bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast estimators for the mean function for functional data with detection limits
Authors: Liu Haiyan , Houwing‐Duistermaat Jeanine
Published: April 2022

In many studies on disease progression, biomarkers are restricted by detection limits, hence informatively missing. Current approaches either ignore the problem by just filling in the value of the detection limit for the missing observations or apply a global approach for estimation of the mean function. The latter is time‐consuming for dense data, and the obtained estimate depends on the whole observed interval which might not be realistic. We will propose novel estimators for the mean function for both unbalanced sparse and dense data subject to the detection limit. We will derive the asymptotic properties of the estimators. We will compare our methods to the existing methods via simulations and illustrate the new methods with a data application. Our methods appear to perform well. For dense data, the approximation methods are computationally much faster than existing methods.
An organ‐specific transcriptomic atlas of the medicinal plant Bletilla striata: Protein‐coding genes, microRNAs, and regulatory networks
Authors: Ma Xiaoxia , Tang Kehua , Tang Zhonghai , Dong Aiwen , Xiao Hang , Meng Yijun , Wang Pu
Published: April 2022

As one of the important species belonging to the Bletilla genus of Orchidaceae, Bletilla striata (Thunb.) Rchb. f., possesses both ornamental and medicinal values. Its dried tubers are used as a traditional Chinese medicine, and several secondary metabolites have been indicated to be the active ingredients. However, the molecular mechanisms related to the regulation of secondary metabolism have not been characterized in B. striata. In this study, integrated analysis of RNA sequencing (RNA‐seq), small RNA sequencing (sRNA‐seq), and degradome sequencing (degradome‐seq) data from three organs (leaf, root, and tuber) of B. striata provided us with a comprehensive view of the microRNA (miRNA)‐mediated regulatory network. Firstly, based on the RNA‐seq data, the organ‐specific expression patterns of the protein‐coding genes, especially for those related to secondary metabolism, were investigated. Secondly, 342 conserved miRNA candidates were identified from B. striata. These miRNAs were assigned to 88 families, some of which were selected for expression pattern analysis. Additionally, 31 hairpin‐structured precursors encoding 23 novel miRNAs were uncovered from the transcriptome assembly. Thirdly, based on the degradome signatures, 1,142 validated miRNA–target pairs (involving 167 conserved miRNAs and six novel miRNAs and 51 target genes) were included in the regulatory network. Organ‐specific expression level comparison between the miRNAs and their targets revealed some interesting miRNA–target pairs. Fourthly, some valuable subnetworks were extracted for further functional studies. Additionally, some regulatory pathways were indicated to be monocot specific. Summarily, our results lay a solid basis for in‐depth studies on the regulatory mechanisms underlying the production of the medicinal ingredients in B. striata.
Use of a videofluoroscopic feeding evaluation to guide management of dogs with congenital idiopathic megaoesophagus
Authors: Lyngby Janne G. , Haines Jillian M. , Guess Sarah C.
Published: April 2022

Background

Evidence‐based guidelines for determining dietary management in dogs with megaoesophagus are lacking.

Objectives

This study looked to compare oesophageal clearance times (ECT) of liquid and two food consistencies using a contrast videofluoroscopy feeding evaluation, and to assess if recommendations made based on findings could improve regurgitation and quality of life in dogs with congenital megaoesophagus.

Methods

Twenty‐one dogs with congenital megaoesophagus and nine healthy dogs received liquid, slurry, and meatball diets containing barium while in an upright position. Follow‐up was performed to determine response to recommendations.

Results

Healthy dogs had significantly shorter median ECT for all consistencies (p < 0.001). In the megaoesophagus group, ECT varied by consistency and individual. The number of dogs in the megaoesophagus group with complete clearance was four (median ECT 10 min) for liquid, five (median ECT 5 min) for slurry, and two (median ECT 5 and 30 min, respectively) for meatballs. Partial clearance was seen in 11 dogs (median clearance 25%) with liquid, seven with slurry (median clearance 50%), and five with meatballs (median clearance 60%). Recommendations included altering current medications (13/21 dogs), diet consistency (6/21), time upright (12/21), water delivery (21/21), and adding activity (7/21). Regurgitation episodes/week decreased significantly from 5.5 to 2.5 (p < 0.001) at follow‐up 3–5 weeks post‐evaluation, with 95% of owners reporting improvement in quality of life. Seventy percent were alive 46–777 days after last recheck. Three dogs died from megaoesophagus associated complications (median survival 461 days after diagnosis).

