Home About us Contact
|
Home About us Contact | ||
|
|
||
Horn
Kinds of Horn Terms modified by Horn Selected AbstractsWHEN ONTOGENY REVEALS WHAT PHYLOGENY HIDES: GAIN AND LOSS OF HORNS DURING DEVELOPMENT AND EVOLUTION OF HORNED BEETLESEVOLUTION, Issue 11 2006Armin P. Moczek Abstract How ecological, developmental and genetic mechanisms interact in the genesis and subsequent diversification of morphological novelties is unknown for the vast majority of traits and organisms. Here we explore the ecological, developmental, and genetic underpinnings of a class of traits that is both novel and highly diverse: beetle horns. Specifically, we focus on the origin and diversification of a particular horn type, those protruding from the pronotum, in the genus Onthophagus, a particularly speciose and morphologically diverse genus of horned beetles. We begin by documenting immature development of nine Onthophagus species and show that all of these species express pronotal horns in a developmentally transient fashion in at least one or both sexes. Similar to species that retain their horns to adulthood, transient horns grow during late larval development and are clearly visible in pupae. However, unlike species that express horns as adults, transient horns are resorbed during pupal development. In a large number of species this mechanisms allows fully horned pupae to molt into entirely hornless adults. Consequently, far more Onthophagus species appear to possess the ability to develop pronotal horns than is indicated by their adult phenotypes. We use our data to expand a recent phylogeny of the genus Onthophagus to explore how the widespread existence of developmentally transient horns alters our understanding of the origin and dynamics of morphological innovation and diversification in this genus. We find that including transient horn development into the phylogeny dramatically reduces the number of independent origins required to explain extant diversity patters and suggest that pronotal horns may have originated only a few times, or possibly only once, during early Onthophagus evolution. We then propose a new and previously undescribed function for pronotal horns during immature development. We provide histological as well as experimental data that illustrate that pronotal horns are crucial for successful ecdysis of the larval head capsule during the larval-to-pupal molt, and that this molting function appears to be unique to the genus Onthophagus and absent in the other scarabaeine genera. We discuss how this additional function may help explain the existence and maintenance of developmentally transient horns, and how at least some horn types of adult beetles may have evolved as exaptations from pupal structures originally evolved to perform an unrelated function. [source] Effects of plant and prey characteristics on the predatory behavior of Delphastus catalinaeENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2006Moshe Guershon Abstract Nymphal setosity of the whitefly Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) has been reported to be induced by mechanical stimuli such as leaf tomentosity, and related to the predatory performance of the coccinellid Delphastus catalinae (Horn) (Coleoptera: Coccinellidae). In this study, a possible adaptive value of this phenomenon for the whitefly is shown through the combined effects of leaf and prey characteristics on the walking and predatory behaviors of the beetle. Leaf tomentosity significantly affected the walking patterns of the beetle and therefore its searching abilities, thus indirectly increasing the influence of prey distribution upon predator's efficiency. Moreover, while searching on tomentose leaves, the beetles showed preference for the smooth prey phenotype. This behavior was found dependent on the experience of the beetle in previous encounters. These results are pertinent to intraspecific competition between the different nymphal phenotypes and to the predatory efficiency of this beetle, which is utilized in biological control of whiteflies. [source] Patterns of calcium-binding proteins support parallel and hierarchical organization of human auditory areasEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2003Oriana Chiry Abstract The human primary auditory cortex (AI) is surrounded by several other auditory areas, which can be identified by cyto-, myelo- and chemoarchitectonic criteria. We report here on the pattern of calcium-binding protein immunoreactivity within these areas. The supratemporal regions of four normal human brains (eight hemispheres) were processed histologically, and serial sections were stained for parvalbumin, calretinin or calbindin. Each calcium-binding protein yielded a specific pattern of labelling, which differed between auditory areas. In AI, defined as area TC [see C. von Economo and L. Horn (1930) Z. Ges. Neurol. Psychiatr.,130, 678,757], parvalbumin labelling was dark in layer IV; several parvalbumin-positive multipolar neurons were distributed in layers III and IV. Calbindin yielded dark labelling in layers I,III and V; it revealed numerous multipolar and pyramidal neurons in layers II and III. Calretinin labelling was lighter than that of parvalbumin or calbindin in AI; calretinin-positive bipolar and bitufted neurons were present in supragranular layers. In non-primary auditory areas, the intensity of labelling tended to become progressively lighter while moving away from AI, with qualitative differences between the cytoarchitectonically defined areas. In analogy to non-human primates, our