bluuebunny/crossref_metadata_2025 huggingface dataset:
High viral frequency in children with gastroesophageal reflux‐related chronic respiratory disorders
Authors: Calabrese Fiorella , Rizzo Stefania , Giacometti Cinzia , Panizzolo Cristina , Turato Graziella , Snijders Deborah , Lunardi Francesca , Vadori Marta , Valente Marialuisa , Saetta Marina , Barbato Angelo
Published: May 2008

Introduction

In the pediatric population chronic respiratory disorders (CRDs) include many pathological entities in which gastroesophageal reflux (GER) may play a role in the induction or persistence of clinical symptoms. It is not well established whether infective agents may be present in lung aspiration. The aim of the work was to investigate whether different infective agents could be found in children with GER‐related CRDs.

Materials and Methods

Extensive microbiological investigations including culture for bacterial agents, serology, direct fluorescent antigen and polymerase chain reaction analyses for different respiratory viruses were performed in 32 children (18 males, 14 females, mean age 5.0 ± 2.4 years). Fifteen children out of 32 considered as “aspirators” (lipid‐laden macrophage index—LLMI—≥86 and pathological pH‐assay) were compared to 17 “non‐aspirators” (LLMI < 86 and normal pH‐assay).

Results

Aspirators were older (6.0 ± 1.9 vs. 4.2 ± 2.5 years, P = 0.006) and less frequently atopic (13% vs. 59%, P = 0.01) than non‐aspirators. A high frequency of viral infections (20/32, 62.5%) was found, with frequent occurrence of multiple infections (10/20, 50%). Aspirators showed more frequent viral infections than non‐aspirators (87% vs. 41%, P = 0.01). Rhinovirus and respiratory syncytial virus were the principal detected viruses in the aspirator group.

Conclusions

Viral infections could play a key role in the pathogenesis of GER‐related CRDs. Pediatr Pulmonol. 2008; 43:690–696. © 2008 Wiley‐Liss, Inc.
Fibrin glue closure of persistent bronchopleural fistula following pneumonectomy for post‐tuberculosis bronchiectasis
Authors: Goussard P. , Gie R.P. , Kling S. , Kritzinger F.E. , van Wyk J. , Janson J. , Andronikou S.
Published: May 2008

We report a case of a persistent bronchopleural fistula following a pneumonectomy for post‐tuberculosis bronchiectasis. The patient had two unsuccessful surgical attempts at closing of the fistula. Further surgical attempts were technically were not possible. Bronchoscopic closure was achieved by injecting human fibrin glue into the fistula via a catheter. Closure of the broncho‐pleural fistula was confirmed by repeated ventilation scan over a period of 2 months. Endoscopic closure of small bronchopleural fistulae is an attractive option in children with significant underlying lung disease. Pediatr Pulmonol. 2008; 43:721–725. © 2008 Wiley‐Liss, Inc.
Reliability and validity of videotaped functional performance tests in ACL‐injured subjects
Authors: von Porat Anette , Holmström Eva , Roos Ewa
Published: May 2008

Background and Purpose. In clinical practice, visual observation is often used to determine functional impairment and to evaluate treatment following a knee injury. The aim of this study was to evaluate the reliability and validity of observational assessments of knee movement pattern quality during five functional tests in subjects with an anterior cruciate ligament (ACL) injury. Method. Twelve ACL‐injured men, mean age 40 years, were video filmed before and after 12 weeks of knee‐specific training when performing five different functional tests: walking, knee bending, step activity, crossover hop on one leg and one‐leg hop. The videos were observed by four physiotherapists, and the knee movement pattern quality, a feature of the loading strategy of the lower extremity, was scored on an 11‐point rating scale. To assess the criterion validity, the observational rating was correlated with the maximum knee flexion angle in landing during the crossover hop determined by a three‐dimensional motion analysis system (VICON). Results. Inter‐observer agreement between the four physiotherapists was moderate to good, ICC1,2 0.57–0.76 for the four test situations. Fair to good correlations were obtained between the observers' assessment and knee flexion angle, r = 0.37–0.61. The crossover hop test or one‐leg hop test was ranked as the most useful test in 172 of 192 occasions (90%) when assessing knee function. Conclusion. The moderate to good inter‐observer reliability and the moderate criterion validity found indicate that the knee movement pattern quality in ACL‐injured subjects can be determined by visual observation of more demanding functional tests such as crossover hop on one leg and one‐leg hop for distance. Copyright © 2008 John Wiley & Sons, Ltd.
Novel small molecule inhibitors for prostate‐specific antigen
Authors: Koistinen Hannu , Wohlfahrt Gerd , Mattsson Johanna M. , Wu Ping , Lahdenperä Juhani , Stenman Ulf‐Håkan
Published: May 2008

Background

Prostate‐specific antigen (PSA or KLK3) has been shown to inhibit angiogenesis, but it might also have tumor promoting activities. Thus, it may be possible to modulate prostate cancer growth by stimulating or inhibiting the activity of PSA. To this end we have previously identified peptides that stimulate the activity of PSA. As peptides have several limitations as drug molecules, we screened a chemical library to find drug‐like compounds that could be used to modulate the function(s) of PSA.

Methods

Almost 50,000 compounds were analyzed for their ability to modulate PSA activity towards a fluorescent PSA‐substrate. The ability of the most active compounds to affect the anti‐angiogenic activity of PSA was analyzed by human umbilical vein endothelial cell (HUVEC) tube formation assay.

