Boundary exchange completes the marine Pb cycle jigsaw.

Material fluxes at the land-ocean interface impact seawater composition and global cycling of elements. However, most attention has been focused on the fluvial dissolved fluxes. For elements like lead (Pb), whose fluvial particulate flux into the ocean is two orders of magnitude higher than the dissolved counterpart, the role of particulates in elemental cycling is potentially important but currently less appreciated. Using both chemical analyses on samples collected from around equatorial Southeast Asia and model simulations, we show that particulate-dissolved exchange is an important mechanism controlling the concentration and isotopic composition of dissolved Pb in the ocean. Our model indicates that Pb contributed from particulate-dissolved exchange at ocean boundaries is larger than, or at least comparable to, other major Pb sources to the seawater before the Anthropocene, when the anthropogenic Pb was absent. Our work highlights the importance of boundary exchange in understanding marine element cycling and weathering-climate feedback.

Effects of climate change on forest plantation productivity in Chile.

Forest plantations in Chile occupy more than 2.2 million ha and are responsible for 2.1% of the GDP of the country's economy. The ability to accurately predictions of plantations productivity under current and future climate has an impact can enhance on forest management and industrial wood production. The use of process-based models to predict forest growth has been instrumental in improving the understanding and quantifying the effects of climate variability, climate change, and the impact of atmospheric CO2 concentration and management practices on forest growth. This study uses the 3-PG model to predict future forest productivity Eucalyptus globulus and Pinus radiata. The study integrates climate data from global circulation models used in CMIP5 for scenarios RCP26 and RCP85, digital soil maps for physical and chemical variables. Temporal and spatial tree growth inventories were used to compare with the 3-PG predictions. The results indicated that forest productivity is predicted to potentially increase stand volume (SV) over the next 50 years by 26% and 24% for the RCP26 scenario and between 73% and 62% for the RCP85 scenario for E. globulus and P. radiata, respectively. The predicted increases can be explained by a combination of higher level of atmospheric CO2 , air temperatures closer to optimum than current, and increases in tree water use efficiency. If the effect of CO2 is not considered, the predicted differences of SV for 2070 are 16% and 14% for the RCP26 scenario and 22% and 14% for RCP85 for the two species. While shifts in climate and increasing CO2 are likely to benefit promote higher productivity, other factors such as lack insufficient availability of soil nutrients, events such as increasing frequency and duration of droughts, longer periods of extreme temperatures, competing vegetation, and occurrence of new pests and diseases may compromise these potential gains.

Monsoonal variations of lead (Pb) in coastal waters around Singapore.

Anthropogenic lead (Pb) has been the overwhelming Pb source to the global ocean, primarily contributed from Pb gasoline and industrial emissions. However, since Pb gasoline has been phased out globally, questions about whether there was a decrease in seawater Pb concentration, or if there are other sources taking over remains unclear in Southeast Asia. Here, combining Pb concentrations in seawater from Singapore Strait in 2010-2017; trap sediment in 2018-2019; and the previously published coral reconstruction covering 1975-2010; we found that the seawater Pb concentration in Singapore Strait over past decades followed the regional gasoline emissions, and no additional major source had contributed the Pb in the seawater since ~2010. The present-day Pb in Singapore Straits' water mainly follows the monsoonal current reversals, with variable degrees of scavenging that peak in inter-monsoon season. Minor Pb sources still contribute to some local-scale variabilities, despite a decadal-scale decreasing trend of Pb in seawater.

Implementation of team-based learning (TBL) in a second year medical school course: does prior experience with TBL improve the impact of this pedagogy?

