bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Brain Occupancy from Plasma Levels using PET: Superiority of Combining Pharmacokinetics with Pharmacodynamics while Modeling the Relationship
Authors: Kim Euitae , Howes Oliver D , Kim Bo-Hyung , Jeong Jae Min , Lee Jae Sung , Jang In-Jin , Shin Sang-Goo , Turkheimer Federico E , Kapur Shitij , Kwon Jun Soo
Published: December 2011

Positron emission tomography (PET) studies of dopamine receptor occupancy can be used to assess dosing of antipsychotics. Typically, studies of antipsychotics have applied pharmacodynamic (PD) modeling alone to characterize the relationship between antipsychotic dose and its effect on the brain. However, a limitation of this approach is that it does not account for the discrepancy between the time courses of plasma concentration and receptor occupancy by antipsychotics. Combined pharmacokinetic—PD (PK—PD) modeling, by incorporating the time dependence of occupancy, is better suited for the reliable analysis of the concentration—occupancy relationship. To determine the effect of time on the concentration—occupancy relationship as a function of analysis approach, we measured dopamine receptor occupancy after the administration of aripiprazole using [11C]raclopride PET and obtained serial measurements of the plasma aripiprazole concentration in 18 volunteers. We then developed a PK—PD model for the relationship, and compared it with conventional approach (PD modeling alone). The hysteresis characteristics were observed in the competitor concentration—occupancy relationship and the value of EC50 was different according to the analysis approach ( EC50 derived from PD modeling alone = 11.1 ng/mL (95% confidence interval (CI) = 10.1 to 12.1); while that derived from combined PK—PD modeling = 8.63 ng/mL (95% CI = 7.75 to 9.51)). This finding suggests that PK—PD modeling is required to obtain reliable prediction of brain occupancy by antipsychotics.
The crystal structure of the Sox4 HMG domain–DNA complex suggests a mechanism for positional interdependence in DNA recognition
Authors: Jauch Ralf , Ng Calista K. L. , Narasimhan Kamesh , Kolatkar Prasanna R.
Published: December 2011

It has recently been proposed that the sequence preferences of DNA-binding TFs (transcription factors) can be well described by models that include the positional interdependence of the nucleotides of the target sites. Such binding models allow for multiple motifs to be invoked, such as principal and secondary motifs differing at two or more nucleotide positions. However, the structural mechanisms underlying the accommodation of such variant motifs by TFs remain elusive. In the present study we examine the crystal structure of the HMG (high-mobility group) domain of Sox4 [Sry (sex-determining region on the Y chromosome)-related HMG box 4] bound to DNA. By comparing this structure with previously solved structures of Sox17 and Sox2, we observed subtle conformational differences at the DNA-binding interface. Furthermore, using quantitative electrophoretic mobility-shift assays we validated the positional interdependence of two nucleotides and the presence of a secondary Sox motif in the affinity landscape of Sox4. These results suggest that a concerted rearrangement of two interface amino acids enables Sox4 to accommodate primary and secondary motifs. The structural adaptations lead to altered dinucleotide preferences that mutually reinforce each other. These analyses underline the complexity of the DNA recognition by TFs and provide an experimental validation for the conceptual framework of positional interdependence and secondary binding motifs.
Endothelial cells and magnesium: implications in atherosclerosis
Authors: Maier Jeanette A. M.
Published: December 2011

There is no doubt that the functional and structural integrity of the endothelium is critical in maintaining vascular homoeostasis and in preventing atherosclerosis. In the light of epidemiological and experimental studies, magnesium deficiency is emerging as an inducer of endothelial dysfunction. In particular, data on the effects of low extracellular magnesium on cultured endothelial cells reinforce the idea that correcting magnesium homoeostasis might be a helpful and inexpensive intervention to prevent and treat endothelial dysfunction and, consequently, atherosclerosis.
Variants of the FTO Gene in Obese Children and their Impact on Body Composition and Metabolism before and after Lifestyle Intervention
Authors: Schum J. , Blumenstock G. , Weber K. , Schweizer R. , Pfaff C. , Schurr N. , Ranke M. , Binder G. , Ehehalt S. ,   for the DISKUS-Study Group
Published: December 2011

To investigate the impact of variants of the FTO gene (rs1421085, rs17817449, rs9939609) in obese children before and after lifestyle intervention.

Design: Longitudinal, clinical intervention study with an increase in physical activity, and nutritional recommendations based on the Optimized Mixed Diet for German Children and Adolescents’ (Research Institute of Child Nutrition, Germany). Study population: 75 overweight children (40 male, mean BMI 30.4±5.5 kg/m2, mean age 12.6±2.6 years). Measurements: Genotyping by means of a TaqMan SNP genotyping assay. Lean and fat mass were determined by means of DXA.

For the whole study population, the 6-month lifestyle intervention resulted in a significant improvement (before intervention minus time point 6 months; mean±SD) in BMI-SDS (0.10±0.17, p<0.001), HOMA (1.41±3.19, p<0.001) and relative fat-mass-SDS (0.09±0.23, p=0.005). Before and after lifestyle intervention, there was no significant difference between heterozygote (n=52) and homozygote (n=21) carriers of the FTO gene in terms of BMI, body composition, and the metabolic profile (Insulin, HOMA, lipids, liver function tests).