Results

In the initial screening we identified two compounds that inhibited PSA activity. Based on these, similar compounds were selected and tested for activity to define structure–activity relationships. Several compounds with micromolar IC50‐values were found, but they were not entirely specific towards PSA, e.g., they inhibited chymotrypsin, which has similar substrate specificity as PSA. However, it was possibly to improve the selectivity of the compounds towards PSA by small structural changes. These compounds inhibited the anti‐angiogenic activity of PSA in the HUVEC model, proving that the proteolytic activity of PSA is essential for inhibition of angiogenesis.

Conclusions

We found several PSA inhibitors that could be useful tools for studying the role of PSA in cancer models and in normal physiology as showed in angiogenesis model. Prostate 68: 1143–1151, 2008. © 2008 Wiley‐Liss, Inc.
Detailed analysis of histopathological parameters in radical prostatectomy specimens and PCA3 urine test results
Authors: van Gils Martijn P.M.Q. , Hessels Daphne , Hulsbergen‐van de Kaa Christina A. , Witjes J. Alfred , Jansen Cornelius F.J. , Mulders Peter F.A. , Rittenhouse Harry G. , Schalken Jack A.
Published: May 2008

Background

Due to the drawbacks of serum prostate‐specific antigen, there is an ongoing search for new diagnostic and prognostic prostate cancer (PCa) markers. PCA3 has proven to be of value in the diagnosis of PCa. However, so far few attempts have been made to investigate the prognostic value of PCA3. Our objective was to further investigate the prognostic value of PCA3.

Methods

In this study we correlated the PCA3 score in urinary sediments after digital rectal examination in 62 men with the classical prognostic parameters assessed in radical prostatectomy specimens (i.e. Gleason score, pathological tumor stage and total tumor volume) and moreover, with the expression of three immunohistochemical markers for PCa biological aggressiveness (i.e. E‐cadherin, alpha‐catenin and EZH2). The results from this study serve as a reflection on and a valuable adjunct to recently published results.

Results

We did not find a significant correlation of the PCA3 score with the classical prognostic parameters assessed in radical prostatectomy specimens or the expression of the immunohistochemical markers for PCa biological aggressiveness. However, we did observe a trend for a higher PCA3 score in significant PCa versus insignificant PCa, aberrant E‐cadherin staining versus normal E‐cadherin staining and increased EZH2 staining versus normal EZH2 staining.

Conclusions

In this study we could not prove the prognostic value of PCA3. Further research with large numbers of men and adequate follow‐up is needed to provide a definitive answer to the question if PCA3 is not only a diagnostic but also a prognostic PCa marker. Prostate 68: 1215–1222, 2008. © 2008 Wiley‐Liss, Inc.
Prostatic inflammation and obstructive voiding in the adult noble rat: Impact of the testosterone to estradiol ratio in serum
Authors: Bernoulli Jenni , Yatkin Emrah , Konkol Yvonne , Talvitie Eva‐Maria , Santti Risto , Streng Tomi
Published: May 2008

BACKGROUND

The age‐related decline of the testosterone to estradiol (T‐to‐E2) ratio in serum is associated with the increased prevalence of prostatic inflammation and lower urinary tract symptoms suggesting obstructive voiding. The impact of the T‐to‐E2 ratio on the development and reversal of non‐bacterial prostatic inflammation and obstructive voiding was tested in adult Noble rats.

METHODS

Adult male Noble rats (n = 16) were treated with estradiol (83 µg/day) and two different doses (280 and 830 µg/day) of testosterone to cause hypoandrogenic and hyperandrogenic states with elevated estrogen. After the 13‐week hormonal treatment, urodynamical measurements and electrical activity recording of the rhabdosphincter muscle were performed under anesthesia. Testosterone, estradiol, and prolactin concentrations in serum were measured and inflammatory changes in the dorsolateral prostate were classified and counted.

RESULTS

Histopathological and urodynamical analyses indicated that the hypoandrogenic animals with a decreased T‐to‐E2 ratio (10 versus > 300 in control) developed prostatic inflammation and non‐obstructive voiding. The hyperandrogenic state with decreased T‐to‐E2 ratio of 50 decreased the aggressiveness of the inflammation and the number of inflamed acini in the prostate and caused urethral obstruction associated with rhabdosphincter dysfunction.

CONCLUSIONS

Different responses of the prostatic inflammation and voiding function to the change in T‐to‐E2 ratio imply that non‐bacterial prostatic inflammation is not a sufficient condition for the development of obstructive voiding. The present study finds no support for the idea that age‐ and/or obesity‐related hypoandrogenic state with a decreased ratio of T‐to‐E2 would cause urethral obstruction. Prostate 68:1296–1306, 2008. © 2008 Wiley‐Liss, Inc.
Rate of biotic colonization following flow restoration below a diversion dam in the Bridge River, British Columbia
Authors: Decker A. Scott , Bradford Michael J. , Higgins Paul S.
Published: May 2008

