A SPLIT-SAMPLE TEST OF EXPERIMENTAL DESIGNS FOR STATED CHOICE MODELS OF ENVIRONMENTAL VALUATION

A stated choice model is used to estimate wetland mitigation preferences. In a split sample mail survey, a main effects design is compared to a randomized design. Although randomized designs estimate main effects less efficiently, several policy relevant interactions were found to be significant, suggesting some merits of randomized designs.Environmental Economics and Policy,

Stated Choice Experiments with Complex Ecosystem Changes: The Effect of Information Formats on Estimated Variances and Choice Parameters

Stated choice experiments about ecosystem changes involve complex information. This study examines whether the format in which ecosystem information is presented to respondents affects stated choice outcomes. Our analysis develops a utility-maximizing model to describe respondent behavior. The model shows how alternative questionnaire formats alter respondents’ use of filtering heuristics and result in differences in preference estimates. Empirical results from a large-scale stated choice experiment confirm that different format presentations of the same information lead to different preference parameter estimates and error variances. A tabular format results in choice parameter estimates with statistically smaller variances than parameters estimated from data obtained with a text-based format. A text-based format also appears to induce greater use of decision heuristics than does a tabular format.choice experiments, heuristics, stated preference, valuation, web surveys, wetland mitigation, Crop Production/Industries, Demand and Price Analysis,

UNTYING A LANCASTRIAN BUNDLE: ECOSYSTEM VALUATION IN WETLAND MITIGATION

A utility-theoretic model indicates that mitigation prices for wetland ecosystems depend on preferences and technical knowledge. Empirical analysis found gaps in respondents' knowledge about such ecosystmes. Valuing wetland types requires dealing with respondents' possible misinformation, by developing tools for informing respondents or by combining service-based valuations with valid technical data.Resource /Energy Economics and Policy,

SPLIT-SAMPLE TESTS OF "DON'T KNOW" AND "INDIFFERENT" RESPONSES IN AN ATTRIBUTE BASED CHOICE MODEL

stated preference, contingent valuation, no opinion, internet survey, Research Methods/ Statistical Methods,

WETLAND USES AND FUNCTIONS AS PERCEIVED BY MID-MICHIGAN RESIDENTS: QUALITATIVE RESEARCH RESULTS

The following report outlines the results of focus group discussions that were conducted to help researchers learn what it is about wetlands, wetland services, and wetland characteristics that matter to people. The participants were asked questions in the areas of natural resources, their prior knowledge of wetlands, wetland types, public policies relating to wetlands, and wetland functions. The focus group discussions reported here were the first set of qualitative discussions in the research project. The purpose of the discussions was to create a basis of information concerning the respondents' perceptions and understanding of wetland uses and functions. These initial focus groups represent a first step in a larger project that will develop and test stated preference instruments for valuing ecosystem characteristics associated with freshwater wetlands. The information on respondents' uses, perceptions, and knowledge of wetland functions will be used to develop survey instruments and serve as the starting point for out wetlands research.Land Economics/Use,

Idiopathic central precocious puberty in girls: presentation factors

<p>Abstract</p> <p>Background</p> <p>It is sometimes difficult to distinguish between premature thelarche and precocious puberty in girls who develop breasts before the age of 8 years. We evaluated the frequencies of the signs associated with breast development and the factors influencing the presentation of girls with idiopathic central precocious puberty (CPP).</p> <p>Methods</p> <p>353 girls monitored 0.9 ± 0.7 year after the onset of CPP.</p> <p>Results</p> <p>The age at CPP was < 3 years in 2%, 3–7 years in 38% and 7–8 years in 60% of cases. Pubic hair was present in 67%, growth rate greater than 2 SDS in 46% and bone age advance greater than 2 years in 33% of cases. Breast development was clinically isolated in 70 (20%) cases. However, only 31 of these (8.8% of the population) had a prepubertal length uterus and gonadotropin responses to gonadotropin releasing hormone and plasma estradiol. The clinical picture of CPP became complete during the year following the initial evaluation.</p> <p>25% of cases were obese. The increase in weight during the previous year (3.7 ± 1.4 kg) and body mass index were positively correlated with the statural growth and bone age advance (P < 0.0001).</p> <p>There was no relationship between the clinical-biological presentation and the age at puberty, the interval between the onset of puberty and evaluation, or the presence of familial CPP.</p> <p>Conclusion</p> <p>The variation in presentation of girls with CPP does not depend on their age, interval between the onset and evaluation, or familial factors. This suggests that there are degrees of hypothalamic-pituitary-ovarian activation that are not explained by these factors.</p