Variants in the FTO gene are common in obese children but have no impact on body composition and metabolism before and after lifestyle intervention.
Characterization of plasma ion source utilizing anode spot with positively biased electrode for stable and high-current ion beam extraction
Authors: Park Yeong-Shin , Lee Yuna , Chung Kyoung-Jae , Hwang Y. S.
Published: December 2011

The operating conditions of a rf plasma ion source utilizing a positively biased electrode have been investigated to develop a stably operating, high-current ion source. Ion beam characteristics such as currents and energies are measured and compared with bias currents by varying the bias voltages on the electrode immersed in the ambient rf plasma. Current-voltage curves of the bias electrode and photographs confirm that a small and dense plasma, so-called anode spot, is formed near an extraction aperture and plays a key role to enhance the performance of the plasma ion source. The ion beam currents from the anode spot are observed to be maximized at the optimum bias voltage near the knee of the characteristic current-voltage curve of the anode spot. Increased potential barrier to obstruct beam extraction is the reason for the reduction of the ion beam current in spite of the increased bias current indicating the density of the anode spot. The optimum bias voltage is measured to be lower at higher operating pressure, which is favorable for stable operation without severe sputtering damage on the electrode. The ion beam current can be further enhanced by increasing the power for the ambient plasma without increasing the bias voltage. In the same manner, noble gases with higher atomic number as a feedstock gas are preferable for extracting higher beam current more stably. Therefore, performance of the plasma ion source with a positively biased electrode can be enhanced by controlling the operating conditions of the anode spot in various manners.
Extreme covariant quantum observables in the case of an Abelian symmetry group and a transitive value space
Authors: Haapasalo Erkka Theodor , Pellonpää Juha-Pekka
Published: December 2011

We represent quantum observables as normalized positive operator valued measures and consider convex sets of observables which are covariant with respect to a unitary representation of a locally compact Abelian symmetry group G. The value space of such observables is a transitive G-space. We characterize the extreme points of covariant observables and also determine the covariant extreme points of the larger set of all quantum observables. The results are applied to position, position difference, and time observables.
Enhancing the sensitivity of magnetoelectric sensors by increasing the operating frequency
Authors: Petrie Jonathan , Viehland Dwight , Gray David , Mandal Sanjay , Sreenivasulu Gollapudi , Srinivasan Gopalan , Edelstein Alan S.
Published: December 2011

We present a field modulation technique that increases the operating frequency of magnetoelectric (ME) sensors so that it can match the mechanical resonance frequency of the sensor. This not only improves the sensitivity but also reduces the effect of 1/f noise that is inherent at low frequencies. The technique, which is shown to apply to both symmetric and asymmetric ME sensors, relies on the strong, nonlinear magnetic field dependence of the magnetostriction. The combination of a lower 1/f noise and enhanced response at resonance has increased the signal to noise ratio of a symmetric sensor by two orders of magnitude. The detection limit of this sensor was lowered from 90 to 7 pT/Hz at 1 Hz in a magnetically unshielded environment.
Preparation of uncapped CdSe1−xSx semiconducting nanocrystals by mechanical alloying
Authors: Tan Guolong , Li Shaohua , Murowchick James B. , Wisner Clarissa , Leventis Nickolas , Peng Zhonghua
Published: December 2011

Composition-tunable ternary CdSe1−xSx nanocrystals are among the most extensively studied alloyed semiconducting quantum dots. They are, however, almost exclusively prepared by wet chemical routes which lead to surface-capped nanoparticles. Herein, we show that simple mechanical alloying can be applied to prepare uncapped CdSe1−xSx nanocrystals through the entire composition range. The resulting nanocrystals have average sizes smaller than 9 nm, are chemically homogenous, and show a linear lattice parameter-composition and close-to-linear band gap-composition relationships, demonstrating the ability for band gap engineering through composition tuning.
Gate-controlled electron
g
-factor in lateral quantum dot molecules
Authors: Ribeiro-Santos D. , Qu Fanyao , Morais P. C. , Lopez-Richard V. , Marques G. E.
Published: December 2011

We investigate theoretically the tunability of the effective electron g-factor in lateral double quantum dots, subjected simultaneously to spin-orbit interaction and vertical electrical and magnetic fields. We find that, by sweeping interdot barrier voltage or by changing interdot distance, the character of the electronic states can be modified from atomic-like to molecular-like and vice-versa. We report theoretical predictions for interdot voltage induced giant effective g-factor and study its dependence on the spin-orbit interaction strength. To avoid numerical artifacts in the single-electron energy spectrum, we adopt a set of modified Gaussian functions as basis, divide the full Hilbert space into orthogonal sub-spaces, and use an exact diagonalization method. In order to correct ill-definitions of g-factor found in the literature, we point out an unambiguous way to evaluate it.
Mid-infrared quantitative spectroscopy by comb-referencing of a quantum-cascade-laser: Application to the CO2 spectrum at 4.3 μm
Authors: Gambetta A. , Gatti D. , Castrillo A. , Galzerano G. , Laporta P. , Gianfrani L. , Marangoni M.
Published: December 2011

