bluuebunny/crossref_metadata_2025 huggingface dataset:
TH‐C‐217BCD‐01: Best in Physics (Imaging) ‐ Evaluation of Apoptosis and Proliferation in Non‐Thermal Pulsed HIFU Treated Mouse Prostate Tumors
Authors: Cvetkovic D , Chen X , Ma C , Chen L
Published: June 2012

Purpose: The underlying mechanism of non‐thermal effects of pulsed high intensity focused ultrasound (pFUS) on normal and tumor tissues is not well understood. Our recent studies showed significant prostate cancer cell killing in vitro and significant prostate tumor growth delay in vivo after pFUS treatment. We hypothesized that these effects of non‐thermal pFUS are due to an increase in cell apoptosis and decrease in cell proliferation. Therefore, the purpose of this study was to analyze the biomarkers of apoptosis and proliferation in prostate tumors after pFUS exposures. Methods: An orthotopic prostate tumor model was established in nude mice. Prostate tumors were sonicated with MR guided pFUS (1MHz, 5W acoustic power, 5Hz frequency; 0.1duty cycle) for 60 sec for each sonication with temperature <42°C (InSightec ExAblate 2000 with a 1.5T GE MR scanner). Untreated tumors were used as controls. The mice were sacrificed at predetermined times up to 7 days following therapy. Tumors were processed for light microscopic examination with H&E staining and immunohistochemical staining for caspase 3 (a marker of apoptosis) and Ki67 (aproliferation marker) expression. Results: Light microscopy revealed the absence of thermal damage and acute destruction of tumor tissues exposed to pFUS. The microvessel walls in the tissues remained intact. There was no change in the extent of hemorrhage upon pFUS treatment over time. The apoptotic index, defined as a percentage of apoptotic cells per total number of cells, peaked at 24 hours after FUS treatment relative to control. There was no dramatic difference in the proliferation indices between different time points. Conclusions: Our results suggested that non‐thermal pulsed pFUS induced caspase 3‐mediated apoptosis and did not produce any thermal damage in the prostate tumor tissues. We are performing additional studies to evaluate blood vessel density and cellular DNA damage upon pFUS treatment.
TH‐D‐BRCD‐02: TG‐51 Addendum ‐ Overview and Implementation
Authors: McEwen M
Published: June 2012

This presentation will describe the new addendum to the AAPM's TG‐51 protocol covering photon beam reference dosimetry, which is in the final stages of review and will be published in 2012. The addendum does not hange either the formalism of TG‐51 or the standard reference conditions (i.e., 10 cm × 10 cm field at 1 m) but provides new chamber‐specific data together with detailed guidance on the relevant factors to take into account when following the TG‐51 protocol. The presentation will review the addendum in some detail with particular focus on: 1) Best practice recommendations to minimize errors and ensure consistent dosimetric reporting, including choice of chamber, experimental procedures, determination of correction factors, and application to FFF linacs.2) An in‐depth discussion of uncertainties with guidance on how the clinical physicist can affect the overall uncertainty in the determination of absorbed dose to water

Learning Objectives:

1. Understand the scope of the TG‐51 addendum or photon beam dosimetry.

2. Understand how the addendum should be implemented to achieve the highest level of accuracy.

3. Understand how to construct an uncertainty budget for the determination of dose at the reference point and how the clinical user can influence the overall value of uncertainty.
TH‐D‐217A‐01: MR Safety Update, 2012: Where Are We, and Where Are We Going?
Authors: Kanal E
Published: June 2012

It has now been almost 3 decades since the introduction of MRI as a vital component of our clinical diagnostic armamentarium. During that time, we have learned much about the potential safety concerns relating to the static and time varying electromagnetic fields used in the MR imaging process, as well as several non‐magnetic field safety issues unique to this modality. Industry application of some of this knowledge has enabled the relatively recent FDA‐approval and clinical introduction of new devices heretofore unavailable that are designed specifically to be conditionally safe in the clinical MR imaging environment. An example of such a device is a cardiac pacemaker system (i.e., pulse generator and accompanying leads) that was designed from the ground up with MR safety as an integral design objective. Until now, patients were referred to undergo MR imaging because of an identified or suspected disease process, such as neurological or musculoskeletal pathology. This was true for almost all patients except for those with significant heart disease. For them, until recently, those whose heart disease was of such a nature that they required the implantation of a cardiac pacemakers were essentially excluded from MRI access, or were permitted careful access on a case by case basis only after intricate procedures and monitoring personnel and capabilities were established or their particular MR imaging procedure. With the advent of MR conditional cardiac pacemaker systems, we have now just begun to embark on an era where people will not be imaged despite their having a cardiac pacemaker — but specifically because of it, as we now can finally include cardiac disease as one of the many pathologic entities for which MR imaging's impressive diagnostic potential can finally be clinically truly applied. This presentation will review the MR safety issues in general and present some recent clinical advances in this area in the form of new tools, new capabilities, and newly published guidelines relating to MR safety. Consultant for Guerbet, Medtronic, Speakers Bureau for Bracco Diagnostics.

