Effects of a Two‐Hour Change in Bedtime on the Sleep of Healthy Seniors

Some of the sleep disruption seen in seniors (>65 yrs) may be due to alteration of the circadian pacemaker phase and/or its phase angle with bedtime. The purpose of this study was to determine the effects of 2 h changes in the timing of bedtime (both earlier and later) on the sleep of seniors. Ten healthy seniors (9 F, 1 M, age 70–82 yrs) were each studied individually during three 120 h sessions (each separated by >2 weeks) in a time‐isolation laboratory. On nights 1 and 2, bedtime and rise‐time occurred at the subjects' habitual times; on nights 3–5, bedtime was specified by the experiment, but rise‐time was at the subjects' discretion (without knowledge of clock time). Under the control condition, subjects went to bed at their habitual bedtime (HBT), under the earlier bedtime condition at (HBT?2 h), and under the later bedtime condition at (HBT+2 h). Sleep was polysomnnographically recorded and rectal temperature continuously monitored. Although total sleep time increased in the earlier compared to the later condition (p<0.01), sleep efficiency decreased and wake after sleep onset increased (p<0.01). Subjective ratings of sleep were also worse under the earlier (HBT?2 h) than under later (HBT+ 2 h) condition (p<0.05). Performance did not differ between the earlier and later conditions. The larger the phase angle between actual bedtime and circadian temperature minimum (Tmin), the longer the time spent in bed and total sleep time, and the worse the sleep efficiency and subjective sleep ratings. There were no effects related to the phase angle between Tmin and rise‐time. The relative benefits of longer vs. more efficient sleep in the elderly require further investigation.     

Unintended Effects of Cardiovascular Drugs on the Pathogenesis of Alzheimer’s Disease

Alzheimer’s disease (AD) is rapidly becoming one of the leading causes of disability and mortality in the elderly. As life-expectancy increases, an increasing number of people will rely on modern medicines to treat age-associated disorders. Among these medications, some might benefit, while others might exacerbate, the pathogenesis of AD. We screened 1,600 FDA approved drugs for β-amyloid (Aβ)-modifying activity and identified drugs that can potentially influence amyloid precursor protein processing. In this study, we focused on cardiovascular drugs and demonstrated that some hypertensive medication can differentially modulate Aβ, both in vitro and in vivo. Our study suggests that some commonly prescribed drugs might exert unintended effects and modulate AD and provides the basis for continuing investigation of the role of individual drugs on a case-by-case basis. This line of investigation will lead to the identification of common medications that are potentially beneficial or detrimental to AD as a reference for physicians to consider when prescribing the most appropriate drugs for their patients, particularly for treating chronic disorders among the growing geriatric population.     

Effects of shear stress on microalgae – A review

Cultivation of microalgae requires consideration of shear stress, which is generated by operations such as mixing, circulation, aeration and pumping that are designed to facilitate mass and heat transfer as well as light distribution in cultures. Excessive shear stress can cause increased cell mortality, decreased growth rate and cell viability, or even cell lysis. This review examines the sources of shear stress in different cultivation systems, shear stress tolerance of different microalgal species and the physiological factors and environmental conditions that may affect shear sensitivity, and potential approaches to mitigate the detrimental effects of shear stress. In general, green algae have the greatest tolerance to shear stress, followed by cyanobacteria, haptophytes, red algae, and diatoms, with dinoflagellates comprising the most shear-sensitive species. The shear-sensitivity of microalgae is determined primarily by cell wall strength, cell morphology and the presence of flagella. Turbulence, eddy size, and viscosity are the most prominent parameters affecting shear stress to microalgal cells during cultivation.     

Meeting of the Strategic Advisory Group of Experts on immunization,October 2009 – Conclusions and recommendations

The conclusions and recommendations from the October 2009 meeting of the Strategic Advisory Group of Experts (SAGE) on immunization have been published in the WHO weekly epidemiological record (December 11, 2009) and are reproduced with the permission.     

