Prosocial Video Game Content, Empathy and Cognitive Ability in a Large Sample of Youth.

Whether playing video games with prosocial content has an influence on empathy among players remains contentious in the research literature. Some evidence suggests playing cooperatively with other gamers enhances empathy, but data have not conclusively linked prosocial content with empathy. Further, mechanisms of this potential relationship are unclear, and little work has been conducted on how cognitive skills, such as fluid reasoning, may mediate this relationship. The current study examines these relationships with a large sample of 3034 youth (27.2% female, Mage = 11.2; range 8-17 at time 1) in Singapore. Data were considered longitudinally across two years in three waves. Ultimately, no evidence emerged that prosocial content in video games had any impact on empathy related outcomes, nor was fluid reasoning a mediator variable for any relationship. However, variables such as social competence and depression and anxiety symptoms were highly related to empathy measures. This evidence adds to the growing debate in the field that video games may not dramatically alter, whether positively or negatively, the development of emotional and behavioral outcomes for youth.

Increased vasculogenesis of endothelial cells in hyaluronic acid augmented fibrin-based natural hydrogels - from in vitro to in vivo models.

Vascularisation efficiency plays an essential role in the success of bulk transplantation, while biocompatibility and safety are major concerns in clinical applications. Fibrin-based hydrogels have been exploited as scaffolds for their advantages in biocompatibility, degradability and mass transportation in various forms. However, the mechanical strength and degree of vascularisation remain unsatisfactory for clinical usage. An interpenetrating hydrogel was developed by adding hyaluronic acid (HA) to a fibrin-based natural hydrogel. The vasculogenesis of endothelial cells (human umbilical vein endothelial cells, HUVECs) was characterised within the gel using both in vitro and in vivo animal studies. The in vitro vascular morphology analysis showed 17.9 % longer mean tube length and 14.3 % higher average thickness in 7 d cultivation within the HA-supplemented hydrogel. The in vivo results showed 51.6 % larger total tube area, 1.8 × longer average tube length and 81.6 % higher cell number in the HA-supplemented hydrogel compared to the hydrogel without HA. The experimental results demonstrated better vascularisation and cell recruitment in the HA- supplemented hydrogel. The material properties of the hydrogels were also analysed using atomic force microscopy (AFM). The results revealed 3.7 × higher elasticity of the HA-supplemented hydrogel, which provided better mechanical strength and support for easy handling during procedures. With the demonstrated advantages, the developed hydrogels showed promise for exploitation in various practical clinical applications.

Xanthophylls increased HDLC level and nuclear factor PPARγ, RXRγ and RARα expression in hens and chicks.

This study was designed to investigate effects of xanthophylls on serum lipid profile (triglyceride, TG; cholesterol, CHO; high-density lipoprotein cholesterol, HDLC; and low-density lipoprotein cholesterol, LDLC) and nuclear factor (peroxisome proliferator-activated receptor gamma, PPARγ; PPAR gamma coactivator 1 alpha, PGC1α; retinoid X receptor gamma, RXRγ; and retinoic acid receptor alpha, RARα) gene expression of breeding hens and chicks. In experiment 1, 432 hens were divided into three groups and fed diets supplemented with 0 (as control group), 20 or 40 mg/kg xanthophylls. Blood was sampled at 7, 14, 21, 28 and 35 days of trial. Liver, duodenum, jejunum and ileum were sampled at 35 days of trial. Results showed that serum HDLC level of hens was increased after dietary 40 mg/kg xanthophyll addition for 21, 28 and 35 days, while serum TG, CHO and LDLC were not affected. Xanthophyll addition also increased PPARγ expression in jejunum, RXRγ expression in duodenum and jejunum, and RARα expression in liver and duodenum. Experiment 2 was a 2 × 2 factorial design. Male chicks hatched from 0 or 40 mg/kg xanthophyll diet of hens were fed diet containing either 0 or 40 mg/kg xanthophylls. Liver, duodenum, jejunum and ileum were sampled at 0, 7, 14 and 21 days after hatching. Blood samples were also collected at 21 days. Results showed that in ovo xanthophylls elevated PPARγ in duodenum and jejunum, and RXRγ and RARα in liver of chicks mainly within 1 week after hatching, while dietary xanthophylls increased serum HDLC level and PPARγ and RXRγ in liver from 2 weeks onwards. In conclusion, our research suggested xanthophylls can regulate serum lipid profile and nuclear factor expression in hens and chicks.

