Robust Linear Regression Research Articles

Resource Aware Bagging Cluster Based Robust Linear Regression Analysis for Sensed Target Object Detection in Wsn

Resource Aware Bagging Cluster Based Robust Linear Regression Analysis for Sensed Target Object Detection in Wsn

T209. EFFECTS OF CHRONIC HALOPERIDOL EXPOSURE ON [3H]RO15-4513 AND [3H]FLUMAZENIL GABA-A RECEPTOR BINDING SITES

BackgroundPost-mortem studies in schizophrenia (SZ) have reported abnormalities in the GABAergic system, more specifically, on αGABA-A receptors (αGABA-A R) (Benes, Kwok, Vincent, & Todtenkopf, 1998; Beneyto, Abbott, Hashimoto, & Lewis, 2011). Consistently, animal models of SZ have also reported changes in these receptor subtypes (Lodge, Behrens, & Grace, 2009; Richetto, Calabrese, Riva, & Meyer, 2014). Preclinical work in the methylazoxymethanol acetate (MAM) animal model of SZ has shown that administration of an α5GABA-A modulating drug rescues the psychosis-like phenotype (hyperdopaminergia) (Gill, Lodge, Cook, Aras, & Grace, 2011). However, this rescue does not occur if the animals are previously administered the first-generation antipsychotic haloperidol (Gill, Cook, Poe, & Grace, 2014). A recent study in patients with first-episode psychosis found increased baseline GABA levels as measured by magnetic resonance spectroscopy (de la Fuente-Sandoval et al., 2017). After 4 weeks of treatment with the antipsychotic risperidone, these GABA levels normalized in the medial prefrontal cortex and decreased at a trend level in the dorsal caudate (de la Fuente-Sandoval et al., 2017). All in all these studies suggest that antipsychotic medication besides directly regulating the dopaminergic system may also be acting on the GABAergic system, but the underlying mechanisms remain unknown. The aim of our study was thus to investigate, for the first time, the effects of clinically-relevant dosages of haloperidol on α5GABA-A R and benzodiazepine-sensitive α1–3;5GABA-A R in healthy rats.MethodsA total of 36 male Sprague-Dawley rats were treated with vehicle, haloperidol 0.5 mg/kg/day or 2 mg/kg/day with an osmotic minipump for 28 days, representing clinically-relevant dosages of antipsychotic administration (Kapur, Vanderspek, Brownlee, & Nobrega, 2003). Quantitative autoradiography was conducted with [3H]Ro15-4513 and [3H]flumazenil, to assess the effects of haloperidol on α5GABA-A R and overall α1–3;5GABA-A R. Optical density measurements from cortical and subcortical regions were obtained from the autoradiographs using the MCID Software and converted into radioactivity values using a robust linear regression on GraphPad Prism. All data were analyzed using a mixed-effects model ANOVA on the same software and considered significant at p<0.05 with FDR correction for multiple comparisons.ResultsAdministration of chronic haloperidol showed a dose-specific increase in [3H]Ro15-4513 in the dorsal CA1 area of the hippocampus, showing an increase in binding in the 0.5 mg/kg/day vs. vehicle (p<0.01; q<0.01) and a decrease in the 2 mg/kg/day vs. the 0.5 group (p<0.05; q<0.01). In the nucleus accumbens, there was a significant reduction in [3H]Ro15-4513 binding in the higher-dose group compared to the 0.5 mg/kg/day group (p<0.001; q<0.001). In contrast, haloperidol exposure relayed a general increase in [3H]flumazenil binding across all the regions of interest explored (p<0.05).DiscussionThis is the first study to investigate, in healthy rats, the effects of clinically-relevant doses of haloperidol on GABA-A R binding in a receptor-subtype specific manner. Our results show that exposure to haloperidol causes changes in α5GABA-A R predominantly in the dorsal CA1 and the nucleus accumbens. An overall change in benzodiazepine-sensitive α1–3;5GABA-A R is also observed, irrespective of region. These results suggest that exposure to antipsychotic medication impacts the GABAergic system and should be considered when testing new pharmacological strategies in humans that have been exposed to antipsychotic medication.

Investigating predictors of community integration in individuals after stroke in a residential setting: A longitutinal study.

