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In this work, nonlinear variational optimization is used for obtaining minimal seeds for the formation of turbulent bands in channel flow. Using nonlinear optimization together with energy bisection, we have found that the minimal energy threshold for obtaining spatially patterned turbulence scales with Re-8.5 for Re > 1000. The minimal seed, which is different to that found in a much smaller domain, is characterized by a spot-like structure surrounded by a low-amplitude large-scale quadrupolar flow filling the whole domain. This minimal-energy perturbation of the laminar flow has dominant wavelengths close to 4 in the streamwise direction and 1 in the spanwise direction, and is characterized by a spatial localization increasing with the Reynolds number. At Re ≲ 1200, the minimal seed evolves in time, creating an isolated oblique band, whereas for Re ≲ 1200, a quasi-spanwise-symmetric evolution is observed, giving rise to two distinct bands. A similar evolution is found also at low Re for non-minimal optimal perturbations. This highlights two different mechanisms of formation of turbulent bands in channel flow, depending on the Reynolds number and initial energy of the perturbation. The selection of one of these two mechanisms appears to be dependent on the probability of decay of the newly created stripe, which increases with time, but decreases with the Reynolds number. [ABSTRACT FROM AUTHOR]

A new mathematical framework is proposed for characterizing the coherent motion of fluctuations around a mean turbulent channel flow. We search for statistically invariant coherent solutions of the unsteady Reynolds-averaged Navier–Stokes equations written in a perturbative form with respect to the turbulent mean flow, using a suitable approximation of the Reynolds stress tensor. This is achieved by setting up a continuation procedure of known solutions of the perturbative Navier–Stokes equations, based on the continuous increase of the turbulent eddy viscosity towards its turbulent value. The recovered solutions, being sustained only in the presence of the Reynolds stress tensor, are representative of the statistically coherent motion of turbulent flows. For small friction Reynolds number and/or domain size, the statistically invariant motion is almost identical to the corresponding invariant solution of the Navier–Stokes equations. Whereas, for sufficiently large friction number and/or domain size, it considerably departs from the starting invariant solution of the Navier–Stokes equations, presenting spatial structures, main wavelengths and scaling very close to those characterizing both large- and small-scale motion of turbulent channel flows. This article is part of the theme issue 'Mathematical problems in physical fluid dynamics (part 2)'. [ABSTRACT FROM AUTHOR]

Recently, many authors have investigated the origin and growth of turbulent bands in shear flows, highlighting the role of streaks and their inflectional instability in the process of band generation and sustainment. Recalling that streaks are created by an optimal transient growth mechanism, and motivated by the observation of a strong increase of the disturbance kinetic energy corresponding to the creation of turbulent bands, we use linear and nonlinear energy optimisations in a tilted domain to unveil the main mechanisms allowing the creation of a turbulent band in a channel flow. Linear transient growth analysis shows an optimal growth for wavenumbers having an angle of approximately 35°, close to the peak values of the premultiplied energy spectra of direct numerical simulations. This linear optimal perturbation generates oblique streaks, which, for a sufficiently large initial energy, induce turbulence in the whole domain, due to the lack of spatial localisation. However, spatially localised perturbations obtained by adding nonlinear effects to the optimisation or by artificially confining the linear optimal to a localised region in the transverse direction are characterised by a large-scale flow and lead to the generation of a localised turbulent band. These results suggest that two main elements are needed for inducing turbulent bands in a tilted domain: (i) a linear energy growth mechanism, such as the lift-up, for generating large-amplitude flow structures, which produce inflection points; (ii) spatial localisation, linked to the presence or generation of large-scale vortices. We show that these elements alone generate isolated turbulent bands also in large non-tilted domains. [ABSTRACT FROM AUTHOR]

Summary: A 3‐year‐old Warmblood gelding was evaluated for intermittent respiratory distress and an inspiratory noise. These signs were mainly observed at exercise but sometimes occurred at rest as well. At the age of 2 months, a severe episode of respiratory distress had necessitated a temporary tracheotomy, which had then healed uneventfully. Examination of the patient and resting endoscopy revealed no structural laryngeal alterations. Exercise endoscopy revealed episodes of active bilateral laryngeal adduction during inspiration. Spirometrically, a corresponding impairment of inspiratory airflow was identified. These abnormalities were most pronounced at the trot but they occurred at magnitudes of inspiratory airflow lower than those inducing dynamic arytenoid collapse in horses with recurrent laryngeal neuropathy. Therefore, the diagnosis of a laryngeal dyskinesia characterised by an active bilateral arytenoid adduction during inspiration was made. No specific treatment was implemented. Three years later, the owner reported that the condition was markedly improved and the horse was used for pleasure riding. [ABSTRACT FROM AUTHOR]

