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Terms modified by Unsuitable Selected AbstractsFast Volume Rendering and Data Classification Using Multiresolution in Min-Max OctreesCOMPUTER GRAPHICS FORUM, Issue 3 2000Feng Dong Large-sized volume datasets have recently become commonplace and users are now demanding that volume-rendering techniques to visualise such data provide acceptable results on relatively modest computing platforms. The widespread use of the Internet for the transmission and/or rendering of volume data is also exerting increasing demands on software providers. Multiresolution can address these issues in an elegant way. One of the fastest volume-rendering alrogithms is that proposed by Lacroute & Levoy 1 , which is based on shear-warp factorisation and min-max octrees (MMOs). Unfortunately, since an MMO captures only a single resolution of a volume dataset, this method is unsuitable for rendering datasets in a multiresolution form. This paper adapts the above algorithm to multiresolution volume rendering to enable near-real-time interaction to take place on a standard PC. It also permits the user to modify classification functions and/or resolution during rendering with no significant loss of rendering speed. A newly-developed data structure based on the MMO is employed, the multiresolution min-max octree, M 3 O, which captures the spatial coherence for datasets at all resolutions. Speed is enhanced by the use of multiresolution opacity transfer functions for rapidly determining and discarding transparent dataset regions. Some experimental results on sample volume datasets are presented. [source] Sentinel Lymph Node Excision and PET-CT in the Initial Stage of Malignant Melanoma: A Retrospective Analysis of 61 Patients with Malignant Melanoma in American Joint Committee on Cancer Stages I and IIDERMATOLOGIC SURGERY, Issue 4 2010JOACHIM KLODE MD BACKGROUND AND OBJECTIVES Sentinel lymph node excision (SLNE) for the detection of regional nodal metastases and staging of malignant melanoma has resulted in some controversies in international discussions. Positron emission tomography with computerized tomography (PET-CT), a noninvasive imaging procedure for the detection of regional nodal metastases, has increasingly become of interest. Our study is a direct comparison of SLNE and PET-CT in patients with early-stage malignant melanoma. MATERIALS AND METHODS We retrospectively analyzed data from 61 patients with primary malignant melanoma with a Breslow index greater than 1.0 mm. RESULTS Metastatic SLNs were found in 14 patients (23%); 17 metastatic lymph nodes were detected overall, only one of which was identified preoperatively using PET-CT. Thus, PET-CT showed a sensitivity of 5.9% and a negative predictive value of 78%. CONCLUSION SLNE is much more sensitive than PET-CT in discovering small lymph node metastases. We consider PET-CT unsuitable for the evaluation of early regional lymphatic tumor dissemination in this patient population and recommend that it be limited to malignant melanomas of American Joint Committee on Cancer stages III and IV. We therefore recommend the routine use of SLNE for tumor staging and stratification for adjuvant therapy of patients with stage I and II malignant melanoma. The authors have indicated no significant interest with commercial supporters. [source] Nonoperative treatment of four esophageal perforations with hemostatic clipsDISEASES OF THE ESOPHAGUS, Issue 5 2007A. Fischer SUMMARY., Spontaneous or iatrogenic esophageal perforations are despite advances of modern surgery and intensive care medicine still potentially life-threatening events with a considerable mortality rate. Recently, encouraging results on the sealing of esophageal perforations by placement of endoluminal prostheses were reported. However, if the perforation is very proximal (close to the larynx) or very distal (involving the cardia), the situation is to our experience unsuitable for stent therapy. In these special cases non-operative treatment is still possible by application of hemostatic metal clips. We present four cases unsuitable for stent therapy where the perforation was sealed by endoscopic clip application. All patients had an uneventful recovery. Non-operative treatment of esophageal perforations with hemostatic metal clips is feasible and safe in cases not treatable with self-expanding metal stents. [source] Alcohol Septal Ablation in a Young Patient after Aortic Valve ReplacementECHOCARDIOGRAPHY, Issue 3 2009Fadi G. Hage M.D. A 38-year-old male presented with heart failure symptoms and was diagnosed with aortic valve endocarditis and underlying aortic stenosis in the absence of concentric hypertrophy or bicuspid aortic valve and underwent aortic valve replacement but continued to have symptoms which were then attributed to hypertrophic cardiomyopathy with dynamic left ventricular outflow tract obstruction. He was determined to be unsuitable for myomectomy and underwent successful alcohol septal ablation using transthoracic echocardiographic Doppler and continuous wave velocity monitoring without requiring to cross the aortic valve or to perform transatrial septostomy and left ventricular pressure monitoring. When crossing the aortic valve is a relative or absolute contraindication like in our index case, continuous Doppler velocity recording is a safe and effective alternative approach to monitor the outflow gradient while performing alcohol septal ablation. [source] Determination of ribavirin in human serum and plasma by capillary electrophoresisELECTROPHORESIS, Issue 10-11 2004Michael C. Breadmore Abstract The electrophoretic separation of ribavirin and 5-methylcytidine (internal standard) by capillary electrophoresis was examined. Separation was achieved using reverse polarity in a 100 mM borate electrolyte, pH 9.1, with 5 mM spermine added to reduce the electroosmotic flow. Sample preparation based on