bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐copy sequences reveal distinct evolution of the rye B chromosome
Authors: Klemme Sonja , Banaei‐Moghaddam Ali Mohammad , Macas Jiri , Wicker Thomas , Novák Petr , Houben Andreas
Published: April 2013

B chromosomes (Bs) are supernumerary chromosomes that vary in number among individuals of the same species. Because of their dispensable nature, their non‐Mendelian inheritance and their origin from A chromosomes (As), one might assume that Bs followed a different evolutionary pathway from As, this being reflected in differences in their high‐copy DNA constitution. We provide detailed insight into the composition and distribution of rye (Secale cereale) B‐located high‐copy sequences.

A‐ and B‐specific high‐copy sequences were identified in silico. Mobile elements and satellite sequences were verified by fluorescence in situ hybridization (FISH). Replication was analyzed via EdU incorporation.

Although most repeats are similarly distributed along As and Bs, several transposons are either amplified or depleted on the B. An accumulation of B‐enriched satellites was found mostly in the nondisjunction control region of the B, which is transcriptionally active and late‐replicating. All B‐enriched sequences are not unique to the B but are also present in other Secale species, suggesting the origin of the B from As of the same genus.

Our findings highlight the differences between As and Bs. Although Bs originated from As, they have since taken a separate evolutionary pathway.
‘Balancing risk’ after fall‐induced hip fracture: the older person's need for information
Authors: McMillan Laura , Booth Joanne , Currie Kay , Howe Tracey
Published: April 2013

Background

Hip fracture is a significant cause of morbidity and mortality in older people. Healthcare professionals have a role to identify and respond to challenges and concerns that older people face as they strive to manage risk of future falls and rebuild confidence and independence after discharge.

Aims and objectives

This study aimed to explore the postdischarge concerns of older people after fall‐induced hip fracture.

Method

Glaser's approach to the grounded theory method guided qualitative interviews conducted with 19 older people in their own homes up to 3 months post discharge, in two health authority areas.

Results

A theory of ‘taking control’ was generated. ‘Balancing risk’ emerged as a key strategy that older people employed to help them to take control after discharge home. Older people attempted to control or ‘balance’ their risk of future falls and dependence by implementing two further strategies: ‘protective guarding’ and ‘following orders’. The instinctive strategy of protective guarding and the learned strategy of following orders were implemented simultaneously and were characterised by older people aiming to pace their progress and balance risk safely and appropriately. To apply these strategies, older people required information from healthcare professionals. In circumstances where older people did not receive or did not understand the information provided, they were left ‘grasping to understand’ and were more likely to miscalculate risk. This leads to damaged confidence and in some cases further falls.

Conclusions

The concept of balancing risk aims to help healthcare professionals understand the older person's perspective of hip fracture and to recognise the efforts that people make to guard against further injury and dependence in the early postdischarge period.

Implications for practice

Our study suggests that engaging older people and their relatives in discussions to acknowledge their perceptions of future risk and to provide appropriate information on managing risk is crucial, as this will enable older people to balance risk safely and ultimately rebuild independence.
PUBLIC–PRIVATE INTERACTION IN CONTRACTING: GOVERNANCE STRATEGIES IN THE COMPETITIVE DIALOGUE OF DUTCH INFRASTRUCTURE PROJECTS
Authors: LENFERINK SANDER , TILLEMA TAEDE , ARTS JOS
Published: April 2013

The competitive dialogue (CD) procurement procedure aims to structure and facilitate public–private interaction in procurement. In this article we examine the CD procedures of four complex Dutch road infrastructure projects and explore how the mix in public–private interaction between the three governance strategies of cooperation, competition, and coordination is conditioned by various external influences. We found that public authorities' strict legal coordination can structure the CD process, but may divert attention from the required interaction on project‐specific complexities. Combined with private contractors' focus on competition, this does not stimulate public–private cooperation. We conclude that CD is a promising tool for facilitating public–private interaction, but, in practice, the optimal mix of governance strategies is not achieved. We recommend strengthening cooperation by encouraging public and private tender organizations to collaboratively search for opportunities to deal with complexity in planning.
Characterizing morphological traits and estimating genetic relationship for intermediate soybean collected from South Korea
Authors: Vu Dang Toan , Baek Kwang‐Hyun , Tuan Nghia La , Park Euiho
Published: April 2013

Twenty‐two wild, 16 intermediate and 20 cultivated soybean varieties were used to analyse relationships among the species of subgenus Soja, genus Glycine using 11 morphological traits and simple sequence repeat (SSR) markers. These genotypes using eleven agronomic characteristics were divided into three clusters: cluster I included 20 G. max, cluster II included 12 intermediate, and cluster III included 22 G. soja and four intermediate lines. Genetic relationships among the species of subgenus Soja showed three distinct clusters. Cluster I consisted of 20 G. max cultivars and two intermediate type lines, and cluster II consisted of 13 intermediate type and two G. soja lines; however, cluster III consisted of 20 G. soja and one intermediate type lines. These phenotypic and genetic data suggest that the intermediate type lines could be distinguished between G. max and G. soja lines. However, the intermediate type could not be classified as a new species.
Photolysis and Thermolysis of Pyridyl Carbonyl Azide Monolayers on Single‐Crystal Platinum
Authors: Adkinson Dana K. , Magri David C. , Pitters Jason L. , Griffiths Keith , Norton Peter R. , Workentin Mark S.
Published: April 2013

