Neurodegenerative disease pathways are perturbed in patients with cancer who self-report cognitive changes and anxiety: A pathway impact analysis.

BACKGROUND: Cancer-related cognitive impairment (CRCI) and anxiety co-occur in patients with cancer. Little is known about mechanisms for the co-occurrence of these two symptoms. The purposes of this secondary analysis were to evaluate for perturbed pathways associated with the co-occurrence of self-reported CRCI and anxiety in patients with low versus high levels of these two symptoms and to identify potential mechanisms for the co-occurrence of CRCI and anxiety using biological processes common across any perturbed neurodegenerative disease pathways. METHODS: Patients completed the Attentional Function Index and the Spielberger State-Trait Anxiety Inventory six times over two cycles of chemotherapy. Based on findings from a previous latent profile analysis, patients were grouped into none versus both high levels of these symptoms. Gene expression was quantified, and pathway impact analyses were performed. Signaling pathways for evaluation were defined with the Kyoto Encyclopedia of Genes and Genomes database. RESULTS: A total of 451 patients had data available for analysis. Approximately 85.0% of patients were in the none class and 15.0% were in the both high class. Pathway impact analyses identified five perturbed pathways related to neurodegenerative diseases (i.e., amyotrophic lateral sclerosis, Huntington disease, Parkinson disease, prion disease, and pathways of neurodegeneration-multiple diseases). Apoptosis, mitochondrial dysfunction, oxidative stress, and endoplasmic reticulum stress were common biological processes across these pathways. CONCLUSIONS: This study is the first to describe perturbations in neurodegenerative disease pathways associated with CRCI and anxiety in patients receiving chemotherapy. These findings provide new insights into potential targets for the development of mechanistically based interventions.

Digital rhythm training improves reading fluency in children.

Musical instrument training has been linked to improved academic and cognitive abilities in children, but it remains unclear why this occurs. Moreover, access to instrument training is not always feasible, thereby leaving less fortunate children without opportunity to benefit from such training. Although music-based video games may be more accessible to a broader population, research is lacking regarding their benefits on academic and cognitive performance. To address this gap, we assessed a custom-designed, digital rhythm training game as a proxy for instrument training to evaluate its ability to engender benefits in math and reading abilities. Furthermore, we tested for changes in core cognitive functions related to math and reading to inform how rhythm training may facilitate improved academic abilities. Classrooms of 8-9 year old children were randomized to receive either 6 weeks of rhythm training (N = 32) or classroom instruction as usual (control; N = 21). Compared to the control group, results showed that rhythm training improved reading, but not math, fluency. Assessments of cognition showed that rhythm training also led to improved rhythmic timing and language-based executive function (Stroop task), but not sustained attention, inhibitory control, or working memory. Interestingly, only the improvements in rhythmic timing correlated with improvements in reading ability. Together, these results provide novel evidence that a digital platform may serve as a proxy for musical instrument training to facilitate reading fluency in children, and that such reading improvements are related to enhanced rhythmic timing ability and not other cognitive functions associated with reading performance. RESEARCH HIGHLIGHTS: Digital rhythm training in the classroom can improve reading fluency in 8-9 year old children Improvements in reading fluency were positively correlated with enhanced rhythmic timing ability Alterations in reading fluency were not predicted by changes in other executive functions that support reading A digital platform may be a convenient and cost-effective means to provide musical rhythm training, which in turn, can facilitate academic skills.

Climate change and land cover effects on water yield in a subtropical watershed spanning the yungas-chaco transition of Argentina.

The demand for mountain water resources is increasing, and their availability is threatened by climate change, emphasizing the urgency for effective protection and management. The upper Sali-Dulce watershed holds vital significance as it contributes the majority of the Sali-Dulce water resources, supporting a densely populated dry region in Northwestern Argentina, covering an area of 24,217 km2. However, the potential impact of climate change and land use/land cover change on water yield in this watershed remains uncertain. This study employs the InVEST Annual Water Yield model to analyze the average water yield in the watershed and evaluate its potential changes under future scenarios of climate and land use/land cover change. InVEST was calibrated using data from multiple river gauges located across the watershed, indicating satisfactory performance (R2 = 0.751, p-value = 0.0054). Precipitation and evapotranspiration were the most important variables explaining water yield in the area, followed by land use. Water yield showed a notable concentration in the montane area with 40% of the watershed accounting for 80% of the water yield, underscoring the importance of conserving natural land cover in this critical zone. Climate change scenarios project an increase in water yield ranging from 21 to 75%, while the effects of land cover change scenarios on water yield vary, with reforestation scenarios leading to reductions of up to 15% and expansions in non-irrigated agriculture resulting in increases of up to 40%. Additionally, water yield distribution may become more concentrated or dispersed, largely dependent on the type of land cover. The combined scenarios highlight the pivotal role of land cover in adapting to climate change. Our findings provide valuable insights for designing future studies and developing policies aimed at implementing effective adaptation strategies to climate change within the Salí-Dulce watershed.

