bluuebunny/crossref_metadata_2025 huggingface dataset:
Electron Microscopic Examination of the Dormant Spore and the Sporulation of Paenibacillus motobuensis Strain MC10
Authors: Iida Ken‐ichiro , Amako Kazunobu , Takade Akemi , Ueda Yasuichi , Yoshida Shin‐ichi
Published: November 2013

We previously reported a new species Paenibacillus motobuensis. The type strain MC10 was stained Gram‐negative, but had a Gram‐positive cell wall structure and its spore had a characteristic star shape. The spore and sporulation process of P. motobuensis strain MC10 were examined by electron microscopy using the technique of freeze‐substitution in thin sectioning. The structure of the dormant spore was basically the same as that of the other Bacillus spp. The core of the spore was enveloped with two main spore components, the cortex and the spore coat. In thin section, the spore showed a star‐shaped image, which was derived from the structure of the spore coat, which is composed of three layers, namely the inner, middle and outer spore coat. The middle coat was an electron‐dense thick layer and had a characteristic ridge. By scanning electron microscopic observation, the ridges were seen running parallel to the long axis of the oval‐shaped spore. The process of sporulation was essentially the same as that of the other Bacillus spp. The forespore was engulfed by the mother cell membrane, then the spore coat and the cortex were accumulated in the space between the mother cell membrane and forespore membrane. The mother cell membrane seemed to participate in the synthesis of the spore coat. MC10 strain showed almost identical heat resistance to that of B. subtilis.
Enhancement of Legionella pneumophila Culture Isolation from Microenvironments by Macrophage Infectivity Potentiator (mip) Gene‐Specific Nested Polymerase Chain Reaction
Authors: Nintasen Rungrat , Utrarachkij Fuangfa , Siripanichgon Kanokrat , Bhumiratana Adisak , Suzuki Yasuhiko , Suthienkul Orasa
Published: November 2013

The combination of a Legionella pneumophila culture isolation technique and macrophage infectivity potentiator (mip) gene‐specific nested polymerase chain reaction (PCR) is pivotal for effective routine use in an environmental water system laboratory. Detection of Legionella organisms in 169 environmental samples was performed by using modified buffered charcoal yeast extract (MBCYE) agar for conventional culture. Nested PCR specific for L. pneumophila was performed using boiled genomic DNA extracts from filtered and Chelex 100‐treated water samples, or by using silica‐gel membrane spin column‐eluted DNA from concentrated pond, canal and river samples. Overall, the nested PCR was twelvefold more sensitive than the culture method. The target amplicons (471 basepairs) of all 4 biochemically characterized L. pneumophila isolates were sequenced. They had homology at the DNA and protein levels to 3′ proximity of the mip‐coding gene of L. pneumophila deposited in genome databases. EcoRI‐ or KpnI‐digested PCR fragments with expected sizes were also confirmed in all 52 PCR‐positive samples that were isolated from cooling towers and condenser drains. Viable but nonculturable L. pneumophila might have been present in 48 PCR‐positive samples. This study demonstrates that detection of the genetically stable mip gene by nested PCR with a modified process of water sample preparation can be rapidly and effectively used to enhance isolation of the L. pneumophila taxon from microenvironments.
Mathematical Modeling of Severe Acute Respiratory Syndrome Nosocomial Transmission in Japan: The Dynamics of Incident Cases and Prevalent Cases
Authors: Fukutome Ayako , Watashi Koichi , Kawakami Norito , Ishikawa Hirofumi
Published: November 2013

An outbreak of Severe Acute Respiratory Syndrome (SARS) occurred in Hong Kong in late February 2003, resulting in 8,096 cumulative cases with 774 deaths. The outbreak was amplified by nosocomial transmission in many hospitals. Using mathematical modeling, we simulated the number of new incident and prevalent cases of SARS after one infected person was admitted to a hospital (index case). The simulation was tested stochastically using the SEIR model based on previously reported Gamma distributions. We estimated the duration time until 10 beds in negative pressure rooms in Chiyoda‐ku, one of the 23 wards in Tokyo, were fully occupied with SARS‐infected patients. We determined the impact of an increasing number of days on the number of prevalent cases until the index case was isolated. The prevalent cases increase exponentially along with the increase of the non‐isolation period of the index case, and all the beds were fully occupied if the index case was not isolated until more than 6 days. However even 2 days non‐isolation period of the index case could fill up all the beds when 16% of secondary infections are transmitted outside the hospital. There is a possibility that an epidemic will occur with the isolation of the index case even at early days if the infection is transmitted outside the hospital. The simulation results revealed that it was important to recognize and isolate SARS patients as early as possible and also to prevent the transmission spreading outside the hospital to control an epidemic.
Interleukin‐17 as an Effector Molecule of Innate and Acquired Immunity against Infections
Authors: Matsuzaki Goro , Umemura Masayuki
Published: November 2013