BACKGROUND: We have shown that use of Team-based learning (TBL) in a first-year Infectious Diseases (ID) course improved final examination and course performance. Therefore, we implemented TBL in the second-year Women's Health (WH) course to improve acquisition of course content. We hypothesized that prior experience with TBL in the first-year of medical school would lead to a strong correlation between TBL performance in the first and second years. METHODS: Our study is a retrospective review of student TBL and final examination performance in the ID and WH courses. The ID course has weekly TBL exercises that cover all course material, while the WH course has one TBL that covers a small portion of the course material. Final examination and TBL individual readiness assurance test (iRAT) scores in the ID and WH courses from three classes (n = 226) were obtained with institutional review board approval. Statistical analyses were performed including comparisons of means and correlation studies. RESULTS: Average WH iRAT scores were significantly higher than ID iRAT scores (9.19 vs. 7.40,p < 0.01), and iRAT scores in both courses were highly correlated (r = 0.35,p < 0.01). When stratifying students based on WH course performance, in struggling students, iRAT but not final examination scores were higher in the WH course than the ID course (8.73 vs. 7.00,p < 0.01 and 82.45 vs. 80.51,p > 0.05, respectively). CONCLUSIONS: Our results suggest that prior experience with TBL improves TBL iRAT scores, especially in struggling students. Prior TBL experience is also associated with consistent iRAT performance between first- and second-year courses in high performing students.

Weekly team-based learning scores and participation are better predictors of successful course performance than case-based learning performance: role of assessment incentive structure.

BACKGROUND: Incentives for preparation and participation in case-based (CBL) and team-based learning (TBL) differ by virtue of differences in assessment, allowing us to evaluate the role these incentives play in preparation and participation in these activities as well as overall course performance. METHODS: Weekly TBL and CBL participation and performance as well as performance on the course final examination were recorded. Student participation was quantified and correlated with: (1) CBL preparation, participation, teamwork and completion of learning objectives scores, and (2) TBL individual readiness assurance test (iRAT) scores. RESULTS: Student final examination scores (n = 95) were more strongly correlated with TBL than CBL performance. No significant correlation was found between iRAT and CBL scores. Student participation was measured in 3 CBL groups (8 students/group) and 4 TBL teams (6 students/team). TBL participation was more strongly correlated with final examination scores than CBL participation. TBL participation was also correlated with iRAT scores. CBL scores for preparation, participation, teamwork and completion of learning objectives did not significantly correlate with iRAT scores or TBL participation. CONCLUSION: These results suggest that the assessment incentives and methods used in TBL result in student performance that better predicts performance on summative examinations.

Effectiveness of a Team-Based Learning exercise in the learning outcomes of a medical pharmacology course: insight from struggling students.

We have previously reported that multiple Team-Based Learning (TBL™) exercises in a 4-week pre-clinical medical school course improved final exam performance and significantly reduced the number of course failures. Here, we conducted a long-term study, with eight cohorts of first-year medical students, to determine whether the implementation of a single TBL individual readiness assessment test (iRAT) exercise in a 4-week medical school pharmacology course produces similar effects in overall course performance. We implemented a single TBL iRAT exercise that covered the subjects addressed during one week of the medical pharmacology course, with the four most recent cohorts of students matriculating at Cooper Medical School of Rowan University (n = 403). The first four cohorts matriculating at CMSRU did not participate in the TBL exercises (n = 266). Correlation of individual student TBL iRAT and final examination scores in the medical pharmacology course was compared to a second, unrelated first-year course (physiology) to control for variation in student performance between cohorts. We found that there was a significant moderate correlation between final examination and TBL iRAT scores (r = 0.49, p < 0.01, n = 403). Interestingly this moderate correlation was seen in students performing in the lower 25th percentile on the course final examination (r = 0.41, p < 0.01, n = 101) and negligible in students performing in the upper 25th percentile (r = 0.11, n = 101, p > 0.05). Implementation of the single TBL exercise also significantly reduced variance or range of student final examination performance compared to the group of the first four cohorts. These results suggest that implementation of a single TBL exercise, which covers only one week of content delivered in a 1-month medical pharmacology course, benefits first-year medical students by reducing the disparity in knowledge acquisition among them and providing a means to identify students who may struggle with course content.

Cannabinoid 2 receptors regulate dopamine 2 receptor expression by a beta-arrestin 2 and GRK5-dependent mechanism in neuronal cells.

