Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Distant

  • area distant
  • km distant
  • site distant

  • Terms modified by Distant

  • distant area
  • distant control
  • distant dipolar field
  • distant disease
  • distant failure
  • distant future
  • distant locality
  • distant locations
  • distant metastase
  • distant metastasis
  • distant metastasis-free survival
  • distant organ
  • distant past
  • distant population
  • distant recurrence
  • distant relapse
  • distant relationship
  • distant relationships
  • distant relative
  • distant site

  • Selected Abstracts

    Can intra-specific genetic variation in arbuscular mycorrhizal fungi (Glomus etunicatum) affect a mesophyll-feeding herbivore (Tupiocoris notatus Distant)?

    Abstract 1.,Arbuscular mycorrhizal fungal (AMF) infection can have negative, positive or neutral effects on insect herbivore populations, but patterns are difficult to predict. 2.,Intra-specific genetic variation in nutrient uptake ability between fungal isolates may also have indirect effects on insect herbivores due to changes in plant quality. In preliminary studies mirid (Tupiocoris notatus) populations were significantly reduced on tobacco (Nicotiana rustica) colonised by AMF but it was unknown if same-species fungal isolates differed in their effect. 3.,An experiment was performed as a first test of the effect of intra-specific genetic variation in the mycorrhizal fungus Glomus etunicatum on mirid nymphal population structure, dynamics, and growth rate. 4.,Mirid nymphal populations were lower on mycorrhizal fungal-infected plants. Population size, however, did not differ between the mycorrhizal isolates. While no statistical difference in population between isolates was found, one isolate consistently had 1.7,2.4 times lower mirid populations compared with the controls, indicating that the magnitude of effect is different between mycorrhizal isolates. 5.,The significantly negative effect of AMF on mirid populations likely resulted from AMF-induced changes in plant quality (e.g. increased defence). This study lends further support to recent demonstrations that below-ground symbionts significantly influence above-ground processes. In addition, mycorrhizal fungi can affect insect population structure, which may have consequences for future herbivory. [source]

    Sexual conflicts, loss of flight, and fitness gains in locomotion of polymorphic water striders

    Pablo Perez Goodwyn
    Abstract In insect wing polymorphism, morphs with fully developed, intermediate, and without wings are recognized. The morphs are interpreted as a trade-off between flight and flightlessness; the benefits of flight are counterbalanced by the costs of development and the maintenance of wings and flight muscles. Such a trade-off has been widely shown for reproductive and developmental parameters, and wing reduction is associated with species of stable habitats. However, in this context, the role of water locomotion performance has not been well explored. We chose seven water striders (Heteroptera: Gerridae) as a model to study this trade-off and its relation to sexual conflicts, namely, Aquarius elongatus (Uhler), Aquarius paludum (Fabr.), Gerris insularis (Motschulsky), Gerris nepalensis Distant, Gerris latiabdominis Miyamoto, Metrocoris histrio (White), and Rhagadotarsus kraepelini Breddin. We estimated the locomotion performance as the legs' stroke force, measured on tethered specimens placed on water with a force transducer attached to their backs. By dividing force by body weight, we made performance comparisons. We found a positive relationship between weight and force, and a negative one between weight and the force-to-weight ratio among species. The trade-off between water and flight locomotion was manifested as differences in performance in terms of the force/weight ratio. However, the bias toward winged or wing-reduced morphs was species dependent, and presumably related to habitat preference. Water strider species favouring a permanent habitat (G. nepalensis) showed higher performance in the apterous morph, but in those favouring temporary habitats (A. paludum and R. kraepelini) morphs' performance did not differ significantly. Males had higher performance than females in all but three species studied (namely, A. elongatus, G. nepalensis, and R. kraepelini); these three have a type II mating strategy with minimized mating struggle. We hypothesized that in type I mating system, in which males must struggle strongly to subdue the female, males should outperform females to copulate successfully. This was not necessarily true among males of species with type II mating. [source]

    Temporal Elements in the Spatial Extension of Production Networks

    GROWTH AND CHANGE, Issue 4 2006
    ABSTRACT The spatial extension of production networks presents a significant challenge to managers accustomed to reducing lead times by geographically contracting supply chains. This paper extends the theory on time in transportation by defining the elements of transport time, order time, timing, punctuality, and frequency and elaborating on their characteristics. Structured along these elements, it analyses the consequences of extending production networks from within a mature economic region, mainly the EU-15, U.S., and Japan, first to adjacent and then to nearby and finally distant low-cost regions. Distance obviously affects the transport quality in all time dimensions. Except for air parcel services that globally match what road transport offers within an economic region, the longer the distance, the lower the time-related performance. Distant, low-cost regions, meaning China and India, also imply a polarisation between air and sea transport at opposite ends of the time, cost, and capacity scales. This supply gap restricts the types of products traded. The conceptual framework is illustrated in the setting of a global vehicle manufacturer spatially extending its sourcing. It demands that sequenced sub-assemblies and small, cheap, and generic components are delivered from the vicinity of each assembly plant. Batched components can be sourced from adjacent regions, but deliveries from longer distances imply storage at pick-up points to fulfil their time requirements. Hence, the suppliers must offer the manufacturing firm deliveries as if they produce relatively close to the assembly plants. [source]

