Response of Maize and Sorghum to Excess Boron and Salinity

We have analyzed the stress-associated proteins in a high-rubber-yielding guayule (Parthenium argentatum Gray cv. 11591) leaves. Protein profiles in leaf fractions, resolved by SDS-PAGE and visualized by Coomassie Brilliant Blue staining, were different under various stresses. Changes in 25, 34 and 74 kDa polypeptides were noticed in response to low night temperature treatment while 24, 40, 47 and 81 kDa proteins responded to low irradiance. 23, 50, 75 and 82 kDa proteins were altered in response to drought stress. Certain proteins may play a significant role in the acquisition of tolerance in parenchyma cells of guayule leaves and might be useful markers to study adaptation in guayule plants. This revised version was published online in July 2006 with corrections to the Cover Date.     

Long-Term Weight Loss and Breakfast in Subjects in the National Weight Control Registry

Objective: To examine breakfast consumption in subjects maintaining a weight loss in the National Weight Control Registry (NWCR). Research Methods and Procedures: A cross-sectional study in which 2959 subjects in the NWCR completed demographic and weight history questionnaires as well as questions about their current breakfast consumption. All subjects had maintained a weight loss of at least 13.6 kg (30 lb) for at least 1 year; on average these subjects had lost 32 kg and kept it off for 6 years. Results: A large proportion of NWCR subjects (2313 or 78%) reported regularly eating breakfast every day of the week. Only 114 subjects (4%) reported never eating breakfast. There was no difference in reported energy intake between breakfast eaters and non-eaters, but breakfast eaters reported slightly more physical activity than non-breakfast eaters (p = 0.05). Discussion: Eating breakfast is a characteristic common to successful weight loss maintainers and may be a factor in their success.     

Vision and Eating Behavior

Objective: Eating behavior is influenced by internal and external factors. Vision is one part of the complex pattern of factors influencing the amount of food consumed during a meal. The aim of this study was to explore the impact of vision on the microstructure of eating behavior and the subjective motivation to eat. Research Methods and Procedures: Nine blind subjects and nine matched seeing control subjects consumed a standardized meal registered by VIKTOR, an eating monitor, measuring the microstructure of the eating behavior. The eating behavior of the control subjects was registered twice, with and without blindfold. Results: The eating behavior of the blind subjects did not differ from that of seeing control subjects. However, the eating behavior of seeing subjects eating with blindfold demonstrated a clear impact of vision on eating behavior. When blindfolded, subjects ate 22% less food (p < 0.05), had shorter meal durations (p < 0.05), and had less decelerated eating curves (p < 0.05). Despite a smaller amount of food consumed when blindfolded, the reported feeling of fullness was identical to that reported after the larger meal consumed without blindfold. Discussion: The importance of vision in regulating our eating behavior is further stressed in this study. Eating with a blindfold decreased the intake of food, without making subjects feel less full. Eating blindfolded, therefore, may force subjects to rely more on internal signals. These results might be used as an aid in the development of new treatment strategies for obese subjects.     

Binge Eating and Eating‐Related Cognitions and Behavior in Ethnically Diverse Obese Women

Objective: To examine binge eating and eating‐related cognitions and behavior in a sample of ethnically diverse women who are severely obese and seeking bariatric surgery. Research Methods and Procedures: Female bariatric surgery candidates (62 African Americans, 18 Latinas, 130 whites) completed questionnaires on binge eating and eating‐related cognitions and behavior and completed a structured clinical interview to confirm binge‐eating disorder diagnosis. Results: Ethnic minorities and whites did not differ in rates of binge‐eating disorder (26.3%), binges per week (M = 0.95), or dietary restraint. Ethnic minorities reported less disinhibition, and there was a trend to report less hunger awareness than whites. After controlling for BMI and education, ethnicity accounted for significant variance in disinhibition (4%; p < 0.01). Ethnic minorities were younger, became overweight at a later age, and were overweight for fewer years than whites. Discussion: Results suggest that ethnicity exerts an important influence on disinhibition and that ethnic differences are not caused by BMI or education. Findings point to the need to continue to investigate the role of ethnicity, binge eating, and disinhibition in severely obese women, so that culturally appropriate services can be provided.     

Development,validation and reliability of the Chrononutrition Profile - Questionnaire

ABSTRACT

Chrononutrition, or the circadian timing of food intake, has garnered attention as a topic of study due to its associations with health (e.g. weight gain); however, a valid and reliable assessment of chrononutrition in daily life has not yet been developed. This paper details the development and initial reliability and validity testing of the Chrononutrition Profile – Questionnaire (CP-Q). The CP-Q assesses six components of chrononutrition that are likely to influence health (breakfast skipping, largest meal, evening eating, evening latency, night eating, and eating window). This questionnaire is designed to assess general chrononutrition behaviors and preferred timing of food intake. The CP-Q can be used as a sole evaluation of chrononutrition, and can also be utilized in conjunction with existing dietary measures to provide a comprehensive assessment of one’s eating behaviors. This measure offers health-care professionals, researchers, and stakeholders a cost-effective and comprehensive method of evaluating chrononutrition and identifying targets for health improvement.     

