bluuebunny/crossref_metadata_2025 huggingface dataset:
Family Relations in the Genomic Era: Communicating about Intergenerational Transmission of Risk for Disability
Authors: Bailey Donald B. , Lewis Megan A. , Roche Myra , Powell Cynthia M.
Published: January 2014

Interest in the familial aspects of disability has heightened in recent years. Three forms of disability—hearing loss, Fragile X syndrome, and autism spectrum disorders—are used here to illustrate the complex and rapidly evolving understanding of the meaning and nature of heritability and carrier status for disability. The authors raise six questions to address if the promise of genomic research leads to real benefits for families: (a) Is the public interested in carrier testing? (b) Who is responsible for carrier testing? (c) Is the public prepared to use genomic information? (d) Should genomic testing or information about testing be tailored to specific audiences or target populations? (e) What strategies can be used to enable informed decision‐making? (f) How will carrier testing affect family relationships and communication patterns? These and other factors will require a comprehensive analysis of the individual and societal implications for family relations in the genomic era.
Minocycline attenuates HIV‐1 infection and suppresses chronic immune activation in humanized NOD/LtsZ‐scidIL‐2Rγnull mice
Authors: Singh Maneesh , Singh Pratibha , Vaira Dolores , Amand Mathieu , Rahmouni Souad , Moutschen Michel
Published: January 2014

More than a quarter of a century of research has established chronic immune activation and dysfunctional T cells as central features of chronic HIV infection and subsequent immunodeficiency. Consequently, the search for a new immunomodulatory therapy that could reduce immune activation and improve T‐cell function has been increased. However, the lack of small animal models for in vivo HIV study has hampered progress. In the current study, we have investigated a model of cord blood haematopoietic progenitor cells (CB‐HPCs) ‐transplanted humanized NOD/LtsZ‐scidIL‐2Rγnull mice in which progression of HIV infection is associated with widespread chronic immune activation and inflammation. Indeed, HIV infection in humanized NSG mice caused up‐regulation of several T‐cell immune activation markers such as CD38, HLA‐DR, CD69 and co‐receptor CCR5. T‐cell exhaustion markers PD‐1 and CTLA‐4 were found to be significantly up‐regulated on T cells. Moreover, increased plasmatic levels of lipopolysaccharide, sCD14 and interleukin‐10 were also observed in infected mice. Treatment with minocycline resulted in a significant decrease of expression of cellular and plasma immune activation markers, inhibition of HIV replication and improved T‐cell counts in HIV‐infected humanized NSG mice. The study demonstrates that minocycline could be an effective, low‐cost adjunctive treatment to regulate chronic immune activation and replication of HIV.
Pulse Electric Current–Aided Reactive Sintering of High‐Purity Zr3Al3C5
Authors: Zhou Jie , Qiu Fagui , Shen Lu , Li Fangzhi , Xue Jianming , Barsoum Michel W. , Huang Qing
Published: January 2014

Herein, we report on the in situ reactive synthesis and simultaneous densification of a high‐purity ternary Zr3Al3C5 phase via pulse electric current sintering (PECS) of Zr/Al/graphite powder mixtures with a molar ratio of 3:3.2:4.8. The phases and microstructure evolution in the 580°C–1800°C temperature range were characterized by X‐ray diffraction, real‐time sintering curves, and a scanning electron microscope equipped with an energy dispersive spectroscope. An additive‐free, fully dense Zr3Al3C5 compound was obtained at 1800°C using a load corresponding to a stress of 35 MPa for 20 min. The final product was comprised of 96.61 wt% Zr3Al3C5, 3.14 wt% ZrC, and 0.25 wt% Zr2Al3C4; the relative density was 97%.
A Novel Approach to Improve Properties of BiFeO3 Nanomultiferroics
Authors: Arya Ghanshyam , Kotnala Ravinder K. , Negi Nainjeet Singh
Published: January 2014

In this study we report the synthesis of Bi1−xInxFe1−yTiyO3 (0 ≤ x ≤ 0.1, 0 ≤ y ≤ 0.05) nanoparticles by a simple cost effective solution combustion method. Pure BFO samples shows distorted rhombohedral perovskite structure with space group R3c which is also supported by Fourier transform infrared spectra study. The codoping of In and Ti at A–B sites of BFO (BIFTO) partially distorts the crystal structure, increases the lattice strain, reduces the average particle size (14 nm), and increases the Fe3+/Fe2+ ratio which significantly affect the observed results. The saturation magnetization increases significantly upon codoping (4.60 emu/gm) by about 12 times than that of pure BFO (0.4 emu/gm). The improved ferromagnetic properties upon codoping is further manifestated in large value of linear magnetoelectric coupling coefficient (4.8 mV/cmOe) which further provides an indirect evidence for the collapse of space modulated spin structure. The activation energy increases with codoping (0.68 eV), although less than 1 eV which indicates that the conduction is still dominated by charged defects.
Spectroscopic Studies of Nanopowder and Nanoceramics La2Hf2O7:Pr Scintillator
Authors: Trojan‐Piegza Joanna , Gierlotka Stanislaw , Zych Eugeniusz , Lojkowski Witold
Published: January 2014