AimTo identify potential predictors of community integration in individuals after stroke using a residential setting-based strategy.MethodA prospective cohort of post-stroke individuals was recruited from the Stroke Unit of the Roberto Santos General Hospital (UAVC-HGRS). All included individuals were aged over 18 years, received a diagnosis of ischemic stroke confirmed by neuroimaging and resided in the city of Salvador (Bahia, Brazil). Following discharge from the stroke unit, the individuals themselves, or their responsible parties, were contacted by telephone to schedule a home visit no less than three months after discharge. All subjects were examined in their homes, at which time the Community Integration Questionnaire (CIQ) was also applied. A robust linear regression model was used to assess community reintegration using CIQ score as the outcome variable.ResultsA total of 124 individuals effectively fulfilled the eligibility criteria: 51.6% were females, the median (IQR) age was 63(53–69) years, 82.3% were non-white, 53.2% were married, the median (IQR) of years of schooling was 6 (4–12) and family income averaged two minimum monthly wages. Investigated individuals presented a median (IQR) NIH Stroke Scale (NIHSS) score of 7 (4–12). Multivariate linear regression identified the following independent predictors of community integration: age (β = -0.095; 95% CI = -0.165 to -0.025; p = 0.008), diabetes mellitus (β = -2.348; 95% CI = -4.125 to -0.571; p = 0.010), smoking habit (β = -2.951; 95% CI = -5.081 to -0.821; p = 0.007), functional capacity upon hospital discharge (β = 0.168; 95% CI = 0.093 to 0.242; p = <0.001) and stroke severity (β = -0.163; CI = -0.318 to -0.009); p = 0.038).ConclusionsRegardless of length of time since stroke, individuals present restrictions that compromise their reintegration into their respective communities. The demographic, clinical and functional factors identified herein as potential predictors should be considered when conducting regular follow-up, as well as in the rehabilitation of individuals after stroke with the purpose to identify the interventions necessary to optimize their reintegration into the community.

Modelling the effect of a dedicated hip fracture unit on patient outcomes using segmented robust linear regression techniques

IntroductionTypically, a healthcare intervention is evaluated by comparing data before and after its implementation using statistical tests. Comparing group means can miss underlying trends and lead to erroneous conclusions. Segmented linear regression can be used to reveal secular trends but is susceptible to outliers. We described a novel method using segmented robust regression techniques to evaluate the effect of introducing a dedicated hip fracture unit (HFU). MethodsWe retrospectively analysed patient outcomes from a total of 2777 patients sustaining proximal femoral fragility fractures over a 6-year period at a Level 1 Major Trauma Centre. We compared time to surgical intervention and length of hospital stay before and after the implementation of the HFU using group comparison tests, segmented ordinary regression and robust regression techniques to evaluate the effect of the intervention. ResultsGroup comparison tests did not identify a significant difference in time to surgery pre and post- HFU. Segmented regression revealed that there was a significant reduction in time to surgery but that this predated the introduction of the HFU. Group comparison tests did not identify a significant difference in length of stay pre and post-HFU. Ordinary segmented regression demonstrated that there was a constant reduction in length of stay, which accelerated after the introduction of the HFU. Robust regression identified that this change occurred prior to the HFU. DiscussionThere was a significant decrease in time to surgical intervention during the study period that occurred long before the introduction of the HFU, and that cannot be attributed to the HFU itself. Length of stay started dropping early in the study period and was unrelated to the HFU. However, with robust regression we concluded that the HFU was effective in reducing relatively long hospital stays (outliers).Several explanatory factors that may have affected the observed trends in time to surgery and length of stay were identified. ConclusionRobust regression is a useful adjunct to ordinary segmented linear regression techniques in modelling retrospective time-series and dealing with outliers. The changes observed in hip fracture patient outcomes over a 6-year period was likely multifactorial.

Epigenome-Wide Association Study Reveals Duration of Breastfeeding Is Associated with Epigenetic Differences in Children.

