Center Wing Research Articles

The role of the T-box gene optomotor-blind in patterning the Drosophila wing

The development of the Drosophila wing is governed by the action of two morphogens encoded by the genes decapentaplegic ( dpp; a member of the BMP gene family) and wingless ( wg; a member of the WNT gene family), which promote cell proliferation and pattern the wing. Along the anterior/posterior (A/P) axis, the precise expression of decapentaplegic and its receptors is required for the transcriptional regulation of specific target genes. In the present work, we analyze the function of the T-box gene optomotor-blind ( omb), a decapentaplegic target gene. The wings of optomotor-blind mutants have two apparently opposite phenotypes: the central wing is severely reduced and shows massive cell death, mainly in the distal-most wing, and the lateral wing shows extra cell proliferation. Here, we present genetic evidence that optomotor-blind is required to establish the graded expression of the decapentaplegic type I receptor encoded by the gene thick veins ( tkv) to repress the expression of the gene master of thickveins and also to activate the expression of spalt ( sal) and vestigial ( vg), two decapentaplegic target genes. optomotor-blind plays a role in wing development downstream of decapentaplegic by controlling the expression of its receptor thick veins and by mediating the activation of target genes required for the correct development of the wing. The lack of optomotor-blind produces massive cell death in its expression domain, which leads to the mis-activation of the Notch pathway and the overproliferation of lateral wing cells.

High Spatial Resolution Observations of Pores and the Formation of a Rudimentary Penumbra

We present high spatial resolution observation of small-scale magnetic activity in solar active region NOAA 9539. The observations were obtained on 2001 July 15 using the 65 cm vacuum reflector and 25 cm refractor of the Big Bear Solar Observatory (BBSO). The data sets include time series of speckle reconstructed continuum images at 5200 A, Hα filtergrams (blue line wing, line center, and red line wing), and line-of-sight magnetograms. Two pores, separated by a light bridge, were located in the central part of NOAA 9539. The formation of penumbral filaments near the light bridge indicated a sudden change of the local magnetic field topology from almost vertical to strongly inclined magnetic fields, which allowed cool material previously suspended in a filament to stream downward. During the downward motion of the cool material, Hα Dopplergrams revealed twisted streamlines along the filament. Finally, there are several well-defined Hα brightenings, Ellerman bombs (EBs), occurred near the region where the downflow of materials fell in. The EBs reside near a magnetic inversion line and are stationary, as opposed to EBs associated with moving magnetic features. We also found that the horizontal flow field of the white-light images derived from local correlation tracking is different from the previous observations. The horizontal movements in the superpenumbrae of leading sunspot and the following sunspots are opposite.

Bayan hentbolcuların görsel ve işitsel reaksiyon zaman farklılıklarının incelenmesi

Bayan hentbolculardan orta oyun kurucu, pivot ve kanat oyuncularının görsel ve işitsel reaksiyon zamanlarının incelenmesi amacı ile yapılan bu çalışmaya yaş ortalamaları 21.17 ± 1.50 olan 30 bayan hentbolcu denek olarak katılmıştır. Türkiye Bayanlar Hentbol 1. Ligi’nde, Ankara’da oynayan bu hentbolculardan 9’u pivot, 9’u orta oyun kurucu, 12’si kanat oyuncusudur.Görsel ve işitsel reaksiyon zaman ölçümleri Newtest 1000 Aleti ile yapılmıştır.r. Araştırmadan elde edilen veriler ‘’Çoklu ANOVA’’, ‘’Pearson Momentler Çarpımı Korelasyon Tekniği’’ ve ‘’ t Testi ‘’ ile analiz edilmiştir. İstatistiksel analizler sonucunda hentbolcuların oynadıkları pozisyonlara göre ( orta oyun kurucu, pivot ve kanat ) görsel ve işitsel reaksiyon zamanları arasında anlamlı bir fark saptanmamıştır (p >0.05). Bayan hentbolculardan orta oyun kurucular ve pivot oyuncularının görsel ve işitsel reaksiyon zamanları arasında anlamlı bir ilişki saptanırken ( p < 0.05 ), kanat oyuncularının görsel ve işitsel reaksiyon zamanları arasında anlamlı bir ilişki saptanmamıştır (p > 0.05). Sonuç olarak, orta oyun kurucu, pivot ve kanat oyuncularının görsel ve işitsel reaksiyon zamanları arasında anlamlı bir fark saptanmamıştır (p > 0.05)

