Ecological analyses of nesting success in evening grosbeaks

Summary We studied the nesting success of Evening Grosbeaks (Coccothraustes vespertinus) inhabiting two areas of the Front Range of the Rocky Mountains of Colorado from 1983–1987. Sixty-four nests were followed during building, incubating, brooding, and fledging; 54.7% were successful (young fledged). The largest number of nests failed during incubation. Nests started later were more successful than nests begun earlier in the season. Failure was most likely due to severe weather, abandonment during building, or predation. Specific habitat characteristics of grosbeak nesting sites and where nests were placed in trees were consistently associated with nesting success. Successful nests, when compared with nests that failed, were: (1) built in more open areas characterized by dispersed vegetation and a higher minimum canopy, (2) oriented in more southerly directions, (3) built closer to the main trunk of the nest tree, and (4) built in larger trees. Current ideas about whether or not birds actually select nest-sites are briefly discussed. We conclude that some grosbeaks optimally select nest sites where the likelihood of producing fledglings is higher than in other areas.     

High frequency of adventitious shoot regeneration from commercial cultivars of evening primrose (Oenothera spp.) using thidiazuron

Evening primrose (Oenothera spp.) is grown commercially for its seed oil that contains gamma linolenic acid (GLA), a valuable food supplement and pharmaceutical. There is considerable interest in the potential of genetic engineering to improve yields of GLA in evening primrose, and attention has focused on the current state of tissue‐culture knowledge in this species which is a prerequisite for genetic transformation. Published protocols for the regeneration of plants from leaf or cotyledon material of Oenothera spp. are available, but these prove unsatisfactory when applied to commercial cultivars used in this study. An efficient method for regenerating three commercial cultivars of evening primrose Rigel, Merlin and Vulcan was developed using thidiazuron (TDZ) as a growth regulator. Explants from one month old seedlings were cultivated in vitro; a large number of buds were induced directly from strips of leaves, cotyledons and stems when cultured on Murashige and Skoog (MS) basal medium containing TDZ and indole‐butyric acid (IBA). Shoots that were excised and placed onto MS basal medium, supplemented with IBA, rooted with 85–90% efficiency. Plantlets were transferred to soil after 6–8 wk. TDZ stimulated the regeneration process, and its effects were enhanced when combined with IBA or indole‐3‐acetic acid (IAA). The methods developed may be a useful advance toward improvement of this oil seed crop through genetic modification.     

Evening chronotype,late weekend sleep times and social jetlag as possible causes of sleep curtailment after maintaining perennial DST: ain’t they as black as they are painted?

ABSTRACT

People sleep less in response to setting social clocks earlier relative to the sun clocks. We proposed here a model-based approach for estimating sleep loss as the difference between weekend and weekday risetimes divided on the difference between weekend risetime and weekday bedtime. We compared this approach with a traditional approach to estimating sleep curtailment as the difference in weekly average sleep duration in two conditions. Weekday and weekend sleep times reported for 320 samples provided possibility of testing whether evening types with later weekend sleep times and larger social jetlag differ from morning types with earlier weekend sleep times and smaller social jetlag on amount of sleep lost (1) throughout the week and (2) in response to an advance of weekday wakeups, for instance, after the expected installation of perennial Daylight Saving Time (DST). We found that (1) an amount of sleep lost due to advancing shift of weekday wakeups depends upon neither chronotype nor weekend sleep times nor social jetlag, (2) a very large amount of sleep is usually lost by evening types with later weekend sleep times and larger social jetlag and (3) an essential sleep loss is caused by our usual work/school schedules, even in morning types with early weekend sleep times and small social jetlag. As compared to such permanent sleep losses experienced by any types, an additional loss due to switching from Standard Time (ST) to perennial DST are expected to be relatively small. We also found that the traditional way of calculation of sleep curtailment leads to paradoxical conclusions, such as (1) sleep loss is larger when social jetlag is smaller, not larger, (2) sleep loss is larger when weekend sleep times are earlier, not later, (3) despite 1-h difference between two student samples in weekday wakeups, their sleep losses can be identical.     

Phytochemical characterization of potential nutraceutical ingredients from Evening Primrose oil (Oenothera biennis L.)