Clinical relevance of biomarkers of oxidative stress

SIGNIFICANCE Oxidative stress is considered to be an important component of various diseases. A vast number of methods have been developed and used in virtually all diseases to measure the extent and nature of oxidative stress, ranging from oxidation of DNA to proteins, lipids, and free amino acids. Recent Advances: An increased understanding of the biology behind diseases and redox biology has led to more specific and sensitive tools to measure oxidative stress markers, which are very diverse and sometimes very low in abundance. CRITICAL ISSUES The literature is very heterogeneous. It is often difficult to draw general conclusions on the significance of oxidative stress biomarkers, as only in a limited proportion of diseases have a range of different biomarkers been used, and different biomarkers have been used to study different diseases. In addition, biomarkers are often measured using nonspecific methods, while specific methodologies are often too sophisticated or laborious for routine clinical use. FUTURE DIRECTIONS Several markers of oxidative stress still represent a viable biomarker opportunity for clinical use. However, positive findings with currently used biomarkers still need to be validated in larger sample sizes and compared with current clinical standards to establish them as clinical diagnostics. It is important to realize that oxidative stress is a nuanced phenomenon that is difficult to characterize, and one biomarker is not necessarily better than others. The vast diversity in oxidative stress between diseases and conditions has to be taken into account when selecting the most appropriate biomarker. Antioxid. Redox Signal. 00, 000-000

Increasing follow-up questionnaire response rates in a randomized controlled trial of telehealth for depression: three embedded controlled studies

Background: Attrition is problematic in trials, and may be exacerbated in longer studies, telehealth trials and participants with depression – three features of The Healthlines Study. Advance notification, including a photograph and using action-oriented email subject lines might increase response rates, but require further investigation. We examined the effectiveness of these interventions in three embedded Healthlines studies. Methods: Based in different trial sites, participants with depression were alternately allocated to be pre-called or not ahead of the 8-month follow-up questionnaire (Study 1), randomized to receive a research team photograph or not with their 12-month questionnaire (Study 2), and randomized to receive an action-oriented (‘ACTION REQUIRED’) or standard (‘Questionnaire reminder’) 12-month email reminder (Study 3). Participants could complete online or postal questionnaires, and received up to five questionnaire reminders. The primary outcome was completion of the Patient Health Questionnaire (PHQ-9). Secondary outcome measures were the number of reminders and time to questionnaire completion. Results: Of a total of 609 Healthlines depression participants, 190, 251 and 231 participants were included in Studies 1–3 (intervention: 95, 126 and 115), respectively. Outcome completion was ≥90 % across studies, with no differences between trial arms (Study 1: OR 0.38, 95 % CI 0.07–2.10; Study 2: OR 0.84, 95 % CI 0.26–2.66; Study 3: OR 0.53 95 % CI 0.19–1.49). Pre-called participants were less likely to require a reminder (48.4 % vs 62.1 %, OR 0.41, 95 % CI 0.21–0.78), required fewer reminders (adjusted difference in means −0.67, 95 % CI −1.13 to −0.20), and completed follow-up quicker (median 8 vs 15 days, HR 1.35, 95 % CI 1.00–1.82) than control subjects. There were no significant between-group differences in Studies 2 or 3. Conclusions: Eventual response rates in this trial were high, with no further improvement from these interventions. While the photograph and email interventions were ineffective, pre-calling participants reduced time to completion. This strategy might be helpful when the timing of study completion is important. Researchers perceived a substantial benefit from the reduction in reminders with pre-calling, despite no overall decrease in net effort after accounting for pre-notification

Mitochondrial GSH determines the toxic or therapeutic potential of superoxide scavenging in steatohepatitis

BACKGROUND & AIMS: Steatohepatitis (SH) is associated with mitochondrial dysfunction and excessive production of superoxide, which can then be converted into H(2)O(2) by SOD2. Since mitochondrial GSH (mGSH) plays a critical role in H(2)O(2) reduction, we explored the interplay between superoxide, H(2)O(2), and mGSH in nutritional and genetic models of SH, which exhibit mGSH depletion. METHODS: We used isolated mitochondria and primary hepatocytes, as well as in vivo SH models showing mGSH depletion to test the consequences of superoxide scavenging. RESULTS: In isolated mitochondria and primary hepatocytes, superoxide scavenging by SOD mimetics or purified SOD decreased superoxide and peroxynitrite generation but increased H(2)O(2) following mGSH depletion, despite mitochondrial peroxiredoxin/thioredoxin defense. Selective mGSH depletion sensitized hepatocytes to cell death induced by SOD mimetics, and this was prevented by RIP1 kinase inhibition with necrostatin-1 or GSH repletion with GSH ethyl ester (GSHee). Mice fed the methionine-choline deficient (MCD) diet or MAT1A(-/-) mice exhibited reduced SOD2 activity; in vivo treatment with SOD mimetics increased liver damage, inflammation, and fibrosis, despite a decreased superoxide and 3-nitrotyrosine immunoreactivity, effects that were ameliorated by mGSH replenishment with GSHee, but not NAC. As a proof-of-principle of the detrimental role of superoxide scavenging when mGSH was depleted transgenic mice overexpressing SOD2 exhibited enhanced susceptibility to MCD-mediated SH. CONCLUSIONS: These findings underscore a critical role for mGSH in the therapeutic potential of superoxide scavenging in SH, and suggest that the combined approach of superoxide scavenging with mGSH replenishment may be important in SH