bluuebunny/crossref_metadata_2025 huggingface dataset:
Is it necessary to penalize impulsive noise +5 dB due to higher risk of hearing damage?
Authors: Aranda de Toro Miguel Angel , Ordoñez Rodrigo , Reuter Karen , Hammershøi Dorte
Published: June 2011

It is studied whether the +5 dB penalty for impulsiveness established by ISO 1999:1990 accounts for a higher risk of noise-induced hearing loss. A total of 16 normal-hearing human subjects were exposed for 10 min to two types of binaural industrial-recordings: (1) a continuous broad-band noise normalized to LEX,8 h = 80 dBA and (2) the combination of the previous stimulus with an impulsive noise normalized to LEX,8 h = 75 + 5db penalty = 80 dBA (peak level 117 dBC and repetition rate of 0.5 impacts per second). Distortion product otoacoustic emissions (DPOAEs) were measured in a broad frequency range before and in the following 90 min after the exposure. The group results show that the continuous exposure had a bigger impact on DPOAE levels, with a maximum DPOAE shift of approximately 5 dB in the frequency range of 2–3.15 kHz during the first 10 min of the recovery. No evident DPOAE shift is seen for the impulsive + continuous stimulus. The results indicate that the penalty overestimated the effects on DPOAE levels and support the concept that the risk of hearing loss from low-level impulses may be predicted on an equal-energy basis.
The just audible tonality of short exponential and Gaussian pure tone bursts
Authors: Mohlin Peter
Published: June 2011

This paper reports on listening tests performed to investigate the just audible tonality (JAT) of decaying pure tone bursts. Both exponential and Gaussian functions are used to shape the envelopes of the tone bursts and critical band center frequencies between 150 and 7000 Hz are studied. Loudness compensation is implemented to compensate for the reduced loudness of short tone bursts and attack functions are used for minimizing clicks. By using the method of limits, a sequence of tone bursts with increasing decay times and constant frequencies is presented to the listeners at 0.9 s intervals. The first burst in the sequence which is perceived as being tonal is indicated by the listeners. When that happens, the decay times of the tone bursts decrease and the listeners are asked to select the first tone burst with no audible tonality. The listeners are allowed to freely define tonality. No reference is given. For frequencies above 3.4 kHz, the results indicate that tonality is just audible for tone burst lengths of approximately 2.6–3.0 ms. For the lowest stimuli frequencies, the corresponding burst length is approximately 20–23 ms.
Eddy-current non-inertial displacement sensing for underwater infrasound measurements
Authors: Donskoy Dimitri M. , Cray Benjamin A.
Published: June 2011

A non-inertial sensing approach for an Acoustic Vector Sensor (AVS), which utilizes eddy-current displacement sensors and operates well at Ultra-Low Frequencies (ULF), is described here. In the past, most ULF measurements (from mHertz to approximately 10 Hertz) have been conducted using heavy geophones or seismometers that must be installed on the seafloor; these sensors are not suitable for water column measurements. Currently, there are no readily available compact and affordable underwater AVS that operate within this frequency region. Test results have confirmed the validity of the proposed eddy-current AVS design and have demonstrated high acoustic sensitivity.
Masked auditory thresholds in three species of birds, as measured by the auditory brainstem response (L)
Authors: Noirot Isabelle C. , Brittan-Powell Elizabeth F. , Dooling Robert J.
Published: June 2011

Auditory brainstem responses (ABRs) were recorded in adult budgerigars, canaries, and zebra finches in quiet and in three levels of white noise for tone stimuli between 1 and 4 kHz. Similar to behavioral results, masked ABR thresholds increased linearly with increasing noise levels. When the three species are considered together, ABR-derived CRs were higher than behavioral CRs by 18–23 dB between 2 and 4 kHz and by about 30 dB at 1 kHz. This study clarifies the utility of using ABRs for estimating masked auditory thresholds in natural environmental noises in species that cannot be tested behaviorally.
Wind noise at microphones within and across hearing aids at wind speeds below and above microphone saturation
Authors: Zakis Justin A.
Published: June 2011

The variation of wind noise at hearing-aid microphones with wind speed, wind azimuth, and hearing-aid style was investigated. Comparisons were made across behind-the-ear (BTE) and completely-in-canal (CIC) devices, and between microphones within BTE devices. One CIC device and two BTE devices were placed on a Knowles Electronics Manikin for Acoustic Research. The smaller BTE device had vented plastic windshields around its microphone ports while the larger BTE device had none. The microphone output signals were digitally recorded in wind generated at 0, 3, 6, and 12 m/s at 8 wind azimuths. The microphone output signals were saturated at 12 m/s with wind-noise levels of up to 116 dB SPL at the microphone output. Wind-noise levels differed by up to 12 dB between microphones within the same BTE device, and across BTE devices by up to 6 or 8 dB for front or rear microphones, respectively. On average, wind-noise levels were lowest with the CIC device and highest at the rear microphone of the smaller BTE device. Engineering and clinical implications are discussed.
Scattering of obliquely incident shear waves from a cylindrical cavity
Authors: Aldrin John C. , Blodgett Mark P. , Lindgren Eric A. , Steffes Gary J. , Knopp Jeremy S.
Published: June 2011

