bluuebunny/crossref_metadata_2025 huggingface dataset:
Reynolds Stress Anisotropy Based Turbulent Eddy Viscosity Model Applied to Numerical Ocean Models
Authors: Maity Subhendu , Warrior Hari
Published: June 2011

The present state-of-the-art ocean models use an eddy viscosity that depends on structure parameter (Cμ). In this paper we use a Reynolds stress anisotropy based formulation for the eddy viscosity because in addition to the value of turbulent kinetic energy, it also depends on the degree of anisotropy. The formulation is incorporated into the General Ocean Turbulence Model (GOTM) and simulated using the famous test case of Ocean Weather Station (OWS) Papa experiment. Even if there is not much of an improvement in terms of results with this model, it can be very easily incorporated into the ocean models removing cumbersome equations for structure parameters.
Bimodal listeners are not sensitive to interaural time differences in unmodulated low-frequency stimuli (L)
Authors: Lenssen Anneke , Francart Tom , Brokx Jan , Wouters Jan
Published: June 2011

Sensitivity to interaural time differences (ITDs) with unmodulated low-frequency stimuli was assessed in bimodal listeners who had previously shown to be good performers in ITD experiments. Two types of stimuli were used: (1) an acoustic sinusoid combined with an electric transposed signal and (2) an acoustic sinusoid combined with an electric clicktrain. No or very low sensitivity to ITD was found for these stimuli, even though subjects were highly trained on the task and were intensively tested in multiple test sessions. In previous studies with users of a cochlear implant (CI) and a contralateral hearing aid (HA) (bimodal listeners), sensitivity was shown to ITD with modulated stimuli with frequency content between 600 and 3600 Hz. The outcomes of the current study imply that in speech processing design for users of a CI in combination with a HA on the contralateral side, the emphasis should be more on providing salient envelope ITD cues than on preserving fine-timing ITD cues present in acoustic signals.
Closed form solutions for the acoustical impulse response over a masslike or an absorbing plane
Authors: Ochmann Martin
Published: June 2011

The transient sound field caused by a Dirac delta impulse function above an infinite locally reacting plane can be calculated by applying the inverse Fourier transform of the corresponding half-space Green’s function in frequency domain. As a starting point, the representation given by Ochmann [J. Acoust. Soc. Am. 116(6), 3304–3311 (2004)] is used, which consists of discrete and continuous superposition of point sources. For a locally reacting plane with masslike character and also with pure absorbing behavior, it is possible to express the resulting impulse response in closed form. Such a result is surprising, because corresponding formulations in the frequency domain are not available yet. Hence, the first main result is the closed form solution Eq. (22) for an impulse response over an infinite plane with a pure imaginary impedance. The second main result is the closed form solution Eq. (53) for an impulse response over an infinite plane with a pure real impedance. As a particular application of both main results, a convolution technique is used for deriving formulas for point sources with a general time dependency. For special signals like an exponentially decaying time signal or a triangular shaped impulse, the resulting sound field can be presented in terms of elementary functions.
A particle filtering approach for spatial arrival time tracking in ocean acoustics
Authors: Jain Rashi , Michalopoulou Zoi-Heleni
Published: June 2011

The focus of this work is on arrival time and amplitude estimation from acoustic signals recorded at spatially separated hydrophones in the ocean. A particle filtering approach is developed that treats arrival times as “targets” and tracks their “location” across receivers, also modeling arrival time gradient. The method is evaluated via Monte Carlo simulations and is compared to a maximum likelihood estimator, which does not relate arrivals at neighboring receivers. The comparison demonstrates a significant advantage in using the particle filter. It is also shown that posterior probability density functions of times and amplitudes become readily available with particle filtering.
Laryngeal electromyographic responses to perturbations in voice pitch auditory feedback
Authors: Liu Hanjun , Behroozmand Roozbeh , Bove Michel , Larson Charles R
Published: June 2011

The present study was conducted to test the hypothesis that intrinsic laryngeal muscles are involved in producing voice fundamental frequency (F0) responses to perturbations in voice pitch auditory feedback. Electromyography (EMG) recordings of the cricothyroid and thyroarytenoid muscles were made with hooked-wire electrodes, while subjects sustained vowel phonations at three different voice F0 levels (conversational, high pitch in head register, and falsetto register) and received randomized pitch shifts (±100 or ±300 cents) in their voice auditory feedback. The median latencies from stimulus onset to the peak in the EMG and voice F0 responses were 167 and 224 ms, respectively. Among the three different F0 levels, the falsetto register produced compensatory EMG responses that occurred prior to vocal responses and increased along with rising voice F0 responses and decreased for falling F0 responses. For the conversational and high voice levels, the EMG response timing was more variable than in the falsetto voice, and changes in EMG activity with relevance to the vocal responses did not follow the consistent trend observed in the falsetto condition. The data from the falsetto condition suggest that both the cricothyroid and thyroarytenoid muscles are involved in generating the compensatory vocal responses to pitch-shifted voice feedback.
An efficient method for computing backscattering from Born objects of arbitrary shape
Authors: Pees Edward H.
Published: June 2011