results suggest differences in intrinsic organization between auditory areas that are compatible with parallel and hierarchical processing of auditory information. [source] Anatomy of Primary Afferents and Projection Neurones in the Rat Spinal Dorsal Horn with Particular Emphasis on Substance P and the Neurokinin 1 ReceptorEXPERIMENTAL PHYSIOLOGY, Issue 2 2002A. J. Todd The dorsal horn of the spinal cord plays an important role in transmitting information from nociceptive primary afferent neurones to the brain; however, our knowledge of its neuronal and synaptic organisation is still limited. Nociceptive afferents terminate mainly in laminae I and II and some of these contain substance P. Many projection neurones are located in lamina I and these send axons to various parts of the brain, including the caudal ventrolateral medulla (CVLM), parabrachial area, periaqueductal grey matter and thalamus. The neurokinin 1 (NK1) receptor on which substance P acts is expressed by certain neurones in the dorsal horn, including approximately 80% of lamina I projection neurones. There is also a population of large NK1 receptor-immunoreactive neurones with cell bodies in laminae III and IV which project to the CVLM and parabrachial area. It has been shown that the lamina III/IV NK1 receptor-immunoreactive projection neurones are densely and selectively innervated by substance P-containing primary afferent neurones, and there is evidence that these afferents also target lamina I projection neurones with the receptor. Both types of neurone are innervated by descending serotoninergic axons from the medullary raphe nuclei. The lamina III/IV neurones also receive numerous synapses from axons of local inhibitory interneurones which contain GABA and neuropeptide Y, and again this input shows some specificity since post-synaptic dorsal column neurones which also have cell bodies in laminae III and IV receive few contacts from neuropeptide Y-containing axons. These observations indicate that there are specific patterns of synaptic connectivity within the spinal dorsal horn. [source] Aggresome formation by anti-Ras intracellular scFv fragmentsFEBS JOURNAL, Issue 2 2001The fate of the antigen, antibody complex Diverting the antigen from its normal intracellular location to other compartments in an antibody-mediated way represents a mode of action for intracellular antibodies [Cardinale, A., Lener, M., Messina, S., Cattaneo, A. & Biocca, S. (1998) FEBS Lett.,439, 197,202; Lener, M., Horn, I.R., Cardinale, A., Messina, S., Nielsen, U.B., Rybak, S.M., Hoogenboom, H.R., Cattaneo, A. & Biocca, S. (2000) Eur J Biochem.267, 1196,205]. In the case of p21Ras, the sequestration of the antigen in aggregated structures in the cytoplasm of transfected cells leads to the inhibition of its biological function. We have further investigated the intracellular fate of the antigen,antibody complex by analyzing the effect of proteasome inhibitors on the formation and the intracellular localization of the aggregates. Overexpression of anti-Ras scFv fragments or inhibition of proteasomes activity leads to the formation of large perinuclear aggresomes formed of ubiquitinated-scFv fragments in which p21Ras is sequestered and degraded in an antibody-mediated way. Disruption of microtubules by nocodazole completely abrogates the accumulation of scFv fragments in a single aggresome and induces the dispersion of these structures in the periphery of the cell. Cotransfection of the GFP-scFv with a myc-tagged ubiquitin and colocalization with specific anti-proteasome antibodies indicate the recruitment of exogenous ubiquitin and proteasomes to the newly formed aggresomes. Taken together these results suggest that the intracellular antigen,antibody complex is naturally addressed to the ubiquitin,proteasome pathway and that the mechanism of ubiquitination does not inhibit the antibody binding properties and the capacity to block the antigen function. [source] Do endogenous seasonal cycles of food intake influence foraging behaviour and intake by grazing sheep?FUNCTIONAL ECOLOGY, Issue 5 2000G. R. Iason Abstract 1.,Large herbivores living in temperate regions show different degrees of seasonal biological variation, including voluntary food intake (VFI). The decline of VFI in winter has been hypothesized to be an evolved response to lower food availability or quality, which can act as an internal constraint on food intake. 2.,The hypotheses were tested that (i) animals that have a greater inherent seasonal variation of VFI, measured indoors under ad libitum conditions, would also have a greater seasonal variation in intake and grazing behaviour under field conditions, and (ii) greater seasonal variation in intake and grazing behaviour under field conditions would be expressed at a higher level of food availability. 3.,The intake and grazing behaviour in summer and winter, of three breeds of sheep, were compared at two levels of food availability (at pasture heights of 3·7 and 5·4 cm). The breeds were known to have contrasting degrees of seasonal variation in food intake when fed ad libitum; the VFI of the Shetland (SH) and Scottish Blackface (BF) sheep varies greatly between seasons whereas that of the Dorset Horn (DH) is less seasonally variable. 4.,All three breeds consistently increased their rates of biting and duration of grazing activity in the winter, taking many more smaller bites each day than in the summer, and both digestibility and intake were lower in winter than in summer. 