Learning Objectives:

1. Define the major and minor categories of potential safety concerns in the magnetic resonance imaging environment

2. Become aware of the recent advances in, and FDA approval of, cardiac pacing systems and their safe intra‐MRI utilization

3. Review some of the modifications in the recently produced “American College of Radiology Guidance Document for Safe MR Practices:2012” and compare it to the prior 2007 version of this document.
TH‐A‐213CD‐09: The Use of Scintillating Fibers for Proton Imaging Purposes
Authors: Depauw N , Seco J
Published: June 2012

Purpose: To determine the feasibility of using scintillating fibers for proton imaging purposes.Methods and Materials: This study considered 2mm × 2mm square BCF‐20 bicron fibers from Saint‐Gobains CrystalsTM which emit a green spectrum with a peak at 492nm, and present a 2.7ns decay time, therefore making them suitable for particle‐by‐particle analysis. Photomultiplier Tubes (PMT) with approximately 3ns response pulses and 2×2.5mm sensitive areas were coupled to the fibers. Particle interactions were acquired with a fast oscilloscope (1.5GHz, 20Gs/s) for single event analysis, as well as with a multichannel data acquisition system for stream of events using multiple fibers simultaneously. A mono‐chromatic proton beam set to different energies was used to irradiate individual fibers and the light output spectrum was recorded. Two individual fibers, one with and one without optical grease at the fiber‐PMT interface, were also used for measurements in order to assess the benefit from using optical grease. Results: Individual pulses were first recorded to assess the quality of the system. This highlighted the non‐relevance of using optical grease versus a direct fiber‐PMT interface. Light spectra were subsequently acquired with different incident proton energies. These correspond to the light output from each fiber, hence the energy deposited (dE/dx) by single protons inside the scintillator. The obtained data is in good agreement with the ICRU data which shows that scintillating fibers can be used to record incident energy from protons on a particle‐by‐particle basis. Conclusions: Preliminary results show that scintillating fibers could be used for proton imaging. A prototype made of 64 scintillating fibers (2 perpendicular arrays of 32 channels) is currently under conception at MGH, and avant‐garde pictures will soon be acquired with this first‐of‐a‐kind proton radiography system.
An unexpected cause of proximal myopathy
Authors: Townsend Sarah Ann , Smith Matt , Harris Wyn , Chudleigh Richard
Published: June 2012

A 25-year-old man presented with a short history of profound proximal muscle weakness such that he was unable to stand. Laboratory investigations demonstrated hypokalaemia and mildly elevated serum creatine kinase. He reported a history of 8–10 episodes of less severe weakness in the preceding 8 years and his mother reported similar symptoms. The combination of weakness and hypokalaemia with a probable family history suggested the diagnosis of hypokalaemic periodic paralysis. He was treated with intravenous and oral potassium supplementation, and regained full power within 24 h.
Evaluation of the effectiveness of neuromuscular training to reduce anterior cruciate ligament injury in female athletes: a critical review of relative risk reduction and numbers-needed-to-treat analyses
Authors: Sugimoto Dai , Myer Gregory D , McKeon Jennifer M , Hewett Timothy E
Published: June 2012

Since previous numbers-needed-to-treat (NNT) and relative risk reduction (RRR) report, a few studies were published to evaluate prophylactic effectiveness of neuromuscular training for anterior cruciate ligament (ACL) injury in female athletes. The purpose of the current analyses was to determine the effectiveness of neuromuscular training interventions in reducing both non-contact and overall ACL injury risk in female athletes through RRR and NNT. The keywords ‘knee’, ‘anterior cruciate ligament’, ‘ACL’, ‘prospective’, ‘neuromuscular’, ‘training’, ‘female’ and ‘prevention’ were searched to find studies published from 1995 to 2011 in PubMed and EBSCO (CINAHL, Health source, MEDLINE and SPORT Discus). Inclusion criteria required that relevant studies: recruited physically active young girls as subjects, documented the number of ACL injuries, employed a neuromuscular training intervention, and used a prospective controlled study design. The numbers of non-contact and overall ACL injuries, subjects and observation time period were used to calculate RRR and NNT for each study. A total of 12 studies met the inclusion criteria. There was a 73.4% (95% CI 62.5% to 81.1%) and 43.8% (95% CI 28.9% to 55.5%) of RRR for non-contact and overall ACL injuries. From the NNT analysis, it was determined that, respectively, 108 (95% CI 86 to 150) and 120 (95% CI 74 to 316) individuals would need to be trained to prevent one non-contact or one overall ACL injury over the course of one competitive season. Although the RRR analysis indicated prophylactic benefits of neuromuscular training, the relatively large NNT indicated that many athletes are needed to prevent one ACL injury. A future direction to reduce NNT and improve the efficiency of ACL injury-prevention strategies is to develop a screening system for identifying at-risk athletes.
Celebrating a tradition of innovation
Authors: McAulay Katy , Yam Philippa
Published: June 2012

This year, Glasgow Veterinary School marks its 150th anniversary. Katy McAulay and Philippa Yam at Glasgow reflect on some of its achievements and look forward to its ongoing success
The distribution of dissolved aluminum in Atlantic salmon (Salmo salar) rivers of Atlantic Canada and its potential effect on aquatic populations
Authors: Dennis Ian F. , Clair Thomas A.
Published: June 2012

