bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Annealing on the Early Hydration of Tricalcium Silicate
Authors: Bazzoni Amélie , Cantoni Marco , Scrivener Karen L.
Published: December 2013

It was recently proposed that the induction period observed during the hydration of tricalcium silicate could be explained by the build‐up of ions in solution. Due to the importance of defects in this mechanism, this work describes the effect of different annealing effects on the defect structure and hydration behavior of C3S. The impact of annealing on the crystal structure was checked by X‐ray diffraction and the defect structure studied by transmission electron microscopy. The hydration kinetics were followed by isothermal calorimetry of pastes. Scanning electron microscopy was used to look at the microstructure formation. It was observed that grinding created a highly deformed layer on the surface of the grains, which disappeared after annealing. The defect structure was closely related to the length of the induction period observed in pastes by calorimetry. There was no observable effect on the morphology of C–S–H during hydration, but the number of calcium hydroxide nuclei was less in pastes from annealed material.
Sapotaceae biogeography supportsNewCaledonia being an oldDarwinian island
Authors: Swenson Ulf , Nylinder Stephan , Munzinger Jérôme
Published: December 2013

Aim

Panbiogeographers suggest that the biome in New Caledonia is of vicariant origin, dating from the Cretaceous – rather than being the result of repeated dispersal sincec. 37 Ma, when the area is postulated to have re‐emerged afterc. 15 million years of submergence. Distributions of the plant family Sapotaceae were used as a model system to test this, and to elucidate the probabilities of ancestral areas, all phrased in six hypotheses.

Location

Australasia and the Pacific.

Methods

We used a recently published dataset with extensive sampling (168 terminals) from the subfamily Chrysophylloideae and three nuclear ribosomalDNAmarkers. Phylogenetic divergence times and ancestral areas were estimated in a Bayesian framework usingbeast, a relaxed clock method, and with fossil calibration points. Area transition probabilities were modelled using a reversible rate matrix, assigning equal prior probability to each transition between two areas.

Results

Our analyses suggest that Sapotaceae arrived and diversified in New Caledonia nine times during the period 4.2–33.1 Ma. All crown‐node radiations occurred in the Miocene or Pliocene, with stem splits reaching back into the Oligocene. Australia and New Guinea are the most likely source areas for Sapotaceae in New Caledonia, but this archipelago has never acted as a stepping stone for Sapotaceae to disperse into the Pacific.

Main conclusions

Repeated dispersal is the only mechanism able to explain the range expansion of Sapotaceae into New Caledonia. The family has successfully colonized the main island nine times since its re‐emergence in the Eocene. We reject the panbiogeographical hypotheses that representatives of Sapotaceae in New Caledonia originated in the Cretaceous, differentiated due to vicariance, and were of Pacific origin. We therefore argue that New Caledonia is an old Darwinian island. The Pacific has been colonized repeatedly and terminal lineages are never older than the islands they inhabit (except for Hawaii). Chrysophylloideae extended across Wallace's Line into Southeast Asia around 20 Ma, when the Australian continent came into juxtaposition with Eurasia.
Long Pacing Pulses Reduce Phrenic Nerve Stimulation in Left Ventricular Pacing
Authors: HJORTSHØJ SØREN , HEATH FINN , HAUGLAND MORTEN , ESCHEN OLE , THØGERSEN ANNA MARGRETHE , RIAHI SAM , TOFT EGON , STRUIJK JOHANNES JAN
Published: December 2013

Long Pulses in LV Pacing

Introduction

Phrenic nerve stimulation is a major obstacle in cardiac resynchronization therapy (CRT). Activation characteristics of the heart and phrenic nerve are different with higher chronaxie for the heart. Therefore, longer pulse durations could be beneficial in preventing phrenic nerve stimulation during CRT due to a decreased threshold for the heart compared with the phrenic nerve.

We investigated if long pulse durations decreased left ventricular (LV) thresholds relatively to phrenic nerve thresholds in humans.

Methods and Results

Eleven patients, with indication for CRT and phrenic nerve stimulation at the intended pacing site, underwent determination of thresholds for the heart and phrenic nerve at different pulse durations (0.3–2.9 milliseconds). The resulting strength duration curves were analyzed by determining chronaxie and rheobase. Comparisons for those parameters were made between the heart and phrenic nerve, and between the models of Weiss and Lapicque as well.

In 9 of 11 cases, the thresholds decreased faster for the LV than for the phrenic nerve with increasing pulse duration. In 3 cases, the thresholds changed from unfavorable for LV stimulation to more than a factor 2 in favor of the LV. The greatest change occurred for pulse durations up to 1.5 milliseconds. The chronaxie of the heart was significantly higher than the chronaxie of the phrenic nerve (0.47 milliseconds vs. 0.22 milliseconds [P = 0.029, Lapicque] and 0.79 milliseconds vs. 0.27 milliseconds [P = 0.033, Weiss]).

Conclusion

Long pulse durations lead to a decreased threshold of the heart relatively to the phrenic nerve and may prevent stimulation of the phrenic nerve in a clinical setting.
Long‐term study of infliximab for psoriasis in daily practice: drug survival depends on combined treatment, obesity and infusion reactions
Authors: Spertino J. , López‐Ferrer A. , Vilarrasa E. , Puig L.
Published: December 2013

Background

Infiximab has been shown to be highly effective in phase III clinical trials, but limited information is available regarding drug survival and maintenance of efficacy beyond 1 year in real‐life clinical setting.