Several small studies have shown associations between breastfeeding and genome-wide DNA methylation (DNAm). We performed a comprehensive Epigenome-Wide Association Study (EWAS) to identify associations between breastfeeding and DNAm patterns in childhood. We analysed DNAm data from the Isle of Wight Birth Cohort at birth, 10, 18 and 26 years. The feeding method was categorized as breastfeeding duration >3 months and >6 months, and exclusive breastfeeding duration >3 months. EWASs using robust linear regression were performed to identify differentially methylated positions (DMPs) in breastfed and non-breastfed children at age 10 (false discovery rate of 5%). Differentially methylated regions (DMRs) were identified using comb-p. The persistence of significant associations was evaluated in neonates and individuals at 18 and 26 years. Two DMPs, in genes SNX25 and LINC00840, were significantly associated with breastfeeding duration >6 months at 10 years and was replicated for >3 months of exclusive breastfeeding. Additionally, a significant DMR spanning the gene FDFT1 was identified in 10-year-old children who were exposed to a breastfeeding duration >3 months. None of these signals persisted to 18 or 26 years. This study lends further support for a suggestive role of DNAm in the known benefits of breastfeeding on a child’s future health.

Retrieval of Sea Surface Temperature From HY-2A Scanning Microwave Radiometer

The scanning microwave radiometer (RM) onboard the Haiyang-2A (HY-2A) satellite has low-frequency channels with the capability of observing sea surface temperature (SST) from space. To improve the accuracy of the HY-2A RM SST data, the intercalibration of RM brightness temperature (BT) and SST retrieval were carried out. Based on the simulated BTs using the microwave radiative transfer model (RTM), the double-difference approach was applied to perform the intercalibration of RM BTs for the 10.7, 18.7, 23.8, and 37.0 GHz channels, with the Global Precipitation Measurement (GPM) Microwave Imager (GMI) as the reference. The RM 6.6-GHz BTs were corrected with the RTM modeled BT on account of a lack of the similar channel in GMI. The comparison of RM original BTs with GMI and modeled BTs showed large biases and the strong dependence on latitude. We obtained latitude-dependent coefficients using robust linear regression for RM BT correction and applied recalibrated RM BTs for the SST retrieval. The validation of the RM retrieved SST showed the bias of −0.12 °C and the robust standard deviation (RSD) of 1.10 °C compared with buoy SST in the region between 70°S and 70°N. In the tropical and subtropical regions, the bias was −0.12 °C and the RSD was 0.93 °C. In addition, the relationships between the SST difference and the sea surface and atmospheric parameters were investigated. Both statistics of validation results and error analysis indicated significant improvement of RM SST accuracy.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: Comparison of Isthmic Versus Degenerative Spondylolisthesis

Minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) is a common surgical procedure for treatment of degenerative spondylolisthesis (DS) but remains controversial for treatment of isthmic spondylolisthesis (IS). Few studies have compared IS and DS outcomes after MIS TLIF. Therefore, the objective of the current study was to compare outcomes of patients with IS and DS after MIS TLIF. A retrospective cohort analysis was performed on a prospectively maintained database of patients who underwent a primary, 1-level MIS TLIF for grade I or II IS or DS. Grade I and II DS and grade I IS patients were treated with MIS TLIF via a unilateral tubular approach, whereas the grade II IS patients were treated via a bilateral tubular approach. Differences in patient demographics and preoperative characteristics were assessed using independent sample t tests and χ2 tests. The type of spondylolisthesis and its effect on postoperative outcomes was analyzed using Poisson regression with robust error variance (binary outcomes) or linear regression (continuous outcomes) adjusted for preoperative characteristics. Subgroup analysis comparing grade I IS versus DS and grade II IS versus DS was performed. A total of 223 patients were included (IS: 62 [27.8%]; DS: 161 [72.2%]). IS patients were younger (P < .001), had a lower comorbidity burden (P < .001), and a greater incidence of grade II spondylolisthesis (P < .001) at L5-S1 (P < .001) than the DS cohort. Patients with IS experienced longer operative times (P < .001) and lower, but not statistically significant, arthrodesis rates compared to the DS cohort. No differences were observed in the remaining preoperative patient characteristics, perioperative or postoperative outcomes. Despite being younger and having a lower comorbidity burden than the DS cohort, similar outcomes were observed after MIS TLIF for IS patients. 3. These results suggest MIS TLIF is an appropriate treatment option for IS patients despite the increased instability inherent with IS.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: Comparison of Grade I Versus Grade II Isthmic Spondylolisthesis.