Summary: Background: Guttural pouch mycosis (GPM) is a cause of nasal discharge, dysphagia and fatal haemorrhage in the horse. Objectives: To report the complications and success of salpingopharyngeal fistulation in horses with GPM. We hypothesised that creating a direct static opening into the guttural pouch from the pharynx would cause a regression of fungal plaques due to a change in the guttural pouch environment and that this treatment would result in resolution of infection prior to secondary complications. Study design: Retrospective case series. Methods: The medical records of all horses diagnosed with GPM that were presented to New Bolton Center between the years 2006 and 2017 were examined retrospectively. Seven cases of guttural pouch mycosis treated with salpingopharyngostomy without other surgical intervention were included. Information collected included signalment, presenting complaint, which pouch was affected, size and location of the plaques, laryngeal and pharyngeal function, concurrent medical therapy, location of the fistula, surgical time, time to resolution of clinical signs, time to full resolution of the mycotic plaque, and patency of the salpingopharyngostomy site. Results: Nasal discharge resolved in 10–30 days post‐operatively in all cases where nasal discharge was present. The mycotic plaques showed complete resolution at time points ranging from 1 to 6 months post‐operatively. No case developed epistaxis or neurological deficits post‐operatively that were not present at presentation. Main limitations: There were differing adjunctive treatments between cases. This technique is not appropriate for horses that have had epistaxis or are currently bleeding. Conclusions: Salpingopharyngostomy can minimise cost of treatment, be performed on an outpatient basis and provide better exposure of the infected area with few complications. This case series documents seven cases treated with this method that resolved the infection without any further complications of the mycosis. [ABSTRACT FROM AUTHOR]

That situation is very different from the horse that has an underlying neuromuscular problem that is causing a primary functional inability of the oropharynx resulting in the dysphagia and possibly persistent palate displacement. If the palate is persistently above the epiglottis despite multiple stimulated swallows, a lateral radiograph (as was performed in this case report) can yield valuable information about any structural abnormalities associated with the epiglottis or palate. Infrequently entrapment of the epiglottis can precipitate persistent displacement of the palate, or the ventral surface of the epiglottis can be very abnormal and result in significant performance problem or dysphagia while appearing normal on the dorsal surface. [Extracted from the article]

Summary: Recurrent laryngeal neuropathy appears to be a simple problem that should have a simple solution, yet the complexity and dynamic nature of laryngeal function is underappreciated. This review highlights the challenges and accomplishments that work towards that greater understanding of what is necessary to find a successful solution. [ABSTRACT FROM AUTHOR]

This review outlines the recent advances in the knowledge on aerobic and respiratory growth of lactic acid bacteria, focusing on the features of respiration-competent lactobacilli. The species of the genus Lactobacillus have been traditionally classified as oxygen-tolerant anaerobes, but it has been demonstrated that several strains are able to use oxygen as a substrate in reactions mediated by flavin oxidases and, in some cases, to synthesize a minimal respiratory chain. The occurrence of genes related to aerobic and respiratory metabolism and to oxidative stress response apparently correlates with the taxonomic position of lactobacilli. Members of the ecologically versatile Lactobacillus casei, L. plantarum and L. sakei groups are apparently best equipped to deal with aerobic/respiratory growth. The shift from anaerobic growth to aerobic (oxygen) and/or respiratory promoting (oxygen, exogenous haem and menaquinone) conditions offers physiological advantages and affects the pattern of metabolite production in several species. Even if this does not result in dramatic increases in biomass production and growth rate, cells grown in these conditions have improved tolerance to heat and oxidative stresses. An overview of benefits and of the potential applications of Lactobacillus cultures grown under aerobic or respiratory conditions is also discussed. [ABSTRACT FROM AUTHOR]

Aims To evaluate the effect of cultivation (anaerobiosis vs respiration) and Tween 80 supplementation on the production of metabolites and on the composition of membrane fatty acids ( FAs) in Lactobacillus casei N87. Methods and Results Anaerobic and respiratory growth, with or without Tween 80 supplementation, was carried out in a chemically defined medium. Production of biomass, organic acids, volatile organic compounds ( VOCs), consumption of amino acids and changes in membrane FAs were investigated. Respiration altered the central metabolism rerouting pyruvate away from lactate accumulation, while Tween 80 had a minor effect on metabolic pathways. VOCs were mainly affected by growth conditions and significant amounts of diacetyl were produced by respiratory cultures. Respiration increased desaturation of membrane lipids and Tween 80 improved the production of essential polyunsaturated FAs. Palmitic acid decreased in Tween-supplemented aerated cultures. Conclusions Combination of Tween 80 and respiratory growth promoted production of biomass and aroma compounds and affected the composition of membrane FAs in Lact. casei N87. Significance and Impact of the Study Respiration might be exploited in Lact. casei as a natural strategy for the enhanced production of aroma compounds. [ABSTRACT FROM AUTHOR]

Aims Members of the Lactobacillus casei and Lactobacillus plantarum groups are capable of aerobic and respiratory growth. However, they grow poorly in aerobiosis in the currently available chemically defined media, suggesting that aerobic and respiratory growth require further supplementation. Methods and Results The effect of Tween 80, l-alanine, l-asparagine, l-aspartate, l-proline and l-serine on anaerobic and respiratory growth of Lact. casei N87 was investigated using a 25 factorial design. The effectiveness of modified CDM ( mCDM) was validated on 21 strains of Lact. casei and Lact. plantarum groups. Tween 80 supplementation did not affect anaerobic growth, but improved respiratory growth. l-asparagine, l-proline and l-serine were stimulatory for respiring cells, while the presence of l-aspartate, generally, impaired biomass production. mCDM promoted the growth of Lact. casei and Lact. plantarum, with best results for strains showing a respiratory phenotype. Conclusions The nutritional requirements of anaerobic and respiratory cultures of members of the Lact. casei and Lact. plantarum groups differ. Tween 80 and selected amino acids derived from pathways related to TCA cycle, pyruvate conversion and NADH recycling are required for respiration. Significance and Impact of the Study The availability of mCDM will facilitate the study of aerobic metabolism of lactobacilli under controlled conditions. [ABSTRACT FROM AUTHOR]