Effects of 12‐Hour Rotating Shifts on Menstrual Cycles of Photoelectronic Workers in Taiwan

12 h rotating shifts are common in high‐tech industries in Taiwan. The aim of this longitudinal study was to evaluate the effect of the disruption of circadian rhythms by the shift schedule on menstrual cycle length (MCL) and regularity of female workers at an optoelectronic company in Taiwan. We recruited females who worked rotating shifts in a clean room environment as the shift‐work group and female office workers who worked normal business hours as the comparison group. Every participant recorded their MCL for each menstruation cycle up to eight consecutive months prospectively and provided demographic characteristics, reproductive history, and menstrual characteristics. We collected data on 1,135 and 117 menstruation cycles in the shift‐work (n=280) and comparison groups (n=49). Whereas the two groups had similar group means for MCL and number of menstrual bleeding days, the prevalence of menstrual cycle irregularity (cycles<25 or>35 days) was higher in the shift‐work group (p=0.04). Univariate and multivariate logistic regression analyses demonstrated that rotating shift work was an independent predictor of menstrual cycle irregularity (odds ratio=1.71, 95% confidence interval: 1.03–2.88) after adjusting for shift‐work history, employment duration, coffee consumption, and pre‐employment menstrual cycle irregularity. Although further study is required to confirm our findings plus to explore prevention and control measures, our data indicate rotating shift work can increase the risk of MCL irregularity.     

Effects of short term pollution on the level of fluctuating asymmetry – a case study using damselflies

Fluctuating asymmetry (FA), a measure of developmental stability, has been suggested as a monitoring tool for environmental pollution. However, there have been few investigations into the effects of short term pollution on the level of FA. This paper explores effects of exposing late instar larvae to short term pollution on the level of FA in the wings of adult damselflies. In these insects FA in wing length and in cell patterns have different windows of opportunity in relation to environmental stress. If increased environmental stress is applied after the window of opportunity of one trait had closed, while the window of the other trait was still open then the level of FA of the first trait should not be altered whereas that of the latter should increase. If short term pollution killed part of a population, symmetrical individuals (low FA) should survive better than highly asymmetrical ones, because FA reflects the overall ability of an individual to cope with stress. If the pollution event occurred at a time when the level of FA was already fixed, the level of FA of the remaining population should be lower than that in controls. An experiment was carried out, using 10 artificial ponds, each holding a population of larvae of the damselfly Xanthocnemis zealandica (McLachlan). Damselfly larvae were exposed to carbaryl at a nominal concentration of 100 g l^–1, which reduced emergence success after 10–20 days by ca. 50%. Based on laboratory experiments, it was assumed that despite the high mortality, the short exposure to carbaryl late in the last instar would ensure that the wing cell patterns of the damselflies were not altered by the increased stress. The level of FA in wing length increased in the damselflies surviving the exposure to carbaryl but the level of FA in cell patterns did not differ significantly between the treatment and the control. The effects of differential mortality, as well as the effects of pollution, on the level of FA in traits with different windows of opportunity need further investigation.     

Effects of Electrical Currents on Desmodium gyrans Leaflet Movements – Experiments Using a Current Clamp Technique

The leaflet rhythm of Desmodium gyrans, the period of which is in the minute range, was investigated by application of direct current pulses through the pulvinus. The current was generated in a current clamp device, and applied via a 0.1 mm copper wire electrode to the tip of the leaflet and to the base of the leaf stalk. Currents of 2, 5 or 10 µA were applied for 1 s, being kept at a constant value by the clamp electronics. The phase shift was in all cases a delay, attained after transients of four or five periods. The shifts were longer with increasing current. The electronic equipment developed to attain the current pulses is described.     

Effects of ground water and harvest intensity on alkaline grassland ecosystem dynamics – a simulation study

A model for the alkaline grassland ecosystems, MAGE, was applied to plant communities dominated by three species. Field observations on two communities dominated respectively by Puccinellia tenuiflora and Suaeda corniculata were used to parameterize the model for multiple species interaction. The model behaves reasonably in following the seasonal variations of water content, soluble sodium cation and calcium cation in surface soil, as well as biomass of the plant communities.Simulations were run to investigate the effects of ground water quality, ground water table depth, maximum non-capillary porosity in surface soil and harvest intensity, on ecosystem dynamics. The results indicated that ground water sodium concentration and ground water table depth had primary control on soil alkalization and vegetation status. The improvement of soil conditions by vegetation is limited to an extent with moderate ground water depth and sodium concentration. Non-capillary pores are critical for vegetation to affect the soil alkalization/de-alkalization process, but the effect of non-capillary pores tends to saturate when maximum non-capillary porosity is greater than 0.1.     