5.,Contrary to expectation, the DH ewes had the highest seasonal difference of dry matter intake at pasture, whereas the SH breed had the lowest variation of intake between seasons. 6.,This experiment provides no evidence that differences between seasons in intake and foraging behaviour in the field vary with the animals' degree of endogenous seasonal variation in VFI. Variation between seasons was consistent at both levels of resource availability, suggesting that it resulted from seasonal changes in food quality (digestibility) rather than biomass availability. It is not easy to extrapolate from laboratory feeding studies, where animals' own physiological constraints apply, to foraging ecology in the field, where constraints imposed by the environment may be more important. [source] Talkin''Bout My Generation :Memories of 1968 in Recent German NovelsGERMAN LIFE AND LETTERS, Issue 2 2006Monika Shafi This article examines the depiction of 1968 in the novel Rot (2001) by Uwe Timm, in the narrative Mein Jahrhundert (1999) by Günter Grass, and in the autobiographical novel Die Brücke vom goldenen Horn (1998) by Emine Sevgi Özdamar, asking to what extent the concept of generation, understood sociologically and symbolically, is useful in analysing West Germany's 1968 generation and its legacy. The three authors display not only contrasting generational, literary and political profiles, they also entertain a different relationship to German mainstream culture. It becomes clear that Özdamar's novel unsettles precisely this dichotomy between the German mainstream and a multicultural niche-discourse in its intense engagement with the 1968 movement in Germany and Europe. Her text therefore invites us to reconsider the value of the generational parameter in assessing the events of 1968. [source] Variability of the recent climate of eastern AfricaINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 6 2004Carl J. Schreck III Abstract The primary objective of this study is to investigate the recent variability of the eastern African climate. The region of interest is also known as the Greater Horn of Africa (GHA), and comprises the countries of Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Rwanda, Somalia, Sudan, Uganda, and Tanzania. The analysis was based primarily on the construction of empirical orthogonal functions (EOFs) of gauge rainfall data and on CPC Merged Analysis of Precipitation (CMAP) data, derived from a combination of rain-gauge observations and satellite estimates. The investigation is based on the period 1961,2001 for the ,short rains' season of eastern Africa of October through to December. The EOF analysis was supplemented by projection of National Centers for Environmental Prediction wind data onto the rainfall eigenmodes to understand the rainfall,circulation relationships. Furthermore, correlation and composite analyses have been performed with the Climatic Research Unit globally averaged surface-temperature time series to explore the potential relationship between the climate of eastern Africa and global warming. The most dominant mode of variability (EOF1) based on CMAP data over eastern Africa corresponds to El Niño,southern oscillation (ENSO) climate variability. It is associated with above-normal rainfall amounts during the short rains throughout the entire region, except for Sudan. The corresponding anomalous low-level circulation is dominated by easterly inflow from the Indian Ocean, and to a lesser extent the Congo tropical rain forest, into the positive rainfall anomaly region that extends across most of eastern Africa. The easterly inflow into eastern Africa is part of diffluent outflow from the maritime continent during the warm ENSO events. The second eastern African EOF (trend mode) is associated with decadal variability. In distinct contrast from the ENSO mode pattern, the trend mode is characterized by positive rainfall anomalies over the northern sector of eastern Africa and opposite conditions over the southern sector. This rainfall trend mode eluded detection in previous studies that did not include recent decades of data, because the signal was still relatively weak. The wind projection onto this mode indicates that the primary flow that feeds the positive anomaly region over the northern part of eastern Africa emanates primarily from the rainfall-deficient southern region of eastern Africa and Sudan. Although we do not assign attribution of the trend mode to global warming (in part because of the relatively short period of analysis), the evidence, based on our results and previous studies, strongly suggests a potential connection. Copyright © 2004 Royal Meteorological Society. [source] Contradictions and Limits of Neoliberal European Governance: From Lisbon to Lisbon , Edited by B. van Apeldoorn, J. Drahokoupil and L. HornJCMS: JOURNAL OF COMMON MARKET STUDIES, Issue 5 2009PETER SLOMINSKI No abstract is available for this article. [source] Dry season ecology of riverine tiger beetles in Kruger National Park, South AfricaAFRICAN JOURNAL OF ECOLOGY, Issue 2 2008Jonathan R. Mawdsley Abstract The life cycles of many African species of tiger beetles (Insecta: Coleoptera: Cicindelidae) exhibit pronounced seasonality, with adult emergence and reproductive activity closely associated with seasonal rains. Anecdotal reports have suggested that adults of certain riverine tiger beetle species may be active during the dry season near perennial water sources. To test this hypothesis, fifteen sites along three perennial rivers in Kruger National Park, South Africa, were surveyed for tiger beetles in early