    Ecology of the fruit spotting bug, Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae) in cashew plantations, with particular reference to the potential for its biological control

    Renkang Peng
    Abstract, The fruit spotting bug, Amblypelta lutescens lutescens, is one of the principal insect pests of cashews in Australia. Its population dynamics were studied using field observations and long-term monitoring to find suitable management methods. Observations of bugs reared in netting bags showed a sequence of change in bug-damage symptoms after 12 h and up to 3 d. Field observations revealed that adults preferred to feed and rest on the shady side of the tree. The number of bugs observed accounted for only 17,35% of the total variability in the number of damaged shoots, suggesting that the number of flushing shoots (leaf, flower or young nuts) with fresh damage symptoms was a more reliable parameter for determining the presence and level of activity of bugs than was a direct estimate of the number of bugs. The green tree ant, Oecophylla smaragdina (F), was the most important factor regulating bug populations. When predation was excluded as a factor, the number of flushing shoots and maximum temperature accounted for 80% of the total variability in the bug damage. Green tree ants should be considered as an important biological control agent for fruit spotting bug, and monitoring should be commenced when cashew trees start to flush (using damaged shoots as indicator). [source]

    Egg parasitoids of Australian Coreidae (Hemiptera)

    Ian D Naumann
    Abstract Ten microhymenopteran species are recorded as parasitoids of the eggs of coreid bugs in Australia: Chrysochalcissa olivacea Girault (Torymidae) from Amorbus biguttatus Stål and Pternistria bispina Stål; two species of Anastatus Motschulsky (Eupelmidae) from Mictis profana (F.), Amorbus alternatus Dallas, Amblypelta lutescens lutescens (Distant) and an unidentified coreid; Xenoencyrtus hemipterus (Girault) (Encyrtidae) from Amorbus obscuricornis (Westwood) and Gelonus tasmanicus (Le Guillou); Ooencyrtus caurus Huang and Noyes (Encyrtidae) from A. lutescens lutescens;Centrodora darwini (Girault) (Aphelinidae) from an unidentified coreid; and four species of Gryon Haliday (Scelionidae) from Aulacosternum nigrorubrum (Dallas), A. lutescens lutescens, Amorbus rubicundus Stål, Mictis caja Stål, M. profana and an unidentified coreid. Alternate hosts and biological control prospects are discussed. [source]

    Two new species of Diaphyta Bergroth with notes on the genus (Hemiptera: Pentatomidae)

    FJD McDonald
    Abstract Diaphyta fulvescens (Dallas), Diaphyta pulchra (Dallas), Diaphyta rosea Bergroth and Diaphyta tasmani (Distant) are partly redescribed. Diaphyta evansorum sp. n. and Diaphyta richardsi sp. n. are described from Western Australia. Periboea rufofulva Jensen-Haarup is synonymised with Diaphyta tasmani. A key to species of Diaphyta is given. [source]

    Interrelating within the families of young psychotherapy outpatients

    Argyroula E. Kalaitzaki
    Interrelating is a combination of relating to and being related to by another. The Couple's Relating to Each Other Questionnaires (CREOQ) and the Family Members Interrelating Questionnaires (FMIQ) measure negative forms of both self and other relating, across a close/distant and an upper/lower axis. These were used to measure the interrelating between the parents of young adults, and between young adults and their parents, in a sample of young, Greek, psychotherapy outpatients and a comparable sample of non- patients. In a proportion of both samples, the interrelating of the young adults was compared with that of a well sibling. The patients' parents were significantly more distant towards each other than those of the non-patients. The interrelating between the patients and their parents was markedly worse than that between the non-patients and their parents. It was also markedly worse between the patients and their parents than between the siblings and their parents.,Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Use of Premontane Moist Forest and Shade Coffee Agroecosystems by Army Ants in Western Panama