Aims Lactobacillus plantarum is a lactic acid bacterium involved in the production of many fermented foods. Recently, several studies have demonstrated that aerobic or respiratory metabolism in this species leads to improved technological and stress response properties. Methods and Results We investigated respiratory growth, metabolite production and stress resistance of Lact. plantarum C17 during batch, fed-batch and chemostat cultivations under respiratory conditions. Sixty mutants were selected for their ability to tolerate oxidative stress using H2O2 and menadione as selective agents and further screened for their capability to growth under anaerobic, respiratory and oxidative stress conditions. Dilution rate clearly affected the physiological state of cells and, generally, slow-growing cultures had improved survival to stresses, catalase production and oxygen uptake. Most mutants were more competitive in terms of biomass production and ROS degradation compared with wild-type strain (wt) C17 and two of these (C17-m19 and C17-m58) were selected for further experiments. Conclusions This work confirms that, in Lact. plantarum, respiration and low growth rates confer physiological and metabolic advantages compared with anaerobic cultivation. Significance and Impact of the Study Our strategy of natural selection successfully provides a rapid and inexpensive screening for a large number of strains and represents a food-grade approach of practical relevance in the production of starter and probiotic cultures. [ABSTRACT FROM AUTHOR]

Aerobic metabolism and response to oxidative stress and starvation were studied in 11 Lactobacillus plantarum, L. paraplantarum and L. pentosus strains in order to assess the impact of aerobic metabolism on the growth and on the stress response. The strains were grown in aerobiosis without supplementation (AE), with hemin (AEH) or with hemin and menaquinone (AEHM) supplementation and in anaerobiosis (AN) in a complex buffered substrate. Growth rate, biomass yield, glucose and O consumption, production of lactic acid and HO, catalase activity, oxidative and starvation stress tolerance were evaluated. Aerobic growth increased biomass yield in late stationary phase. Further increase in yield was obtained with both hemin (H) and menaquinone (M) addition. With few exceptions, the increase in biomass correlated with the decrease of lactic acid which, however, decreased in anaerobic conditions as well in some strains. Addition of H or H + M increased growth rate for some strains but reduced the duration of the lag phase. HO production was found only for aerobic growth with no supplementation due to catalase production when hemin was supplemented. To our knowledge this is the first study in which the advantages of aerobic growth with H or H + M in improving tolerance of oxidative stress and long-term survival is demonstrated on several strains of the L. plantarum group. The results may have significant technological consequences for both starter and probiotic production. [ABSTRACT FROM AUTHOR]

Aims The aim of the study is to gain further insight on the respiratory behaviour of Lactobacillus plantarum and its consequences on stress tolerance. Methods and Results We investigated the effect of temperature and respiration on the growth and stress (heat, oxidative, freezing, freeze-drying) response of Lact. plantarum C17 during batch cultivations. Temperature as well as respiration clearly affected the physiological state of cells, and generally, cultures grown under respiratory conditions exhibited improved tolerance of some stresses (heat, oxidative, freezing) compared to those obtained in anaerobiosis. Our results revealed that the activities in cell-free extracts of the main enzymes related to aerobic metabolism, POX (pyruvate oxidase) and NPR ( NADH peroxidase), were significantly affected by temperature. POX was completely inhibited at 37°C, while the activity of NPR slightly increased at 25°C, indicating that in Lact. plantarum, the temperature of growth may be involved in the activation and modulation of aerobic/respiratory metabolism. Conclusions We confirmed that respiration confers robustness to Lact. plantarum cells, allowing a greater stress tolerance and advantages in the production of starter and probiotic cultures. Significance and Impact of the Study This is the first study on respiratory metabolism on a strain other than the model strains WCFS1; novel information on the role of temperature in the modulation of aerobic/respiratory metabolism in Lact. plantarum is presented. [ABSTRACT FROM AUTHOR]

