Climate variability in the subarctic area for the last 2 millennia

To put recent climate change in perspective, it is necessary to extend the instrumental climate records with proxy data from paleoclimate archives. Arctic climate variability for the last 2 millennia has been investigated using statistical and signal analyses from three regionally averaged records from the North Atlantic, Siberia and Alaska based on many types of proxy data archived in the Arctic 2k database v1.1.1. In the North Atlantic and Alaska, the major climatic trend is characterized by long-term cooling interrupted by recent warming that started at the beginning of the 19th century. This cooling is visible in the Siberian region at two sites, warming at the others. The cooling of the Little Ice Age (LIA) was identified from the individual series, but it is characterized by wide-range spatial and temporal expression of climate variability, in contrary to the Medieval Climate Anomaly. The LIA started at the earliest by around AD 1200 and ended at the latest in the middle of the 20th century. The widespread temporal coverage of the LIA did not show regional consistency or particular spatial distribution and did not show a relationship with archive or proxy type either. A focus on the last 2 centuries shows a recent warming characterized by a well-marked warming trend parallel with increasing greenhouse gas emissions. It also shows a multidecadal variability likely due to natural processes acting on the internal climate system on a regional scale. A similar to 16-30-year cycle is found in Alaska and seems to be linked to the Pacific Decadal Oscillation, whereas similar to 20-30- and similar to 50-90-year periodicities characterize the North Atlantic climate variability, likely in relation with the Atlantic Multidecadal Oscillation. These regional features are probably linked to the sea ice cover fluctuations through ice-temperature positive feedback.Peer reviewe

Comparison of manual and artificial intelligence based quantification of myocardial strain by feature tracking - a cardiovascular MR study in health and disease

OBJECTIVES: The analysis of myocardial deformation using feature tracking in cardiovascular MR allows for the assessment of global and segmental strain values. The aim of this study was to compare strain values derived from artificial intelligence (AI)-based contours with manually derived strain values in healthy volunteers and patients with cardiac pathologies. MATERIALS AND METHODS: A cohort of 136 subjects (60 healthy volunteers and 76 patients; of those including 46 cases with left ventricular hypertrophy (LVH) of varying etiology and 30 cases with chronic myocardial infarction) was analyzed. Comparisons were based on quantitative strain analysis and on a geometric level by the Dice similarity coefficient (DSC) of the segmentations. Strain quantification was performed in 3 long-axis slices and short-axis (SAX) stack with epi- and endocardial contours in end-diastole. AI contours were checked for plausibility and potential errors in the tracking algorithm. RESULTS: AI-derived strain values overestimated radial strain (+ 1.8 ± 1.7% (mean difference ± standard deviation); p = 0.03) and underestimated circumferential (- 0.8 ± 0.8%; p = 0.02) and longitudinal strain (- 0.1 ± 0.8%; p = 0.54). Pairwise group comparisons revealed no significant differences for global strain. The DSC showed good agreement for healthy volunteers (85.3 ± 10.3% for SAX) and patients (80.8 ± 9.6% for SAX). In 27 cases (27/76; 35.5%), a tracking error was found, predominantly (24/27; 88.9%) in the LVH group and 22 of those (22/27; 81.5%) at the insertion of the papillary muscle in lateral segments. CONCLUSIONS: Strain analysis based on AI-segmented images shows good results in healthy volunteers and in most of the patient groups. Hypertrophied ventricles remain a challenge for contouring and feature tracking. CLINICAL RELEVANCE STATEMENT: AI-based segmentations can help to streamline and standardize strain analysis by feature tracking. KEY POINTS: • Assessment of strain in cardiovascular magnetic resonance by feature tracking can generate global and segmental strain values. • Commercially available artificial intelligence algorithms provide segmentation for strain analysis comparable to manual segmentation. • Hypertrophied ventricles are challenging in regards of strain analysis by feature tracking

Three-dimensional computational model of a blood oxygenator reconstructed from micro-CT scans