A robust phase-lock of a quantum-cascade-laser to a near-infrared frequency-comb allows absorption spectra of a CO2 gas sample to be acquired at different pressures with extreme repeatability and accuracy by tuning the repetition-rate of the comb, thus ensuring an absolute frequency scale on the acquired spectra. The method proves useful to retrieve traceable spectroscopic parameters such as line-center frequencies, line intensity factors, pressure shift, and pressure broadening coefficients, with unprecedented quality from the metrological point of view.
Modal dependence of dissipation in silicon nitride drum resonators
Authors: Adiga V. P. , Ilic B. , Barton R. A. , Wilson-Rae I. , Craighead H. G. , Parpia J. M.
Published: December 2011

We have fabricated large (≤400 μm diameter) high tensile stress SiN membrane mechanical resonators and measured the resonant frequency and quality factors (Q) of different modes of oscillation using optical interferometric detection. We observe that the dissipation (Q−1) is limited by clamping loss for pure radial modes, but higher order azimuthal modes are limited by a mechanism which appears to be intrinsic to the material. The observed dissipation is strongly dependent on size of the membrane and mode type. Appropriate choice of size and operating mode allows the selection of optimum resonator designs for applications in mass sensing and optomechanical experiments.
Phase-locking regimes of photonic crystal nanocavity laser arrays
Authors: Suhr T. , Kristensen P. T. , Mørk J.
Published: December 2011

We model and analyze the dynamical properties of coupled photonic crystal nanocavity lasers. The model includes Purcell enhancement of the spontaneous emission and intercavity coupling. The coupling strength between neighboring cavities is an essential parameter, and by performing finite-difference time-domain calculations, the typical coupling strength is extracted for realistic structures. Phase-locking regimes are identified, and their stability with respect to parameter variation is investigated. The results suggest that quantum well devices are not well suited for phase-locked nanocavity laser array devices.
Role for B-cell adapter for PI3K (BCAP) as a signaling adapter linking Toll-like receptors (TLRs) to serine/threonine kinases PI3K/Akt
Authors: Troutman Ty Dale , Hu Wei , Fulenchek Stephanie , Yamazaki Tetsuo , Kurosaki Tomohiro , Bazan J. Fernando , Pasare Chandrashekhar
Published: December 2011

Toll like receptors (TLRs) use Toll–IL-1 receptor (TIR) domain-containing adapters, such as myeloid differentiation primary response gene 88 (MyD88) and TIR domain-containing adapter inducing IFN-β (TRIF), to induce activation of transcription factors, including NF-κB, MAP kinases, and IFN regulatory factors. TLR signaling also leads to activation of PI3K, but the molecular mechanism is not understood. Here we have discovered a unique role for B-cell adapter for PI3K (BCAP) in the TLR-signaling pathway. We find that BCAP has a functional N-terminal TIR homology domain and links TLR signaling to activation of PI3K. In addition, BCAP negatively regulates proinflammatory cytokine secretion upon TLR stimulation. In vivo, the absence of BCAP leads to exaggerated recruitment of inflammatory myeloid cells following infections and enhanced susceptibility to dextran sulfate sodium-induced colitis. Our results demonstrate that BCAP is a unique TIR domain-containing TLR signaling adapter crucial for linking TLRs to PI3K activation and regulating the inflammatory response.
Bringing the ‘folk’ into applied linguistics
Authors: Wilton Antje , Stegu Martin
Published: December 2011

As applied linguistics is mainly concerned with solving the language-related problems of laypeople, the examination of folk views constitutes an important research field and its relevance is illustrated in this issue of the AILA review. In this introductory article, we address some of the more general aspects that need to be considered in the scientific investigation of folk views of language and communication. Among those aspects are the nature and significance of folk knowledge and folk attitudes for applied linguistics, the social construction of the roles of expert, scientist and layperson, and the connection between folk linguistic research and other related approaches. As a general introduction into the topic, this contribution prepares the ground for the other articles collected in this issue.
Linking past and present
Authors: Wilton Antje , Wochele Holger
Published: December 2011

In this paper, we focus on comments on language issues from a historical perspective. The concept of the layperson (non-linguist) is discussed to identify laypeople and lay comments in history when the modern concept of a linguist did not yet exist. Two studies show how the historical perspective complements modern research on folk linguistics.

Firstly, historical comments about Latin will be put in relation to comments about English, focusing on their roles as linguae francae and exploring the potential and application of the ‘Latin Analogy’.

Secondly, an analysis of language appraisal texts of French and Romanian from 1500 to the present shows that the topoi used are still reflected in today’s perception of the languages by their native speakers, affecting the attractiveness of the languages for second language learners.
Folk beliefs about second language learning and teaching
Authors: Pasquale Michael
Published: December 2011

What do students and teachers believe about the second language learning process? What if these beliefs are in conflict with each other or with prevailing applied linguistic theories? These are the types of questions that are investigated within folk linguistic research. Some researchers have taken a quantitative approach that relied on questionnaires (e.g., Horwitz 1985), while others have delved into the cognitive foundations of beliefs (e.g., Woods 2003). Lastly, some have used discoursal approaches which use discourse analytic (e.g., Pasquale & Preston, forthcoming) and culturally contextualized approaches (e.g., Barcelos 1995) suggesting that folk belief is a dynamic process. Therefore, a discoursal approach may provide insights into respondents’ reasoning rather than what might be considered more static domains of belief.
Iridescence and spectral filtering of the gyroid-type photonic crystals in
Parides sesostris
wing scales
Authors: Wilts Bodo D. , Michielsen Kristel , De Raedt Hans , Stavenga Doekele G.
Published: December 2011

