A comparative study on sub-filament organization in primary myofilaments of basalar direct flight and tibial extensor muscles of the lepidopteran,Achalarus lyciades

Summary Primary myofilaments of direct flight muscle fibers are hexagonally arranged, are surrounded by six secondary myofilaments, and are composed of two sub-unit-fibrils, 90–120 Å in diameter, at mid-sarcomere levels. Primary myofilaments are resolvable into electron-densities 15–25 Å in diameter, which number 3–4 in each sub-fibril at mid-sarcomere levels, and number 6–8 elsewhere. Primary myofilaments of tibial extensor muscle are not found in hexagonal arrays, are surrounded by 10–12 secondary myofilaments, and are resolvable into electron densities which are 15–25 Å in diameter similar to primary myofilaments of basalar flight muscle. However, a binary sub-fibril structure at mid-sarcomere levels is lacking in tibial extensor muscle fibers.The functional significance of the two-sub-fibril organization of myofilaments at midsarcomere levels in basalar direct flight muscle is not known, but may be related to the high rate of excitation-contraction cycles in these muscles.Supported by U.S.P.H.S. No. NB-06285. — The author wishes to express his grateful appreciation for the technical assistance given by Mrs. Ann Florendo during the course of this investigation.     

Global dynamics of a selection model for the growth of a population with genotypic fertility differences

A population growth model is considered for a one locus two allele problem with selection based entirely on fertility differences. A local stability analysis is carried out for the critical points — which include possible polymorphic states — of the resulting nonlinear differential equations. The methods of dynamical systems theory are applied to obtain limiting genotypic proportions for every initial state. Thus the results are global and there are no periodic solutions.Research for this paper was partially supported by the National Science and Engineering Research Council of Canada Grant NSERC A-8130Research for this paper was partially supported by the National Science and Engineering Research Council of Canada Grant NSERC A-4823Research supported by NSF Grant MCS 7901069. A portion of the work was carried out while the author was a Visiting Professor at the University of Utah, Salt Lake City, Utah     

Stanford Workshop on Extraterrestrial civilization Opening a new Scientific Dialog

A workshop, held at Stanford University on August 29 and 30, 1974, brought together two groups of scientists interested in extraterrestrial civilization (ETC). Group A is comprised of scientists studying the problem theoretically in terms of physical, astronomical and biological knowledge, and those considering searching for extraterrestrial radio signals which might provide evidence for ETC. Group B comprises scientists pursuing the UFO problem their activities comprise analysis of soft evidence such as eye-witness reports, and of hard evidence such as photographs. Discussion at the Workshop centered on the following topics: the existence of ETC; interstellar travel; interstellar communication; human contact with ETC; UFO evidence; evaluation of the UFO phenomenon; and assessment of our ignorance. It was generally agreed that radio search for ETC is a promising endeavor. Althought it was agreed that study of the UFO problem is a justifiable pursuit, members of Group A chose to remain skeptical in the absence of unimpeachable evidence concerning the nature of the phenomenon.     

Geographical distribution and the origin of life: The development of early nineteenth-century British explanations