Studies from the 1980s concluded that aluminum (Al) was not a significant contributor to Atlantic salmon ( Salmo salar ) toxicity in Nova Scotia, located on Canada’s Atlantic coast, because of the presence of dissolved organic matter that rendered ionic Al (Ali) biologically inaccessible. Since this earlier work, new interpretations of Alieffects, as well as improved techniques for its measurement, have been developed. However, no new data interpretation has been done to see if the conclusions reached in earlier work for Atlantic Canada were still valid. We sampled 97 salmon rivers from the provinces of New Brunswick (NB), Nova Scotia (NS), and the island of Newfoundland (NF) to determine total and Aliconcentrations to see if results exceeded newer toxicity standards established by the European Inland Fisheries Advisory Commission. We found that southwestern NS, the region with the greatest loss of salmon populations, has seven rivers where autumn Alivalues exceed values identified as toxic to aquatic life. A further three rivers exceed guidelines in NF. Our work shows that the sources of toxicity for salmon and other aquatic species in acidified environments are more complex than previously thought.
Population dynamics of marine fishes at low abundance
Authors: Keith David M. , Hutchings Jeffrey A.
Published: June 2012

The recovery of depleted species depends on their population dynamics at low abundance. Classical population growth models, applied widely in fisheries science, assume that per capita offspring production increases as abundance declines (compensation). However, slow or absent recovery by many depleted fishes might reflect unexpectedly weak compensation or the presence of Allee effects (depensation). Using meta-analytical techniques to describe reproductive dynamics, we find considerable variability among 207 exploited marine fish stocks (104 species) in how standardized per capita population growth changes with abundance. Although many species exhibit strong compensatory dynamics (negative density dependence), others show much weaker compensation than expected, and some exhibit evidence of an Allee effect, such as Atlantic cod ( Gadus morhua ) and Alaskan walleye pollock ( Theragra chalcogramma ). As data at low levels of abundance become increasingly available, it appears that compensation, while strong in some species, is comparatively weak or nonexistent in others, thus providing an explanation for why the recovery of some depleted stocks, despite reductions in exploitation, has been considerably less than what classic models of population growth would otherwise suggest.
Elevated mercury levels in biota along an agricultural land use gradient in the Oldman River basin, Alberta
Authors: Brinkmann Lars , Rasmussen Joseph B.
Published: June 2012

This study examines relationships between anthropogenic influence and mercury concentrations in biota along an elevational river gradient with intensifying agricultural and urban land use in the Oldman River basin, Alberta, Canada. We use nitrogen stable isotope signatures (δ15N) indicative of anthropogenic sources of N to indicate the extent of land use influence on the river ecosystem. δ15N values in biota increased by 4.2‰ along the river gradient, consistent with increasing nitrogen sources from sewage and manure. Mercury concentrations in longnose dace ( Rhinichthys cataractae ), suckers ( Catostomus catostomus , Catostomus commersonii ), and net-spinning caddisfly larvae, the most abundant macroinvertebrates, all increased downstream; dace ranged from 0.023 ppm total mercury below the Oldman reservoir to 0.10 ppm total mercury downstream of Lethbridge. Dace consumed mostly insect larvae, and no increase in trophic position (as estimated by δ15N) was observed along the gradient. Fish directly exposed to agricultural and urban effluents had significantly lower mercury levels, or showed no difference, relative to reference sites, which suggests that these effluents play no significant role in elevating mercury levels in river food webs.
Nutritional stress and body condition in the Great Gray Owl (Strix nebulosa) during winter irruptive migrations
Authors: Graves Gary R. , Newsome Seth D. , Willard David E. , Grosshuesch David A. , Wurzel William W. , Fogel Marilyn L.
Published: June 2012

The largest irruptive migration of the Great Gray Owl ( Strix nebulosa Forster, 1772) recorded since 1831 occurred in Minnesota, USA, during the winter of 2004–2005. We tested the hypothesis that morphometric indicators of nutritional stress covary with stable isotope signatures in a sample of 265 owls killed by vehicle collisions. The ratio of carbon to nitrogen in muscle (C/Nmuscle) was shown to be a reliable proxy of nutritional stress. δ13C values for liver and muscle were significantly higher in owls in poor condition, reflecting the depletion of lipid reserves in fasting individuals. On the other hand, δ15N values for liver and muscle were marginally lower or unchanged in owls in poor condition. Stomachs of emaciated owls were less likely to contain prey, implying that many nutritionally stressed individuals were too weak to hunt and were near the tipping point of irreversible fasts. In a broader context, sexual differences in the correlative relationships between stable isotope signatures, C/N, and body condition suggest that the consequences of reversed sexual size dimorphism extend to physiological processes during the nonbreeding season.
Autonomic mediation of the interdependence between variability signals of heart rate and blood pressure in the lizard Gallotia galloti
Authors: De Vera Luis , Rial Rubén V. , Pereda Ernesto , González Julián J.
Published: June 2012