Interleukin (IL)‐17 is a proinflammatory cytokine which induces differentiation and migration of neutrophils through induction of cytokines and chemokines including granulocyte‐colony stimulating factor and CXCL8/IL‐8. IL‐17‐producing CD4+ T cells (Th17) have pivotal role in pathogenesis of autoimmune diseases. IL‐17 is also involved in protective immunity against various infections. IL‐17 has important role in induction of neutrophil‐mediated protective immune response against extracellular bacterial or fungal pathogens such as Klebsiella pneumoniae and Candida albicans. Importance of IL‐17 in protection against intracellular pathogens including Mycobacterium has also been reported. Interestingly, not only CD4+ T cells but atypical CD4–CD8– T cells expressing T cell receptor (TCR) γδ produce IL‐17, and IL‐17 producing cells participate in both innate and acquired immune response to infections. Furthermore, neutrophil induction may not be the only mechanism of IL‐17‐mediated protective immunity. IL‐17 seems to participate in host defense through regulation of cell‐mediated immunity or induction of antimicrobial peptides such as β‐defensins. In this review, we summarize recent progress on the role of IL‐17 in immune response against infections, and discuss possible application of IL‐17 in prevention and treatment of infectious diseases.
Basic science behind trabecular meshwork surgeries
Authors: OVERBY D
Published: November 2013

Trans‐trabecular meshwork surgeries attempt to lower intraocular pressure (IOP) by shunting across the trabecular meshwork (TM) that is believed to generate the bulk of aqueous humour outflow resistance. Despite elevated TM resistance in glaucoma, newer trans‐TM surgeries appear to be less successful at lowering IOP compared to traditional filtration surgeries (Mosaed et al. Trans. Am. Ophthalmol. Soc., 2009). To understand the mechanism and possible limitations of trans‐TM surgeries, we review the anatomy and basic science of outflow resistance generation within the TM and post‐TM aqueous vessels. These studies provide estimates of IOP expected from trans‐TM shunts and reveal obstacles that may limit the efficacy of trans‐TM surgeries.
Aspidistra lingyunensis sp. nov. (Asparagaceae) from limestone areas in Guangxi, China
Authors: Lin Chun‐Rui , Guo Lun‐Fa , Bin Zhu‐Fang
Published: November 2013

Aspidistra lingyunensis C. R. Lin & L. F. Guo (Asparagaceae) is described and illustrated as a new species from limestone areas in northwestern Guangxi, China. It resembles A. obconica C. R. Lin & Yan Liu in leaf size and its obconical and purplish red pistil, but differs by having a yellowish white perianth, with lobes oblong, explanate, 6–7 mm long, subequal to tube and a white stigma surface, ca 3 mm in diameter. The new species is rare, currently known only from northwestern Guangxi.
Folate intake and the risk of upper gastrointestinal cancers: A systematic review and meta‐analysis
Authors: Tio Martin , Andrici Juliana , Cox Michael R , Eslick Guy D
Published: November 2013

Background and Aim

There is conflicting evidence on the association between folate intake and the risk of upper gastrointestinal tract cancers. In order to further elucidate this relationship, we performed a systematic review and quantitative meta‐analysis of folate intake and the risk of esophageal, gastric, and pancreatic cancer.

Methods

Four electronic databases (Medline, PubMed, Embase, and Current Contents Connect) were searched to July 26, 2013, with no language restrictions for observational studies that measured folate intake and the risk of esophageal cancer, gastric cancer, or pancreatic cancer. Pooled odds ratios and 95% confidence intervals were calculated using a random effects model.

Results

The meta‐analysis of dietary folate and esophageal cancer risk comprising of nine retrospective studies showed a decreased risk of esophageal cancer (odds ratio [OR] 0.59; 95% confidence interval [95% CI] 0.51–0.69). The meta‐analysis of dietary folate and gastric cancer risk comprising of 16 studies showed no association (OR 0.94; 95% CI 0.78–1.14). The meta‐analysis of dietary folate and pancreatic cancer risk comprising of eight studies showed a decreased risk of pancreatic cancer (OR 0.66; 95% CI 0.49–0.89).

Conclusion

Dietary folate intake is associated with a decreased risk of esophageal and pancreatic cancer, but not gastric cancer. Interpretation of these relationships is complicated by significant heterogeneity between studies when pooled, and by small numbers of studies available to analyze when stratification is performed to reduce heterogeneity.
Natural history of postvascular‐phase iso‐enhanced lesions on the sonogram in chronic liver diseases
Authors: Kondo Takayuki , Maruyama Hitoshi , Sekimoto Tadashi , Shimada Taro , Takahashi Masanori , Chiba Tetsuhiro , Kanai Fumihiko , Yokosuka Osamu , Yamaguchi Tadashi
Published: November 2013

Background and Aim

This study examined the natural history of postvascular‐phase iso‐enhanced lesions (PIELs) on contrast‐enhanced sonograms to determine the potential risk and predictive factors for developing hepatocellular carcinoma (HCC) in chronic liver diseases.

Methods

This prospective study included 87 PIELs on contrast‐enhanced sonograms (postvascular‐phase: 10 min post‐injection of perflubutane microbubbles) in 72 patients with chronic liver diseases (45 males and 27 females; age 65.0 ± 10.8y; PIEL diameter 12.5 ± 4.2 mm). The PIELs were followed up by ultrasound/contrast‐enhanced ultrasound, computed tomography, or magnetic resonance imaging at 3 to 6 months intervals.