An Evaluation of the Multifactorial Model of Cancer-Related Cognitive Impairment.

BACKGROUND: Up to 45% of patients report cancer-related cognitive impairment (CRCI). A variety of characteristics are associated with the occurrence and/or severity of CRCI. However, an important gap in knowledge of risk factors for CRCI is the relative contribution of each factor. The multifactorial model of cancer-related cognitive impairment (MMCRCI) is a conceptual model of CRCI that can be used to evaluate the strength of relationships between various factors and CRCI. OBJECTIVES: The purpose of this study was to use structural regression methods to evaluate the MMCRCI using data from a large sample of outpatients receiving chemotherapy ( n = 1,343). Specifically, the relationships between self-reported CRCI and four MMCRCI concepts (i.e., social determinants of health, patient-specific factors, treatment factors, and co-occurring symptoms) were examined. The goals were to determine how well the four concepts predicted CRCI and determine the relative contribution of each concept to deficits in perceived cognitive function. METHODS: This study is part of a larger, longitudinal study that evaluated the symptom experience of oncology outpatients receiving chemotherapy. Adult patients were diagnosed with breast, gastrointestinal, gynecological, or lung cancer; had received chemotherapy within the preceding 4 weeks; were scheduled to receive at least two additional cycles of chemotherapy; were able to read, write, and understand English; and gave written informed consent. Self-reported CRCI was assessed using the attentional function index. Available study data were used to define the latent variables. RESULTS: On average, patients were 57 years of age, college educated, and with a mean Karnofsky Performance Status score of 80. Of the four concepts evaluated, whereas co-occurring symptoms explained the largest amount of variance in CRCI, treatment factors explained the smallest amount of variance. A simultaneous structural regression model that estimated the joint effect of the four exogenous latent variables on the CRCI latent variable was not significant. DISCUSSION: These findings suggest that testing individual components of the MMCRCI may provide useful information on the relationships among various risk factors, as well as refinements of the model. In terms of risk factors for CRCI, co-occurring symptoms may be more significant than treatment factors, patient-specific factors, and/or social determinants of health in patients receiving chemotherapy.

Ultra-processed foods consumption reduces dietary diversity and micronutrient intake in the Mexican population.

BACKGROUND: Currently, 30% of the total energy intake in the Mexican diet comes from ultra-processed foods. Although its consumption is associated with high intakes of added sugar and saturated fats and low intakes of dietary fibre, there is no evidence regarding its association with dietary diversity and micronutrient intake. The present study evaluated the association between ultra-processed foods consumption with dietary diversity and micronutrient intake in Mexico. METHODS: Ultra-processed foods items were identified in a 24-h recall from a sample of 10,087 participants aged ≥ 1 year. The minimum dietary diversity (MDD) was established by using the Food and Agriculture Organization 10 food group indicators with unprocessed, minimally processed and processed foods. The study conducted multiple linear regression models to evaluate the association between quintiles of energy contribution of ultra-processed foods with dietary diversity and micronutrient intake. RESULTS: A high consumption of ultra-processed foods was associated with a low dietary diversity and micronutrients intake. The association between ultra-processed foods and MDD was not linear (47.1%, 57.1%, 52.5%, 45.0% and 28.0% of participants achieved the MDD). On the other hand, the association was linear and negatively associated with: niacin, pantothenic acid, pyridoxine, folate, vitamin B12 , vitamin C, vitamin E, zinc, calcium, magnesium, potassium and phosphorus (p < 0.05). CONCLUSIONS: These findings are relevant in the context of the double burden of malnutrition currently faced in Mexico. Increasing dietary diversity and micronutrient intake is essential by discouraging ultra-processed foods consumption. However, other strategies are also needed to promote the dietary diversity and increase the consumption of unprocessed and minimally processed foods.