Prior work has proposed the use of ultrasonic angle-beam shear wave techniques to detect cracks of varying angular location around fastener sites by generating and detecting creeping waves. To better understand the nature of the scattering problem and quantify the role of creeping waves in fastener site inspections, a 3D analytical model was developed for the propagation and scattering of an obliquely incident plane shear wave from a cylindrical cavity with arbitrary shear wave polarization. The generation and decay of the spiral creeping waves was found to be dependent on both the angle of incidence and polarization of the plane shear wave. A difference between the angle of displacement in 3D and the direction of propagation for the spiral creeping wave was observed and attributed to differences in the curvature of the cavity surface for the tangential and vertical (z) directions. Using the model, practical insight was presented on measuring the displacement response in the far-field from the hole. Both analytical and experimental results highlighted the value of the diffracted and leaky spiral creeping wave signals for nondestructive evaluation of a crack located on the cavity. Last, array and signal processing methods are discussed to improve the resolution of the weaker creeping wave signals in the presence of noise.
Memory for the locations of environmental sounds
Authors: Martin Russell L. , Flanagan Patrick , McAnally Ken I. , Eberle Geoff
Published: June 2011

The accuracy with which a single source of sound can be localized has been examined in many studies, but very few studies have examined the ability of participants to determine the absolute locations of multiple sources of sound. The current study assessed participants’ abilities to determine and remember the locations of up to six sources of environmental sound that were positioned at a range of azimuths and elevations in virtual auditory space. In experiment 1, a sequence of one to six sounds was presented one, three, or five times in each trial and the target sound was nominated following presentation of the last sequence. In experiment 2, memory load was held constant by nominating the target sound prior to a single sequence presentation. Localization accuracy was observed to decrease as the number of sounds was increased to three or more under the conditions of experiment 1, but not those of experiment 2. In experiment 1, localization was more accurate when sequences were presented more than once. Pronounced primacy and recency effects were observed for the six sound conditions in experiment 1. An analysis of errors for those conditions indicated that immediate temporal errors, but not immediate spatial errors, were over-represented.
O-Glycosylated Cell Wall Proteins Are Essential in Root Hair Growth
Authors: Velasquez Silvia M. , Ricardi Martiniano M. , Dorosz Javier Gloazzo , Fernandez Paula V. , Nadra Alejandro D. , Pol-Fachin Laercio , Egelund Jack , Gille Sascha , Harholt Jesper , Ciancia Marina , Verli Hugo , Pauly Markus , Bacic Antony , Olsen Carl Erik , Ulvskov Peter , Petersen Bent Larsen , Somerville Chris , Iusem Norberto D. , Estevez Jose M.
Published: June 2011

Sequential protein posttranslational modifications facilitate cell wall self-assembly and root hair elongation in
Arabidopsis
.
An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy
Authors: Levan A. J. , Tanvir N. R. , Cenko S. B. , Perley D. A. , Wiersema K. , Bloom J. S. , Fruchter A. S. , Postigo A. de Ugarte , O’Brien P. T. , Butler N. , van der Horst A. J. , Leloudas G. , Morgan A. N. , Misra K. , Bower G. C. , Farihi J. , Tunnicliffe R. L. , Modjaz M. , Silverman J. M. , Hjorth J. , Thöne C. , Cucchiara A. , Cerón J. M. Castro , Castro-Tirado A. J. , Arnold J. A. , Bremer M. , Brodie J. P. , Carroll T. , Cooper M. C. , Curran P. A. , Cutri R. M. , Ehle J. , Forbes D. , Fynbo J. , Gorosabel J. , Graham J. , Hoffman D. I. , Guziy S. , Jakobsson P. , Kamble A. , Kerr T. , Kasliwal M. M. , Kouveliotou C. , Kocevski D. , Law N. M. , Nugent P. E. , Ofek E. O. , Poznanski D. , Quimby R. M. , Rol E. , Romanowsky A. J. , Sánchez-Ramírez R. , Schulze S. , Singh N. , van Spaandonk L. , Starling R. L. C. , Strom R. G. , Tello J. C. , Vaduvescu O. , Wheatley P. J. , Wijers R. A. M. J. , Winters J. M. , Xu D.
Published: June 2011

A recent bright emission observed by the Swift satellite is due to the sudden accretion of a star onto a massive black hole.
Danish Sperm Counts Spark Data Dispute
Authors: Vogel Gretchen
Published: June 2011

A scientific scuffle over the sperm counts of Danish men has highlighted a tricky question: To whom do data belong?
Toxin-Antitoxin Systems Influence Biofilm and Persister Cell Formation and the General Stress Response
Authors: Wang Xiaoxue , Wood Thomas K.
Published: June 2011

In many genomes, toxin-antitoxin (TA) systems have been identified; however, their role in cell physiology has been unclear. Here we examine the evidence that TA systems are involved in biofilm formation and persister cell formation and that these systems may be important regulators of the switch from the planktonic to the biofilm lifestyle as a stress response by their control of secondary messenger 3′,5′-cyclic diguanylic acid. Specifically, upon stress, the sequence-specific mRNA interferases MqsR and MazF mediate cell survival. In addition, we propose that TA systems are not redundant, as they may have developed to respond to specific stresses.
Hepatitis C Virus Infection Causes Cell Cycle Arrest at the Level of Initiation of Mitosis
Authors: Kannan Rathi P. , Hensley Lucinda L. , Evers Lauren E. , Lemon Stanley M. , McGivern David R.
Published: June 2011

