1,814 research outputs found
Neural origins of basal diencephalon in teleost fishes: Radial versus tangential migration
Teleost fish possess large lateral diencephalic regions such as the torus lateralis, the preglomerular area, and the diffuse nucleus of the hypothalamic inferior lobe. While their developmental origins traditionally were suggested to lie in diencephalic midline ventricular proliferative zones, more remote midbrain origins were reported recently. This review focuses on the preglomerular region and summarizes the data supporting three existing hypotheses on its developmental origins. The conclusion is that lateral torus, diffuse nucleus of hypothalamic inferior lobe, and preglomerular region are part of the diencephalon, but have a multiregional origin provided by both radially and tangentially migrating cells forming these regions in question
Chromatic induction and the layout of colours within a complex scene
AbstractA target’s apparent colour is influenced by the colours in its surrounding. If the surrounding consists of a single coloured surface, the influence is a shift ‘away’ from the surface’s colour. If the surface is more than 1° from the target area the shift is very small. If there are many surfaces, then not only the average luminance and chromaticity of the surfaces matters, but also the chromatic variability. It is not yet clear whether it makes any difference where the chromatic variability is within the scene, so we constructed stimuli in which the chromatic variability was restricted to certain regions. We found that it made very little difference where the chromatic variability was located. The extent to which the average colour of nearby surfaces influences the apparent colour of the target seems to depend on the average chromatic variability of the whole scene
A new method for tracking of motor skill learning through practical application of Fitts’ law
This article is made available through the Brunel Open Access Publishing Fund.A novel upper limb motor skill measure, task productivity rate (TPR) was developed integrating speed and spatial error, delivered by a practical motor skill rehabilitation task (MSRT). This prototype task involved placement of 5 short pegs horizontally on a spatially configured rail array. The stability of TPR was tested on 18 healthy right-handed adults (10 women, 8 men, median age 29 years) in a prospective single-session quantitative within-subjects study design. Manipulations of movement rate 10% faster and slower relative to normative states did not significantly affect TPR, F(1.387, 25.009) = 2.465, p = .121. A significant linear association between completion time and error was highest during the normative state condition (Pearson's r = .455, p < .05). Findings provided evidence that improvements in TPR over time reflected motor learning with possible changes in coregulation behavior underlying practice under different conditions. These findings extend Fitts’ law theory to tracking of practical motor skill using a dexterity task, which could have potential clinical applications in rehabilitation
Drifting snow measurements on the Greenland Ice Sheet and their application for model evaluation
This paper presents autonomous drifting snow observations performed on the
Greenland Ice Sheet in the fall of 2012. High-frequency snow particle counter
(SPC) observations at ~ 1 m above the surface provided drifting snow
number fluxes and size distributions; these were combined with meteorological
observations at six levels. We identify two types of drifting snow events:
katabatic events are relatively cold and dry, with prevalent winds from the
southeast, whereas synoptic events are short lived, warm and wet.