    Dina L. Roberts
    Behavioral and distributional studies of these two species have been confined largely to humid lowland forest. We conducted intensive systematic area searches at elevations between 1200 and 1800 m in western Panama to assess the distribution of both species in intact premontane moist forest, shade coffee plantations, and sun coffee plantations. Both species were repeatedly observed in forest, shade coffee plantations close to forest, and shade coffee plantations distant from forest. Neither species was observed in sun coffee plantations. We believe that retention of certain forest-like characteristics in the traditional shade coffee farm contributes to the persistence of these forest organisms in modified landscapes. Large canopy trees not only provide shade that buffers temperature extremes but also supply the ground layer with regular inputs of leaf litter and coarse woody debris from fallen trunks. Both E. burchelli and L. praedator hunt in leaf litter, and E. burchelli uses coarse woody debris as nesting sites ( bivouacs). There were significantly fewer potential bivouacs available in sun coffee plantations than in forest and shade coffee habitats. Also, litter depth was less in sun coffee than in forest and shade coffee. Our results provide the first evidence that shade coffee plantations can provide additional habitat for E. burchelli and L. praedator, top predators of the leaf litter arthropod community. E. burchelli and L. praedator act as critical links between swarm-attendant bird species and leaf-litter arthropods, providing an easily exploited food resource that would otherwise be unavailable for many birds. Continued conversion of shade coffee plantations to sun coffee plantations could have negative effects on army ants and associated biodiversity. Resumen: Las hormigas arrierras Neotropicales, Eciton burchelli y Labidus praedator ( Hymenoptera: Formicidae: Ecitoninae) son especies que requieren de extensas áreas de hábitat para cazar. Los estudios conductuales y de la distribución de estas especies se han realizado principalmente en bosques húmedos en tierras bajas. Desarrollamos búsquedas sistemáticas intensivas en elevaciones entre 1200 y 1800 msnm en Panama occidental para determinar la distribución de ambas especies en bosque húmedo premontano intacto, en plantaciones de café con y sin sombra. Las dos especies fueron observadas recurrentemente en bosque y en plantaciones de café de sombra cercanos y lejanos al bosque. Consideramos que la retención de ciertas características del bosque en las plantaciones de café de sombra contribuye a la persistencia de estos organismos de bosque en ambientes modificados. Los árboles no solo proporcionan sombra que amortigua la temperatura, sino que proporcionan hojarasca y restos leñosos de troncos caídos. Tanto E. burchelli como L. praedator cazan en la hojarasca, E. burchelli utiliza restos leñosos para anidar (vivaques). Encontramos significativamente menos vivaques en plantaciones de café sin sombra al compararlos con bosque y plantaciones de café con sombra. Asimismo, la profundidad de la capa de hojarasca fue menor en plantaciones de café sin sombra en comparación con bosque y plantaciones de café con sombra. Nuestros resultados proporcionan la primera evidencia de que las plantaciones con sombra proporcionan hábitat adicional para E. burchelli y L. praedator, depredadores de la comunidad de artrópodos en la hojarasca. E. burchelli y L. praedator actúan como eslabones críticos entre especies de aves que se alimentan de hormigas y los artrópodos de la hojarasca, proporcionando un recurso alimenticio fácilmente explotado que de otra manera no estaría disponible para muchas aves. La continua transformación de plantaciones de café con sombra a plantaciones sin sombra pudiera tener efectos negativos sobre las hormigas arrieras y la biodiversidad asociada. [source]

    Post-conflict Statebuilding and State Legitimacy: From Negative to Positive Peace?

    David Roberts
    ABSTRACT This article is concerned with the potential that statebuilding interventions have to institutionalize social justice, in addition to their more immediate ,negative' peace mandates, and the impact this might have, both on local state legitimacy and the character of the ,peace' that might follow. Much recent scholarship has stressed the legitimacy of a state's behaviour in relation to conformity to global governance norms or democratic ,best practice'. Less evident is a discussion of the extent to which post-conflict polities are able to engender the societal legitimacy central to political stability. As long as this level of legitimacy is absent (and it is hard to generate), civil society is likely to remain distant from the state, and peace and stability may remain elusive. A solution to this may be to apply existing international legislation centred in the UN and the ILO to compel international organizations and national states to deliver basic needs security through their institutions. This has the effect of stimulating local-level state legitimacy while simultaneously formalizing social justice and positive peacebuilding. [source]

    Conservation and expression of IQ-domain-containing calpacitin gene products (neuromodulin/GAP-43, neurogranin/RC3) in the adult and developing oscine song control system

    David F. Clayton
    Abstract Songbirds are appreciated for the insights they provide into regulated neural plasticity. Here, we describe the comparative analysis and brain expression of two gene sequences encoding probable regulators of synaptic plasticity in songbirds: neuromodulin (GAP-43) and neurogranin (RC3). Both are members of the calpacitin family and share a distinctive conserved core domain that mediates interactions between calcium, calmodulin, and protein kinase C signaling pathways. Comparative sequence analysis is consistent with known phylogenetic relationships, with songbirds most closely related to chicken and progressively more distant from mammals and fish. The C-terminus of neurogranin is different in birds and mammals, and antibodies to the protein reveal high expression in adult zebra finches in cerebellar Purkinje cells, which has not been observed in other species. RNAs for both proteins are generally abundant in the telencephalon yet markedly reduced in certain nuclei of the song control system in adult canaries and zebra finches: neuromodulin RNA is very low in RA and HVC (relative to the surrounding pallial areas), whereas neurogranin RNA is conspicuously low in Area X (relative to surrounding striatum). In both cases, this selective downregulation develops in the zebra finch during the juvenile song learning period, 25,45 days after hatching. These results suggest molecular parallels to the robust stability of the adult avian song control circuit. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2009 [source]


    Tsutomu Namikawa
    We report a rare case of early gastric cancer confined to the mucosal layer with extensive duodenal invasion, curatively removed with distal gastrectomy. An 84-year-old Japanese woman was referred to our hospital with gastric cancer. A barium meal examination and esophagogastroduodenoscopy revealed an irregular nodulated lesion measuring 6.5 x 5.5 cm in the gastric antrum and an aggregation of small nodules in the duodenal bulb. A biopsy specimen showed well-differentiated adenocarcinoma. The patient underwent distal gastrectomy with partial resection of the duodenal region containing the tumor and regional lymph node dissection, with no complication. Histological examination of the resected tissue confirmed well-differentiated adenocarcinoma limited to the mucosal layer and without lymph node metastasis. The cancer extended into the duodenum as far as 38 mm distant from the pyloric ring, and the resected margins were free of cancer cells. Gastric cancer located adjacent to the pyloric ring thus has the potential for duodenal invasion, even when tumor invasion is confined to the mucosal layer. In such cases, care should be taken during examinations to detect duodenal invasion, and the distal surgical margin must be negative given sufficient duodenal resection. [source]

