Health Advice from Internet Discussion Forums: How Bad Is Dangerous?

Background: Concerns over online health information–seeking behavior point to the potential harm incorrect, incomplete, or biased information may cause. However, systematic reviews of health information have found few examples of documented harm that can be directly attributed to poor quality information found online. Objective: The aim of this study was to improve our understanding of the quality and quality characteristics of information found in online discussion forum websites so that their likely value as a peer-to-peer health information–sharing platform could be assessed. Methods: A total of 25 health discussion threads were selected across 3 websites (Reddit, Mumsnet, and Patient) covering 3 health conditions (human immunodeficiency virus [HIV], diabetes, and chickenpox). Assessors were asked to rate information found in the discussion threads according to 5 criteria: accuracy, completeness, how sensible the replies were, how they thought the questioner would act, and how useful they thought the questioner would find the replies. Results: In all, 78 fully completed assessments were returned by 17 individuals (8 were qualified medical doctors, 9 were not). When the ratings awarded in the assessments were analyzed, 25 of the assessments placed the discussion threads in the highest possible score band rating them between 5 and 10 overall, 38 rated them between 11 and 15, 12 rated them between 16 and 20, and 3 placed the discussion thread they assessed in the lowest rating band (21-25). This suggests that health threads on Internet discussion forum websites are more likely than not (by a factor of 4:1) to contain information of high or reasonably high quality. Extremely poor information is rare; the lowest available assessment rating was awarded only 11 times out of a possible 353, whereas the highest was awarded 54 times. Only 3 of 78 fully completed assessments rated a discussion thread in the lowest possible overall band of 21 to 25, whereas 25 of 78 rated it in the highest of 5 to 10. Quality assessments differed depending on the health condition (chickenpox appeared 17 times in the 20 lowest-rated threads, HIV twice, and diabetes once). Although assessors tended to agree on which discussion threads contained good quality information, what constituted poor quality information appeared to be more subjective. Conclusions: Most of the information assessed in this study was considered by qualified medical doctors and nonmedically qualified respondents to be of reasonably good quality. Although a small amount of information was assessed as poor, not all respondents agreed that the original questioner would have been led to act inappropriately based on the information presented. This suggests that discussion forum websites may be a useful platform through which people can ask health-related questions and receive answers of acceptable quality

Exposure to Fumonisins and the Occurrence of Neural Tube Defects along the Texas–Mexico Border

Along the Texas–Mexico border, the prevalence of neural tube defects (NTDs) among Mexican-American women doubled during 1990–1991. The human outbreak began during the same crop year as epizootics attributed to exposure to fumonisin, a mycotoxin that often contaminates corn. Because Mexican Americans in Texas consume large quantities of corn, primarily in the form of tortillas, they may be exposed to high levels of fumonisins. We examined whether or not maternal exposure to fumonisins increases the risk of NTDs in offspring using a population-based case–control study. We estimated fumonisin exposure from a postpartum sphinganine:sphingosine (sa:so) ratio, a biomarker for fumonisin exposure measured in maternal serum, and from maternal recall of periconceptional corn tortilla intake. After adjusting for confounders, moderate (301–400) compared with low (≤ 100) consumption of tortillas during the first trimester was associated with increased odds ratios (ORs) of having an NTD-affected pregnancy (OR = 2.4; 95% confidence interval, 1.1–5.3). No increased risks were observed at intakes higher than 400 tortillas (OR = 0.8 for 401–800, OR = 1.0 for > 800). Based on the postpartum sa:so ratio, increasing levels of fumonisin exposure were associated with increasing ORs for NTD occurrences, except for the highest exposure category (sa:so > 0.35). Our findings suggest that fumonisin exposure increases the risk of NTD, proportionate to dose, up to a threshold level, at which point fetal death may be more likely to occur. These results also call for population studies that can more directly measure individual fumonisin intakes and assess effects on the developing embryo

Behavioral Mechanism during Human Sperm Chemotaxis: Involvement of Hyperactivation

When mammalian spermatozoa become capacitated they acquire, among other activities, chemotactic responsiveness and the ability to exhibit occasional events of hyperactivated motility—a vigorous motility type with large amplitudes of head displacement. Although a number of roles have been proposed for this type of motility, its function is still obscure. Here we provide evidence suggesting that hyperactivation is part of the chemotactic response. By analyzing tracks of spermatozoa swimming in a spatial chemoattractant gradient we demonstrate that, in such a gradient, the level of hyperactivation events is significantly lower than in proper controls. This suggests that upon sensing an increase in the chemoattractant concentration capacitated cells repress their hyperactivation events and thus maintain their course of swimming toward the chemoattractant. Furthermore, in response to a temporal concentration jump achieved by photorelease of the chemoattractant progesterone from its caged form, the responsive cells exhibited a delayed turn, often accompanied by hyperactivation events or an even more intense response in the form of flagellar arrest. This study suggests that the function of hyperactivation is to cause a rather sharp turn during the chemotactic response of capacitated cells so as to assist them to reorient according to the chemoattractant gradient. On the basis of these results a model for the behavior of spermatozoa responding to a spatial chemoattractant gradient is proposed

Electronic Coherence Dephasing in Excitonic Molecular Complexes: Role of Markov and Secular Approximations