The photochemical and thermal reactivity of a number of acyl azide‐substituted pyridine compounds, namely nicotinyl azide, isonicotinyl azide, picolinyl azide and dinicotinyl azide with investigated as saturated monolayers on a single‐crystal Pt(111) surface in an ultrahigh vacuum chamber. Multilayers of the substrates exhibited a maximum rate of desorption at 270 K, above which, stable saturated monolayers formed as characterized by reflection‐absorption infrared spectroscopy by observation of C=O and N3 bands at 1700 cm−1, and 2100 and 1300 cm−1 respectively. The monolayers were stable up to 400 K. Photolysis of the monolayer (or heating above 400 K) results in the formation of the respective isocyanate intermediate after loss of nitrogen as evidenced by the appearance of a new infrared band at 2260 cm−1 with concomitant loss of the azide bands. The resulting isocyanate saturated monolayer is stable in absence of nucleophiles, but can be quenched with appropriate nucleophiles.
Quantitative trait loci and candidate genes associated with starch pasting viscosity characteristics in cassava (Manihot esculenta Crantz)
Authors: Thanyasiriwat T. , Sraphet S. , Whankaew S. , Boonseng O. , Bao J. , Lightfoot D. A. , Tangphatsornruang S. , Triwitayakorn K.
Published: April 2013

Starch pasting viscosity is an important quality trait in cassava (Manihot esculenta Crantz) cultivars. The aim here was to identify loci and candidate genes associated with the starch pasting viscosity. Quantitative trait loci (QTL) mapping for seven pasting viscosity parameters was carried out using 100 lines of an F1 mapping population from a cross between two cassava cultivars Huay Bong 60 and Hanatee. Starch samples were obtained from roots of cassava grown in 2008 and 2009 at Rayong, and in 2009 at Lop Buri province, Thailand. The traits showed continuous distribution among the F1 progeny with transgressive variation. Fifteen QTL were identified from mean trait data, with Logarithm of Odds (LOD) values from 2.77–13.01 and phenotype variations explained (PVE) from10.0–48.4%. In addition, 48 QTL were identified in separate environments. The LOD values ranged from 2.55–8.68 and explained 6.6–43.7% of phenotype variation. The loci were located on 19 linkage groups. The most important QTL for pasting temperature (PT) (qPT.1LG1) from mean trait values showed largest effect with highest LOD value (13.01) and PVE (48.4%). The QTL co‐localised with PT and pasting time (PTi) loci that were identified in separate environments. Candidate genes were identified within the QTL peak regions. However, the major genes of interest, encoding the family of glycosyl or glucosyl transferases and hydrolases, were located at the periphery of QTL peaks. The loci identified could be effectively applied in breeding programmes to improve cassava starch quality. Alleles of candidate genes should be further studied in order to better understand their effects on starch quality traits.
Combined effects of light and nitrate supplies on the growth, photosynthesis and ultraviolet‐absorbing compounds in marine macroalga Gracilaria lemaneiformis (Rhodophyta), with special reference to the effects of solar ultraviolet radiation
Authors: Zheng Yangqiao
Published: April 2013

It is well known that light and nutrients are essential to plants; however, there are few investigations in which these have been studied in combination on macroalgae, especially when solar ultraviolet radiation (UVR) is concerned. We cultured the red alga Gracilaria lemaneiformis (Bory) at different nitrate concentrations and light levels with or without UVR for 24 days. The results showed that nitrate supply markedly enhanced the growth and photosynthesis, increased the absorptivity of UV‐absorbing compounds (UVACs), and decreased photoinhibition in the presence of UVR. The thalli that received photosynthetically active radiation (PAR) treatment exhibited higher growth rates than those that received PAR + UVR at ambient or enhanced nitrate concentrations. However, under PAR + UVR treatment, the absorptivity of UVACs was higher than that of PAR and fluctuated with light levels. UVR was found to reduce the maximal net photosynthetic rate, apparent photosynthetic efficiency and light‐saturating irradiance while increasing the dark respiration rate, and inducing higher inhibition of growth and photosynthesis under high light versus under low light. Ultraviolet B significantly induced the synthesis of UVACs but led to higher inhibition on growth and photosynthesis than ultraviolet A.
Phylogenetic analysis of ITS2 sequences suggests the taxonomic re‐structuring of Dunaliella viridis (Chlorophyceae, Dunaliellales)
Authors: Assunção Patrícia , Jaén‐Molina Ruth , Caujapé‐Castells Juli , Wolf Matthias , Buchheim Mark A. , de la Jara Adelina , Freijanes Karen , Carmona Laura , Mendoza Héctor
Published: April 2013

