Extensive

Distribution by Scientific Domains
Distribution within Medical Sciences

Terms modified by Extensive

  • extensive accumulation
  • extensive alopecia areata
  • extensive analysis
  • extensive area
  • extensive array
  • extensive attention
  • extensive body
  • extensive cell death
  • extensive change
  • extensive characterization
  • extensive colitis
  • extensive collection
  • extensive damage
  • extensive data
  • extensive data set
  • extensive database
  • extensive description
  • extensive development
  • extensive discussion
  • extensive disease
  • extensive distribution
  • extensive effort
  • extensive evaluation
  • extensive evidence
  • extensive experience
  • extensive experiment
  • extensive exposure
  • extensive fibrosis
  • extensive field studies
  • extensive form
  • extensive gene flow
  • extensive glaciation
  • extensive grazing
  • extensive heterogeneity
  • extensive hybridization
  • extensive hydrogen bonding
  • extensive hydrogen-bonding network
  • extensive inflammation
  • extensive information
  • extensive interaction
  • extensive interview
  • extensive introgression
  • extensive investigation
  • extensive involvement
  • extensive knowledge
  • extensive lesion
  • extensive list
  • extensive literature
  • extensive literature review
  • extensive literature search
  • extensive loss
  • extensive margin
  • extensive necrosis
  • extensive network
  • extensive nmr
  • extensive nmr studies
  • extensive parametric studies
  • extensive procedure
  • extensive range
  • extensive remodeling
  • extensive report
  • extensive research
  • extensive resection
  • extensive review
  • extensive sampling
  • extensive search
  • extensive sensitivity analysis
  • extensive series
  • extensive set
  • extensive simulation
  • extensive simulation experiment
  • extensive simulation studies
  • extensive simulation study
  • extensive spectroscopic analysis
  • extensive studies
  • extensive study
  • extensive surgery
  • extensive survey
  • extensive test
  • extensive training
  • extensive use
  • extensive validation
  • extensive variation
  • extensive work
  • extensive work-up
  • extensive workup

  • Selected Abstracts


    MARGINS AND OUTCOME OF SCREEN-DETECTED BREAST CANCER WITH EXTENSIVE IN SITU COMPONENT

    ANZ JOURNAL OF SURGERY, Issue 7 2006
    Paul R. B. Kitchen
    Background: In situ disease surrounding invasive tumours is an important consideration in the management of patients with early breast cancer. This study of screen-detected breast cancers assessed the influence of in situ disease including an extensive in situ component (defined as ductal carcinoma in situ involving more than 25% of the area within the invasive tumour) on surgical management, local recurrence and survival of a group of patients. Methods: A total of 595 cases of invasive breast cancer detected at St Vincent's BreastScreen were retrospectively reviewed to determine presence and extent of in situ disease, the surgical procedure and adequacy of excision. Outcome was examined in a cohort of 126 cases. Results: A total of 438 (74%) patients had in situ foci in or around the invasive tumour and 107 (18%) were defined as extensive in situ component (EIC)-positive. The initial procedure was mastectomy in 20% of the cases and breast-conserving surgery in 80% including 18% who underwent further surgery. Re-excision (P = 0.02) or mastectomy (P = 0.01) was more often required in patients with EIC. After definitive local excision, margins were close or involved with invasive disease in 3% but the patients with EIC were more likely to have margins close or involved with in situ disease (16 vs 2%; P = 0.001). There were seven deaths and one local invasive recurrence in the follow-up group and none of the deaths were in patients who were EIC-positive. Conclusions: EIC predicts for a higher rate of re-excision and/or mastectomy. For patients with EIC, there is an acceptably low risk of local recurrence if margins are clear. [source]


    Errors in the Interpretation of Mohs Histopathology Sections Over a 1-Year Fellowship

    DERMATOLOGIC SURGERY, Issue 12 2008
    MICHAEL E. MURPHY MD
    BACKGROUND Errors can occur in the interpretation of Mohs histopathology sections. Errors in histology interpretation can lead to incomplete removal of cancer and cancer persistence or the unnecessary removal of uninvolved tissue. Extensive proctored training is necessary to reduce these errors to an absolute minimum level. OBJECTIVE To analyze and quantify the number of cases and the amount of time required to reach a satisfactory level of expertise in the reading and interpretation of Mohs histopathology. METHODS A single-institution pilot study was designed to track errors in the interpretation and mapping of Mohs histopathology sections. A Mohs surgery fellow independently preread Mohs cases and rendered his interpretation on the Mohs map. One of the Mohs program directors subsequently reviewed and corrected all cases. Errors were scored on a graded scale and tracked over the 1-year fellowship to determine the number of cases and amount of time necessary to reduce errors to a baseline minimal level. RESULTS One thousand four hundred ninety-one Mohs surgery cases were required to generate 1,347 pathology specimens for review and grading over 6 months of Mohs surgery fellowship before reducing errors to a minimum acceptable level of less than 1 critical error per 100 cases read. CONCLUSIONS The number of cases and time required to reduce errors in the interpretation of Mohs histology is substantial. Direct and immediate mentored correction of errors is essential for improvement. These results can act as a guide for Mohs surgery training programs to help determine the minimum number of directly proctored cases required to obtain expertise in this crucial component of Mohs surgery. [source]


