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Variable Length (variable + length)
Selected AbstractsAssembly of 1D Nanostructures into Sub-micrometer Diameter Fibrils with Controlled and Variable Length by Dielectrophoresis,ADVANCED MATERIALS, Issue 16 2003J. Tang A dielectrophoresis method for manipulation, alignment, and assembly of 1D nanostructures is reported. Processed carbon nanotubes dispersed in water are assembled into micro-electrodes and fibrils of variable and controllable length from ,,1 ,m to over 1 cm (see Figure). The method allows of parallel fabrication, and the fibrils could find applications as probes for scanning probe microscopes, electrodes, and conducting wires. [source] QoS in IntServ-based IP networks: the peak rate policingEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 4 2003Lorenzo Battaglia In the last few years, IP has moved towards resource reservation, with the task to guarantee in the future Quality of Service (QoS). This has led to flow admission control algorithms based on the negotiation of standardised traffic parameters. QoS can be guaranteed in any network, a priori from the used technology, only if the used admission control algorithm wisely shares the network's resources among the users. Any admission control algorithm on its turn can do so, only if every user respects the negotiated traffic parameters. Since any user could, maliciously or not, send at a higher rate than negotiated, i.e. use a higher share of resources than the negotiated one, in every network in which admission control is performed, a policing algorithm is used. An ideal policer should guarantee to reject no packet of a well-behaved user and police contract violation as rigidly as possible. All this independently of the characteristics of the monitored stream and of the background traffic. This holds also for Integrated Services (IS) based IP networks. In these networks, every user negotiates a peak and an average rate. In this paper we present the solution to the peak rate policing issue. We adapt the Generic Cell Rate Algorithm (GCRA), well-known policer used in ATM networks, to police the peak rate of flows of packets with variable length. We intuitively call this modified GCRA Generic Packet Rate Algorithm (GPRA) and dimension its parameters so that independently of the characteristics of the policed flow and of the background traffic, no packets of a well-behaved user are rejected and that the flows of any misbehaving user are rigidly policed. Copyright © 2003 AEI. [source] Structural characterization of a novel branching pattern in the lipopolysaccharide from nontypeable Haemophilus influenzaeFEBS JOURNAL, Issue 14 2003Martin Månsson Structural analysis of the lipopolysaccharide (LPS) from nontypeable Haemophilus influenzae strain 981 has been achieved using NMR spectroscopy and ESI-MS on O -deacylated LPS and core oligosaccharide (OS) material as well as by ESI-MSn on permethylated dephosphorylated OS. A heterogeneous glycoform population was identified, resulting from the variable length of the OS branches attached to the glucose residue in the common structural element of H. influenzae LPS, l -,- d -Hepp -(1,2)-[PEtn,6]- l -,- d -Hepp -(1,3)-[,- d -Glcxp-(1,4)]- l -,- d -Hepp -(1,5)-[PPEtn,4]-,-Kdop -(2,6)-Lipid A. Notably, the O-6 position of the ,- d -Glcp residue was either substituted by PCho or the disaccharide branch ,- d -Galp -(1,4)- d -,- d -Hepp, while the O-4 position was substituted by the globotetraose unit, ,- d -GalpNAc-(1,3)-,- d -Galp -(1,4)-,- d -Galp -(1,4)-,- d -Glcp, or sequentially truncated versions thereof. This is the first time a branching sugar residue has been reported in the outer-core region of H. influenzae LPS. Additionally, a PEtn group was identified at O-3 of the distal heptose residue in the inner-core. [source] Gold Nanoparticles Stabilized by Acetylene-Functionalized Multidentate Thioether Ligands: Building Blocks for Nanoparticle SuperstructuresADVANCED FUNCTIONAL MATERIALS, Issue 21 2009Torsten Peterle Abstract Aiming at the formation of inorganic/organic hybrid gold nanoparticle superstructures, the design and synthesis of acetylene-monofunctionalized multidentate thioether ligands and their ability to stabilize gold nanoparticles are presented. Rather monodisperse gold particles with diameters of about 1,nm are obtained, which are coated by a small number of ligands, each comprising a silyl-protected acetylene. The acetylene is attached at the end of a rigid ethynylene-phenylene unit of variable length, leading to functionalized gold nanoparticles carrying acetylenes at different distances from the nanoparticle surface. These particles are interlinked by diacetylene formation and are investigated by transmission electron microscopy and UV/vis spectroscopy, revealing the formation of nanoparticle aggregates and small superstructures such as dimers or trimers