Sintered nanoceramics of Pr‐doped lanthanum hafnate, La2Hf2O7:Pr, were prepared by means of a high‐pressure sintering technique using nanopowders made by Pechini method. Structure, morphology, and spectroscopic properties of the ceramics compared to the starting powder are presented and discussed. Emission and excitation spectra recorded at room temperature as well as at 7 K using synchrotron radiation are presented together with results of luminescence kinetics measurements. In ceramics, at 7 K, the Pr3+ luminescence from 3P0 (blue‐green, green, and red region) and 1D2 (red) levels is accompanied by a broad‐band emission located in the 380–530 nm range of wavelengths, whereas powders gives only the Pr3+‐related luminescence. Depending on the excitation wavelength, the broad‐band emission maximum moves between 430 and 470 nm indicating superposition of at least two components. In sintered nanoceramics, the lifetimes of Pr3+ emissions from 3P0 and 1D2 levels were by 10%–20% shorter compared to the powder. The existence of different luminescence centers was proved by the selective emission decays examination. The fast 5d → 4f luminescence of Pr3+ was not observed from either of the two types of La2Hf2O7:Pr materials.
Microstructure of a Ce0.1Zr0.9O2–MgAl2O4 Ceramic Matrix Composite for Use in Dentistry
Authors: Krumeich Frank , Wörle Micheal , Nesper Reinhard , Höland Marlies , Ritzberger Christian , Rothbrust Frank , Chevalier Jerome , Rheinberger Volker M. , Höland Wolfram
Published: January 2014

A ceramic matrix composite (CMC) with the chemical composition of 90 wt% Ce0.1Zr0.9O2 and 10 wt% MgAl2O4 was produced by filter‐pressing, drying, and heat treatment at 1400°C. The internal microstructure was studied using the transmission electron microscopy (TEM) technique combined with energy‐dispersive X‐ray spectroscopy. Because of the intended use in dentistry, the surfaces of the as‐fired and of the mechanically treated samples were characterized by atomic force microscopy (AFM) and X‐ray diffraction (XRD Rietveld analysis). This study revealed that Ce0.1Zr0.9O2 and MgAl2O4 spinel are the only crystalline phases present in the CMC material. Nevertheless, apart from the tetragonal Ce0.1Zr0.9O2, its monoclinic phase was identified as a third crystal phase in the as‐fired sample with an amount of ~2.5 wt%, at the surface of polished (5.3 wt%) and roughened (8 wt%) specimens. In sum, the microstructure of the CMC material is homogeneous and can be modified by mechanical surface treatment leading to a partial transformation of the tetragonal phase of the Ce0.1Zr0.9O2 component into the monoclinic one. This partial transformation is also visible in AFM, with occurrence of transformation bands. The mechanism yield in surface compressive stress can be determined according to the Williamson and Hall method. The authors conclude that the absence of microcrack formation during polishing or roughening confirms the high flaw tolerance of such a CMC material.
Cystathionine γ‐lyase, an Enzyme Related to the Reverse Transsulfuration Pathway, is Functional in Leishmania spp.
Authors: Giordana Lucila , Mantilla Brian Suárez , Santana Marianela , Silber Ariel M. , Nowicki Cristina
Published: January 2014

Leishmania parasites seem capable of producing cysteine by de novo biosynthesis, similarly to bacteria, some pathogenic protists, and plants. In Leishmania spp., cysteine synthase (CS) and cystathionine β‐synthase (CBS) are expected to participate in this metabolic process. Moreover, the reverse transsulfuration pathway (RTP) is also predicted to be operative in this trypanosomatid because CBS also catalyzes the condensation of serine with homocysteine, and a gene encoding a putative cystathionine γ‐lyase (CGL) is present in all the sequenced genomes. Our results show that indeed, Leishmania major CGL is able to rescue the wild‐type phenotype of a Saccharomyces cerevisiae CGL‐null mutant and is susceptible to inhibition by an irreversible CGL inhibitor, DL‐propargylglycine (PAG). In Leishmania promastigotes, CGL and CS are cytosolic enzymes. The coexistence of de novo synthesis with the RTP is extremely rare in most living organisms; however, despite this potentially high redundancy in cysteine production, PAG arrests the proliferation of L. major promastigotes with an IC50 of approximately 65 μM. These findings raise new questions regarding the biological role of CGL in these pathogens and indicate the need for understanding the molecular mechanism of PAG action in vivo to identify the potential targets affected by this drug.
Influence of surface free energy of denture base and liner materials onCandida albicansbiofilms
Authors: da Silva Wander J. , Leal Cristiane Maria B. , Viu Flávia C. , Gonçalves Letícia M. , Barbosa Célia Marisa R. , Del Bel Cury Altair A.
Published: January 2014

Aim

This study aimed to evaluate the influence of surface free energy (SFE) of denture base and liner materials onCandida albicansbiofilm development.

Methods

Discs were fabricated using poly(methyl methacrylate) acrylic resin and poly(ethyl methacrylate) denture liner, according to the manufacturers' instructions. ForSFEtest, discs were pellicle‐coated with saliva alone, saliva + blood plasma, or blood plasma alone.Candida albicansbiofilms were allowed to form on pellicle‐coated discs for 48 h. Biofilms were evaluated for cell counts, metabolic activity, and structural characteristics at adhesion phase (after 1.5 h of development) and at biofilm maturity (after 48 h of development). Data were analyzed byanovaand Tukey tests using a significance level of 5%.