Evening Primrose oil (EPO) is a natural product extracted by cold-pressed from Oenothera biennis L. seeds. EPO is widely used as a dietary supplement from which beneficial effects have been reported in rheumatic and arthritic conditions, atopic dermatitis, psoriasis, premenstrual and menopausal syndrome, and diabetic neuropathy. The beneficial effects of EPO are thought to be due to its γ-linolenic acid content; in contrast, little effort has been expended to characterize the non-triglyceridic constituents of EPO. In order to evaluate its potential as source of functional food ingredients our aim in this work has been identified and quantified the different components of EPO by different techniques (GC–MS and HPLC). The lipid profile showed that oleic (7%), linoleic (74%) and γ-linolenic (9%) were the most abundance fatty acids. Unsaponifiable matter and subfractions were obtained by CEE/2568/91. Separation of the compounds under study was achieved giving a reasonable analysis time and good resolution. A yield (1.82–1.95%) of unsaponifiable matter was obtained and levels of saturated hydrocarbons (0.291.97 ± 14.85 mg) were noticed. β-Sitosterol (7952.00 ± 342.25 mg/kg oil) and campesterol (883.32 ± 0.45 mg/kg oil) were predominant in phytosterol fraction (9573 mg/kg oil), while tetracosanol (236.93 ± 2.32 mg/kg oil) and hexacosanol (289.92 ± 3.41 mg/kg oil) in linear aliphatic alcohol fraction (798.04 ± 5.66 mg/kg oil). In the phenolic fraction (55.49 ± 2.76 mg/kg oil), ferulic acid (25.23 ± 2.64 mg/kg oil) was the major component. From the results obtained, it can be suggested that the Evening Primrose oil can be considered an interesting alimentary source of substances of nutraceutical value.     

Morningness/Eveningness and Satisfaction With Life in a Polish Sample

Previous studies have provided evidence that eveningness could be related to disadvantageous individual characteristics. The hypothesis that more evening-oriented individuals exhibit lower satisfaction with life has been tested by Randler using a sample of 164 German university students, and this showed that eveningness is associated with lower satisfaction with life (r?=?.177). The aim of the present study was to answer the question of whether or not this relationship is culturally independent, and would exist if a sample from another geographical location and culture had been studied. A sample of 349 residents (149 men) aged between 13 and 59 yrs from two Polish cities completed the Morningness-Eveningness Questionnaire and the Satisfaction with Life Scale. Analysis revealed that morningness was related to greater life satisfaction (r?=?.105), regardless of age and sex. The magnitude of this relationship did not differ significantly between the Polish and the German sample, which suggests that the magnitude and direction of association between morningness/eveningness and satisfaction with life could be independent of culture or geographical location. (Author correspondence: E-mail: konrad.jankowski@psych.uw.edu.pl)     

Associations Between Chronotypes,Psychopathology, and Personality Among Incoming College Students

Chronotye is associated with age, sex, personality, and parental monitoring during childhood. The evening type is associated with poor school performance, sleep problems, anxious/depressive symptoms, tobacco smoking, caffeine consumption, alcohol drinking, and suicidality in adolescents. The present study tested the relationships between chronotype and a wide range of psychopathology and personality traits among 2919 incoming undergraduate students. Each participant completed a self-administered questionnaire that included demographics, plus the Morningness-Eveningness (M-E) scale, Brief Symptom Rating Scale (BSRS), Tridimensional Personality Questionnaire, and Maudesley Personality Inventory. The t-score distribution of the M-E scale was used to form the morning (t-score >60, n?=?419), evening (t-score <40, n?=?371), and intermediate (40?≤?t-score?≤?60, n?=?2129) groups. Multivariable regression was employed for data analysis. For males, the evening type scored higher on all subscales of the BSRS than the morning type, except phobic anxiety. For females, the evening type had higher scores than the other two types on all subscales, except in obsession/compulsion and phobic anxiety, where the evening type only scored higher than the intermediate type. The evening type of both sexes also scored higher than the morning type in novelty seeking, harm avoidance, and neurotic personality characteristics, but lower than the morning type in extraversion and social desirability. In reward dependence, the evening type scored lowest for males, but there was no difference for females. The findings of the evening type being associated with possible psychopathology and certain types of personality have public health implications, that is, chronotype needs to be taken into account in the development of mental health prevention programs and assessment of and intervention for mental problems in young adults. (Author correspondence: gaushufe@ntu.edu.tw)     

