1,743 research outputs found
Nutrients, Eutrophic Response, and Fish Anomalies in the Little Miami River, Ohio
Author Institution: Dept of Biological Sciences, Northern Kentucky University, Highland Heights, KYAuthor Institution: University of Cincinnati, Dept of Biological Sciences, Cincinnati, OHWe documented the eutrophic and chemical environment in the Little Miami River (LMR) to better understand the interaction between eutrophication, eutrophic response variables, and the health of aquatic organisms. Total phosphorus (TP) and soluble reactive phosphorus (SRP), nitrogen, dissolved oxygen (DO), benthic and sestonic algal biomass, benthic phosphorus storage, aqueous trace metals (Cd, Cr, Cu, Se, Zn), heavy metals (Al, Fe, Mn) and major cations (Ca, K, Mg, Na, Si) were analyzed at
twelve sites over two summers. Results showed excess TP (>70 ug/L, p <0.05) and SRP (≥62.5 ug/L, p <0.05), borderline nuisance benthic algal biomass (mg/L chlorophyll a/m2) (periphyton: mean = 73.8 +/- 74.2,
n = 125; Cladophora: mean = 216.7 +/- 380.7, n = 54), excess benthic phosphorus storage (mg P/m2) (periphyton: mean = 45.5 +/- 23.2, n = 64; Cladophora: mean = 129.3 +/- 224, n = 52), and high daytime DO (mean = 9.1 +/- 1.5 mg/L, n = 132). Previous studies showed aqueous phosphorus concentration and diurnal DO swings were positively correlated with fish anomalies (OEPA 1995, 2000). In this study, however, periphyton phosphorus (P) was the only eutrophic response variable to correlate with the distribution of fish anomalies reported by OEPA in 1995 and 2000, and the association was negative (R2 =
0.143, p = 0.002, m = -1.634, df = 1, 62). We concluded that aqueous nutrients, eutrophic response variables, and/or water chemistry alone did not explain the occurrence of fish anomalies in the LMR
The NexSTEM Program: A Community Assets Program that Fosters the Next Generation of STEM Leaders
Underrepresentation in science, technology, engineering, and mathematics (STEM) fields by individuals with low socioeconomic status (SES) is a long-standing concern. Funded in late 2018, the NexSTEM Program (the “Program”) is a National Science Foundation multi-institution consortia S-STEM grant-funded program at Illinois Wesleyan University (IWU), Illinois State University (ISU), and Heartland Community College (HCC) with the goal of reducing barriers for low SES students from Central Illinois enrolling in and completing STEM degree programs at the three institutions and identifying effective, and sustainable, programmatic components. To help address barriers, the Program awards 2- and 4-year scholarships to academically successful students with significant financial need, and pairs the scholarships with multi-level mentoring, academic supports, and hands-on STEM research project involvement beginning in the first semester of college for both 2-year and 4-year students. Uniquely, HCC students who want to transfer to IWU or ISU can take their scholarship with them as they complete their 4-year STEM degree. The Program has now onboarded 2 cohorts of largely Pell-eligible first year students pursuing an eligible STEM major at one of the three IHEs. This presentation will discuss program structure, interim outcomes related to the current cohorts, and implications for the efficacy of this model in improving retention and representation in STEM
Optical tweezers: wideband microrheology
Microrheology is a branch of rheology having the same principles as
conventional bulk rheology, but working on micron length scales and micro-litre
volumes.
Optical tweezers have been successfully used with Newtonian fluids for
rheological purposes such as determining fluid viscosity. Conversely, when
optical tweezers are used to measure the viscoelastic properties of complex
fluids the results are either limited to the material's high-frequency
response, discarding important information related to the low-frequency
behavior, or they are supplemented by low-frequency measurements performed with
different techniques, often without presenting an overlapping region of clear
agreement between the sets of results. We present a simple experimental
procedure to perform microrheological measurements over the widest frequency
range possible with optical tweezers. A generalised Langevin equation is used
to relate the frequency-dependent moduli of the complex fluid to the
time-dependent trajectory of a probe particle as it flips between two optical
traps that alternately switch on and off.Comment: 13 pages, 6 figures, submitted to Special Issue of the Journal of
Optic
Measuring storage and loss moduli using optical tweezers: broadband microrheology
We present an experimental procedure to perform broadband microrheological
measurements with optical tweezers. A generalised Langevin equation is adopted
to relate the time-dependent trajectory of a particle in an imposed flow to the
frequency-dependent moduli of the complex fluid. This procedure allows us to
measure the material linear viscoelastic properties across the widest frequency
range achievable with optical tweezers.Comment: 5 pages, 3 figure
Feasibility of a self-completed history questionnaire in women requesting repeat combined hormonal contraception.