A method is presented for efficiently computing the propagating pressure field backscattered by an arbitrarily shaped, weakly scattering, three-dimensional object. This is accomplished by drawing upon a previously reported relationship between the boundary condition on a two-dimensional radiating aperture and the pressure propagating along an axis normal to the aperture, and the fundamental theorem of diffraction tomography, which relates the Fourier transform of an object function to its scattered pressure field. Together, these two results are used to derive an integral formula that expresses the pressure field backscattered from an object as a one-dimensional Fourier transform of its scattering amplitude. This formula is then utilized to compute the backscattered pressure field from a uniform fluid sphere in the first Born approximation; the results of which are compared to the rigorous partial wave expansion.
Engaging concert hall acoustics is made up of temporal envelope preserving reflections
Authors: Lokki Tapio , Pätynen Jukka , Tervo Sakari , Siltanen Samuel , Savioja Lauri
Published: June 2011

Strong, exciting, and engaging sound is perceived in the best concert halls. Here, it is shown that wideband early reflections that preserve the temporal envelope of sound contribute to the clear and open acoustics with strong bass. Such reflections are fused with the direct sound due to the precedence effect. In contrast, reflections that distort the temporal envelope render the sound weak and muddy because they partially break down the precedence. The presented findings are based on the earlier psychoacoustics research, and confirmed by a perceptual evaluation with six simulated concert halls that have same monaural room acoustical parameter values according to ISO3382-1.
On the acoustic-radiation-induced strain and stress in elastic solids with quadratic nonlinearity (L)
Authors: Qu Jianmin , Jacobs Laurence J. , Nagy Peter B.
Published: June 2011

This letter demonstrates that an eigenstrain is induced when a wave propagates through an elastic solid with quadratic nonlinearity. It is shown that this eigenstrain is intrinsic to the material, but the mean stress and the total mean strain are not. Instead, the mean stress and total means strain also depend on the boundary conditions, so care must be taken when using the static deformation to measure the acoustic nonlinearity parameter of a solid.
Spectro-temporal envelope changes caused by temporal fine structure modification
Authors: Kates James M.
Published: June 2011

The study of speech from which the temporal fine structure (TFS) has been removed has become an important research area. Common procedures for removing TFS include noise and tone vocoders. In the noise vocoder, bands of noise are modulated by the envelope of the speech within each band, and in the tone vocoder the carrier is a sinusoid at the center of each frequency band. Five different procedures for removing TFS are evaluated in this paper: the noise vocoder, a low-noise noise approach in which the noise envelope is replaced by the speech envelope in each frequency band, phase randomization within each band, the tone vocoder, and sinusoidal modeling with random phase. The effects of TFS modification on the speech envelope are evaluated using an index based on the envelope time-frequency modulation. The results show that for all of the TFS techniques implemented in this study, there is a substantial loss in the accuracy of reproduction of the envelope time-frequency modulation. The tone vocoder gives the best accuracy, followed by the procedure that replaces the noise envelope with the speech envelope in each band.
Enhancing a tone by shifting its frequency or intensity
Authors: Erviti Mayalen , Semal Catherine , Demany Laurent
Published: June 2011

When a test sound consisting of pure tones with equal intensities is preceded by a precursor sound identical to the test sound except for a reduction in the intensity of one tone, an auditory “enhancement” phenomenon occurs: In the test sound, the tone which was previously softer stands out perceptually. Here, enhancement was investigated using inharmonic sounds made up of five pure tones well resolved in the auditory periphery. It was found that enhancement can be elicited not only by increases in intensity but also by shifts in frequency. In both cases, when the precursor and test sounds are separated by a 500-ms delay, inserting a burst of pink noise during the delay has little effect on enhancement. Presenting the precursor and test sounds to opposite ears rather than to the same ear significantly reduces the enhancement resulting from increases in intensity, but not the enhancement resulting from shifts in frequency. This difference suggests that the mechanisms of enhancement are not identical for the two types of change. For frequency shifts, enhancement may be partly based on the existence of automatic “frequency-shift detectors” [Demany and Ramos, J. Acoust. Soc. Am. 117, 833–841 (2005)].
Experimental validation of the sound transmission of rectangular baffled plates with general elastic boundary conditions
Authors: Ou Dayi , Mak Cheuk Ming
Published: June 2011

Several prediction methods have recently been developed for systematically studying the effects of general boundary conditions on the sound transmission loss (STL) of plate-like structures. But corresponding experimental validation studies remain scarce owing to the difficulty of obtaining accurate boundary conditions for practical structures. This paper presents a convincing experiment conducted on a baffled plate system to validate the STL prediction model in a previous paper by Yu et al. [Noise Control Eng. J. 58(2), 187–200, 2010]. A method is proposed to determine the boundary conditions of this system, and experimental STL compares well with the predictions based on the identified boundary condition.
A Molecular Mechanism for Circadian Clock Negative Feedback
Authors: Duong Hao A. , Robles Maria S. , Knutti Darko , Weitz Charles J.
Published: June 2011

New cogs in the mammalian circadian clock are identified.
Three-Dimensional Plasmon Rulers
Authors: Liu Na , Hentschel Mario , Weiss Thomas , Alivisatos A. Paul , Giessen Harald
Published: June 2011

The optical response of a fabricated nanostructure can be used to determine distances in three dimensions.
Direct Ubiquitination of Pattern Recognition Receptor FLS2 Attenuates Plant Innate Immunity
Authors: Lu Dongping , Lin Wenwei , Gao Xiquan , Wu Shujing , Cheng Cheng , Avila Julian , Heese Antje , Devarenne Timothy P. , He Ping , Shan Libo
Published: June 2011

Targeted degradation of bacterial sensing proteins keeps plant defenses from running amok.
A Tale of Two Earthquakes
Authors: Heki Kosuke
Published: June 2011

