bluuebunny/crossref_metadata_2025 huggingface dataset:
Global analysis of Drosophila Cys2-His2 zinc finger proteins reveals a multitude of novel recognition motifs and binding determinants
Authors: Enuameh Metewo Selase , Asriyan Yuna , Richards Adam , Christensen Ryan G. , Hall Victoria L. , Kazemian Majid , Zhu Cong , Pham Hannah , Cheng Qiong , Blatti Charles , Brasefield Jessie A. , Basciotta Matthew D. , Ou Jianhong , McNulty Joseph C. , Zhu Lihua J. , Celniker Susan E. , Sinha Saurabh , Stormo Gary D. , Brodsky Michael H. , Wolfe Scot A.
Published: March 2013

Cys2-His2 zinc finger proteins (ZFPs) are the largest group of transcription factors in higher metazoans. A complete characterization of these ZFPs and their associated target sequences is pivotal to fully annotate transcriptional regulatory networks in metazoan genomes. As a first step in this process, we have characterized the DNA-binding specificities of 129 zinc finger sets from Drosophila using a bacterial one-hybrid system. This data set contains the DNA-binding specificities for at least one encoded ZFP from 70 unique genes and 23 alternate splice isoforms representing the largest set of characterized ZFPs from any organism described to date. These recognition motifs can be used to predict genomic binding sites for these factors within the fruit fly genome. Subsets of fingers from these ZFPs were characterized to define their orientation and register on their recognition sequences, thereby allowing us to define the recognition diversity within this finger set. We find that the characterized fingers can specify 47 of the 64 possible DNA triplets. To confirm the utility of our finger recognition models, we employed subsets of Drosophila fingers in combination with an existing archive of artificial zinc finger modules to create ZFPs with novel DNA-binding specificity. These hybrids of natural and artificial fingers can be used to create functional zinc finger nucleases for editing vertebrate genomes.
Selective occurrence of Rhizobiales in frost flowers on the surface of young sea ice near Barrow, Alaska and distribution in the polar marine rare biosphere
Authors: Bowman J. S. , Larose C. , Vogel T. M. , Deming J. W.
Published: March 2013

Frost flowers are highly saline ice structures that grow on the surface of young sea ice, a spatially extensive environment of increasing importance in the Arctic Ocean. In a previous study, we reported organic components of frost flowers in the form of elevated levels of bacteria and exopolymers relative to underlying ice. Here, DNA was extracted from frost flowers and young sea ice, collected in springtime from a frozen lead offshore of Barrow, Alaska, to identify bacteria in these understudied environments. Evaluation of the distribution of 16S rRNA genes via four methods (microarray analysis, T‐RFLP, clone library and shotgun metagenomic sequencing) indicated distinctive bacterial assemblages between the two environments, with frost flowers appearing to select for Rhizobiales. A phylogenetic placement approach, used to evaluate the distribution of similar Rhizobiales sequences in other polar marine studies, indicated that some of the observed strains represent widely distributed members of the marine rare biosphere in both the Arctic and Antarctic.
Genomic analysis of the biocontrol strain Pseudomonas fluorescens Pf29Arp with evidence of T3SS and T6SS gene expression on plant roots
Authors: Marchi Muriel , Boutin Morgane , Gazengel Kévin , Rispe Claude , Gauthier Jean‐Pierre , Guillerm‐Erckelboudt Anne‐Yvonne , Lebreton Lionel , Barret Matthieu , Daval Stéphanie , Sarniguet Alain
Published: March 2013

Several bacterial strains of the Pseudomonas genus provide plant growth stimulation, plant protection against pests or bioremediation. Among these bacteria, P. fluorescens Pf29Arp reduces the severity of take‐all, a disease caused by the pathogenic fungus Gaeumannomyces graminis var. tritici (Ggt) on wheat roots. In this study, we obtained a draft genome of Pf29Arp and subsequent comparative genomic analyses have revealed that this bacterial strain is closely related to strains of the ‘P. brassicacearum‐like’ subgroup including P. brassicacearum ssp. brassicacearum NFM421 and P. fluorescens F113. Despite an overall chromosomal organization similar to these strains, a number of features including antibiotic synthesis gene clusters from secondary metabolism are not found in the Pf29Arp genome. But Pf29Arp possesses different protein secretion systems including type III (T3SS) and type VI (T6SS) secretion systems. Pf29Arp is the first Pseudomonas sp. strain described with four T6SS clusters (cluster I, II, III and IV). In addition, some protein‐coding genes involved in the assembly of these secretion systems are basally expressed during Pf29Arp colonization of healthy wheat roots and display different expression patterns on necrotized roots caused by Ggt. These data suggest a role of T3SS and T6SS in the Pf29Arp adaptation to different root environments.
Subtype selectivity of α+β− site ligands of GABAA receptors: identification of the first highly specific positive modulators at α6β2/3γ2 receptors
Authors: Varagic Zdravko , Ramerstorfer Joachim , Huang Shengming , Rallapalli Sundari , Sarto‐Jackson Isabella , Cook James , Sieghart Werner , Ernst Margot
Published: March 2013

Background and Purpose

GABAA receptors are the major inhibitory neurotransmitter receptors in the mammalian brain and the target of many clinically important drugs interacting with different binding sites. Recently, we demonstrated that CGS 9895 (2‐(4‐methoxyphenyl)‐2H‐pyrazolo[4,3‐c]quinolin‐3(5H)‐one) elicits a strong and subtype‐dependent enhancement of GABA‐induced currents via a novel drug‐binding site at extracellular αx+βy− (x = 1–6, y = 1–3) interfaces. Here, we investigated 16 structural analogues of CGS 9895 for their ability to modulate GABA‐induced currents of various GABAA receptor subtypes.