We have previously reported that the repeated exposure to cannabinoids upregulates and enhances the activity of serotonin 2A (5-HT2A) and dopamine 2 (D2) receptors and facilitates the formation of D2-5-HT2A receptor heterodimers in the rat prefrontal cortex and two neuronal cell lines. Because the repeated exposure to cannabinoids has been associated with adverse neuropsychiatric disorders, this study investigated the mechanisms that underly the cannabinoid-mediated regulation of D2 receptor expression in a neuronal cell model, CLU213 cells. We initially tested the effects of repeated exposure (72 h) to a non-selective cannabinoid agonist (1 nM CP55940), a selective CB1 receptor agonist (15 nM ACEA), or a selective CB2 receptor drug (1 nM GP1a) on the expression of postsynaptic D2 (D2L) receptors in CLU213 cells. Repeated CP55940, GP1a, or ACEA treatments significantly increased D2L receptor protein levels (99 % ± 7%, 30 % ± 7%, and 39 % ± 5% increases compared with control levels, respectively). Repeated exposure to both GP1a and ACEA increased D2L receptor protein levels by 73 % ± 8%. Interestingly, CP55940 and GP1a, but not ACEA, upregulated D2 mRNA. Using cells that were stably transfected with short-hairpin RNA (shRNA) lentiviral particles targeting CB2 receptors, G protein-coupled receptor kinase 5 (GRK5), and ß-arrestin 2, we found that CB2 receptors regulated D2 expression through a mechanism that is dependent on GRK5, ß-arrestin 2, and extracellular signal-related kinase (ERK)1/2. We also found that repeated exposure to either ACEA or GP1a selectively stimulated the protein and mRNA expression of GRK proteins. ACEA significantly upregulated GRK2 proteins, whereas GP1a upregulated GRK5 protein expression. Our results identified mechanisms associated with the upregulation of D2 receptors in neuronal cells after the repeated exposure to cannabinoids. These data can shed light on the mechanisms that can be targeted to prevent potential adverse effects, while simultaneously determining the therapeutic benefits of cannabinoids.

Assessment of Pathology Learning Modules With Virtual Microscopy in a Preclinical Medical School Curriculum.

OBJECTIVES: To evaluate the ability of pathology modules to promote learning of pathology-related course content in a preclinical medical education curriculum. METHODS: Pathology modules were created for the "Hematology/Oncology" and "Women's Health" (WH) courses. Students were recruited over 2 consecutive academic years; cohorts 1 and 2 refer to 2 separate groups of students in years 1 and 2, respectively, of the study. Course performance data were collected. RESULTS: Use of pathology modules resulted in a statistically significant higher correlation between performance on the final examination and pathology-related questions in the Hematology/Oncology course and written examination and pathology-related questions in cohort 1 in the WH course. There was statistically significant improvement (P = .026) on pathology-related laboratory practical examination questions in the WH course for cohort 1, and no other statistically significant improvement for the other cohorts and examinations. The percentage of students completing all or part of the modules was highest in the WH course for cohort 1 (60%) compared with WH course cohort 2 (33%) and Hematology/Oncology cohort 1 (30%) and cohort 2 (39%). CONCLUSIONS: Pathology modules may improve acquisition and retention of pathology-related course content when used appropriately.

Lipoprotein receptor SR-B1 deficiency enhances adipose tissue inflammation and reduces susceptibility to hepatic steatosis during diet-induced obesity in mice.