Networks of GPS detectors can provide a detailed picture of the dynamics of earthquakes before, during, and after the event.
Assessment of the Genetic Susceptibility of Sheep to Scrapie by Protein Misfolding Cyclic Amplification and Comparison with Experimental Scrapie Transmission Studies
Authors: Bucalossi Cecilia , Cosseddu GianMario , D'Agostino Claudia , Di Bari Michele Angelo , Chiappini Barbara , Conte Michela , Rosone Francesca , De Grossi Luigi , Scavia Gaia , Agrimi Umberto , Nonno Romolo , Vaccari Gabriele
Published: June 2011

The susceptibility of sheep to scrapie is influenced mainly by the prion protein polymorphisms A136V, R154H, and Q171R/H. Here we analyzed the ability of protein misfolding cyclic amplification (PMCA) to model the genetic susceptibility of sheep to scrapie. For this purpose, we studied the efficiency of brain homogenates from sheep with different PrP genotypes to support PrP
Sc
amplification by PMCA using an ARQ/ARQ scrapie inoculum. The results were then compared with those obtained
in vivo
using the same sheep breed, genotypes, and scrapie inoculum. Genotypes associated with susceptibility (ARQ/ARQ, ARQ/AHQ, and AHQ/ARH) were able to sustain PrP
Sc
amplification in PMCA reactions, while genotypes associated with resistance to scrapie (ARQ/ARR and ARR/ARR) were unable to support the
in vitro
conversion. The incubation times of the experimental infection were then compared with the
in vitro
amplification factors. Linear regression analysis showed that the efficiency of
in vitro
PrP
Sc
amplification of the different genotypes was indeed inversely proportional to their incubation times. Finally, the rare ARQK
176
/ARQK
176
genotype, for which no
in vivo
data are available, was studied by PMCA. No amplification was obtained, suggesting ARQK
176
/ARQK
176
as an additional genotype associated with resistance, at least to the isolate tested. Our results indicate a direct correlation between the ability of different PrP genotypes to undergo PrP
C
-to-PrP
Sc
conversion by PMCA and their
in vivo
susceptibility and point to PMCA as an alternative to transmission studies and a potential tool to test the susceptibility of numerous sheep PrP genotypes to a variety of prion sources.
Liposomal Nanocontainers as Models for Viral Infection: Monitoring Viral Genomic RNA Transfer through Lipid Membranes
Authors: Bilek Gerhard , Matscheko Nena M. , Pickl-Herk Angela , Weiss Victor U. , Subirats Xavier , Kenndler Ernst , Blaas Dieter
Published: June 2011

After uptake into target cells, many nonenveloped viruses undergo conformational changes in the low-pH environment of the endocytic compartment. This results in exposure of amphipathic viral peptides and/or hydrophobic protein domains that are inserted into and either disrupt or perforate the vesicular membranes. The viral nucleic acids thereby gain access to the cytosol and initiate replication. We here demonstrate the
in vitro
transfer of the single-stranded positive-sense RNA genome of human rhinovirus 2 into liposomes decorated with recombinant very-low-density lipoprotein receptor fragments. Membrane-attached virions were exposed to pH 5.4, mimicking the
in vivo
pH environment of late endosomes. This triggered the release of the RNA whose arrival in the liposomal lumen was detected via
in situ
cDNA synthesis by encapsulated reverse transcriptase. Subsequently, cDNA was PCR amplified. At a low ratio between virions and lipids, RNA transfer was positively correlated with virus concentration. However, membranes became leaky at higher virus concentrations, which resulted in decreased cDNA synthesis. In accordance with earlier
in vivo
data, the RNA passes through the lipid membrane without causing gross damage to vesicles at physiologically relevant virus concentrations.
Role of TRIM5α RING Domain E3 Ubiquitin Ligase Activity in Capsid Disassembly, Reverse Transcription Blockade, and Restriction of Simian Immunodeficiency Virus
Authors: Kim Jonghwa , Tipper Christopher , Sodroski Joseph
Published: June 2011

The mammalian tripartite motif protein, TRIM5α, recognizes retroviral capsids entering the cytoplasm and blocks virus infection. Depending on the particular TRIM5α protein and retrovirus, complete disruption of the TRIM5α RING domain decreases virus-restricting activity to various degrees. TRIM5α exhibits RING domain-dependent E3 ubiquitin ligase activity, but the specific role of this activity in viral restriction is unknown. We created a panel of African green monkey TRIM5α (TRIM5αAGM) mutants, many of which are specifically altered in RING domain E3 ubiquitin ligase function, and characterized the phenotypes of these mutants with respect to restriction of simian and human immunodeficiency viruses (SIVmacand HIV-1, respectively). TRIM5αAGMubiquitin ligase activity was essential for both the accelerated disassembly of SIVmaccapsids and the disruption of reverse transcription. The levels of SIVmacparticulate capsids in the cytosol of target cells expressing the TRIM5α variants strongly correlated with the levels of viral late reverse transcripts. RING-mediated ubiquitylation and B30.2(SPRY) domain-determined capsid binding independently contributed to the potency of SIVmacrestriction by TRIM5αAGM. In contrast, TRIM5α proteins attenuated in RING ubiquitin ligase function still accelerated HIV-1 capsid disassembly, inhibited reverse transcription, and blocked infection. Replacement of the helix-4/5 loop in the SIVmaccapsid with the corresponding region of the HIV-1 capsid diminished the dependence of restriction on TRIM5α RING function. Thus, ubiquitylation mediated by the RING domain of TRIM5αAGMis essential for blocking SIVmacinfection at the stage of capsid uncoating.
Oncogenic IRFs Provide a Survival Advantage for Epstein-Barr Virus- or Human T-Cell Leukemia Virus Type 1-Transformed Cells through Induction of BIC Expression
Authors: Wang Ling , Toomey Ngoc L. , Diaz Luis A. , Walker Gail , Ramos Juan C. , Barber Glen N. , Ning Shunbin
Published: June 2011

