409 research outputs found
Agent programming in the cognitive era
It is claimed that, in the nascent âCognitive Eraâ, intelligent systems will be trained using machine learning techniques rather than programmed by software developers. A contrary point of view argues that machine learning has limitations, and, taken in isolation, cannot form the basis of autonomous systems capable of intelligent behaviour in complex environments. In this paper, we explore the contributions that agent-oriented programming can make to the development of future intelligent systems. We briefly review the state of the art in agent programming, focussing particularly on BDI-based agent programming languages, and discuss previous work on integrating AI techniques (including machine learning) in agent-oriented programming. We argue that the unique strengths of BDI agent languages provide an ideal framework for integrating the wide range of AI capabilities necessary for progress towards the next-generation of intelligent systems. We identify a range of possible approaches to integrating AI into a BDI agent architecture. Some of these approaches, e.g., âAI as a serviceâ, exploit immediate synergies between rapidly maturing AI techniques and agent programming, while others, e.g., âAI embedded into agentsâ raise more fundamental research questions, and we sketch a programme of research directed towards identifying the most appropriate ways of integrating AI capabilities into agent programs
A Prospective Cohort Study on the Intergenerational Transmission of Childhood Adversity and Subsequent Risk of Psychotic Experiences in Adolescence
BACKGROUND AND HYPOTHESIS: Previous studies have shown a robust relationship between childhood adversity and subsequent psychotic symptoms. However, the role of familial risk factors underlying this relationship remains largely unclear. Here, we tested whether offspring childhood adversity and postnatal maternal psychopathology mediated the relationship between maternal childhood adversity and offspring psychotic experiences. STUDY DESIGN: N = 3068 mother-offspring dyads were included. Maternal history of childhood adversity was retrospectively assessed using the Childhood Trauma Questionnaire during pregnancy. Maternal psychopathology was assessed during and after pregnancy. Twenty-four offspring childhood adversities were assessed by maternal interview when the child was 10 years old. Offspring psychotic experiences were examined using self-report at 14 years. Structural equation mediation models were conducted to explore whether maternal postnatal psychopathology and offspring childhood adversities sequentially mediated the relationship between maternal childhood adversity and offspring psychotic experiences. Analyses were adjusted for sociodemographic confounders. STUDY RESULTS: Maternal history of childhood adversity was associated with offspring childhood adversities (β = 0.12, 95% CI: 0.09 to 0.16). Offspring childhood adversity mediated the association of maternal childhood adversity with offspring hallucinations (βindirect effect = 0.008, 95% CI: 0.002 to 0.014, proportion mediated = 16.3%) and delusions (βindirect effect = 0.006, 95% CI: 0.000 to 0.012, proportion mediated = 13.1%). CONCLUSIONS: Intergenerational transmission of childhood adversity can be considered of relevance in the etiology of psychosis vulnerability and can potentially serve as a modifiable risk factor
Fine-tuning polyoxometalate non-linear optical chromophores: a molecular electronic âGoldilocksâ effect
A new aryl-imido polyoxometalate non-linear optical chromophore (POMophore) with a diphenylamino donor group attains the highest βzzz, 0 value (196 Ă 10â30 esu by Hyper-Rayleigh Scattering, HRS), and best transparency/non-linearity trade off yet for such materials. Stark spectroscopic and DFT investigation of this compound, plus NMe2 and carbazole analogues, show that its high performance results from a combination of strongly dipolar electronic transitions, and strong electronic communication across the Ď-system
Congenital spinal tumor in a patient with encephalocele and hydrocephalus: a case report
<p>Abstract</p> <p>Introduction</p> <p>Encephalocele is a rare congenital abnormality of the central nervous system, where brain tissue protrudes from a defect in the skull. Some anomalies are associated with encephalocele. However, the association of spinal teratoma and encephalocele has not been reported in the English literature.</p> <p>Case presentation</p> <p>We report the case of an Iranian girl with a history of encephalocele surgery, who, at the age of four years, developed an intramedullary spinal teratoma, and discuss the pathogenesis of this association.</p> <p>Conclusion</p> <p>To the best of our knowledge, this is the first report of an association between encephalocele and spinal teratoma.</p
Organoimido-Polyoxometalate Nonlinear Optical Chromophores: A Structural, Spectroscopic, and Computational Study