acetonitrile protein precipitation was found to be unsuitable for ribavirin analysis in patient samples due to insufficient sensitivity and interferences. Solid-phase extraction employing phenyl boronic acid cartridges provided cleaner separations. Using this approach with 500 ,L sample and reconstitution of the dried extract into 100 ,L of 33% v/v 100 mM phosphate buffer, pH 6.4 / 67% v/v acetonitrile, the detection and quantitation limits were determined to be 0.05 and 0.10 ,g/mL, respectively, a sensitivity that is suitable for therapeutic drug monitoring of ribavirin in human plasma and serum samples. The method was validated and compared to a high-performance liquid chromatography (HPLC) method, showing excellent agreement between the two for a set of samples that stemmed from patients being treated with ribavirin and interferon-,-2b for a hepatitis C virus infection. [source] Life table and heat tolerance of Acyrthosiphon pisum (Hemiptera: Aphididae) in subtropical TaiwanENTOMOLOGICAL SCIENCE, Issue 3 2008Wei-Nung LU Abstract The effect of temperature on the life table of Acyrthosiphon pisum reared on Pisum sativum was evaluated under laboratory conditions using temperatures of 10, 15, 20, 25, 30, and 35°C. The development time of juvenile A. pisum decreased with increasing temperature (from 21.3 days at 10°C to 4.7 days at 35°C). Adult longevity also decreased with increasing temperature (from 53.2 days at 10°C to 2.3 days at 35°C). Interestingly, 70% and 25% of A. pisum nymphs reared at 30°C and 35°C, respectively, successfully developed into adults. These temperatures have previously been considered unsuitable for A. pisum development. However, adult aphids reared at 30°C and 35°C failed to reproduce. Linear regression analysis revealed that the lower development threshold of A. pisum was 153.1 degree-days above 1.9°C. Maximal average reproductive capability was observed at 10°C for A. pisum adults, with each adult producing more than 120 nymphs. The intrinsic rate of increase (rm) of A. pisum increased from 0.124/day at 10°C to 0.337/day at 25°C, whereas opposite trends were observed for the net reproductive rate (R0) and the mean generation time (GT). At 20°C and 25°C, the intrinsic rate of increase of A. pisum was significantly higher than at 10°C and 15°C (P < 0.0001), indicating that 20°C and 25°C are within the optimal range for the growth of A. pisum, and that 30°C is beyond the upper threshold limit for reproduction, which involves a temperature range that is narrower than that of the survival range (upper limit is unknown, but above 35°C). [source] Multiple genetic tests for susceptibility to smoking do not outperform simple family historyADDICTION, Issue 1 2009Coral E. Gartner ABSTRACT Aims To evaluate the utility of using predictive genetic screening of the population for susceptibility to smoking. Methods The results of meta-analyses of genetic association studies of smoking behaviour were used to create simulated data sets using Monte Carlo methods. The ability of the genetic tests to screen for smoking was assessed using receiver operator characteristic curve analysis. The result was compared to prediction using simple family history information. To identify the circumstances in which predictive genetic testing would potentially justify screening we simulated tests using larger numbers of alleles (10, 15 and 20) that varied in prevalence from 10 to 50% and in strength of association [relative risks (RRs) of 1.2,2.1]. Results A test based on the RRs and prevalence of five susceptibility alleles derived from meta-analyses of genetic association studies of smoking performed similarly to chance and no better than the prediction based on simple family history. Increasing the number of alleles from five to 20 improved the predictive ability of genetic screening only modestly when using genes with the effect sizes reported to date. Conclusions This panel of genetic tests would be unsuitable for population screening. This situation is unlikely to be improved upon by screening based on more genetic tests. Given the similarity with associations found for other polygenic conditions, our results also suggest that using multiple genes to screen the general population for genetic susceptibility to polygenic disorders will be of limited utility. [source] Levetiracetam in the Treatment of Idiopathic Generalized EpilepsiesEPILEPSIA, Issue 2005Richard Grünewald Summary:, Since its introduction into clinical practice in 1999, levetiracetam, the S enantiomer of piracetam, has rapidly found a secure place, initially in the therapy of partial onset seizures and subsequently in the treatment of idiopathic generalized epilepsies (IGE). It has many of the properties of an "ideal" antiepileptic drug, including rapid absorption, linear pharmokinetics, and sparse drug interactions. Tolerabiliy is generally excellent in both adults and children, although tiredness is a common dose-limiting adverse effect. Occasionally the drug can precipitate behavioral abnormalities, especially in patients with learning disability. There is a wide safety margin in overdose. In common with most antiepileptic drugs its mode of action remains uncertain. Levetiracetam binds to a specific site in the brain, influences intracellular calcium currents and reverses negative allosteric modulators of GABA- and glycine-gated currents in vitro. Its effectiveness has been demonstrated in animal models of epilepsy and in clinical trials of partial onset and IGE. Treatment of IGEs may be straightforward, with many patients demonstrating an excellent and robust response to valproate monotherapy. However, there remains a significant minority of patients for whom valproate is unsuitable, including those who experience unacceptable adverse effects (e.g., weight gain or hair loss) and women of childbearing age in whom the teratogenic potential of valproate is unacceptable. Therapeutic