while the nanoparticles themselves retain their integrity. The interparticle distance in small nanoparticle superstructures reflects the ethynylene-phenylene spacer length corroborating the wet chemical interlinking as the origin of these organic/inorganic hybrid structures. [source] Palindromic AT-rich repeat in the NF1 gene is hypervariable in humans and evolutionarily conserved in primates,HUMAN MUTATION, Issue 4 2005Hidehito Inagaki Abstract Palindromic sequences are dispersed in the human genome and may cause chromosomal translocations in humans. They constitute unsequenced gaps in the human genome because of their resistance to PCR amplification, cloning into vectors, and sequencing. We have overcome these difficulties by using a combination of optimized PCR conditions, cloning in a recombination-deficient E. coli strain, and RNA polymerases in sequencing. Using these methods, we analyzed a palindromic AT-rich repeat (PATRR) in the neurofibromatosis type 1 (NF1) gene on chromosome 17 (17PATRR). The 17PATRR manifests a size polymorphism due to a highly variable length of (AT)n dinucleotide repeats within the PATRR. 17PATRRs can be categorized into two types: a longer one that comprises a nearly or completely perfect palindrome, and a shorter one that represents its deleted asymmetric derivative. In vitro analysis shows that the longer 17PATRR is more likely to form a cruciform structure than the shorter one. Two reported t(17;22)(q11;q11) patients with NF1, whose breakpoints were identified within the 17PATRR, have translocations that are derived from perfect or nearly perfect palindromic alleles. This implies that the symmetric structure of a PATRR can induce a translocation. We identified conserved PATRRs within the NF1 gene in great apes and similar inverted repeats in two Old World monkeys, but not in New World monkeys or other mammals. This indicates that the palindromic region appeared approximately 25 million years ago and elongated during primate evolution. Although such palindromic regions are usually unstable and disappear rapidly due to deletion, the 17PATRR in the NF1 gene was stably conserved during evolution for reasons that are still unknown. Hum Mutat 26(4), 332,342, 2005. © 2005 Wiley-Liss, Inc. [source] The CAG repeat polymorphism within the androgen receptor gene and maleness,INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2003Michael Zitzmann Summary The androgen testosterone and its metabolite dihydrotestosterone exert their effects on gene expression and thus effect maleness via the androgen receptor (AR). A diverse range of clinical conditions starting with complete androgen insensitivity has been correlated with mutations in the AR. Subtle modulations of the transcriptional activity induced by the AR have also been observed and frequently assigned to a polyglutamine stretch of variable length within the N-terminal domain of the receptor. This stretch is encoded by a variable number of CAG triplets in exon 1 of the AR gene located on the X chromosome. First observations of pathologically elongated AR CAG repeats in patients with X-linked spino-bulbar muscular atrophy showing marked hypoandrogenic traits were supplemented by partially conflicting findings of statistical significance also within the normal range of CAG repeat length: an involvement of prostate tissue, spermatogenesis, bone density, hair growth, cardiovascular risk factors and psychological factors has been demonstrated. The highly polymorphic nature of glutamine residues within the AR protein implies a subtle gradation of androgenicity among individuals within an environment of normal testosterone levels providing relevant ligand binding to ARs. This modulation of androgen effects may be small but continuously present during a man's lifetime and, hence, exerts effects that are measurable in many tissues as various degrees of androgenicity and represents a relevant effector of maleness. It remains to be elucidated whether these insights are important enough to become part of individually useful laboratory assessments. [source] Towards Continuous Flow, Highly Enantioselective Allylic Amination: Ligand Design, Optimization and SupportingADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009Dana Popa Abstract A family of enantiopure diphenylphosphinooxazolines (PHOX) containing in their structures a sterically tunable alkoxymethyl group (-CH2OR) has been optimized for the palladium-catalyzed asymmetric allylic amination. The optimal catalyst (R=CH3), depicting very high catalytic activity and broad scope applicability, has been further modified to include an ,-alkynyloxy substituent of variable length for polymer supporting via click chemistry, and has been anchored onto slightly cross-linked azidomethyl poly(styrene). The length of a polymethylene chain connecting the PHOX unit with the 1,2,3-triazole linker has been optimized, and