We analyzed the ITS2 primary and secondary structure (including Compensatory Base Changes (CBCs)) of 17 new Dunaliella strains (11 D. viridis, two D. tertiolecta, and four Dunaliella sp.), and compared these with other Dunaliella sequences available from the ITS2 database to circumscribe their taxonomic position. The ITS2 primary and secondary structure analysis positioned the majority of D. viridis strains in four main clades, showing that D. viridis is polyphyletic. The detection of at least one CBC among these clades strongly suggests that they could correspond to different biological species. Unexpectedly, while D. viridis var. euchlora (CCAP19/21) was positioned within the subgenus Dunaliella, D. viridis var. palmelloides (CCAP11/34) was positioned clearly outside this subgenus, suggesting that this taxon may not be properly placed in Dunaliella. Furthermore, the detection of at least three compensatory base changes (CBCs) between D. viridis var. palmelloides (CCAP11/34) and the other strains analyzed, confirm that this strain is a different species. For these reasons we propose re‐naming D. viridis var. palmelloides (CCAP11/34) to incertae sedis, and D. viridis var. euchlora (CCAP19/21) to Dunaliella sp. Therefore, the ITS2 primary and secondary structure data suggest a taxonomic re‐structuring of D. viridis.
Seasonal development of five Cephaleuros species (Trentepohliaceae, Chlorophyta) on the leaves of woody plants and the behaviors of their gametes and zoospores
Authors: Suto Yasuo , Ohtani Shuji
Published: April 2013

The infection cycle of five Cephaleuros species – C. aucubae, C. biolophus, C. japonicus, C. microcellularis, and C. virescens – was clarified by investigating seasonal development and gamete and zoospore behavior at study sites in Matsue, Shimane Prefecture, Japan. Fresh thalli or lesions appeared on the leaves of various woody plants from August and continued to develop in general from April to September in the following year. Gametangia and zoosporangia matured on 2‐ and 3‐year‐old leaves. Gametes were released in C. microcellularis samples collected from late March to late May and in samples of the other four species collected from late April to late July. Zoospores were released in C. biolophus, C. japonicus, and C. virescens samples collected from mid‐May to early August. In the present study, gametes did not conjugate but germinated like zoospores to produce new plants. After inoculation with zoospores and gametes that behave as asexual spores, fresh thalli or lesions became evident in 2–5 months following inoculation and gametes and zoospores were produced on the developed thalli or lesions the following year; one cycle of the infection was completed per year in the study area.
Australian Laurencia majuscula (Rhodophyta, Rhodomelaceae) and the Brazilian Laurencia dendroidea are conspecific
Authors: Metti Yola , Millar Alan J.K. , Cassano Valeria , Fujii Mutue T.
Published: April 2013

Morphological and molecular studies have been undertaken on two species of the red algal genus Laurencia J.V.Lamouroux: Laurencia majuscula (Harvey) A.H.S. Lucas and Laurencia dendroidea J.Agardh, both from their type localities. The phylogenetic position of these species was inferred by analysis of the chloroplast‐encoded rbcL gene sequences from 24 taxa. In all phylogenetic analyses, the Australian Laurencia majuscula and the Brazilian L. dendroidea formed a well‐supported monophyletic clade within the Laurencia sensu stricto. This clade was divided into two subclades corresponding to each geographical region; however, the genetic divergence between Australian L. majuscula and Brazilian L. dendroidea was only 0–1.35%. Examination of the type specimens and sequences of freshly collected samples of both Laurencia majuscula and L. dendroidea show the two to be conspecific despite their disjunct type localities.
A Poetics of the natural: sensation, decorum, and bodily appeal in Puttenham's Art of English Poesy
Authors: Wiseman Rebecca
Published: April 2013

This article addresses courtier‐poet Puttenham's sprawling 1589 treatise on English poetics, focusing especially on one of the text's central tensions: the relationship between poetry as constructed commodity and the receptive body as natural, sensual, universal in its responses and affinities. I suggest that Puttenham's treatise is not merely a guide for poetic composition but also a sustained exploration of what it means to be a hearer and reader of poetry. The Art of English Poesy is as interested in theorizing the physiological and social dimensions of the poetic encounter as it is in offering a set of instructions to aspiring courtier‐poets. Puttenham analyses this encounter in terms of an aesthetic ideal of proportionate composition and response; as a partnership flourishing under the conditions of a universal natural order; and as a crucial social tool, essential to decorum and courtly success. Yet Puttenham's central claim is for the supremacy of the receptive body as the ultimate arbiter of poetic quality.
How Solid Is the Dutch (and the British) National Risk Assessment? Overview and Decision‐Theoretic Evaluation
Authors: Vlek Charles
Published: April 2013

Internationally, national risk assessment (NRA) is rapidly gaining government sympathy as a science‐based approach toward prioritizing the management of national hazards and threats, with the Netherlands and the United Kingdom in leading positions since 2007. NRAs are proliferating in Europe; they are also conducted in Australia, Canada, New Zealand, and the United States, while regional RAs now exist for over 100 Dutch or British provinces or counties. Focused on the Dutch NRA (DNRA) and supported by specific examples, summaries and evaluations are given of its (1) scenario development, (2) impact assessment, (3) likelihood estimation, (4) risk diagram, and (5) capability analysis. Despite the DNRA's thorough elaboration, apparent weaknesses are lack of stakeholder involvement, possibility of false‐positive risk scenarios, rigid multicriteria impact evaluation, hybrid methods for likelihood estimation, half‐hearted use of a “probability × effect” definition of risk, forced comparison of divergent risk scenarios, and unclear decision rules for risk acceptance and safety enhancement. Such weaknesses are not unique for the DNRA. In line with a somewhat reserved encouragement by the OECD (Studies in Risk Management. Innovation in Country Risk Management. Paris: OECD, 2009), the scientific solidity of NRA results so far is questioned, and several improvements are suggested. One critical point is that expert‐driven NRAs may preempt political judgments and decisions by national security authorities. External review and validation of major NRA components is recommended for strengthening overall results as a reliable basis for national and/or regional safety policies. Meanwhile, a broader, more transactional concept of risk may lead to better national and regional risk assessments.
Influences on Call Outcomes among Veteran Callers to the National Veterans Crisis Line
Authors: Britton Peter C. , Bossarte Robert M. , Thompson Caitlin , Kemp Janet , Conner Kenneth R.
Published: April 2013

