bluuebunny/crossref_metadata_2025 huggingface dataset:
Parameters optimization for cooperative sensing in multi‐channel cognitive radio networks
Authors: Yang Wei , Guan Donglin , Ye Xiqing , Dou Wenhua
Published: June 2012

In this paper, we propose a relatively complete and robust optimization model under the scenario where multisecondary users cooperatively sense multi‐channels. The objective of this model is to maximize the system throughput, meanwhile aims to jointly optimize the parameters including the sensing time and the weight coefficients of the sampling results. Because this model is a nonlinear optimization model, we instead adopt a heuristic sequential parameters optimization method (SPO) to solve the model. The method begins with deriving the lower bound of the objective function of the optimization model. Then, it maximizes this lower bound by optimizing the weight coefficients through solving a series of suboptimal problems using Lagrange method. Given that the weight coefficients are found, it finally transforms the problem into another monotonic programming problem and exploits a fast‐convergent polyblock algorithm to find an optimized sensing time parameter. We finally conduct extensive experiments by simulations. The results demonstrate that, in terms of the throughput gained by the system, SPO can deliver a solution that is up to 99.3% of the optimal on average, which indicates that SPO can solve the proposed optimization model effectively. In addition, we also show the performance advantage of the proposed model on improving the system throughput by comparing with other state‐of‐the‐art optimization models. Wireless Communications and Mobile Computing. Copyright © 2012 John Wiley & Sons, Ltd.
Disjunctivism, hallucinations, and metacognition
Authors: Jérôme Dokic , Jean‐Rémy Martin
Published: June 2012

Perceptual experiences have been construed either as representational mental states—Representationalism—or as direct mental relations to the external world—Disjunctivism. Both conceptions are critical reactions to the so‐called ‘Argument from Hallucination’, according to which perceptions cannot be about the external world, since they are subjectively indiscriminable from other, hallucinatory experiences, which are about sense‐data or mind‐dependent entities. Representationalism agrees that perceptions and hallucinations share their most specific mental kind, but accounts for hallucinations asmisrepresentations of the external world. According to Disjunctivism, the phenomenal character of perceptions is exhausted by worldly objects and features, and thus must be different from the phenomenal character of hallucinations. Disjunctivism claims that subjective indiscriminability is not the result of a common experiential ground, but is because of our inability to discriminate, from the inside, hallucinations from perceptions. At first sight, Representationalism is more congenial to the way cognitive science deals with perception. However, empirically oriented revisions of Disjunctivism could be developed and tested by giving a metacognitive account of hallucinations. Two versions of this account can be formulated, depending on whether metacognition is understood as explicit metarepresentation or as implicit monitoring of first‐order informational states. The first version faces serious objections, but the second is more promising, as it embodies a more realistic view of perceptual phenomenology as having both sensory and affective aspects. Affect‐based phenomenology is constituted by various metacognitive feelings, such as the feeling of being perceptually confronted with the world itself, rather than with pictures or mere representations.WIREs Cogn Sci2012 doi: 10.1002/wcs.1190

This article is categorized under:

Philosophy > Consciousness
A vortex panel model for the simulation of the wake flow past a vertical axis wind turbine in dynamic stall
Authors: Zanon Alessandro , Giannattasio Pietro , Simão Ferreira Carlos J.
Published: June 2012

A 2D vortex panel model with a viscous boundary layer formulation has been developed for the numerical simulation of a vertical axis wind turbine (VAWT), including the operation in dynamic stall. The model uses the ‘double wake’ concept to reproduce the main features of the unsteady separated flow, including the formation and shedding of strong vortical structures and the wake–blade interaction. The potential flow equations are solved together with the integral boundary layer equations by using a semi‐inverse iterative algorithm. A new criterion for the reattachment of the boundary layer during the downstroke of a dynamically stalled aerofoil is implemented. The model has been validated against experimental data of steady aerofoils and pitching aerofoils in dynamic stall at high and low Reynolds numbers (Re = 1.5 × 106 and Re = 5 × 104). For the low Reynolds number case, time‐resolved 2D particle image velocimetry (PIV) measurements have been performed on a pitching NACA 0012 aerofoil in dynamic stall. The PIV vorticity fields past the oscillating aerofoil are used to test the model capability of capturing the formation, growth and release of the strong leading edge vortex that characterizes the dynamic stall. Furthermore, the forces extracted from the PIV velocity fields are compared with the predicted ones for a quantitative validation of the model. Finally, the model is applied to the computation of the wake flow past a VAWT in dynamic stall; the predicted vorticity fields and forces are in good agreement with phase‐locked PIV data and CFD‐DES available in the literature. Copyright © 2012 John Wiley & Sons, Ltd.
Perspectives on the ARE as it turns 25 years old
Authors: Beisang Daniel , Bohjanen Paul R.
Published: June 2012