the first polymer-supported PHOX ligands for the highly enantioselective allylic amination have been prepared in this manner. Conditions for catalyst recovery and reuse in microwave-promoted amination reactions have been established, and the system has been finally adapted to continuous flow operation. [source] Solving the irregular strip packing problem via guided local search for overlap minimizationINTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 6 2009Shunji Umetani Abstract The irregular strip-packing problem (ISP) requires a given set of non-convex polygons to be placed without overlap within a rectangular container having a fixed width and a variable length, which is to be minimized. As a core sub-problem to solve ISP, we consider an overlap minimization problem (OMP) whose objective is to place all polygons into a container with given width and length so that the total amount of overlap between polygons is made as small as possible. We propose to use directional penetration depths to measure the amount of overlap between a pair of polygons, and present an efficient algorithm to find a position with the minimum overlap for each polygon when it is translated in a specified direction. Based on this, we develop a local search algorithm for OMP that translates a polygon in horizontal and vertical directions alternately. Then we incorporate it in our algorithm for OMP, which is a variant of the guided local search algorithm. Computational results show that our algorithm improves the best-known values of some well-known benchmark instances. [source] Efficient Biocatalytic Cleavage and Recovery of Organic Substrates Supported on Soluble PolymersADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2007Dario Pasini Abstract The applicability of novel solution-phase supports in combination with enzymes for biocatalytic transformations is reported. Ex novo designed styrene-based copolymers, bearing a phenylacetic residue in variable loadings and linked as a pendant group to the macromolecular backbone, through a spacer of variable length, have been synthesized and characterized. These derivatives are compatible and can be used as soluble supports in combination with immobilized penicillin G acylase (PGA , EC 3.5.1.11) for the biocatalytic cleavage of the covalently anchored organic substrate in quantitative yields, in water or water/dimethylformamide solvent mixtures, with recovery of the immobilized enzyme with negligible losses in activity. [source] The Effect of Changing Practice on Fall Prevention in a Rehabilitative Hospital: The Hospital Injury Prevention StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2004Michael Vassallo FRCP Objectives: To determine whether a change in practice to introduce a multidisciplinary fall-prevention program can reduce falls and injury in nonacute patients in a rehabilitation hospital. Design: A quasi-experimental study. Setting: Three geriatric wards with a similar design, equipment, staffing levels, and skill mix. Participants: Eight hundred twenty-five consecutive patients. Intervention: The patients' fall-risk status was assessed using the Downton Score. Current practice was maintained on the two control wards (n=550). On the experimental ward (n=275), a fall-prevention program was introduced. A multidisciplinary team met weekly specifically to discuss patients' fall risk and formulate a targeted plan. Patients at risk were identified using wristbands; risk factors were corrected or environmental changes made to enhance safety. Measurements: Primary outcomes were number of fallers, recurrent fallers, total falls, patients sustaining injury, and falls per occupied bed days. Secondary outcomes were place of discharge and mortality. Results: Patients were matched for age and risk status. Control wards had proportionally more fallers (20.2% vs 14.2%: P=.033), patients sustaining injury (8.2% vs 4%: P=.025), and total number of falls (170 vs 72: P=.045). These results did not remain significant after controlling for differing length of stay. There was no reduction in recurrent fallers (6.4% vs 4.7%: P=.43) and no effect on place of discharge (home discharges; 57.5% vs 60.7%: P=.41) or mortality (15.3% vs 13.8%: P=.60). Conclusion: This study shows that falls might be reduced in a multidisciplinary fall-prevention program, but the results are not definitive because of the borderline significance achieved and the variable length of stay. More research on fall prevention in hospital is required, particularly as to what interventions, if any, are effective at reducing falls in this group of patients. [source] Structure of magnetic poly(oxyethylene),siloxane nanohybrids doped with FeII and FeIIIJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2003N. J. O. Silva Hybrid organic,inorganic nanocomposites doped with FeII and FeIII ions and exhibiting interesting magnetic properties