The cover scales on the wing of the Emerald-patched Cattleheart butterfly,
Parides sesostris
, contain gyroid-type biological photonic crystals that brightly reflect green light. A pigment, which absorbs maximally at approximately 395 nm, is immersed predominantly throughout the elaborate upper lamina. This pigment acts as a long-pass filter shaping the reflectance spectrum of the underlying photonic crystals. The additional effect of the filtering is that the spatial distribution of the scale reflectance is approximately angle-independent, leading to a stable wing pattern contrast. The spectral tuning of the original reflectance is verified by photonic band structure modelling.
Individual variation and the resolution of conflict over parental care in penduline tits
Authors: van Dijk René E. , Székely Tamás , Komdeur Jan , Pogány Ákos , Fawcett Tim W. , Weissing Franz J.
Published: December 2011

Eurasian penduline tits (
Remiz pendulinus
) have an unusually diverse breeding system consisting of frequent male and female polygamy, and uniparental care by the male or the female. Intriguingly, 30 to 40 per cent of all nests are deserted by both parents. To understand the evolution of this diverse breeding system and frequent clutch desertion, we use 6 years of field data to derive fitness expectations for males and females depending on whether or not they care for their offspring. The resulting payoff matrix corresponds to an asymmetric Snowdrift Game with two alternative evolutionarily stable strategies (ESSs): female-only and male-only care. This, however, does not explain the polymorphism in care strategies and frequent biparental desertion, because theory predicts that one of the two ESSs should have spread to fixation. Using a bootstrapping approach, we demonstrate that taking account of individual variation in payoffs explains the patterns of care better than a model based on the average population payoff matrix. In particular, a model incorporating differences in male attractiveness closely predicts the observed frequencies of male and female desertion. Our work highlights the need for a new generation of individual-based evolutionary game-theoretic models.
Characterization of Pseudomonas aeruginosa isolates from dogs and cats in Japan: current status of antimicrobial resistance and prevailing resistance mechanisms
Authors: Harada Kazuki , Arima Sayuri , Niina Ayaka , Kataoka Yasushi , Takahashi Toshio
Published: December 2011

Seventy‐three Pseudomonas aeruginosa isolates were collected from dogs and cats in Japan to investigate antimicrobial susceptibility and resistance mechanisms to anti‐pseudomonal agents. Resistance rates against orbifloxacin, enrofloxacin, ciprofloxacin, cefotaxime, aztreonam and gentamicin were 34.2, 31.5, 20.5, 17.8, 12.3 and 4.1%, respectively. The degree of resistance to cefotaxime, orbifloxacin, and enrofloxacin was greatly affected by efflux pump inhibitors, indicating overexpression of efflux pump contributes to these resistances. Notably, orbifloxacin and enrofloxacin resistance was observed even in isolates without mutations in the target sites. This is the first report on cephalosporin‐ and fluoroquinolone‐resistant isolates of P. aeruginosa from Japanese companion animals.
Pharmacokinetics of tildipirosin in bovine plasma, lung tissue, and bronchial fluid (from live, nonanesthetized cattle)
Authors: MENGE M. , ROSE M. , BOHLAND C. , ZSCHIESCHE E. , KILP S. , METZ W. , ALLAN M. , RÖPKE R. , NÜRNBERGER M.
Published: December 2011

Menge, M., Rose, M., Bohland, C., Zschiesche, E., Kilp, S., Metz, W., Allan, M., Röpke, R., Nürnberger, M. Pharmacokinetics of tildipirosin in bovine plasma, lung tissue, and bronchial fluid (from live, nonanesthetized cattle). J. vet. Pharmacol. Therap. 35, 550–559.

The pharmacokinetics of tildipirosin (Zuprevo® 180 mg/mL solution for injection for cattle), a novel 16‐membered macrolide for treatment, control, and prevention of bovine respiratory disease, were investigated in studies collecting blood plasma, lung tissue, and in vivo samples of bronchial fluid (BF) from cattle. After single subcutaneous (s.c.) injection at 4 mg/kg body weight, maximum plasma concentration (Cmax) was 0.7 μg/mL. Tmax was 23 min. Mean residence time from the time of dosing to the time of last measurable concentration (MRTlast) and terminal half‐life (T1/2) was 6 and 9 days, respectively. A strong dose–response relationship with no significant sex effect was shown for both Cmax and area under the plasma concentration–time curve from time 0 to the last sampling time with a quantifiable drug concentration (AUClast) over the range of doses up to 6 mg/kg. Absolute bioavailability was 78.9%. The volume of distribution based on the terminal phase (Vz) was 49.4 L/kg, and the plasma clearance was 144 mL/h/kg. The time–concentration profile of tildipirosin in BF and lung far exceeded those in blood plasma. In lung, tildipirosin concentrations reached 9.2 μg/g at 4 h, peaked at 14.8 μg/g at day 1, and slowly declined to 2.0 μg/g at day 28. In BF, the concentration of tildipirosin reached 1.5 and 3.0 μg/g at 4 and 10 h, maintained a plateau of about 3.5 μg/g between day 1 and 3, and slowly declined to 1.0 at day 21. T1/2 in lung and BF was approximately 10 and 11 days. Tildipirosin is rapidly and extensively distributed to the respiratory tract followed by slow elimination.
Travel‐related disseminated Penicillium marneffei infection in a renal transplant patient
Authors: Hart J. , Dyer J.R. , Clark B.M. , McLellan D.G. , Perera S. , Ferrari P.
Published: December 2011