response to lamotrigine in this group is often disappointing, and many clinicians now are turning to the choice of levetiracetam. Efficacy in generalized tonic,clonic seizures and myoclonus is usually apparent and some patients experience improvement in typical absences. Experience of combinations of levetiracetam with other antiepileptic drugs is limited in IGE and the responses are largely anecdotal. In our hands, patients with refractory IGEs may respond to combinations of levetiracetam with valproate, lamotrigine, and phenobarbital, and adverse effects when they occur are usually limited to tiredness. Levetiracetam does not interact with the oral contraceptive pill, simplifying treatment in women of childbearing age. Although animal data look encouraging, questions over levetiracetam's teratogenic potential and overall safety in pregnancy will remain for many years to come. [source] In search of stable soil organic carbon fractions: a comparison of methods applied to soils labelled with 14C for 40 days or 40 yearsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2008S. Bruun Summary A reliable method for the isolation of a stable fraction of soil organic carbon (SOC) would be very helpful for improving our understanding of the mechanisms responsible for stabilization of SOC and the dynamics of SOC turnover. We tested acid hydrolysis, physical fractionation (particle density/size), photo-oxidation, treatment with chemical oxidants (NaOCl and NaS2O8) and thermal treatment on two soils incubated with 14C-labelled barley straw for either 40 days or 40 years. Different intensities of the treatments were included. Acid hydrolysis, photo-oxidation and treatment with a chemical oxidant consistently removed more 40-year-old C than 40-day-old C, which suggests that the isolated fractions contained a large proportion of material with a relatively rapid turnover. The clay + silt associated SOC fraction contained a small proportion of 40-day-old C and a large proportion of 40-year-old C. This is consistent with a SOC fraction with medium turnover. The thermal treatment removed more 40-year-old C than 40-day-old C. At 400°C there was still a small proportion of the 40-year-old C remaining, whereas almost all the 40-day-old C was removed. This is consistent with a stable SOC fraction. However, because only 2,3% of the C remained after this treatment, the isolated SOC fraction may be of little quantitative importance. Furthermore, the thermally resistant fraction is likely to be heavily altered by the treatment, and therefore unsuitable for further studies of the chemical nature of stable SOC. [source] Analysing soil variation in two dimensions with the discrete wavelet transformEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2004R. M. Lark Summary Complex spatial variation in soil can be analysed by wavelets into contributions at several scales or resolutions. The first applications were to data recorded at regular intervals in one dimension, i.e. on transects. The theory extends readily to two dimensions, but the application to small sets of gridded data such as one is likely to have from a soil survey requires special adaptation. This paper describes the extension of wavelet theory to two dimensions. The adaptation of the wavelet filters near the limits of a region that was successful in one dimension proved unsuitable in two dimensions. We therefore had to pad the data out symmetrically beyond the limits to minimize edge effects. With the above modifications and Daubechies's wavelet with two vanishing moments the analysis is applied to soil thickness, slope gradient, and direct solar beam radiation at the land surface recorded at 100-m intervals on a 60 × 101 square grid in south-west England. The analysis revealed contributions to the variance at several scales and for different directions and correlations between the variables that were not evident in maps of the original data. In particular, it showed how the thickness of the soil increasingly matches the geological structure with increasing dilation of the wavelet, this relationship being local to the strongly aligned outcrops. The analysis reveals a similar pattern in slope gradient, and a negative correlation with soil thickness, most clearly evident at the coarser scales. The solar beam radiation integrates slope gradient and azimuth, and the analysis emphasizes the relations with topography at the various spatial scales and reveals additional effects of aspect on soil thickness. [source] Preliminary evaluation of electroencephalographic entrainment using thalamocortical modellingEXPERT SYSTEMS, Issue 4 2009Dean Cvetkovic Abstract: The concept of linked oscillators in biological control systems has long been established. Frequency entrainment is a predominant explanation behind many biological rhythms. In this paper a preliminary examination of electroencephalographic entrainment is made to survey the possibility and methods of achieving signal entrainment at the highest level of neurological organization and function. A model of the thalamocortical system is employed to generate simulated electroencephalographic signals and is tested in various configurations in the search for entrainment under very simple conditions. Additionally, an analysis of the coupled Van der Pol model of the circadian rhythm controller is performed to identify the possibility of affecting that system with a drastically different coupling input signal. We were able to conclude that overall signal shape can have a significant impact on the entrainment characteristics of the system. Due to the nature of the underlying mathematical structure of the model, by examining the circadian rhythm controller, we found that it is unsuitable for entrainment to an incident entraining signal of much higher frequency. [source] Microstructure and Properties of an HfB2 -SiC Composite for Ultra High Temperature Applications,ADVANCED