OBJECTIVE: To measure agreement between the client's and the clinician's responses to questions regarding client history as answered on a questionnaire based on the UK Medical Eligibility Criteria for Contraceptive Use (UKMEC) for combined hormonal contraception (CHC). METHODS: Clients aged 18 years and over, attending a central London community contraceptive clinic requesting a repeat supply of CHC, completed a history questionnaire and an evaluation form. Clinicians then completed their copy of the same questionnaire during the consultation. Percentage agreement and the Kappa statistic were used to assess the level of client-clinician agreement. RESULTS: Data from 328 client-clinician pairs were analysed. Agreement was above 93% for all identified risk factors. There was complete agreement for thrombosis, diabetes, stroke, cancer and liver problems. Least agreement was noted in the recording of migraine and abnormal bleeding. For all risk factors except smoking, the proportion of clients reporting a risk factor was more than the proportion of clinicians reporting a risk factor. No clinically important information relevant to a particular client's use of CHC was missed and none of them would have been wrongly prescribed the CHC based just on their self-completed questionnaires. Most women (97%) were happy with this method of history taking. CONCLUSIONS: A self-completed history questionnaire is acceptable to women and can potentially replace traditional routine medical history taking for continuing CHC. Women completed the questionnaire with a high degree of reliability. There was complete client-clinician agreement on UKMEC Category 4 criteria. Overall, clients reported more risk factors than clinicians, which increases the safety of the questionnaire
Degradation and forgone removals increase the carbon impact of intact forest loss by 626%
Intact tropical forests, free from substantial anthropogenic influence, store and sequester large amounts of atmospheric carbon but are currently neglected in international climate policy. We show that between 2000 and 2013, direct clearance of intact tropical forest areas accounted for 3.2% of gross carbon emissions from all deforestation across the pantropics. However, full carbon accounting requires the consideration of forgone carbon sequestration, selective logging, edge effects, and defaunation. When these factors were considered, the net carbon impact resulting from intact tropical forest loss between 2000 and 2013 increased by a factor of 6 (626%), from 0.34 (0.37 to 0.21) to 2.12 (2.85 to 1.00) petagrams of carbon (equivalent to approximately 2 years of global land use change emissions). The climate mitigation value of conserving the 549 million ha of tropical forest that remains intact is therefore significant but will soon dwindle if their rate of loss continues to accelerate
Microrheology with optical tweezers: data analysis
We present a data analysis procedure that provides the solution to a long-standing issue in microrheology studies, i.e. the evaluation of the fluids' linear viscoelastic properties from the analysis of a finite set of experimental data, describing (for instance) the time-dependent mean-square displacement of suspended probe particles experiencing Brownian fluctuations. We report, for the first time in the literature, the linear viscoelastic response of an optically trapped bead suspended in a Newtonian fluid, over the entire range of experimentally accessible frequencies. The general validity of the proposed method makes it transferable to the majority of microrheology and rheology techniques
Psychiatric diagnoses and criminal convictions in youth: a population-based study of comorbidities of diagnoses
Background: Psychiatric diagnoses are important risk factors for criminal convictions, but few longitudinal studies have examined comorbidity patterns in relation to youth criminal convictions.
Aim: To explore associations between specific psychiatric diagnoses (substance use disorder (SUD), ADHD, depression, PTSD, intellectual disabilities (ID), and autism spectrum disorders (ASD)) and comorbidities of internalizing, externalizing, or neurodevelopmental diagnoses (NDD) in relation to risk of non-violent or violent criminal convictions in youth, including potential sex differences.
Methods: Data on 1,411,538 individuals born in Sweden (1985–1998) were obtained from national population-based registers. Exposure was psychiatric diagnoses and outcome was criminal convictions between ages 15 and 20.
Results: 17% of individuals had a psychiatric diagnosis, of whom 20% were convicted of a crime. All diagnoses, except ID and ASD, increased the risk of non-violent and violent crimes. Comorbidities of externalizing and internalizing diagnoses heightened the risk compared to single diagnoses. NDD increased the risk among SUD, depression, and PTSD, while NDD comorbid with another NDD decreased the risk for criminal convictions.
Conclusion: Of the three comorbidity categories, externalizing disorders heightened risk the most, followed by internalizing disorders. This study highlights specific risk patterns for criminal convictions related to comorbidities, and to crime type and sex
Pregnancy in teenagers diagnosed with type 1 diabetes mellitus in childhood: a national population-based e-cohort study
The aim of this study was to describe the characteristics and outcomes of pregnancies in a national cohort of teenage (<20 years) and young adult women (≥20 years) with and without childhood-onset (<15 years) type 1 diabetes. We hypothesised that, owing to poor glycaemic control during the teenage years, pregnancy outcomes would be poorer in teenage mothers with type 1 diabetes than young adult mothers with type 1 diabetes and mothers without diabetes
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