Background and study aims: Colorectal cancer (CRC) screening aims to reduce mortality by detecting cancers at an early stage and removing adenomatous polyps at an acceptable cost. The aim of the current study were to assess the outcomes and costs of the first two biennial rounds of a population-based CRC screening program using the immunochemical fecal occult blood test (i-FOBT) in a northern Italian province. Methods: All residents aged 50-69 yearswere invited to take part in a biennial screening program using a 1-day i-FOBT, followed by colonoscopy in positive individuals. The i-FOBT uptake, compliance to colonoscopy, detection rate for cancer or advanced adenomas according to age and sex, and direct cost analysis were carried out separately for the 1st and 2nd rounds of screening. Results: In 78083 (1st round) and 81619 (2nd round) individuals whowere invited to screening, the participation rates were 49.7% and 54.4% and i-FOBT positivity rates were 6.2% and 5.8 %, respectively. Detection rates for cancer and advanced adenomas were lower in the 2nd screening compared with the 1st one (1.6‰ vs. 2.5‰ for cancers and 15.8‰ vs. 17.9‰ for advanced adenomas, respectively), whereas positive predictive values for cancer and advanced adenoma were similar in both rounds. In 165 adenocarcinomas detected, 52% were Dukes' stage A and 21% were stage B. All cost indicators were slightly higher in the 1st round of screening compared with the 2nd. The direct cost per cancer or advanced adenoma detection was similar in the two rounds (€1252 and €1260, respectively). Conclusions: Compliance and diagnostic yield of i-FOBT screening were satisfactory. Most detected cancers were at a very early stage. Program costs were reasonable and did not increase with repeat screening. Screening could contribute to decreasing the cost of CRC care by improving the stage at diagnosis. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) are used as starter or probiotic cultures in the food and pharmaceutical industries and, therefore, rapid and accurate methods for the detection of their viability are of practical relevance. In this study 10 LAB strains, belonging to the genera Enterococcus, Lactococcus, Leuconostoc, Lactobacillus, Streptococcus and Weissella, were subjected to heat and oxidative stresses and cell injury or death was assessed comparing different fluorescent probes (Syto 9; Propidium Iodide, PI; 4,6-diamidino-2-phenylindole, DAPI; 5,(6)-carboxyfluorescein diacetate, cFDA) to identify the stain combination which most reliably allowed the detection of live/metabolically active and dead cells. Protocols for specimen preparation and staining were optimized and a simple procedure for automated cell counts was developed using NIH ImageJ macros. Cysteine and semi-solid agar solution were efficiently used as anti-fading agent and mounting medium, respectively. The double staining cFDA-PI apparently offered the best and most versatile indication of both cell metabolic activity and membrane integrity. An excellent correlation between manual and automated cell counts for the majority of strain/stain combinations was found. This work provides a simple protocol for specimen preparation and staining based on the use of safe, easy to prepare and inexpensive reagents as compared to other methods. Additionally, the automated cell count procedure developed can be applied to several bacterial species and allows an increase in the number of experimental trials and the reproducibility and sensitivity of the analysis. [ABSTRACT FROM AUTHOR]

Summary Exercising upper airway endoscopic evaluation was performed in 7 horses with a history of poor performance after partial arytenoidectomy. Treadmill endoscopy revealed axial deviation of the ipsilateral aryepiglottic fold in all horses. Dynamic collapse of one or more additional upper airway structures was also observed. In 4 horses, laser resection of soft tissue structures that obstructed the upper airway was performed. After laser surgery, 3 horses raced and one performed adequately as a riding horse. Of the remaining 3 horses, 2 raced at a lower class and one performed adequately as a riding horse. In this population of horses, dynamic endoscopy of the upper airway was critical for case management. Based on our observations, horses post arytenoidectomy can have dynamic collapse of the ipsilateral aryepiglottic fold and laser resection of the fold may help resolve the performance problem. [ABSTRACT FROM AUTHOR]

In previous studies we demonstrated that a relatively large diversity of stress response patterns (acid, osmotic, oxidative, heat) exists among Streptococcus thermophilus strains. Changes in protein expression, evaluated by SDS-PAGE in 4 wild strains (CNBL7035, TH681, Y3, Sfi39) and in three Sfi39 mutants in which hrcA, ctsR and rr01 genes were inactivated showed that significant variations of proteins involved in general stress response (GSR) occur as a function of growth phase, adaptation and inactivation of stress response regulators. In this work we re-evaluate the previous results comparing two unsupervised (Hierarchical Cluster Analysis, HCA, and Principal Component Analysis, PCA) and one supervised (Partial Least Square Regression, PLSR) statistical techniques for the ability to extract information from SDS-PAGE patterns of wild type and mutant strains of S. thermophilus and to uncover relationships between protein patterns and stress tolerance. HCA and PCA are two purely descriptive techniques. The HCA showed that SDS-PAGE is an efficient tool to differentiate strains but did not shed any light on the relationships between band intensity and strain, growth phase or adaptation treatment. PCA helped to identify group of bands which covaried with the stress input factors but also not allow to find a relationship between protein expression and stress tolerance. The PLS regression, even with the limitations due to the data set used in this study, appears as an extremely promising tools for the identification of complex relationships between design and response variables in the analysis of SDS-PAGE patterns of whole cell proteins. [ABSTRACT FROM AUTHOR]

