Home About us Contact
|
Home About us Contact | ||
|
|
||
Valuable Alternative (valuable + alternative)
Selected AbstractsDoublecortin expression levels in adult brain reflect neurogenesisEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2005Sebastien Couillard-Despres Abstract Progress in the field of neurogenesis is currently limited by the lack of tools enabling fast and quantitative analysis of neurogenesis in the adult brain. Doublecortin (DCX) has recently been used as a marker for neurogenesis. However, it was not clear whether DCX could be used to assess modulations occurring in the rate of neurogenesis in the adult mammalian central nervous system following lesioning or stimulatory factors. Using two paradigms increasing neurogenesis levels (physical activity and epileptic seizures), we demonstrate that quantification of DCX-expressing cells allows for an accurate measurement of modulations in the rate of adult neurogenesis. Importantly, we excluded induction of DCX expression during physiological or reactive gliogenesis and excluded also DCX re-expression during regenerative axonal growth. Our data validate DCX as a reliable and specific marker that reflects levels of adult neurogenesis and its modulation. We demonstrate that DCX is a valuable alternative to techniques currently used to measure the levels of neurogenesis. Importantly, in contrast to conventional techniques, analysis of neurogenesis through the detection of DCX does not require in vivo labelling of proliferating cells, thereby opening new avenues for the study of human neurogenesis under normal and pathological conditions. [source] Effects of reminiscence and life review on late-life depression: a meta-analysisINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 12 2003Ernst Bohlmeijer Abstract Aim To assess the effectiveness of reminiscence and life review on late-life depression across different target groups and treatment modalities. Method Twenty controlled outcome studies were retrieved from Psychlit, Medline and Dissertation Abstracts. For each study a standardised effect size, d, was calculated and a random-effects meta-analysis was conducted. Results An overall effect size of 0.84 (95% Confidence Intervals (CI)=0.31,1.37) was found, indicating a statistically and clinically significant effect of reminiscence and life review on depressive symptomatology in elderly people. This effect is comparable to the effects commonly found for pharmacotherapy and psychological treatments. The effect was larger in subjects with elevated depressive symptomatology (d=1.23) as compared to other subjects (d=0.37). Other characteristics of the subjects or interventions were not found to be related to increased or decreased effect sizes. Discussion Reminiscence and life review are potentially effective treatments for depressive symptoms in the elderly and may thus offer a valuable alternative to psychotherapy or pharmacotherapy. Especially in non-institutionalised elderly people,who often have untreated depression,it may prove to be an effective, safe and acceptable form of treatment. Randomized trials with sufficient statistical power are necessary to confirm the results of this study. Copyright © 2003 John Wiley & Sons, Ltd. [source] The Addition Reaction of Samarium Enolates and 2-Haloenolates Derived from Esters, and Amides to Imines.ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 20094-Diamino Esters or Amides, Totally Stereoselective Synthesis of Enantiopure Abstract The addition reaction of samarium enolates and 2-haloenolates derived from esters and amides to imines takes place in an efficient manner. A novel protocol to perform the addition reaction of samarium enolates derived from esters or amides to chiral 2-aminoimines, with total stereoselectivity and without racemization, is also reported. The use of samarium enolates in place of other classic metallic enolates (lithium, magnesium, etc.) could be a valuable alternative to obtain enantiopure 3,4-diamino esters or amides, when enolates of low basicity are necessary. [source] Laparoscopic pyeloplasty for ureteropelvic junction obstruction: Outcome of initial 12 proceduresINTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2004MASATSUGU IWAMURA Abstract Background:, Open pyeloplasty has been the gold standard for surgical treatment of ureteropelvic junction (UPJ) obstruction, enjoying a long-term success rate exceeding 90%. Unfortunately, this procedure requires a muscle incision that entails some degree of morbidity. We have, therefore, investigated the feasibility of laparoscopic pyeloplasty for UPJ obstruction and