bluuebunny/crossref_metadata_2025 huggingface dataset:
Noble gas adsorption with and without mechanical stress: Not Martian signatures but fractionated air
Authors: SCHWENZER Susanne P. , HERRMANN Siegfried , OTT Ulrich
Published: July 2012

Abstract– Sample preparation, involving physical and chemical methods, is an unavoidable step in geochemical analysis. From a noble gas perspective, the two important effects are loss of sample gas and/or incorporation of air, which are significant sources of analytical artifacts. This article reports on the effects of sample exposure to laboratory air without mechanical influence and during sample grinding. The experiments include pure adsorption on terrestrial analog materials (gibbsite and olivine) and grinding of Martian meteorites. A consistent observation is the presence of an elementally fractionated air component in the samples studied. This is a critical form of terrestrial contamination in meteorites as it often mimics the heavy noble gas signatures of known extra‐terrestrial end‐members that are the basis of important conclusions about the origin and evolution of a meteorite. Although the effects of such contamination can be minimized by avoiding elaborate sample preparation protocols, caution should be exercised in interpreting the elemental ratios (Ar/Xe, Kr/Xe), especially in the low‐temperature step extractions. The experiments can also be transferred to the investigation of Martian meteorites with long terrestrial residence times, and to Mars, where the Mars Science Laboratory mission will be able to measure noble gas signatures in the current atmosphere and in rocks and soils collected on the surface in Gale crater.
A new model for the origin of Type‐B and Fluffy Type‐A CAIs: Analogies to remelted compound chondrules
Authors: RUBIN Alan E.
Published: July 2012

Abstract– In the scenario developed here, most types of calcium‐aluminum‐rich inclusions (CAIs) formed near the Sun where they developed Wark‐Lovering rims before being transported by aerodynamic forces throughout the nebula. The amount of ambient dust in the nebula varied with heliocentric distance, peaking in the CV–CK formation location. Literature data show that accretionary rims (which occur outside the Wark‐Lovering rims) around CAIs contain substantial 16O‐rich forsterite, suggesting that, at this time, the ambient dust in the nebula consisted largely of 16O‐rich forsterite. Individual sub‐millimeter‐size Compact Type‐A CAIs (each surrounded by a Wark‐Lovering rim) collided in the CV–CK region and stuck together (in a manner similar to that of sibling compound chondrules); the CTAs were mixed with small amounts of 16O‐rich mafic dust and formed centimeter‐size compound objects (large Fluffy Type‐A CAIs) after experiencing minor melting. In contrast to other types of CAIs, centimeter‐size Type‐B CAIs formed directly in the CV–CK region after gehlenite‐rich Compact Type‐A CAIs collided and stuck together, incorporated significant amounts of 16O‐rich forsteritic dust (on the order of 10–15%) and probably some anorthite, and experienced extensive melting and partial evaporation. (Enveloping compound chondrules formed in an analogous manner.) In those cases where appreciably higher amounts of 16O‐rich forsterite (on the order of 25%) (and perhaps minor anorthite and pyroxene) were incorporated into compound Type‐A objects prior to melting, centimeter‐size forsterite‐bearing Type‐B CAIs (B3 inclusions) were produced. Type‐B1 inclusions formed from B2 inclusions that collided with and stuck to melilite‐rich Compact Type‐A CAIs and experienced high‐temperature processing.
A noble gas and cosmogenic radionuclide analysis of two ordinary chondrites from Almahata Sitta
Authors: MEIER Matthias M. M. , WELTEN Kees C. , CAFFEE Marc W. , FRIEDRICH Jon M. , JENNISKENS Peter , NISHIIZUMI Kunihiko , SHADDAD Muawia H. , WIELER Rainer
Published: July 2012

Abstract– We present the results of a noble gas (He, Ne, Ar) and cosmogenic radionuclide (10Be, 26Al, 36Cl) analysis of two chondritic fragments (#A100, L4 and #25, H5) found in the Almahata Sitta strewn field in Sudan. We confirm their earlier attribution to the same fall as the ureilites dominating the strewn field, based on the following findings: (1) both chondrite samples indicate a preatmospheric radius of approximately 300 g cm−2, consistent with the preatmospheric size of asteroid 2008 TC3 that produced the Almahata Sitta strewn field; (2) both have, within error, a 21Ne/26Al‐based cosmic ray exposure age of approximately 20 Ma, identical to the reported ages of Almahata Sitta ureilites; (3) both exhibit hints of ureilitic Ar in the trapped component. We discuss a possible earlier irradiation phase for the two fragments of approximately 10–20 Ma, visible only in cosmogenic 38Ar. We also discuss the approximately 3.8 Ga (4He) and approximately 4.6 Ga (40Ar) gas retention ages, measured in both chondritic fragments. These imply that the two chondrite fragments were incorporated into the ureilite host early in solar system evolution, and that the parent asteroid from which 2008 TC3 is derived has not experienced a large break‐up event in the last 3.8 Ga.
Adiabatic Wall Temperature Evaluation in a High Speed Turbine
Authors: Pinilla V. , Solano J. P. , Paniagua G. , Anthony R. J.
Published: July 2012