Cardiopulmonary bypass procedures are one of the most common operations and blood oxygenators are the centre piece for the heart-lung machines. Blood oxygenators have been tested as entire devices but intricate details on the flow field inside the oxygenators remain unknown. In this study, a novel method is presented to analyse the flow field inside oxygenators based on micro Computed Tomography (μCT) scans. Two Hollow Fibre Membrane (HFM) oxygenator prototypes were scanned and three-dimensional full scale models that capture the device-specific fibre distributions are set up for computational fluid dynamics analysis. The blood flow through the oxygenator is modelled as a non-Newtonian fluid. The results were compared against the flow solution through an ideal fibre distribution and show the importance of a uniform distribution of fibres and that the oxygenators analysed are not susceptible to flow directionality as mass flow versus area remain the same. However the pressure drop across the oxygenator is dependent on flow rate and direction. By comparing residence time of blood against the time frame to fully saturate blood with oxygen we highlight the potential of this method as design optimisation tool.In conclusion, image-based reconstruction is found to be a feasible route to assess oxygenator performance through flow modelling. It offers the possibility to review a product as manufactured rather than as designed, which is a valuable insight as a precursor to the approval processes. Finally, the flow analysis presented may be extended, at computational cost, to include species transport in further studies

Portuguese validation of the Bergen Facebook Addiction Scale: an Empirical Study

Previous research on Social Networking Sites (SNSs) addiction have suggest the need to improve assessment of this behavioral addiction. The present study aimed at validating a Portuguese version of the Bergen Facebook Addiction Scale (BFAS), a widely used instrument to assess addiction to Facebook. A study was conducted in a sample of 509 Portuguese adolescent using an online survey. The psychometric properties (construct validity, criterion validity, and reliability) of the Portuguese BFAS was scrutinized. The results from the psychometric analyses suggested that the new validated instrument had excellent psychometric properties. The CFA confirmed the original one-factor solution of the BFAS and criterion validity was warranted. The reliability of the BFAS was supported by satisfactory levels of internal consistency as measured by the Cronbach’s alpha (α = .83), composite reliability (CR = .82), and factor determinacy (FD = .91). Overall, the results provided empirical support for the validity and reliability of the Portuguese BFAS. Moreover, the results were highly comparable with the findings of the original development study of the BFAS and cross-cultural support for the scale was obtained

Efectos y beneficios del entrenamiento de fuerza en pacientes con cáncer: revisión sistemática de la literatura

Introduction: cancer is among the diseases having the greatest mortality rates and the cause of many disabilities worldwide. The practice of exercise is developed as an adjuvant therapy along with the cancer treatment to reduce mortality and disability in the different types of cancer.Objective: to identify the effects of strength training on cancer patients.Methods: a complete review of the medical literature was conducted until December 2018, scientific articles published in indexed bases from 2015 to 2018. The studies included were in population over 18 years old with cancer diagnosis regardless of sociodemographic characteristics, type or stage of cancer. The data extracted were on the population, intervention and control groups, type of cancer, period, frequency of intervention and results.Results: during the first search 36071 titles of clinical study were found in specialized journals. 10 experimental studies were chosen. Multiple positive effects were found, as well as components that should be taken into account when performing strength training on cancer patients or cancer survivors.Conclusions: strength training in patients with cancer or survivors of this disease, helps them to improve their symptoms as well as their quality of life, strength, improved mobility and pain, among others. Also, strength training is beneficial to patients without causing adverse effects or long-term complications.Introducción: El cáncer se encuentra entre las enfermedades con mayor mortalidad y causante de un gran número de discapacidades a nivel mundial. El ejercicio surge como un coadyuvante del tratamiento oncológico para disminuir la mortalidad y discapacidad en los diferentes tipos de cáncer.Objetivo: Identificar los efectos del entrenamiento de fuerza en pacientes con cáncer.Método:  Se realizó una revisión de la literatura hasta diciembre del 2018, de artículos científicos publicados en bases de indexadas desde 2015 y hasta 2018. Los estudios incluidos fueron en población mayor a 18 años con diagnóstico de cáncer sin importar características sociodemográficas, tipo o estadio del cáncer. Los datos extraídos fueron sobre la población, grupos de intervención y control, tipo de cáncer, periodo, frecuencia de la intervención y resultados.Resultados: Durante la primera búsqueda 36071 títulos de estudios clínicos fueron encontrados en revistas especializadas. Al final 10 estudios de carácter experimental fueron seleccionados. En dichos estudios, múltiples efectos fueron encontrados, así como componentes que se deben tener en cuenta a realizar un entrenamiento de fuerza en pacientes con cáncer o sobrevivientes del mismo.Conclusiones: El entrenamiento de fuerza en pacientes con cáncer o sobrevivientes de esta enfermedad, les ayuda a mejorar su sintomatología al igual que su calidad de vida, fatiga, fuerza, mejoría en la movilidad y el dolor, entre otros. Así mismo, el entrenamiento de fuerza es beneficioso para los pacientes sin causar efectos adversos o complicaciones a largo plazo