Conclusions

The findings of this study suggest that a videofluoroscopic feeding evaluation may help guide management of dogs with congenital megaoesophagus.
Hyperandrogenism and Polycystic ovary syndrome: Effects in pregnancy and offspring development
Authors: Abruzzese Giselle A. , Silva Aimé F. , Velazquez Mariela E. , Ferrer Maria‐José , Motta Alicia B.
Published: April 2022

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women of reproductive age. Its etiology remains unclear. It is suggested that environmental factors, and particularly the intrauterine environment, play key roles in PCOS development. Besides the role of androgens in PCOS pathogenesis, exposure to endocrine disruptors, as is Bisphenol A, could also contribute to its development. Although PCOS is considered one of the leading causes of ovarian infertility, many PCOS patients can get pregnant. Some of them by natural conception and others by assisted reproductive technique treatments. As hyperandrogenism (one of PCOS main features) affects ovarian and uterine functions, PCOS women, despite reaching pregnancy, could present high‐risk pregnancies, including implantation failure, an increased risk of gestational diabetes, preeclampsia, and preterm birth. Moreover, hyperandrogenism may also be maintained in these women during pregnancy. Therefore, as an altered uterine milieu, including hormonal imbalance, could affect the developing organisms, monitoring these patients throughout pregnancy and their offspring development is highly relevant. The present review focuses on the impact of androgenism and PCOS on fertility issues and pregnancy‐related outcomes and offspring development. The evidence suggests that the increased risk of pregnancy complications and adverse offspring outcomes of PCOS women would be due to the factors involved in the syndrome pathogenesis and the related co‐morbidities. A better understanding of the involved mechanisms is still needed and could contribute to a better management of these women and their offspring.

This article is categorized under:

Reproductive System Diseases > Molecular and Cellular Physiology

Reproductive System Diseases > Environmental Factors
Russian and Turkish Migration Regimes in a Comparative Perspective
Authors: Urinboyev Rustamjon , Eraliev Sherzod
Published: April 2022

Global political developments, economic growth and trade liberalization since the 1980s have changed the political and economic landscapes of most regions in the world. First, the collapse of the Soviet Union (and the communist regimes in Central and Eastern Europe) lead to the movement of large segments of populations. For example, the dissolution of the Soviet Union alone left tens of millions of people divided into several countries.
Schützende Bewältigung: Eine Grounded Theory
Authors: Logeswaran Araththy
Published: April 2022

In diesem Kapitel möchte ich die Ergebnisse meiner Analyse zusammenführen und das Theoriemodell der Schützenden Bewältigung vorstellen. Es handelt sich hierbei um eine Handlungstheorie. Diese Art von Theorie erklärt die Interaktionsprozesse zwischen Individuen und/oder Gruppen. Schützende Bewältigung ist ein Phänomen, das bei Menschen mit Diskriminierungserfahrung eine zentrale Rolle bei der Handlungsauswahl spielt. Die Befragten verwendeten in ihren erzählerischen Rekonstruktionen wiederkehrend den Begriff schützen, worauf ich aufmerksam wurde, bevor ich das Phänomen als solches identifizierte.
On the L∞ formulation of Chern-Simons theories
Authors: Salgado S.
Published: April 2022

Abstract

L∞ algebras have been largely studied as algebraic frameworks in the formulation of gauge theories in which the gauge symmetries and the dynamics of the interacting theories are contained in a set of products acting on a graded vector space. On the other hand, FDAs are differential algebras that generalize Lie algebras by including higher-degree differential forms in their differential equations. In this article, we review the dual relation between FDAs and L∞ algebras. We study the formulation of standard Chern-Simons theories in terms of L∞ algebras and extend the results to FDA-based gauge theories. We focus on two cases, namely a flat (or zero-curvature) theory and a generalized Chern-Simons theory, both including high-degree differential forms as fundamental fields.
AdS3×S2 in IIB with small $$ \mathcal{N} $$ = (4, 0) supersymmetry
Authors: Macpherson Niall T. , Ramirez Anayeli
Published: April 2022

Abstract

We consider warped AdS3×S2×M5 backgrounds in type II supergravity preserving small $$ \mathcal{N} $$
N
= (4, 0) supersymmetry. We show that imposing $$ \mathcal{N} $$
N
= (4, 0) supersymmetry imposes between 0 and 3 a priori isometries in the internal M5. In this work we focus on classes of solution where M5 exhibits no a priori isometry which imposes additional constraints. Solving these in IIA forces M5 to support an SU(2)-structure, a class already studied in [10], while in IIB one arrives at two broad new classes with identity-structure that we reduce to local expressions for the physical fields and PDEs.
Numerical and experimental validation of gas metal arc welding on AISI 441 ferritic stainless steel through mechanical and microstructural analysis
Authors: Caruso Serafino , Umbrello Domenico
Published: April 2022

Residual stresses and strains, distortions, heat-affected zone (HAZ), grain size changes and hardness variation during gas metal arc welding (GMAW), are fundamental aspects to study and control during welding processes. For this reason, numerical simulations of the welding processes represent the more frequently used tool to better analyse the several aspects characterizing this joining process with the aim to reduce lead time and production costs. In the present study, an uncoupled 3D thermo-mechanical analysis was carried out by two commercial finite element method (FEM) software to model an experimental single bead GMAW of AISI 441 at different processes set-up. The experimental HAZ and measured temperatures were used to calibrate the heat source of both the used numerical codes, then a validation phase was done to test the robustness of the two developed analytical procedures. One software was used to predict the residual stresses and strains and the distortions of the welded components, while in the second software, a user routine was implemented, including a physical based model and the Hall-Petch (H-P) equation, to predict grain size change and hardness evolution, respectively. The results demonstrate that the predicted mechanical and microstructural aspects agree with those experimentally found showing the reliability of the two codes in predicting the thermal phenomena characterizing the HAZ during the analysed welding process.
Automated measurement of total kidney volume from 3D ultrasound images of patients affected by polycystic kidney disease and comparison to MR measurements
Authors: Jagtap Jaidip M. , Gregory Adriana V. , Homes Heather L. , Wright Darryl E. , Edwards Marie E. , Akkus Zeynettin , Erickson Bradley J. , Kline Timothy L.
Published: April 2022

Purpose

Total kidney volume (TKV) is the most important imaging biomarker for quantifying the severity of autosomal-dominant polycystic kidney disease (ADPKD). 3D ultrasound (US) can accurately measure kidney volume compared to 2D US; however, manual segmentation is tedious and requires expert annotators. We investigated a deep learning-based approach for automated segmentation of TKV from 3D US in ADPKD patients.