[Clinicopathologic features of drug-induced vanishing bile duct syndrome].

Vanishing bile duct syndrome (VBDS) manifests as progressive destruction and disappearance of the intrahepatic bile duct caused by various factors and cholestasis. VBDS associated with drug-induced liver injury (D-VBDS) is an important etiology of VBDS, and immune disorder or immune imbalance may be the main pathogenesis. According to its clinical symptoms, serological markers, and course of the disease, D-VBDS is classified into major form and minor form, and its clinical features are based on various pathomorphological findings. Its prognosis is associated various factors including regeneration of bile duct cells, number of bile duct injuries, level and range of bile duct injury, bile duct proliferation, and compensatory shunt of bile duct branches. This disease has various clinical outcomes; most patients have good prognosis after drug withdrawal, and some patients may experience cholestatic cirrhosis, liver failure, and even death. Due to the clinical manifestation and biochemical changes are similar to the primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), it need to identify by clinical physician.

Students' Perceptions of Motivational Climate and Enjoyment in Finnish Physical Education: A Latent Profile Analysis.

The purpose of this study was to identify student clusters with homogenous profiles in perceptions of task- and ego-involving, autonomy, and social relatedness supporting motivational climate in school physical education. Additionally, we investigated whether different motivational climate groups differed in their enjoyment in PE. Participants of the study were 2 594 girls and 1 803 boys, aged 14-15 years. Students responded to questionnaires assessing their perception of motivational climate and enjoyment in physical education. Latent profile analyses produced a five-cluster solution labeled 1) 'low autonomy, relatedness, task, and moderate ego climate' group', 2) 'low autonomy, relatedness, and high task and ego climate, 3) 'moderate autonomy, relatedness, task and ego climate' group 4) 'high autonomy, relatedness, task, and moderate ego climate' group, and 5) 'high relatedness and task but moderate autonomy and ego climate' group. Analyses of variance showed that students in clusters 4 and 5 perceived the highest level of enjoyment whereas students in cluster 1 experienced the lowest level of enjoyment. The results showed that the students' perceptions of various motivational climates created differential levels of enjoyment in PE classes. Key pointsLatent profile analyses produced a five-cluster solution labeled 1) 'low autonomy, relatedness, task, and moderate ego climate' group', 2) 'low autonomy, relatedness, and high task and ego climate, 3) 'moderate autonomy, relatedness, task and ego climate' group 4) 'high autonomy, relatedness, task, and moderate ego climate' group, and 5) 'high relatedness and task but moderate autonomy and ego climate' group.Analyses of variance showed that clusters 4 and 5 perceived the highest level of enjoyment whereas cluster 1 experienced the lowest level of enjoyment. The results showed that the students' perceptions of motivational climate create differential levels of enjoyment in PE classes.

Effects of longitudinal baffles on particles settling in a sedimentation basin.

This study was conducted to evaluate the effects of longitudinal baffles on particles settling performance within a full-scale sedimentation basin with a flow rate of 1,000 m(3)/hr. Comparative experiments on turbidity removal efficiency and sludge deposit distribution were performed in longitudinally baffled and non-baffled sedimentation basins. The turbidity removal rate in the baffled sedimentation basin was observed to be higher than that in the non-baffled basin. In addition, the depth of the sludge deposit in the baffled sedimentation basin was approximately 20% less than that in the non-baffled sedimentation basin, and the sludge concentration was 10% higher. To explain these results and to further investigate the effects of longitudinal baffles, the authors performed computational fluid dynamics (CFD) simulation for both basin types. The results of this CFD simulation indicated that the flow, particularly near the outlet orifice, was more stable in the longitudinally baffled sedimentation basin. Moreover, it could be concluded that the longitudinal baffle enables a fully developed flow and is thus more effective for sedimentation.

