50 research outputs found

    Alfvenic waves in polar spicules

    Full text link
    Context. For investigating spicules from the photosphere to coronal heights, the new Hinode/SOT long series of high resolution observations from Space taken in CaII H line emission offers an improved way to look at their remarkable dynamical behavior using images free of seeing effects. They should be put in the context of the huge amount of already accumulated material from ground-based instruments, including high- resolution spectra of off-limb spicules. Results. The surge-like behavior of solar polar region spicules supports the untwisting multi-component interpretation of spicules exhibiting helical dynamics. Several tall spicules are found with (i) upward and downward flows similar at lower and middle-levels, the rate of upward motion being slightly higher at high levels; (ii) the left and right-hand velocities are also increasing with height; (iii) a large number of multi-component spicules show shearing motion of both left-handed and right-handed senses occurring simultaneously, which might be understood as twisting (or untwisting) threads. The number of turns depends on the overall diameter of the structure made of components and changes from at least one turn for the smallest structure to at most two or three turns for surge-like broad structures; the curvature along the spicule corresponds to a low turn number similar to a transverse kink mode oscillation along the threads.Comment: 8 pages, 10 figures, Accepted in Astronomy and Astrophysic

    Hemodynamic effect of atrioventricular and interventricular dyssynchrony in patients with biventricular pacing: Implications for the pacemaker syndrome

    Get PDF
    Background/Objectives: Pacemaker syndrome was mainly described as the sequel of atrioventricular (AV) dyssynchrony. The role of interventricular (VV) dyssynchrony has not been studied yet. The aims of this study were to noninvasively assess the hemodynamic effects of different ventricular pacing sites with and without AV and VV dyssynchrony and to observe the patients for clinical symptoms of the pacemaker syndrome during the AV sequential and ventricular-only pacing modes. Materials and Methods: Between March 2009 and February 2010, 40 patients (28 men; mean age, 61 ± 15 years) with biventricular (BiV) device were enrolled. Mean systolic and diastolic blood pressures (BP) of 5 beats were measured 5 minutes after each mode change using fingertip plethysmography. The patients were also observed for the occurrence of symptoms suggestive of the pacemaker syndrome, including dyspnea, palpitations, dizziness, presyncope, and syncope. Results: There was no difference in mean systolic BP among different ventricular-only pacing modes (all P = NS). However, mean systolic BP was significantly higher in AV sequential biventricular pacing (DDD-BiV) compared with ventricular-only pacing modes (all P0.05). Conclusions: The present study showed that the non-AV sequential BiV and LV pacing may have no significant benefit compared with RV pacing in terms of systolic blood pressure. However, there was marked hemodynamic improvement following mode change to AV sequential BiV pacing. This study may have important implications for pathogenesis of pacemaker syndrome

    Biallelic SQSTM1 mutations in early-onset, variably progressive neurodegeneration.

    Get PDF
    OBJECTIVE: To characterize clinically and molecularly an early-onset, variably progressive neurodegenerative disorder characterized by a cerebellar syndrome with severe ataxia, gaze palsy, dyskinesia, dystonia, and cognitive decline affecting 11 individuals from 3 consanguineous families. METHODS: We used whole-exome sequencing (WES) (families 1 and 2) and a combined approach based on homozygosity mapping and WES (family 3). We performed in vitro studies to explore the effect of the nontruncating SQSTM1 mutation on protein function and the effect of impaired SQSTM1 function on autophagy. We analyzed the consequences of sqstm1 down-modulation on the structural integrity of the cerebellum in vivo using zebrafish as a model. RESULTS: We identified 3 homozygous inactivating variants, including a splice site substitution (c.301+2T>A) causing aberrant transcript processing and accelerated degradation of a resulting protein lacking exon 2, as well as 2 truncating changes (c.875_876insT and c.934_936delinsTGA). We show that loss of SQSTM1 causes impaired production of ubiquitin-positive protein aggregates in response to misfolded protein stress and decelerated autophagic flux. The consequences of sqstm1 down-modulation on the structural integrity of the cerebellum in zebrafish documented a variable but reproducible phenotype characterized by cerebellum anomalies ranging from depletion of axonal connections to complete atrophy. We provide a detailed clinical characterization of the disorder; the natural history is reported for 2 siblings who have been followed up for >20 years. CONCLUSIONS: This study offers an accurate clinical characterization of this recently recognized neurodegenerative disorder caused by biallelic inactivating mutations in SQSTM1 and links this phenotype to defective selective autophagy