Objectives

To analyse the efficacy and safety of infliximab in a large number of patients with a long follow‐up and to identify clinical factors associated with long‐term drug survival.

Methods

A retrospective review of patients with moderate‐to‐severe psoriasis treated with infliximab from March 2004 to August 2012 at a tertiary dermatology centre was carried out.

Results

In total, 63 treatment courses with infliximab were administered to 56 patients. The mean duration of treatment was 31.6 months. The only significant positive predictor of drug survival was combination treatment [hazard ratio (HR) vs. monotherapy 2.90, 95% confidence interval (CI) 1.42–5.92]. Significant negative predictors of drug survival were obesity (HR 0.40, 95% CI 0.19–0.87) and infusion reactions (HR 0.40, 95% CI 0.19–0.87). Infusion reactions occurred in 13 (23%) of our patients and were a reason for discontinuation of treatment in 5.

Conclusions

This retrospective review of a cohort of patients with moderate‐to‐severe psoriasis treated with infliximab in daily practice shows that the PASI75 response rates at 24 and 52 weeks of treatment are similar to those of the pivotal studies, but 37 courses of treatment (59%) had to be discontinued after a median of 12 months. The major cause for discontinuation was loss of response, in 18 cases. Combination treatment, obesity and infusion reactions were found to be predictors of drug survival.
Uncertainty decomposition and reduction in river flood forecasting: Belgian case study
Authors: Van Steenbergen N. , Willems P.
Published: December 2013

Uncertainty is a key factor to be taken into account in river flood forecasting. Every forecast is subject to several sources of uncertainty. Knowledge on the relative importance of the different sources would be useful to determine the most effective improvement actions to reduce the uncertainty. In this paper, three key uncertainty sources are studied for hydrological flood forecasting in the Belgian case study of the Rivierbeek: model uncertainty, forecasted rainfall uncertainty and uncertainty in the initial conditions. A non‐parametric data‐based approach is used to quantify the total uncertainty in the forecasts. By resimulating in the model historical forecasts with optimal initial conditions and observed rainfall, the uncertainty generated by each of the key sources could be identified. In order to reduce the model uncertainty, which was primarily identified as the most important source of uncertainty, a step‐wise physically based calibration technique was suggested. After recalibration of the model with this technique, a significant reduction of the contribution of the model uncertainty to the total forecast uncertainty could be achieved. Further improvement of the initial conditions, identified as the second most important uncertainty source for short lead times, could be obtained by applying data assimilation. Both uncertainty reduction techniques combined led to a reduction of the total forecast uncertainty with 30% to 40%.
Effects of different head–neck positions on the larynges of ridden horses
Authors: Zebisch A. , May A. , Reese S. , Gehlen H.
Published: December 2013

Hyperflexion, that is the strong deflection of the horse's head, poll and neck, is a prevalent training technique in equitation. Hyperflexion has come under criticism in recent years for being suspected of affecting the horses' well‐being contrary to animal welfare. The goal of the present study is a comparison between the impacts of different poll‐neck positions on findings in the upper respiratory tract of ridden horses. For this purpose, video recordings of the larynges of 14 horses were taken using an overground endoscope. The videos were recorded at rest and during three different riding phases: firstly, in a stretching posture, secondly, in a working position and, thirdly, in hyperflexion. A comparison between the analyses of the working position and hyperflexion phases revealed a significant reduction in the laryngeal opening area (p = 0.001) with a value of 8.2 ± 5.0%. Furthermore, other parameters of the larynx evaluated also showed a significant diminishment. These changes did not correlate with the age of the horses or their level of education, and they were independent of the individual anatomical conditions of the poll‐neck region. In summary, it can be stated that hyperflexion causes a considerable compression of the larynx.
Methylglyoxal resistance in Bacillus subtilis: contributions of bacillithiol‐dependent and independent pathways
Authors: Chandrangsu Pete , Dusi Renata , Hamilton Chris J. , Helmann John D.
Published: December 2013

Methylglyoxal (MG) is a toxic by‐product of glycolysis that damages DNA and proteins ultimately leading to cell death. Protection from MG is often conferred by a glutathione‐dependent glyoxalase pathway. However, glutathione is absent from the low‐GC Gram‐positive Firmicutes, such as Bacillus subtilis. The identification of bacillithiol (BSH) as the major low‐molecular‐weight thiol in the Firmicutes raises the possibility that BSH is involved in MG detoxification. Here, we demonstrate that MG can rapidly and specifically deplete BSH in cells, and we identify both BSH‐dependent and BSH‐independent MG resistance pathways. The BSH‐dependent pathway utilizes glyoxalase I (GlxA, formerly YwbC) and glyoxalase II (GlxB, formerly YurT) to convert MG to d‐lactate. The critical step in this pathway is the activation of the KhtSTU K+ efflux pump by the S‐lactoyl‐BSH intermediate, which leads to cytoplasmic acidification. We show that cytoplasmic acidification is both necessary and sufficient for maximal protection from MG. Two additional MG detoxification pathways operate independent of BSH. The first involves three enzymes (YdeA, YraA and YfkM) which are predicted to be homologues of glyoxalase III that converts MG to d‐lactate, and the second involves YhdN, previously shown to be a broad specificity aldo‐keto reductase that converts MG to acetol.
Search for novel targets of the PII signal transduction protein in Bacteria identifies the BCCP component of acetyl‐CoA carboxylase as a PII binding partner
Authors: Rodrigues Thiago E. , Gerhardt Edileusa C. M. , Oliveira Marco A. , Chubatsu Leda S. , Pedrosa Fabio O. , Souza Emanuel M. , Souza Gustavo A. , Müller‐Santos Marcelo , Huergo Luciano F.
Published: December 2013