miR-155, processed from the B-cell integration cluster (BIC), is one of the few well-studied microRNAs (miRNAs) and is involved in both innate immunity and tumorigenesis. BIC/miR-155 is induced by distinct signaling pathways, but little is known about the underlying mechanisms. We have identified two conserved potential interferon (IFN) regulatory factor (IRF)-binding/interferon-stimulated response element motifs in the
Bic
gene promoter. Two oncogenic IRFs, IRF4 and -7, in addition to some other members of the family, bind to and significantly transactivate the
Bic
promoter. Correspondingly, the endogenous levels of IRF4 and -7 are correlated with that of the BIC transcript in Epstein-Barr virus (EBV)-transformed cells. However, RNA interference studies have shown that depletion of IRF4, rather than of IRF7, dramatically decreases the endogenous level of BIC by up to 70% in EBV- or human T-cell leukemia virus type 1 (HTLV1)-transformed cell lines and results in apoptosis and reduction of proliferation rates that are restored by transient expression of miR-155. Moreover, the endogenous levels of the miR-155 target, SHIP1, are consistently elevated in EBV- and HTLV1-transformed cell lines stably expressing shIRF4. In contrast, transient expression of IRF4 decreases the SHIP1 level in EBV-negative B cells. Furthermore, the level of IRF4 mRNA is significantly correlated with that of BIC in adult T-cell lymphoma/leukemia (ATLL) tumors. These results show that IRF4 plays an important role in the regulation of BIC in the context of EBV and HTLV1 infection. Our findings have identified
Bic
as the first miRNA-encoding gene for IRFs and provide evidence for a novel molecular mechanism underlying the IRF/BIC pathway in viral oncogenesis.
Nuclear Envelope Breakdown Can Substitute for Primary Envelopment-Mediated Nuclear Egress of Herpesviruses
Authors: Klupp Barbara G. , Granzow Harald , Mettenleiter Thomas C.
Published: June 2011

Herpesvirus nucleocapsids assemble in the nucleus but mature to infectious virions in the cytoplasm. To gain access to this cellular compartment, nucleocapsids are translocated to the cytoplasm by primary envelopment at the inner nuclear membrane and subsequent fusion of the primary envelope with the outer nuclear membrane. The conserved viral pUL34 and pUL31 proteins play a crucial role in this process. In their absence, viral replication is strongly impaired but not totally abolished. We used the residual infectivity of a pUL34-deleted mutant of the alphaherpesvirus pseudorabies virus (PrV) for reversion analysis. To this end, PrV-ΔUL34 was serially passaged in rabbit kidney cells until final titers of the mutant virus PrV-ΔUL34Pass were comparable to those of wild-type PrV. PrV-ΔUL34Pass produced infectious progeny independently of the pUL34/pUL31 nuclear egress complex and the pUS3 protein kinase. Ultrastructural analyses demonstrated that this effect was due to virus-induced disintegration of the nuclear envelope, thereby releasing immature and mature capsids into the cytosol for secondary envelopment. Our data indicate that nuclear egress primarily serves to transfer capsids through the intact nuclear envelope. Immature and mature intranuclear capsids are competent for further virion maturation once they reach the cytoplasm. However, nuclear egress exhibits a strong bias for nucleocapsids, thereby also functioning as a quality control checkpoint which is abolished by herpesvirus-induced nuclear envelope breakdown.
RCVS CertAVP update
Authors: Viner Bradley
Published: June 2011

In 2002, the Education Strategy Steering Group (ESSG) set up by the RCVS produced a report entitled ‘Veterinary education and training: a framework for 2010 and beyond’. Among the ESSG's proposals was the establishment of modular RCVS certificates that would provide a more accessible framework to encourage postgraduate education in practice than the old style of qualification. The ESSG also stated that ‘achievement of a certificate, or working towards certificate modules, should become the norm for new practitioners’. Examinations for the old certificate are now being wound down. With the first group of candidates having received the new RCVS certificates of advanced veterinary practice (CertAVP) in 2010, and with many more registered for around 4000 individual modules spanning a wide range of different subjects, Bradley Viner reviews the status of the new qualification and opportunities for further development.
Comments on the dilemma in the May issue: ‘Pet insurance problem’
Authors: Mullan Siobhan
Published: June 2011

