102 research outputs found
Eye-position dependence of torsional velocity during interaural translation, horizontal pursuit, and yaw-axis rotation in humans
AbstractThe translational vestibulo-ocular reflex (tVOR) stabilizes an image on the fovea during linear movements of the head. It has been suggested that the tVOR may share pathways with the pursuit system. We asked whether the tVOR and pursuit would be similar in their behavior relative to Listing’s Law. We compared torsional eye velocity as a function of vertical orbital position during interaural translation, pursuit, and yaw-axis rotation. We found that the eye-position-dependence of torsion was similar during translation and pursuit, which differed from that during yaw-axis rotation. These findings further support a close relationship between the mechanisms that generate pursuit and the tVOR
Способ профилактики и лечения послеоперационного гипотиреоза путем аутотрансплантации ткани щитовидной железы
Мета роботи - розробка ефективного способу хірургічного лікування й профілактики післяопераційного гіпотиреозу. Запропоновано спосіб профілактики та лікування післяопераційного гіпотиреозу методом аутотрансплантації щитоподібної залози. Наведені результати демонструють простоту, доступність і безпеку цього методу. Результати та обговорення. Ступінь гормональної компенсації після тиреоїдєктомії з аутотрансплантацією тиреоїдної тканини залежить від загальної маси аутографа, ваги пацієнта. Лікування післяопераційного гіпотиреозу методом аутотрансплантації оксігенованої тиреоїдної тканини щитоподібної залози є ефективним, простим, легким у виконанні, економічно доступним та доцільним.The aim - is to develop an affective method of surgical treatment of a postoperation hypothyroidism. Material and methods. The method of prophylaxis and treatment of a hypothyroidism by autotransplantation of a thyroid tissue worked out. For correction of postsurgical hypothyroidism the autotransplantation of oxygenated thyroid gland was performed with the following clinical-laboratory dynamics. Good results after autotransplantation of a thyroid tissue demonstrate the the simplicity,availability,safety and cheapness of this method of prophylaxis and treatment of a postoperation hypothyroidism. Completeness of hormonal compensation after thyroidectomy with autotransplantation of a thyroid tissue depends on weight of autografts, body weight of patient. Treatment of postoperation hypothyroidism by autotransplantation of a thyroid tissue is effective, simple, easy implemented and cost effective
Visual fixation and continuous head rotations have minimal effect on set-point adaptation to magnetic vestibular stimulation
Background: Strong static magnetic fields such as those in an MRI machine can induce sensations of self-motion and nystagmus. The proposed mechanism is a Lorentz force resulting from the interaction between strong static magnetic fields and ionic currents in the inner ear endolymph that causes displacement of the semicircular canal cupulae. Nystagmus persists throughout an individual's exposure to the magnetic field, though its slow-phase velocity partially declines due to adaptation. After leaving the magnetic field an after effect occurs in which the nystagmus and sensations of rotation reverse direction, reflecting the adaptation that occurred while inside the MRI. However, the effects of visual fixation and of head shaking on this early type of vestibular adaptation are unknown. Methods: Three-dimensional infrared video-oculography was performed in six individuals just before, during (5, 20, or 60 min) and after (4, 15, or 20 min) lying supine inside a 7T MRI scanner. Trials began by entering the magnetic field in darkness followed 60 s later, either by light with visual fixation and head still, or by continuous yaw head rotations (2 Hz) in either darkness or light with visual fixation. Subjects were always placed in darkness 10 or 30 s before exiting the bore. In control conditions subjects remained in the dark with the head still for the entire duration. Results: In darkness with head still all subjects developed horizontal nystagmus inside the magnetic field, with slow-phase velocity partially decreasing over time. An after effect followed on exiting the magnet, with nystagmus in the opposite direction. Nystagmus was suppressed during visual fixation; however, after resuming darkness just before exiting the magnet, nystagmus returned with velocity close to the control condition and with a comparable after effect. Similar after effects occurred with continuous yaw head rotations while in the scanner whether in darkness or light. Conclusions: Visual fixation and sustained head shaking either in the dark or with fixation inside a strong static magnetic field have minimal impact on the short-term mechanisms that attempt to null unwanted spontaneous nystagmus when the head is still, so called VOR set-point adaptation. This contrasts with the critical influence of vision and slippage of images on the retina on the dynamic (gain and direction) components of VOR adaptation
Can induced gravity isotropize Bianchi I, V, or IX Universes?