Conclusions By the 1840s and 1850s biogeographical theory had polarized into two opposing views — both of which had their origins in the sixteenth or seventeenth centuries. At issue in this polarization was the question of God's involvement with His creation. At one end of the spectrum were Sclater, Agassiz, Kirby, and others who saw a neatly designed world in which geographical distributions were planned and executed by the hand of God at creation. For most of these naturalists, organisms were created en masse within the regions they now occupy. Disjunct distributions were proof to them that God had indeed created species in situ as many individuals. These naturalists hoped to reveal God's biogeographical plan by discovering His regions of creation. They had hoped to demonstrate a neatly devised set of regions of creation which might be applicable to all creatures, but in attempting to do so, they arrived at conflicting sets of delineations — thus helping to undermine their conceptions of nature in which design (both idealist and utilitarian) played an important part.⁹³ At the other end of the biogeographical spectrum were the theoretical ideas of Prichard and Lyell, who viewed a more remote God — one who allowed His creation to be shaped and modified by secondary laws. Lyell in particular wished to leave considerations of design aside, hoping to demonstrate that the shape of the present creation is due to natural laws. Prichard and Lyell saw God's role in the creation of species (and distributions) as being extremely limited. In fact, the regions of creation seen today are in actuality only natural artifacts produced by migrations and barriers. They saw distributions being in constant flux, as was the rest of nature.Those supporting the views of Prichard and Lyell spent a great deal of effort in attempting to remove a major obstacle in their paths — disjunct distributions. If disjunct distributions were indeed the products of separate creative acts, as Sclater and others claimed, then the arguments of Prichard and Lyell would be negated. For if the creation of a species was shown to be the product of multiple creations, then what was the need of migrations and dispersal mechanisms? Also at stake, of course, was the concept of species based upon generation. Darwin was well aware that if the supernatural implications of disjunct distributions could not be refuted, then his evolutionary system — founded upon a species concept based on descent — would be in peril.⁹⁴ A further barrier to the acceptance of the Prichard/Lyell view was the fact that those sympathetic to a nonsupernatural explanation of disjunct distributions could not agree upon a natural explanation for those anomalies, and an internal debate between naturalists within this group raged for decades.⁹⁵ By 1859 a biogeographical stalemate had occurred. Sclater and others, supporting their static view of nature, continued to look for regions of creation, pointing to disjunct distributions in support of their arguments, while those favorable to the views of Prichard and Lyell continued to search for natural explanations for such biogeographical anomalies.The key needed to resolve the biogeographical debate was a credible theory for species origins. By 1858 there were essentially three options for British naturalists: supernatural creation, Lamarckian transmutation, or natural creation. A few British naturalists grasped at these straws, but most workers preferred the option of remaining silent until a more viable explanation for the origin and distribution of species could be advanced.⁹⁶ And not until the publication of Darwin's theory did that explanation become available.     

Great tits do not compensate over time for a radio‐tag‐induced reduction in escape‐flight performance

The use of biologging and tracking devices is widespread in avian behavioral and ecological studies. Carrying these devices rarely has major behavioral or fitness effects in the wild, yet it may still impact animals in more subtle ways, such as during high power demanding escape maneuvers. Here, we tested whether or not great tits (Parus major) carrying a backpack radio‐tag changed their body mass or flight behavior over time to compensate for the detrimental effect of carrying a tag. We tested 18 great tits, randomly assigned to a control (untagged) or one of two different types of a radio‐tag as used in previous studies in the wild (0.9 g or 1.2 g; ~5% or ~6–7% of body mass, respectively), and determined their upward escape‐flight performance 1, 7, 14, and 28 days after tagging. In between experiments, birds were housed in large free‐flight aviaries. For each escape‐flight, we used high‐speed 3D videography to determine flight paths, escape‐flight speed, wingbeat frequency, and actuator disk loading (ratio between the bird weight and aerodynamic thrust production capacity). Tagged birds flew upward with lower escape‐flight speeds, caused by an increased actuator disk loading. During the 28‐day period, all groups slightly increased their body mass and their in‐flight wingbeat frequency. In addition, during this period, all groups of birds increased their escape‐flight speed, but tagged birds did so at a lower rate than untagged birds. This suggests that birds may increase their escape‐flight performance through skill learning; however, tagged birds still remained slower than controls. Our findings suggest that tagging a songbird can have a prolonged effect on the performance of rapid flight maneuvers. Given the absence of tag effects on reproduction and survival in most songbird radio‐tagging studies, tagged birds in the wild might adjust their risk‐taking behavior to avoid performing rapid flight maneuvers.     