Engine development requires accurate estimates of the heat loads. Estimates of the convective heat fluxes are particularly vital to assess the thermomechanical integrity of the turbomachinery components. This paper reports an experimental heat transfer research in a one and a half turbine stage, composed of a high-pressure turbine and a low-pressure vane. Measurements were performed in a compression tube facility at the von Karman Institute, able to reproduce engine representative Reynolds and Mach numbers. Double-layered thin film gauges were used to monitor the time-dependent temperature distribution around the airfoil. Several tests at different metal temperatures were performed to derive the adiabatic wall temperature. This research allowed quantifying the independent effects on the unsteady heat flux of the gas temperature fluctuations and boundary layer unsteadiness.
Stress and Stress Intensity Factor Near Notches in Thick Cylinders
Authors: Parker Anthony P. , Troiano Edward , Underwood John H.
Published: July 2012

This work investigates the impact of semi-elliptical notches (erosion grooves) at the bore of pressurized and autofrettaged thick cylinders. It provides a robust yet rapid method to determine the rapidly varying stress in the near-notch region prior to crack development and crack tip stress intensity factor after a crack develops at the notch root. The procedure involves a sequence of asymptotic solutions and adjustments. A superposition is presented for the stress concentration factor (SCF) of a small edge notch in a pressurized cylinder with bore pressure infiltrating and acting upon the notch surface. A procedure for adjusting this SCF to account for a varying pre-existing stress field is described. This provides accurate predictions for notch depths of up to 15% of wall thickness. Stress variation beyond the notch root is determined by scaling analytic solutions. Solution accuracy appears to be approximately 5%. Stress profiles were used to calculate stress intensity factor (SIF) for cracks emanating from the notch root and deep into the wall. There are notable differences between SIF behavior in the pressurized tube and in the autofrettaged tube. The main reason for this difference is that compressive reyielding near the notch disrupts the residual compressive stress profile over an extended distance. This leads to the conclusion that a crack originating from a notch in an autofrettaged tube exhibits a much higher cyclic SIF range during pressurization than the same length crack originating from the bore. This will cause higher fatigue crack growth rates and shorter fatigue lifetimes.
Optimal Design of a
4-DOF SCARA Type Parallel Robot Using Dynamic Performance Indices and Angular
Constraints
Authors: Liu Songtao , Huang Tian , Mei Jiangping , Zhao Xueman , Wang Panfeng , Chetwynd Derek G.
Published: July 2012

This paper deals with the optimal design of a 4-DOF SCARA type (three translations and one rotation) parallel robot using dynamic performance indices and angular constraints within and amongst limbs. The architecture of the robot is briefly addressed with emphasis on the mechanical realization of the articulated traveling plate for achieving a lightweight yet rigid design. On the basis of the kinematic singularity analysis, two types of transmission angle constraints are considered to ensure the kinematic performance. A simplified model of rigid body dynamics is then formulated, with which two global dynamic performance indices are proposed for minimization by taking into account both inertial and centrifugal/Coriolis effects. In addition, the servomotor specifications are estimated using the Extended Adept Cycle. The proposed approach has successfully been employed to develop a prototype machine.
Recurrent vitreous haemorrhage and epidural haematoma in a child with hypofibrinogenaemia
Authors: Mansour Ahmad M , Jaroudi Mahmoud O
Published: July 2012

A 14-month-old male infant was brought by parents for redness of the right eye of 18 days duration. Exam and B-scan ultrasonography revealed total hyphema, dense vitreous haemorrhage and lens subluxation in the right eye while CT disclosed right small epidural haematoma. The left eye had neither retinal haemorrhage nor disc oedema. There was no sign of shaken baby syndrome. Fibrinogen level in the blood was very low. The parents are first-degree cousins with two family members having hypofibrinogenaemia. Vitreous haemorrhage recurred after surgical intervention resulting in phthisis and loss of vision. Hypofibrinogenaemia needs to be included in the differential diagnosis of ocular haemorrhage and vision loss.
THE EVIDENTIAL REASONING APPROACH FOR RISK MANAGEMENT IN LARGE ENTERPRISES
Authors: TANG DAWEI , YANG JIAN-BO , BAMFORD DAVID , XU DONG-LING , WAUGH MARGARET , BAMFORD JIM , ZHANG SHULIAN
Published: July 2012

