LLukas22/scidocs huggingface dataset:
Normalized metal artifact reduction (NMAR) in computed tomography.

PURPOSE
While modern clinical CT scanners under normal circumstances produce high quality images, severe artifacts degrade the image quality and the diagnostic value if metal prostheses or other metal objects are present in the field of measurement. Standard methods for metal artifact reduction (MAR) replace those parts of the projection data that are affected by metal (the so-called metal trace or metal shadow) by interpolation. However, while sinogram interpolation methods efficiently remove metal artifacts, new artifacts are often introduced, as interpolation cannot completely recover the information from the metal trace. The purpose of this work is to introduce a generalized normalization technique for MAR, allowing for efficient reduction of metal artifacts while adding almost no new ones. The method presented is compared to a standard MAR method, as well as MAR using simple length normalization.


METHODS
In the first step, metal is segmented in the image domain by thresholding. A 3D forward projection identifies the metal trace in the original projections. Before interpolation, the projections are normalized based on a 3D forward projection of a prior image. This prior image is obtained, for example, by a multithreshold segmentation of the initial image. The original rawdata are divided by the projection data of the prior image and, after interpolation, denormalized again. Simulations and measurements are performed to compare normalized metal artifact reduction (NMAR) to standard MAR with linear interpolation and MAR based on simple length normalization.


RESULTS
Promising results for clinical spiral cone-beam data are presented in this work. Included are patients with hip prostheses, dental fillings, and spine fixation, which were scanned at pitch values ranging from 0.9 to 3.2. Image quality is improved considerably, particularly for metal implants within bone structures or in their proximity. The improvements are evaluated by comparing profiles through images and sinograms for the different methods and by inspecting ROIs. NMAR outperforms both other methods in all cases. It reduces metal artifacts to a minimum, even close to metal regions. Even for patients with dental fillings, which cause most severe artifacts, satisfactory results are obtained with NMAR. In contrast to other methods, NMAR prevents the usual blurring of structures close to metal implants if the metal artifacts are moderate.


CONCLUSIONS
NMAR clearly outperforms the other methods for both moderate and severe artifacts. The proposed method reliably reduces metal artifacts from simulated as well as from clinical CT data. Computationally efficient and inexpensive compared to iterative methods, NMAR can be used as an additional step in any conventional sinogram inpainting-based MAR method.
Non-use of day care services for dementia in Singapore - a dilemma for caregivers.

BACKGROUND
Day care services for patients with dementia (PWD) are generally under-utilized worldwide despite evidence of positive outcomes, such as improved behavioral, psychological, and cognitive functioning for patients, and reduced caregiver burden. This study sought to gain an in-depth understanding of the reasons for non-utilization of day care services in Singapore using qualitative methodology.


METHODS
A purposive sample of 16 caregivers of PWD who had never attended day care services participated in semi-structured interviews. Interviews were audio-recorded and transcribed verbatim. Data analysis was based on an Interpretative Phenomenological Analysis framework.


FINDINGS
Caregivers recognized the importance of engagement for PWD, yet were constrained by patients' refusal to attend day care, which caregivers attributed to the patients' negative beliefs about day care and fear of abandonment by their families. Caregivers also raised concerns about service delivery issues, the suitability of activities at day care, and their perceptions of the patients' ability to integrate into the setting. Non-utilization was also related to caregivers' low perceived need due to the availability of alternative care arrangements (e.g. having a domestic helper and adequate family support).


CONCLUSIONS
Caregivers generally understand the value of day care but several factors tip the balance in favor of non-use. These include culturally bound caregiving values and perceptions, and inadequacies in service delivery. Negative perceptions about services highlight the need to enhance the image and standards of day care and increase awareness of the benefits of day care for PWD beyond its custodial role.
The epidemiology of Kawasaki disease: a global update.

Kawasaki disease (KD) is a childhood vasculitis and the most frequent cause of paediatric acquired heart disease in North America, Europe and Japan. It is increasingly recognised in rapidly industrialising countries such as China and India where it may replace rheumatic heart disease as the most common cause of acquired heart disease in children. We review the current global epidemiology of KD and discuss some public health implications.
A taxonomy of wireless micro-sensor network models

In future smart environments, wireless sensor networks will play a key role in sensing, collecting, and disseminating information about environmental phenomena. Sensing applications represent a new paradigm for network operation, one that has different goals from more traditional wireless networks. This paper examines this emerging field to classify wireless micro-sensor networks according to different communication functions, data delivery models, and network dynamics. This taxonomy will aid in defining appropriate communication infrastructures for different sensor network application sub-spaces, allowing network designers to choose the protocol architecture that best matches the goals of their application. In addition, this taxonomy will enable new sensor network models to be defined for use in further research in this area.
Optimizing daily agent scheduling in a multiskill call center

