bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysing content and patterns of interaction for improving the learning design of networked learning environments
Authors: Haya Pablo A. , Daems Oliver , Malzahn Nils , Castellanos Jorge , Hoppe Heinz Ulrich
Published: March 2015

Learning Analytics constitutes a key tool for supporting Learning Design and teacher‐led inquiry into student learning. In this paper, we demonstrate how a Social Learning Analytics toolkit can combine social network analysis and content analysis for supporting a global and formal teacher inquiry. This toolkit not only supports teachers in improving the organisation of the learning process but also generates important input to improve the students' reflection on their own learning. Our examples show how combinations of different levels of analysis can provide deep insight in the learning process. We report a case study that exemplifies the main features of our approach and the kind of outcomes that can be obtained. Commenting and rating processes on videos are analysed based on user traces from a social learning platform. Finally, we point out implications on the learning design for networked learning environments in general.
BRCA/Fanconi anemia pathway implicates chemoresistance to gemcitabine in biliary tract cancer
Authors: Nakashima Shinsuke , Kobayashi Shogo , Nagano Hiroaki , Tomokuni Akira , Tomimaru Yoshito , Asaoka Tadafumi , Hama Naoki , Wada Hiroshi , Kawamoto Koichi , Marubashi Shigeru , Eguchi Hidetoshi , Doki Yuichiro , Mori Masaki
Published: March 2015

The BRCA/Fanconi anemia (FA) pathway plays a key role in the repair of DNA double strand breaks. We focused on this pathway to clarify chemoresistance mechanisms in biliary tract cancer (BTC). We also investigated changes in the CD24+/44+ population that may be involved in chemoresistance, as this population likely includes cancer stem cells. We used three BTC cell lines to establish gemcitabine (GEM)‐resistant (GR) cells and evaluated the expression of BRCA/FA pathway components, chemoresistance, and the effect of BRCA/FA pathway inhibition on the CD24+/44+ population. FANCD2 and CD24 expression were evaluated in 108 resected BTC specimens. GR cells highly expressed the BRCA/FA components. The BRCA/FA pathway was upregulated by GEM and cisplatin (CDDP) exposure. Inhibition using siRNA and RAD51 inhibitor sensitized GR cells to GEM or CDDP. The CD24+/44+ population was increased in GR and parent BTC cells treated with GEM or CDDP and highly expressed BRCA/FA genes. FANCD2 was related to CD24 expression in resected BTC specimens. Inhibition of the BRCA/FA pathway under GEM reduced the CD24+/44+ population in MzChA1‐GR cells. Thus, high expression of the BRCA/FA pathway is one mechanism of chemoresistance against GEM and/or CDDP and is related to the CD24+/44+ population in BTC.
Study of the application of modified thiourea dioxide discharge agent inD5 non‐aqueous medium
Authors: Zhou Lan , Shan Jiang , Liu Xiaoyun , Shao Jianzhong
Published: March 2015

In view of the low solubility of thiourea dioxide in water and its inertia to most chemical reagents, a novel non‐aqueous medium, decamethylcyclopentasiloxane, was introduced to replace water in the grinding process for better dispersibility and discharge stability. In this study, the effects of different grinding methods on the particle size distribution and surface appearance of thiourea dioxide were studied. The influences of aqueous and decamethylcyclopentasiloxane media on the discharge stability of thiourea dioxide in discharge paste were compared. The whiteness, handle, and the tensile strength of the discharge‐printed fabric were evaluated. The results showed that the wet grinding process endowed thiourea dioxide with smaller particle sizes and narrower size distributions in the presence of dispersants. Decamethylcyclopentasiloxane as a non‐aqueous medium was beneficial in maintaining good discharge stability of thiourea dioxide for a longer time. The fabrics discharged by the prepared thiourea dioxide printing paste had favourable whiteness, good handle, and acceptable tensile strength.
Merkel cell carcinoma arising within a poroma: report of two cases
Authors: Molina‐Ruiz Ana M. , Bernárdez Claudia , Requena Luis , Rütten Arno
Published: March 2015

Merkel cell carcinoma (MCC) has been reported in association with other types of cutaneous neoplasms within the same lesion, including squamous cell carcinoma, Bowen's disease, actinic keratosis, follicular cysts, trichoblastoma and lentigo maligna, among others. However, the association of MCC and sweat gland tumors has never been described in the literature. We report two unique cases of MCC that developed within cutaneous poromas. A 56‐year‐old male (Patient 1) and an 81‐year‐old female (Patient 2) presented with nodules on the upper arm and lower back, respectively. Histopathologic study of both cases revealed a tumor in the dermis composed of poroid and cuticular cells intermingled with a proliferation of small round cells that showed characteristic histopathological and immunohistochemical features of MCC. In both cases, the two neoplasms were tightly admixed and distinct, suggesting that the MCC could have developed within a previously existing poroma. No morphological features of transition between the two tumors were seen. Neoplastic cells of MCC expressed immunoreactivity for chromogranin, synaptophysin, neuron‐specific enolase, CAM 5.2 and cytokeratin 20, the last two markers showing the characteristic paranuclear dot‐like pattern. In contrast, the poroma cells only expressed cytokeratin MNF116. Metastatic deposits were not identified in the regional lymph nodes or distantly.
Primary cutaneous cribriform carcinoma: report of six cases with clinicopathologic data and immunohistochemical profile
Authors: Arps David P. , Chan May P. , Patel Rajiv M. , Andea Aleodor A.
Published: March 2015

Background

Primary cutaneous cribriform carcinoma (PCCC) is a rare and under‐recognized variant of sweat gland carcinoma, characterized by anastomosing tubules and solid nests producing a sieve‐like appearance.

