bluuebunny/crossref_metadata_2025 huggingface dataset:
The color of mass culture: spectral characteristics of a shallow water column through shade‐limited algal growth dynamics1
Authors: Hewes Christopher D.
Published: January 2016

It is envisioned that mass algal cultivation for commercial biofuels production will entail the use of large raceway pond systems, which typically have shade‐limited photosynthetic growth within depths of 20–30 cm. The attenuation of light and spectral qualities of red, green, and blue wavelengths in a 20‐cm water column as a function of Chl‐a concentration during exponential and linear phases of growth dynamics for the marine diatom Thalassiosira pseudonana was examined under laboratory conditions. While photosynthetically available radiation (PAR) was in excess throughout the water column during the phase of exponential growth, PAR became rate limiting differently for red, green, and blue wavelengths during the phase of linear growth. The transition from exponential to linear growth occurred at 1–2 mg Chl‐a · L−1, whereby a scalar ~5 μmol photons · m−2 · s−1 at 20‐cm depth was found to occur as would be anticipated having the compensation point for where rates of photosynthesis and respiration are equal. During the phase of linear growth, red wavelengths became increasingly dominant at depth as Chl‐a concentrations increased, being contrary to the optical conditions for those natural bodies of water that forced the evolution of phytoplankton photosynthesis. It is hypothesized this dramatic difference in water column optics between natural and synthetic environments could influence a variety of biological reactions, importantly non‐photochemical quenching capacities, which could negatively impact crop yield.
Sonata Theory, Secondary Themes and Continuous Expositions: Dialogues with Form‐Functional Theory
Authors: HEPOKOSKI JAMES A.
Published: February 2016

With regard to the definition of secondary (or subordinate) themes within Classical‐style expositions, Sonata Theory and form‐functional theory proceed from different understandings of the style, role and structural purpose of such themes. From the more integrative standpoint of Sonata Theory, the form‐functional understanding, while logically tight, is insufficiently attentive to rhetorical, punctuational and thematic factors that also lie at the core of expositional practice in the second half of the eighteenth century. This article updates my thoughts on secondary‐theme definition in this era, underscoring once again the need for flexibility and musical sensitivity in the application of the ‘no MC, no S’ guideline. Along the way, I outline a broader historical argument to suggest that, beginning around 1750, the strategic introduction of an emphatic medial caesura (or punctuational ‘hard break’) into the centre of what we now call sonata expositions effectively and immediately divided any such exposition into two separate parts. Each of the two parts is usually subdivisible into two separate action‐zones, resulting in a de facto {P TR}’{S/C} pattern, each zone of which soon came to call for its own generically appropriate harmonic and thematic/rhetorical treatment. Under the zonal concept of expositional formatting (precipitated by the presence of an MC), the secondary theme is best construed as that characteristic, new theme that marks the post‐MC onset of the second part. Expositions without an interior MC present us with a different situation, one in which it can be counterintuitive – or at least analytically unnecessary – to posit the presence of a subordinate theme in the zonal sense: one need not presume that all mid‐expositional V:PACs are preceded by a subordinate theme. The article also considers how most productively to interpret a transition‐ending dominant‐lock leading to an MC and concludes by discussing how and why it is possible for a transition‐ending V:PAC to articulate an MC that then gives way to the onset of a characteristic secondary theme.
Case of McLeod syndrome with a novel genetic mutation
Authors: Narumi Shinsuke , Natori Tatsunori , Miyazawa Haruna , Kato Tadayoshi , Yonezawa Hisashi , Nishino Ichizo , Nakamura Masayuki , Sano Akira , Terayama Yasuo
Published: February 2016

McLeod syndrome is a rare neuroacanthocytosis caused by mutation of the XK gene. Acanthocytes in peripheral blood, systemic chorea, neuropathy, myopathy and increased serum levels of creatine kinase are observed in this syndrome, and mental manifestations and cardiomyopathy can also arise as complications. Various mutations in the XK gene have been reported, but the pathological condition in McLeod syndrome is unclear because of a lack of reports. We report a 64‐year‐old man with McLeod syndrome who showed increased levels of creatine kinase, and muscle atrophy and weakness in bilateral lower limbs. Peripheral blood smear showed numerous acanthocytes, and reduced levels of Kell antigen and the absence of XK protein suggested McLeod syndrome. Genetic analysis showed a mutation of c.del724_729TGTAGinsGGTCCTCTTTACC on exon 3 of the XK gene. To our knowledge, this is a novel genetic mutation in the XK gene.
Effect of simulation on knowledge, self‐confidence, and skill performance in the USA: A quasi‐experimental study
Authors: Bowling Ann M. , Underwood Patricia W.
Published: February 2016

