Short stature, hyperkalemia and acidosis: A defect in renal transport of potassium

Short stature, hyperkalemia, and acidosis: A defect in renal transport of potassium. An eleven-year-old boy presented with short stature, hyperkalemia, and metabolic acidosis. No endocrine cause for a short stature could be demonstrated. Renal function, as assessed by inulin and PAH clearances, concentrating and diluting capacity, and ability to acidify the urine and to excrete net acid, was normal. No defect was detected in adrenal secretion of, or renal responsiveness to, aldosterone. A low renal threshold for bicarbonate was documented which apparently explained the acidosis. However, correction of the acidosis by administration of sodium bicarbonate did not influence the hyperkalemia, making it unlikely that an abnormality in bicarbonate reabsorption was the primary defect. Chlorothiazide induced a fall in serum potassium and a rise in serum bicarbonate to normal levels. During bicarbonate loading the rates of excretion of potassium in urine were consistently below those observed in control subjects. It appeared, therefore, that the patient had a primary abnormality in potassium excretion. The resulting hyperkalemia caused urinary loss of bicarbonate and systemic acidosis. Correction of both the acidosis and hyperkalemia by chronic administration of chlorothiazide and sodium bicarbonate has resulted in resumption of normal growth.Retard de croissance, hyperkaliéme et acidose: Un déficit du transport rénal du potassium. Un enfant de 11 ans avait un retard de croissance, une hyperkaliémie et une acidose métabolique. Aucune cause endocrine du retard de croissance n'a été trouvée. La fonction rénale, estimée par les clearances de l'inuline et du PAH, la capacité de concentration et de dilution et la capacité d'acidifier l'urine, était normales. Aucun déficit de la secrétion d'aldostérone ou de la réponse rénale à l'aldostérone n'a été mis en évidence. Un seuil rénal bas des bicarbonates a été découvert, qui explique apparemment l'acidose. Cependant la correction de l'acidose par l'administration de bicarbonate de sodium n'a pas influencé l'hyperkaliémie, ce qui rend peu probable que le déficit de la réabsorption de bicarbonate soit la cause de l'ensemble. Le Chlorothiazide a déterminé une baisse de la kaliéme et une augmentation du bicarbonate plasmatique jusqu'à des valeurs normales. Pendant une charge en bicarbonate les débits d'excretion du potassium dans les urines ont été nettement inférieurs à ceux obtenus chez des sujets témoins. Il apparaît donc que le malade a une anomalie primitive de l'excrétion de potassium. L'hyperkaliémie qui en est la conséquence a déterminé une perte de bicarbonate dans les urines et une acidose systémique. La correction de l'acidose et de l'hyperkaliémie par l'administration permanente de Chlorothiazide et de bicarbonate de sodium a eu pour résultat une reprise de la croissance normale

Spelling in adolescents with dyslexia: errors and modes of assessment

In this study we focused on the spelling of high-functioning students with dyslexia. We made a detailed classification of the errors in a word and sentence dictation task made by 100 students with dyslexia and 100 matched control students. All participants were in the first year of their bachelor’s studies and had Dutch as mother tongue. Three main error categories were distinguished: phonological, orthographic, and grammatical errors (on the basis of morphology and language-specific spelling rules). The results indicated that higher-education students with dyslexia made on average twice as many spelling errors as the controls, with effect sizes of d ≥ 2. When the errors were classified as phonological, orthographic, or grammatical, we found a slight dominance of phonological errors in students with dyslexia. Sentence dictation did not provide more information than word dictation in the correct classification of students with and without dyslexia

Does Perceptual Belongingness Affect Lightness Constancy?

Scientists have shown that two equal grey patches may differ in lightness when belonging to different reflecting surfaces. We extend this investigation to the constancy domain. In a CRT simulation of a bipartite field of illumination, we manipulated the arrangement of twelve patches: six squares and six diamonds. Patches of the same shape could be placed: (i) all within the same illumination field; or (ii) forming a row across the illumination fields. Furthermore, we manipulated proximity between the innermost patches and the illumination edge. The patches could be (i) touching (forming an X-junction); or (ii) not touching (not forming an X-junction). Observers were asked to perform a lightness match between two additional patches, one illuminated and the other in shadow. We found better lightness constancy when the patches of the same shape formed a row across the fields, with no effect of X-junctions

Gauge links for transverse momentum dependent correlators at tree-level

In this paper we discuss the incorporation of gauge links in hadronic matrix elements that describe the soft hadronic physics in high energy scattering processes. In this description the matrix elements appear in soft correlators and they contain non-local combinations of quark and gluon fields. In our description we go beyond the collinear approach in which case also the dependence on transverse momenta of partons is taken into consideration. The non-locality in the transverse direction leads to a complex gauge link structure for the full process, in which color is entangled, even at tree-level. We show that at tree-level in a 1-parton unintegrated (1PU) situation, in which only the transverse momentum of one of the initial state hadrons is relevant, one can get a factorized expression involving transverse momentum dependent (TMD) distribution functions. We point out problems at the level of two initial state hadrons, even for relatively simple processes such as Drell-Yan scattering.Comment: 25 pages, corrected typos and updated reference