Methods

Six cases of PCCC were clinically, histopathologically and immunophenotypically studied.

Results

All cases showed an unencapsulated, nodular dermal tumor composed of solid and cribriform nests, cords and tubules embedded within a desmoplastic stroma. Some tubules showed micropapillary projections reminiscent of tubular adenoma, and intraluminal thin bridges resembling adenomatoid tumor. One case showed a predominantly solid component. Only two cases showed very focal decapitation secretion. Tumor cells expressed CK7, CK5/6, EMA, CEA, S‐100, BerEP4 and c‐kit and were negative for cytokeratin 20, estrogen receptor/progesterone receptor (ER/PR), androgen receptor and GCDFP‐15. Calponin, p63 and smooth muscle actin (SMA) showed absence of a myoepithelial layer.

Conclusions

Contrary to the original reports, our series shows that PCCC may be predominantly solid with only a minor cribriform component, and expresses c‐kit and S‐100 which may potentially lead to the misdiagnosis of adenoid cystic carcinoma. Immunohistochemical stains may aid in distinction from tubular adenoma. Current data suggest a favorable outcome, as metastatic disease has not been reported to date.
A high molecular mass zinc transporter MTP12 forms a functional heteromeric complex with MTP5 in the Golgi in Arabidopsis thaliana
Authors: Fujiwara Takashi , Kawachi Miki , Sato Yori , Mori Haruki , Kutsuna Natsumaro , Hasezawa Seiichiro , Maeshima Masayoshi
Published: March 2015

Zinc (Zn) is an essential micronutrient required for plant growth and development. In Arabidopsis thaliana, several families of Zn transporters engaged in Zn import, export and intracellular compartmentalization play important roles in Zn homeostasis. We describe a novel Zn transporter, A. thaliana metal tolerance protein 12 (AtMTP12), which belongs to the cation diffusion facilitator family. AtMTP12 is predicted to consist of 798 amino acids and have 14 transmembrane segments. The expression of AtMTP12 in suspension‐cultured cells was not affected by Zn deficiency or excess. Heterologous expression in a mutant of budding yeast (Saccharomyces cerevisiae) that lacks Msc2p, an orthologue of AtMTP12, revealed that AtMTP12 complements the growth phenotype of the msc2 mutant when AtMTP5t1, one of the splicing variants of AtMTP5, is coexpressed. Transient expression of AtMTP12‐fused green fluorescent protein in A. thaliana mesophyll protoplasts demonstrated that AtMTP12 is localized to the Golgi apparatus. Moreover, AtMTP12 and AtMTP5t1 interact in the Golgi, as determined by a bimolecular fluorescence complementation assay. These results suggest that AtMTP12 forms a functional complex with AtMTP5t1 to transport Zn into the Golgi.

Database

Nucleotide sequence data for full‐length of AtMTP12 is available in the DDBJ/EMBL/GenBank database under accession number AB986563.
The NHS Health Check programme: insights from a qualitative study of patients
Authors: Ismail Hanif , Atkin Karl
Published: March 2015

Objective

To provide an insight into the process of patients receiving Health Checks and to determine the extent to which patients were supported to reduce the risks of developing cardiovascular disease through behaviour change.

Methods

Semi‐structured qualitative interviews were undertaken with 45 patients about their initial experiences of undertaking a Health Check. They were followed up 1 year later to assess whether the behavioural changes reported after the Health Check had been maintained.

Results

Patients expressed a need for individualized support in order to stay motivated and to adopt long‐term diet and lifestyle changes.

Conclusions

Those involved in the delivery of the programme need to adopt a consistent approach in terms of explaining the purpose of the Health Check, communicating risk and consider the challenges and the barriers that influence behaviour change.
Synthesis and Characterization of La and Nd Co‐Doped Bismuth Titanate Ferroelectric Ceramics
Authors: Islam Muhammad Aminul , Islam Muhammad Saidul , Gafur Muhammad Abdul
Published: March 2015

La and Nd co‐doped bismuth titanate Bi3 (LaxNd1−x)Ti3O12 (x = 0.4, 0.5, and 0.6) [BLNT] samples were prepared by solid‐state reaction method. XRD pattern of calcined powder of BLNT ceramics indicates a single phase of bismuth‐layered perovskite structure with no visible impurity phase. The sintered BLNT ceramics showed a uniform microstructure having spherical type grain. Dielectric constant was increased by co‐doping due to increase in lattice distortion. Dielectric loss, AC conductance, and leakage current were drastically reduced due to La and Nd co‐doping. Better performance was observed for the composition Bi3 (LaxNd1−x)Ti3O12, (x = 0.5).
Treatment of patients with multiple myeloma who are not eligible for stem cell transplantation: position statement of the myeloma foundation of Australia Medical and Scientific Advisory Group
Authors: Quach H. , Joshua D. , Ho J. , Szer J. , Spencer A. , Harrison S. , Mollee P. , Roberts A. , Horvath N. , Talaulikar D. , To B. , Zannettino A. , Brown R. , Catley L. , Augustson B. , Jaksic W. , Gibson J. , Prince H. M.
Published: March 2015

