10 research outputs found
On the design and implementation of broadcast and global combine operations using the postal model
There are a number of models that were proposed in recent years for message passing parallel systems. Examples are the postal model and its generalization the LogP model. In the postal model a parameter λ is used to model the communication latency of the message-passing system. Each node during each round can send a fixed-size message and, simultaneously, receive a message of the same size. Furthermore, a message sent out during round r will incur a latency of hand will arrive at the receiving node at round r + λ - 1.
Our goal in this paper is to bridge the gap between the theoretical modeling and the practical implementation. In particular, we investigate a number of practical issues related to the design and implementation of two collective communication operations, namely, the broadcast operation and the global combine operation. Those practical issues include, for example, 1) techniques for measurement of the value of λ on a given machine, 2) creating efficient broadcast algorithms that get the latency hand the number of nodes n as parameters and 3) creating efficient global combine algorithms for parallel machines with λ which is not an integer. We propose solutions that address those practical issues and present results of an experimental study of the new algorithms on the Intel Delta machine. Our main conclusion is that the postal model can help in performance prediction and tuning, for example, a properly tuned broadcast improves the known implementation by more than 20%
Anxiety-like behavior in Rett syndrome: characteristics and assessment by anxiety scales
Dalmatien und seine Volkskunst
Copia digital. España : Ministerio de Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2021Fecha de 1911 tomada de la British LibraryVol. I (72 p.) -- Vol. II (68 h. de grab.
Age of diagnosis in Rett syndrome: patterns of recognition among diagnosticians and risk factors for late diagnosis.
Diagnosis of Rett syndrome (RTT) is often delayed. We sought to determine the type of physician who typically makes the RTT diagnosis and to identify risk factors for delayed diagnosis.A total of 1085 participants from the multicenter longitudinal RTT natural history study with classic and atypical RTT were recruited between 2006 and 2014. Age of diagnosis, diagnostician, diagnostic criteria, and clinical and developmental data were collected.Among 919 classic and 166 atypical RTT participants, the median diagnosis age was 2.7 years (interquartile range 2.0-4.1) in classic and 3.8 years (interquartile range 2.3-6.9) in atypical RTT. Pediatricians made the diagnosis of classic RTT rarely (5.2%); however, the proportion diagnosed by pediatricians has increased since 2006. Since the first diagnostic criteria, the age of diagnosis decreased among subspecialists but not pediatricians. Odds of a pediatrician making the diagnosis of classic RTT were higher if a child stopped responding to parental interaction, and lower if they possessed gastroesophageal reflux, specific stereotypies, lost babbling, or the ability to follow commands. Delayed acquisition of basic gross motor skills or finger feeding was associated with younger diagnosis; delayed acquisition of higher level fine motor skills, later onset of supportive features, and normal head circumference were associated with late diagnosis. Thirty-three percent with microcephaly before 2.5 years were diagnosed after the median age of 2.7 years.Age of RTT diagnosis has improved among subspecialists, and pediatricians have made the diagnosis of classic RTT more frequently since 2006. Strategies for educating diagnosticians should incorporate specific risk factors for delayed diagnosis
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Placebo‐controlled crossover assessment of mecasermin for the treatment of Rett syndrome
Abstract Objective: To measure the efficacy of mecasermin (recombinant human insulin‐like growth factor 1, rhIGF‐1), for treating symptoms of Rett syndrome (RTT) in a pediatric population using a double‐blind crossover study design. Methods: Thirty girls with classic RTT in postregression stage were randomly assigned to placebo or rhIGF‐1 in treatment period 1 and crossed over to the opposite assignment for period 2 (both 20 weeks), separated by a 28‐week washout period. The primary endpoints were as follows: Anxiety Depression and Mood Scale (ADAMS) Social Avoidance subscale, Rett Syndrome Behaviour Questionnaire (RSBQ) Fear/Anxiety subscale, Parent Target Symptom Visual Analog Scale (PTSVAS) top three concerns, Clinical Global Impression (CGI), Parent Global Impression (PGI), and the Kerr severity scale. Cardiorespiratory‐ and electroencephalography (EEG)‐based biomarkers were also analyzed. Results: There were no significant differences between randomization groups. The majority of AEs were mild to moderate, although 12 episodes of serious AEs occurred. The Kerr severity scale, ADAMS Depressed Mood subscale, Visual Analog Scale Hyperventilation, and delta average power change scores significantly increased, implying worsening of symptoms. Electroencephalography (EEG) parameters also deteriorated. A secondary analysis of subjects who were not involved in a placebo recall confirmed most of these findings. However, it also revealed improvements on a measure of stereotypic behavior and another of social communication. Interpretation As in the phase 1 trial, rhIGF‐1 was safe; however, the drug did not reveal significant improvement, and some parameters worsened