The Laboratory Characterization of Jet Fuel Vapor and Liquid

Jet fuel (Jet A, Jet A1) was characterized using two gas chromatographic techniques. Headspace gas chromatography (HS-GC) was used to determine component partial pressures and total vapor pressures by measuring vapor densities in equilibrium with the liquid fuel. Component partial pressures and total vapor pressures were also derived from analysis of the neat jet fuel liquid by determining liquid component mole fraction and using this result with Raoult's law to calculate vapor pressure. Measurements of some of the fuel vapor samples were made at 40, 50, and 60 °C and at vapor volume-to-liquid volume (V/L) ratios of 274 and 1.2, representing, respectively, a nearly empty (2.9 kg/m3) and a half-filled (364 kg/m3) center wing tank (CWT) in a Boeing 747-100 series aircraft. The temperatures and V/L ratios were chosen to cover the range of conditions that could exist in the CWT under some aircraft operations. Measurements of other fuel vapor samples were made at the individual fuel flash point temperatures (V/L = 1.2). Characterization of the liquid fuels was done by simple injections of the neat liquids onto a temperature-programmed gas chromatograph. Results from the liquid analyses were used to calculate fuel vapor properties for comparison with the HS-GC results. Results from both characterization methods were used to predict fuel flammability by calculating fuel-to-air (F/A) mass ratios for jet fuels under different use conditions. These F/A ratio results were compared with ratios determined for the fuels at their flash points.

Pentadactyl pattern of the avian wing autopodium and pyramid reduction hypothesis.

We report herein that a pentadactyl developmental pattern is evident in early wing morphogenesis of Gallus (chicken) and Struthio (ostrich). Five avascular zones (spatially predestined locations of contiguous metacarpal and phalangeal aggregation) and four interdigital vascular spaces are established by the regression patterns of autopodial vasculature. Transient vestiges of the first and fifth metacarpals are confirmed histologically and histochemically. They lie within the preaxial-most and postaxial-most avascular zones, respectively. These observations reveal conservative patterning of the avian hand and corroborate a II-III-IV metacarpal interpretation, argue for II-III-IV identity of ossified digits in birds, and favour a simple reduction rather than a homeotic shift in terms of the phenotype expressed by Hox genes in the phylogeny of the avian manus. We suggest that gradual, bilateral reduction of phalanges and metacarpals, via apoptosis mediated by BMP, occurred during the evolution of birds (Pyramid Reduction Hypothesis). This is congruent with the establishment of a central wing axis that became co-opted for coordinated movements. On the basis of evidence presented here, the direct avian ancestor is predicted to have been five-fingered with dominant digits (+ metacarpals) as follow: II, III, IV.

Roll damping characteristics of a small fishing vessel with a central wing

The roll damping characteristics of three models of a 3-ton class fishing vessel representing the bare hull, hull with bilge keels, and hull with bilge keels and a central wing are investigated by the free roll decay tests in calm water and also in uniform head waves in a towing tank. Speed and roll initial angle and OG (distance between the centers of gravity and roll) are varied to check their dependence on roll damping. The experimental results are compared with the numerical results of mathematical modeling by the energy method and the energy dissipation patterns are also compared for these three models. The bilge keel contributes significantly to the increment of the roll damping for zero speed but as speed increases, the lift generated by the central wing contributes significantly to the roll damping increase. In addition, it is shown that the roll damping is more or less influenced by the regular head waves.