    Gray Matter Changes in Parkinson's and Alzheimer's Disease and Relation to Cognition

    Get PDF
    Purpose of Review We summarize structural (s)MRI findings of gray matter (GM) atrophy related to cognitive impairment in Alzheimer's disease (AD) and Parkinson's disease (PD) in light of new analytical approaches and recent longitudinal studies results. Recent Findings The hippocampus-to-cortex ratio seems to be the best sMRI biomarker to discriminate between various AD subtypes, following the spatial distribution of tau pathology, and predict rate of cognitive decline. PD is clinically far more variable than AD, with heterogeneous underlying brain pathology. Novel multivariate approaches have been used to describe patterns of early subcortical and cortical changes that relate to more malignant courses of PD. New emerging analytical approaches that combine structural MRI data with clinical and other biomarker outcomes hold promise for detecting specific GM changes in the early stages of PD and preclinical AD that may predict mild cognitive impairment and dementia conversion

    Phenotypic continuum of NFU1-related disorders.

    Get PDF
    Bi-allelic variants in Iron-Sulfur Cluster Scaffold (NFU1) have previously been associated with multiple mitochondrial dysfunctions syndrome 1 (MMDS1) characterized by early-onset rapidly fatal leukoencephalopathy. We report 19 affected individuals from 10 independent families with ultra-rare bi-allelic NFU1 missense variants associated with a spectrum of early-onset pure to complex hereditary spastic paraplegia (HSP) phenotype with a longer survival (16/19) on one end and neurodevelopmental delay with severe hypotonia (3/19) on the other. Reversible or irreversible neurological decompensation after a febrile illness was common in the cohort, and there were invariable white matter abnormalities on neuroimaging. The study suggests that MMDS1 and HSP could be the two ends of the NFU1-related phenotypic continuum

    Explanation of parent gender difference on needs of children of parent with mental illness: a qualitative research

    No full text
    Background: Parents play an important role in a child's life. The roles of parents are impaired by mental illness and this issue affects the child’s needs and meets them. Objective: This study was designed and conducted to explain gender differences of parents with mental illness on their children needs. Methods: This study was conducted using the grounded theory. Semi structured interviews were conducted with 17 participants in Qazvin 2010, selected based on purposeful and theoretical sampling. Participants included children of patients with mental disorders, their families and mental health professionals (nurses, clinical psychologist and counselor). Data were analyzed using constant comparison method suggested by Strauss & Corbin 1998. Findings: Economic and social outcomes are two major problems occur in father illness, But focus of outcomes of mother's illness is emotional. Although all participants believed except Parents gender, their illness affected on children; but mother illness has serious outcomes. Conclusion: With respect to children problems in parents' mental illness, a special place for children should be considered in the patient care plan, especially when the mother has mental illness that this issue is more important

    Side Effects of Intravenous Streptokinase in Different Age Groups Patients with Acute Myocardial Infarction

    No full text
    Abstract Background & aim: Myocardial infarction is one of the most common cardiovascular diseases. Streptokinase is used in patients with myocardial infarction with ST-segment elevation. The aim of this study was to compare the side effects of intravenous streptokinase in acute myocardial infarction patients in different age groups. Methods: In the present analytic descriptive study, the samples included 100 eligible patients which received intravenous streptokinase. The research instrument was a questionnaire consisting of two parts: the first part was used to measure the underlying data and the second part to evaluate the side effects of intravenous streptokinase,. Data were analyzed by chi-square statistical tests. Results: There were no significant adverse events between intravenous streptokinase and different age groups ((P>0.05).). The most common side effects of this drug were cardiovascular complications in different age groups. Conclusion: the use of streptokinase intravenous drug in different age groups is associated with risk of cardiovascular complications. Key words: age, side effects, streptokinase, acute myocardial infarction, thrombolytic therapy, ST elevatio
    corecore