Disrupted seasonal biology impacts health, food security and ecosystems.

The rhythm of life on earth is shaped by seasonal changes in the environment. Plants and animals show profound annual cycles in physiology, health, morphology, behaviour and demography in response to environmental cues. Seasonal biology impacts ecosystems and agriculture, with consequences for humans and biodiversity. Human populations show robust annual rhythms in health and well-being, and the birth month can have lasting effects that persist throughout life. This review emphasizes the need for a better understanding of seasonal biology against the backdrop of its rapidly progressing disruption through climate change, human lifestyles and other anthropogenic impact. Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security. Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality. In this review, we introduce scenarios of seasonal disruption, highlight key aspects of seasonal biology and summarize from biomedical, anthropological, veterinary, agricultural and environmental perspectives the recent evidence for seasonal desynchronization between environmental factors and internal rhythms. Because annual rhythms are pervasive across biological systems, they provide a common framework for trans-disciplinary research.

Preparation of homogeneous samples of double-labelled protein suitable for single-molecule FRET measurements.

Preparation of pure and homogenous site specifically single- and double-labelled biopolymers suitable for spectroscopic determination of structural characteristics is a major current challenge in biopolymers chemistry. In particular, proper analysis of single-molecule Förster resonance energy transfer measurements is based on the spectral characteristics of the probes. Heterogeneity of any of the probes may introduce errors in the analysis, and hence, care must be taken to avoid preparation of inhomogeneous labelled biopolymer samples. When we prepared samples of Escherichia coli adenylate kinase (AK) mutants labelled with either Atto 488 or Atto 647N, the products were spectrally inhomogeneous and the composition of the mixture changed gradually over time. We show here that the inhomogeneity was not a result of variation in the dye interaction with neighbouring side chains. Rather, the slow drift of the spectral characteristics of the probes was a characteristic of an irreversible chemical transformation probably due to the hydrolysis of the succinimide ring of the attached dye into its succinamic acid form. Overnight incubation of the labelled protein in mild basic solution accelerated the interconversion, yielding homogeneous labelled samples. Using this procedure, we obtained stable homogenous AK mutant labelled at residues 142 and 188.

Optomotor response in human infants to apparent motion: evidence of innateness.

Human infants were placed inside a stationary cylinder containing a columnar pattern like that used to elicit the optokinetic reflex. By sequential illumnination of the columns, the pattern was made to appear to rotate. Optokinetic nystagmus was clearly evoked in 64.7 percent of the subjects, with a weak-positive response in an additional 11.8 percent.

Optomotor responses to monocular stimulation: relation to visual system organization.

Results of tests on 4 mammalian, 19 reptilian, and 17 avian species confirmed the prediction that lack of optomotor response to monocular optokinetic stimulation in one of the two horizontal directions would correlate with afoveate retinal organization, whereas consistent optomotor responses to monocular stimulation in either horizontal direction would correlate with foveate organization.

Paradoxical sleep in two species of avian predator (Falconiformes).

Periods of disconjugate. and conjugate eye movements occur during the sleep cycle in Buteo jamaicensis arborealis and Herpetotheres cachinnans chapmanni. Electromyograms are essentially isoelectric throughout sleep. Slow waves appear only in short bursts of low amplitude in contrast to the long trains of high-amplitude waves reported for chickens and pigeons.

Safety and immunogenicity of a Vero-cell-derived, inactivated Japanese encephalitis vaccine: a non-inferiority, phase III, randomised controlled trial.

BACKGROUND: Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in southeast Asia. Although no treatment is currently available, vaccination effectively prevents the disease. In a non-inferiority study, we aimed to compare the safety and immunogenicity of a novel, second-generation, inactivated candidate vaccine for JEV with a licensed, mouse-brain-derived vaccine. METHODS: We included 867 adults in a multicentre, multinational, observer-blinded, randomised controlled phase III trial. Study sites were located in the USA, Germany, and Austria. Volunteers received either the JEV test vaccine intramuscularly on a two-dose schedule (on days 0 and 28; n=430) or the licensed vaccine subcutaneously according to its recommended three-dose schedule (on days 0, 7, and 28; n=437). The primary endpoint was immunogenicity, with respect to neutralising JEV-specific antibodies assessed by a plaque-reduction neutralisation test, which was assessable in 725 patients in the per-protocol population. This trial is registered as a clinical trial, EudraCT number 2004-002474-36. FINDINGS: The safety profile of the test vaccine was good, and its local tolerability profile was more favourable than that of the licensed vaccine. Frequency of adverse events was similar between treatment groups, and vaccine-related adverse events were generally mild. The seroconversion rate of the test vaccine was 98% compared with 95% for the licensed vaccine on day 56 (95% CI for the difference -1.33 to 3.43). Geometric mean titre for recipients of the test vaccine was 244 (range 5-19 783), compared with 102 (5-1864) for the licensed vaccine (ratio 2.3 [95% CI 1.967-2.75]). INTERPRETATION: The test JEV vaccine has a promising immunogenicity and safety profile.

