Luminescence Induced in Intact Leaves and Isolated Chloroplasts by Alcohols and Other Substances

Elodea leaves and spinach chloroplasts emit red light when treated with alcohols or certain other solvents for chlorophyll. The intensity of the light, the lag phase and the threshold concentration vary considerably between different alcohols. Light emission from a leaf starts a few seconds to a few minutes after the addition of alcohol to the medium, reaches a maximum after 2–45 minutes (sometimes more) and then continues for many hours. Despite the faintness of the glow, the total number of photons given off from a leaf after addition of alcohol may exceed the number of photons given off from the same sample as long-lived afterglow after saturating irradiation with far-red light. The maximum yield of photons per chlorophyll molecule is a little more than 10^–5. The alcohol-induced luminescence is not influenced by a decrease in the oxygen tension to one fifth of the normal. Electron micrographs of treated leaves reveal that the thylakoid lipids contract to drops at the edges of the grana. Treatment of isolated chloroplasts with ethanol results in light emission when the concentration is high enough to dissolve the chlorophyll. It is estimated that the surface free energy in the thylakoid lipid-aqueous interface, due to ordinary interfacial tension, is large enough to account for the light emission observed when the interfaces contract or disappear.     

Colonization in metapopulations: a review of theory and observations

In metapopulation dynamics turnover of populations in isolated patches may be frequent. Regional survival of a species in such a system with frequent extinctions hinges on its colonization ability. Colonization is more than just dispersal; when a propagule reaches a new patch it faces higher extinction probabilities than does an established population. Extinction models as well as empirical data suggest that a large propagule with a potential for rapid increase in a varying environment, or with a low mortality rate in an environment perceived as constant, has a higher probability of successful colonization. Large variation in population size when it is still small increases the risk of failure. Factors introducing such variation are demographic stochasticity and environmental variation. It is hard to single out demographic traits that ensure good colonizing ability, since colonization can be achieved in many different ways, but generalists and species with self-fertilization seem to be superior.     

Survival and habitat preferences of adult Bolitophagus reticulatus

1. Data from a 4-year mark–recapture study of the fungivorous tenebrionid beetle Bolitophagus reticulatus at a locality in central Sweden and a trapping study of the species elsewhere in the same region are used to describe the survival and habitat preferences of the species.
2. The adult beetle was found to survive for up to three winters. A minimum estimate of the yearly survival rate was 0.20.
3. The beetle was found to occur preferentially on tree trunks that were either standing or lying but only touching the ground along a minor part of their length; that were relatively thick; and that carried many Fomes fomentarius sporocarps. In contrast to previous information for this species, the beetle was found to use living sporocarps to a large extent, and not only dead ones.
4. An experiment with beetles given a choice between living and dead fungus tissue indicated that pairs of one male and one female beetle preferred living fungus while single beetles preferred dead fungus.     

Separation of two species standing as Alopecosa aculeata (Clerck) by morphological, behavioural and ecological characters, with remarks on related species in the pulverulenta group (Araneae, Lycosidae)

Study of numerous specimens identified as Alopecosa aculeata (Clerck), according to the prevailing concept, revealed two morphologically distinct forms concluded to represent distinct species. In Sweden, the two species are sympatric. One is identified as A. taeniata (C. L. Koch) [earlier regarded as conspccific with either A. aculeata or A. pulverulenta (Clerck)], here found to be widely distributed (outside Sweden material examined from Norway, Finland, the U.S.S.R., the F.R.G., Austria, Switzerland, France, and Italy). Alopecosa aculeata and A. taeniata (both with neotypes designated) are rcdescribed and illustrated. Their courtship behaviour is distinctly different and their habitat preference differs in part. Information on morphology, courtship behaviour, habitat, and phenology in the allied A. cuneata (Clerck) and A. pulverulenta is given. Connections between certain morphological characters and behavioural traits are discussed. A few cases of parasitism by insects (Acroceridac: Ogcodes and Ichncumonidac: Gelis) in A. aculeata are reported.     