The association of caller and call characteristics with proximal outcomes of Veterans Crisis Line calls were examined. From October 1–7, 2010, 665 veterans with recent suicidal ideation or a history of attempted suicide called the Veterans Crisis Line; 646 had complete data and were included in the analyses. A multivariable multinomial logistic regression was conducted to identify correlates of a favorable outcome (a resolution or a referral) when compared to an unfavorable outcome (no resolution or referral). A multivariable logistic regression was used to identify correlates of responder‐rated caller risk in a subset of calls. Approximately 84% of calls ended with a favorable outcome, 25% with a resolution, and 59% with a referral to a local health care provider. Calls from high‐risk callers had greater odds of ending with a referral than without a resolution or referral, as did weekday calls (6:00 am to 5:59 pm EST, Monday through Friday). Responders used caller intent to die and the absence of future plans to determine caller risk. Findings suggest that the Veterans Crisis Line is a useful mechanism for generating referrals for high‐risk veteran callers. Responders appeared to use known risk and protective factors to determine caller risk.
Identification of two new HLA class II alleles: DRB1*01:50 and DQB1*05:18
Authors: Swelsen W. T. N. , Hartog K. S. , Lardy N. M.
Published: April 2013

Two new human leukocyte antigen (HLA) class II alleles were identified during routine sequence‐based typing.
Probabilistic Modeling of Discourse‐Aware Sentence Processing
Authors: Dubey Amit , Keller Frank , Sturt Patrick
Published: April 2013

Probabilistic models of sentence comprehension are increasingly relevant to questions concerning human language processing. However, such models are often limited to syntactic factors. This restriction is unrealistic in light of experimental results suggesting interactions between syntax and other forms of linguistic information in human sentence processing. To address this limitation, this article introduces two sentence processing models that augment a syntactic component with information about discourse co‐reference. The novel combination of probabilistic syntactic components with co‐reference classifiers permits them to more closely mimic human behavior than existing models. The first model uses a deep model of linguistics, based in part on probabilistic logic, allowing it to make qualitative predictions on experimental data; the second model uses shallow processing to make quantitative predictions on a broad‐coverage reading‐time corpus.
TEST: A Tropic, Embodied, and Situated Theory of Cognition
Authors: Myachykov Andriy , Scheepers Christoph , Fischer Martin H. , Kessler Klaus
Published: April 2013

TESTis a novel taxonomy of knowledge representations based on three distinct hierarchically organized representational features:Tropism, Embodiment, andSituatedness. Tropicrepresentational features reflect constraints of the physical world on the agent's ability to form, reactivate, and enrichembodied(i.e., resulting from the agent's bodily constraints) conceptual representations embedded insituatedcontexts. The proposed hierarchy entails that representations can, in principle, have tropic features without necessarily having situated and/or embodied features. On the other hand, representations that are situated and/or embodied are likely to be simultaneously tropic. Hence, although we propose tropism as the most general term, the hierarchical relationship between embodiment and situatedness is more on a par, such that the dominance of one component over the other relies on the distinction between offline storage versus online generation as well as on representation‐specific properties.
Putative pore‐loops of TMEM16/anoctamin channels affect channel density in cell membranes
Authors: Adomaviciene Aiste , Smith Keith J. , Garnett Hannah , Tammaro Paolo
Published: April 2013

Key points

The recently identified TMEM16/anoctamin protein family includes Ca2+‐activated Cl− channels (TMEM16A and TMEM16B), a Ca2+‐activated non‐selective cation channel (TMEM16F) and proteins for which the function remains unclear.

TMEM16 channel proteins consist of eight putative transmembrane domains (TMs) with the 5th and 6th TMs flanking a loop predicted to protrude deep into the membrane. Recent studies suggest that this re‐entrant loop may compose part of the pore of TMEM16A channels while also containing residues involved in Ca2+ binding.

Here, we investigate the functional role of the putative pore‐loop by examining the electrophysiological properties of chimeras produced by transplanting this region between TMEM16 family members with different conduction properties and Ca2+ sensitivities.

We revealed that the putative pore‐loop of TMEM16 channels has an unexpected role in controlling the whole‐cell Ca2+‐activated Cl− conductance by regulating the number of functional channels present on the plasma membrane.