    Permo-Triassic development from Ireland to Norway: basin architecture and regional controls

    GEOLOGICAL JOURNAL, Issue 6 2009
    tolfová
    Abstract Extensive occurrences of Permo-Triassic strata are preserved along the Northwest European Atlantic margin. Seismic reflection and well data are used to describe large-scale Permo-Triassic basin geometries along a swath of the continental shelf more than 2000,km long extending from the Irish to the mid-Norwegian sectors. Successions in the Celtic Sea, the flanks of the Irish Rockall Basin, basins west and north of Scotland, and the Trøndelag and Horda platforms west of Norway are described. The large-scale Permo-Triassic depositional geometries commonly represent erosional remnants of larger basins modified by later rifting episodes, uplift, inversion and continental breakup. However, the interpreted geometries reveal spatial and temporal differences in rifting style. The basins developed above a complex mosaic of petrologically heterogeneous crustal terranes with inherited crustal fabrics, which had a significant impact on the depositional basin geometries. Small Permian basins with growth faulting developed in the southern Celtic Sea region. Extensive, uniformly thick Triassic strata are characteristic of the wide rift basins in the southeastern Rockall Basin and northwest of the Solan Bank High. Thick, fault-controlled basins developed in the Horda and Trøndelag platform regions. The main controls on Permo-Triassic basin architecture are (a) crustal thickness and composition, which determined the development of narrow or wide rift basin geometries, (b) inherited Variscan, Caledonian and Precambrian basement structures and (c) pre-rift palaeotopography. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    Extensive and recalcitrant verrucae vulgares of the great toe treated with imiquimod 5% cream

    JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2003
    L Atzori
    [source]


    Extensive and deep dermatophytosis caused by Trichophyton mentagrophytes var. Interdigitalis in an HIV-1 positive patient

    JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 1 2000
    Ma Muñoz-Pèrez
    Abstract Background,Cutaneous infections are common in HIV-1 positive patients and are usually severe, recurrent, and caused by microorganisms that are unusual in immunocompetent patients. Objective,We report a case of an HIV-1-positive 23-year-old male, with a history of intravenous drug use, in stage C-II (CDC ,86), with a CD4 lymphocyte count of 335 cells/mm3. He had multiple, large erythematous, circinate and pustular plaques on his abdomen, back, arms and legs. Results,We isolated Trichophyton mentagrophytes var. interdigitalis from the lesions. The biopsy showed suppurative deep dermatophytosis and folliculitis. The patient satisfactorily responded to itraconazole (100 mg/d for 14 days). Conclusion,This is the first reported case of deep dermatophytosis caused by T. mentagrophytes in an HIV-positive patient. [source]


    Outcome and prognostic factor analysis of 217 consecutive isolated limb perfusions with tumor necrosis factor-, and melphalan for limb-threatening soft tissue sarcoma

    CANCER, Issue 8 2006
    Dirk J. Grunhagen M.D.
    Abstract BACKGROUND Extensive and mutilating surgery is often required for locally advanced soft tissue sarcoma (STS) of the limb. As it has become apparent that amputation for STS does not improve survival rates, the interest in limb-preserving approaches has increased. Isolated limb perfusion (ILP) with tumor necrosis factor-, (TNF) and melphalan is successful in providing local tumor control and enables limb-preserving surgery in a majority of cases. A mature, large, single-institution experience with 217 consecutive ILPs for STS of the extremity is reported. METHODS At a prospectively maintained database at a tertiary referral center, 217 ILPs were performed from July 1991 to July 2003 in 197 patients with locally advanced STS of the extremity. ILPs were performed at mild hyperthermic conditions with 1,4 mg of TNF and 10,13 mg/L limb-volume melphalan (M) for leg and arm perfusions, respectively. RESULTS The overall response rate was 75%. Limb salvage was achieved in 87% of the perfused limbs. Median survival post-ILP was 57 months and prognostic factors for survival were Trojani grade of the tumor and ILP for single versus multiple STS. The procedure could be performed safely, with a perioperative mortality of 0.5% in all patients with no age limit (median age, 54 yrs; range, 12,91). Systemic and locoregional toxicity were modest and easily manageable. CONCLUSION TNF+M-based ILP can provide limb salvage in a significant percentage of patients with locally advanced STS and has therefore gained a permanent place in the multimodality treatment of STS. Cancer 2006. © 2006 American Cancer Society. [source]


    Insight into the Solvation and Isomerization of 3-Halo-1-azaallylic Anions from Ab Initio Metadynamics Calculations and NMR Experiments

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2009
    Reinout Declerck Dr.
    Long live theZisomer! The solvation and isomerization properties of lithiated 3-chloro-1-azaallylic anions in tetrahydrofuran are revealed. Extensive and convincing evidence is obtained from state-of-the-art first-principle molecular dynamics and metadynamics simulations in an explicit periodic solvent model, together with detailed NMR experiments. [source]


    Limiting light-induced lipid peroxidation and vitamin loss in infant parenteral nutrition by adding multivitamin preparations to Intralipid