Bounds on transverse momentum dependent distribution and fragmentation functions

We give bounds on the distribution and fragmentation functions that appear at leading order in deep inelastic 1-particle inclusive leptoproduction or in Drell-Yan processes. These bounds simply follow from positivity of the defining matrix elements and are an important guidance in estimating the magnitude of the azimuthal and spin asymmetries in these processes.Comment: 5 pages, Revtex, 3 Postscript figures, version with minor changes, to be published in Physical Review Letter

A polarized version of the CCFM equation for gluons

A derivation for a polarized CCFM evolution equation which is suitable to describe the scaling behavior of the the unintegrated polarized gluon density is given. We discuss the properties of this polarized CCFM equation and compare it to the standard CCFM equation in the unpolarized case.Comment: 15 pages, 6 figures, RevTeX, some minor typos corrected, version to appear in Phys. Rev.

First-year performance of 1-0 containerized Douglas-fir seedlings on droughty sites in southwestern Oregon

The effects of artificial shading and aspect on the performance of 1-0 container-grown Douglas-fir seedlings were evaluated 1 year after outplanting on four different aspects in southwest Oregon. The test areas, all characterized by steep slopes and shallow, skeletal soils with a surface mantle of loose rock and logging slash, have histories of repeated reforestation failure. Seedling survival was greatest on north and south slopes. Shadecards improved survival by 16 percent on the south slope and significantly increased height growth on the west slope. Artificial shading on east and west aspects produced seedlings with significantly smaller diameters than those without shading. Shadecards are recommended for south and west aspects with skeletal soils. Surface movement of debris and rock may be a significant factor in seedling survival during the first year. Protecting seedlings from animal damage and downslope movement of materials with Vexar tubes is recommended for sites where both problems exist

Behaviour of motor unit action potential rate, estimated from surface EMG, as a measure of muscle activation level

BACKGROUND: Surface electromyography (EMG) parameters such as root-mean-square value (RMS) are commonly used to assess the muscle activation level that is imposed by the central nervous system (CNS). However, RMS is influenced not only by motor control aspects, but also by peripheral properties of the muscle and recording setup. To assess motor control separately, the number of motor unit action potentials (MUAPs) per second, or MUAP Rate (MR) is a potentially useful measure. MR is the sum of the firing rates of the contributing MUs and as such reflects the two parameters that the CNS uses for motor control: number of MUs and firing rate. MR can be estimated from multi-channel surface EMG recordings. The objective of this study was to explore the behaviour of estimated MR (eMR) in relation to number of active MUs and firing rate. Furthermore, the influence of parameters related to peripheral muscle properties and recording setup (number of fibers per MU, fiber diameter, thickness of the subcutaneous layer, signal-to-noise-ratio) on eMR was compared with their influence on RMS. METHODS: Physiological parameters were varied in a simulation model that generated multi-channel EMG signals. The behaviour of eMR in simulated conditions was compared with its behaviour in experimental conditions. Experimental data was obtained from the upper trapezius muscle during a shoulder elevation task (20–100 N). RESULTS: The simulations showed strong, monotonously increasing relations between eMR and number of active MUs and firing rate (r(2 )> 0.95). Because of unrecognized superimpositions of MUAPs, eMR was substantially lower than the actual MUAP Rate (aMR). The percentage of detected MUAPs decreased with aMR, but the relation between eMR and aMR was rather stable in all simulated conditions. In contrast to RMS, eMR was not affected by number of fibers per MU, fiber diameter and thickness of the subcutaneous layer. Experimental data showed a strong relation between eMR and force (individual second order polynomial regression: 0.96 < r(2 )< 0.99). CONCLUSION: Although the actual number of MUAPs in the signal cannot be accurately extracted with the present method, the stability of the relation between eMR and aMR and its independence of muscle properties make eMR a suitable parameter to assess the input from the CNS to the muscle at low contraction levels non-invasively

A genome-wide DNA methylation signature for SETD1B-related syndrome

SETD1B is a component of a histone methyltransferase complex that specifically methylates Lys-4 of histone H3 (H3K4) and is responsible for the epigenetic control of chromatin structure and gene expression. De novo microdeletions encompassing this gene as well as de novo missense mutations were previously linked to syndromic intellectual disability (ID). Here, we identify a specific hypermethylation signature associated with loss of function mutations in the SETD1B gene which may be used as an epigenetic marker supporting the diagnosis of syndromic SETD1B-related diseases. We demonstrate the clinical utility of this unique epi-signature by reclassifying previously identified SETD1B VUS (variant of uncertain significance) in two patients

A genome-wide DNA methylation signature for SETD1B-related syndrome

SETD1B is a component of a histone methyltransferase complex that specifically methylates Lys-4 of histone H3 (H3K4) and is responsible for the epigenetic control of chromatin structure and gene expression. De novo microdeletions encompassing this gene as well as de novo missense mutations were previously linked to syndromic intellectual disability (ID). Here, we identify a specific hypermethylation signature associated with loss of function mutations in the SETD1B gene which may be used as an epigenetic marker supporting the diagnosis of syndromic SETD1B-related diseases. We demonstrate the clinical utility of this unique epi-signature by reclassifying previously identified SETD1B VUS (variant of uncertain significance) in two patients