Abstract  The recently identified TMEM16/anoctamin protein family includes Ca2+‐activated anion channels (TMEM16A, TMEM16B), a cation channel (TMEM16F) and proteins with unclear function. TMEM16 channels consist of eight putative transmembrane domains (TMs) with TM5–TM6 flanking a re‐entrant loop thought to form the pore. In TMEM16A this region has also been suggested to contain residues involved in Ca2+ binding. The role of the putative pore‐loop of TMEM16 channels was investigated using a chimeric approach. Heterologous expression of either TMEM16A or TMEM16B resulted in whole‐cell anion currents with very similar conduction properties but distinct kinetics and degrees of sensitivity to Ca2+. Furthermore, whole‐cell currents mediated by TMEM16A channels were ∼six times larger than TMEM16B‐mediated currents. Replacement of the putative pore‐loop of TMEM16A with that of TMEM16B (TMEM16A‐B channels) reduced the currents by ∼six‐fold, while the opposite modification (TMEM16B‐A channels) produced a ∼six‐fold increase in the currents. Unexpectedly, these changes were not secondary to variations in channel gating by Ca2+ or voltage, nor were they due to changes in single‐channel conductance. Instead, they depended on the number of functional channels present on the plasma membrane. Generation of additional, smaller chimeras within the putative pore‐loop of TMEM16A and TMEM16B led to the identification of a region containing a non‐canonical trafficking motif. Chimeras composed of the putative pore‐loop of TMEM16F transplanted into the TMEM16A protein scaffold did not conduct anions or cations. These data suggest that the putative pore‐loop does not form a complete, transferable pore domain. Furthermore, our data reveal an unexpected role for the putative pore‐loop of TMEM16A and TMEM16B channels in the control of the whole‐cell Ca2+‐activated Cl− conductance.
The role of endogenous molecules in modulating pain through transient receptor potential vanilloid 1 (TRPV1)
Authors: Morales‐Lázaro Sara L. , Simon Sidney A. , Rosenbaum Tamara
Published: April 2013

Key points

TRPV1 (transient receptor potential vanilloid 1) channels are found throughout the body in epithelial cells and in peripheral and central terminals in neurons. They exert a variety of functions ranging from inflammation, to nociception and pain.

TRPV1 is a molecular integrator in that it can be activated by different endogenous stimuli. These interact to alter the channels’ properties, thereby changing the threshold to a given stimulus and resulting in sensitization.

TRPV1 has numerous agonists and antagonists, including lipids and their metabolites, as well as gases and ions. Here, we detail what is known about the mechanisms used by endogenous molecules to modulate the activity of this important transducer for environmental and painful stimuli.

Understanding how these compounds modify TRPV1 activity will allow us to comprehend how some pathologies are associated with its deregulation.

Abstract  Pain is a physiological response to a noxious stimulus that decreases the quality of life of those sufferring from it. Research aimed at finding new therapeutic targets for the treatment of several maladies, including pain, has led to the discovery of numerous molecular regulators of ion channels in primary afferent nociceptive neurons. Among these receptors is TRPV1 (transient receptor potential vanilloid 1), a member of the TRP family of ion channels. TRPV1 is a calcium‐permeable channel, which is activated or modulated by diverse exogenous noxious stimuli such as high temperatures, changes in pH, and irritant and pungent compounds, and by selected molecules released during tissue damage and inflammatory processes. During the last decade the number of endogenous regulators of TRPV1's activity has increased to include lipids that can negatively regulate TRPV1, as is the case for cholesterol and PIP2 (phosphatidylinositol 4,5‐biphosphate) while, in contrast, other lipids produced in response to tissue injury and ischaemic processes are known to positively regulate TRPV1. Among the latter, lysophosphatidic acid activates TRPV1 while amines such as N‐acyl‐ethanolamines and N‐acyl‐dopamines can sensitize or directly activate TRPV1. It has also been found that nucleotides such as ATP act as mediators of chemically induced nociception and pain and gases, such as hydrogen sulphide and nitric oxide, lead to TRPV1 activation. Finally, the products of lipoxygenases and omega‐3 fatty acids among other molecules, such as divalent cations, have also been shown to endogenously regulate TRPV1 activity. Here we provide a comprehensive review of endogenous small molecules that regulate the function of TRPV1. Acting through mechanisms that lead to sensitization and desensitization of TRPV1, these molecules regulate pathways involved in pain and nociception. Understanding how these compounds modify TRPV1 activity will allow us to comprehend how some pathologies are associated with its deregulation.
Harmonin enhances voltage‐dependent facilitation of Cav1.3 channels and synchronous exocytosis in mouse inner hair cells
Authors: Gregory Frederick D. , Pangršič Tina , Calin‐Jageman Irina E. , Moser Tobias , Lee Amy
Published: April 2013

Key points

Cav1.3 Ca2+ channels mediate sound transmission by triggering presynaptic exocytosis of glutamate from cochlear inner hair cells (IHCs).

Harmonin is a PDZ‐domain‐containing protein in IHCs that is altered in Usher syndrome, a form of deaf–blindness in humans.

We show that harmonin enhances Cav1.3 voltage‐dependent facilitation (VDF) in transfected HEK293T cells in a manner that depends on the identity of the auxiliary Ca2+ channel β subunit.

Cav1.3 VDF is impaired, and synchronous exocytosis and the Ca2+ efficiency of exocytosis are reduced, in IHCs from deaf‐circler mice expressing a mutant form of harmonin (dfcr) that cannot interact with Cav1.3.

We conclude that harmonin regulates presynaptic function in mouse IHCs, which adds to our understanding of the factors that may influence hearing impairment in Usher syndrome.

