An Investigation of the Impact of Embedding Learning Strategies into Developmental Mathematics Curriculum

More than two-thirds of first-year community college students require remediation in reading and/or mathematics before they can take college-level courses. Among these underprepared students who take the recommended developmental mathematics courses to become college-ready, less than one-third successfully complete these courses, posing a barrier to their access to a college education. Developmental education has been criticized and has undergone various institutional reforms, but limited research has investigated the mathematical perspectives of community college students in developmental mathematics courses. The two research questions that I investigated were: what effects does taking a developmental mathematics course that incorporates learning and study strategies have on students’ strategic learning skills; and how do students in a developmental mathematics course incorporating learning and study strategies describe their learning experiences? The theoretical frameworks of social cognitive theory and the framework for student success (productive persistence) guided the design of my investigation. To conduct this investigation, I used a mixed methods design, gathering both quantitative and qualitative data from 65 participants enrolled in a developmental mathematics course using a reform-oriented curriculum at a community college. Participants took the 60-item Learning and Study Strategies Inventory (LASSI) early in the course and again near the end of the course, completing written reflections on a brief survey after each LASSI. I examined quantitative data addressing the first research question, followed by a qualitative analysis of survey data that address the second research question. To gain further insights, I conducted interviews with 10 participants after each LASSI. The quantitative analysis of the change in LASSI scores over the course of the semester revealed increases in some learning and study strategies. This was supported with comments from students in both written surveys and interviews. I present evidence of how taking a developmental mathematics course using reform-oriented curriculum both lowered Anxiety and improved Information Processing among the n=65, as well as improved Concentration and bolstered Using Academic Resources among the 10 interviewees. The qualitative analysis of the written surveys and interview data revealed more insights about the students’ learning experiences in the classroom both related to, and extending beyond, the 10 learning and study strategies assessed by the LASSI scales. Supporting evidence from written surveys and interview data led to five additional emergent themes impacting the student experience: Doing College, Barriers, Teacher Impact, Groupwork, and Growth Mindset. These factors were largely non-cognitive in nature, revealing psychological factors that influenced student persistence and student success. A discussion of limitations, suggestions, and recommendations for future research is also included

Multidimensional integration of absorbances: An approach to absolute analyte detection

The problem of absolute analyte detection is considered in this paper. It is shown that integration in absorbance, not in intensity, is a pre-requisite for absolute detection in atomic absorption spectrometry. A design for an atomic absorption spectrometer of the future is described which measures absorbance resolved in three key areas: wavelength, space and time. Intensity must be measured with sufficient temporal, spatial and spectral resolution to guarantee the accuracy of the computed absorbance. Technically, such measurements can be made simultaneously with a continuum source, a high resolution echelle spectrometer and a two dimensional solid-state array detector. All computed absorbances are fully background and stray light corrected. With such measurements, and a proper optical configuration, absolute analyte detection can become a reality and the possibility of absolute analysis becomes more obtainable

Analytical Challenges and Metrological Approaches to Ensuring Dietary Supplement Quality: International Perspectives

The increased utilization of metrology resources and expanded application of its’ approaches in the development of internationally agreed upon measurements can lay the basis for regulatory harmonization, support reproducible research, and advance scientific understanding, especially of dietary supplements and herbal medicines. Yet, metrology is often underappreciated and underutilized in dealing with the many challenges presented by these chemically complex preparations. This article discusses the utility of applying rigorous analytical techniques and adopting metrological principles more widely in studying dietary supplement products and ingredients, particularly medicinal plants and other botanicals. An assessment of current and emerging dietary supplement characterization methods is provided, including targeted and non-targeted techniques, as well as data analysis and evaluation approaches, with a focus on chemometrics, toxicity, dosage form performance, and data management. Quality assessment, statistical methods, and optimized methods for data management are also discussed. Case studies provide examples of applying metrological principles in thorough analytical characterization of supplement composition to clarify their health effects. A new frontier for metrology in dietary supplement science is described, including opportunities to improve methods for analysis and data management, development of relevant standards and good practices, and communication of these developments to researchers and analysts, as well as to regulatory and policy decision makers in the public and private sectors. The promotion of closer interactions between analytical, clinical, and pharmaceutical scientists who are involved in research and product development with metrologists who develop standards and methodological guidelines is critical to advance research on dietary supplement characterization and health effects

Pesticides in house dust from urban and farmworker households in California: an observational measurement study