Enterprise Risk Management (ERM) is a framework that is used by large organizations to manage risk as a whole. The key difference between ERM and traditional risk management is that in the latter risks are managed individually, whilst the former requires the aggregation of risks to facilitate risk management. However, current methods for risk aggregation have various limitations when applied under the context of ERM, such as the requirement for accurate and complete information about risk factors, the inability to handle different kinds of uncertainty which are inevitable during the risk aggregation process, and so on. Due to its unique advantages in accommodating different forms of both complete and incomplete information and handling different kinds of uncertainty, the Evidential Reasoning (ER) approach together with its implementation entitled Intelligent Decision System (IDS) is introduced in this paper for risk aggregation in ERM to overcome the limitations and to provide a comprehensive analysis for risk management based on the aggregation result. To demonstrate the applicability of the ER approach and IDS in ERM, a case study is analyzed in detail regarding risk aggregation and risk management for a health care organization in North England.
A CONSISTENT IMPUTATION GENERATION METHOD FOR LINGUISTIC COOPERATIVE GAMES AND ITS APPLICATION TO RISK AVERSION
Authors: LIN JIAN , ZHANG QIANG
Published: July 2012

Cooperative game theory is very useful to risk aversion problems in economics and management systems. The existing methods only focus on the situation payoffs take the form of numerical values, ones take the form of linguistic labels are seldom discussed. The aim of this study is to propose the consistent imputation for cooperative games under a linguistic environment. To support risk aversion, a 2-tuple linguistic representation is employed to obtain the valid results and avoid the loss of linguistic information. This paper firstly defines some concepts for linguistic cooperative games, such as linguistic imputation, carrier, core and null player. A set of their desirable properties are also discussed. The linguistic Shapley value is then presented based on three axioms. Moreover, the existence and uniqueness of the linguistic Shapley value are discussed in detail. To adjust the linguistic imputation in accordance with the cardinality of a given original linguistic label set, an adjustment algorithm for generating consistent imputation is proposed. Finally, we give the application of linguistic imputation in solving risk aversion problems to illustrate the validity of the consistent imputation generation (CIG) method.
MODELING THE STABILITY OF A COMPUTER SYSTEM
Authors: LOPEZ VICTORIA , MIÑANA GUADALUPE
Published: July 2012

Performance, reliability and safety are relevant factors when analyzing or designing a computer system. Many studies about on performance are based on monitoring and analyzing data from a computer system. One of the most useful pieces of data is the Load Average (LA) that which shows the load average of the system in the last minute, the sequence of in the last five minutes and the sequence of in the last fifteen last minutes. There are a lot ofmany studies of the system performance based on the load average. This is shown by mean means of monitoring the commands of the operative system, but sometimes they are sometimes difficult to understand and far of removed from human intuition. The aim of this paper is to show demonstrate a new procedure that allows us to determine the stability of a computer system from a list of load average sample data. The idea is shown as an algorithm based in statistic analysis, the aggregation of information and its formal specification. The result is an evaluation of the stability of the load and the computer system by monitoring but without adding any overhead to the system. In addition, the procedure can be used as a software monitor for risk prevention of on any vulnerable system.
A QUALITATIVE DECISION MAKING MODEL BASED ON BELIEF LINGUISTIC RULE BASED INFERENCE METHODOLOGY
Authors: LI WENJIANG , LIU JUN , WANG HUI , CALZADA ALBERTO , RODRIGUEZ ROSA M. , MARTINEZ LUIS
Published: July 2012

This paper focuses on an inference methodology based on a belief linguistic rule base (B-LRB) for qualitative decision support. It is termed 'linguistic rule-base' instead of 'fuzzy rule-base' because the use of membership functions associated with the linguistic terms are unnecessary or do not play a key role. The features of B-LRB, the ways to generate a B-LRB, and the inference procedure based on B-LRB are specified, along with an illustrate example applied to evaluate consumer trustworthiness in Internet marketing to show how it works, its applicability and feasibility.
HARVESTING IP-BASED VALUE POTENTIAL: THE INTELLECTUAL PROPERTY SCORECARD AS A MECHANISM TO CAPITALIZE ON TECHNOLOGICAL INNOVATION, KNOWLEDGE, AND IP
Authors: KHOTA IRFAAN , PRETORIUS LEON
Published: July 2012

There is a staggering decline in the capitalization of intellectual property (IP) and low levels of investment in R&D, particularly with respect to emerging nations within the global IP environment, which limits accelerated industrial growth. In most emerging markets, this necessitates that management address multiple competencies better, that exploit organizational resources, knowledge, and management ability, to adapt faster than the competition. Our research offers a management model to address this management challenge strategically.

This research also indicates that IP as a value creation mechanism is currently not a top management priority although investors increasingly look toward good IP management as an indicator of future organizational growth. The research presents the IP Scorecard, a further inductive development of Kaplan and Norton's traditional Balanced Scorecard. The IP Scorecard is a strategic management tool that enables management to drive a robust industrial growth strategy that is explicitly positioned within the knowledge economy, identifying target areas for organizational development around knowledge and IP management, in order to achieve the competitive higher-ground, by strategically creating and capitalizing on value arising from innovation and R&D activities.