[Research progress on dual immune regulation of neutrophils in periodontal inflammation].

Periodontitis is a chronic inflammatory condition of the periodontal tissues triggered by bacterial biofilm, leading to manifestations such as gingival bleeding, tooth mobility, and eventual exfoliation. Neutrophils exhibit a dual role throughout the course of periodontitis, both in defense against pathogens and in potentially detrimental effects on periodontal tissues. This article elucidates the intricate mechanisms underlying the dual functions of neutrophils in periodontitis, including respiratory burst, neutrophil extracellular traps (NETs) formation, degranulation, and phagocytosis. By providing a comprehensive understanding of neutrophils involvement in periodontitis, this study aims to empower clinicians with insights into the pathogenesis of periodontitis, thereby fostering novel strategies for its prevention and treatment.

Effects of a Chinese medical herbs complex on cellular immunity and toxicity-related conditions of breast cancer patients.

Rose geranium (Pelargonium graveolens, Geraniaceae) has anti-cancer and anti-inflammatory properties, and promotes wound healing. Similarly, Ganoderma tsugae (Ganodermataceae), Codonopsis pilosula (Campanulaceae) and Angelica sinensis (Apiaceae) are traditional Chinese herbs associated with immunomodulatory functions. In the present study, a randomised, double-blind, placebo-controlled study was conducted to examine whether the Chinese medicinal herb complex, RG-CMH, which represents a mixture of rose geranium and extracts of G. tsugae, C. pilosula and A. sinensis, can improve the immune cell count of cancer patients receiving chemotherapy and/or radiotherapy to prevent leucopenia and immune impairment that usually occurs during cancer therapy. A total of fifty-eight breast cancer patients who received chemotherapy or radiotherapy were enrolled. Immune cell levels in patient serum were determined before, and following, 6 weeks of cancer treatment for patients receiving either an RG-CMH or a placebo. Administration of RG-CMH was associated with a significant reduction in levels of leucocytes from 31·5 % for the placebo group to 13·4 % for the RG-CMH group. Similarly, levels of neutrophils significantly decreased from 35·6 % for the placebo group to 11·0 % for the RG-CMH group. RG-CMH intervention was also associated with a decrease in levels of T cells, helper T cells, cytotoxic T cells and natural killer cells compared with the placebo group. However, these differences between the two groups were not statistically significant. In conclusion, administration of RG-CMH to patients receiving chemotherapy/radiotherapy may have the capacity to delay, or ease, the reduction in levels of leucocytes and neutrophils that are experienced by patients during cancer treatment.

Aggressive Video Games Are Not a Risk Factor for Mental Health Problems in Youth: A Longitudinal Study.

Recent preregistered studies and analyses have suggested that links between aggressive video games (AVGs) and aggression-related outcomes may have been exaggerated in previous literature. However, concerns about AVGs remain. Although the impact of aggressive games on aggressive behaviors has been the subject of approximately a dozen preregistered studies, the potential impact of aggressive games on the player's mental health symptoms has not been the subject of similar preregistered analyses. In the current study, a sample of more than 3000 youth from Singapore were examined by using preregistered analyses to determine whether early exposure to aggressive games was predictive of anxiety, depression, somatic symptoms, or attention deficit hyperactivity disorder 2 years later. Analyses suggested that exposure to AVGs is not a risk factor for later mental health symptoms.

Prevalence and Survival Impact of Self-Reported Symptom and Psychological Distress Among Patients With Multiple Myeloma.