The PII family comprises a group of widely distributed signal transduction proteins. The archetypal function of PII is to regulate nitrogen metabolism in bacteria. As PII can sense a range of metabolic signals, it has been suggested that the number of metabolic pathways regulated by PII may be much greater than described in the literature. In order to provide experimental evidence for this hypothesis a PII protein affinity column was used to identify PII targets in Azospirillum brasilense. One of the PII partners identified was the biotin carboxyl carrier protein (BCCP), a component of the acetyl‐CoA carboxylase which catalyses the committed step in fatty acid biosynthesis. As BCCP had been previously identified as a PII target in Arabidopsis thaliana we hypothesized that the PII–BCCP interaction would be conserved throughout Bacteria. In vitro experiments using purified proteins confirmed that the PII–BCCP interaction is conserved in Escherichia coli. The BCCP–PII interaction required MgATP and was dissociated by increasing 2‐oxoglutarate. The interaction was modestly affected by the post‐translational uridylylation status of PII; however, it was completely dependent on the post‐translational biotinylation of BCCP.
Changes in peptidergic neurotransmission during postoperative ileus in rat circular jejunal muscle
Authors: Goetz B. , Benhaqi P. , Glatzle J. , Müller M. H. , Schmitt S. M. , Brändli A. W. , Kreis M. E. , Kasparek M. S.
Published: December 2013

Background

Our aim was to explore unknown changes in neurotransmission with vasoactive intestinal peptide (VIP) and Substance P (Sub P) during postoperative ileus (POI).

Methods

Contractile activity of rat circular jejunal muscle strips was studied in five groups (n = 6/group): Naïve controls, sham controls 12 h and 3 days after laparotomy, and rats 12 h, 3 days after induction of POI. Dose‐responses to VIP (10−10–10−7 M), Sub P (3 × 10−10–3 × 10−7 M), and electrical field stimulation (EFS, to study endogenous release of neurotransmitters) were studied with different antagonists. Intestinal transit, inflammatory cells and immunoreactivity for VIP and Sub P were investigated in the bowel wall and cellular Finkel osteo sarcoma expression was determined in vagal afferent and efferent nuclei of the brainstem.

Key Results

Postoperative ileus characterized by delayed intestinal transit and intramural inflammation was associated with an increased inhibitory effect of VIP on contractile activity. A biphasic impact was observed for Sub P with a decrease in its excitatory potential on contractility at 12 h, followed by a later increase 3 days postoperatively. Inhibitory response to EFS was increased, whereas the excitatory response decreased in ileus animals. VIP expression was increased in all postoperative animals while only animals 3 days after ileus induction showed increased Sub P expression in the myenteric plexus. These changes were associated with an activation of afferent but not efferent vagal nuclei in the brain stem.

Conclusions & Inferences

Specific, time‐dependent changes in peptidergic neurotransmission with VIP and Sub P occur during POI that are associated with vagal afferent activation, but are independent of the activation of efferent vagal pathways.
ThePseudomonas syringaetypeIIIeffectorHopD1 suppresses effector‐triggered immunity, localizes to the endoplasmic reticulum, and targets theArabidopsis transcription factorNTL9
Authors: Block Anna , Toruño Tania Y. , Elowsky Christian G. , Zhang Chi , Steinbrenner Jens , Beynon Jim , Alfano James R.
Published: December 2013

Pseudomonas syringaetypeIIIeffectors are known to suppress plant immunity to promote bacterial virulence. However, the activities and targets of these effectors are not well understood.

We used genetic, molecular, and cell biology methods to characterize the activities, localization, and target of theHopD1 typeIIIeffector inArabidopsis.

HopD1 contributes toP. syringaevirulence inArabidopsis and reduces effector‐triggered immunity (ETI) responses but not pathogen‐associated molecular pattern‐triggered immunity (PTI) responses. Plants expressingHopD1 supported increased growth ofETI‐inducingP. syringaestrains compared with wild‐typeArabidopsis. We show thatHopD1 interacts with the membrane‐tetheredArabidopsis transcription factorNTL9 and demonstrate that this interaction occurs at the endoplasmic reticulum (ER). AP. syringae hopD1mutant andETI‐inducingP. syringaestrains exhibited enhanced growth onArabidopsisntl9mutant plants. Conversely, growth ofP. syringaestrains was reduced in plants expressing a constitutively activeNTL9 derivative, indicating thatNTL9 is a positive regulator of plant immunity. Furthermore,HopD1 inhibited the induction ofNTL9‐regulated genes duringETIbut notPTI.

HopD1 contributes toP. syringaevirulence in part by targetingNTL9, resulting in the suppression ofETIresponses but notPTIresponses and the promotion of plant pathogenicity.
Impact of suspected food allergy on emotional distress and family life of parents prior to allergy diagnosis
Authors: Knibb Rebecca C. , Semper Heather
Published: December 2013

Background

Food allergy is associated with psychological distress in both child and parent. It is unknown whether parental distress is present prior to clinical diagnosis or whether experiences at clinic can reduce any distress present. This study aimed to assess anxiety and depression in parents and the impact of suspected food allergy on the lives of families before and after a visit to an allergy clinic.