Short Term Effects of Tucuruí Dam (Amazonia, Brazil) on the Trophic Organization of Fish Communities

A dam on a river course induces numerous changes in the aquatic environment both in the newly formed reservoir and in the river downstream. These changes modify the food resources available to fishes. As a consequence, fish communities undergo rapid transformations particularly in terms of trophic organization. Tucuruí Dam, closed on the Tocantins River, Brazil, in September 1984, formed a large reservoir of approximately 2200km². Analyses of fish stomach contents were performed before and after the completion of the dam in the downstream section of the river as well as in the reservoir. Resource availability was seen through the relative contribution of food items in supporting the biomass. Main changes caused by the dam consisted of an increase in fishes as a food resource and of a parallel decrease of sediment both in the reservoir and in the downstream part of the river. In addition, in the downstream section, the relative contribution of plankton as a food resource diminished after dam closure. We identified 8 feeding regimes before dam closure. From them the trophic structure of fish communities were established and compared. Most of the community biomass was from specialist feeders. Contribution of piscivores increased after closure; planktivores became unimportant after closure downstream. Some species were shown to change their diet in the transformed environments either downstream or in the reservoir. However, these changes in individual species diet did not seem to play a major role in the transformation of trophic structure of the fish communities.     

Daily variation of marine cladoceran densities in a tropical bay – Brazil

This contribution presents the daily variation of marine cladoceran densities in Guanabara Bay. The samples were obtained by vertical tows with a 200 m mesh-size conical net at different times over a 4-day period in September, 1995. Penilia avirostris was the most common species, followed by Evadne tergestina and E. spinifera. These organisms presented higher densities at nightfall. Physical factors like tide and light are responsible for the highest densities. High tide and nightfall time are requested conditions for the P. avirostris and E. tergestina abundance. Temperature and salinity appear to have no relation with cladoceran densities.     

When Is Group Membership Zero-Sum? Effects of Ethnicity,Threat, and Social Identity on Dual National Identity

This paper presents an investigation into marginalizing racism, a form of prejudice whereby ingroup members claim that specific individuals belong to their group, but also exclude them by not granting them all of the privileges of a full ingroup member. One manifestation of this is that perceived degree of outgroup membership will covary negatively with degree of ingroup membership. That is, group membership may be treated as a zero-sum quantity (e.g., one cannot be both Australian and Iraqi). Study 1 demonstrated that judges allocate more zero-sum membership assignments and lower combined membership in their country of origin and their adopted country to high-threat migrants than low-threat migrants. Study 2 identified a subtle type of zero-sum reasoning which holds that stronger degree of membership in one’s original nationality constrains membership in a new nationality to a greater extent than stronger membership in the new nationality constrains membership in one’s original nationality. This pattern is quite general, being replicated in large samples from four nations (USA, UK, India, and China). Taken together, these studies suggest that marginalizing racism is more than a belief that people retain a “stain” from membership in their original group. Marginalizing racism also manifests itself as conditional zero-sum beliefs about multiple group memberships.     

The F38-Like Group,a New Group of Caprine Mycoplasmas?

This paper concerns the taxonomic status of the F38-like group (MacOwan), a prime determinant of contagious caprine pleuropneumonia (CCPP). Extensive biochemical and serological investigations on strain F38 are reported. Some complex serological relationships with other mycoplasma species are revealed. The results, taken in conjunction with earlier published work on geno-typic characters, lead to the conclusion that final classification of these organisms should await further comparative studies of a number of field strains with a related group of strains classified as M. capri-colum. The characterization of F38 confirms its partial relationship to the “M. mycoides group” of ovine/caprine/bovine mycoplasmas, and has also revealed a very close phenotypic relationship to the bovine mycoplasma serogroup 7, a finding of potential diagnostic and epidemiological importance.     

Stakeholders’ Perceptions on Shortage of Healthcare Workers in Primary Healthcare in Botswana: Focus Group Discussions

Background

An adequate health workforce force is central to universal health coverage and positive public health outcomes. However many African countries have critical shortages of healthcare workers, which are worse in primary healthcare. The aim of this study was to explore the perceptions of healthcare workers, policy makers and the community on the shortage of healthcare workers in Botswana.