Abstract  Cav1.3 channels mediate Ca2+ influx that triggers exocytosis of glutamate at cochlear inner hair cell (IHC) synapses. Harmonin is a PDZ‐domain‐containing protein that interacts with the C‐terminus of the Cav1.3 α1 subunit (α11.3) and controls cell surface Cav1.3 levels by promoting ubiquitin‐dependent proteosomal degradation. However, PDZ‐domain‐containing proteins have diverse functions and regulate other Cav1.3 properties, which could collectively influence presynaptic transmitter release. Here, we report that harmonin binding to the α11.3 distal C‐terminus (dCT) enhances voltage‐dependent facilitation (VDF) of Cav1.3 currents both in transfected HEK293T cells and in mouse inner hair cells. In HEK293T cells, this effect of harmonin was greater for Cav1.3 channels containing the auxiliary Cavβ1 than with the β2 auxiliary subunit. Cav1.3 channels lacking the α11.3 dCT were insensitive to harmonin modulation. Moreover, the ‘deaf‐circler’dfcr mutant form of harmonin, which does not interact with the α11.3 dCT, did not promote VDF. In mature IHCs from mice expressing the dfcr harmonin mutant, Cav1.3 VDF was less than in control IHCs. This difference was not observed between control and dfcr IHCs prior to hearing onset. Membrane capacitance recordings from dfcr IHCs revealed a role for harmonin in synchronous exocytosis and in increasing the efficiency of Ca2+ influx for triggering exocytosis. Collectively, our results indicate a multifaceted presynaptic role of harmonin in IHCs in regulating Cav1.3 Ca2+ channels and exocytosis.
Influence of Proximity of the Seabed on Hydrodynamic Forces on a Submarine Piggyback Pipeline Under Wave Action
Authors: Cheng Xiaofei , Wang Yongxue , Wang Guoyu
Published: April 2013

Experimental investigations were mainly carried out to clarify the influence of the seabed proximity on hydrodynamic forces on a submarine piggyback pipeline under regular and irregular wave action. Nondimensional force coefficients for drag, inertia and lift on the piggyback pipeline were obtained with an equivalent diameter based on the Morison equation. The effect of the gap ratio e/D between the bottom of the large pipeline and the seabed on force coefficients of the piggyback pipeline was studied. The results indicated that the force coefficients initially decreased and then remained constant when e/D was beyond 0.5. In addition, a two-dimensional hybrid numerical model, FEM-k-ω-VOF, was applied for a numerical analysis. A comparison of numerical and experimental results showed that the calculated values of wave forces agreed well with those of the experiments and that the numerical model can be employed to predict the hydrodynamic forces on the submarine piggyback pipeline.
The Effect of Third-Order Nonlinearities on the Statistical Distributions of Wave Heights, Crests and Troughs in Bimodal Crossing Seas
Authors: Petrova Petya G. , Aziz Tayfun M. , Guedes Soares C.
Published: April 2013

This paper investigates the effect of third-order nonlinearities on the statistical distributions of wave heights, crests, and troughs of waves mechanically generated in a deep-water basin and simulating two crossing systems characterized by bimodal spectra. The observed statistics exhibits various effects of third-order nonlinearities, in a manner dependent on both the distance from the wave-maker and the angle between the mean directions of the component wave systems. In order to isolate and demonstrate the effects of third-order nonlinearities by themselves, the vertically asymmetric distortions induced by second-order bound waves are removed from the observed time series. It appears then that the distributions of wave crests, troughs and heights extracted from the nonskewed records clearly deviate from the Rayleigh distribution, suggesting that the waves are characterized by nonlinear corrections of higher-order than the typical of second-order waves. Nonetheless, some models developed for weakly nonlinear second-order waves can still be used in describing wave heights, crests and troughs in mixed seas, provided that the relevant distribution parameters are modified, so as to reflect the effects of third-order corrections and some basic characteristics of the mixed seas.
Load Rejection Tests and Their Dynamic Simulations With a 150 kW Class Microsteam Turbine
Authors: Nakano Susumu , Tsubouchi Kuniyoshi , Shiraiwa Hiroyuki , Hayashi Kazutaka , Yamada Hiroyuki
Published: April 2013

A simulation method for load rejection with a 150 kW class radial inflow steam turbine system was proposed to determine over rotational speed at load rejection. Simulations were carried out for several parameters of valves which are operated in an emergency. In addition, load rejection tests were carried out to confirm the machine reliability and to obtain results for comparison with the simulation results. Simulation results show that operation delay times of the steam release and vacuum break valves greatly affect over rotational speed at load rejection. Load rejection tests were done for generator outputs from 69 kW to 113 kW. Maximum over rotational speed of 54,160 rpm was measured at the generator output of 113 kW. Over rotational speed calculated by the dynamic simulation has relatively good agreement with the result for the operation delay time of 0.21 s. If the operation delay time of the steam release valves are kept as 0.21 s at the load rejection for the rated load of 150 kW, the over rotational speed is suppressed within 55,200 rpm which is less than the allowed rotational speed of 56,100 rpm.
Numerical Study of the Implementation of an Active Control Turbocharger on Automotive Diesel Engines
Authors: Galindo J. , Dolz V. , Tiseira A. , Gozalbo R.
Published: April 2013