Penicillium marneffei is a thermally dimorphic fungus that causes severe human immunodeficiency virus‐related opportunistic infection in endemic areas of Southeast Asia and has rarely been reported in solid organ transplant (SOT) recipients. We report here the case of an Australian renal transplant patient who presented with disseminated P. marneffei infection shortly after a 10‐day holiday to Vietnam, and review all previously published cases of penicilliosis associated with renal transplantation. This is the first reported case, to our knowledge, of P. marneffei infection in an SOT recipient acquired during travel to an endemic country, and highlights the importance of an accurate travel history when opportunistic infection is suspected, as well as giving appropriate health advice to transplant patients who travel.
How does hepatitis B virus infection react to hepatocellular carcinoma treatment?
Authors: Wong Grace L‐H
Published: December 2011

See article in J. Gastroenterol. Hepatol. 2012; 27: 158–164.
Balloon‐occluded retrograde transvenous obliteration: One step beyond obliteration of gastric varices
Authors: Kawanaka Hirofumi
Published: December 2011

See article in J. Gastroenterol. Hepatol. 2012; 27: 137–141.
Histological features of non‐alcoholic fatty liver disease: What is important?
Authors: Hashimoto Etsuko , Tokushige Katsutoshi , Farrell Geoffrey C
Published: December 2011

See article in J. Gastroenterol. Hepatol. 2012; 27: 142–148.
Data‐driven models for regional coral‐reef dynamics
Authors: Żychaluk Kamila , Bruno John F. , Clancy Damian , McClanahan Tim R. , Spencer Matthew
Published: December 2011

Ecology Letters (2011)

Coral reefs have been affected by natural and anthropogenic disturbances. Coral cover has declined on many reefs, and macroalgae have increased on some. The existence of alternative stable states with high or low coral cover has been widely debated, but not clearly established. We evaluate the evidence for alternative stable states in benthic coral‐reef dynamics in the Caribbean, Kenya and Great Barrier Reef (GBR), using stochastic semi‐parametric models based on large numbers of time series of cover of hard corals, macroalgae and other components. Only the GBR showed a consistent short‐term regional decline in coral cover. There was no evidence for regional increases in macroalgae. The equilibrium distributions of our models were close to recently observed distributions, and differed among regions. In all three regions, the equilibrium distributions were unimodal rather than bimodal, and thus did not suggest the existence of alternative stable states on a regional scale, under current conditions.
Text Matters: Some Reflections on the Forging of a New Constitutional Jurisprudence in South Africa
Authors: O'Regan Kate
Published: December 2011

The South African Constitution establishes a constitutional democracy with a strong form of constitutional review. The Constitutional Court is required to declare invalid any legislation or conduct of the President which is inconsistent with the Constitution. The author, a former judge of the Constitutional Court, argues that the text of the Constitution has been an important determinant of the Court's jurisprudence, both in relation to the Court's jurisprudence concerning the institutional structures established by the Constitution and its Bill of Rights jurisprudence.
Good Faith, Flawed Assets and the Emasculation of the UK Anti‐Deprivation Rule
Authors: Worthington Sarah
Published: December 2011

The Supreme Court's unanimous decision in Belmont Park Investments Pty Ltd v BNY Corporate Trustee Services Ltd and Lehman Brothers Special Financing Inc is of major significance to lenders, especially those in the global structured finance market. This case confirms the validity of commonly used insolvency‐triggered secured‐priority flip clauses, and, more generally, suggests a dramatically reduced role for the common law anti‐deprivation principle. The decision may not fully resolve market uncertainty, however, given the particular analysis adopted in the case itself (analysed here) and its divergence from the US statutory approach to the same principle.
Musculature Tissue Engineering to Repair Abdominal Wall Hernia
Authors: Zhang Lu , Li Qiong , Qin Jian , Gu Yan
Published: December 2011

Hernia repair is one of the most frequently performed operations in surgical clinics. Tissue engineering provides insights for the treatment of abdominal wall hernias and other disorders involving deficiencies in the musculature. The present review summarizes the mechanisms of muscle development and regeneration and provides an overview of tissue engineering strategies for the construction of muscles.
Deferoxamine Attenuates Lipid Peroxidation, Blocks Interleukin‐6 Production, Ameliorates Sepsis Inflammatory Response Syndrome, and Confers Renoprotection After Acute Hepatic Ischemia in Pigs
Authors: Vlahakos Demetrios , Arkadopoulos Nikolaos , Kostopanagiotou Georgia , Siasiakou Sofia , Kaklamanis Loukas , Degiannis Dimitrios , Demonakou Maria , Smyrniotis Vassilios
Published: December 2011