Options for treatment of elderly patients with multiple myeloma have expanded substantially following the development of immunomodulatory drugs (IMiD), proteasome inhibitors and with enhancement in safety of high‐dose therapy and autologous stem cell transplant (HDT + ASCT). The recognition of biological heterogeneity among elderly patients has made delivery of therapy more challenging. An individualised approach to treatment selection is recommended in an era in which highly efficacious treatment options are available for transplant‐ineligible patients. Here, we summarise recommendations for patients who are considered unsuitable for HDT + ASCT, including pretreatment considerations, and induction, maintenance and supportive care therapies.
Calibration Weighting Methods for Complex Surveys
Authors: Wu Changbao , Lu Wilson W.
Published: March 2015

This paper presents a careful investigation of the three popular calibration weighting methods: (i) generalised regression; (ii) generalised exponential tilting and (iii) generalised pseudo empirical likelihood, with a major focus on computational aspects of the methods and some empirical evidences on calibrated weights. We also propose a simple weight trimming method for range‐restricted calibration. The finite sample behaviour of the weights obtained by the three calibration weighting methods and the effectiveness of the proposed weight trimming method are examined through limited simulation studies.
Textures and traction: how tube‐dwelling polychaetes get a leg up
Authors: Merz Rachel Ann
Published: March 2015

By controlling the traction between its body and the tube wall, a tube‐dwelling polychaete can move efficiently from one end of its tube to the other, brace its body during normal functions (e.g., ventilation and feeding), and anchor within its tube avoiding removal by predators. To examine the potential physical interaction between worms and the tubes they live in, scanning electron microscopy was used to reveal and quantify the morphology of worm bodies and the tubes they produce for species representing 13 families of tube‐dwelling polychaetes. In the tubes of most species there were macroscopic or nearly macroscopic (~10 μm–1 mm) bumps or ridges that protruded slightly into the lumen of the tube; these could provide purchase as a worm moves or anchors. At this scale (~10 μm‐1 mm), the surfaces of the chaetal heads that interact with the tube wall were typically small enough to fit within spaces between these bumps (created by the inward projection of exogenous materials incorporated into the tube wall) or ridges (made by secretions on the interior surface of the tube). At a finer scale (0.01–10 μm), there was a second overlap in size, usually between the dentition on the surfaces of chaetae that interact with the tube walls and the texture provided by the secreted strands or microscopic inclusions of the inner linings. These linings had a surprising diversity of micro‐textures. The most common micro‐texture was a “fabric” of secreted threads, but there were also orderly micro‐ridges, wrinkles, and rugose surfaces provided by microorganisms incorporated into the inner tube lining. Understanding the fine structures of tubes in conjunction with the morphologies of the worms that build them gives insight into how tubes are constructed and how worms live within them.
The impact of R&D‐specific factors on the attractiveness of small‐ and medium‐sized enterprises as partners vis‐à‐vis alliance formation in large emerging economies
Authors: De Mattos Claudio , Burgess Thomas F. , Shaw Nicky E.
Published: March 2015

This study examines the impact of research and development (R&D)‐specific factors in determining the likelihood of small‐ and medium‐sized enterprises (SMEs) from developed countries to be attractive partners vis‐à‐vis forming alliances with SMEs from large emerging economies (LEEs). This study is founded on the knowledge‐accessing theory of alliance formation, which emphasises the higher efficiency gains of knowledge application as opposed to knowledge generation. We extend this theory to SMEs on the basis that smaller firms, because of their resources constraints and drive to survive, are likely to use alliances to access external knowledge bases leading to new product development (NPD) opportunities because of the low feasibility of acquiring knowledge. As a mix of complex knowledge is necessary to develop most modern products and services, SMEs are also likely to adopt a more flexible operational approach and to accept compromises to forge knowledge‐accessing alliances. We illustrate this theoretical development using primary data collected from British and German biotechnology SMEs, declaring the intention prospectively to form alliances with their counterparts in Brazil. Binary logistic regression was used to identify the factors influencing the likelihood of a firm as an attractive alliance partner. Our results indicate that R&D‐specific factors influence the likelihood of firms to be attractive alliance partners. In particular, firms showing an in‐house innovation history focused on one or few products are more likely to be attractive alliance partners with LEE firms than those that do not. Another R&D‐specific predictor that enhances the chances of alliance partner attractiveness with LEE firms is the firm's focused searching and identifying capability relative to technology or equipment that demonstrates good prospects to improve the firm's line of products. A third predictor refers to the firm's awareness regarding non‐cost obstacles for its own technological development. Implications for policy makers and practitioners are also discussed.
Patent management in entrepreneurial SMEs: a literature review and an empirical study of innovation appropriation, patent propensity, and motives
Authors: Holgersson Marcus
Published: March 2015

Managers make a number of strategic choices when trying to capture returns from innovation investments, including what appropriation strategy to use and whether or not to patent, strategic choices that depend among other things on firm size. Previous literature, being reviewed in this paper, shows that the patent propensity is lower in small and medium‐sized enterprises (SMEs) than in large firms and that patenting as means for appropriation is of less importance amongSMEs. Chief executive officers (CEOs) and/or research and development (R&D) managers of 26 entrepreneurialSMEshave been interviewed to explain these differences and to provide insight on how patenting is used inSMEs. The patent competence was low among the studiedSMEs, and internal patent resources were found to be important for effective and efficient use of the patent system, for application as well as monitoring and enforcement. While of limited perceived importance for protecting inventions in entrepreneurialSMEs, patents were used to attract customers and venture capital, which is of utmost importance for the survival and growth of these firms. Thus, patenting has an important role to play even in firms where the protective function of patents is secondary.
In vivo time‐sequential histological study focused on melanocytes: suggestion of golden time for intervention to prevent post‐laser pigmentary changes
Authors: Song H.S. , Park J.‐Y. , Kim S.J. , Kang H.Y.
Published: March 2015

Background

Post‐inflammatory pigmentary changes after laser treatments are challenging adverse effect.