Active control turbocharger (ACT) has been proposed as a way to improve turbocharger performance under highly pulsating exhaust flows. This technique implies that the variable geometry mechanism in the turbine is used to optimize its position as a function of the instantaneous mass flow during the engine cycle. Tests presented in the literature showed promising results in a pulsating gas-stand. In this work, a modeling study has been conducted at different engine conditions aimed to quantify the gain in on-engine conditions and to develop a strategy to integrate the ACT system within the engine. Different ways of changing the displacement of the variable mechanism have been analyzed by means of a one-dimensional gas dynamic model. The simulations have been carried out at constant engine operating points defined by fixed air-to-fuel ratio for different mechanism displacement functions around an average position that guarantees the desired amount of intake air. The benefits in overall engine efficiency are lower to those predicted in the literature. It can be concluded that it is not possible to use the ACT system to optimize the turbine operating point and at the same time to control the engine operating point.
Aerodynamic Optimization of High-Pressure Turbines for Lean-Burn Combustion System
Authors: Shahpar Shahrokh , Caloni Stefano
Published: April 2013

Modern lean-burn combustors make use of high flow swirl to maintain flame stability. The swirling flow can persist downstream of the turbine first vane, changing the loading on the rotor, leading to a reduction in efficiency. This paper presents the results of an automatic optimization study carried out to mitigate the effect of high swirling flow on a high pressure turbine stage. A high-fidelity computational fluid dynamics (CFD)-based design optimization using a multipoint approximation (response surface) method is carried out to produce a new vane and a new rotor configuration with a significantly improved aerodynamic performance. It is demonstrated that the novel optimization methodology can cope well with a number of near equality constraints needed for a practical design.
Integration of a Dual-Mode SI-HCCI Engine Into Various Vehicle Architectures
Authors: Lawler Benjamin J. , Filipi Zoran S.
Published: April 2013

A simulation study was performed to evaluate the potential fuel economy benefits of integrating a dual-mode SI-HCCI engine into various vehicle architectures. The vehicle configurations that were considered include a conventional vehicle and a mild parallel hybrid electric vehicle. The two configurations were modeled and compared in detail for a given engine size (2.0 L) over the EPA UDDS (city) and highway cycles. The results show that the dual-mode engine in the conventional vehicle offers a modest gain in vehicle fuel economy of approximately 5–7%. The gains were modest because the baseline (the SI engine in the conventional vehicle) is relatively advanced with a six-speed automated manual transmission. The mild parallel hybrid with the SI engine achieved 32% better fuel economy than the conventional vehicle in the city, but only 6% on the highway. For the dual-mode engine in the mild parallel hybrid, a specific control strategy was used to manipulate engine operation in an attempt to minimize the number of engine mode transitions and maximize the time spent in HCCI. The parallel hybrid with the dual-mode engine and modified control strategy provides dramatic improvements of up to 48% for city driving, demonstrating that the addition of HCCI has a more significant impact with mild parallel hybrids than with conventional vehicles. Finally, a systematic study of engine sizing provides guidelines for selecting the best option for a given vehicle application.
Vibrations of Pipes and Their Supporting Beams Caused by Tank Bulging Mode
Authors: Utsumi M. , Ishida K.
Published: April 2013

The vibrations of pipes and their supporting beams caused by the tank bulging mode are analyzed. A computationally efficient semianalytical approach is presented by introducing a local velocity potential for each pipe and developing a reduced order model for the frame structure consisting of the pipes and their supporting beams. To enable the analysis, the system of governing equations and boundary conditions is derived in a variational form. Numerical results show that large bending stress occurs in the supporting beams attached to the lower part of the tank wall. This bending stress can be reduced by decreasing the outer diameter of the supporting beams based on the fact that the dependence of the bulging-mode-induced displacements of the supporting beams on their stiffness is weak. This stress reduction method does not increase but decreases the stiffness of the supporting beams and therefore the cost, unlike many methods for improving structural reliability. A method for reducing the axial compressive stress in the supporting beams is also investigated.
Heat Transport in Evacuated Perlite Powders for Super-Insulated Long-Term Storages up to 300 °C
Authors: Beikircher Thomas , Demharter Matthias
Published: April 2013

Vacuum super insulation (VSI) with expanded perlite powder is commonly used at cryogenic temperatures, but principally can also be adapted to applications at higher temperatures, such as the long-term storage of hot water in solar thermal systems. Due to the lack of experimental data in the respective temperature range, especially without external load, thermal conductivity measurements have been performed with commercial perlite powder up to 150°C mean sample temperature, corresponding to storage temperatures of around 300°C. Two different experimental geometries have been used: a guarded hot plate (GHP) setup and a cut-off concentric cylinder (CCC) apparatus. Furthermore, the radiative heat transport has been determined separately by extinction measurements using Fourier transform infrared (FTIR) spectroscopy. In addition to the laboratory experiments, a real-size prototype of a solar VSI-storage tank with 16.4 m3 water storage volume has been constructed, and the effective thermal conductivity of the perlite insulation has been determined from a heat loss measurement. The heat transport in evacuated perlite has also been treated theoretically using common models and approaches for gas heat conduction, solid-body conduction and heat transfer by thermal radiation. For the coupling between solid-body and gas conduction which occurs in the intergranular spaces of a powder material, a simple model has been developed. The total effective thermal conductivity λeff of a vacuum super insulation with dry, evacuated perlite powder (p≤0.01 mbar,ρ≈60 kg/m3) amounts to 0.007–0.016 W/mK for mean sample temperatures between 50°C and 150°C, compared to 0.003–0.005 W/mK at cryogenic temperatures. For the real-size storage prototype, the value λeff=0.009 W/mK has been obtained at T=90°C (storage temperature), p = 0.08 mbar and ρ=92.4 kg/m3, which compares to 0.03–0.06 W/mK for dry conventional storage insulations. With the applied theoretical models and approaches, the effective thermal conductivity of evacuated perlite and its individual contributions can successfully be described at different densities (55-95 kg/m3), compression methods, vacuum pressures (10-3-1000 mbar) and filling gases (air, Ar, Kr) up to mean sample temperatures of T=150°C. With regard to practical purposes, it has shown that vacuum super insulation with perlite is a suitable and economic method to achieve low thermal conductivities also at medium storage temperatures.
A Review of the Dynamics of Cavitating Pumps
Authors: Earls Brennen Christopher
Published: April 2013