Results

Twenty patients developed HCCs during the study period (median, 22.0 months). The cumulative risk of HCC occurrence was 7.9% at 1 year and 36.0% at 3 years. The presence of coexistent HCC (hazard ratio [HR], 4.975; 95% confidence interval [CI], 1.729–14.316; P = 0.003) and alpha‐fetoprotein > 20 ng/mL (HR, 4.104; 95% CI, 1.621–10.392; P = 0.003) were significant factors for the risk of HCC occurrence. Fourteen of these lesions were diagnosed as HCCs that developed from iso‐enhanced lesions. Cumulative HCC occurrence rates from PIEL > 14 mm was 23.5% at 1 year and 46.3% at 3 years. Cox regression analysis showed that PIEL > 14 mm (HR, 6.780; 95% CI, 2.060–22.32; P = 0.002) and alpha‐fetoprotein > 20 ng/mL (HR, 4.892; 95% CI, 1.559–15.350; P = 0.007) were statistically significant factors for HCC occurrence.

Conclusions

Patients with coexistent HCC, alpha‐fetoprotein > 20 ng/mL, or PIEL > 14 mm should be carefully monitored because of the high potential for HCC occurrence.
Myocardial perfusion defects in patients with chronic hepatitis B infection
Authors: Maruyama Shigeo , Koda Masahiko , Murawaki Yoshikazu
Published: November 2013

Background and Aim

The association between hepatitis B virus (HBV) infection and myocardial injury has yet to be elucidated. We sought to investigate myocardial conditions in patients with chronic HBV infection.

Methods

In 47 consecutive patients with chronic hepatitis B who had no overt heart disease, we performed electrocardiography, echocardiography, serum tests for myocardial injury, and thallium‐201 myocardial scintigraphy. Myocardial perfusion defects were confirmed by the severity score (SS), which was calculated as the sum of thallium‐201 perfusion defect scores. The SS was followed before and after interferon (IFN) therapy in 10 patients.

Results

Abnormal ECGs were found in 9% of patients with chronic hepatitis B. SS values in the hepatitis group were significantly higher than in the control group (P < 0.0001). Abnormal SS values were found in 47% of the chronic hepatitis B patients. Independent factors related to higher pretreatment SS were serum HBV DNA titer and IgG level. After interferon (IFN) therapy, the SS values of responders were significantly reduced (P ≤ 0.02); SS values of nonresponders were not significantly different before and after IFN therapy. SS values altered following IFN therapy, along with serum IgG concentrations.

Conclusions

Myocardial perfusion defects were found in 47% of the patients with chronic hepatitis B and improved along with HBV reduction with IFN administration. SS improvement was closely correlated with decreases in serum IgG levels.
Neurovascular protection by post‐ischemic intravenous injections of the lipoxin A4 receptor agonist, BML‐111, in a rat model of ischemic stroke
Authors: Hawkins Kimberly E. , DeMars Kelly M. , Singh Jonathan , Yang Changjun , Cho Henry S. , Frankowski Jan C. , Doré Sylvain , Candelario‐Jalil Eduardo
Published: November 2013

Resolution of inflammation is an emerging new strategy to reduce damage following ischemic stroke. Lipoxin A4 (LXA4) is an anti‐inflammatory, pro‐resolution lipid mediator with high affinity binding to ALX, the lipoxin A4 receptor. Since LXA4 is rapidly inactivated, potent analogs have been created, including the ALX agonist BML‐111. We hypothesized that post‐ischemic intravenous administration of BML‐111 would provide protection to the neurovascular unit and reduce neuroinflammation in a rat stroke model. Animals were subjected to 90 min of middle cerebral artery occlusion (MCAO) and BML‐111 was injected 100 min and 24 h after stroke onset and animals euthanized at 48 h. Post‐ischemic treatment with BML‐111 significantly reduced infarct size, decreased vasogenic edema, protected against blood–brain barrier disruption, and reduced hemorrhagic transformation. Matrix metalloproteinase‐9 and matrix metalloproteinase‐3 were significantly reduced following BML‐111 treatment. Administration of BML‐111 dramatically decreased microglial activation, as seen with CD68, and neutrophil infiltration and recruitment, as assessed by levels of myeloperoxidase and intracellular adhesion molecule‐1. The tight junction protein zona occludens‐1 was protected from degradation following treatment with BML‐111. These results indicate that post‐ischemic activation of ALX has pro‐resolution effects that limit the inflammatory damage in the cerebral cortex and helps maintain blood–brain barrier integrity after ischemic stroke.

image

Lipoxin A4 (LXA4) is a potent anti‐inflammatory, pro‐resolution mediator. Post‐ischemic injections of BML‐111, a LXA4 receptor agonist, significantly reduced infarct size, matrix metalloproteinases, microglial activation, and neutrophil infiltration, while providing protection to the blood–brain barrier at 48 h following middle cerebral artery occlusion in rats. This suggests that activation and enhancement of the LXA4 resolution pathway may be a new target for therapeutics aimed at reducing neuroinflammation following ischemic stroke.
Landscape genetics and wing morphometrics show a lack of structuring across island and coastal populations of the drone fly in theMediterranean
Authors: Francuski L. , Djurakic M. , Ståhls G. , Milankov V.
Published: November 2013