We analyze if Bianchi I, V, and IX models in the Induced Gravity (IG) theory
can evolve to a Friedmann--Roberson--Walker (FRW) expansion due to the
non--minimal coupling of gravity and the scalar field. The analytical results
that we found for the Brans-Dicke (BD) theory are now applied to the IG theory
which has ( being the square ratio of the Higgs to
Planck mass) in a cosmological era in which the IG--potential is not
significant. We find that the isotropization mechanism crucially depends on the
value of . Its smallness also permits inflationary solutions. For the
Bianch V model inflation due to the Higgs potential takes place afterwads, and
subsequently the spontaneous symmetry breaking (SSB) ends with an effective FRW
evolution. The ordinary tests of successful cosmology are well satisfied.Comment: 24 pages, 5 figures, to be published in Phys. Rev. D1
Investigating Guided Extensive Reading And Vocabulary Knowledge Performance Among Remedial Esl Learners In A Public University In Malaysia
Penyelidikan menyokong pembacaan ekstensif, yang tertumpu pada pembelajaran kebetulan (incidental learning), sebagai wadah utama bagi perkembangan pengetahuan kosa kata bahasa kedua/asing.
Research supports extensive reading, which draws on incidental learning, as a primary tool for second/foreign language vocabulary knowledge development
APOL1 genotype-associated morphologic changes among patients with focal segmental glomerulosclerosis
Background: The G1 and G2 alleles of apolipoprotein L1 (APOL1) are common in the Black population and associated with increased risk of focal segmental glomerulosclerosis (FSGS). The molecular mechanisms linking APOL1 risk variants with FSGS are not clearly understood, and APOL1’s natural absence in laboratory animals makes studying its pathobiology challenging. Methods: In a cohort of 90 Black patients with either FSGS or minimal change disease (MCD) enrolled in the Nephrotic Syndrome Study Network (58% pediatric onset), we used kidney biopsy traits as an intermediate outcome to help illuminate tissue-based consequences of APOL1 risk variants and expression. We tested associations between APOL1 risk alleles or glomerular APOL1 mRNA expression and 83 light- or electron-microscopy traits measuring structural and cellular kidney changes. Results: Under both recessive and dominant models in the FSGS patient subgroup (61%), APOL1 risk variants were significantly correlated (defined as FDR <0.1) with decreased global mesangial hypercellularity, decreased condensation of cytoskeleton, and increased tubular microcysts. No significant correlations were detected in MCD cohort. Independent of risk alleles, glomerular APOL1 expression in FSGS patients was not correlated with morphologic features. Conclusions: While APOL1-associated FSGS is associated with two risk alleles, both one and two risk alleles are associated with cellular/tissue changes in this study of FSGS patients. Our lack of discovery of a large group of tissue differences in FSGS and no significant difference in MCD may be due to the lack of power but also supports investigating whether machine learning methods may more sensitively detect APOL1-associated changes
Multiethnic Meta-Analysis Identifies RAI1 as a Possible Obstructive Sleep Apnea-related Quantitative Trait Locus in Men.
Obstructive sleep apnea (OSA) is a common heritable disorder displaying marked sexual dimorphism in disease prevalence and progression. Previous genetic association studies have identified a few genetic loci associated with OSA and related quantitative traits, but they have only focused on single ethnic groups, and a large proportion of the heritability remains unexplained. The apnea-hypopnea index (AHI) is a commonly used quantitative measure characterizing OSA severity. Because OSA differs by sex, and the pathophysiology of obstructive events differ in rapid eye movement (REM) and non-REM (NREM) sleep, we hypothesized that additional genetic association signals would be identified by analyzing the NREM/REM-specific AHI and by conducting sex-specific analyses in multiethnic samples. We performed genome-wide association tests for up to 19,733 participants of African, Asian, European, and Hispanic/Latino American ancestry in 7 studies. We identified rs12936587 on chromosome 17 as a possible quantitative trait locus for NREM AHI in men (N = 6,737; P = 1.7 × 10 <sup>-8</sup> ) but not in women (P = 0.77). The association with NREM AHI was replicated in a physiological research study (N = 67; P = 0.047). This locus overlapping the RAI1 gene and encompassing genes PEMT1, SREBF1, and RASD1 was previously reported to be associated with coronary artery disease, lipid metabolism, and implicated in Potocki-Lupski syndrome and Smith-Magenis syndrome, which are characterized by abnormal sleep phenotypes. We also identified gene-by-sex interactions in suggestive association regions, suggesting that genetic variants for AHI appear to vary by sex, consistent with the clinical observations of strong sexual dimorphism
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