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Terms modified by Resulting Selected AbstractsCHARACTER DISPLACEMENT AS THE "BEST OF A BAD SITUATION": FITNESS TRADE-OFFS RESULTING FROM SELECTION TO MINIMIZE RESOURCE AND MATE COMPETITIONEVOLUTION, Issue 10 2005Karin S. Pfennig Abstract Character displacement has long been considered a major cause of adaptive diversification. When species compete for resources or mates, character displacement minimizes competition by promoting divergence in phenotypes associated with resource use (ecological character displacement) or mate attraction (reproductive character displacement). In this study, we investigated whether character displacement can also have pleiotropic effects that lead to fitness trade-offs between the benefits of avoiding competition and costs accrued in other fitness components. We show that both reproductive and ecological character displacement have caused spadefoot toads to evolve smaller body size in the presence of a heterospecific competitor. Although this shift in size likely arose as a by-product of character displacement acting to promote divergence between species in mating behavior and larval development, it concomitantly reduces offspring survival, female fecundity, and sexual selection on males. Thus, character displacement may represent the "best of a bad situation" in that it lessens competition, but at a cost. Individuals in sympatry with the displaced phenotype will have higher fitness than those without the displaced trait because they experience reduced competition, but they may have reduced fitness relative to individuals in allopatry. Such a fitness trade-off can limit the conditions under which character displacement evolves and may even increase the risk of "Darwinian extinction" in sympatric populations. Consequently, character displacement may not always promote diversification in the manner that is often expected. [source] Letter: Nipple Asymmetry Resulting from Lesion Excision and Use of a Purse-String SutureDERMATOLOGIC SURGERY, Issue 8 2007FIACS, LAWRENCE M. FIELD MD No abstract is available for this article. [source] Eruptive Epidermoid Cysts Resulting from Treatment with ImiquimodDERMATOLOGIC SURGERY, Issue 7 2005Chelsy L. Marty MD Background Because of its unique mechanism of action and safety profile, imiquimod, a topical immune response modifier, is used for many benign and malignant dermatologic conditions. Adverse effects are typically limited to treatment site erythema and erosion. Objective To describe a newly recognized adverse effect of imiquimod. Methods A 79-year-old woman being treated with imiquimod 5 days per week for a nodular basal cell developed a verrucous plaque over the treatment area after 7 weeks of therapy. Results Scouting biopsies demonstrated multiple comedones and ruptured epidermoid cysts. There was no evidence of residual basal cell carcinoma. Conclusions Imiquimod is a new and novel treatment option for cutaneous malignancies. We report its successful use in the treatment of a nodular basal cell carcinoma. The multiple comedones and ruptured epidermoid cysts are newly reported adverse effects of imiquimod therapy. [source] Salt-Sensitive Hypertension Resulting From Nitric Oxide Synthase Inhibition is Associated with Loss of Regulation of Angiotensin II in the RatEXPERIMENTAL PHYSIOLOGY, Issue 1 2002G. Hodge In the Dahl salt-sensitive hypertensive rat, a diet containing L-arginine, the natural substrate for nitric oxide synthase, abrogates the hypertension. We postulated that nitric oxide synthase inhibition might induce a salt-sensitive form of hypertension and that this salt sensitivity might be linked to a loss of the regulatory effect of sodium ingestion on angiotensin II (Ang II) and angiotensinogen. Male Wistar-Kyoto rats were randomised to a diet containing 0.008%, 2.2% or 4.4% sodium chloride and to treatment with the NO synthase inhibitor L-NAME (10 mg kg,1 day,1) in the drinking water, or drinking water alone (Controls) for 4 weeks. Blood pressure was measured by tail cuff plethysmography twice weekly. After 4 weeks, the rats were anaesthetised and truncal blood collected for determination of angiotensinogen, renin, angiotensin I (Ang I), Ang II and aldosterone concentrations as well as angiotensin-converting enzyme (ACE) activity. Systolic blood pressure increased with increasing dietary sodium intake in the L-NAME-treated rats (P < 0.05). Plasma renin and aldosterone concentrations decreased with increasing dietary sodium intake in both Control and L-NAME-treated rats. Ang I and ACE activity were unchanged by increasing dietary sodium intake. In contrast, the plasma concentration of Ang II and angiotensinogen increased with increasing dietary sodium (P < 0.05 and P < 0.005, respectively). Treatment with the Ang II receptor blocker, losartan, reversed the blood pressure increase. We conclude that treatment with L-NAME induces an