Method

Fifteen focus group discussions were conducted with three groups of policy makers, six groups of healthcare workers and six groups of community members in rural, urban and remote rural health districts of Botswana. All the participants were 18 years and older. Recruitment was purposive and the framework method was used to inductively analyse the data.

Results

There was a perceived shortage of healthcare workers in primary healthcare, which was believed to result from an increased need for health services, inequitable distribution of healthcare workers, migration and too few such workers being trained. Migration was mainly the result of unfavourable personal and family factors, weak and ineffective healthcare and human resources management, low salaries and inadequate incentives for rural and remote area service.

Conclusions

Botswana has a perceived shortage of healthcare workers, which is worse in primary healthcare and rural areas, as a result of multiple complex factors. To address the scarcity the country should train adequate numbers of healthcare workers and distribute them equitably to sufficiently resourced healthcare facilities. They should be competently managed and adequately remunerated and the living conditions and rural infrastructure should also be improved.     

Effects of night shift on the cognitive load of physicians and urinary steroid hormone profiles – a randomized crossover trial

Mental and physical stress is common in physicians during night shifts. Neurocognitive effects of sleep deprivation as well as alterations in hormonal and metabolic parameters have previously been described. The aim of this crossover study was to evaluate the effects of night-shift work with partial sleep deprivation on steroid hormone excretion and possible associations with mood, sleep characteristics and cognitive functions in physicians.

In total, 34 physicians (mean age 42 ± 8.5 years, 76.5% male) from different departments of the General Hospital of Vienna, Austria, were randomly assigned to two conditions: a regular day shift (8 h on duty, condition 1) and a continuous day-night shift (24 h on duty, condition 2). In both conditions, physicians collected a 24 h urine sample for steroid hormone concentration analysis and further completed psychological tests, including the sleep questionnaire (SF-A), the questionnaire for mental state (MDBF) and the computer-assisted visual memory test (FVW) before and at the end of their shifts, respectively.

Although mean sleep deprivation during night shift was relatively small (~1.5 h) the impairment in participants’ mental state was high in all three dimensions (mood, vigilance and agitation, p ≤ 0.001). Sleep quality (SQ), feeling of being recovered after sleep and mental balance decreased (p ≤ 0.001), whereas mental exhaustion increased (p < 0.05). Moreover, we could show a nearly linear relationship between most of these self-rating items. Testing visual memory participants made significantly more mistakes after night shift (p = 0.011), however, mostly in incorrectly identified items and not in correctly identified ones (FVW). SQ and false identified items were negatively correlated, whereas SQ and time of reaction were positively associated. It is assumed that after night shift, a tendency exists to make faster wrong decisions. SQ did not influence correctly identified items in FVW. In contrast to previous investigations, we found that only excretion rates for pregnanetriol and androsterone/etiocholanolone ratios (p < 0.05, respectively) were slightly reduced in 24-h urine samples after night shift. A considerable stimulation of the adrenocortical axis could not be affirmed. In general, dehydroepiandrosteron (DHEA) was negatively associated with the sense of recreation after sleep and with the time of reaction and positively correlated with correctly identified items in the FVW test.

These results, on the one hand, are in line with previous findings indicating that stress and sleep deprivation suppress gonadal steroids, but, on the other hand, do not imply significant adrenocortical-axis stimulation (e.g. an increase of cortisol) during the day-night shift.     

Effects of algicide (copper sulfate) application on short-term fluctuations of phytoplankton in Lake Paranoá, central Brazil.

Short-term fluctuations and structure of phytoplankton were examined for two months in the dry season (August-September/1997) in a eutrophic reservoir of central Brazil. Algicide treatment for the control of Microcystis aeruginosa bloom influenced the short-term variation pattern of the phytoplankton community. Algicide treatment was effective in controlling M. aeruginosa bloom, but it also influenced the Cylindrospermopsis raciborskii population. These species retained low densities, showing small colonies and trichomes, respectively. Drops in Cyanobacteria populations following algicide treatment were succeeded by progressive increase in Chlorophyta. The shifts in environmental conditions may have allowed the development of this group. In this study correspondence analysis of abundance data for phytoplankton assemblage in lake Paranoa revealed that available light, rather than chlorophyll-a, total suspended material, and water temperature, accounted for most of the short-term fluctuation in phytoplankton structure during algicide application. Canonical correspondence analysis (CCA) showed the primary importance of water transparency changes in abundance of taxa in the community. Algicide treatment for the control of nuisance blooms is discussed as a contribution to improved efficiency in reservoir management.     