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is often used to treat low-grade isthmic spondylolisthesis (IS). No studies have compared surgical outcomes for grade I and II IS following MIS-TLIF. Therefore, the objective of the current study was to compare outcomes between patients with grade I and II IS following MIS-TLIF. A retrospective cohort analysis was performed on a prospectively maintained database of patients who underwent a primary 1-level MIS-TLIF for treatment of IS between 2007 and 2015. Grade I patients underwent a unilateral tubular approach with a single interbody cage and bilateral pedicle screw instrumentation. Grade II patients underwent a bilateral tubular approach with bilateral interbody cage and pedicle screw placement. Baseline patient demographics and characteristics were compared using Student t test and χ2 analysis. Differences in peri- and postoperative outcomes were assessed using Poisson regression with robust error variance or linear regression adjusted for perioperative variables. A total of 58 patients with IS underwent MIS-TLIF; 21 (36.2%) were grade I and 37 (63.8%) were grade II. The grade I cohort was younger (42.2 versus 50.6 years, P = .029); no other differences in preoperative variables were observed. No significant differences in operative time, estimated blood loss, length of hospital stay, postoperative visual analogue scale scores, or complication and revision rates were demonstrated between cohorts. Arthrodesis rate was lower in the grade I cohort, though not statistically significant. Despite the grade I cohort being younger with less-severe diagnoses, the grade II cohort experienced similar outcomes. This finding may be due to the grade II cohort receiving bilateral cages, potentially providing a better fusion environment. These results suggest that MIS-TLIF provides sufficient stabilization and fusion for treatment of grade II IS despite increased vertebral body displacement. In addition, MIS-TLIF with bilateral approach and interbody cage placement should be examined for treatment of high-grade IS cases.

Alcohol Consumption, Brain Amyloid-β Deposition, and Brain Structural Integrity Among Older Adults Free of Dementia.

Light to moderate alcohol consumption has been variably associated with lower or higher risk of dementia, but effects on Alzheimer's disease pathology are less clear. We determined whether late-life alcohol consumption was associated with Alzheimer's disease pathology among older adults. We assessed the associations of alcohol consumption self-reported in 2000-2002 with brain amyloid-β deposition on PET scans, and white matter lesion and hippocampal volume on MRIs measured 7-9 years later in 189 participants of the Ginkgo Evaluation of Memory Study (age 75-87 years at baseline) who were free of clinical dementia, using multivariable-adjusted and inverse probability-weighted robust linear regression models. Alcohol consumption was not statistically significantly associated with amyloid-β deposition (standardized uptake value ratio difference per drink: -0.013 [95% CI: -0.027, 0.002]). Both non-drinkers and participants consuming ≥1 drink(s)/week had higher white matter lesion volume (% intracranial volume) than did the reference group of those consuming <1 drink/week (differences: 0.25 % [95% CI: 0.01, 0.50]; 0.26 % [95% CI: 0.02, 0.50]). The association of alcohol consumption and hippocampal volume was modified by age (p = 0.02). Among participants younger than 77 years, participants consuming 1-7 drinks/week had larger hippocampal volume compared with participants consuming <1 drink/week. Alcohol consumption was not statistically significantly associated with amyloid-β deposition 7-9 years later. Non-drinking and greater alcohol consumption were associated with higher white matter lesion volume compared with drinking <1 drink/week. Moderate drinking was associated with higher hippocampal volume in younger individuals. Given the selective nature of this population and adverse health effects of excessive alcohol consumption, these findings warrant further investigation, but cannot be translated into clinical recommendations.

Peak Width of Skeletonized Mean Diffusivity as a Marker of Diffuse Cerebrovascular Damage.

BackgroundThe peak width of skeletonized mean diffusivity (PSMD) has been proposed as a fully automated imaging marker of relevance to cerebral small vessel disease (SVD). We assessed PSMD in relation to conventional SVD markers, global measures of neurodegeneration, and cognition.Methods145 participants underwent 3T brain MRI and cognitive assessment. 112 were patients with mild cognitive impairment, Alzheimer’s disease, progressive supranuclear palsy, dementia with Lewy bodies, or frontotemporal dementia. PSMD, SVD burden [white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS), microbleeds, lacunes], average mean diffusivity (MD), gray matter (GM), white matter (WM), and total intracranial volume were quantified. Robust linear regression was conducted to examine associations between variables. Dominance analysis assessed the relative importance of markers in predicting various outcomes. Regional analyses examined spatial overlap between PSMD and WMH.ResultsPSMD was associated with global and regional SVD measures, especially WMH and microbleeds. Dominance analysis demonstrated that among SVD markers, WMH was the strongest predictor of PSMD. Furthermore, PSMD was more closely associated to WMH than with GM and WM volumes. PSMD was associated with WMH across all regions, and correlations were not significantly stronger in corresponding regions (e.g., frontal PSMD and frontal WMH) compared to non-corresponding regions. PSMD outperformed all four conventional SVD markers and MD in predicting cognition, but was comparable to GM and WM volumes.DiscussionPSMD was robustly associated with established SVD markers. This new measure appears to be a marker of diffuse brain injury, largely due to vascular pathology, and may be a useful and convenient metric of overall cerebrovascular burden.