Experimental Approach

Recombinant GABAA receptor subtypes were expressed in Xenopus laevis oocytes and investigated by the two‐electrode voltage clamp method.

Key Results

Most of the compounds investigated were able to modulate GABA‐induced currents of αβ and αβγ receptors to a comparable extent, suggesting that the effect of these drugs is not dependent on the benzodiazepine site of GABAA receptors. Steric hindrance experiments demonstrated that these compounds exert their action predominantly via the αx+βy− (x = 1–6, y = 1–3) interfaces. Whereas some compounds are unselectively modulating a broad range of receptor subtypes, other compounds feature remarkable functional selectivity for the α6β3γ2 receptor, or behave as null modulators at some receptor subtypes investigated.

Conclusion and Implications

Pyrazoloquinolinones and pyrazolopyridinones represent the first prototypes of drugs exerting benzodiazepine‐like modulatory effects via the α+β− interface of GABAA receptors. The discovery of modulators with functional subtype selectivity at this class of binding sites provides a highly useful tool for the investigation of α6β2/3γ2 receptor function, and may lead to novel therapeutic principles.

Linked Article

This article is accompanied by Varagic et al., pp. 371–383 of this issue. To view this article visit http://dx.doi.org/10.1111/bph.12151
Adherence to Enhanced Recovery After Surgery and length of stay after colonic resection
Authors: Cakir H. , van Stijn M. F. M. , Lopes Cardozo A. M. F. , Langenhorst B. L. A. M. , Schreurs W. H. , van der Ploeg T. J. , Bemelman W. A. , Houdijk A. P. J.
Published: March 2013

Aim

The Enhanced Recovery After Surgery (ERAS) programme is a multimodal approach to improve peri‐operative care in colon surgery. The aim of this study was to report on the adherence to and outcomes of ERAS in the first years after implementation.

Method

Data of patients undergoing elective colon resections for malignancy in 2006 until 2010 were compared with patients receiving conventional care in 2005. Retrospective analysis was performed including length of stay (LOS), protocol adherence and complications. The predictive values of ERAS items and baseline characteristics on LOS and complications were analysed using univariate and multivariate analysis.

Results

Length of stay (LOS) was significantly shorter in 2006 and 2007 (P ≤ 0.009 and P ≤ 0.004) but not in 2008 and 2009. The mean adherence rate to the ERAS items was 84.1% in 2006 and 2007 and 72.4% in 2008 and 2009 (P < 0.001). In 2005, 2008 and 2009 LOS was significantly shorter for laparoscopically operated patients than for patients with open resections (P < 0.002, P < 0.001 and P < 0.004 respectively). Multivariate analysis showed that age, laparoscopic surgery, removal of nasogastric tube before extubation, mobilization within 24 h after surgery, starting nonsteroidal anti‐inflammatory drugs at day 1 and removal of thoracic epidural analgesia at day 2 were independent predictors of LOS.

Conclusion

Strict adherence to the ERAS protocol was associated with reduced LOS and improved outcome in elective colon surgery for malignancy. These benefits were lost when protocol adherence was lower. Embedding the ERAS protocol into an organization and repetitive education are vital to sustain its beneficial effects on LOS and outcome.
A flexibility framework to understand the adaptation of small coffee and honey producers facing market shocks
Authors: Bathfield Benjamin , Gasselin Pierre , López‐Ridaura Santiago , Vandame Rémy
Published: March 2013

Small‐scale coffee producers are particularly exposed to a very fluctuant market. The present work aims at characterising the adaptation of small‐scale coffee and honey producers to the 1999–2003 coffee crisis in the Guatemalan Highlands from a systemic and agronomical perspective. Working with a homogeneous sample of 34 families we identify up to 27 different flexibility mechanisms. A qualitative analysis of families' life histories was combined with classification methods. Besides confirming the importance of the availability resources and some well known adaptive responses, such as workload intensification, expenses reduction or the importance of social networks, the classification of households reveals a sequence in the implementation of flexibility mechanisms. The focus on the combination of coffee and honey productions also suggests changing the traditional approaches to agricultural processes toward the adoption of a more systemic perspective. The possible impacts of these findings on technical extension and construction of public policies are then discussed.
HIV and “People on the Move”: Six Strategies to Reduce Risk and Vulnerability during the Migration Process
Authors: Haour‐Knipe Mary , de Zalduondo Barbara , Samuels Fiona , Molesworth Kate , Sehgal Sarita
Published: March 2013