The AU‐rich element (ARE) was discovered in 1986 as a conserved mRNA sequence found in the 3′ untranslated region of the TNF‐α transcript and other transcripts encoding cytokines and inflammatory mediators. Shortly thereafter, the ARE was shown to function as a regulator of mRNA degradation, and AREs were later shown to regulate other posttranscriptional mechanisms such as translation and mRNA localization. AREs coordinately regulate networks of chemokine, cytokine, and growth regulatory transcripts involved in cellular activation, proliferation, and inflammation. ARE‐mediated regulation is carried out by a host of ARE‐binding proteins, whose activity is regulated in a cell type and activation‐dependent manner. The last 25 years of ARE research has offered insight into the mechanisms and regulation of ARE‐mediated mRNA decay, and has provided a road map for the discovery of additional mRNA regulatory motifs. The future of ARE research will transition from a discovery phase to a phase focused on translating basic biological findings into novel therapeutic targets. Our understanding of ARE‐mediated gene regulation and posttranscriptional control has implications for many fields of study including developmental biology, neuroscience, immunobiology, and cancer biology. WIREs RNA 2012 doi: 10.1002/wrna.1125

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications

RNA Turnover and Surveillance > Regulation of RNA Stability

RNA in Disease and Development > RNA in Disease
Preliminary Findings of Fecal Gonadal Hormone Concentrations in Six Captive Sea Otters (Enhydra lutris) after Deslorelin Implantation
Authors: Larson S. , Belting T. , Rifenbury K. , Fisher G. , Boutelle S. M.
Published: July 2012

The sea otter (Enhydra lutris) is a popular exhibit animal in many zoos and aquariums worldwide. Captive sea otters from these populations are owned by the United States Fish and Wildlife Service (USFWS). The USFWS has requested that these sea otters be prevented from breeding in order to save captive space for wild rescued animals. Sea otters are often housed in mixed sex groups, therefore a chemical contraceptive method or surgical removal of gonads must be used to prevent potential pregnancy. The contraceptive, Suprelorin® or deslorelin, has been used in many different species to effectively suppress reproduction but duration of effect may vary not only between species but also individuals. Here, we report the effects of one to several consecutive deslorelin implants on gonadal reproductive hormones found in fecal samples from six captive sea otters (two males and four females) compared to two control otters (one male and one female) housed at three zoological institutions. We documented the longitudinal hormone signatures of many stages of the contraceptive cycle including pretreatment (PT), stimulatory phase (S), effective contraception (EC), and hormone reversal (HR) that was characterized by a return to normal hormone levels. Deslorelin was found to be an effective contraceptive in sea otters and was found to be reversible documented by a live birth following treatment, however the duration of suppression in females was much longer than expected with a 6‐month and a 1‐year implant lasting between 3 and 4 years in females. Zoo Biol. 32:307–315, 2013. © 2012 Wiley Periodicals, Inc.
Classical Galactosaemia in Ireland: incidence, complications and outcomes of treatment
Authors: Coss K. P. , Doran P. P. , Owoeye C. , Codd M. B. , Hamid N. , Mayne P. D. , Crushell E. , Knerr I. , Monavari A. A. , Treacy E. P.
Published: July 2012

Newborn screening for the inborn error of metabolism, classical galactosaemia prevents life‐threatening complications in the neonatal period. It does not however influence the development of long‐term complications and the complex pathophysiology of this rare disease remains poorly understood. The objective of this study was to report the development of a healthcare database (using Distiller Version 2.1) to review the epidemiology of classical galactosaemia in Ireland since initiation of newborn screening in 1972 and the long‐term clinical outcomes of all patients attending the National Centre for Inherited Metabolic Disorders (NCIMD). Since 1982, the average live birth incidence rate of classical galactosaemia in the total Irish population was approximately 1:16,476 births. This reflects a high incidence in the Irish ‘Traveller’ population, with an estimated birth incidence of 1:33,917 in the non‐Traveller Irish population. Despite early initiation of treatment (dietary galactose restriction), the long‐term outcomes of classical galactosaemia in the Irish patient population are poor; 30.6 % of patients ≥6 yrs have IQs <70, 49.6 % of patients ≥2.5 yrs have speech or language impairments and 91.2 % of females ≥13 yrs suffer from hypergonadotrophic hypogonadism (HH) possibly leading to decreased fertility. These findings are consistent with the international experience. This emphasizes the requirement for continued clinical research in this complex disorder.
Micromechanical assessment of an internal stability criterion
Authors: Shire T. , O’Sullivan C.
Published: June 2012

The internal stability of a soil is a measure of its susceptibility to suffusion and suffosion, two forms of internal erosion. The internal stability of granular filters must be carefully considered when designing new embankment dams and assessing the risk associated with existing embankment dams. Current guidelines for assessing the internal stability of such filters were empirically derived from macroscale observations and consider the shape of the particle-size distribution curve. These guidelines lack a fundamental, scientific micromechanical basis. The initiation and propagation of internal erosion is clearly a particle-scale phenomenon, and this paper applies particulate mechanics to provide a micromechanical justification for one currently used stability criterion. The study used discrete element simulations of idealised virtual soil samples that had various degrees of internal stability when assessed using the criterion proposed by Kézdi [10]. The internal topologies of stable and unstable samples were analysed by considering the distributions of inter-particle contact forces, the number of particle–particle contacts and the average particle stresses. Clear correlations are observed between the filter stability criterion and the average number of contacts per particle and the probability that a given particle participates in stress transmission. The phenomenon of a critical fines content, at which the existing guidelines are no longer considered to be valid, is also considered.
Birth-related femoral fracture in newborns: Risk factors and management
Authors: Kancherla Ramprasad , Sankineani Sukesh Rao , Naranje Sameer , Rijal Laxman , Kumar Ramakant , Ansari Tahir , Trikha Vivek
Published: June 2012

Purpose

Femoral shaft fracture following birth in newborns is a very rare injury. However, the risk factors for, mechanism of and management of these injuries remain a matter of debate. We describe our observations in a tertiary centre.