Autonomic nervous system (ANS) involvement in the mediation of the synchronization between beat-to-beat RR interval variability (RRIV) and systolic blood pressure variability (SBPV) signals of the lizard Gallotia galloti (Oudart, 1839) was investigated through linear and nonlinear time series analysis methods in a pharmacological blockade context. The ANS blockers used were atropine, prazosin, and propranolol. The interdependence between the signals was quantified by means of the magnitude-squared coherence (MSC), which measures amplitude and phase linear synchronization; the phase lag index (PLI), which evaluates the phase synchronization; and the index L, which quantifies the generalized linear and nonlinear synchronization. Atropine decreased the PLI in the low-frequency (LF: 0.01–0.05 Hz) range; prazosin decreased the MSC in the medium-frequency (MF: 0.06–0.15 Hz) range; and propranolol did not alter any of the interdependence measures. It is suggested that (i) the cholinoceptor activity mediates the phase cardiovascular synchronization in the LF range; (ii) the α1-adrenoceptor activity mediates the amplitude and phase linear cardiovascular synchronization in the MF range; and (iii) the β-adrenoceptor activity plays no role in mediating any dynamics of cardiovascular synchronization in the studied frequency range. When comparing these results with those in mammals, a lesser overall autonomic involvement in the mediation of the studied cardiovascular interdependences is seen in reptiles.
VIRASORO CORRELATION FUNCTIONS FOR VERTEX OPERATOR ALGEBRAS
Authors: HURLEY DONNY , TUITE MICHAEL P.
Published: June 2012

We consider all genus zero and genus one correlation functions for the Virasoro vacuum descendants of a vertex operator algebra. These are described in terms of explicit generating functions that can be combinatorially expressed in terms of graph theory related to derangements in the genus zero case and to partial permutations in the genus one case.
CONFORMATIONAL DYNAMICS OF HIV-1 PROTEASE: A COMPARATIVE MOLECULAR DYNAMICS SIMULATION STUDY WITH MULTIPLE AMBER FORCE FIELDS
Authors: MEHER BISWA RANJAN , SATISH KUMAR MATTAPARTHI VENKATA , SHARMA SMRITI , BANDYOPADHYAY PRADIPTA
Published: June 2012

Flap dynamics of HIV-1 protease (HIV-pr) controls the entry of inhibitors and substrates to the active site. Dynamical models from previous simulations are not all consistent with each other and not all are supported by the NMR results. In the present work, the effect of force field on the dynamics of HIV-pr is investigated by MD simulations using three AMBER force fields ff99, ff99SB, and ff03. The generalized order parameters for amide backbone are calculated from the three force fields and compared with the NMR S2 values. We found that the ff99SB and ff03 force field calculated order parameters agree reasonably well with the NMR S2 values, whereas ff99 calculated values deviate most from the NMR order parameters. Stereochemical geometry of protein models from each force field also agrees well with the remarks from NMR S2 values. However, between ff99SB and ff03, there are several differences, most notably in the loop regions. It is found that these loops are, in general, more flexible in the ff03 force field. This results in a larger active site cavity in the simulation with the ff03 force field. The effect of this difference in computer-aided drug design against flexible receptors is discussed.
A NEW METHOD FOR CROSS POLARIZED DELAY CALIBRATION OF RADIO INTERFEROMETERS
Authors: COTTON W. D.
Published: June 2012

Radio interferometers can measure the full polarization state of incoming waves by cross-correlating all combinations of two orthogonal polarizations at each antenna. The independent sets of electronics used to detect the two polarization states will introduce a differential instrumental delay between the two data streams. The usual technique of separate calibration of the parallel-hand sets of visibilities still allows for an arbitrary offset in group delay and phase between the two parallel systems. In order to use the cross-polarized visibilities, this instrumental offset must be determined and removed. This paper describes one such technique and explores its application in the Obit package. The technique is successfully applied to some EVLA data using both strongly and weakly polarized calibrators.
Endogenous H2S is required for hypoxic sensing by carotid body glomus cells
Authors: Makarenko Vladislav V. , Nanduri Jayasri , Raghuraman Gayatri , Fox Aaron P. , Gadalla Moataz M. , Kumar Ganesh K. , Snyder Solomon H. , Prabhakar Nanduri R.
Published: June 2012

H2S generated by the enzyme cystathionine-γ-lyase (CSE) has been implicated in O2 sensing by the carotid body. The objectives of the present study were to determine whether glomus cells, the primary site of hypoxic sensing in the carotid body, generate H2S in an O2-sensitive manner and whether endogenous H2S is required for O2 sensing by glomus cells. Experiments were performed on glomus cells harvested from anesthetized adult rats as well as age and sex-matched CSE+/+ and CSE−/− mice. Physiological levels of hypoxia (Po2 ∼30 mmHg) increased H2S levels in glomus cells, and dl-propargylglycine (PAG), a CSE inhibitor, prevented this response in a dose-dependent manner. Catecholamine (CA) secretion from glomus cells was monitored by carbon-fiber amperometry. Hypoxia increased CA secretion from rat and mouse glomus cells, and this response was markedly attenuated by PAG and in cells from CSE−/− mice. CA secretion evoked by 40 mM KCl, however, was unaffected by PAG or CSE deletion. Exogenous application of a H2S donor (50 μM NaHS) increased cytosolic Ca2+ concentration ([Ca2+]i) in glomus cells, with a time course and magnitude that are similar to that produced by hypoxia. [Ca2+]i responses to NaHS and hypoxia were markedly attenuated in the presence of Ca2+-free medium or cadmium chloride, a pan voltage-gated Ca2+ channel blocker, or nifedipine, an L-type Ca2+ channel inhibitor, suggesting that both hypoxia and H2S share common Ca2+-activating mechanisms. These results demonstrate that H2S generated by CSE is a physiologic mediator of the glomus cell's response to hypoxia.
Fluid shear stress induces differentiation of circulating phenotype endothelial progenitor cells
Authors: Obi Syotaro , Masuda Haruchika , Shizuno Tomoko , Sato Atsuko , Yamamoto Kimiko , Ando Joji , Abe Yusuke , Asahara Takayuki
Published: June 2012