ENGINEERING MATERIALS, Issue 5 2004F. Monteverde An ultra-high-temperature ceramic (UHTC) based on HfB2 was produced. The microstructure consisted of fine and regular diboride grains (2 ,m average size), with SiC particulate distributed intergranularly, not rarely in clustered formation, and low levels of secondary phases were identified. The resulting thermo-mechanical properties proved interesting results for microhardness and fracture toughness. The microstructural alteration experienced within the explored temperature range renders the material unsuitable for service in extreme conditions of temperature and pressure. [source] Modelling the response of sprinklers in compartment firesFIRE AND MATERIALS, Issue 3 2001A. K. Gupta Alpert's expressions are used extensively to calculate the maximum temperature and velocity in the ceiling-jet at any distance, r, from the fire axis. These expressions are valid for unconfined ceilings insofar as the environment outside the ceiling-jet is uniform in temperature and is atmospheric ambient. In compartments the outward flow of hot gases is checked by the presence of bounding walls and so a layer of hot gases is formed in the upper portion of the compartment. The environment outside the ceiling-jet is no longer ambient atmospheric. Expressions due to Alpert becomes unsuitable, unless the effects of the accumulated hot layer are included in these expressions. The effect of the upper layer temperature has been taken by assuming that since the ceiling-jet is completely submerged in the upper hot gas layer, the entrained gases are drawn from this layer only instead of the ambient atmospheric air at T,. Thus T, has been replaced by TL in the Alpert's empirical expression for ceiling-jet temperatures. The proposed equation is then used to calculate the response time of sprinklers fitted in compartments of varying sizes. Calculations have been done for identical conditions to those employed by Evans and compared. Comparison has also been made with Cooper's LAVENT model predictions. The study shows that the present model is capable of predicting the maximum, as well as average, temperatures in the ceiling-jets submerged in the hot gas layer. Copyright © 2001 John Wiley & Sons, Ltd. [source] REACH-driven developments in analysis and physicochemistry,FLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2010A. Chaintreau Abstract The enforcement of the REACH regulation in the fragrance domain has created new challenges for the analytical and physical chemist. Many chemicals used as perfumery ingredients are hydrophobic, because low-polar compounds exhibit a higher substantivity (i.e. persistence after application) than do polar compounds. As a result, the usual protocols are often unsuitable and new methods must be developed. Biodegradation studies sometimes call for the quantification of traces of such hydrophobic analytes in complex media (e.g. waste water, aqueous surfactant solutions). Existing sample preparation techniques are either inefficient or time consuming. A new approach is proposed, based on single-use absorbants, which allows accurate quantification down to the 100 ppb range. This extremely simple technique allows good throughput analyses. Determining the environmental profile of a compound requires the determination of some physical constants. Among these, solubility in water can be obtained from theoretical models or experimentally, but the resulting values may greatly differ as a function of the model or the protocol. Several experimental approaches are critically discussed and compared with a reference technique. The air-to-water partition coefficients are determined by using an improved version of the previously developed static-and-trapped headspace technique. Copyright © 2009 John Wiley & Sons, Ltd. [source] Analysis of adobe wall composition at the Chaves-Hummingbird Site, New Mexico, by diffuse reflectance spectrophotometryGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 8 2007William Balsam This article investigates adobe wall construction materials utilized by prehistoric inhabitants of Chaves-Hummingbird Pueblo, an ancestral Pueblo village located ,20 miles west of Albuquerque, New Mexico. The walls were constructed with native clay-rich soils some time between approximately 1275,1450 A.D. Samples were analyzed with a diffuse reflectance spectrophotometer from the near ultraviolet (NUV) through the visible (VIS) and into the near infrared (NIR) region of the electromagnetic spectrum. Cluster analysis of samples from 275 adobe walls and 36 soil locations surrounding the pueblo room blocks indicates four clusters. Comparison of typical samples from the four clusters indicates that they are very similar and are distinguished by minor variations in the three primary spectrally determined components, Na-Ca montmorillonite, bentonite, and goethite. In general, clusters correspond with room construction episodes that are discernible through patterns of wall bonding and abutment recorded during the archaeological investigation of the site. This suggests that during different phases of construction the source of the wall adobe changed. Many of the soil samples are included in wall clusters and therefore reveal a potential source of material used for adobe, adjacent soils. However, not all the soil surrounding the pueblo grouped with wall clusters indicating a preference for certain soil types and that some soils were probably unsuitable for making adobe. Therefore, diversity in spectrally identified construction materials provides insights into source locations and possible construction preferences of the site inhabitants. © 2007 Wiley Periodicals, Inc. [source] Delineating the rupture planes of an earthquake doublet using Source-Scanning Algorithm: application to the 2005 March 3 Ilan Doublet, northeast TaiwanGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2010Chih-Wen Kan SUMMARY