Results

Saliva + blood plasma pellicles had a higherSFEcompared to pellicles of saliva or blood plasma alone (P < 0.001). Differences inSFEby pellicle‐coating did not affect the cell counts, metabolic activity, or structure at the adhesion phase (P > 0.05). In contrast, the presence of blood plasma resulted in higher cell counts, biovolume, and thickness of mature biofilms on both materials (P < 0.001).

Conclusions

Increases inSFEfrom pellicle‐coating leads to robust matureC. albicansbiofilms on both denture materials.
Effect of configuration factor on gap formation in hybrid composite resin, low‐shrinkage composite resin and resin‐modified glass ionomer
Authors: Boroujeni Parvin M. , Mousavinasab Sayyed M. , Hasanli Elham
Published: January 2014

Aim

Polymerization shrinkage is one of the important factors in creation of gap between dental structure and composite resin restorations. The aim of this study was to evaluate the effect of configuration factor (C‐factor) on gap formation in a hybrid composite resin, a low shrinkage composite resin and a resin modified glass ionomer restorative material.

Methods

Cylindrical dentin cavities with 5.0 mm diameter and three different depths (1.0, 2.0 and 3.0 mm) were prepared on the occlusal surface of 99 human molars and the cavities assigned into three groups (each of 33). Each group contained three subgroups depend on the different depths and then cavities restored using resin modified glass ionomer (Fuji II LC Improved) and two type composite resins (Filtek P90 and Filtek Z250). Then the restorations were cut into two sections in a mesiodistal direction in the middle of restorations. Gaps were measured on mesial, distal and pulpal floor of the cavities, using a stereomicroscope.

Results

Data analyses using Kruskal–Wallist and Mann–Whitney tests. Increasing C‐factor from 1.8 to 3.4 had no effect on the gap formation in two type composite resins, but Fuji II LC Improved showed significant effect of increasing C‐factor on gap formation. Taken together, when C‐factor increased from 1.8 up to 3.4 had no significant effect on gap formation in two tested resin composites. Although, Filtek P90 restorations showed smaller gap formation in cavities walls compared to Filtek Z250 restorations.

Conclusions

High C‐factor values generated the largest gap formation. Silorane‐based composite was more efficient for cavity sealing than methacrylate‐based composites and resin modified glass ionomer.
Rereading the Kripkean Intuition on Reference
Authors: Flanagan Brian
Published: January 2014

Saul Kripke's thought experiments on the reference of proper names target the theory that the properties which identify a term's referent are the subject of an implicit agreement. Recently, survey versions of the experiments have been thought to show that intuitions about reference are culturally contingent. Proposing a revisionary interpretation, this article argues, first, that Kripke's Cicero/Feynman experiment reveals that every name user knows enough to be capable of identifying the same individual as the name's most informed users. Second, the article shows that Kripke's presentation of the Gödel/Jonah experiment is ambiguous with respect to the properties attributed to the referent. Disambiguated, the experiment fails to reveal that name users may be mistaken in every unique property they attribute. Since the experiment's ambiguity is replicated in survey presentations, cross‐cultural variation in survey response fails to show that intuitions about reference are culturally contingent.
Secretion and functional display of fusion proteins through the curli biogenesis pathway
Authors: Van Gerven Nani , Goyal Parveen , Vandenbussche Guy , De Kerpel Maia , Jonckheere Wim , De Greve Henri , Remaut Han
Published: January 2014

Curli are functional amyloids expressed as fibres on the surface of Enterobacteriaceae. Contrary to the protein misfolding events associated with pathogenic amyloidosis, curli are the result of a dedicated biosynthetic pathway. A specialized transporter in the outer membrane, CsgG, operates in conjunction with the two accessory proteins CsgE and CsgF to secrete curlin subunits to the extracellular surface, where they nucleate into cross‐beta strand fibres. Here we investigate the substrate tolerance of the CsgG transporter and the capability of heterologous sequences to be built into curli fibres. Non‐native polypeptides ranging up to at least 260 residues were exported when fused to the curli subunit CsgA. Secretion efficiency depended on the folding properties of the passenger sequences, with substrates exceeding an approximately 2 nm transverse diameter blocking passage through the transport channel. Secretion of smaller passengers was compatible with prior DsbA‐mediated disulphide bridge formation in the fusion partner, indicating that CsgG is capable of translocating non‐linear polypeptide stretches. Using fusions we further demonstrate the exported or secreted heterologous passenger proteins can attain their native, active fold, establishing curli biogenesis pathway as a platform for the secretion and surface display of small heterologous proteins.
Psychotherapy role expectations and experiences – Discrepancy and therapeutic alliance among patients with substance use disorders
Authors: Frankl My , Philips Björn , Wennberg Peter
Published: January 2014

Objectives

The main aim of the study was to examine how the discrepancy between role expectations prior to psychotherapy and experiences of ongoing psychotherapy related to therapeutic alliance. We hypothesized that a similarity between patient role expectations and experiences would be associated with a stronger alliance. The study also examined whether different dimensions of psychotherapy role expectations predicted retention in psychotherapy.