Neuropsychological profile associated to PKAN in its initial phase: a case series report.

Pantothenase kinase-associated neurodegeneration (PKAN) is characterized by an abnormal accumulation of iron in basal ganglia and progressing varied extrapyramidal clinical symptoms. There are few studies on the cognitive symptoms and their development. The aim of this study is to explore the neuropsychological profile of PKAN patients in the initial stages of the disorder, when there are relatively fewer motor limitations. we present a full neuropsychological examination of three female cases (two early and one late onset). perception and spatial cognition were within normal range. Performance on other tasks were mixed, except for primary impairments in inhibition, flexibility, and cognitive fluency, which were consistent across cases. unlike most previous studies which report adults with major motor impairment, we present cases of young participants with minor motor difficulties. The results of the neuropsychological assessment - potentially less confounded by poor motor functioning during examination - are compatible with impairments in the fronto-subcortical circuits in the early phases of the disease. This could explain frequent misdiagnoses (e.g., with attention deficit hyperactivity disorder) in initial referrals.

Resting-State Functional Networks Correlate with Motor Performance in a Complex Visuomotor Task: An EEG Microstate Pilot Study on Healthy Individuals.

Developing motor and cognitive skills is needed to achieve expert (motor) performance or functional recovery from a neurological condition, e.g., after stroke. While extensive practice plays an essential role in the acquisition of good motor performance, it is still unknown whether certain person-specific traits may predetermine the rate of motor learning. In particular, learners' functional brain organisation might play an important role in appropriately performing motor tasks. In this paper, we aimed to study how two critical cognitive brain networks-the Attention Network (AN) and the Default Mode Network (DMN)-affect the posterior motor performance in a complex visuomotor task: virtual surfing. We hypothesised that the preactivation of the AN would affect how participants divert their attention towards external stimuli, resulting in robust motor performance. Conversely, the excessive involvement of the DMN-linked to internally diverted attention and mind-wandering-would be detrimental for posterior motor performance. We extracted seven widely accepted microstates-representing participants mind states at rest-out of the Electroencephalography (EEG) resting-state recordings of 36 healthy volunteers, prior to execution of the virtual surfing task. By correlating neural biomarkers (microstates) and motor behavioural metrics, we confirmed that the preactivation of the posterior DMN was correlated with poor posterior performance in the motor task. However, we only found a non-significant association between AN preactivation and the posterior motor performance. In this EEG study, we propose the preactivation of the posterior DMN-imaged using EEG microstates-as a neural trait related to poor posterior motor performance. Our findings suggest that the role of the executive control system is to preserve an homeostasis between the AN and the DMN. Therefore, neurofeedback-based downregulation of DMN preactivation could help optimise motor training.

Tracking the impacts of climate change on human health via indicators: lessons from the Lancet Countdown.

BACKGROUND: In the past decades, climate change has been impacting human lives and health via extreme weather and climate events and alterations in labour capacity, food security, and the prevalence and geographical distribution of infectious diseases across the globe. Climate change and health indicators (CCHIs) are workable tools designed to capture the complex set of interdependent interactions through which climate change is affecting human health. Since 2015, a novel sub-set of CCHIs, focusing on climate change impacts, exposures, and vulnerability indicators (CCIEVIs) has been developed, refined, and integrated by Working Group 1 of the "Lancet Countdown: Tracking Progress on Health and Climate Change", an international collaboration across disciplines that include climate, geography, epidemiology, occupation health, and economics. DISCUSSION: This research in practice article is a reflective narrative documenting how we have developed CCIEVIs as a discrete set of quantifiable indicators that are updated annually to provide the most recent picture of climate change's impacts on human health. In our experience, the main challenge was to define globally relevant indicators that also have local relevance and as such can support decision making across multiple spatial scales. We found a hazard, exposure, and vulnerability framework to be effective in this regard. We here describe how we used such a framework to define CCIEVIs based on both data availability and the indicators' relevance to climate change and human health. We also report on how CCIEVIs have been improved and added to, detailing the underlying data and methods, and in doing so provide the defining quality criteria for Lancet Countdown CCIEVIs. CONCLUSIONS: Our experience shows that CCIEVIs can effectively contribute to a world-wide monitoring system that aims to track, communicate, and harness evidence on climate-induced health impacts towards effective intervention strategies. An ongoing challenge is how to improve CCIEVIs so that the description of the linkages between climate change and human health can become more and more comprehensive.