<p>Abstract</p> <p>Background</p> <p>Studies report that residential use of pesticides in low-income homes is common because of poor housing conditions and pest infestations; however, exposure data on contemporary-use pesticides in low-income households is limited. We conducted a study in low-income homes from urban and agricultural communities to: characterize and compare house dust levels of agricultural and residential-use pesticides; evaluate the correlation of pesticide concentrations in samples collected several days apart; examine whether concentrations of pesticides phased-out for residential uses, but still used in agriculture (i.e., chlorpyrifos and diazinon) have declined in homes in the agricultural community; and estimate resident children's pesticide exposures via inadvertent dust ingestion.</p> <p>Methods</p> <p>In 2006, we collected up to two dust samples 5-8 days apart from each of 13 urban homes in Oakland, California and 15 farmworker homes in Salinas, California, an agricultural community (54 samples total). We measured 22 insecticides including organophosphates (chlorpyrifos, diazinon, diazinon-oxon, malathion, methidathion, methyl parathion, phorate, and tetrachlorvinphos) and pyrethroids (allethrin-two isomers, bifenthrin, cypermethrin-four isomers, deltamethrin, esfenvalerate, imiprothrin, permethrin-two isomers, prallethrin, and sumithrin), one phthalate herbicide (chlorthal-dimethyl), one dicarboximide fungicide (iprodione), and one pesticide synergist (piperonyl butoxide).</p> <p>Results</p> <p>More than half of the households reported applying pesticides indoors. Analytes frequently detected in both locations included chlorpyrifos, diazinon, permethrin, allethrin, cypermethrin, and piperonyl butoxide; no differences in concentrations or loadings were observed between locations for these analytes. Chlorthal-dimethyl was detected solely in farmworker homes, suggesting contamination due to regional agricultural use. Concentrations in samples collected 5-8 days apart in the same home were strongly correlated for the majority of the frequently detected analytes (Spearman ρ = 0.70-1.00, p < 0.01). Additionally, diazinon and chlorpyrifos concentrations in Salinas farmworker homes were 40-80% lower than concentrations reported in samples from Salinas farmworker homes studied between 2000-2002, suggesting a temporal reduction after their residential phase-out. Finally, estimated non-dietary pesticide intake for resident children did not exceed current U.S. Environmental Protection Agency's (U.S. EPA) recommended chronic reference doses (RfDs).</p> <p>Conclusion</p> <p>Low-income children are potentially exposed to a mixture of pesticides as a result of poorer housing quality. Historical or current pesticide use indoors is likely to contribute to ongoing exposures. Agricultural pesticide use may also contribute to additional exposures to some pesticides in rural areas. Although children's non-dietary intake did not exceed U.S. EPA RfDs for select pesticides, this does not ensure that children are free of any health risks as RfDs have their own limitations, and the children may be exposed indoors via other pathways. The frequent pesticide use reported and high detection of several home-use pesticides in house dust suggests that families would benefit from integrated pest management strategies to control pests and minimize current and future exposures.</p

Dietary flavonoid intake and risk of incident depression in midlife and older women

Background: The impact of dietary flavonoid intakes on risk of depression is unclear. Objective: We prospectively examined associations between estimated habitual intakes of dietary flavonoids and depression risk. Design: We followed 82,643 women without a previous history of depression at baseline from the Nurses’ Health Study [(NHS) aged 53–80 y] and the Nurses’ Health Study II [(NHSII) aged 36–55 y]. Intakes of total flavonoids and subclasses (flavonols, flavones, flavanones, anthocyanins, flavan-3-ols, polymeric flavonoids, and proanthocyanidins) were calculated from validated food-frequency questionnaires collected every 2–4 y. Depression was defined as physician- or clinician-diagnosed depression or antidepressant use and was self-reported in response to periodic questionnaires. Cox proportional hazards models were performed to examine associations. Results: A total of 10,752 incident depression cases occurred during a 10-y follow-up. Inverse associations between flavonol, flavone, and flavanone intakes and depression risk were observed. Pooled multivariable-adjusted HRs (95% CIs) were 0.93 (0.88, 0.99), 0.92 (0.86, 0.98), and 0.90 (0.85, 0.96) when comparing the highest (quintile 5) with the lowest (quintile 1) quintiles, respectively, with evidence of linear trends across quintiles (P-trend = 0.0004–0.08). In flavonoid-rich food-based analyses, the HR was 0.82 (95% CI: 0.74, 0.91) among participants who consumed ≥2 servings citrus fruit or juices/d compared with <1 serving/wk. In the NHS only, total flavonoids, polymers, and proanthocyanidin intakes showed significant (9–12%) lower depression risks. In analyses among late-life NHS participants (aged ≥65 y at baseline or during follow-up), for whom we were able to incorporate depressive symptoms into the outcome definition, higher intakes of all flavonoid subclasses except for flavan-3-ols were associated with significantly lower depression risk; flavones and proanthocyanidins showed the strongest associations (HR for both: 0.83; 95% CI: 0.77, 0.90). Conclusions: Higher flavonoid intakes may be associated with lower depression risk, particularly among older women. Further studies are needed to confirm these associations

Multidimensional integration of absorbances: An approach to absolute analyte detection

The problem of absolute analyte detection is considered in this paper. It is shown that integration in absorbance, not in intensity, is a pre-requisite for absolute detection in atomic absorption spectrometry. A design for an atomic absorption spectrometer of the future is described which measures absorbance resolved in three key areas: wavelength, space and time. Intensity must be measured with sufficient temporal, spatial and spectral resolution to guarantee the accuracy of the computed absorbance. Technically, such measurements can be made simultaneously with a continuum source, a high resolution echelle spectrometer and a two dimensional solid-state array detector. All computed absorbances are fully background and stray light corrected. With such measurements, and a proper optical configuration, absolute analyte detection can become a reality and the possibility of absolute analysis becomes more obtainable