A new winged seed from the Permian of China

Two specimens of a new type of winged seed, Semenalatum paucum Dilcher, Mei et Du, sp. nov., from the Huaibei Coal Field, Lower Shihhotse Formation of Early Permian age are described and discussed. It is suggested that this winged seed has coniferous affinities because there are sterile scales on one side of the seed, there is an inverted ovule, the seed is bilaterally symmetrical and the wings are formed from the outer integument of the seed coat. The seed has two lateral wings and a short central wing. The two lateral wings of the seed are oriented obliquely to the seed so it would have spun as it moved through the air reducing the settling time. The two specimens probably were transported from an upland flora into a Permian coal-forming swamp and are found in association with plants such as Lepidodendron, Lobatannularia, Gigantonoclea, Pecopteris and Caulopteris.

Eclipse Mapping of the Accretion Disk Wind in the Cataclysmic Variable UX Ursae Majoris

We present the results of an effort to model recent HST eclipse observations of the C IV 1550 A resonance line in the high-inclination nova-like cataclysmic variable UX UMa. Assuming this line to be predominantly wind-formed, we are able to roughly reproduce the shapes and strengths of the observed line profiles (both away from and during eclipse) within the framework of a simple kinematic model in which the outflow is described as a rotating, biconical accretion disk wind. Our preferred model also matches most of the detailed behavior of different parts of the C IV line profile (blue wing, line center, and red wing) as a function of orbital phase. The most important result of our modeling is that it strongly suggests the presence of a high column (NH ~ 1023 cm-2), relatively dense (ne 4 × 1012 cm-3), and only slowly outflowing (vpoloidal vescape) transition region between the disk photosphere and the fast-moving wind. We also find that the outflow from UX UMa is probably only moderately collimated (the outer opening angle of our preferred model is θmax 65°). Finally, the rotational disturbance seen in the data is fitted reasonably well by our model, in which the rotational component of motion in the wind is fixed by conserving the specific angular momentum of the outflowing material. The implications of these results for dynamical models of disk-driven winds are discussed.

The time-resolved ADMR in the photolysis of the polymethylene-linked system of xanthone and xanthene: Power dependence

The time-resolved ADMR (absorption-detected magnetic resonance) spectrum of the polymethylene linked biradical generated in the photolysis of α-(xanthene-2-carbonyloxy)-ω-(xanthene-2-carbonyloxy) dodecane is observed at various microwave power. When the lower microwave power is low, the ADMR spectrum is totally negative (the absorbance of xanthyl radical decreases by the microwave irradiation) and is interpreted in terms of the hyperfine structure of the terminal radicals. In contrast with this, the ADMR spectrum obtained at high microwave field consists of two components: central component and wing component. The central component is positive and is interpreted in terms of the deceleration of the intersystem crossing by microwave, which is known as the spin locking. The wing component is negative and the linewidth is much larger than that of the central one. It is ascribed to the transitions from |T+1> and |T−1> states to singlet state having a slight |T0> character. It is proposed that the width of the time resolved spectrum is due to the fluctuation of the exchange integral (modulated exchange integral) by the motion of the polymethylene chain. The time dependence of the central and wing components and the conditions for observation of them are discussed.

Eclipse Mapping of the Accretion Disk Wind in the Cataclysmic Variable UX UMa

AbstractWe present the results of an effort to model recent HST eclipse observations of the wind-formed C, ɪv 1550Å resonance line in the high-inclination nova-like variable UX UMa (Mason et al. 1995, Baptista et al. 1995). Within the framework of a simple kinematic model, in which the outflow is described as a rotating, biconical accretion disk wind (Knigge et al. 1995), we are able to reproduce not only the shapes and strengths of the observed line profiles both away from and during eclipse, but also most of the detailed behaviour of different parts of the line (blue wing, line centre and red wing) as a function of orbital phase (Figure 1).The most important result of our modeling is that it strongly suggests the presence of a vertically extended (H ~ few × 10 RWD), relatively dense (ne ~ 1013 cm−3) and only slowly-outflowing (υpoloidal &lt;&lt; υescape) transition region between the disk photosphere and the fast-moving wind. Thus the best current data already demand that the simplified picture of accretion disks and winds as quasi-independent physical phenomena should be replaced by a unified theory of accretion disk atmospheres. It may be important in this context that, barring strong contamination of the observed C ɪv wind line by an underlying disk-formed component, the evidence for rotation in the outflow is unambiguous: the observed line flux light curves clearly exhibit a rotational disturbance that is well matched by our simple model of a rotating disk wind.