Methods

One hundred and twenty‐four parents visiting an allergy clinic for the first time to have their child assessed for food allergy completed a study‐specific questionnaire and the Hospital Anxiety and Depression Scale; 50 parents completed these 4–6 wk later in their own home.

Results

Most parents (86.4%) reported suspected food allergy had an impact on their family life prior to clinic attendance; 76% had made changes to their child's diet. 32.5% of parents had mild‐to‐severe anxiety before their clinic visit; 17.5% had mild‐to‐moderate depression. Post‐clinic, 40% had mild‐to‐severe anxiety; 13.1% had mild‐to‐moderate depression. There were no significant differences in anxiety (p = 0.34) or depression scores (p = 0.09) before and after the clinic visit.

Conclusions

Anxiety and depression is present in a small proportion of parents prior to diagnosis of food allergy in their child and this does not reduce in the short term after the clinic visit. Identification of parents at risk of suffering from distress is needed and ways in which we communicate allergy information before and at clinic should be investigated to see if we can reduce distress.
Field performance of transgenic sugarcane produced using Agrobacterium and biolistics methods
Authors: Joyce Priya , Hermann Scott , O'Connell Anthony , Dinh Quang , Shumbe Leonard , Lakshmanan Prakash
Published: December 2013

Future genetic improvement of sugarcane depends, in part, on the ability to produce high‐yielding transgenic cultivars with improved traits such as herbicide and insect resistance. Here, transgenic sugarcane plants generated by different transformation methods were assessed for field performance over 3 years. Agrobacterium‐mediated (Agro) transgenic events (35) were produced using four different Agrobacterium tumefaciens strains, while biolistic (Biol) transgenic events (48) were produced using either minimal linearized DNA (LDNA) transgene cassettes with 5′, 3′ or blunt ends or whole circular plasmid (PDNA) vectors containing the same transgenes. A combined analysis showed a reduction in growth and cane yield in Biol, Agro as well as untransformed tissue culture (TC) events, compared with the parent clone (PC) Q117 (no transformation or tissue culture) in the plant, first ratoon and second ratoon crops. However, when individual events were analysed separately, yields of some transgenic events from both Agro and Biol were comparable to PC, suggesting that either transformation method can produce commercially suitable clones. Interestingly, a greater percentage of Biol transformants were similar to PC for growth and yield than Agro clones. Crop ratoonability and sugar yield components (Brix%, Pol%, and commercial cane sugar (CCS)) were unaffected by transformation or tissue culture. Transgene expression remained stable over different crop cycles and increased with plant maturity. Transgene copy number did not influence transgene expression, and both transformation methods produced low transgene copy number events. No consistent pattern of genetic changes was detected in the test population using three DNA fingerprinting techniques.
Effects of divergent selection for seed protein content in high‐protein vs. food‐grade populations of early maturity soybean
Authors: Sato Takashi , Van Schoote Melanie , Wagentristl Helmut , Vollmann Johann
Published: December 2013

Due to the growing need for vegetable protein in Central European agriculture, there is interest in producing food‐grade soybeans, which are higher in seed protein and sucrose content and have a larger seed size than conventional soybeans. As protein content of conventional soybean is often below 400 g/kg, either high‐protein or food‐grade donors were crossed with adapted genotypes in order to increase their protein level. After divergent selection for protein content, lines were evaluated for seed quality characters across three environments in Austria. The objectives of this research were to determine the roles of genetic background and the selection for protein content on food‐grade soybean traits. While seed protein content of adapted parents was between 395 and 420 g/kg, its range was from 410 to 490 g/kg for the high‐protein and from 390 to 450 g/kg for the food‐grade lines, respectively. However, food‐grade populations were superior in seed size and sucrose content and revealed different correlation patterns between quality traits as compared to high‐protein populations, which demonstrates their usefulness for developing soybeans with improved quality.
Skin Disorders Associated with Obesity in Children and Adolescents: A Population‐Based Study
Authors: Mirmirani Paradi , Carpenter Diane M.
Published: December 2013

Obesity in children is a major public health concern in the United States. The objectives of the current study were to determine the prevalence of various groups of cutaneous disorders in obese children and adolescents and to compare the use of dermatology services in obese subjects with that those with a normal body mass index (BMI). This was a retrospective, population‐based study at the Kaiser Permanente Northern California Managed Healthcare System. The main outcome measures were the relative risk of cutaneous disorders associated with insulin resistance, androgen excess, bacterial infection, fungal infection, viral infection, inflammation, mechanical changes, and other skin conditions (hidradenitis, hyperhidrosis) in three weight groups (normal, overweight, obese) and the number of dermatology visits. A total of 248,775 subjects were included. Bivariate analyses showed a higher proportion of insulin resistance disorders, bacterial infection, fungal infection, inflammatory disorders, mechanical changes, and other skin conditions in obese subjects than in subjects with a normal BMI (p < 0.001). Disorders of androgen excess and viral infection were significantly less common in obese subjects (p < 0.001). Obese subjects had significantly lower odds of having at least one dermatology encounter than subjects with a normal BMI (odds ratio = 0.92, 95% confidence interval 0.88, 0.96, p = 0.003). Early onset obesity is associated with cutaneous disorders characterized by hyperproliferation, inflammation, bacterial and fungal infection, and mechanical changes but lower rates of disorders of androgen excess and viral infection. The use of dermatology services was not greater in obese patients. Heightened recognition and further analysis of adipose tissue as an endocrine organ that is capable of affecting the skin is warranted.
Hemolytic uremic syndrome related to cryptosporidium infection in an immunocompetent child
Authors: Printza Nikoleta , Sapountzi Evdoxia , Dotis John , Papachristou Fotios
Published: December 2013