increase in blood pressure that is at least in part salt sensitive. Further, the salt-sensitive component appears to be Ang II-dependent, as it was associated with increasing plasma Ang II levels and could be reversed by treatment with an Ang II receptor antagonist. [source] Solid-State NMR Investigations of the Unusual Effects Resulting from the Nanoconfinement of Water within Amphiphilic Crosslinked Polymer NetworksADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Ryutaro Ohashi Abstract Two types of solid-state 19F NMR spectroscopy experiments are used to characterize phase-separated hyperbranched fluoropolymer,poly(ethylene glycol) (HBFP,PEG) crosslinked networks. Mobile (soft) domains are detected in the HBFP phase by a rotor-synchronized Hahn echo under magic-angle spinning conditions, and rigid (hard) domains by a solid echo with no magic-angle spinning. The mobility of chains is detected in the PEG phase by 1H,,,13C cross-polarization transfers with 1H spin-lock filters with and without magic-angle spinning. The interface between HBFP and PEG phases is detected by a third experiment, which utilized a 19F,,,1H,(spin diffusion),1H,,,13C double transfer with 13C solid-echo detection. The results of these experiments show that composition-dependent PEG inclusions in the HBFP glass rigidify on hydration, consistent with an increase in macroscopic tensile strength. [source] Cut1/separase C-terminus affects spindle pole body positioning in interphase of fission yeast: pointed nuclear formationGENES TO CELLS, Issue 11 2002Takahiro Nakamura Background: The separase-securin complex is required for anaphase. Separase activated by securin destruction cleaves the cohesin subunit Scc1/Rad21 enriched in kinetochores. Fission yeast Cut1/separase resides in interphase cytoplasm and mobilizes to the spindle and the spindle pole bodies (SPBs) in mitosis, while Cut2/securin remains in the nucleus from interphase to metaphase, and temporarily locates at the short spindle. Results: We here report a novel SPB-led dynamic nuclear movement in fission yeast, when the Cut1 C-terminal fragment is over-expressed. The tip of the pointed nucleus contained both SPB and centromeric DNA, and rapidly moved along the bundled cytoplasmic microtubules. The same pointed nucleus was produced when the human separase C-fragment was over-expressed. The pointed nuclear formation did not require the protease site of separase, but required the conserved C-terminus and a microtubule- and kinetochore-binding protein Mtc1/Alp14, a homologue of frog XMAP215 and budding yeast Stu2. The movement-inducing C-fragment should be cytoplasmic, as the pointed nucleus was abolished when the fragment contained the NLS (nuclear localization signal). Conclusions: Overproduced separase C-fragment abolishes correct SPB-positioning in interphase. Resulting pointed nuclear formation (alternatively called ,pigtail movement') requires cytoplasmic microtubules and Mtc1/Alp14. [source] Water Deficit Reduced Fertility of Young Microspores Resulting in a Decline of Viable Mature Pollen and Grain Set in RiceJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2009G. N. Nguyen Abstract Pollen formation in rice (Oryza sativa L.) is highly vulnerable to environmental stresses such as heat, chilling and drought. In rice plants exposed to drought during male reproductive development, the most obvious damage often observed is a decline in the number of engorged pollen and grain set. This has been well characterized in rice under chilling and to a lesser extent under drought stress. Moreover, detailed literature on the immediate effects of drought on developing young microspores in rice is still limited. Here, we report findings from experiments on rice plants exposed to water deficit for three consecutive days during early stages of anther development. When the osmotic potential of the growing medium was equal to or less than ,0.5 MPa, as induced by polyethylene glycol, the leaf water potential was significantly lowered and grain set was reduced. A strong correlation between grain set and viable young microspores (P < 0.001, r2 = 0.8223) indicates that water deficit immediately reduced fertility of rice plants at the time of exposure. This result suggests a new underlying mechanism of water deficit-induced pollen abortion in rice. [source] Canine COL1A2 Mutation Resulting in C-Terminal Truncation of Pro-,2(I) and Severe Osteogenesis ImperfectaJOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2001Bonnie G. Campbell Abstract RNA and type I collagen were analyzed from cultured skin fibroblasts of a Beagle puppy with fractures consistent with type III osteogenesis imperfecta (OI). In a nonisotopic RNAse cleavage assay (NIRCA), the proband's RNA had a unique cleavage pattern in the region of COL1A2 encoding the C-propeptide. DNA sequence analyses identified a mutation in which nucleotides 3991-3994 ("CTAG") were replaced