Chronopharmacology of Captopril plus Hydrochlorothiazide in Hypertension: Morning Versus Evening Dosing

Blood pressure follows a strong circadian rhythm in normotensive people and in patients with primary hypertension. This may have several implications for antihypertensive therapy, including the time of dosing. For this reason we studied the influence of different dosing times on the antihypertensive effect over 24 h using ambulatory blood pressure monitoring (ABPM). We studied 13 male patients with moderate hypertension with controlled blood pressure over 12 months under a fixed combination of captopril and hydrochlorothiazide. The dosage of the combination therapy was then halved and given as one evening and then as one morning dose, each for 3 weeks. The combination therapy given twice daily showed a good 24-h antihypertensive effect after 12 months of treatment. During the following 6 weeks the mean 24-h blood pressure did not increase under half dosage, irrespective of whether under evening or morning dosing. However, mean daytime values (systolic and diastolic) of ABPM were significantly higher with evening dosing when compared both with full dosage and with half dosage given in the morning. The mean arterial blood pressure over 24 h showed the same differences as systolic and diastolic blood pressure, whereas heart rate was not significantly different between the three therapeutic regimens. ABPM seems to be an ideal method for chronopharmacological investigations under everyday conditions. Our study demonstrated significant differences in daytime blood pressure but not in 24-h blood pressure between morning and evening dosing of a fixed antihypertensive combination therapy.     

TEMPERATURE PROFILES,AND THE EFFECT OF SLEEP ON THEM,IN RELATION TO MORNINGNESS-EVENINGNESS IN HEALTHY FEMALE SUBJECTS

There were 15 healthy female subjects, differing in their position on the “morningness-eveningness” scale, studied for 7 consecutive days, first while living a sedentary lifestyle and sleeping between midnight and 08:00 and then while undergoing a “constant routine.” Rectal temperature was measured at regular intervals throughout this time, and the results were subjected to cosinor analysis both before and after “purification” for the effects of physical activity. Results showed that there was a phase difference in the circadian rhythm of core temperature that was associated with the morningness score, with calculations that “morning types” would be phased earlier than “evening types” by up to about 3h. This difference in phase (which was also statistically significant when the group was divided by a median split into a “morning group” and an “evening group”) could not be attributed to effects of waking activity and existed in spite of the subjects keeping the same sleep-wake schedule. Moreover, it persisted when the subjects' data had been purified and when the data were obtained from the constant routine. That is, there was an endogenous component to this difference in phase of the core temperature. The morning group also showed a greater fall of core temperature during sleep; this was assessed in two ways, the main one being a comparison of constant routine and nychthemeral data sets after correction for any effects of activity. Even though the morning group was sleeping at a later phase of their circadian temperature rhythm than was the evening group, neither group showed a fall of temperature due to sleep that varied with time elapsed since the temperature acrophase. It is concluded that another factor that differs between morning and evening types is responsible for this difference. (Chronobiology International, 18(2), 227–247, 2001)     

ELF3 recruitment to the PRR9 promoter requires other Evening Complex members in the Arabidopsis circadian clock

Biological timekeeping is essential for proper growth and development. Organisms such as the model plant Arabidopsis use the circadian clock to coordinate biological processes with the environment so that changes in conditions are anticipated and processes favorably phased. Despite the identification of numerous clock genes, knowledge of their molecular connectivity and influence on output programs remains limited. We recently showed LUX encodes a sequence-specific DNA-binding protein that directly regulates expression of the morning clock gene PRR9. We also showed that LUX interacts with the evening-phased proteins ELF3 and ELF4 to form a complex called the Evening Complex (EC). The EC binds the PIF4 and PIF5 promoters to control hypocotyl growth as a clock output. Here we provide evidence that LUX also recruits ELF3 to the PRR9 promoter. As with the PIF4 and PIF5 promoters, both LUX and its close homolog NOX are required for recruitment. Hence the entire EC likely functions together as part of the core clock oscillator to optimize plant fitness.