    Nodule-aggregating lesion of the ileum: Report of a case and a review of the literature

    Norikazu Sakamoto
    We describe here a rare case of nodule-aggregating lesion of the terminal ileum detected by colonoscopy. An 82-year-old Japanese woman was admitted to our hospital with diarrhea. Colonoscopy revealed a flat elevated tumor with conglomerated nodular surface involving the entire circumference of the terminal ileum, suggesting a nodule-aggregating lesion. Magnifying the colonoscopic view showed the branch-like or gyrus-like pits. On biopsy, the tumor was diagnosed as a tubulovillous adenoma. Retrograde ileogram using a colonoscope revealed an elevated tumor with nodular irregularity, measuring 5 cm in length. Ileocecal resection was performed. Macroscopically, the tumor in the terminal ileum, 8 cm distant from the ileocecal valve, showed a nodule-aggregating lesion, measuring 44 × 60 × 6 mm in size. Histologically, the tumor showed a focal carcinoma in tubulovillous adenoma. To our knowledge, this is the fifth case of early cancer of the ileum in Japan, and the first case of nodule-aggregating lesion of the ileum detected by colonoscopy in the world. [source]

    Naturalization and invasion of alien plants: concepts and definitions

    David M. Richardson
    Abstract., Much confusion exists in the English-language literature on plant invasions concerning the terms ,naturalized' and ,invasive' and their associated concepts. Several authors have used these terms in proposing schemes for conceptualizing the sequence of events from introduction to invasion, but often imprecisely, erroneously or in contradictory ways. This greatly complicates the formulation of robust generalizations in invasion ecology. Based on an extensive and critical survey of the literature we defined a minimum set of key terms related to a graphic scheme which conceptualizes the naturalization/invasion process. Introduction means that the plant (or its propagule) has been transported by humans across a major geographical barrier. Naturalization starts when abiotic and biotic barriers to survival are surmounted and when various barriers to regular reproduction are overcome. Invasion further requires that introduced plants produce reproductive offspring in areas distant from sites of introduction (approximate scales: > 100 m over < 50 years for taxa spreading by seeds and other propagules; > 6 m/3 years for taxa spreading by roots, rhizomes, stolons or creeping stems). Taxa that can cope with the abiotic environment and biota in the general area may invade disturbed, seminatural communities. Invasion of successionally mature, undisturbed communities usually requires that the alien taxon overcomes a different category of barriers. We propose that the term ,invasive' should be used without any inference to environmental or economic impact. Terms like ,pests' and ,weeds' are suitable labels for the 50,80% of invaders that have harmful effects. About 10% of invasive plants that change the character, condition, form, or nature of ecosystems over substantial areas may be termed ,transformers'. [source]

    Growth and maturation of metatarsals and their taxonomic significance in the jerboas Allactaga and Jaculus (Rodentia: Dipodidae)

    ACTA ZOOLOGICA, Issue 2 2005
    A. A. B. Shahin
    Abstract The development of metatarsals in Allactaga tetradactyla, Jaculus jaculus jaculus and J. orientalis was studied and their taxonomic significance was elucidated. The five metatarsals, as a rule, are developed and ossified in the three species, but variation in the fate of the first and fifth metatarsals was found. Ossification begins in the median part of the metatarsals; however, it appears in the distal part of the digits' phalanges, beginning with the third phalanx. The first metatarsal appears just distal to the entocuneiform and develops as a small, separate bone located either in close contact with the distal end of the entocuneiform in A. tetradactyla or completely fused with it, forming a compound bone, in both of J. j. jaculus and J. orientalis. The second, third and fourth metatarsals differentiate distal to the mesocuneiform, ectocuneiform and cuboid, respectively, and fuse with one another into a single long cannon bone in all species. Nevertheless, the fifth metatarsal differentiates ventro-lateral to the head of the fourth metatarsal and ossifies ventral to the head process of the developing cannon bone. The fifth metatarsal either extends to articulate with the phalanges of the fourth digit in A. tetradactyla or persists as a separate, small bone in both of J. j. jaculus and J. orientalis. On this basis, it is concluded that J. jaculus and J. orientalis are both distinct congeneric species and are somewhat more distant from A. tetradactyla. [source]

    The worldwide airline network and the dispersal of exotic species: 2007,2010

    ECOGRAPHY, Issue 1 2009
    Andrew J. Tatem
    International air travel has played a significant role in driving recent increases in the rates of biological invasion and spread of infectious diseases. By providing high speed, busy transport links between spatially distant, but climatically similar regions of the world, the worldwide airline network (WAN) increases the risks of deliberate or accidental movements and establishment of climatically sensitive exotic organisms. With traffic levels continuing to rise and climates changing regionally, these risks will vary, both seasonally and year-by-year. Here, detailed estimates of air traffic trends and climate changes for the period 2007-2010 are used to examine the likely directions and magnitudes of changes in climatically sensitive organism invasion risk across the WAN. Analysis of over 144 million flights from 2007-2010 shows that by 2010, the WAN is likely to change little overall in terms of connecting regions with similar climates, but anticipated increases in traffic and local variations in climatic changes should increase the risks of exotic species movement on the WAN and establishment in new areas. These overall shifts mask spatially and temporally heterogenous changes across the WAN, where, for example, traffic increases and climatic convergence by July 2010 between parts of China and northern Europe and North America raise the likelihood of exotic species invasions, whereas anticipated climatic shifts may actually reduce invasion risks into much of eastern Europe. [source]