We examine and compare simulation-based algorithms for solving the agent scheduling problem in a multiskill call center. This problem consists in minimizing the total costs of agents under constraints on the expected service level per call type, per period, and aggregated. We propose a solution approach that combines simulation with integer or linear programming, with cut generation. In our numerical experiments with realistic problem instances, this approach performs better than all other methods proposed previously for this problem. We also show that the two-step approach, which is the standard method for solving this problem, sometimes yield solutions that are highly suboptimal and inferior to those obtained by our proposed method. 2009 Published by Elsevier B.V.
Rise and fall of the Eastern Great Indonesian arc recorded by the assembly, dispersion and accretion of the Banda Terrane, Timor

New age, petrochemical and structural data indicate that the Banda Terrane is a remnant of a Jurassic to Eocene arc–trench system that formed the eastern part of the Great Indonesian arc. The arc system rifted apart during Eocene to Miocene supra-subduction zone sea floor spreading, which dispersed ridges of Banda Terrane embedded in young oceanic crust as far south as Sumba and Timor. In Timor the Banda Terrane is well exposed as high-level thrust sheets that were detached from the edge of the Banda Sea upper plate and uplifted by collision with the passive margin of NW Australia. The thrust sheets contain a distinctive assemblage of medium grade metamorphic rocks overlain by Cretaceous to Miocene forearc basin deposits. New U/Pb age data presented here indicate igneous zircons are less than 162 Ma with a cluster of ages at 83 Ma and 35 Ma. Ar/Ar plateau ages of various mineral phases from metamorphic units all cluster at between 32–38 Ma. These data yield a cooling curve that shows exhumation from around 550 °C to the surface between 36–28 Ma. After this time there is no evidence of metamorphism of the Banda Terrane, including its accretion to the edge of the Australian continental margin during the Pliocene. These data link the Banda Terrane to similar rocks and events documented throughout the eastern edge of the Sunda Shelf and the Banda Sea floor. © 2006 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
Daytime depression in tree stem CO2 efflux rates: is it caused by low stem turgor pressure?

BACKGROUND AND AIMS
Daytime CO2 efflux rates (FCO2) from tree stems are often reported to be lower than expected from the exponential relationship between temperature and respiration. Explanations of daytime depression in FCO2 have focused on the possible role of internal CO2 transport in the xylem. However, another possible cause that has been overlooked is the daily dynamics of the water status in the living stem tissues and its influence on stem growth rate and thus respiration. The objective of this study was to assess the daily dynamics of stem water status and growth rate and to determine the extent to which they may be linked to daily variations in stem FCO2.


METHODS
FCO2 of young beech and oak stems were measured under controlled conditions. Relative stem turgor pressure (Psi(p)), obtained from simulations with the 'RCGro' model, was used as an indicator of the water status in the living stem tissues. Daily dynamics of stem growth were derived from Psi(p): growth was assumed to occur when Psi(p) exceeded a relative threshold value.


KEY RESULTS
There was a strong correspondence between fluctuations in FCO2 and simulated Psi(p). The non-growth conditions during daytime coincided with depressions in FCO2. Moreover, FCO2 responded to changes in Psi(p) in the absence of growth, indicating also that maintenance processes were influenced by the water status in the living stem tissues.


CONCLUSIONS
Daytime depressions in stem FCO2 correlate with the daily dynamics of turgor, as a measure of the water status in the living stem tissues: it is suggested that water status of tree stems is a potentially important determinant of stem FCO2, as it influences the rate of growth and maintenance processes in the living tissues of the stem.
Effects of constraint-induced movement therapy on patients with chronic motor deficits after stroke: a replication.

BACKGROUND AND PURPOSE
Constraint-induced movement therapy (CI therapy) has previously been shown to produce large improvements in actual amount of use of a more affected upper extremity in the "real-world" environment in patients with chronic stroke (ie, >1 year after the event). This work was carried out in an American laboratory. Our aim was to determine whether these results could be replicated in another laboratory located in Germany, operating within the context of a healthcare system in which administration of conventional types of physical therapy is generally more extensive than in the United States.


METHODS
Fifteen chronic stroke patients were given CI therapy, involving restriction of movement of the intact upper extremity by placing it in a sling for 90% of waking hours for 12 days and training (by shaping) of the more affected extremity for 7 hours on the 8 weekdays during that period.