Ten organoimido polyoxometalate (POM) based chromophores have been synthesized and studied by hyperRayleigh Scattering (HRS), Stark and Resonance Raman spectroscopies and DFT calculations. HRS β0 values for chromophores with resonance electron donors are significant (up to 139 Ă 10-30 esu, ca. 5 Ă that of the DAS+ cation), but systems with no donor, or the âNO2 acceptor show no activity, in some cases despite large DFT-predicted β-values. In active systems with short (phenyl) Ď-bridges, β0-values comfortably exceed that of the purely organic structural analogue N,N-dimethyl-4-nitroaniline (DMPNA), and intrinsic β-values, β0/N3/2 (N = number of bridge Ď-electrons) thus appear to break empirical performance limits (β0/N3/2 vs Îťmax) for planar organic systems. However, β0-values obtained for extended systems with a diphenylacetylene bridge are comparable to or lower than that of their nitro analogue N,N-dimethyl-4-[(4-nitrophenyl)ethynyl]-aniline (DMNPEA). Resonance Raman spectroscopy confirms involvement of the POM in the electronic transitions whether donor groups are present or not, but Stark spectroscopy indicates that in their absence the transitions have little dipolar character (hence NLO inactive), consistent with DFT-calculated frontier orbitals which extend over both POM and organic group. Stark and DFT also suggest that β is enhanced in the short compounds because extension of charge transfer (CT) onto the POM increases excited state dipole moment changes. With extended Ď-systems this effect does not increase CT distances relative to a âNO2 acceptor, so β0-values do not exceed that of DMNPEA. Overall, our results show that: (i) the organoimidoâPOM unit is an efficient acceptor for 2nd order NLO, but an ineffective donor; (ii) the nature of electronic transitions in arylimido-POMs is strongly influenced by the substituents of the aryl group; and (iii) organoimido-POMs outperform organic acceptors with short Ď-bridges, but lose their advantage with extended Ď-conjugation
Identification of individual exosome-like vesicles by surface enhanced Raman spectroscopy
Exosome-like vesicles (ELVs) are a novel class of biomarkers that are receiving a lot of attention for the detection of cancer at an early stage. In this study the feasibility of using a surface enhanced Raman spectroscopy (SERS) based method to distinguish between ELVs derived from different cellular origins is evaluated. A gold nanoparticle based shell is deposited on the surface of ELVs derived from cancerous and healthy cells, which enhances the Raman signal while maintaining a colloidal suspension of individual vesicles. This nanocoating allows the recording of SERS spectra from single vesicles. By using partial least squares discriminant analysis on the obtained spectra, vesicles from different origin can be distinguished, even when present in the same mixture. This proof-of-concept study paves the way for noninvasive (cancer) diagnostic tools based on exosomal SERS fingerprinting in combination with multivariate statistical analysis
The PREVENT study to evaluate the effectiveness and acceptability of a community-based intervention to prevent childhood tuberculosis in Lesotho: study protocol for a cluster randomized controlled trial
Background
Effective, evidence-based interventions to prevent childhood tuberculosis (TB) in high TB/HIV-burden, resource-limited settings are urgently needed. There is limited implementation of evidence-based contact management strategies, including isoniazid preventive therapy (IPT), for child contacts of TB cases in Lesotho.
Methods/design
This mixed-methods implementation science study utilizes a two-arm cluster-randomized trial design with randomization at the health facility level. The study aims to evaluate the effectiveness and acceptability of a combination community-based intervention (CBI) versus standard of care (SOC) for the management of child TB contacts. The study includes three phases: (I) exploratory phase; (II) intervention implementation and testing phase; (III) post-intervention explanatory phase. Healthcare provider interviews to inform intervention refinement (phase I) were completed in December 2015. In phase II, 10 health facilities were randomized to deliver the CBI or SOC, with stratification by facility type (i.e., hospital vs. health center). CBI holistically addresses the complex provider-related, patient-related, and caregiver-related barriers to prevention of childhood TB through nurse training and mentorship; health education for caregivers and patients by village health workers; adherence support using text messaging and village health workers; and multidisciplinary team meetings, where programmatic data are reviewed and challenges and solutions are discussed. SOC sites follow country guidelines for child TB contact management. Routine TB program data will be abstracted for all adult TB cases newly registered during the study period and their child contacts from TB registers and cards. The anticipated sample size is 1080 child contacts. Primary outcomes are yield (number) of child contacts, including childrenâ<â5Â years of age and HIV-positive childrenâ<â15Â years of age; IPT initiation; and IPT completion. Secondary outcomes include HIV testing; yield of active prevalent TB among child contacts; and acceptability and utilization of CBI components. Intervention implementation began in February 2016 and is ongoing. Post-intervention interviews with healthcare providers and caregivers (phase III) commenced in February 2017.