Health-related quality of life after heart surgery – Identification of high-risk patients: A cohort study

This cohort study evaluated factors, which have been shown to be relevant for Health-Related Quality of Live (HRQL) after cardiac surgery and investigated the combinatory impact on HRQL. Additionally, the aim was to introduce a first attempt to developing a risk estimation model which could identify patients at risk for impaired HRQL. For this single-centre cohort study, 6099 cardiac surgical patients (60% isolated coronary bypass surgery) filled in the Nottingham Health Profile (NHP) for the evaluation of HRQL six months after surgery and provided information regarding their medical and socio-demographic status. For the NHP scores the deviation to the matched normative data of a healthy sample was calculated. A robust linear regression examined factors that influence HRQL. As a next step, based on the regression model, a risk estimation model was developed which is a first attempt to classify patients into risk categories. Male gender, age below 60 or between 60 and 74 years, living alone, no occupation, bypass surgery, NYHA status II, III or IV and chest pain were identified as risk factors to determine impaired HRQL. The model explains 29.13% of the variance. Based on the risk estimation model 27.4% were classified as medium or high risk. For the first time a multilevel method was applied to evaluate HRQL after heart surgery showing that socio-demographic variables are important co-factors to dyspnea and chest pain. We take a first attempt in developing a new approach that should encourage further research in this field to frame a screening tool that may help identifying patients at risk in the future.

Maternal fatty acid concentrations and newborn DNA methylation

Preconception nutrition sets the stage for a healthy pregnancy. Maternal fatty acids (FAs) are related to beneficial neonatal outcomes with DNA methylation proposed as a mechanism; however, few studies have investigated this association and none with preconception FAs. We examined the relations of maternal plasma FA concentrations at preconception (n=346) and 8 weeks of gestation (n=374) with newborn DNA methylation. The Effects of Aspirin in Gestation and Reproduction Trial (2006-2012) randomly assigned women with previous pregnancy loss to low dose aspirin or placebo prior to conception. We measured maternal plasma phospholipid FA concentration at preconception (on average 4 mo before pregnancy) and 8 weeks of gestation. Cord blood DNA from singletons was measured using the MethylationEPIC BeadChip. We used robust linear regression to test the associations of FA concentration with methylation β-values of each CpG site, adjusting for estimated cell count using a cord blood reference, sample plate, maternal sociodemographic characteristics, cholesterol, infant sex, and epigenetic-derived ancestry. False discovery rate correction was used for multiple testing. Mean ± SD concentrations of preconception marine (20:5n-3+22:6n-3+22:5n-3) and ω-6 PUFAs, SFAs, MUFAs, and trans FAs were 4.7 ± 1.2, 38.0 ± 2.0, 39.4 ± 1.8, 11.6 ± 1.1, and 1.0 ± 0.4 % of total FA, respectively; concentrations at 8 weeks of gestation were similar. Preconception marine PUFA concentration was associated with higher methylation at GRAMD2 (P=1.1×10-8), LOXL1 (P=5.5×10-8), SIK3 (P=1.6×10-7), HTR1B (P=1.9×10-7), and MCC (P=2.1×10-7) genes. Preconception SFA concentration was associated with higher methylation at KIF25-AS1 and lower methylation at SLC39A14; other associations exhibited sensitivity to outliers. The trans FA concentration was related to lower methylation at 3 sites and higher methylation at 1 site. FAs at 8 weeks of gestation were largely unrelated to DNA methylation. Maternal preconception FAs are related to newborn DNA methylation of specific CpG sites, highlighting the importance of examining nutritional exposures preconceptionally. This trial was registered at clinicaltrials.gov as NCT00467363.

