bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlations of TOP2A gene aberrations and expression of topoisomerase IIα protein and TOP2A mRNA expression in primary breast cancer: A retrospective study of 86 cases using fluorescence in situ hybridization and immunohistochemistry
Authors: Meng Hui , Chen Renyin , Li Wencai , Xu Li , Xu Lina
Published: March 2012

Our aim in this study was to assess the status of TOP2A gene aberrations (no change/amplification or deletion) and its correlations with topoisomerase IIα (Topo IIα) protein and TOP2A mRNA expression, respectively. TOP2A amplification, Topo IIα protein expression and TOP2A mRNA expression were assessed using samples of 86 cases of breast cancer by fluorescence in fluorescence in situ hybridization, quantitative real‐time polymerase chain reaction and immunohistochemistry, respectively. Twenty two (22.57%) had amplification/deletion of TOP2A gene. Twenty eight (32.56%) tumor samples were 17q polysomy or monosomy. Topo IIα protein was expressed in 57 cases (66.27%, 57/86): 22 cases (38.62%, 22/57) and 35 cases (61.40%, 35/57) had amplification/deletion and no change of TOP2A gene, respectively. These three groups showed significant differences by one‐way analysis of variance (P < 0.001). The average Ct values of TOP2A mRNA expression in the tumors with deletion, amplification and no change of TOP2A gene were 27.00, 27.33 and 31.66, respectively. We demonstrated that the TOP2A gene was amplified or deleted in breast cancer, with a significant correlation with high expressions of Topo IIα protein and TOP2A mRNA expression. Ki‐67 expression index (mean = 14.9) decreased significantly in cases wherein TOP2A gene had no change and Her2/neu protein expression was weakly positive (0−1+, P < 0.001).
Large bowel obstruction due to colorectal carcinoma can be safely treated by colonic stent insertion – case series from a UK district general hospital
Authors: Blake P. , Delicata R. , Cross N. , Sturgeon G. , Hargest R.
Published: March 2012

Aim  The aim of this study is to audit our outcomes and experience of colonic stent insertion for malignant bowel obstruction.

Method  Retrospective audit of all stent insertions in a single district general hospital between August 2003 and December 2009. All patients had presented with acute bowel obstruction caused by malignant colorectal disease and details were collected prospectively and contemporaneously onto a database. Stent insertion was a combined endoscopic and fluoroscopic procedure involving a colorectal surgeon and consultant radiologist.

Results  Stenting was attempted on 62 occasions in 54 patients. The technical success rate was 86% and the clinical success rate 84%. The indications for stenting were for relief of acute bowel obstruction, palliation and as a bridge to surgery. There were complications in 14 cases (22.5%) including three perforations and one perioperative mortality. There were three cases of stent migration, six cases of re‐stenosis and two stents became impacted with stool. There were no incidents of acute or delayed haemorrhage in any patients.

Conclusion  Our experience shows that stenting for obstructing colorectal cancer is a safe and effective method of alleviating acute and impending bowel obstruction and can be provided safely and effectively in a district general hospital.
The hero, the anima and the claustrum: anality and idealization
Authors: Meredith‐Owen William
Published: March 2012

Abstract:  Joe Redfearn's (1979) classic paper ‘The captive, the treasure, the hero and the anal stage of development’ is recognized as seminal to the development of Jungian thought about anality, particularly its integration with mainstream (Freudian, Kleinian) psychoanalytic perspectives. This paper develops such an approach through drawing on contributions from Meltzer, Green, Bion, Chasseguet‐Smirgel and Kernberg. More specifically, it is argued that over‐investment in hero and anima archetypal configurations may represent an attempt to replace the resource of the internal parental couple that, at the level of unconscious phantasy, has been destroyed by the aggrieved child's attack on the primal scene. Unless this usually dissociated sadism can be integrated, the creative epistemophilic instinct may remain blunted, giving rise, through projective identification, to the adoption of a pseudo‐adult identity based on appropriation or assertion. This in turn may lead to manic attempts to reach authentic (‘animating’) experience through the (often erotized) excitement of heroic endeavour.

Consideration of both Redfearn's and the author's own clinical material demonstrates how close attention to process as well as content is fundamental to revealing and addressing such likely‐to‐be dissociated scenarios.
A broadly tuned mouse odorant receptor that detects nitrotoluenes
Authors: Li Jingyi , Haddad Rafi , Chen Sisi , Santos Vanessa , Luetje Charles W.
Published: March 2012

J. Neurochem. (2012) 121, 881–890.

Mammals employ large numbers of odorant receptors to sample and identify volatile chemicals in the environment. These receptors are thought to vary not only in specificity for particular odorants, but also in breadth of tuning. That is, some odorant receptors are narrowly focused on a few closely related structures, while other odorant receptors may be ‘broadly tuned’, responding to a wide variety of odorant structures. In this study, we have performed a detailed examination the mouse odorant receptor MOR256‐17, demonstrating that this receptor is broadly tuned. This receptor responds to odorant structures that span a significant portion of a multi‐dimensional odor space. However, we found that broad tuning was not a defining characteristic of other members the MOR256 subfamily. Two additional members of this odorant receptor subfamily (MOR256‐8 and MOR256‐22) were more narrowly focused on small sets of odorant structures. Interestingly, the receptive range of MOR256‐17 encompassed a variety of nitrotoluenes, including various trinitrotoluene synthesis intermediates, degradation products and trinitrotoluene itself, suggesting the potential utility of odorant receptors in the development of sensing technologies for the detection of explosives and other forms of contraband.
Subjected Subjects? On Judith Butler's Paradox of Interpellation
Authors: Davis Noela
Published: March 2012