Method

We used axially acquired 3D US-kidney images in 22 ADPKD patients where each patient and each kidney were scanned three times, resulting in 132 scans that were manually segmented. We trained a convolutional neural network to segment the whole kidney and measure TKV. All patients were subsequently imaged with MRI for measurement comparison.

Results

Our method automatically segmented polycystic kidneys in 3D US images obtaining an average Dice coefficient of 0.80 on the test dataset. The kidney volume measurement compared with linear regression coefficient and bias from human tracing were R2 = 0.81, and − 4.42%, and between AI and reference standard were R2 = 0.93, and − 4.12%, respectively. MRI and US measured kidney volumes had R2 = 0.84 and a bias of 7.47%.

Conclusion

This is the first study applying deep learning to 3D US in ADPKD. Our method shows promising performance for auto-segmentation of kidneys using 3D US to measure TKV, close to human tracing and MRI measurement. This imaging and analysis method may be useful in a number of settings, including pediatric imaging, clinical studies, and longitudinal tracking of patient disease progression.

Graphical abstract
The role of the angular gyrus in semantic cognition: a synthesis of five functional neuroimaging studies
Authors: Kuhnke Philipp , Chapman Curtiss A. , Cheung Vincent K. M. , Turker Sabrina , Graessner Astrid , Martin Sandra , Williams Kathleen A. , Hartwigsen Gesa
Published: April 2022

Semantic knowledge is central to human cognition. The angular gyrus (AG) is widely considered a key brain region for semantic cognition. However, the role of the AG in semantic processing is controversial. Key controversies concern response polarity (activation vs. deactivation) and its relation to task difficulty, lateralization (left vs. right AG), and functional–anatomical subdivision (PGa vs. PGp subregions). Here, we combined the fMRI data of five studies on semantic processing (n = 172) and analyzed the response profiles from the same anatomical regions-of-interest for left and right PGa and PGp. We found that the AG was consistently deactivated during non-semantic conditions, whereas response polarity during semantic conditions was inconsistent. However, the AG consistently showed relative response differences between semantic and non-semantic conditions, and between different semantic conditions. A combined analysis across all studies revealed that AG responses could be best explained by separable effects of task difficulty and semantic processing demand. Task difficulty effects were stronger in PGa than PGp, regardless of hemisphere. Semantic effects were stronger in left than right AG, regardless of subregion. These results suggest that the AG is engaged in both domain-general task-difficulty-related processes and domain-specific semantic processes. In semantic processing, we propose that left AG acts as a “multimodal convergence zone” that binds different semantic features associated with the same concept, enabling efficient access to task-relevant features.
Hairy cell leukemia: a specific 17-gene expression signature points to new targets for therapy
Authors: Maitre Elsa , Cornet Edouard , Debliquis Agathe , Drenou Bernard , Gravey François , Chollet Didier , Cheze Stephane , Docquier Mylène , Troussard Xavier , Matthes Thomas
Published: April 2022

Background

Hairy cell leukemia (HCL) is a rare chronic B cell malignancy, characterized by infiltration of bone marrow, blood and spleen by typical “hairy cells” that bear the BRAFV600E mutation. However, in addition to the intrinsic activation of the MAP kinase pathway as a consequence of the BRAFV600E mutation, the potential participation of other signaling pathways to the pathophysiology of the disease remains unclear as the precise origin of the malignant hairy B cells.

Materials and methods

Using mRNA gene expression profiling based on the Nanostring technology and the analysis of 290 genes with crucial roles in B cell lymphomas, we defined a 17 gene expression signature specific for HCL.

Results

Separate analysis of samples from classical and variant forms of hairy cell leukemia showed almost similar mRNA expression profiles apart from overexpression in vHCL of the immune checkpointsCD274andPDCD1LG2and underexpression ofFAS. Our results point to a post-germinal memory B cell origin and in some samples to the activation of the non-canonical NF-κB pathway.

Conclusions

This study provides a better understanding of the pathogenesis of HCL and describes new and potential targets for treatment approaches and guidance for studies in the molecular mechanisms of HCL.
A qualitative study to understand the experience of somatostatin analog treatments from the perspective of patients with neuroendocrine tumors
Authors: Seo Caroline , Horodniceanu Erica , Shah Rachel , Goldstein Grace , Ray David , Bennett Bonita , Phan Alexandria , McCarrier Kelly
Published: April 2022

Purpose

Neuroendocrine tumors (NETs) negatively impact patients’ quality of life. Octreotide long-acting release (LAR) and lanreotide depot are somatostatin analogs (SSAs) approved to treat NETs. The study objective was to explore SSA treatment experiences and preferences of patients with NETs.