    DNA sequence-based analysis of the Pseudomonas species

    Magdalena Mulet
    Summary Partial sequences of four core ,housekeeping' genes (16S rRNA, gyrB, rpoB and rpoD) of the type strains of 107 Pseudomonas species were analysed in order to obtain a comprehensive view regarding the phylogenetic relationships within the Pseudomonas genus. Gene trees allowed the discrimination of two lineages or intrageneric groups (IG), called IG P. aeruginosa and IG P. fluorescens. The first IG P. aeruginosa, was divided into three main groups, represented by the species P. aeruginosa, P. stutzeri and P. oleovorans. The second IG was divided into six groups, represented by the species P. fluorescens, P. syringae, P. lutea, P. putida, P. anguilliseptica and P. straminea. The P. fluorescens group was the most complex and included nine subgroups, represented by the species P. fluorescens, P. gessardi, P. fragi, P. mandelii, P. jesseni, P. koreensis, P. corrugata, P. chlororaphis and P. asplenii. Pseudomonas rhizospherae was affiliated with the P. fluorescens IG in the phylogenetic analysis but was independent of any group. Some species were located on phylogenetic branches that were distant from defined clusters, such as those represented by the P. oryzihabitans group and the type strains P. pachastrellae, P. pertucinogena and P. luteola. Additionally, 17 strains of P. aeruginosa, ,P. entomophila', P. fluorescens, P. putida, P. syringae and P. stutzeri, for which genome sequences have been determined, have been included to compare the results obtained in the analysis of four housekeeping genes with those obtained from whole genome analyses. [source]

    Ascomycetes associated with ectomycorrhizas: molecular diversity and ecology with particular reference to the Helotiales

    Leho Tedersoo
    Summary Mycorrhizosphere microbes enhance functioning of the plant,soil interface, but little is known of their ecology. This study aims to characterize the ascomycete communities associated with ectomycorrhizas in two Tasmanian wet sclerophyll forests. We hypothesize that both the phyto- and mycobiont, mantle type, soil microbiotope and geographical distance affect the diversity and occurrence of the associated ascomycetes. Using the culture-independent rDNA sequence analysis, we demonstrate a high diversity of these fungi on different hosts and habitats. Plant host has the strongest effect on the occurrence of the dominant species and community composition of ectomycorrhiza-associated fungi. Root endophytes, soil saprobes, myco-, phyto- and entomopathogens contribute to the ectomycorrhiza-associated ascomycete community. Taxonomically these Ascomycota mostly belong to the orders Helotiales, Hypocreales, Chaetothyriales and Sordariales. Members of Helotiales from both Tasmania and the Northern Hemisphere are phylogenetically closely related to root endophytes and ericoid mycorrhizal fungi, suggesting their strong ecological and evolutionary links. Ectomycorrhizal mycobionts from Australia and the Northern Hemisphere are taxonomically unrelated to each other and phylogenetically distant to other helotialean root-associated fungi, indicating independent evolution. The ubiquity and diversity of the secondary root-associated fungi should be considered in studies of mycorrhizal communities to avoid overestimating the richness of true symbionts. [source]

    Mitochondrial control region variation in bank voles (Clethrionomys glareolus) is not related to Chernobyl radiation exposure

    Heather N. Meeks
    Abstract ,Three previous studies at Chernobyl, Ukraine, documented elevated mitochondrial DNA diversity in bank voles (Clethrionomys glareolus) from radioactively contaminated sites. Little evidence was found to link patterns of diversity in contaminated areas to radiation exposure, but the experimental design precluded discriminating among alternative explanations for elevated diversity in exposed groups. Reference sites selected for the studies were relatively distant from contaminated sites and, additionally, were separated from contaminated sites by large river systems; thus, we hypothesized that differences among sites were correlated with geographic isolation rather than with radiation exposure. For the present study, we added three reference sites, which were selected based on minimal radioactive contamination, proximity to contaminated sites, and absence of obvious barriers to dispersal. We hypothesized that neighboring reference sites should exhibit levels and patterns of diversity similar to those of contaminated sites if the previously detected differences were, in fact, caused by geographic isolation. Indeed, levels of diversity in nearby reference sites are comparable to levels in contaminated sites. Additionally, nearby reference sites contain several haplotypes not observed at other study sites. Our results suggest that levels of diversity in contaminated regions are more plausibly explained by ecological and historical factors than by increased mutational pressure resulting from exposure to Chernobyl radiation. [source]

    Evaluation of epileptogenic networks in children with tuberous sclerosis complex using EEG-fMRI