Methods

Ten cases of femoral shaft fracture encountered during a study period from January 2005 to December 2009 were evaluated. The demographic details, risk factors during birth, systemic illness, mode of delivery, type of fracture and management used were documented, and an analysis was performed.

Results

Mean gestational age was 37.2 weeks. Mean time to diagnose was 4 days. Two patients had subtrochanteric fracture, and eight patients had mid-shaft fracture. Most patients had breech presentation and had been born by Caesarean section. All patients showed complete union at the end of 4 weeks. No residual angulation or limb length discrepancy was noted after mean follow-up of 5 years.

Conclusions

Thorough clinical examination and proper orthopaedic consult in the event of doubtful presentation help in early diagnosis and management. These fractures have good prognosis at long-term follow-up.
Childhood Circumstances and the Intergenerational Transmission of Socioeconomic Status
Authors: Carvalho Leandro
Published: July 2012

A large literature has documented the intergenerational transmission of socioeconomic status (SES). However, the mechanisms by which SES transmits across generations are still little understood. This article investigates whether characteristics determined in childhood play an important role in the intergenerational transmission. Using data from the Cebu Longitudinal Health and Nutrition Survey, I document the extent to which childhood human capital accounts for the intergenerational SES correlation. My results imply that childhood health and nutrition, cognitive and noncognitive abilities, and early schooling account for between one-third and one-half of the relationship between parents’ SES and their offspring’s SES.
Non-collapsing in fully non-linear curvature flows
Authors: Andrews Ben , Langford Mat , McCoy James
Published: June 2012

We consider compact, embedded hypersurfaces of Euclidean spaces evolving by fully non-linear flows in which the normal speed of motion is a homogeneous degree one, concave or convex function of the principal curvatures, and prove a non-collapsing estimate: Precisely, the function which gives the curvature of the largest interior ball touching the hypersurface at each point is a subsolution of the linearized flow equation if the speed is concave. If the speed is convex then there is an analogous statement for exterior balls. In particular, if the hypersurface moves with positive speed and the speed is concave in the principal curvatures, the curvature of the largest touching interior ball is bounded by a multiple of the speed as long as the solution exists. The proof uses a maximum principle applied to a function of two points on the evolving hypersurface. We illustrate the techniques required for dealing with such functions in a proof of the known containment principle for flows of hypersurfaces.
Surgical Risk Factors in Geriatric Perioperative Patients
Authors: Bashaw Marie , Scott Dana N.
Published: June 2012

The geriatric population is growing in number, and risk factors commonly seen in this population of patients can seriously affect the outcomes of surgical interventions. Identification of surgical risk factors (eg, hearing and vision loss, inadequate nutrition, preexisting conditions) and early intervention by the perioperative nurse to plan for, correct, or accommodate physical limitations often can minimize or eliminate problems and potential complications.
Is It Time for Family Presence During Resuscitation in the OR?
Authors: Balogh‐Mitchell Cathy
Published: June 2012

Family presence during resuscitation (FPDR) is a growing trend in many areas of health care facilities, and it may be time to consider allowing FPDR in the OR as well. Health care providers cite concerns against FPDR, however, including psychological trauma of family members, medical litigation, performance anxiety of staff members affecting performance quality, team member distractions, problems maintaining sterility, and questions regarding a patient's right to FPDR. The circulating nurse may be an appropriate person to advocate for the patient's wishes to allow family members access to the OR during resuscitation efforts. Two hospitals in Spokane, Washington, have implemented a hospital‐wide FPDR policy, allowing family presence in the emergency department, trauma rooms, labor and delivery rooms, and on patient care floors. Committee members developed guidelines for FPDR in the OR, educated hospital staff members, and presented the concept of FPDR to surgery executive committee members.
Parental Presence During Pediatric Anesthesia Induction
Authors: Scully Susan M.
Published: June 2012

Children undergoing a surgical intervention may experience anxiety before anesthesia induction. This article reviews six research studies that examined the efficacy of parental presence during the induction of anesthesia. Study researchers compared the premedication midazolam, behavioral distraction, and parental presence as measures to lessen anxiety during anesthesia induction. The reviewed articles indicate that parental presence alone is the least effective means of decreasing a child's anxiety during the induction of anesthesia.
Clinical Issues—July 2012
Authors: Burlingame Byron L.
Published: June 2012

This Month

Defining areas of the surgical suite

Key words: restricted, unrestricted, semirestricted, building code, HVAC, environmental controls.

