Effectiveness of a web-based intervention aimed at healthy dietary and physical activity behavior: a randomized controlled trial about users and usage

Background:\ud Recent studies have shown the potential of Web-based interventions for changing dietary and physical activity (PA) behavior. However, the pathways of these changes are not clear. In addition, nonusage poses a threat to these interventions. Little is known of characteristics of participants that predict usage.\ud \ud Objective:\ud In this study we investigated the users and effect of the Healthy Weight Assistant (HWA), a Web-based intervention aimed at healthy dietary and PA behavior. We investigated the value of a proposed framework (including social and economic factors, condition-related factors, patient-related factors, reasons for use, and satisfaction) to predict which participants are users and which participants are nonusers. Additionally, we investigated the effectiveness of the HWA on the primary outcomes, self-reported dietary and physical activity behavior.\ud \ud Methods:\ud Our design was a two-armed randomized controlled trial that compared the HWA with a waiting list control condition. A total of 150 participants were allocated to the waiting list group, and 147 participants were allocated to the intervention group. Online questionnaires were filled out before the intervention period started and after the intervention period of 12 weeks. After the intervention period, respondents in the waiting list group could use the intervention. Objective usage data was obtained from the application itself.\ud \ud Results:\ud In the intervention group, 64% (81/147) of respondents used the HWA at least once and were categorized as “users.” Of these, 49% (40/81) used the application only once. Increased age and not having a chronic condition increased the odds of having used the HWA (age: beta = 0.04, P = .02; chronic condition: beta = 2.24, P = .003). Within the intervention group, users scored better on dietary behavior and on knowledge about healthy behavior than nonusers (self-reported diet: χ22 = 8.4, P = .02; knowledge: F1,125 = 4.194, P = .04). Furthermore, users underestimated their behavior more often than nonusers, and nonusers overestimated their behavior more often than users (insight into dietary behavior: χ22 = 8.2, P = .02). Intention-to-treat analyses showed no meaningful significant effects of the intervention. Exploratory analyses of differences between pretest and posttest scores of users, nonusers, and the control group showed that on dietary behavior only the nonusers significantly improved (effect size r = −.23, P = .03), while on physical activity behavior only the users significantly improved (effect size r = −.17, P = .03).\ud \ud Conclusions:\ud Respondents did not use the application as intended. From the proposed framework, a social and economic factor (age) and a condition-related factor (chronic condition) predicted usage. Moreover, users were healthier and more knowledgeable about healthy behavior than nonusers. We found no apparent effects of the intervention, although exploratory analyses showed that choosing to use or not to use the intervention led to different outcomes. Combined with the differences between groups at baseline, this seems to imply that these groups are truly different and should be treated as separate entities

Current epidemiological evidence for predisposition to high or low intensity human helminth infection: a systematic review

Background: The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis. It is estimated that almost 2 billion people worldwide are infected with helminths. Whilst the WHO treatment guidelines for helminth infections are mostly aimed at controlling morbidity, there has been a recent shift with some countries moving towards goals of disease elimination through mass drug administration, especially for LF and onchocerciasis. However, as prevalence is driven lower, treating entire populations may no longer be the most efficient or cost-effective strategy. Instead, it may be beneficial to identify individuals or demographic groups who are persistently infected, often termed as being “predisposed” to infection, and target treatment at them. Methods: The authors searched Embase, MEDLINE, Global Health, and Web of Science for all English language, humanbased papers investigating predisposition to helminth infections published up to October 31st, 2017. The varying definitions used to describe predisposition, and the statistical tests used to determine its presence, are summarised. Evidence for predisposition is presented, stratified by helminth species, and risk factors for predisposition to infection are identified and discussed. Results: In total, 43 papers were identified, summarising results from 34 different studies in 23 countries. Consistent evidence of predisposition to infection with certain species of human helminth was identified. Children were regularly found to experience greater predisposition to Ascaris lumbricoides, Schistosoma mansoni and S. haematobium than adults. Females were found to be more predisposed to A. lumbricoides infection than were males. Household clustering of infection was identified for A. lumbricoides, T. trichiura and S. japonicum. Ascaris lumbricoides and T. trichiura also showed evidence of familial predisposition. Whilst strong evidence for predisposition to hookworm infection was identified, findings with regards to which groups were affected were considerably more varied than for other helminth species. Conclusion: This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species. However, further research is needed to identify reasons for the reported differences between demographic groups. Molecular epidemiological methods associated with whole genome sequencing to determine ‘who infects whom’ may shed more light on the factors generating predisposition