Chronic infection with the hepatitis C virus (HCV) is associated with increased risk for hepatocellular carcinoma (HCC). Chronic immune-mediated inflammation is likely to be an important factor in the development of HCV-associated HCC, but direct effects of HCV infection on the host cell cycle may also play a role. Although overexpression studies have revealed multiple interactions between HCV-encoded proteins and host cell cycle regulators and tumor suppressor proteins, the relevance of these observations to HCV-associated liver disease is not clear. We determined the net effect of these interactions on regulation of the cell cycle in the context of virus infection. Flow cytometry of HCV-infected carboxyfluorescein succinimidyl ester-labeled hepatoma cells indicated a slowdown in proliferation that correlated with abundance of viral antigen. A decrease in the proportions of infected cells in G
1
and S phases with an accumulation of cells in G
2
/M phase was observed, compared to mock-infected controls. Dramatic decreases in markers of mitosis, such as phospho-histone H3, in infected cells suggested a block to mitotic entry. In common with findings described in the published literature, we observed caspase 3 activation, suggesting that cell cycle arrest is associated with apoptosis. Differences were observed in patterns of cell cycle disturbance and levels of apoptosis with different strains of HCV. However, the data suggest that cell cycle arrest at the interface of G
2
and mitosis is a common feature of HCV infection.
Expression and Functional Characterization of the RIG-I-Like Receptors MDA5 and LGP2 in Rainbow Trout (Oncorhynchus mykiss)
Authors: Chang Mingxian , Collet Bertrand , Nie Pin , Lester Katherine , Campbell Scott , Secombes Christopher J. , Zou Jun
Published: June 2011

The retinoic acid-inducible gene I (RIG-I)-like receptors (RLR) comprise three homologues: RIG-I, melanoma differentiation-associated gene 5 (MDA5), and laboratory of genetics and physiology 2 (LGP2). They activate the host interferon (IFN) system upon recognition of viral RNA pathogen-associated molecular patterns (PAMPs) in the cytoplasm. Bioinformatic analysis of the sequenced vertebrate genomes suggests that the cytosolic surveillance system is conserved in lower vertebrates, and recent functional studies have confirmed that RIG-I is important to fish antiviral immunity. In this study, we have identified MDA5 and LGP2 homologues from rainbow trout
Oncorhynchus mykiss
and an additional LGP2 variant with an incomplete C-terminal domain of RIG-I. Trout MDA5 and LGP2 were constitutively produced in fibroblast and macrophage cell lines and upregulated by poly(I:C), recombinant IFN, or infection by RNA viruses (viral hemorrhagic septicemia virus and salmon alphavirus) with a single-stranded positive or negative genome. Overexpression of MDA5 and LGP2 but not of the LGP2 variant resulted in significant accumulation of Mx transcripts in cultured cells, which correlated with a marked enhancement of protection against viral infection. These results demonstrate that both MDA5 and LGP2 are important RLRs in host surveillance against infection of both negative and positive viruses and that the LGP2 variant with a deletion of 54 amino acids at the C terminus acts as a negative regulator for LGP2-elicited antiviral signaling by competing for the viral RNA PAMPs. Interestingly, MDA5 expression was not affected by overexpressed LGP2 in transfected cells and vice versa, suggesting that they likely act in parallel as positive regulators for IFN production.
Inhibition of p53 by Adenovirus Type 12 E1B-55K Deregulates Cell Cycle Control and Sensitizes Tumor Cells to Genotoxic Agents
Authors: Li Qiang , Zhao Lisa Y. , Zheng Zhi , Yang Heng , Santiago Aleixo , Liao Daiqing
Published: June 2011

Adenovirus E1B-55K represses p53-mediated transcription. However, the phenotypic consequence of p53 inhibition by E1B-55K for cell cycle regulation and drug sensitivity in tumor cells has not been examined. In HCT116 cells with constitutive E1B-55K expression, the activation of p53 target genes such as the p21, Mdm2, and Puma genes was attenuated, despite markedly elevated p53 protein levels. HCT116 cells with E1B-55K expression displayed a cell cycle profile similar to that of the isogenic HCT116p53
−/−
cells, including unhindered S-phase entry despite DNA damage. Surprisingly, E1B-55K-expressing cells were more sensitive to drug treatment than parental cells. Compared to HCT116 cells, HCT116p53
−/−
cells were more susceptible to both doxorubicin and etoposide, and E1B-55K expression had no effects on drug treatment. E1B-55K expression increased the rate of cell proliferation in HCT116 but not in HCT116p53
−/−
cells. Thus, deregulation of p53-mediated cell cycle control by E1B-55K probably underlies sensitization of HCT116 cells to anticancer drugs. Consistently, E1B-55K expression in A549, A172, and HepG2 cells, all containing wild-type (wt) p53, also enhanced etoposide-induced cytotoxicity, whereas in p53-null H1299 cells, E1B-55K had no effects. We generated several E1B-55K mutants with mutations at positions occupied by the conserved Phe/Trp/His residues. Most of these mutants showed no or reduced binding to p53, although some of them could still stabilize p53, suggesting that binding might not be essential for E1B-55K-induced p53 stabilization. Despite heightened p53 protein levels in cells expressing certain E1B-55K mutants, p53 activity was largely suppressed. Furthermore, most of these E1B-55K mutants could sensitize HCT116 cells to etoposide and doxorubicin. These results indicate that E1B-55K might have utility for enhancing chemotherapy.
The Viral Nucleoprotein Determines Mx Sensitivity of Influenza A Viruses
Authors: Zimmermann Petra , Mänz Benjamin , Haller Otto , Schwemmle Martin , Kochs Georg
Published: June 2011