RESULTS
Patients showed a significant and very large degree of improvement from before to after treatment on a laboratory motor test and on a test assessing amount of use of the affected extremity in activities of daily living in the life setting (effect sizes, 0.9 and 2.2, respectively), with no decrement in performance at 6-month follow-up. During a pretreatment control test-retest interval, there were no significant changes on these tests.


CONCLUSIONS
Results replicate in Germany the findings with CI therapy in an American laboratory, suggesting that the intervention has general applicability.
Effects of Exercise in the Treatment of Overweight and Obese Children and Adolescents: A Systematic Review of Meta-Analyses

PURPOSE
Conduct a systematic review of previous meta-analyses addressing the effects of exercise in the treatment of overweight and obese children and adolescents.


METHODS
Previous meta-analyses of randomized controlled exercise trials that assessed adiposity in overweight and obese children and adolescents were included by searching nine electronic databases and cross-referencing from retrieved studies. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument. The alpha level for statistical significance was set at P ≤ 0.05.


RESULTS
Of the 308 studies reviewed, two aggregate data meta-analyses representing 14 and 17 studies and 481 and 701 boys and girls met all eligibility criteria. Methodological quality was 64% and 73%. For both studies, statistically significant reductions in percent body fat were observed (P = 0.006 and P < 0.00001). The number-needed-to treat (NNT) was 4 and 3 with an estimated 24.5 and 31.5 million overweight and obese children in the world potentially benefitting, 2.8 and 3.6 million in the US. No other measures of adiposity (BMI-related measures, body weight, and central obesity) were statistically significant.


CONCLUSIONS
Exercise is efficacious for reducing percent body fat in overweight and obese children and adolescents. Insufficient evidence exists to suggest that exercise reduces other measures of adiposity.
Molluscum contagiosum in Greek children: a case series.

BACKGROUND
Epidemiological studies of molluscum contagiosum (MC) in children are limited.


PATIENTS AND METHOD
Between 1997 and 1999, 110 children with MC (60 boys, 50 girls, mean age: 4.8 years) were studied. Treatment consisted of removal of all MC lesions in a single session by sterilized tweezers.


RESULTS
In children aged < or = 2 years, the MC lesions were located mainly on the face, whereas in older children they were located on the trunk. Twenty children had atopic dermatitis (18.2% vs. 5% of Greek children aged 1-6 years; P < 0.001). Four children had numerous and recurrent MC lesions without any other systemic manifestations. In these children, humoral and cellular immunities were found to be normal. Seventy-seven children (70%) were cured after one treatment session, 22 children (20%) after a second session and 11 (10%) after > or = three sessions. No patients experienced secondary bacterial infection or scarring.


CONCLUSIONS
In contrast to cool climates where the age of peak incidence of MC in children is 10-12 years, in a warm country such as Greece, it is at the younger age of 4.8 years. In young children aged 2 years, the MC lesions are located mainly on the face, whereas in older children they are located on the trunk. Atopic dermatitis is a predisposing factor for MC. In cases where MC lesions are numerous and/or persist but there are no other signs of systemic infections, the possibility of immunodeficiency is minimal. Removal of MC lesions by tweezers is an efficient, simple and inexpensive method of treatment without sequelae.
Climate and Wildlife

Overwhelming international scientific consensus confirms that human activities are disturbing Earth’s climate and effects from this are already affecting biodiversity and human health-but it's not to late to help!
Conversational agents in healthcare: a systematic review

Objective
Our objective was to review the characteristics, current applications, and evaluation measures of conversational agents with unconstrained natural language input capabilities used for health-related purposes.


Methods
We searched PubMed, Embase, CINAHL, PsycInfo, and ACM Digital using a predefined search strategy. Studies were included if they focused on consumers or healthcare professionals; involved a conversational agent using any unconstrained natural language input; and reported evaluation measures resulting from user interaction with the system. Studies were screened by independent reviewers and Cohen's kappa measured inter-coder agreement.


Results
The database search retrieved 1513 citations; 17 articles (14 different conversational agents) met the inclusion criteria. Dialogue management strategies were mostly finite-state and frame-based (6 and 7 conversational agents, respectively); agent-based strategies were present in one type of system. Two studies were randomized controlled trials (RCTs), 1 was cross-sectional, and the remaining were quasi-experimental. Half of the conversational agents supported consumers with health tasks such as self-care. The only RCT evaluating the efficacy of a conversational agent found a significant effect in reducing depression symptoms (effect size d = 0.44, p = .04). Patient safety was rarely evaluated in the included studies.


Conclusions
The use of conversational agents with unconstrained natural language input capabilities for health-related purposes is an emerging field of research, where the few published studies were mainly quasi-experimental, and rarely evaluated efficacy or safety. Future studies would benefit from more robust experimental designs and standardized reporting.