Mobile, migrant and displaced people require specific attention with regard to HIV vulnerability, including information and services tailored to their social, cultural and economic backgrounds and to the phase of mobility. Too few studies have systematically documented the needs of people on the move in this regard or evaluated the existing responses to meeting these needs. Most studies and programme descriptions focus on specific populations at country or community levels. Few compare and contrast different population groups, and few are regional or cross‐continental in scope. Most are purely descriptive, and lack a theoretical framework. The aim of this article is to precipitate more structured international comparisons – and questions – that will fill some of the evidence and programming gaps defined.
Fatherhood and Transmission in the Context of Migration: An Irish and a Polish Case
Authors: Brannen Julia , Mooney Ann , Wigfall Valerie , Parutis Violetta
Published: March 2013

The article compares men's biographies and fatherhood across two generations among the Irish and the Polish, who represent different waves of migration to Britain, focusing on two chains of fathers and sons. It examines different aspects of transmission between fathers and sons and, in the context of migration, the part that generational experience played in how men identify (or not) with their own fathers and repeated or changed their fatherhood practices. A comparative approach suggests the importance of taking account of the life course, the historical moment of migration, and the ways in which migration complicates intergenerational family relations by creating structural and relational ambivalences as the younger generation seeks to make its own mark. However ambivalences are managed and often coexist with solidaristic relations in terms of providing reciprocal support across the generations and in the fathers' identification with their fathers' strong work ethic and provider role. As fathers they are more involved in their children's lives than their fathers were but their employment conditions typically continue to constrain this.
Probabilistic stopping rules for GRASP heuristics and extensions
Authors: Ribeiro Celso C. , Rosseti Isabel , Souza Reinaldo C.
Published: March 2013

The main drawback of most metaheuristics is the absence of effective stopping criteria. Most implementations of such algorithms stop after performing a given maximum number of iterations or a given maximum number of consecutive iterations without improvement in the best‐known solution value, or after the stabilization of the set of elite solutions found along the search. We propose effective probabilistic stopping rules for randomized metaheuristics such as GRASP (Greedy Randomized Adaptive Search Procedures). We show how the probability density function of the solution values obtained along the iterations of such algorithms can be used to implement stopping rules based on the tradeoff between solution quality and the time needed to find a solution that might improve the best solution found. We show experimentally that, in the particular case of GRASP heuristics, the solution values obtained along its iterations fit a normal distribution that may be used to give an online estimation of the number of solutions obtained in forthcoming iterations that might be at least as good as the incumbent. This estimation is used to validate the stopping rule based on the tradeoff between solution quality and the time needed to find a solution that might improve the incumbent. The robustness of this strategy is illustrated and validated by a thorough computational study reporting results obtained with GRASP implementations to four different combinatorial optimization problems.
Why Refugees Rebel: Towards a Comprehensive Theory of Refugee Militarization
Authors: Lebson Mike
Published: March 2013

Militarization by refugees can have problematic outcomes. It can undermine the sovereignty and stability of the host state, perpetuate a transnational conflict and obstruct international efforts to resolve it, and present difficulties in the provision of humanitarian assistance to needy populations. Existing literature privileges structural explanations for militarization while neglecting the agency, interests and internal politics of refugee groups. In this paper, I offer a comprehensive theory of refugee militarization that emphasizes the importance of endogenous factors, including political and economic motivations, in the context of broader structural factors, including political opportunities and resource mobilization, mediated by the presence of militancy entrepreneurs. This theory helps integrate the motivation of refugees, and the discursive framing used by militancy entrepreneurs to mobilize them, with capacity for militant activity. The need for case studies and specific policy recommendations for host states, non‐governmental organizations and international stakeholders are discussed.
Longitudinal measurement invariance of psychosocial measures in physical activity research: an application to adolescent data
Authors: Roesch Scott C. , Norman Gregory J. , Merz Erin L. , Sallis James F. , Patrick Kevin
Published: March 2013

The current study served as a practical and substantive guide to establishing longitudinal measurement invariance of psychosocial measures commonly used in adolescent physical activity (PA) research. Psychosocial data on an initial sample of 878 adolescents (ages 11–15) recruited through primary care providers were provided at baseline, 6, 12, and 24 months. The target measures included family support, peer support, decisional balance (pros, cons), self‐efficacy, and behavioral strategies. Five of the six psychosocial measures exhibited strict longitudinal measurement invariance, with the sixth measure (self‐efficacy) exhibiting strong longitudinal measurement invariance. These findings support the equivalence of these measures across time, and provide the foundation to substantively interpret group differences and associations involving these measures and PA.
The role of ecology in the geographical separation of blood parasites infecting an insular bird
Authors: Cornuault Josselin , Khimoun Aurélie , Harrigan Ryan J. , Bourgeois Yann X. C. , Milá Borja , Thébaud Christophe , Heeb Philipp
Published: March 2013

Aim

Niche modelling is increasingly used to predict species' geographical distributions or to infer the evolutionary or ecological processes that constrain them, but relatively few studies have examined the ecological processes governing the distributions of parasites. Among such processes, niche divergence is frequently invoked to explain species range variation. Here, we test whether the geographical distributions of two lineages of Leucocytozoon (Haemosporida) avian parasites are linked to climatic conditions and whether niche divergence can explain their geographical separation.