In health care, high‐fidelity simulation has been shown to result in increased student learning outcomes when compared to low‐fidelity simulation. With educational facilities investing significant amounts of money into purchasing high‐fidelity simulators, it is imperative to identify if the midlevel simulator, which is less costly, will result in the same learning outcomes. In this study, we examined the effect of midlevel‐fidelity simulation versus low‐fidelity simulation on Bachelor of Science in Nursing nursing students' knowledge, self‐confidence, and skill performance. A quasi‐experimental design examined the effects of midlevel‐fidelity simulation (n = 37) versus low‐fidelity simulation (case study) (n = 37) in junior‐level nursing students. There was a significant difference for both groups in knowledge and skill performance (measured with a mini Objective Structured Clinical Examination), but not between the groups. Unexpectedly, the case‐study group had a higher level of self‐confidence (self‐reported). The results of this study indicate that further research is needed to support faculties' selection of learning strategies with the lowest cost and highest effectiveness in achieving the desired learning outcomes.
New risks: the intended and unintended effects of mental health reform
Authors: Wilson Stacey C , Carryer Jenny , Brannelly Tula
Published: February 2016

In crisis situations, the authority of the nurse is legitimised by legal powers and professional knowledge. Crisis stakeholders include those who directly use services and their families, and a wide range of health, social service and justice agencies. Alternative strategies such as therapeutic risk taking from the perspective of socially inclusive recovery policy coexist in a sometimes uneasy relationship with mental health legislation. A critical discourse analysis was undertaken to examine mental health policies and guidelines, and we interviewed service users, families, nurses and the police about experiences of accessing services. For those who attempt to access services early in crisis, as is suggested to lead to a better outcome, provision of services and rights appear to be reversed by an attempt to exclude them through practices that screen them out, rather than prioritising a choice in access.
Increased diversification rates follow shifts to bisexuality in liverworts
Authors: Laenen Benjamin , Machac Antonin , Gradstein S. Robbert , Shaw Blanka , Patiño Jairo , Désamoré Aurélie , Goffinet Bernard , Cox Cymon J. , Shaw A. Jonathan , Vanderpoorten Alain
Published: February 2016

Shifts in sexual systems are one of the key drivers of species diversification. In contrast to angiosperms, unisexuality prevails in bryophytes. Here, we test the hypotheses that bisexuality evolved from an ancestral unisexual condition and is a key innovation in liverworts.

We investigate whether shifts in sexual systems influence diversification using hidden state speciation and extinction analysis (HiSSE). This new method compares the effects of the variable of interest to the best‐fitting latent variable, yielding robust and conservative tests.

We find that the transitions in sexual systems are significantly biased toward unisexuality, even though bisexuality is coupled with increased diversification. Sexual systems are strongly conserved deep within the liverwort tree but become much more labile toward the present.

Bisexuality appears to be a key innovation in liverworts. Its effects on diversification are presumably mediated by the interplay of high fertilization rates, massive spore production and long‐distance dispersal, which may separately or together have facilitated liverwort speciation, suppressed their extinction, or both. Importantly, shifts in liverwort sexual systems have the opposite effect when compared to angiosperms, leading to contrasting diversification patterns between the two groups. The high prevalence of unisexuality among liverworts suggests, however, a strong selection for sexual dimorphism.
Recent similarity in distribution ranges does not mean a similar postglacial history: a phylogeographical study of the boreal tree species Alnus incana based on microsatellite and chloroplast DNA variation
Authors: Mandák Bohumil , Havrdová Alena , Krak Karol , Hadincová Věroslava , Vít Petr , Zákravský Petr , Douda Jan
Published: February 2016

We reconstructed the historical pattern of postglacial biogeographic range expansion of the boreal tree species Alnus incana in Europe.

To assess population genetic structure and diversity, we performed a combined analysis of nuclear microsatellite loci and chloroplast DNA sequences (65 populations, 1004 individuals).

Analysis of haplotype and microsatellite diversity revealed that southeastern refugial populations situated in the Carpathians and the Balkan Peninsula did not spread north and cannot be considered as important source populations for postglacial recolonization of Europe; populations in Eastern Europe did not establish Fennoscandian populations; populations in Fennoscandia and Eastern Europe have no unique genetic cluster, but represent a mix with a predominant cluster typical for Central Europe; and that colonization of Fennoscandia and Eastern Europe took place from Central Europe.

Our findings highlight the importance of an effective refugium in Central Europe located outside classical southern refugia confirming the existence of northern refugia for boreal trees in Europe. The postglacial range expansion of A. incana did not follow the model established for Picea abies. Fennoscandian populations are not derived from Eastern European ones, but from Central European ones.
Evidence for foliar endophytic nitrogen fixation in a widely distributed subalpine conifer
Authors: Moyes Andrew B. , Kueppers Lara M. , Pett‐Ridge Jennifer , Carper Dana L. , Vandehey Nick , O'Neil James , Frank A. Carolin
Published: February 2016

Coniferous forest nitrogen (N) budgets indicate unknown sources of N. A consistent association between limber pine (Pinus flexilis) and potential N2‐fixing acetic acid bacteria (AAB) indicates that native foliar endophytes may supply subalpine forests with N.