    ACTA PAEDIATRICA, Issue 3 2001
    KM Silvers
    Parenteral lipids are susceptible to light-induced peroxidation, particularly under phototherapy. Ascorbic acid is protective. The aim of this study was to investigate whether dark delivery tubing and/or coadministration of multivitamin preparations could prevent peroxidation of Intralipid without undue vitamin loss. In experiments carried out on the benchtop, lipid peroxidation occurred in ambient light and was more extensive under phototherapy. Dark tubing decreased peroxide formation, but only by about 65%. In simulated clinical conditions in which solutions were pumped through standard clear or dark minibore plastic tubing, Intralipid accumulated lipid peroxides as measured by the FOX assay (280 ,M) or as triglyceride hydroperoxides (52 ,M). Multivitamin preparations (MVIP or Soluvit/Vitlipid) inhibited peroxide formation almost completely, and were fully protective when used with dark tubing. There was loss of riboflavin (65% from Soluvit and 35% from MVIP) in clear tubing but this was decreased to 18% and 11%, respectively, in dark tubing. Ascorbate loss was 20% (MVIP) and 50% (Soluvit) and only slightly less in dark tubing. Ascorbate loss was also seen in the absence of Intralipid and is due to riboflavin-induced photo-oxidation. Conclusion: Multivitamin preparations protect Intralipid against light-induced formation of lipid hydroperoxides, and administering multivitamins with Intralipid via dark delivery tubing provides a practical way of preventing peroxidation of the lipid while limiting vitamin loss. This procedure should be considered for routine use as well as with phototherapy. [source]


    Sparse points matching by combining 3D mesh saliency with statistical descriptors

    COMPUTER GRAPHICS FORUM, Issue 2 2008
    U. Castellani
    Abstract This paper proposes new methodology for the detection and matching of salient points over several views of an object. The process is composed by three main phases. In the first step, detection is carried out by adopting a new perceptually-inspired 3D saliency measure. Such measure allows the detection of few sparse salient points that characterize distinctive portions of the surface. In the second step, a statistical learning approach is considered to describe salient points across different views. Each salient point is modelled by a Hidden Markov Model (HMM), which is trained in an unsupervised way by using contextual 3D neighborhood information, thus providing a robust and invariant point signature. Finally, in the third step, matching among points of different views is performed by evaluating a pairwise similarity measure among HMMs. An extensive and comparative experimental session has been carried out, considering real objects acquired by a 3D scanner from different points of view, where objects come from standard 3D databases. Results are promising, as the detection of salient points is reliable, and the matching is robust and accurate. [source]


    Tracking Fragmentation of Natural Communities and Changes in Land Cover: Applications of Landsat Data for Conservation in an Urban Landscape (Chicago Wilderness)

    CONSERVATION BIOLOGY, Issue 4 2001
    Yeqiao Wang
    Within the metropolis survive some of the world's best remaining examples of eastern tallgrass prairie, oak savanna, open oak woodland, and prairie wetland. Chicago Wilderness is more than 81,000 ha of protected areas in the urban and suburban matrix. It also is the name of the coalition of more than 110 organizations committed to the survival of these natural lands. The long-term health of these imperiled communities depends on proper management of the more extensive, restorable lands that surround and connect the patches of high-quality habitat. Information critical to the success of conservation efforts in the region includes (1) a current vegetation map of Chicago Wilderness in sufficient detail to allow quantitative goal setting for the region's biodiversity recovery plan; (2) quantified fragmentation status of the natural communities; and (3) patterns of land-cover change and their effects on the vitality of communities under threat. We used multispectral data from the Landsat thematic mapper (October 1997) and associated ground truthing to produce a current vegetation map. With multitemporal remote-sensing data (acquired in 1972, 1985, and 1997), we derived land-cover maps of the region at roughly equivalent intervals over the past 25 years. Analyses with geographic information system models reveal rapid acceleration of urban and suburban sprawl over the past 12 years. Satellite images provide striking visual comparisons of land use and health. They also provide banks of geographically referenced data that make quantitative tracking of trends possible. The data on habitat degradation and fragmentation are the biological foundation of quantitative goals for regional restoration. Resumen: En Chicago hay una concentración de comunidades naturales globalmente significativas sorprendentemente alta. En la metrópolis sobreviven algunos de los mejores ejemplos mundiales remanentes de praderas de pastos orientales, sabanas de roble, bosques abiertos de roble y humedales de pradera. Chicago Wilderness es más de 81,000 ha de áreas protegidas en la matriz urbana y suburbana. También es el nombre de una coalición de más de 110 organizaciones dedicadas a la supervivencia de esas tierras naturales. La salud a largo plazo de estas comunidades amenazadas depende del manejo adecuado de las tierras, más extensas y restaurables, que rodean y conectan a los fragmentos de hábitat de alta calidad. La información crítica para el éxito de los esfuerzos de conservación en la región incluye: (1) un mapa actualizado de la vegetación de Chicago Wilderness con suficiente detalle para que la definición de metas cuantitativas para el plan de recuperación de la región sea posible; (2) cuantificación de la fragmentación de las comunidades naturales y (3) patrones de cambio de cobertura de suelo y sus efectos sobre la vitalidad de las comunidades amenazadas. Utilizamos datos multiespectrales del mapeador temático Landsat (octubre 1997) y verificaciones de campo asociadas para producir el mapa actualizado de vegetación. Con datos de percepción remota multitemporales (obtenidos en 1972, 1985 y 1997), derivamos los mapas de cobertura de suelo en la región en intervalos equivalentes en los últimos 25 años. El análisis de los modelos SIG revela una rápida aceleramiento del crecimiento urbano y suburbano en los últimos 12 años. Las imágenes de satélite proporcionan comparaciones visuales notables del uso y condición del suelo. También proporcionan bancos de datos referenciados geográficamente que hacen posible el rastreo de tendencias cuantitativas. Los datos de degradación y fragmentación del hábitat son la base biológica de metas cuantitativas para la restauración regional. [source]