The dilemma in the May issue concerned a veterinary surgeon who was reprimanded by their manager for including details of a newly identified condition in the clinical notes of a long‐standing client's dog (In Practice, May 2011, volume 33, pages 237–238). The owner had recently taken out pet insurance and risked being refused cover for the investigations and treatment being proposed. The manager suggested that such details should be omitted until the owner had secured the necessary pet insurance, but the veterinary surgeon was uncomfortable with this instruction. Glen Cousquer commented that, from a legal perspective, the practitioner was essentially being asked to defraud the insurance company. However, a utilitarian approach to the dilemma might well try to weigh up the good that might arise through turning a blind eye and judge that the benefits to the patient, client and practice outweighed the damage to the insurance company. He noted, however, that this might be an overly simplistic view of the problem, as the veterinary employee also had duties to the profession, society and the greater good. These wider duties could be easily overlooked, especially when faced with more immediate concerns, including the veterinary surgeon's wish to please their employer (or at least not displease them) and avoid placing their own employment in jeopardy. As a possible way forward, the need to behave honestly could gently be explained to the client, with help provided to check the terms of any insurance policy. A careful evaluation of all the clinical options could be made and the client fully supported in making the right decision for their pet. It would also be appropriate to carefully review the advice and information provided to clients about pet insurance and the anticipated costs of veterinary care, and how they could plan to meet these costs over the lifetime of a pet.
Forensic veterinary medicine
Authors: Munro Ranald , Munro Helen
Published: June 2011

An article in the May 2011 issue of In Practice (volume 33, pages 220–227) discussed the fundamentals of forensic veterinary medicine and considered the protocol for investigating and reporting on cases involving live animals. However, if animals linked to suspected breaches of criminal law or civil proceedings of some nature die, or are euthanased, a forensic postmortem examination will be required. The aims of this examination are to provide the opportunity to describe and record all lesions or injuries, and to allow objective interpretation of these changes. Postmortem examinations must be conducted in a manner and to a sufficiently high standard that reassures the courts that the results are comprehensive and soundly based. They should include both external and internal examination of the cadaver, which involves removing the internal organs, including the brain, from the body for detailed examination. This article provides an overview of forensic veterinary pathology, using two common causes of death and injury in animals presented for forensic postmortem examination – neglect and blunt force injuries – to illustrate a practical approach to postmortem examination of such cases.
Cattle health schemes
Authors: Statham Jonathan
Published: June 2011

Multifactorial or management diseases such as mastitis, lameness, infertility, calf pneumonia and calf diarrhoea represent significant costs for both the dairy and beef industries. A number of cattle health schemes, comprising a variety of tools and services, have thus evolved to help control these conditions. This article describes how these programmes might be used to provide proactive veterinary herd health. Cattle health schemes aimed at single‐agent infectious disease control were discussed in an article published in the May issue of In Practice (volume 33, pp 210–217).
Non-cirrhotic portal fibrosis: one disease with many names? An analysis from morphological study of native explant livers with end stage chronic liver disease
Authors: Nayak Nabeen C , Jain Deepali , Saigal Sanjiv , Soin Arvind S
Published: June 2011

Background

A group of non-cirrhotic chronic liver diseases, all with sustained portal hypertension and clinically mistaken as cirrhosis, have been described under various names, apparently because of differences in pathological features. The pathogenesis is uncertain and they were believed to have a good prognosis until it was recently shown, from study of explant livers, that they had progressed to end stage disease, needing liver transplantation.

Aims

To describe detailed morphological features of such end stage non-cirrhotic disease and examine whether the diseases bearing various names are different or represent variable morphological expressions of one entity.

Methods

Morphological features of 10 native explant livers from patients with pre-transplant diagnosis of end stage cirrhosis but finally categorised as non-cirrhotic portal fibrosis were analysed along with the relevant clinical information.

Results

Besides absence of criteria for cirrhosis, variable grades of obliterative changes in portal vein branches and portal fibrosis were consistently seen in all livers. Fibrous intimal thickening with luminal compromise in some medium and large sized portal veins was randomly distributed but appeared characteristic of this disease, very likely representing organised mural thrombi. Areas of closely placed nodular hyperplastic parenchyma separated by compressed hepatocytes, megasinusoids and peliotic changes were seen only in a proportion of cases.

Conclusion

Non-cirrhotic portal fibrosis is a justifiable name for this disease that can progress to end stage liver disease. It represents a single entity that has been considered as different diseases and given various names on the basis of the dominant element in its heterogeneous morphological manifestation.
Crossing the boundaries
Authors: Belcher T. , Newell D. G.
Published: June 2011

In the past, research on zoonotic diseases has been fragmented. Teresa Belcher and Diane Newell discuss the formation of Med‐Vet‐Net, a ‘virtual institute’, which aims to integrate activity between researchers in human and veterinary medicine across the European Union
Working in parallel, learning in parallel?
Authors: Quentin‐Baxter M. , Spencer J. A. , Rhind S. M.
Published: June 2011

Despite significant similarities between training and practice in human and veterinary medicine, the two professions tend to articulate, rather than merge, in areas of potential overlap, including education, say Megan Quentin‐Baxter, John Spencer and Susan Rhind. Here, they compare education in the human and veterinary fields, outlining key similarities and differences
Survey of zoonoses recorded in Scotland between 1993 and 2002
Authors: Stewart W. C. , Pollock K. G. J. , Browning L. M. , Young D. , Smith‐Palmer A. , Reilly W. J.
Published: June 2011