To assess whether the P. flexilis–AAB association is consistent across years, we re‐sampled P. flexilis twigs at Niwot Ridge, CO and characterized needle endophyte communities via 16S rRNA Illumina sequencing. To investigate whether endophytes have access to foliar N2, we incubated twigs with 13N2‐enriched air and imaged radioisotope distribution in needles, the first experiment of its kind using 13N. We used the acetylene reduction assay to test for nitrogenase activity within P. flexilis twigs four times from June to September.

We found evidence for N2 fixation in P. flexilis foliage. N2 diffused readily into needles and nitrogenase activity was positive across sampling dates. We estimate that this association could provide 6.8–13.6 μg N m−2 d−1 to P. flexilis stands. AAB dominated the P. flexilis needle endophyte community.

We propose that foliar endophytes represent a low‐cost, evolutionarily stable N2‐fixing strategy for long‐lived conifers. This novel source of biological N2 fixation has fundamental implications for understanding forest N budgets.
Macroeconomic Uncertainty and Oil Price Volatility
Authors: Van Robays Ine
Published: January 2016

This paper shows that higher macroeconomic uncertainty causes higher oil price volatility. Regimes of low and high uncertainty are identified in a threshold VAR model in which the effects of structural oil demand and supply shocks are estimated. The results show that higher macroeconomic uncertainty, as measured by global industrial production volatility, significantly increases the sensitivity of oil prices to shocks in oil demand and supply. This occurs as uncertainty lowers the price elasticity of oil demand and supply. The difference in the estimated oil price elasticities is economically meaningful as the price impact of a similar change in oil production might double when it hits the economy in uncertain times. As such, varying uncertainty can explain why oil price volatility is typically higher during periods such as financial crises and recessions, and why oil price volatility changes over time more generally.
The genomic landscape of cutaneous melanoma
Authors: Zhang Tongwu , Dutton‐Regester Ken , Brown Kevin M. , Hayward Nicholas K.
Published: February 2016

Somatic mutation analysis of melanoma has been performed at the single gene level extensively over the past several decades. This has provided considerable insight into the critical pathways controlling melanoma initiation and progression. During the last 5 yr, next‐generation sequencing (NGS) has enabled even more comprehensive mutational screening at the level of multigene panels, exomes and genomes. These studies have uncovered many new and unexpected players in melanoma development. The recent landmark study from The Cancer Genome Atlas (TCGA) consortium describing the genomic architecture of 333 cutaneous melanomas provides the largest and broadest analysis to date on the somatic aberrations underlying melanoma genesis. It thus seems timely to review the mutational landscape of melanoma and highlight the key genes and cellular pathways that appear to drive this cancer.
Favorable outcome to glucocorticoid therapy for engraftment syndrome in pediatric autologous hematopoietic cell transplant
Authors: Abongwa Chenue , Abu‐Arja Rolla , Rumelhart Stephen , Lazarus Hillard M. , Abusin Ghada
Published: February 2016

ES remains an important cause of morbidity and mortality in children undergoing auto‐HCT. Glucocorticoid use in ES is an area of debate. We retrospectively analyzed single‐institution experience from September 2000 through December 2012 to evaluate the use of glucocorticoids in auto‐HCT patients. ES was defined by the occurrence of new onset of non‐infectious fever plus diarrhea, rash, or pulmonary infiltrates 24‐h before or within five days after neutrophil engraftment. Sixty‐five pediatric patients (<21 yr) with different solid tumors underwent auto‐HCTs in the study period. Fifteen patients (23%) fulfilled criteria for ES, of which 13 received methylprednisolone (2 mg/kg IV for 3–5 days). Clinical improvement occurred in all patients within 48 h without significant complications. In the non‐ES group, 11 patients received glucocorticoid without significant complications as well. MEL‐based regimens were found to be significant factor for ES (p < 0.05). Fever, edema, non‐infectious diarrhea, and serum albumin concentration were statistically different between the two groups. Median hospital length of stay was higher in the ES group. Conclusion: ES is a common complication in children after auto‐HCT and short‐course glucocorticoid therapy is an effective and well‐tolerated treatment, even in those who did not completely fulfill diagnostic criteria.
Maturation of 5′ ends of plant mitochondrial RNAs
Authors: Binder Stefan , Stoll Katrin , Stoll Birgit
Published: February 2016

