bluuebunny/crossref_metadata_2025 huggingface dataset:
Septic sialoadenitis in equids: A retrospective study of 18 cases (1998–2010)
Authors: Kilcoyne I. , Watson J. L. , Spier S. J. , Whitcomb M. B. , Vaughan B.
Published: January 2014

Reason for performing study

Septic sialoadenitis, although uncommonly reported in equids, is a significant cause of pain, inappetence, dysphagia and discomfort. There are currently few reported cases possibly as a result of its infrequent occurrence.

Objectives

To review cases presenting with sialoadenitis and describe the presenting complaints, results of diagnostic tests, treatment and outcome.

Study design

Retrospective case series.

Methods

Records were reviewed for equids presenting to the UC Davis William R. Pritchard Veterinary Medical Teaching Hospital between 1998 and 2010 for salivary gland swelling. Equids were included if a diagnosis of septic sialoadenitis was made based on a combination of oral examination and/or ultrasonographic findings and/or microbial culture. Data collected included age, breed, presenting complaints, diagnostic results, treatment and outcome.

Results

Eighteen equids were diagnosed with septic sialoadenitis affecting the parotid gland (11) or the mandibular salivary gland (7). Ultrasound was useful to differentiate whether the mandibular or parotid salivary gland was involved. Affected equids ranged in age from 4 to 30 years (mean 17.7 years). Fourteen of 15 (93.3%) equids that underwent a complete oral examination had dental or other oral abnormalities. Six of 18 cases had evidence of sialolithiasis. Culture of the infected salivary gland or secretions was performed in 9 equids and all yielded growth of Fusobacterium sp. along with other aerobic and anaerobic bacteria. Infection resolved in 15/18 cases (83.3%) and 2/18 (11.1%) were subjected to euthanasia.

Conclusions

Dental disease and sialolith formation may play important roles in the development of septic sialoadenitis in equids. Anaerobic infection should be assumed in all cases and affected horses should be treated for this until culture and sensitivity results are available. Prognosis is favourable (83.3%) with appropriate treatment.
Climate change and the politics of causal reasoning: the case of climate change and migration
Authors: Nicholson Calum T M
Published: January 2014

In the face of climate change, political and policy discussion is often framed by a concern with causal impacts on the societal status quo. Illustrated with the case study of the literature and debate on the relationship between climate change and migration, this paper argues that the search for causal understanding can be a blind alley for substantive research, and it is imperative for the research community to be aware of this possibility. To this end, the paper presents a tripartite heuristic framework, using the logic of an ‘epidemiology’, which allows such blind alleys to be identified, explained and collapsed. It goes on to then outline what remains for research in light of such a critique – in general, in terms of human geography and with specific regard to ‘forced migration’ scholarship and ‘migration studies’. The core admonition is that potentially more is lost than gained when discussion and debate in both academic and policy contexts fails to begin by reflexively interrogating the specific forms of causal reasoning that are implicit in any attempt to substantively analyse the impact of climate change on any particular subjectively defined dependent societal variable, such as ‘migration’. Failing to do so results not only in the waste of finite research resources, but also allows currency to accrue to otherwise equivocal constructs, thereby leaving them ripe for politically expedient manipulation.
A policy on the move? Spatial planning and State Actors in the post‐devolutionary UK and Ireland
Authors: Clifford Ben , Morphet Janice
Published: January 2014

Devolution has led to a dramatic restructuring of the UK state over the last 15 years. Planning is a devolved function and a concerted process of ‘planning reform’ has been implemented by devolved (and central) government since devolution, including a move from ‘land‐use’ to ‘spatial planning’. Despite some expectations of, and pressure for, policy divergence post devolution, we draw on findings of discourse analysis to demonstrate how there are common framings and understandings of the concept of ‘spatial planning’ present in the policy documents of all the UK administrations, and in Ireland. As such, we conceptualise spatial planning as what, after Peck and Theodore (2010, Geoforum 41 169–74), we might consider a ‘policy on the move’. Policy mobility is a fundamentally geographical phenomenon and its presence here raises questions about the mechanisms by which spatial planning has been mobilised. Drawing on interview data, we highlight the role of civil servants who meet through the British–Irish Council's workstream on spatial planning and a forum known as the ‘Five Administrations’ meetings. The relational connections between these state actors suggest that they are key ‘transfer agents’ and their role helps explain some of the path dependency in planning reform post devolution.
Do Good Fences Make Good Neighbors? The Cross Border Impact of Casino Entrance
Authors: Hicks Michael J.
Published: January 2014

This study estimates the impact of casino entrance in adjacent counties on aggregate and selected subsector incomes on counties adjacent in Indiana from 1990 to 2008. Employing a spatial econometric model and an approach that combines pre‐casino entrance forecasts and actual income changes, this study finds very modest increases in income growth in casino counties in the econometric model but adjacent county income declines which are economically irrelevant. The forecast approach mirrors, with less precision, this finding. These findings suggest that welfare effects of casinos are more geographically distributed than the literature has yet reported primarily because of the redistribution of retail trade.
Facilitators to Promoting Health in Schools: Is School Health Climate the Key?
Authors: Lucarelli Jennifer F. , Alaimo Katherine , Mang Ellen , Martin Caroline , Miles Richard , Bailey Deborah , Kelleher Deanne K. , Drzal Nicholas B. , Liu Hui
Published: January 2014

BACKGROUND

Schools can promote healthy eating in adolescents. This study used a qualitative approach to examine barriers and facilitators to healthy eating in schools.