Discussion
The PREVENT study tests the effectiveness and acceptability of a novel combination CBI for child TB contact management in Lesotho. If effective, CBI will have important implications for addressing childhood TB in Lesotho and elsewhere.
Trial registration
ClinicalTrials.gov,
NCT02662829
. Registered on 15 January 2016
Dietary fibre intake is associated with serum levels of uraemic toxins in children with chronic kidney disease
Imbalanced colonic microbial metabolism plays a pivotal role in generating protein-bound uraemic toxins (PBUTs), which accumulate with deteriorating kidney function and contribute to the uraemic burden of children with chronic kidney disease (CKD). Dietary choices impact the gut microbiome and metabolism. The aim of this study was to investigate the relation between dietary fibre and gut-derived PBUTs in paediatric CKD. Sixty-one (44 male) CKD children (9 +/- 5 years) were prospectively followed for two years. Dietary fibre intake was evaluated by either 24-h recalls (73%) or 3-day food records (27%) at the same time of blood sampling for assessment of total and free serum levels of different PBUTs using liquid chromatography. We used linear mixed models to assess associations between fibre intake and PBUT levels. We found an inverse association between increase in fibre consumption (g/day) and serum concentrations of free indoxyl sulfate (-3.1% (-5.9%; -0.3%) (p = 0.035)), free p-cresyl sulfate (-2.5% (-4.7%; -0.3%) (p = 0.034)), total indole acetic acid (IAA) (-1.6% (-3.0%; -0.3%) (p = 0.020)), free IAA (-6.6% (-9.3%; -3.7%) (p < 0.001)), total serum p-cresyl glucuronide (pCG) (-3.0% (-5.6%; -0.5%) (p = 0.021)) and free pCG levels (-3.3% (-5.8%; -0.8%) (p = 0.010)). The observed associations between dietary fibre intake and the investigated PBUTs highlight potential benefits of fibre intake for the paediatric CKD population. The present observational findings should inform and guide adaptations of dietary prescriptions in children with CKD
Occupational and leisure time physical activity in contrasting relation to ambulatory blood pressure
Background: While moderate and vigorous leisure time physical activities are well documented to decrease the risk for cardiovascular disease, several studies have demonstrated an increased risk for cardiovascular disease in workers with high occupational activity. Research on the underlying causes to the contrasting effects of occupational and leisure time physical activity on cardiovascular health is lacking. The aim of this study was to examine the relation of objective and self-report measures of occupational and leisure time physical activity with 24-h ambulatory systolic blood pressure (BP).
Methods: Results for self-reported physical activity are based on observations in 182 workers (60% male, mean age 51 years), while valid objective physical activity data were available in 151 participants. The usual level of physical activity was assessed by 5 items from the Job Content Questionnaire (high physical effort, lifting heavy loads, rapid physical activity, awkward body positions and awkward positions of head or arms at work) and one item asking about the general level of physical activity during non-working time. On a regular working day, participants wore an ambulatory BP monitor and an accelerometer physical activity monitor during 24 h. Associations were examined by means of Analysis of Covariance.
Results: Workers with an overall high level of self-reported occupational physical activity as well as those who reported to often lift heavy loads at work had a higher mean systolic BP at work, at home and during sleep. However, no associations were observed between objectively measured occupational physical activity and BP. In contrast, those with objectively measured high proportion of moderate and vigorous leisure time physical activity had a significantly lower mean systolic BP during daytime, while no differences were observed according to self-reported level of leisure time physical activity.
Conclusions: These findings suggest that workers reporting static occupational physical activities, unlike general physically demanding tasks characterized by dynamic movements of large muscle groups, are related to a higher daily systolic BP, while high objective levels of moderate and vigorous leisure time physical activity are related to lower daytime systolic BP. Ambulatory systolic BP may be a physiological explanatory factor for the contrasting effects of occupational and leisure time physical activity
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