Trunk Muscle Activation at the Initiation and Braking of Bilateral Shoulder Flexion Movements of Different Amplitudes

The aim of this study was to investigate if trunk muscle activation patterns during rapid bilateral shoulder flexions are affected by movement amplitude. Eleven healthy males performed shoulder flexion movements starting from a position with arms along sides (0°) to either 45°, 90° or 180°. EMG was measured bilaterally from transversus abdominis (TrA), obliquus internus (OI) with intra-muscular electrodes, and from rectus abdominis (RA), erector spinae (ES) and deltoideus with surface electrodes. 3D kinematics was recorded and inverse dynamics was used to calculate the reactive linear forces and torque about the shoulders and the linear and angular impulses. The sequencing of trunk muscle onsets at the initiation of arm movements was the same across movement amplitudes with ES as the first muscle activated, followed by TrA, RA and OI. All arm movements induced a flexion angular impulse about the shoulders during acceleration that was reversed during deceleration. Increased movement amplitude led to shortened onset latencies of the abdominal muscles and increased level of activation in TrA and ES. The activation magnitude of TrA was similar in acceleration and deceleration where the other muscles were specific to acceleration or deceleration. The findings show that arm movements need to be standardized when used as a method to evaluate trunk muscle activation patterns and that inclusion of the deceleration of the arms in the analysis allow the study of the relationship between trunk muscle activation and direction of perturbing torque during one and the same arm movement.     

New modeling approach for bounding flight in birds

A new modeling approach is presented which accounts for the unsteady motion features and dynamics characteristics of bounding flight. For this purpose, a realistic mathematical model is developed to describe the flight dynamics of a bird with regard to a motion which comprises flapping and bound phases involving acceleration and deceleration as well as, simultaneously, pull-up and push-down maneuvers. Furthermore, a mathematical optimization method is used for determining that bounding flight mode which yields the minimum energy expenditure per range. Thus, it can be shown to what extent bounding flight is aerodynamically superior to continuous flapping flight, yielding a reduction in the energy expenditure in the speed range practically above the maximum range speed. Moreover, the role of the body lift for the efficiency of bounding flight is identified and quantified. Introducing an appropriate non-dimensionalization of the relations describing the bird’s flight dynamics, results of generally valid nature are derived for the addressed items.     

Flights of fear: a mechanical wing whistle sounds the alarm in a flocking bird

Animals often form groups to increase collective vigilance and allow early detection of predators, but this benefit of sociality relies on rapid transfer of information. Among birds, alarm calls are not present in all species, while other proposed mechanisms of information transfer are inefficient. We tested whether wing sounds can encode reliable information on danger. Individuals taking off in alarm fly more quickly or ascend more steeply, so may produce different sounds in alarmed than in routine flight, which then act as reliable cues of alarm, or honest ‘index’ signals in which a signal''s meaning is associated with its method of production. We show that crested pigeons, Ocyphaps lophotes, which have modified flight feathers, produce distinct wing ‘whistles’ in alarmed flight, and that individuals take off in alarm only after playback of alarmed whistles. Furthermore, amplitude-manipulated playbacks showed that response depends on whistle structure, such as tempo, not simply amplitude. We believe this is the first demonstration that flight noise can send information about alarm, and suggest that take-off noise could provide a cue of alarm in many flocking species, with feather modification evolving specifically to signal alarm in some. Similar reliable cues or index signals could occur in other animals.     

A post-embedding avidin-biotin peroxidase system to demonstrate the light and electron microscopic localization of lectin binding sites in rat kidney tubules

Summary A post-embedding method for the light and electron microscopic demonstration of lectin binding sites in rat kidney tubules is described. The use of biotinylated lectins, followed by treatment with avidin peroxidase and the DAB—H₂O₂ sequence, produced intense staining of acrylic sections at the electron microscope level: brush borders and associated structures, cytoplasmic granules, basal infoldings and basement membrane—plasmalemmal interfaces of proximal tubules bound erythrophytohaemagglutinin, while distal tubules were mainly unstained. At the light microscope level, epoxy resin sections showed a similar staining pattern after etching, as did acrylic resin sections after intensification of the final reaction product. The binding of wheatgerm agglutinin to cytoplasmic granules and brush border structures in the proximal tubules was abolished, at both the light and electron microscope levels, by the competing sugar tri-N—acetylchitotriose. Epoxy resin ultrathin sections required etching before staining was achieved in the electron microscope, and results were far inferior to those obtained with acrylic resin. This method allows rapid and inexpensive screening of large numbers of lectins, if required, at both the light and electron microscope levels, using reagents that are stable for long periods of time.     