In August 2000, a continuous flow release was initiated below a diversion dam in the Bridge River, British Columbia, to rewater 4 km of stream bed that had been without flow for 37 years. Within a month after the start of flows, periphyton and invertebrate populations were present in the previously dry reach. Juvenile salmonids were common downstream of the rewetted reach, but only a few moved upstream to the new habitats after flow restoration. However, adult salmon quickly colonized the rewetted area and spawned 1–8 months after the onset of flow. Age‐0 salmonid abundance was high 1 year later and appeared to be largely due to successful spawning in the new reach rather than the upstream migration of juveniles. We conclude that the full colonization of the new reach will take more than a year as a consequence of the migratory patterns of the salmonids species in the river, and that monitoring programs for habitat restoration should be cognizant of the lags in the response of target populations because of their life histories. Copyright © 2008 John Wiley & Sons, Ltd.
Positional identity and science teacher professional development
Authors: Moore Felicia M.
Published: May 2008

The aim of this study was to understand the positional identity of three African American secondary science teachers. Positional identity was operationally defined in terms of race, ethnicity, economic status, gender, religion, and age. Positional identity was posited to inform why diverse teachers with differing knowledge and experiences in science exist. An analysis of the findings suggested that the teachers' positional identity was defined beyond race, ethnicity and gender. Although the three science teachers came from very similar social backgrounds and were members of the same racial/ethnic group (African American), their positionality manifested itself in different ways: meanings of their life experiences; orientations to professional development; and future career goals in science education. Thus they possessed multiple positional identities that intersected in various ways which resulted in them having different perceptions of the world and subjectivities as science teachers. Implications included addressing positional identity and the creation of professional development models that are framed around incorporating teacher identity in addition to furthering teachers' personal and professional advancement within science education. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 684–710, 2008
FDG‐PET findings in patients with galactosaemia
Authors: Dubroff J. G. , Ficicioglu C. , Segal S. , Wintering N. A. , Alavi A. , Newberg A. B.
Published: May 2008

Despite treatment with a galactose‐restricted diet, many galactosaemia patients develop lifelong cognitive impairment, speech abnormalities and a gamut of neurological problems including cognitive impairment and tremors. No study has explored changes in cerebral glucose metabolism in patients with galactosaemia. Five patients with galactosaemia had ages ranging from 20 to 40 years (mean age 28 years) and eight similarly aged controls received brain [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) scans. PET scans were analysed using a previously validated template methodology of regions of interest (ROIs). Count ratios for each anatomical ROI were compared between the galactosaemic patients and the healthy controls. Statistical parametric mapping (SPM) software was also used to further analyse the data. ROI analysis showed that galactosaemic patients had significant bilateral decreases in cerebral glucose metabolism in the superior temporal gyrus, medial occipital lobe, parietal lobe, cerebellum, calcarine cortex, superior frontal cortex, and superior parietal cortex when compared with controls. Significant increases were seen in the cingulate gyrus and temporal poles, bilaterally. SPM analysis revealed foci of decreased glucose metabolism in the caudate, cerebellum, precentral gyrus and cerebellar tonsils of galactosaemic patients. SPM also showed increased glucose metabolism in the subcallosal gyrus and claustrum. The results show significant abnormalities in cerebral function in patients with galactosaemia, particularly with widespread decreases in cortical metabolism. These abnormalities appear to be in brain regions that may be associated with the neuropsychological deficits in these patients. PET brain scans may be of value in galactosaemia patients to evaluate for dysfunction.
Congenital disorder of glycosylation type Ix: Review of clinical spectrum and diagnostic steps
Authors: Morava É. , Wosik H. , Kárteszi J. , Guillard M. , Adamowicz M. , Sykut‐Cegielska J. , Hadzsiev K. , Wevers R. A. , Lefeber D. J.
Published: May 2008

Congenital disorder of glycosylation type I (CDG I) represent a rapidly growing group of inherited multisystem disorders with 13 genetically established subtypes (CDG Ia to CDG Im), and a high number of biochemically unresolved cases (CDG Ix). Further diagnostic effort and prognosis counselling are very challenging in these children. In the current study, we reviewed the clinical records of 10 CDG Ix patients and compared the data with 13 CDG Ix patients published in the literature in search for specific symptoms to create clinical subgroups. The most frequent findings were rather nonspecific, including developmental delay and axial hypotonia. Several features were found that are uncommon in CDG syndrome, such as elevated creatine kinase or arthrogryposis. Distinct ophthalmological abnormalities were observed including optic nerve atrophy, cataract and glaucoma. Two subgroups could be established: one with a pure neurological presentation and the other with a neurological‐multivisceral form. The first group had a significantly better prognosis. The unique presentation of microcephaly, seizures, ascites, hepatomegaly, nephrotic syndrome and severe developmental delay was observed in one child diagnosed with CDG Ik. Establishing clinical subgroups and increasing the number of patients within the subgroups may lead the way towards the genetic defect in children with a so far unsolved type of the congenital disorders of glycosylation. Raising awareness for less common, non‐CDG specific clinical features such as congenital joint contractures, movement disorders or ophthalmological anomalies will encourage clinicians to think of CDG in its more unusual presentation. Clinical grouping also helps to determine the prognosis and provide better counselling for the families.
Plant diversity patterns and their relationships with soil and climatic factors along an altitudinal gradient in the middle Tianshan Mountain area, Xinjiang, China
Authors: Sang Weiguo
Published: May 2008