Aim: To compare the changes in the upper lip (UL) length after performing incisions with scalpel and electrocautery for maxillary impaction. Patients and methods: Patients submitted to maxillary superior repositioning greater than 3 mm were randomly assigned to two groups. Only cases with a smaller maxillary advancement were included. Incisions were made with scalpel in Group 1 and with electrocautery in Group 2. Pre- and post-operative lateral cephalometric radiographs were used to calculate the changes in the UL length (subnasal and stomium superior), and superior movement of the UL relative to maxillary impaction. Results: Sixteen patients that underwent maxillary impaction were evaluated. Four patients were previously excluded. The mean maxillary impaction was 4.85 mm and the mean advancement was 1.87 mm. The mean UL shortening was 0.53 mm, and the mean UL superior movement relative to maxillary impaction was 11.88%. In the five patients of Group 1, the mean lip shortening was 0.32 mm and superior movement of the UL relative to maxillary impaction was 10.91% on average. The seven patients of Group 2 presented a mean lip shortening of 0.68 mm, and superior movement of the UL relative to maxillary impaction was 15.41% on average. Conclusion: Although Group 2 showed greater UL shortening than Group 1, it was not statistically significant. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: Loss of arytenoid abduction is a common post operative complication of laryngoplasty without a definitive cause. It has been a clinical impression during laryngoplasty surgery that there is great conformational variability along the caudal edge of the Thoroughbred cricoid cartilage that could impact post operative retention of suture position. A change in suture position would probably lead to some loss of abduction. Defining any structural variability of the cricoid would be an initial step in determining whether this variability could impact on the retention of suture position. Hypothesis: Anatomical variations in the larynx of Thoroughbred horses may be detected and measured using objective analysis and computed tomography. Methods: Larynges were harvested from 15 mature Thoroughbred horses. Helical CT scans were performed on each specimen. Three independent observers performed a series of measurements on 2D and 3D reconstruction images using digital software. Measurements included the lateral cricoid angle, the caudal cricoid prominences, the distance to the cricoid slope, the angle of the cricoarytenoid joints (CAJ), the cricoid thickness and the suture angle. Mean, standard deviation, coefficient of variation and linear regression analysis were performed among all observers and all measurements. Results: Notable conformational differences were evident on the 3D reconstructions. The highest degree of variability was found in 3 measurements: the distance to the lateral cricoid slope, the lateral cricoid angle and the cricoid thickness. A larger left CAJ angle directly and significantly correlated with a larger suture angle. Conclusions: There are notable conformational differences among cricoid specimens in the Thoroughbred larynx. Potential relevance: The morphometric differences identified may impact on optimal prosthesis placement and long-term retention. Since a larger lateral cricoid angle may facilitate abduction loss secondary to a displaced and loosened suture, alternative techniques for suture placement may be of value to prevent arytenoid abduction loss. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: Although well documented in racehorses, there is paucity in the literature regarding the prevalence of dynamic upper airway abnormalities in nonracing performance horses. Objective: To describe upper airway function of nonracing performance horses with abnormal respiratory noise and/or poor performance via exercising upper airway videoendoscopy. Methods: Medical records of nonracing performance horses admitted for exercising evaluation with a chief complaint of abnormal respiratory noise and/or poor performance were reviewed. All horses had video recordings of resting and exercising upper airway endoscopy. Relationships between horse demographics, resting endoscopic findings, treadmill intensity and implementation of head and neck flexion during exercise with exercising endoscopic findings were examined. Results: Dynamic upper airway obstructions were observed in 72% of examinations. Head and neck flexion was necessary to obtain a diagnosis in 21 horses. Pharyngeal wall collapse was the most prevalent upper airway abnormality, observed in 31% of the examinations. Complex abnormalities were noted in 27% of the examinations. Resting laryngeal dysfunction was significantly associated with dynamic arytenoid collapse and the odds of detecting intermittent dorsal displacement of the soft palate (DDSP) during exercise in horses with resting DDSP was only 7.7%. Exercising endoscopic observations were different from the resting observations in 54% of examinations. Conclusions: Dynamic upper airway obstructions were common in nonracing performance horses with respiratory noise and/or poor performance. Resting endoscopy was only helpful in determining exercising abnormalities with recurrent laryngeal neuropathy. Potential relevance: This study emphasises the importance of exercising endoscopic evaluation in nonracing performance horses with abnormal respiratory noise and/or poor performance for accurate assessment of dynamic upper airway function. [ABSTRACT FROM AUTHOR]

Summary A case of paranasal sinus fibromatosis in an 11-year-old Thoroughbred gelding is reported. At admission the gelding underwent a unilateral frontal sinusotomy and a paranasal sinus mass was extensively debulked. The mass was diagnosed via histopathology as a desmoid fibromatosis with bone invasion, reactive osteoclastic osteolysis and osteoproliferation. The gelding had radiographic evidence of slow recurrence of the mass 8 months post operatively. The histopathological appearance and short-term outcome are presented for this previously undiagnosed condition of the horse. Recognition of paranasal fibromatosis and the resultant differentiation from other types of paranasal sinus neoplasia may allow for improved prognostication of equine sinus lesions. [ABSTRACT FROM AUTHOR]