Design

A naturalistic study design was used with data collected prior to therapy and during the first 6 months of therapy.

Method

Patients with substance use disorders completed the Psychotherapy Expectation Questionnaire‐short version (PEX‐S) at the time of therapy assessment. A subsample of these patients (n = 41; n = 24 in individual therapy and n = 17 in group therapy) provided data from therapy including psychotherapy experiences (also measured with PEX‐S) and therapeutic alliance, measured with Working Alliance Questionnaire‐short version.

Results

For patients in group therapy, discrepancy between role expectations and experiences correlated negatively with alliance. Expectations prior to psychotherapy characterized by defensiveness correlated negatively with therapy retention.

Conclusion

The finding that disconfirmation of patients' role expectations in group therapy were associated with weaker therapeutic alliance highlights the importance of discussing psychotherapy expectations at an early stage in treatment. Expectations characterized by defensiveness predicted worse retention in psychotherapy, which indicates that the PEX‐S can be helpful in detecting patients at risk for dropout.

Practitioner points

In targeting a patient's role expectancies prior to treatment, possible discrepancies between patient and therapist are made visible and possible to examine.

Clarifying the patient's role expectations and the therapist's rationale might be a first step towards establishing a strong working alliance.

Surveying the patient's defensiveness tendencies at the beginning of therapy offers a chance to discuss possible fears and other obstacles concerning therapy.

Discrepancy between the patient's role expectations prior to treatment and their actual experiences of psychotherapy render valuable information that can be of use in the therapy process.
Loss of XRCC1 confers a metastatic phenotype to melanoma cells and is associated with poor survival in patients with melanoma
Authors: Bhandaru Madhuri , Martinka Magdalena , Li Gang , Rotte Anand
Published: January 2014

Ultraviolet (UV) radiation‐induced DNA damage and genomic instability is one of the leading causes for melanoma. X‐ray repair cross‐complementary protein 1, XRCC1, plays a critically important role in base excision repair pathway. This study was therefore performed to analyze the correlation between XRCC1 expression, melanoma progression, and patient survival. Using a tissue microarray with a total of 119 patients with melanoma, we demonstrate that loss of XRCC1 expression is associated with the progression of disease from dysplastic nevi to primary melanoma and to metastatic melanoma. We found that the loss of XRCC1 was correlated with the progression of melanoma from AJCC stage II to stage III and with worse overall and disease‐specific 5‐yr and 10‐yr survival of patients with melanoma. Furthermore, we also illustrate the inhibitory effect of XRCC1 on melanoma cell invasion and migration, which are the regulatory events in melanoma metastasis.
Inconsistencies in care of the pediatric hematopoietic stem cell transplant recipient with respiratory failure: Opportunity for standardization and improved outcome
Authors: Rowan Courtney M. , Nitu Mara E. , Rigby Mark R
Published: January 2014

There is variability in critical care outcome of the HSCT recipient. One potential reason may be due to the inconsistent ventilation approaches. To quantitate this variability, we conducted a survey to assess self‐reported use of ventilation and adjunctive strategies for the HSCT recipient. Electronic survey, open from June 2012 through January 201, distributed through the Pediatric Acute Lung Injury and Sepsis Investigators network electronic mailing list. Ninety‐four individual responses were from 36 different institutions. The majority indicated that HSCT recipients requiring critical care were admitted to the general PICU. The vast majority (89%) endorsed routine practice of low‐tidal‐volume ventilation strategies. More than half stated that pressure‐regulated volume control is the starting mode of choice. Eighty‐three percent felt their group practiced early initiation of lung protective strategies. Eleven percent encouraged “early transition” to HFOV. Inhaled nitric oxide and milrinone were reported at the highest frequencies, but the majority used these empirically. Opinions regarding variables that affect outcomes of the HSCT were diverse. The estimated mortality of HSCT patients with respiratory was highly variable. Strategies for ventilation and oxygenation, use of HFOV, and adjunctive therapies are variable among pediatric intensivists.
Liver transplantation in a child with multifocal hepatocellular carcinoma hepatitis C and management of post‐transplant viral recurrence using boceprevir
Authors: Malik Saloni , Dekio Fumiko , Wen Jessica W.
Published: January 2014

HCV infection is the leading cause of liver transplantation in the adult population in the United States. HCV infection occurs in 0.2–0.4% of the pediatric population and progression to HCC is uncommon. Liver transplantation for HCV in children is rare. In this report, we present a case of pediatric patient with HCV and multifocal HCC at the age of 13 who underwent successful liver transplantation. While good graft function was initially observed, at one month after transplant, he experienced significant hepatitis C recurrence. He was treated with low‐accelerating dose regimen antiviral therapy of PEG‐IFN and RBV, followed by addition of a protease inhibitor, boceprevir, which led to viral clearance. To our knowledge, this is the first case report describing the post‐transplant course of a child transplanted for HCV and HCC, and the first pediatric case report on using the triple therapy for management of post‐liver transplant recurrence of HCV. This case report demonstrates the need for increased vigilance of surveillance for HCC during childhood.
Trade and Industrial Policies with Heterogeneous Firms: The Role of Country Asymmetries
Authors: Pflüger Michael , Russek Stephan
Published: January 2014

