Redefinition of the Urostylidae (Ciliophora,Hypotrichida) on the Basis of Morphogenetic Characters*

SYNOPSIS Examination of stained specimens (protargol and nigrosinbutanol) of hypotrich ciliates during division allows understanding of morphogenesis of buccal structures and cirri. Midventral, frontal, and transverse cirri in both proter and opisthe of Urostyla marina differentiate from a longitudinal series of numerous oblique ciliary streaks in a manner similar to that of Bakuella, Holosticha, Keronopsii. Pseudourostyla, and Uroleptus. This pattern differs markedly from that in Amphisiella, Kahliella, Paraholosticha, and Paraurostyla, in which the fronto-ventral and transverse cirri arise from a series of fewer (2–5) ciliary streaks in a longitudinal or fan-like array. Rows of marginal cirri in U. marina arise independently, as in Urostyla grandis. On the basis of comparisons of both structural and morphogenetic features of this and other hypotrichs, the family Urostylidae is redefined to contain Urostyla (type), Bakuella, Holosticha, Keronopsis, Pseudourostyla, and Uroleptus. Other genera formerly contained in the families Holostichidae and Urostylidae are placed in synonymy, assigned to other families, or held in uncertain familial relationship pending their rediscovery and further investigation.     

The role of feedback during singing and flight in Drosophila melanogaster

ABSTRACT. During Drosophila courtship 'pulse song', muscle potentials occur at two points during the cycle of neuromuscular events which result in a sound pulse being produced. The dorsal longitudinal, second and third dorsal ventral and axillary muscles show potentials 18 ms before each sound pulse while the first dorsal ventral, basalar and sternobasalar muscles fire 3 ms after the onset of each pulse. The timing of these events remains unaltered in animals with the antennae removed, indicating that acoustic feedback is not an important factor. Courting vestigial flies, in the absence of detectable wing base movements, produce indirect muscle potentials at the appropriate song inter-pulse intervals. Thus proprioceptive feedback is also unimportant in determining the intervals between pulses. During putative 'sine song', 'pulse song' and flight in vestigial flies, however, the timing of basalar muscle potentials is abnormal. Also, if the wing is driven externally at a frequency different from that of normal flight, basalar and, to a lesser extent, first dorsal ventral muscles, are phase locked to the driving frequency. These two results suggest that the timing of those muscles which fire at the beginning of the sound pulses is set by proprioceptive feedback. A model of song production is proposed which takes into account the data from this and from previously published papers.     

Aspects of sandfly biology in southern Switzerland

Abstract. During three field surveys of phlebotomine sandflies in the region of Sessa, Minor Malcantone, southern Switzerland, annually 1987-89, Phlebotomus pemiciosus and P.mascittii were caught regularly by means of light traps, but only when the traps were in close association with humans. The most productive catching sites were in the middle of Sessa village, in basements or partially closed shelters in the immediate vicinity of human dwellings. All catching sites outside the village were negative. The only other sandfly species caught was Sergentomyia minuta, four specimens only. P.pemiciosus and P.mascittii always occurred together and were found to feed - at least occasionally – on human blood. Glucose and fructose were identified in wild-caught sandflies of both species. A breeding place of P.mascittii was identified in the basement of a house in the middle of Sessa. Analyses of soil samples revealed moderately loamy humus with a slightly acidic pH (5.6).     

DEVELOPMENT OF AN ACCEEPTABILITY CONSTRAINT FOR A LINEAR PROGRAMMING MODEL IN FOOD FORMULATION

Control of a product's market acceptability can be a difficulty when using linear programming models in food formulation. The development of an acceptability constraint was demonstrated for a linear programming model used for the formulation of fresh turkey bratwurst, a coarse ground type sausage. Development was in two stages. First, an experimental design and in-house panel determined quantitative relationships between the product's textural attributes and turkey meat ingredients. Second, the product toughness relationship was utilized to develop three formulations with different levels of toughness. These formulations were market tested using the acceptor set size as the measure of market acceptability. A relationship between product toughness and acceptor set size was determined, into which was substituted the toughness f (ingredients) relationship. This yielded acceptor set size as a f (ingredients) that was added to the least cost linear programming model in the form of an acceptability constraint.     

Response of Leaf Spectral Reflectance in Loblolly Pine to Increased Atmospheric Ozone and Precipitation Acidity

Leaf reflectance responses to increased ozone and precipitationacidity were determined at visible (400–720 nm) and infra-red(720–2500 nm) wavelengths for field-grown seedlings ofloblolly pine (Pinus taeda L.). Treatments were maintained continuouslyfrom 3 April to 3 November. In a relatively ozone-sensitivevariety of pine, increased ozone decreased visible and infra-redreflectance by late May. By late August, continued exposureto ozone increased visible and infra-red reflectance. As oflate November, ozone at 17ambient or greater concentrationshad increased visible reflectance substantially in an ozone-insensitiveas well as the ozone-sensitive variety. Acidic precipitationdecreased visible and infra-red reflectances in both varietiesin May and decreased infra-red reflectances in the ozone-sensitivevariety in August, but did not produce significant reflectanceresponses in November. Visible reflectance responses to ozoneand acidic precipitation, particularly those near 700 nm, werespectrally similar to reflectance responses reported previouslyfor other deleterious environmental influences. Key words: Pinus taeda, reflectance, ozone, acidic precipitation     

Developmental plasticity in a meristic character: the number of tentacles in the lophophore of a bryozoan species

There is increasing interest among evolutionary biologists in developmental plasticity. Previously ignored by many as being irrelevant to evolution because a plastic response to an environmental change is not inherited, the current, more positive, view of plasticity focuses on the fact that, although any individual plastic response is nonheritable, the overall pattern of developmental response to environmental variation (i.e. the developmental reaction norm) is heritable and may vary among genotypes within a population. Characters subject to plastic variation, like those that are entirely genetically determined, may vary in continuous, meristic or discrete ways. Of these, the least work has been carried out on meristic variation. In the present study, we contribute to the rectification of this imbalance by examining the plastic response of the number of tentacles in the lophophore of a species of bryozoan, Membranipora membranacea, to three environmental variables: temperature, salinity and food concentration. Because the approach taken was an experimental one, unlike the majority of studies of bryozoan tentacles to date, we are able to make statements about the causality of variation in tentacle number. The main conclusions of the present study are: (1) that plastic responses occur to all three environmental variables; (2) that these are part of a more generalized plastic response in the overall development of the zooids rather than being lophophore‐specific; and (3) that the issue of whether the relevant developmental reaction norms are adaptive or not is an open (and interesting) question. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 541–551.