Correct identification of the fault plane(s) associated with an earthquake doublet is a very challenging problem because the pair of events often occurs in close space and time with almost the same magnitude. Most long-period waveforms of an earthquake doublet are severely tangled and thus unsuitable for conventional waveform inversion methods. In this study, we try to resolve this issue by utilizing the recently developed Source-Scanning Algorithm (SSA). The SSA systematically searches the model space for seismic sources whose times and locations are most compatible with the observed arrivals of large amplitudes on seismograms. The identification of a seismic source is based on the brightness function, which is defined as the summation of the normalized waveform amplitudes at the predicted arrival times at all stations. By illuminating the spatiotemporal distribution of asperities during an earthquake's source process, we are able to constrain the orientation of the rupture propagation that, in turn, leads to the identification of the fault plane. A series of synthetic experiments are performed to test SSA's resolution under various scenarios including different directions of rupture propagation, imperfect station coverage and short origin time difference between the two events of a doublet. Because only short-period records are needed in the analysis, the proposed method is best suited for an earthquake doublet with a short time gap between the two events. Using the 2005 Ilan doublet (the origin time difference is only 70 s) that occurred in northeast Taiwan as an example, we show that the trace of the brightest spots moves towards the west and infer the E,W-striking plane to be the actual fault plane. [source] Spectral estimation on a sphere in geophysics and cosmologyGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2008F. A. Dahlen SUMMARY We address the problem of estimating the spherical-harmonic power spectrum of a statistically isotropic scalar signal from noise-contaminated data on a region of the unit sphere. Three different methods of spectral estimation are considered: (i) the spherical analogue of the one-dimensional (1-D) periodogram, (ii) the maximum-likelihood method and (iii) a spherical analogue of the 1-D multitaper method. The periodogram exhibits strong spectral leakage, especially for small regions of area A, 4,, and is generally unsuitable for spherical spectral analysis applications, just as it is in 1-D. The maximum-likelihood method is particularly useful in the case of nearly-whole-sphere coverage, A, 4,, and has been widely used in cosmology to estimate the spectrum of the cosmic microwave background radiation from spacecraft observations. The spherical multitaper method affords easy control over the fundamental trade-off between spectral resolution and variance, and is easily implemented regardless of the region size, requiring neither non-linear iteration nor large-scale matrix inversion. As a result, the method is ideally suited for most applications in geophysics, geodesy or planetary science, where the objective is to obtain a spatially localized estimate of the spectrum of a signal from noisy data within a pre-selected and typically small region. [source] Functional connexin "hemichannels": A critical appraisalGLIA, Issue 7 2006David C. Spray Abstract "Hemichannels" are defined as the halves of gap junction channels (also termed connexons) that are contributed by one cell; "hemichannels" are considered to be functional if they are open in nonjunctional membranes in the absence of pairing with partners from adjacent cells. Several recent reviews have summarized the blossoming literature regarding functional "hemichannels", in some cases encyclopedically. However, most of these previous reviews have been written with the assumption that all data reporting "hemichannel" involvement really have studied phenomena in which connexons actually form the permeability or conductance pathway. In this review, we have taken a slightly different approach. We review the concept of "hemichannels", summarize properties that might be expected of half gap junctions and evaluate the extent to which the properties of presumptive "hemichannels" match expectations. Then we consider functions attributed to hemichannels, provide an overview of other channel types that might fulfill similar roles and provide sets of criteria that might be applied to verify involvement of connexin hemichannels in cell and tissue function. One firm conclusion is reached. The study of hemichannels is technically challenging and fraught with opportunities for misinterpretation, so that future studies must apply rigorous standards for detection of hemichannel expression and function. At the same time there are reasons to expect surprises, including the possibility that some time honored techniques for studying gap junctions may prove unsuitable for detecting hemichannels. We advise hemichannel researchers to proceed with caution and an open mind. © 2006 Wiley-Liss, Inc. [source] Rainfall distribution is the main driver of runoff under future CO2 -concentration in a temperate deciduous forestGLOBAL CHANGE BIOLOGY, Issue 1 2010SEBASTIAN LEUZINGER Abstract Reduced stomatal conductance under elevated CO2 results in increased soil moisture, provided all other factors remain constant. Whether this results in increased runoff critically depends on the interaction of rainfall patterns, soil water storage capacity and plant responses. To test the sensitivity of runoff to these parameters under elevated CO2, we combine transpiration and soil moisture data from the Swiss Canopy Crane FACE experiment (SCC, 14 30,35 m tall deciduous broad-leaved trees under elevated CO2) with 104 years of daily precipitation data from an adjacent weather station to drive a three-layer bucket model (mean yearly precipitation 794 mm). The model adequately predicts the water budget of a