Objective

To suggest an ideal time period with regard to intervention to prevent post‐laser pigmentary changes, an in vivo time‐sequential histological study focused on melanocytes was performed.

Methods

The back skin of four volunteers was irradiated with Q‐switched alexandrite laser (QSAL). In one subject (subject 4), topical corticosteroid was applied onto the irradiated skin from the time of irradiation to day 28. In all subjects, time‐sequential skin biopsies were performed at baseline, an immediate time after irradiation, day 2, day 7, and day 28. Histological and immunohistochemical analyses were conducted.

Results

Q‐switched alexandrite laser led to the successful removal of pigments and most melanocytes from the epidermis in all subjects. At day 28, there was increased epidermal pigmentation in the skin of the subjects 1–3. It was noted that numerous activated melanocytes appeared on day 7, continued to be observed until day 28. However, in the subject 4, the melanocyte activation and post‐laser pigmentary changes were not observed.

Conclusion

In regard to intervene melanocyte activation, at least 1 week after laser treatment is suggested as a ‘golden’ time period to prevent pigmentary changes.
Evaluation of an antigen‐capture EIA for the diagnosis of hepatitis E virus infection
Authors: Zhao C. , Geng Y. , Harrison T. J. , Huang W. , Song A. , Wang Y.
Published: March 2015

An enzyme immunoassay (EIA) has been developed for hepatitis E virus (HEV) antigen (HEV‐Ag) detection and marketed in China. This study aimed to evaluate the sensitivity of the assay and assess the value of HEV‐Ag detection in the diagnosis of HEV infection in comparison with HEV RNA detection. Using serial dilutions of a genotype 4 HEV strain, significant correlation was found between the EIA (S/CO) and HEV RNA (IU/mL) concentration in the range 103.5 to 100.5 IU/mL HEV RNA, the Pearson correlation coefficient r approached 0.97. The EIA detection limit was 54.6 IU/mL, compared to 24 IU/mL for HEV RNA using real‐time RT‐PCR. In clinical samples from hepatitis E patients, the HEV‐Ag and HEV RNA positivity rates were 55.6% (65/117) and 60.7% (71/117) in sera and 76.7% (56/73) and 84.9% (62/73) in stools, and the concordance of these two markers was 77.8% in sera and 80.8% in stools. In serum samples, the HEV‐Ag positivity rate and the concordance between HEV‐Ag and HEV RNA were inversely proportional to the presence of anti‐HEV antibody. The presence of anti‐HEV IgG could reduce the S/CO of the HEV‐Ag EIA. These results reveal a significant correlation between the detection of HEV‐Ag and HEV RNA. The sensitivity of the HEV‐Ag EIA was lower than real‐time RT‐PCR but could be higher than conventional nested RT‐PCR. Therefore, the detection of HEV‐Ag in serum and faeces is valuable for the diagnosis and prognosis of HEV infection in developing regions where real‐time RT‐PCR is not available.
Evolution and selection of Rhg1, a copy‐number variant nematode‐resistance locus
Authors: Lee Tong Geon , Kumar Indrajit , Diers Brian W. , Hudson Matthew E.
Published: March 2015

The soybean cyst nematode (SCN) resistance locus Rhg1 is a tandem repeat of a 31.2 kb unit of the soybean genome. Each 31.2‐kb unit contains four genes. One allele of Rhg1, Rhg1‐b, is responsible for protecting most US soybean production from SCN. Whole‐genome sequencing was performed, and PCR assays were developed to investigate allelic variation in sequence and copy number of the Rhg1 locus across a population of soybean germplasm accessions. Four distinct sequences of the 31.2‐kb repeat unit were identified, and some Rhg1 alleles carry up to three different types of repeat unit. The total number of copies of the repeat varies from 1 to 10 per haploid genome. Both copy number and sequence of the repeat correlate with the resistance phenotype, and the Rhg1 locus shows strong signatures of selection. Significant linkage disequilibrium in the genome outside the boundaries of the repeat allowed the Rhg1 genotype to be inferred using high‐density single nucleotide polymorphism genotyping of 15 996 accessions. Over 860 germplasm accessions were found likely to possess Rhg1 alleles. The regions surrounding the repeat show indications of non‐neutral evolution and high genetic variability in populations from different geographic locations, but without evidence of fixation of the resistant genotype. A compelling explanation of these results is that balancing selection is in operation at Rhg1.
The Postimplantation Electrocardiogram Predicts Clinical Response to Cardiac Resynchronization Therapy
Authors: COVERSTONE EDWARD , SHEEHY JUSTIN , KLEIGER ROBERT E. , SMITH TIMOTHY W.
Published: March 2015

Background

Biventricular (BiV) pacing for cardiac resynchronization therapy (CRT) is intended to improve left ventricular function by coordinating systolic activity of the septum and free walls. Optimal resynchronization should be manifested by 12‐lead electrocardiogram (ECG) patterns consistent with resynchronized activation, a tall (≥4 mm) R wave in V1, and predominant negative deflection in lead I (RV1SI). We investigated whether the presence or absence of RV1SI predicts heart failure outcomes within 1 year of CRT implant.