BACKGROUND: Advances in the management of multiple myeloma (MM) have extended survival and reduced painful skeletal-related events. As MM is evolving toward a chronic disease, we sought to determine the prevalence of self-reported symptom burden and psychological distress, and to determine the association of distress with survival. METHODS: The CPASS-7 patient-reported outcome instrument was administered to a convenience sample of MM patients at 7 outpatient cancer centers. RESULTS: A total of 239 patients completed the CPASS-7 between September 2015 and October 2016%; 57% of respondents were male, and median age was 67 years. Forty-eight percent were concerned that they could not do the things they wanted to do, with 33% reporting decreased performance status. Financial toxicity concerns were self-reported by 44%, with family burdens noted in 24%. Although depression was reported by only 15%, 41% noted lack of pleasure. Pain was a concern in 36%. With a median follow-up of 316 days since CPASS-7 completion, 13% of patients had died. A high total distress score was noted in 57 (24%) and trended toward an association with a decreased survival rate compared to the 182 patients (76%) with a low total distress score (P = .066). The 6-month survival rates for patients with high and low distress scores were 86% and 96%, respectively, and 12-month survival rates were 76% and 87%, respectively. CONCLUSION: Despite dramatic improvements in survival among patients with MM, symptom, financial, and psychosocial concerns continue to be major patient concerns. As MM becomes a chronic disease, additional attention to addressing these issues is required.

Extent of laminin-5 assembly and secretion effect junctional epidermolysis bullosa phenotype.

Junctional epidermolysis bullosa (JEB) is an autosomal recessive skin blistering disease with both lethal and nonlethal forms, with most patients shown to have defects in laminin-5. We analyzed the location of mutations, gene expression levels, and protein chain assembly of the laminin-5 heterotrimer in six JEB patients to determine how the type of genetic lesion influences the pathophysiology of JEB. Mutations within laminin-5 genes were diversely located, with the most severe forms of JEB correlating best with premature termination codons, rather than mapping to any particular protein domain. In all six JEB patients, the laminin-5 assembly intermediates we observed were as predicted by our previous work indicating that the alpha3beta3gamma2 heterotrimer assembles intracellularly via a beta3gamma2 heterodimer intermediate. Since assembly precedes secretion, mutations that disrupt protein-protein interactions needed for assembly are predicted to limit the secretion of laminin-5, and likely to interfere with function. However, our data indicate that typically the most severe mutations diminish mRNA stability, and serve as functional null alleles that block chain assembly by resulting in either a deficiency (in the nonlethal mitis variety) or a complete absence (in lethal Herlitz-JEB) of one of the chains needed for laminin-5 heterotrimer assembly.

Pulmonary changes induced by trans,trans-2,4-decadienal, a component of cooking oil fumes.

Cooking oil fumes (COF) are known to be associated with respiratory diseases and risk of lung cancer. Involvement of trans,trans-2,4-decadienal (tt-DDE), a major component in COF, is suspected. Male CD-1(R) (ICR) mice were intratracheally instilled with either 8 or 24 mg.kg(-1) tt-DDE weekly for 8 weeks. Total numbers and types of cells in bronchoalveolar lavage fluid (BALF), as well as pathological changes, and inflammatory gene modulations in the lung tissues were assessed. We demonstrated that the number of alveolar macrophages in the BALF was significantly increased in tt-DDE-exposed animals. Histologically, there was a dose-correlated increase in epithelial hyperplasia and granulomatous nodules at the bronchioloalveolar junctions (BAJ). Although both Clara and alveolar type II cells were present in the BAJ lesion, only Clara cells were actively proliferative. However, only alveolar type II cells were found in the BAJ granulomatous nodules. Enhanced accumulation of phosphorylated signal transducer and activator of transcription 3 (pSTAT3), a known pro-carcinogenic factor, was also detected in many alveolar type II cells at the BAJ lesions. As both BAJ hyperplasia and enhanced pSTAT3 accumulation are known risk factors associated with increased lung adenocarcinoma development, these findings suggest that tt-DDE may pose a risk in lung carcinogenesis.