We compare four different types of equations of motion for reduced density matrix of a system of molecular excitons interacting with thermodynamic bath. All four equations are of second order in the linear system-bath interaction Hamiltonian, with different approximations applied in their derivation. In particular we compare time-nonlocal equations obtained from so-called Nakajima-Zwanzig identity and the time-local equations resulting from the partial ordering prescription of the cummulant expansion. In each of these equations we alternatively apply secular approximation to decouple population and coherence dynamics from each other. We focus on the dynamics of intraband electronic coherences of the excitonic system which can be traced by coherent two-dimensional spectroscopy. We discuss the applicability of the four relaxation theories to simulations of population and coherence dynamics, and identify features of the two-dimensional coherent spectrum that allow us to distinguish time-nonlocal effects.Comment: 14 pages, 8 figure

Co-firing of biomass with coals Part 1. Thermogravimetric kinetic analysis of combustion of fir (abies bornmulleriana) wood

The chemical composition and reactivity of fir (Abies bornmulleriana) wood under non-isothermal thermogravimetric (TG) conditions were studied. Oxidation of the wood sample at temperatures near 600 A degrees C caused the loss of aliphatics from the structure of the wood and created a char heavily containing C-O functionalities and of highly aromatic character. On-line FTIR recordings of the combustion of wood indicated the oxidation of carbonaceous and hydrogen content of the wood and release of some hydrocarbons due to pyrolysis reactions that occurred during combustion of the wood. TG analysis was used to study combustion of fir wood. Non-isothermal TG data were used to evaluate the kinetics of the combustion of this carbonaceous material. The article reports application of Ozawa-Flynn-Wall model to deal with non-isothermal TG data for the evaluation of the activation energy corresponding to the combustion of the fir wood. The average activation energy related to fir wood combustion was 128.9 kJ/mol, and the average reaction order for the combustion of wood was calculated as 0.30

Late Silurian zircon U–Pb ages from the Ludlow and Downton bone beds, Welsh Basin, UK

The Ludlow Bone Bed (Welsh Basin) is a critical stratigraphic horizon and contains a rich assemblage of fish scales. Units above provide insights into the early evolution of animal and plant life. The bed has not yet been radioisotopically dated. Here, we report 207 secondary ion mass spectrometry (SIMS) ages from 102 zircon (ZrSiO4) grains from the Ludlow (n = 2) and stratigraphically higher Downton (n = 1) bone beds. SIMS ages are middle Ordovician (471.6 ± 20.7 Ma) to late Devonian (375.7 ± 14.6 Ma, 238U–206Pb, ±1σ analytical uncertainty). Cathodoluminescence images show that the youngest ages appear affected by alteration. Chemical abrasion isotope dilution thermal ionization mass spectrometry (CA-ID-TIMS) U–Pb geochronology was utilized to improve precision. Detrital zircon grains from Downton yield 424.91 ± 0.34/0.42/0.63 Ma and from Ludlow 424.85 ± 0.32/0.41/0.62 Ma (n = 5 each, 238U–206Pb, ±2σ analytical, tracer or systematic uncertainty). These ages provide a maximum deposition age. Results overlap the basal Přídolí age (423.0 ± 2.3 Ma) in its stratotype (Požáry Section, Reporyje, Prague, Czech Republic). The Ludlow Bone Bed marks the base of the local Downton Group, which has previously been correlated with the base of the Přídolí Series. The CA-ID-TIMS ages are older than those for other land arthropod-bearing sediments, such as the Cowie Harbour Fish Bed and Rhynie Chert.© 2020 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/ licenses/by/4.0/). Published by The Geological Society of London. Publishing disclaimer: www.geolsoc.org.uk/pub_ethic

Chapter 4: Effective Search Strategies for Systematic Reviews of Medical Tests

This article discusses techniques that are appropriate when developing search strategies for systematic reviews of medical tests. This includes general advice for searching for systematic reviews and issues specific to systematic reviews of medical tests. Diagnostic search filters are currently not sufficiently developed for use when searching for systematic reviews. Instead, authors should construct a highly sensitive search strategy that uses both controlled vocabulary and text words. A comprehensive search should include multiple databases and sources of grey literature. A list of subject-specific databases is included in this article

Effects of systematic asymmetric discounting on physician-patient interactions: a theoretical framework to explain poor compliance with lifestyle counseling

BACKGROUND: This study advances the use of a utility model to model physician-patient interactions from the perspectives of physicians and patients. PRESENTATION OF THE HYPOTHESIS: In cases involving acute care, patient counseling involves a relatively straightforward transfer of information from the physician to a patient. The patient has less information than the physician on the impact the condition and its treatment have on utility. In decisions involving lifestyle changes, the patient may have more information than the physician on his/her utility of consumption; moreover, differences in discounting future health may contribute significantly to differences between patients' preferences and physicians' recommendations. TESTING THE HYPOTHESIS: The expectation of differences in internal discount rate between patients and their physicians is discussed. IMPLICATIONS OF THE HYPOTHESIS: This utility model provides a conceptual basis for the finding that educational approaches alone may not effect changes in patient behavior and suggests other economic variables that could be targeted in the attempt to produce healthier behavior

Spontaneous bilateral distal ulna fracture: an unusual complication in a rheumatoid patient

Bilateral ulna stress fractures are extremely rare. Patients with rheumatoid arthritis have osteopenic bone secondary to a variety of causes. We report a case of bilateral stress fractures of the ulna in an elderly patient with rheumatoid arthritis, and literature on this condition is reviewed. Prompt recognition and activity modification are essential to treat this rare injury. Recovery can take up to 12 weeks