METHODS

Case studies were conducted with 8 low‐income Michigan middle schools. Interviews were conducted with 1 administrator, the food service director, and 1 member of the coordinated school health team at each school.

RESULTS

Barriers included budgetary constraints leading to low prioritization of health initiatives; availability of unhealthy competitive foods; and perceptions that students would not eat healthy foods. Schools had made improvements to foods and increased nutrition education. Support from administrators, teamwork among staff, and acknowledging student preferences facilitated positive changes. Schools with a key set of characteristics, (presence of a coordinated school health team, nutrition policies, and a school health champion) made more improvements.

CONCLUSIONS

The set of key characteristics identified in successful schools may represent a school's health climate. While models of school climate have been utilized in the educational field in relation to academic outcomes, a health‐specific model of school climate would be useful in guiding school health practitioners and researchers and may improve the effectiveness of interventions aimed at improving student dietary intake and other health behaviors.
Mental Health Service Use Among High School Students Exposed to Interpersonal Violence
Authors: Green Jennifer Greif , Johnson Renee M. , Dunn Erin C. , Lindsey Michael , Xuan Ziming , Zaslavsky Alan M.
Published: January 2014

BACKGROUND

Violence‐exposed youth rarely receive mental health services, even though exposure increases risk for academic and psychosocial problems. This study examines the association between violence exposure and mental health service contact. The 4 forms of violence exposure were peer, family, sexual, and witnessing.

METHODS

Data are from 1534 Boston public high school students who participated in a 2008 self‐report survey of violence exposure and its correlates. Multivariate logistic regressions estimated associations between each form of violence with service contact, then examined whether associations persisted when controlling for suicidality and self‐injurious behaviors.

RESULTS

In unadjusted models, violence‐exposed students more often reported service contact than their peers. However, in multivariate models, only exposure to family (odds ratio [OR] = 1.69, 95% confidence interval [CI] = 1.23‐2.31) and sexual violence (OR = 2.34, 95% CI = 1.29‐4.20) were associated with service contact. Associations attenuated when controlling for suicidality and self‐injurious behaviors, indicating they were largely explained by self‐harm. Sexual violence alone remained associated with mental health service contact in fully adjusted models, but only for girls (OR=3.32, 95% CI=1.30‐8.45), suggesting sex‐specific pathways.

CONCLUSIONS

Associations between adolescent violence exposure and mental health service contact vary by forms of exposure. Outreach to a broader set of exposed youth may reduce the impact of violence and its consequences for vulnerable students.
Weight Status Misperception as Related to Selected Health Risk Behaviors Among Middle School Students
Authors: Martin Brian C. , Dalton William T. , Williams Stacey L. , Slawson Deborah L. , Dunn Michael S. , Johns‐Wommack Rebecca
Published: January 2014

BACKGROUND

Weight misperception has been documented among children although the impact on health risk behaviors is less understood, particularly among middle school students. The goals of this study were to describe sociodemographic differences in actual and perceived weight, correspondence between actual and perceived weight, and weight‐related health risk behaviors, as well as to examine weight misperception and interactions with sociodemographic variables in explaining weight‐related health risk behaviors.

METHODS

Participants were recruited at 11 public school districts participating in the Tennessee Coordinated School Health (CSH) pilot program. A total of 10,273 middle school students completed the Centers for Disease Control and Prevention's Youth Risk Behavior Survey administered by teachers in the school setting.

RESULTS

Findings revealed sociodemographic differences in actual and perceived weight as well as weight misperception. Although overestimating one's weight was significantly related to greater likelihood of weight‐related health risk behaviors, significant interactions showed this relationship to be especially pronounced in females. Additional distinctions based on sociodemographic variables are indicated.

CONCLUSIONS

Results highlight the importance of screening for health risk behaviors including weight misperception among middle school students. The CSH program offers an opportunity to understand health risk behaviors among students while also informing and evaluating methods for intervention.
Comparison of Media Literacy and Usual Education to Prevent Tobacco Use: A Cluster‐Randomized Trial
Authors: Primack Brian A. , Douglas Erika L. , Land Stephanie R. , Miller Elizabeth , Fine Michael J.
Published: January 2014

BACKGROUND

Media literacy programs have shown potential for reduction of adolescent tobacco use. We aimed to determine if an anti‐smoking media literacy curriculum improves students' media literacy and affects factors related to adolescent smoking.

METHODS

We recruited 1170 9th‐grade students from 64 classrooms in 3 public urban high schools. Students were randomized by classroom to a media literacy curriculum versus a standard educational program. In an intent‐to‐treat analysis, we used multilevel modeling to determine if changes in study outcomes were associated with the curricular intervention, controlling for baseline student covariates and the clustering of students within classrooms.