with "TGTCATTGG." The first seven bases of the inserted sequence were identical to nucleotides 4002-4008 of the normal canine COL1A2 sequence. The resulting frameshift changed 30 amino acids and introduced a premature stop codon. Reverse-transcription polymerase chain reaction (RT-PCR) with primers flanking the mutation site amplified two complementary DNA (cDNA) fragments for the proband and a single product for the control. Restriction enzyme digestions also were consistent with a heterozygous mutation in the proband. Type I procollagen labeled with [3H]proline was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Increased density of pC-,2(I) suggested comigration with the similarly sized pro-,2(I) derived from the mutant allele. Furthermore, ,-chains were overhydroxylated and the ratio of ,1(I):,2(I) was 3.2:1, consistent with the presence of ,1(I) homotrimers. Analyses of COL1A2 and type I collagen were both consistent with the described heterozygous mutation affecting the pro-,2(I) C-propeptide and confirmed a diagnosis of OI. [source] Delayed Presentation of Injury to the Sinus of Valsalva with Aortic Regurgitation Resulting from Penetrating Cardiac WoundsJOURNAL OF CARDIAC SURGERY, Issue 3 2003Narutoshi Hibino M.D. An emergency operation was performed successfully to repair the penetrating cardiac injury of the right ventricular outflow tract without using cardiopulmonary bypass. Two years after the operation, he was complained of dyspnea and a continuous murmur was detected. Echocardiography and cardiac catheterization revealed aorto-right ventricular fistula in the sinus of valsalva with aortic regurgitation. In operation, the healed laceration of the right coronary cusp and the fistula between aorta and right ventricle were identified. The fistula was closed using a Dacron patch and the aortic valve was replaced with a mechanical valve. Long-term follow-up of penetrating thoracic injuries is important for detecting underlying intracardiac lesions. (J Card Surg 2003;18:236-239) [source] Ear Necrosis Resulting from the Endovascular Onyx-18 Embolization of a Dural Arteriovenous Fistula Fed by the Posterior Auricular ArteryJOURNAL OF NEUROIMAGING, Issue 3 2009Brian T. Jankowitz MD ABSTRACT BACKGROUND AND PURPOSE The treatment of a dural arteriovenous fistula (DAVF) can involve surgery, radiosurgery, or endovascular embolization. New embolization techniques and agents have expanded the role of endovascular treatment. METHODS We report the endovascular embolization with Onyx-18 of a DAVF fed by the posterior auricular artery. RESULTS The DAVF was successfully embolized; however, the patient's ear developed ischemic necrosis of the superolateral pinna. CONCLUSIONS Onyx-18 can provide high rates of success in the treatment of DAVFs in well-selected patients. Risks of end organ ischemia must be considered during endovascular embolization and when counseling patients regarding procedural risk. [source] Processing Conditions and Aging Effect on the Morphology of PZT Electrospun Nanofibers, and Dielectric Properties of the Resulting 3,3 PZT/Polymer CompositeJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2009Ebru Mensur Alkoy Lead zirconate titanate (PZT) nanofibers are obtained by electrospinning a sol,gel based solution and polyvinyl pyrrolidone (PVP) polymer, and by subsequent sintering of the electrospun precursor fibers. The average diameter of the precursor PZT/PVP green fibers has increased with the aging of the precursor solution along with an increase in the viscosity. Bead-free uniform green PZT/PVP fibers were collected at about an ,230 nm average fiber diameter using a 28 wt% PVP ratio solution with a viscosity of 290 mPa. Shrinkage of 40% was recorded on the fiber diameter after sintering. The X-ray diffraction pattern of the annealed PZT fibers exhibits no preferred orientation and a perovskite phase. Preparation of 3,3 nanocomposites by the infusion of polyvinylester into the nanofiber mat facilitates successful handling of the fragile mats and enables measurements of the dielectric properties. The dielectric constant of the PZT/polyvinylester nanocomposite of about 10% fiber volume fraction was found to be fairly stable and vary from 72 to 62 within the measurement range. The dielectric loss of the composite is below 0.08 at low frequencies and reaches a stable value of 0.04 for most of the measured frequencies. [source] Phytosterols,what plant breeders should focus onJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2001Tatu A Miettinen Abstract The present paper compares effects of plant stanol and sterol esters on metabolism of cholesterol and plant sterols in studies designed to lower serum cholesterol in man. The ultimate aim is to emphasize factors on which plant breeders should focus when trying to develop new nutritionally interesting plant products for effective lowering of serum cholesterol and plant sterol levels. The findings