The generation of mature RNAs, i.e. mRNAs, rRNAs or tRNAs, is a complex process in all genetic systems. RNA‐internal processes such as splicing or RNA editing, but also posttranscriptional processes modulating 5′ and 3′ termini of transcripts, contribute to RNA maturation. In this article, we focus on the posttranscriptional formation of 5′ termini of mitochondrial RNAs in seed plants, with particular emphasis on the model plant species Arabidopsis thaliana (Arabidopsis). We will summarize the progress made in recent studies of proteins involved in this process. In addition, we will evaluate whether 5′ processing proceeds endo‐ or exo‐nucleolytically. Despite the considerable progress made, many details of this process remain unsolved. In particular, it is still unclear why there is frequent 5′ processing of many mRNAs although impaired processing does not interfere with mitochondrial function and plant fitness. Thus, the importance of 5′ processing for plant mitochondria is still puzzling.
The Validity of a Brief Risk Assessment Tool for Predicting Suicidal Behavior in Veterans Utilizing VHA Mental Health Care
Authors: Doran Neal , De Peralta Sharon , Depp Colin , Dishman Ben , Gold Lindsay , Marshall Robert , Miller Dawn , Vitale Shannon , Tiamson‐Kassab Maria
Published: January 2016

Suicide risk among military veterans is an important and ongoing concern. The Veterans Administration (VA) mandates suicide risk screening of all veterans seen for mental health issues, but little is known about the effectiveness of this screening. A retrospective chart review to examine all suicide risk screens at VA San Diego between October and December 2012 (n = 3,365) was conducted to assess whether results were associated with suicidal behavior over the subsequent 12 months. Patients judged to be at increased risk for suicide were 3 to 16 times more likely to attempt suicide and 7 to 25 times more likely to engage in self‐directed violence over the next 12 months compared with others. The screening tool may be a useful addition to clinical practice.
An Analysis of Germanium–Silicon/Silicon Strained Superlattice Structure Using Convergent Beam Electron Diffraction
Authors: Mogili N. V. V. , Tanner D. A. , Nakahara S.
Published: January 2016

Strained superlattices (SSLs) are typically found inside the p‐n junction area of semiconductor devices and consist of very thin alternating layers of different material. There exists a small lattice mismatch between these materials which results in localised strain, as in the case of germanium‐silicon/silicon SSLs. Strain measurements using a convergent beam electron diffraction (CBED) technique inside a transmission electron microscope (TEM) have indicated that the strain measured normal to these germanium–silicon/silicon SSLs varies almost sinusoidally, in spite of theoretical predictions which indicate a much sharper change in strain between these layers. A theoretical formulation involving an elasticity solution has been developed to predict the strain inside these SSL structures. The comparison of theoretical and experimental results clearly quantifies the effect of beam size on the spatial resolution of CBED measurements. Given that beam size is critically dependent on the spot size of the beam, the convergence angle, the specimen thickness and the position of the focused plane, these parameters are all clearly accounted for in the theoretical predictions.
Progressive Visualization of Complex 3D Models Over the Internet
Authors: Chen Jing , Li Jiawei , Li Mo
Published: February 2016

The online transmission and real‐time rendering of complex 3D models have always been a bottleneck which limits the performance of Web 3D simulation systems. To improve the efficiency of data transmission and mesh reconstruction, this article proposes a novel progressive mesh structure. In the first stage of progressive visualization, the base data and the base index generated by vertex clustering simplification are transmitted to the client for the fundamental rendering. Then the incremental data and corresponding indexes at higher levels are transmitted, as the viewpoint approaches the simulation object. The multi‐scale incremental data organization benefits the performance and efficiency of the Web 3D simulation system by separately transmitting and reconstructing the corresponding level of mesh details. To demonstrate the adaptability and reliability of this algorithm, we developed an experimental prototype system to conduct a series of experiments. The results of experiments show that the improved progressive mesh structure described in this article takes good advantage of the vertex clustering simplification scheme to increase the efficiency of online transmission and mesh reconstruction, and the average frame rate of the progressive visualization has been increased to some extent, especially for massive data in large scale scenes.
Management of hyperhaemolysis after a transfusion in sickle‐cell patients
Authors: Bartolucci P. , Noizat Pirenne F. , Habibi A.
Published: January 2016

Transfusion is a corner stone treatment of sickle cell disease complications. However one of the serious complications of transfusions is represented by the delayed haemolytic transfusion reaction (DHTR) with a significant mortality. It is due to a massive intravascular haemolysis of both transfused and autologous red blood cells. It occurs between 5 to 20 days after a transfusion and is accompanied by a vaso‐occlusive crisis and haemoglobinuria in almost all cases. The evolution can be life‐threatening because of the appearance of a severe acute chest syndrome or a multi organ failure. About half patients are transferred in Intensive Care Unit. The biological diagnosis of DHTR is made by the rapid decline, or disappearance, of Hb A in sickle cell patients who were previously transfused. This event is associated with a significant increase of lactico‐dehydrogenase (LDH) and worsening of anemia due to haemolysis. Allo antibodies are not found in 30%. DHTR is under diagnosed because of the delay between the transfusion and the symptoms, which mimic sickle cell vaso occlusive crises. This can lead to further transfusions that worsen the evolution and are ineffective. Because of the severity of this manifestation many treatment have been tried to improve the outcome as steroids, immunoglobulins, rituximab or eculizumab, without consensual guidelines. Early diagnosis of DHTR should help to decide the appropriate treatment, and avoid reiteration of transfusions. Transfusion indications should be maximally restricted in patients with previous post‐transfusion haemolysis.
Inpatient Pressure Ulcer Prevalence in an Acute Care Hospital Using Evidence‐Based Practice
Authors: Beal M. Elizabeth , Smith Kimberly
Published: January 2016

Background

A national goal was set in 2004 for decreasing hospital‐acquired pressure ulcers (HAPUs). A mean to achieve that goal was initiated in 2005 with long‐term care facilities. Acute care facilities, with encouragement from the Centers for Medicare and Medicaid Services, took action.