Effects of the 1997–1998 El Niño on the cnidarian community of a high turbidity coral reef system (northern Bahia,Brazil)

We are reporting on the results of a 4-year study that allowed for the analysis of the effects of the 1997–1998 El Niño Southern Oscillation (ENSO) event on the cnidarian community of the naturally high-turbidity reefs of northern Bahia, Brazil. Cnidarian densities were significantly different between pre- and post-ENSO years, with significant consequent changes in community composition. BIOENV analysis identified variations in turbidity, mean temperature variance, and cloud cover as the factors best explaining changes in the community. We suggest that the 1997–1998 ENSO event, the most intense on record, had a differential effect on the cnidarian community. Highest mortalities were suffered by minute hydroid colonies, partial mortality by octocorals and actiniarians, while large hydroid colonies and scleractinians were the least affected. Such an ability to survive under the stressful environmental regime imposed by this ENSO event is attributed to the presence of morphological pre-adaptations (e.g., size of colony polyps, abundance of certain nematocyst types) and the inherent phenotypic plasticity that results from long-term exposure to naturally stressful conditions.     

Effects of elevated ultraviolet-B radiation on a plant–herbivore interaction

Enhanced ultraviolet-B (UV-B) radiation may have multiple effects on both plants and animals and affect plant–herbivore interactions directly and indirectly by inducing changes in host plant quality. In this study, we examined combined effects of UV-B and herbivory on the defence of the mountain birch (Betula pubescens ssp. czerepanovii) and also the effects of enhanced UV-B radiation on a geometrid with an outbreak cycle: the autumnal moth (Epirrita autumnata). We established an experiment mimicking ozone depletion of 30% (a relevant level when simulating ozone depletion above Northern Lapland). Both arctic species responded only slightly to the enhanced level of UV-B radiation, which may indicate that these species are already adapted to a broader range of UV-B radiation. UV-B exposure slightly induced the accumulation of myricetin glycosides but had no significant effect on the contents of quercetin or kaempferol derivatives. Mountain birch seedlings responded more efficiently to herbivory wounding than to enhanced UV-B exposure. Herbivory induced the activities of foliar oxidases that had earlier been shown to impair both feeding and growth of moth larvae. In contrast, the contents of foliar phenolics did not show the same response in different clones, except for a decrease in the contents of tannin precursors. The induction of foliar phenoloxidase activities is a specific defence response of mountain birches against insect herbivory. To conclude, our results do not support the hypothesis that the outbreak cycle of the autumnal moth can be explained by the cycles of solar activity and UV-B.     

Genetic and Familial Environmental Effects on Suicide – An Adoption Study of Siblings

Background

While there is clear evidence of familial influences on suicide, the origin of these is less certain. We have investigated genetic and familial environmental factors by studying the occurrence of suicide in biological and adoptive siblings of adoptees who died by suicide compared to siblings of surviving adoptees.

Method

We used the Danish Adoption Register and Danish population registers to compare 221 siblings of adoptees who died by suicide with the siblings of 1,903 adoptees who did not die by suicide. All adoptions in the Danish Adoption Register are non-familial, i.e. the adoptive parents are biologically unrelated to the adoptee. Analyses were conducted on incidence rates of suicide in biological and adoptive siblings given occurrence of suicide in the adoptees while also taking into account psychiatric disorders.

Results

The risk of suicide in full siblings of adoptees who died by suicide before age 60 years was significantly higher than in full siblings of adoptees who had not died by suicide (incidence rate ratios (IRR) = 5.01; 95% confidence interval [CI] = 1.28 - 19.6). This increase persisted after adjustment for history of psychiatric admission of siblings (IRR = 4.19; 95% CI = 1.00 - 17.5).

Conclusions

Genetic factors influence risk of suicide, probably independently of psychiatric disorder. This is relevant in provision of advice to families, including possible prevention of suicide.