Endothelial progenitor cells (EPCs) are mobilized from bone marrow to peripheral blood, and contribute to angiogenesis in tissue. In the process, EPCs are exposed to shear stress generated by blood flow and tissue fluid flow. Our previous study showed that shear stress induces differentiation of mature EPCs in adhesive phenotype into mature endothelial cells and, moreover, arterial endothelial cells. In this study we investigated whether immature EPCs in a circulating phenotype differentiate into mature EPCs in response to shear stress. When floating-circulating phenotype EPCs derived from ex vivo expanded human cord blood were exposed to controlled levels of shear stress in a flow-loading device, the bioactivities of adhesion, migration, proliferation, antiapoptosis, tube formation, and differentiated type of EPC colony formation increased. The surface protein expression rate of the endothelial markers VEGF receptor 1 (VEGF-R1) and -2 (VEGF-R2), VE-cadherin, Tie2, VCAM1, integrin αv/β3, and E-selectin increased in shear-stressed EPCs. The VEGF-R1, VEGF-R2, VE-cadherin, and Tie2 protein increases were dependent on the magnitude of shear stress. The mRNA levels of VEGF-R1, VEGF-R2, VE-cadherin, Tie2, endothelial nitric oxide synthase, matrix metalloproteinase 9, and VEGF increased in shear-stressed EPCs. Inhibitor analysis showed that the phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signal transduction pathway is a potent activator of adhesion, proliferation, tube formation, and differentiation in response to shear stress. Western blot analysis revealed that shear stress activated the VEGF-R2 phosphorylation in a ligand-independent manner. These results indicate that shear stress increases differentiation, adhesion, migration, proliferation, antiapoptosis, and vasculogenesis of circulating phenotype EPCs by activation of VEGF-R2 and the PI3K/Akt/mTOR signal transduction pathway.
Direct interaction of Plin2 with lipids on the surface of lipid droplets: a live cell FRET analysis
Authors: McIntosh Avery L. , Senthivinayagam Subramanian , Moon Kenneth C. , Gupta Shipra , Lwande Joel S. , Murphy Cameron C. , Storey Stephen M. , Atshaves Barbara P.
Published: June 2012

Despite increasing awareness of the health risks associated with excess lipid storage in cells and tissues, knowledge of events governing lipid exchange at the surface of lipid droplets remains unclear. To address this issue, fluorescence resonance energy transfer (FRET) was performed to examine live cell interactions of Plin2 with lipids involved in maintaining lipid droplet structure and function. FRET efficiencies ( E) between CFP-labeled Plin2 and fluorescently labeled phosphatidylcholine, sphingomyelin, stearic acid, and cholesterol were quantitated on a pixel-by-pixel basis to generate FRET image maps that specified areas with high E (>60%) in lipid droplets. The mean E and the distance R between the probes indicated a high yield of energy transfer and demonstrated molecular distances on the order of 44–57 Å, in keeping with direct molecular contact. In contrast, FRET between CFP-Plin2 and Nile red was not detected, indicating that the CFP-Plin2/Nile red interaction was beyond FRET proximity (>100 Å). An examination of the effect of Plin2 on cellular metabolism revealed that triacylglycerol, fatty acid, and cholesteryl ester content increased while diacylglycerol remained constant in CFP-Plin2-overexpressing cells. Total phospholipids also increased, reflecting increased phosphatidylcholine and sphingomyelin. Consistent with these results, expression levels of enzymes involved in triacylglycerol, cholesteryl ester, and phospholipid synthesis were significantly upregulated in CFP-Plin2-expressing cells while those associated with lipolysis either decreased or were unaffected. Taken together, these data show for the first time that Plin2 interacts directly with lipids on the surface of lipid droplets and influences levels of key enzymes and lipids involved in maintaining lipid droplet structure and function.
Discharge patterns in the lateral superior olive of decerebrate cats
Authors: Greene Nathaniel T. , Davis Kevin A.
Published: June 2012

Anatomical and pharmacological studies have shown that the lateral superior olive (LSO) receives inputs from a number of sources and that LSO cells can alter the balance of their own excitatory and inhibitory drive. It is thus likely that the ongoing sound-evoked responses of LSO cells reflect a complex interplay of excitatory and inhibitory events, which may be affected by anesthesia. The goal of this study was to characterize the temporal discharge patterns of single units in the LSO of unanesthetized, decerebrate cats in response to long-duration ipsilateral best-frequency tone bursts. A decision tree is presented to partition LSO units on the basis of poststimulus time histogram shape, adaptation of instantaneous firing rate as a function of time, and sustained discharge rate. The results suggest that LSO discharge patterns form a continuum with four archetypes: sustained choppers that show two or more peaks of activity at stimulus onset and little adaptation of rate throughout the response, transient choppers that undergo a decrease in rate that eventually stabilizes with time, primary-like units that display an initial peak of activity followed by a monotonic decline in rate to a steady-state value, and onset-sustained units that exhibit an initial peak of activity at stimulus onset followed by a low sustained activity. Compared with the chopper units, the nonchopper units tend to show longer first-spike latencies, lower peak firing rates, and more irregular sustained discharge patterns. Modeling studies show that the full range of LSO response types can be obtained from an underlying sustained chopper by varying the strength and latency of a sound-driven ipsilateral inhibition relative to that of excitation. Together, these results suggest that inhibition plays a major role in shaping the temporal discharge patterns of units in unanesthetized preparations.
Assessment of Echocardiography and Biomarkers for the Extended Prediction of Cardiotoxicity in Patients Treated With Anthracyclines, Taxanes, and Trastuzumab
Authors: Sawaya Heloisa , Sebag Igal A. , Plana Juan Carlos , Januzzi James L. , Ky Bonnie , Tan Timothy C. , Cohen Victor , Banchs Jose , Carver Joseph R. , Wiegers Susan E. , Martin Randolph P. , Picard Michael H. , Gerszten Robert E. , Halpern Elkan F. , Passeri Jonathan , Kuter Irene , Scherrer-Crosbie Marielle
Published: June 2012