Methods

Two independent physicians reviewed the paced ECG of 213 patients post‐CRT device implantation with disputes resolved by a third reviewer. The primary end points of all‐cause death, unplanned hospitalization, left ventricular assist device implant, or transplant within a 1‐year follow‐up were blindly adjudicated according to standard definitions. Groups were compared via Kaplan‐Meier estimates and Cox proportional hazards models to determine association with event‐free survival.

Results

Among CRT patients postimplantation, 56 (26.3%) exhibited the RV1SI pattern on ECG. Patients with the RV1SI pattern were significantly less likely to achieve the primary end point as compared to patients without the RV1SI pattern (33.9% vs 52.2%; Log Rank P = 0.022). This difference was driven by a significantly lower risk for unplanned hospitalization among patients with the RV1SI pattern (hazard ratio = 0.510; confidence interval [0.298, 0.876]). The predictive value remained after adjustment for potential confounders (P = 0.004).

Conclusions

The 12‐lead ECG postimplantation predicts clinical outcomes of BiV pacing. Such prediction may be useful in predicting the need for alternative or advanced heart failure therapies. Further study into ECG patterns may help to prospectively guide CRT.
A retrospective study of medical comorbidities in psychogeriatric patients
Authors: Goh Anita M.Y. , Westphal Alissa , Daws Teresa , Gascoigne‐Cohen Sophie , Hamilton Bridget , Lautenschlager Nicola T.
Published: March 2015

Background

This study contributes further research into the assessment and treatment of older psychiatric patients with medical comorbidities.

Methods

A retrospective file audit was conducted at the acute inpatient psychogeriatric unit of St Vincent's Aged Mental Health Service, Melbourne, in order to determine the prevalence of certain medical comorbidities and the nature of medical interventions provided for psychogeriatric inpatients.

Results

This study, investigating 165 admissions into an acute inpatient psychogeriatric unit, highlights that psychiatric and medical comorbidities are routine in this population: the vast majority (91.5%) of all inpatients had at least one medical comorbidity.

Conclusions

As the population ages, psychogeriatric wards are likely to see more of the oldest‐olds, who are likely to have comorbid medical illnesses. Currently, appropriate detection, investigation, and management of these illnesses are often suboptimal and can affect quality of life, increase mortality, and complicate treatment. This paper adds to the literature about the need for integrating medical and psychiatric care to create a more comprehensive strategy for treating the older person with psychiatric illness.
Tidal‐flow restoration provides little nesting habitat for a globally vulnerable saltmarsh bird
Authors: Elphick Chris S. , Meiman Susan , Rubega Margaret A.
Published: March 2015

Tidal marshes are among the most threatened habitats on Earth because of their limited natural extent, a long history of human drainage and modification, and anticipated future sea‐level rise. Tidal marshes also provide services to humans and support species of high conservation interest. Consequently, millions of dollars have been spent on tidal marsh restoration throughout North America. Southern New England has a long history of tidal marsh restorations, often focused on removal of the invasive plantPhragmites australis. Working in 18 Connecticut marshes, we examined the bird community in 21 plots in restoration sites and 19 plots in reference sites. Restoration plots were divided into those in marshes where management involved restoring tidal flow and those where directPhragmitescontrol (e.g. cutting, herbicide) was used. Saltmarsh sparrowsAmmodramus caudacutus, which are considered globally vulnerable to extinction, were less common where tidal flow had been restored than at reference sites and nested in only one of 14 tidal‐flow restoration plots. No abundance differences were found for large wading birds, willetsTringa semipalmata, or seaside sparrowsAmmodramus maritimus. Vegetation at sites where tidal flow had been restored showed characteristics typical of lower‐elevation marsh, which is unsuitable for nesting saltmarsh sparrows. We conclude that, although tidal‐flow restorations in Connecticut controlPhragmitesand restore native saltmarsh vegetation, they produce conditions that are largely unsuitable for one of the highest conservation priority species found in easternU.S.salt marshes.
Loci and candidate gene identification for resistance to Sclerotinia sclerotiorum in soybean (Glycine max L. Merr.) via association and linkage maps
Authors: Zhao Xue , Han Yingpeng , Li Yinghui , Liu Dongyuan , Sun Mingming , Zhao Yue , Lv Chunmei , Li Dongmei , Yang Zhijiang , Huang Long , Teng Weili , Qiu Lijuan , Zheng Hongkun , Li Wenbin
Published: March 2015