September, 2006. Thirteen sites yielded adult beetles, with six species represented [Chaetodera regalis (Dejean), Cylindera disjuncta (Dejean), Habrodera nilotica (Dejean), Lophyra neglecta intermediola (Horn), Lophyridia fimbriata imperatrix (Srnka), and Myriochile melancholica (Fabricius)]. Microhabitat associations of adults of all six species and ovipositional/larval substrates of five of the six species are reported, along with observations on predatory and reproductive behaviours and the possible presence of an anti-predator chemical defence in C. regalis and L. fimbriata imperatrix. Résumé Le cycle vital de nombreuses espèces de Cicindèles (colépotères) africains présente une saisonnalité prononcée, l'émergence des adultes et l'activité reproductrice étant étroitement liées aux pluies saisonnières. Quelques rapports ont suggéré que les adultes de certaines espèces riveraines de cicindèles pourraient être actives en saison sèche à proximité de sources d'eau permanentes. Pour tester cette hypothèse, on a surveillé 15 sites le long de trois rivières permanentes dans le Parc National Kruger, en Afrique du Sud, au cours du mois de septembre 2006. Treize sites abritaient des cicindèles adultes, avec six espèces représentées, (Chaetodera regalis (Dejean), Cylindera disjuncta (Dejean), Habrodera nilotica (Dejean), Lophyra neglecta intermediola (Horn), Lophyridia fimbriata imperatrix (Srnka), and Myriochile melancholica (Fabricius). On a rapporté les associations d'adultes des six espèces et les substrats oviposition/larves pour cinq des six espèces dans les microhabitats, de même que des observations sur les comportements prédateur et reproducteur et sur la présence possible d'une défense chimique anti-prédateur chez C. regalis et L. fimbriata imperatrix. [source] Failures of the state failure debate: Evidence from the Somali territories,JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 1 2009Tobias Hagmann Abstract Much of the current literature on state failure and collapse suffers from serious conceptual flaws. It ignores the variegated types of empirical statehood that exist on the ground, it conflates the absence of a central government with anarchy, it creates an unhelpful distinction between ,accomplished' and ,failed' states, and it is guided by a teleological belief in the convergence of all nation-states. Particularly African states figure prominently in this debate and are frequently portrayed in almost pathological terms. Proposing a comparative analysis of politics in the Somali inhabited territories of the Horn of Africa, this article challenges state failure discourses on both theoretical and empirical grounds. We draw attention to the multiple processes of state-building and forms of statehood that have emerged in Somalia, and the neighbouring Somalia region of Ethiopia, since 1991. The analysis of the different trajectories of these Somali political orders reveals that state formation in Africa contradicts central tenets of the state failure debate and that external state-building interventions should recognise and engage with sub-national political entities. Copyright © 2008 John Wiley & Sons, Ltd. [source] Isolation and characterization of microsatellite markers from Teretrius nigrescens Lewis (Coleoptera: Histeridae), predator of the storage pest Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)MOLECULAR ECOLOGY RESOURCES, Issue 4 2009A. B. OMONDI Abstract Teretrius nigrescens is a predator of the larger grain borer (LGB) Prostephanus truncatus, an invasive post-harvest pest in Africa. We describe the isolation and characterization of 24 novel polymorphic microsatellite markers and their testing on a population from Honduras. Alleles per locus ranged between 2 and 12, and observed heterozygosity between 0.037 and 0.646. Six loci deviated significantly from Hardy,Weinberg equilibrium and showed evidence of null alleles. These markers will be useful for studies of the predator's population structure and characterizing populations for control of LGB. [source] Cattell,Horn,Carroll abilities and cognitive tests: What we've learned from 20 years of research,PSYCHOLOGY IN THE SCHOOLS, Issue 7 2010Timothy Z. Keith This article reviews factor-analytic research on individually administered intelligence tests from a Cattell,Horn,Carroll (CHC) perspective. Although most new and revised tests of intelligence are based, at least in part, on CHC theory, earlier versions generally were not. Our review suggests that whether or not they were based on CHC theory, the factors derived from both new and previous versions of most tests are well explained by the theory. Especially useful for understanding the theory and tests are cross-battery analyses using multiple measures from multiple instruments. There are issues that need further explanation, of course, about CHC theory and tests derived from that theory. We address a few of these issues including those related to comprehension,knowledge (Gc) and memory factors, as well as issues related to factor retention in factor analysis. © 2010 Wiley Periodicals, Inc. [source] Cattell,Horn,Carroll cognitive-achievement relations: What we have learned from the past 20 years of researchPSYCHOLOGY IN THE SCHOOLS, Issue 7 2010Kevin S. McGrew Contemporary Cattell,Horn,Carroll (CHC) theory of cognitive abilities has evolved over the past 20 years and serves as the theoretical foundation for a number of current cognitive ability assessments. CHC theory provides a means by which we can better understand the relationships between cognitive