Feasibility of generating synthetic CT from T1-weighted MRI using a linear mixed-effects regression model

Generation of synthetic computed tomography (sCT) for magnetic resonance imaging (MRI)-only radiotherapy is emerging as a promising direction because it can eliminate the registration error and simplify clinical workflow. The goal of this study was to generate accurate sCT from standard T1-weighted MRI for brain patients. CT and MRI data of twelve patients with brain tumors were retrospectively collected. Linear mixed-effects regression models were fitted between CT and T1-weighted MRI intensities for different segments in the brain. The whole brain sCTs were generated by combining predicted segments together. Mean absolute error (MAE) between real CTs and sCTs across all patients was 71.1 ±5.5 Hounsfield Unit (HU). Average differences in the HU values were 1.7 ±7.1 HU (gray matter), 0.9 ±5.1 HU (white matter), -24.7 ±8.0 HU (cerebrospinal fluid), 76.4 ±17.8 HU (bone), 20.9 ±20.4 HU (fat), -69.4 ±28.3 HU (air). A simple regression technique has been devised that is capable of producing accurate HU maps from standard T1-weighted MRI, and exceptionally low MAE values indicate accurate prediction of sCTs. Improvement is needed in segmenting MRI using a more automatic approach

Report on Provider-Client Interaction From 68 Methadone Maintenance Clinics in China.

Provider-client interaction is an integral of clinical practice and central to the delivery of high-quality medical care. This article examines factors related to the provider-client interaction in the context of methadone maintenance treatment (MMT). Data were collected from 68 MMT clinics in China. In total, 418 service providers participated in the survey. Linear mixed effects regression models were performed to identify factors associated with provider-client interaction. It was observed that negative attitude toward drug users was associated with lower level of provider-client interaction and less time spent with each client. Other factors associated with lower level of interaction included being female, being younger, being a nurse, and fewer years in medical field. Higher provider-client interaction was associated with provider reported job satisfaction. The findings of this study call for a need to address provider negative attitudes that can impact provider-client interaction and the effectiveness of MMT. Future intervention efforts targeting MMT providers should be tailored by gender, provider type, and medical experiences

Emergent Organizational Networks: The Case of Food Hub Managers’ Advice Network

The literature on food hubs reveals networks play a critical role in food hub practitioners’ ability to gather information useful for their enterprises. However, there is a lack of knowledge on how the practitioners choose from whom to get information or advice. This study examines the role of individual-, tie-, and network characteristics on the likelihood of receiving advice. By collecting data from managers in the U.S. state of Michigan, the study applied the generalized linear mixed-effects regression method. The results show the strength of tie, transitivity, reciprocity, and alter’s area of expertise affect the likelihood of receiving advice

The role of gesture delay in coda /r/ weakening: an articulatory, auditory and acoustic study

The cross-linguistic tendency of coda consonants to weaken, vocalize, or be deleted is shown to have a phonetic basis, resulting from gesture reduction, or variation in gesture timing. This study investigates the effects of the timing of the anterior tongue gesture for coda /r/ on acoustics and perceived strength of rhoticity, making use of two sociolects of Central Scotland (working- and middle-class) where coda /r/ is weakening and strengthening, respectively. Previous articulatory analysis revealed a strong tendency for these sociolects to use different coda /r/ tongue configurations—working- and middle-class speakers tend to use tip/front raised and bunched variants, respectively; however, this finding does not explain working-class /r/ weakening. A correlational analysis in the current study showed a robust relationship between anterior lingual gesture timing, F3, and percept of rhoticity. A linear mixed effects regression analysis showed that both speaker social class and linguistic factors (word structure and the checked/unchecked status of the prerhotic vowel) had significant effects on tongue gesture timing and formant values. This study provides further evidence that gesture delay can be a phonetic mechanism for coda rhotic weakening and apparent loss, but social class emerges as the dominant factor driving lingual gesture timing variation

Step Number and Aerobic Minute Exercise Prescription and Progression in Stroke: A Roadmap

Background: While higher therapeutic intensity improves motor recovery after stroke, translating findings from successful studies is challenging without clear exercise intensity targets. We show in the DOSE trial1 more than double the steps and aerobic minutes within a session can be achieved compared with usual care and translates to improved long-term walking outcomes. Objective: We modeled data from this successful higher intensity multi-site RCT to develop targets for prescribing and progressing exercise for varying levels of walking impairment after stroke. Methods: In twenty-five individuals in inpatient rehabilitation, twenty sessions were monitored for a total of 500 one-hour physical therapy sessions. For the 500 sessions, step number and aerobic minute progression were modeled using linear mixed effects regression. Using formulas from the linear mixed effects regression, targets were calculated. Results: The model for step number included session number and baseline walking speed, and for aerobic minutes, session number and age. For steps, there was an increase of 73 steps per session. With baseline walking speed, for every 0.1 m/s increase, a corresponding increase of 302 steps was predicted. For aerobic minutes, there was an increase of.56 minutes of aerobic activity (ie, 34 seconds) per session. For every year increase in age, a decrease of.39 minutes (ie, 23 seconds) was predicted. Conclusions: Using data associated with better walking outcomes, we provide step number and aerobic minute targets that future studies can cross-validate. As walking speed and age are collected at admission, these models allow for uptake of routine measurement of therapeutic intensity. Registration: www.clinicaltrials.gov; NCT01915368

An intervention to improve provider-patient interaction at methadone maintenance treatment in China.