    Clinical and histological alterations in the surrounding periodontium of dog's teeth submitted for an intrusive luxation

    DENTAL TRAUMATOLOGY, Issue 3 2008
    Janaína Cristina Gomes
    An impact device was used on 12 teeth of six adult dogs with the purpose of making a dislocation on the long axis of these teeth. Of the teeth that suffer intrusion luxation, two did not receive treatment and ten were replaced by orthodontic extrusion with activated springs of 100 gf. The traction was initiated either immediately after the trauma or 7 days later. Observation time was 40 days. Endodontic therapy with calcium hydroxide was performed on the fourteenth day after the intrusive luxation. The intruded teeth that did not receive appropriate treatment had signs of extensive and progressive inflammatory resorption. The teeth that were moved immediately after the trauma had lesser degree of replacement resorption compared with those that were extruded 7 days after the trauma. [source]


    Hypothermic insult to the periodontium: a model for the study of aseptic tooth resorption

    DENTAL TRAUMATOLOGY, Issue 1 2000
    C. W. Dreyer
    Abstract , The aim of the current investigation was to define an animal model for the study of hard tissue resorption by examining the responses of the periodontal ligament (PDL) to both single and multiple episodes of hypothermic injury to the crowns of rat teeth. A group of 12 male rats weighing 200,250 g were anesthetized, and pellets of dry ice (CO2) were applied once to the crowns of the right first maxillary molars for continuous periods of 10 or 20 min. Animals were sacrificed at 2, 7, 14 and 28 days and tissues were processed for routine histological examination. A second group of eight animals and a third group of 12 animals were subjected to three applications of dry ice over a period of 1 week and sacrificed at 2 and 14 days respectively after the final application. In addition to thermal insult, the periodontium of teeth from a fourth group of six rats was subjected to mechanical trauma. Examination of the sections from the group undergoing a single freezing episode revealed that, by 1 week, shallow resorption lacunae had appeared on the root surface. These became more extensive after 14 days. At the same time hyaline degeneration was evident in the PDL. Within this group, teeth subjected to the longer 20-min application times generally showed more extensive injuries. By 28 days, evidence of repair was observed with reparative cementum beginning to line the resorption lacunae in the root dentin. Sections from animals subjected to multiple episodes of thermal trauma and those subjected to additional mechanical insult showed more extensive external root resorption than those from single-injury animals. It was concluded that low temperature stimuli applied to the crowns of rat molars were capable of eliciting a sterile degenerative response in the PDL which, in turn, resulted in external root resorption. Furthermore, the degree of this tissue injury was commensurate with the duration and number of exposures to the trauma. The results also indicated that progression of the resorptive process required periodic exposure to the injury, in the absence of which repair to the damaged root occurred. [source]


    Angiokeratoma Circumscriptum Naeviforme: Successful Treatment with Carbon-Dioxide Laser Vaporization

    DERMATOLOGIC SURGERY, Issue 2 2005
    Jesús del Pozo MD
    Background Angiokeratoma circumscriptum naeviforme (ACN) is an unusual type of localized angiokeratoma that occurs more frequently in females and is usually located on the buttocks or thighs, showing a unilateral distribution. ACN usually causes large lesions, which may require laser ablation because they often are too extensive to perform surgical excision. Carbon-dioxide laser is a known alternative for treating angiokeratomas. Objective Report of two cases of ACN treated with carbon-dioxide laser vaporization. Patients and methods A 28-year-old woman with a hyperkeratotic, violaceus plaque on her left buttock and a 24-year-old woman with a similar lesion on her right buttock were treated with a carbon-dioxide laser. Two laser passes were performed on each lesion within a single session. Results A successful cosmetic aspect of treated areas was obtained, with minimal pigmentary or textural changes. After a 2-year follow-up in the first patient and a 6-month follow-up in the second patient, no recurrence of the lesions was observed. Conclusions Our results, obtaining relevant cosmetic improvement after a few sessions of treatment, with low morbidity and minimal secondary effects, suggest that continuous-wave carbon-dioxide laser vaporization is a safe and effective treatment for ACN. JESÚS DEL POZO, MD, AND EDUARDO FONSECA, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]