Aims

Pressure ulcer prevention efforts at MaineGeneral Medical Center (MGMC), a 192‐bed acute care hospital in Augusta, Maine, sought to reduce HAPU prevalence from a mean of 7.8% in 2005.

Methods

A retrospective study over a 10‐year period, from 2005 through 2014, tracked HAPUs and evidence‐based practice (EBP) initiatives to decrease the annual mean prevalence rate.

Results

The annual mean HAPU prevalence rate of 7.8% in 2005 decreased to 1.4% in 2011, then maintaining this level through 2014 at MGMC. Evidence‐based practices for pressure ulcer prevention were implemented using data collection tools from the National Database of Nursing Quality Indicators; guidelines from the National Pressure Ulcer Advisory Panel; and procedural guidance tools from the 5 Million Lives Campaign and the Agency for Healthcare Research and Quality.

Conclusions

Accurate data collection methods and evidence‐based guidelines are vital to improving care; yet planning with annual review, fostering an EBP culture, by‐in of stakeholders, and education, are the means to long‐term consistent implementation of pressure ulcer prevention measures.

Linking Evidence to Action

Keys to decreasing and maintaining the rate were based on effective scientific evidence for prevention of pressure ulcers: assessment tools, education, planning guidance, documentation, and evidence‐based practice guidelines.
Analyzing and Comparing Basel III Sensitivity Based Approach for the Interest Rate Risk in the Trading Book
Authors: Sayah Mabelle
Published: January 2016

A bank’s capital charge computation is a widely discussed topic with new approaches emerging continuously. Each bank computes this figure using internal methodologies in order to reflect its capital adequacy; however, a more homogeneous model is recommended by the Basel committee to enable judging the situation of these financial institutions and relating different banks among each other.In this paper, we compare different numerical and econometric models to the Sensitivity Based Approach (SBA) implemented by the Basel Committee on Banking Supervision (BCBS) under Basel III in its December 2014 (rev. March 2015) publication in order to compute the capital charge in the trading book. We study the influence of having several currencies and maturities within the portfolio and try to define the time horizon and confidence level implied by Basel’s III approach through an application on bonds portfolios.By implementing several approaches, we are able to find equivalent VaRs to the one computed by the SBA on a pre-defined confidence level (97.5%). However, the time horizon differs according to the chosen methodology and ranges from 1 month up to 1 year.
The Attributes of Japanese Corporate Governance Influencing the Quality of Internal Controls
Authors: Uemura Hiroshi
Published: January 2016

This study examines the corporate governance characteristics that influence the improvement in the quality of internal controls. Previous studies suggest that corporate governance independence and expertise affect the quality of internal controls (Krishnan et al. 2005; Hoitash et al. 2009). In Japan, however, any company that discloses significant deficiencies (SD) in internal controls has the motive to increase the independence of corporate governance to mitigate any subsequent negative consequences. As a result, independent directors are made the scapegoats, rather than allowing them to fulfill the expectation of improvement in the quality of internal controls. On the other hand, directors with financial expertise that have a high status in a company do influence the improvement in SD in internal controls. This suggests that in Japan it is important to provide financial experts with the power and authority to improve the quality of internal controls in the short term, due to the difference in the provisions between the Financial Instruments and Exchange Act (J-SOX) and the Sarbanes–Oxley Act (SOX). The requirements in Japanese Corporate Law (JCL) for independent directors are not as strict as those within SOX. Therefore, companies in which the boards are able to promote expert directors to important positions improve the quality of internal controls more often than those that are not. It is thus revealed that auditors should be able to discuss with the financial experts as to what is required to improve any significant deficiencies that are detected in the process of internal control audits.
Extracellular vesicles in cardiovascular calcification: expanding current paradigms
Authors: Krohn Jona B. , Hutcheson Joshua D. , Martínez‐Martínez Eduardo , Aikawa Elena
Published: January 2016