Alpha brainwave training and perception of time passing: Preliminary findings

The ability to generate alpha brainwaves has been associated with the self-regulation of stress. It has been suggested that generation of these brainwaves, above what is to be expected in a normal 24-hour EEG, contributes to an expanded state of consciousness. This study attempted to test Newman's theory that expansion of consciousness could be observed in perception of time passing. Twenty female college students were randomly assigned to an alpha brainwave training or beta (mock) brainwave training group. Following ten 30-minute training sessions over a five-week period of time, each subject in each group was asked to produce ten randomly assigned time intervals. Mean scores were obtained for each of the ten intervals for each group. An analysis of variance with repeated measures was used to analyze the time interval perceptions of each group. According to results obtained, both main effects and interaction effects were highly significant (p<.0001). This study offers a beginning effort to examine the consciousness altering capability of alpha brain-wave generation.The author wishes to acknowledge Dr. Alton J. DeLong for his generosity in reviewing this paper and offering such helpful support and suggestions.     

Features of the underwater light climate just below the surface in some New Zealand inland waters

1. Using sampling rates of 8–64 Hz we found clear indications of extensive and high frequency fluctuations of underwater photosynthetically active radiation (PAR) just below the surface (0.016–1.1 m) in some New Zealand water bodies. High variability and flashing occurred down to at least 3 m depth.
2. PAR variability increased under the influence of bright sunshine if wind roughening of the surface took place. Concomitantly, the average PAR levels declined by about 10%. However, even when the surface was shaded, high variability of PAR persisted.
3. Under a calm surface, PAR irradiance followed a log normal distribution. This occurred independently of the presence of direct sunlight. However, when the surface was roughened by wind in sunshine, PAR immediately switched to a Gumbel (extreme value type EV1) distribution.
4. Neither wave action nor wave focusing of incident irradiance would explain the wide range of PAR close to the water surface, although both factors add to the PAR variability.
5. The data indicate that transmittance through the surface is highly variable at the temporal and spatial scales studied, and that the irregularity of the air–water interface is instrumental in bringing about the observed fluctuations of PAR just below the surface.     

Effects of Some Chemical Compounds on the Slow, Far-red Induced Afterglow from Leaves of Elodea and the Lack of Effect of N-methyl Phena zonium Methosulfate on Far-red induced Glucose Uptake in Chlorella

N-methyl phenozonium methosulfate,3–(3,4-dichlorophe-nyl)–l, l-dimethylurea and carbonylcyanide-m-chlorophenyl hydrazone have similar effects on the slow, far-red induced afterglow component in intact Elodea leaves as has previously been shown for Chlorella. The first compound increases the rate constant for emission. Contrary to the case with Chlorella, it also markedly increases the total amount of light emitted from 10 sec. to infinity (maximally by 50 percent). The second compound decreases the rate constant and the amount of light, and the third compound increases the rate constant and decreases the amount of light. Electron micrographs are compared with the hypothetical units that can be deduced from the afterglow experiments, and it is found that the small thylakoids (“grana thylakoids”) have a size of the same order of magnitude as that expected for the afterglow units. The afterglow from Elodea, in contrast to that from Chlorella, is not affected by desaspidin except at extremely high concentrations. Far-red induced glucose uptake in Chlorella is not affected by 10^–7M N-methyl phenazonium methosulfate, which was previously shown to have a large effect on afterglow kinetics in the same organism.     

Sperm ultrastructure in Myxinidocotyle and Acanthocotyle (Platyhelminthes, Monogenea, Acanthocotylidae)

Spermatozoa of Myxinidocotyle californica from the hagfish Eptatretus stoutii and of Acanthocotyle lobianchi from the skate Raja clavata show a similar ultrastructure: two axoncmes of the 9 + 1 type in parallel with the nucleus-and one mitochondrion. In the released Acanthocotyle spermatozoa nucleus and mitochondrion both have a triangular cross-section. No cortical microtubules are present. The ultrastructure of these two acanthocotylid spermatozoa thus corresponds to sperm pattern 2 according to Justine et al. (1985). This pattern is derived from the more primitive pattern 1, which in the Monogenea is found only in the Oligonchoinea Bychowsky, 1937 or the Polyopisthocotylea sensu Justine et al.