This paper explores the role of country asymmetries for trade and industrial policies with heterogeneous firms. The analysis delivers a number of novel results. First, trade policies, infrastructure policies and industrial policies which improve the business conditions in one country have negative productivity and welfare effects on the trading partner. Second, symmetric trade liberalization is immiserizing for a trading partner whose business conditions are inferior. Third, there are gains from trade even for a country whose monopolistically competitive sector with heterogeneous firms is wiped out by switching from autarky to trade.
Uncertain Productivity Growth and the Choice between FDI and Export
Authors: Yalcin Erdal , Sala Davide
Published: January 2014

While determinants of FDI patterns have received widespread attention, the timing of their surge remains largely unexplained. According to the proximity–concentration trade‐off argument, a surge in FDI in times of decaying international transportation costs seemingly represents a paradox. Besides transportation costs, other factors have contextually changed: in particular, the uncertainty that firms bear has increased. Enriching the classical choice problem of a multinational firm with insights from the literature on investment under uncertainty, we illustrate how different types of uncertainty determine the timing and optimal entry mode (i.e. FDI or export) of a multinational enterprise into a new market.
Economic Development and Determinants of Environmental Concern
Authors: Dorsch Michael T.
Published: January 2014

Objective

This article examines the extent to which individual‐level determinants of environmental concern in underdeveloped economies differ from those in advanced economies.

Methods

To measure environmental concern, I use survey responses to environmental questions asked in 40 countries from the 2005–2008 wave of the World Values Survey. My econometric analysis tests the extent to which individual‐level determinants of environmental concern are conditional upon the level of national economic development.

Results

I find that proxies for objective environmental problems do not explain environmental concern at any level of development. Furthermore, in both advanced and underdeveloped economies, environmental concern is determined by subjective value orientations, but the effect is stronger in the advanced economies.

Conclusions

The findings reinforce the notion that environmentalism is value driven and support a generalized interpretation of postmaterialism in which the relevance of subjective values for explaining environmental concern increases as countries develop.
Is It Really Tolerance? Expanding the Knowledge About Diversity for the Creative Class
Authors: Wimark Thomas
Published: January 2014

Among current theories on regional development the creative capital has received major attention. Several assessments of the theory have shown that tolerance and creativity cannot be ignored. However, as the focus in these assessments mainly has been to replicate the results of Richard Florida, they have put less emphasis on the issues the tolerance measures pose. This paper argues that tolerance has only been measured by diverse population and that this is insufficient. To solve this issue a variety of tolerance measures are introduced and underlying effects of other variables are tested for. Surprisingly, the only measure significant in the model is the bohemian measure. On the one hand, this renders support for the creative capital theory and suggests that attracting bohemian employees can gain economic growth. On the other hand, it problematises the tolerance concept and indicates that tolerance is hard to grasp and add to economic models.
The development and evaluation of options for improving future UK blood component labelling – outcome of the 2013 UK hospital survey
Authors: Nightingale M. J. , Brazier A. M. , McArthur K. , Jones J. , Cardigan R. , Lodge L. , MacLennan S. ,   on behalf of the UK Blood Services Blood Component Label Steering and Work Groups
Published: January 2014

Background/Objectives

UK blood component labels have evolved to accommodate a plethora of information. Concern has, however, been expressed that current UK labelling is too ‘cluttered’, detracting from the clarity of critical information. This prompted a holistic review of labelling and available information technology (IT) with the aim of improving the situation.

Methods/Materials

A survey was circulated requiring UK hospital participants to rank each item of information on the label according to its ‘criticality’ and assess three novel ‘future’ and one ‘transition’ prototype labels. Prototypes were based on applicable regulatory standards, best practice guidance, international benchmark data and UK expert input. The prototypes support steps towards ‘full face’ label printing and utilise 2D and quick response (QR) barcodes.

Results

Two‐hundred eleven completed surveys were received identifying 110 contributing hospitals with 41% from clinical staff, 37% from transfusion laboratory staff and 22% from transfusion practitioners. There was excellent agreement between the three groups on the critical information, i.e. blood group, expiry date, blood component name, unique donation identification number (DIN) and blood component volume but far less on the other information, especially the various warning messages. Of the ‘future’ labels, option 3 (closest to the current ‘quadrant model’) was most popular. Option 1, with its additional inverted section replicating critical information was least popular and prompted significant safety concerns.

Conclusion

The prototype labels correctly identified the critical items of information and extensive comments confirmed that this was more prominently and clearly displayed. Laboratory staff commented that the transition label was essential to enable IT systems to be adapted.
Memory consolidation in humans: new evidence and opportunities
Authors: Maguire Eleanor A.
Published: January 2014

New Findings

What is the topic of this review?

This lecture is concerned with autobiographical memory representations, how they evolve and change over time, and the brain regions that support them.

What advances does it highlight?

The use of high resolution structural and functional magnetic resonance imaging combined with methods such as multi‐voxel pattern analysis are opening up new opportunities to study memory consolidation in vivo in humans.