Methods

Qualitative interviews were conducted in US adults (≥ 21 years) with NETs who had ≥ 6 months’ treatment with each SSA and transitioned from octreotide LAR to lanreotide depot within the previous year. Participants were asked open-ended questions about their experiences with octreotide LAR and lanreotide depot, treatment preferences, and SSA treatment attributes.

Results

Twenty participants (mean age: 58 years; 90% female; 85% white) completed interviews. The most common reasons for treatment transition were doctor recommendation (70%), treatment not working as expected (55%), and injection type preference (45%). Participants reported 34 unique favorable attributes of SSA treatment and 82 unique unfavorable attributes. Symptom control was the most frequently reported favorable attribute (associated with octreotide LAR by 60% of participants and lanreotide depot by 65%). Painful injection (65%) was most frequently cited unfavorable attribute for octreotide LAR and injection experience dependent on administrator (35%) for lanreotide depot. The three SSA treatment attributes rated as most important were side effects, symptom control, and ability to stabilize tumor.

Conclusion

Our qualitative data provide valuable insight into the treatment attributes that patients with NETs consider important when making SSA treatment decisions. Factors related to injection administration, side effects, and symptom control are important to patients and should be included in patient-provider communications in clinical contexts.
Developing a mealybug pheromone monitoring tool to enhance IPM practices in New Zealand vineyards
Authors: Sullivan Nicola J. , Bell Vaughn A. , Butler Ruth C. , Wallis Roger , Ramesh Remya , Reddy D. Srinivasa , Twidle Andrew M. , Bunn Barry , Unelius C. Rikard , Manning Lee-Anne M. , Suckling David M.
Published: April 2022

Mealybugs are phloem-feeding insects found on many crops worldwide. In New Zealand vineyards, they transmit the economically important Grapevine leafroll-associated virus 3 (GLRaV-3). For some mealybug species, synthetic sex pheromones have been commercialised, and are used as monitoring tools. The mealybugs Pseudococcus longispinus and Pseudococcus calceolariae are major pests in many New Zealand vineyards. We present work on the development of a combined P. longispinus and P. calceolariae pheromone lure. The optimal dose for monitoring P. longispinus was found to be 10 µg of the (S)-(+)-enantiomer, either alone or in the racemic mixture. Addition of the corresponding alcohol did not improve trap catch of P. longispinus. Both the P. longispinus and the P. calceolariae pheromone lures remained active in the field for 90 days. Combining the 2 species’ pheromones had no negative effects on male mealybug trap catch for either species. We conclude that the pheromone ester alone is the best lure for the male P. longispinus. Combining the two mealybug species’ pheromones into a single lure provides the New Zealand viticultural industry with an efficient monitoring tool. Late-vintage deployment of baited lures will provide information on mealybug abundance and local distribution that will inform the scope of future insecticide programmes, to target areas based on need rather than an area-wide application by default.
Experimental long-term sub-normothermic machine perfusion for non-allocable human liver grafts: first data towards feasibility
Authors: Leber Bettina , Schlechter Stephanie , Weber Jennifer , Rohrhofer Lisa , Niedrist Tobias , Aigelsreiter Ariane , Stiegler Philipp , Schemmer Peter
Published: April 2022

Background

Patients with end-stage liver disease can only be cured by liver transplantation. Due to the gap between demand and supply, surgeons are forced to use expanded criteria donor (ECD) organs, which are more susceptible to ischemia–reperfusion injury (IRI). Therefore, enhanced storing techniques are required. Machine perfusion (MP) has moved into the spotlight of research because of its feasibility for investigating liver function prior to implantation. However, as the perfect MP protocol has not yet been found, we aimed to investigate the potential of sub-normothermic (SN)MP in this field.

Methods

Non-allocable human livers were subjected to 24 h of SNMP at 21 °C after delivery to the study team. Perfusion was performed with Custodiol® (Dr. Franz Köhler Chemie, Bensheim, Germany) or Belzer MPS® (Bridge to Life Europe, London, UK) and perfusate liver parameters were determined. For determination of biliary conditions, pH, glucose, and HCO3- levels were measured.

Results

Liver parameters were slightly increased irrespective of perfusate or reason for liver rejection during 24 h of perfusion. Six livers failed to produce bile completely, whereas the remaining 10 livers produced between 2.4 ml and 179 ml of bile. Biliary carbonate was increased in all but one liver. The bile-glucose-to-perfusate-glucose ratio was near 1 for most of the organs and bile pH was above 7 in all but one case.

Conclusion

This study provides promising data on the feasibility of long-term SNMP as a tool to gain time during MP to optimize ECD organs to decrease the gap between organ demand and supply.