    EPILEPSIA, Issue 5 2008
    Julia Jacobs
    Summary Purpose: Ninety percent of patients with tuberous sclerosis complex (TSC) have epilepsy. Identification of epileptogenic areas can be difficult and studies are needed to characterize the epileptogenic network in more detail. Methods: Five children with TSC and focal epilepsy were studied using simultaneous EEG and functional MRI recordings. Tubers were marked by a neuroradiologist on the anatomical MRI. Spike-associated BOLD (blood oxygenation level-dependent) responses were superimposed with lesions. Results: Thirteen different types of interictal epileptiform discharges (IED) were analyzed with 12 showing a BOLD response, all involving more than one tuber. Five studies had tubers with activations exclusively within the lesion, three studies had lesional activations extending to perilesional areas, and two studies had activations involving exclusively perilesional areas of at least one tuber. Deactivations exclusively within a tuber were found in six studies, lesional deactivations extending to perilesional areas were found in four studies, and tubers with exclusively perilesional deactivations were found in five studies. A BOLD response was found in at least one tuber in the lobe of IED generation and presumed seizure onset (according to telemetry) in all patients. In four patients, the same tubers were involved following different IED localizations. The observed changes were always multifocal, sometimes involving tubers distant from the IED field. Discussion: These findings suggest extended epileptogenic networks in patients with TSC, which exceed networks described in PET and SPECT studies. It was possible to identify specific interictally active tubers. EEG-fMRI provides a noninvasive method to select tubers and areas at their borders for further presurgical investigations. [source]

    rTMS Reveals Premotor Cortex Dysfunction in Frontal Lobe Epilepsy

    EPILEPSIA, Issue 2 2007
    Wolfgang N. Löscher
    Summary:,Purpose: Studies of motor cortex excitability provided evidence that focal epilepsies may alter the excitability of cortical areas distant from the epileptogenic zone. In order to explore this hypothesis we studied the functional connectivity between premotor and motor cortex in seven patients with frontal lobe epilepsy and seizure onset zone outside the premotor or motor cortex. Methods: Low-frequency subthreshold repetitive transcranial magnetic stimulation was applied to the premotor cortex and its impact on motor cortex excitability was measured by the amplitude of motor-evoked potentials in response to direct suprathreshold stimulation of the motor cortex. Results: Stimulation of the premotor cortex of the non-epileptogenic hemisphere resulted in a progressive and significant inhibition of the motor cortex as evidenced by a reduction of motor evoked potential amplitude. On the other hand, stimulation of the premotor cortex of the epileptogenic hemisphere failed to inhibit the motor cortex. The reduced inhibition of the motor cortex by remote areas was additionally supported by the significantly shorter cortical silent periods obtained after stimulation of the motor cortex of the epileptogenic hemisphere. Conclusion: These results show that the functional connectivity between premotor and motor cortex or motor cortex interneuronal excitability is impaired in the epileptogenic hemisphere in frontal lobe epilepsy while it is normal in the nonepileptogenic hemisphere. [source]

    Cumulative adversity and drug dependence in young adults: racial/ethnic contrasts

    ADDICTION, Issue 3 2003
    R. Jay Turner
    ABSTRACT Aims To study cumulative exposure to stressors as a risk factor for drug dependence, and evaluate whether group differences in exposure contribute to differences in prevalence. Design Cross-sectional community survey of life-time adverse experiences and substance and psychiatric disorders. Setting Data collected between 1997 and 2000 in Miami,Dade County, USA. Participants A total of 1803 former Miami,Dade public school students, 93% between ages 19 and 21 years when interviewed. Males and females of Cuban origin, other Caribbean basin Hispanics, African-Americans and non-Hispanic whites are represented equally. Measurements Drug dependence disorder assessed by DSM-IV criteria using the Composite International Diagnostic Interview, and a 41-item checklist of life-time exposure to major and potentially traumatic experiences. Both measures include age at time of first occurrence. Findings Life-time rate of drug dependence disorder (total 14.3%) did not vary significantly (P > 0.05) by socio-economic group. Male rate (17.6%) was significantly greater than female rate (10.9%). The African-American rate (6.5%) was dramatically lower than non-Hispanic white (17.0%), Cuban (18.1%) and non-Cuban Hispanic (16.0%) rates despite their dramatically higher exposure to adversity. Twenty-eight of 33 individual adversities were associated with the subsequent onset of drug dependence (P < 0.05). Cumulative life-time exposure was greatest for males and for African-Americans, and was associated inversely with socio-economic level. Multivariate discrete-time event history analysis revealed significant independent effects of distal (>1 year earlier) and proximal (previous year) exposure to adverse events (P < 0.05), controlling for childhood conduct disorder, attention deficit hyperactive disorder and previous psychiatric disorder. Conclusions Life-time cumulative exposure to distant as well as more recent adversity predicts risk of subsequent drug dependence, although it does not explain ethnic group differences in risk. [source]

    Subjective mental time: the functional architecture of projecting the self to past and future