Soybean white mold (SWM), caused by Sclerotinia sclerotiorum ((Lib.) W. Phillips), is currently considered to be the second most important cause of soybean yield loss due to disease. Research is needed to identify SWM‐resistant germplasm and gain a better understanding of the genetic and molecular basis of SWM resistance in soybean. Stem pigmentation after treatment with oxaloacetic acid is an effective indicator of resistance to SWM. A total of 128 recombinant inbred lines (RILs) derived from a cross of ‘Maple Arrow’ (partial resistant to SWM) and ‘Hefeng 25’ (susceptible) and 330 diverse soybean cultivars were screened for the soluble pigment concentration of their stems, which were treated with oxalic acid. Four quantitative trait loci (QTLs) underlying soluble pigment concentration were detected by linkage mapping of the RILs. Three hundred and thirty soybean cultivars were sequenced using the whole‐genome encompassing approach and 25 179 single‐nucleotide polymorphisms (SNPs) were detected for the fine mapping of SWM resistance genes by genome‐wide association studies. Three out of five SNP markers representing a linkage disequilibrium (LD) block and a single locus on chromosome 13 (Gm13) were significantly associated with the soluble pigment content of stems. Three more SNPs that represented three minor QTLs for the soluble pigment content of stems were identified on another three chromosomes by association mapping. A major locus with the largest effect on Gm13 was found both by linkage and association mapping. Four potential candidate genes involved in disease response or the anthocyanin biosynthesis pathway were identified at the locus near the significant SNPs (<60 kbp). The beneficial allele and candidate genes should be useful in soybean breeding for improving resistance to SWM.
SnRK1 from Arabidopsis thaliana is an atypical AMPK
Authors: Emanuelle Shane , Hossain Mohammed Iqbal , Moller Isabel E. , Pedersen Henriette L. , van de Meene Allison M. L. , Doblin Monika S. , Koay Ann , Oakhill Jonathan S. , Scott John W. , Willats William G. T. , Kemp Bruce E. , Bacic Antony , Gooley Paul R. , Stapleton David I.
Published: March 2015

SNF1‐related protein kinase 1 (SnRK1) is the plant orthologue of the evolutionarily‐conserved SNF1/AMPK/SnRK1 protein kinase family that contributes to cellular energy homeostasis. Functional as heterotrimers, family members comprise a catalytic α subunit and non‐catalytic β and γ subunits; multiple isoforms of each subunit type exist, giving rise to various isoenzymes. The Arabidopsis thaliana genome contains homologues of each subunit type, and, in addition, two atypical subunits, β3 and βγ, with unique domain architecture, that are found only amongst plants, suggesting atypical heterotrimers. The AtSnRK1 subunit structure was determined using recombinant protein expression and endogenous co‐immunoprecipitation, and six unique isoenzyme combinations were identified. Each heterotrimeric isoenzyme comprises a catalytic α subunit together with the unique βγ subunit and one of three non‐catalytic β subunits: β1, β2 or the plant‐specific β3 isoform. Thus, the AtSnRK1 heterotrimers contain the atypical βγ subunit rather than a conventional γ subunit. Mammalian AMPK heterotrimers are phosphorylated on the T–loop (pThr175/176) within both catalytic a subunits. However, AtSnRK1 is insensitive to AMP and ADP, and is resistant to T–loop dephosphorylation by protein phosphatases, a process that inactivates other SNF1/AMPK family members. In addition, we show that SnRK1 is inhibited by a heat‐labile, >30 kDa, soluble proteinaceous factor that is present in the lysate of young rosette leaves. Finally, none of the three SnRK1 carbohydrate‐binding modules, located in the β1, β2 and βγ subunits, associate with various carbohydrates, including starch, the plant analogue of glycogen to which AMPK binds in vitro. These data clearly demonstrate that AtSnRK1 is an atypical member of the SNF1/AMPK/SnRK1 family.
Extensions de représentations de de Rham et vecteurs localement algébriques
Authors: Dospinescu Gabriel
Published: March 2015

Let${\rm\Pi}$be an irreducible unitary completion of a locally algebraic$\text{GL}_{2}(\mathbf{Q}_{p})$-representation. We describe those first-order deformations of${\rm\Pi}$which are themselves completions of a locally algebraic representation. This answers a question of Paškūnas and has direct applications to the Breuil–Mézard conjecture.
Simplified Mathematical Representations of Single Shaft Gas Turbines in Mechanical Drive Service
Authors: Rowen William I.
Published: March 2015

There have been several recent applications of large single shaft, heavy duty gas turbines in mechanical drive service, powering high horsepower, multi-casing compressors. This variable speed application of a traditional constant speed driver, with a more limited operating speed range, has created a need for simplified but accurate mathematical representations that can be incorporated into overall process simulations to allow interactive dynamic evaluation of the complete system.

This paper presents simplified mathematical representations of four gas turbines covering the horsepower range from 26,000 HP to 108,000 HP. The models incorporate both the control and fuel system characteristics as well as those of the turbomachinery. Although gas fuel is assumed, listed references can be used to accomodate liquid fuel. The models are suitable for a wide range of ambient temperatures, and the influence of axial flow compressor variable inlet guide vanes is included in the models as appropriate to the actual machinery configuration.
Experimental and Theoretical Analysis of the Flow in a Centrifugal Compressor Volute
Authors: Ayder E. , Van den Braembussche R. , Brasz J. J.
Published: March 2015

Detailed measurements of the swirling flow in a centrifugal compressor volute with elliptical cross section are presented.

They show important variations of the swirl- and throughflow velocity, total and static pressure distribution at the different volute cross sections and at the diffuser exit.

The basic mechanisms defining the complex 3D flow structure are clarified. The different sources of pressure losses have been investigated and used to improve the prediction capability of one dimensional mean streamline analysis correlations.