Judith Butler's theory of the constitution of subjectivity conceptualizes the subject as a performative materialization of its social environment. In her theory Butler utilizes Louis Althusser's notion of interpellation, and she critiques the constitutive paradoxes to which its tautological framing leads. Although there is no pre‐existing subject, as it is constituted in the turn to the interpellative hail, Butler nonetheless theorizes a guilt and compulsion acting on an “individual” that compels his or her turn to answer the hail. There is a price to pay for subjectivity in Butler's schema: the reprimand of the interpellative law that punishes at the same time as it constitutes. But a return to Althusser's text finds that he does not rely so much on coercion and guilt in his explanation of the subject's answer to the hail. Althusser can instead be read as suggesting that we are already an instantiation and enactment of power‐ideology and, to paraphrase Michel Foucault, are already the principle of our own “subjection.” This contests the notion that we are in any way compelled to submit to an external, punitive force to become subjects. As subjects, we are always‐already the embodiment of the field of society‐power‐ideology.
Women's Writing and the Early Modern Genre Wars
Authors: Green Karen
Published: March 2012

This paper explores two phases of the early modern genre wars. The first was fought by Marie de Gournay, in her “Preface” to Montaigne's Essays, on behalf of her adoptive father and in defense of his naked and masculine prose. The second was fought half a century later by Nicholas Boileau in opposition to Gournay's feminizing successor, Madeleine de Scudéry. In this debate Gournay's position is egalitarian, whereas Scudéry's approximates to a feminism of difference. It is claimed that both female protagonists in this early debate occlude the female body. The far more sexually explicit prose of Mary Delarivier Manley is then used to raise the question: is it genre, or is it, rather, the very nature of erotic sexuality, that makes it so difficult for women to masterfully expose themselves as authoritative subjects?
A NEW METHOD OF CYSTOCARP DEVELOPMENT IN THE RED ALGAL GENUS CALLOPHYLLIS (KALLYMENIACEAE) FROM CHILE1
Authors: Lin Showe‐Mei , D’Archino Roberta , Hommersand Max H.
Published: March 2012

Traditional studies suggest that the Kallymeniaceae can be divided into two major groups, a nonprocarpic Kallymenia group, in which carposporophyte formation involves an auxiliary cell branch system separate from the carpogonial branch system, and a procarpic Callophyllis group, in which the carpogonial branch system gives rise to the carposporophyte directly after fertilization. Based on our phylogenetic studies and unpublished observations, the two groups each contain both procarpic and nonprocarpic genera. Here, we describe a new method of reproductive development in Callophyllis concepcionensis Arakaki, Alveal et Ramírez from Chile. The carpogonial branch system consists of a supporting cell bearing both a three‐celled carpogonial branch with trichogyne and two‐lobed “subsidiary” cells. After fertilization, large numbers of secondary subcortical and medullary cells are produced. Lobes of the carpogonial branch system cut off connecting cells containing enlarged, presumably diploid nuclei that fuse with these secondary vegetative cells and deposit their nuclei. Derivative enlarged nuclei are transferred from one vegetative cell to another, which ultimately cut off gonimoblast initials that form filaments that surround the central primary medullary cells and produce carposporangia. The repeated involvement of vegetative cells in gonimoblast formation is a new observation, not only in Callophyllis, but in red algae generally. These results call for a revised classification of the Kallymeniaceae based on new morphological and molecular studies.
NEUTRAL LIPID AND CARBOHYDRATE PRODUCTIVITIES AS A RESPONSE TO NITROGEN STATUS IN ISOCHRYSIS SP. (T‐ISO; HAPTOPHYCEAE): STARVATION VERSUS LIMITATION1
Authors: Lacour Thomas , Sciandra Antoine , Talec Amélie , Mayzaud Patrick , Bernard Olivier
Published: March 2012

Partitioning of the carbon (C) fixed during photosynthesis between neutral lipids (NL) and carbohydrates was investigated in Isochrysis sp. (Haptophyceae) in relation to its nitrogen (N) status. Using batch and nitrate‐limited continuous cultures, we studied the response of these energy reserve pools to both conditions of N starvation and limitation. During N starvation, NL and carbohydrate quotas increased but their specific growth rates (specific rates of variation, μCAR and μNL) decreased. When cells were successively deprived and then resupplied with NO3, both carbohydrates and neutral lipids were inversely related to the N quota (N:C). These negative relationships were not identical during N impoverishment and replenishment, indicating a hysteresis phenomenon between N and C reserve mobilizations. Cells acclimated to increasing degrees of N limitation in steady‐state chemostat cultures showed decreasing NL quota and increasing carbohydrate quota. N starvation led to a visible but only transient increase of NL productivity. In continuous cultures, the highest NL productivity was obtained for the highest experimented dilution rate (D = 1.0 d−1; i.e., for non N‐limited growth conditions), whereas the highest carbohydrate productivity was obtained at D = 0.67 d−1. We used these results to discuss the nitrogen conditions that optimize NL productivities in the context of biofuel production.
Preserving the Public Interest in Highway Public–Private Partnerships: A Case Study of the State of Texas
Authors: BUNCH BEVERLY
Published: March 2012