temperate deciduous forest and runoff from a nearby gauging station. A simulation run over all 104 years based on measured sap flow responses resulted in only 5.5 mm (2.9%) increased ecosystem runoff under elevated CO2. Out of the 37 986 days (1 January 1901,31 December 2004), only 576 days produce higher runoff in the elevated CO2 scenario. Only 1 out of 17 years produces a CO2 -signal >20 mm a,1, which mostly depends on a few single days when runoff under elevated CO2 exceeds runoff under ambient conditions. The maximum signal for a double preindustrial CO2 -concentration under the past century daily rainfall regime is an additional runoff of 46 mm. More than half of all years produce a signal of <5 mm a,1, because trees consume the ,extra' moisture during prolonged dry weather. Increased runoff under elevated CO2 is nine times more sensitive to variations in rain pattern than to the applied reduction in transpiration under elevated CO2. Thus the key driver of increased runoff under future CO2 -concentration is the day by day rainfall pattern. We argue that increased runoff due to a first-order plant physiological CO2 -effect will be very small (<3%) in a landscape dominated by temperate deciduous forests, and will hardly increase flooding risk in forest catchments. Monthly rainfall sums are unsuitable to realistically model such CO2 effects. These findings may apply to other ecosystems with comparable soil water storage capacity. [source] Climate change and plant invasions: restoration opportunities ahead?GLOBAL CHANGE BIOLOGY, Issue 6 2009BETHANY A. BRADLEY Abstract Rather than simply enhancing invasion risk, climate change may also reduce invasive plant competitiveness if conditions become climatically unsuitable. Using bioclimatic envelope modeling, we show that climate change could result in both range expansion and contraction for five widespread and dominant invasive plants in the western United States. Yellow starthistle (Centaurea solstitialis) and tamarisk (Tamarix spp.) are likely to expand with climate change. Cheatgrass (Bromus tectorum) and spotted knapweed (Centaurea biebersteinii) are likely to shift in range, leading to both expansion and contraction. Leafy spurge (Euphorbia esula) is likely to contract. The retreat of once-intractable invasive species could create restoration opportunities across millions of hectares. Identifying and establishing native or novel species in places where invasive species contract will pose a considerable challenge for ecologists and land managers. This challenge must be addressed before other undesirable species invade and eliminate restoration opportunities. [source] Not seeing the ocean for the islands: the mediating influence of matrix-based processes on forest fragmentation effectsGLOBAL ECOLOGY, Issue 1 2006John A. Kupfer ABSTRACT The pervasive influence of island biogeography theory on forest fragmentation research has often led to a misleading conceptualization of landscapes as areas of forest/habitat and ,non-forest/non-habitat' and an overriding focus on processes within forest remnants at the expense of research in the human-modified matrix. The matrix, however, may be neither uniformly unsuitable as habitat nor serve as a fully,absorbing barrier to the dispersal of forest taxa. In this paper, we present a conceptual model that addresses how forest habitat loss and fragmentation affect biodiversity through reduction of the resource base, subdivision of populations, alterations of species interactions and disturbance regimes, modifications of microclimate and increases in the presence of invasive species and human pressures on remnants. While we acknowledge the importance of changes associated with the forest remnants themselves (e.g. decreased forest area and increased isolation of forest patches), we stress that the extent, intensity and permanence of alterations to the matrix will have an overriding influence on area and isolation effects and emphasize the potential roles of the matrix as not only a barrier but also as habitat, source and conduit. Our intention is to argue for shifting the examination of forest fragmentation effects away from a patch-based perspective focused on factors such as patch area and distance metrics to a landscape mosaic perspective that recognizes the importance of gradients in habitat conditions. [source] Hospital inpatients' experiences of access to food: a qualitative interview and observational studyHEALTH EXPECTATIONS, Issue 3 2008Smriti Naithani BSc MSc Abstract Background, Hospital surveys indicate that overall patients are satisfied with hospital food. However undernutrition is common and associated with a number of negative clinical outcomes. There is little information regarding food access from the patients' perspective. Purpose, To examine in-patients' experiences of access to food in hospitals. Methods, Qualitative semi-structured interviews with 48 patients from eight acute wards in two London teaching hospitals. Responses were coded and analysed thematically using NVivo. Results, Most patients were satisfied with the quality of the meals, which met their expectations. Almost half of the patients reported feeling hungry during their stay and identified a variety of difficulties in accessing food. These were categorized as: organizational barriers (e.g. unsuitable serving times, menus not enabling informed decision about what food met their needs, inflexible ordering systems); physical barriers (not in a comfortable position to eat, food out of reach, utensils or packaging presenting difficulties for eating); and environmental factors (e.g. staff interrupting during mealtimes, disruptive and noisy behaviour of other patients, repetitive sounds or unpleasant smells). Surgical and elderly patients and those with physical disabilities experienced greatest difficulty accessing food, whereas younger patients were more concerned about choice, timing