TheMediterranean basin is a region of species richness, rarity and endemism, and is thus an area of significant conservation importance. Conservation of insect biodiversity benefits pollination services in the fragmentedMediterranean landscape. However, the question of the distribution patterns of an important long‐distance pollen disperser, the hoverflyEristalis tenax(Diptera,Syrphidae), remains open. Therefore, we explored the spatial distribution of genetic and phenotypic diversity of this species across theCentral‐EasternMediterranean. Connectivity between continental and island populations ofE. tenaxwas studied by integrating molecular (allozyme loci and mitochondrialDNAsequences of the cytochromecoxidase subunit I gene) and phenotypic data (wing geometric morphometrics). Allozyme (FSTvalues,STRUCTUREanalysis, analysis of molecular variance) and phenotypic data (wing shape) and landscape genetics (Alleles in Space analysis) suggest thatE. tenaxpopulations within theMediterranean are largely connected, and that there is an absence of large‐scale geographic structuring. Intraspecific variability was only 1.54% among samples, and theMediterranean populations showed an almost complete lack ofCOI mtDNAhaplotype diversity. Thus, our results suggest thatE. tenaxpopulations are well mixed, and that a considerable amount of gene flow takes place, even among populations that are a great distance apart. AsE. tenax's ecological amplitude is wide, and the species is therefore widespread in both natural and man‐made landscapes, it probably maintains a high level of population similarity by its large population sizes (as revealed by theθparameter) and constant intermixing among populations. From an applied point of view, large‐scale species intermixing enables pollen spread across distant island plant populations, especially those threatened by extinction.
Care of hepatitis C virus infection in France: modifications in three consecutive surveys between 1995 and 2010
Authors: Geri Guillaume , Maynard Marianne , Rosenthal Eric , Fontaine Hélène , Lacombe Karine , Slama Laurence , Goujard Cécile , Loustaud‐Ratti Véronique , Bergmann Jean‐François , Morlat Philippe , Vittecoq Daniel , Alric Laurent , Cacoub Patrice
Published: November 2013

Background & Aims

To determine the characteristics of hepatitis C (HCV)‐infected patients in 2010 and compare this survey with those reported in 1995 and 2001.

Patients and methods

Observational multicentre study conducted in 2010 in French internal medicine, infectious diseases and hepatology departments.

Results

A total of 1621 HCV infected patients (mean age 50.1 ± 10.7 years; sex ratio M/F 1.8; genotype 1: 55.7%) were included. Of these, 910 (56.1%) were HIV–HCV co‐infected, 463 (40.4%) were asymptomatic and 184 (16.1%) had cirrhosis at inclusion in this study. Positive viraemia was found in 1,025 patients (65.5%) at inclusion in this study. A complete pretreatment evaluation including investigation for HCV RNA, genotype determination and liver fibrosis was performed in 96.5, 80.5 and 68.7% of the 1,621 patients respectively. Previous and ongoing HCV treatments were noted in 49.6% and 20.1% of patients respectively. A sustained virological response (SVR) was observed in 271/801 (38.3%) patients, i.e. 44.1% and 30.7% in co‐infected and mono‐infected patients respectively. Cirrhosis was more frequent in the 2010 than in the 2001 and 1995 surveys (16.1% vs. 10.4% and 7.4% respectively; P < 0.0001). A complete pretreatment evaluation was performed in 57.9% and 50.9% of patients in 2010 and 2001 (P < 0.0001). Liver fibrosis evaluation was more frequent in 2010 than in the 2001 and 1995 surveys (68.7% vs. 62.7% and 28.7%, respectively, P < 0.0001).

Conclusion

The care of HCV‐infected patients has changed significantly in ‘real life’ through an improvement of pretreatment evaluation before the antiviral introduction and the increased use of antivirals. New HCV therapy combinations including protease inhibitors are warranted to increase the SVR rate.
A comparative systems analysis of polysaccharide‐elicited responses in Neurospora crassa reveals carbon source‐specific cellular adaptations
Authors: Benz J. Philipp , Chau Bryant H. , Zheng Diana , Bauer Stefan , Glass N. Louise , Somerville Chris R.
Published: November 2013

Filamentous fungi are powerful producers of hydrolytic enzymes for the deconstruction of plant cell wall polysaccharides. However, the central question of how these sugars are perceived in the context of the complex cell wall matrix remains largely elusive. To address this question in a systematic fashion we performed an extensive comparative systems analysis of how the model filamentous fungus Neurospora crassa responds to the three main cell wall polysaccharides: pectin, hemicellulose and cellulose. We found the pectic response to be largely independent of the cellulolytic one with some overlap to hemicellulose, and in its extent surprisingly high, suggesting advantages for the fungus beyond being a mere carbon source. Our approach furthermore allowed us to identify carbon source‐specific adaptations, such as the induction of the unfolded protein response on cellulose, and a commonly induced set of 29 genes likely involved in carbon scouting. Moreover, by hierarchical clustering we generated a coexpression matrix useful for the discovery of new components involved in polysaccharide utilization. This is exemplified by the identification of lat‐1, which we demonstrate to encode for the physiologically relevant arabinose transporter in Neurospora. The analyses presented here are an important step towards understanding fungal degradation processes of complex biomass.
Incongruence between multi‐locus sequence analysis (MLSA) and whole‐genome‐based phylogenies: Pseudomonas syringae pathovar pisi as a cautionary tale
Authors: Baltrus David A. , Dougherty Kevin , Beckstrom‐Sternberg Stephen M. , Beckstrom‐Sternberg James S. , Foster Jeffrey T.
Published: November 2013