    The apparent volumes of distribution of H1 receptor antagonists

    DERMATOLOGIC THERAPY, Issue 4 2000
    Jean-Paul Tillement
    ABSTRACT: The apparent volume of distribution (VD) of a drug estimates its distribution into the body. Referring to the volume of exchangeable water (0.6 L/kg body weight), it indicates if tissue distribution is extensive when VD is greater than 0.6 L/kg or poor if VD is less than 0.6 L/kg. Its interest in the selection of an appropriate drug is found after comparing the map of selected targets (mainly receptors) to be reached by the drug, the accessibility of these targets by the drug, and the VD necessary and sufficient to reach them. This analysis is here applied to H1 receptor antagonists, a pharmacologic class, where target cells, endothelial cells such as eosinophils, mastocytes, basophils, and smooth fibers have receptors on the external side of cell membranes and thus are more readily accessible from blood than toxic sites located inside cells (heart, brain, liver). Of the H1 receptor antagonists marketed today, cetirizine has the lowest VD, 0.4 L/kg, enough to reach selected targets without extensive distribution in organs where it would be useless. These characteristics are related to its chemical amphoteric structure. [source]


    The ,Iranian Diaspora' and the New Media: From Political Action to Humanitarian Help

    DEVELOPMENT AND CHANGE, Issue 4 2009
    Halleh Ghorashi
    ABSTRACT This article looks at the shifting position of the ,Iranian diaspora' in relation to Iran as it is influenced by online and offline transnational networks. In the 1980s the exilic identity of a large part of the Iranian diaspora was the core factor in establishing an extended, yet exclusive form of transnational network. Since then, the patterns of identity within this community have shifted towards a more inclusive network as a result of those transnational connections, leading to more extensive and intense connections and activities between the Iranian diaspora and Iranians in Iran. The main concern of the article is to examine how the narratives of identity are constructed and transformed within Iranian (charity) networks and to identify the factors that contribute to this transformation. The authors use the transnational lens to view diasporic positioning as linked to development issues. New technological sources help diaspora groups, in this case Iranians, to build virtual embedded ties that transcend nation states and borders. Yet, the study also shows that these transnational connections can still be challenged by the nation state, as has been the case with recent developments in Iran. [source]


    Metastatic mammary carcinomas with endocrine features: Potential diagnostic pitfalls

    DIAGNOSTIC CYTOPATHOLOGY, Issue 1 2005
    Anjali Saqi M.D.
    Abstract Mammary carcinomas with endocrine differentiation (MCED) are an uncommon subtype of breast carcinomas that are morphologically indistinguishable from low-grade endocrine neoplasms arising in other organs. Aspirates of MCED yield relatively monotonous cells with eccentrically placed nuclei containing characteristic "salt and pepper" chromatin. In the breast, these features represent MCED. In extramammary sites, the differential is more extensive, and diagnosing MCED metastates to the lung, a common location for primary and metastatic endocrine tumors, can be a challenging task, with significant clinical implications. Although primary MCED have been described extensively in the cytology literature, secondary pulmonary MCED have not been reported to the best of our knowledge. We report three cases of MCED metastatic to the lung and present the cytological and immunohistochemical features. Diagn. Cytopathol. 2005;33:49,53. © 2005 Wiley-Liss, Inc. [source]


    Naturalization and invasion of alien plants: concepts and definitions

    DIVERSITY AND DISTRIBUTIONS, Issue 2 2000
    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]


    Accelerating drug development: methodology to support first-in-man pharmacokinetic studies by the use of drug candidate microdosing

    DRUG DEVELOPMENT RESEARCH, Issue 1 2007
    Matthew A. McLean
    Abstract Microdosing of experimental therapeutics in humans offers a number of benefits to the drug development process. Microdosing, conducted under an exploratory Investigational New Drug (IND) application, entails administration of a sub-pharmacological dose of a new chemical entity (NCE) that allows for early evaluation of human pharmacokinetics. Such information can be pivotal for: (1) selecting a compound for full drug development from a small group of candidates; (2) defining the amount of material needed for early development; and (3) setting the initial Phase I dose regimen in humans. Appropriate safety studies must be conducted to support microdosing in humans, but the requirements are generally less extensive than those needed to support a traditional IND. To date, microdosing has not been broadly applied by the pharmaceutical industry due to concerns about analytical sensitivity and the possibility of non-linear pharmacokinetics at extremely low doses. The primary method for detecting analytes following microdosing until now has been accelerator mass spectrometry, which is expensive, not generally available, and requires test agents to be radiolabeled. Presented in this report is an example of pharmacokinetics analysis using LC/MS/MS following microdosing of an experimental agent in cynomolgus monkeys. The results show good linearity in plasma pharmacokinetics for oral doses of 10,mg/kg (therapeutic dose) and 0.0005,mg/kg (microdose) of the test agent. The results also demonstrate the feasibility of applying standard laboratory analytics to support microdosing in humans and raise the possibility of establishing an animal model to screen for compounds having non-linear pharmacokinetics at low dose levels. Drug Dev. Res. 68:14,22, 2007. © 2007 Wiley-Liss, Inc. [source]


    Defining the OE hearg: a preliminary archaeological and topographic examination of hearg place names and their hinterlands