abilities and academic achievement, an important component of learning disabilities identification and instructional planning. A research synthesis of the extant CHC cognitive-achievement (COG-ACH) research literature is reported. Systematic and operationally defined research synthesis procedures were employed to address limitations present in the only prior attempted synthesis. Nineteen studies met the criteria for inclusion, which yielded 134 analyses. The 134 analyses were organized by three age groups (6,8, 9,13, and 14,19) and by four achievement domains (basic reading skills, reading comprehension, basic math skills, and math reasoning). The results reveal a much more nuanced set of CHC COG-ACH relations than was identified in the only prior review because of (a) breadth of cognitive abilities and measures (broad vs. narrow), (b) breadth of achievement domains (e.g., basic reading skills and reading comprehension vs. broad reading), and (c) developmental (age) status. The findings argue for selective, flexible, and referral-focused intelligence testing, particularly in the context of emerging Response to Intervention (RTI) assessment models. The results suggest that narrow CHC abilities should be the primary focus of instructionally relevant intelligence testing. Furthermore, the finding that more than 90% of the available research is based on the Woodcock,Johnson Battery argues for significant caution in generalizing the findings to other batteries. CHC-based COG-ACH research with other intelligence batteries is recommended. © 2010 Wiley Periodicals, Inc. [source] Confirmatory factor analysis of the KABC-II in preschool children,PSYCHOLOGY IN THE SCHOOLS, Issue 6 2009Kimberly E. Morgan The present study assessed the Kaufman Assessment Battery for Children, Second Edition (KABC-II) in relation to the synthesized Cattell,Horn,Carroll (CHC) theory of intelligence with a preschool sample. Participants were 200 preschool children between four and five years of age. A confirmatory factor analysis (CFA) was conducted, and different variations of the CHC model were examined to determine which provided the best representation of the proposed underlying CHC constructs tested by the KABC-II. The models included one similar to Spearman's g, a contemporary two-stratum model consisting of fluid and crystallized intelligence (Gf-Gc model), and a synthesized CHC broad factor +g model. The last was the empirically validated theory of interest in this study. Results of the CFA revealed that the broad factor +g CHC model was the best overall design to explain KABC-II results. © 2009 Wiley Periodicals, Inc. [source] Out of Arabia,The settlement of Island Soqotra as revealed by mitochondrial and Y chromosome genetic diversityAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Viktor, erný Abstract The Soqotra archipelago is one of the most isolated landmasses in the world, situated at the mouth of the Gulf of Aden between the Horn of Africa and southern Arabia. The main island of Soqotra lies not far from the proposed southern migration route of anatomically modern humans out of Africa ,60,000 years ago (kya), suggesting the island may harbor traces of that first dispersal. Nothing is known about the timing and origin of the first Soqotri settlers. The oldest historical visitors to the island in the 15th century reported only the presence of an ancient population. We collected samples throughout the island and analyzed mitochondrial DNA and Y-chromosomal variation. We found little African influence among the indigenous people of the island. Although the island population likely experienced founder effects, links to the Arabian Peninsula or southwestern Asia can still be found. In comparison with datasets from neighboring regions, the Soqotri population shows evidence of long-term isolation and autochthonous evolution of several mitochondrial haplogroups. Specifically, we identified two high-frequency founder lineages that have not been detected in any other populations and classified them as a new R0a1a1 subclade. Recent expansion of the novel lineages is consistent with a Holocene settlement of the island ,6 kya. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Case of Pregnancy in Two Cows with Unicorn Horn of the Uterus either by Artificial Insemination at Ipsilateral or Embryo Transfer at Contralateral Corpus Luteum in the OvaryREPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2008C Moriyama Contents Two Holstein heifers and a cow were diagnosed with White Heifer Disease by ultrasonography. Case 1 was a 14 month-old heifer with aplasia of both sides of the uterine horn. In case 2, a primiparous cow and case 3, an 18 month-old heifer, both showed aplasia of the right uterine horn. Case 2 became pregnant by artificial insemination at ipsilateral ovulatory follicle and corpus luteum in the left ovary, while case 3 became pregnant by embryo transfer at 7 days after oestrus with contralateral corpus luteum in the right ovary. [source] The T allele at the g.1471620G>T in the EDG1 gene associated with high marbling in Japanese Black cattle is at a low frequency in breeds not selected for marblingANIMAL SCIENCE JOURNAL, Issue 1 2010Naoto WATANABE ABSTRACT Our previous study detected a single nucleotide polymorphism (SNP), g.1471620G>T, in the 5, flanking region of the endothelial differentiation sphingolipid G-protein-coupled receptor 1 (EDG1) gene, which has been considered as a positional functional candidate for the gene responsible for marbling, and showed association of the