Protocol Registration
The protocol for this systematic review is registered at PROSPERO with the number CRD42017065917.
GMM-based classification from noisy features

We consider Gaussian mixture model (GMM)-based classification from noisy features, where the uncertainty over each feature is represented by a Gaussian distribution. For that purpose, we first propose a new GMM training and decoding criterion called log-likelihood integration which, as opposed to the conventional likelihood integration criterion, does not rely on any assumption regarding the distribution of the data. Secondly, we introduce two new Expectation Maximization (EM) algorithms for the two criteria, that allow to learn GMMs directly from noisy features. We then evaluate and compare the behaviors of two proposed algorithms with a categorization task on artificial data and speech data with additive artificial noise, assuming the uncertainty parameters are known. Experiments demonstrate the superiority of the likelihood integration criterion with the newly proposed EM learning in all tested configurations, thus giving rise to a new family of learning approaches that are insensitive to the heterogeneity of the noise characteristics between testing and training data.
Early Intervention May Prevent the Development of Posttraumatic Stress Disorder: A Randomized Pilot Civilian Study with Modified Prolonged Exposure

BACKGROUND
Posttraumatic stress disorder (PTSD) is a major public health concern with long-term sequelae. There are no accepted interventions delivered in the immediate aftermath of trauma. This study tested an early intervention aimed at modifying the memory to prevent the development of PTSD before memory consolidation.


METHODS
Patients (n = 137) were randomly assigned to receive three sessions of an early intervention beginning in the emergency department compared with an assessment only control group. Posttraumatic stress reactions (PTSR) were assessed at 4 and 12 weeks postinjury and depression at baseline and week 4. The intervention consisted of modified prolonged exposure including imaginal exposure to the trauma memory, processing of traumatic material, and in vivo and imaginal exposure homework.


RESULTS
Patients were assessed an average of 11.79 hours posttrauma. Intervention participants reported significantly lower PTSR than the assessment group at 4 weeks postinjury, p < .01, and at 12 weeks postinjury, p < .05, and significantly lower depressive symptoms at week 4 than the assessment group, p < .05. In a subgroup analysis, the intervention was the most effective at reducing PTSD in rape victims at week 4 (p = .004) and week 12 (p = .05).


CONCLUSIONS
These findings suggest that the modified prolonged exposure intervention initiated within hours of the trauma in the emergency department is successful at reducing PTSR and depression symptoms 1 and 3 months after trauma exposure and is safe and feasible. This is the first behavioral intervention delivered immediately posttrauma that has been shown to be effective at reducing PTSR.
Unpacking Neighborhood Influences on Education Outcomes: Setting the Stage for Future Research

Johnson Health Policy Seminar for helpful comments on previous versions of this paper. The views expressed here are those of the authors and should not be interpreted as those of the Congressional Budget Office Summary Most existing social science research on neighborhoods conceptualizes neighborhood effects at the macro level, hypothesizing how general neighborhood characteristics such as the poverty rate affect a variety of individual and family outcomes. Contemporary research on this topic has largely failed to recognize the diverse types of families living in poor neighborhoods or the potentially wide variety of ways that they may respond to a given set of neighborhood conditions. Our core argument is that future neighborhood research must seriously consider this diversity both conceptually and methodologically. Our hypothesis is that there is considerable heterogeneity in the experiences of youth in the same neighborhood that might vary by their personal or family resources, their ability to cope with or navigate neighborhood circumstances, and the decisions youth and their family make about how, with whom, and where their time is spent. Depending on these and other factors, different youth may get a different " dose " of their neighborhood. This heterogeneity can generate substantial variation in how a given neighborhood characteristic affects any one youth. Youth who live in the same neighborhood may experience it in different ways, leading to " effect heterogeneity, " neighborhood effects of different direction or magnitude for different youth. With a call to pay closer attention to effect heterogeneity as the core of our argument, we motivate future neighborhood research through a simple model that considers youth educational outcomes as a function of neighborhood context, neighborhood exposure, individual vulnerability to neighborhood effects, and non-neighborhood educational inputs. Moving this research agenda forward requires three steps. First, researchers need to shift focus away from broad theories of neighborhood effects and examine the specific mechanisms through which the characteristics of a neighborhood might affect an individual. By " mechanisms " we mean the 1 2 social, economic, and cultural processes that create associations between the compositional or demographic characteristics of neighborhoods, such as neighborhood poverty, and individual educational outcomes, such as achievement scores or educational attainment. Second, neighborhood research desperately needs new and far more nuanced data. In particular, we need data that measure how individuals and families of different types allocate their time between different places, the extent of exposure to different people and …