We have previously shown that deferoxamine (DFO) infusion protected myocardium against reperfusion injury in patients undergoing open heart surgery, and reduced brain edema, intracranial pressure, and lung injury in pigs with acute hepatic ischemia (AHI). The purpose of this research was to study if DFO could attenuate sepsis inflammatory response syndrome (SIRS) and confer renoprotection in the same model of AHI in anesthetized pigs. Fourteen animals were randomly allocated to two groups. In the Group DFO (n = 7), 150 mg/kg of DFO dissolved in normal saline was continuously infused in animals undergoing hepatic devascularization and portacaval anastomosis. The control group (Group C, n = 7) underwent the same surgical procedure and received the same volume of normal saline infusion. Animals were euthanized after 24 h. Hematological, biochemical parameters, malondialdehyde (MDA), and cytokines (interleukin [IL]‐1β, IL‐6, IL‐8, IL‐10, and tumor necrosis factor‐α) were determined from sera obtained at baseline, at 12 h, and after euthanasia. Hematoxylin–eosin and terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate nick end labeling were used to evaluate necrosis and apoptosis, respectively, in kidney sections obtained after euthanasia. A rapid and substantial elevation (more than 100‐fold) of serum IL‐6 levels was observed in Group C reaching peak at the end of the experiment, associated with increased production of oxygen free radicals and lipid peroxidation (MDA 3.2 ± 0.1 nmol/mL at baseline and 5.5 ± 0.9 nmol/mL at the end of the experiment, P < 0.05) and various manifestations of SIRS and multiple organ dysfunction (MOD), including elevation of high‐sensitivity C‐reactive protein, severe hypotension, leukocytosis, thrombocytopenia, hypoproteinemia, and increased serum levels of lactate dehydrogenase (fourfold), alkaline phosphatase (fourfold), alanine aminotransferase (14‐fold), and ammonia (sevenfold). In sharp contrast, IL‐6 production and lipid peroxidation were completely blocked in DFO‐treated animals offering remarkable resistance to the development of SIRS and MOD. Profound proteinuria, strips of extensive necrosis of tubular epithelial cells, and occasional apoptotic tubular epithelial cells were already present in Group C, but not in Group DFO animals at the time of euthanasia. DFO infusion attenuated lipid peroxidation, blocked IL‐6 production, and substantially diminished SIRS and MOD, including tubulointerstitial damage in pigs after acute ischemic hepatic failure. This finding shows that iron, IL‐6, and lipid peroxidation are important participants in the pathophysiology of renal injury in the course of generalized inflammation and provides novel pathways of therapeutic interventions for renal protection.
Perceived Support, Belonging, and Possible Selves Strategies Among Incarcerated Juvenile Offenders1
Authors: CLINKINBEARD SAMANTHA S. , MURRAY COLLEEN I.
Published: December 2011

Possible selves theory (Markus & Nurius, 1986) suggests that future‐oriented expectations, fears, and strategies are constrained by feedback in one's sociocultural context. The current paper represents a preliminary look into the relationship between support in one's immediate context and the development of strategies for the achievement of desired future selves. Youthful offenders (N = 543) were surveyed in secured treatment facilities in Alaska, Idaho, Nevada, and Oregon. Program belonging was a consistent predictor of strategy generation among both males and females, and attributional support from a staff person was significant among males. The findings support further examination of interpersonal interactions as they relate to future‐oriented planning and point to a need for further investigation into the development of concrete strategies.
Stability, chaos and entrapment of stars in very wide pairs
Authors: Makarov Valeri V.
Published: December 2011

The relative motion of stars and other celestial objects in very wide pairs, separated by distances of the order of 1 pc, is strongly influenced by the tidal gravitational potential of the Galaxy. The Coriolis component of the horizontal tidal force in the rotating reference frame tends to disrupt such marginally bound pairs. However, even extremely wide pairs of bodies can be bound over intervals of time comparable to the Hubble time, under appropriate initial conditions. Here we show that for arbitrary chosen initial coordinates of a pair of stars, there exists a volume of the space of initial velocity components where the orbits remain bound in the planar tidal field for longer than 10 Gyr, even though the initial separation is well outside the Jacobi radius. The boundary of this phase space of stable orbits is fractal, and the motion at the boundary conditions is clearly chaotic. We found that the pairs may remain confined for several Gyr, and then suddenly disintegrate due to a particularly close rendezvous. By reversing such long-term stable orbits, we find that entrapment of unrelated stars into wide pairs is possible, but should be quite rare. Careful analysis of precision astrometry surveys revealed that extremely wide pairs of stars are present in significant numbers in the Galaxy. These results are expected to help in discriminating the cases of genuine binarity and chance entrapment, and to make inroads in testing the limits of Newtonian gravitation.
Comparison of in-vivo and in-silico methods used for prediction of tissue: plasma partition coefficients in rat
Authors: Graham Helen , Walker Mike , Jones Owen , Yates James , Galetin Aleksandra , Aarons Leon
Published: December 2011

Objectives

To use methods from the literature to predict rat tissue:plasma partition coefficients (Kps) and volume of distribution values. Determine which model provides the most accurate predictions to increase confidence in the use of predicted pharmacokinetic parameters in physiologically based pharmacokinetic modelling.

Methods

Six models were used to predict Kps and four to predict Vss for a dataset of 81 compounds in 11 rat tissues, and the predictions were compared with experimentally derived values.