Scavenger receptor class B type 1 (SR-B1) is a membrane lipoprotein receptor/lipid transporter involved in the pathogenesis of atherosclerosis, but its role in obesity and fatty liver development is unclear. Here, we determined the effects of SR-B1 deficiency on plasma metabolic and inflammatory parameters as well as fat deposition in adipose tissue and liver during obesity. To induce obesity, we performed high-fat diet (HFD) exposure for 12 weeks in male SR-B1 knock-out (SR-B1-/-, n = 14) and wild-type (WT, n = 12) mice. Compared to HFD-fed WT mice, plasma from HFD-fed SR-B1-/- animals exhibited increased total cholesterol, triglycerides (TG) and tumor necrosis factor-α (TNF-α) levels. In addition, hypertrophied adipocytes and macrophage-containing crown-like structures (CLS) were observed in adipose tissue from HFD-fed SR-B1 deficient mice. Remarkably, liver from obese SR-B1-/- mice showed attenuated TG content, dysregulation in hepatic peroxisome proliferator-activated receptors (PPARs) expression, increased hepatic TG secretion, and altered hepatic fatty acid (FA) composition. In conclusion, we show that SR-B1 deficiency alters the metabolic environment of obese mice through modulation of liver and adipose tissue lipid accumulation. Our findings provide the basis for further elucidation of SR-B1's role in obesity and fatty liver, two major public health issues that increase the risk of advanced chronic diseases and overall mortality.

Aspectos cognitivos y legales en personas mayores: "Sano Juicio"

In Chile, 7.1% of people aged over 60 years have some type of cognitive disorder. The frequency of the latter increases to 13% in people between 75-79 years and 36.2% in people over 85 years. The concept of mild cognitive impairment (MCI) and dementia have evolved over time. The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) uses the term minor and major neurocognitive disorder, replacing the DCL and dementia respectively. Major cognitive disorder impairs functional performance while minor disorders does not. There is an arbitrary discrimination against the elderly. A form of discrimination is the request made by some notaries of a medical certification of the cognitive function for older people willing to carry out a legal procedure. This request has the sole effect of pre-establishing evidence in favor of the notary and not protecting the testator or the vulnerable person. Assessing the ability of older people to care for themselves and their possessions has important implications for them and their families, since there is a serious risk of prejudice when someone is declared as disabled. Thus, considering the epidemiology of cognitive disorders in our country we propose a series of legal and medical discussion points aimed to protect autonomy and to protect individuals and their possessions when they have difficulties to control their decisions.

[Cognitive and legal aspects in older people]. / Aspectos cognitivos y legales en personas mayores: "Sano Juicio".

In Chile, 7.1% of people aged over 60 years have some type of cognitive disorder. The frequency of the latter increases to 13% in people between 75-79 years and 36.2% in people over 85 years. The concept of mild cognitive impairment (MCI) and dementia have evolved over time. The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) uses the term minor and major neurocognitive disorder, replacing the DCL and dementia respectively. Major cognitive disorder impairs functional performance while minor disorders does not. There is an arbitrary discrimination against the elderly. A form of discrimination is the request made by some notaries of a medical certification of the cognitive function for older people willing to carry out a legal procedure. This request has the sole effect of pre-establishing evidence in favor of the notary and not protecting the testator or the vulnerable person. Assessing the ability of older people to care for themselves and their possessions has important implications for them and their families, since there is a serious risk of prejudice when someone is declared as disabled. Thus, considering the epidemiology of cognitive disorders in our country we propose a series of legal and medical discussion points aimed to protect autonomy and to protect individuals and their possessions when they have difficulties to control their decisions.

First year medical student performance on weekly team-based learning exercises in an infectious diseases course: insights from top performers and struggling students.

BACKGROUND: In Team-Based Learning (TBL) preparation of relevant coursework during self-directed learning time is evaluated by the individual readiness assurance test (iRAT). We recently reported that student performance on iRATs is strongly correlated with final examination scores in an infectious diseases (ID) course. We now investigated how student preparation for each individual iRAT exercise relates to course performance. METHODS: Two-hundred and sixty medical students were enrolled in this three-year study. Student TBL iRAT scores were collected and correlated with final examination scores using Kruskal-Wallis One-Way ANOVA and Newman-Keul's statistical methods. RESULTS: Students performing in the upper and middle 33rd percentile on the final examination showed highly significant (p < 0.01) weekly improvements in their iRAT scores. However, students performing in the lower 33rd percentile did not show improvement in their iRAT scores until the last week of the course. Although there was a highly significant correlation between final examination and iRAT scores amongst all students participating in the study, this correlation was stronger in students performing in the lower 33rd percentile. CONCLUSIONS: Our data suggest that students who do not consistently prepare for TBL, as evidenced by low iRAT scores, exhibit poorer performance on the final examination. This lack of preparation likely interferes with the efficacy of this learning method. iRAT scores can also be used for early identification of struggling students in need of additional supports. Additionally, changes in TBL incentive structure may provide more tangible rewards for pre-class preparation in particular for struggling students.