A user-centred approach to developing bWell, a mobile app for arm and shoulder exercises after breast cancer treatment

Purpose: The study aim was to develop a mobile application (app) supported by user preferences to optimise self-management of arm and shoulder exercises for upper-limb dysfunction (ULD) after breast cancer treatment. Methods: Focus groups with breast cancer patients were held to identify user needs and requirements. Behaviour change techniques were explored by researchers and discussed during the focus groups. Concepts for content were identified by thematic analysis. A rapid review was conducted to inform the exercise programme. Preliminary testing was carried out to obtain user feedback from breast cancer patients who used the app for 8 weeks post-surgery. Results: Breast cancer patients’ experiences with ULD and exercise advice and routines varied widely. They identified and prioritised several app features: tailored information, video demonstrations of the exercises, push notifications, and tracking and progress features. An evidence-based programme was developed with a physiotherapist with progressive exercises for passive and active mobilisation, stretching and strengthening. The exercise demonstration videos were filmed with a breast cancer patient. Early user testing demonstrated ease of use, and clear and motivating app content. Conclusions: bWell, a novel app for arm and shoulder exercises was developed by breast cancer patients, health care professionals and academics. Further research is warranted to confirm its clinical effectiveness. Implications for Cancer Survivors: Mobile health has great potential to provide patients with information specific to their needs. bWell is a promising way to support breast cancer patients with exercise routines after treatment and may improve future self-management of clinical care

Measurement invariance of the short version of the problematic mobile phone use questionnaire (PMPUQ-SV) across eight languages

The prevalence of mobile phone use across the world has increased greatly over the past two decades. Problematic Mobile Phone Use (PMPU) has been studied in relation to public health and comprises various behaviours, including dangerous, prohibited, and dependent use. These types of problematic mobile phone behaviours are typically assessed with the short version of the Problematic Mobile Phone Use Questionnaire (PMPUQ-SV). However, to date, no study has ever examined the degree to which the PMPU scale assesses the same construct across different languages. The aims of the present study were to (i) determine an optimal factor structure for the PMPUQ-SV among university populations using eight versions of the scale (i.e., French, German, Hungarian, English, Finnish, Italian, Polish, and Spanish); and (ii) simultaneously examine the measurement invariance (MI) of the PMPUQ-SV across all languages. The whole study sample comprised 3038 participants. Descriptive statistics, correlations, and Cronbach's alpha coefficients were extracted from the demographic and PMPUQ-SV items. Individual and multigroup confirmatory factor analyses alongside MI analyses were conducted. Results showed a similar pattern of PMPU across the translated scales. A three-factor model of the PMPUQ-SV fitted the data well and presented with good psychometric properties. Six languages were validated independently, and five were compared via measurement invariance for future cross-cultural comparisons. The present paper contributes to the assessment of problematic mobile phone use because it is the first study to provide a cross-cultural psychometric analysis of the PMPUQ-SV

Problematic social media use: results from a large-scale nationally representative adolescent sample

Despite social media use being one of the most popular activities among adolescents, prevalence estimates among teenage samples of social media (problematic) use are lacking in the field. The present study surveyed a nationally representative Hungarian sample comprising 5,961 adolescents as part of the European School Survey Project on Alcohol and Other Drugs (ESPAD). Using the Bergen Social Media Addiction Scale (BSMAS) and based on latent profile analysis, 4.5% of the adolescents belonged to the at-risk group, and reported low self-esteem, high level of depression symptoms, and elevated social media use. Results also demonstrated that BSMAS has appropriate psychometric properties. It is concluded that adolescents at-risk of problematic social media use should be targeted by school-based prevention and intervention programs