Criteria for endovascular intervention in type B aortic dissection.

BACKGROUND: The use of thoracic endovascular aortic repair (TEVAR) for the management of uncomplicated type B aortic dissection (un-TBAD) remains controversial. There is a lack of consensus over whether pre-emptive TEVAR should be carried out in patients with un-TBAD at risk of progression to complicated TBAD. We present a review of current evidence and seek to suggest criteria where endovascular intervention in un-TBAD may prove beneficial relative to pharmacotherapy alone. METHODS AND MATERIALS: PubMed and Cochrane databases were searched using terms including: type B aortic dissection, risk factors, medical therapy, TEVAR, false lumen (FL) expansion, and mortality. Papers were selected based on title and abstract. RESULTS: Optimal medical therapy remains the mainstay treatment for patients with un-TBAD, however, patients with un-TBAD present with varying degrees of disease progression risk. Factors such as age, aortic morphology, history of connective tissue disorders, FL thrombosis, and aortic branch involvement may potentiate progression from un-TBAD to complicated TBAD. Short- and long-term outcomes associated with TEVAR for TBAD remain promising. CONCLUSION: Pre-emptive TEVAR may be beneficial in patients with un-TBAD presenting with the above factors, however, further prospective research into the optimal timing for TEVAR in un-TBAD is required.

Potentiometric Electronic Tongue for Quantitative Ion Analysis in Natural Mineral Waters.

The present paper addresses the development and use of a new potentiometric electronic tongue for both qualitative and quantitative characterization of natural mineral waters. The electronic tongue is particularly related to the conductivity and ion content of/in the water sample. The analytical system is based on six ion-selective electrodes whose membranes are formulated to provide either cationic or anionic response and considering plasticizers with different dielectric constants (bis(2-ethylhexyl) sebacate, 2-nitrophenyl octyl ether or tricresylphosphate), while keeping the polymeric matrix, i.e., poly(vinyl chloride). Notably, the absence of any ionophore in the membrane provides a general response profile, i.e., no selectivity toward any special ion, which is convenient for the realization of an effective electronic tongue. The dynamic response of the tongue toward water samples of different chemical compositions and geographical locations has been obtained. At the optimized experimental conditions, the tongue presents acceptable repeatability and reproducibility (absence of hysteresis). The principal component analysis of the final potential values observed with the six electrodes allows for the differentiation and classification of the samples according to their conductivity, which is somehow related to the mineralization. Moreover, quantitative determination of the six main ions in the water samples (i.e., chloride, nitrate, hydrogen carbonate, sulfate, sodium, calcium, and magnesium) is possible by means of a simple linear calibration (and cross-validation) model.

Racial and Ethnic Disparities: Essential Workers, Mental Health, and the Coronavirus Pandemic.

Evidence is emerging of the pandemic disproportionately impacting communities of color. This study investigates mental health distress among essential workers during the coronavirus pandemic across race and ethnicity. We evaluate individual responses to the patient health questionnaire and general anxiety disorder questionnaire using a unique, nationally representative data set. Our findings suggest that essential healthcare workers reported the highest rates of mental health distress at the beginning of the coronavirus pandemic. However, when evaluated across race and ethnicity, we find that Black essential healthcare workers disproportionately report symptoms of anxiety; while, Hispanic essential healthcare workers disproportionately report symptoms of depression. Additionally, we find that being a Black or Hispanic essential nonhealthcare worker is associated with higher levels of distress related to anxiety and depression. These findings highlight the additional dimensions to which Black and Hispanic Americans may be disproportionately affected by the coronavirus pandemic. Furthermore, it calls into question how the essential worker classification, compounded by US unemployment policies, is potentially amplifying the mental health distress experienced by workers.

Cancer-related cognitive impairment is associated with perturbations in inflammatory pathways.