Key findings

Kp predictions made by the Rodgers et al. model were the most accurate, with 77% within threefold of experimental values. The Poulin & Theil model was the most accurate for the prediction of Vss, with 87% of predictions within threefold.

Conclusions

This study has shown that in-silico models available in the literature can be used to accurately predict Kp and Vss in rat. The Rodgers et al. model has been shown to provide the most accurate Kp predictions, with consistent accuracy across all drug classes and tissues. It was also the most accurate Vss predictor when no in-vivo data were used as input. However, transporter systems and other mechanisms that are not yet fully understood need to be incorporated into these types of models in the future to further increase their applicability.
Does Nature Have to Be Natural? The Question of Wetland Interpretation
Authors: Jones Barbara K.
Published: December 2011

Through a study of modified natural landscapes, particularly cranberry bogs, this article investigates the broad understandings of nature and wilderness. In relying on a nature as wilderness paradigm to identify what is ecologically valuable, the potential exists to disregard altered nature as ecologically damaged. This approach to understanding nature discounts the value of agricultural sites that demonstrate another way of seeing nature, one that appreciates its resilience. This article strives to understand how current metaphors that define nature as pristine fail to consider how altered nature can and does have significant ecological value.
Zapatista Autonomy in Cartel Mexico: Preserving Smallholder Viability
Authors: Earle Duncan , Simonelli Jeanne
Published: December 2011

A full century after the Mexican Revolution of 1910 and 18 years after the 1994 Zapatista uprising, Mexico, our southern neighbor, is in the throes of another crisis, gripped by an epoch of unprecedented drug‐related violence and war which is bleeding in and out of its borders, both south and north. This report provides an update on continuing Zapatista autonomy, placing the narrative into the context of the impact of the narco wars on Mexican agricultural communities.
Application of Cascade Hand Detection for Touchless Interaction in Virtual Design
Authors: Guan Y. Q. , Tan H. S. , Furtado F. , Tan A.
Published: December 2011

This paper proposes a method for robust hand detection for interactive touchless display using cascade classifier technique. A hardware system comprising a transparent display, two video cameras and a projector is assembled to generate on-display-surface object images for touchless display. A well-trained cascade of boosted classifiers is applied to detect the position of the hand in the object image. Using this method, accurate and robust hand detection for touchless display can be achieved. The detected hand trajectory information can be converted into mouse and keyboard inputs for interactive control and manipulation in virtual applications like virtual assembly and virtual design.
On the Enduring Appeal of Least-Squares Fitting in Computational Coordinate Metrology
Authors: Srinivasan Vijay , Shakarji Craig M. , Morse Edward P.
Published: December 2011

The vast majority of points collected with coordinate measuring machines are not used in isolation; rather, collections of these points are associated with geometric features through fitting routines. In manufacturing applications, there are two fundamental questions that persist about the efficacy of this fitting—first, do the points collected adequately represent the surface under inspection; and second, does the association of substitute (fitted) geometry with the points meet criteria consistent with the standardized geometric specification of the product. This paper addresses the second question for least-squares fitting both as a historical survey of past and current practices, and as a harbinger of the influence of new specification criteria under consideration for international standardization. It also touches upon a set of new issues posed by the international standardization on the first question as related to sampling and least-squares fitting.
The Influence of Inlet Fogging for the Stable Range in a Transonic Compressor Stage
Authors: Luo Mingcong , Zheng Qun , Sun Lanxin , Deng Qingfeng , Li Song , Liu Chunlei , Bhargava Rakesh K.
Published: December 2011

The inlet fogging effects on the stable range of a NASA transonic compressor stage, Stage 35, are numerically simulated and analyzed in this paper. The 3D two-phase flow fields in the compressor stage are investigated under different operating flow conditions with varying levels of the injected water flow rates and the fogging droplets sizes. The special attention is given to the stall and the choking operating points to investigate changes in the stable operating range of the compressor stage as a result of different wet compression conditions. The preliminary results indicate that the inlet fogging has different effects on either the stall and/or the choking range. The change in the stable range of this transonic compressor stage depends on the fogging flow rate and droplets diameters.
Stability Analysis of an Industrial Gas Compressor Supported by Tilting-Pad Bearings Under Different Lubrication Regimes
Authors: Cerda Varela Alejandro , Ferreira Santos Ilmar
Published: December 2011

This work is aimed at a theoretical study of the dynamic behavior of a rotor-tilting pad journal bearing (TPJB) system under different lubrication regimes, namely, thermohydrodynamic (THD), elastohydrodynamic (EHD), and hybrid lubrication regime. The rotor modeled corresponds to an industrial compressor. Special emphasis is put on analyzing the stability map of the rotor when the different lubrication regimes are included into the TPJB modeling. Results show that, for the studied rotor, the inclusion of a THD model is more relevant when compared to an EHD model, as it implies a reduction on the instability onset speed for the rotor. Also, results show the feasibility of extending the stable operating range of the rotor by implementing a hybrid lubrication regime.
Effect of Bond Layer on Bimaterial Assembly Subjected to Uniform Temperature Change
Authors: Sujan D. , Woldemichael Dereje E. , Murthy M. V. V. , Seetharamu K. N.
Published: December 2011