Mechanical properties of bat wing membrane skin

The skin of the bat wing in functionally unique among mammals: it serves as a major locomotor organ in addition to its protective and regulatory functions. We used tensile testing to investigate the mechanical capabilities of wing membrane skin, and compared stiffness, strength, load at failure, and energy absorption among specific wing regions and among a variety of bat taxa. We related these characteristics to the highly architectural fibrous supporting network of the wing membrane. We found that all material properties showed a strong anisotropy. In particular, wing membrane skin shows maximum stiffness and stregth parallel to the wing skeleton, and greatest extensibility parallel to the wing's trailing edge. We also found significant variation among wing regions. The uropatagium (tail membrane) supported the greatest load at failure, and the plagiopatagium (proximal wing membrane between laterl body wall and hand skeleton) is the weakest and most extensible part of the wing. We believe that the increased load bearing ability of the uropatagium relats to its key role in capture of insect prey, and that the great extensibility of the plagiopatagium promotes development of camber near the wing's centre of lift. In interspecific comparisons, energy absorpion and load to failure were greatest in Artibeus jamaicensis, the largest bat in our sample and the species with the highest wing loading, suggesting that wing loading may play a role in dictating the fuctional design of wing membranes.

Laminar organization of frequency‐defined local axons within and between the inferior colliculi of the guinea pig

We present a comprehensive description of the local (intrinsic and commissural) connections in the central nucleus of the inferior colliculi (CNICs) in guinea pig. Focal injections of the anterograde tracer biocytin were made into physiologically identified loci of the CNIC and the spatial organisation of the labeled fibres was revealed with computer-assisted three-dimensional (3-D) reconstruction. The intrinsic fibres form a series of V-shaped laminar plexuses composed of fibres bearing both terminal and en passant boutons. Each laminar plexus has a central wing located in the CNIC that extends into the dorsal cortex and an external wing located in the external cortex. The edge where the two wings intersect delimits the lateral border of the central nucleus with the external cortex. The density of labeled terminals was consistently lower in the cortices than in the CNIC. The laminar plexus connects points of similar frequency within the CNIC. Seen in 3-D, the location, orientation, shape, and area of the laminar plexus vary as a function of best frequency. The commissural fibres ending in the contralateral IC to the injection also form a laminar plexus which is symmetrical to the ipsilateral plexus. Electrolytic lesions placed in the contralateral IC at sites with best frequencies corresponding to those of the injection coincided with the terminals of the commissural fibres in most instances. Possible patterns for the organisation of these connections (point-to-point and diverging) are discussed. Three systems of peripheral axons to the laminar plexus are described: parallel, oblique, and perpendicular to the central wing. The novel parallel system has terminals in both ICs that run parallel to the central wing. It might constitute the anatomical basis for across-frequency interactions. The oblique and perpendicular systems are fibres of passage projecting to the commissure and brachium of the IC, respectively.

Les attitudes éthiques et politiques des protestants réformés en France

Based upon the results of an inquiry into the membership of l'Eglise Réformée de France in the area “Centre-Alpes-Rhône”, this paper identifies some strong features of this group's culture. Long integrated in French society, “les réformés” cultivate “social individualism”, moderation and tolerance towards others. They favour a presence for their church in current affairs, because Christianity cannot be lived without commitment to the world. Their political outlook is predominantly that of moderate socialism, respectful of personal initiatives and freedoms. This culture is particularly well espoused by church activists, but is not shared by all members. A minority culture exists which focuses on moral rules, institutional regulation and rapprochement with Catholicism, favouring political neutrality for the church, but with a personal orientation towards the centre or moderate right wing.