have been obtained by the sol,gel process. The hybrid matrix of these ormosils (organically modified silicates), classed as di-ureasils and termed U(2000), is composed of poly(oxyethylene) chains of variable length grafted to siloxane groups by means of urea crosslinkages. Iron perchlorate and iron nitrate were incorporated in the di-ureasil matrices, leading to compositions within the range 80 ,n, 10, n being the molar ratio of ether-type O atoms per cation. The structure of the doped di-ureasils was investigated by small-angle X-ray scattering (SAXS). For FeII -doped samples, SAXS results suggest the existence of a two-level hierarchical structure. The primary level is composed of spatially correlated siloxane clusters embedded in the polymeric matrix and the secondary, coarser level consists of domains where the siloxane clusters are segregated. The structure of FeIII -doped hybrids is different, revealing the existence of iron oxide based nanoclusters, identified as ferrihydrite by wide-angle X-ray diffraction, dispersed in the hybrid matrix. The magnetic susceptibility of these materials was determined by zero-field-cooling and field-cooling procedures as functions of both temperature and field. The different magnetic features between FeII - and FeIII -doped samples are consistent with the structural differences revealed by SAXS. While FeII -doped composites exhibit a paramagnetic Curie-type behaviour, hybrids containing FeIII ions show thermal and field irreversibilities. [source] Does continuous use of metformin throughout pregnancy improve pregnancy outcomes in women with polycystic ovarian syndrome?JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2008Fauzia Haq Nawaz Abstract Aim:, Polycystic ovarian syndrome (PCOS) is one of the most common endocrinopathies in women of reproductive age. It is associated with hyperinsulinemia and insulin resistance which is further aggravated during pregnancy. This mechanism has a pivotal role in the development of various complications during pregnancy. In the past few years, metformin, an insulin sensitizer, has been extensively evaluated for induction of ovulation. Its therapeutic use during pregnancy is, however, a recent strategy and is a debatable issue. At present, evidence is inadequate to support the long-term use of insulin-sensitizing agents during pregnancy. It is a challenge for both clinicians and researchers to provide good evidence of the safety of metformin for long-term use and during pregnancy. This study aimed to evaluate pregnancy outcomes in women with PCOS who conceived while on metformin treatment, and continued the medication for a variable length of time during pregnancy. Methods:, This case-control study was conducted from January 2005 to December 2006 at the antenatal clinics of the Department of Obstetrics and Gynecology, Aga Khan University, Karachi, Pakistan. The sample included 137 infertile women with PCOS; of these, 105 conceived while taking metformin (cases), while 32 conceived spontaneously without metformin (controls). Outcomes were measured in three groups of cases which were formed according to the duration of use of metformin during pregnancy. Comparison was made between these groups and women with PCOS who conceived spontaneously. Results:, All 137 women in this study had a confirmed diagnosis of PCOS (Rotterdam criteria). These women were followed up during their course of pregnancy; data forms were completed once they had delivered. Cases were divided into three groups: group A, 40 women who stopped metformin between 4,16 weeks of pregnancy; group B, 20 women who received metformin up until 32 weeks of gestation; and group C; 45 women who continued metformin throughout pregnancy. All the groups were matched by age, height and weight. Comparison was in terms of early and late pregnancy complications, intrauterine growth restriction and live birth rates. In groups A, B and C the rate of pregnancy-induced hypertension/pre-eclampsia was 43.7%, 33% and 13.9% respectively (P < 0.020). Rates of gestational diabetes requiring insulin treatment in groups A and B were 18.7% and 33.3% compared to 2.5% in group C (P < 0.004). The rate of intrauterine growth restriction was significantly low in group C: 2.5% compared to 19.2% and 16.6% in groups A and B respectively (P < 0.046). Frequency of preterm labor and live birth rate was significantly better in group C compared to groups A and B. Overall rate of miscarriages was 7.8%. Controls were comparable to group A in terms of early and late pregnancy complications. Conclusion:, In women with PCOS, continuous use of metformin during pregnancy significantly reduced the rate of miscarriage, gestational diabetes requiring insulin treatment and fetal growth restriction. No congenital anomaly, intrauterine death or stillbirth was reported in this study. [source] Membranous obstruction of the inferior vena cava