g.1471620G>T SNP with marbling in Japanese Black beef cattle. In the present study, we investigated the allele frequency distribution of the g.1471620G>T SNP among the 5 cattle breeds, Japanese Black, Japanese Brown, Japanese Short Horn, Holstein, and Brown Swiss breeds. The T allele at the g.1471620G>T SNP associated with high marbling was found at high frequency in Japanese Black breed that has been subjected to a strong selection for high marbling, while the allele was absent or at very low frequencies in the other breeds that have not been strongly selected for high marbling. Based on this finding, we hypothesized that the pressure of the strong selection for high marbling in Japanese Black breed has increased the frequency of the T allele at the g.1471620G>T SNP in the EDG1. [source] RONI HORN'S ICELANDIC ENCYCLOPEDIAART HISTORY, Issue 5 2009MARK GODFREY Since 1990, the American artist Roni Horn has published nine volumes of a book project titled To Place which she calls an ,Icelandic Encyclopaedia'. The books include over 400 photographs. In this paper, I contextualize the project in the history of post-conceptual photographic practices and artists' books. I argue that Horn uses the form of the archive and encyclopedia to undo rather than cement categories and definitions, by constantly shifting the mode of presentation from volume to volume. I look at the way in which genres of portraiture and landscape become one another, and at Horn's treatment of the book form. The essay argues that Iceland has a paradoxical attraction for Horn: it is a place of ,becoming', whose geological identity is mutable, and it is a landscape which allows her to feel centred. These two meanings are communicated through the ways in which photographs are presented to the viewer/reader of the To Place books. [source] WATERY WEATHER by Artangel and Roni HornART HISTORY, Issue 1 2009Gill Perry First page of article [source] Phylogeny of the Pantomorus,Naupactus complex based on morphological and molecular data (Coleoptera: Curculionidae)CLADISTICS, Issue 2 2005María A. Scataglini The Pantomorus,Naupactus complex is a Neotropical group of broad-nosed weevils (Coleoptera: Curculionidae) including several parthenogenetic species usually assigned to the genera Naupactus Dejean, Pantomorus Schoenherr, Asynonychus Crotch, Aramigus Horn, Eurymetopus Schoenherr and Graphognathus Buchanan. Sixteen species were studied to test hypotheses on the monophyly of these genera, and on the origin of the parthenogenetic lineages. A matrix of 30 morphological characters and 999 positions of the Cytochrome Oxidase I gene, was analyzed with separate partitions and simultaneously, under equal and implied weights, and with different transversion/transitions costs. The ILD test indicates that the incongruence between the molecular and morphological data is not significant. Under equal weights, the molecular data resulted in a single tree and morphology in 34 trees; under implied weights morphology gave a different tree, and under TV:TS ,,4:1 molecular and combined analyses resulted in the same optimal tree. According to the latter, Naupactus includes Graphognathus, and is thus paraphyletic and basal regarding remaining genera, Pantomorus is polyphyletic and includes Aramigus and Asynonychus, and Eurymetopus is monophyletic. The species in which apomictic parthenogenesis has been verified (Aramigus tessellatus, Asynonychus cervinus and Graphognathus lecuoloma), belong to different clades of the Pantomorus-Naupactus complex, with basal sexual relatives. © The Willi Hennig Society 2005. [source] Verrucous Carcinoma Presenting as Giant Plantar HornsDERMATOLOGIC SURGERY, Issue 4 2007MOHAMMED A. AlSHAHWAN MD No abstract is available for this article. [source] Analysing the isotopic life history of the alpine ungulates Capra ibex and Rupicapra rupicapra rupicapra through their hornsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 15 2009Inês C. R. Barbosa The horn of ungulate grazers offers a valuable isotopic record of their diet and environment. However, there have been no reports of the spatio-temporal variation of the isotopic composition of horns. We investigated patterns of carbon (,13C) and nitrogen (,15N) isotopic composition along and perpendicular to the horn axis in Capraibex and Rupicaprarupicaprarupicapra to assess the effects of animal age, within-year (seasonal) and inter-annual variation, natural contamination and sampling position on horn isotope composition. Horns of male C. ibex (n,=,23) and R. r. rupicapra (n,=,1) were sampled longitudinally on the front (only R. r. rupicapra) and back side and on the surface and sub-surface. The sides of the R. r. rupicapra horn did not differ in ,13C. In both species, the horn surface had a 0.15, lower ,13C and a higher carbon-to-nitrogen (C/N) ratio than the sub-surface. Washing the horn with water and organic solvents removed material that caused these differences. With age, the ,15N of C. ibex horns increased (+0.1, year,1), C/N ratio increased, and 13C discrimination relative to atmospheric CO2 (13,) increased slightly (+0.03, year,1). Geostatistical analysis of one C. ibex horn revealed systematic patterns of inter-annual and seasonal 13C changes, but 15N changed only seasonally. The work demonstrates that isotopic signals in horns are influenced by natural contamination (,13C), age effects (13, and ,15N), and seasonal (,13C and ,15N) and inter-annual variation (,13C). The methods presented allow us to distinguish between these effects and thus allow the use of horns as isotopic archives of the ecology of these species and their habitat. Copyright © 2009 John Wiley & Sons, Ltd. [source] Immunohistochemical Localization of the Progesterone and Oestrogen , Receptors in the Uterine Horns of the African Giant Rat (Cricetomys gambianus)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2009M.