Confocal Raman microscopy to evaluate anisotropic structures and hydration development. Methodological considerations.

Confocal Raman microscopy is a promising technique to study structural complexity of multi-phase foods and soft materials. This technique overcomes the limitations of traditional microscopic techniques, such as the inability to identify water regions or to map the composition of various phases in situ, without sample disruption or the addition of specific dyes. The objective of this work was to carry out a systematic study on a well-understood model food, pizza cheese, establishing a methodology for data acquisition and handling for confocal Raman microscopy studies of anisotropic protein structures. The study demonstrated that conventional confocal microscopy remains an important tool to study the structure of protein networks. However, confocal Raman microscopy brings added value in the observation of components distribution, for example, water distribution in the protein phase during storage, using line scans or area imaging, and to detect spatial heterogeneities. This research compared different means of processing spectroscopic data, and demonstrates the critical importance of data handling, advocating for detailed methodological descriptions to better compare research results.

Ecophysiological Responses of the Lesser Mealworm Alphitobius diaperinus Exposed to Desiccating Conditions.

In order to improve predictions of the impacts of climate change on insects, this study aimed to uncover how exposure to dry conditions can affect the biology of the invasive pest beetle Alphitobius diaperinus in terms of longevity, activity, water content, metabolic profiles, and fecundity. We measured desiccation resistance in adults of A. diaperinus by recording the time the beetles could survive desiccation stress. We found that the species was highly desiccation resistant, with about 50% of the insects exposed to desiccation being able to survive for 30 days, and some individuals even survived for up to 50 days at 10% ± 2 relative humidity. There was no evidence of active upregulation of sugars or other metabolites which the beetles could have used to better tolerate desiccation. Food deprivation affected both control (food deprivation, no desiccation) and treatment (food deprivation, desiccation) groups, as their metabolic phenotypes changed similarly after 1 week of treatment. Also, the activity of beetles from both control and desiccation treatments was similarly increased 2 weeks after the experiment had started. Even if there were no changes in the metabolic phenotypes of the insects experiencing desiccating conditions, beetles exposed to desiccation for 8 days had a significantly reduced reproductive output as compared with control insects. This result indicated a physiological cost of drought resistance or repair of stress-incurred damages. The exact nature of that effect (e.g., direct or indirect physiological costs) has not yet been described for tenebrionid beetles and should be investigated in future studies.

Thermal plasticity and sensitivity to insecticides in populations of an invasive beetle: Cyfluthrin increases vulnerability to extreme temperature.

Climate change increases average temperatures and the occurrence of extreme weather events, in turn accentuating the risk of organism exposure to temperature stress. When thermal conditions become stressful, the sensitivity of insects toward insecticides can be exacerbated. Likewise, exposure of insects to insecticides can subsequently influence their ability to handle stressful temperatures. Here, we investigated the effects of constant temperature and daily heat spikes, in presence/absence of insecticide treatment (cyfluthrin), on the condition (impairment of mobility) and thermal tolerance to cold (-6 °C) and heat (42.5 °C) of the terrestrial beetle Alphitobius diaperinus. The responses of insects from four populations (three farm-collected populations, one laboratory population) to different durations of extreme temperature exposure were compared. The results showed that the laboratory population was generally more sensitive to extreme cold and heat temperatures, with less than 50% of adults recovering after an exposure at -6 or +42.5 °C for 3h. Significant differences in the level of thermal tolerance were also found among insects from poultry farms. Cyfluthrin exposure incurred detrimental effects to insects' condition in all but one population. For two out of the four populations, mobility impairment was increased when adults were exposed to daily heat spikes (6 h per day at 38 °C) and cyfluthrin simultaneously, compared to cyfluthrin exposure at constant temperatures; yet, no significant interaction between the two stressors was found. Finally, using one farm collected population, effects of pre-exposure to cyfluthrin on extreme temperature tolerance provided another example of the toxicant-induced climate sensitivity in insects.

Understanding structure-mobility relations for perylene tetracarboxydiimide derivatives.

Discotic mesophases are known for their ability to self-assemble into columnar structures and can serve as semiconducting molecular wires. Charge carrier mobility along these wires strongly depends on molecular packing, which is controlled by intermolecular interactions. By combining wide-angle X-ray scattering experiments with molecular dynamics simulations, we elucidate packing motifs of a perylene tetracarboxdiimide derivative, a task which is hard to achieve by using a single experimental or theoretical technique. We then relate the charge mobility to the molecular arrangement, both by pulse-radiolysis time-resolved microwave conductivity experiments and simulations based on the non-adiabatic Marcus charge transfer theory. Our results indicate that the helical molecular arrangement with the 45 degrees twist angle between the neighboring molecules favors hole transport in a compound normally considered as an n-type semiconductor. Statistical analysis shows that the transport is strongly suppressed by structural defects. By linking molecular packing and mobility, we eventually provide a pathway to the rational design of perylenediimide derivatives with high charge mobilities.

Pregnancy, delivery and birth outcome in different stages of maternal multiple sclerosis.

To investigate the influence of maternal multiple sclerosis (MS) on pregnancy, we compared pregnancy, delivery and birth outcome in births prior to onset of MS (pre MS), between MS onset and diagnosis (early MS), and after diagnosis of MS (manifest MS). Mothers with MS were identified through linkage of the Norwegian MS Registry and the Medical Birth Registry of Norway (1967-2002). All pre MS births (n = 1910), early MS births (n = 555), and manifest MS births (n = 308) were compared. There was a significantly lower mean birth weight in term births (adjusted for gestation in weeks, mother's age, time period and caesarean section) in the manifest MS compared to the pre MS group (P = 0.046). The rate of birth complications and interventions did not differ between the three groups. Manifest MS in birth-giving mothers seems to affect birth weight.

The current state of colonoscopy training in family medicine residency programs.

BACKGROUND AND OBJECTIVES: The US Preventive Services Task Force has recommended that all adults ages 50 and over be screened for colorectal cancer. Colonoscopy is the most accurate screening procedure, but the feasibility of colonoscopy as a screening tool is limited by the number of physicians trained to perform it. This study determined the current state of colonoscopy training in US family medicine residency programs. METHODS: We surveyed program directors of all Accreditation Council for Graduate Medical Education-approved family medicine residency programs regarding colonoscopy training. RESULTS: The response rate was 94% (426 of 455). Forty-eight percent (n=201) of directors reported that their program offered colonoscopy training, but only 18% (n=75) of all respondents had actually trained one or more residents to do colonoscopies. Nationally, the mean number of colonoscopies performed per resident was 42.6 +/- 3.9. Regional differences were reported; residents trained in the western United States performed a mean of 69.8 +/- 12.8 colonoscopies per resident. Gastroenterologists in hospital-based gastroenterology suites trained approximately 75% of family medicine residents. Fifteen percent (n=64) of directors reported that 133 (4%) of their July 2002 graduates sought credentials to perform colonoscopy. CONCLUSIONS: Only a minority of family medicine graduates seek credentials to perform colonoscopy, and significant regional differences in training exist.

APN spells success for a heart failure program.

Review the relationship between advanced practice nurse-directed heart failure programs and patient length of stay, mortality, re-admission rate, and adherence to recommended clinical regimens.