Memantine Effects on Electroencephalographic Measures of Putative Excitatory/Inhibitory Balance in Schizophrenia

BackgroundAbnormalities in cortical excitation and inhibition (E/I) balance are thought to underlie sensory and information processing deficits in schizophrenia. Deficits in early auditory information processing mediate both neurocognitive and functional impairment and appear to be normalized by acute pharmacologic challenge with the NMDA antagonist memantine (MEM). MethodsThirty-six subjects with a diagnosis of schizophrenia and 31 healthy control subjects underwent electroencephalographic recordings. Subjects ingested either placebo or MEM (10 or 20 mg) in a double-blind, within-subject, crossover, randomized design. The aperiodic, 1/f-like scaling property of the neural power spectra, which is thought to index relative E/I balance, was estimated using a robust linear regression algorithm. ResultsPatients with schizophrenia had greater aperiodic components compared with healthy control subjects (p < .01, d = 0.64), which was normalized after 20 mg MEM. Analysis revealed a significant dose × diagnosis interaction (p < .0001, d = 0.82). Furthermore, the MEM effect (change in aperiodic component in MEM vs. placebo conditions) was associated with baseline attention and vigilance (r = .54, p < .05) and MEM-induced enhancements in gamma power (r = −.60, p < .01). ConclusionsFindings confirmed E/I balance abnormalities in schizophrenia that were normalized with acute MEM administration and suggest that neurocognitive profiles may predict treatment response based on E/I sensitivity. These data provide proof-of-concept evidence for the utility of E/I balance indices as metrics of acute pharmacologic sensitivity for central nervous system therapeutics.

A note on the convergence rate of MCMC for robust Bayesian multivariate linear regression with proper priors

A note on the convergence rate of MCMC for robust Bayesian multivariate linear regression with proper priors

Robust blood pressure estimation from finger photoplethysmography using age-dependent linear models

Objective: This work aims to develop an efficient and robust age-dependent multiple linear regression (MLR) model to estimate blood pressure (BP) from a single-source photoplethysmography (PPG) and biometrics, which could be embedded in the microcontroller of pulse oximeters. Approach: Hemodynamic features were extracted from the PPG signal using its waveform, derivatives, and biometrics. Whole-based, feature-based, and fusion models were evaluated and compared for different age groups. Their performance was tested using 1086 subjects with a leave-one-subject-out cross-validation. The improvement by adding biometrics and the long-term calibration effect were investigated in detail. The relative importance of each feature was compared between different age groups and the implication was discussed. Main results: The fusion model achieved the best performance in subjects with well-defined PPG features, whereas the feature-based method was better suited for subjects with damped signals. Adding age significantly improved both systolic BP (SBP) and diastolic BP (DBP) estimation accuracy for older subjects (> 50 years old) with well-defined features, while it only improved diastolic BP accuracy for older subjects with damped signals. For younger subjects (≤ 50 years old), the contribution of age was very small. A simple subtraction of subject-specific calibration factors significantly reduced biometric-related errors, which also improved the linearity of BP estimation. The relative importance analysis of input features suggests that separate models are indeed necessary for different age groups with different signal qualities, especially for DBP estimation in older subjects. Significance: This study shows a reasonable BP estimation accuracy with age-dependent MLR models, which may help to equip current pulse oximeters with additional functionalities.

Robust regression via mutivariate regression depth

This paper studies robust regression in the settings of Huber’s $\epsilon$-contamination models. We consider estimators that are maximizers of multivariate regression depth functions. These estimators are shown to achieve minimax rates in the settings of $\epsilon$-contamination models for various regression problems including nonparametric regression, sparse linear regression, reduced rank regression, etc. We also discuss a general notion of depth function for linear operators that has potential applications in robust functional linear regression.

Selection for psychosocial treatment for youth at clinical high risk for psychosis based on the North American Prodrome Longitudinal Study individualized risk calculator.