Location

Réunion, Mascarene archipelago, south‐western Indian Ocean.

Methods

Leucocytozoon prevalence data were obtained by PCR screening of avian blood samples. Prevalence data and 20 environmental layers were used to build species distribution models (SDMs). SDMs were built by averaging the predictions of five different models: random forests (RF), generalized linear models (GLM), generalized additive models (GAM), multivariate adaptive regression splines (MARS) and support vector machines (SVM). Niche identity and background tests were used to test for a role of niche divergence in explaining parasite distributions.

Results

The geographical ranges of the two lineages of Leucocytozoon under study showed little overlap. Species distribution modelling suggested that niche divergence may explain the spatial variation observed in Leucocytozoon distribution, implying that the geographical separation of parasites is linked to environmental conditions. The variables that best explained parasite distribution were all related to precipitation patterns.

Main conclusions

As precipitation cannot directly affect endosymbiotic Leucocytozoon parasites, we suggest that the geographical separation of Leucocytozoon lineages is the result of an underlying geographical structure in the dipteran vectors that transmit these parasites. This illustrates the need to consider the ecology of vectors when predicting the distribution of vector‐borne parasites. Our study also shows that different parasite lineages, contained within broadly defined parasitic taxa, may have very different ecologies, and that these differences should be taken into account when attempting to understand the ecological determinants of parasite distribution and disease emergence.
The Foaming Abilities of Surfactants in Cocoa Butter
Authors: Su‐Jia Shi , Dong Cao , Shi‐Chao Xie
Published: March 2013

The foaming abilities of the nine kinds of surfactants in cocoa butter were researched in this paper. The results showed that only phospholipids had the foaming ability in cocoa butter, and the higher content of phosphatidylcholine in phospholipids, the stronger its foaming ability in the cocoa butter, which was significant for seeking a new method to prepare aerated chocolate. The foaming mechanism of phospholipids in cocoa butter was also discussed in the paper. The foaming mechanism of phospholipids in cocoa butter was different from its foaming mechanism in the water. The possible reason was that the molecular layers of phospholipid liquid crystalline were formed in the interface of air/cocoa butter, which could maintain the stability of the bubbles in cocoa butter. At the same time, we found that the foaming ability of phospholipids in cocoa butter was related with temperature. The spherical bubbles with large diameter and thin wall were easily formed at higher temperature (37C). At the low temperature (30C), the bubbles were also spherical, but with small diameter and thick wall. The small and irregular bubbles were easily formed at the lower temperature (the cocoa butter was partially crystallized at the temperature 26C). The results showed a new train of thought and basic data for the preparation of the aerated chocolate.

Practical Applications

Puffing under vacuum and inflating under high pressure were commonly used in the production of aerated chocolate. This paper showed a method to prepare bubbles in cocoa butter by whipping method in the presence of surfactants, which was significant for seeking a new method to prepare aerated chocolate.
Measuring reliability and validity of a newly developed stress instrument: Newly Diagnosed Breast Cancer Stress Scale
Authors: Lee Tso‐Ying , Chen Hsing‐Hsia , Yeh Mei‐Ling , Li Hui‐Ling , Chou Kuei‐Ru
Published: March 2013

Aims and objectives

To assess the reliability and validity of a developed instrument entitled Newly Diagnosed Breast Cancer Stress Scale.

Background

Distress, clinical anxiety and depression are evident in patients with cancer, leading to poor psychosocial and quality‐of‐life outcomes.

Design

Instrument development study with norm‐referenced measurements.

Methods

Content validity was determined by expert review. Cronbach's α was used to assess internal consistency reliability and product‐moment correlations were conducted. Exploratory factor analysis measured validity of items using varimax rotation method. Criterion‐related validity testing used the Perceived Stress Scale and the convergent validity test of construct validity used the Hospital Anxiety and Depression Scale. A total of 125 women pathologically diagnosed with breast cancer were interviewed on the day prior to initial breast surgery.

Results

After testing, the Newly Diagnosed Breast Cancer Stress Scale consisted of four main factors with 17 items with acceptable reliability and good validity, and its length and time to complete the questionnaire were appropriate. Internal consistency reliability of the scale was shown by Cronbach's α = 0·84, the criterion validity of Perceived Stress Scale‐10 was r = 0·46 (p < 0·001), the convergent validity of Hospital Anxiety and Depression Scale‐14 was r = 0·57 (p < 0·001) for anxiety and r = 0·35 (p < 0·001) for depression.

Conclusions

The Newly Diagnosed Breast Cancer Stress Scale has acceptable reliability and good validity to measure stress in newly diagnosed patients with breast cancer.