A Novel Tool for Problem-Based Learning Case Review.

The success of problem-based learning (PBL) depends on case quality and facilitator preparation. We developed a literature-based tool, the R2ICE form, to improve faculty case review. Its implementation and survey of end users showed the tool was expedient and advantageous. Literature-based tools can guide PBL construction and improve case development.

Participation in Active Learning Correlates to Higher Female Performance in a Pipeline Course for Underrepresented Students in Medicine.

This study was designed to explore the relationship between participation (measured by percentage of time spoken) in team-based learning (TBL) exercises and final examination in a 4-week medical microbiology course for college students from backgrounds underrepresented in medicine (URM). A significant correlation was found between participation and examination scores in lower performing students. Although male participation was higher, a significant correlation between participation and examination scores was found only in females. These data suggest that female participation is based on knowledge of the subject under discussion and that affirmation in TBL positively reinforces self-confidence, increasing student's efficiency during peer teaching.

Implementation of Team-Based Learning: a Tale of Two New Medical Schools.

Team-based learning (TBL) is gaining popularity at medical schools transitioning from lecture-based to active learning curricula. Here, we review challenges and opportunities faced in implementing TBL at 2 new medical schools. We discuss the importance of using meaningful TBL grades as well as the role TBL plays in developing critical reasoning skills and in early identification of struggling students. We also discuss how the concurrent use of learning strategies with different incentive structures such as problem- and case-based learning could foster the development of well-rounded physicians. We hope this monograph helps and even inspires educators implementing TBL at their schools.

A Novel Grading Strategy for Team-Based Learning Exercises in a Hands-on Course in Molecular Biology for Senior Undergraduate Underrepresented Students in Medicine Resulted in Stronger Student Performance.

We developed a hands-on course in molecular biology for undergraduate underrepresented in medicine (URM) students. To incentivize student preparation for team-based learning (TBL) activities, we implemented a novel grading schema that requires a minimum individual readiness assurance test (iRAT) score to share the team group readiness assurance test (gRAT) score. Fifty-one students participated in this 2-year study and were divided in teams of five or six students that worked throughout the course on a unique, hands-on project and also participated in TBL exercises. In the laboratory sessions, students isolated RNA from cultured neuronal cells, synthesized complementary DNA (cDNA), and used gene sequencing to identify a gene relevant in human health and disease. Student participation in TBL was quantified and correlated with performance on individual iRATs and the course final examination. We found that implementation of the novel incentive structure lowered the variance of TBL scores (iRAT and gRAT) and strengthened the correlation between final examination scores and either iRAT scores or percentage participation in TBL. Subgroup analysis showed that with the new grading schema, stronger students benefited more from the gRAT exercises, while more poorly performing students were better helped by individual preparation prior to the iRAT exercise. A combination of two active learning strategies, TBL and hands-on sessions, may strengthen student acquisition of course content and promote teamwork skills. The new incentive structure seems to reduce the disparity in knowledge amongst our students as demonstrated by the reduced iRAT and gRAT score variances. © 2018 International Union of Biochemistry and Molecular Biology, 47(2): 115-123, 2019.

Evaluation of the role of incentive structure on student participation and performance in active learning strategies: A comparison of case-based and team-based learning.