Faced with existing revenues sources that are insufficient to finance highway maintenance and construction needs, some state and local governments are using or considering highway public–private partnerships. These partnerships may be attractive as a way for a government to obtain upfront revenues from the long‐term lease of a road and to shift some of the construction and operations risks to a private firm. However, with these benefits, comes the need to preserve the public interest. This paper discusses issues related to preserving the public interest in highway public–private partnerships and presents a case study of the State of Texas. The case study focuses on an analysis of the strengths and limitations of Texas’ policies and procedures to protect the public interest in the use of long‐term leases for the financing, construction, and operation of new toll roads. The case study also discusses what other governments may be able to learn from Texas’ experiences.
Morphologic Patterns of Lip Prints in a Portuguese Population: A Preliminary Analysis
Authors: Costa Vírginia A. , Caldas Inês M.
Published: March 2012

Abstract:  Lip prints are thought to have the ability to distinguish individuals and, hence, have a potential use in human identification purposes. However, questions remain regarding their utility for sex determination. This study aimed to classify lip prints for different individuals in a Portuguese population and to determine whether sex differences exist. Lip prints of 25 females and 25 males were obtained using dark‐colored lipstick and cellophane tape. Lip prints were analyzed using a magnifying lens and classified according to the Suzuki and Tsuchihashi classification. A Type II pattern was found to be most common. A comparison of lip‐print patterns between males and females showed results with a statistically significant difference: Type III pattern was most common in males, and a Type II pattern in females. This study corroborates the hypothesis that lip prints are able to distinguish individuals and may be useful in sex determination.
Concurrent emergence of multidrug resistance and heat resistance by CTX‐M‐15‐encoding conjugative plasmids in Klebsiella pneumoniae
Authors: Bojer Martin S. , Hammerum Anette M. , Jørgensen Steffen L. , Hansen Frank , Olsen Stefan S. , Krogfelt Karen A. , Struve Carsten
Published: March 2012

A plasmid‐encoded ClpK protein was recently identified as a predictor of a heat‐resistant phenotype in the opportunistic pathogen Klebsiella pneumoniae. This study was undertaken to evaluate the presence of the clpK gene in extended‐spectrum β‐lactamase (ESBL)‐producing K. pneumoniae and to assess the probable co‐transfer of multi‐resistance with the heat resistance phenotype. A Danish collection of 80 ESBL‐producing K. pneumoniae bloodstream infection isolates was screened for clpK by colony hybridization. Nineteen isolates (24%) were positive for clpK; some of them representing major clones identified in Denmark. Among these, nine isolates belonged to a single K. pneumoniae CTX‐M‐15 clone with sequence type (ST)16 exhibiting a heat‐resistant phenotype. This clone has a multi‐hospital occurrence and has also been detected outside Denmark. Horizontal co‐transfer of multiple antibiotic resistances, including the CTX‐M‐15 resistance determinant, and the heat resistance phenotype was observed. Thus, the clpK gene is harbored by different ESBL‐producing K. pneumoniae isolates including a clone of ST16 internationally spread. The co‐localization of clpK on transferable ESBL‐encoding plasmids allowing co‐dissemination of multiple drug resistance with bacterial heat resistance is a highly interesting phenomenon that may further complicate the prevention of spreading of certain successful clones of multi‐resistant K. pneumoniae.
Age‐related prevalence of Methanomassiliicoccus luminyensis in the human gut microbiome
Authors: Dridi Bédis , Henry Mireille , Richet Hervé , Raoult Didier , Drancourt Michel
Published: March 2012

A 16S rDNA sequence‐based investigation of methanogenic Archaea in the human stools found Methanobrevibacter smithii in 99.2% and Methanosphaera stadtmanae in 32.6%. The recently described Methanomassiliicoccus luminyensis found by others to be representative of a new order of methanogenic Archaea was found in 4% of stool specimens. The prevalence of M. luminyensis significantly increased with age, contrary to M. smithii and M. stadtmanae.
LORACS: JAVA software for modeling landscape connectivity and matrix permeability
Authors: Pinto Naiara , Keitt Timothy H. , Wainright Michael
Published: March 2012

GIS tools and remote sensing products have opened the possibility to model the impacts of matrix permeability on a broad range of ecological phenomena. LORACS (Landscape ORganization and Connectivity Survey) is JAVA software containing a GUI interface and an API for easy extensibility. The user inputs maps with the relative costs to move within each pixel and the location of source and target patches. The software outputs Multiple Shortest Paths and Conditional Minimum Transit Cost maps. One key feature is the derivation of uncertainty estimates around path length, cost, and spatial distribution. We use data from the Brazilian Atlantic Forest to illustrate how LORACS can be used to translate assumptions about habitat quality into landscape connectivity patterns.
Dedifferentiation of human epidermal melanocytes into melanoblasts in vitro
Authors: Zhao Zhiguo , Jin Cheng , Ding Keyun , Ge Xiaopeng , Dai Lllan
Published: March 2012