Previous phylogenies, built using a subset of genomic loci, split Pseudomonas syringae pv. pisi into two well‐supported clades and implied convergence in host range for these lineages. The analysis of phenotypic and genotypic data within the context of this phylogenetic relationship implied further convergence at the level of virulence gene loss and acquisition. We generate draft genome assemblies for two additional P. syringae strains, isolated from diseased pea plants, and demonstrate incongruence between phylogenies created from a subset of the data compared with the whole genomes. Our whole‐genome analysis demonstrates that strains classified as pv. pisi actually form a coherent monophyletic clade, so that apparent convergence is actually the product of shared ancestry. We use this example to urge caution when making evolutionary inferences across closely related strains of P. syringae.
Late‐onset Pompe disease after 4 years of enzyme replacement therapy: An autopsy case
Authors: Furusawa Yoshihiko , Mitsuhashi Satomi , Mori‐Yoshimura Madoka , Shimada Yohta , Yamamoto Toshiyuki , Shibuya Makoto , Shimizu Jun , Ohashi Toya , Saito Yuko , Nishino Ichizo , Oya Yasushi , Murata Miho
Published: November 2013

We report an autopsy case of advanced late‐onset Pompe disease (juvenile type). At 15 years‐of‐age, the patient experienced proximal weakness and subsequently required non‐invasive positive pressure ventilation. Enzyme replacement therapy was initiated at 37 years‐of‐age, which improved pinch power and alleviated respiratory distress. At age 41 years, repetitive pneumothorax led to respiratory failure and death. Autopsy excluding the brain showed few vacuoles and periodic acid–Schiff‐positive fibers in the left rectus femoris, compared with the contralateral muscle biopsy carried out at 21 years‐of‐age. Vacuolar changes were also less evident than previous autopsy cases without enzyme replacement therapy. The findings suggest that enzyme replacement therapy might have suppressed myovacuolopathy in our patient with advanced late‐onset Pompe disease. Apart from vacuolopathy, the autopsied muscle showed marked myofiber atrophy and fibrosis, suggesting that disuse atrophy could have contributed to the muscle weakness.
Causes and outcomes of asymptomatic gross haematuria in children
Authors: Lee Joo Hoon , Choi Hae‐won , Lee Yoon Jung , Park Young Seo
Published: November 2013

Aim

Although asymptomatic gross haematuria (GHU) is relatively common in children, its causes and clinical outcomes are not clearly defined.

Methods

Children with asymptomatic GHU were examined and work‐up was performed. Patients with recurrent GHU with proteinuria, or significant proteinuria, were considered for renal biopsy.

Results

The male : female ratio of all patients was 190:75, and the median age at onset of GHU was 6.4 years. Patients were grouped according to abnormalities on initial evaluation as follows: idiopathic (50%), proteinuria (21%), hypercalciuria (14%), sonographic abnormality (7%), hypocomplementaemia (4%), familial (3%), and bleeding tendency (2%). Of patients with idiopathic GHU, 38% had a single episode, and of these, 34% had persistent microscopic haematuria, which resolved on follow‐up. Late onset proteinuria was accompanied in 11% of patients with recurrent GHU. Nutcracker syndrome was diagnosed in one patient with recurrent idiopathic GHU. Of patients with recurrent GHU, 89% had no proteinuria on follow‐up, and GHU and microscopic haematuria resolved in 97% and 89%, respectively.

Conclusions

Our work‐up protocol was useful for diagnosis and follow‐up planning. Asymptomatic GHU in children was most commonly the idiopathic form. Overall, long‐term prognosis appears to be benign; however, careful follow‐up is essential.
Ecological impacts of the late Quaternary megaherbivore extinctions
Authors: Gill Jacquelyn L.
Published: November 2013

As a result of the late Quaternary megafaunal extinctions (50 000–10 000 before present (BP)), most continents today are depauperate of megaherbivores. These extinctions were time‐transgressive, size‐ and taxonomically selective, and were caused by climate change, human hunting, or both. The surviving megaherbivores often act as ecological keystones, which was likely true in the past. In spite of this and extensive research on the causes of the Late Quaternary Extinctions, the long‐term ecological consequences of the loss of the Pleistocene megafauna remained unknown until recently, due to difficulties in linking changes in flora and fauna in paleorecords. The quantification of Sporormiella and other dung fungi have recently allowed for explicit tests of the ecological consequences of megafaunal extirpations in the fossil pollen record. In this paper, I review the impacts of the loss of keystone megaherbivores on vegetation in several paleorecords. A growing number of studies support the hypothesis that the loss of the Pleistocene megafauna resulted in cascading effects on plant community composition, vegetation structure and ecosystem function, including increased fire activity, novel communities and shifts in biomes. Holocene biota thus exist outside the broader evolutionary context of the Cenozoic, and the Late Quaternary Extinctions represent a regime shift for surviving plant and animal species.
The mystery of memory: in search of the past
Authors: Paulson Steve , Aciman André , LeDoux Joseph , Schacter Daniel , Winter Alison
Published: November 2013