How Cheap Is Soaring Flight in Raptors? A Preliminary Investigation in Freely-Flying Vultures

Measuring the costs of soaring, gliding and flapping flight in raptors is challenging, but essential for understanding their ecology. Among raptors, vultures are scavengers that have evolved highly efficient soaring-gliding flight techniques to minimize energy costs to find unpredictable food resources. Using electrocardiogram, GPS and accelerometer bio-loggers, we report the heart rate (HR) of captive griffon vultures (Gyps fulvus and G. himalayensis) trained for freely-flying. HR increased three-fold at take-off (characterized by prolonged flapping flight) and landing (>300 beats-per-minute, (bpm)) compared to baseline levels (80–100 bpm). However, within 10 minutes after the initial flapping phase, HR in soaring/gliding flight dropped to values similar to baseline levels, i.e. slightly lower than theoretically expected. However, the extremely rapid decrease in HR was unexpected, when compared with other marine gliders, such as albatrosses. Weather conditions influenced flight performance and HR was noticeably higher during cloudy compared to sunny conditions when prolonged soaring flight is made easier by thermal ascending air currents. Soaring as a cheap locomotory mode is a crucial adaptation for vultures who spend so long on the wing for wide-ranging movements to find food.     

Phototactic behavior of the ambrosia beetle <Emphasis Type="Italic">Platypus quercivorus</Emphasis> (Murayama) (Coleoptera: Platypodidae) before and after flight

The ambrosia beetle Platypus quercivorus (Coleoptera: Platypodidae) is a vector of the pathogenic fungi, Raffaelea quercivora (Ophiostomatales: Ophiostomataceae), which causes Japanese oak wilt disease. Previous studies have shown that the beetle displays positive phototactic behavior; however, the adaptive significance of this behavior remains unclear. We postulated that positive phototaxis is necessary to allow the beetle to fly skyward immediately after emergence from a tree, and that this taxis changes following a certain period of flight. The present study aimed to clarify the changes in phototactic behavior of P. quercivorus before and after flight by using individual beetles emerging from the trunk of a Quercus crispula (Fagales: Fagaceae) tree that was attacked in 2014. The response of 60 beetles to light was tested ten times each, before and after flight in a flight mill. A generalized linear mixed model was constructed to predict the probability of positive phototaxis of P. quercivorus before and after flight. A best-fit model showed that the probability of positive phototaxis was lower after flight than before. The results suggest that positive phototaxis of P. quercivorus is decreased after flight.     

Electrical Stimulation of Coleopteran Muscle for Initiating Flight

Some researchers have long been interested in reconstructing natural insects into steerable robots or vehicles. However, until recently, these so-called cyborg insects, biobots, or living machines existed only in science fiction. Owing to recent advances in nano/micro manufacturing, data processing, and anatomical and physiological biology, we can now stimulate living insects to induce user-desired motor actions and behaviors. To improve the practicality and applicability of airborne cyborg insects, a reliable and controllable flight initiation protocol is required. This study demonstrates an electrical stimulation protocol that initiates flight in a beetle (Mecynorrhina torquata, Coleoptera). A reliable stimulation protocol was determined by analyzing a pair of dorsal longitudinal muscles (DLMs), flight muscles that oscillate the wings. DLM stimulation has achieved with a high success rate (> 90%), rapid response time (< 1.0 s), and small variation (< 0.33 s; indicating little habituation). Notably, the stimulation of DLMs caused no crucial damage to the free flight ability. In contrast, stimulation of optic lobes, which was earlier demonstrated as a successful flight initiation protocol, destabilized the beetle in flight. Thus, DLM stimulation is a promising secure protocol for inducing flight in cyborg insects or biobots.     