All the human and animal laboratory reports of zoonoses sent to Health Protection Scotland between 1993 and 2002 were identified. There were 24,946 reports from veterinary laboratories, and 94,718 (20 per cent) of the 468,214 reports from medical laboratories were considered to be zoonotic. The most common reports of zoonoses from people were Campylobacter, Salmonella, Cryptosporidium and Giardia species and Escherichia coli O157. The most common reports of zoonoses from animals were Salmonella, Cryptosporidium, Chlamydia and Campylobacter species and Mycobacterium avium paratuberculosis. For all the zoonoses in people, the National Health Service Board areas Borders, Dumfries and Galloway, Forth Valley, Grampian, Lanarkshire and Lothian had a higher than expected standardised incidence rate of infection, whereas Ayrshire and Arran, Fife, Greater Glasgow, Shetland, Tayside and Western Isles had a lower than expected rate. The organisms and diseases considered to be new and emerging were Rhodococcus species, Cyclospora cayetanensis, Leishmania species, Pneumocystis carinii (jiroveci) and bovine spongiform encephalopathy/variant Creutzfeldt‐Jakob disease.
NOETHER–LEFSCHETZ THEORY AND NÉRON–SEVERI GROUP
Authors: DI GENNARO VINCENZO , FRANCO DAVIDE
Published: June 2011

Let Z be a closed subscheme of a smooth complex projective complete intersection variety Y ⊆ ℙN, with dim Y = 2r + 1 ≥ 3. We describe the Néron–Severi group NSr(X) of a general smooth hypersurface X ⊂ Y of sufficiently large degree containing Z.
PROLONGATION ON REGULAR INFINITESIMAL FLAG MANIFOLDS
Authors: NEUSSER KATHARINA
Published: June 2011

Many interesting geometric structures can be described as regular infinitesimal flag structures, which occur as the underlying structures of parabolic geometries. Among these structures we have for instance conformal structures, contact structures, certain types of generic distributions and partially integrable almost CR-structures of hypersurface type. The aim of this article is to develop for a large class of (semi-) linear overdetermined systems of partial differential equations on regular infinitesimal flag manifolds M a conceptual method to rewrite these systems as systems of the form [Formula: see text], where [Formula: see text] is a linear connection on some vector bundle V over M and C : V → T* M ⊗ V is a (vector) bundle map. In particular, if the overdetermined system is linear, [Formula: see text] will be a linear connection on V and hence the dimension of its solution space is bounded by the rank of V. We will see that the rank of V can be easily computed using representation theory.
HARNACK-TYPE INEQUALITIES FOR THE POROUS MEDIUM EQUATION ON A MANIFOLD WITH NON-NEGATIVE RICCI CURVATURE
Authors: CHANG JEONGWOOK , LEE JINHO
Published: June 2011

We derive Harnack-type inequalities for non-negative solutions of the porous medium equation on a complete Riemannian manifold with non-negative Ricci curvature. Along with gradient estimates, reparametrization of a geodesic and time rescaling of a solution are key tools to get the results.
SOME SPLICE QUOTIENT DOUBLE POINTS
Authors: SELL ELIZABETH A.
Published: June 2011

The splice quotients are an interesting class of normal surface singularities with rational homology sphere links. In general, it can be difficult to determine whether or not a singularity is a splice quotient (an analytic condition). We consider splice quotient deformations of splice quotients of the form z2= xa+ yb, and show that in general not all equisingular deformations are splice quotients.
A = 3 CLUSTERING IN NUCLEI
Authors: ABBAS SYED AFSAR , AHMAD SHAKEB
Published: June 2011

Alpha clustering in nuclei at present is a well studied and reasonably well accepted property of the nucleus. Less well appreciated and more ambiguous is the role of A = 3 clustering, i.e. helion and triton, in nuclei. Here we try to place A = 3 clustering in nuclei into its proper perspective, first by pointing out strong experimental evidences which indicate its clear presence in nuclei and second showing as to how to include these A = 3 clusters in a proper and consistent theoretical understanding of the nuclear phenomenon.
ESTIMATION OF THE BREAKUP CROSS-SECTIONS IN 6He + 12C REACTION WITHIN HIGH-ENERGY APPROXIMATION AND MICROSCOPIC OPTICAL POTENTIAL
Authors: LUKYANOV V. K. , ZEMLYANAYA E. V. , LUKYANOV K. V.
Published: June 2011

The breakup cross-sections in the reaction 6 He + 12 C are calculated at about 40 MeV/nucleon using the high-energy approximation (HEA) and with the help of microscopic optical potentials (OP) of interaction with the target nucleus 12 C of the projectile nucleus fragments 4 He and 2n. Considering the di-neutron h = 2n as a single particle the relative motion hα wave function is estimated so that to explain both the separation energy of h in 6 He and the rms radius of the latter. The stripping and absorbtion total cross-sections are calculated and their sum is compared with the total reaction cross-section obtained within a double-folding microscopic OP for the 6 He + 12 C scattering. It is concluded that the breakup cross-sections contribute to about 50% of the total reaction cross-section.
OFF-RESONANCE CANTILEVER DYNAMICS IN THE PRESENCE OF ATTRACTIVE AND REPULSIVE TIP INTERACTION FORCES
Authors: CHAKRABORTY ISHITA , BALACHANDRAN B.
Published: June 2011