Cancer-related cognitive impairment (CRCI) is a significant problem for patients receiving chemotherapy. While a growing amount of pre-clinical and clinical evidence suggests that inflammatory mechanisms underlie CRCI, no clinical studies have evaluated for associations between CRCI and changes in gene expression. Therefore, the purpose of this study was to evaluate for differentially expressed genes and perturbed inflammatory pathways across two independent samples of patients with cancer who did and did not report CRCI. The Attentional Function Index (AFI) was the self-report measure used to assess CRCI. AFI scores of <5 and of >7.5 indicate low versus high levels of cognitive function, respectively. Of the 185 patients in Sample 1, 49.2% had an AFI score of <5 and 50.8% had an AFI score of >7.5. Of the 158 patients in Sample 2, 50.6% had an AFI score of <5 and 49.4% had an AFI score of >7.5. Data from 182 patients in Sample 1 were analyzed using RNA-seq. Data from 158 patients in Sample 2 were analyzed using microarray. Twelve KEGG signaling pathways were significantly perturbed between the AFI groups, five of which were signaling pathways related to inflammatory mechanisms (e.g., cytokine-cytokine receptor interaction, tumor necrosis factor signaling). This study is the first to describe perturbations in inflammatory pathways associated with CRCI. Findings highlight the role of cytokines both in terms of cytokine-specific pathways, as well as pathways involved in cytokine production and cytokine activation. These findings have the potential to identify new targets for therapeutics and lead to the development of interventions to improve cognition in patients with cancer.

Non-Motor Fluctuations in Parkinson's Disease: Validation of the Non-Motor Fluctuation Assessment Questionnaire.

BACKGROUND: In patients with Parkinson's disease (PD), sleep, mood, cognitive, autonomic, and other non-motor symptoms may fluctuate in a manner similar to motor symptoms. OBJECTIVES: To validate a final version of a patient-rated questionnaire that captures the presence and severity of non-motor fluctuations in levodopa-treated PD patients (NoMoFA). METHODS: We recruited PD subjects from five movement disorders centers across the US and Canada. We assessed the internal consistency, floor and ceiling effects, test-retest reliability, and concurrent validity of NoMoFA. Classical test theory and item response theory methods informed item reduction and Delphi process yielded a final questionnaire. RESULTS: Two hundred subjects and their care-partners participated in the study (age: 66.4 ± 9.6 years; disease duration: 9 ± 5.5 years; median Hoehn and Yahr [H&Y] OFF: 3 [range 1-5]; mean Unified Parkinson's Disease Rating Scale (UPDRS) III ON score: 27.4 ± 14.9). Acceptability of the scale was adequate. There were floor effects in 8/28 items. Cronbach's alpha was 0.894. While eight items had "item-to-total" correlations below the cutoff of 0.4, removing these items did not improve Cronbach's alpha. Test-retest reliability was acceptable (intraclass correlation coefficient [ICC] 0.73; 95% confidence interval, 0.64-0.80). Concurrent validity was adequate with all Spearman's rho values comparing NoMoFA score to other measures of parkinsonian severity showing significance and in the expected direction. A final Delphi panel eliminated one item to avoid redundancy. CONCLUSIONS: The final 27-item self-administered NoMoFA is a valid and reliable questionnaire, capturing both static and fluctuating non-motor symptoms in PD. © 2021 International Parkinson and Movement Disorder Society.

A novel in-home digital treatment to improve processing speed in people with multiple sclerosis: A pilot study.

OBJECTIVE: To assess whether a videogame-like digital treatment is superior to a control in improving processing speed in adults with multiple sclerosis (MS). METHODS: Adults with MS and baseline Symbol Digit Modalities Test (SDMT) z-scores between -2 and 0 were enrolled in a double-blind randomized controlled clinical trial. After completing a baseline in-clinic evaluation (Visit 1), they were randomized to complete an in-home, tablet-based videogame-like digital treatment (AKL-T03) or control word game (AKL-T09) for up to 25 minutes/day, 5 days/week, for 6 weeks. A repeat in-clinic evaluation occurred at 6 weeks (Visit 2), and again 8 weeks later to determine persistence of effects (Visit 3). The pre-specified primary outcome was change in SDMT score between Visits 1 and 2. RESULTS: SDMT increased at Visit 2 for participants randomized to both AKL-T03 (p < 0.001) and AKL-T09 (p = 0.024). These respective mean improvements were +6.10 and +3.55 (comparison p = 0.21). At Visit 3, 70% of participants randomized to AKL-T03 maintained a clinically meaningful 4+-point increase in SDMT above their baseline, compared with 37% for AKL-T09 (p = 0.038). CONCLUSION: This in-home digital intervention resulted in substantial and durable improvements in processing speed. A larger randomized controlled clinical trial is planned. TRIAL REGISTRATION: This trial is registered on ClinicalTrials.gov under "NCT03569618," https://clinicaltrials.gov/ct2/show/NCT03569618.