indicate that fat solubility of phytostanol esters followed by their effective intestinal hydrolysis, preferentially of unsaturated fatty acid esters, allows sufficient micellar solubilization of unesterified plant stanols for prevention of cholesterol and plant sterol absorption, and subsequent lowering of their serum concentrations. Plant sterol esters apparently result in similar changes but, in contrast to stanol esters, increase their own absorption. Resulting increased serum plant sterol levels could occasionally approach values seen in phytosterolemia, a strongly atherogenic hereditary metabolic abnormality. Thus, plants producing oils rich in plant stanols esterified with unsaturated fatty aids would be preferable for preparation of functional foods with roughly 2,g/day of plant stanols in reasonable low amounts of calories. © 2001 Society of Chemical Industry. [source] Better land husbandry in Honduras: towards the new paradigm in conserving soil, water and productivityLAND DEGRADATION AND DEVELOPMENT, Issue 3 2002J. Hellin Abstract Land shortages are forcing more smallholder farmers to cultivate tropical steeplands. Resulting accelerated soil erosion is being countered by the promotion of soil conservation (SC) technologies, such as cross-slope barriers, which aim to reduce soil loss and preserve land productivity. However, farmer adoption rates tend to be low. This is often attributed to the farmers' conservatism or lack of education. Research in Honduras's steeplands demonstrates that farmers value SC, provided that it promotes agricultural production. Field research from 1995,98, involving farmed test plots on slopes greater than 35 per cent (19 degrees), demonstrates that at least one typical SC technology,live barriers of Vetiveria zizanioides (vetiver grass),has little or no impact on maize yield. This means that farmers see little benefit from their investment in the SC method. They find that erratic rainfall, pests and diseases and a lack of economic resources are far greater threats to their livelihoods than soil erosion. Consequently, SC has a low priority. Keeping soil in place avoids major off-farm disbenefits. However, the SC technique tested here made no discernible difference to slope foot sediment yields during the life of this study. In sum, a new approach is needed. Promoting ,Better Land Husbandry' strategies, which seek to combine farmers' concerns about productivity with conservationists' concerns about reducing soil erosion,often via cover-management,seem to be the best way forward. Copyright © 2002 John Wiley & Sons, Ltd. [source] Mean-Square Radius of Gyration and Degree of Branching of Highly Branched Copolymers Resulting from the Copolymerization of AB2 With AB MonomersMACROMOLECULAR THEORY AND SIMULATIONS, Issue 8 2004Zhiping Zhou Abstract Summary: The evolution of the various structural units incorporated into hyperbranched polymers formed from the copolymerization of AB2 and AB monomers has been derived by the kinetic scheme. The degree of branching was calculated with a new definition given in this work. The degree of branching monotonously increased with increasing A group conversion (x) and the maximum value could reach 2r/(1,+,r)2, where r is the initial fraction of AB2 monomers in the total. Like the average degree of polymerization, the mean-square radius of gyration of the hyperbranched polymers increased moderately with A group conversion in the range x,<,0.9 and displayed an abrupt rise when the copolymerization neared completion. The characteristic ratio of the mean-square radius of gyration remained constant for the linear polymers. However, the hyperbranched polymers did not possess this character. In comparison with the linear polymerization, the weight average and z -average degree of polymerization increased due to the addition of the branched monomer units AB2 and the mean-square radius of gyration decreased quickly for the products of copolymerization. [source] Delayed Cardiac Perforation by Defibrillator Lead Placed in the Right Ventricular Outflow Tract Resulting in Massive Pericardial EffusionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2008ERNEST W. LAU M.D. A 76-year-old man received a dual-chamber implantable cardioverter defibrillator (ICD), with the defibrillator lead positioned within the right ventricular outflow tract. The lead parameters at the time of implantation were satisfactory and the postprocedure chest X-ray showed the leads were in place. The patient was cardioverted from atrial fibrillation during defibrillation threshold testing and commenced on anticoagulation immediately. One month post implantation, he experienced multiple ventricular tachycardia episodes all successfully treated with antitachycardia pacing and shocks by his ICD, but he fell and hit his chest against a hard surface during one of these attacks. He developed a massive pericardial effusion and computed