Abstract:  Melanoblasts (MB) are also called melanocyte (MC) precursor cells. In recent years, people have successfully cultivated human and mouse MB. Previous studies have shown that EDN3 induces cultivated bird MC to re‐differentiate into double potential progenitor cells of MB. However, no study has reported whether in vitro cultivated human MC can be dedifferentiated. Our research on MC that were purified and cultivated in vitro found that adding 10 nm endothelin 1 (EDN1) (ET‐1) to the MC medium without phorbol 12‐myristate 13‐acetate (PMA) induced a few MC to dedifferentiate and become a new type of cell. This new cell type was separated, purified, cloned and identified using multiple approaches. The results show that 88.7%, 8.69% and 2.5% of this new cell type were cells in the G0‐G1, G2‐M and S stages, respectively. The new cell type did not exhibit an apparent apoptotic peak, and its apoptotic rate was 0.09%. Stage I melanosomes were observed in the cytoplasm and were negative for the DOPA reaction. The cell surface antigen expression was positive for tyrosinase‐related protein 2, negative or positive for c‐kit and negative for S‐100 and HMB45, showing that these cells were dedifferentiated MB of MC. Our findings provided evidence for atavism of mature human MC under certain conditions.
Root fractures: the influence of type of healing and location of fracture on tooth survival rates – an analysis of 492 cases
Authors: Andreasen Jens Ove , Ahrensburg Søren Steno , Tsilingaridis Georgios
Published: March 2012

Abstract –  Aim: The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed. Material and methods: Long‐term survival rates were calculated using data from 492 root‐fractured teeth in 432 patients. The cause of tooth loss was assessed as being the result of either pulp necrosis (including endodontic failures), new traumas or excessive mobility. The statistics used were Kaplan–Meier and the log rank method. Results and Conclusions: The location of the root fracture had a strong significant effect on tooth survival (P = 0.0001). The 10‐year tooth survival of apical root fractures was 89% [95% confidence interval (CI), 78–99%], of mid‐root fractures 78% (CI, 64–92%), of cervical‐mid‐root fractures 67% (CI, 50–85%), and of cervical fractures 33% (CI, 17–49%). The fracture‐healing type offered further prognostic information. No tooth loss was observed in teeth with hard tissue fracture healing regardless of the position of the fracture. For teeth with interposition of connective tissue, the location of the fracture had a significant influence on tooth loss (P = 0.0001). For teeth with connective tissue healing, the estimated 8‐year survival of apical, mid‐root, and cervical‐mid‐root fractures were all more than 80%, whereas the estimated 8‐year survival of cervical fractures was 25% (CI, 7–43%). For teeth with non‐healing with interposition of granulation tissue, the location of the fracture showed a significant influence on tooth loss (P = 0.0001). The cause of tooth loss was found to be very dependent upon the location of the fracture. In conclusion, the long‐term tooth survival of root fractures was strongly influenced by the type of healing and the location of the fracture.
The biogenesis of active protein phosphatase 2A holoenzymes: a tightly regulated process creating phosphatase specificity
Authors: Sents Ward , Ivanova Elitsa , Lambrecht Caroline , Haesen Dorien , Janssens Veerle
Published: March 2012

Protein phosphatase type 2A (PP2A) enzymes constitute a large family of Ser/Thr phosphatases with multiple functions in cellular signaling and physiology. The composition of heterotrimeric PP2A holoenzymes, resulting from the combinatorial assembly of a catalytic C subunit, a structural A subunit, and regulatory B‐type subunit, provides the essential determinants for substrate specificity, subcellular targeting, and fine‐tuning of phosphatase activity, largely explaining why PP2A is functionally involved in so many diverse physiological processes, sometimes in seemingly opposing ways. In this review, we highlight how PP2A holoenzyme biogenesis and enzymatic activity are controlled by a sophisticatedly coordinated network of five PP2A modulators, consisting of α4, phosphatase 2A phosphatase activator (PTPA), leucine carboxyl methyl transferase 1 (LCMT1), PP2A methyl esterase 1 (PME‐1) and, potentially, target of rapamycin signaling pathway regulator‐like 1 (TIPRL1), which serve to prevent promiscuous phosphatase activity until the holoenzyme is completely assembled. Likewise, these modulators may come into play when PP2A holoenzymes are disassembled following particular cellular stresses. Malfunctioning of these cellular control mechanisms contributes to human disease. The potential therapeutic benefits or pitfalls of interfering with these regulatory mechanisms will be briefly discussed.
Phenotyping for Abiotic Stress Tolerance in MaizeF
Authors: Masuka Benhilda , Araus Jose Luis , Das Biswanath , Sonder Kai , Cairns Jill E.
Published: March 2012

image
[ Jill E. Cairns ]

The ability to quickly develop germplasm having tolerance to several complex polygenic inherited abiotic and biotic stresses combined is critical to the resilience of cropping systems in the face of climate change. Molecular breeding offers the tools to accelerate cereal breeding; however, suitable phenotyping protocols are essential to ensure that the much‐anticipated benefits of molecular breeding can be realized. To facilitate the full potential of molecular tools, greater emphasis needs to be given to reducing the within‐experimental site variability, application of stress and characterization of the environment and appropriate phenotyping tools. Yield is a function of many processes throughout the plant cycle, and thus integrative traits that encompass crop performance over time or organization level (i.e. canopy level) will provide a better alternative to instantaneous measurements which provide only a snapshot of a given plant process. Many new phenotyping tools based on remote sensing are now available including non‐destructive measurements of growth‐related parameters based on spectral reflectance and infrared thermometry to estimate plant water status. Here we describe key field phenotyping protocols for maize with emphasis on tolerance to drought and low nitrogen.
Financial Markets and Economic Growth*
Authors: Miller Merton H.
Published: March 2012