In dynamic atomic force microscopy (AFM), as the tip of the base-excited micro-cantilever approaches the sample surface, this cantilever tip typically experiences long-range attractive and short-range repulsive forces. Due to the strongly nonlinear nature of these tip-sample interaction forces, various nonlinear phenomena including grazing contact-related phenomena have been observed. With the aim of obtaining a better understanding of such phenomena, a macro-scale experimental system has been constructed with attractive and repulsive tip interactions. In this arrangement, the macro-scale cantilever structure is harmonically excited at its base, a combination of magnets is used to generate the attractive forces, and impacts with a compliant surface are used to produce the repulsive forces. The separation between the tip and the compliant surface is used as a control parameter and the associated qualitative changes in the system dynamics are studied on Poincaré sections constructed by using the excitation frequency as the clock frequency. Off-resonance excitations are considered and a period- doubling window is observed for near-grazing impacts when the excitation frequency is in between the first and the second natural frequencies of the system. To explore the experimental observations further, a reduced-order model of the macro-scale system is developed with Derjaguin–Muller–Toporov (DMT) contact mechanics. The dynamics of the reduced-order system is found to agree well with the corresponding experimental observations. The nonlinear phenomenon observed during off-resonance excitations can form a basis for engineering grazing (zero-speed) impacts or low-speed impacts between a tapping mode AFM cantilever tip and the considered sample. In addition, the macro-scale experimental arrangement can serve as a vehicle to understand the dynamics of elastic structures subjected to different combinations of attractive and repulsive tip forces.
DYNAMICS AND BUCKLING OF SANDWICH PANELS WITH STEPPED FACINGS
Authors: NGUYEN CODY H. , BUTUKURI RAMANJANEYA R. , CHANDRASHEKHARA K. , BIRMAN VICTOR
Published: June 2011

Sandwich panels have been developed to either produce lighter structures capable of carrying prescribed loads or increase the load-carrying capacity subject to limitations on weight. In these panels, facings carry bending and in-plane loads while the core functions similarly to the web of a beam, mostly resisting transverse shear. Improvements in the load-carrying capacity of sandwich panels can be achieved through modifications in their geometry, boundary conditions, and material distribution. One of the methods recently considered by the authors is based on using facings with a step-wise variable thickness that increases at the critical region of the structure.1 It was illustrated that the strength of a sandwich panel can be considerably enhanced using such stepped facings, without a detrimental increase of the weight. The present paper expands the study of the feasibility of the stepped-facing sandwich panel concept concentrating on three structural problems, i.e. a possible improvement in stability, changes in the natural frequencies, and forced dynamic response to the explosive blast. It is illustrated that the stepped-facing design can improve stability of the panel and its response to blast loading. However, fundamental frequencies of stepped-facing panels decrease compared to those in their conventional equal-weight counterparts. Such decrease is detrimental in the majority of engineering applications representing a limitation of stepped-facing panels. Nevertheless, the usefulness of the stepped-facing design is proven in the problems of bending, stability, and blast loading. Numerous examples presented in the paper validate our suggestion that the combination of a relatively simple manufacturing process and an improved structural response of sandwich panels with stepped facings may present the designer with an attractive alternative to conventional sandwich structures.
Improved fatigue resistance in Gsα-deficient and aging mouse skeletal muscles due to adaptive increases in slow fibers
Authors: Feng Han-Zhong , Chen Min , Weinstein Lee S. , Jin J.-P.
Published: June 2011

Genetically modified mice with deficiency of the G protein α-subunit (Gsα) in skeletal muscle showed metabolic abnormality with reduced glucose tolerance, low muscle mass, and low contractile force, along with a fast-to-slow-fiber-type switch (Chen M, Feng HZ, Gupta D, Kelleher J, Dickerson KE, Wang J, Hunt D, Jou W, Gavrilova O, Jin JP, Weinstein LS. Am J Physiol Cell Physiol 296: C930–C940, 2009). Here we investigated a hypothesis that the switching to more slow fibers is an adaptive response with specific benefit. The results showed that, corresponding to the switch of myosin isoforms, the thin-filament regulatory proteins troponin T and troponin I both switched to their slow isoforms in the atrophic soleus muscle of 3-mo-old Gsα-deficient mice. This fiber-type switch involving coordinated changes of both thick- and thin-myofilament proteins progressed in the Gsα-deficient soleus muscles of 18- to 24-mo-old mice, as reflected by the expression of solely slow isoforms of myosin and troponin. Compared with age-matched controls, Gsα-deficient soleus muscles with higher proportion of slow fibers exhibited slower contractile and relaxation kinetics and lower developed force, but significantly increased resistance to fatigue, followed by a better recovery. Gsα-deficient soleus muscles of neonatal and 3-wk-old mice did not show the increase in slow fibers. Therefore, the fast-to-slow-fiber-type switch in Gsα deficiency at older ages was likely an adaptive response. The benefit of higher fatigue resistance in adaption to metabolic deficiency and aging provides a mechanism to sustain skeletal muscle function in diabetic patients and elderly individuals.
Exercise-induced pyruvate dehydrogenase activation is not affected by 7 days of bed rest
Authors: Kiilerich Kristian , Ringholm Stine , Biensø Rasmus S. , Fisher James P. , Iversen Ninna , van Hall Gerrit , Wojtaszewski Jørgen F. P. , Saltin Bengt , Lundby Carsten , Calbet Jose A. L. , Pilegaard Henriette
Published: June 2011