The IP Scorecard sensitizes management on where and how to carve out competitive turf, particularly from a knowledge and IP value creation perspective, seeking ultimately to enhance corporate/shareholder and product-life-cycle value. The paper encompasses limited field research findings on key IP-related strategic management considerations that promote leadership in innovation and R&D, across the product life cycle.
NONVOLATILE SPINTRONICS: PERSPECTIVES ON INSTANT-ON NONVOLATILE NANOELECTRONIC SYSTEMS
Authors: WANG K. L. , AMIRI P. KHALILI
Published: July 2012

Instant-on nonvolatile electronics, which can be powered on/off instantaneously without the loss of information, represents a new and emerging paradigm in electronics. Nonvolatile circuits consisting of volatile CMOS, combined with nonvolatile nanoscale magnetic memory, can make electronics nonvolatile at the gate, circuit and system levels. When high speed magnetic memory is embedded in CMOS logic circuits, it may help resolve the two major challenges faced in continuing CMOS scaling: Power dissipation and variability of devices. We will give a brief overview of the current challenges of CMOS in terms of energy dissipation and variability. Then, we describe emerging nonvolatile memory (NVM) options, particularly those spintronic solutions such as magnetoresistive random access memory (MRAM) based on spin transfer torque (STT) and voltage-controlled magnetoelectric (ME) write mechanisms. We will then discuss the use of STT memory for embedded application, e.g., replacing volatile CMOS Static RAM (SRAM), followed by discussion of integration of CMOS reconfigurable circuits with STT-RAM. We will then present the scaling limits of the STT memory and discuss its critical performance parameters, particularly related to switching energy. To further reduce the switching energy, we present the concept of electric field control of magnetism, and discuss approaches to realize this new mechanism in realizing low switching energy, allowing for implementation of nonvolatility at the logic gate level, and eventually at the transistor level with a magnetoelectric gate (MeGate). For nonvolatile logic (NVL), we present and discuss as an example an approach using interference of spin waves, which will have NVL operations remembering the state of computation. Finally, we will discuss the potential impact and implications of this new paradigm on low energy dissipation instant-on nonvolatile systems.
WIPI-1 Positive Autophagosome-Like Vesicles Entrap PathogenicStaphylococcus aureusfor Lysosomal Degradation
Authors: Mauthe Mario , Yu Wenqi , Krut Oleg , Krönke Martin , Götz Friedrich , Robenek Horst , Proikas-Cezanne Tassula
Published: July 2012

Invading pathogens provoke the autophagic machinery and, in a process termed xenophagy, the host cell survives because autophagy is employed as a safeguard for pathogens that escaped phagosomes. However, some pathogens can manipulate the autophagic pathway and replicate within the niche of generated autophagosome-like vesicles. By automated fluorescence-based high content analyses, we demonstrate thatStaphylococcus aureusstrains (USA300, HG001, SA113) stimulate autophagy and become entrapped in intracellular PtdIns(3)P-enriched vesicles that are decorated with human WIPI-1, an essential PtdIns(3)P effector of canonical autophagy and membrane protein of both phagophores and autophagosomes. Further,agr-positiveS. aureus(USA300, HG001) strains were more efficiently entrapped in WIPI-1 positive autophagosome-like vesicles when compared toagr-negative cells (SA113). By confocal and electron microscopy we provide evidence that single- and multiple-Staphylococci entrapped undergo cell division. Moreover, the number of WIPI-1 positive autophagosome-like vesicles entrapping Staphylococci significantly increased upon (i) lysosomal inhibition by bafilomycin A1and (ii) blocking PIKfyve-mediated PtdIns(3,5)P2generation by YM201636. In summary, our results provide evidence that the PtdIns(3)P effector function of WIPI-1 is utilized during xenophagy ofStaphylococcus aureus. We suggest that invadingS. aureuscells become entrapped in autophagosome-like WIPI-1 positive vesicles targeted for lysosomal degradation in nonprofessional host cells.
Unusual Foreign Bodies in the Orofacial Region
Authors: Passi Sidhi , Sharma Neeraj
Published: July 2012

Foreign bodies may be deposited in the oral cavity either by traumatic injury or iatrogenically. Among the commonly encountered iatrogenic foreign bodies are restorative materials like amalgam, obturation materials, broken instruments, needles, and so forth. The discovery of foreign bodies in the teeth is a special situation, which is often diagnosed accidentally. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, location of the foreign body, and the difficulty involved in its retrieval. It is more common to find this situation in children as it is a well-known fact that children often tend to have the habit of placing foreign objects in the mouth. Sometimes the foreign objects get stuck in the root canals of the teeth, which the children do not reveal to their parents due to fear. These foreign objects may act as a potential source of infection and may later lead to a painful condition. This paper discusses the presence of unusual foreign bodies—a tip of the metallic compass, stapler pin, copper strip, and a broken sewing needle impregnated in the gingiva and their management.
Actual Situation of Thromboembolic Prophylaxis in Obesity Surgery: Data of Quality Assurance in Bariatric Surgery in Germany
Authors: Stroh Christine , Luderer D. , Weiner R. , Horbach T. , Ludwig K. , Benedix F. , Wolff Stefanie , Knoll C. , Lippert H. , Manger T.
Published: July 2012