Phase-Shifts of Apparent Orcadian Rhythms Due to West and East Transmeridian Flights or to Corresponding Night-Shift Sleep Displacements

Phase movements of apparent circadian rhythms during 2 wk of forward or backward displacement of the sleep-wake cycle were investigated in four experimental series in a subject. The 7-hr delay or advance of sleep due to a westward or an eastward transmeridian flight was duplicated by corresponding sleep displacements during experimental night shifts. Sudden phase advances (or delays) by several hours were observed in the rhythms of continuously recorded rectal temperature and urinary excretion rates (4-hr collection intervals) of adrenaline, noradrenaline and aldosterone the first day after sleep-wake displacement. The desired 7-hr phase-shifts were reached more quickly and completely when the phase was delayed than when it was advanced. In addition, the best-fitting period of these rhythms became shorter than 24 hr when the phase was delayed, and longer than 24 hr when it was advanced. The apparent rhythms of urine flow and electrolyte excretions (potassium, sodium, zinc) were much weaker and their phase movements more irregular than those of hormonal excretion. It is concluded that the sudden phase-shifts resulted from the immediate adaptation of the exogenous components of the rhythms to the demands of the displaced sleep-wake patterns (masking effects) and that the true phase-shifts of the endogenous components followed more slowly and gradually.     

Night shift work and osteoporosis among female blue-collar workers in Poland - a pilot study

ABSTRACT

Osteoporosis is an important public health problem worldwide. Although a number of factors that affect bone structure have been described; thus far, the current knowledge of occupational factors that may have an influence on bone tissue metabolism is strongly limited. Published studies indicate night shift work and the related circadian rhythm disruption may be considered as plausible underlying factors. The aim of the present study was to assess the potential association between night shift work and bone mineral density (BMD) among female blue-collar workers in Poland. A cross-sectional study was carried out among 194 female blue-collar workers >40 years of age employed in industrial plants. The operating system of work consisted of three work shifts clockwise rotation: morning (06:00–14:00 h), afternoon (14:00–22:00 h), and night (22:00–06:00 h), with five consecutive shifts per week followed by a free weekend. A questionnaire survey, based on a Polish version of The European vertebral osteoporosis study (EVOS) questionnaire, a validated instrument, was administered. Data on current job characteristics, job seniority, and lifetime duration of night shift work were also collected. BMD of the lumbar spine and hip (both total femur and femoral neck) was measured using dual-energy X-ray absorptiometry. Multivariate linear regression models were run, with bone mineralization parameters as dependent variables, as well as night work characteristics and important confounders. Statistical analysis was performed separately for premenopausal and postmenopausal women. The analyses adjusted for confounders did not reveal any significant differences between current or lifetime experience of night shift work and BMD among both premenopausal and postmenopausal women. However, the outcomes supported the well-established correlation with factors, such as age, BMI, and menopausal status. BMD at the three sites measured was significantly associated with BMI (p < .001) and inversely associated with age (p < .001) in the total study population. Postmenopausal women had significantly lower BMD than did premenopausal women (p < .001). The study findings indicate that in the population of Polish female blue-collar workers, the system of work does not seem to be associated with the development of osteoporosis.     

Coping with shift work-related circadian disruption: A mixed-methods case study on napping and caffeine use in Australian nurses and midwives

ABSTRACT

Introduction: Two of the most ubiquitous fatigue countermeasures used by shift-working nurses are napping and caffeine. This mixed-methods case study investigated the ways nurses and midwives utilised napping and caffeine countermeasures to cope with shift work, and associated sleep, physical health and psychological health outcomes.

Materials and Methods: N = 130 Australian shift-working nurses and midwives (mean age = 44 years, range = 21–67, 115F, 15M) completed the Standard Shiftwork Index. A sub-set of 22 nurses and midwives completed an in-depth interview.

Results: Nearly 70% of participants reported napping. Those who napped during night shifts had significantly less total sleep time before (F_2,75 = 5.5, p < 0.01) and between days off (F_2,82 = 3.9, p < 0.05). By the end of the night shift, average hours of time awake were significantly less for prophylactic and on-shift nappers compared to non-nappers (F_2,85 = 97.2, p < 0.001). Since starting shift work, the percentage of high caffeine consumers (>400 mg/day) increased from 15% to 33% of the sample and an average of 4 (SD = 2) caffeinated beverages per day was reported. Increased caffeine consumption was associated with greater sleep disturbance (r = 0.26, p < 0.05), psychological distress (r = 0.37, p < 0.001), abdomen pain (r = 0.27, p < 0.05) and weight gain since starting shift work (r = 0.25, p < 0.05). Interviews confirmed these relationships and revealed that caffeine consumption on night shift was common, whereas napping on night shift was dependent on a number of factors including ability to sleep during the day.