Insect photoperiodism and circadian clocks: models and mechanisms.

Photoperiodic clocks allow organisms to predict the coming season. In insects, the seasonal adaptive response mainly takes the form of diapause. The extensively studied photoperiodic clock in insects was primarily characterized by a "black-box" approach, resulting in numerous cybernetic models. This is in contrast with the circadian clock, which has been dissected pragmatically at the molecular level, particularly in Drosophila. Unfortunately, Drosophila melanogaster, the favorite model organism for circadian studies, does not demonstrate a pronounced seasonal response, and consequently molecular analysis has not progressed in this area. In the current article, the authors explore different ways in which identified molecular components of the circadian pacemaker may play a role in photoperiodism. Future progress in understanding the Drosophila circadian pacemaker, particularly as further output components are identified, may provide a direct link between the clock and photoperiodism. In addition, with improved molecular tools, it is now possible to turn to other insects that have a more dramatic photoperiodic response.

Effects of otolithic vestibular stimulation on sleep.

This study evaluated the effects of otolithic vestibular stimulation in the form of a linearly accelerated parallel swing on nighttime sleep parameters and daytime sleep tendency in eight normal subjects. The protocol consisted of one adaptation night following by two motion nights, one adaptation night followed by two stationary nights, and two Multiple Sleep Latency Tests (MSLT), one motion and one stationary. On the motion nights, there was a decrease in stage 2 percentage as well as a facilitative effect on sleep latency on the last night. In addition, an increase in the number of rapid eye movements (REMs) per night was found without a significant alteration of REM sleep amount or latency. No significant differences were found between the motion and stationary MSLT days.

Prediction of respiratory distress syndrome by the fetal lung maturity analyzer microviscosimeter on newborn gastric aspirate.

To predict the development of respiratory distress syndrome (RDS), the authors determined the fluorescent polarization values on gastric aspirates obtained from 67 premature infants within 30 minutes of birth. In 29 cases these results were also compared with the fluorescent polarization values measured on the corresponding amniotic fluid samples. Measurements for microviscosity were made by fetal lung maturity analyzer. Among 15 of 67 premature infants who developed RDS, the fluorescent value measured on gastric aspirates in all 15 infants was greater than 0.320. The fluorescent polarization values were less than 0.320 in all 52 infants in whom RDS did not develop, a predictability of 100%. Direct comparison found fluorescent polarization values measured on gastric aspirates to be somewhat lower than the corresponding amniotic fluid fluorescent polarization values. The results indicate that gastric aspirate obtained within 30 minutes of birth contains swallowed amniotic fluid. In cases where amniotic fluid samples were not available for surfactant evaluation prenatally, the determination of fluorescent polarization values on the newborn's gastric aspirate may accurately predict the development of RDS. The use of the fetal lung maturity analyzer microviscosimeter provides a simple, reliable, and rapid (45 minutes) method for assessment of surfactant in premature infants.

The wind-evoked escape behavior of the cricket Gryllus bimaculatus: integration of behavioral elements

The wind-evoked escape behavior of freely ranging crickets (Gryllus bimaculatus) was studied using high-speed video and film analysis. The escape response can be of three types: a turn, a jump or a turn + jump. Any of these can be followed by running. The turn is similar to that of the cockroach, in terms of the details of body and leg movements. A jump occurs only when the cricket has its back to the wind, either because the stimulus came approximately from behind or because the cricket had first turned away from the wind and then jumped. The jump, like that of locust, requires some form of energy storage and quick release to obtain the necessary power. Locusts use long-term co-activation of antagonistic leg motor neurons to produce mechanical energy storage. By contrast, crickets do not appear to co-activate antagonistic leg motor neurons. Possible alternative energy storage and release mechanisms are discussed.

Antinuclear autoantibodies in sera of healthy pregnant women and their offspring.