RESULTS

Among participants, mean age was 14.5 years and 51% were male, with no significant differences in baseline characteristics between groups. Smoking media literacy changed more among intervention participants compared with control participants (0.24 vs. 0.08, p < .001). Compared with controls, intervention students exhibited a greater reduction in the perceived prevalence of smoking (−14.0% vs. −4.6%, p < .001). Among those initially susceptible to smoking, intervention participants more commonly reverted to being nonsusceptible post‐intervention (24% vs. 16%, p = .08).

CONCLUSIONS

A school‐based media literacy curriculum is more effective than a standard educational program in teaching media literacy and improving perceptions of the true prevalence of smoking among adolescents.
The Optimal Structure for Public Debt
Authors: Kuhle Wolfgang
Published: January 2014

We study risk‐sharing through public debt in a two‐generations‐overlapping model. If bonds and wage‐indexed social security service a given initial obligation, there exists a set of Pareto‐efficient debt structures. This set is characterized by conflicting interests of current and yet unborn cohorts over the factor‐price risk allocation. If both size and composition of the debt are choice variables, these conflicting interests can be reconciled. Changes in the debt's composition reallocate factor‐price risks, while changes in its size reallocate resources. This separation of risk‐sharing and crowding‐out narrows the set of efficient debt structures until only one remains.
Knowledge with and Without Belief
Authors: Veber Michael
Published: January 2014

This article argues for the thesis that the distinction between propositional and doxastic justification should be extended to knowledge. A consequence of this thesis is that there is a type of knowledge that requires belief and a type that does not. A familiar example strikingly similar to the sort of example used to introduce the propositional/doxastic justification makes a prima facie case. Additional theoretical advantages are revealed when the distinction is applied within the context of some recent epistemological debates. These include debates over the knowledge account of assertion, testimonial knowledge, self‐deception, and the question of whether knowledge can be essentially based on falsehood. It is contended that the sort of distinction offered here provides a way to settle these debates and, at the same time, acknowledge what is correct in the opposing positions.
The HAMP signal‐conversion domain: static two‐state or dynamic three‐state?
Authors: Stewart Valley
Published: January 2014

The 50‐residue HAMP domain converts input signal into output response in a variety of transmembrane signal transduction proteins, including methyl‐accepting chemotaxis proteins and histidine kinases. HAMP domains are present in many other contexts as well. Despite focused study over the past decade, the question remains: How does this small domain play such a large role for so many different proteins? Analysis of structural models for the Afl1503 and Aer2 HAMP domains has generated hypotheses in which the HAMP domain assumes either of two discrete forms that generate opposing signal output. In contrast, genetic analysis of the HAMP domain from the Tsr methyl‐accepting chemotaxis protein resulted in a distinct hypothesis, the biphasic dynamic bundle. In this hypothesis, signalling involves differential packing stabilities of the HAMP domain four‐helix bundle, marked by at least three distinct states. Here I summarize and compare these hypotheses in the context of a deletion analysis that further explores the biphasic dynamic bundle hypothesis.
Tracking of chromosome dynamics in live Streptococcus pneumoniae reveals that transcription promotes chromosome segregation
Authors: Kjos Morten , Veening Jan‐Willem
Published: January 2014

Chromosome segregation is an essential part of the bacterial cell cycle but is poorly characterized in oval‐shaped streptococci. Using time‐lapse fluorescence microscopy and total internal reflection fluorescence microscopy, we have tracked the dynamics of chromosome segregation in live cells of the human pathogen Streptococcus pneumoniae. Our observations show that the chromosome segregation process last for two‐thirds of the total cell cycle; the origin region segregates rapidly in the early stages of the cell cycle while nucleoid segregation finishes just before cell division. Previously we have demonstrated that the DNA‐binding protein ParB and the condensin SMC promote efficient chromosome segregation, likely by an active mechanism. We now show that in the absence of SMC, cell division can occur over the unsegregated chromosomes. However, neither smc nor parB are essential in S. pneumoniae, suggesting the importance of additional mechanisms. Here we have identified the process of transcription as one of these mechanisms important for chromosome segregation in S. pneumoniae. Transcription inhibitors rifampicin and streptolydigin as well as mutants affected in transcription elongation cause chromosome segregation defects. Together, our results highlight the importance of passive (or indirect) processes such as transcription for chromosome segregation in oval‐shaped bacteria.
Assessments of genetic diversity and anthracnose disease response among Zimbabwe sorghum germplasm
Authors: Cuevas Hugo E. , Prom Louis K. , Erpelding John E. , Brotons Veronica
Published: January 2014