We are endlessly fascinated by memory; we desire to improve it and fear its loss. While it has long been recognized that brain regions such as the hippocampus are vital for supporting memories of our past experiences (autobiographical memories), we still lack fundamental knowledge about the mechanisms involved. This is because the study of specific neural signatures of autobiographical memories in vivo in humans presents a significant challenge. However, recent developments in high‐resolution structural and functional magnetic resonance imaging coupled with advanced analytical methods now permit access to the neural substrates of memory representations that has hitherto been precluded in humans. Here, I describe how the application of ‘decoding’ techniques to brain‐imaging data is beginning to disclose how individual autobiographical memory representations evolve over time, deepening our understanding of systems‐level consolidation. In particular, this prompts new questions about the roles of the hippocampus and ventromedial prefrontal cortex and offers new opportunities to interrogate the elusive memory trace that has for so long confounded neuroscientists.
Role of the carotid body chemoreceptors in baroreflex control of blood pressure during hypoglycaemia in humans
Authors: Limberg Jacqueline K. , Taylor Jennifer L. , Dube Simmi , Basu Rita , Basu Ananda , Joyner Michael J. , Wehrwein Erica A.
Published: January 2014

New Findings

What is the central question of this study?

Activation of the carotid body chemoreceptors with hypoxia alters baroreceptor‐mediated responses in humans. We aimed to examine whether this relationship can be translated to other chemoreceptor stimuli (i.e. hypoglycaemia).

What is the main finding and its importance?

We show that hypoglycaemia‐mediated changes in heart rate variability and baroreflex sensitivity cannot be attributed exclusively to the carotid chemoreceptors; however, the chemoreceptors play a role in resetting the baroreflex working range during hypoglycaemia. These results provide a potential mechanism for impaired glycaemic control and increased risk of cardiac arrhythmias in patients with carotid chemoreceptor overactivity (i.e. sleep apnoea).

Activation of the carotid body chemoreceptors with hypoxia alters baroreceptor‐mediated responses. We aimed to examine whether this relationship can be translated to other chemoreceptor stimuli (i.e. hypoglycaemia) by testing the following hypotheses: (i) activation of the carotid body chemoreceptors with hypoglycaemia would reduce spontaneous cardiac baroreflex sensitivity (sCBRS) in healthy humans; and (ii) desensitization of the carotid chemoreceptors with hyperoxia would restore sCBRS to baseline levels during hypoglycaemia. Ten young healthy adults completed two 180 min hyperinsulinaemic [2 mU (kg fat‐free mass)−1 min−1], hypoglycaemic (∼3.2 μmol ml−1) clamps, separated by at least 1 week and randomized to normoxia (arterial partial pressure of O2, 122 ± 10 mmHg) or hyperoxia (arterial partial pressure of O2, 424 ± 123 mmHg; to blunt activation of the carotid body glomus cells). Changes in heart rate, blood pressure, plasma catecholamines, heart rate variability (HRV) and sCBRS were assessed. During hypoglycaemia, HRV and sCBRS were reduced (P < 0.05) and the baroreflex working range was shifted to higher heart rates. When hyperoxia was superimposed on hypoglycaemia, there was a greater reduction in blood pressure and a blunted rise in heart rate when compared with normoxic conditions (P < 0.05); however, there was no detectable effect of hyperoxia on sCBRS or HRV during hypoglycaemia (P > 0.05). In summary, hypoglycaemia‐mediated changes in HRV and sCBRS cannot be attributed exclusively to the carotid chemoreceptors; however, the chemoreceptors appear to play a role in resetting the baroreflex working range during hypoglycaemia.
Properties of regenerated mouse extensor digitorum longus muscle following notexin injury
Authors: Head S. I. , Houweling P. J. , Chan S. , Chen G. , Hardeman E. C.
Published: January 2014

New Findings

What is the central question of this study?

In dystrophinopathies, regenerated muscles contain branched fibres. We have hypothesized that, once a threshold is reached, part of the susceptibility of dystrophic muscle to damage is due to the presence of branched fibres, not the absence of dystrophin. Here, we explore the novel question: ‘Does dystrophin‐positive, regenerated muscle containing branched fibres also show an increased susceptibility to contraction‐induced damage?’

What is the main finding and its importance?

One round of notexin regeneration produces a dystrophin‐positive muscle containing 29% branched fibres, which is below threshold and not more susceptible than wild‐type muscle to damage. This muscle would serve as an ideal control for young mdx mice.

Muscles of mdx mice are known to be more susceptible to contraction‐induced damage than wild‐type muscle. However, it is not clear whether this is because of dystrophin deficiency or because of the abnormal branching morphology of dystrophic muscle fibres. This distinction has an important bearing on our traditional understanding of the function of dystrophin as a mechanical stabilizer of the sarcolemma. In this study, we address the question: ‘Does dystrophin‐positive, regenerated muscle containing branched fibres also show an increased susceptibility to contraction‐induced damage?’ We produced a model of fibre branching by injecting dystrophin‐positive extensor digitorum longus muscles with notexin. The regenerated muscle was examined at 21 days postinjection. Notexin‐injected muscle contained 29% branched fibres and was not more susceptible to damage from mild eccentric contractions than contralateral saline‐injected control muscle. Regenerated muscles also had greater mass, greater cross‐sectional area and lower specific force than control muscles. We conclude that the number of branched fibres in this regenerated muscle is below the threshold needed to increase susceptibility to damage. However, it would serve as an ideal control for muscles of young mdx mice, allowing for clearer differentiation of the effects of dystrophin deficiency from the effects of fibre regeneration and morphology.
Reflex control of inflammation by sympathetic nerves, not the vagus
Authors: Martelli D. , Yao S. T. , McKinley M. J. , McAllen R. M.
Published: January 2014

Key points

It is believed that the CNS controls inflammation via the autonomic nervous system, but the strength of this action and the neural pathways responsible are unclear.

