A Problem of Relative, Constrained Motion

We develop a new method to determine the acceleration of a block sliding down along the face of a moving wedge. We have been able to link the solution of this problem to that of the inclined plane problem of elementary physics, thus providing a simpler solution to it.Comment: 4 pages, 3 figure

Kinesiophobia in migraine

Pain aggravation by movement and avoidance of movement (kinesiophobia) is often reported by patients during migraine attacks. Yet its specific contribution to migraine diagnosis is undetermined. To characterize the frequency and severity of kinesiophobia during migraine and its role in the diagnosis of primary headaches, we questioned 150 patients (126 women and 24 men, average age 38.5 yrs) with migraine (n = 111) or tension-type headache (TTH) (n = 39) about aggravation of pain by bending forward, brisk head movements (jolt), and avoidance of movement during the attacks. The degree of pain worsening by each stimulus was measured through a visual analog scale and compared to worsening produced by other sensory stimuli such as light, sound, and smell. The discrimination power of kinesiophobia between migraine and TTH was calculated, using the International Classification of Headache Disorders criteria as gold standard. Sensitivity/specificity of studied symptoms was high in differentiating the 2 headache types: bending forward: 98%/85.7%; jolt: 96.3%/81.6%; and immobility during the attacks: 100%/70%. The degree of kinesiophobia was identical to photo- and phonophobia in migraine patients. We conclude that kinesiophobia discriminates between migraine and TTH. Bending forward and jolt may be useful additional questions to ask patients for the differentiation of headache attacks. PERSPECTIVE: This article evaluates the specific role of movement (movement-induced pain aggravation and avoidance of movement) in primary headaches. Kinesophobia is an easy symptom to screen, explained by migraine pathophysiology, and proved to be a sensitive and specific measure to identify migraine attacks when compared to tension-type headache

Geotechnical Performance of a Tunnel in Soft Ground

The analysis of a tunnel section excavated through soft ground is presented. The tunnel construction was monitored and its behavior is compared with results obtained by a numerical simulation. The field instrumentation and the geotechnical properties of the site are presented and the modeling of the soil behavior using Lade\u27s model discussed

Critical phenomena and quantum phase transition in long range Heisenberg antiferromagnetic chains

Antiferromagnetic Hamiltonians with short-range, non-frustrating interactions are well-known to exhibit long range magnetic order in dimensions, $d\geq 2$ but exhibit only quasi long range order, with power law decay of correlations, in d=1 (for half-integer spin). On the other hand, non-frustrating long range interactions can induce long range order in d=1. We study Hamiltonians in which the long range interactions have an adjustable amplitude lambda, as well as an adjustable power-law $1/|x|^\alpha$, using a combination of quantum Monte Carlo and analytic methods: spin-wave, large-N non-linear sigma model, and renormalization group methods. We map out the phase diagram in the lambda-alpha plane and study the nature of the critical line separating the phases with long range and quasi long range order. We find that this corresponds to a novel line of critical points with continuously varying critical exponents and a dynamical exponent, z<1.Comment: 27 pages, 12 figures. RG flow added. Final version to appear in JSTA

Cerebral venous thrombosis: retrospective analysis of 49 cases

Introduction: Cerebral Venous Thrombosis (CVT) is a rare and potentially life-threatening disease, accounting for about 0.5% of stroke cases. However, it is believed to be an underdiagnosed condition. Early diagnosis requires a high degree of suspicion and appropriate use of imaging modalities. Objectives: Imagiological and clinical characterization of CVT cases diagnosed at our hospital from 2004 to 2007. Methods: This study was a retrospective, cross-sectional analysis from 2004 to 2007, using our institution database. We reviewed hospital discharge data to assess the incidence of CVT. The study population consisted of 49 patients. Retrospective review of the clinical data and imaging studies of these patients was then performed. Results: Of the 49 patients with confirmed CVT, 38 were female. Patient age varied between 16 and 75 years, with an average of 42.6 years. Thrombotic risk factors were found in 43 patients; the most frequent was dyslipidemia (n = 22) followed by oral contraceptive use (n = 18). Initial head Computerized Tomography (CT) was normal in six cases. Diagnosis was made by Magnetic Resonance (MR) in 38 cases, Cerebral CT-Venography in 10 cases and Digital Subtraction Angiography in one case. Average time from onset of symptoms to diagnosis was nine days; this was not significantly different when comparing the group diagnosed by MR with the group diagnosed by CT-Venography. Right transverse sinus was the most frequent location of thrombosis (n = 36). Only in four cases thrombosis did not involve the lateral sinuses. Conclusions: Lateral sinus thrombosis is a frequent variety of CVT, accounting for 91.8% of our cases. A negative Head CT scan does not exclude the presence of cerebral venous thrombosis; therefore appropriate imaging study should be performed whenever there's a high degree of clinical suspicion. Cerebral CT-Venography seems to be a good alternative to MR for the diagnosis of CVT

Apparent dominance of the G1-G3 genetic cluster of echinococcus granulosus strains in the central inland region of Portugal

Infection by the larval stage of the cestode Echinococcus granulosus causes a disease known as cystic echinococcosis or hydatidosis, which is one of the most widespread zoonotic infections of veterinary and medical importance. Numerous studies have shown that E. granulosus exists as a complex of strains differing in a wide variety of criteria. Ten distinct genotypes (G1-G10) have been identified with potential impact on the pathology, epidemiology and the effect of the measures implemented for the control of hydatidosis. Our main objective was to carry out a preliminary analysis of the genotypes of E. granulosus circulating in the central inland region of Portugal. Parasite samples (hydatid cysts, n=27) were isolated from the liver and lung of sheep and cattle. The DNA extracted from protoscoleces isolated from the fertile cysts served a template for the PCR amplification of part of the mitochondrial cytochrome c oxidase subunit 1 (cox1), ATP synthase F0 subunit 6 (atp6) as well as the large (rrnL/16S) and small (rrnS/12S) ribosomal RNA genes. Similarity searches with homologous sequences in the databanks indicated very high similarity with references assigned to the G1, G3 and/or G1-G3 complex of Echinococcus strains. Phylogenetic analysis (Bayesian approach) supported these observations, and confirmed the assignment of all the analyzed sequences to the G1-G3 genetic cluster

Rotação de cultivares como uma estratégia para o manejo da antracnose do sorgo.

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Natural polymorphisms of HIV type 2 pol sequences from drug-naive individuals

Until today, the susceptibility of human immunodeficiency virus type 2 (HIV-2) to protease and nucleosidic reverse-transcriptase inhibitors (PI and NRTI, respectively) has not been clearly documented. In this report we studied HIV-2 proviral sequences (n = 30) from drug-naive patients. Our results revealed that several amino acid positions in the protease and reverse transcriptase coding sequence harbored residues that have been associated with drug resistance in HIV-1-infected patients. In particular, the M46I substitution in the protease was detected in 90% of the sequences analyzed, which, together with the other substitutions identified, may indicate a reduced susceptibility of HIV-2-infected drug-naive patients to PI. Furthermore, interpretation of genotypic data with four available algorithms, developed for interpretation of HIV-1 sequence data, suggested nonoverlapping profiles of drug resistance

Recomendação para o controle químico da helmintosporiose do sorgo (Exserohilum turcicum).

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Uso integrado da resistência genética e aplicação de fungicidas para o manejo da antracnose do sorgo.

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