The presence of autoantibodies in the fetus has previously been investigated in the offspring of mothers with autoimmune diseases, but not in the offspring of healthy pregnant women. Employing the ELISA method, we examine four SLE-associated auto-antibodies (anti-dsDNA, anti-ssDNA, anti-poly(I), and anti-cardiolipin) in sera obtained from 196 healthy pregnant women and their offspring. All detected autoantibodies in maternal and blood cord sera were of the IgM isotype. Thirty-four maternal sera (17.3%) were positive for one or more tested autoantibodies: 16 (8.1%) for one autoantibody alone, 17 (8.6%) for two autoantibodies, and one (0.5%) for three autoantibodies; 1.5%, 5.6%, 9.6%, and 10.2% of the maternal sera were positive for autoantibodies against dsDNA, ssDNA, poly(I), and cardiolipin, respectively. In only one blood cord serum sample was an autoantibody (IgM anti-ssDNA) detected. This infant was born to a healthy seronegative mother. The finding that all offspring of IgM seropositive mothers are IgM seronegative is not surprising since maternal IgM autoantibodies do not cross the placenta. The finding of an IgM seropositive infant born to an IgM seronegative mother may indicate that the fetus is capable of self-production of autoantibodies.

Predictors of lung function in infants at high risk of atopy: effect of allergen avoidance.

Children of atopic parents are recognised as being at higher risk of developing bronchial asthma, drawing the attention of prevention strategies towards this population. Due to recent advances, lung function abnormalities in asthmatic children may now be measured early in life. The aim ofthis investigation was to examine possible predictors of lung function development in a sub sample of high-risk infants who took part in an allergy avoidance study In 60 babies of atopic parents, measurements of upper airways inflammation were performed at 4 weeks of age, respiratory symptoms were assessed at 6 and 12 months of age, and lung function (Vmax, FRC) was measured at 18 months by the rapid thoracoabdominal compression technique. Twenty-eight babies were enrolled in an allergen avoidance program, and 32 recruited as controls. No significant differences were detected for V'max,FRC between the intervention group (mean 331 ml s(-1)) and the control group (359 ml s(-1)), P = 0.382. A multiple linear regression model could explain levels of V'max FRC by weight gain since birth (beta = -35.35 ml s(-1) kg(-1), P = 0.022) and by eosinophilic cationic protein (ECP) (beta = -0.95 ml s(-1) microl(-1), P = 0.044), but not by intervention. Lung function measured at the age of 18 months in high-risk children is associated with weight gain and nasal ECF.

Evaluation of reliability of history in women complaining of urinary stress incontinence.

It was the aim of this study to evaluate critically the value of history in patients complaining of urinary stress incontinence. Diagnosis was established mainly by radiologic and cystomanometric assessment. History included 21 symptoms subdivided into various items. Only 3 symptoms were proven significant in distinguishing between various diagnostic groups. Assessment of stress incontinence should be regarded as incomplete without other means of evaluation in addition to history.

[The effect of inhalable dust particles (PN10) on lung function and respiratory symptoms of school children in Lower Austria]. / Der Einfluss von inhalierbaren Staubpartikeln (PM10) auf Lungenfunktion und respiratorische Symptome bei niederösterreichischen Volksschulkindern.

The effect of PM10 (particulate matter less than 10 microns in diameter) on respiratory symptoms and lung function was evaluated in 881 children (aged 8 to 11 years) in 8 communities in Lower Austria. In each community, air pollution data (PM10, SO2, NO2, O3) were collected. The examination of each child included a questionnaire (spring 1996), and two lung function tests (autumn 1995, spring 1996). Statistically significant relationships were observed between PM10 levels (annual mean, 15.8-26.9 micrograms/m3) and parameters of lung function (adjusted for sex, height, atopy, passive smoking, altitude, temperature). A 10 micrograms/m3 increase in the last two weeks' mean PM10 in spring 1996 was associated with a 0.05% decrease in FVC, a 0.05% decrease in FEV1, a 0.15% decrease in MEF50, and a 0.13% decrease in MEF75-25. Furthermore, a 10 micrograms/m3 increase in last year's mean PM10 was associated with a 0.07% decrease in FVC. No association between the prevalence of respiratory symptoms and the last year's mean PM10-exposure was found. Our study demonstrates a small effect of low-level particulate air pollution on lung function of healthy school children.

[Restoration of fertility following excision of an intracranial hydatid cyst]. / Restitution de la fertilité après exérèse d'un kyste hydatique intra-crânien.

An unusual case of a 31 year-old Bedouin women, with secondary infertility of 13 years' duration who conceived twice spontaneously after removal of a hydatic cyst from her frontal lobe is reported. The reproductive function was restored probably by releasing the hypothalamic-pituitary axis from the pressure exerted by the cyst.