Long-term (24 h) sub-normothermic liver machine perfusion seems to be possible, although some adjustments to the protocol might be necessary to improve the general outcome. This has so far been shown for normothermic machine perfusion, bearing some drawbacks compared to the sub-normothermic variant.
Hydraulic jumps with low inflow Froude numbers: air–water surface patterns and transverse distributions of two-phase flow properties
Authors: Wüthrich Davide , Shi Rui , Chanson Hubert
Published: April 2022

Hydraulic jumps are commonly employed as energy dissipators to guarantee long-term operation of hydraulic structures. A comprehensive and in-depth understanding of their main features is therefore fundamental. In this context, the current study focused on hydraulic jumps with low Froude numbers, i.e. Fr1 = 2.1 and 2.4, at relatively high Reynolds number: Re ~2 × 105. Experimental tests employed a combination of dual-tip phase-detection probes and ultra-high-speed video camera to provide a comprehensive characterisation of the main air-water flow properties of the hydraulic jump, including surface flow features, void fraction, bubble count rate and interfacial velocities. The current research also focused on the transverse distributions of air-water flow properties, i.e. across the channel width, with the results revealing lower values of void fraction and bubble count rate next to the sidewalls compared to the channel centreline data. Such a spatial variability in the transverse direction questions whether data near the side walls may be truly representative of the behaviour in the bulk of the flow, raising the issue of sidewall effects in image-based techniques. Overall, these findings provide new information to both researchers and practitioners for a better understanding of the physical processes inside the hydraulic jump with low Froude numbers, leading to an optimised design of hydraulic structures.

Article Highlights

Experimental investigation of air-water flow properties in hydraulic jumps with low Froude numbers

Detailed description of the main air-water surface features on the breaking roller

Transversal distribution of the air-water flow properties across the channel width and comparison between centreline and sidewall.
SRCMIMM: the software requirements change management and implementation maturity model in the domain of global software development industry
Authors: Akbar Muhammad Azeem , Khan Arif Ali , Mahmood Sajjad , Mishra Alok
Published: April 2022

The software industry has widely adopted global software development (GSD) to gain economic benefits. Organizations that engage in GSD face various challenges, the majority being associated with requirements change management (RCM). The key motive of this study is to develop a requirement change management and implementation maturity model (SRCMIMM) for the GSD industry that could help the practitioners to assess and manage their RCM activities. A systematic literature review and questionnaire survey approach are used to identify and validate the critical success factors (CSFs), critical challenges (CCHs), and the related best practices of the RCM process. The investigated CSFs and CCHs are classified into five maturity levels based on the concepts of the existing maturity models in other domains, practitioners’ feedback, and academic research. Every maturity level comprises different CSFs and CCHs that can help assess and manage a firm's RCM capability. To evaluate the effectiveness of the proposed model, four case studies are conducted in different GSD firms. The SRCMIMM has been developed to assist GSD organizations in improving their RCM process in efficiency and effectiveness.
Religion, Health, and Life Satisfaction Among Somali and Gambian Women in Norway
Authors: Lien Inger-Lise
Published: April 2022

This article describes and analyses the religious justifications for the life satisfaction reported by two groups of Muslim women. Approximately, twenty Somali women and twenty Gambian women, living in Norway, who had experienced trauma and pain due to female genital mutilation/cutting as well as other traumas and hardships, were interviewed. While the Somali women adhere to conservative Islam and try to cope with their life through endurance and patience, the Gambians belong to a Sufi tradition and verbalise their dissatisfaction in order to receive help from Sufi saints. Therefore, there are two religious codes, here called emotionologies, within the Muslim tradition that have different impacts on the expression of life satisfaction and women’s ways of coping with pain and suffering.
A Krylov-Schur-like method for computing the best rank-(r1,r2,r3) approximation of large and sparse tensors
Authors: Eldén Lars , Dehghan Maryam
Published: April 2022

The paper is concerned with methods for computing the best low multilinear rank approximation of large and sparse tensors. Krylov-type methods have been used for this problem; here block versions are introduced. For the computation of partial eigenvalue and singular value decompositions of matrices the Krylov-Schur (restarted Arnoldi) method is used. A generalization of this method to tensors is described, for computing the best low multilinear rank approximation of large and sparse tensors. In analogy to the matrix case, the large tensor is only accessed in multiplications between the tensor and blocks of vectors, thus avoiding excessive memory usage. It is proved that if the starting approximation is good enough, then the tensor Krylov-Schur method is convergent. Numerical examples are given for synthetic tensors and sparse tensors from applications, which demonstrate that for most large problems the Krylov-Schur method converges faster and more robustly than higher order orthogonal iteration.
Polypharmacy and trajectories of health-related quality of life in older adults: an Australian cohort study
Authors: Aljeaidi Muhamad S. , Haaksma Miriam L. , Tan Edwin C. K.
Published: April 2022

Background

Health-related quality of life (HRQoL) is an important outcome measure when considering medical treatment; however, the impact of polypharmacy on trajectories of HRQoL over time is unknown. This study aimed to investigate the association between polypharmacy status and trajectories of HRQoL in older adults.

Methods

A longitudinal cohort study of 2181 community-dwelling adults, 65 years and older, who participated in the 2013 to 2017 waves of the Household Income and Labour Dynamics in Australia (HILDA) Survey. Polypharmacy was defined as the regular use of ≥ 5 prescription medications. Polypharmacy status was categorised into no polypharmacy, in 2013 only (baseline only polypharmacy), in 2017 only (incident polypharmacy) or at both time points (persistent polypharmacy). HRQoL was assessed through the SF-36 questionnaire generating two summary scores: physical component summary (PCS) and mental component summary (MCS). Linear mixed-effects models stratified according to polypharmacy status and change in comorbidities were used to assess trajectories of HRQoL.