The progress of radiobiological models in modern radiotherapy with emphasis on the uncertainty issue.

Radiobiological models are used in modern radiotherapy to evaluate the biological effects of different treatment plans or modalities. A radiobiological model typically converts a physical quantity (e.g. absorbed dose) to a biological quantity (e.g. cell survival fraction). Currently, the linear-quadratic model (LQM) is the most widely used model. Since it is a deterministic model, the LQM naturally ignores the uncertainties arising from the stochastic randomness of energy depositions along radiation tracks and the inherent unpredictable nature of biological systems. Recently, many studies have revealed the detailed spatial and temporal distributions of DNA damages, e.g. the DNA double strand breaks (DSBs), along various types of radiation tracks traversing a cell nucleus. Studies have also been conducted to unravel the biological pathways that involve in how cells and tissues process DNA damages. As such, the author proposes to start developing a new multi-scale radiobiological model based on the "bottom-up" approach. The model includes a Monte Carlo procedure to treat the stochastic randomness of radiation-induced DNA damages, and it also includes the relevant intercellular and intracellular pathways to allow the DNA damages to evolve into higher-order biological endpoints, e.g. chromosome aberrations, cell death, or tumorigenesis. Because of its stochastic nature, the new model inherently addresses the uncertainty issue being ignored by LQM. More importantly perhaps is that the model opens a new way to study radiation effects that involve biological pathways, and therefore, may have a profound impact on radiotherapy in the future.

Does gender moderate the exercising personality? An examination of continuous and stage-based exercise.

For nearly 60 years, researchers have examined the relationship between personality traits and exercise participation. Rhodes and Smith (2006), using meta-analytic procedures reported that extraversion, conscientiousness, and neuroticism were significantly related to exercise participation (Personality correlates of physical activity: A review and meta-analysis. British Journal of Sports Medicine, 40, 958-965). Gender as a moderator of the personality and exercise relationship remained inconclusive. In addition, researchers have suggested that the stage approach may lend greater insight as to the importance of personality. The investigator's primary purpose was to determine whether gender moderated the personality and exercise relationship. The secondary purpose was to determine the importance of personality within a stage approach. Participants were 827 females and 657 males college-aged students who completed measures of the "big five" personality traits and two exercise measures. The results indicated that gender was not a moderator and that the stage approach offers insight as hypothesized differences resulted in personality between intentional exercisers and non-exercising individuals as well as within exercising individuals.

ASSESSMENT OF AMBIENT NEUTRON DOSE EQUIVALENT IN SPATIALLY FRACTIONATED RADIOTHERAPY WITH PROTONS USING PHYSICAL COLLIMATORS.

New technique is trending in spatially fractionated radiotherapy with protons to utilize the spot scanning together with a physical collimator to obtain minibeams. The primary goal of this study is to quantify ambient neutron dose equivalent (${H}^{\ast }(10)$) due to the secondary neutrons when physical collimator is used to achieve desired minibeams. The ${H}^{\ast }(10)$ per treatment proton dose (D) was assessed using Monte Carlo code TOPAS and measured using WENDI-II detector at different angles (135, 180, 225 and 270 degrees) and distances (11 cm, 58 and 105 cm) from the phantom for two cases: with and without physical collimation. Without collimation $\frac{H^{\ast }(10)}{D}$ varied from 0.0013 to 0.242 mSv/Gy. With collimation $\frac{H^{\ast }(10)}{D}$ varied from 0.017 to 3.23 mSv/Gy. Results show that the secondary neutron dose will increase tenfold when the physical collimator is used. Regardless, it will be low and comparable to the neutron dose produced by conventional passive-scattered proton beams.

Optimization of hexagonal-pattern minibeams for spatially fractionated radiotherapy using proton beam scanning.