Trocar insertion by RN first assistants

Key words: trocar insertion, RNFA scope of practice.
Case Study: Family Presence in the OR for Donation After Cardiac Death
Authors: Reed Charles C. , Gerhardt Susan D. , Shaver Karen , Koebcke Marsha , Mullins Darla
Published: June 2012

Organ donation after cardiac death is an ethical and acceptable practice of providing organs for transplantation. Organ recovery, the removal of life support, and patient death occur in the OR, and, because family members are not present, some feel that they have abandoned their loved one. This article reports a case study of a young woman brought to a level I trauma center with nonsurvivable injuries from a motor vehicle accident. When clinical examinations revealed no hope of recovery, the family agreed to organ donation if the mother could be present in the OR when life support was terminated. Family member presence during organ donation may provide a sense that some good has come of a personal tragedy. Although family requests may be unsettling, advocating for the patient and family is part of the nurse's role.
Anesthesia and Perioperative Care for Aortic Surgery
Authors: Tinkham Michelle R.
Published: June 2012

Anesthesia and Perioperative Care for Aortic Surgery Kathirvel Subramaniam, Kyung W. Park and Balachundhar Subramaniam 2011, Springer 448 pages, hardcover
Volunteering at Home and Abroad: The Essential Guide for Nurses
Authors: Watson Carolyn
Published: June 2012

Volunteering at Home and Abroad: The Essential Guide for Nurses Jeanne Leffers, Julia Plotnick 2011, Sigma Theta Tau International 308 pages, paperback
The Human Body Coloring Book
Authors: Whiteside Dawn
Published: June 2012

The Human Body Coloring Book 2011, DK Publishing 256 pages, paperback
The Maternal and Newborn Health Registry Study of the Global Network for Women's and Children's Health Research
Authors: Goudar Shivaprasad S. , Carlo Waldemar A. , McClure Elizabeth M. , Pasha Omrana , Patel Archana , Esamai Fabian , Chomba Elwyn , Garces Ana , Althabe Fernando , Kodkany Bhalachandra , Sami Neelofar , Derman Richard J. , Hibberd Patricia L. , Liechty Edward A. , Krebs Nancy F. , Hambidge K. Michael , Buekens Pierre , Moore Janet , Wallace Dennis , Jobe Alan H. , Koso‐Thomas Marion , Wright Linda L. , Goldenberg Robert L.
Published: June 2012

Objective

To implement a vital statistics registry system to register pregnant women and document birth outcomes in the Global Network for Women's and Children's Health Research sites in Asia, Africa, and Latin America.

Methods

The Global Network sites began a prospective population‐based pregnancy registry to identify all pregnant women and record pregnancy outcomes up to 42 days post‐delivery in more than 100 defined low‐resource geographic areas (clusters). Pregnant women were registered during pregnancy, with 42‐day maternal and neonatal follow‐up recorded—including care received during the pregnancy and postpartum periods. Recorded outcomes included stillbirth, neonatal mortality, and maternal mortality rates.

Results

In 2010, 72 848 pregnant women were enrolled and 6‐week follow‐up was obtained for 97.8%. Across sites, 40.7%, 24.8%, and 34.5% of births occurred in a hospital, health center, and home setting, respectively. The mean neonatal mortality rate was 23 per 1000 live births, ranging from 8.2 to 48.5 per 1000 live births. The mean stillbirth rate ranged from 13.7 to 54.4 per 1000 births.

Conclusion

The registry is an ongoing study to assess the impact of interventions and trends regarding pregnancy outcomes and measures of care to inform public health.

ClinicalTrial.gov Trial Registration: NCT01073475
Using partial least squares in operations management research: A practical guideline and summary of past research
Authors: Peng David Xiaosong , Lai Fujun
Published: June 2012

The partial least squares (PLS) approach to structural equation modeling (SEM) has been widely adopted in business research fields such as information systems, consumer behavior, and marketing. The use of PLS in the field of operations management is also growing. However, questions still exist among some operations management researchers regarding whether and how PLS should be used. To address these questions, our study provides a practical guideline for using PLS and uses examples from the operations management literature to demonstrate how the specific points in this guideline can be applied. In addition, our study reviews and summarizes the use of PLS in the recent operations management literature according to our guideline. The main contribution of this study is to present a practical guideline for evaluating and using PLS that is tailored to the operations management field.
Forest cover, socioeconomics, and reported flood frequency in developing countries
Authors: Ferreira Susana , Ghimire Ramesh
Published: July 2012