Precipitating snow during synoptic events disturbs the drifting snow
measurements. Output of the regional atmospheric climate model RACMO2, which
includes the drifting snow routine PIEKTUK-B, agrees well with the observed
near-surface climate at the site, as well as with the frequency and timing of
drifting snow events. Direct comparisons with the SPC observations at 1 m
reveal that the model overestimates the horizontal snow transport at this
level, which can be related to an overestimation of saltation and the typical
size of drifting snow particles
Activity of high-dose epirubicin combined with gemcitabine in advanced non-small-cell lung cancer: a multicenter phase I and II study
The aim of the study was to evaluate efficacy and tolerance of epirubicin and gemcitabine as first-line chemotherapy in patients with advanced non-small-cell lung cancer. A phase I study was performed with the combination of escalating doses of epirubicin intravenously on day 1 and a fixed dose of gemcitabine on days 1 and 8 of a 21-day cycle. Eighteen patients were included in the phase I part of the study before the maximum tolerated dose was found. Dose-limiting toxicity was febrile neutropenia. The phase II part of the study was continued with epirubicin 100 mg m−2on day 1 and gemcitabine 1125 mg m−2on days 1 and 8 of a 21-day cycle. Forty-three chemotherapy-naive patients were included. The median age of the patients was 60 years (range 26–75). Most patients (74%) were in stage IV. Granulocytopenia CTC grade 4 occurred in 32.5% and thrombocytopenia grade 4 in 11.6% of cycles. Febrile neutropenia occurred in six patients. Non-haematological toxicity was mainly mucositis CTC grade 2 and 3 in 35% of patients. The tumour response rate was 49% (95% confidence interval (CI) 35–63%). The median survival time for the patients was 42 weeks (95% CI 13–69). © 2000 Cancer Research Campaig
The effects of long-term open-air fumigation with SO2 on a field crop of broad bean (Vicia faba L.) : II. Effects on growth components, leaf area development and elemental composition
The Achilles heel of decision making system in termites
Mitochondrial beta-oxidation of long-chain fatty acids requires the concerted action of three tightly integrated membrane-bound enzymes (carnitine palmitoyltransferase I and II and carnitine/acylcarnitine translocase) that transport them into mitochondria. Neonatal onset of carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal recessive, often lethal disorder of this transport. We describe a novel splice-site mutation in the CPT II gene, found in a Moroccan family, of which four out of five children have died from the neonatal form of CPT II deficiency. Mutation detection studies at the mRNA level in the CPT II gene implied that the affected children were homozygous for the previously reported 534T insertion followed by a 25-bp deletion (encompassing bases 534-558). Studies of genomic DNA, however, revealed all patients to be compound heterozygous for this 534T ins/del 25 mutation, and for a new g-->a splice-site mutation in the splice-acceptor site of intron 2. Because of these findings, prenatal diagnosis was performed in chorionic villi of three new pregnancies. This did not reveal new compound heterozygous genotypes, and, after uneventful pregnancies, all children appeared to be healthy. The new mutation is the first splice-site mutation ever identified in CPT II deficiency. The fact that it was not discovered in the patient's cDNA makes this study another example of the incompleteness of mutation detection at the mRNA level in cases where a mutation leads to aberrant splicing or nonsense-mediated messenger deca
The Dutch secret: how to provide safe drinking water without chlorine in the Netherlands
The Netherlands is one of the few countries where chlorine is not used at all, neither for primary disinfection nor to maintain a residual disinfectant in the distribution network. The Dutch approach that allows production and distribution of drinking water without the use of chlorine while not compromising microbial safety at the tap, can be summarized as follows: <br> 1. Use the best source available, in order of preference:<br> &nbsp;&nbsp;&nbsp;&nbsp;&ndash; microbiologically safe groundwater,<br> &nbsp;&nbsp;&nbsp;&nbsp;&ndash; surface water with soil passage such as artificial recharge or bank filtration,<br> &nbsp;&nbsp;&nbsp;&nbsp;&ndash; direct treatment of surface water in a multiple barrier treatment;<br> 2. Use a preferred physical process treatment such as sedimentation, filtration and UV-disinfection. If absolutely necessary, also oxidation by means of ozone or peroxide can be used, but chlorine is avoided;<br> 3. Prevent ingress of contamination during distribution;<br> 4. Prevent microbial growth in the distribution system by production and distribution of biologically stable (biostable) water and the use of biostable materials;<br> 5. Monitor for timely detection of any failure of the system to prevent significant health consequences. <br><br> New developments in safe drinking water in the Netherlands include the adaptation of the Dutch drinking water decree, implementation of quantitative microbial risk assessment (QMRA) by water companies and research into source water quality, drinking water treatment efficacy, safe distribution and biostability of drinking water during distribution and <i>Legionella</i>. This paper summarizes how the Dutch water companies warrant the safety of the drinking water without chlorine
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