Background—

Because cancer patients survive longer, the impact of cardiotoxicity associated with the use of cancer treatments escalates. The present study investigates whether early alterations of myocardial strain and blood biomarkers predict incident cardiotoxicity in patients with breast cancer during treatment with anthracyclines, taxanes, and trastuzumab.

Methods and Results—

Eighty-one women with newly diagnosed human epidermal growth factor receptor 2–positive breast cancer, treated with anthracyclines followed by taxanes and trastuzumab were enrolled to be evaluated every 3 months during their cancer therapy (total of 15 months) using echocardiograms and blood samples. Left ventricular ejection fraction, peak systolic longitudinal, radial, and circumferential myocardial strain were calculated. Ultrasensitive troponin I, N-terminal pro–B-type natriuretic peptide, and the interleukin family member (ST2) were also measured. Left ventricular ejection fraction decreased (64 ± 5% to 59 ± 6%;
P
<0.0001) over 15 months. Twenty-six patients (32%, [22%–43%]) developed cardiotoxicity as defined by the Cardiac Review and Evaluation Committee Reviewing Trastuzumab; of these patients, 5 (6%, [2%–14%]) had symptoms of heart failure. Peak systolic longitudinal myocardial strain and ultrasensitive troponin I measured at the completion of anthracyclines treatment predicted the subsequent development of cardiotoxicity; no significant associations were observed for left ventricular ejection fraction, N-terminal pro–B-type natriuretic peptide, and ST2. Longitudinal strain was <19% in all patients who later developed heart failure.

Conclusions—

In patients with breast cancer treated with anthracyclines, taxanes, and trastuzumab, systolic longitudinal myocardial strain and ultrasensitive troponin I measured at the completion of anthracyclines therapy are useful in the prediction of subsequent cardiotoxicity and may help guide treatment to avoid cardiac side-effects.
Evaluation of elastic properties of interpenetrating phase composites by mesh-free method
Authors: Agarwal Ankit , Singh I V , Mishra BK
Published: June 2012

Interpenetrating phase composites can be defined as multiphase materials in which each phase is three-dimensionally interconnected throughout the structure. The unique geometry of the reinforcement offers improved combination of mechanical and physical properties. Over the years, a lot of efforts have been put to study these composites experimentally. However, due to the complexity in microstructure and randomness in behaviour of interpenetrating phase composite, the modelling of these composites has not been sufficiently studied so far. Therefore, in this study, two models, namely, unit cell and self-consistent models have been presented to find the elastic properties of interpenetrating phase composites. All influencing parameters such as volume fraction and random geometry are duly incorporated in these models. These models are analysed by a mesh-free method known as element-free Galerkin method. The effective properties of these composites are calculated by an effective medium approximation approach. The real microstructure of interpenetrating phase composites is partially interpenetrating and partially particulate in nature; hence, a control parameter has been included in the model to simulate this behaviour. The main feature of the proposed unit cell model is that it is easy to implement and less time consuming as compared to three-dimensional existing model and characterises all the governing features of interpenetrating phase composite microstructure.
Investigation on the high velocity impact properties of glass-reinforced fiber metal laminates
Authors: Ahmadi H , Liaghat GH , Sabouri H , Bidkhouri E
Published: June 2012

The resistance of glass-reinforced laminates with different thickness ratio (ratio of glass/epoxy plies thickness to aluminum sheets thickness) subjected to high-velocity impact is investigated experimentally and analytically. The tests are carried out by a light gas gun and a 14 g blunt cylindrical projectile. The ballistic limit velocity and specific perforation energy is used for comparing results. The failure mechanisms that absorbed projectile’s energy during perforation process are studied by examining the damaged samples. This examining helped us to derive an analytical expression to predict the ballistic limit and specific perforation energy. The good agreement between experimental and analytical results shows well mathematical modeling. The results indicate that global deformation of aluminum sheets had the most effect on absorbing energy. Increasing the number of composite plies may enhance the absorbed energy of a fiber metal laminate but also increases weight and cause to be away from the optimum condition. Besides these two procedures, a numerical analysis is done and the results compared with previous ones and are commented upon.
Concurrent fitness evaluations in searching for the optimal process conditions of Al matrix nanocomposites by linearly decreasing weight
Authors: Mazahery Ali , Shabani Mohsen Ostad , Alizadeh Mehdi , Tofigh Ali Asghar
Published: June 2012