The USDA‐ARS National Plant Germplasm System maintains a Zimbabwe sorghum collection of 1235 accessions from different provinces. This germplasm has not been extensively employed in US breeding programmes due to the lack of phenotypic and genetic characterization. Therefore, 68 accessions from Zimbabwe were phenotyped, and evaluated for their anthracnose response for two consecutive years, and genetically characterized with 21 simple sequence repeat markers. Phenotypic analysis showed significant differences among accessions with plant height and panicle length being the most variable traits. Likewise, 25 accessions were anthracnose resistant, nine showed variable responses and 34 were susceptible. Genetic analysis identified 174 alleles with an average of 8.3 alleles and 11.8 genotypes per locus and a polymorphic information content of 0.60. These results reflect a moderate genetically diverse germplasm. Neighbour‐joining clustering analysis revealed that the majority of anthracnose‐resistant accessions showed high genetic relatedness; therefore, this germplasm might represent one to six new sources of resistances. Results presented herein show that the Zimbabwe collection contains valuable germplasm for breeding programmes and is an important source of anthracnose resistance.
The incidence and body site of skin cancers in the population groups of South Africa
Authors: Norval Mary , Kellett Patricia , Wright Caradee Yael
Published: January 2014

Background/Purpose

Data regarding basal cell carcinoma (BCC), squamous cell carcinoma of the skin (SSCC) and cutaneous melanoma (CM) in multiracial populations are sparse. Here the incidence and body site of these tumours in the South African population in 2000–2004 were analysed.

Methods

Annual age‐standardized incidences and body sites of BCC, SSCC and CM in black, coloured, Asian and white groups were obtained from histological confirmed cases, reported to the National Cancer Registry.

Results

Highest annual incidences of BCC, SSCC and CM occurred in the white group, followed by coloured, then Asian and then black. BCCs and SSCCs were about twice as common in males than females. CM was the least frequent skin tumour, and BCC the most frequent, except in black people. The head was the commonest body site for SSCC and BCC in all groups and both sexes, whereas the lower limb was the predominant site for CM in black people. Mean age at diagnosis was generally mid‐50s for CM, and mid‐60s for BCC and SSCC.

Conclusions

In South Africa, differences in reported incidence rates and body sites of skin tumours by population group and sex occur. Host characteristics, particularly skin phototype, and personal behaviour are likely to affect the risk of these cancers.
Currency Unions, Export Margins, and Product Differentiation: An Empirical Assessment for European Monetary Union
Authors: Badinger Harald , Türkcan Kemal
Published: January 2014

This paper reconsiders the trade effects of the euro, providing a decomposition into its effects on the extensive margin and intensive margin. Furthermore, it relates the more disaggregated estimates for 93 two‐digit HS product groups to the elasticity of substitution, thereby testing a key hypothesis of heterogenous firm trade theory. The estimates for the period 1996–2011 suggest a trade effect of the euro of some 28%, which has mainly materialized through the intensive margin. A negative net effect of the euro on the extensive margin is found for several product groups, supporting anecdotal evidence that firms have consolidated their product varieties in response to the elimination of exchange rate variability. Finally, the disaggregated estimates are in line with heterogenous firm trade theory models, suggesting that a large elasticity of substitution dampens the effect of a trade cost reduction on the extensive margin and amplifies its effect on the intensive margin.
Large deletions involving the regulatory upstream regions of A4GALT give rise to principally novel P1PK‐null alleles
Authors: Westman Julia S. , Hellberg Åsa , Peyrard Thierry , Thuresson Britt , Olsson Martin L.
Published: January 2014

Background

Cells of the clinically important p histo‐blood group phenotype lack P1, Pk, and P glycosphingolipid antigens. All cases investigated so far are due to alterations in the 4‐α‐galactosyltransferase‐encoding Exon 3 of A4GALT. Repetitive elements in the genome can mediate DNA rearrangements, the most abundant being the Alu family of repeats.

Study Design and Methods

The aim of this study was to determine the genetic basis of three p samples with intact A4GALT open reading frames, using long‐range polymerase chain reaction (PCR) and sequencing. In addition, transcript measurements were performed with quantitative PCR.

Results

This is the first report of the p phenotype as the result of large deletions in A4GALT, comprising the proposed promoter and noncoding Exons 1 and 2a. The breakpoints were different in all three samples and revealed the presence of Alu or MIRb sequences directly flanking, or in close proximity to, all junctions. Furthermore, no A4GALT transcripts could be detected.

Conclusion

In summary, our data elucidate a new explanation underlying the p phenotype, implicating the deleted regions of A4GALT as crucial for P1 and Pk synthesis, possibly due to loss of binding sites for erythroid transcription factors. Furthermore, analysis of these regions will improve genetic blood group prediction.
Ectopic release of glutamate contributes to spillover at parallel fibre synapses in the cerebellum
Authors: Balakrishnan Saju , Dobson Katharine L. , Jackson Claire , Bellamy Tomas C.
Published: January 2014

Key points

Release of neurotransmitter can sometimes occur outside of the synaptic cleft, a process known as ectopic release.

Spillover of the excitatory transmitter glutamate between synapses occurs when parallel fibres in the cerebellum are stimulated at high frequencies.

We investigated the effect of activity‐dependent and pharmacological reduction of ectopic release on the time course of postsynaptic currents and found that the decay time is reduced, suggesting that ectopic release contributes to spillover at the synapses.

This finding suggests that ectopic transmission can cause activation of extrasynaptic receptors even at low frequencies, and so may play a significant role in synaptic plasticity.