In this reprinting of the Nobel Prize‐winning financial economist's classic statement about the origins of financial crises, the Southeast Asian crisis of the late 1990s is attributed “not to too much reliance on financial markets, but to too little.” Like the U.S. economy a century ago, the emerging Asian economies did not then—and do not now—have well‐developed capital markets and remain heavily dependent on their banking systems to finance growth. But for all its benefits, banking is not only basically 19th‐century technology, but disaster‐prone technology. And in the summer of 1997, a banking‐driven disaster struck in East Asia, just as it had struck so many times before in U.S. history.

During the 20th century, the author argues, the U.S. economy reduced its dependence on banks by developing “dispersed and decentralized” financial markets. In so doing, it increased the efficiency of the capital allocation process and reduced the economy's vulnerability to the credit crunches that have recurred throughout U.S. history. By contrast, Japan has not reduced its economy's dependence on banks, and its efforts to deal with its banking problems during the crisis of the late'90s served only to destabilize itself as well as its neighbors. Developing countries in Asia and elsewhere are urged not to follow the Japanese example, but to take measures aimed at developing financial markets and institutions that will either substitute for or, in some cases, complement bank products and services.
CHEMOSTRATIGRAPHY OF CENOMANIAN–TURONIAN CARBONATES OF THE SARVAK FORMATION, SOUTHERN IRAN
Authors: Hajikazemi E. , Al‐Aasm I.S. , Coniglio M.
Published: March 2012

Stable‐isotope and trace‐element analyses from five surface and subsurface sections of the mid‐Cretaceous Sarvak Formation in southern and offshore Iran confirm the presence of the regional‐scale Turonian unconformity and of a more local Cenomanian–Turonian unconformity. The geochemical results indicate the presence of previously unrecognized and/or undifferentiated subaerial exposure surfaces. Sarvak Formation carbonates at or near palaeo‐exposure surfaces show varying degrees of diagenetic modification, and more extensive alteration is associated with longer periods of exposure. The subaerial exposure and associated diagenetic processes greatly influenced reservoir quality and amplified karstification and evolution of porosity in the Upper Sarvak Formation.

The palaeo‐exposure surfaces are identified by their negative δ13C values (as low as – 6.4%) and negative δ18O values (as low as –9.4%), together with low Sr concentrations and relatively high 87Sr/86Sr ratios. These geochemical characteristics are interpreted to be the result of the interaction of the Sarvak Formation carbonates with meteoric waters charged with atmospheric CO2. The meteoric waters also caused karstification and soil formation which in some places extends a few metres below the exposure surfaces. Depleted carbon values were not recorded in areas where palaeosols are not well developed or where the uppermost layers of the Sarvak Formation have been removed by erosion.
Comparative Echocardiographic and Clinical Features of Hypertrophic Cardiomyopathy in 5 Breeds of Cats: A Retrospective Analysis of 344 Cases (2001–2011)
Authors: Trehiou‐Sechi E. , Tissier R. , Gouni V. , Misbach C. , Petit A.M.P. , Balouka D. , Carlos Sampedrano C. , Castaignet M. , Pouchelon J.‐L. , Chetboul V.
Published: March 2012

Background

Primary hypertrophic cardiomyopathy (HCM) is the most common feline heart disease and has been demonstrated to be inherited in some breeds. However, few studies have comparedHCMphenotypes and survival according to breed.

Objectives

To compare epidemiological characteristics, clinical findings, left ventricular (LV) geometric patterns, and survival in several breeds of cats withHCM.

Animals

Three hundred and forty‐four cats from 5 different breeds (Persian, Domestic Shorthair [DS], Sphynx, Maine coon [MC], and Chartreux) with primaryHCMdiagnosed by conventional echocardiography.

Methods

Retrospective study. Cats were classified according to breed and clinical status.

Results

Age at the time of diagnosis was lower (P < .001) inMC(median age, 2.5 years) and Sphynx (3.5 years) than in other breeds (OB), ie, 8.0, 8.0, and 11.0 years forDS, Chartreux, and Persians, respectively. The prevalence ofLVoutflow tract obstruction was higher (P < .001) in Persians (23/41; 56%) than inOB(115/303; 38%). Age at the first cardiac event was lower (P < .01) inMC(median age, 2.5 years) than inOB(7.0 years). All cats surviving > 15 years of age wereDS, Persians, or Chartreux. Sudden death (representing 24% of all cardiac deaths) was observed only in 3 breeds (DS,MC, and Sphynx).

Conclusion and Clinical Importance

As in humans, felineHCMis characterized by marked phenotypic variability with several breed‐dependent features regarding epidemiology,LVgeometric patterns, and clinical course (ie, age at diagnosis, 1st cardiac event, and cause of death).
Statistical evaluation of parameters estimating autocorrelation and individual heterogeneity in longitudinal studies
Authors: Hamel Sandra , Yoccoz Nigel G. , Gaillard Jean‐Michel
Published: March 2012

1. Autocorrelation and individual heterogeneity are now considered to reflect biological processes rather than simply being a nuisance requiring to be accounted for. Before using parameter estimates that represent autocorrelation and individual heterogeneity to infer biological processes, a statistical evaluation of their precision and accuracy is required to validate their use.