In this article, the effect of nanoceramic reinforcements on the mechanical properties of aluminum matrix composites was critically reviewed. Reinforcement of an Al alloy with nanoceramic particulates is expected to improve its tensile strength. This article also reports the role of an integrated optimization approach using an artificial neural network and a modified particle swarm to solve a process parameter design problem in casting of this class of metal matrix nanocomposites. The artificial neural network is used to obtain the relationships between decision variables and the performance measures of interest, while the particle swarm is used to perform the optimization with multiple objectives.
Land Reform as a Counterinsurgency Policy
Authors: Albertus Michael , Kaplan Oliver
Published: June 2012

Can targeted land reform reduce levels of civil war conflict by mitigating the factors that contribute to rural rebellion? This article uses new micro-level data on land reform and insurgency at the municipal level from Colombia from 1988 to 2000, a country with high rates of land inequality and informal land ownership, to test whether land reform undercut subsequent guerrilla activity. The reform had two distinct aspects. Politically powerful large landholders blocked most large-scale reform, which resulted primarily in an enduring, low-intensity, and geographically dispersed reform that spurred low levels of insurgent activity. Larger-scale reforms were only implemented in areas that threatened serious violence and had the potential to harm elite interests, and in these limited areas reform reduced guerrilla activity. This suggests that while land reform can be an effective counterinsurgency policy, it may be politically difficult to implement at a sufficient scale because it threatens the status quo.
Private Military Companies, Opportunities, and Termination of Civil Wars in Africa
Authors: Akcinaroglu Seden , Radziszewski Elizabeth
Published: June 2012

The article analyzes the impact of private military companies (PMCs) on the duration of civil wars in Africa from 1990 to 2008. We develop an “opportunity structure” theory to argue that while PMCs are profit-oriented entities, the prevalent opportunities in conflicts will determine how they behave in war zones. Empirical findings for civil wars with at least 1,000 battle deaths show that as level of competition among government-hired PMCs increases, they are more likely to deliver optimal services and help bring an end to violence. In the absence of competition, the prevalent structure creates opportunities for PMCs to underperform in order to maximize profits by staying in conflicts longer. The authors also show that swift cessation of hostilities could benefit those profit-seeking PMCs that are compensated with contracts to extract natural resources because resource extraction generates more wealth in peace time. In such cases, the prevalent opportunities in conflict create an incentive for companies to deliver optimal service and terminate hostilities.
Global Capital, the State, and Chinese Workers
Authors: Ngai Pun , Chan Jenny
Published: June 2012

In 2010, a startling 18 young migrant workers attempted suicide at Foxconn Technology Group production facilities in China. This article looks into the development of the Foxconn Corporation to understand the advent of capital expansion and its impact on frontline workers’ lives in China. It also provides an account of how the state facilitates Foxconn’s production expansion as a form of monopoly capital. Foxconn stands out as a new phenomenon of capital expansion because of the incomparable speed and scale of its capital accumulation in all regions of China. This article explores how the workers at Foxconn, the world’s largest electronics manufacturer, have been subjected to work pressure and desperation that might lead to suicides on the one hand but also open up daily and collective resistance on the other hand.
Beyond CEO Tenure
Authors: Weng David H. , Lin Zhiang (John)
Published: June 2012

Prior research on strategic changes has asserted that long-tenured CEOs are less likely to initiate strategic changes. The authors argue that this assertion may exclude CEOs’ prior experiences since it implicitly assumes that all new CEOs have the same inclination toward change. By viewing CEOs as individuals embedded within experiences and relationships throughout their careers, the authors propose that CEO newness—a concept integrating prior board experience, prior heir apparent experience, and length in the current position—can provide a more complete assessment of a new CEO’s tendency toward change. They further argue that the impact of CEO newness on strategic changes will be moderated by the strategic distance between a focal firm and a CEO’s previous firm, as well as by industry similarity between the two firms. The authors’ analyses of U.S. computer firms from 1994 to 2007 support their arguments, suggesting that it is useful to adopt the concept of CEO newness while considering its boundary conditions in order to better understand strategic changes.
Pathological Study of Chronic Pulmonary Toxicity Induced by Intratracheally Instilled Asian Sand Dust (Kosa)
Authors: Naota Misaki , Shiotsu Shizuka , Shimada Akinori , Kohara Yukari , Morita Takehito , Inoue Kenichiro , Takano Hirohisa
Published: June 2012

Asian sand dust (ASD) events are associated with an increase in pulmonary morbidity and mortality. The number of ASD events has increased rapidly in the east Asian region since 2000. To study the chronic lung toxicity of ASD, saline suspensions of low doses (200 and 400 µg) and high doses (800 and 3,000 µg) of ASD were intratracheally instilled into ICR mice. Animals were sacrificed at 24 hr, 1 week, or 1, 2, or 3 months after instillation. Histopathological examination revealed that ASD induced acute inflammation at 24 hr after instillation. The acute inflammation was transient and subsided at 1 week and 1 month after instillation. At 2 and 3 months after instillation, focal infiltration of lymphocytes with accumulation of epithelioid macrophages, which is a suggestive finding of transformation to granuloma, and granuloma formation were occasionally observed. Aggregation of macrophages containing particles was observed in the pulmonary lymph nodes at 3 months after instillation in high-dose groups. Prolonged inflammatory foci (granuloma) and presence of ASD particles in pulmonary lymph nodes would have a chance to induce immunological modulation leading to adverse health effects in the exposed animals.
Revisiting the Debate over the Bottom of the Pyramid Market
Authors: Agnihotri Arpita
Published: June 2012