Relevance to clinical practice

The Newly Diagnosed Breast Cancer Stress Scale can provide healthcare workers with an instrument to better identify stress levels in newly diagnosed breast cancer patients and provide valuable information when defining psychosocial care interventions.
Going where traditional markers have not gone before: utility of and promise for RAD sequencing in marine invertebrate phylogeography and population genomics
Authors: Reitzel A. M. , Herrera S. , Layden M. J. , Martindale M. Q. , Shank T. M.
Published: March 2013

Characterization of large numbers of single‐nucleotide polymorphisms (SNPs) throughout a genome has the power to refine the understanding of population demographic history and to identify genomic regions under selection in natural populations. To this end, population genomic approaches that harness the power of next‐generation sequencing to understand the ecology and evolution of marine invertebrates represent a boon to test long‐standing questions in marine biology and conservation. We employed restriction‐site‐associated DNA sequencing (RAD‐seq) to identify SNPs in natural populations of the sea anemone Nematostella vectensis, an emerging cnidarian model with a broad geographic range in estuarine habitats in North and South America, and portions of England. We identified hundreds of SNP‐containing tags in thousands of RAD loci from 30 barcoded individuals inhabiting four locations from Nova Scotia to South Carolina. Population genomic analyses using high‐confidence SNPs resulted in a highly‐resolved phylogeography, a result not achieved in previous studies using traditional markers. Plots of locus‐specific FST against heterozygosity suggest that a majority of polymorphic sites are neutral, with a smaller proportion suggesting evidence for balancing selection. Loci inferred to be under balancing selection were mapped to the genome, where 90% were located in gene bodies, indicating potential targets of selection. The results from analyses with and without a reference genome supported similar conclusions, further highlighting RAD‐seq as a method that can be efficiently applied to species lacking existing genomic resources. We discuss the utility of RAD‐seq approaches in burgeoning Nematostella research as well as in other cnidarian species, particularly corals and jellyfishes, to determine phylogeographic relationships of populations and identify regions of the genome undergoing selection.
Automated peritoneal dialysis in Hong Kong: There are two distinct groups of patients
Authors: Kwan Bonnie Ching‐Ha , Chow Kai‐Ming , Ma Terry King‐Wing , Yu Vincent , Law Man‐Ching , Leung Chi‐Bon , Li Philip Kam‐Tao , Szeto Cheuk‐Chun
Published: March 2013

Aim

To compare the clinical outcome between continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) in specific subgroups of patients.

Methods

We reviewed the clinical outcome of 90 consecutive incident APD patients and 180 CAPD patients in our centre.

Results

The median follow up was 21.9 months (inter‐quartile range, 9.5 to 46.5 months). The APD group was younger and had a lower Charlson's score than the CAPD group. Furthermore, the APD group had a highly skewed distribution of the Charlson's score, indicating the possibility of two different groups of patients. Multivariate analysis showed that in addition to the treatment mode (APD vs CAPD) and Charlson's score, there was a significant interaction between the two (P = 0.043) on patient survival. For patients with Charlson's score ≤6, the APD group had a significantly better patient survival than the CAPD group (78.3% vs 65.4% at 5 years, P = 0.039), while for patients with Charlson's score ≥7, the APD group had a worse patient survival than the CAPD group (16.3% vs 48.4% at 5 years, P = 0.028). Similarly, Charlson's score and its interaction with treatment mode, but not the APD group per se, were independent predictors of technique survival (P = 0.013). For patients with Charlson's score ≥7, the APD group had a significantly lower technique survival than the CAPD group (8.8% vs 34.3%, P = 0.001), while for patients with Charlson's score ≤6, the technique survival was similar (44.4% vs 42.5%, P = 0.15). Peritonitis‐free survival was 35.2% and 32.2% for APD and CAPD groups, respectively (P = 0.021), and the difference was not affected by Charlson's score.

Conclusions

Comorbid diseases had a significant interaction with the mode of PD on patient and technique survival of incident PD patients. Our result suggests that APD may offer benefit in, and only in, young patients with minimal comorbid diseases.
A rare case of calibre persistent labial artery presenting as a mucocoele
Authors: Aga F. , Mukhtar Z. , Hardee P.
Published: March 2013

We present a case of a patient presenting with a lesion consistent with a mucocoele on the lower labial mucosa, which upon biopsy instead revealed a rare anomaly called a ‘calibre persistent artery’. The aim of this article is to bring this rarely reported lesion to the attention of clinicians, and to emphasise the importance of correct assessment of a lump.
The experimental governing of mobility and trade on the China‐Laos frontier: The Tai Lue case
Authors: Diana Antonella
Published: March 2013

This paper discusses the governing of subjects and objects' mobility in the context of trans‐border rice and corn trade on the China‐Laos frontier. It traces the attempts by a group of ethnic Tai Lue traders from China to assert themselves as ‘flexible subjects’ and economically triumphant actors on the Upper Mekong market in the era of economic regionalization. It illustrates how, between 2005 and mid‐2006, the traders' economic success relied on a variety of ‘border strategies’. ‘Border strategies’ include a gender‐balanced organization of trade, the instrumental deployment of trans‐border ethnicity, the appropriation of a Han style of business, the opportunistic reliance on the Chinese administration's ‘regime of graduated mobility’, and the enactment of a ‘war‐machine’ against Lao state agents. Yet, in late 2006, a new wave of state authoritarianism, enmeshed in corporate accumulation processes, inhibited the traders' success. The paper suggests that, unlike what some defenders of globalization and transnational theories maintain, in the age of economic regionalization, the alleged flexibility and increased mobility of subjects and objects across the borders of the Greater Mekong Subregion remain conditional on an unpredictable mechanism of loosening and tightening. This is part of a long‐applied governing pattern of ‘experimentation under hierarchy’ on the Sino‐Lao frontier.
Managing migration in the Greater Mekong Subregion: Regulation, extra‐legal relation and extortion
Authors: Latt Sai S.W.
Published: March 2013