The tangential flow loss model, under decelerating flow conditions, and friction loss model are confirmed. New emprical loss coefficients are proposed for the exit cone loss model and the tangential flow loss model for the case of accelerating flow in the volute.
A Combustor Diffuser of Annular Configuration Suitable for Industrial Gas Turbines
Authors: Adkins R. C. , Benim A. C. , Escher P. C. , Hellat J. , Koenig W. M.
Published: March 2015

A pre-combustor diffuser, suitable for outboard annular combustors has been successfully demonstrated. The diffuser, which incorporates a 180 degree bend and practicalities such as support struts, was shown to produce a pressure recovery and flow stability which would be superior to most inline annular diffusers. Guidelines for the design of such diffusers are discussed.
An Investigation of Post Stall Transients and Recoverability of Axial Compression Systems: Part I — A Simplified Method
Authors: Jun Hu , Cai Tang Guo , Min Zhang Hui
Published: March 2015

Using the theory developed by Moore and Greitzer, a simplified approximate method is proposed to calculate the evolution of the mass flow, pressure rise, and the growth and decay of rotating stall cell during post stall transients or recovery process in multistage arial compression systems. The method leads to a set of three simultaneous nonlinear first order partial differential equations, and for the numerical solution, a simple explicit time marching method can be used. It is shewa that a study of rotating-statt-like and surge-like motion, recoverability from rotating stall or surge, and limited parameters can be carried out through this method. It has been found that, except the two general types of distinct flow instabilities (rotating stall and surge), there is another type of instability in arial compression systems, which has the basic characteristic of both rotating stall and surge. Some qualitative comparisons with available experimental results and some qualitative comparisons with test data are made in this paper. It shows that the proposed model is very simple, accurate and dependable.
Turbulence Evaluation Within the Secondary Flow Region of a Turbine Cascade
Authors: Gregory-Smith D. G. , Biesinger Th.
Published: March 2015

Three-dimensional turbulent and mean velocity fields have been measured within a large-scale axial turbine cascade. The results indicate a complex turbulent flow field especially within the secondary vortex. The turbulence is shown to he significantly non-isotropic, and the production and dissipation terms in the turbulent kinetic energy equation have been evaluated in order to illustrate the unusual turbulence behaviour. Comparisons with a Navier-Stokes computation indicate areas for improvement in turbulence and transition modelling.
Three Dimensional Transonic Flow Measurements in an Axial Turbine With Conical Walls
Authors: Kost F.
Published: March 2015

To investigate the spatial flow structure caused by sweep and dihedral effects in turbomachinery blade rows, detailed measurements have been conducted in the windtunnel for rotating annular cascades of DLR-Göttingen. The special configuration investigated, consisted of a turbine rotor equipped with straight blades, a conical hub and a conical casing with a cone half-angle of 30°. Numerous flow data are obtained from surface pressure distributions at seven radial blade sections and from Laser velocimetry upstream, downstream and inside the rotor. As the Laser-Two-Focus technique is a two-dimensional one, two laser velocity measurements at different angles bad to be taken at each meaurement location in the flow, in order to get the three components of velocity. The measurement accuracy of the three derived Mach number components in the blade relative system has been evaluated and stored together with mean and fluctuating values at each measurement location.
Shroud Heat Transfer Measurements From a Rotating Cavity With an Axial Throughflow of Air
Authors: Long C. A. , Tucker P. G.
Published: March 2015

The paper discusses measurements of heat transfer obtained from the inside surface of the peripheral shroud. The experiments were carried out on a rotating cavity, comprising two 0.985m diameter discs, separated by an axial gap of 0.065 m and bounded at the circumference by a carbon fibre shroud. Tests were conducted with a heated shroud and either unheated or heated discs. When heated, the discs had the same temperature level and surface temperature distribution. Two different temperature distributions were tested; the surface temperature either increased, or decreased with radius. The effects of disc, shroud and air temperature levels were also studied. Tests were carried out for the range of axial throughflow rates and speeds: 0.0025 ≤ m ≤ 0.2 kg/s and 12.5 ≤ Ω ≤ 125 rad/sec, respectively. Measurements were also made of the temperature of the air inside the cavity.

The shroud Nusselt numbers are found to depend on a Grashof number which is defined using the centripetal acceleration. Providing the correct reference temperature is used, the measured Nusselt numbers also show similarity to those predicted by an established correlation for a horizontal plate in air. The heat transfer from the shroud is only weakly affected by the disc surface temperature distribution and temperature level.

The heat transfer from the shroud appears to be affected by the Rossby number. A significant enhancement to the rotationally-induced free convection occurs in the regions: 2 ≤ Ro ≤ 4 and Ro 4 ≥ 20. The first of these corresponds to a region where vortex breakdown has been observed. In the second region, the Rossby number may be sufficiently large for the central throughflow to directly affect the shroud heat transfer.

Heating the shroud does not appear to significantly affect the heat transfer from the discs.
Compressible Flow Pressure Losses in Wye-Junctions
Authors: Abou-Haidar N. I. , Dixon S. L.
Published: March 2015

This paper considers the compressible flow pressure losses in sharp cornered wye-junctions with symmetrical branches under dividing and combining flow conditions. Determination of the additional total pressure losses occurring in flow through several three-leg junctions, using dry air as the working fluid, has been made experimentally. Results covering a wide speed range up to choking are presented for three different wye-junction geometries. Separate flow visualisation Schlieren tests detected the presence of normal shock waves, located at up to one duct diameter downstream of the junction, and therefore confirmed the choking of the flow at the vena contracta. The highest attainable Mach number (M3) of the averaged whole flow was 0.9 for one of the dividing flow geometries and 0.65 for several of the combining flow cases. These values of M3 were the maximum possible and hence represent a limiting condition dictated by choking. In general, the compressible flow loss coefficients, caused by the presence of the wye-junctions, can be expected to be higher for dividing flows and lower for combining flows than would be the case for incompressible flows because of the influence of Mach number (M3) on the magnitude of the denominator.
Hot Streaks and Phantom Cooling in a Turbine Rotor Passage: Part 1 — Separate Effects
Authors: Roback Richard J. , Dring Robert P.
Published: March 2015

This paper presents experimental documentation and analytical correlations demonstrating the effects of hot streak accumulation and phantom cooling on turbine rotor airfoil surface temperature. Results are shown which quantify the impact of (1) a non-uniform temperature profile at the entrance of a turbine due to combustor-generated hot and cold streaks, and (2) cooling air discharged from the trailing edge of the upstream stator.