-C. Madekurozwa Summary The present study investigated the immunolocalization of the progesterone and oestrogen , receptors in the uterine horns of the African giant rat during the oestrous cycle. The progesterone and oestrogen , receptors were demonstrated in various cellular constituents of the endometrium, myometrium and perimetrium. The intensity of progesterone and oestrogen , receptor immunostaining in the endometrial and myometrial layers of the uterine horns varied during the oestrous cycle. The intensity of oestrogen , receptor immunoreactivity in the luminal epithelium was high during pro-oestrus, oestrus and dioestrus. Progesterone and oestrogen , receptor immunoreactivity in the endometrial epithelia was absent during metoestrus. Moderate to strong immunostaining for the progesterone and oestrogen , receptors was demonstrated in the myometrial smooth muscle cells during pro-oestrus, oestrus and dioestrus. The intensity of progesterone and oestrogen , receptor immunostaining in the myometrial smooth muscle cells was low during metoestrus. Stromal cells in the perimetrium consistently expressed progesterone and oestrogen , receptor immunoreactivity throughout the oestrous cycle. The findings of the study indicate that in the giant rat the immunolocalization of the progesterone and oestrogen , receptors, in endometrial and myometrial regions of the uterine horns, varies during the oestrous cycle. [source] Intra-amniotic endotoxin accelerates lung maturation in fetal rabbitsACTA PAEDIATRICA, Issue 1 2001Kristina Bry The hypothesis that endotoxin in amniotic fluid accelerates fetal lung maturation was tested. On day 25 of gestation, LPS (5 ,g/fetus) was injected intra-amniotically into one uterine horn of eight New Zealand white rabbits, whereas the contralateral amniotic sacs were injected with saline vehicle. The fetuses were delivered 48 h after LPS administration and their lungs were studied. One dam went into premature labor prior to the 48 h time point and was excluded from the study. Mean white cell counts in amniotic fluid and bronchoalveolar lavage fluid from LPS-treated fetuses were increased 3.2-fold (p= 0.04) and 9.9-fold (p= 0.04), respectively. Fetal weights and lung weights were not affected by LPS. Surfactant protein SP-A and SP-B mRNA expressions in LPS-treated fetuses were increased 2.3-fold (p= 0.03) and 1.4-fold (p= 0.04), respectively. Static lung compliance was increased in animals treated with LPS (p= 0.001). Lungs from LPS-treated animals had better aeration than those of controls. Mean volume of inflation-fixed lungs of LPS-treated fetuses was 1.7 times greater than that of controls (p= 0.03). Conclusion: Intra-uterine exposure to LPS increases surfactant protein expression and improves lung stability and aeration in preterm animals. [source] Recurrent Ingrown Big Toenails Are Efficiently Treated by CO2 LaserDERMATOLOGIC SURGERY, Issue 6 2002Francis Serour MD background. Surgery for onychocryptosis has a high rate of recurrence. objective. To evaluate CO2 laser partial matricectomy for recurrent onychocryptosis. methods. One hundred ninety-six consecutive patients (predominantly teenagers) previously unsuccessfully treated by surgery underwent CO2 laser for recurrent onychocryptosis. After a digital nerve block and a simple partial nail plate avulsion, the laser was used (5 W, defocused 2 mm beam in continuous mode) to vaporize the matrix, the lateral horn, and the lateral nail groove, including local granulation tissue if present. Follow-up was at least 12 months. results. Three hundred forty-four matricectomies were performed. Disease was mostly at stage II and III, with severe local infection in 24 cases (12.2%). All wounds healed in 21.9 ± 3.2 days, with no postoperative local infection or prolonged exudative drainage. Onychocryptosis reoccurred in 5 of 344 treated margins (1.45%, average 15 months), all after primary bilateral matricectomy. Spicules in the lateral nail groove occurred in 14 of 344 treated margins (4%, average 5.9 months), mostly after primary bilateral matricectomy (7 cases) and in infected margins (8 cases). One patient developed a neuroma in the lateral nail groove. conclusion. CO2 laser is effective for the treatment of recurrent onychocryptosis. Bilateral matricectomy and local infection seem to be the predisposing factors for recurrence and postoperative spicule growth. [source] Development of the proepicardium in Xenopus laevisDEVELOPMENTAL DYNAMICS, Issue 10 2008Maike Jahr Abstract The proepicardium (PE) is an embryonic progenitor cell population, which provides the epicardium, the majority of the cardiac interstitium, the coronary vasculature and possibly some cardiomyocytes. Recent studies have documented (1) the presence of bilaterally paired PE anlagen in several vertebrates, and (2) species-specific differences in the fate of the left and right PE anlagen. Here, we document PE development in Xenopus laevis (stages 37,46). The PE appears at stage 41 in the form of a cone-shaped accumulation of mesothelial cells covering the pericardial surface of the right horn of the sinus venosus. No such structure appears on the left sinus horn. At the end of stage 41, the tip of the PE establishes a firm contact