    EARLY MEDIEVAL EUROPE, Issue 4 2007
    Sarah Semple
    The OE term hearg is interpreted variously as ,pagan temple', ,hilltop sanctuary' and even ,idol'. It is a rare survival in the English place-name record. When it can be identified, the place name is commonly considered to refer to a location of pre-Christian religious activity, specifically a pagan Anglo-Saxon temple. Taking inspiration from the extensive and methodologically well-advanced studies in Scandinavia, which have successfully related place-name evidence for cultic and religious sites with the archaeology and topography of these localities, this paper adopts and uses a similar methodology to investigate the archaeological and topographic character of a selection of hearg locations. The traditional interpretations of the place name are questioned and evidence is presented that these sites are characterized by long-lived, localized cult practice spanning the late prehistoric to early historic periods, but with activity reaching a zenith in the late Iron Age to Romano-British eras, rather than the fifth to seventh centuries AD. [source]


    Optical remote mapping of rivers at sub-meter resolutions and watershed extents

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 1 2008
    W. Andrew Marcus
    Abstract At watershed extents, our understanding of river form, process and function is largely based on locally intensive mapping of river reaches, or on spatially extensive but low density data scattered throughout a watershed (e.g. cross sections). The net effect has been to characterize streams as discontinuous systems. Recent advances in optical remote sensing of rivers indicate that it should now be possible to generate accurate and continuous maps of in-stream habitats, depths, algae, wood, stream power and other features at sub-meter resolutions across entire watersheds so long as the water is clear and the aerial view is unobstructed. Such maps would transform river science and management by providing improved data, better models and explanation, and enhanced applications. Obstacles to achieving this vision include variations in optics associated with shadows, water clarity, variable substrates and target,sun angle geometry. Logistical obstacles are primarily due to the reliance of existing ground validation procedures on time-of-flight field measurements, which are impossible to accomplish at watershed extents, particularly in large and difficult to access river basins. Philosophical issues must also be addressed that relate to the expectations around accuracy assessment, the need for and utility of physically based models to evaluate remote sensing results and the ethics of revealing information about river resources at fine spatial resolutions. Despite these obstacles and issues, catchment extent remote river mapping is now feasible, as is demonstrated by a proof-of-concept example for the Nueces River, Texas, and examples of how different image types (radar, lidar, thermal) could be merged with optical imagery. The greatest obstacle to development and implementation of more remote sensing, catchment scale ,river observatories' is the absence of broadly based funding initiatives to support collaborative research by multiple investigators in different river settings. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Dunefoot dynamics along the Dutch coast

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2002
    B. G. Ruessink
    Abstract The dynamics of the dunefoot along a 160 km portion of the Dutch coast has been investigated based on a data set of annual surveys dating back to as early as 1850. The linearly detrended (or residual) dunefoot positions comprise an alongshore uniform and an alongshore non-uniform component. The former is expressed as 10 to 15 m of landward retreat along extensive (>10 km) stretches of coast during years with severe storm surges and as up to 5 m of seaward advance during years without significant storm activity. The latter, alongshore non-uniform component is organized in sandwave-like patterns, which may have a longevity of decades to up to the duration of the entire data set (150 years). Their wavelengths vary along the coast, from 3·5 to 10 km; migration rates are 0,200 m a,1. Dunefoot sandwaves are shown to be the shoreward extensions of similar sandwave patterns in the beach position. The non-uniform dunefoot behaviour constitutes at least 80 per cent of the total residual dunefoot dynamics, implying that along the Dutch coast residual dunefoot variability is controlled by temporal and spatial variability in beach characteristics, and not by storm-induced uniform erosion. Various potential mechanisms causing beach sandwaves are discussed. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Movement patterns of endangered Roanoke logperch (Percina rex)

    ECOLOGY OF FRESHWATER FISH, Issue 3 2008
    J. H. Roberts
    Abstract,,, Using mark,recapture methods, we studied movements of endangered Roanoke logperch (Percina rex Jordan & Evermann), a benthic darter, at 12 riffle,run sites over a 9-year-long period in the Roanoke River, Virginia, USA. Our primary objective was to characterise movements among transects within sites, but we opportunistically recorded two between-site movements as well. Our recapture rate was low (22 of 485 marked fish), but most recaptured fish exhibited movements between tagging and recapture, relocating either to another transect within a site (12 fish) or to another site altogether (two fish). Within sites, Roanoke logperch exhibited fidelity over time to the areas in which they were initially marked. These restricted areas were lengthier than transects (>15 m) but shorter than entire riffle,runs (<150 m). The two between-site movements were extensive (3.2 and 2.5 km), observed over a long mark,recapture interval (2 and 5 years, respectively), and may have represented migratory or dispersal movements. Their detection required an unusually extensive study design. Both small- and large-scale movements fulfil important ecological functions for Roanoke logperch, and greater study of such movements in this and other darter species is needed to inform conservation choices. [source]


    EARLY ISLAMIC CHARITIES AS CATALYSTS OF INSTITUTIONAL INNOVATION

    ECONOMIC AFFAIRS, Issue 3 2010
    Benedikt Koehler
    Islamic societies may appear unsuitable catalysts for fostering individual enterprise and institutional innovation. This view is challenged by examination of the evolution of charities in early Islam, the so-called waqf. Mohammed's prescription of providing alms engendered an extensive and varied range of charitable institutions. One example is the creation of Islam's earliest centres of higher learning, madrasahs. Key concepts of Common Law, such as trusts, may have copied Islamic legal concepts; the constitutions of the earliest colleges of Oxford and Cambridge universities replicated the design of charitable madrasahs. [source]