and the delivery of food. Conclusions, Hospital in-patients often experienced feeling hungry and having difficulty accessing food. These problems generally remain hidden because staff fail to notice and because patients are reluctant to request assistance. [source] Clofarabine in the treatment of poor risk acute myeloid leukaemiaHEMATOLOGICAL ONCOLOGY, Issue 3 2010Janusz Krawczyk Abstract Clofarabine is a second generation nucleoside analogue. It inhibits DNA repair and activates the mitochondrial apoptotic pathway leading to cell death. In vitro clofarabine has demonstrated synergy with daunorubicin and Ara-C and in phase II clinical trials has shown promising activity in poor risk Acute myeloid leukaemia (AML) patients. In our institution over a 24 month period 22 AML patients (11 M, 11 F) with poor risk features, deemed unsuitable for standard therapy, were treated with clofarabine, alone (eight patients) or in combination (14 patients) for up to three cycles of treatment. The median age was 67.5 years (24,76) with 16 patients > 60 years. At the time of treatment 18 patients had active AML. Four patients intolerant of standard induction received clofarabine as consolidation. The overall response rate (ORR) for the 18 patients with active AML was 61%, nine patients (50%) achieving a complete response (CR). Induction and consolidation were well tolerated with no unexpected toxicities. Predictably, all patients developed grade 4 neutropenia but the median duration was only 20 days (17,120). Induction mortality was acceptable at 17%. In conclusion, clofarabine (alone or in combination) is active in poor risk AML with an acceptable safety profile and should be considered a potential option in poor risk AML patients. Copyright © 2009 John Wiley & Sons, Ltd. [source] Resection of renal metastases to the pancreas: a surgical challengeHPB, Issue 3 2003D Zacharoulis Background Metastasis to the pancreas from renal cell carcinoma (RCC) is distinctly uncommon. Most cases are detected at an advanced stage of the disease and are thus unsuitable for resection. A solitary RCC metastasis to the head of pancreas is rarely encountered and, although it is potentially amenable to surgical resection, surgeons may be hesitant to perform pancreatoduodenectomy. Cases outlines Two patients with a solitary RCC metastasis to the head of pancreas were treated by pancreatoduodenectomy, while a third with multiple RCC metastases declined any treatment. Two of the patients were asymptomatic, and one presented with anaemia and mild abdominal pain. Computed tomography (CT) and angiography were used to exclude other metastases and to assess resectability of the pancreatic tumour. All three patients are still alive, those with resectable disease at 2 years and 9 years and the one with irresectable disease at 4 years. Discussion Isolated RCC metastasis to the pancreas is a rare event. Patients present either on follow-up imaging or with symptoms such as mild abdominal pain, weight loss, jaundice, anaemia or gastrointestinal bleeding (whether occult or overt). Dynamic spiral CT can visualise the tumour and exclude distant metastasis. Angiography often reveals a highly vascularised tumour and will help to assess resectability. In the absence of widespread disease, pancreatic resection can provide long-term survival in metastatic RCC, although few cases have been reported with lengthy follow-up. The prognosis is better than for pancreatic adenocarcinoma. [source] Marine and human activity influences on the groundwater quality of southern Korinthos area (Greece)HYDROLOGICAL PROCESSES, Issue 12 2003G. Stamatis Abstract In this paper the groundwater quality of the southern part of Korinthos region (north-east Peloponnese) is discussed. The geology is characterized by a thick sequence of Neogene marls alternating with sandstones, overlain by superficial Quaternary deposits. The latter consist of a mixture of loose materials such as conglomerates, marly sandstones, sands and clay to silty sands. The area is crossed by a fault system parallel to the coastline, and the Quaternary sediments have formed extended Tyrrhenian marine terraces. Two aquifers have been identified in the area. The first is unconfined and occurs within the Quaternary sediments whereas the other is a deep confined aquifer occurring within the underlying Neogene marl series. Analysis of hydrochemical evolution over the past 30 years has indicated significant deterioration of quality owing to seawater intrusion and nitrate pollution. The various sources of pollution have rendered, to a large extent, shallow groundwater unsuitable not only for potable water supply but also for irrigation purposes. However, this is not the case for the deeper confined aquifer. Statistical analysis was used to explore the evolution of salinization during the years 1968 and 1998. In view of the alarming conditions caused by the documented groundwater quality deterioration, the need for integrated water resources management is stressed to maintain the socio-economic growth of the region studied. Copyright © 2003 John Wiley & Sons, Ltd. [source] Modelling the benefits of American Mink Mustela vison management options for terns in west ScotlandIBIS, Issue 2008NORMAN RATCLIFFE American Mink Mustela vison is a semi-aquatic predator that has invaded the west coast of Scotland and many of its associated islands. We developed a GIS model of their potential range based on their dispersal abilities and habitat use, which revealed that most islands in west Scotland are accessible to Mink, and that these host a large proportion of the region's Common Sterna hirundo and Arctic Terns S. paradisaea. Mink are predators on tern eggs and chicks, and statistical modelling of long-term productivity data demonstrated that unprotected sites within their range have an average productivity of 0.33 chicks per pair, whereas that at sites where Mink were trapped