and its causal relation to hepatocellular carcinomaLIVER INTERNATIONAL, Issue 1 2006M. C. Kew Abstract: Although rare in most countries, membranous obstruction of the inferior vena cava (MOIVC) occurs more frequently in Nepal, South Africa, Japan, India, China, and Korea. The occlusive lesion always occurs at approximately the level of the diaphragm. It commonly takes the form of a membrane, but may be a fibrotic occlusion of variable length. Controversy exists as to whether MOIVC is a developmental abnormality or a result of organization of a thrombus in the hepatic portion of the inferior vena cava. The outstanding physical sign associated with MOIVC are large truncal collateral vessels with a cephalad flow. A dilated vena azygous is seen on chest radiography. Definitive diagnosis is made by contrast inferior vena cavography. The long-standing obstruction to hepatic venous flow causes severe centrolobular fibrosis and predisposes to the development of hepatocellular carcinoma (HCC). Percutaneous balloon angioplasty, transatrial membranotomy, or more complex vena caval and portal decompression surgery should be performed to prevent these complications. HCC occurs in more than 40% of South African Black and Japanese patients with MOIVC, but less often in other populations. It is thought to result from the tumour-promoting effect of continuous hepatocyte necrosis, although the associated environmental risk factors have not been identified. [source] Macroanatomical Investigation of the Aorticorenal Ganglion in 1-Day-Old Infant SheepANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2009J. Kle, kowska-Nawrot Summary The aorticorenal gland belongs to the paired splanchnic ganglion, which is the main component of the coeliac plexus. It lies near the renal artery and suprarenal gland. The research was conducted on 13 1-day-old infant sheep , eight males and five females. Based on the conducted studies, it was concluded that the aorticorenal ganglion is characterized by the variable location in relation to the abdominal aorta, renal artery, caudal vena cava and suprarenal gland (holotopy), the thoracic and lumbar segment of the vertebral column (skeletotopy) (between L1 and L3) and also a different shape (elongated, round, triangular, oval) as well as variable length (the aorticorenal ganglion is longer on the left side of the body; 2.72 mm) and distance from the caudal end of the suprarenal gland (longer on the left side of the body; 8.34 mm). With regard to the sex of the animal, the ganglion is the longest on the left side in ewes (3.02 mm), while in rams it is the longest on the right side (2.68 mm). Regarding the division according to sex, the longest segment was observed on the right side in ewes (9.27 mm), and the shortest segment in rams was also on the right side (6.84 mm). [source] 84 One year results of a French, multicentre, prospective clinical study of act® (adjustable continence therapy) for the treatment of female of stress urinary incontinence due to intrinsic sphincter deficiencyBJU INTERNATIONAL, Issue 2006E. CHARTIER KASTLER Introduction:, This Prospective, multicentre clinical investigation sought to assess the feasibility and efficacy of the adjustable balloons ACT® for treatment of female Stress Urinary Incontinence SUI with ISD. Materials and Methods:, The ACT® implant consists of a two-lumen conduit of variable length with an expandable silicone balloon (0.5,8 cc) on the proximal end and a distal subcutaneous titanium port. Two balloons were placed periurethrally at the bladder neck. Continence rate (no leakage during direct visual stress test with 250 ml placed in the bladder), improvement, failures, quality of life (I-QoL) and morbidity were assessed. Results:, Sixty-seven patients (62 ± 9.8-years-old) were implanted in France during 75 procedures (8 revisions). Average follow-up was 12 months. At baseline, urethral closure pressure was 22.5 ± 10.8 cm H2Oand 39 patients (58%) had previously undergone at least one surgery for SUI. Continence increased from 0% at baseline to 57% at1 year and I-QoL improved from 39.4 ± 19 at baseline to 63.7 ± 23.3 at one year. Balloon adjustment was required in 64% of patients. Complications included erosion (11%), spontaneously resolved retention (2%) and infection (4%). Conclusion:, ACT® offers a viable alternative for the treatment of SUI in female with ISD. The implantation is a minimally invasive and efficient procedure and stable over time therapy for patients with severe SUI with ISD. Implantation can be done under local anaesthesia. The positioning of ACT® treatment versus artificial urinary sphincter still needs to be determined. [source] Self-Aggregation Tendency of Zirconocenium Ion Pairs Which Model Polymer-Chain-Carrying Species in Aromatic and Aliphatic Solvents with Low PolarityCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2008Luca Rocchigiani From pairs