Vascular calcification is a major contributor to the progression of cardiovascular disease, one of the leading causes of death in industrialized countries. New evidence on the mechanisms of mineralization identified calcification‐competent extracellular vesicles (EVs) derived from smooth muscle cells, valvular interstitial cells and macrophages as the mediators of calcification in diseased heart valves and atherosclerotic plaques. However, the regulation of EV release and the mechanisms of interaction between EVs and the extracellular matrix leading to the formation of destabilizing microcalcifications remain unclear. This review focuses on current limits in our understanding of EVs in cardiovascular disease and opens up new perspectives on calcific EV biogenesis, release and functions within and beyond vascular calcification. We propose that, unlike bone‐derived matrix vesicles, a large population of EVs implicated in cardiovascular calcification are of exosomal origin. Moreover, the milieu‐dependent loading of EVs with microRNA and calcification inhibitors fetuin‐A and matrix Gla protein suggests a novel role for EVs in intercellular communication, adding a new mechanism to the pathogenesis of vascular mineralization. Similarly, the cell type‐dependent enrichment of annexins 2, 5 or 6 in calcifying EVs posits one of several emerging factors implicated in the regulation of EV release and calcifying potential. This review aims to emphasize the role of EVs as essential mediators of calcification, a major determinant of cardiovascular mortality. Based on recent findings, we pinpoint potential targets for novel therapies to slow down the progression and promote the stability of atherosclerotic plaques.

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Evaluation of Rock Mechanical Properties Alteration During Matrix Stimulation With Chelating Agents
Authors: Barri Assad , Mahmoud Mohamed , Elkatatny Salaheldin
Published: January 2016

Well stimulation using acidic solutions is widely used to treat carbonate formations. The acidic fluids remove the near-wellbore damage and create channels around the wellbore by dissolving fraction of the carbonate rocks. Many stimulation fluids have been used such as hydrochloric acid (HCl) acid, organic acids, and chelating agents to stimulate carbonate reservoirs. Wormholes that are created by these fluids are very effective and will yield negative skin values and this will enhance the well productivity. In addition to the wormhole creation, the diffusion of these fluids inside the pores of the rock may create significant and permanent changes in the rock mechanical properties. These changes can eventually lead to weakening the rock strength, which may lead to future formation damage due to the wellbore instability. In this paper, the effect of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) chelating agents on the carbonate rocks elastic properties was investigated. The effect of wormholes created by chelating agent on the rock mechanical properties was investigated. Computed tomography (CT) scan and acoustic measurements were conducted on the core samples before and after matrix stimulation treatments. Experimental results showed that the mechanical properties of strong rocks such as Indiana limestone (IL) cores were not affected when chelating agents were used to stimulate those cores. On the other hand, less strong rocks such as Austin chalk (AC) show significant alteration on the rock elastic properties when chelating agents were used as stimulation fluids.
Development of a Soft Pneumatic Sock for Robot-Assisted Ankle Exercise
Authors: Low Fan-Zhe , Tan Hong Han , Lim Jeong Hoon , Yeow Chen-Hua
Published: January 2016

Deep vein thrombosis (DVT) is a severe medical condition that affects many patients around the world, where one of the main causes is commonly associated with prolonged immobilization. Current mechanical prophylaxis systems, such as the compression stockings and intermittent pneumatic compression devices, have yet to show strong efficacy in preventing DVT. The current study aimed to develop a soft pneumatic sock prototype that uses soft extension pneumatic actuators to provide assisted ankle dorsiflexion–plantarflexion motion, so as to prevent the occurrence of DVT. The prototype was evaluated for its efficacy to provide the required dorsiflexion–plantarflexion motion by donning and actuating the prototype on simulated ankle–foot models with various ankle joint stiffness values. Our results showed that the soft extension actuators in the sock prototype provided controllable assisted ankle plantarflexion through actuator extension and ankle dorsiflexion through actuator contraction, where in our study, the actuations extended to 129.9–146.8% of its original length. Furthermore, the sock was able to achieve consistent range of motion at the simulated ankle joint across different joint stiffness values (range of motion: 27.5 ± 6.0 deg). This study demonstrated the feasibility of using soft extension pneumatic actuators to provide robot-assisted ankle dorsiflexion–plantarflexion motion, which will act as an adjunct to physiotherapists to optimize therapy time for bedridden patients and therefore may reduce the risk of developing DVT.
Numerical Simulations of Hollow-Cone Injection and Gasoline Compression Ignition Combustion With Naphtha Fuels
Authors: Badra Jihad A. , Sim Jaeheon , Elwardany Ahmed , Jaasim Mohammed , Viollet Yoann , Chang Junseok , Amer Amer , Im Hong G.
Published: January 2016