report here the outcomes of our early cases. The median follow up is 25 months (range, 12,42 months). Methods:, Between March 1999 and September 2001 we performed laparoscopic pyeloplasty on 12 ureters in 11 patients presenting with symptomatic hydronephrosis, secondary to a short stenosis of the UPJ or to ventrally crossing vessels; bilateral pyeloplasty was performed as a single procedure in one patient. We performed dismembered Anderson,Hynes pyeloplasty, Fenger plasty and Y-V plasty in eight, two and two ureters, respectively. All procedures were carried out transperitoneally. Results:, The procedure was completed successfully in all cases. Crossing vessels were noted in six of 12 ureters (50.0%). Mean operative time and blood loss in 11 patients (including one bilateral case) were 272.8 min (range, 175,480 min) and 96.4 mL (range, 20,340 mL), respectively. Postoperative complications were noted in two patients (18.2%): one instance of prolonged urine leakage and one anastomotic re-stricture. Eleven of 12 ureters (91.6%) demonstrated a patent UPJ on excretory urography and/or improvement of renal function on diuretic renography at a minimum follow up of 12 months. Conclusion:, Although the procedure requires advanced laparoscopic skills, it can be safely and successfully completed as frequently as the conventional open procedure. Laparoscopic pyeloplasty seems to be a valuable alternative to open pyeloplasty for UPJ obstruction. [source] Wavelength selection with Tabu SearchJOURNAL OF CHEMOMETRICS, Issue 8-9 2003J. A. Hageman Abstract This paper introduces Tabu Search in analytical chemistry by applying it to wavelength selection. Tabu Search is a deterministic global optimization technique loosely based on concepts from artificial intelligence. Wavelength selection is a method which can be used for improving the quality of calibration models. Tabu Search uses basic, problem-specific operators to explore a search space, and memory to keep track of parts already visited. Several implementational aspects of wavelength selection with Tabu Search will be discussed. Two ways of memorizing the search space are investigated: storing the actual solutions and storing the steps necessary to create them. Parameters associated with Tabu Search are configured with a Plackett,Burman design. In addition, two extension schemes for Tabu Search, intensification and diversification, have been implemented and are applied with good results. Eventually, two implementations of wavelength selection with Tabu Search are tested, one which searches for a solution with a constant number of wavelengths and one with a variable number of wavelengths. Both implementations are compared with results obtained by wavelength selection methods based on simulated annealing (SA) and genetic algorithms (GAs). It is demonstrated with three real-world data sets that Tabu Search performs equally well as and can be a valuable alternative to SA and GAs. The improvements in predictive abilities increased by a factor of 20 for data set 1 and by a factor of 2 for data sets 2 and 3. In addition, when the number of wavelengths in a solution is variable, measurements on the coverage of the search space show that the coverage is usually higher for Tabu Search compared with SA and GAs. Copyright © 2003 John Wiley & Sons, Ltd. [source] Collective Household Models: Principles and Main ResultsJOURNAL OF ECONOMIC SURVEYS, Issue 4 2002Frederic Vermeulen In the traditional approach to consumer behaviour it is assumed that households behave as if they were single decision-making units. This approach has methodological, empirical and welfare economic deficiencies. A valuable alternative to the traditional model is the collective approach to household behaviour. The collective approach explicitly takes account of the fact that multi-person households consist of several members which may have different preferences. Among these household members, an intrahousehold bargaining process is assumed to take place. In addition to providing an introduction to the collective approach, this survey intends to show how different collective household models, each with their own aims and assumptions, are connected. [source] A Novel Process for the Recovery of Polyphenols from Grape (Vitis vinifera L.) PomaceJOURNAL OF FOOD SCIENCE, Issue 2 2005Dietmar Kammerer ABSTRACT: A novel process for enzyme-assisted extraction of polyphenols from winery by-products was established on a pilot-plant scale. Optimization of enzymatic hydrolysis of grape skins, that is, selection of pectinolytic and cellulolytic enzymes, enzyme-substrate ratio, and