Host restriction factors play a crucial role in preventing trans-species transmission of viral pathogens. In mammals, the interferon-induced Mx GTPases are powerful antiviral proteins restricting orthomyxoviruses. Hence, the human MxA GTPase may function as an efficient barrier against zoonotic introduction of influenza A viruses into the human population. Successful viruses are likely to acquire adaptive mutations allowing them to evade MxA restriction. We compared the 2009 pandemic influenza A virus [strain A/Hamburg/4/09 (pH1N1)] with a highly pathogenic avian H5N1 isolate [strain A/Thailand/1(KAN-1)/04] for their relative sensitivities to human MxA and murine Mx1. The H5N1 virus was highly sensitive to both Mx GTPases, whereas the pandemic H1N1 virus was almost insensitive. Substitutions of the viral polymerase subunits or the nucleoprotein (NP) in a polymerase reconstitution assay demonstrated that NP was the main determinant of Mx sensitivity. The NP of H5N1 conferred Mx sensitivity to the pandemic H1N1 polymerase, whereas the NP of pandemic H1N1 rendered the H5N1 polymerase insensitive. Reassortant viruses which expressed the NP of H5N1 in a pH1N1 genetic background and vice versa were generated. Congenic Mx1-positive mice survived intranasal infection with these reassortants if the challenge virus contained the avian NP. In contrast, they succumbed to infection if the NP of pH1N1 origin was present. These findings clearly indicate that the origin of NP determines Mx sensitivity and that human influenza viruses acquired adaptive mutations to evade MxA restriction. This also explains our previous observations that human and avian influenza A viruses differ in their sensitivities to Mx.
Charged Residues in Hepatitis C Virus NS4B Are Critical for Multiple NS4B Functions in RNA Replication
Authors: Blight Keril J.
Published: June 2011

The nonstructural 4B (NS4B) protein of hepatitis C virus (HCV) plays a central role in the formation of the HCV replication complex. To gain insight into the role of charged residues for NS4B function in HCV RNA replication, alanine substitutions were engineered in place of 28 charged residues residing in the N- and C-terminal cytoplasmic domains of the NS4B protein of the HCV genotype 1b strain Con1. Eleven single charged-to-alanine mutants were not viable, while the remaining mutants were replication competent, albeit to differing degrees. By selecting revertants, second-site mutations were identified for one of the lethal NS4B mutations. Second-site mutations mapped to NS4B and partially suppressed the lethal replication phenotype. Further analyses showed that three NS4B mutations disrupted the formation of putative replication complexes, one mutation altered the stability of the NS4B protein, and cleavage at the NS4B/5A junction was significantly delayed by another mutation. Individual charged-to-alanine mutations did not affect interactions between the NS4B and NS3-4A proteins. A triple charged-to-alanine mutation produced a temperature-sensitive replication phenotype with no detectable RNA replication at 39°C, demonstrating that conditional mutations can be obtained by altering the charge characteristics of NS4B. Finally, NS4B mutations dispensable for efficient Con1 RNA replication were tested in the context of the chimeric genotype 2a virus, but significant defects in infectious-virus production were not detected. Taken together, these findings highlight the importance of charged residues for multiple NS4B functions in HCV RNA replication, including the formation of a functional replication complex.
Funnel plots for comparing provider performance based on patient-reported outcome measures
Authors: Neuburger Jenny , Cromwell David A , Hutchings Andrew , Black Nick , van der Meulen Jan H
Published: June 2011

Background

Patient-reported outcome measures (PROMs) often produce skewed distributions of individual scores after a healthcare intervention. For health performance indicators derived from skewed distributions, funnel plots designed with symmetric control limits may increase the risk of false alarms about poor performance.

Aim

To investigate the accuracy of funnel plots with symmetric control limits when comparing provider performance based on PROMs.

Methods

The authors used a database containing condition-specific PROMs for 17 453 hip replacements and 7656 varicose vein procedures performed by providers in the English NHS. The mean postoperative PROM score, adjusted for patient characteristics, was used as the measure of performance. To compare performance, symmetric 99.8% control limits were calculated on funnel plots, 3 SDs away from the overall mean on either side. These were compared to control limits derived directly from percentiles of simulated (bootstrap) distributions of mean scores.

Results

The simulated control limits on funnel plots for both procedures were asymmetric. The empirical probability of falling outside the symmetric 99.8% ‘poor performance’ control limit was inflated from the stipulated rate of 0.1% to 0.2–0.3% for provider sample sizes of up to 150 procedures. The authors observed that, out of 237 providers of hip replacement, eight had adjusted mean scores that exceeded the symmetric ‘poor performance’ limit compared with only five that exceeded the corresponding simulated limit. In other words, three (1.3%) were differently classified. For varicose vein surgery, five out of 160 providers exceeded the symmetric limit and four exceeded the simulated limit, that is, 1 (0.6%) was differently classified.

Conclusions

When designing funnel plots for comparisons of provider performance based on highly skewed data, the use of simulated control limits should be considered.
Bringing out the best in people
Authors: Aylott Anne‐Marie Svendsen
Published: June 2011

Whether it is within the practice or within your home and personal relationships, bringing out the best in the people around you is one way to help your business, family and friends grow into happier and healthier places and individuals. To do this, you first have to truly and firmly believe that there is a ‘best’ in other people, or at the very least that they can do ‘better’. This article describes how to assess your own attitudes and beliefs, which can then be used to encourage others to improve their performance and achieve greater things.
Recurrent diarrhoea in cats
Authors: Cooper Sarah
Published: June 2011