Gasoline compression ignition (GCI), also known as partially premixed compression ignition (PPCI) and gasoline direct injection compression ignition (GDICI), engines have been considered an attractive alternative to traditional spark ignition (SI) engines. Lean-burn combustion with the direct injection of fuel eliminates throttle losses for higher thermodynamic efficiencies, and the precise control of the mixture compositions allows better emission performance such as NOx and particulate matter (PM). Recently, low octane gasoline fuel has been identified as a viable option for the GCI engine applications due to its longer ignition delay characteristics compared to diesel and lighter evaporation compared to gasoline fuel (Chang et al., 2012, “Enabling High Efficiency Direct Injection Engine With Naphtha Fuel Through Partially Premixed Charge Compression Ignition Combustion,” SAE Technical Paper No. 2012-01-0677). The feasibility of such a concept has been demonstrated by experimental investigations at Saudi Aramco (Chang et al., 2012, “Enabling High Efficiency Direct Injection Engine With Naphtha Fuel Through Partially Premixed Charge Compression Ignition Combustion,” SAE Technical Paper No. 2012-01-0677; Chang et al., 2013, “Fuel Economy Potential of Partially Premixed Compression Ignition (PPCI) Combustion With Naphtha Fuel,” SAE Technical Paper No. 2013-01-2701). The present study aims to develop predictive capabilities for low octane gasoline fuel compression ignition (CI) engines with accurate characterization of the spray dynamics and combustion processes. Full three-dimensional simulations were conducted using converge as a basic modeling framework, using Reynolds-averaged Navier–Stokes (RANS) turbulent mixing models. An outwardly opening hollow-cone spray injector was characterized and validated against existing and new experimental data. An emphasis was made on the spray penetration characteristics. Various spray breakup and collision models have been tested and compared with the experimental data. An optimum combination has been identified and applied in the combusting GCI simulations. Linear instability sheet atomization (LISA) breakup model and modified Kelvin–Helmholtz and Rayleigh–Taylor (KH-RT) break models proved to work the best for the investigated injector. Comparisons between various existing spray models and a parametric study have been carried out to study the effects of various spray parameters. The fuel effects have been tested by using three different primary reference fuel (PRF) and toluene primary reference fuel (TPRF) surrogates. The effects of fuel temperature and chemical kinetic mechanisms have also been studied. The heating and evaporative characteristics of the low octane gasoline fuel and its PRF and TPRF surrogates were examined.
Temperature of Food and Drink Intake Matters
Authors: Vincent Wong Kaufui
Published: January 2016

The U.S. Government determines the guidelines for daily diet of humans in their various life stages. The current guidelines for caloric intake are about 2800 cal daily for the adult male, and about 600 cal less for the adult female. This work brings up the point that with the growing diversity of the population, these caloric intake guidelines need to consider the effect of temperature at the time the food is consumed. The motivation of this study is diversity; it is recognized that the Chinese and South Korean cuisines typically have high temperatures when served, whereas much of standard American food is consumed at room temperature. The thermal capacity of the food consumed has not been taken into consideration. It is likely that the “empty” calories related to consumption of hot foods are helpful, in keeping the body warm without the risk of weight gain. They may also be used judiciously to lose weight.
Transverse Compression of Tendons
Authors: Samuel Salisbury S. T. , Paul Buckley C. , Zavatsky Amy B.
Published: February 2016

A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon.
Numerical Simulation of Focused Shock Shear Waves in Soft Solids and a Two-Dimensional Nonlinear Homogeneous Model of the Brain
Authors: Giammarinaro B. , Coulouvrat F. , Pinton G.
Published: February 2016

Shear waves that propagate in soft solids, such as the brain, are strongly nonlinear and can develop into shock waves in less than one wavelength. We hypothesize that these shear shock waves could be responsible for certain types of traumatic brain injuries (TBI) and that the spherical geometry of the skull bone could focus shear waves deep in the brain, generating diffuse axonal injuries. Theoretical models and numerical methods that describe nonlinear polarized shear waves in soft solids such as the brain are presented. They include the cubic nonlinearities that are characteristic of soft solids and the specific types of nonclassical attenuation and dispersion observed in soft tissues and the brain. The numerical methods are validated with analytical solutions, where possible, and with self-similar scaling laws where no known solutions exist. Initial conditions based on a human head X-ray microtomography (CT) were used to simulate focused shear shock waves in the brain. Three regimes are investigated with shock wave formation distances of 2.54 m, 0.018 m, and 0.0064 m. We demonstrate that under realistic loading scenarios, with nonlinear properties consistent with measurements in the brain, and when the shock wave propagation distance and focal distance coincide, nonlinear propagation can easily overcome attenuation to generate shear shocks deep inside the brain. Due to these effects, the accelerations in the focal are larger by a factor of 15 compared to acceleration at the skull surface. These results suggest that shock wave focusing could be responsible for diffuse axonal injuries.
Aerodynamic Design of Separate-Jet Exhausts for Future Civil Aero-engines—Part II: Design Space Exploration, Surrogate Modeling, and Optimization
Authors: Goulos Ioannis , Otter John , Stankowski Tomasz , MacManus David , Grech Nicholas , Sheaf Christopher
Published: February 2016