The results help us understand how signalling in and around the synapse can alter network activity in the cerebellum, a brain region essential for fine motor coordination.

In the rat cerebellar molecular layer, spillover of glutamate between parallel fibre synapses can lead to activation of perisynaptic receptors that mediate short‐ and long‐term plasticity. This effect is greatest when clusters of fibres are stimulated at high frequencies, suggesting that glutamate clearance mechanisms must be overwhelmed before spillover can occur. However, parallel fibres can also release transmitter directly into the extracellular space, from ‘ectopic’ release sites. Ectopic transmission activates AMPA receptors on the Bergmann glial cell processes that envelop parallel fibre synapses, but the possible contribution of this extrasynaptic release to intersynaptic communication has not been explored. We exploited long‐term depression of ectopic transmission, and selective pharmacology, to investigate the impact of these release sites on the time course of Purkinje neuron excitatory postsynaptic currents (EPSCs). Depletion of ectopic release pools by activity‐dependent long‐term depression decreased EPSC decay time, revealing a ‘late’ current that is present when fibres are stimulated at low frequencies. This effect was enhanced when glutamate transporters were inhibited, and reduced when extracellular diffusion was impeded. Blockade of N‐type Ca2+ channels inhibited ectopic transmission to Bergmann glia and decreased EPSC decay time. Similarly, perfusion of the Ca2+ chelator EGTA‐AM into the slice progressively eliminated ectopic transmission to glia and decreased EPSC decay time with closely similar time courses. Collectively, this evidence suggests that ectopically released glutamate contributes to spillover transmission, and that ectopic release therefore degrades the spatial precision of synapses that fire infrequently, and may make them more prone to exhibit plasticity.
Plasticity and modified loudness following short-term unilateral deprivation: Evidence of multiple gain mechanisms within the auditory system
Authors: Munro Kevin J. , Turtle Charlotte , Schaette Roland
Published: January 2014

Auditory deprivation and stimulation can change the threshold of the acoustic middle ear reflex as well as loudness in adult listeners. However, it has remained unclear whether changes in these measures are due to the same mechanism. In this study, deprivation was achieved using a monaural earplug that was worn by listeners for 7 days. Acoustic reflex thresholds (ARTs) and categorical loudness ratings were measured using a blinded design in which the experimenter was unaware of which ear had been plugged. Immediately after terminating unilateral deprivation, ARTs were obtained at a lower sound pressure level in the ear that had been fitted with an earplug and at a higher sound pressure level in the control ear. In contrast, categorical judgments of loudness changed in the same direction in both ears with a given stimulus level reported as louder after unilateral deprivation. The relationship between changes to the ART and loudness judgments was not statistically significant. For both the ARTs and the categorical loudness judgments, most of the changes had disappeared within 24 h after earplug removal. The changes in ARTs, as a consequence of unilateral sound deprivation, are consistent with a gain control mechanism; however, the lack of relationship with the categorical loudness judgments, and the different pattern of findings for each measure, suggests the possibility of multiple gain mechanisms.
Detection of the closure-burst transitions of stops and affricates in continuous speech using the plosion index
Authors: Ananthapadmanabha T. V. , Prathosh A. P. , Ramakrishnan A. G.
Published: January 2014

Automatic and accurate detection of the closure-burst transition events of stops and affricates serves many applications in speech processing. A temporal measure named the plosion index is proposed to detect such events, which are characterized by an abrupt increase in energy. Using the maxima of the pitch-synchronous normalized cross correlation as an additional temporal feature, a rule-based algorithm is designed that aims at selecting only those events associated with the closure-burst transitions of stops and affricates. The performance of the algorithm, characterized by receiver operating characteristic curves and temporal accuracy, is evaluated using the labeled closure-burst transitions of stops and affricates of the entire TIMIT test and training databases. The robustness of the algorithm is studied with respect to global white and babble noise as well as local noise using the TIMIT test set and on telephone quality speech using the NTIMIT test set. For these experiments, the proposed algorithm, which does not require explicit statistical training and is based on two one-dimensional temporal measures, gives a performance comparable to or better than the state-of-the-art methods. In addition, to test the scalability, the algorithm is applied on the Buckeye conversational speech corpus and databases of two Indian languages.
Sound absorption of a finite micro-perforated panel backed by a shunted loudspeaker
Authors: Tao Jiancheng , Jing Ruixiang , Qiu Xiaojun
Published: January 2014

Deep back cavities are usually required for micro-perforated panel (MPP) constructions to achieve good low frequency absorption. To overcome the problem, a close-box loudspeaker with a shunted circuit is proposed to substitute the back wall of the cavity of the MPP constructions to constitute a composite absorber. Based on the equivalent circuit model, the acoustic impedance of the shunted loudspeaker is formulated first, then a prediction model of the sound absorption of the MPP backed by shunted loudspeaker is developed by employing the mode solution of a finite size MPP coupled by an air cavity with an impendence back wall. The MPP absorbs mid to high frequency sound, and with properly adjusted electrical parameters of its shunted circuit, the shunted loudspeaker absorbs low frequency sound, so the composite absorber provides a compact solution to broadband sound control. Numerical simulations and experiments are carried out to validate the model.
Low frequency acoustic resonances in urban courtyards
Authors: Molerón Miguel , Félix Simon , Pagneux Vincent , Richoux Olivier
Published: January 2014