Recurrent diarrhoea is a common presentation in both first‐opinion and referral practice. Diarrhoea can be defined as acute, chronic (lasting two or more weeks) or recurrent (where the problem is episodic with normal periods in between). Recurrent and chronic diarrhoea can be distressing and frustrating for cat, owner and veterinary surgeon alike. This article describes a logical approach to the diagnosis and treatment of recurrent diarrhoea in cats.
Getting the best results from veterinary histopathology
Authors: Stidworthy Mark , Priestnall Simon
Published: June 2011

The use of histopathology in the clinical work‐up of a case can often provide valuable information to help practitioners ascertain a specific diagnosis or guide the approach to treatment. Successful histopathology relies on appropriate clinical sampling and tissue preparation for laboratory submission, as well as good communication between the clinician and the pathologist. This article outlines the key concepts and practical steps underlying the production of a histology slide from a tissue specimen, and explains the role of the veterinary pathologist in providing a report based on evidence derived from examination of that slide, an understanding of which should improve practitioners' confidence in the results of histopathology.
Integrated working
Authors: Donaldson L. J. , Reynolds D. J.
Published: June 2011

In a joint article, the UK ’s Chief Medical Officer, Sir Liam Donaldson, and the Chief Veterinary Officer, Dr Debby Reynolds, discuss strategic collaboration between the medical and veterinary professions at government level
Veterinarians and food safety
Authors: Clarke K. A.
Published: June 2011

Since the early days of veterinary science, vets have played an important part in protecting public health through controls over the safety of food of animal origin. Traditionally, public health has been treated as a topic separate from the mainstream veterinary subjects of diagnosis and treatment of animal disease. However, there is now increasing awareness of the interconnection between animal and human health, and between the work of vets in production animal practice and those in food safety and other disciplines, as Kenneth Clarke explains
HOMOTOPY RELATIONS FOR TOPOLOGICAL VOA
Authors: ZEITLIN ANTON M.
Published: June 2011

We consider a parameter-dependent version of the homotopy associative part of the Lian–Zuckerman homotopy algebra and provide an interpretation of the multilinear operations of this algebra in terms of integrals over certain polytopes. We explicitly prove the pentagon relation up to homotopy and propose a construction of the higher operations.
A NEW FUZZY MULTI CRITERIA DECISION MAKING MODEL FOR OPEN PIT MINES EQUIPMENT SELECTION
Authors: AGHAJANI BAZZAZI ABBAS , OSANLOO MORTEZA , KARIMI BEHROOZ
Published: June 2011

Nowadays, the capital cost of open-pit mining equipment is very high so any mistake in the selection of quantity, type and capacity of equipment may cause irreparable impact on the net present value of mining project. Mine planning engineers generally use their intuition and experience in decision making even though equipment selection is a complex multi criteria decision problem. Considering the tangible along with intangible factors in the mine equipment selection problem, this paper proposes a new method of multi criteria decision making (MCDM) that makes it possible to select the optimal equipment that satisfies the decision maker. In a real-world situation, because of incomplete or non-obtainable information, the data (attributes) are often not deterministic but they are usually fuzzy-imprecise. Our proposed model considers objective, critical, and subjective factors as the three main common factors in equipment selection analysis. The last two factors, critical and subjective factors, are defined by decision maker's judgments for more adoption with real world problems. A case study is presented to illustrate the use of the proposed model and to demonstrate the capability of the model. The result of this study shows significant reduction of time consumption of calculation and good precision compared to customary methods such as Chang's fuzzy AHP method.
MICROSCOPIC NEUTRON OPTICAL POTENTIAL IN THE ENERGY REGION 65–225 MeV
Authors: RAFI SYED , HAIDER W.
Published: June 2011

In the present work, we report a microscopic optical potential analysis of the extensive neutron elastic scattering data from 12 C , 40 Ca and 208 Pb in the 65–225 MeV energy region. Brueckner–Hartree–Fock method has been used to calculate the optical potential, where one requires internucleon potential to calculate reaction matrices which are then folded over the nucleon densities in the target nuclei. We report the predictions of the calculated potential using Argonne v-18 and Urbana v-14 local nucleon–nucleon potentials. The modern potential v-18 has been used for the first time to calculate the nucleon–nucleus optical potential. We also compare our predictions with the empirical potentials. The results indicate that the predictions of our microscopic potential are in better agreement with the experimental data as compared with the empirical global optical potentials.
EXPLOITING DELAYED NONLINEAR FEEDBACK FOR SENSING BASED ON BIFURCATION MORPHING
Authors: LIM JOOSUP , EPUREANU BOGDAN I.
Published: June 2011

Bifurcation morphing created by means of nonlinear feedback excitation is a vibration-based method for sensing. In this work, several new studies are presented to connect previously demonstrated theory to increasingly more practical applications. In particular, in the process of designing nonlinear feedback auxiliary signals, time delays in the circuitry are unavoidable. Advantages as well as possible side effects and disadvantages of time delays are discussed. Furthermore, additional time delay is considered as a new design parameter. Increasing the time delay has advantages such as enhanced robustness and sensitivity, which are demonstrated computationally. Moreover, calibration using multiple sensor locations is discussed. A clamped-free cantilever beam structure is modeled and used for computational validation. The beam model resembles cantilever-based resonant sensor systems. Thus, potential applications of the new algorithm are discussed and the results stress the importance of nonlinear features for enhancing sensing performance in mechanical sensors without structural modifications.
DYNAMICS OF SHALLOW CABLES UNDER TURBULENT WIND: A NONLINEAR FINITE ELEMENT APPROACH
Authors: IMPOLLONIA NICOLA , RICCIARDI GIUSEPPE , SAITTA FERNANDO
Published: June 2011