Composite material repairs to metallic airframe components

The repair of metal structures by using composite materials is a technology that was pioneered in Australia, and excellent results have been obtained in over 500 repairs of corrosion and fatigue cracking. This paper will present details of the first in-service composite material repair applied to metal structure on USAF C-141B operational aircraft. This engineering study evaluated five locations representing both fatigue and corrosion cracking susceptible areas on the C-141B strategic airlift transport aircraft. Repairs using either boron/epoxy or graphite/epoxy are beneficial for crack retardation, end fastener effect relief, and field stress reduction. The most obvious time saving feature of these repairs is that no fastener removal or installation is involved. Extensive structural analysis utilizing finite element modeling was done to ensure that the repair design not only would have the requisite strength and durability but also would reduce the inspection burden after the aircraft was returned to service. A test program was also undertaken to substantiate the analytical investigation. Typical results from the finite element models as well as the specimen and component tests will be presented. Finally, the step-by-step procedure by which an actual boron/epoxy repair was applied to a fatigue crack on a C-141 center wing will be reported and lessons learned will summarize the benefits of applying the technology.

Needs and constraints for coordinated programs of photospheric and chromospheric studies of flares

Suggestions for a coordinated observing program of the photospheric and chromospheric components of a flare are given; the maximum efficiency can be reached only if simultaneous measurements of coronal emission component may be obtained. The observing program has to be changed according to the different characteristics of a flare in each phase of its development. During the build-up phase it is of particular interest to establish the correlation between the photospheric velocity field (determined from bidimensional spectroscopic images in the 5576 Fe I line) and the magnetic field. During the transient explosive phase particular emphasys should be given to high time resolution observations (at least 1 sec) in order to correlate the response of chromospheric and photospheric signatures to the energy release producing the impusive phase in the hard X-ray and microwave emission. Observations with different filters in the center and red wing of the H α line, in CN (0-0) band and in some continuous windows are suggested in order to have time and spatial resolution as high as possible. Spectral observations in the region 3400 – 4300 Å give the possibility to measure the red shift of the Balmer lines presumably associated to the chromospheric condensation moving downward. When the flare atmosphere may be considered in pressure balance (after tens of seconds) the time resolution is not crucial and the H α and Na-D 2 line profile may be obtained with the Zeiss and UBF filter used in bidimensional spectroscopic mode. H α line gives the possibility to test the effect of the heating mechanism while the Na-D 2 line is useful to monitor the penetration depth of the flare disturbance.

Patterns and Variability of Growth in the Yellow-Eyed Penguin

Growth of Yellow-eyed Penguin (Megadyptes antipodes) chicks was monitored at six breeding areas over one season, and at two breeding areas over three seasons to describe the growth pattern and determine the degree of interseasonal and interlocality variation in growth rates. Growth parameters measured were weight, bill depth, flipper area, and lengths of culmen, skull, foot, central tail feathers, wing (humerus), and flipper. Data were fitted to logistic curves which were compared using a weighted least squares technique from the Maximum Likelihood Program (Ross et al. 1980). Observed seasonal and geographical variations in growth rates were small and appeared to reflect variations in food supply. Variations in growth rates of morphometric parameters were small or absent, with few differences in final fledging size. Dimensions with invariable growth rates were those that were smaller than average at maturity. Skull and foot + claw were least variable, implying high priority in the allocation of resources during development. Foot + claw was first to reach asymptotic size, followed by wing and flipper (area and length). This pattern of growth is consistent with that of other penguin species. Feet may grow quickly to allow heat loss until the flippers can function as thermal windows. Bill dimensions did not reach adult size by the end of the fledging period.