Urban courtyards can be regarded as open cavities in the urban area, in which resonances can be excited by waves generated in the neighboring streets. The aim of the present work is to experimentally and numerically investigate low frequency resonance phenomena in these configurations. Experiments are carried out in a scale model and a numerical study is performed with a coupled modal-finite elements method. The method enables the three-dimensional modeling of the acoustic field and thus to take into account the interactions between the courtyard and the street canyon that occur above the roof level, a particular characteristic of wave propagation in urban areas. The attention is focused on two aspects, the amplification of the sound level inside the courtyard and the acoustic attenuation in the street due to resonances. Experimental and numerical results are in good agreement and show a strong resonant behavior of these configurations.
Effects of noise suppression on intelligibility. II: An attempt to validate physical metrics
Authors: Hilkhuysen Gaston , Gaubitch Nikolay , Brookes Mike , Huckvale Mark
Published: January 2014

Using the data presented in the accompanying paper [Hilkhuysen et al., J. Acoust. Soc. Am. 131, 531–539 (2012)], the ability of six metrics to predict intelligibility of speech in noise before and after noise suppression was studied. The metrics considered were the Speech Intelligibility Index (SII), the fractional Articulation Index (fAI), the coherence intelligibility index based on the mid-levels in speech (CSIImid), an extension of the Normalized Coherence Metric (NCM+), a part of the speech-based envelope power model (pre-sEPSM), and the Short Term Objective Intelligibility measure (STOI). Three of the measures, SII, CSIImid, and NCM+, overpredicted intelligibility after noise reduction, whereas fAI underpredicted these intelligibilities. The pre-sEPSM metric worked well for speech in babble but failed with car noise. STOI gave the best predictions, but overall the size of intelligibility prediction errors were greater than the change in intelligibility caused by noise suppression. Suggestions for improvements of the metrics are discussed.
Updated parameters and expanded simulation options for a model of the auditory periphery
Authors: Zilany Muhammad S. A. , Bruce Ian C. , Carney Laurel H.
Published: January 2014

A phenomenological model of the auditory periphery in cats was previously developed by Zilany and colleagues [J. Acoust. Soc. Am. 126, 2390–2412 (2009)] to examine the detailed transformation of acoustic signals into the auditory-nerve representation. In this paper, a few issues arising from the responses of the previous version have been addressed. The parameters of the synapse model have been readjusted to better simulate reported physiological discharge rates at saturation for higher characteristic frequencies [Liberman, J. Acoust. Soc. Am. 63, 442–455 (1978)]. This modification also corrects the responses of higher-characteristic frequency (CF) model fibers to low-frequency tones that were erroneously much higher than the responses of low-CF model fibers in the previous version. In addition, an analytical method has been implemented to compute the mean discharge rate and variance from the model's synapse output that takes into account the effects of absolute refractoriness.
Recognition memory in noise for speech of varying intelligibility
Authors: Gilbert Rachael C. , Chandrasekaran Bharath , Smiljanic Rajka
Published: January 2014

This study investigated the extent to which noise impacts normal-hearing young adults' speech processing of sentences that vary in intelligibility. Intelligibility and recognition memory in noise were examined for conversational and clear speech sentences recorded in quiet (quiet speech, QS) and in response to the environmental noise (noise-adapted speech, NAS). Results showed that (1) increased intelligibility through conversational-to-clear speech modifications led to improved recognition memory and (2) NAS presented a more naturalistic speech adaptation to noise compared to QS, leading to more accurate word recognition and enhanced sentence recognition memory. These results demonstrate that acoustic-phonetic modifications implemented in listener-oriented speech enhance speech-in-noise processing beyond word recognition. Effortful speech processing in challenging listening environments can thus be improved by speaking style adaptations on the part of the talker. In addition to enhanced intelligibility, a substantial improvement in recognition memory can be achieved through speaker adaptations to the environment and to the listener when in adverse conditions.
Differences in subjective loudness and annoyance depending on the road traffic noise spectrum
Authors: Torija Antonio J. , Flindell Ian H.
Published: January 2014

There is at present no consensus about the relative importance of low frequency content in urban road traffic noise. The hypothesis underlying this research is that changes to different parts of the spectrum will have different effects depending on which part of the spectrum is subjectively dominant in any particular situation. This letter reports a simple listening experiment which demonstrates this effect using typical urban main road traffic noise in which the low frequency content is physically dominant without necessarily being subjectively dominant.
Nocturnal air, road, and rail traffic noise and daytime cognitive performance and annoyance
Authors: Elmenhorst Eva-Maria , Quehl Julia , Müller Uwe , Basner Mathias
Published: January 2014