Conclusion: This study identified reasons shift workers chose to engage in or abstain from napping and consuming caffeine, and how these strategies related to poor sleep and health outcomes. Further research is required to help develop recommendations for shift workers regarding napping and caffeine consumption as fatigue countermeasures, whilst taking into account the associated hazards of each strategy.     

Bright-light exposure during daytime sleeping affects nocturnal melatonin secretion after simulated night work

The guidelines for night and shift workers recommend that after night work, they should sleep in a dark environment during the daytime. However, staying in a dark environment during the daytime reduces nocturnal melatonin secretion and delays its onset. Daytime bright-light exposure after night work is important for melatonin synthesis the subsequent night and for maintaining the circadian rhythms. However, it is not clear whether daytime sleeping after night work should be in a dim- or a bright-light environment for maintaining melatonin secretion. The aim of this study, therefore, was to evaluate the effect of bright-light exposure during daytime sleeping on nocturnal melatonin secretion after simulated night work. Twelve healthy male subjects, aged 24.8 ± 4.6 (mean ± SD), participated in 3-day sessions under two experimental conditions, bright light or dim light, in a random order. On the first day, the subjects entered the experimental room at 16:00 and saliva samples were collected every hour between 18:00 and 00:00 under dim-light conditions. Between 00:00 and 08:00, they participated in tasks that simulated night work. At 10:00 the next morning, they slept for 6 hours under either a bright-light condition (>3000 lx) or a dim-light condition (<50 lx). In the evening, saliva samples were collected as on the first day. The saliva samples were analyzed for melatonin concentration. Activity and sleep times were recorded by a wrist device worn throughout the experiment. In the statistical analysis, the time courses of melatonin concentration were compared between the two conditions by three-way repeated measurements ANOVA (light condition, day and time of day). The change in dim light melatonin onset (ΔDLMO) between the first and second days, and daytime and nocturnal sleep parameters after the simulated night work were compared between the light conditions using paired t-tests. The ANOVA results indicated a significant interaction (light condition and3 day) (p = .006). Post hoc tests indicated that in the dim-light condition, the melatonin concentration was significantly lower on the second day than on the first day (p = .046); however, in the bright-light condition, there was no significant difference in the melatonin concentration between the days (p = .560). There was a significant difference in ΔDLMO between the conditions (p = .015): DLMO after sleeping was advanced by 11.1 ± 17.4 min under bright-light conditions but delayed for 7.2 ± 13.6 min after sleeping under dim-light conditions. No significant differences were found in any sleep parameter. Our study demonstrated that daytime sleeping under bright-light conditions after night work could not reduce late evening melatonin secretion until midnight or delay the phase of melatonin secretion without decreasing the quality of the daytime sleeping. Thus, these results suggested that, to enhance melatonin secretion and to maintain their conventional sleep–wake cycle, after night work, shift workers should sleep during the daytime under bright-light conditions rather than dim-light conditions.     

Pollination and reproductive system of synchronopatric species of Cactaceae (Cactoideae) subject to interspecific flow of pollen: an example of ecological adaptation in the Brazilian Chaco

• Three synchronopatric Cactaceae species, Echinopsis rhodotricha, Harrisia balansae and Praecereus saxicola, have mostly nocturnal anthesis and similar flowers, characteristics that motivated us to perform a comparative study of reproductive ecology.
• Reproductive phenology was sampled monthly from December 2014 to November 2015. We describe floral biology, breeding system via pollination treatments and evaluate floral visitors from focal and filming observations. Pollen grains found on moth proboscis were compared among cactus species under light microscopy. We used fluorescent dye particles to test intra‐ and interspecific pollen flow.
• These three species have extended flowering with greater intensity in the wet season, causing high overlap. They have white and hypocrateriformis flowers that open at twilight or nightfall and last about 15 h. H. balansae seems to be self‐incompatible, while E. rhodotricha presented self‐compatibility. P. saxicola presented self‐fertility, but most of the population seems to be self‐incompatible. We suggest sphingophily for the three species, but only P. saxicola was visited by Manduca rustica (Sphingidae). However, we observed pollen grains of all three species on the proboscis of moths, especially M. rustica and M. sexta. Prolonged anthesis allowed bees (herein considered as secondary pollinators) to visit flowers of E. rhodotricha and P. saxicola.
• It can be concluded that the studied species share nocturnal and diurnal pollinators, suggesting interspecific pollen flow, which, however, could not be detected with fluorescent dye particles. In view of the low frequency of primary pollinators, it appears that these three species have different reproductive strategies, ensuring the fruiting and production of viable seeds.