Patterns of plant diversity along the altitudinal gradient of Tianshan in central Xinjiang, China were examined. Plant and environment characteristics were surveyed from higher, south of Bogeda peak, to lower, north of Guerbantonggute desert. There were a total of 341 vascular plant, 295 herbage, 41 shrub, and seven tree species in the sampled plots. The plant richness of vegetation types generally showed a unimodal pattern along altitude, with a bimodal change of plant species number at 100‐m intervals of altitudinal samples. The two belts of higher plant richness were in transient areas between vegetation types, the first in areas from dry grass to forest, and the second from forest to sub‐alpine grass and bush. The beta diversity varied with altitudinal changes, with herbaceous species accounting for most species, and thus had similar species turnover patterns to total species. Matching the change of richness of plant species to environmental factors along altitude and correlating these by redundancy analysis revealed that the environmental factors controlling species richness and its pattern were the combined effects of temperature, precipitation, soil water, and nutrition. Water was more important at low altitude, and temperature at high altitude, and soil chemical and physical characters at middle altitudes. This study provides insights into plant diversity conservation of Bogeda Natural Reserve Areas in Tianshan Mountain.
Using an iliotibial tract for patellar dislocation in children
Authors: Hung Nguyen Ngoc
Published: May 2008

Objective

To evaluate the clinical and functional results of surgical treatment of patellar dislocation in children.

Material and methods

A prospective study was undertaken from January 1995 to December 2004. Patients who suffered from patellar dislocation after receiving intramuscular antibiotic injections to quadriceps were recruited. A complete history of each patient was recorded, and both a clinical and a roentgenographic examination were performed preoperatively. Patellar dislocation was classified according to Bensahel's criteria. The iliotibial tract and lateral retinacula was released to restore the tension of the medial retinaculum. Quadricepsplasty was used in all patients for full flexion of knee.

Results

There were nine males and 65 females in this study. All 74 patients (76 knees) developed dislocation of the patella after repeated intramuscular injections of antibiotic(s) into the quadriceps muscle. Fifty-six knees (73.7%) were type 1, and 20 knees (26.3%) were type 2 (Bensahel's classification). In all, we attained excellent results in 56 knees (73.7%), good results in 17 knees (22.4%), and fair results in three knees (3.9%). There have been no poor results or recurrences so far.

Conclusion

Use of the iliotibial tract, adequate lateral retinacular release, restoration of the tension of the medial retinaculum and associated quadricepsplasty achieved a high success rate. The technique is simple, safe and effective in skeletally immature children.
Evaluation of the ipsilateral knee more than 40 years after successful closed reduction of DDH
Authors: Peterlein Christian-Dominik , Schofer Markus , Tibesku Carsten O. , Weinstein Stuart L. , Fuchs-Winkelmann Susanne
Published: May 2008

Aim of the study

We asked whether the ipsilateral knee of patients treated by closed reduction for developmental hip dislocation (DDH) is affected by osteoarthritis (OA) more than 40 years later.

Materials and methods

In total, 61 patients (71 hips) with the diagnosis of DDH were included in the study. The average age at the time of closed reduction was 17.9 months. The follow-up after closed reduction averaged 44.4 years. We determined the following parameters on radiographs, taken in the standing position: minimal joint space width in the medial and lateral compartments of the knee, minimal joint space width of the hip joint, radiological signs of osteoarthritis of the knee and the hip joints (Kellgren and Lawrence), knee alignment, acetabular roof obliquity (AC angle), depth of the acetabulum (ACM angle) and center–edge angle (CE angle) according to Wiberg. All radiographs were measured twice manually with ruler and goniometer by two independent investigators. Interobserver and intraobserver reliability (test–retest) was calculated for all parameters.

Results

We observed that patients with bilateral DDH had significantly more joint space narrowing in the medial compartment of the knee joints than those with unilateral DDH. The length of follow-up correlated with radiological signs of OA in the hip, but not in the knee.

Conclusion

We found a significant difference in medial compartment joint space narrowing between patients with unilateral DDH and those with bilateral DDH. The Kellgren–Lawrence classification, however, showed no significant differences between uni- and bilateral DDH. The knee alignment was always at the threshold of physiological values.
Co‐regulation of constitutive nitric oxide synthases and NADPH oxidase by the small GTPase Rac
Authors: Selvakumar Balakrishnan , Hess Douglas T. , Goldschmidt-Clermont Pascal J. , Stamler Jonathan S.
Published: May 2008

Nitric oxide (NO), generated by NO synthases (NOSs), has multifarious roles in signal transduction. Reactive oxygen species (ROS), generated by ubiquitous NADPH oxidases (NOXs), also participate in cellular signaling. However, the coordination of signals conveyed by NO and ROS is poorly understood. We show that the small GTPase Rac, a component of some NOXs, also interacts with and regulates the constitutively‐expressed NOSs. Cellular NO and production increase or decrease together following activation or inhibition of Rac, and Rac inhibition reveals transduction mechanisms that depend upon NO (vasodilation), ROS (actin polymerization) or both (cytoskeletal organization). Thus, signaling by NO and ROS may be coordinated through a common control element.
UCA1, a non‐protein‐coding RNA up‐regulated in bladder carcinoma and embryo, influencing cell growth and promoting invasion
Authors: Wang Fan , Li Xu , Xie XiaoJuan , Zhao Le , Chen Wei
Published: May 2008