Hemolytic‐uremic syndrome (HUS) is characterized by the clinical and laboratory manifestations of acute renal failure, thrombocytopenia and microangiopathic hemolytic anemia. In children, the majority of cases occur after an infectious diarrhea mainly associated with the serotype Escherichia coli O157:H7. We present a case of a 5‐year‐old boy with post‐diarrhea HUS due to cryptosporidium. The child remained on peritoneal dialysis for 24 days. However, he had a full recovery of his renal function and 6 months later, his overall condition was still very good. This is a particularly interesting case, not only due to the exceptionally rare cause of HUS, that is, the cryptosporidium, but also because of the serious gastroenteritis caused by the cryptosporidium in an immunocompetent child. It seems that in cases of post‐diarrhea HUS, apart from E. coli O157:H7, even the rarest causes of gastroenteritis should be investigated.
Metabolic analysis of the increased adventitious rooting mutant of Artemisia annua reveals a role for the plant monoterpene borneol in adventitious root formation
Authors: Tian Na , Liu Shuoqian , Li Juan , Xu Wenwen , Yuan Lin , Huang Jianan , Liu Zhonghua
Published: December 2013

Adventitious root (AR) formation is a critical process for plant clonal propagation. The role of plant secondary metabolites in AR formation is still poorly understood. Chemical and physical mutagenesis in combination with somatic variation were performed on Artemisia annua in order to obtain a mutant with changes in adventitious rooting and composition of plant secondary metabolites. Metabolic and morphological analyses of the iar (increased adventitious rooting) mutant coupled with in vitro assays were used to elucidate the relationship between plant secondary metabolites and AR formation. The only detected differences between the iar mutant and wild‐type were rooting capacity and borneol/camphor content. Consistent with this, treatment with borneol in vitro promoted adventitious rooting in wild‐type. The enhanced rooting did not continue upon removal of borneol. The iar mutant displayed no significant differences in AR formation upon treatment with camphor. Together, our results suggest that borneol promotes adventitious rooting whereas camphor has no effect on AR formation.
Iron and Infection in Hemodialysis Patients
Authors: Ishida Julie H. , Johansen Kirsten L.
Published: December 2013

Intravenous iron is an important component of the treatment of anemia of end‐stage renal disease (ESRD), but it is biologically plausible that iron could increase the risk of infection through impairment of neutrophil and T‐cell function and promotion of microbial growth. Any such increase in risk would be particularly important because infection is a significant cause of mortality and morbidity in dialysis patients. The overall evidence favors an association between iron and infection in hemodialysis patients, but the optimal iron management strategy to minimize infection risk has yet to be identified. There is a need for further research on this topic, particularly in light of increased utilization of intravenous iron following implementation of the bundledESRDreimbursement system.
Identification of a novel HLA‐DRB1*14 allele, HLA‐DRB1*14:143, by sequence‐based typing
Authors: Huo M.‐R. , Xi B. , Yu Y. , Li D.
Published: December 2013

The novel HLA‐DRB1*14:143 allele differs from DRB1*14:10 by two nucleotide substitutions at positions 344 and 345 of exon 2.
Sulfate availability affects ABA levels and germination response to ABA and salt stress in Arabidopsis thaliana
Authors: Cao Min‐Jie , Wang Zhen , Zhao Qing , Mao Jie‐Li , Speiser Anna , Wirtz Markus , Hell Rüdiger , Zhu Jian‐Kang , Xiang Cheng‐Bin
Published: December 2013

Sulfur‐containing compounds play a critical role in the response of plants to abiotic stress factors including drought. The phytohormone abscisic acid (ABA) is the key regulator of responses to drought and high‐salt stress. However, our knowledge about interaction of S‐metabolism and ABA biosynthesis is scarce. Here we report that sulfate supply affects synthesis and steady‐state levels of ABA in Arabidopsis wild‐type seedlings. By using different mutants of the sulfate uptake and reduction pathway, we confirmed the impact of sulfate supply on steady‐state ABA content in Arabidopsis and demonstrated that this impact was due to cysteine availability. Loss of the chloroplast sulfate transporter3;1 function (sultr3;1) resulted in significantly decreased aldehyde oxidase (AO) activity and ABA levels in seedlings and seeds. These mutant phenotypes could be reverted by exogenous application of cysteine or ectopic expression of SULTR3;1. In addition the sultr3;1 mutant showed a decrease of xanthine dehydrogenase activity, but not of nitrate reductase, strongly indicating that in seedlings cysteine availability limits activity of the molybdenum co‐factor sulfurase, ABA3, which requires cysteine as the S‐donor for sulfuration. Transcription of ABA3 and NCED3, encoding another key enzyme of the ABA biosynthesis pathway, was regulated by S‐supply in wild‐type seedlings. In contrast, ABA up‐regulated the transcript level of SULTR3;1 and other S‐metabolism‐related genes. Our results provide evidence for a significant co‐regulation of S‐metabolism and ABA biosynthesis that operates to ensure sufficient cysteine for AO maturation and highlights the importance of sulfur for stress tolerance of plants.
Trafficking of the myrosinase‐associated proteinGLL23 requiresNUC/MVP1/GOLD36/ERMO3 and the p24 proteinCYB
Authors: Jancowski Sylwia , Catching Amanda , Pighin Jamie , Kudo Takamasa , Foissner Ilse , Wasteneys Geoffrey O.
Published: December 2013