The aerodynamic performance of the bypass exhaust system is key to the success of future civil turbofan engines. This is due to current design trends in civil aviation dictating continuous improvement in propulsive efficiency by reducing specific thrust and increasing bypass ratio (BPR). This paper aims to develop an integrated framework targeting the automatic design optimization of separate-jet exhaust systems for future aero-engine architectures. The core method of the proposed approach is based on a standalone exhaust design tool comprising modules for cycle analysis, geometry parameterization, mesh generation, and Reynolds-averaged Navier–Stokes (RANS) flow solution. A comprehensive optimization strategy has been structured comprising design space exploration (DSE), response surface modeling (RSM) algorithms, as well as state-of-the-art global/genetic optimization methods. The overall framework has been deployed to optimize the aerodynamic design of two civil aero-engines with separate-jet exhausts, representative of current and future engine architectures, respectively. A set of optimum exhaust designs have been obtained for each investigated engine and subsequently compared against their reciprocal baselines established using the current industry practice in terms of exhaust design. The obtained results indicate that the optimization could lead to designs with significant increase in net propulsive force, compared to their respective notional baselines. It is shown that the developed approach is implicitly able to identify and mitigate undesirable flow-features that may compromise the aerodynamic performance of the exhaust system. The proposed method enables the aerodynamic design of optimum separate-jet exhaust systems for a user-specified engine cycle, using only a limited set of standard nozzle design variables. Furthermore, it enables to quantify, correlate, and understand the aerodynamic behavior of any separate-jet exhaust system for any specified engine architecture. Hence, the overall framework constitutes an enabling technology toward the design of optimally configured exhaust systems, consequently leading to increased overall engine thrust and reduced specific fuel consumption (SFC).
Hypersingular meshless method using double-layer potentials for three-dimensional exterior acoustic problems
Authors: Young D. L. , Chen K. H. , Liu T. Y. , Wu C. S.
Published: January 2016

Three-dimensional exterior acoustic problems with irregular domains are solved using a hypersingular meshless method. In particular, the method of fundamental solutions (MFS) is used to formulate and analyze such acoustic problems. It is well known that source points for MFS cannot be located on the real boundary due to the singularity of the kernel functions. Thus, the diagonal terms of the influence matrices are unobtainable when source points are located on the boundary. An efficient approach is proposed to overcome such difficulties, when the MFS is used for three-dimensional exterior acoustic problems. This work is an extension of previous research on two-dimensional problems. The solution of the problem is expressed in terms of a double-layer potential representation on the physical boundary. Three examples are presented in which the proposed method is compared to the MFS and boundary element method. Good numerical performance is demonstrated by the proposed hypersingular meshless method.
Complete Genome Sequence of Pseudomonas brassicacearum LBUM300, a Disease-Suppressive Bacterium with Antagonistic Activity toward Fungal, Oomycete, and Bacterial Plant Pathogens
Authors: Novinscak Amy , Gadkar Vijay J. , Joly David L. , Filion Martin
Published: January 2016

Pseudomonas brassicacearum
LBUM300, a plant rhizosphere-inhabiting bacterium, produces 2,4-diacetylphloroglucinol and hydrogen cyanide and has shown antagonistic activity against the plant pathogens
Verticillium dahliae
,
Phytophthora cactorum
, and
Clavibacter michiganensis
subsp.
michiganensis
. Here, we report the complete genome sequence of
P. brassicacearum
LBUM300.
Rare gynaecological emergency: massive intraperitoneal haemorrhage from spontaneous rupture of a superficial vessel on a large leiomyoma
Authors: Gulati Nidhi , Raman Srimathy , Srinivasan Maheshwari , Bakour Shagaf
Published: January 2016

Uterine leiomyomas rarely present as gynaecological emergencies. We report a case of a 29-year-old nulliparous woman, with a negative pregnancy test, who presented with collapse and an admission haemoglobin count of 68 g/L. Urgent CT of the abdomen revealed a 14×19×10 cm uterine fibroid and intraperitoneal free fluid. Emergency laparotomy confirmed massive intraperitoneal haemorrhage from a large serosal vessel on top of a 19 cm subserosal fibroid. A myomectomy was performed, preserving this patient's fertility. Histopathology confirmed a benign leiomyoma with hydropic changes.
Mesenteric lymphangioma mimicking a cystic ovarian mass on imaging
Authors: Hitzerd Emilie , van Hamont Dennis , Pijnenborg Johanna M A
Published: February 2016

Pelvic cystic masses are frequently observed in women. Most lesions are benign and of ovarian origin. However, non-ovarian lesions can be easily confused with cystic ovarian masses on imaging, which hampers diagnostic and therapeutic management. In this report, a rare case of mesenteric lymphangioma mimicking an ovarian cystic mass, discovered as an incidental finding on orthopaedic MRI in an adult female, is presented. The report highlights the sometimes difficult diagnostic process of pelvic cystic masses, due to an extensive differential diagnosis and the fact that imaging is often inconclusive. Even though most cystic masses are of ovarian origin, non-ovarian causes can mimic ovarian masses and should be considered as differential diagnoses. Surgical exploration may be necessary to exclude malignant causes.