Background. Evidence-based data on optimal approach for prophylaxis of deep venous thrombosis (VTE) and pulmonary embolism (PE) in bariatric operations is discussed. Using antithrombotic prophylaxis weight adjusted the risk of VTE and its complications have to be balanced with the increased bleeding risk. Methods. Since 2005 the current situation for bariatric surgery has been examined by quality assurance study in Germany. As a prospective multicenter observational study, data on the type, regimen, and time course of VTE prophylaxis were documented. The incidences of clinically diagnosed VTE or PE were derived during the in-hospital course and follow up. Results. Overall, 11,835 bariatric procedures were performed between January 2005 and December 2010. Most performed procedures were 2730 gastric banding (GB); 4901 Roux-en-Y-gastric bypass (RYGBP) procedures, and 3026 sleeve gastrectomies (SG). Study collective includes 72.5% (mean BMI 48.1 kg/m2) female and 27.5% (mean BMI 50.5 kg/m2) male patients. Incidence of VTE was 0.06% and of PE 0.08%. Conclusion. VTE prophylaxis regimen depends on BMI and the type of procedure. Despite the low incidence of VTE and PE there is a lack of evidence. Therefore, prospective randomized studies are necessary to determine the optimal VTE prophylaxis for bariatric surgical patients.
Numerical Simulation of Sloshing Phenomena in Cubic Tank with Multiple Baffles
Authors: Xue Mi-An , Zheng Jinhai , Lin Pengzhi
Published: July 2012

A two‐phase fluid flow model solving Navier‐Stokes equations was employed in this paper to investigate liquid sloshing phenomena in cubic tank with horizontal baffle, perforated vertical baffle, and their combinatorial configurations under the harmonic motion excitation. Laboratory experiment of liquid sloshing in cubic tank with perforated vertical baffle was carried out to validate the present numerical model. Fairly good agreements were obtained from the comparisons between the present numerical results and the present experimental data, available numerical data. Liquid sloshing in cubic tank with multiple baffles was investigated numerically in detail under different external excitation frequencies. Power spectrum of the time series of free surface elevation was presented with the aid of fast Fourier transform technique. The dynamic impact pressures acting on the normal and parallel sidewalls were discussed in detail.
Effect of Crude Leaf Extracts onColletotrichum gloeosporioides(Penz.) Sacc.
Authors: Bussaman Prapassorn , Namsena Piyarat , Rattanasena Paweena , Chandrapatya Angsuman
Published: July 2012

Colletotrichum gloeosporioides(Penz.) Sacc. is a fungus that causes anthracnose disease in tropical fruit plants, resulting in damages of the fruit plants and low yield and quality of fruits. The use of chemical fungicides is common for management of this disease, but it also results in the development of fungal resistance to the chemicals. Therefore, this study aims toin vitroevaluate the efficacy of 14 crude leaf extracts againstC. gloeosporioides. The results showed thatPiper sarmentosumleaf extracts, using 80% of ethanol, methanol, and chloroform as solvents, were found to have very high antifungal activities. Crude methanol extract ofP. sarmentosumleaves could effectively inhibit the growth of fungal mycelium (100%), followed by crude chloroform extract (81.85%) and 80% ethanol extract (45.50%). Maximum inhibition ofC. gloeosporioidesspore germination could be obtained after application with crude methanol extract ofP. sarmentosumleaves and crude chloroform extract ofMentha cordifolialeaves at 1.25 and 2.5%, respectively. In conclusion, crude extracts ofP. sarmentosumleaves were found to be highly effective for inhibiting bothC. gloeosporioidesmycelium growth and spore germination, and they have a potential as the new natural fungicides for management of anthracnose disease.
Analysis on the Incidence of the Fibularis Quartus Muscle Using Magnetic Resonance Imaging
Authors: Rios Nascimento Sérgio Ricardo , Watanabe Costa Renata , Ruiz Cristiane Regina , Wafae Nader
Published: July 2012

Objective. Quantify the presence of the fibularis quartus muscle and correlate it with the individual's sex and concomitant presence of the fibularis tertius muscle. Materials and Methods. We evaluated 211 magnetic resonance examinations (43.13% men and 56.87% women) on the ankle and hindfoot, produced between 2009 and 2011. Results. The fourth fibularis muscle was found to be present in 7.62% of the examinations and 75% of these also contained the fibularis tertius muscle. Conclusion. The incidence of the fourth fibularis muscle is variable; moreover, its incidence does not depend on the individual's gender or the presence of the fibularis tertius muscle.
The Mutations Associated with Dilated Cardiomyopathy
Authors: Parvari Ruti , Levitas Aviva
Published: July 2012