2. Using simulated data, we evaluated accuracy and precision of temporal autocorrelation and individual heterogeneity estimates provided by different statistical models. We compared estimates across different intensity of individual variation and life histories, and sampling effort. We focused on recurrent binary variables because statistical evaluations of models describing binary processes have often been overlooked although several evolutionary and ecological processes are expressed as binary variables (e.g. probability of annual reproduction, plant annual flowering and detection, seasonal migration decision).

3. Our results showed that autocorrelation and individual heterogeneity were generally better estimated using a ‘time series’ modelling approach, but that a ‘state dependence’ modelling approach also provided fair estimates in most cases. The latter method was even more robust when data sets included missing values. Data sets including missing values or consisting of very short times series resulted in important bias in some instances.

4. Models ignoring either individual heterogeneity or autocorrelation performed poorly, illustrating the fundamental association between these two processes, and demonstrating that the complex structure of autocorrelation and individual heterogeneity patterns is difficult to tackle using simple models.

5. Our work’s major finding is the demonstration that autocorrelation and individual heterogeneity need to be both accounted for to provide reliable estimates even in studies focusing on only one of these processes. Our study also offers a set of practical recommendations for helping researchers modelling these two processes depending on their scientific aims and the structure of their data. Finally, our results illustrate that more research is required for estimating individual heterogeneity when positive temporal autocorrelation is expected because none of the models evaluated provided suitable estimates.
Effects of ventricular pacing protocol on electrical restitution assessments in guinea‐pig heart
Authors: Osadchii Oleg E.
Published: March 2012

The steep slope of the rate adaptation of ventricular action potential duration (APD) is thought to indicate profibrillatory tendency. In cardiac patients, APD restitution is commonly assessed by extrasystolic (S1–S2) stimulations rather than dynamic pacing, because the latter may provoke myocardial ischaemia. In this study, ventricular APD and effective refractory period (ERP) were measured in perfused guinea‐pig hearts to determine whether S1–S2 stimulations and dynamic pacing may have similar value in APD restitution assessments aimed to predict arrhythmic risk. The maximal restitution slope was greater upon S1–S2 stimulation than dynamic pacing at the epicardium (S1–S2, 1.2 ± 0.08; dynamic, 0.72 ± 0.06; P= 0.0004) and endocardium (S1–S2, 1.45 ± 0.08; dynamic, 0.95 ± 0.06; P= 0.0003). This difference was partly accounted for by an effect of the previous pacing history, as evidenced by flattening of APD restitution upon reductions in the regular beating interval prior to S2 application. Furthermore, shorter ERP than APD relationships enabled ventricular capture at shorter diastolic intervals during S1–S2 stimulation than dynamic pacing at the epicardium (S1–S2, −1 ± 3 ms; dynamic, 35 ± 3 ms; P < 0.0001) and endocardium (S1–S2, −1 ± 7 ms; dynamic, 38 ± 3 ms; P < 0.0001), thereby contributing to greater maximal restitution slope values. Flecainide, a Na+ channel blocker, increased the ERP‐to‐APD ratio and eliminated early premature beats (diastolic interval of ∼0 ms), thereby flattening the S1–S2 restitution curve, but had no effect on dynamic restitution. In hypokalaemia‐induced arrhythmogenicity, a reduction in ventricular fibrillation threshold was paralleled by increased steepness of dynamic APD restitution, while no change in the maximal restitution slope was revealed by S1–S2 stimulations. In summary, changes in electrical restitution obtained from extrasystolic stimulations may dissociate from those revealed by dynamic pacing. These findings therefore challenge the value of electrical restitution assessments based on extrasystolic stimulation alone, as commonly performed in the clinical setting.
Nanofluids and Their Properties
Authors: Puliti Gianluca , Paolucci Samuel , Sen Mihir
Published: March 2012

Nanofluids belong to a new class of fluids with enhanced thermophysical properties and heat transfer performance. A broad spectrum of applications in science and engineering could potentially benefit from them. The potential market for nanofluids in heat transfer applications is estimated to be over 2 billion dollars per year, and likely to grow even further in the next few years. The available literature on nanofluids will be thoroughly reviewed in this article. Starting from their definition, and their scientific and engineering significance, the discussion will then turn to the literature. A review of the most noteworthy and recent experiments in thermal conductivity, viscosity, heat convection and specific heat will be mentioned, together with various speculations on the meaning of the results. A comprehensive list of empirical models available in the literature based on these speculations will be discussed next. To complete the literature review, numerical studies on nanofluids will also be discussed. The paper will close with a closer look at the various challenges of nanofluids, both in their production and their application. The vast majority of the experiments in the literature shows enhancement in the thermal conductivity, viscosity, and heat convection of nanofluids. However, the enhancements do not seem to follow classical effective medium theories, and an explanation for this anomalous behavior of nanofluids is still largely unknown.
Preliminary Design and Performance Estimation of Radial Inflow Turbines: An Automated Approach
Authors: Ventura Carlos A.M. , Jacobs Peter A. , Rowlands Andrew S. , Petrie-Repar Paul , Sauret Emilie
Published: March 2012