In anaesthetized rats we measured the inflammatory response to lipopolysaccharide (LPS, 60 μg kg−1, i.v.) by plasma tumour necrosis factor α (TNFα) levels 90 min later.

Bilateral section of the splanchnic sympathetic nerves before LPS treatment resulted in a 5‐fold increase in the plasma TNFα response, but bilateral vagotomy had no effect.

LPS treatment strongly increased efferent activity in the splanchnic sympathetic nerve and its splenic branch; vagotomy did not affect this.

These results show that, besides directly stimulating inflammation, LPS engages a powerful anti‐inflammatory reflex that can inhibit the plasma TNFα response by 80%.

The reflex efferent arm is in the splanchnic sympathetic nerves; the vagi play no part.

We investigated a neural reflex that controls the strength of inflammatory responses to immune challenge – the inflammatory reflex. In anaesthetized rats challenged with intravenous lipopolysaccharide (LPS, 60 μg kg−1), we found strong increases in plasma levels of the key inflammatory mediator tumour necrosis factor α (TNFα) 90 min later. Those levels were unaffected by previous bilateral cervical vagotomy, but were enhanced approximately 5‐fold if the greater splanchnic sympathetic nerves had been cut. Sham surgery had no effect, and plasma corticosterone levels were unaffected by nerve sections, so could not explain this result. Electrophysiological recordings demonstrated that efferent neural activity in the splanchnic nerve and its splenic branch was strongly increased by LPS treatment. Splenic nerve activity was dependent on inputs from the splanchnic nerves: vagotomy had no effect on the activity in either nerve. Together, these data demonstrate that immune challenge with this dose of LPS activates a neural reflex that is powerful enough to cause an 80% suppression of the acute systemic inflammatory response. The efferent arm of this reflex is in the splanchnic sympathetic nerves, not the vagi as previously proposed. As with other physiological responses to immune challenge, the afferent pathway is presumptively humoral: the present data show that vagal afferents play no measurable part. Because inflammation sits at the gateway to immune responses, this reflex could play an important role in immune function as well as inflammatory diseases.
High resolution acoustic measurement system and beam pattern reconstruction method for bat echolocation emissions
Authors: Gaudette Jason E. , Kloepper Laura N. , Warnecke Michaela , Simmons James A.
Published: January 2014

Measurements of the transmit beam patterns emitted by echolocating bats have previously been limited to cross-sectional planes or averaged over multiple signals using sparse microphone arrays. To date, no high-resolution measurements of individual bat transmit beams have been reported in the literature. Recent studies indicate that bats may change the time-frequency structure of their calls depending on the task, and suggest that their beam patterns are more dynamic than previously thought. To investigate beam pattern dynamics in a variety of bat species, a high-density reconfigurable microphone array was designed and constructed using low-cost ultrasonic microphones and custom electronic circuitry. The planar array is 1.83 m wide by 1.42 m tall with microphones positioned on a 2.54 cm square grid. The system can capture up to 228 channels simultaneously at a 500 kHz sampling rate. Beam patterns are reconstructed in azimuth, elevation, and frequency for visualization and further analysis. Validation of the array measurement system and post-processing functions is shown by reconstructing the beam pattern of a transducer with a fixed circular aperture and comparing the result with a theoretical model. To demonstrate the system in use, transmit beam patterns of the big brown bat, Eptesicus fuscus, are shown.
Response of an artificially blown clarinet to different blowing pressure profiles
Authors: Bergeot Baptiste , Almeida André , Gazengel Bruno , Vergez Christophe , Ferrand Didier
Published: January 2014

Using an artificial mouth with an accurate pressure control, the onset of the pressure oscillations inside the mouthpiece of a simplified clarinet is studied experimentally. Two time profiles are used for the blowing pressure: in a first set of experiments the pressure is increased at constant rates, then decreased at the same rate. In a second set of experiments the pressure rises at a constant rate and is then kept constant for an arbitrary period of time. In both cases the experiments are repeated for different increase rates. Numerical simulations using a simplified clarinet model blown with a constantly increasing mouth pressure are compared to the oscillating pressure obtained inside the mouthpiece. Both show that the beginning of the oscillations appears at a higher pressure values than the theoretical static threshold pressure, a manifestation of bifurcation delay. Experiments performed using an interrupted increase in mouth pressure show that the beginning of the oscillation occurs close to the stop in the increase of the pressure. Experimental results also highlight that the speed of the onset transient of the sound is roughly the same, independently of the duration of the increase phase of the blowing pressure.
Finite-difference simulations of transient radiation from a finite-length pipe
Authors: Tengelsen Daniel R. , Anderson Brian E. , Villamizar Vianey , Leishman Timothy W.
Published: January 2014