time-temperature regime of enzymatic treatment, was conducted on a laboratory scale. Enzyme activities were monitored by viscosity measurement of resuspended grape pomace and by quantification of oligomeric pectin and cellulose degradation products released from cell wall material. Optimal conditions were obtained with 5000 ppm (based on dry matter) of a pectinolytic and 2500 ppm of a cellulolytic enzyme preparation, respectively, at 50°C, which were also applied in pilot-plant scale experiments. Concomitant determination of individual polyphenolics demonstrated a significantly improved yield for most compounds when compared with experiments without enzyme addition. Recovery rates were comparable to those obtained when grape pomace was extracted using sulfite. Pre-extraction of the pomace with hot water followed by treatment with cell wall degrading enzymes even increased yields of phenolic compounds. Only some quercetin glycosides and malvidin coumaroylglucoside were partly hydrolyzed due to enzyme side activities. This new process may provide a valuable alternative to the application of sulfite, which is considered crucial in food processing. [source] Manipulation of crystal shape by cycles of growth and dissolutionAICHE JOURNAL, Issue 6 2007Ryan C. Snyder Abstract A method for the manipulation of crystal shape by using cycles of growth and dissolution is presented, representing a unique process-based solution to an important product quality concern. Using 3-D shape evolution models for faceted crystal growth and dissolution, results are reported for cycling both an illustrative crystal system, as well as a physical plate-like system. The results show that crystal shape can be manipulated by cycling when the relative growth and dissolution rates are anisotropic, which can be caused by differences in growth mechanism, asymmetry in super/undersaturation, and by the use of surface active additives. Since this method of crystal shape enhancement uses the existing liquid solution, it could be a valuable alternative to the traditional methods which often require changes in the chemical nature of the solution, for example, by changing solvent. © 2007 American Institute of Chemical Engineers AIChE J, 2007 [source] THE USE OF NEAR INFRARED REFLECTANCE SPECTROMETRY FOR CHARACTERIZATION OF BROWN ALGAL TISSUE,JOURNAL OF PHYCOLOGY, Issue 5 2010Kyra B. Hay Measuring qualitative traits of plant tissue is important to understand how plants respond to environmental change and biotic interactions. Near infrared reflectance spectrometry (NIRS) is a cost-, time-, and sample-effective method of measuring chemical components in organic samples commonly used in the agricultural and pharmaceutical industries. To assess the applicability of NIRS to measure the ecologically important tissue traits of carbon, nitrogen, and phlorotannins (secondary metabolites) in brown algae, we developed NIRS calibration models for these constituents in dried Sargassum flavicans (F. K. Mertens) C. Agardh tissue. We then tested if the developed NIRS models could detect changes in the tissue composition of S. flavicans induced by experimental manipulation of temperature and nutrient availability. To develop the NIRS models, we used partial least squares regression to determine the statistical relationship between trait values determined in laboratory assays and the NIRS spectral data of S. flavicans calibration samples. Models with high predictive power were developed for all three constituents that successfully detected changes in carbon, nitrogen, and phlorotannin content in the experimentally manipulated S. flavicans tissue. Phlorotannin content in S. flavicans was inversely related to nitrogen availability, and nitrogen, temperature, and tissue age interacted to significantly affect phlorotannin content, demonstrating the importance of studies that investigate these three variables simultaneously. Given the speed of analysis, accuracy, small tissue requirements, and ability to measure multiple traits simultaneously without consuming the sample tissue, NIRS is a valuable alternative to traditional methods for determining algal tissue traits, especially in studies where tissue is limited. [source] Systematic review: the role of self-expanding plastic stents for benign oesophageal stricturesALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 12 2010A. REPICI Aliment Pharmacol Ther,31, 1268,1275 Summary Background, Treatment of refractory or recurrent benign oesophageal strictures is demanding and surgery may be the only available option. The role of self-expanding plastic stents (SEPS) in the