A non‐protein‐coding RNA,UCA1, has been cloned from human bladder TCC cell line BLZ‐211 by using 5′ and 3′ RACE. TheUCA1full‐length cDNA was 1442 bp. RT‐PCR analysis indicated thatUCA1is an embryonic development and bladder cancer‐associated RNA. The proliferative, migrative, invasive, and drug resistance behaviors of human bladder TCC cell line BLS‐211 were enhanced by exogenousUCA1expression in vitro. Several potential target genes ofUCA1were identified through microarray analysis. Moreover, the expression ofUCA1also increased tumorigenic potential of BLS‐211 cells in nude mice. Results from the present study suggested thatUCA1might play a pivotal role in bladder cancer progression and embryonic development.
Spatial and temporal down‐regulation of transgene expression using the TRSID‐silencer in mice: Application to Prnp
Authors: Gallozzi Micaela , Béringue Vincent , Decaunes Pauline , Le Dur Annick , Le Roux Karine , Tilly Gaëlle , Le Guillou Sandrine , Herzog Laetitia , Peyre Coralie , Ladroue Aline , Chapuis Jérôme , Vilotte Marthe , Passet Bruno , Costa José , Chenais Nathalie , Le Provost Fabienne , Laude Hubert , Vilotte Jean-Luc
Published: May 2008

Spatial and temporal control of ovine prion protein (Prnp) gene expression was achieved in mice using two transgenes: a Prnp minigene with tet‐operator sequences inserted 5′ to exon 1 and a mouse neurofilament genomic clone carrying the chimeric‐repressor TRSID cDNA. In bi‐transgenic mice, ovine PrPC expression could be reversibly controlled in neuronal cells by doxycycline treatment whereas it remains constant in other cell types. Overall, this model opens opportunities to assess the involvement of cell types in prion diseases and PrP physiological function. It demonstrates the potentiality of the TRSID‐silencer to precisely control temporal and spatial gene expression in vivo.
BOUNDEDNESS OF IMPULSIVE FUNCTIONAL DIFFERENTIAL EQUATIONS WITH VARIABLE IMPULSIVE PERTURBATIONS
Authors: Stamova I. M.
Published: May 2008

In the present paper an initial value problem for impulsive functional differential equations with variable impulsive perturbations is considered. By means of piecewise continuous functions coupled with the Razumikhin technique, sufficient conditions for boundedness of solutions of such equations are found.
Peripartal feeding strategy with differentn-6:n-3 ratios in sows: effect on gene expression in backfat white adipose tissue postpartum
Authors: Papadopoulos Georgios A. , Erkens Tim , Maes Dominiek G. D. , Peelman Luc J. , van Kempen Theo A. T. G. , Buyse Johan , Janssens Geert P. J.
Published: May 2008

The aim of this study was to describe the effects of two diets differing inn-6:n-3 ratio and prepartal feeding regime on gene expression of PPARγ1a/1b, PPARγ1c/1d, PPARγ2, PPARγ coactivator 1A (PPARGC1A), GLUT4, TNFα, adiponectin, leptin, leptin receptor (LEPR), fatty acid binding protein 4 (FABP4), lipoprotein lipase (LPL) in sows' white adipose tissue on the first day of lactation. The relationship between mRNA expression of these genes and circulating insulin, leptin and thyroid hormones was also considered. Diets contained a low (supplemented with fish oil; f group) or a high (supplemented with sunflower oil; s group)n-6:n-3 ratio and were provided from 8 (f8, s8) or 3 d (f3, s3) before parturition (onset day 8 or 3). A lown-6:n-3 ratio reduced the 1 d postpartum expression of PPARγ2 and PPARGC1A but only when applied from 3 d before parturition. Circulating leptin was negatively correlated with mRNA expression of adiponectin, LEPR and LPL, whereas thyroxine was positively correlated with levels of PPARGC1A. In conclusion, the effect of dietary treatments, e.g. altering then-6:n-3 ratio, around parturition on the expression of crucial genes in nutrient metabolism can be modulated by the duration of application before parturition.
Effect of undegradable intake protein supplementation on urea kinetics and microbial use of recycled urea in steers consuming low-quality forage
Authors: Wickersham Tryon A. , Titgemeyer Evan C. , Cochran Robert C. , Wickersham Erin E.
Published: May 2008

We evaluated the effect of undegradable intake protein (UIP) on urea kinetics and microbial incorporation of urea-N in ruminally and duodenally fistulated steers (n4; 319 kg) providedad libitumaccess to grass hay in a 4 × 4 Latin square. Casein was continuously infused abomasally in amounts of 0, 62, 124 and 186 mg N/kg body weight per d to simulate provision of UIP. Periods were 13 d long with 7 d for adaptation and 6 d for collection. Jugular infusion of [15N15N]urea followed by determination of urinary enrichment of [15N15N]urea and [14N15N]urea was used to measure urea kinetics. Forage and N intake increased (quadratic,P < 0·02) with increasing UIP. Urea synthesis was 27·1, 49·9, 82·2 and 85·8 g urea-N/d for 0, 62, 124 and 186 diets, respectively (linear,P < 0·01). The proportion of urea synthesis that entered the gastrointestinal tract was 0·96 for steers receiving no UIP and decreased linearly (P = 0·05) to a low of 0·89 for steers receiving 186. The amount of urea entering the gastrointestinal tract was least for 0 (26·3) and increased (linear,P < 0·01) to 48·7, 77·2 and 76·6 g urea-N/d for 62, 124 and 186 diets, respectively. Microbial incorporation of recycled urea-N increased quadratically (P = 0·04) from 13·9 for 0 to 47·7 g N/d for 124. The proportion of microbial N derived from recycled urea increased (quadratic,P = 0·05) from 0·31 to 0·58 between 0 and 124 and dropped to 0·44 for 186 mg N/kg body weight per d. UIP increased intake of hay and provided a N source for ruminal microbes via urea recycling.
The SPICE carbon isotope excursion in Siberia: a combined study of the upper Middle Cambrian–lowermost Ordovician Kulyumbe River section, northwestern Siberian Platform
Authors: KOUCHINSKY ARTEM , BENGTSON STEFAN , GALLET YVES , KOROVNIKOV IGOR , PAVLOV VLADIMIR , RUNNEGAR BRUCE , SHIELDS GRAHAM , VEIZER JAN , YOUNG EDWARD , ZIEGLER KAREN
Published: May 2008