Results

Older adults with persistent polypharmacy had lowest scores for HRQoL measures from 2013 to 2017. After adjusting for all covariates, those with incident polypharmacy had the steepest annual decline in both the PCS and MCS: − 0.86 in PCS and − 0.76 in MCS for those with decreasing or stable comorbidities, and − 1.20 in PCS and − 0.75 in MCS for those with increasing comorbidities.

Conclusions

Polypharmacy was associated with poorer HRQoL, even after adjusting for confounders. Incident polypharmacy was found to be associated with a clinically important decline in HRQoL and this should be considered when prescribing additional medication to older adults.
Item Response Thresholds Models: A General Class of Models for Varying Types of Items
Authors: Tutz Gerhard
Published: April 2022

A comprehensive class of models is proposed that can be used for continuous, binary, ordered categorical and count type responses. The difficulty of items is described by difficulty functions, which replace the item difficulty parameters that are typically used in item response models. They crucially determine the response distribution and make the models very flexible with regard to the range of distributions that are covered. The model class contains several widely used models as the binary Rasch model and the graded response model as special cases, allows for simplifications, and offers a distribution free alternative to count type items. A major strength of the models is that they can be used for mixed item formats, when different types of items are combined to measure abilities or attitudes. It is an immediate consequence of the comprehensive modeling approach that allows that difficulty functions automatically adapt to the response distribution. Basic properties of the model class are shown. Several real data sets are used to illustrate the flexibility of the models
Plattform-Architekturen
Authors: Dolata Ulrich , Schrape Jan-Felix
Published: April 2022

Das heutige Internet wird durch privatwirtschaftlich betriebene Plattformen der unterschiedlichsten Art geprägt. Dieser Beitrag fragt danach, wie sich die kommerziellen Kommunikations‑, Markt‑, Konsum- und Serviceplattformen als distinkte Unternehmensform fassen lassen. Dazu wird eine basale Unterscheidung zwischen (1) den plattformbetreibenden Unternehmen als organisierenden und strukturierenden Kernen und (2) den ihnen gehörenden Plattformen als mehr oder minder ausgreifenden sozialen Handlungsräumen vorgenommen. Während sich Plattformunternehmen als Organisationen im geradezu klassischen Sinne darstellen lassen, konstituieren die von ihnen betriebenen Internetplattformen soziotechnisch strukturierte Sozial‑, Markt‑, Konsum- oder Serviceräume, in denen soziale Akteure zwar auf der Grundlage detailliert ausgestalteter und technisch eingefasster Regeln, aber zugleich variantenreich und eigenwillig interagieren. Die für die Plattform-Architekturen charakteristischen Koordinations‑, Kontroll- und Verwertungsmechanismen zeichnen sich durch eine starke hierarchische Ausrichtung aus, in die Elemente der Kooptation und des orchestrierten Mitwirkens der Nutzer eingelagert sind. Die Plattformunternehmen haben in dieser hybriden Konstellation ein hohes Maß an strukturgebender, regelsetzender und kontrollierender Macht – und verfügen überdies über den exklusiven Zugriff auf das dort produzierte Rohmaterial an Daten. Diese Macht äußert sich auch, aber längst nicht ausschließlich als rigide Kontrolle, als direktiver Zwang oder einklagbare Rechenschaftspflicht, sondern entfaltet sich für die große Zahl regelkonformer Nutzer weitgehend geräuschlos unter der Oberfläche einer (vermeintlichen) Offenheit, die die Plattformen als Markt- und Sozialräume auch auszeichnet.
Ungleicher Gabentausch – User-Interaktionen und Wertschöpfung auf digitalen Plattformen
Authors: Nachtwey Oliver , Schaupp Simon
Published: April 2022

In diesem Artikel schlagen wir einen relationalen Ansatz zum Verständnis der Wertschöpfung auf digitalen Plattformen wie Social-Media-Kanälen oder kostenlosen Internetdienstleistungen vor. Dabei kombinieren wir Ansätze der Marx’schen und anthropologischen Werttheorie in innovativer Weise und machen sie für ein Verständnis der digitalen Ökonomie fruchtbar. Demnach handelt es sich bei den Interaktionen der Plattform-User nicht, wie verschiedentlich argumentiert wird, um ausgebeutete Arbeit, sondern um Praktiken des Gabentauschs. Dieser Gabentausch bildet die Produktionsbedingung für die Wertschöpfung der Internetplattformen, die durch deren asymmetrisches Interaktionsfeld kontinuierlich reproduziert werden. Es wird deshalb auch nicht das Individuum ausgebeutet, sondern die Gemeinschaft derjenigen, die in diesem Feld handeln. Dies ist in den Geschäftsbedingungen der Plattformen verankert, die festlegen, dass die User ihre Daten nicht nur untereinander, sondern auch an das Unternehmen weitergeben. Dies wiederum ermöglicht einen dreischrittigen Prozess der Kommodifizierung der Daten aufseiten der Plattform. Erstens werden die Daten als Gebrauchswerte von den Plattformen zur Optimierung ihrer eigenen Dienstleistungen angeeignet. Zweitens kommt es zu einer sekundären Kommodifizierung, die im Gegensatz zu anderen Wertschöpfungsprozessen vom Gebrauchswert der Daten abgekoppelt ist. Drittens kommt es zu einer Kybernetisierung, bei der die Beeinflussbarkeit der User an Dritte als Ware verkauft wird.
Sparsifying the least-squares approach to PCA: comparison of lasso and cardinality constraint
Authors: Guerra-Urzola Rosember , de Schipper Niek C. , Tonne Anya , Sijtsma Klaas , Vera Juan C. , Van Deun Katrijn
Published: April 2022