was 253% higher. We assessed the benefits of current Mink control projects for terns in the Western Isles and the remainder of west Scotland using a population modelling approach. This showed that both projects delivered considerable benefits for Common Terns, because a large proportion of their numbers were within the area of the control programmes and in sites that would be accessible to Mink if no control were in operation. For Arctic Terns, the benefits were less clear, as a larger proportion of their numbers were outside the control areas, and many of these were in sites isolated from, or unsuitable for, Mink. We discuss the implications of these findings for future strategic planning of Mink management in west Scotland. [source] Lack of functional erythropoietin receptors of cancer cell linesINTERNATIONAL JOURNAL OF CANCER, Issue 5 2008Magdalena Laugsch Abstract Erythropoietin (Epo) therapy reduces red cell transfusion requirements and improves the quality of life of anemic cancer patients receiving chemotherapy. However, there is concern that Epo may promote tumor growth. We investigated by real-time RT-PCR, immunofluorescence microscopy, Western blotting and cell growth analysis whether human cancer cell lines (SH-SY5Y, MCF7, HepG2, U2-OS, HeLa, HEK293T, RCC4, HCT116, 7860wt and SW480) possess functional Epo receptors (EpoR). We detected EpoR mRNA in all cell lines. Neither hypoxia nor Epo treatment altered the level of EpoR mRNA expression. Four commonly used commercial antibodies proved to be unsuitable for immunoblot procedures because they cross-reacted with several proteins unrelated with EpoR. Depending on the antibody used, EpoR was localized to the plasma membrane, the cytoplasm or the nucleus. Experiments with small interfering RNA showed that EpoR protein was not expressed by the tumor cells except by UT7/Epo leukemia cells, which served as an EpoR positive control line, and by cells transfected with the human EpoR gene. Apart from UT7/Epo, none of the tumor cell lines responded to Epo treatment with phosphorylation of signaling molecules or with cell proliferation. © 2007 Wiley-Liss, Inc. [source] Forced Soft Lithography (FSL): Production of Micro- and Nanostructures in Thin Freestanding Sheets of Chitosan Biopolymer,ADVANCED MATERIALS, Issue 21 2007G. Fernandez A "forced" soft lithography (FSL) technique is described for production of micro- and nanostructures into the surface of polymers at room temperature. The technique can be used with polymer/mould combinations that are unsuitable for conventional soft lithography, and has been used to structure the surface of the Chitosan biopolymer. Theoretical descriptions of the filling of the mould cavities and the possible formation of bubbles in the polymer are given. [source] Comparison of various precipitation downscaling methods for the simulation of streamflow in a rainshadow river basin,INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 8 2003Eric P. Salathé Jr Abstract Global simulations of precipitation from climate models lack sufficient resolution and contain large biases that make them unsuitable for regional studies, such as forcing hydrologic simulations. In this study, the effectiveness of several methods to downscale large-scale precipitation is examined. To facilitate comparisons with observations and to remove uncertainties in other fields, large-scale predictor fields to be downscaled are taken from the National Centers for Environmental Prediction,National Center for Atmospheric Research reanalyses. Three downscaling methods are used: (1): a local scaling of the simulated large-scale precipitation; (2) a modified scaling of simulated precipitation that takes into account the large-scale wind field; and (3) an analogue method with 1000 hPa heights as predictor. A hydrologic model of the Yakima River in central Washington state, USA, is then forced by the three downscaled precipitation datasets. Simulations with the raw large-scale precipitation and gridded observations are also made. Comparisons among these simulated flows reveal the effectiveness of the downscaling methods. The local scaling of the simulated large-scale precipitation is shown to be quite successful and simple to implement. Furthermore, the tuning of the downscaling methods is valid across phases of the Pacific decadal oscillation, suggesting that the methods are applicable to climate-change studies. Copyright © 2003 Royal Meteorological Society [source] Wireless video streaming with TCP and simultaneous MAC packet transmission (SMPT),INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2004Frank H. P. Fitzek Abstract Video streaming is expected to account for a large portion of the traffic in future networks, including wireless networks. It is widely accepted that the user datagram protocol (UDP) is the preferred transport protocol for video streaming and that the transmission control protocol (TCP) is unsuitable for streaming. The widespread use of UDP, however, has a number of drawbacks, such as unfairness and possible congestion collapse, which are avoided by TCP. In this paper we investigate the use of TCP as the transport layer protocol for streaming video in a multi-code CDMA cellular wireless system. Our approach is to stabilize the TCP throughput over the wireless links by employing a recently developed simultaneous MAC packet transmission (SMPT) approach at the link layer. We study the capacity, i.e. the number of customers per cell, and the quality of service for streaming video in the uplink direction. Our extensive simulations indicate that streaming over TCP in conjunction with SMPT gives good performance for video encoded in a closed loop, i.e. with rate control. We have also found that TCP is unsuitable (even in conjunction with SMPT) for streaming the more variable open-loop encoded video. Copyright © 2004 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||||||||||||||