An integrated, high-resolution chemostratigraphic (C, O and Sr isotopes) and magnetostratigraphic study through the upper Middle Cambrian–lowermost Ordovician shallow-marine carbonates of the northwestern margin of the Siberian Platform is reported. The interval was analysed at the Kulyumbe section, which is exposed along the Kulyumbe River, an eastern tributary of the Enisej River. It comprises the upper Ust'-Brus, Labaz, Orakta, Kulyumbe, Ujgur and lower Iltyk formations and includes the Steptoean positive carbon isotopic excursion (SPICE) studied here in detail from upper Cambrian carbonates of the Siberian Platform for the first time. The peak of the excursion, showing δ13C positive values as high as +4.6‰ and least-altered87Sr/86Sr ratios of 0.70909, is reported herein from the Yurakhian Horizon of the Kulyumbe Formation. The stratigraphic position of the SPICE excursion does not support traditional correlation of the boundary between the Orakta and Labaz formations at the Kulyumbe River with its supposedly equivalent level in Australia, Laurentia, South China and Kazakhstan, where theGlyptagnostus stolidotusandG. reticulatusbiozones are known to immediately precede the SPICE excursion and span the Middle–Upper Cambrian boundary. The Cambrian–Ordovician boundary is probably situated in the middle Nyajan Horizon of the Iltyk Formation, in which carbon isotope values show a local maximum below a decrease in the upper part of the Nyajan Horizon, attributed herein to the Tremadocian Stage. A refined magnetic polarity sequence confirms that the geomagnetic reversal frequency was very high during Middle Cambrian times at 7–10 reversals per Ma, assuming a total duration of about 10 Ma and up to 100 magnetic intervals in the Middle Cambrian. By contrast, the sequence attributed herein to the Upper Cambrian on chemostratigraphic grounds contains only 10–11 magnetic intervals.
Amplifier and resonator dynamics of a low-Reynolds-number recirculation bubble in a global framework
Authors: MARQUET OLIVIER , SIPP DENIS , CHOMAZ JEAN-MARC , JACQUIN LAURENT
Published: May 2008

The stability behaviour of a low-Reynolds-number recirculation flow developing in a curved channel is investigated using a global formulation of hydrodynamic stability theory. Both the resonator and amplifier dynamics are investigated. The resonator dynamics, which results from the ability of the flow to self-sustain perturbations, is studied through a modal stability analysis. In agreement with the literature, the flow becomes globally unstable via a three-dimensional stationary mode. The amplifier dynamics, which is characterized by the ability of the flow to exhibit large transient amplifications of initial perturbations, is studied by looking for the two- and three-dimensional initial perturbations that maximize the energy gain over a given time horizon. The optimal initial two-dimensional perturbations have the form of wave packets localized in the upstream part of the recirculation bubble. It is shown that they are first amplified while travelling downstream along the shear layer of the recirculation bubble and then decay when leaving the recirculation bubble. Maximal energy gain is thus achieved for a time horizon approximately corresponding to the propagation of the wave packet along the whole recirculation bubble. The resonator and amplifier dynamics are associated with different types of structures in the flow: three-dimensional steady structures for the resonator dynamics and nearly two-dimensional unsteady structures for the amplifier dynamics. A comparison of the strength of the two dynamics is proposed. The transient energetic growth of the two-dimensional unsteady perturbations is large at moderate time, compared to the very weak exponential growth of the three-dimensional stationary mode. This suggests that, as soon as there is noise in the system, the amplifier dynamics dominates the resonator dynamics, thus explaining the appearance of unsteadiness rather than the emergence of stationary structures in similar experimental flows.
Two-dimensional and axisymmetric viscous flow in apertures
Authors: DABIRI SADEGH , SIRIGNANO WILLIAM A. , JOSEPH DANIEL D.
Published: May 2008

The flow in a plane liquid jet from an aperture is obtained by direct simulation of the Navier–Stokes equations. The gas–liquid interface is tracked using the level set method. Flows are calculated for different Reynolds and Weber numbers. When We = ∞, the maximum value of the discharge coefficient appears around Re = O(100). The regions that are vulnerable to cavitation owing to the total stress are identified from calculations based on Navier–Stokes equations and viscous potential flow; the two calculations yield similar results for high Reynolds numbers. We prove that the classical potential flow solution does not give rise to a normal component of the rate of strain at the free streamline. Therefore, the normal component of the irrotational viscous stresses also vanishes and cannot change the shape of the free surface. The results of calculations of flows governed by the Navier–Stokes equations are close to those for viscous potential flow outside the vorticity layers at solid boundaries. The Navier–Stokes solutions for the axisymmetric aperture are also given for two values of Reynolds numbers. The results for axisymmetric and planar apertures are qualitatively similar, but the axisymmetric apertures have a lower discharge coefficient and less contraction.
The limiting form of inertial instability in geophysical flows
Authors: GRIFFITHS STEPHEN D.
Published: May 2008