tomography confirmed cardiac perforation by the defibrillator lead. Pericardiocentesis was performed and the defibrillator lead replaced with a different model positioned at the right ventricular apex. The patient made an uneventful recovery. The management and avoidance of delayed cardiac perforation by transvenous leads were discussed. [source] Runaway Pulse Generator Malfunction Resulting from Undetected Battery DepletionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2002PUGAZHENDHI VIJAYARAMAN VIJAYARAMAN, P., et al.: Runaway Pulse Generator Malfunction Resulting from Undetected Battery Depletion. Runaway pacemaker is an uncommon, potentially lethal circuit malfunction characterized by sudden onset of erratic pacing at rapid nonphysiological rates. Two patients with a single chamber pacemaker (Medtronic ST 8331 and 8419) presented with episodic dizziness. ECG revealed recurrent decrescendo amplitude episodes of runaway stimuli at 2,400 and 2,600 ppm, approximately 3 seconds in duration, separated by pacing at 62.5 and 65 ppm, respectively. Fortunately the runaway stimuli were subthreshold and did not result in capture of the ventricle. Emergency pulse generator replacement was uneventful. Both leads were normal and both pulse generators had low battery voltages at 1.488 and 1.78 V, respectively. [source] Minimum capital requirement calculations for UK futuresTHE JOURNAL OF FUTURES MARKETS, Issue 2 2004John Cotter Key to the imposition of appropriate minimum capital requirements on a daily basis is accurate volatility estimation. Here, measures are presented based on discrete estimation of aggregated high-frequency UK futures realizations underpinned by a continuous time framework. Squared and absolute returns are incorporated into the measurement process so as to rely on the quadratic variation of a diffusion process and be robust in the presence of fat tails. The realized volatility estimates incorporate the long memory property. The dynamics of the volatility variable are adequately captured. Resulting rescaled returns are applied to minimum capital requirement calculations. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:193,220, 2004 [source] Effectiveness of Amitriptyline Versus Cough Suppressants in the Treatment of Chronic Cough Resulting From Postviral Vagal Neuropathy,THE LARYNGOSCOPE, Issue 12 2006Anita Jeyakumar MD Abstract Objective: The objective of this prospective, randomized, controlled study (N = 28) was to evaluate the effectiveness of amitriptyline versus cough suppressants in the treatment of chronic cough resulting from postviral vagal neuropathy. Methods: Patients were selected based on a clinical history consistent with postviral vagal neuropathy and a history of an antecedent upper respiratory tract infection. All patients had been tried on antireflux medication (proton pump inhibitors) and had a negative chest x-ray before presentation. All were nonsmokers without a history of asthma. Patients on angiotensin-converting enzyme inhibitors were excluded from the study. All patients completed a pretreatment, validated cough-specific quality-of-life (QOL) survey. Patients were randomized by chart numbers to either 10 mg amitriptyline at bedtime or 10 to 100 mg/5 mL, 10 mL codeine/guaifenesin every 6 hours standing dose while awake. Both groups were instructed to complete 10 days of therapy and then asked to subjectively rate the reduction in the frequency and severity of their cough by 100%, 75%, 50%, 25%, or 0% as well as completing the posttreatment cough QOL questionnaire. Those patients experiencing a 75% to 100% reduction were recorded as having a complete response, 25% to 50% a partial response, and 0% as having no response. Final results and the cough QOL survey were recorded and used for statistical analysis. Results: A majority of patients in the amitriptyline group achieved a complete response on the initial dose of 10 mg. None of the codeine/guaifenesin group achieved a complete response. The data were analyzed using a logistic regression model, and amitriptyline was found to be a highly significant predictor of a greater than 50% response when compared with codeine/guaifenesin (P = .0007). The same data were analyzed using a proportional odds model and similar results were noted. Conclusions: Chronic cough can have a profound impact on the psychosocial function of patients. The most common causes of a persisting cough in the absence of infection or chronic smoking are laryngopharyngeal reflux, asthma, particularly the cough variant, allergy, rhinosinusitis, bronchitis, and medications, in particular angiotensin-converting enzyme inhibitors. Currently, there are few effective treatments for cough with an acceptable therapeutic ratio and more selective drugs with a more favorable side effect profile are needed. This is this first prospective, randomized, controlled study comparing the effectiveness of amitriptyline