Aims: To investigate the effect of pH, water activity ( aw) and temperature on the growth of Weissella cibaria DBPZ1006, a lactic acid bacterium isolated from sourdoughs. Methods and Results: The kinetics of growth of W. cibaria DBPZ1006 was investigated during batch fermentations as a function of pH (4·0–8·0), aw (0·935–0·994) and temperature (10–45°C) in a rich medium. The growth curve parameters (lag time, growth rate and asymptote) were estimated using the dynamic model of Baranyi and Roberts (1994. A dynamic approach to predicting bacterial growth in food. Int J Food Microbiol 23, 277–294). The effect of pH, aw and temperature on maximum specific growth rate (μmax) were estimated by fitting a cardinal model. μmax under optimal conditions (pH = 6·6, aw = 0·994, T = 36·3°C) was estimated to be 0·93 h−1. Minimum and maximum estimated pH and temperature for growth were 3·6 and 8·15, and 9·0°C and 47·8°C, respectively, while minimum aw was 0·918 (equivalent to 12·2% w/v NaCl). Conclusions: Weissella cibaria DBPZ1006 is a fast-growing heterofermentative strain, which could be used in a mixed starter culture for making bread. Significance and Impact of the Study: This is the first study reporting the modelling of the growth of W. cibaria, a species that is increasingly being used as a starter in sourdough and vegetable fermentations. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: The effectiveness and best method to perform a partial arytenoidectomy in racehorses is unclear. This study was performed to evaluate the success of and complications that can occur after a unilateral partial arytenoidectomy with primary mucosal closure in Thoroughbred racehorses. Hypothesis: Partial arytenoidectomy is an effective surgical procedure to return Thoroughbred racehorses, afflicted by arytenoid chondropathy or a failed laryngoplasty, to preoperative levels of performance. Methods: Seventy-six Thoroughbred racehorses admitted to the New Bolton Centre between 1992 and 2006 were assessed. Information was obtained from the medical records about the horse, laryngeal abnormalities, surgery and other findings during hospitalisation. Racing information was evaluated relative to those independent variables by an analysis of variance with a level of significance of P<0.05. Results: Arytenoid chondropathy was the presenting complaint in 54 horses and failed laryngoplasty in 22 horses. Thirteen horses (17%) underwent a second surgery for laser excision of intralaryngeal granulation tissue at the arytenoidectomy site. Seventy-three horses were discharged from the hospital and racing outcome was evaluated. Sixty horses (82%) raced after surgery and 46 horses (63%) raced 5 or more times after surgery. The median time from surgery to the first start was 6 months. The average earnings/start was not significantly different before and after surgery. There was no association between earnings after surgery and age, gender, location of lesion, type of lesion, duration of tracheal intubation or undergoing a second surgery. Conclusions and potential relevance: A Thoroughbred racehorse is likely to race after a unilateral partial arytenoidectomy with primary mucosal closure and return to a preoperative level of performance. [ABSTRACT FROM AUTHOR]

Aim:  To characterize the genetic and phenotypic diversity of 33 strains of Lactobacillus rossiae. Methods and Results:  Genotypic identification was carried out by partial 16S rRNA gene sequence analysis. Genetic diversity was evaluated by RAPD–PCR analysis. Phenotypic diversity was evaluated through fermentative profile by Biolog system, proteinase and peptidase activities using synthetic substrates, and acidification capacity and amino acid profile during sourdough fermentation. The genetic analyses excluded clonal relatedness among the strains used. A large phenotypic diversity was found. It mainly concerned the capacity to use carbon sources available in sourdough during fermentation, the quotient of fermentation and the peptidase activities, especially towards proline containing synthetic substrates. The free amino acid profiles differed either for the total concentration or for the type of amino acids. With a few exceptions, proteinase activity towards wheat albumins and globulins was weak. Conclusions:  Overall, no relationships between genetic and physiological analyses were found, and the strains examined showed a marked genetic and phenotypic heterogeneity. L. rossiae strains had interesting properties for application in sourdough fermentation. Although some strains combined several technological traits, the association of more strains seemed to be a requisite to get optimal sourdough characteristics. Significance and Impact of the Study:  It represents the first characterization of the diversity within the L. rossiae species. Besides, it may represent an example of computerized analysis of genotypic and phenotypic information to select strains for improving sourdough characteristics. [ABSTRACT FROM AUTHOR]

Summary Reasons for performing study: Little information exists regarding talus fractures in the horse and there have been no previously published case series of racehorses diagnosed with incomplete sagittal fracture of the talus. Objective: To describe the diagnosis, treatment and post injury performance of horses with incomplete sagittal fracture of the talus. Methods: Medical records of 11 racehorses (8 Standardbreds and 3 Thoroughbreds) admitted between January 1992 and January 1999 were reviewed. Subject details, anamnesis, results of lameness examination, radiographs and nuclear scintigraphic findings were evaluated. Racing performance was assessed by comparing pre- and post injury race records. Results: Nuclear scintigraphic examination, performed in 8 of the 11 horses, revealed focal increased radiopharmaceutical uptake in the proximal aspect of the affected talus. Fractures could best be seen on dorsal 10-20° lateral-plantaromedial oblique radiographs; all had raced pre-injury. All horses were treated conservatively and follow-up information was available for 8 horses, of which 7 raced after injury. Performance in 3 horses was improved, in 1 it was unchanged and in 3 horses performance declined. Conclusions: Horses with incomplete fracture of the talus have a good prognosis for return to racing after conservative management. Potential relevance: Incomplete sagittal fracture of the talus should be considered as a cause of hindlimb lameness in racehorses. Further research is necessary to determine the pathophysiology of these fractures. [ABSTRACT FROM AUTHOR]