A universal fascination with how we remember, forget, and create false memories cuts across the arts and sciences, as do the questions of how and where memories are formed and preserved. Moderated by Steve Paulson, executive producer and host of To the Best of Our Knowledge, novelist and comparative literature professor André Aciman (City University of New York), neuroscientist Joseph LeDoux (New York University), psychologist Daniel Schacter (Harvard University), and historian of science and medicine Alison Winter (University of Chicago) discuss how memory impacts our perception of ourselves, the development of personality, and the ability to construct and reconstruct our past experience. The following is an edited transcript of the discussion that occurred November 14, 2012, 7:00–8:15 PM, at the New York Academy of Sciences in New York City.
Neonatal Hyperpigmentation: Diagnosis of Familial Glucocorticoid Deficiency with a Novel Mutation in the Melanocortin‐2 Receptor Gene
Authors: Jacoby Elad , Barzilai Aviv , Laufer Joseph , Pade Shai , Anikster Yair , Pinhas‐Hamiel Orit , Greenberger Shoshana
Published: November 2013

Familial glucocorticoid deficiency (FGD), a rare autosomal recessive disorder of insensitivity to adrenocorticotropic hormone (ACTH), is characterized by isolated glucocorticoid deficiency and preserved mineralocorticoid production. The clinical features include generalized hyperpigmentation, hypoglycemia, failure to thrive, and recurrent infections. Here we describe the case of an infant who exhibited generalized hyperpigmentation and hypoglycemia. A high morning blood ACTH level and low blood cortisol level confirmed the diagnosis of FGD. The patient was found to be homozygous for a novel mutation in the melanocortin‐2 receptor gene (635insC, I154H). Early initiation of corticosteroid treatment led to normalization of morning blood ACTH levels and the patient thrived, with subsequent fading of the hyperpigmentation.
Preadjusted Non-Parametric Estimation of a Conditional Distribution Function
Authors: Veraverbeke Noël , Gijbels Irène , Omelka Marek
Published: November 2013

The paper deals with non-parametric estimation of a conditional distribution function. We suggest a method of preadjusting the original observations non-parametrically through location and scale, to reduce the bias of the estimator. We derive the asymptotic properties of the estimator proposed. A simulation study investigating the finite sample performances of the estimators discussed is provided and reveals the gain that can be achieved. It is also shown how the idea of the preadjusting opens the path to improved estimators in other settings such as conditional quantile and density estimation, and conditional survival function estimation in the case of censored data.
Two-stage Adaptive Randomization for Delayed Response in Clinical Trials
Authors: Xu Jiajing , Yin Guosheng
Published: November 2013

Despite the widespread use of equal randomization in clinical trials, response-adaptive randomization has attracted considerable interest. There is typically a prerun of equal randomization before the implementation of response-adaptive randomization, although it is often not clear how many subjects are needed in this prephase, and in practice the number of patients in the equal randomization stage is often arbitrary. Another concern that is associated with realtime response-adaptive randomization is that trial conduct often requires patients' responses to be immediately available after the treatment, whereas clinical responses may take a relatively long period of time to exhibit. To resolve these two issues, we propose a two-stage procedure to achieve a balance between power and response, which is equipped with a likelihood ratio test before skewing the allocation probability towards a better treatment. Furthermore, we develop a non-parametric fractional model and a parametric survival design with an optimal allocation scheme to tackle the common problem caused by delayed response. We evaluate the operating characteristics of the two-stage designs through extensive simulation studies and illustrate them with a human immunodeficiency virus clinical trial. Numerical results show that the methods proposed satisfactorily resolve the arbitrary size of the equal randomization phase and the delayed response problem in response-adaptive randomization.
The plant fossil record reflects just two great extinction events
Authors: Cascales‐Miñana Borja , Cleal Christopher J.
Published: November 2013

Five great taxonomic extinctions (the so‐called ‘Big Five Mass Extinctions’) are widely recognized in life history, at the end of the Ordovician, Frasnian (Late Devonian), Permian, Triassic and Cretaceous. All of them were originally identified in the marine fossil record and have been interpreted as the result of abrupt global environmental changes. Previous evidence has suggested that terrestrial biota were also subjected to ecological disruption during these events, but it is unknown whether they suffered the same level of large‐scale taxonomic disruption as marine organisms. Here we show that the plant fossil record in fact only provides evidence of two mass taxonomic extinction events, one through the Carboniferous‐Permian transition, the other during middle‐late Permian times. This differs significantly from the mass extinctions recognized in the marine realm and suggests that vascular plants have a special capacity for surviving abrupt environmental changes.
Theoretical Film Cooling Performance of Multi Trench Configurations on Flat Plate
Authors: Abdala Antar M. M. , Zheng Qun , Elwekeel Fifi N. M.
Published: November 2013

In the present work, computational simulations was made using ANSYS CFX to predict the improvements in film cooling performance with multi trench. Multi-trench configuration consists of two trenches together, one wider trench and the other is narrow trench that extruded from the wider one. Several blowing ratios in the range (0.5:5) were investigated. By using the multi trench configuration, the coolant jet impacted the trench wall two times allowing increasing the spreading of coolant laterally in the trench, reducing jet velocity and jet completely covered on the surface. The results indicate that this configuration increased adiabatic effectiveness as blowing ratio increased. No observed film blow-off at all blowing ratios. The adiabatic film effectiveness of multi trench case outperformed the narrow trench case, laidback fan-shaped hole, fan-shaped hole and cylinder hole at different blowing ratios. An additional benefit is the low flow rate will provide the same cooling effect by using multi trench configuration.
Advances in the Development of a Micro-Gas Turbine Engine at Onera
Authors: Dessornes O. , Landais S. , Valle R. , Fourmaux A. , Burguburu S. , Zwyssig C. , Kozanecki Z.
Published: November 2013

To reduce the size and weight of power generation machines for portable devices, several systems to replace the currently used heavy batteries are being investigated worldwide. As micro gas turbines are expected to offer the highest power density, several research groups launched programs to develop ultra micro gas turbines: IHI firm (Japan), PowerMEMS Consortium (Belgium).

