1,150 research outputs found
Sleep, Wakefulness, Dreams and Memory
Sleep-wakefulness cycle mechanisms shown in central neural activity change
Superfluidity in a Doped Helium Droplet
Path Integral Monte Carlo calculations of the superfluid density throughout
^4He droplets doped with linear impurities (HCN)_n are presented. After
deriving a local estimator for the superfluid density distribution, we find a
decreased superfluid response in the first solvation layer. This effective
normal fluid exhibits temperature dependence similar to that of a
two-dimensional helium system.Comment: 4 pages, 6 figure
RF Circuit linearity optimization using a general weak nonlinearity model
This paper focuses on optimizing the linearity in known RF circuits, by exploring the circuit design space that is usually available in today’s deep submicron CMOS technologies. Instead of using brute force numerical optimizers we apply a generalized weak nonlinearity model that only involves AC transfer functions to derive simple equations for obtaining design insights. The generalized weak nonlinearity model is applied to three known RF circuits: a cascode common source amplifier, a common gate LNA and a CMOS attenuator. It is shown that in deep submicron CMOS technologies the cascode transistor in both the common source amplifier and in the common gate amplifier significantly contributes IM3 distortion. Some design insights are presented for reducing the cascode transistor related distortion, among which moderate inversion biasing that improves IIP3 by 10 dB up to 5 GHz in a 90 nm CMOS process. For the attenuator, a wideband IM3 cancellation technique is introduced and demonstrated using simulations
A multi-step P-cell for LNA design automation
This paper presents a novel way to efficiently implement parametric cells (P-cells). A narrow-band LNA is used as demonstration vehicle. In the P-cell, circuit parameters such as transistor size, bias condition and passive values are determined automatically for any given reachable target performance. To achieve both high accuracy and relatively high speed, a new iterative stepped approach is used with respect to speed and accuracy, starting with moderate-accuracy and fast optimization that yields the starting point for the next higheraccuracy and slower optimization step. The presented approach can be extended to other types of circuits
A superfluid hydrodynamic model for the enhanced moments of inertia of molecules in liquid 4He
We present a superfluid hydrodynamic model for the increase in moment of
inertia, , of molecules rotating in liquid He. The static
inhomogeneous He density around each molecule (calculated using the Orsay-Paris
liquid He density functional) is assumed to adiabatically follow the
rotation of the molecule. We find that the values created by the
viscousless and irrotational flow are in good agreement with the observed
increases for several molecules [ OCS, (HCN), HCCCN, and HCCCH ]. For
HCN and HCCH, our model substantially overestimates . This is likely
to result from a (partial) breakdown of the adiabatic following approximation.Comment: 4 pages, 1 eps figure, corrected version of published paper. Erratum
has been submitted for change
Screening, diagnosis and treatment of hypertension in obese children: an international policy comparison
Hypertension in obese children may require a different diagnostic and treatment approach from that for children with secondary hypertension, yet there is neither consensus nor a clear guideline. The aim of this study was to assess how obese children with hypertension are currently diagnosed and treated by paediatric nephrologists, what obstacles exist and what can be improved. In the period May–November 2014, an online questionnaire was sent to all members of the European Society for Paediatric Nephrology (n = 2148). Questions focused on current practices and obstacles regarding screening, diagnosis and treatment of hypertension in obese children. A total of 214 paediatric nephrologists responded. Although nearly 100 % agreed that screening of obese children for hypertension is indicated, it was current practice in only 56 % of participating countries; 88 % of respondents diagnosed hypertension with 24-h ambulatory blood pressure measurement. Diagnostics used to rule out causes or consequences of hypertension varied among the respondents; they included, in particular, the use of serum renin/aldosterone, urine sodium/potassium, and dimercaptosuccinic acid scan. Concerning treatment, 45 % of respondents preferred to start treatment with a lifestyle program, 2 % with antihypertensive medication, and 40 % with both. For 73 % of respondents, angiotensin-converting enzyme-inhibitors or angiotensin receptor blockers were the drugs of first choice. The findings of this study emphasize the urgent need for an international guideline for screening, diagnosis and treatment of hypertension in obese children
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
Better together?:A randomized controlled microtrial comparing different levels of therapist and parental involvement in exposure-based treatment of childhood specific phobia
INTRODUCTION: Exposure is often limited to homework assignments in routine clinical care. The current study compares minimally-guided (MGE) and parent-guided (PGE) out-session homework formats to the 'golden standard' of therapist-guided in-session exposure with minimally-guided exposure at home (TGE).METHODS: Children with specific phobia (N = 55, age 8-12, 56% girls) participated in a single-blind, randomized controlled microtrial with a four-week baseline-treatment period design. Clinical interviews, behavioral avoidance tests, and self-report measures were assessed at pre-treatment, post-treatment, and at one-month follow-up.RESULTS: TGE resulted in a larger decline of specific phobia severity from baseline to post-treatment compared to MGE but not compared to PGE. Parental anxiety was found to be a moderator of less treatment efficacy of PGE from baseline to post-treatment. Overall, there was no meaningful difference in efficacy of TGE versus MGE or PGE from baseline to follow-up.CONCLUSIONS: These findings suggest that for improving short-term treatment gains, exposure exercises can best be conducted with the help of a therapist within the therapy session before they are conducted as homework assignments outside the therapy session. However, for long-term treatment gains exposure exercises can be handled by the child itself or with help of its parents.</p
- …