In classic cable theory, vibrations are usually analyzed by writing the equations of motion in the neighborhood of the initial equilibrium configuration. Furthermore, a fundamental difference exists between out-of-plane motions, which basically corresponds to the linear behavior of a taut string and in-plane motion, where self-weight determines a sagged initial profile. This work makes use of a continuous approach to establish the initial shape of the cable when it is subjected to wind or fluid flow arbitrarily directed and employed a novel nonlinear finite element technique in order to investigate the dynamics present around the initial equilibrium shape of the cable. Stochastic solutions in the frequency domain are derived for a wind-exposed cable after linearization of the problem. By applying the proper orthogonal decomposition (POD) technique with the aim of reducing computational effort, an approach to simulate modal wind forces is proposed and applied to the nonlinear equations of motion.
The synthesis and characterization of a side-by-side iron phthalocyanine dimer
Authors: He Wei , Lieberman Marya
Published: June 2011

The QCA paradigm is one of the approaches to decrease the size scale of computing devices. When molecules are used as QCA cells, they may be able to perform computing at room temperature. This paper describes a novel molecular QCA cell candidate which is a side-by-side iron phthalocyanine dimer, and an investigation of its optical and redox properties. The new dodeca(pentyloxy) substituted side-by-side iron phthalocyanine dimer, along with the octa(pentyloxy) iron phthalocyanine monomer, are soluble in non-polar organic solvents. These compounds were isolated by gel permeation chromatography (GPC) and high-performance liquid chromatography (HPLC) to final purities of 98% and 99%, respectively. The NMR spectra of both compounds in CDCl3 are broad due to aggregation, but become well resolved after the addition of the coordinating solvent pyridine-d5. Addition of pyridine also gives changes in the UV-vis spectra and electrochemical peaks of both monomer and dimer in dichloromethane indicative of axial iron coordination. The electrochemical data indicates the loss of pyridine ligands from the oxidized products of both monomer and dimer. The comproportionation constant of side-by-side phthalocyanine dimer shows that its oxidized and reduced mixed-valence complexes are fairly stable. The dimer is thus a candidate for molecular QCA systems.
Tumor Vessel Development and Expansion in Ewing's Sarcoma: A Review of the Vasculogenesis Process and Clinical Trials with Vascular-Targeting Agents
Authors: Stewart Keri S. , Kleinerman Eugenie S.
Published: June 2011

Ewing's sarcoma accounts for a disproportionately high portion of the overall pediatric mortality rate compared to its rare incidence in the pediatric population. Little progress has been made since the introduction of traditional chemotherapies, and understanding the biology of the tumor is critical for developing new therapies. Ewing's sarcomas rely on a functional vascular supply, which is formed by a combination of angiogenesis and vasculogenesis. Recent insights into the molecular regulation of bone marrow (BM) cell participation in vascular development have identified VEGF, SDF-1α, and DLL4 as critical players in the vasculogenesis process. Clinical trials using vascular targeting agents, specifically targeting VEGF or DLL4, are underway.
Lymphadenectomy in Management of Invasive Bladder Cancer
Authors: Youssef Ramy F. , Raj Ganesh V.
Published: June 2011

Radical cystectomy with pelvic lymphadenectomy represents the gold standard for treatment of muscle-invasive bladder cancer. Extent of the lymph node dissection and lymph node involvement during radical cystectomy are the most powerful prognostic factors associated with poor oncological outcome. However, the optimal boundaries of the lymph node dissection during a radical cystectomy are controversial. The published literature based mostly on retrospective studies suggests that increasing the number of nodes excised may have therapeutic and diagnostic benefits without significantly increasing the surgical morbidity. These conclusions are, however, influenced by selection and surgeon biases, inconsistencies in the quality of the surgery, and node count variability. In this paper, we establish the current understanding about the utility of lymphadenectomy during a radical cystectomy for muscle-invasive bladder cancer.
Applications of Propargyl Esters of Amino Acids in Solution-Phase Peptide Synthesis
Authors: Ramapanicker Ramesh , Gupta Rohit , Megha Rajendran , Chandrasekaran Srinivasan
Published: June 2011

Propargyl esters are employed as effective protecting groups for the carboxyl group during solution-phase peptide synthesis. The propargyl ester groups can be introduced onto free amino acids by treating them with propargyl alcohol saturated with HCl. The reaction between propargyl groups and tetrathiomolybdate is exploited to deblock the propargyl esters. The removal of the propargyl group with the neutral reagent tetrathiomolybdate ensures that most of the other protecting groups used in peptide synthesis are untouched. Both acid labile and base labile protecting groups can be removed in the presence of a propargyl ester. Amino acids protected as propargyl esters are employed to synthesize di- to tetrapeptides in solution-phase demonstrating the possible synthetic utilities of the methodology. The methodology described here could be a valuable addition to currently available strategies for peptide synthesis.
On Decays ofZ′into Unparticle Stuff
Authors: Kozlov G. A. , Gorbunov I. N.
Published: June 2011

We study the decay of aZ′-boson intoU-unparticle and a photon. The extended Landau-Yang theorem is used. The clear photon signal would make the decayZ′→γUas an additional contribution mode for study of unparticle physics.
Protective Effects of Prepubertal Genistein Exposure on Mammary Tumorigenesis Are Dependent on BRCA1 Expression
Authors: de Assis Sonia , Warri Anni , Benitez Carlos , Helferich William , Hilakivi-Clarke Leena
Published: June 2011