Generation time and albumin evolution

The albumins of long-generation animals such as man and chimpanzee are shown to be no less evolved immunologically than those of some short generation time rodents such as rat, mouse, and hamster. This finding casts very serious doubt on certain assumptions concerning the times of divergence of these species made by DNA hybridization workers. As these assumptions have led them to conclude that generation time is a key factor controlling the rate of genomic or DNA evolution, this latter conclusion is also made suspect. The molecular clock concept—that it is absolute time which determines the amount of protein and DNA evolution—is, on the other hand, strengthened.This research was supported by NSF grants GB-20750 to the author and GB-13119 to Dr. A. C. Wilson.     

In vitro test of self-incompatibility in Malus domestica

Summary An in vitro assay in which self-incompatible pollen of Malus domestica is selectively inhibited is described. This assay involves heat-labile substances diffusing from the stylar tissues — in particular, glycoproteins found in the protein extract of styles. In the presence of the self-style extract, a dramatic decrease in total protein concentration in the culture medium was revealed at 30-min germination. Pretreatment of the self-pollen with 100 mM glucose prevented this drop in protein level; moreover, tube growth was entirely restored. A possible explanation in terms of protein-carbohydrate complementation is suggested.     

Editorial

These are heady times. As the new millennium dawns, the field of zoology is more exciting than ever. Phylogenetic relations among animals are rapidly being refined or revised in light of new data and powerful new analyses. These revelations in turn are rekindling interest in the function, development, and evolution of animals from all branches of the zoological tree. Tools and insights derived from work on a few model organisms are being applied widely to fill in significant gaps in our knowledge about how the astonishing diversity of animal characteristics evolved.Paralleling this new excitement is an upheaval in scientific publishing. Increasingly specialized journals are sprouting up worldwide as publishers rush to embrace emerging areas of excitement. Electronic communication is re-defining expectations about how new knowledge is disseminated both in format and in mode of transmission and about the time from submission to publication. For established journals to survive, they too must evolve.This journal, ZOOLOGY, is evolving to meet the needs and expectations of the modern community of animal biologists. It aims to promote research like that of it's founder J.W. Spengel — that explicitly emphasizes comparative aspects of animal biology. With the rapid growth of phylogenetic information, ZOOLOGY now offers a venue where the full impact of recent phylogenetic advances on our understanding of animal form, function, development, and evolution can be addressed. An ambitious new group of editors, a new advisory board, and a professionally staffed editorial office, are working to rejuvenate ZOOLOGY as an internationally recognized leader in comparative animal biology.ZOOLOGY has a distinguished place in the pantheon of animal biology journals. It ranks among the oldest continuously published journals in Germany. Founded in 1886 as Zoologische Jahrbücher it quickly rose to prominence among European zoological journals. In the early 1990's, after political and social upheavaling some European countries and after the reunification of Germany, the journal took a more international approach under a new title, ZOOLOGY — ANALYSIS OF COMPLEX SYSTEMS (ZACS). For the last four years, ZOOLOGY has also worked in close cooperation with the German Zoological Society and this tradition will continue. Once each year, it will publish review lectures presented at the annual meeting of the Society. A supplement to ZOOLOGY, containing the abstracts of oral and poster presentations of the annual meeting, will also be produced in conjunction with the German Zoological Society.But the new ZOOLOGY also recognizes the increasing importance of rapid and international communication in all areas of animal biology. It therefore aims to reduce publication time drastically and to enhance the speed and rigor of the review process. The new editors and editorial board are committed to maintaining the highest scientific standards and also to remaining flexible enough to adjust to the ever changing field of animal biology. Recognizing the increasing importance of rapid, effective, international communication, the new ZOOLOGY will offer:— the highest scientific standards— a short review time— a publication time schedule of three months after acceptance— color plates free of charge (at the editors' discretion)— an online version published in advance of the printed journal— free E-mail Table of Contents alerts so papers are widely publicized— papers abstracted/indexed by all the major scientific indexing servicesAs the new cover and the more accessible layout inside this issues show, the change has already begun. The future holds great promise for animal biology. Join us as Zoology strives to fulfil that promise.Spring 2001J. Matthias StarckThomas C. BoschA. Richard PalmerKiyokazu Agata     