At Onera, a research program called DecaWatt is under development in order to realize a demonstrator of a micro gas turbine engine in the 50 to 100 Watts electrical power range. A single-stage gas turbine is currently being studied. First of all, a calculation of the overall efficiency of the micro gas turbine engine has been carried out according to the pressure ratio, the turbine inlet temperature and the compressor and turbine efficiencies. With realistic hypotheses, we could obtain an overall efficiency of about 5% to 10% which leads to around 200 W/kg when taking into account the mass of the micro gas turbine engine, its electronics, fuel and packaging. Moreover, the specific energy could be in the range 300 to 600 Wh/kg which exceeds largely the performance of secondary batteries.

To develop such a micro gas turbine engine, experimental and computational work focused on:

• a 10 mm in diameter centrifugal compressor, with the objective to obtain a pressure ratio of about 2.5

• a radial inflow turbine

• journal and thrust gas bearings (lobe bearings and spiral grooves) and their manufacturing

• a small combustor working with hydrogen or hydrocarbon gaseous fuel (propane)

• a high rotation speed micro-generator

• the choice of materials

Components of this tiny engine were tested prior to the test with all the parts assembled together. Tests of the generator at 700,000 rpm showed a very good efficiency of this component. In the same way, compressor testing has been performed up to 500,000 rpm and has shown that the nominal compression rate at the 840,000 rpm nominal speed should be nearly reached.
Prolonged MCrAlY Coating Lifetime by Means of the LPPS Process
Authors: Thoma Martin , Scrivani Andrea
Published: November 2013

It is state of the art that MCrAlY powder is sprayed by LPPS or alternatively by HVOF either as an environmental protective coating or as a bond coat of the TBC on hot section parts of the turbine. The lifetime of the MCrAlY coating can be predicted by the two different losses of the Aluminum content causing a β-depletion of the β NiAl-phase of MCrAlY: the Al loss by the oxidation on the surface and the Al loss by the interdiffusion into the substrate. These effects were analyzed with a NiCoCrAlYRe and a CoNiCrAlY coating sprayed by LPPS and HVOF. Long term oxidation tests demonstrate: the coatings sprayed by LPPS have less β-depletion by diffusion compared to the coatings sprayed by HVOF. This was evaluated for the tested alloy-coating combinations. The β-depletion caused by oxidation is dependent on the MCrAlY: the NiCoCrAlYRe coating has less β-depletion when sprayed by LPPS while in the CoNiCrAlY coating the β-depletion caused by oxidation is lower in the HVOF sprayed coating.
Design and Development of the Inter-Turbine Structure and Power Turbine for MTR390-E Turboshaft Engine
Authors: de la Calzada Pedro , Villanueva Miguel A. , Parra Jorge , Ruiz-Gopegui Juan I.
Published: November 2013

The MTR390-E is a turboshaft engine of 1000 kW class developed for the TIGER European helicopter. The project was launched back in 2004 and was certified in 2011. The engine is based on the previous MTR390-2C engine but redesigned for 14% more power at high and hot conditions. ITP is the design authority of the inter-turbine duct (ITD) and structure (IC) and the two stages Power Turbine (PT) as part of the MTRI European consortium (MTU, Turbomeca, RR, ITP) for the design and development of the Enhanced engine.

The requirement of higher power, while maintaining the physical envelope of the engine for avoiding changes in the helicopter, led to higher mass flow and turbine inlet temperature. Consequently, the Mach number along the ITD and the PT was increased. A local increase in the flowpath around the area of the ITD and the NGV1 maximum thickness is introduced to avoid high peak Mach numbers and to reduce the flow diffusion. The PT aerofoils feature higher flow velocities leading to transonic Mach numbers at the suction side. The increase in temperature drove the introduction of internal cooling on the ITD and the NGV1 to maintain similar materials while avoiding risk of melting at Super Emergency Conditions (SUP).

Due to the high shaft rotation speed and high operating temperatures the blades are subject to very high mechanical demanding conditions. Single crystal materials are used in both stages where also tip shroud cut outs were introduced to reduce centrifugal stresses. Life requirements were met in both statics and rotating parts.

A complete development test plan was performed to achieve certification and qualification with 7 development engines and 4 flight proto engines. Performance was demonstrated at sea level and altitude conditions.

Successful mechanical condition of parts was obtained after the 150-hrs Type Test plus additional SUP shots. Also good conditions were obtained after sand ingestion test. Good mechanical robustness was proved all along the development programme.
A Novel Methodology for Optimal Design of Compressor Plants Using Probabilistic Plant Design
Authors: Kurz Rainer , Thorp Joseph M. , Zentmyer Eric G. , Brun Klaus
Published: November 2013

Equipment sizing decisions in the Oil and Gas Industry often have to be made based on incomplete data. Often, the exact process conditions are based on numerous assumptions about well performance, market conditions, environmental conditions and others. Since the ultimate goal is to meet production commitments, the traditional way of addressing this is, to use worst case conditions, and often adding margins onto these. This will invariably lead to plants that are oversized, in some instances by large margins. In reality, the operating conditions are very rarely the assumed worst case conditions, but they are usually more benign most of the time. Plants designed based on worst case conditions, once in operation, will therefore usually not operate under optimum conditions, have reduced flexibility, and therefore cause both higher capital expenses and operating expenses.