to double pairs: Zirconocene ion pairs bearing an aliphatic chain of variable length were synthesized and investigated by means of NOE and diffusion NMR spectroscopy experiments. The presence of long aliphatic chains allowed an unprecedented investigation of their self-aggregation tendency in cyclohexane (see figure), which has a dielectric constant similar to that of isoparaffins used in industrial plants. [source] Jejunal access loop cholangiogram and intervention using image guided accessJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 1 2010KS Amitha Vikrama Summary Jejunal access loop is fashioned in patients who undergo Roux en Y hepaticojejunostomy and biliary intervention is anticipated on follow up. Post-operative study of the biliary tree through the access loop is usually done under fluoroscopic guidance. We present a series of 20 access loop cholangiograms performed in our institution between August 2004 and November 2008. We aimed to evaluate the safety and efficacy of the procedure and to highlight the role of CT guidance in procuring access. Access loop was accessed using CT (n = 13), ultrasound (n = 3) or fluoroscopic guidance (n = 4). Fluoroscopy was used for performing cholangiograms and interventions. Twelve studies had balloon plasty of the stricture at anastomotic site or high up in the hepatic ducts. Seven studies showed normal cholangiogram. Plasty was unsuccessful in one study. Technical success in accessing the jejunal access loop was 100%; in cannulation of anastomotic site and balloon plasty it was 95%. One case required two attempts. Procedure-related complications were not seen. All patients who underwent balloon plasty of the stricture were doing well for variable lengths of time. Access loop cholangiogram and interventions are safe and effective. CT guidance in locating/procuring the access loop is a good technique. [source] A shared promoter region suggests a common ancestor for the human VCX/Y, SPANX, and CSAG gene families and the murine CYPT familyMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2008Martin A. Hansen Abstract Many testis-specific genes from the sex chromosomes are subject to rapid evolution, which can make it difficult to identify murine genes in the human genome. The murine CYPT gene family includes 15 members, but orthologs were undetectable in the human genome. However, using refined homology search, sequences corresponding to the shared promoter region of the CYPT family were identified at 39 loci. Most loci were located immediately upstream of genes belonging to the VCX/Y, SPANX, or CSAG gene families. Sequence comparison of the loci revealed a conserved CYPT promoter-like (CPL) element featuring TATA and CCAAT boxes. The expression of members of the three families harboring the CPL resembled the murine expression of the CYPT family, with weak expression in late pachytene spermatocytes and predominant expression in spermatids, but some genes were also weakly expressed in somatic cells and in other germ cell types. The genomic regions harboring the gene families were rich in direct and inverted segmental duplications (SD), which may facilitate gene conversion and rapid evolution. The conserved CPL and the common expression profiles suggest that the human VCX/Y, SPANX, and CSAG2 gene families together with the murine SPANX gene and the CYPT family may share a common ancestor. Finally, we present evidence that VCX/Y and SPANX may be paralogs with a similar protein structure consisting of C terminal acidic repeats of variable lengths. Mol. Reprod. Dev. 75: 219,229, 2008. © 2007 Wiley-Liss, Inc. [source] Effect of Saccharomyces cerevisiae F12 on volatile compounds in wines at three different stages of industrial biological ageingAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2 2008D. MUÑOZ Abstract Background and Aims: Wines subjected to biological ageing for variable lengths of time were inoculated with Saccharomyces cerevisiae F12 and were microaerated in order to reduce their overall ageing time. Methods and Results: Volatile compounds as determined by gas chromatography (GC) and GC,mass spectrometry (MS) were grouped according to their aroma descriptors into nine odourant classes, which exhibited similar changes in wines obtained by traditional ageing, and in others inoculated with S. cerevisiae F12 and microaerated. A tasting panel found the wine previously aged for 2 years and inoculated with S. cerevisiae F12 to be of better quality than the identical wine subjected to no inoculation. Conclusion: Based on the results, the ageing time for wines previously aged under typical winery conditions for 0 and 2 years can be shortened by the inoculation of S. cerevisiae F12 flor yeasts. Significance of the Study: The biological ageing system used allows the production cost of fino wines to be reduced by shortening the ageing process. [source] | |||||||||||||||||||