One major aim of the Greater Mekong Subregion (GMS) integration programme, supported by the Asian Development Bank (ADB), is to foster regional ‘community’ for sharing resources, people and financial flows. This ‘community’ is the target of both economic growth and poverty reduction. The emphasis on ‘community’ in the ADB's mushrooming quantity of documents raises important questions about what kinds of people are included, in what roles and with what kinds of support and protection. This paper explores these questions in relation to the political economy of regulating ethnic migrants from Myanmar working in Thailand. This paper argues that extra‐legal relations between migrants and state/para‐state agents constitute a crucial part of regulation. In transferring the regulation of migration to the national scale, the ADB inadvertently reinforces national differences between Thais and cross‐border people. Additionally, the complicated and fluctuating implementation of national regulations in both countries leaves migrants subject to violence and extortion from state and quasi‐state agents in Thailand. This paper shows that the dynamics of global capitalism require ‘deportable labour’ supplied by ethnic migrants who are included in the GMS community as the most invisible, vulnerable and exploited members.
Imagining the borderlands: Contending stories of a resource frontier in Muang Sing
Authors: Lagerqvist Yayoi Fujita
Published: March 2013

Muang Sing in Luang Namtha province, an administrative district of northern Laos bordering Myanmar and China, has been portrayed by the Lao government and international development agencies as a ‘poor’ rural region in need of development. To developers, Muang Sing's remoteness from major towns and the livelihoods of ethnic people such as the Akha in the uplands based on swidden agriculture and opium production characterized ‘poverty’. To address this rural poverty, state and development agencies devised land use zoning that would demarcate and regulate various land uses in line with a rural development plan for the district. This vision for regulated development began to go awry, however, as farmers and traders in Muang Sing launched their own rapid social and economic changes. In contrast to the official image of a backward rural district in need of outside assistance, this paper portrays farmers and local entrepreneurs of the Muang Sing borderlands as actively transforming their lives and agricultural landscapes. This paper challenges the official version of a remote, poor district untouched by regional trade through a focus on narratives of local people. Ethnographic research reveals the dynamic micro‐processes of agrarian transformation during recent decades to highlight the centrality of borderland people in reworking their lives and agricultural landscapes through cross‐border relationships in China.
On the Constitutive Property Reply: Commentary onCampbell
Authors: Moore Dwayne
Published: March 2013

For the nonreductive physicalist, behavioural effects have a complete physiological explanation and a distinct psychological explanation. In a series of papersJaegwonKim argues that there can be no more than a single complete and independent explanation of any one event, thereby excluding the psychological explanation. For his own part,Kim includes psychological explanations through the use of an extensional model of explanatory individuation. Numerous critics have pointed out the counterintuitive results of this extensional model of explanatory individuation. In a recent article in this journal,NeilCampbell suggests thatKim's property exemplification account of events provides the conceptual resources to dodge this objection. In this article I argue that this appeal to the property exemplification account does not work in the crucial case of mental explanation.
Numerical Calculations of the Turbulent Flow Through a Controlled Diffusion Compressor Cascade
Authors: Kang Shin-Hyoung , Lee Joon Sik , Choi Myung-Ryul , Kim Kyung-Yup
Published: March 2013

The viscous flow through a controlled diffusion (CD) compressor cascade was calculated and compared with the measured data for two different test conditions. A control volume method was used, which has been developed for a generalized nonorthogonal coordinate system. The discretized equations for the physical covariant velocity components were obtained by an algebraic manipulation of the discretized equations for the Cartesian velocity components. Low Reynolds number k–ε turbulence models were used to obtain the eddy viscosity. The numerical scheme using the low Reynolds number k–ε turbulence model reasonably predicted the general performance, i.e, mean outlet flow angle and loss coefficients. The development of the shear layer along the pressure and suction sides was well estimated, and the physical features found in the experiment were reasonably well confirmed in the simulation. However, the calculated profiles of mean velocity and turbulent kinetic energy in the near wake show considerable disagreement with the measured values.
Experimental Investigation of the Flow in Diffusers Behind an Axial Flow Compressor
Authors: Zierer T.
Published: March 2013

The flow fields of four diffusers situated at the rear of a one-stage axial flow compressor were experimentally investigated. Through modification of the compressor operating point, a wide range of variations of the side wall boundary layers and the radial velocity distribution outside of the boundary layers at diffuser inlet could be achieved. The three-dimensional flow field at both diffuser inlet and outlet is analyzed. Changes of inlet blockage and radial velocity distribution and their resulting effects on pressure recovery are thoroughly presented. Compared with the results of measurements at diffusers, typically with ducted flow inlet conditions, higher values of pressure recovery are observed. Established design rules, based on investigations of diffusers with carefully developed inlet flow, are checked regarding their applicability for diffusers in turbomachine environments.
Effects of Free-Stream Turbulence Intensity on a Boundary Layer Recovering From Concave Curvature Effects
Authors: Kestoras M. D. , Simon T. W.
Published: March 2013