The authors outline a new probabilistic methodology that provides a framework for more intelligent process-machine designs. A standardized framework using Monte Carlo simulation and risk analysis is presented that more accurately defines process uncertainty and its impact on machine performance. Case studies are presented that highlight the methodology as applied to critical turbo-machinery.
SOFC/mGT Coupling: Different Options With Standard Boosters
Authors: Larosa Luca , Ferrari Mario L. , Magistri Loredana , Massardo Aristide F.
Published: November 2013

In this paper an innovative SOFC hybrid system is proposed, equipped with ejector-based cathodic recirculation. The cathodic flow is preheated by recirculating hot exhausts. However, this approach needs higher pressure values than those available with commercial micro gas turbines (mGT): a possible but expensive solution could be to design a completely new mGT. Another option could be to use a booster with the function of re-compressor installed between the mGT compressor and the ejector (in order to increase ejector inlet pressure). This choice allows the use of commercial machines with a substantial cost reduction by comparison with designing a new micro gas turbine. Moreover, this layout is able to separate the compressor ratio of the mGT from the ejector inlet pressure, generating more flexibility from the point of view of the control system.

In this paper, a thermodynamic study of this machine coupling is carried out considering the hybrid system emulator developed by TPG at the University of Genoa. For this purpose, three different boosting approaches were examined with a steady-state model built in Matlab-Simulink environment. The results presented here were obtained to show emulator performance and flexibility. Available power and thermal aspects are discussed in detail.
Flow Field Investigations on the Effect of Rib Placement in a Cooling Channel With Film-Cooling
Authors: Kunze Martin , Vogeler Konrad
Published: November 2013

This paper presents experimental investigations on flat plate film-cooling in combination with a ribbed cooling channel. The effect of rib placement on the film-cooling injection and the flow in the cooling channel was studied. The velocity fields were measured using optical laser measurement techniques as LDA (Laser-Doppler-Anemometry) and PIV (Particle-Image-Velocimetry). A row of three cylindrical film holes is placed in the center rib segment of the cooling channel. The dimensionless rib-to-hole position s/D is varied from 4.5 to 10.5. The investigations are conducted at isothermal conditions for a variation of the coolant Reynolds number Rec,Dh from 10000 up to 60000 and for three blowing rates M = 0.5, 0.75 and 1.00.

The flow field results for the film-cooling injection showed only small influence of the rib placement. Due to different coolant-to-main flow pressure ratios across the row, a slight non-uniform share of coolant flow occurs. Intense streamwise mixing and decay of the turbulence in the film jet was observed within the first 10 hole diameters. Enhancement of the turbulence intensity inside the jet core was found with increasing coolant Reynolds numbers.

Inside the internal cooling channel, the flow field showed significant influence of the rib position which is most pronounced at low Reynolds number (Rec,Dh = 10000) and high blowing ratios (M = 1.0). The effect becomes significantly smaller when the Reynolds number is increased. This is mainly attributed to the strongly increasing channel mass flow which equals to a decreasing suction ratio SR = uh/uc of the holes. The experimental results are compared to comprehensive numerical simulations.
Centrifugal Compressor Design Impacts: Lean and Meridional Shape
Authors: Xu Cheng , Amano R. S.
Published: November 2013

Optimization procedures are widely used in centrifugal compressor developments to enable high efficiency and wide operating ranges of compressors. It is very important to understand how to set the parameters and which parameter needs to be optimized. This paper demonstrates a case study on the importance of mechanical and structure combination optimization and also discusses the meridional impacts of compressor performance.

Recently, the high pressure ratio and the efficiency of centrifugal compressors require impeller designs to pay attention to multi-disciplinary optimization. High efficiency and a wide operation range are always the design goal. The geometry of the blades and the meridional profile are very important contributors to compressor performance and structure reliability. Therefore, it is critical to consider all aspects of compressor optimization. The goal of currently used centrifugal compressors is to design a compressor with the same back-disc diameter with the best efficiency and the highest-pressure ratio.
Development and Application of a Transported PDF Method on Unstructured Three-Dimensional Grids for the Prediction of Nitric Oxides
Authors: Fiolitakis Andreas , Ess Peter , Gerlinger Peter , Aigner Manfred
Published: November 2013

The present work explores the capability of the transported PDF (probability density function) method to predict nitric oxide (NO) formation in turbulent combustion. To this end a hybrid finite-volume/Lagrangian Monte-Carlo method is implemented into the THETA code of the German Aerospace Center (DLR). In this hybrid approach the transported PDF method governs the evolution of the thermochemical variables, whereas the flow field evolution is computed with a RANS (Reynolds-Averaged Navier Stokes) method. The method is used to compute a turbulent hydrogen-air flame and a methane-air flame and computational results are compared to experimental data. In order to assess the advantages of the transported PDF method, the flame computations are repeated with the “laminar chemistry” approach as well as with an “assumed PDF” method, which are both computationally cheaper. The present study reveals that the transported PDF method provides the highest accuracy in predicting the overall flame structure and nitric oxide formation.