The Production of Propionic Acid from Pentoses by Propionibacterium pentosaceum

Propionibacterium pentosaceum attacks pentoses (xylose, arabinose) with the production of propionic and acetic acids

Reduction of Acetylmethylcarbinol and Diacetyl to 2,3-Butylene Glycol by the citric acid fermenting streptococci of butter cultures

When acetylmethylcarbinol or diacetyl was added to a tomato bouillon culture of one of the citric acid fermenting streptococci normally present in butter cultures, there was a rapid disappearance of the added reagent and an increase in 2,3-butylene glycol. The amount of the glycol produced accounted, in a general way, for the acetylmethylcarbinol or diacetyl that disappeared. The added reagent did not usually disappear completely. In trials with acetylmethylcarbinol the change of the carbinol to the glycol was delayed when sulfuric acid was added in amounts to yield a pH of from 3.8 to 4.0. There was also a change of acetylmethylcarbinol or diacetyl to 2,3-butylene glycol when one of these reagents was added to a milk culture of one of the organisms. With the diacetyl there was an increase in the acetylmethylcarbinol as well as in the 2,3-butylene glycol, and the increase in the carbinol was greater than the increase in the glycol. The added reagent did not disappear completely in any of the trials. When various amounts of sulfuric acid were added to milk cultures of the organisms, acetylmethylcarbinol was not produced at the higher pH values but was produced at the lower values, while 2,3-butylene glycol was produced at both the higher and lower pH values. There was less of the glycol formed at the lower pH values than at the higher ones. The total molarities of acetylmethylcarbinol and 2,3-butylene glycol showed an increase as the pH was lowered, although there were some irregularities in the increase with one of the organisms. The addition of 0.65 percent citric acid to a milk culture of one of the organisms resulted in an increase in both acetylmethylcarbinol and 2,3-butylene glycol. The reduction of acetylmethylcarbinol, which had been added to a milk culture of one of the organisms, to 2,3-butylene glycol was not delayed by potassium nitrate in the quantity used but was delayed by the largest amount of hydrogen peroxide employed. In pure cultures of the citric acid fermenting streptococci which had been acidified with sulfuric acid to a pH of about 3.9, the addition of acetaldehyde or propionaldehyde increased the amount of acetylmethylcarbinol present after 96 hours at 21 °C. but decreased the amount of 2,3-butylene glycol and also commonly decreased the total molarities of the two compounds. These results suggest that the increased production of acetylmethylcarbinol is accounted for by a decrease in the reduction of the carbinol to the corresponding glycol, rather than to an aldehyde condensation involving, in part, the added aldehyde. In butter cultures the decrease in acetylmethylcarbinol was accompanied by an increase in 2,3-butylene glycol, and there was commonly an increase, from one examination to the next, in the total molarities of the two compounds. When ripened butter cultures were neutralized to a low acidity there was a rapid decrease in the acetylmethylcarbinol, and in some of the trials this was followed by an increase. The decrease in the carbinol was accompanied by a rapid increase in 2,3-butylene glycol, and there was also an increase in the total molarities of the two compounds. Hydrogen peroxide, in certain concentrations, delayed the reduction of acetylmethylcarbinol to 2,3-butylene glycol as did also 1 percent sodium fumarate or 12 percent sodium chloride. Ice water temperatures also delayed the reduction in either neutralized or unneutralized cultures, but the reduction was more rapid with neutralization than without

The Effect of Steffen Waste on the Fermentation of Pentosans from the Corn Stalk

It was found that Steffen waste furnishes a suitable source of nitrogen, salts, and buffers for the growth of Aerobacter pectinovorum on pentosan material prepared from corn-stalks

Criticism of the Use of Coomassie Brilliant Blue G-250 for the Quantitative Determination of Proteins

Peer Reviewe

Evaluation of an Interactive Web-based Application to Promote Healthy Behavior in Order to Maintain a Healthy Weight - Preliminary Findings

Web-based interactive applications may combine the interactive and tailored nature of successful behavior change interventions with the wide reach needed to target the general population. There is a lack of insight in the requirements for successful interactive Web-based applications in prevention. The objective of this research is to evaluate the Healthy Weight Assistant (HWA) of the Netherlands Nutrition Centre and give recommendations for optimization of this application. This study consists of questionnaires (n=703, follow-up n=431), real-time usability-tests, log-file analysis and qualitative analysis. From the preliminary results we see that improvement with maximum effect and minimal change of the HWA can be found in motivation to keep using the application and motivation to change behavior. This can be achieved by sending automatic (tailored) reminders, restructuring the second stage in the application (motivation and goal setting) and by adding a tab 'my goals' to the application