A comprehensive one-dimensional meanline design approach for radial inflow turbines is described in the present work. An original code was developed in Python that takes a novel approach to the automatic selection of feasible machines based on pre-defined performance or geometry characteristics for a given application. It comprises a brute-force search algorithm that traverses the entire search space based on key non-dimensional parameters and rotational speed. In this study, an in-depth analysis and subsequent implementation of relevant loss models as well as selection criteria for radial inflow turbines is addressed. Comparison with previously published designs, as well as other available codes, showed good agreement. Sample (real and theoretical) test cases were trialed and results showed good agreement when compared to other available codes. The presented approach was found to be valid and the model was found to be a useful tool with regards to the preliminary design and performance estimation of radial inflow turbines, enabling its integration with other thermodynamic cycle analysis and three-dimensional blade design codes.
Performance Study of a Planar Solid Oxide Fuel Cell Using a COMSOL Based 2D Model and Actual Cell Testing Geometry and Operating Conditions
Authors: DiGiuseppe Gianfranco , Gowda Yeshwanth Javare , Honnagondanahalli Naveen Kumar
Published: March 2012

This paper reports a new electrochemical performance study performed on a planar SOFC cell. This study consists of a 2D model developed using a commercial software, namely Comsol Multiphysics. The model includes fluid dynamics, electrochemistry, electrical conduction, and diffusion physics. This model was built using the actual button cell testing geometry and using experimental data for validation purposes. The objective of this study is to understand the effects of the testing setup used on the cell performance, and to recommend an improved design or geometry where the cell performance is independent of any flow maldistribution in both the air and fuel side of the SOFC cell. The air and fuel flow rates are studied to determine the effects on the cell performance. The effects of electrode porosities are studied together with the fuel and air flow rates. The distance from the SOFC cell to the discharge fuel feed tube and air chamber geometry are studied as well. The modeling results indicate that the SOFC electrochemical performance becomes independent of any flow maldistribution at relatively high flow rates for both fuel and air. Reduced electrode porosities play a role in the cell performance, and larger flow rates are required in order to achieve a cell performance independent of flow rates. The cell performance is also affected by the distance from the SOFC cell to the fuel discharge tube and the air chamber geometry. The behavior seen in the cell performance can be explained by a non-uniform mole fraction of reactants near the electrode surface.
An Experimental Investigation of Air Water Flow Through Different Flow Field Designs of a PEMFC Bipolar Plate in the Presence of Micronized Wax
Authors: Utturkar Aditya , Mukherjee Abhijit
Published: March 2012

Water, a byproduct of the chemical reaction in a Proton Exchange Membrane Fuel Cell (PEMFC), is removed by the air flowing over the cathode. However, when water production rate is more than its rate of removal, water may flood the fuel cell cathode, cutting off the air supply and stopping the reaction. A bio-mimetic solution to the water management problem was proposed in an earlier work where micronized wax was introduced along with the air that would help encapsulate the water droplets facilitating their quick removal from the fuel cell. Based on earlier results, further investigation is done to study different bi-polar flow field designs for effective water management, using bio-mimetic micronized wax. The different flow field designs studied in this work consists of parallel and single serpentine channels on graphite plates under simulated fuel cell load conditions. The effect of micronized wax on the two-phase flow regimes at different flow field orientations is also analyzed. It is clearly observed that the presence of micronized wax significantly helps in water movement in all air flow channels designs and orientations. It is hypothesized that introduction of micronized wax along with the air flow will allow the use of parallel flow field bi-polar plate designs in operating fuel cells with significantly reduced air side pressure drop instead of the prevalent single serpentine channel flow field designs.
Oxygen Reduction Reaction Evaluation of Platinum Catalysts Formed via the Reactive Spray Deposition Technique
Authors: Roller Justin , Maric Radenka , Neagu Roberto , Orfino Frank
Published: March 2012

Reactive Spray Deposition Technology (RSDT) is a fabrication process developed for the 1-step deposition of platinum catalyst, carbon support and ionomer directly onto a Nafion® membrane. The process involves pumping a platinum-organic solute dissolved in a combustible solvent through an atomizer. The spray is then combusted and nanosized particles of platinum are produced and subsequently cooled by a gas quench. Once the reaction plume is cooled a secondary set of nozzles is used to inject the carbon support and ionomer. The quench air cools the reactive zone enough to allow direct deposition onto a Nafion® electrolyte or a glassy carbon electrode. This arrangement thus realizes a process for one-step catalyst formation, dispersion onto carbon and direct deposition onto an electrolyte membrane. The independent control of the three components allows for real-time control of the carbon, platinum, and ionomer ratios in the final electrode. In this research work we examine the oxygen reduction reaction via a rotating disc three electrode set-up to understand the intrinsic activity of the as-sprayed platinum. The mass and specific activities were measured in a 0.1 M perchloric acid electrolyte under different deposition conditions and loading was verified by atomic emission spectroscopy inductively coupled plasma (AES-ICP). A range of microscopy images for visualization of the microstructure are also presented. The initial results show that the RSDT technique is capable of producing catalysts with oxygen reduction mass activity at 0.9 V of 200 mA/mgPt rotating at 1600 rpm and 30 °C.
Comparison of Water Thickness Profiles of Compressed PEMFC GDLs
Authors: Challa Pradyumna , Hinebaugh James , Bazylak A.
Published: March 2012