Requirement for integrins during Drosophila wing development

The position-specific (PS) integrins of Drosophila are highly homologous to vertebrate integrins, most of which are cell-surface receptors for extracellular matrix components. Integrins are heterodimers, each consisting of noncovalently associated alpha- and beta-subunits. As for the subfamilies of vertebrate integrins, the same beta-subunit is found in both Drosophila PS integrins, combined with a specific alpha-subunit to generate either a complete functional PS1 or PS2 integrin. Both alpha- and beta-subunits are large transmembrane proteins (relative molecular masses greater than 100,000). Either one or both of these two PS integrins are expressed in most fly tissues during development. A particularly intriguing pattern of expression is found in the mature wing imaginal disc, where the PS1 integrin is expressed primarily on the presumptive dorsal wing epithelium, and the PS2 integrin is found almost exclusively on the ventral epithelium. Immediately after pupariation, the central wing pouch evaginates, folding along its centre to appose the epithelia that will secret the dorsal and ventral surfaces of the adult wing blade. Here we report the results of a genetic analysis indicating that both of the PS integrins are required to maintain the close apposition of the dorsal and ventral wing epithelia during morphogenesis. Also, we conclude that the integrins are not necessary for the maintenance of the cell lineage restriction between the two presumptive wing surfaces in the developing imaginal disc.

Plasma motions in an emerging flux region

Ultraviolet spectra of C IV show large nonthermal broadening in an area of emerging flux. These nonthermal motions are observed at a very early stage of reconnecting field lines. The spectra can be traced to small, rapidly changing surge or filament-like features which are seen in the center, blue, and red wing of H-alpha. They seem to have the characteristics of macrospicules or explosive events. They are precursors of the reconnection process. Plasma turbulence and/or plasma waves in the reconnecting plasma may cause the broad C IV line profiles. The activity in the transition zone precedes the formation of a bright chromospheric loop system.

Projections of brainstem core cholinergic and non-cholinergic neurons of cat to intralaminar and reticular thalamic nuclei

We combined the retrograde transport of wheat germ agglutinin conjugated with horseradish peroxidase with choline acetyltransferase immunohistochemistry to study the projections of cholinergic and non-cholinergic neurons of the upper brainstem core to rostral and caudal intralaminar thalamic nuclei, reticular thalamic complex and zona incerta in the cat. After wheat germ agglutinin horseradish peroxidase injections in the rostral pole of the reticular thalamic nucleus, the distribution and amount of retrogradely labeled brainstem neurons were similar to those found after tracer injection in thalamic relay nuclei (see preceding paper42). After wheat germ agglutinin horseradish peroxidase injections in the caudal intralaminar centrum medianum parafascicular complex, rostral intralaminar central lateral paracentral wing, and zona incerta, the numbers of retrogradely labeled brainstem neurons were more than three times higher than those found after injections in thalamic relay nuclei. The larger numbers of horseradish peroxidase-positive brainstem reticular neurons after tracer injections in intralaminar or zona incerta injections results from a more substantial proportion of labeled neurons in the central tegmental field at rostral midbrain (perirubral) levels and in the ventromedial part of the pontine reticular formation, ipsi- and contralaterally to the injection site. Of all retrogradely labeled neurons in the caudal midbrain core at the level of the cholinergic peribrachial area and laterodorsal tegmental nucleus. 45ȁ50% were also choline acetyltransferase-positive alter the injections into central lateral paracentral and reticular nuclei, while only 25% were also choline acetyltransferase-positive after the injection into the centrum medianum parafascicular complex.These findings are discussed in the light of physiological evidence of brainstem cholinergic mechanisms involved in the blockade of synchronized oscillations and in activation processes of thalamocortical systems.

Mycetoma in a Grand Eclectus (Eclectus roratus roratus) Parrot

A Grand Eclectus parrot with central nervous system disturbances and wing paralysis was necropsied. There were two grayish-black nodules in the upper left thoracic cavity and one nodule in the lower left lung. In addition, several nodules were present in the cerebral hemispheres and optic lobes. The cerebellum had extensive areas of granulomatous lesions. Microscopically, brown-staining hyphae were observed in the nodules. Curvularia geniculata was isolated from the lesions. A diagnosis of mycetoma was based on histologic lesions and isolation of fungus from the lesions.