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A preterm newborn (36 weeks, 2000 g) was diagnosed with hepatic hemangiomas during routine screening. Echocardiography revealed cardiac hemangiomas and pericardial effusion, requiring drainage. Propranolol was initiated for hepatic involvement. Over three years, cardiac and hepatic hemangiomas regressed without complications. This rare coexistence highlights the importance of multidisciplinary management and long-term follow-up.
Reducing the risk of human immunodeficiency virus type 1 (HIV-1) transmission is still a public health priority. The development of effective control strategies relies on the quantification of the effects of prophylactic and therapeutic measures in disease incidence. Although several assays can be used to estimate HIV incidence, these estimates are limited by the poor performance of these assays in distinguishing recent from long-standing infections. To address such limitation, we have developed an assay to titrate p24-specific IgG3 antibodies as a marker of recent infection. The assay is based on a recombinant p24 protein capable to detect total IgG antibodies in sera using a liquid micro array and enzyme-linked immunosorbent assay. Subsequently, the assay was optimised to detect and titrate anti-p24 IgG3 responses in a panel of sequential specimens from seroconverters over 24 months. The kinetics of p24-specific IgG3 titres revealed a transient peak in the 4 to 5-month period after seroconversion. It was followed by a sharp decline, allowing infections with less than 6 months to be distinguished from older ones. The developed assay exhibited a mean duration of recent infection of 144 days and a false-recent rate of ca. 14%. Our findings show that HIV-1 p24-specific IgG3 titres can be used as a tool to evaluate HIV incidence in serosurveys and to monitor the efficacy of vaccines and other transmission control strategies.
Individuals with autism spectrum disorders (ASDs) are characterized by social communication difficulties and behavioural rigidity. Difficulties in learning from others are one of the most devastating features of this group of conditions. Nevertheless, the nature of learning difficulties in ASDs is still unclear. Given the relevance of implicit learning for social and communicative functioning, a link has been hypothesized between ASDs and implicit learning deficit. However, studies that have employed formal testing of implicit learning in ASDs provided mixed results.
Method.
We undertook a systematic search of studies that examined implicit learning in ASDs using serial reaction time (SRT), alternating serial reaction time (ASRT), pursuit rotor (PR), and contextual cueing (CC) tasks, and synthesized the data using meta-analysis. A total of 11 studies were identified, representing data from 407 individuals with ASDs and typically developing comparison participants.
Results.
The results indicate that individuals with ASDs do not differ in any task considered [SRT and ASRT task: standardized mean difference (SMD) −0.18, 95% confidence interval (CI) −0.71 to 0.36; PR task: SMD −0.34, 95% CI −1.04 to 0.36; CC task: SMD 0.27, 95% CI −0.07 to 0.60].
Conclusions.
Based on our synthesis of the existing literature, we conclude that individuals with ASDs can learn implicitly, supporting the hypothesis that implicit learning deficits do not represent a core feature in ASDs.
Observing another person performing a complex action accelerates the observer's acquisition of the same action and limits the time-consuming process of learning by trial and error. Learning by observation requires specific skills such as attending, imitating and understanding contingencies. Individuals with autism spectrum disorder (ASD) exhibit deficits in these skills.
Method
The performance of 20 ASD children was compared with that of a group of typically developing (TD) children matched for chronological age (CA), IQ and gender on tasks of learning of a visuomotor sequence by observation or by trial and error. Acquiring the correct sequence involved three phases: a detection phase (DP), in which participants discovered the correct sequence and learned how to perform the task; an exercise phase (EP), in which they reproduced the sequence until performance was error free; and an automatization phase (AP), in which by repeating the error-free sequence they became accurate and speedy.
Results
In the DP, ASD children were impaired in detecting a sequence by trial and error only when the task was proposed as first, whereas they were as efficient as TD children in detecting a sequence by observation. In the EP, ASD children were as efficient as TD children. In the AP, ASD children were impaired in automatizing the sequence. Although the positive effect of learning by observation was evident, ASD children made a high number of imitative errors, indicating marked tendencies to hyperimitate.
Conclusions
These findings demonstrate the imitative abilities of ASD children although the presence of imitative errors indicates an impairment in the control of imitative behaviours.
Accurate monitoring and integration of both internal and external feedback is crucial for guiding current and future behavior. These aspects of performance monitoring are commonly indexed by two event-related potential (ERP) components: error-related negativity (ERN) and feedback negativity (FN). The ERN indexes internal response monitoring and is sensitive to the commission of erroneous versus correct responses, and the FN indexes external feedback monitoring of positive versus negative outcomes. Although individuals with schizophrenia consistently demonstrate a diminished ERN, the integrity of the FN has received minimal consideration.
Method
The current research sought to clarify the scope of feedback processing impairments in schizophrenia in two studies: study 1 examined the ERN elicited in a flanker task in 16 out-patients and 14 healthy controls; study 2 examined the FN on a simple monetary gambling task in expanded samples of 35 out-patients and 33 healthy controls.
Results
Study 1 replicated prior reports of an impaired ERN in schizophrenia. By contrast, patients and controls demonstrated comparable FN differentiation between reward and non-reward feedback in study 2.
Conclusions
The differential pattern across tasks suggests that basic sensitivity to external feedback indicating reward versus non-reward is intact in schizophrenia, at least under the relatively simple task conditions used in this study. Further efforts to specify intact and impaired reward-processing subcomponents in schizophrenia may help to shed light on the diminished motivation and goal-seeking behavior that are commonly seen in this disorder.
In this work we mainly report on the analyses of polycrystalline silicon carbide films grown by Electron Cyclotron Resonance Chemical Vapor Deposition (ECR-CVD) on Si (100) and Si (111) substrates. Structural properties of the films have been analyzed by X-ray diffractometry, transmission electron microscopy and micro-Raman spectroscopy. Samples deposited with optimized deposition conditions, show a polycrystalline columnar structure with lateral crystal dimensions ranging from 300 up to 1400 Å and an orientation close to that of the Si substrates.
NiSi and Ni2Si layers on silicon substrates as well as high fluence Si(As) ion implanted layers,have been rapidly melted by 30 ns Nd laser pulse irradiation.The energy density ranged between 0.4 and 1.2 J/cm2. Bilayer structures have been observed when the energy density has been chosen properly.
Buried epitaxial layers together with an amorphous or a policrystalline layer on top,have been detected by RBS and TEM measurements.
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