Experiments are conducted on a flat recovery wall downstream of sustained concave curvature in the presence of high free-stream turbulence (TI ∼ 8%). This flow simulates some of the features of the flow on the latter parts of the pressure surface of a gas turbine airfoil. The combined effects of concave curvature and TI, both present in the flow over a turbine airfoil, have so far been little studied. Computation of such flows with standard turbulence closure models has not been particularly successful. This experiment attempts to characterize the turbulence characteristics of this flow. In the present study, a turbulent boundary layer grows from the leading edge of a concave wall, then passes onto a downstream flat wall. Results show that turbulence intensities increase profoundly in the outer region of the boundary layer over the recovery wall. Near-wall turbulent eddies appear to lift off the recovery wall and a “stabilized” region forms near the wall. In contrast to a low-free-stream turbulence intensity flow, turbulent eddies penetrate the outer parts of the “stabilized” region where sharp velocity and temperature gradients exist. These eddies can more readily transfer momentum and heat. As a result, skin friction coefficients and Stanton numbers on the recovery wall are 20 and 10 percent, respectively, above their values in the low-free-stream turbulence intensity case. Stanton numbers do not undershoot flat-wall expectations at the same Reδ2 values as seen in the low-TI case. Remarkably, the velocity distribution in the core of the flow over the recovery wall exhibits a negative gradient normal to the wall under high-free-stream turbulence intensity conditions. This velocity distribution appears to be the result of two effects: (1) cross transport of kinetic energy by boundary work in the upstream curved flow and (2) readjustment of static pressure profiles in response to the removal of concave curvature.
Effect of Permeable Ribs on Heat Transfer and Friction in a Rectangular Channel
Authors: Hwang Jenn-Jiang , Liou Tong-Miin
Published: March 2013

Heat transfer and friction characteristics in a rectangular channel with perforated ribs arranged in-line on two opposite walls are investigated experimentally. Five perforated rib open-area ratios (0, 10, 22, 38, and 44 percent) and three rib pitch-to-height ratios (10, 15, and 20) are examined. The Reynolds number ranges from 5000 to 50,000. The rib height-to-channel hydraulic diameter ratio and the channel aspect ratio are 0.081 and 4, respectively. Laser holographic interferometry is employed not only to measure the heat transfer coefficients of the ribbed wall but also to determine the rib apparent permeability. It is found that ribs with appropriately high open-area ratio and high Reynolds number are permeable, and the critical Reynolds number for evidence of flow permeability decreases with increasing rib open-area ratio. Results of local heat transfer coefficients further show that the permeable ribs have an advantage of obviating hot spots. Moreover, the duct with permeable ribs gives a higher thermal performance than that with solid ribs.
Computed Eccentricity Effects on Turbine Rim Seals at Engine Conditions With a Mainstream
Authors: Guo Z. , Rhode D. L. , Davis F. M.
Published: March 2013

A previously verified axisymmetric Navier–Stokes computer code was extended for three-dimensional computation of eccentric rim seals of almost any configuration. All compressibility and thermal/momentum interaction effects are completely included, and the temperature, pressure, and Reynolds number of the mainstream, coolant stream, and turbine wheel are fixed at actual engine conditions. Regardless of the seal eccentricity, both ingress and egress are found between θ = −30 and 100 deg, which encompasses the location of maximum radial clearance at θ = 0 deg. All other θ locations within the rim seal show only egress, as does the concentric base case for all circumferential locations. Further, the maximum ingress occurs near θ = 30 deg for all eccentricities. This is found to produce a blade root/retainer temperature rise from the concentric case of 390 percent at 50 percent eccentricity and a 77 percent rise at 7.5 percent eccentricity. In addition, the nature of an increased eccentricity causing a decreased seal effectiveness is examined, along with the corresponding increase of cavity-averaged temperature.
Experimental and Numerical Investigation of a Shock Wave Within a Swept Shrouded Propfan Rotor
Authors: Helming K.
Published: March 2013

Laser velocity measurements are conducted in a swept propfan rotor in order to investigate the local transonic flow region on the suction surface at high subsonic inlet Mach numbers. The velocity measurements are accompanied by a three-dimensional Navier–Stokes calculation for a selected operating point. The good agreement between computed and measured flow field gives some confidence to study the local three-dimensional passage shock on the suction surface by using the numerical procedure. Apart from the computed three-dimensional shock, structure is investigated in detail. By considering streamlines, it is concluded whether the shock wave is normal or oblique. The results are compared with the one-dimensional shock conditions.
Improved Blade Profile Loss and Deviation Angle Models for Advanced Transonic Compressor Bladings: Part II—A Model for Supersonic Flow
Authors: Ko¨nig W. M. , Hennecke D. K. , Fottner L.
Published: March 2013