treatment of these strictures is still controversial because of the conflicting results of various studies. Aim, To analyse with regard to SEPS: technical and clinical success, factors associated with outcome, and safety. Methods, Pooled-data analysis of a systematic review of the literature. Clinical success was defined as no need for further endoscopic or surgical treatment after SEPS removal. Results, Data of 10 studies with 130 treated patients were included. SEPS insertion was technically successful in 128 of 130 patients (98%, 95% CI = 96,100%). Clinical success was achieved in 68 patients (52%, 95% CI = 44,61%) and this was found to be lower in those with a cervical localization of the stricture (33% vs. 54%; P < 0.05). Early (<4 weeks) migration of the stent was reported in 19 (24%, 95% CI = 14,32%) cases, while post-insertion endoscopic re-intervention was required in 25 (21%, 95% CI = 14,28%). Major clinical complications occurred in 12 patients (9%, 95% CI = 4,14%), resulting in death of one (0.8%) patient. Conclusions, Our pooled-data analysis showed a favourable risk/benefit ratio when SEPS are applied in patients with recurrent or refractory benign oesophageal strictures. This supports the use of SEPS before referring patients to surgery, and they are a valuable alternative to repeat endoscopic dilation. [source] Description of the chemical and pharmacological characteristics of a new hemisynthetic ultra-low-molecular-weight heparin, AVE5026JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2009C. VISKOV Summary.,Background and objectives: AVE5026 is a novel, hemisynthetic, ultra-low-molecular-weight heparin (ULMWH), which is in clinical development for prevention of venous thromboembolism. Its unique structural features result from the highly selective depolymerization of heparin by the phosphazene base that protects the antithrombin (AT)-binding site from destruction. In the present paper, we describe the chemical and biological characteristics of AVE5026, as well as its effects on experimental thrombosis as compared to those of the low-molecular-weight heparin (LMWH) enoxaparin after a single subcutaneous (s.c.) administration in certain animal models. Method and results: AVE5026 has a higher anti-factor Xa (anti-FXa) activity (,160 U mg,1) along with a catalytic anti-thrombin (anti-FIIa) activity (,2 U mg,1) as a result of its structure being strongly enriched in specific AT-binding oligosaccharides. In human plasma, potent inhibition of thrombin generation by AVE5026 was closely related to its anti-FXa activity. In a rat venous thrombosis model, AVE5026 showed a dose-dependent antithrombotic activity comparable to that of enoxaparin (ED50-AVE5026 = 1.6 mg kg,1, ED50-enoxaparin = 2.8 mg kg,1). Interestingly, non-occlusive venous thrombosis in rabbits was inhibited by an ED50 of 0.1 mg kg,1 AVE5026, whereas 0.316 mg kg,1 enoxaparin was not active. In a canine model, similarly to enoxaparin (ED50 = 1.3 mg kg,1), AVE5026 dose-dependently inhibited arterial thrombosis (ED50 = 2.0 mg kg,1). At equipotent doses, AVE5026 did not affect bleeding parameters, whereas enoxaparin showed increased hemorrhage in rats, rabbits and dogs. Conclusion: These unique structural attributes distinguish AVE5026 from the LMWH class. Based on these data in well-established arterial and venous thrombosis models, AVE5026 could represent a valuable alternative in thrombosis prevention with an improved benefit-risk profile as compared to that of enoxaparin. [source] A Review of Electrical Stimulation to Treat Motility Dysfunctions in the Digestive Tract: Effects and Stimulation PatternsNEUROMODULATION, Issue 2 2007Cristian Sevcencu PhD ABSTRACT Electrical stimulation of the digestive organs may become a valuable alternative to pharmaceutical and surgical approaches to the treatment of gastrointestinal motor dysfunctions. For more than 40 years, encouraging results with electrical stimulation to activate motility in gastrointestinal organs have been published. The most significant achievements with this work have been either stimulation to attenuate the symptoms of gastroparesis or stimulation to modify the feeding behavior in obese patients. In addition, animal studies have investigated the different stimulation systems and methods to activate or inhibit transit in the small and large intestines. This article presents a review of the published literature on electrical stimulation of the stomach and intestines. [source] Attitudes to prenatal and preimplantation diagnosis in Saudi parents at genetic riskPRENATAL DIAGNOSIS, Issue 11 2006Ayman Alsulaiman Abstract Background