g. blaiotta, c. pennacchia, f. villani, a. ricciardi, r. tofalo and e. parente. 2004. Evaluation of composition and evolution of the coagulase-negative staphylococci (CNS) communities in two traditionally fermented sausages (salsiccia and soppressata lucana) produced in Basilicata, southern Italy. A culture-dependent approach based on isolation on selective media and identification with phenotypic and molecular methods was used. Phenotypic data of 471 strains were analysed by multivariate statistical methods by using 28 strains from culture collections and 48 strains identified by molecular methods (such as 16S rDNA sequencing, species-specific PCR assays, intergenic spacer region-PCR and PCR-denaturing gradient gel electrophoresis) as a reference. The CNS microflora of the sausages was found to be dominated by different biotypes of Staphylococcus xylosus (51·2%), followed by S. pulvereri/ vitulus, S. equorum and S. saprophyticus (13·4, 10·2 and 10%, respectively). Other species ( S. succinus, S. pasteuri, S. epidermidis, S. warneri and Macrococcus caseolyticus) were also present at lower levels. Identification of 25% of the isolates was impossible. The composition of CNS communities varied significantly with sausage type, plant and ripening time and clear differences were found among communities of salsiccia and soppressata at the end of ripening. Phenotypic characterization, supported by molecular and statistical analyses, can be considered a useful approach for typing a large number of isolates and for monitoring the evolution of staphylococcal communities during sausage fermentation but does not always provide a satisfactory identification of the isolates. [ABSTRACT FROM AUTHOR]

Aims: To evaluate the effect of yeast extract (YE) concentration, temperature and pH on growth and exopolysaccharide (EPS) production in a whey-based medium by Streptococcus thermophilus SY and to characterize the partially purified EPS. Methods and Results: Factorial experiments and empirical model building were used to optimize fermentation conditions and the chemical composition, average molecular weight (MW) and rheological properties of aqueous dispersions of the EPS were determined. Exopolysaccharide production was growth associated and was higher (152 mg l–1 ) at pH 6·4 and 36°C with 4 g l–1 YE. High performance size exclusion chromatography of the partially purified EPS showed two peaks, with a weight average MW of 2 × 106 and 5 × 104 , respectively. The EPS was a heteropolysaccharide, with a glucose : galactose : rhamnose ratio of 2 : 4·5 : 1. Its water dispersions had a pseudoplastic behaviour and showed a higher viscosity of xanthan solutions. Significance and Impact of the Study: The fermentation conditions and some properties of an EPS produced by Strep. thermophilus , a dairy starter organism, were described. [ABSTRACT FROM AUTHOR]

Growth and alginate production by Azotobacter vinelandii DSM576 as a function of initial ammonium sulphate concentration (0.45–1.05 g l-1) and agitation speed (300–700 rpm) were studied in batch fermentations at controlled pH. The time course of growth, alginate production and substrate consumption and the effect of nitrogen concentration and agitation speed on kinetic parameters and on maximum alginate molecular weight (MW) was modelled using empirical equations. The kinetics of growth, alginate production and polymerization were deeply affected by agitation speed and, to a lesser extent, by inorganic nitrogen concentration. Average and maximum specific growth rate and maximum alginate MW all increased with agitation speed, and were higher at intermediate ammonium sulphate concentration. Maximum alginate MW (>250,000) was obtained at high agitation speed (600–700 rpm) and alginate depolymerization was limited or did not occur at all when the agitation speed was higher than 500 rpm, while at 400 rpm depolymerization significantly reduced the alginate. However, alginate yield was negatively affected by increasing agitation speed. A good compromise between alginate yield (>2 g l-1) and quality (MW>250,000) was obtained with agitation speed of 500–600 rpm and 0.75–0.90 g l-1 of ammonium sulphate. Journal of Industrial Microbiology & Biotechnology (2000) 25, 242–248. [ABSTRACT FROM AUTHOR]

Bacteriocins produced by lactic acid bacteria are a heterogeneous group of peptide inhibitors which include lantibiotics (class I, e.g. nisin), small heat-stable peptides (class II, e.g. pediocin AcH/PA1) and large heat-labile proteins (class III, e.g. helveticin J). Many bacteriocins belonging to the first two groups can be successfully used to inhibit undesirable microorganisms in foods, but only nisin is produced industrially and is licensed for use as a food preservative in a partially purified form. This review focuses on the production and purification of class I and class II bacteriocins from lactic acid bacteria. Bacteriocin production is growth associated but the yield of bacteriocin per unit biomass is affected by several factors, including the producing strain, media (carbohydrate and nitrogen sources, cations, etc.) and fermentation conditions (pH, temperature, agitation, aeration and dilution rate in continuous fermentations). Continuous fermentation processes with cell recycle or immobilized cells can result in a dramatic improvement in productivity over batch fermentations. Several simple recovery processes, based on adsorbing bacteriocin on resins or silica compounds, have been developed and can be used to build integrated production processes. [ABSTRACT FROM AUTHOR]