Sparse PCA methods are used to overcome the difficulty of interpreting the solution obtained from PCA. However, constraining PCA to obtain sparse solutions is an intractable problem, especially in a high-dimensional setting. Penalized methods are used to obtain sparse solutions due to their computational tractability. Nevertheless, recent developments permit efficiently obtaining good solutions of cardinality-constrained PCA problems allowing comparison between these approaches. Here, we conduct a comparison between a penalized PCA method with its cardinality-constrained counterpart for the least-squares formulation of PCA imposing sparseness on the component weights. We compare the penalized and cardinality-constrained methods through a simulation study that estimates the sparse structure’s recovery, mean absolute bias, mean variance, and mean squared error. Additionally, we use a high-dimensional data set to illustrate the methods in practice. Results suggest that using cardinality-constrained methods leads to better recovery of the sparse structure.
Surgical management of a traumatic elbow dislocation with disruption of the brachial artery
Authors: Habarta Johanna , Jordan Martin , Meffert Rainer , Huflage Henner , Schmalzl Jonas
Published: April 2022

Background

Dislocations of the elbow are the second most common dislocations of humeral joints following the shoulder. Besides numerous possible concomitant injuries of the collateral ligaments or the extensor or flexor apparatus, an accompanying disruption of the brachial artery is a rare occurrence. In the following, such a case is presented and discussed.

Method

A 70-year-old woman sustained a closed posterior elbow dislocation with accompanying disruption of the brachial artery due to a fall in a domestic environment. Pulselessness of the radial artery led to a computed tomography angiography being performed, which confirmed the diagnosis. Direct operative vascular reconstruction with a vein insert was carried out. Due to strong swelling of the soft tissue, other examinations of the elbow could not be performed initially. A redislocation a few days later led to an operative stabilization of the elbow joint.

Results

The final consultation 4 months postoperatively showed a stable, centered elbow joint and a normal perfusion of the affected arm. The elbow function was good with a range of motion of 0/0/110° of extension/flexion.

Conclusion

An elbow dislocation is a complex injury. An accurate clinical examination of possible concomitant injuries is important and should be repeated in the first few days after the occurrence. Vascular reconstruction should be performed immediately. In the case of persistent joint instability, an operative stabilization is indicated and may be supported by a hinged external fixator.
What does it take to learn about teaching and learning in classrooms across cultures?
Authors: Emanuelsson Jonas , Sahlström Fritjof
Published: April 2022

Beginning in the 1960s and early seventies, classroom research contributed to understandings and insights concerning the complexities and diversities of teaching. In the late 1990s, classroom research began to also include student voices in the classroom. Socio-cultural theory turned the empirical focus toward student interaction, and methodological development made new insights possible. The impact of this paradigmatic change is still in progress. At the same time, a rapid growth in international comparative classroom studies emerged, where the two most recognized comparative classroom research initiatives have been the TIMSS Video Studies, the first one initiated in 1995 at the University of California, Los Angeles, and the Learner’s Perspective Study (LPS), initiated in 1999, at the University of Melbourne’s International Center for Classroom Research (ICCR). In this paper, we ask what it takes to carry out successful international classroom research, using the LPS as an example. The analysis shows that the LPS project design made it possible for research groups from different countries and cultures to participate in building a sustainable community of research practice specialized in working with the complexities in the study of teaching and learning in classrooms. Of particular importance was the intense and sustained collaborative work on data, where researchers of varying seniority and experience met and carried out scholarly work in relation to a shared dataset. While also having disadvantages, the heavy emphasis on data was crucial for creating and sustaining a reflexive international research community.
Substance Use Among Youth During the COVID-19 Pandemic: a Systematic Review
Authors: Layman Hannah M. , Thorisdottir Ingibjorg Eva , Halldorsdottir Thorhildur , Sigfusdottir Inga Dora , Allegrante John P. , Kristjansson Alfgeir Logi
Published: April 2022

Purpose of Review

To review the literature on the trends in substance use among youth during the coronavirus SARS-CoV-2 (COVID-19) pandemic.

Recent Findings

The pandemic has given rise to concerns about the mental health and social well-being of youth, including its potential to increase or exacerbate substance use behaviors. This systematic review identified and included 49 studies of use across alcohol, cannabis, tobacco, e-cigarettes/vaping, and other drugs, and unspecified substances. The majority of studies across all categories of youth substance use reported reductions in prevalence, except in the case of other drugs and unspecified drug and substance use, which included three studies that reported an increase in use and three studies that reported decrease in use.