To test the hypothesis that physical inactivity impairs the exercise-induced modulation of pyruvate dehydrogenase (PDH), six healthy normally physically active male subjects completed 7 days of bed rest. Before and immediately after the bed rest, the subjects completed an oral glucose tolerance test (OGTT) and a one-legged knee extensor exercise bout [45 min at 60% maximal load (Wmax)] with muscle biopsies obtained from vastus lateralis before, immediately after exercise, and at 3 h of recovery. Blood samples were taken from the femoral vein and artery before and after 40 min of exercise. Glucose intake elicited a larger ( P ≤ 0.05) insulin response after bed rest than before, indicating glucose intolerance. There were no differences in lactate release/uptake across the exercising muscle before and after bed rest, but glucose uptake after 40 min of exercise was larger ( P ≤ 0.05) before bed rest than after. Muscle glycogen content tended to be higher (0.05< P ≤ 0.10) after bed rest than before, but muscle glycogen breakdown in response to exercise was similar before and after bed rest. PDH-E1α protein content did not change in response to bed rest or in response to the exercise intervention. Exercise increased ( P ≤ 0.05) the activity of PDH in the active form (PDHa) and induced ( P ≤ 0.05) dephosphorylation of PDH-E1α on Ser293, Ser295 and Ser300, with no difference before and after bed rest. In conclusion, although 7 days of bed rest induced whole body glucose intolerance, exercise-induced PDH regulation in skeletal muscle was not changed. This suggests that exercise-induced PDH regulation in skeletal muscle is maintained in glucose-intolerant (e.g., insulin resistant) individuals.
Conductance catheter measurements of lumen area of stenotic coronary arteries: theory and experiment
Authors: Choi Hyo Won , Farren Neil D. , Zhang Zhen-Du , Huo Yunlong , Kassab Ghassan S.
Published: June 2011

An injection of saline solution is required for the measurement of vessel lumen area using a conductance catheter. The injection of room temperature saline to displace blood in a vessel inevitably involves mass and heat transport and electric field conductance. The objective of the present study is to understand the accuracy of conductance method based on the phenomena associated with the saline injection into a stenotic blood vessel. Computational fluid dynamics were performed to simulate flow and its relation to transport and electric field in a stenotic artery for two different sized conductance catheters (0.9 and 0.35 mm diameter) over a range of occlusions [56–84% cross-sectional area (CSA) stenosis]. The results suggest that the performance of conductance catheter is dependent on catheter size and severity of stenosis more significantly for 0.9 mm than for 0.35 mm catheter. Specifically, the time of detection of 95% of injected saline solution at the detection electrodes was shown to range from 0.67 to 3.7 s and 0.82 to 0.94 s for 0.9 mm and 0.35 mm catheter, respectively. The results also suggest that the detection electrodes of conductance catheter should be placed outside of flow recirculation region distal to the stenosis to minimize the detection time. Finally, the simulations show that the accuracy in distal CSA measurements, however, is not significantly altered by whether the position of detection electrodes is inside or outside of recirculation zone (error was within 12% regardless of detection electrodes position). The results were experimentally validated for one lesion geometry and the simulation results are within 8% of actual measurements. The simulation of conductance catheter injection method may lead to further optimization of device and method for accurate sizing of diseased coronary arteries, which has clinical relevance to percutaneous intervention.
Primary Iliac Venous Leiomyosarcoma: A Rare Cause of Deep Vein Thrombosis in a Young Patient
Authors: Oliveira Nelson , Dias Emanuel , Lima Ricardo , Oliveira Fernando , Cássio Isabel
Published: June 2011

Introduction. Primary venous tumours are a rare cause of deep vein thrombosis. The authors present a case where the definitive diagnosis was delayed by inconclusive complementary imaging.Clinical Case. A thirty-seven-year-old female presented with an iliofemoral venous thrombosis of the right lower limb. The patient had presented with an episode of femoral-popliteal vein thrombosis five months before and was currently under anticoagulation.Phlegmasia alba dolensinstalled progressively, as thrombus rapidly extended to the inferior vena cava despite systemic thrombolysis and anticoagulation. Diagnostic imaging failed to identify the underlying aetiology of the deep vein thrombosis. The definitive diagnosis of primary venous leiomyosarcoma was reached by a subcutaneous abdominal wall nodule biopsy.Conclusion. Primary venous leiomyosarcoma of the iliac vein is a rare cause of deep vein thrombosis, which must be considered in young patients with recurrent or refractory to treatment deep vein thrombosis.
Smart Integrated Sensor for Multiple Detections of Glucose and L-Lactate Using On-Chip Electrochemical System
Authors: Yamazaki Tomoyuki , Ikeda Takaaki , Lim Byounghyun , Okumura Koichi , Ishida Makoto , Sawada Kazuaki
Published: June 2011

Multiple sensor electrodes, a supplementary electrode, a reference electrode, and signal-processing circuits were integrated on a single chip to develop a chip-shaped electrochemical sensing system. L-lactate and glucose were measured using on-chip working electrodes modified by polyion complex to immobilize lactate oxidase and glucose oxidase, respectively. Cyclic voltammetry measurements were conducted using an on-chip potentiostat. Selective and quantitative detection of glucose and L-lactate and the interference behavior were studied. Hydrogen peroxide generated by enzymatic reactions was detected by an increase in anodic oxidation current. Reaction currents at +0.7 V versus Ag/AgCl were used to obtain calibration plots. The measured dynamic ranges for L-lactate and glucose were 0.2–1.0 mM and 2.0–8.0 mM, respectively. The sensitivities were 65 nA/mM and 15 nA/mM, respectively, using a working electrode of 0.5 mm2. The 3σdetection limit was 0.19 mM and 1.1 mM, respectively. We have achieved multiple biomaterial detections on a circuit-equipped single chip. This integrated electrochemical sensor chip could be the best candidate for realizing point-of-care testing due to its portability and potential for mass production.