Various studies indicate that at the same noise level and during the daytime, annoyance increases in the order of rail, road, and aircraft noise. The present study investigates if the same ranking can be found for annoyance to nocturnal exposure and next day cognitive performance. Annoyance ratings and performance change during combined noise exposure were also tested. In the laboratory 72 participants were exposed to air, road, or rail traffic noise and all combinations. The number of noise events and LAS,eq were kept constant. Each morning noise annoyance questionnaires and performance tasks were administered. Aircraft noise annoyance ranked first followed by railway and road noise. A possible explanation is the longer duration of aircraft noise events used in this study compared to road and railway noise events. In contrast to road and rail traffic, aircraft noise annoyance was higher after nights with combined exposure. Pooled noise exposure data showed small but significant impairments in reaction times (6 ms) compared to nights without noise. The noise sources did not have a differential impact on performance. Combined exposure to multiple traffic noise sources did not induce stronger impairments than a single noise source. This was reflected also in low workload ratings.
Characteristics of the 2f1-f2 distortion product otoacoustic emission in a normal hearing population
Authors: Poling Gayla L. , Siegel Jonathan H. , Lee Jungmee , Lee Jungwha , Dhar Sumitrajit
Published: January 2014

Distortion-product otoacoustic emission (DPOAE) fine structure and component characteristics are reported between 0.75 and 16 kHz in 356 clinically normal hearing human subjects ages 10 to 65 yr. Stimulus tones at 55/40, 65/55, and 75/75 dB SPL were delivered using custom designed drivers and a calibration method that compensated for the depth of insertion of the otoacoustic emission (OAE) probe in the ear canal. DPOAE fine structure depth and spacing were found to be consistent with previous reports with depth varying between 3 and 7 dB and average spacing ratios (f/Δf) between 15 and 25 depending on stimulus level and frequency. In general, fine structure depth increased with increasing frequency, likely due to a diminishing difference between DPOAE component levels. Fine structure spacing became wider with increasing age above 8 kHz. DPOAE components were extracted using the inverse fast Fourier transform method, adhering to a strict signal to noise ratio criterion for clearer interpretation. Component data from four age groups between 18 and 55 yr old were available for the stimulus levels of 75/75 dB SPL. The age groups could be differentiated with greater than 90% accuracy when using the level of the component presumed to originate from the DPOAE characteristic frequency place. This accuracy held even for frequencies at and below 4 kHz where the age groups exhibited similar average hearing thresholds.
Effects of tonotopicity, adaptation, modulation tuning, and temporal coherence in “primitive” auditory stream segregation
Authors: Christiansen Simon Krogholt , Jepsen Morten Løve , Dau Torsten
Published: January 2014

The perceptual organization of two-tone sequences into auditory streams was investigated using a modeling framework consisting of an auditory pre-processing front end [Dau et al., J. Acoust. Soc. Am. 102, 2892–2905 (1997)] combined with a temporal coherence-analysis back end [Elhilali et al., Neuron 61, 317–329 (2009)]. Two experimental paradigms were considered: (i) Stream segregation as a function of tone repetition time (TRT) and frequency separation (Δf) and (ii) grouping of distant spectral components based on onset/offset synchrony. The simulated and experimental results of the present study supported the hypothesis that forward masking enhances the ability to perceptually segregate spectrally close tone sequences. Furthermore, the modeling suggested that effects of neural adaptation and processing though modulation-frequency selective filters may enhance the sensitivity to onset asynchrony of spectral components, facilitating the listeners' ability to segregate temporally overlapping sounds into separate auditory objects. Overall, the modeling framework may be useful to study the contributions of bottom-up auditory features on “primitive” grouping, also in more complex acoustic scenarios than those considered here.
Acoustical Standards News
Authors: Blaeser Susan B. , Schomer Paul D.
Published: January 2014

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes catalogs of Acoustical Standards, both National and International. To receive copies of the latest Standards catalogs, please contact Susan B. Blaeser.

Comments are welcomed on all material in Acoustical Standards News.

This Acoustical Standards News section in JASA, as well as the National and International Catalogs of Acoustical Standards, and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org.
PIP
3
Induces the Recycling of Receptor Tyrosine Kinases
Authors: Laketa Vibor , Zarbakhsh Sirus , Traynor-Kaplan Alexis , MacNamara Aidan , Subramanian Devaraj , Putyrski Mateusz , Mueller Rainer , Nadler André , Mentel Matthias , Saez-Rodriguez Julio , Pepperkok Rainer , Schultz Carsten
Published: January 2014

EGFR is recycled to the cell surface in response to the phosphoinositide PIP
3
.
Developing Neurons Make the Cut
Authors: Hines Pamela J.
Published: January 2014

During vertebrate neuronal development, the apical membrane is shed, allowing further differentiation.
Carbon Budding in the Ocean
Authors: Ash Caroline
Published: January 2014

The abundant marine cyanobacterium
Prochlorococcus
sheds membrane vesicles that may contribute to carbon budgets.
Noncoded Competition
Authors: Ferrarelli Leslie K.
Published: January 2014