Neural and Behavioral Responses During Self-Evaluative Processes Differ in Youth With and Without Autism
Lessons to be learned: how a comprehensive neurobiological framework of atypical reading development can inform educational practice
Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
In this paper we will list a few important goals that need to be addressed in
the next decade, also taking into account the current discordances between the
different cosmological probes, such as the disagreement in the value of the
Hubble constant , the -- tension, and other less
statistically significant anomalies. While these discordances can still be in
part the result of systematic errors, their persistence after several years of
accurate analysis strongly hints at cracks in the standard cosmological
scenario and the necessity for new physics or generalisations beyond the
standard model. In this paper, we focus on the tension between
the {\it Planck} CMB estimate of the Hubble constant and the SH0ES
collaboration measurements. After showing the evaluations made from
different teams using different methods and geometric calibrations, we list a
few interesting new physics models that could alleviate this tension and
discuss how the next decade's experiments will be crucial. Moreover, we focus
on the tension of the {\it Planck} CMB data with weak lensing measurements and
redshift surveys, about the value of the matter energy density , and
the amplitude or rate of the growth of structure (). We
list a few interesting models proposed for alleviating this tension, and we
discuss the importance of trying to fit a full array of data with a single
model and not just one parameter at a time. Additionally, we present a wide
range of other less discussed anomalies at a statistical significance level
lower than the -- tensions which may also constitute hints towards
new physics, and we discuss possible generic theoretical approaches that can
collectively explain the non-standard nature of these signals.[Abridged]Comment: Contribution to Snowmass 2021. 224 pages, 27 figures. Accepted for
publication in JHEA
Cosmology intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies
The standard Λ Cold Dark Matter (ΛCDM) cosmological model provides a good description of a wide range of astrophysical and cosmological data. However, there are a few big open questions that make the standard model look like an approximation to a more realistic scenario yet to be found. In this paper, we list a few important goals that need to be addressed in the next decade, taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant H0, the σ8–S8 tension, and other less statistically significant anomalies. While these discordances can still be in part the result of systematic errors, their persistence after several years of accurate analysis strongly hints at cracks in the standard cosmological scenario and the necessity for new physics or generalisations beyond the standard model. In this paper, we focus on the 5.0σ tension between the Planck CMB estimate of the Hubble constant H0 and the SH0ES collaboration measurements. After showing the H0 evaluations made from different teams using different methods and geometric calibrations, we list a few interesting new physics models that could alleviate this tension and discuss how the next decade's experiments will be crucial. Moreover, we focus on the tension of the Planck CMB data with weak lensing measurements and redshift surveys, about the value of the matter energy density Ωm, and the amplitude or rate of the growth of structure (σ8,fσ8). We list a few interesting models proposed for alleviating this tension, and we discuss the importance of trying to fit a full array of data with a single model and not just one parameter at a time. Additionally, we present a wide range of other less discussed anomalies at a statistical significance level lower than the H0–S8 tensions which may also constitute hints towards new physics, and we discuss possible generic theoretical approaches that can collectively explain the non-standard nature of these signals. Finally, we give an overview of upgraded experiments and next-generation space missions and facilities on Earth that will be of crucial importance to address all these open questions