Prenatal diagnosis (PND) is only available for severe abnormality in Saudi Arabia, and preimplantation genetic diagnosis (PGD) has been proposed as a valuable alternative. The acceptability of PGD is unexplored, and may ultimately determine the value of this technology in Saudi Arabia. This study reports attitudes towards PND and PGD of Saudi couples offered genetic counselling following the birth of a child with a single gene or chromosomal condition. Methods Thirty couples attending the King Faisal Specialist Hospital and Research Centre in Riyadh were interviewed using a semi-structured questionnaire. One couple had previous experience of PND and none had experience of PGD or IVF. Results Eight of the 30 couples (27%) would only accept PGD; four (13%) only PND; three (10%) either technology; the remainder would accept neither test, or were unsure. The main concerns of those who would accept neither technology were related to personal religious views. Specific concerns about PGD related to the IVF procedure, the risk of multiple pregnancies, the chance of mistakes and the chance of not getting pregnant. A high proportion of couples (six out of seven; 86%) who had a child with thalassaemia expressed interest in PGD, and all would be prepared to use technology to avoid having an affected child. Views were more mixed for the other conditions. Conclusion PGD is acceptable to many couples and for some, it represents a valuable alternative to PND. However, parents' concerns are complex, and the acceptability of different reproductive technologies must be established on an individual basis. Copyright © 2006 John Wiley & Sons, Ltd. [source] Changing patterns in interventional bronchoscopyRESPIROLOGY, Issue 4 2009Nikolaos ZIAS ABSTRACT Background and objective: Many interventional tools for airway disorders can now be delivered via flexible bronchoscopy (FB), including neodymium-yttrium aluminium garnet laser, electrocautery, argon plasma coagulation, cryotherapy, balloon dilatation and metal or hybrid stents. Comparison of outcomes for patients undergoing rigid bronchoscopy (RB) with those treated using FB highlights the usefulness of the FB approach. Methods: A retrospective medical record review of all interventional bronchoscopy procedures performed at Lahey Clinic over the past 8 years was conducted. Patients were categorized into two groups according to the procedure used, that is, RB (251 patients), and FB (161 patients) groups. Patients with malignancies were included as a separate subgroup, comprising 178 RB and 117 FB patients. For every procedure, the location of the lesion, patient survival from the first interventional procedure performed, and in patients with malignancy, additional treatments received such as chemotherapy and radiation were recorded. Results: Ninety per cent of RB procedures were performed in patients with tracheal or main stem lesions, while over half the patients undergoing FB had more distal lesions. A trend towards increasing use of FB for interventional procedures in recent years was noted. Conclusions: FB is a valuable alternative to RB for treating less advanced malignant disease or distal airway lesions. [source] Living-Donor Liver Transplantation for HepatoblastomaAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2005Mureo Kasahara Hepatoblastoma is the most common malignant liver tumor in children. Recently, liver transplantation has been indicated for unresectable hepatoblastoma. We retrospectively reviewed 14 children with a diagnosis of hepatoblastoma who had undergone living-donor liver transplantation (LDLT) at Kyoto University Hospital. During the period from June 1990 to December 2004, 607 children underwent LDLT. Of these interventions, 2.3% were performed for hepatoblastoma. Based on radiological findings, the pre-treatment extent of disease (PRETEXT) grouping was used for pre-treatment staging of the tumor. There were grade III in seven patients and grade IV in seven patients. Thirteen patients received chemotherapy, and seven underwent hepatectomy 11 times. Immunosuppressive treatment consisted of tacrolimus monotherapy in 11 patients. Actuarial 1- and 5-year graft and patient survival rates were 78.6% and 65.5%. The poor prognostic factors were macroscopic venous invasion and extrahepatic involvement with 1-year and 5-year survival rates of 33.0% and 0%. Pediatric patients without these factors showed an acceptable 5-year survival rate of 90.9%. LDLT provides a valuable alternative with excellent results in children with hepatoblastoma because it allows optimal timing of the liver transplantation, given the