The instability of a rotating, stratified flow with arbitrary horizontal cross-stream shear is studied, in the context of linear normal modes with along-stream wavenumberkand vertical wavenumberm. A class of solutions are developed which are highly localized in the horizontal cross-stream direction around a particular streamline. A Rayleigh–Schrödinger perturbation analysis is performed, yielding asymptotic series for the frequency and structure of these solutions in terms ofkandm. The accuracy of the approximation improves as the vertical wavenumber increases, and typically also as the along-stream wavenumber decreases. This is shown to correspond to a near-inertial limit, in which the solutions are localized around the global minimum offQ, wherefis the Coriolis parameter andQis the vertical component of the absolute vorticity. The limiting solutions are near-inertial waves or inertial instabilities, according to whether the minimum value offQis positive or negative.

We focus on the latter case, and investigate how the growth rate and structure of the solutions changes withmandk. Moving away from the inertial limit, we show that the growth rate always decreases, as the inertial balance is broken by a stabilizing cross-stream pressure gradient. We argue that these solutions should be described as non-symmetric inertial instabilities, even though their spatial structure is quite different to that of the symmetric inertial instabilities obtained whenkis equal to zero.

We use the analytical results to predict the growth rates and phase speeds for the inertial instability of some simple shear flows. By comparing with results obtained numerically, it is shown that accurate predictions are obtained by using the first two or three terms of the perturbation expansion, even for relatively small values of the vertical wavenumber. Limiting expressions for the growth rate and phase speed are given explicitly for non-zerok, for both a hyperbolic-tangent velocity profile on anf-plane, and a uniform shear flow on an equatorial β-plane.
Moving contact line on chemically patterned surfaces
Authors: WANG XIAO-PING , QIAN TIEZHENG , SHENG PING
Published: May 2008

We simulate the moving contact line in two-dimensional chemically patterned channels using a diffuse-interface model with the generalized Navier boundary condition. The motion of the fluid–fluid interface in confined immiscible two-phase flows is modulated by the chemical pattern on the top and bottom surfaces, leading to a stick–slip behaviour of the contact line. The extra dissipation induced by this oscillatory contact-line motion is significant and increases rapidly with the wettability contrast of the pattern. A critical value of the wettability contrast is identified above which the effect of diffusion becomes important, leading to the interesting behaviour of fluid–fluid interface breaking, with the transport of the non-wetting fluid being assisted and mediated by rapid diffusion through the wetting fluid. Near the critical value, the time-averaged extra dissipation scales as U, the displacement velocity. By decreasing the period of the pattern, we show the solid surface to be characterized by an effective contact angle whose value depends on the material characteristics and composition of the patterned surfaces.
Critical conditions and composite Froude numbers for layered flow with transverse variations in velocity
Authors: PRATT LARRY J.
Published: May 2008

A condition is derived for the hydraulic criticality of a 2-layer flow with transverse variations in both layer velocities and thicknesses. The condition can be expressed in terms of a generalized composite Froude number. The derivation can be extended in order to obtain a critical condition for an N-layer system. The results apply to inviscid flows subject to the usual hydraulic approximation of gradual variations along the channel and is restricted to flows in which the velocity remains single-signed within any given layer. For an intermediate layer with a partial segment of sluggish flow, the long-wave dynamics of the overlying and underlying layers become decoupled.
Viscoplastic fluid displacements in horizontal narrow eccentric annuli: stratification and travelling wave solutions
Authors: CARRASCO-TEJA M. , FRIGAARD I. A. , SEYMOUR B. R. , STOREY S.
Published: May 2008

We consider laminar displacement flows in narrow eccentric annuli, oriented horizontally, between two fluids of Herschel–Bulkley type, (i.e. including Newtonian, power-law and Bingham models). This situation is modelled via a Hele-Shaw approach. Whereas slumping and stratification would be expected in the absence of any imposed flow rate, for a displacement flow we show that there are often steady-state travelling wave solutions in this displacement. These may exist even at large eccentricities and for large density differences between the fluids. When heavy fluids displace light fluids, annular eccentricity opposes buoyancy and steady states are more prevalent than when light fluids displace heavy fluids. For large ratios of buoyancy forces to viscous forces we derive a lubrication-style displacement model. This simplification allows us to find necessary and sufficient conditions under which a displacement can be steady, which can be expressed conveniently in terms of a consistency ratio. It is interesting that buoyancy does not appear in the critical conditions for a horizontal well. Instead a competition between fluid rheologies and eccentricity is the determining factor. Buoyancy acts only to determine the axial length of the steady-state profile.
Collisions of solid particles with vortex rings in superfluid helium
Authors: KIVOTIDES DEMOSTHENES , WILKIN S. LOUISE
Published: May 2008