In this paper, through-plane liquid water distribution is analyzed for two polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layers (GDLs). The experiments were conducted in an ex situ flow field apparatus with 1 mm square channels at two distinct flow rates to mimic water production rates of 0.2 and 1.5 A/cm2 in a PEMFC. Synchrotron radiography, which involves high intensity monochromatic X-ray beams, was used to obtain images with a spatial and temporal resolution of 20–25 μm and 0.9 s, respectively. Freudenberg H2315 I6 exhibited significantly higher amounts of water than Toray TGP-H-090 at the instance of breakthrough, where breakthrough describes the event in which liquid water reaches the flow fields. While Freudenberg H2315 I6 exhibited a significant overall decrease in liquid water content throughout the GDL shortly after breakthrough, Toray TGP-H-090 appeared to retain breakthrough water-levels post-breakthrough. It was also observed that the amount of liquid water content in Toray TGP-H-090 (10%.wt PTFE) decreased significantly when the liquid water injection rate increased from 1 μL/min to 8 μL/min.
Simultaneous Turbine Speed Regulation and Fuel Cell Airflow Tracking of a SOFC/GT Hybrid Plant With the Use of Airflow Bypass Valves
Authors: Tsai Alex , Tucker David , Clippinger David
Published: March 2012

This paper studies a novel control methodology aimed at regulating and tracking turbo machinery synchronous speed and fuel cell mass flow rate of a SOFC/GT hardware simulation facility with the sole use of airflow bypass valves. The hybrid facility under consideration consists of a 120kW auxiliary power unit gas turbine coupled to a 300kW SOFC hardware simulator. The hybrid simulator allows testing of a wide variety of fuel cell models under a Hardware-in-the-Loop configuration. Small changes in fuel cell cathode airflow have shown to have a large impact on system performance. Without simultaneous control of turbine speed via load or auxiliary fuel, fuel cell airflow tracking requires an alternate actuator methodology. The use of bypass valves to control mass flow rate and decouple turbine speed allows for a greater flexibility and feasibility of implementation at the larger scale, where synchronous speeds are required. This work utilizes empirically derived Transfer Functions (TF) as the system model and applies a Fuzzy Logic (FL) control algorithm that can be easily incorporated to nonlinear models of direct fired recuperated hybrid plants having similar configurations. This methodology is tested on a SIMULINK/MATLAB platform for various perturbations of turbine load and fuel cell heat exhaust.
Exergy and Economic Analysis of Catalytic Coal Gasifiers Coupled With Solid Oxide Fuel Cells
Authors: Siefert Nicholas , Litster Shawn
Published: March 2012

The National Energy Technology Laboratory (NETL) has undertaken a review of coal gasification technologies that integrate with solid oxide fuel cells (SOFC) to achieve system efficiencies near 60% while capturing and sequestering >90% of the carbon dioxide [1–2]. One way to achieve an overall system efficiency of greater than 60% is in a power plant in which a catalytic coal gasifier produces a syngas with a methane composition of roughly 25% on a dry volume basis and this is sent to a SOFC, with CO2 capture occurring either before or after the SOFC. Integration of a catalytic gasifier with a SOFC, as opposed to a conventional entrained flow gasifier, is improved due to (a) decreased exergy destruction inside a catalytic, steam-coal gasifier producing a high-methane content syngas, and (b) decreased exergy destruction in the SOFC due to the ability to operate at lower air stoichiometric flow ratios. For example, thermal management of the SOFC is greatly improved due to the steam-methane reforming in the anode of the fuel cell. This paper has two main goals. First, we converted the levelized cost of electricity (LCOE) estimates of various research groups into an average internal rate of return on investment (IRR) in order to make comparisons between their results, and to underscore the increased rate of return on investment for advanced integrated gasification fuel cell systems with carbon capture & sequestration (IGFC-CCS) compared with conventional integrated gasification combined cycle (IGCC-CCS) systems and pulverized coal combustion (PCC-CCS) systems. Using capital, labor, and fuel costs from previous researchers and using an average price of baseload electricity generation of $61.50 / MW-hr, we calculated inflation-adjusted IRR values of up to 13%/yr for catalytic gasification with pressurized fuel cell and carbon dioxide capture and storage (CCS), whereas we calculate an IRR of ∼4%/yr and ∼2%/yr for new, conventional IGCC-CCS and PCC-CCS, respectively. If the carbon dioxide is used for enhanced oil recovery rather than for saline aquifer storage, then the IRR values improve to 16%/yr, 10%/yr, and 8%/yr, respectively. For comparison, the IRR of a new conventional IGCC or PCC power plant without CO2 capture are estimated to be 11%/yr and 15.0%/yr, respectively. Second, we conducted an exergy analysis of two different configurations in which syngas from a catalytic gasifier fuels a SOFC. In the first case, the CO2 is captured before the SOFC, and the anode tail gas is sent back to the catalytic gasifier. In the second case, the anode tail gas is oxy-combusted using oxygen ion ceramic membranes and then CO2 is captured for sequestration. In both cases, we find that the system efficiency is greater than 60%. These values compare well with previous system analysis [1–4]. In future work, we plan to calculate the IRR of these two cases and compare with previous economic analyses conducted at NETL [1–2].