In Part 1 of this paper, experimental results are shown for a range of controlling variables to identify where streak accumulation and phantom cooling were most likely to be strongest. These variables include streak-to-free stream density ratio, streak injection location and coolant-to-free stream density and velocity ratios.

In Part 2 of this paper, experimental results are shown for the combined effects of hot streak and stator coolant. An analytic model is also presented to correlate the experimental results.
Carbon Monoxide Emissions From Gas Turbines as Influenced by Ambient Temperature and Turbine Load
Authors: Hung W. S. Y.
Published: March 2015

The emissions of carbon monoxide (CO) from gas turbines are typically below 100 ppmvd @ 15% O2 at design full-load operating conditions. The use of water/steam to reduce NOx emissions from gas turbines results in an increase in CO emissions from gas turbines. This is particularly true when increased rates of water/steam injection are used to meet stringent NOx limits.

Regulations limiting CO emissions from stationary gas turbines were first initiated in the late 1980’s by the Federal Republic of Germany and the state of New Jersey in the United States. Since these regulations are silent on ambient and load corrections, these CO limits could be the limiting factor in the current development of dry low NOx combustion systems by gas turbine manufacturers. In addition, since manufacturers are usually quite specific regarding the conditions for CO guarantees, a conflict for the gas turbine user, who is responsible for the permit application, is readily apparent.

This paper attempts to characterize the CO emissions from gas turbines as a function of ambient temperature and turbine load. An ambient temperature correction equation for CO emissions, based on previous work, is presented. The intent is to provide more extensive information on CO emissions such that better defined CO limits can be adopted. Ultimately, this should help the combustion design engineers in developing improved dry low emissions combustion systems for the gas turbine industry.
Emissions Reduction by Varying the Swirler Airflow Split in Advanced Gas Turbine Combustors
Authors: Micklow Gerald J. , Roychoudhury Subir , Nguyen H. Lee , Cline Michael C.
Published: March 2015

A rich burn/quick mix/lean burn (RQL) combustor concept for reducing pollutant emissions is currently under investigation at the NASA Lewis Research Center (LeRC). A numerical study was performed to investigate the chemically reactive flow with liquid spray injection for the RQL combustor. The RQL combustor consists of an airblast atomizer fuel injector, a rich burn section, a converging connecting pipe, a quick mix zone, a diverging connecting pipe and a lean combustion zone. For computational efficiency, the combustor was split into two sub systems, i.e. the fuel nozzle/rich burn section and the quick mix/lean burn section.

The current study investigates the effect of varying the mass flow rate split between the swirler passages for an equivalence ratio of 2.0 on fuel distribution, temperature distribution, and emissions for the fuel nozzle/rich burn section of an RQL combustor. The input conditions used in the study were chosen based on tests completed at LeRC. It is seen that optimizing these parameters can substantially improve combustor performance and reduce combustor emissions. The optimal mass flow rate split for reducing NOx emissions based on the numerical study was the same as found by experiment at LeRC.
Semianalytical Correlations for NOx, CO, and UHC Emissions
Authors: Rizk N. K. , Mongia H. C.
Published: March 2015

To meet the future goals of reduced emissions produced by gas turbine combustors, a better understanding of the process of formation of various pollutants is required. Both empirical and analytical approaches are used to provide the exhaust concentrations of pollutants of interest such as NOx, CO, and unburned hydrocarbon with varying degrees of success. In the present investigation, an emission model that simulates the combustor by a number of reactors representing various combustion zones is proposed. A detailed chemical kinetic scheme was used to provide a fundamental basis for the derivation of a number of expressions that simulate the reaction scheme. The model addresses the combined effects of spray evaporation and mixing in the reaction zone. The model validation included the utilization of a large data base obtained for an annular combustor of a modern turbopropulsion engine. In addition to the satisfactory agreement with the measurements, the model provided insight into the regions within the combustor that could be responsible for the excessive formation of emissions. Methods to reduce the emissions may be implemented in light of such information.
Evaluation of Low NOx Combustor Concepts for Aeroderivative Gas Turbine Engines
Authors: McVey J. B. , Padget F. C. , Rosfjord T. J. , Hu A. S. , Peracchio A. A. , Schlein B. , Tegel D. R.
Published: March 2015

An experimental program was conducted to evaluate low NOx combustor concepts applicable to natural-gas-burning aeroderivative gas turbine engines operating at a nominal pressure ratio of 20:1. Gas sampling measurements at the exit of the primary zone of high-shear and lean premixed burners were acquired under elevated entrance pressure and temperature conditions over a range of primary zone equivalence ratios. Piloting systems were incorporated in most of the burner designs to achieve satisfactory burner operability. Both swirl stabilized and perforated-plate (grid) stabilized burners were found to produce NOx levels lower than the current engine goal of 25 ppm (15% O2).