Recent findings suggest that family-focused therapy (FFT) is effective for individuals at clinical high-risk for psychosis (CHR-P). As outcomes of CHR-P individuals are quite varied, certain psychosocial interventions may be differentially effective in subgroups. The present study examined change in positive symptoms for CHR-P individuals at different levels of predicted risk for conversion to psychosis who received either FFT, a brief form of family education termed enhanced care (EC) or treatment as usual. Participants were drawn from the North American Prodromal Longitudinal Study (NAPLS2). A subset of NAPLS2 participants completed a randomized study involving FFT or EC. The present study includes participants from the FFT-CHR sub-study and non-randomized NAPLS2 participants. Predicted risk of conversion was calculated using the Individualized Risk Calculator for Psychosis. Robust linear regressions evaluated whether the association between predicted risk of conversion and positive symptom change differed across intervention groups. A total of 94 participants from the FFT-CHR sub-study (FFT-CHR n = 50, EC n = 44) and 401 non-randomized NAPLS2 participants were included in this study. There was a treatment group by predicted risk of conversion interaction that predicted positive symptom improvement: higher risk individuals improved more with FFT-CHR than EC or the non-randomized NAPLS group, whereas lower-risk individuals did not differ in positive symptom improvement across treatment groups (FFT-CHR vs EC: P = .03, β = 20.27; FFT-CHR vs NAPLS2: P < .001, β = 28.40). Intensive treatments such as FFT-CHR may be most appropriate for individuals at the highest levels of clinical risk for psychosis.

An Exploratory Study for Assessment of Multimodal Semantic Memory in Colombian Children.

.Semantic memory (SM) is a type of long-term memory associated with the storage of general information about the world. Here we assessed the characteristics of the SM battery, developed by Catricalà et al. (2013), in a sample of Colombian children. This battery was originally conceived to evaluate adults, and features six subtests that assess SM in different modalities, using a common set of 48 stimuli in both living and nonliving categories. The design of the current study is of a cross-sectional and exploratory type. The sample was composed of 111 children, 57 boys (51%) and 54 girls (49%), who were 6 (n = 68) and 7 (n = 43) years old and had no intellectual disability. Robust linear regression models and correlation networks were used. We found an effect of age on general intelligence after correcting for gender, and no differences on the six subtest scores after corrections for gender and age were performed. Furthermore, age was found to be positively associated with the naming of colored photographs (β = .75, p = .039), naming in response to an oral description (β = 1.81, p = .039), picture sorting at four levels (β = 7.22, p = .029), and sentence verification (β = 26.66, p = .01). In addition, there were differences between the results obtained in adults in the original study and in the children of our study. This exploratory study supports the feasibility of the Spanish translation of the Catricalà et al. (2013) battery to assess SM in children with a nonclinical condition. Future studies are needed to evaluate the psychometric properties of this SM battery, and to corroborate and expand our findings in a larger sample of control children, and in children with some degree of intellectual disability or suffering of some neurodegenerative or psychiatric conditions.

Newborn and childhood differential DNA methylation and liver fat in school-age children

BackgroundNon-alcoholic fatty liver disease is the most common chronic liver disease in children in western countries. Adverse early-life exposures are associated with higher liver fat percentages in children. Differential DNA methylation may underlie these associations. We aimed to identify differential DNA methylation in newborns and children associated with liver fat accumulation in childhood. We also examined whether DNA methylation at 22 cytosine-phosphate-guanine sites (CpGs) associated with adult non-alcoholic fatty liver disease is associated with liver fat in children. Within a population-based prospective cohort study, we analyzed epigenome-wide DNA methylation data of 785 newborns and 344 10-year-old children in relation to liver fat fraction at 10 years. DNA methylation was measured using the Infinium HumanMethylation450 BeadChip (Illumina). We measured liver fat fraction by Magnetic Resonance Imaging. Associations of single CpG DNA methylation at the two-time points with liver fat accumulation were analyzed using robust linear regression models. We also analyzed differentially methylation regions using the dmrff package. We looked-up associations of 22 known adult CpGs at both ages with liver fat at 10 years.ResultsThe median liver fat fraction was 2.0% (95% range 1.3, 5.1). No single CpGs and no differentially methylated regions were associated with liver fat accumulation. None of the 22 known adult CpGs were associated with liver fat in children.ConclusionsDNA methylation at birth and in childhood was not associated with liver fat accumulation in 10-year-old children in this study. This may be due to modest sample sizes or DNA methylation changes being a consequence rather than a determinant of liver fat.

Robust Nonparametric Regression for Heavy-Tailed Data

We propose a robust nonparametric regression method that can deal with heavy-tailed noise and also a heavy-tailed input variable. We decompose the trajectory matrix of the response variable of the regression problem to extract the regression function in a nonparametric way. We implement the decomposition in a robust way using iterative robust linear regressions. We show the effectiveness of the proposed method on synthetic and real data in comparison with two other nonparametric methods and a robust linear method.