with the developing ventricle. A secondary tissue bridge is established facilitating the transfer of PE cells to the heart. During stages 41,46, this tissue bridge is visible in vivo through the transparent body wall. Corresponding to the morphological data, the PE marker gene Tbx18 is expressed only on the right sinus horn suggesting a right-sided origin of the PE. Left,right lineage tracing has confirmed this idea. These results show that Xenopus PE development proceeds in a bilaterally asymmetric pattern as previously observed in chicks. We speculate that asymmetric PE development is controlled by signals from left,right signaling pathways and that the PE is an indicator for right-sidedness in Xenopus embryos. Xenopus might be a good model to uncover the role of left,right signaling pathways in the control of asymmetric PE development. Developmental Dynamics 237:3088,3096, 2008. © 2008 Wiley-Liss, Inc. [source] Neural precursor cells from a fatal human motoneuron disease differentiate despite aberrant gene expressionDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2007Niklas Pakkasjärvi Abstract Precursor cells of the human central nervous system can be cultured in vitro to reveal pathogenesis of diseases or developmental disorders. Here, we have studied the biology of neural precursor cells (NPCs) from patients of lethal congenital contracture syndrome (LCCS), a severe motoneuron disease leading to prenatal death before the 32nd gestational week. LCCS fetuses are immobile because of a motoneuron defect, seen as degeneration of the anterior horn and descending tracts of the developing spinal cord. The genetic defect for the syndrome is unknown. We show that NPCs isolated postmortem from LCCS fetuses grow and are maintained in culture, but display increased cell cycle activity. Global transcript analysis of undifferentiated LCCS precursor cells present with changes in EGF-related signaling when compared with healthy age-matched human controls. Further, we show that LCCS-derived NPCs differentiate into cells of neuronal and glial lineage and that the initial differentiation is not accompanied by overt apoptosis. Cells expressing markers Islet-1 and Hb9 are also generated from the LCCS NPCs, suggesting that the pathogenic mechanism of LCCS does not directly affect the differentiation capacity or survival of the cells, but the absence of motoneurons in LCCS may be caused by a noncell autonomous mechanism. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Is Dialetheism an Idealism?DIALECTICA, Issue 2 2007The Russellian Fallacy, the Dialetheist's Dilemma In his famous work on vagueness, Russell named ,fallacy of verbalism' the fallacy that consists in mistaking the properties of words for the properties of things. In this paper, I examine two (clusters of) mainstream paraconsistent logical theories , the non-adjunctive and relevant approaches ,, and show that, if they are given a strongly paraconsistent or dialetheic reading, the charge of committing the Russellian Fallacy can be raised against them in a sophisticated way, by appealing to the intuitive reading of their underlying semantics. The meaning of ,intuitive reading' is clarified by exploiting a well-established distinction between pure and applied semantics. If the proposed arguments go through, the dialetheist or strong paraconsistentist faces the following Dilemma: either she must withdraw her claim to have exhibited true contradictions in a metaphysically robust sense , therefore, inconsistent objects and/or states of affairs that make those contradictions true; or she has to give up realism on truth, and embrace some form of anti-realistic (idealistic, or broadly constructivist) metaphysics. Sticking to the second horn of the Dilemma, though, appears to be promising: it could lead to a collapse of the very distinction, commonly held in the literature, between a weak and a strong form of paraconsistency , and this could be a welcome result for a dialetheist. [source] T-type calcium channels: an emerging therapeutic target for the treatment of painDRUG DEVELOPMENT RESEARCH, Issue 4 2006Terrance P. Snutch Abstract It has become generally accepted that presynaptic high voltage,activated N-type calcium channels located in the spinal dorsal horn are a validated clinical target for therapeutic interventions associated with severe intractable pain. Low voltage,activated (T-type) calcium channels play a number of critical roles in nervous system function, including controlling thalamocortical bursting behaviours and the generation of spike wave discharges associated with slow wave sleep patterns. There is a growing body of evidence that T-type calcium channels also contribute in several ways to both acute and neuropathic nociceptive behaviours. In the one instance, the Cav3.1 T-type channel isoform likely contributes an anti-nociceptive function in thalamocortical central signalling, possibly through the activation of inhibitory nRT neurons. In another instance, the Cav3.2 T-type calcium channel subtype acts at the level of primary afferents in a strongly pro-nociceptive manner in both acute and neuropathic models. While a number of classes of existing clinical agents non-selectively block T-type calcium channels, there are no subtype-specific drugs yet available. The development of agents selectively targeting peripheral Cav3.2 T-type calcium channels may represent an attractive new avenue for therapeutic intervention. Drug Dev. Res. 67:404,415, 2006. © 2006 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||||||||