Cardiomyopathy is an important cause of heart failure and a major indication for heart transplantation in children and adults. This paper describes the state of the genetic knowledge of dilated cardiomyopathy (DCM). The identification of the causing mutation is important since presymptomatic interventions of DCM have proven value in preventing morbidity and mortality. Additionally, as in general in genetic studies, the identification of the mutated genes has a direct clinical impact for the families and population involved. Identifying causative mutations immediately amplifies the possibilities for disease prevention through carrier screening and prenatal testing. This often lifts a burden of social isolation from affected families, since healthy family members can be assured of having healthy children. Identification of the mutated genes holds the potential to lead to the understanding of disease etiology, pathophysiology, and therefore potential therapy. This paper presents the genetic variations, or disease-causing mutations, contributing to the pathogenesis of hereditary DCM, and tries to relate these to the functions of the mutated genes.
RefractoryClostridium difficileInfection Successfully Treated with Tigecycline, Rifaximin, and Vancomycin
Authors: Lao Dominador , Chiang Tom , Gomez Eric
Published: July 2012

The occurrence ofClostridium difficilecolitis is on the rise and has become more difficult to manage with standard therapy. Thus, the need for alternative treatments is essential. Tigecycline is a glycylcycline antibiotic that has been shown to be effective againstC. difficilethrough several published case reports and inin vitrostudies. We present a case ofC. difficilecolitis that failed to respond to metronidazole and oral vancomycin therapy, but improved on a combination of rifaximin, tigecycline, and vancomycin.
Aortic Dissection and Renal Failure in a Patient with Severe Hypothyroidism
Authors: Brooke Valerie , Goswami Sangeeta , Mohanty Arpan , Kasi Pashtoon Murtaza
Published: July 2012

Acute aortic dissection (AAD) is a life-threatening condition associated with high morbidity and mortality. The most important recognized acquired cause that leads to dissection is chronic arterial hypertension. With respect to the anuria and renal failure, aortic dissection is not something that is always considered and is still not a very common presentation unless both renal arteries come off the false lumen of the dissection. However, when present, preoperative renal failure in patients with acute type B dissection has been noted to be an independent predictor of mortality. Early recognition and diagnosis is the key and as noted by previous studies as well, almost a third of these patients are initially worked up for other causes until later when they are diagnosed with aortic dissection. Here we present a case of a patient presenting with severe hypothyroidism, long-standing hypertension, and anuria. Through the case, we highlight the importance of having aortic dissection as an important differential in patients presenting with anuria who have a long standing history of uncontrolled hypertension. Pathophysiology relating to severe hypothyroidism-induced renal dysfunction is also discussed.
Stent-Assisted Coiling Treatment of Pediatric Traumatic Pseudoaneurysm Resulting from Tumor Surgery
Authors: Ogilvy Christopher S. , Tawk Rabih G. , Mokin Maxim , Yang Xinyu , Levy Elad I. , Hopkins L. Nelson , Siddiqui Adnan H.
Published: July 2012

Background: Traumatic intracranial pseudoaneurysms in children are typically the result of blunt or penetrating head injury. There are isolated reports of pseudoaneurysm as the result of intracranial aneurysm surgery in both adults and children. Treatment of these lesions, both surgically and endovascularly, can be complicated due to the known variability of arterial wall thickness in traumatic pseudoaneurysms. Case Report: We describe a child who underwent successful craniopharyngioma resection following staged surgical procedures. Follow-up imaging 8 months after the operation demonstrated an enlarging pseudoaneurysm of the left supraclinoid carotid artery. The lesion was successfully treated with stenting of the vessel and coil placement between the stent and the aneurysmal segment of the artery. Follow-up angiographic imaging 6 months later revealed complete obliteration of the aneurysm and normalization of the carotid artery lumen. Conclusion: To our knowledge, this is the first report of a pseudoaneurysm secondary to a surgical intervention in childhood that was treated with stent-assisted coiling. This strategy of vascular reconstruction is increasingly used in adults and appears safe to implement in the pediatric population. However, the long-term outcomes and the value of using an antiplatelet regimen in this young population are still to be determined.
Loss of Estrogen Receptor α Signaling Leads to Insulin Resistance and Obesity in Young and Adult Female Mice
Authors: Manrique Camila , Lastra Guido , Habibi Javad , Mugerfeld Irina , Garro Mona , Sowers James R.
Published: July 2012