Proteins detrimental to endoplasmic reticulum (ER) morphology need to be efficiently exported. Here, we identify two mechanisms that control trafficking ofArabidopsis thalianaGLL23, a 43 kDaGDSL‐like lipase implicated in glucosinolate metabolism through its association with the β‐glucosidase myrosinase. Using immunofluorescence, we identified two mutants that showed aberrant accumulation ofGLL23: large perinuclearERaggregates in thenuclear cage(nuc) mutant; and small compartments contiguous with the peripheral ER in thecytoplasmic bodies(cyb) mutant. Live imaging of fluorescently tagged GLL23 confirmed its presence in thenucandcybcompartments, but lack of fluorescent signals in the wild‐type plants suggested thatGLL23 is normally post‐translationally modified forERexport.NUCencodes theMVP1/GOLD36/ERMO3 myrosinase‐associated protein, previously shown to have vacuolar distribution.CYBis anERandGolgi‐localized p24 typeImembrane protein component of coat protein complex (COP) vesicles, animal and yeast homologues of which are known to be involved in selective cargo sorting forER–Golgi export. WithoutNUC,GLL23 accumulates in theERthis situation suggests thatNUCis in fact active in theER. WithoutCYB, bothGLL23 andNUCwere found to accumulate incybcompartments, consistent with a role forNUCinGLL23 processing and indicated thatGLL23 is the likely sorting target of theCYBp24 protein.
Detection of endogenous cortisol in equine tears and blood at rest and after simulated stress
Authors: Monk Caroline S. , Hart Kelsey A. , Berghaus Roy D. , Norton Natalie A. , Moore Phillip A. , Myrna Kathern E.
Published: December 2013

Objective

To determine whether cortisol is present in equine tears at rest and during simulated stress and compare tear cortisol to serum free and total cortisol.

Materials and methods

Fourteen healthy adult horses were included. Paired tear total cortisol and serum total and free cortisol concentrations were measured with ELISA, chemiluminescent immunoassay, and ultrafiltration methodology, respectively, in 10 horses at rest once daily for five consecutive days. In an additional four horses, paired tear and serum samples were collected for cortisol measurement before and after adrenocorticotropic hormone (ACTH) stimulation (cosyntropin, 1 μg/kg IV).

Results

Cortisol was detectable in equine tears at rest. Following ACTH stimulation, tear cortisol increased significantly from baseline at 60–120 min (P ≤ 0.001). Serum total and free cortisol also increased significantly at 30–180 min after ACTH stimulation (P ≤ 0.001). Both serum and tear cortisol returned to baseline concentrations by 360 min. Changes in tear cortisol were similarly associated with changes in serum total and free cortisol, although high tear cortisol concentrations suggest a portion of tear cortisol may be protein‐bound.

Discussion

Cortisol is present in equine tears and increases in concert with serum cortisol following ACTH stimulation. Further study is needed to determine whether endogenous cortisol in tears contributes to ocular pathology.
Assessment of the ability of the Privigen® purification process to deplete thrombogenic factor XIa from plasma
Authors: Komenda M. , Stadler D. , Malinas T. , Moses M. , Pragst I. , Herzog E. , Schmutz P. , Minnig K. , El Menyawi I.
Published: December 2013

Background and objectives

Activated clotting factor FXI (FXIa) has been postulated to play a significant role in thromboembolic events potentially associated with the administration of intravenous immunoglobulin. The purpose of this study was to demonstrate that thrombogenic agents, in particular FXIa and FXI, are depleted or inactivated in Privigen®.

Materials and methods

The ability of the purification process to deplete FXIa from plasma was studied. All steps of the Privigen® production were investigated for potential activation of FXI to FXIa with spiking experiments.

Results

Privigen® contains no procoagulant activity as determined by FXIa chromogenic assay, non‐activated partial thromboplastin time (NaPTT) and thrombin generation assays (TGA, FXIa‐like activity). The coagulation times were >200 s in the NaPTT test. FXIa was below the detection limit of 0·14 ng/ml (chromogenic assay) and below the quantification limit of 0·2 ng/ml (TGA). FXIa spiking experiments showed that the analytical methods used can detect traces of procoagulant activity in immunoglobulin samples. FXIa spiking and kinetic experiments during the octanoic acid fractionation step showed that a substantial reduction in FXIa specific activity (by ≥99·9% within 40 min of octanoic acid incubation) was reached already at an early stage of the manufacturing process. These results were confirmed in vivo: in a modified Wessler test, no thrombus was reported.