    A NEW THEORY OF THE BUDGETARY PROCESS

    ECONOMICS & POLITICS, Issue 1 2006
    SOUMAYA M. TOHAMY
    This paper offers an alternative to the view that budgetary decisions are incremental because they are complex, extensive, and conflicted. Our model interprets incrementalism as the result of a legislative political strategy in response to interest group politics and economic conditions. Accordingly, a legislator chooses between single-period budgeting or multiperiod budgeting, where single-period budgeting is associated with a greater chance of non-incremental budgeting outcomes. We use a statistical procedure developed by Dezhbakhsh et al. (2003) for identifying non-incremental outcomes to test the implications of the model. Results support the model's predictions: a higher discount rate and a persistently large deficit appear to cause departures from incremental budgeting; Democrats' control over the political process have a similar effect, while a higher inflation rate has an opposite effect. [source]


    Longitudinal patterns of gambling activities and associated risk factors in college students

    ADDICTION, Issue 7 2009
    Anna E. Goudriaan
    ABSTRACT Aims To investigate which clusters of gambling activities exist within a longitudinal study of college health, how membership in gambling clusters change over time and whether particular clusters of gambling are associated with unhealthy risk behaviour. Design Four-year longitudinal study (2002,2006). Setting Large, public university. Participants Undergraduate college students. Measurements Ten common gambling activities were measured during 4 consecutive college years (years 1,4). Clusters of gambling activities were examined using latent class analyses. Relations between gambling clusters and gender, Greek membership, alcohol use, drug use, personality indicators of behavioural undercontrol and psychological distress were examined. Findings Four latent gambling classes were identified: (1) a low-gambling class, (2) a card gambling class, (3) a casino/slots gambling class and (4) an extensive gambling class. Over the first college years a high probability of transitioning from the low-gambling class and the card gambling class into the casino/slots gambling class was present. Membership in the card, casino/slots and extensive gambling classes were associated with higher scores on alcohol/drug use, novelty seeking and self-identified gambling problems compared to the low-gambling class. The extensive gambling class scored higher than the other gambling classes on risk factors. Conclusions Extensive gamblers and card gamblers are at higher risk for problem gambling and other risky health behaviours. Prospective examinations of class membership suggested that being in the extensive and the low gambling classes was highly stable across the 4 years of college. [source]


    Correlates of Board Empowerment in Small Companies

    ENTREPRENEURSHIP THEORY AND PRACTICE, Issue 5 2007
    Jonas Gabrielsson
    This study seeks to advance the understanding of board empowerment in small companies. Predictions based on agency and resource dependency theories were used to examine how contingency factors correlate with board empowerment, in this study conceptualized as a larger number of board members, a higher representation of outside directors, and separate CEO and board chair positions. Statistical analyses on a sample of 135 small companies gave ample support for the agency-theoretic prediction that board empowerment in small companies is a response to satisfy the demands from owners not directly involved in managing the company. Other factors influencing board empowerment were younger CEOs, high degree of exports, and past poor company performance. The influence of these contingency factors, however, was not as strong and extensive as the presence of outside owners. The article ends with a discussion of the findings and their implications for understanding boards and governance in small companies. [source]


    Biodegradation during contaminant transport in porous media: 7.

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005
    Impact of multiple-degrader community dynamics
    Abstract The biodegradation and transport of phenanthrene in porous media containing multiple populations of phenanthrene degraders is examined with a series of miscible-displacement experiments. A long-term experiment was conducted with a soil containing an indigenous microbial community comprised of 25 identified phenanthrene-degrading isolates. The rate and magnitude of phenanthrene biodegradation oscillated throughout the six-month experiment. This behavior, at least in part, is attributed to multiple-population dynamics associated with the indigenous community of phenanthrene degraders, the composition of which changed during the experiment. This hypothesis is supported by the results of experiments conducted using sterilized porous media that were inoculated with selected isolates obtained from the indigenous soil community. The results of experiments conducted with sterilized soil inoculated with isolate A exhibited an initial extended period of steady phenanthrene effluent concentrations, followed by a uniform decline. The results of experiments conducted using sterilized sand for single-isolate systems with one of three selected isolates and for systems of two-isolate combinations, indicate the existence of apparent synergistic and antagonistic interactions among the isolates. For example, phenanthrene biodegradation was relatively extensive and occurred without a lag phase for isolate A alone. However, biodegradation was constrained when isolate A and B were combined, indicating an antagonistic interaction. Conversely, whereas extensive lag phases were exhibited by both isolates B and C for the single-isolate experiments, there was minimal lag when isolates B and C were combined, indicating a synergistic interaction. [source]