Scholars have debated the nature of the market at the bottom of the pyramid (BOP). Challenging assumptions about these customers, C. K. Prahalad has described numerous success stories of multinational companies who targeted low-income people as their customers. However, other scholars have raised questions about Prahalad’s propositions and the economic and ethical realities facing firms doing business at the BOP. Interestingly, though many projects have failed with the BOP market, firms operating in emerging markets have successfully implemented these programs in the mass market. Thus, many products and services, such as automobiles and hotels, have now become an affordable possibility for the mass segment. This commentary summarizes the debate over Prahalad’s propositions and explains their current status.
Roy’s Specific Life Values and the Philosophical Assumption of Veritivity
Authors: Hanna Debra R.
Published: June 2012

Roman Catholic beliefs that form the basis for Roy’s life values are discussed to help others understand veritivity and the Roy adaptation model more clearly. Veritivity, the main philosophical assumption of the Roy adaptation model, shapes it, and Roy’s assumption of humanism in a unique way. Veritivity has a theocentric focus, with anthropological values. Roy views human beings as individuals in community with a loving Creator and with others. Truth, freedom, and moral ends are discussed in terms of veritivity and in terms of contemporary values.
Protecting the Discipline
Authors: Florczak Kristine L. , Buenting Julie Ann
Published: June 2012

The focus of this column is the idea of collaborative research as part of sweeping changes that the Institute of Medicine has recommended for the future of nursing. An overview of the recommendations will be presented followed by a cursory review of the concept of collaboration, and a discussion of a theoretical model. Barriers to interdisciplinary collaboration will also be entertained. Finally, loosely coupled systems will be proposed as a way to protect the profession of nursing.
Effects of self-promoted curing behaviors on properties of phthalonitrile/epoxy copolymer
Authors: Guo Heng , Zou Yanke , Chen Zhiran , Zhang Jiandong , Zhan Yingqing , Yang Jian , Liu Xiaobo
Published: June 2012

Thermosetting blends of 4-aminophenoxyphthalonitrile (APN)/epoxy resin (ER) were investigated by differential scanning calorimetry (DSC), dynamic rheological analysis and thermogravimetric analysis (TGA). The self-promoted curing behaviors and processing properties of the APN/ER blends and prepolymers were studied by DSC and rheological analysis under dynamic and isothermal conditions. The APN/ER blends and prepolymers exhibited two-step polymerization reactions in the absence of any other curing additives. The APN/ER blends and prepolymers had large processing windows with low melt viscosity, and the size of the processing windows was dependent on the APN monomer concentration. The thermal behaviors of the APN/ER copolymers were studied by TGA. These cured copolymers exhibited decomposition temperatures over 367 oC in either flowing nitrogen or air, and high char yield at 800 oC of 68% under nitrogen atmosphere. Consequently, these studies revealed that the APN/ER system exhibits attractive self-promoted curing reaction, desirable processing feature, excellent thermal and thermal-oxidative stabilities, and high char yields. The APN/ER copolymer will be a good candidate as a matrix for high-performance polymeric materials.
Review of Fatal and Severe Cases of Box Jellyfish Envenomation in Thailand
Authors: Thaikruea Lakkana , Siriariyaporn Potjaman , Wutthanarungsan Rochana , Smithsuwan Punnarai
Published: June 2012

The study aimed to describe severe and fatal cases of box jellyfish stings in Thailand. Medical records were reviewed and patients, relatives, health staffs, and witnesses were interviewed. The pictures of suspected box jellyfish were sent via e-mail to experts in the toxic jellyfish network for further identification. There were at least 8 cases of box jellyfish envenomation, with 4 fatal and 4 near-fatal cases. There were an equal number of male and female patients from 4 to 26 years of age. In each case, there was immediate severe pain followed by systemic reactions. Immediately after exposure to the sting, 7 victims collapsed experiencing severe pain at the tentacle marks, respiratory failure, and cardiac arrest. All patients had tentacle marks on their bodies. In none of the fatal cases was vinegar applied to the tentacle marks as first aid, but 3 out of the 4 near-fatal cases were treated with a vinegar application.
Associations of Depressive Symptoms With Health Behaviors, Stress, and Self-assessed Health Status in Hawai’i
Authors: Pomp Sarah , Keller Stefan , Maddock Jay E.
Published: June 2012

Background. The aim of this cross-sectional study was to examine how depressive symptoms are associated with health behaviors, stress, and self-assessed health status in the population of Hawai’i. Methods. Randomized phone calls were made using computer assistant telephone interviews. A regression analysis with depressive symptoms as the outcome and sociodemographic variables, health behaviors, stress, and health status as predictors was conducted in 1483 adults. Results. Depressive symptoms were associated with stress (β = .32), alcohol consumption (β = .19), health status (β = −.10), fast food consumption (β = .06), avoidance of fat (β = −.06), and fruit and vegetable consumption (β = .06). Moreover, depressive symptoms were linked to being female (β = .06), being single (β = −.06), and being Caucasian compared with being Native Hawaiian (β = −.06) or Japanese (β = −.08). The overall explained variance was 22%. Conclusion. Depressive symptoms correlate with health risk behaviors and might be considered as a risk for chronic diseases.