This study investigated whether prepubertal dietary exposure to genistein reduces mammary tumorigenesis by upregulating Brca1 expression in mice. Heterozygous Brca1+/− mice and their wild-type (WT) littermates were fed control AIN93G diet or 500 ppm genistein–supplemented AIN93G diet from postnatal day (PND) 15 to PND30 and then switched to AIN93G diet. Prepubertal dietary exposure to genistein reduced 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary incidence (P = 0.029) and aggressiveness of the tumors (P < 0.001) in the WT mice and upregulated the expression of Brca1 in their mammary glands (P = 0.04). In contrast, prepubertal genistein diet neither significantly reduced mammary tumorigenesis or tumor aggressivity nor increased Brca1 mRNA expression in the Brca1+/− mice. These results may be related to the opposing effects of prepubertal genistein diet on the expression of Rankl and CK5/CK18 ratio (marker of luminal epithelial cell differentiation) in the mammary gland and estrogen receptor (ER-α) and progesterone receptor (PgR) protein levels in the mammary tumor: these all were reduced in the WT mice or increased in Brca1+/− mice. Both the WT and Brca1+/− mice exhibited reduced levels of amphiregulin, CK5, and CK18, delayed ductal elongation and a reduction in terminal end bud number in the normal mammary gland, and reduced HER-2 protein levels in the mammary tumors; however, these effects were not sufficient to significantly reduce mammary tumorigenesis in Brca1+/− mice. Our results show that upregulation of Brca1 may be required for prepubertal dietary genistein exposure to reduce later mammary tumorigenesis, perhaps because in the absence of this upregulation, mice do not exhibit genistein-induced downregulation of ER-α, PgR, and Rankl. Cancer Prev Res; 4(9); 1436–48. ©2011 AACR.
Plasma Leptin Levels and Risk of Breast Cancer in Premenopausal Women
Authors: Harris Holly R. , Tworoger Shelley S. , Hankinson Susan E. , Rosner Bernard A. , Michels Karin B.
Published: June 2011

Body mass index (BMI) is inversely related to the risk of premenopausal breast cancer, but the underlying biological mechanisms of this association are poorly understood. Leptin, a peptide hormone produced primarily by adipocytes, is a potential mediator of the BMI association because BMI and total body fat are positively associated with circulating leptin levels and leptin and its receptor are overexpressed in breast tumors. We conducted a prospective case–control study nested within the Nurses' Health Study II cohort examining the association between plasma leptin levels in premenopausal women and breast cancer risk. Leptin was measured in blood samples collected between 1996 and 1999. The analysis included 330 incident breast cancer cases diagnosed after blood collection and 636 matched controls. Logistic regression models, controlling for breast cancer risk factors, were used to calculate ORs and 95% CIs. After adjustment for BMI at age 18, weight change since age 18 to blood draw, and other breast cancer risk factors, plasma leptin levels were inversely associated with breast cancer risk (OR for top vs. bottom quartile = 0.55; 95% CI = 0.31–0.99; Ptrend = 0.04). Adjustment for BMI at blood draw attenuated the association (OR = 0.69; 95% CI = 0.38–1.23; Ptrend = 0.26). Our results suggest that leptin may be inversely associated with breast cancer risk, but it is unclear whether any part of this association is independent of BMI. Cancer Prev Res; 4(9); 1449–56. ©2011 AACR.
17β-Estradiol and Tamoxifen Prevent Gastric Cancer by Modulating Leukocyte Recruitment and Oncogenic Pathways in Helicobacter Pylori–Infected INS-GAS Male Mice
Authors: Sheh Alexander , Ge Zhongming , Parry Nicola M.A. , Muthupalani Sureshkumar , Rager Julia E. , Raczynski Arkadiusz R. , Mobley Melissa W. , McCabe Amanda F. , Fry Rebecca C. , Wang Timothy C. , Fox James G.
Published: June 2011

Helicobacter pylori infection promotes male predominant gastric adenocarcinoma in humans. Estrogens reduce gastric cancer risk and previous studies showed that prophylactic 17β-estradiol (E2) in INS-GAS mice decreases H. pylori–induced carcinogenesis. We examined the effect of E2 and tamoxifen (TAM) on H. pylori–induced gastric cancer in male and female INS-GAS mice. After confirming robust gastric pathology at 16 weeks postinfection (WPI), mice were implanted with E2, TAM, both E2 and TAM, or placebo pellets for 12 weeks. At 28 WPI, gastric histopathology, gene expression, and immune cell infiltration were evaluated and serum inflammatory cytokines measured. After treatment, no gastric cancer was observed in H. pylori–infected males receiving E2 and/or TAM, whereas 40% of infected untreated males developed gastric cancer. E2, TAM, and their combination significantly reduced gastric precancerous lesions in infected males compared with infected untreated males (P < 0.001, 0.01, and 0.01, respectively). However, TAM did not alter female pathology regardless of infection status. Differentially expressed genes from males treated with E2 or TAM (n = 363 and n = 144, Q < 0.05) associated highly with cancer and cellular movement, indicating overlapping pathways in the reduction of gastric lesions. E2 or TAM deregulated genes associated with metastasis (PLAUR and MMP10) and Wnt inhibition (FZD6 and SFRP2). Compared with controls, E2 decreased gastric mRNA (Q < 0.05) and serum levels (P < 0.05) of CXCL1, a neutrophil chemokine, leading to decreased neutrophil infiltration (P < 0.01). Prevention of H. pylori–induced gastric cancer by E2 and TAM may be mediated by estrogen signaling and is associated with decreased CXCL1, decreased neutrophil counts, and downregulation of oncogenic pathways. Cancer Prev Res; 4(9); 1426–35. ©2011 AACR.
Cholesterol transfer from normal and atherogenic low density lipoproteins to Mycoplasma membranes.
Authors: Mitschelen J J , St Clair R W , Hester S H
Published: June 2011