Correction: Application of an Adaptive, Digital, Game-Based Approach for Cognitive Assessment in Multiple Sclerosis: Observational Study.

[This corrects the article DOI: 10.2196/24356.].

Assessing Cognitive Function in Multiple Sclerosis With Digital Tools: Observational Study.

BACKGROUND: Cognitive impairment (CI) is one of the most prevalent symptoms of multiple sclerosis (MS). However, it is difficult to include cognitive assessment as part of MS standard care since the comprehensive neuropsychological examinations are usually time-consuming and extensive. OBJECTIVE: To improve access to CI assessment, we evaluated the feasibility and potential assessment sensitivity of a tablet-based cognitive battery in patients with MS. METHODS: In total, 53 participants with MS (24 [45%] with CI and 29 [55%] without CI) and 24 non-MS participants were assessed with a tablet-based cognitive battery (Adaptive Cognitive Evaluation [ACE]) and standard cognitive measures, including the Symbol Digit Modalities Test (SDMT) and the Paced Auditory Serial Addition Test (PASAT). Associations between performance in ACE and the SDMT/PASAT were explored, with group comparisons to evaluate whether ACE modules can capture group-level differences. RESULTS: Correlations between performance in ACE and the SDMT (R=-0.57, P<.001), as well as PASAT (R=-0.39, P=.01), were observed. Compared to non-MS and non-CI MS groups, the CI MS group showed a slower reaction time (CI MS vs non-MS: P<.001; CI MS vs non-CI MS: P=.004) and a higher attention cost (CI MS vs non-MS: P=.02; CI MS vs non-CI MS: P<.001). CONCLUSIONS: These results provide preliminary evidence that ACE, a tablet-based cognitive assessment battery, provides modules that could potentially serve as a digital cognitive assessment for people with MS. TRIAL REGISTRATION: ClinicalTrials.gov NCT03569618; https://clinicaltrials.gov/ct2/show/NCT03569618.

Trunk Muscle Endurance in Individuals With and Without a History of Anterior Cruciate Ligament Reconstruction.

ABSTRACT: Werner, DM and Barrios, JA. Trunk muscle endurance in individuals with and without a history of anterior cruciate ligament reconstruction. J Strength Cond Res 35(1): 118-123, 2021-Anterior cruciate ligament (ACL) rupture is one of the most common knee injuries and often leads to surgery. Second injury after an ACL reconstruction (ACLR) is a major risk after rehabilitation, and may be linked to persistent postoperative deficits in muscular strength and endurance. Trunk muscle endurance has not been well studied after ACLR. Therefore, the purpose of this study was to compare trunk endurance using the established McGill testing battery in 20 individuals who had previously undergone ACLR at least 1 year before with 20 controls matched for sex frequency, limb dominance, age, body mass index, and activity level. Four static positional holds to failure were performed in random order, with time in seconds recorded as the primary dependent variable. Mann-Whitney U tests using an alpha level of 0.05 were conducted comparing hold times for all positions between groups. Effect sizes were also calculated between groups. Deficits in trunk extension endurance were observed in the surgical group. The results of this study suggest that contemporary rehabilitation schemes after ACLR do not fully address trunk endurance deficits. Health care professionals delivering postoperative rehabilitation after ACLR may consider direct assessment of trunk endurance and targeted exercise training to address potential deficits.

Mechanisms for Pd-Au enrichment in porphyry-epithermal ores of the Elatsite deposit, Bulgaria.