The transcript of a protein-coding gene acts independently as a microRNA sponge to promote lung cancer.
Rapid Conversion of Pseudomonas aeruginosa to a Spherical Cell Morphotype Facilitates Tolerance to Carbapenems and Penicillins but Increases Susceptibility to Antimicrobial Peptides
Authors: Monahan Leigh G. , Turnbull Lynne , Osvath Sarah R. , Birch Debra , Charles Ian G. , Whitchurch Cynthia B.
Published: January 2014

The Gram-negative human pathogen
Pseudomonas aeruginosa
tolerates high concentrations of β-lactam antibiotics. Despite inhibiting the growth of the organism, these cell wall-targeting drugs exhibit remarkably little bactericidal activity. However, the mechanisms underlying β-lactam tolerance are currently unclear. Here, we show that
P. aeruginosa
undergoes a rapid
en masse
transition from normal rod-shaped cells to viable cell wall-defective spherical cells when treated with β-lactams from the widely used carbapenem and penicillin classes. When the antibiotic is removed, the entire population of spherical cells quickly converts back to the normal bacillary form. Our results demonstrate that these rapid population-wide cell morphotype transitions function as a strategy to survive antibiotic exposure. Taking advantage of these findings, we have developed a novel approach to efficiently kill
P. aeruginosa
by using carbapenem treatment to induce
en masse
transition to the spherical cell morphotype and then exploiting the relative fragility and sensitivity of these cells to killing by antimicrobial peptides (AMPs) that are relatively inactive against
P. aeruginosa
bacillary cells. This approach could broaden the repertoire of antimicrobial compounds used to treat
P. aeruginosa
and serve as a basis for developing new therapeutic agents to combat bacterial infections.
Molecular Basis for the Differential Quinolone Susceptibility of Mycobacterial DNA Gyrase
Authors: Kumar Rupesh , Madhumathi Bhavani Shankar , Nagaraja Valakunja
Published: January 2014

DNA gyrase is a type II topoisomerase that catalyzes the introduction of negative supercoils in the genomes of eubacteria. Fluoroquinolones (FQs), successful as drugs clinically, target the enzyme to trap the gyrase-DNA complex, leading to the accumulation of double-strand breaks in the genome. Mycobacteria are less susceptible to commonly used FQs. However, an 8-methoxy-substituted FQ, moxifloxacin (MFX), is a potent antimycobacterial, and a higher susceptibility of mycobacterial gyrase to MFX has been demonstrated. Although several models explain the mechanism of FQ action and gyrase-DNA-FQ interaction, the basis for the differential susceptibility of mycobacterial gyrase to various FQs is not understood. We have addressed the basis of the differential susceptibility of the gyrase and revisited the mode of action of FQs. We demonstrate that FQs bind both
Escherichia coli
and
Mycobacterium tuberculosis
gyrases in the absence of DNA and that the addition of DNA enhances the drug binding. The FQs bind primarily to the GyrA subunit of mycobacterial gyrase, while in
E. coli
holoenzyme is the target. The binding of MFX to GyrA of
M. tuberculosis
correlates with its effectiveness as a better inhibitor of the enzyme and its efficacy in cell killing.
Metabolism and Pharmacokinetics of the Anti-Hepatitis C Virus Nucleotide Prodrug GS-6620
Authors: Murakami Eisuke , Wang Ting , Babusis Darius , Lepist Eve-Irene , Sauer Dorothea , Park Yeojin , Vela Jennifer E. , Shih Robert , Birkus Gabriel , Stefanidis Dimitrios , Kim Choung U. , Cho Aesop , Ray Adrian S.
Published: January 2014

The anti-hepatitis C virus nucleotide prodrug GS-6620 employs a double-prodrug approach, with
l
-alanine-isopropyl ester and phenol moieties attached to the 5′-phosphate that release the nucleoside monophosphate in hepatocytes and a 3′-isobutyryl ester added to improve permeability and oral bioavailability. Consistent with the stability found in intestinal homogenates, following oral administration, intact prodrug levels in blood plasma were the highest in dogs, followed by monkeys, and then were the lowest in hamsters. In contrast, liver levels of the triphosphate metabolite at the equivalent surface area-adjusted doses were highest in hamsters, followed by in dogs and monkeys. Studies in isolated primary hepatocytes suggest that relatively poor oral absorption in hamsters and monkeys was compensated for by relatively efficient hepatocyte activation. As intestinal absorption was found to be critical to the effectiveness of GS-6620 in nonclinical species, stomach pH, formulation, and food effect studies were completed in dogs. Consistent with
in vitro
absorption studies in Caco-2 cells, the absorption of GS-6620 was found to be complex and highly dependent on concentration. Higher rates of metabolism were observed at lower concentrations that were unable to saturate intestinal efflux transporters. In first-in-human clinical trials, the oral administration of GS-6620 resulted in poor plasma exposure relative to that observed in dogs and in large pharmacokinetic and pharmacodynamic variabilities. While a double-prodrug approach, including a 3′-isobutyryl ester, provided higher intrinsic intestinal permeability, this substitution appeared to be a metabolic liability, resulting in extensive intestinal metabolism and relatively poor oral absorption in humans.