In this paper, we analyze the determinants of the number of large floods reported since 1990. Using the same sample of countries as Bradshaw et al. (2007), and, like them, omitting socioeconomic characteristics from the analysis, we found that a reduction in natural forest cover is associated with an increase in the reported count of large floods. This result does not hold in any of three new analyses we perform. First, we expand the sample to include all the developing countries and all countries for which data were available but were omitted in their study. Second, and more importantly, since forest management is just one possible channel through which humans can influence reported flood frequency, we account for other important human–flood interactions. People are typically responsible for deforestation, but they are also responsible for other land use changes (e.g., urbanization), for floodplain and flood emergency management, and for reporting the floods. Thus, in our analysis we account for population, urban population growth, income, and corruption. Third, we exploit the panel nature of the data to control for unobserved country and time heterogeneity. We conclude that not only is the link between forest cover and reported flood frequency at the country level not robust, it also seems to be driven by sample selection and omitted variable bias. The human impact on the reported frequency of large floods at the country level is not through deforestation.
Wind‐induced atmospheric escape: Titan
Authors: Hartle R. E. , Johnson R. E. , Sittler E. C. , Sarantos M. , Simpson D. G.
Published: July 2012

Rapid thermospheric flows can significantly enhance the atmospheric loss rates and structures of atmospheric coronae of planetary bodies. Using descriptions of atmospheric escape based on molecular kinetic models, we show that such flows at the exobase of Titan could significantly increase the calculated constituent thermal and nonthermal escape rates. In particular, we show here that the effect of thermospheric winds at the exobase cannot be ignored when calculating the escape of methane from Titan. Such enhancements are likely also relevant to Pluto and exoplanet atmospheres.
Nuclear movement during myotube formation is microtubule and dynein dependent and is regulated by Cdc42, Par6 and Par3
Authors: Cadot Bruno , Gache Vincent , Vasyutina Elena , Falcone Sestina , Birchmeier Carmen , Gomes Edgar R
Published: June 2012

Cells actively position their nucleus within the cytoplasm. One striking example is observed during skeletal myogenesis. Differentiated myoblasts fuse to form a multinucleated myotube with nuclei positioned in the centre of the syncytium by an unknown mechanism. Here, we describe that the nucleus of a myoblast moves rapidly after fusion towards the central myotube nuclei. This movement is driven by microtubules and dynein/dynactin complex, and requires Cdc42, Par6 and Par3. We found that Par6β and dynactin accumulate at the nuclear envelope of differentiated myoblasts and myotubes, and this accumulation is dependent on Par6 and Par3 proteins but not on microtubules. These results suggest a mechanism where nuclear movement after fusion is driven by microtubules that emanate from one nucleus that are pulled by dynein/dynactin complex anchored to the nuclear envelope of another nucleus.
Src‐dependent autophagic degradation of Ret in FAK‐signalling‐defective cancer cells
Authors: Sandilands Emma , Serrels Bryan , Wilkinson Simon , Frame Margaret C
Published: June 2012

We have recently described that autophagic targeting of Src maintains cancer cell viability when FAK signalling is defective. Here, we show that the Ret tyrosine kinase is also degraded by autophagy in cancer cells with altered/reduced FAK signalling, preventing its binding to FAK at integrin adhesions. Inhibition of autophagy restores Ret localization to focal adhesions. Importantly, Src kinase activity is required to target Ret to autophagosomes and enhance Ret degradation. Src is thus a general mediator of selective autophagic targeting of adhesion‐linked kinases, and Ret a second FAK‐binding tyrosine kinase degraded through autophagy in cancer cells under adhesion stress. Src—by controlling not only its own degradation but also that of other FAK‐binding partners—allows cancer cell survival, suggesting a new therapeutic strategy.
Mps1 promotes rapid centromere accumulation of Aurora B
Authors: van der Waal Maike S , Saurin Adrian T , Vromans Martijn J M , Vleugel Mathijs , Wurzenberger Claudia , Gerlich Daniel W , Medema René H , Kops Geert J P L , Lens Susanne M A
Published: June 2012

Aurora B localization to mitotic centromeres, which is required for proper chromosome alignment during mitosis, relies on Haspin‐dependent histone H3 phosphorylation and on Bub1‐dependent histone H2A phosphorylation—which interacts with Borealin through a Shugoshin (Sgo) intermediate. We demonstrate that Mps1 stimulates the latter recruitment axis. Mps1 activity enhances H2A‐T120ph and is critical for Sgo1 recruitment to centromeres, thereby promoting Aurora B centromere recruitment in early mitosis. Importantly, chromosome biorientation defects caused by Mps1 inhibition are improved by restoring Aurora B centromere recruitment. As Mps1 kinetochore localization reciprocally depends on Aurora B, we propose that this Aurora B‐Mps1 recruitment circuitry cooperates with the Aurora B‐Haspin feedback loop to ensure rapid centromere accumulation of Aurora B at the onset of mitosis.
Adoptive transfer of CD34+ cells during murine sepsis rebalances macrophage lipopolysaccharide responses
Authors: Brudecki Laura , Ferguson Donald A , McCall Charles E , El Gazzar Mohamed
Published: June 2012