When two thin plates or layers are bonded together, an extremely thin bond layer of third material exists between the two layers. This research work examines the effect of bond layer on the interfacial shearing and peeling stresses in a bimaterial model. Earlier papers on this topic are based on several mutually contradictory expressions for the shear compliance of the bond layer. This paper is aimed at resolving this ambiguity and presents derivation of shear compliance on a rational basis. A numerical example is carried out for a silicon-copper system with a gold-tin solder bond layer. The results obtained are likely to be useful in interfacial stress evaluation and physical design of bimaterial assemblies used in microelectronics and photonics applications.
Targeted Particle Tracking in Computational Models of Human Carotid Bifurcations
Authors: Marshall Ian
Published: December 2011

A significant and largely unsolved problem of computational fluid dynamics (CFD) simulation of flow in anatomically relevant geometries is that very few calculated pathlines pass through regions of complex flow. This in turn limits the ability of CFD-based simulations of imaging techniques (such as MRI) to correctly predict in vivo performance. In this work, I present two methods designed to overcome this filling problem, firstly, by releasing additional particles from areas of the flow inlet that lead directly to the complex flow region (“preferential seeding”) and, secondly, by tracking particles both “downstream” and “upstream” from seed points within the complex flow region itself. I use the human carotid bifurcation as an example of complex blood flow that is of great clinical interest. Both idealized and healthy volunteer geometries are investigated. With uniform seeding in the inlet plane (in the common carotid artery (CCA)) of an idealized bifurcation geometry, approximately half the particles passed through the internal carotid artery (ICA) and half through the external carotid artery. However, of those particles entering the ICA, only 16% passed directly through the carotid bulb region. Preferential seeding from selected regions of the CCA was able to increase this figure to 47%. In the second method, seeding of particles within the carotid bulb region itself led to a very high proportion (97%) of pathlines running from CCA to ICA. Seeding of particles in the bulb plane of three healthy volunteer carotid bifurcation geometries led to much better filling of the bulb regions than by particles seeded at the inlet alone. In all cases, visualization of the origin and behavior of recirculating particles led to useful insights into the complex flow patterns. Both seeding methods produced significant improvements in filling the carotid bulb region with particle tracks compared with uniform seeding at the inlet and led to an improved understanding of the complex flow patterns. The methods described may be combined and are generally applicable to CFD studies of fluid and gas flow and are, therefore, of relevance in hemodynamics, respiratory mechanics, and medical imaging science.
Tortuosity Triggers Platelet Activation and Thrombus Formation in Microvessels
Authors: Chesnutt Jennifer K. W. , Han Hai-Chao
Published: December 2011

Tortuous blood vessels are often seen in humans in association with thrombosis, atherosclerosis, hypertension, and aging. Vessel tortuosity can cause high fluid shear stress, likely promoting thrombosis. However, the underlying physical mechanisms and microscale processes are poorly understood. Accordingly, the objectives of this study were to develop and use a new computational approach to determine the effects of venule tortuosity and fluid velocity on thrombus initiation. The transport, collision, shear-induced activation, and receptor-ligand adhesion of individual platelets in thrombus formation were simulated using discrete element method. The shear-induced activation model assumed that a platelet became activated if it experienced a shear stress above a relative critical shear stress or if it contacted an activated platelet. Venules of various levels of tortuosity were simulated for a mean flow velocity of 0.10 cm s−1, and a tortuous arteriole was simulated for a mean velocity of 0.47 cm s−1. Our results showed that thrombus was initiated at inner walls in curved regions due to platelet activation in agreement with experimental studies. Increased venule tortuosity modified fluid flow to hasten thrombus initiation. Compared to the same sized venule, flow in the arteriole generated a higher amount of mural thrombi and platelet activation rate. The results suggest that the extent of tortuosity is an important factor in thrombus initiation in microvessels.
Electron field emission from undoped polycrystalline diamond particles synthesized by microwave-plasma chemical vapor deposition
Authors: Nose Kenji , Fujita Ryuhei , Kamiko Masao , Mitsuda Yoshitaka
Published: December 2011

Electron emission from polycrystalline diamond particles (PDPs) was obtained at low electric fields in the absence of intentional doping. The PDPs were synthesized on a silicon substrate using microwave-plasma chemical vapor deposition accompanied by bias-enhanced nucleation. Polycrystalline diamond particles of two different sizes, i.e., ∼500 nm and 2 to 5 μm, were obtained, the surfaces of which were covered with small crystal grains composed of fine facets. Electron emission from the PDPs was characterized by Fowler-Nordheim tunneling with low turn-on-field values (0.8 – 2.0 V/μm) and a low barrier height of 0.02 eV. An emission current greater than 5 μA was maintained for over 24 h in a cathode based on the developed PDPs. In contrast, single-crystalline diamond particles prepared for comparative purposes exhibited no emission up to 2.5 V/μm. Auger electron spectroscopy revealed that the surface oxygen content modified by annealing in air did not affect the emission properties. The macroscopic spatial distribution of the emission spots was roughly consistent with the population density distribution of PDPs on the cathode. It is postulated that emission from the PDPs arises as a result of the small crystal grains on the surface and the presence of a sp2-bonded phase in the grain boundaries, which enabled strong field enhancement and carrier transport through the undoped diamond particles.
A New Twist in a Fibrous Condition
Authors: Shum Anthony K.
Published: December 2011

Regulatory T cells stimulate pulmonary fibrosis.