The Effect of Long-term Space Flights on Human Urine Proteins Functionally Related to Endothelium

It is known that long-term space flights lead to dysregulation of the cardiovascular system, and the endothelium is the most important functional element of such dysregulation. In order to find the signs of endothelial dysfunction in cosmonauts who have been in long-term space flights, we collected urine samples from 21 cosmonauts before the flight and on the first and seventh days after landing. The urine samples were investigated by chromatography–mass spectrometry analysis. Proteins were identified using the MaxQuant software and the SwissProt database. The software package Perseus was used for semi-quantitative analysis. The reconstruction of associative molecular networks was performed using the ANDSystem software. We identified 200 different proteins in urine samples of 21 Russian cosmonauts. The ANDSystem software made it possible to determine seven processes related to endothelium functioning. These processes had direct relations to 17 urine proteins, which were functionally associated with the endothelium. At the same time, eight proteins (such as serotransferrin, prostate-specific antigen, fibrinogen gamma chain, UFO tyrosine kinase receptor, aminopeptidase N, vascular cell adhesion molecule 1, osteopontin, and syndecan-4) were significantly changed (p < 0.01) at different points of the recovery period (the first and seventh days). Thus, we performed the first study of the urine protein composition in cosmonauts for the evaluation of signs of endothelial dysfunction after space flight using proteomics methods.     

Corner detection in curvilinear dot grouping

Corners, or discontinuities in orientation, are one of the most salient and useful properties of contours. But how sensitive are we in detecting them, and what does this sensitivity imply about the processes by which corners can be detected. In this paper we address both of these questions, starting with the observation that changing the samplign phase of a curve changes the geometry of its discrete trace, or the set of discrete (retinotopic) points onto which the curve projects. This motivates our stimuli — dotted curves —and our experimental design: if curves are represented by dots, the placement of the dots effects whether or not corners are perceived. Specifically, we present quantitative data on sensitivity to discontinuities as a function of dot phase, and address its theoretical explanation within a two-stage model of orientation selection. Curvature plays a key role in this model, and, finally, the model and experimental data are brought together by showing that a very coarse approximation to change in curvature (or differences in local curvature estimates) is sufficent to account for the psychophysical data on sensitivity to discontinuities.     

Spectral analysis of dual jerk waveforms in congenital nystagmus

Congenital nystagmus (CN) is a disorder of the ocular motility characterized by oscillatory eye movements preventing the correct fixation of a target. Many typical waveforms of eye position recordings have been recognized and classified in the literature: in jerk CN a slow phase eye movement is followed by a fast phase, giving rise to a typical saw-tooth waveform, while in pendular CN the eyes exhibit a periodic motion, giving rise to an approximately sinusoidal waveform. Dual jerk waveforms seemed to show small, rapid oscillations superimposed on a jerk-like waveform, thus being originary classified as a mixture of jerk and pendular CN. On the contrary, a theoretical model of CN has appeared recently, which suggests a possible interpretation of the small amplitude oscillations in dual jerk waveforms as consecutive pieces of growing and decaying exponentials.By spectral analysis of dual jerk waveforms in a number of patients with CN, we show that the oscillations are truly sinusoidal in nature, thus suggesting the possibility of a different explanation of dual jerk waveforms in CN.Preliminary results of this work were presented at XIV ICMP —International Congress of Medical Physics, Espoo, Finland, 11–16 August 1985