    Shahar Arzy
    Abstract Human experience takes place in the line of mental time (MT) created through ,self-projection' of oneself to different time-points in the past or future. Here we manipulated self-projection in MT not only with respect to one's life events but also with respect to one's faces from different past and future time-points. Behavioural and event-related functional magnetic resonance imaging activity showed three independent effects characterized by (i) similarity between past recollection and future imagination, (ii) facilitation of judgements related to the future as compared with the past, and (iii) facilitation of judgements related to time-points distant from the present. These effects were found with respect to faces and events, and also suggest that brain mechanisms of MT are independent of whether actual life episodes have to be re-experienced or pre-experienced, recruiting a common cerebral network including the anteromedial temporal, posterior parietal, inferior frontal, temporo-parietal and insular cortices. These behavioural and neural data suggest that self-projection in time is a fundamental aspect of MT, relying on neural structures encoding memory, mental imagery and self. [source]

    Effects of masticatory muscle function on craniofacial morphology in growing ferrets (Mustela putorius furo)

    Tailun He
    Studying the effects of masticatory muscle function on craniofacial morphology in animal models with different masticatory systems is important for further understanding of related issues in humans. Forty 5-wk-old male ferrets were equally divided into two groups. One group was fed a diet of hard pellets (HDG) and the other group was fed the same diet but softened with water (SDG). Lateral and dorsoventral cephalograms were taken on each group after 6 months. Cephalometric measurements were performed by digital procedures. For SDG ferrets, the hard palate plane was more distant from the cranial base plane, and canines were more proclined compared with HDG ferrets. The SDG ferrets were also found to have smaller interfrontal and interparietal widths, and a slenderer zygomatic arch than the HDG ferrets. In the mandible, the coronoid process was generally shorter and narrower for the SDG ferrets. The effects of the altered masticatory muscle function on craniofacial morphology in growing ferrets seemed to differ from those previously reported in other animal models studied under similar experimental conditions. Such differences in the effects are presumably related to the differences in the mode of mastication, craniofacial anatomy and growth pattern in different animal models. [source]

    Proximate, "Parallel-In-Plane" Preoriented Bis(diazenes) , In-Plane Delocalized Bis(homoconjugated) 4N/5(6)e Anions

    Eberhard Beckmann
    Abstract Synthetic details are presented for a series of more or less rigid, "parallel-in-plane" preoriented bis(diazenes), with N=N/N=N distances (d) of 3.3,2.9 Å and interorbital angles (,) of 142,164° (X-ray crystal structures). DFT calculations (B3LYP/6,31G*) and one-/two-electron reduction experiments with the two least preoriented, most "distant" bis(diazenes) (dN=N/N=N ca. 3.3 Å; , 142,146°) provide more insight into the structural prerequisites for bis(homoconjugative) in-plane electron delocalization in 4N/5e radical anions and 4N/6e dianions. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    The effect of linguistic abstraction on interpersonal distance

    Margreet Reitsma-van Rooijen
    It is well known that people describe positive behaviors of others close to them (e.g., in-group member, friend) in abstract terms, but with concrete terms in the case of people who they are not close to (e.g., out-group member, enemy). In contrast, negative behaviors of people who we are close to are described in concrete terms, but in abstract terms for people who are distant. However, the communicative impact of such subtle differences in language use on a receiver who is also the actor of the behavior being described has never been addressed. We hypothesized and found that a positive abstract message compared to a positive concrete message leads to perceived proximity to the sender, while a negative abstract message compared to a negative concrete message leads to perceived distance. The implications of this study, which is the first to show the communicative impact of biased language use, are discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    ,-Adrenoceptor gene variation and intermediate physiological traits: prediction of distant phenotype

    John H. Eisenach
    Intermediate physiological phenotype is the genetic and environmental influence on functional physiological characteristics with direct prognostic relevance to distant, more complex phenotypes, such as cardiovascular and metabolic disease. Increasingly available and affordable genotyping techniques have created an explosion of information on candidate gene variation and its relationship to intermediate physiological traits. Variation in ,-adrenoceptor genes is an intense focus of investigation because ,-adrenoceptors are: (1) ubiquitous in organ system distribution; (2) integral to a multitude of physiological processes; (3) well described in cardiovascular and metabolic disease; and (4) major pharmacological treatment targets. Furthermore, knowledge of functional gene variants in these receptors predates the description of the human genome. This review highlights the influence of common gene variation in the three ,-adrenoceptor subtypes on intermediate physiological phenotype predictive of cardiovascular disease and obesity. Although further information is needed to replicate this information across populations, this review condenses and summarizes growing trends in specific pleiotropic effects of ,-adrenoceptor polymorphisms and suggests which variants may be predictive of distant phenotype. [source]

    Purification of three aminotransferases from Hydrogenobacter thermophilus TK-6 , novel types of alanine or glycine aminotransferase