Porphyry Cu can contain significant concentrations of platinum-group elements (PGE: Os, Ir, Ru, Rh, Pt, Pd). In this study, we provide a comprehensive in situ analysis of noble metals (PGE, Au, Ag) for (Cu-Fe)-rich sulfides from the Elatsite, one of the world's PGE-richest porphyry Cu deposits. These data, acquired using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), indicate that Pd was concentrated in all the (Cu-Fe)-rich sulfides at ppm-levels, with higher values in pyrite (~6 ppm) formed at the latest epithermal stage (i.e., quartz-galena-sphalerite assemblage) than in bornite and chalcopyrite (<5 ppm) from the hypogene quartz-magnetite-bornite-chalcopyrite ores. Likewise, Au is significantly more concentrated in pyrite (~5 ppm) than in the (Cu-Fe)-rich sulfides (≤0.08 ppm). In contrast, Ag reaches hundreds of ppm in pyrite and bornite (~240 ppm) but is in much lesser amounts in chalcopyrite (<25 ppm). The inspection of the time-resolved spectra collected during LA-IPC-MS analyses indicates that noble metals are present in the sulfides in two forms: (1) structurally bound (i.e., solid solution) in the lattice of sulfides and, (2) as nano- to micron-sized inclusions (Pd-Te and Au). These observations are further confirmed by careful investigations of the PGE-rich (Cu-Fe)-rich sulfides by combining high-spatial resolution of field emission scanning electron microscope (FESEM) and focused ion beam and high-resolution transmission electron microscopy (FIB/HRTEM). A typical Pd-bearing mineral includes the composition PdTe2 close to the ideal merenskyite but with a distinct crystallographic structure, whereas Au is mainly found as native element. Our detailed mineralogical study coupled with previous knowledge on noble-metal inclusions in the studied ores reveals that noble metal enrichment in the Elatsite porphyry ores was mainly precipitated from droplets of Au-Pd-Ag telluride melt (s) entrained in the high-temperature hydrothermal fluid. These telluride melts could separate at the time of fluid unmixing from the silicate magma or already be present in the latter either derived from deep-seated crustal or mantle sources. Significant enrichment in Pd and Au (the latter correlated with As) in low-temperature pyrite is interpreted as remobilization of these noble metals from pre-existing hypogene ores during the epithermal overprinting.

Score-based tests for detecting heterogeneity in linear mixed models.

Cross-level interactions among fixed effects in linear mixed models (also known as multilevel models) can be complicated by heterogeneity stemming from random effects and residuals. When heterogeneity is present, tests of fixed effects (including cross-level interaction terms) are subject to inflated type I or type II error. While the impact of variance change/heterogeneity has been noticed in the literature, few methods have been proposed to detect this heterogeneity in a simple, systematic way. In addition, when heterogeneity among clusters is detected, researchers often wish to know which clusters' variances differed from the others. In this study, we utilize a recently proposed family of score-based tests to distinguish between cross-level interactions and heterogeneity in variance components, also providing information about specific clusters that exhibit heterogeneity. These score-based tests only require estimation of the null model (when variance homogeneity is assumed to hold), and they have been previously applied to psychometric models to detect measurement invariance. In this paper, we extend the tests to linear mixed models, allowing us to use the tests to differentiate between interaction and heterogeneity. We detail the tests' implementation and performance via simulation, provide an empirical example of the tests' use in practice, and provide code illustrating the tests' general application.

Enhanced Attention Using Head-mounted Virtual Reality.

Some evidence suggests that experiencing a given scenario using virtual reality (VR) may engage greater attentional resources than experiencing the same scenario on a 2D computer monitor. However, the underlying neural processes associated with these VR-related effects, especially those pertaining to current consumer-friendly head-mounted displays of virtual reality (HMD-VR), remain unclear. Here, two experiments were conducted to compare task performance and EEG-based neural metrics captured during a perceptual discrimination task presented on two different viewing platforms. Forty participants (20-25 years old) completed this task using both an HMD-VR and traditional computer monitor in a within-group, randomized design. Although Experiment I (n = 20) was solely behavioral in design, Experiment II (n = 20) utilized combined EEG recordings to interrogate the neural correlates underlying potential performance differences across platforms. These experiments revealed that (1) there was no significant difference in the amount of arousal measured between platforms and (2) selective attention abilities in HMD-VR environment were enhanced from both a behavioral and neural perspective. These findings suggest that the allocation of attentional resources in HMD-VR may be superior to approaches more typically used to assess these abilities (e.g., desktop/laptop/tablet computers with 2D screens).