absence of delay between the completion of chemotherapy and planned liver transplantation. [source] Awake tracheal intubation using the SensascopeÔ in 13 patients with an anticipated difficult airwayANAESTHESIA, Issue 5 2010R. Greif Summary We present the use of the SensaScopeÔ, an S-shaped rigid fibreoptic scope with a flexible distal end, in a series of 13 patients at high risk of, or known to have, a difficult intubation. Patients received conscious sedation with midazolam or fentanyl combined with a remifentanil infusion and topical lidocaine to the oral mucosa and to the trachea via a trans-cricoid injection. Spontaneous ventilation was maintained until confirmation of tracheal intubation. In all cases, tracheal intubation was achieved using the SensaScope. The median (IQR [range]) insertion time (measured from the time the facemask was taken away from the face until an end-expiratory CO2 reading was visible on the monitor) was 58 s (38,111 [28,300]s). In nine of the 13 cases, advancement of the SensaScope into the trachea was easy. Difficulties included a poor view associated with a bleeding diathesis and saliva, transient loss of spontaneous breathing, and difficulty in advancing the tracheal tube in a patient with unforeseen tracheal narrowing. A poor view in two patients was partially improved by a high continuous flow of oxygen. The SensaScope may be a valuable alternative to other rigid or flexible fibreoptic scopes for awake intubation of spontaneously breathing patients with a predicted difficult airway. [source] Clinical outcome of microsurgical subinguinal varicocelectomy in infertile menANDROLOGIA, Issue 2 2001A. Jungwirth The present study assesses the clinical outcome of microsurgical subinguinal varicocelectomy in infertile men, especially with regard to sperm count, motility and fertility. Between June 1990 and October 1998, 272 patients had subinguinal microsurgical varicocelectomy operations for clinical varicoceles, and their long-term results were assessed. In nearly all the patients there was a significant improvement in sperm count and sperm motility after 3 and 6 months. Very few complications arose from this procedure. We concluded that microsurgical subinguinal varicocelectomy is an effective treatment for clinical varicoceles in infertile men. The significant improvement in the quality of spermatozoa, the low complication rates and the remarkably high pregnancy rates make this a valuable alternative to in vitro reproduction techniques. [source] Synthesis, Structural Diversity, and Ligand-Transfer Potential of (Carbene)copper(I) ComplexesHELVETICA CHIMICA ACTA, Issue 6 2009Galmari Venkatachalam Abstract Copper(I) complexes comprising different N-heterocyclic carbene ligands were prepared via in situ deprotonation and metallation. Depending on the wingtip groups on the carbene ligand (alkyl vs. aryl, chelating or monodentate), a variety of different structural motifs were identified, such as a trigonal planar geometry (alkyl wingtips) and an unprecedented see-saw-type structure (pyridinyl wingtip groups). While aryl wingtip groups increase the stability of the complexes, alkyl substituents induce rapid demetallation in the presence of moisture. The reactivity of these complexes was used to establish a carbene-transfer protocol, which is illustrated by the formation of new cyclic thiourea compounds (transfer to sulfur) and new (carbene)ruthenium(II) complexes (transfer to ruthenium). This suggests that (carbene)copper(I) complexes could become valuable alternatives to (carbene)silver(I) complexes for synthesizing (carbene)metal systems via transmetallation. [source] Identification of Hemodynamically Significant Restenosis after Percutaneous Transluminal Coronary Angioplasty in Acute Myocardial Infarction by Transesophageal Dobutamine Stress Echocardiography and Comparison with Myocardial Single Photon Emission Computed TomographyJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 3 2001STEPHAN ROSENKRANZ M.D. Background: Beside thrombolysis, percutaneous transluminal coronary angioplasty (PTCA) has become a well-established treatment for acute myocardial infarction. However, restenosis occurs in approximately 15%-40 % of patients. Despite a frequently occurring infarct-related regional systolic dysfunction at rest, the identification of hemodynamically relevant restenosis seems important in terms of risk stratification, adequate treatment, and possible improvement of prognosis in these patients. This study was designed to assess the role of transesophageal dobutamine stress echocardiography and myocardial scintigraphy for