    FEBS JOURNAL, Issue 8 2010
    Enzymes, catalysis
    Aminotransferases catalyse synthetic and degradative reactions of amino acids, and serve as a key linkage between central carbon and nitrogen metabolism in most organisms. In this study, three aminotransferases (AT1, AT2 and AT3) were purified and characterized from Hydrogenobacter thermophilus, a hydrogen-oxidizing chemolithoautotrophic bacterium, which has been reported to possess unique features in its carbon and nitrogen anabolism. AT1, AT2 and AT3 exhibited glutamate:oxaloacetate aminotransferase, glutamate:pyruvate aminotransferase and alanine:glyoxylate aminotransferase activities, respectively. In addition, both AT1 and AT2 catalysed a glutamate:glyoxylate aminotransferase reaction. Interestingly, phylogenetic analysis showed that AT2 belongs to aminotransferase family IV, whereas known glutamate:pyruvate aminotransferases and glutamate:glyoxylate aminotransferases are members of family I,. In contrast, AT3 was classified into family I, distant from eukaryotic alanine:glyoxylate aminotransferases which belong to family IV. Although Thermococcus litoralis alanine:glyoxylate aminotransferase is the sole known example of family I alanine:glyoxylate aminotransferases, it is indicated that this alanine:glyoxylate aminotransferase and AT3 are derived from distinct lineages within family I, because neither high sequence similarity nor putative substrate-binding residues are shared by these two enzymes. To our knowledge, this study is the first report of the primary structure of bacterial glutamate:glyoxylate aminotransferase and alanine:glyoxylate aminotransferase, and demonstrates the presence of novel types of aminotransferase phylogenetically distinct from known eukaryotic and archaeal isozymes. [source]

    Identification of the structural determinant responsible for the phosphorylation of G-protein activated potassium channel 1 by cAMP-dependent protein kinase

    FEBS JOURNAL, Issue 21 2009
    Carmen Müllner
    Besides being activated by G-protein ,/, subunits, G-protein activated potassium channels (GIRKs) are regulated by cAMP-dependent protein kinase. Back-phosphorylation experiments have revealed that the GIRK1 subunit is phosphorylated in vivo upon protein kinase A activation in Xenopus oocytes, whereas phosphorylation was eliminated when protein kinase A was blocked. In vitro phosphorylation experiments using truncated versions of GIRK1 revealed that the structural determinant is located within the distant, unique cytosolic C-terminus of GIRK1. Serine 385, serine 401 and threonine 407 were identified to be responsible for the incorporation of radioactive 32P into the protein. Furthermore, the functional effects of cAMP injections into oocytes on currents produced by GIRK1 homooligomers were significantly reduced when these three amino acids were mutated. The data obtained in the present study provide information about the structural determinants that are responsible for protein kinase A phosphorylation and the regulation of GIRK channels. Structured digital abstract ,,MINT-7260296, MINT-7260317, MINT-7260333, MINT-7260347, MINT-7260361, MINT-7260270: PKA-cs (uniprotkb:P00517) phosphorylates (MI:0217) Girk1 (uniprotkb:P63251) by protein kinase assay (MI:0424) [source]

    Identification of alternative promoter usage for the matrix Gla protein gene

    FEBS JOURNAL, Issue 6 2005
    Evidence for differential expression during early development in Xenopus laevis
    Recent cloning of the Xenopus laevis (Xl) matrix Gla protein (MGP) gene indicated the presence of a conserved overall structure for this gene between mammals and amphibians but identified an additional 5,-exon, not detected in mammals, flanked by a functional, calcium-sensitive promoter, 3042 bp distant from the ATG initiation codon. DNA sequence analysis identified a second TATA-like DNA motif located at the 3, end of intron 1 and adjacent to the ATG-containing second exon. This putative proximal promoter was found to direct transcription of the luciferase reporter gene in the X. laevis A6 cell line, a result confirmed by subsequent deletion mutant analysis. RT-PCR analysis of XlMGP gene expression during early development identified a different temporal expression of the two transcripts, strongly suggesting differential promoter activation under the control of either maternally inherited or developmentally induced regulatory factors. Our results provide further evidence of the usefulness of nonmammalian model systems to elucidate the complex regulation of MGP gene transcription and raise the possibility that a similar mechanism of regulation may also exist in mammals. [source]

    Improved microseismic event location by inclusion of a priori dip particle motion: a case study from Ekofisk

    G.A. Jones
    ABSTRACT Microseismic monitoring in petroleum settings provides insights into induced and naturally occurring stress changes. Such data are commonly acquired using an array of sensors in a borehole, providing measures of arrival times and polarizations. Events are located using 1D velocity models, P- and S-wave arrival times and the azimuths of P-wave particle motions. However in the case of all the sensors being deployed in a vertical or near-vertical borehole, such analysis leads to an inherent 180° ambiguity in the source location. Here we present a location procedure that removes this ambiguity by using the dip of the particle motion as an a priori information to constrain the initial source location. The new procedure is demonstrated with a dataset acquired during hydraulic fracture stimulation, where we know which side of the monitoring well the events are located. Using a 5 -step location procedure, we then reinvestigate a microseismic data set acquired in April 1997 at the Ekofisk oilfield in the North Sea. Traveltimes for 2683 candidate events are manually picked. A noise-weighted analytic-signal polarization analysis is used to estimate the dip and azimuth of P-wave particle motions. A modified t-test is used to statistically assess the reliability of event location. As a result, 1462 events are located but 627 are deemed to be statistically reliable. The application of a hierarchal cluster analysis highlights coherent structures that cluster around wells and inferred faults. Most events cluster at a depth of roughly 3km in the Ekofisk chalk formation but very little seismicity is observed from the underlying Tor chalk formation, which is separated from the Ekofisk formation by an impermeable layer. We see no evidence for seismicity in the overburden but such events may be too distant to detect. The resulting picture of microseismicity at Ekofisk is very different from those presented in previous studies. [source]