The far-field radiation originating from a finite-length pipe is well studied, especially for steady-state conditions. However, because all physical systems do not begin in steady state, these radiation characteristics are only valid after the transient portion of the solution has decayed. Understanding transient radiation characteristics may be important (particularly for systems transmitting very short-duration signals), as they can differ quite significantly. A numerical complication to this problem involves dealing with a sharp corner in the domain of interest. While many numerical studies have attempted to couple solutions from the domains inside and outside a pipe, the analysis presented in this work treats the computational domain as a single region by expressing the entire physical domain as a map from a simple rectangular domain in generalized curvilinear coordinates. This method will be introduced in detail and general results of transient radiation will be presented for an infinitely baffled, finite-length pipe using the finite-difference method expressed in generalized curvilinear coordinates. Comparison will be made to previous results [P. Stepanishen and R. A. Tougas, J. Acoust. Soc. Am. 93, 3074–3084 (1993)] that used a semi-analytic approach with certain assumptions.
A Danish open-set speech corpus for competing-speech studies
Authors: Bo Nielsen Jens , Dau Torsten , Neher Tobias
Published: January 2014

Studies investigating speech-on-speech masking effects commonly use closed-set speech materials such as the coordinate response measure [Bolia et al. (2000). J. Acoust. Soc. Am. 107, 1065–1066]. However, these studies typically result in very low (i.e., negative) speech recognition thresholds (SRTs) when the competing speech signals are spatially separated. To achieve higher SRTs that correspond more closely to natural communication situations, an open-set, low-context, multi-talker speech corpus was developed. Three sets of 268 unique Danish sentences were created, and each set was recorded with one of three professional female talkers. The intelligibility of each sentence in the presence of speech-shaped noise was measured. For each talker, 200 approximately equally intelligible sentences were then selected and systematically distributed into 10 test lists. Test list homogeneity was assessed in a setup with a frontal target sentence and two concurrent masker sentences at ±50° azimuth. For a group of 16 normal-hearing listeners and a group of 15 elderly (linearly aided) hearing-impaired listeners, overall SRTs of, respectively, +1.3 dB and +6.3 dB target-to-masker ratio were obtained. The new corpus was found to be very sensitive to inter-individual differences and produced consistent results across test lists. The corpus is publicly available.
Simulating acoustic scattering from atmospheric temperature fluctuations using a k-space method
Authors: Hargreaves Jonathan A. , Kendrick Paul , von Hünerbein Sabine
Published: January 2014

This paper describes a numerical method for simulating far-field scattering from small regions of inhomogeneous temperature fluctuations. Such scattering is of interest since it is the mechanism by which acoustic wind velocity profiling devices (Doppler SODAR) receive backscatter. The method may therefore be used to better understand the scattering mechanisms in operation and may eventually provide a numerical test-bed for developing improved SODAR signals and post-processing algorithms. The method combines an analytical incident sound model with a k-space model of the scattered sound close to the inhomogeneous region and a near-to-far-field transform to obtain far-field scattering patterns. Results from two test case atmospheres are presented: one with periodic temperature fluctuations with height and one with stochastic temperature fluctuations given by the Kolmogorov spectrum. Good agreement is seen with theoretically predicted far-field scattering and the implications for multi-frequency SODAR design are discussed.
Wave propagation through penetrable scatterers in a waveguide and through a penetrable grating
Authors: Maurel Agnès , Mercier Jean-François , Félix Simon
Published: January 2014

A multimodal method based on the admittance matrix is used to analyze wave propagation through scatterers of arbitrary shape. Two cases are considered: a waveguide containing scatterers, and the scattering of a plane wave at oblique incidence to an infinite periodic row of scatterers. In both cases, the problem reduces to a system of two sets of first-order differential equations for the modal components of the wavefield, similar to the system obtained in the rigorous coupled wave analysis. The system can be solved numerically using the admittance matrix, which leads to a stable numerical method, the basic properties of which are discussed (convergence, reciprocity, energy conservation). Alternatively, the admittance matrix can be used to get analytical results in the weak scattering approximation. This is done using the plane wave approximation, leading to a generalized version of the Webster equation and using a perturbative method to analyze the Wood anomalies and Fano resonances.
Speech enhancement using empirical mode decomposition and the Teager–Kaiser energy operator
Authors: Khaldi Kais , Boudraa Abdel-Ouahab , Komaty Ali
Published: January 2014

In this paper a speech denoising strategy based on time adaptive thresholding of intrinsic modes functions (IMFs) of the signal, extracted by empirical mode decomposition (EMD), is introduced. The denoised signal is reconstructed by the superposition of its adaptive thresholded IMFs. Adaptive thresholds are estimated using the Teager–Kaiser energy operator (TKEO) of signal IMFs. More precisely, TKEO identifies the type of frame by expanding differences between speech and non-speech frames in each IMF. Based on the EMD, the proposed speech denoising scheme is a fully data-driven approach. The method is tested on speech signals with different noise levels and the results are compared to EMD-shrinkage and wavelet transform (WT) coupled with TKEO. Speech enhancement performance is evaluated using output signal to noise ratio (SNR) and perceptual evaluation of speech quality (PESQ) measure. Based on the analyzed speech signals, the proposed enhancement scheme performs better than WT-TKEO and EMD-shrinkage approaches in terms of output SNR and PESQ. The noise is greatly reduced using time-adaptive thresholding than universal thresholding. The study is limited to signals corrupted by additive white Gaussian noise.