versus codeine/guaifenesin for select cases of chronic cough resulting from suspected postviral vagal neuropathy. [source] Haplotype Misclassification Resulting from Statistical Reconstruction and Genotype Error, and Its Impact on Association EstimatesANNALS OF HUMAN GENETICS, Issue 5 2010Claudia Lamina Summary Haplotypes are an important concept for genetic association studies, but involve uncertainty due to statistical reconstruction from single nucleotide polymorphism (SNP) genotypes and genotype error. We developed a re-sampling approach to quantify haplotype misclassification probabilities and implemented the MC-SIMEX approach to tackle this as a 3 × 3 misclassification problem. Using a previously published approach as a benchmark for comparison, we evaluated the performance of our approach by simulations and exemplified it on real data from 15 SNPs of the APM1 gene. Misclassification due to reconstruction error was small for most, but notable for some, especially rarer haplotypes. Genotype error added misclassification to all haplotypes resulting in a non-negligible drop in sensitivity. In our real data example, the bias of association estimates due to reconstruction error alone reached ,48.2% for a 1% genotype error, indicating that haplotype misclassification should not be ignored if high genotype error can be expected. Our 3 × 3 misclassification view of haplotype error adds a novel perspective to currently used methods based on genotype intensities and expected number of haplotype copies. Our findings give a sense of the impact of haplotype error under realistic scenarios and underscore the importance of high-quality genotyping, in which case the bias in haplotype association estimates is negligible. [source] Biological Reactions Resulting from Endotoxin Adsorbed on Dialysis Membrane: An In Vitro StudyARTIFICIAL ORGANS, Issue 2 2004Kenji Tsuchida Abstract:, Some types of dialysis membrane are known to adsorb endotoxin (ET). It is suggested that the biocompatibility of dialysis membrane is enhanced by adsorption and inhibition of ET. This study attempts to clarify the membrane-mediated biological reaction of the ET that is adsorbed to a dialysis membrane. After a dialysis circuit was prepared, contaminated dialysate was introduced on the dialysate side of a polyether polymer alloy (PEPA) membrane that adsorbs ET while saline solution or blood were introduced on the blood side, and the difference in ET adsorption between the two set-ups was measured. Further, the side filled with blood was left standing for 2 h, after which the changes in the amount of interleukin 1 receptor antagonist (IL-1Ra) produced from the whole blood were also assayed. Significantly more ET was adsorbed to the dialysis membrane when blood rather than saline was on the other side. In addition, the IL-1Ra production from the dialysis membrane that adsorbed ET was significantly higher. The ET adsorbed to the dialysis membrane may influence a living body even if it does not pass through the membrane. Accordingly, it is difficult to assume that the adsorption of ET to the membrane enhances its biocompatibility. [source] Quantifying the Magnitude of Baseline Covariate Imbalances Resulting from Selection Bias in Randomized Clinical TrialsBIOMETRICAL JOURNAL, Issue 2 2005Vance W. Berger Abstract Selection bias is most common in observational studies, when patients select their own treatments or treatments are assigned based on patient characteristics, such as disease severity. This first-order selection bias, as we call it, is eliminated by randomization, but there is residual selection bias that may occur even in randomized trials which occurs when, subconsciously or otherwise, an investigator uses advance knowledge of upcoming treatment allocations as the basis for deciding whom to enroll. For example, patients more likely to respond may be preferentially enrolled when the active treatment is due to be allocated, and patients less likely to respond may be enrolled when the control group is due to be allocated. If the upcoming allocations can be observed in their entirety, then we will call the resulting selection bias second-order selection bias. Allocation concealment minimizes the ability to observe upcoming allocations, yet upcoming allocations may still be predicted (imperfectly), or even determined with certainty, if at least some of the previous allocations are known, and if restrictions (such as randomized blocks) were placed on the randomization. This mechanism, based on prediction but not observation of upcoming allocations, is the third-order selection bias that is controlled by perfectly successful masking, but without perfect masking is not controlled even by the combination of advance randomization and allocation concealment. Our purpose is to quantify the magnitude of baseline imbalance that can result from third-order selection bias when the randomized block procedure is used. The smaller the block sizes, the more accurately one can predict future treatment assignments in the same block as known previous assignments, so this magnitude will depend on the block size, as well as on the level of certainty about upcoming allocations required to bias the patient selection. We find that a binary covariate can, on average, be up to 50% unbalanced by third-order selection bias. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] ChemInform Abstract: Cascade Resulting in the Reductive Ethynylation of Aldehydes: Dissection of Its Compounds.CHEMINFORM, Issue 33 2010Dongjoo Lee Abstract A variety of aldehydes are homologated by two carbon atoms. [source] ChemInform Abstract: Ionic Liquid-H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPO.CHEMINFORM, Issue 32 2009Ruijun Hu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Nucleation Process in the Cavity of a 48-Tungstophosphate Wheel Resulting in a 16-Metal-Center Iron Oxide Nanocluster.CHEMINFORM, Issue 19 2008Ulrich Kortz Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Hybrid Polymerization of Vinyl and Hetero-Ring Groups of Glycidyl Methacrylate Resulting in Thermoresponsive Hyperbranched Polymers Displaying a Wide Range of Lower Critical Solution TemperaturesCHEMISTRY - A EUROPEAN JOURNAL, Issue 31 2009Zhifeng Jia Dr. Abstract Hybrid polymerization of glycidyl methacrylate (GMA) with potassium hydride (KH) and various oligo(ethylene glycol)s as the initiating system, in which both vinyl polymerization and ring-opening polymerization occur simultaneously, generates hyperbranched poly(ether-ester)s. The reaction process has been followed by an in situ nuclear magnetic resonance technique. The experimental results indicate that both the vinyl and epoxy groups of GMA undergo polymerization, with the reactivity of the latter being much higher than that of the former. Interestingly, the resulting hyperbranched polymers exhibit a sharp phase transition in water at the lower critical solution temperature (LCST). Significantly, the LCST values can be accurately controlled from 0 to 100,°C by changing the hydrophilic/hydrophobic balance of GMA and various oligo(ethylene glycol)s or by modification of the precursor polymer through acetylation. This novel stimuli-responsive hyperbranched polymer is a promising candidate for a new generation of commercially viable thermoresponsive polymers following on from the widely used poly(N- isopropylacrylamide) (PNIPAM). [source] Ionic liquid-H2O Resulting in a Highly Chemoselective Oxidation of Benzylic Alcohols in the Presence of Aliphatic Analogues Catalyzed by Immobilized TEMPOCHINESE JOURNAL OF CHEMISTRY, Issue 3 2009Ruijun HU Abstract In ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6])-H2O, a highly chemoselective oxidation of benzylic alcohols in the presence of aliphatic ones to the corresponding hydroxyl benzyl aldehydes and ketones was allowed in high yields using N -chlorosuccinimide (NCS)/NaBr/IL-TEMPO (ionic liquid immobilized 2,2,6,6-tetramethylpiperidine-1-oxyl) as a facile and effective catalytic oxidation system. The medium, [bmim][PF6], together with the catalyst IL-TEMPO could be easily recycled for ten runs without any influence on the efficacy of the reaction in terms of yield and selectivity of the product. [source] Shrinkability Maps for Content-Aware Video ResizingCOMPUTER GRAPHICS FORUM, Issue 7 2008Yi-Fei Zhang Abstract A novel method is given for content-aware video resizing, i.e. targeting video to a new resolution (which may involve aspect ratio change) from the original. We precompute a per-pixel cumulative shrinkability map which takes into account both the importance of each pixel and the need for continuity in the resized result. (If both x and y resizing are required, two separate shrinkability maps are used, otherwise one suffices). A random walk model is used for efficient offline computation of the shrinkability maps. The latter are stored with the video to create a multi-sized video, which permits arbitrary-sized new versions of the video to be later very efficiently created in real-time, e.g. by a video-on-demand server supplying video streams to multiple devices with different resolutions. These shrinkability maps are highly compressible, so the resulting multi-sized videos are typically less than three times the size of the original compressed video. A scaling function operates on the multi-sized video, to give the new pixel locations in the result, giving a high-quality content-aware resized video. Despite the great efficiency and low storage requirements for our method, we produce results of comparable quality to state-of-the-art methods for content-aware image and video resizing. [source] Effects of repeated injections of fibroblast-stimulating lipopeptide-1 on fever, formation of cytokines, and on the responsiveness to endotoxin in guinea-pigsACTA PHYSIOLOGICA, Issue 1 2009A. Greis Abstract