BACKGROUND: Student participation is important for the success of active learning strategies, but participation is often linked to the level of preparation. At our institution, we use two types of active learning activities, a modified case-based learning exercise called active learning groups (ALG) and team-based learning (TBL). These strategies have different assessment and incentive structures for participation. Non-cognitive skills are assessed in ALG using a subjective five-point Likert scale. In TBL, assessment of individual student preparation is based on a multiple choice quiz conducted at the beginning of each session. METHODS: We studied first-year medical student participation and performance in ALG and TBL as well as performance on course final examinations. RESULTS: Student performance in TBL, but not in ALG, was strongly correlated with final examination scores. Additionally, in students who performed in the upper 33rd percentile on the final examination, there was a positive correlation between final examination performance and participation in TBL and ALG. This correlation was not seen in students who performed in the lower 33rd percentile on the final examinations. CONCLUSIONS: Our results suggest that assessments of medical knowledge during active learning exercises could supplement non-cognitive assessments and could be good predictors of performance on summative examinations.

An update of the Pb isotope inventory in post leaded-petrol Singapore environments.

Pb is a trace metal that tracks anthropogenic pollution in natural environments. Despite recent leaded petrol phase out around Southeast Asia, the region's growth has resulted in continued exposure of Pb from a variety of sources. In this study, sources of Pb into Singapore, a highly urbanised city-state situated in the central axis of Southeast Asia, are investigated using isotopic ratios and concentrations. We compiled data from our previous analyses of aerosols, incineration fly ash and sediments, with new data from analyses of soil from gas stations, water from runoff and round-island coastal seawater to obtain a spatio-temporal overview of sources of Pb into the Singapore environment. Using 206Pb/207Pb ratio, we identified three main Pb source origins: natural Pb (1.215 ± 0.001), historic/remnant leaded petrol (1.123 ± 0.013), and present-day industrial and incinerated waste (1.148 ± 0.005). Deep reservoir sediments bore larger traces of Pb from leaded petrol, but present-day runoff waters and coastal seawater were a mix of industrial and natural sources with somewhat variable concentrations. We found temporal variability in Pb isotopic ratio in aerosols indicating alternating transboundary Pb sources to Singapore that correspond to seasonal changes in monsoon winds. By contrast, seasonal monsoon circulation did not significantly influence isotopic ratios of coastal seawater Pb. Instead, seawater Pb was driven more by location differences, suggesting stronger local-scale drivers of Pb such as point sources, water flushing, and isotope exchange. The combination of multiple historic and current sources of Pb shown in this study highlights the need for continued monitoring of Pb in Southeast Asia, especially in light of emerging industries and potential large sources of Pb such as coal combustion.

Spatial and temporal distributions of polycyclic aromatic hydrocarbons in the Northern Arabian Gulf sediments.

Surficial sediment samples were collected from 25 locations within Kuwait Bay and outside the Bay, in the Northwestern Arabian Gulf, to access recent polycyclic aromatic hydrocarbon pollution in Kuwait. Time trends in the depositional history of PAHs to this portion of the Arabian Gulf was reconstructed from the analysis of a dated sediment core. Intersite differences in concentration exist although these differences were not statistically significant (p=0.08). However, organic carbon normalized concentrations within Kuwait Bay were 4 times higher than the average concentrations outside the Bay and were shown to be statistically significant (p<0.001). The sedimentary record showed that ΣPAHs concentration fluctuated between 12 and 25ngg-1 before 1970. Concentrations then increased sharply to a maximum of 45ngg-1 around the late 1970s and early 1980s followed by an exponential decrease in concentration to pre-1970 "background" concentrations of between 12 and 25ngg-1.

Adenoid Cystic Carcinoma of Bartholin's Gland: Case Report.

Primary adenoid cystic carcinoma (ACC) of Bartholin's gland is a rare gynecologic malignancy. We report a case of locally advanced ACC of Bartholin's gland. A 62-year-old presented with left Bartholin's gland carcinoma and underwent left radical vulvectomy, left-sided inguinal-femoral lymph node dissection, posterior pelvic exenteration, and pedicle abdominal muscle flap. On her 3 months follow-up exam she was disease free.Pelvic exenteration for thetreatment of this rare disease in the vulva is a potential curative option.