BackgroundThis study evaluated an intervention aiming to improve methadone maintenance therapy (MMT) service providers' interaction with their patients in China.MethodsSixty-eight MMT clinics were randomized to either an intervention or a control condition. Providers in the intervention group attended three group training sessions to enhance their communication skills. Trained providers were encouraged to practice the taught communication skills through provider-initiated individual sessions with their patients. A total of 418 service providers completed assessments from baseline to 24-month. Linear mixed-effects regression models were used to compare self-reported short-term and sustained improvement in provider-patient interaction between the intervention and the control conditions.ResultsThe intervention group service providers perceived significantly greater short-term and sustained improvement in provider-patient interaction compared to the control group service providers (estimated difference (±SE): 1.20 (0.24) and 1.35 (0.33), respectively; p-values < 0.0001). Providers' baseline job satisfaction was significantly associated with a greater perceived improvement in provider-patient interaction for both periods (reg. coef. (±SE): 0.02 (0.01) and 0.04 (0.01) for short-term and sustained periods, respectively; p-values < 0.01).ConclusionStudy findings suggest that the intervention could be beneficial for improving perceived provider-patient interaction in MMT programs. Service providers' job satisfaction should be addressed in training programs for the improvement of provider-patient interaction

Gender Differences in Depressive Symptoms Among HIV-Positive Concordant and Discordant Heterosexual Couples in China.

HIV seropositive individuals and their heterosexual partners/spouses, either seropositive or seronegative, are facing several mental health challenges. The objective of this study was to examine gender differences in depressive symptoms among HIV-positive concordant and HIV-discordant couples. We identified heterosexual couples from participants of a randomized controlled trial conducted in Anhui province, China. A total of 265 couples, comprising 129 HIV+ male/HIV- female couples, 98 HIV- male/HIV+ female couples, and 38 HIV-positive concordant couples, were included in the analyses. We collected data using the computer-assisted personal interview method. We used a linear mixed-effects regression model to assess whether gender differences in depressive symptoms varied across couple types. HIV-positive women reported a significantly higher level of depressive symptoms than their partners/spouses. HIV-positive women with HIV-positive partners had higher depressive symptoms than those with HIV-negative partners, whereas HIV-positive men reported similar levels of depressive symptoms regardless of their partners' serostatus. Among the concordant couples, those with the highest annual family income showed the greatest gender differences in depressive symptoms. We suggest that family interventions should be gender- and couple-type specific and that mental health counseling is warranted not only for HIV-positive women but also for HIV-negative women in an HIV-affected relationship

Spatial heterogeneity in projected leprosy trends in India

Background: Leprosy is caused by infection with Mycobacterium leprae and is characterized by peripheral nerve damage and skin lesions. The disease is classified into paucibacillary (PB) and multibacillary (MB) leprosy. The 2012 London Declaration formulated the following targets for leprosy control: (1) global interruption of transmission or elimination by 2020, and (2) reduction of grade-2 disabilities in newly detected cases to below 1 per million population at a global level by 2020. Leprosy is treatable, but diagnosis, access to treatment and treatment adherence (all necessary to curtail transmission) represent major challenges. Globally, new case detection rates for leprosy have remained fairly stable in the past decade, with India responsible for more than half of cases reported annually. Methods: We analyzed publicly available data from the Indian Ministry of Health and Family Welfare, and fit linear mixed-effects regression models to leprosy case detection trends reported at the district level. We assessed correlation of the new district-level case detection rate for leprosy with several state-level regressors: TB incidence, BCG coverage, fraction of cases exhibiting grade 2 disability at diagnosis, fraction of cases in children, and fraction multibacillary. Results: Our analyses suggest an endemic disease in very slow decline, with substantial spatial heterogeneity at both district and state levels. Enhanced active case finding was associated with a higher case detection rate. Conclusions: Trend analysis of reported new detection rates from India does not support a thesis of rapid progress in leprosy control

Semantic typology: New approaches to crosslinguistic variation in language and cognition

This article presents an overview of the goals and methods of semantic typology, the study of the distribution of semantic categories across languages. Results from this field inform theoretical accounts of syntax-semantics interface phenomena, as well as the nature of the relationship between language and cognition. This article discusses a variety of quantitative methods that represent recent efforts in semantic typology to (i) discover patterns in the distribution of independent variables and (ii) predict the distribution of dependent variables in relation to identified independent variables. Such methods include Multi-Dimensional Scaling, Hierarchical Cluster Analysis, and Generalized Linear Mixed Effects regression analyses. We identify and discuss notable published examples of these methods used in semantic typology