We have performed self-consistent computations of the interactions between a superfluid vortex-ring and a solid particle for two different vortex-ring sizes and over a wide range of temperatures. In all cases, the particle and the vortex eventually separate. For temperature T = 0 K, larger rings tend to trap the particle more effectively than smaller rings. Trying to escape the vortex, the particle follows a spiralling trajectory that could be experimentally detected. The dominant dynamical process is the excitation and propagation of Kelvin waves along the vortices. For T > 0 K, particle–vortex collision induces particle vibrations that are normal to the particle's direction of motion and might be experimentally detectable. In contrast to the T = 0 K case, smaller rings induce larger particle oscillation velocities. With increasing temperature, enhanced mutual friction damping of Kelvin waves leads to the damping of both the intensity and frequency of post-collision particle vibrations. Moreover, higher temperatures increase the relative impact of the Stokes drag force on particle motion.
Acoustic resonances and trapped modes in pipes and tunnels
Authors: HEIN STEFAN , KOCH WERNER
Published: May 2008

Acoustic resonances of simple three-dimensional finite-length structures in an infinitely long cylindrical pipe are investigated numerically by solving an eigenvalue problem. To avoid unphysical reflections at the finite grid boundaries placed in the uniform cross-sections of the pipe, perfectly matched layer absorbing boundary conditions are applied in the form of the complex scaling method of atomic and molecular physics. Examples of the structures investigated are sound-hard spheres, cylinders, cavities and closed side branches. Several truly trapped modes with zero radiation loss are identified for frequencies below the first cutoff frequency of the pipe. Such trapped modes can be excited aerodynamically by coherent vortices if the frequency of the shed vortices is close to a resonant frequency. Furthermore, numerical evidence is presented for the existence of isolated embedded trapped modes for annular cavities above the first cutoff frequency and for closed side branches below the first cutoff frequency. As applications of engineering interest, the acoustic resonances are computed for a ball-type valve and around a simple model of a high-speed train in an infinitely long tunnel.
Safety of sublingual grass pollen immunotherapy after anaphylaxis
Authors: Nichani J R , de Carpentier J
Published: May 2008

Aim:

To demonstrate that sublingual immunotherapy is a safe treatment option in patients who have previously suffered anaphylaxis when undergoing subcutaneous grass pollen immunotherapy.

Case report:

We report two patients who developed a systemic anaphylactic reaction following subcutaneous grass pollen immunotherapy, resulting in discontinuation of treatment. Following treatment of the acute anaphylactic episode, both patients were subsequently safely commenced on sublingual grass pollen immunotherapy.

Conclusion:

Injection immunotherapy has a relatively low risk of severe adverse events, although anaphylaxis is a potentially fatal complication and usually results in termination of the immunotherapy programme. Sublingual immunotherapy has a safer side effect profile than subcutaneous immunotherapy, with no reported cases of anaphylaxis.
Formulation of enteral diets for use in jejunal enteral feeding
Authors: Silk D. B. A.
Published: May 2008

Nasogastric enteral feeding is not tolerated in patients with gastric atony and in many critically-ill patients in whom gastric emptying may be delayed and in whom gastro-oesophageal regurgitation may lead to pulmonary aspiration of enteral feed and the development of pneumonia. Initial attempts to overcome these problems led to the development of post pyloric enteral feeding techniques with the infusion port of the tubes positioned in the duodenum. In many centres this technique is still the most practised post-pyloric enteral feeding technique. Nasoduodenal feeding tubes often retroperistalse into the stomach. The technique of choice, therefore, in these difficult patients is to position the infusion port of the feeding tube well distal to the ligament of trietz (post ligament of trietz nasojejunal enteral tube feeding). While nasogastric and nasoduodenal enteral feeding techniques have been shown to elicit a stimulatory exocrine pancreatic response, distal jejunal enteral feeding does not. During this mode of feeding the ileal brake is activated and pancreatic exocrine pancreatic secretion inhibited by the action of the released peptide YY and glucagon-like peptide-1 hormones, in turn the inhibition of pancreatic secretion being the result of inhibition of trypsin secretion. In the light of the findings showing the absence of a stimulatory pancreatic exocrine response to nasojejunal enteral feeding these patients should receive a predigested rather than a polymeric enteral diet.
Non-sibling parasites (Strepsiptera) develop together in the same paper wasp
Authors: VANNINI L. , CARAPELLI A. , FRATI F. , BEANI L.
Published: May 2008

Host discrimination by immature host-seeking endoparasites is a complex and somewhat unexplored topic. In the case of multiple infections, conflicts among conspecifics may occur to monopolize space and resources in the same host. Two or more 1st instar larvae ofXenos vesparum(Strepsiptera, Stylopidae) may enter into aPolistes dominulus(Hymenoptera, Vespidae) larva and develop together until the adult stage of both parasite and host. We carried out a screening of mitochondrial haplotypes inX. vesparumindividuals extracted from superparasitized wasps taken in 5 naturally infected nests from different areas of Tuscany (Italy), to assess whether non-sibling parasites may infect the same colony and host. In total, we obtained 12 different haplotypes out of 122 genotyped individuals of both sexes: 17 of 34 superparasitized wasps hosted parasites that originated from females differing in their haplotypes. To date, this is the first described case of superparasitism with non-sibling host-seeking larvae infecting a single individual hymenopteran host. In addition, at least in heavily infected colonies, there is evidence of a male-biased sex-ratio and synchronous development of the parasites, regardless of their haplotypes. Finally, the distribution of haplotypes per nest is consistent with either phoretic infection or larvipositing on nests by means of superparasitized wasps.