    Fate and effects of triclosan in activated sludge

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2002
    Thomas W. Federle
    Abstract Triclosan (TCS; 5-chloro-2-[2,4-dichloro-phenoxy]-phenol) is a widely used antimicrobial agent. To understand its fate during sewage treatment, the biodegradation and removal of TCS were determined in activated sludge. In addition, the effects of TCS on treatment processes were assessed. Fate was determined by examining the biodegradation and removal of TCS radiolabeled with 14C in the 2,4-dichlorphenoxy ring in laboratory batch mineralization experiments and bench-top continuous activated-sludge (CAS) systems. In batch experiments with unacclimated sludge, TCS was mineralized to 14CO2, but the total yield varied as a function of test concentration. Systems that were redosed with TCS exhibited more extensive and faster mineralization, indicating that adaptation was a critical factor determining the rate and extent of biodegradation. In a CAS study in which the influent level of TCS was incrementally increased from 40 ,g/L to 2,000 ,g/L, removal of the parent compound exceeded 98.5% and removal of total radioactivity (parent and metabolites) exceeded 85%. Between 1.5 and 4.5% of TCS in the influent was sorbed to the wasted solids, whereas >94% underwent primary biodegradation and 81 to 92% was mineralized to CO2 or incorporated in biomass. Increasing levels of TCS in the influent had no major adverse effects on any wastewater treatment process, including chemical oxygen demand, biological oxygen demand, and ammonia removal. In a subsequent experiment, a CAS system, acclimated to TCS at 35 ,g/L, received two separate 4-h shock loads of 750 ,g/L TCS. Neither removal of TCS nor treatment processes exhibited major adverse effects. An additional CAS study was conducted to examine the removal of a low level (10 ,g/L) of TCS. Removal of parent equaled 94.7%, and biodegradation remained the dominant removal mechanism. A subsequent series of CAS experiments examined removal at four influent concentrations (7.5, 11, 20, and 50 ,g/L) of TCS and demonstrated that removal of parent ranged from 98.2 to 99.3% and was independent of concentration. Although TCS removal across all experiments appeared unrelated to influent concentration, removal was significantly correlated (r2 = 0.87) with chemical oxygen demand removal, indicating that TCS removal was related to overall treatment efficiency of specific CAS units. In conclusion, the experiments show that TCS is extensively biodegraded and removed in activated-sludge systems and is unlikely to upset sewage treatment processes at levels expected in household and manufacturing wastewaters. [source]


    A comparison of five fMRI protocols for mapping speech comprehension systems

    EPILEPSIA, Issue 12 2008
    Jeffrey R. Binder
    Summary Aims:, Many fMRI protocols for localizing speech comprehension have been described, but there has been little quantitative comparison of these methods. We compared five such protocols in terms of areas activated, extent of activation, and lateralization. Methods:, fMRI BOLD signals were measured in 26 healthy adults during passive listening and active tasks using words and tones. Contrasts were designed to identify speech perception and semantic processing systems. Activation extent and lateralization were quantified by counting activated voxels in each hemisphere for each participant. Results:, Passive listening to words produced bilateral superior temporal activation. After controlling for prelinguistic auditory processing, only a small area in the left superior temporal sulcus responded selectively to speech. Active tasks engaged an extensive, bilateral attention, and executive processing network. Optimal results (consistent activation and strongly lateralized pattern) were obtained by contrasting an active semantic decision task with a tone decision task. There was striking similarity between the network of brain regions activated by the semantic task and the network of brain regions that showed task-induced deactivation, suggesting that semantic processing occurs during the resting state. Conclusions:, fMRI protocols for mapping speech comprehension systems differ dramatically in pattern, extent, and lateralization of activation. Brain regions involved in semantic processing were identified only when an active, nonlinguistic task was used as a baseline, supporting the notion that semantic processing occurs whenever attentional resources are not controlled. Identification of these lexical-semantic regions is particularly important for predicting language outcome in patients undergoing temporal lobe surgery. [source]


    Voxel-based T2 Relaxation Rate Measurements in Temporal Lobe Epilepsy (TLE) with and without Mesial Temporal Sclerosis

    EPILEPSIA, Issue 2 2007
    Susanne G. Mueller
    Summary:,Introduction: Quantitative measurements of T2 relaxation in the hippocampus for focus lateralization in mesial temporal lobe epilepsy (mTLE) are well established. Less is known to what degree such relaxation abnormalities also affect regions beyond the ipsilateral hippocampus. Therefore, the aim of this study was to characterize extent and distribution pattern of extrahippocampal relaxation abnormalities in TLE with (TLE-MTS) and without MRI evidence of mesial-temporal sclerosis (TLE-no). Methods: Double spin echo images (TE1/2: 20/80 ms) acquired in 24 TLE-MTS and 18 TLE-no were used to calculate relaxation rate maps. These maps were analyzed by SPM2 and by selecting regions of interest (ROI) in the hippocampus and several extrahippocampal brain regions. Results: In TLE-MTS, the results of the SPM and ROI analysis were in good agreement and showed the most severe relaxation rate decreases in the ipsilateral hippocampus but also in other ipsilateral temporal regions, orbitofrontal, and parietal regions and to a lesser degree in contralateral frontal regions. The relaxation rate decreases in TLE-no were confined to small regions in the ipsilateral anterior inferior and medial temporal lobe in the SPM analysis while ROI analysis showed additional regions in the ipsilateral hippocampus, amygdala, and anterior cingulate. Conclusion: TLE-MTS showed extensive, widespread but predominantly ipsilateral temporal and also extratemporal T2 relaxation rate decreases. In contrast, the findings of the SPM and ROI analyses in TLE-no suggested that if relaxation rate decreases are present, they are less uniform and generally milder than in TLE-MTS. This further supports the hypothesis that TLE-no is a distinct clinicopathological entity from TLE-MTS and probably heterogeneous in itself. [source]