Effective treatment of the acute systemic inflammatory response associated with sepsis is lacking, but likely will require new ways to rebalance dysregulated immune responses. One challenge is that human sepsis often is diagnosed too late to reduce the hyperinflammation of early sepsis. Another is that the sequential response to sepsis inflammation rapidly generates an adaptive and immunosuppressive state, which by epigenetic imprint may last for months or years. Emerging data support that the immunosuppressive phase of sepsis can both directly reprogram gene expression of circulating and tissue cells, and disrupt development and differentiation of myeloid precursor cells into competent immunocytes. We recently reported that adoptive transfer of bone marrow CD34+ cells into mice after sepsis induction by cecal ligation and puncture significantly improves late‐sepsis survival by enhancing bacterial clearance through improved neutrophil and macrophage phagocytosis. That study, however, did not examine whether CD34+ transfer can modify noninfectious acute systemic inflammatory responses. Here, we report that CD34+ cell transfer mice that have survived late sepsis also resist lethal lipopolysaccharide (LPS)‐induced inflammatory shock (88% lived vs 0% of naive mice). The CD34+ cell‐recipient survivor mice administered LPS had globally reduced levels of circulating inflammatory mediators compared with naive mice, but their peritoneal and bone marrow‐derived macrophages (BMDMs), unlike those from naïve mice, remained LPS responsive ex vivo. We further found that CD34+ cell transfer into LPS‐challenged naïve mice had diminished immunosuppression, as assessed by ex vivo responses of peritoneal and BMDMs to LPS challenge. We conclude that CD34+ cell adoptive transfer rebalances dysregulated immune responses associated with sepsis and endotoxin shock.
Rapid thermal annealing of sputter-deposited ZnO:Al films for microcrystalline Si thin-film solar cells
Authors: Koshino H. , Tang Z. , Sato S. , Shimizu H. , Fujii Y. , Hanajiri T. , Shirai H.
Published: June 2012

Rapid thermal annealing of sputter-deposited ZnO and Al-doped ZnO (AZO) films with and without an amorphous silicon (a-Si) capping layer was investigated using a radio-frequency (rf) argon thermal plasma jet of argon at atmospheric pressure. The resistivity of bare ZnO films on glass decreased from 108 to 104–105 Ω cm at maximum surface temperatures Tmaxs above 650 °C, whereas the resistivity increased from 10-4 to 10-3–10-2Ω cm for bare AZO films. On the other hand, the resistivity of AZO films with a 30-nm-thick a-Si capping layer remained below 10-4Ω cm, even after TPJ annealing at a Tmax of 825 °C. The film crystallization of both AZO and a-Si layers was promoted without the formation of an intermixing layer. Additionally, the crystallization of phosphorous- and boron-doped a-Si layers at the sample surface was promoted, compared to that of intrinsic a-Si under the identical plasma annealing conditions. The TPJ annealing of n+-a-Si/textured AZO was applied for single junction n-i-p microcrystalline Si thin-film solar cells.
Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities
Authors: Dhakal Pashupati , Ciovati Gianluigi , Rigby Wayne , Wallace John , Myneni Ganapati Rao
Published: July 2012

Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low (∼120 °C) and high (∼800 °C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 °C with a maximum pressure of ∼1 × 10−5 Torr and the maximum achievable temperature is estimated to be higher than 2000 °C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 °C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of ∼2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.
Design of roll-to-roll printing equipment with multiple printing methods for multi-layer printing
Authors: Kim Chung Hwan , Jo Jeongdai , Lee Seung-Hyun
Published: July 2012

In this paper, a novel design concept for roll-to-roll printing equipment used for manufacturing printed electronic devices by multi-layer printing is presented. The roll-to-roll printing system mainly consists of printing units for patterning the circuits, tension control components such as feeders, dancers, load cells, register measurement and control units, and the drying units. It has three printing units which allow switching among the gravure, gravure-offset, and flexo printing methods by changing the web path and the placements of the cylinders. Therefore, depending on the application devices and the corresponding inks used, each printing unit can be easily adjusted to the required printing method. The appropriate printing method can be chosen depending on the desired printing properties such as thickness, roughness, and printing quality. To provide an example of the application of the designed printing equipment, we present the results of printing tests showing the variations in the printing properties of the ink for different printing methods.
Necessary conditions of the equivalence of canonical and grand canonical ensembles in Coulomb system thermodynamics
Authors: Bobrov V. B. , Sokolov I. M. , Trigger S. A.
Published: July 2012

It was found that the equivalence of the grand canonical and canonical ensembles for the Coulomb systems is possible only when charged particles of different types in calculating the physical quantities are considered as formally “independent” ones, and the quasi-neutrality condition is used in the final stage of calculations. The phase equilibrium condition is obtained and the expression is derived for the isothermal compressibility of matter as a two-component Coulomb system, which corresponds to the known limit relations for static structure factors. On this basis, it is demonstrated that the critical point of matter, considering as the Coulomb system is determined from the condition of vanishing mean square of fluctuations of the total charge per unit volume.
Surface analysis using a new plasma assisted desorption/ionisation source for mass spectrometry in ambient air
Authors: Bowfield A. , Barrett D. A. , Alexander M. R. , Ortori C. A. , Rutten F. M. , Salter T. L. , Gilmore I. S. , Bradley J. W.
Published: July 2012