This paper presents a review of some of the recent developments in our understanding of the dynamics and instabilities caused by cavitation in pumps. Focus is placed on presently available data for the transfer functions for cavitating pumps and inducers, particularly on the compliance and mass flow gain factor, which are so critical for pump and system stability. The resonant frequency for cavitating pumps is introduced and contexted. Finally, emphasis is placed on the paucity of our understanding of pump dynamics when the device or system is subjected to global oscillation.
Force Measurement and Analysis for Magnetic Field–Assisted Finishing
Authors: Ganguly Vasishta , Schmitz Tony , Graziano Arthur , Yamaguchi Hitomi
Published: April 2013

Magnetic field–assisted finishing (MAF) is used to polish free-form surfaces. The material removal mechanism can be described as a flexible “magnetic brush” that consists of ferromagnetic particles and abrasives that arrange themselves in the working gap between the magnet and the workpiece. Relative motion between the brush and the workpiece causes microcutting and improves surface finish. In this study, the contributions of the magnetic and polishing force components to the total force were evaluated. The effect of varying the polishing conditions, such as the working gap and the size of the ferromagnetic iron particles, on polishing forces, surface roughness, and material removal rate was also analyzed. It was observed that the polishing forces varied considerably with working gap. Also, the iron particle size was found to have a strong relation to the rate at which the surface roughness improved. Surface roughness values of 2–3 nm were achieved.
Ensemble Empirical Mode Decomposition-Based Teager Energy Spectrum for Bearing Fault Diagnosis
Authors: Feng Zhipeng , Zuo Ming J. , Hao Rujiang , Chu Fulei , Lee Jay
Published: April 2013

Periodic impulses in vibration signals and its repeating frequency are the key indicators for diagnosing the local damage of rolling element bearings. A new method based on ensemble empirical mode decomposition (EEMD) and the Teager energy operator is proposed to extract the characteristic frequency of bearing fault. The signal is firstly decomposed into monocomponents by means of EEMD to satisfy the monocomponent requirement by the Teager energy operator. Then, the intrinsic mode function (IMF) of interest is selected according to its correlation with the original signal and its kurtosis. Next, the Teager energy operator is applied to the selected IMF to detect fault-induced impulses. Finally, Fourier transform is applied to the obtained Teager energy series to identify the repeating frequency of fault-induced periodic impulses and thereby to diagnose bearing faults. The principle of the method is illustrated by the analyses of simulated bearing vibration signals. Its effectiveness in extracting the characteristic frequency of bearing faults, and especially its performance in identifying the symptoms of weak and compound faults, are validated by the experimental signal analyses of both seeded fault experiments and a run-to-failure test. Comparison studies show its better performance than, or complements to, the traditional spectral analysis and the squared envelope spectral analysis methods.
Noncontact Manipulation of Light Objects Based on Parameter Modulations of Acoustic Pressure Nodes
Authors: Park Joong-kyoo , Ro Paul I.
Published: April 2013

An investigation of noncontact manipulation techniques based on acoustic levitation was undertaken in air. The standing wave acoustic levitation (SWAL) was observed when standing waves trap small objects at pressure nodes. In this paper, two ultrasonic bolt-clamped Langevin type transducers (BLTs) generating traveling waves by modulating parameters of the two traveling waves were used to manipulate a trapped object. Frequency, amplitude, and phase modulations of the two actuators were exploited. From simulation and experiments, the phase modulation was prominent among other methods due to its long range and smooth operation. It is also found that angles between two actuators affect the trajectory of the trapped object during the parameter modulations. Sinusoidal and elliptic paths of the object were observed experimentally through a combination of parameters at certain tilt angles.
Investigation of Choking and Combustion Products' Swirling Frequency Effects on Gas Turbine Compressor Blade Fractures
Authors: Poursaeidi E. , Arablu M. , Yahya Meymandi M. A. , Mohammadi Arhani M. R.
Published: April 2013

Premature fracture failure of blades occurred in four of a refinery's gas turbine compressors. In order to evaluate the probability of combustion instability's effects on failure of the blades; i.e., choking and chamber resonance problems, 3D models of the combustion chamber structure and combustion flow were studied with finite element and computation fluid dynamics codes, respectively. Comparison of results of combustion chamber natural frequencies with combustion swirl frequency showed that the chamber structure is not under resonance. In order to verify probability of choking, the combustion product flow's Mach number was studied. Results of the Mach number distribution showed that the flow is subsonic in the transition piece area but, due to existence of supersonic flow conditions near the swirl vanes it may become supersonic in some critical conditions. Thus, it is suggested to operators that, for avoiding choking probabilities, it is better that engine operation be maintained close to optimum design conditions. Results of simulations showed that the fracture of the blades is not due to combustion problems.