Background/Aims: There are important sex-related differences in the prevalence of obesity, type 2 diabetes mellitus and cardiovascular disease. Indeed, premenopausal women have a lower prevalence of these conditions relative to age-matched men. Estrogen participates in the modulation of insulin sensitivity, energy balance, and body composition. In this paper, we investigated the impact of estrogen signaling through estrogen receptor α (ERα) on systemic insulin sensitivity and insulin signaling in skeletal muscle. Methods: In 14- and 30-week-old female ERα knockout (ERαKO) mice and age-matched controls, we assessed insulin sensitivity by a euglycemic-hyperinsulinemic clamp and intraperitoneal glucose tolerance testing. Blood pressure was evaluated by tail cuff and telemetry. We studied ex vivo insulin-stimulated glucose uptake in skeletal muscle tissue, as well as insulin metabolic signaling molecule phosphorylation by immunoblotting and oxidative stress by immunostaining for 3-nitrotyrosine. Results: Body weight was higher in ERαKO mice at 14 and 30 weeks of age. At 30 weeks, intraperitoneal glucose tolerance testing and clamp results demonstrated impaired systemic insulin sensitivity in ERαKO mice. Insulin-stimulated glucose uptake in soleus was lower in ERαKO mice at both ages. The insulin receptor substrate 1/phosphatidylinositol 3-kinase association and the activation of protein kinase B were decreased in ERαKO mice, whereas immunostaining for 3-nitrotyrosine was increased. Conclusions: Our data demonstrate a critical age-dependent role for estrogen signaling through ERα on whole-body insulin sensitivity and insulin metabolic signaling in skeletal muscle tissue. These findings have potential translational implications for the prevention and management of type 2 diabetes mellitus and cardiovascular disease in women, who are at increased risk for these conditions.
Novel Uromodulin Mutation in Familial Juvenile Hyperuricemic Nephropathy
Authors: Wei Xin , Xu Ricong , Yang Zhenhua , Li Zhijian , Liao Yunhua , Johnson Richard J. , Yu Xueqing , Chen Wei
Published: July 2012

Background: Familial juvenile hyperuricemic nephropathy (FJHN) is an autosomal dominant disorder characterized by early onset of hyperuricemia, decreased fractional renal urate excretion and progressive interstitial nephropathy. Mutations in the uromodulin (UMOD) gene encoding uromodulin/Tamm-Horsfall, a glycosylphosphatidylinositol (GPI)-anchored protein, cause this disease. Methods: One Chinese family with 13 FJHN-affected individuals is described. Clinical data, blood and urine samples of 7 affected members (all alive patients in this family) and 15 unaffected members were collected. Mutation analysis of the UMOD gene was performed by polymerase chain reaction and direct sequencing. Urinary uromodulin from affected or unaffected members of this family and healthy controls was examined by enzyme-linked immunosorbent assay kit. Expression of uromodulin in renal tissue was shown with immunofluorescence. Results: A novel mutation (p.T605G) within the uromodulin GPI anchor signal segment was identified in the affected individuals of this FJHN family. There was a markedly increased expression of uromodulin in renal tissue and significantly decreased urinary excretion of uromodulin in affected patients with an estimated glomerular filtration rate <60 ml/min/1.73 m2. Conclusions: The present study reported a novel mutation in exon 9 of UMOD in the Chinese Han population, within the GPI anchor signal segment of uromodulin. Since the GPI anchor is linked with the release or secretion of proteins, our finding may provide further evidence for the underlying mechanism of decreased urinary excretion of uromodulin in FJHN.
Experiments in Context and Contexting
Authors: Asdal Kristin , Moser Ingunn
Published: July 2012

What is context and how to deal with it? The context issue has been a key concern in Science and Technology Studies (STS). This is linked to the understanding that science is culture. But how? The irreductionist program from the early eighties sought to solve the problem by doing away with context altogether—for the benefit of worlds in the making. This special issue takes its points of departure in this irreductionist program, its source of inspirations, as well as its reworkings. The aim is not to solve the context problem but rather to experiment with context and what we label contexting.
Applying contribution analysis: Lessons from five years of practice
Authors: Delahais Thomas , Toulemonde Jacques
Published: July 2012

Contribution analysis (CA) has been advocated and discussed more than it has been applied. This article draws on five evaluations applying CA in the context of EU policies in the areas of development aid, agriculture, employment, and governance. Over the last five years, the authors have developed their capacity to implement the six steps of CA and especially to draft contribution stories and to make contribution claims. These practical efforts have, in turn, caused them to explore the foundations of the approach and refine and operationalize key concepts such as contribution claim, causal mechanism, and strength of evidence.
Corticospinal tract integrity and motor function following neonatal stroke: a case study
Authors: Gordon Anne L , Wood Amanda , Tournier Jacques Donald , Hunt Rod W
Published: July 2012

Background

New MRI techniques enable visualisation of corticospinal tracts and cortical motor activity. The objective of this case study was to describe the magnetic resonance evidence of corticospinal pathway reorganisation following neonatal stroke.

Case presentation

An 11 year old boy with a neonatal right middle cerebral artery territory ischaemic stroke was studied. Functional MRI was undertaken with a whole hand squeezing task, comparing areas of cortical activation between hands. White matter tracts, seeded from the area of peak activation in the cortex, were visualised using a diffusion weighted imaging probabilistic tractography method. Standardised evaluations of unilateral and bilateral motor function were undertaken. Clinically, the child presented with a left hemiparesis. Functional MRI demonstrated that movement of the hemiparetic hand resulted in activation in the ipsi-lesional (right) hemisphere only. Diffusion tractography revealed pathways in the right (lesioned) hemisphere tracked perilesionally to the cortical area identified by functional MRI.