The authors report on a modified micro-plasma assisted desorption/ionisation (PADI) device which creates plasma through the breakdown of ambient air rather than utilising an independent noble gas flow. This new micro-PADI device is used as an ion source for ambient mass spectrometry to analyse species released from the surfaces of polytetrafluoroethylene, and generic ibuprofen and paracetamol tablets through remote activation of the surface by the plasma. The mass spectra from these surfaces compare favourably to those produced by a PADI device constructed using an earlier design and confirm that the new ion source is an effective device which can be used to achieve ambient mass spectrometry with improved spatial resolution.
Length-scale dependent relaxation shear modulus and viscoelastic hydrodynamic interactions in polymer liquids
Authors: Semenov A. N. , Farago J. , Meyer H.
Published: July 2012

A quantitative theory of hydrodynamic interactions in unentangled polymer melts and concentrated solutions is presented. The study is focussed on the pre-Rouse transient time regimes (t < τR, the Rouse relaxation time) where the hydrodynamic response is governed mainly by the viscoelastic effects. It is shown that transient viscoelastic hydrodynamic interactions are not suppressed (screened) at large distances and are virtually independent of polymer molecular mass. A number of transient regimes of unusual and qualitatively different behavior of isotropic and anisotropic hydrodynamic response functions are elucidated. The regimes are characterized in terms of two main length-scale dependent characteristic times: momentum spreading time τi ∝ r4/3 and viscoelastic time τ* ∝ r4. It is shown that for t > τi the viscoelastic hydrodynamic interactions can be described in terms of the time or length scale dependent effective viscosity which, for t < τR and/or for r < Rcoil, turns out to be much lower than the macroscopic “polymer” viscosity ηm. The theory also involves a quantitative analysis of the length-scale dependent stress relaxation in polymer melts. The general predictions for hydrodynamic interactions in thermostated systems with Langevin friction are obtained as well.
Impact of pentacene film thickness on the photoresponse spectra: Determination of the photocarrier generation mechanism
Authors: Gorgolis S. , Giannopoulou A. , Anastassopoulos D. , Kounavis P.
Published: July 2012

Photocurrent response, optical absorption, and x-ray diffraction (XRD) measurements in pentacene films grown on glass substrates are performed in order to obtain an insight into the mobile photocarriers generation mechanism. For film thickness of the order of 50 nm and lower, the photocurrent response spectra are found to follow the optical absorption spectra demonstrating the so-called symbatic response. Upon increasing the film thickness, the photoresponse demonstrates a transition to the so-called antibatic response, which is characterized by a maximum and minimum photocurrent for photon energies of minimum and maximum optical absorption, respectively. The experimental results are not in accordance with the model of important surface recombination rate. By taking into account the XRD patterns, the experimental photoresponse spectra can be reproduced by model simulations assuming efficient exciton dissociation at a narrow layer of the order of 20 nm near the pentacene-substrate interface. The simulated spectra are found sensitive to the film thickness, the absolute optical absorption coefficient, and the diffusion exciton length. By comparing the experimental with the simulated spectra, it is deduced that the excitons, which are created by optical excitation in the spectral region of 1.7-2.2 eV, diffuse with a diffusion length of the order of 10-80 nm to the pentacene-substrate interface where efficiently dissociate into mobile charge carriers.
Investigation of the mechanical bending and frequency shift induced by adsorption and temperature using micro- and nanocantilever sensors
Authors: Feng Lu , Gao Fengling , Liu Meihua , Wang Shibin , Li Linan , Shen Min , Wang Zhiyong
Published: July 2012

The marked progress in MEMS/NEMS technology has demanded the development of a fundamental understanding of cantilever-based sensing principles. One of the challenges of cantilever-based detection is identifying and discerning the most influenced parameters responsible for the observed changes in the cantilever response. For example, effects of various force fields such as those induced by atom/molecular adsorption and variations in temperature may occur simultaneously, increasing the number of parameters that need to be concurrently measured to ensure the reliability of sensors. In this paper, we, therefore, systematically investigate the interplay between these two distinctly different mechanisms and attendant mechanical response. To this end, a theory model is proposed to predict the mechanical bending and resonance frequency shift of micro- and nanocantilevers taking into account atom/molecular adsorption and variations in temperature at the same time. The adsorption induced mechanical responses of microcantilevers are modeled for the van der Waals interaction in presence of surface effect. Thermal effects addressed here include the thermal mismatch between the substrate and coating layer owing to different thermal expansion coefficients and the temperature-dependent material properties. The theoretical and computational model developed here will allow one to gain an insight into not only the mechanical responses observed experimentally but also the fundamental, novel detection principles for sensing applications.
Orientation-dependent hardness and strain rate sensitivity in nanotwin copper
Authors: Ye J. C. , Wang Y. M. , Barbee T. W. , Hamza A. V.
Published: July 2012

We observe a strong twin-orientation dependent hardness and strain rate sensitivity (m) in nanotwin copper. A highest m value of 0.059 ± 0.004 and an activation volume (V) of ∼10b3 are measured when deformation is predominately vertical to twin boundaries (TBs), whereas a much smaller m and larger V are observed for the direction parallel to TBs. Dislocation density is found to have a stronger impact on m and V in nanotwin materials, compared to that in coarse-grained materials.
Nanofluidic preconcentration and detection of nanoparticles
Authors: Mitra Anirban , Ignatovich Filipp , Novotny Lukas
Published: July 2012