Overall, the results of this review suggest that the prevalence of youth substance use has largely declined during the pandemic. Youth substance use in the post-pandemic years will require monitoring and continued surveillance.
Land Use Spatial Optimization Using Accessibility Maps to Integrate Land Use and Transport in Urban Areas
Authors: Wang Zhongqi , Han Qi , De Vries Bauke
Published: April 2022

The scarcity of urban land resources requires a well-organized spatial layout of land use to better accommodate human activities, however, as a widely accepted concept, the integration of land use and transport is not given due consideration in land use spatial optimization (LUSO). This paper aims to integrate land use and transport in LUSO to support urban land use planning. Maximizing accessibility fitness, which follows the underlying logic between land use types and transport characteristics, is introduced into multi-objective land use spatial optimization (MOLUSO) modelling to address transport considerations, together with widely-used objectives such as maximizing compactness, compatibility, and suitability. The transport characteristics, in this study, are identified by driving accessibility, cycling accessibility, and walking accessibility. Accessibility maps, which quantify and visualize the spatial variances in accessibility fitness for different land use types, are developed based on the empirical results of the relationship between land use types and transport characteristics for LUSO and addressing policy issues. The 4-objective LUSO model and a corresponding non-dominated sorting genetic algorithm (NSGA-II) based optimization method constitute a prototype decision support system (DSS) for urban land use planning. Decision-makers (e.g., planning departments) can choose an ideal solution to accommodate urban development needs from a set of Pareto-optimal alternatives generated by the DSS. The approaches to creating accessibility maps and MOLUSO modelling are demonstrated by the case study of Eindhoven, the Netherlands. This study advocates limited changes to the current land use pattern in urban planning, and the LUSO emphasizes urban renewal and upgrading rather than new town planning.
Kink in an English Field: The Drinking, Drug use and Sexual Practices of English Festival-Goers Who Engage in Kink
Authors: McCormack Mark , Measham Fiona , Measham Maria , Wignall Liam
Published: April 2022

Little is known about the other leisure activities of people who engage in kink, including sexual practices and the use of alcohol and other drugs. This article examines the drinking, illicit drug use and sexual practices of people who engage in kink from a novel sample of attendees at an English festival. Of 966 respondents, 64 reported having engaged in kink within the past 12 months. We provide evidence of these respondents’ self-reported demographic characteristics, alcohol and other drug use in their lifetime and within the past 12 months, as well as other sexual practices they engaged in. This study illustrates the value of accessing participants through in situ festival fieldwork to understand kink practices, and helps us move beyond notions of clustered risky activities toward a leisure studies approach to understanding the practices of people who engage in kink.
Dynamics of cavity soliton driven by chirped optical pulses in Kerr resonators
Authors: Pan Jianxing , Xu Chaoyu , Wu Zhichao , Zhang Jing , Huang Tianye , Shum Perry Ping
Published: April 2022

Recent researches have demonstrated that pulsed driving is an effective method to increase the temporal overlap between cavity soliton (CS) and pump field, thereby increasing the pump-to-comb conversion efficiency. The amplitude-modulated inhomogeneity of the background wave causes the solitons to drift toward edges of the driving pulse. To eliminate the multiple temporal trapping positions, induced by the spontaneous symmetry breaking, we propose the chirped pulse driving for deterministic single soliton generation. We theoretically explain the physical mechanism of the chirp pulse driving, as the combination of amplitude and phase modulation. Our numerical simulations demonstrate the chirp is responsible for the single soliton generation. A detailed investigation for dynamics of CSs sustained by chirped pulses, shows the recovery of spontaneous symmetry breaking. In addition, the desynchronized chirped pulse driving is also considered here. Considering a weak chirp parameter, the desynchronization-dependent trapping position diagram is divided into multiple areas including two CSs, a single CS, two oscillating CSs, and no CS. With a sufficient chirp parameter considered, the trapping position curve becomes a monotonous function of the desynchronized drift velocity, which indicates deterministic single soliton generation.

Graphic Abstract
Tailored Forming of hybrid bulk metal components
Authors: Behrens Bernd-Arno , Uhe Johanna , Ross Ingo , Peddinghaus Julius , Ursinus Jonathan , Matthias Tim , Bährisch Susanne
Published: April 2022

Multi-material bulk metal components allow for a resource efficient and functionally structured component design, with a load adaptation achieved in certain functional areas by using similar and dissimilar material combinations. One possibility for the production of hybrid bulk metal components is Tailored Forming, in which pre-joined semi-finished products are hot-formed using novel process chains. By means of Tailored Forming, the properties of the joining zone are geometrically and thermomechanically influenced during the forming process. Based on this motivation, forming processes (die forging, impact extrusion) coupled with adapted inductive heating strategies were designed using numerical simulations and successfully realised in the following work in order to produce demonstrator components with serial or coaxial material arrangements. The quality of the joining zone was investigated through metallographic and SEM imaging, tensile tests and life cycle tests. By selecting suitable materials, it was possible to achieve weight savings of 22% for a pinion shaft and up to 40% for a bearing bush in the material combination of steel and aluminium with sufficient strength for the respective application. It was shown that the intermetallic phases formed after friction welding barely grow during the forming process. By adjusting the heat treatment of the aluminium, the growth of the IMP can also be reduced in this process step. Furthermore, for steel-steel components alloy savings of up to 51% with regard to chromium could be achieved when using low-alloy steel as a substitute for high-alloy steel parts in less loaded sections. The welded microstructure of a cladded bearing washer could be transformed into a homogeneous fine-grained microstructure by forming. The lifetime of tailored formed washers nearly reached those of high-alloyed mono-material components.