 10 months after exposure all dogs were found to be infected by Leishmania, and on month 2 of exposure they all showed a significant reduction in PBMC activation by mitogens. Our results indicate that suppression of the lymphoproliferative response is a common occurrence in dogs already at the beginning of an established leishmanial infection. # 1999 Elsevier Science B.V. All rights reserved

Electronic states and transport properties in the Kronig-Penney model with correlated compositional and structural disorder

We study the structure of the electronic states and the transport properties of a Kronig-Penney model with weak compositional and structural disorder. Using a perturbative approach we obtain an analytical expression for the localisation length which is valid for disorder with arbitrary correlations. We show how to generate disorder with self- and cross-correlations and we analyse both the known delocalisation effects of the long-range self-correlations and new effects produced by cross-correlations. We finally discuss how both kinds of correlations alter the transport properties in Kronig-Penney models of finite size.Comment: 23 pages, 5 figure

Multiple congenital bilateral trigger digits in a 2-year-old child: case report

Trigger finger is a rare condition in children. In this paper, we report on a 2-year-old boy with multiple congenital bilateral trigger digits. The patient had no history of perinatal trauma, viral or bacterial infections, or metabolic disorders. The patient was treated with physiotherapy for one year. At the one-year follow-up, the boy presented with six trigger fingers (3 on the right hand, 3 on the left hand). Neither thumb was involved. The six trigger fingers were treated surgically: first, the right-hand trigger fingers and, six months later, those of the left hand. After each operation, a 4-week brace in extension was applied to the operated hand. The symptoms were completely resolved after surgical treatment. Many authors have recommended surgical release for the treatment of trigger finger in children; empirical treatment with physiotherapy may be an option when symptoms present or appear at an older age

Post-traumatic malunion of the proximal phalanx of the finger. Medium-term results in 24 cases treated by "in situ" osteotomy

We report the clinical and radiographic medium-term results obtained for 20 patients (24 fingers) treated surgically for post-traumatic malunion of the proximal phalanx of the finger. In all cases we performed a corrective osteoclasia or osteotomy at the site of malunion, followed by miniplate and screw fixation or by screw fixation only. The corrective osteoclasia was performed when malalignment was addressed within six weeks after injury. Two patients who had two fractures underwent additional surgery (tenolysis and/or capsulolysis) to improve function and ROM. At the final follow-up, at a mean of 24 months after corrective surgery, good or excellent clinical and radiographic results were obtained in all the patients. The pseudoclaw deformity disappeared in all cases in which a volar angulation deformity was present. An average improvement of about 30% in the range of motion of the MP and PIP joints was observed; only 4 patients complained of mild pain at the maximum degrees of articular excursion of the MP and PIP joints. All the patients presented an improvement in grip strength. The mean DASH score in our series was 5 points. In two of the four cases treated by an intra-articular corrective osteotomy, mild radiographic signs of osteoarthritis at the MP joint were present. The data for this study confirm that "in situ" osteotomy stabilized by miniplates and/or screws is an effective procedure to correct post-traumatic malunions of the proximal phalanges of the fingers

Immune effects of four Fusarium-Toxins ( FB1, ZEA, NIV, DON) on the proliferation of Jurkat cells and porcine lymphocytes: in vitro study.

Fusarium toxins are secondary metabolites produced by fungi belonging to Fusarium spp., commonly found as contaminants in products of vegetable origin, particularly in cereal grains, in regions with temperate climate in Europe, America and Asia. Numerous toxic effects are attributed to mycotoxins both in humans and animals, such as mutagenic, cencerogenic and teratogenic properties. Moreover, some of them can alter normal immune responses when they are present in food at levels lower than those necessary to cause the symptoms of mycotoxicosis. In the present work, we evaluated the immunomodulatory effects of four Fusarium toxins (FB1, ZEA, NIV, DON) using two different experimental models: Jurkat cells and porcine lymphocytes. In addition to the activity of single mycotoxins, we evaluated possible interactions between Fusarium toxins to reproduce experimental conditions in vitro as near as possible to field conditions. Our results revealed the immunomodulatory properties of the mycotoxin objects of the current study. They also underline the interest in studying possible interactions among different mycotoxins, particularly among those mainly present in food such as Fusarium mycotoxins, not only regarding their toxicodinamic aspect but also to define tolerable maximum levels of Fusarium toxins in food

Importance of the morphology and structure of the primary aggregates for the dispersibility of carbon nanotubes in polymer melts

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Contrast Enhancement of Optical Coherence Tomography Images Using Branched Gold Nanoparticles

We propose the use of branched gold nanoparticles (B-GNPs) as a contrast agent for optical coherence tomography (OCT) imaging. Our results show that even when the central source of our OCT (1325 nm) is too far from the maximum peak of the plasmon resonance, branched nanoparticles scatter light very efficiently at this wavelength. B-GNPs were tested as a contrast agent in water and agarose-TiO2 tissue phantoms; the estimated increments in contrast were 9.19 dB and 15.07 dB for branched nanoparticles in water with concentrations of 2.2×109 NPs/mL and 6.6×109 NPs/mL, respectively, while for agarose-TiO2 tissue phantoms the estimated value was 3.17 dB. These results show the promising application of B-GNPs as a contrast agent for tissue imaging using OCT, not only for sources at 1325 nm but also at other central wavelengths located between 800 and 1000 nm

Impact of parental involvement on the communication skills of children with autism

In pursuit of every individual’s access to education regardless of one’s statusin life, the Philippines establishedspecial education(SPED) centers to caterto children with special needs.Children with autism are the expectedbeneficiaries of these centers. This research assessed the impact of parentalinvolvement on the communication skills of children with autism at a SPEDcenter in Cebu City, Cebu, Philippines. Their teachers, regardingtheircommunication skills, assessed thirty children with autism. At the sametime, parents were asked to rate their extent of involvement in their child’sschool activities using survey questionnaires. Different statistical tools wereused to treat the data gathered, such as the weighted mean, standarddeviation, andPearsonproduct moment correlation coefficient. Resultsrevealed that parents were involved in the school activities of their children.However, the children had a moderate manifestation of communicationskills. It was found that there is a moderate positive significant relationshipbetween the parents’involvement and the communication skills of thechildren. Thus, teachers are encouraged to design programs for the childrenthat would involvethe parents in enhancing the communication skills ofchildren with autism