Application of Flow Microflorometry to the Study of Algal Cells and Isolated Chloroplasts

The applicability of flow microfluorometry (FMF) to the studyof chlorophyll-containing cells was investigated through theuse of the blue-green alga Agmenellum quadruplicatum, the greenalgae Trebouxia, Chlorella, and Euglena spp., and isolated spinachchloroplasts. When excited by laser radiation (488 nm), algalcells emitted fluorescence with intensity positively relatedto the chloro-phyll content. The chlorophyll fluorescent signalswere used further as a differential criterion in determiningrelative size based on light scattering logic and to sort mixturesof algal cells having different chlorophyll content The FMFalso was useful in estimating nucleic acid and protein contentin completely dechlorophyUized algal cells with the use of ethidiumbromide (EB) and fluoresceinisothiocyanate (FITC), respectively.     

Synchronization of larval emergence in winter moth (Operophtera brumata L.) and budburst in pedunculate oak (Quercus robur L.) under simulated climate change

1. The hypothesis that a 3 °C elevation in temperature and doubled CO₂ concentration would have no effect on the synchronization of winter moth egg hatch with budburst in oak was tested by comparing the separate and interactive effects of ambient and elevated (+ 3 °C) temperature and ambient and elevated (doubled to 340 p.p.m.) CO₂ in eight experimental Solardomes. In addition, an outdoor control was compared with the ambient temperature/CO₂ treatment combination.
2. Elevated temperature accelerated darkening (preceding egg hatch by about 5–10 days) and hatching of eggs developing off the trees; elevated CO₂ had no effect. The same effects were observed in eggs developing on the trees.
3. Within treatments, date of egg hatch was the same on trees with early or late budburst.
4. Egg darkening and budburst were closely synchronized at both ambient and elevated temperatures.
5. Both eggs and trees required fewer cumulative heat units (day degrees > 4 °C), for hatching and budburst, respectively, at ambient than elevated temperatures. The requirements in the outdoor control treatment were similar to those in the ambient Solardome treatment.
6. Egg hatch between 10 and 25 °C, on a temperature gradient in the laboratory, required a constant number of heat units; fewer were required below 10 °C.
7. Elevated temperatures, in the Solardomes and the field, delayed adult emergence from the pupae.
8. The results suggest that a general increase in temperature with climatic change would not affect the closeness of the synchronization between egg hatch of winter moth and budburst of oak.     

Neomegamphopas kunduchii sp. nov. (Crust: Amphipoda) from East Africa, with a discussion of gnathopodal dominance in isaeid amphipods

A new species of Neomegamphopus Shoemaker, is described from East Africa. Ledoyerella gen. nov. is erected to include Lembos caputphotis Ledoyer and L. isochelatus Ledoyer, and Maragopsis gen. nov. to include Lemboides bidentata Ledoyer. It is suggested that the Aoridae sensu stricto are a distinct and easily recognizable family and should not be considered merely as polyphyletic offshoots of the Isaeidae. The hypothesis is put forward, that “neomegamphid” amphipods have been derived from ancestral isaeid stock which did not exhibit a marked secondary sexual development of the gnathopoda, while genera such as Aloiloi and Aorchoides are more recent derivatives of isaeids by a process of axial reversal of gnathopod dominance.     

Transport Equations and Criteria for Active Transport

The relation between driving forces and the flux of solutesthat would be expected in a passive system is derived. Thisrelation is a differential equation and different solutionsare obtained which apply to different experimental conditions.Solutions are given for the cases of pure convective flow, diffusion,electrophoretic mobility, balance between diffusive and electricalforces, and transport in the presence of both concentrationand voltage differences.     

Type specimens and identity of the described species of Conus.

During the third decade of the 19th century, 21 authors described 35 Recent and 11 fossil species of Conus , in 26 separate publications. This brought to 532 the number of species-group names in the genus introduced up to 1830. Only five fossil and seven Recent species are now considered valid. Two additional valid Recent species were described but were given preoccupied names. The remaining nominal species are concluded to be junior or contemporaneous synonyms (19), nomina dubia (11), of infrasubspecific rank (1), or not now considered Conus (1). At present 160 valid species of Conus are recognized from the species-group names described between 1758 and 1830. Of these, 138 are extant and 22 are known only as Tertiary fossils. Nine otherwise valid species, six Recent and three fossil, were described but were given preoccupied names.     

Optimal Foraging Theory and the Psychology of Learning

The development of optimization theory has made important contributionsto the study of animal behavior. But the optimization approachneeds to be integrated with other methods of ethology and psychology.For example, the ability to learn is an important componentof efficient foraging behavior in many species, and the psychologyof animal learning could contribute substantially to testingand extending the predictions of optimal foraging theory.     

Statistical hypothesis testing in intraspecific phylogeography: nested clade phylogeographical analysis vs. approximate Bayesian computation

Nested clade phylogeographical analysis (NCPA) and approximate Bayesian computation (ABC) have been used to test phylogeographical hypotheses. Multilocus NCPA tests null hypotheses, whereas ABC discriminates among a finite set of alternatives. The interpretive criteria of NCPA are explicit and allow complex models to be built from simple components. The interpretive criteria of ABC are ad hoc and require the specification of a complete phylogeographical model. The conclusions from ABC are often influenced by implicit assumptions arising from the many parameters needed to specify a complex model. These complex models confound many assumptions so that biological interpretations are difficult. Sampling error is accounted for in NCPA, but ABC ignores important sources of sampling error that creates pseudo-statistical power. NCPA generates the full sampling distribution of its statistics, but ABC only yields local probabilities, which in turn make it impossible to distinguish between a good fitting model, a non-informative model, and an over-determined model. Both NCPA and ABC use approximations, but convergences of the approximations used in NCPA are well defined whereas those in ABC are not. NCPA can analyse a large number of locations, but ABC cannot. Finally, the dimensionality of tested hypothesis is known in NCPA, but not for ABC. As a consequence, the 'probabilities' generated by ABC are not true probabilities and are statistically non-interpretable. Accordingly, ABC should not be used for hypothesis testing, but simulation approaches are valuable when used in conjunction with NCPA or other methods that do not rely on highly parameterized models.     

Pulsed pheromone stimuli affect the temporal response of antennal receptor neurones of the adult cabbage looper moth

Abstract. Male cabbage looper moths, Trichoplusia ni (Hiibner) (Lepidoptera: Noctuidae), fly upwind in response to pheromone blends produced and released by calling conspecific females. Specialized sensilla on the male antenna contain sensitive, highly specific olfactory receptor neurones which respond to constant olfactory signals, with a phasic-tonic pattern of action potential discharge. Olfactory stimuli in nature are not uniform. They are thought to consist of pulses of odours whose distribution is shaped by wind and local environmental features. We begin to evaluate this natural situation by stimulating pheromone-sensitive sensilla with short (200 ms) paired pulses of the major component of the female's pheromone blend, (Z)-7-dodecen-l-ol acetate (Z-7,12:AC). Different stimulus protocols in which the pulses were separated from each other by varying intervals were evaluated. The interval between pulses had a large effect on the phasic component of the response. Intervals between pulses as short as 30 ms reduced the response to a second pulse by > 50%. When the intervals between pulses were longer than 3 s, significant differences were not seen between the responses to the first and second pulse. Implications for male orientation in natural, female-produced, pheromone plumes are discussed.