PURPOSE: In this study, we investigated computationally and experimentally a hexagonal-pattern array of spatially fractionated proton minibeams produced by proton pencil beam scanning (PBS) technique. Spatial fractionation of dose delivery with millimeter or submillimeter beam size has proven to be a promising approach to significantly increase the normal tissue tolerance. Our goals are to obtain an optimized minibeam design and to show that it is feasible to implement the optimized minibeams at the existing proton clinics. METHODS: An optimized minibeam arrangement is one that would produce high peak-to-valley dose ratios (PVDRs) in normal tissues and a PVDR approaching unity at the Bragg peak. Using Monte Carlo (MC) code TOPAS we simulated proton pencil beams that mimic those available at the existing proton therapy facilities and obtained a hexagonal-pattern array of minibeams by collimating the proton pencil beams through the 1-3 mm diameter pinholes of a collimator. We optimized the minibeam design by considering different combinations of parameters including collimator material and thickness (t), center-to-center (c-t-c) distance, and beam size. The optimized minibeam design was then evaluated for normal tissue sparing against the uniform pencil beam scanning (PBS) by calculating the therapeutic advantage (TA) in terms of cell survival fraction. Verification measurements using radiochromic films were performed at the Emory proton therapy center (EPTC). RESULTS: Optimized hexagonal-pattern minibeams having PVDRs of >10 at phantom surface and of >3 at depths up to 6 cm were achieved with 2 mm diameter modulated proton minibeams (with proton energies between 120 and 140 MeV) corresponding to a spread-out-Bragg-peak (SOBP) over the depth of 10-14 cm. The results of the film measurements agree with the MC results within 10%. The TA of the 2 mm minibeams against the uniform PBS is >3 from phantom surface to the depth of 5 cm and then smoothly drops to ~1.5 as it approaches the proximal edge of the SOBP. For 2 mm minibeams and 6 mm c-t-c distance, we delivered 1.72 Gy at SOBP for 7.2 × 7.2 × 4 cm3 volume in 48 s. CONCLUSIONS: We conclude that it is feasible to implement the optimized hexagonal-pattern 2 mm proton minibeam radiotherapy at the existing proton clinics, because desirable PVDRs and TAs are achievable and the treatment time is reasonable.

A comparison of the effects of clozapine and its metabolite norclozapine on metabolic dysregulation in rodent models.

RATIONALE: The second generation antipsychotic drug clozapine is a psychotherapeutic agent with superior efficacy for treatment-resistant schizophrenia. Clozapine is associated with a low likelihood of neurological side-effects, but a high propensity to induce weight gain and metabolic dysregulation. The primary metabolite of clozapine is norclozapine (N-Desmethylclozapine), which has psychoactive properties itself, but its effects on metabolic function remains unknown. The goal of the present study was to determine whether directly administered norclozapine could cause metabolic dysregulation, similar to clozapine. METHODS: Adult female rats were treated with a range of doses of clozapine and norclozapine (0.5, 2, 8 & 20 mg/kg, i.p.) and then subjected to the intraperitoneal glucose tolerance test (IGTT), where glucose levels were recorded for 2 h following a glucose challenge. In parallel, rats were tested with two doses of clozapine and norclozapine (2 & 20 mg/kg, i.p.) in the hyperinsulinemic-euglycemic clamp (HIEC), to measure whole body insulin resistance. RESULTS: In the IGTT, clozapine demonstrated dose-dependent effects on fasting glucose levels and total glucose area-under-the-curve following the glucose challenge, with the two highest doses strongly increasing glucose levels. Only the highest dose of norclozapine increased fasting glucose levels, and caused a non-significant increase in glucose levels following the challenge. By contrast, both doses of clozapine and norclozapine caused a potent and long-lasting decrease in the glucose infusion rate in the HIEC, indicating that both compounds cause whole body insulin resistance. ABSTRACT: While not as potent as its parent compound, norclozapine clearly exerts acute metabolic effects, particularly on insulin resistance. This article is part of the issue entitled 'Special Issue on Antipsychotics'.