New blading concepts as used in modern transonic axial-flow compressors require improved loss and deviation angle correlations. The new model presented in this paper incorporates several elements and treats blade-row flows having subsonic and supersonic inlet conditions separately. The second part of the present report focuses on the extension of a well-known correlation for cascade losses at supersonic inlet flows. It was originally established for DCA bladings and is now modified to reflect the flow situation in blade rows having low-cambered, arbitrarily designed blades including precompression blades. Finally, the steady loss increase from subsonic to supersonic inlet-flow velocities demonstrates the matched performance of the different correlations of the new model.
Effect of Plenum Crossflow on Heat (Mass) Transfer Near and Within the Entrance of Film Cooling Holes
Authors: Goldstein R. J. , Cho H. H. , Jabbari M. Y.
Published: March 2013

Convective heat/mass transfer near and within the entrance region of film cooling holes supplied with air from an internal duct (plenum) behind the cooling holes has been measured using a naphthalene sublimation technique. The experiments are conducted for duct Reynolds number, based on the duct inlet flow condition, of 1800 to 13,500, which results in a range of hole Reynolds numbers of 8000 to 30,000, close to actual engine operating conditions. The flow entering the hole can be considered a combination of flow along a 90 deg tube bend and a sudden contraction duct flow. The flow separates at the inner corner and a secondary flow is induced by the centrifugal force associated with the streamline curvature. The mass transfer coefficient for the duct wall (surface of film-cooled plate) with a cooling hole is three to five times higher than for a fully developed duct flow. With a smaller duct, the overall transfer coefficient on the hole entrance surface increases due to the higher duct Reynolds numbers, but the flow has less secondary flow effects within the smaller space. Generally, transfer coefficients on the hole entrance surface are largely unaffected by the duct end presence, but the transfer coefficient is larger downstream for a short distance from the center of the last hole to the duct end. In tests with multiple film cooling holes, the flow at the first hole is more of a curved duct flow (strong secondary flow) and the flow at the last hole is more of a sink-like flow. At the middle hole, the flow is a combination of both flows. The mass transfer rates on the inner hole surfaces are found to be the same for holes with corresponding positions relative to the duct end, although the total number of open holes is different.
Film Cooling From a Single Row of Holes Oriented in Spanwise/Normal Planes
Authors: Ligrani P. M. , Ramsey A. E.
Published: March 2013

Experimental results are presented that describe the development and structure of flow downstream of a single row of film-cooling holes inclined at 30 deg from the test surface in spanwise/normal planes. With this configuration, holes are spaced 6d apart in the spanwise direction in a single row. Results are presented for a ratio of injectant density to free-stream density near 1.0, and injection blowing ratios from 0.5 to 1.5. Compared to results measured downstream of simple angle (streamwise) oriented holes, spanwise-averaged adiabatic effectiveness values are significantly higher for the same spanwise hole spacing, normalized streamwise location x/d, and blowing ratio m when m = 1.0 and 1.5 for x/d < 80. The injectant from the spanwise/normal holes is also less likely to lift off of the test surface than injectant from simple angle holes. This is because lateral components of momentum keep higher concentrations of injectant in closer proximity to the surface. As a result, local adiabatic effectiveness values show significantly greater spanwise variations and higher local maxima at locations immediately downstream of the holes. Spanwise-averaged iso-energetic Stanton number ratios range between 1.07 and 1.26, which are significantly higher than values measured downstream of two other injection configurations (one of which is simple angle, streamwise holes) when compared at the same x/d and blowing ratio.
Application of a Multi-Block CFD Code to Investigate the Impact of Geometry Modeling on Centrifugal Compressor Flow Field Predictions
Authors: Hathaway M. D. , Wood J. R.
Published: March 2013

CFD codes capable of utilizing multi-block grids provide the capability to analyze the complete geometry of centrifugal compressors including, among others, multiple splitter rows, tip clearance, blunt trailing edges, fillets, and slots between moving and stationary surfaces. Attendant with this increased capability is potentially increased grid setup time and more computational overhead—CPU time and memory requirements—with the resultant increase in “wall clock” time to obtain a solution. If the increase in “difficulty” of obtaining a solution significantly improves the solution from that obtained by modeling the features of the tip clearance flow or the typical bluntness of a centrifugal compressor’s trailing edge, then the additional burden is worthwhile. However, if the additional information obtained is of marginal use, then modeling of certain features of the geometry may provide reasonable solutions for designers to make comparative choices when pursuing a new design. In this spirit a sequence of grids were generated to study the relative importance of modeling versus detailed gridding of the tip gap and blunt trailing edge regions of the NASA large low-speed centrifugal compressor for which there is considerable detailed internal laser anemometry data available for comparison. The results indicate: (1) There is no significant difference in predicted tip clearance mass flow rate whether the tip gap is gridded or modeled. (2) Gridding rather than modeling the trailing edge results in better predictions of some flow details downstream of the impeller, but otherwise appears to offer no great benefits. (3) The pitchwise variation of absolute flow angle decreases rapidly up to 8 percent impeller radius ratio and much more slowly thereafter. Although some improvements in prediction of flow field details are realized as a result of analyzing the actual geometry there is no clear consensus that any of the grids investigated produced superior results in every case when compared to the measurements. However, if a multi-block code is available, it should be used, as it has the propensity for enabling better predictions than a single block code, which requires modeling of certain geometry features. If a single block code must be used, some guidance is offered for modeling those geometry features that cannot be directly gridded.