Conclusion

The Privigen® manufacturing process has the capability to remove thrombogenic factors: octanoic acid precipitation, designed to remove a variety of contaminants during immunoglobulin purification, also removes almost all FXIa from plasma and further purification steps do not activate FXI.
Time-Independent Plasticity Related to Critical Point of Free Energy Function and Functional
Authors: Yang Q. , Liu Y. R. , Feng X. Q. , Yu S. W.
Published: December 2013

In this paper, time-independent plasticity is addressed within the thermodynamic framework with internal variables by Rice (1971, “Inelastic Constitutive Relations for Solids: An Internal Variable Theory and Its Application to Metal Plasticity,” J. Mech. Phys. Solids, 19, pp. 433–455). It is shown in this paper that the existence of a free energy function along with thermodynamic equilibrium conditions directly leads to associated flow rules. The time-independent inelastic behaviors can be fully determined by the Hessian matrix at the nondegenerate critical point of the free energy function. The normality rule of Hill and Rice (1973, “Elastic Potentials and the Structure of Inelastic Constitutive Laws,” SIAM J. Appl. Math., 25, pp. 448–461) or the Il'yushin (1961, “On a Postulate of Plasticity,” J. Appl. Math. Mech. 25, pp. 746–750) postulate is just a stability requirement of the thermodynamic equilibrium. The existence of a free energy functional which is not a direct function of the internal variables, along with thermodynamic equilibrium conditions also leads to associated flow rules. The time-independent inelastic behaviors with the free energy functional can be fully determined by the quasi Hessian matrix at the quasi critical point of the free energy functional. With the free energy functional, the thermodynamic forces conjugate to the internal variables are nonconservative and are constructed based on Darboux theorem. Based on the constructed nonconservative forces, it is shown that there may exist several possible thermodynamic equilibrium mechanisms for the thermodynamic system of the material sample. Therefore, the associated flow rules based on free energy functionals may degenerate into nonassociated flow rules. The symmetry of the conjugate forces plays a central role for the characteristics of time-independent plasticity.
An Investigation of Flow, Mechanical, and Thermal Performance of Conventional and Pressure-Balanced Brush Seals
Authors: Pekris Michael J. , Franceschini Gervas , Gillespie David R. H.
Published: December 2013

Compliant contacting filament seals such as brush seals are well known to give improved leakage performance and hence specific fuel consumption benefit compared to labyrinth seals. The design of the brush seal must be robust across a range of operating pressures, rotor speeds, and radial build-offset tolerances. Importantly the wear characteristics of the seal must be well understood to allow a secondary air system suitable for operation over the entire engine life to be designed. A test rig at the University of Oxford is described which was developed for the testing of brush seals at engine-representative speeds, pressures, and seal housing eccentricities. The test rig allows the leakage, torque, and temperature rise in the rotor to be characterized as functions of the differential pressure(s) across the seal and the speed of rotation. Tests were run on two different geometries of bristle pack with conventional, passive, and active pressure-balanced backing ring configurations. Comparison of the experimental results indicates that the hysteresis inherent in conventional brush seal design could compromise performance (due to increased leakage) or life (due to exacerbated wear) as a result of reduced compliance. The inclusion of active pressure-balanced backing rings in the seal designs are shown to alleviate the problem of bristle–backing ring friction, but this is associated with increased blow-down forces which could result in a significant seal-life penalty. The best performing seal was concluded to be the passive pressure-balanced configuration, which achieves the best compromise between leakage and seal torque. Seals incorporating passive pressure-balanced backing rings are also shown to have improved heat transfer performance in comparison to other designs.
Cytoskeletal Mechanics Regulating Amoeboid Cell Locomotion
Authors: Álvarez-González Begoña , Bastounis Effie , Meili Ruedi , del Álamo Juan C. , Firtel Richard , Lasheras Juan C.
Published: December 2013

Migrating cells exert traction forces when moving. Amoeboid cell migration is a common type of cell migration that appears in many physiological and pathological processes and is performed by a wide variety of cell types. Understanding the coupling of the biochemistry and mechanics underlying the process of migration has the potential to guide the development of pharmacological treatment or genetic manipulations to treat a wide range of diseases. The measurement of the spatiotemporal evolution of the traction forces that produce the movement is an important aspect for the characterization of the locomotion mechanics. There are several methods to calculate the traction forces exerted by the cells. Currently the most commonly used ones are traction force microscopy methods based on the measurement of the deformation induced by the cells on elastic substrate on which they are moving. Amoeboid cells migrate by implementing a motility cycle based on the sequential repetition of four phases. In this paper, we review the role that specific cytoskeletal components play in the regulation of the cell migration mechanics. We investigate the role of specific cytoskeletal components regarding the ability of the cells to perform the motility cycle effectively and the generation of traction forces. The actin nucleation in the leading edge of the cell, carried by the ARP2/3 complex activated through the SCAR/WAVE complex, has shown to be fundamental to the execution of the cyclic movement and to the generation of the traction forces. The protein PIR121, a member of the SCAR/WAVE complex, is essential to the proper regulation of the periodic movement and the protein SCAR, also included in the SCAR/WAVE complex, is necessary for the generation of the traction forces during migration. The protein Myosin II, an important F-actin cross-linker and motor protein, is essential to cytoskeletal contractility and to the generation and proper organization of the traction forces during migration.
Development of a Two-Dimensional Sail Analysis Code for Use as a Teaching Tool in an Undergraduate Fluid Dynamics Course
Authors: Spall Robert
Published: December 2013