The fast detection and characterization of nanoparticles, such as viruses or environmental pollutants, are important in fields ranging from biosensing to quality control. However, most existing techniques have practical throughput limitations, which significantly limit their applicability to low analyte concentrations. Here, we present an integrated nanofluidic scheme for preconcentration and subsequent detection of nanoparticle samples within a continuous flow-through system. Using a Brownian ratchet mechanism, we increase the nanoparticle concentration ∼27-fold. Single nanoparticles are subsequently detected and characterized by optical heterodyne interferometry. A wide range of potential applications can be foreseen, including real-time analysis of clinically relevant virus samples and contamination control of processing fluids used in the semiconductor industry.
Inner-layer intensities for the flat-plate turbulent boundary layer combining a predictive wall-model with large-eddy simulations
Authors: Inoue M. , Mathis R. , Marusic I. , Pullin D. I.
Published: July 2012

Time series velocity signals obtained from large-eddy simulations (LES) within the logarithmic region of the zero-pressure gradient turbulent boundary layer over a smooth wall are used in combination with an empirical, predictive inner-outer wall model [I. Marusic, R. Mathis, and N. Hutchins, “Predictive model for wall-bounded turbulent flow,” Science 329, 193 (2010)10.1126/science.1188765] to calculate the statistics of the fluctuating streamwise velocity in the inner region. Results, including spectra and moments up to fourth order, are compared with equivalent predictions using experimental time series, as well as with direct experimental measurements at Reynolds numbers Reτ = 7300, 13 600, and 19 000. The LES combined with the wall model are then used to extend the inner-layer predictions to Reynolds numbers Reτ = 62 000, 100 000, and 200 000 that lie within a gap in log (Reτ) space between laboratory measurements and surface-layer, atmospheric experiments. The present results support a loglike increase in the near-wall peak of the streamwise turbulence intensities with Reτ and also provide a means of extending LES results at large Reynolds numbers to the near-wall region of wall-bounded turbulent flows.
Tuning electronic and magnetic properties of zigzag graphene nanoribbons by large-scale bending
Authors: Hu Xiaohui , Sun Litao , Krasheninnikov Arkady V.
Published: July 2012

Using density-functional theory calculations, we show that the electronic and magnetic properties of zigzag graphene nanoribbons (ZGNRs) are highly sensitive to large scale curvature. As the curvature increases, the system experiences a transformation from the antiferromagnetic state to a nonmagnetic state and then back to the antiferromagnetic state. The energy gap first remains almost invariant and then decreases monotonically. The results demonstrate a facile strategy to tune the electronic and magnetic properties of ZGNRs, and furthermore provide an avenue to design versatile electronic and spin devices.
Communication: Thermodynamic signatures of cluster formation in fluids with competing interactions
Authors: Bomont Jean-Marc , Bretonnet Jean-Louis , Costa Dino , Hansen Jean-Pierre
Published: July 2012

Convergent theoretical evidence, based on self-consistent integral equations for the pair structure and on Monte Carlo simulations, is presented for the existence of small simultaneous jump discontinuities of several thermodynamic and structural properties of systems of colloidal particles with competing short-range attractive and long-range repulsive interactions, under physical conditions close to the onset of particle clustering. The discontinuities thus provide a signature of the transition from a homogeneous fluid phase to a locally inhomogeneous cluster phase.
Quantum optomechanics
Authors: Aspelmeyer Markus , Meystre Pierre , Schwab Keith
Published: July 2012

Aided by optical cavitiesand superconductingcircuits, researchers are coaxing ever-larger objects to wiggle, shake, and flex in ways that are distinctly quantum mechanical.
State-space prediction of soil respiration time series in temperate, semi-arid grassland in northern China
Authors: Jia Xiaoxu , Shao Ming'an , Wei Xiaorong
Published: July 2012

The prediction of soil respiration (Rs) has traditionally been studied using classical statistical methods. These methods do not consider temporal/spatial coordinates and assume independence between samples. The aim was to determine the primary factors influencing Rs and to develop a state-space model able to predict soil respiration. This study was conducted during one growing season, from July to October 2010, in temperate, semi-arid grassland. Data were collected for Rs, air temperature, soil surface temperature, soil temperature at a depth of 5 cm, soil moisture, air pressure, and relative humidity. Additionally, a novel autoregressive state-space method was used to simulate and predict Rs based on primary factors, and the quality of prediction was compared with the quality of prediction using classical statistics. Soil surface temperature and soil moisture were identified as primary factors affecting Rs. The state-space model that included soil surface temperature was a simple but effective model, accounting for 95% of the variation in Rs. The classical statistical models, however, represented only 39–69% of the variation in Rs. Furthermore, the quality of prediction of the state-space models was consistently much better than the quality from the classical statistical methods. State-space analysis is an effective tool for studying the temporal relationships between soil respiration and influencing factors. Additionally, the state-space method is recommended for predicting soil respiration using soil surface temperature in semi-arid grassland in northern China.