Aims:, We investigated, whether the Toll-like receptors (TLRs)-2/6-agonist fibroblast-stimulating lipopeptide-1 (FSL-1), like the TLR-4 agonist lipopolysaccharide (LPS), induces a state of tolerance. We further tested the influence of repeated pre-treatment with FSL-1 on the animals' responsiveness to LPS. Methods:, Abdominal temperature was recorded in unrestrained guinea-pigs with intra-abdominally implanted radiotransmitters. Circulating concentrations of tumour necrosis factor (TNF) and interleukin-6 (IL-6) were measured with specific bioassays. We tested the effects of intra-arterial (i.a.) or intraperitoneal (i.p.) injections of 100 ,g kg,1 FSL-1, repeated five times at intervals of 3 days. The animals' responses to i.a. or i.p. injections of 10 ,g kg,1 LPS were determined another 3 days later and compared to those of naïve guinea-pigs. Results:, The FSL-1-induced TNF peak was significantly attenuated starting with the third i.a. administration, while fever was unimpaired and the IL-6-peak just tended to decrease. Fever and IL-6 in response to i.a. injections of LPS were identical in both groups, while circulating TNF was higher in naïve compared to FSL-1 pre-treated animals. The effects of repeated i.p. injections of FSL-1 were more pronounced resulting in attenuation of fever as well as circulating TNF and IL-6, the strongest reduction observed after the third stimulation with FSL-1. Repeated i.p. pre-treatment with FSL-1 induced hyporesponsiveness to i.p. administration of LPS compared to naïve animals with regard to fever and especially with regard to LPS-induced formation of cytokines. Conclusions:, There is a development of tolerance to FSL-1 and cross-tolerance between FSL-1 and LPS depending on the route of administration of the respective TLR-2/6 and TLR-4 agonists. [source] Improved Plasma Spray Torch Stability Through Multi-Electrode DesignCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7 2007J. Schein Abstract Coating production by thermal plasma spray is dependent on the residence time of particles in the plasma jet produced by the gas flow inside a plasma torch. To ensure a high fraction of well-molten particles to be accelerated towards the substrate a long reproducible residence time is needed. This can be achieved by a long plasma jet with little or no temporal variation in length and temperature. While single electrode plasma torches need an unstable attachment of the anodic arc root in order to avoid excess erosion, which also causes an unstable plasma jet, multi-electrode torches allow operation with fixed anode attachments by subdividing the anode current by the number of electrodes used, and thereby thus reducing the power input for each separated arc root. Once the steady anode attachment has been obtained the produced plasma jet exhibits a steady characteristic, but also looses rotational symmetry. The separation can be achieved by using either multi anode or multi cathode geometry with appropriate electrical control. Both version have been produced with 3 electrodes each resulting in two systems known as the Delta Gun (3 anodes) and Triplex (3 cathodes). (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Gram-negative meningitis and infections in individuals treated with intrathecal baclofen for spasticity: a retrospective studyDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 6 2006Colleen A Wunderlich MD MSc The aim of this retrospective study was to describe signs, symptoms, and clinical outcomes of individuals undergoing intrathecal baclofen (ITB) therapy who experienced pumprelated Gram-negative infections including meningitis. Participants included 12 individuals (nine males, three females) aged 10 to 32 years (mean 17y 9mo), nine of whom had quadriplegic CP. A total of 571 baclofen pump surgeries were performed with 45 total infections. Of the 45 infections, 12 were by Gram-negative organisms, two resulting in meningitis. Ten of 12 Gram-negative infections (21 site encounters) occurred within 60 days of surgery. Eleven of 12 pumps were explanted. By site encounters, Pseudomonas aeruginosa accounted for eight Gram-negative infections, Escherichia coli for five, Proteus for three, Enterobacter cloacae for two, and Klebsiella, Enterobacter aerogenes, and Enterobacter vulnaris for one each. Two individuals with Gram-negative meningitis were admitted 72 to 96 hours after hospital discharge following pump replacement. Both patients had rapid deterioration requiring transfer to the pediatric intensive care unit, and developed coagulopathy and decrease in responsiveness. Both have improved and have elected not to replace the ITB pump. In Gram-negative infections in ITB therapy, the progression of signs and symptoms can be swift and devastating. Identification of the infectious agent in such cases is imperative; these infections can quickly become life threatening. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||