identification of hemodynamically significant restenosis after PTCA for acute myocardial infarction. Methods: Multiplane transesophageal stress echocardiography (dobutamine 5, 10, 20, 30, and 40 ,g/kg per min) studies and myocardial single photon emission computed tomography (SPECT) studies were performed in 40 patients, all of whom underwent PTCA in the setting of acute myocardial infarction , 4 months prior to the test. Repeated coronary angiography was performed in all study patients who showed stress-induced perfusion defects or wall-motion abnormalities, or both. Results: Significant restenosis (, 50%) was angiographically found in 15 (37.5%) of 40 patients. Of these 15 patients, transesophageal dobutamine stress echocardiography identified restenosis in 12 (80%) and myocardial SPECT in 14 (93%), yielding diagnostic agreement in 70% of patients. Echocardiographic detection of restenosis was based mainly on a biphasic response to increasing doses of dobutamine. Sensitivity and specificity for identification of hemodynamically relevant restenosis in individual patients was 80% and 92%, respectively for dobutamine stress echocardiography versus 93% and 68% for myocardial SPECT. Conclusions: Both transesophageal dobutamine stress echocardiography and myocardial SPECT were highly sensitive in identifying significant restenosis after PTCA for acute myocardial infarction. Therefore, either test, as a single diagnostic tool or especially if performed together, are clinically valuable alternatives to coronary angiography for the detection of restenosis after PTCA for acute myocardial infarction. [source] Substitutes for grazing in semi-natural grasslands , do mowing or mulching represent valuable alternatives to maintain vegetation structure?JOURNAL OF VEGETATION SCIENCE, Issue 6 2009Christine Römermann Abstract Question: Which management treatments are suitable to replace historically applied grazing regimes? How and why does vegetation structure change following changes in management? Location: Semi-natural calcareous dry grasslands in southwest Germany. Methods: We analysed changes in floristic and functional composition induced by different management treatments (grazing, mowing, mulching, succession) in long-term experimental sites. First, floristic and functional distances between the initial conditions and the following years were determined. Second, we used RLQ analyses to include data on abiotic conditions, vegetation composition and functional traits in one common analysis. Finally, we applied cluster analyses on RLQ species scores to deduce functional groups. Results: In contrast to the historical management regime of grazing, all alternative management treatments led to changes in floristic and functional composition, depending on their intensity with respect to biomass removal. The distance analyses showed that mulching twice per year and mowing did not lead to strong changes in floristic or functional composition. However, RLQ analysis clearly provided evidence that only the grazed sites are in equilibrium, indicating that vegetation change still goes ahead. Conclusions: The current study clearly shows that RLQ is a powerful tool to elucidate ongoing processes that may remain hidden when separately analysing floristic and functional data. Alternative management treatments are not appropriate to sustain the typical disturbance dynamics of species-rich semi-natural grasslands. The less frequent an alternative management treatment is with respect to biomass removal, the less the floristic and functional structure can be maintained. [source] Use of Renewable Raw Materials in the Chemical Industry , Beyond Sugar and StarchCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2008K. Muffler Abstract Classical energy sources such as petroleum oil and natural gas make up the fundamental materials on which modern industrial chemical parks are based. According to the finite availability of these consuetudinary resources and due to the increasing demand for energy from developing countries and the related rise in prices of oil and natural gas, renewable resources must be considered as valuable alternatives. Discussions about climate change with regard to alternatives in energy production are preceded very fervidly but alternatives have to be examined from a matter-of-fact based economic and scientific point of view. Therefore, this review is focussed on alternative sources such as wood and other agricultural residues with respect to their potential as future energy resources as well as building blocks for chemical synthesis processes. [source] | |||||||||||||||||||