A typical undergraduate fluid dynamics course includes sections on Bernoulli’s equation, flow visualization, and lift and drag for external flows. The purpose of this work has been to develop a fully interactive, two-dimensional potential flow solver using a panel method for flow over thin-sail geometries to aid in student understanding of these topics. The user may specify either rigid sail shapes, or flexible sails in which the final equilibrium shapes are determined by the pressure distribution. The solver was developed in Fortran 90/95. The user interface and graphics routines were developed using the high-level plotting library DISLIN. A variety of controls are available to adjust sail shapes and angles-of-attack. Available graphics include velocity vectors, pressure coefficient contours, and streamlines. Lift, axial and normal force coefficients are also output in the form of bar graphs. The code was recently introduced in an undergraduate fluid dynamics class taught by the author, and is available from the author’s website for download.
Study on Flow Characteristics Downstream of Annular Inlet Guide Vanes
Authors: Kudo Masanori , Nishibe Koichi , Takahashi Masayuki , Sato Kotaro , Tsujimoto Yoshinobu
Published: December 2013

The main objectives of the present study are to identify the dominant parameters responsible for the generation of unsteady flow, determine the conditions under which flow oscillations are produced and the relation between the flow characteristics and the number of vanes with identical solidity. The flow instabilities downstream of inlet guide vanes (IGV) are clarified experimentally and by numerical simulation. The conditions for the onset of flow instability, including the number of cells and the oscillation characteristics of the unsteady flow, are discussed based on measured pressure fluctuations and the propagating angular velocity ratio of the instability for various radius ratios (r3/r2). The effectiveness of adjusting the number of vanes to control the flow instabilities is also discussed.
Effect of Geometry on Droplet Generation in a Microfluidic T-Junction
Authors: Loizou Katerina , Thielemans Wim , Hewakandamby Buddhika N.
Published: December 2013

The main aim of this study is to examine how the droplet formation in microfluidic T-junctions is influenced by the cross-section and aspect ratio of the microchannels. Several studies focusing on droplet formation in microfluidic devices have investigated the effect of geometry on droplet generation in terms of the ratio between the width of the main channel and the width of the side arm of the T-junction. However, the contribution of the aspect ratio and thus that of the cross-section on the mechanism of break up has not been examined thoroughly with most of the existing work performed in the squeezing regime. Two different microchannel geometries of varying aspect ratios are employed in an attempt to quantify the effect of the ratio between the width of the main channel and the height of the channel on droplet formation. As both height and width of microchannels affect the area on which shear stress acts deforming the dispersed phase fluid thread up to the limit of detaching a droplet, it is postulated that geometry and specifically cross-section of the main channel contribute on the droplet break-up mechanisms and should not be neglected. The above hypothesis is examined in detail, comparing the volume of generated microdroplets at constant flowrate ratios and superficial velocities of continuous phase in two microchannel systems of two different aspect ratios operating at dripping regime. High-speed imaging has been utilised to visualise and measure droplets formed at different flowrates corresponding to constant superficial velocities. Comparing volumes of generated droplets in the two geometries of area ratio near 1.5, a significant increase in volume is reported for the larger aspect ratio utilised, at all superficial velocities tested. As both superficial velocity of continuous phase and flowrate ratio are fixed, superficial velocity of dispersed phase varies. However this variation is not considered to be large enough to justify the significant increase in the droplet volume. Therefore it can be concluded that droplet generation is influenced by the aspect ratio and thus the cross-section of the main channel and its effect should not be depreciated. The paper will present supporting evidence in detail and a comparison of the findings with the existing theories which are mainly focused on the squeezing regime.
Drop Deposition Technique on Low Energy Surface
Authors: Waghmare Prashant R. , Das Siddhartha , Mitra Sushanta K.
Published: December 2013

In this paper we propose a new technique for drop deposition on low energy surfaces, which addresses the limitations of the classical drop deposition technique. In this classical technique, a drop is deposited on a surface by bringing a needle, holding the drop, in proximity to the solid surface. Therefore, irrespective of whether the solid surface is in air or under a liquid, it becomes extremely difficult to deposit the drop on low energy surfaces owing to the large differences between the drop-needle and the drop-substrate adhesion forces (or surface energies). In our discussed method, we overcome this difficulty for low energy surfaces immersed in a liquid. For surfaces under liquid, there is an interface in addition to the solid-liquid interface: this interface is the air-liquid interface, where the liquid gets exhausted. In our technique, we cater the (un)favorable drop spreading dynamics at this interface to ensure that the drop gets deposited on the under-liquid surface.
Material Point Method and Adaptive Meshing Applied to Fluid-Structure Interaction (FSI) Problems
Authors: Mao Shaolin
Published: December 2013

Material point method (MPM) is a powerful tool to handle material large deformation, discontinuities, and material moving interfaces problems where typical finite element methods (FEMs) could be very expensive and frequently fail. Material point method, in essence, is a weak formulation of the Particle-in-cell (PIC) method which has been developed initially for fluid dynamic problems. Recent years have seen extensive development of algorithm and impressive applications of MPM in engineering problems. Compared to its big success in material and structure modeling, the application of MPM to multiphase flows and fluid-structure interactions (FSIs) problems is relative scarce, in particular, the studies of fluid-induced deformation and motion of solids are limited due to their highly computational cost. In this short paper we discuss the computational efficiency by combining MPM with the adaptive mesh refinement (AMR) techniques to simulate FSI problems. Several test cases of 2D and 3D fluid-solid coupling flow problems are simulated and analyzed. The comparison with previous simulation results is shown in detail.