Understanding students' motivation in project work: a 2 x 2 achievement goal approach.

BACKGROUND: The project work (PW) initiative was launched in 2000 by the Ministry of Education, Singapore, to encourage application of knowledge across disciplines, and to develop thinking, communication, collaboration, and metacognitive skills. Although PW has been introduced for a few years, few studies have examined the motivation of students in PW, especially with the use of the recently proposed 2 x 2 achievement goal framework. AIM: To use a cluster analytic approach to identify students' achievement goal profiles at an intra-individual level, and to examine their links to various psychological characteristics and perceived outcomes in PW. SAMPLE: Participants were 491 Secondary 2 students (mean age = 13.78, SD = 0.77) from two government coeducational schools. METHOD: Cluster analysis was performed to identify distinct subgroups of students with similar achievement goal profiles. One-way MANOVAs, followed by post hoc Tukey HSD tests for pairwise comparisons were used to determine whether there was any significant difference amongst clusters in terms of the psychological characteristics and perceived outcomes in PW. RESULTS: Four distinct clusters of students were identified. The cluster with high achievement goals and the cluster with moderately high goals had the most positive psychological characteristics and perceived outcomes. In contrast, the cluster with very low scores for all four achievement goals had the most maladaptive profile. CONCLUSION: The study provides support for the 2 x 2 achievement goal framework, and demonstrates that multiple goals can operate simultaneously. However, it highlights the need for cross-cultural studies to look into the approach-avoidance dimension in the 2 x 2 achievement goal framework.

A cell-by-cell Monte Carlo simulation for assessing radiation-induced DNA double strand breaks.

This paper presents a cell-by-cell Monte Carlo simulation study that combines charged particle track structure data with an interphase cell nucleus model to quantify DNA double strand breaks (DSBs), spatial distribution of DSBs in a cell nucleus, and resulting potentially lethal or mutagenic events (PLMEs) between DSBs in close proximity. Cell nucleus is simulated according to the chromosome territory-interchromatin compartment (CT-IC) model in that chromatin content is unevenly distributed in chromatin domains (CDs) and IC with a chromatin compaction ratio of 22:1. A particle track structure coordinate (PTSC) library was first generated for each particle type, energy, and dose based on a large number of particle track data obtained by running the Monte Carlo track structure code Geant4-DNA. To assess the DNA DSBs of a cell for a specific particle type, energy, and dose, the corresponding PTSC was selected and "map overlaid" onto 960 unique cell nucleus data sets containing chromatin fiber (CF) locations. Clustering algorithm DBSCAN was next used to identify the clustered energy deposition events occurring inside the CF. These events were then converted to DNA DSBs using a probabilistic approach. The locations of the DSBs thus obtained were, in turn, used to calculate PLMEs within the cell nucleus that can result from DSB proximity and complexity. The results obtained from this simulation study are correctly correlated to the experimental data of DSB yield and the RBE-LET relationships for various types of charged particles and of various energies. The results show agreement with other published radiobiological models.

Competence, autonomy, and relatedness in the classroom: understanding students' motivational processes using the self-determination theory.

The purpose of the current study is to examine the relationships between need satisfaction, motivation, and outcomes as well as the differential effects of the three psychological needs. The sample consisted of 1549 students from 10 secondary schools in Singapore. Structural equation modelling (SEM) analysis showed that students' psychological needs are positively related to autonomous motivation, and this in turn, lead to higher enjoyment, value and lower pressure. On the other hand, the three psychological needs were negatively related to controlled motivation. Controlled motivation was positively related to pressure but negatively related to enjoyment and value. In terms of the differential effects of the three psychological needs, relatedness contributed strongly to autonomous motivation, compared to autonomy and competence. In contrast, while autonomy and relatedness contributed to controlled motivation negatively, competence positively predicted controlled motivation. Finally, competence was found to link to pressure in a negative way. In summary, the findings of the current study provide support to the propositions of SDT and add some insight to the differential effects of the three psychological needs.