The purpose of this study was to determine whether the free cholesterol of hypercholesterolemic low density lipoprotein from cholesterol-fed nonhuman primates has a greater potential for surface transfer to cell membranes than does the free cholesterol of normal low density lipoprotein. The low density lipoproteins were isolated from normal and hypercholesterolemic rhesus and cynomolgus monkeys, incubated with membranes from Acholeplasma laidlawii, a mycoplasma species devoid of cholesterol in its membranes, and the mass transfer of free cholesterol determined by measuring membrane cholesterol content. Since these membranes neither synthesize nor esterify cholesterol, nor degrade the protein or cholesterol ester moieties of low density lipoprotein, they are an ideal model with which to study differences in the cholesterol transfer potential of low density lipoprotein independent of the uptake of the intact low density lipoprotein particle. When added at an equivalent particle concentration, there was greater enrichment of membranes with free cholesterol from hypercholesterolemic low density lipoprotein. Hypercholesterolemic low density lipoprotein, however, contains more cholesterol per particle than normal low density lipoprotein; yet calculations on the basis of equivalent free cholesterol content showed no difference in either the rate or extent of free cholesterol transfer from normal or hypercholesterolemic low density lipoprotein. This was true for the transfer of at least 90% of the free cholesterol from both lipoproteins. These studies indicate that, even though there are marked differences in the cholesterol composition of normal and hypercholesterolemic low density lipoproteins, this does not result in a greater chemical potential for surface transfer of free cholesterol. Consequently, if a difference in the surface transfer of free cholesterol is responsible for the enhanced ability of hypercholesterolemic low density lipoprotein to promote cellular cholesterol accumulation and, perhaps, also atherosclerosis, it must be the result of differences in the interaction to the hypercholesterolemic low density lipoprotein with the more complicated mammalian cell membranes, rather than differences in the chemical potential for cholesterol transfer.
Pre-beta high density lipoprotein. Unique disposition of apolipoprotein A-I increases susceptibility to proteolysis.
Authors: Kunitake S T , Chen G C , Kung S F , Schilling J W , Hardman D A , Kane J P
Published: June 2011

Apolipoprotein A-I-containing lipoproteins (high density lipoproteins, HDL) can be separated into two subfractions, which have pre-beta and alpha electrophoretic mobilities, respectively. These fractions differ in both composition and structure. Some preparations of pre-beta-migrating HDL, but not alpha-migrating HDL, were found to contain two polypeptides with Mr of approximately 26 and 14 kDa, which are scission products of apolipoprotein (apo) A-I. They are recognized by monospecific antibodies to apo A-I and have N-terminal sequences identical to those of mature apo A-I. This proteolytic scission of apo A-I occurs primarily after venipuncture. Immediate addition of protease inhibitors minimized the appearance of the fragments in plasma. To study the relative susceptibilities of pre-beta and alpha HDL to proteolysis, the lipoproteins were incubated in vitro with plasmin. The apo A-I in pre-beta HDL was extensively degraded, but that in alpha-migrating HDL was degraded to a much lesser extent, indicating that the appearance of apo A-I fragments in pre-beta HDL was due to enhanced sensitivity to proteolysis. To varying degrees, thrombin, kallikrein, elastase, arginine C endoprotease, and chymotrypsin also appear to cleave pre-beta HDL faster than alpha HDL. Most of the proteases generated a 12 to 14 kDa peptide fragment under conditions of limited cleavage. These results suggest that the conformational state of apo A-I in pre-beta-migrating HDL or its spatial relationship to lipids is significantly different from that of apo A-I in alpha-migrating HDL.(ABSTRACT TRUNCATED AT 250 WORDS)
Apoprotein E biosynthesis in the cholesterol-fed guinea pig.
Authors: Driscoll D M , Mazzone T , Matsushima T , Getz G S
Published: June 2011

Apoprotein E biosynthesis was evaluated in the livers of guinea pigs fed chow, 1% cholesterol plus 5% corn oil, or 1% cholesterol plus 5% coconut oil for a period of 12 weeks. Hypercholesterolemia was induced by both experimental diets, although the coconut-oil diet resulted in higher levels. The ratios of free cholesterol/cholesterol ester and of free cholesterol/total phospholipid increased in the plasma of these animals. Peak lipid levels were mostly achieved by 8 weeks of diet. Both cholesterol and triglyceride were substantially increased in the liver of animals fed the experimental diets, while phospholipid content was unchanged. The amount of apoprotein E mRNA in the guinea pig livers was evaluated by cell free translation assays and by membrane hybridization. The livers of animals fed corn oil with cholesterol for 4 weeks or 8 weeks contained 2 to 2.5 more apoprotein E mRNA compared to the control livers. With the diet containing coconut oil with cholesterol, the hepatic apoprotein E mRNA increased somewhat later, so that by 8 weeks it was 1.7- to 1.9-fold higher than in the control animals. We conclude that high cholesterol diets, when fed as part of a high saturated or polyunsaturated fat diet, lead to increased hepatic apo E mRNA abundance. The relationship between the increased apo E mRNA levels and the previously described increases in apo E synthesis and circulating apo E levels is discussed.