The influence of pH on growth, and lactic acid and bacteriocin production by Lactococcus lactis subsp. lactis 140 NWC was studied during batch fermentation in a lactose-based complex medium. Growth and lactic acid production were modelled using a simple logistic equation while substrate consumption was found to be a function growth and lactic acid production rate. The optimal pH for growth and lactic acid production was between 6.0 and 6.5. Bacteriocin production showed primary metabolite kinetics. pH had a dramatic effect on the production of the bacteriocin, lactococcin 140. A maximum activity of 15.4 × 10 AU (arbitrary units) 1 was obtained after 7 h at pH 5.5. Maximum bacteriocin activity was achieved before the end of growth and was followed by a decrease in activity, which was due to adsorption to the cells of the producing organism, possibly followed by degradation by specific proteases. Both bacteriocin production and degradation rates were higher at pH 5.0 and 5.5, resulting in sharper activity peaks than at pH 6.0 or 6.5. On the basis of the experimental results a qualitative model for bacteriocin production is proposed. [ABSTRACT FROM AUTHOR]

The influence of pH on growth, and lactic acid and bacteriocin production by Lactococcus lactis subsp. lactis 140 NWC was studied during batch fermentation in a lactose-based complex medium. Growth and lactic acid production were modelled using a simple logistic equation while substrate consumption was found to be a function growth and lactic acid production rate. The optimal pH for growth and lactic acid production was between 6.0 and 6.5. Bacteriocin production showed primary metabolite kinetics. pH had a dramatic effect on the production of the bacteriocin, lactococcin 140. A maximum activity of 15.4 × 10 AU (arbitrary units) 1 was obtained after 7 h at pH 5.5. Maximum bacteriocin activity was achieved before the end of growth and was followed by a decrease in activity, which was due to adsorption to the cells of the producing organism, possibly followed by degradation by specific proteases. Both bacteriocin production and degradation rates were higher at pH 5.0 and 5.5, resulting in sharper activity peaks than at pH 6.0 or 6.5. On the basis of the experimental results a qualitative model for bacteriocin production is proposed. [ABSTRACT FROM AUTHOR]

Fumaric acid production by Rhizopus arrhizus from potato flour was studied at different initial substrate concentrations (S), C/N ratios and fermentation times ( t f) in a composite design experiment. By using response surface methodology and canonical analysis, the experimental values of fumaric acid and mycelial biomass yields and productivity were fitted to the only statistically significant factors with mean percentage errors of 11, 26 and 13%, respectively. Owing to the limited statistical significance of the C/N ratio, it was possible to determine the values of S (25-50 g/l of glucose equivalent) and t f(44-100 h) associated with fumaric acid yields ranging from 60 to 75% and productivities varying from 6 to 8.4 g/l per day. Since such results were in quite good agreement with previous experiments carried out on other starchy materials, the above operating conditions might be used to minimize fumaric acid production costs as a function of the feed-stock used. [ABSTRACT FROM AUTHOR]

The kinetics of growth and alginate production from glucose in a nitrogen and phosphate-rich medium by Azotobacter vinelandii DSM576 were studied in a laboratory fermenter at pH 7 and 35°C. Batch fermentations were carried out both without control of dissolved oxygen concentration (DO) and at 1, 2, 5 and 10% DO. Although growth was faster at higher DO, maximum biomass concentration was lower. No alginate was produced at 10% DO. Alginate production was faster at 5 and 2% DO but higher alginate concentrations and yields were obtained without DO control. Alginate production was growth-associated at 5% DO, but significant amounts of alginate were produced after growth had stopped at lower DO values. In fermentations without DO control the molecular weight of the polymer reached a maximum (11-17.6 × 10[SUP4]) when specific growth rate was between 0.02 and 0.04 h[SUP-1] and residual concentration of ammoniacal nitrogen was between 0.01 and 0.02 g L[SUP-1] and then sharply decreased. [ABSTRACT FROM AUTHOR]

Production of the bacteriocin enterocin 1146 (E1146) by Enterococcus faecium DPC1146 was studied in batch and continuous fermentation. Growth was strongly inhibited by lactic acid. In batch fermentations maximum E1146 activity (2.8 MBU L[SUP-1]) was obtained in 9 h with 20 g L[SUP-1] glucose. Increase in initial glucose concentration did not lead to a proportional increase in E1146 activity. A simple linear model was found to be adequate to explain the relationship between specific bacteriocin production rate and specific growth rate in batch fermentations with initial glucose concentration higher than 20 g L[SUP-1]. Maximum bacteriocin activity (2.9-3.2 MBU L[SUP-1]) was obtained in continuous fermentations at dilution rates between 0.12 and 0.17 h[SUP-1] and specific bacteriocin production rate increased linearly with dilution rate. [ABSTRACT FROM AUTHOR]

The prevalence of primary headache (PH) in a multiple sclerosis (MS) sample vs. control healthy subjects was investigated at a neurological clinic in 2004-2005: 122 of 238 (51%) MS patients and 57 of 238 (23%) controls proved to be affected by headache. The groups did not differ for the rates of PH types. Headache types of MS patients were comparable to those of PH patients that were observed at the same institute in a case-control comparison. First symptoms of headache preceded those of MS in two thirds of cases. Headache features did not significantly change after MS onset. Comorbidity of MS and PH could be explained by some common clinical and biological traits. [ABSTRACT FROM AUTHOR]