Conclusion

Our case demonstrates that neonatal stroke is associated with maintenance of organization of corticospinal pathways sufficient to maintain some degree of hand function in the affected hemisphere. Functional MRI and diffusion weighted imaging tractography may inform our understanding of recovery, organisation and reorganisation and have the potential to monitor responses to intervention following neonatal stroke.
Wyner–Ziv to Baseline H.264 Video Transcoder
Authors: Corrales-García Alberto , Martínez Jose Luis , Fernández-Escribano Gerardo , Villalon Jose Miguel , Kalva Hari , Cuenca Pedro
Published: July 2012

Mobile-to-mobile video communications is one of the most requested services which operator networks can offer. However, in a framework where one mobile device sends video information to another, both transmitter and receptor should employ video encoders and decoders with low complexity. On the one hand, traditional video codecs, such as H.264, are based on architectures which have encoders with higher complexity than decoders. On the other hand, Wyner–Ziv (WZ) video coding (a particular case of distributed video coding) is an innovative paradigm, which provides encoders with less complexity than decoders. Taking advantage of both paradigms, in terms of low complexity algorithms, a suitable solution consists in transcoding from WZ to H.264. Nevertheless, the transcoding process should be carried out in an efficient way so as to avoid major delays in communication; in other words, the transcoding process should perform the conversion without requiring the complete process of decoding and re-encoding. Based on all the algorithms and techniques we have proposed before, a low complexity WZ to H.264 Transcoder for the Baseline Profile is proposed in this article. Firstly, the proposed transcoder can efficiently turn every WZ group of pictures into the common H.264 I11P pattern and, secondly, the proposed transcoder is based on the hypothesis that macroblock coding mode decisions in H.264 video have a high correlation with the distribution of the side information residual in WZ video. The proposed algorithm selects one sub-set of the several coding modes in H.264. Moreover, a dynamic motion estimation technique is proposed in this article for use in combination with the above algorithm. Simulation results show that the proposed transcoder reduces the inter prediction complexity in H.264 by up to 93%, while maintaining coding efficiency.
Chemokine CCL2 and its receptor CCR2 in the medullary dorsal horn are involved in trigeminal neuropathic pain
Authors: Zhang Zhi-Jun , Dong Yu-Lin , Lu Ying , Cao Su , Zhao Zhi-Qi , Gao Yong-Jing
Published: July 2012

Background

Neuropathic pain in the trigeminal system is frequently observed in clinic, but the mechanisms involved are largely unknown. In addition, the function of immune cells and related chemicals in the mechanism of pain has been recognized, whereas few studies have addressed the potential role of chemokines in the trigeminal system in chronic pain. The present study was undertaken to test the hypothesis that chemokine C-C motif ligand 2 (CCL2)-chemokine C-C motif receptor 2 (CCR2) signaling in the trigeminal nucleus is involved in the maintenance of trigeminal neuropathic pain.

Methods

The inferior alveolar nerve and mental nerve transection (IAMNT) was used to induce trigeminal neuropathic pain. The expression of ATF3, CCL2, glial fibrillary acidic protein (GFAP), and CCR2 were detected by immunofluorescence histochemical staining and western blot. The cellular localization of CCL2 and CCR2 were examined by immunofluorescence double staining. The effect of a selective CCR2 antagonist, RS504393 on pain hypersensitivity was checked by behavioral testing.

Results

IAMNT induced persistent (>21 days) heat hyperalgesia of the orofacial region and ATF3 expression in the mandibular division of the trigeminal ganglion. Meanwhile, CCL2 expression was increased in the medullary dorsal horn (MDH) from 3 days to 21 days after IAMNT. The induced CCL2 was colocalized with astroglial marker GFAP, but not with neuronal marker NeuN or microglial marker OX-42. Astrocytes activation was also found in the MDH and it started at 3 days, peaked at 10 days and maintained at 21 days after IAMNT. In addition, CCR2 was upregulated by IAMNT in the ipsilateral medulla and lasted for more than 21 days. CCR2 was mainly colocalized with NeuN and few cells were colocalized with GFAP. Finally, intracisternal injection of CCR2 antagonist, RS504393 (1, 10 μg) significantly attenuated IAMNT-induced heat hyperalgesia.

Conclusion

The data suggest that CCL2-CCR2 signaling may be involved in the maintenance of orofacial neuropathic pain via astroglial–neuronal interaction. Targeting CCL2-CCR2 signaling may be a potentially important new treatment strategy for trigeminal neuralgia.
Complement receptor-3 negatively regulates the phagocytosis of degenerated myelin through tyrosine kinase Syk and cofilin
Authors: Hadas Smadar , Spira Maya , Hanisch Uwe-Karsten , Reichert Fanny , Rotshenker Shlomo
Published: July 2012

Background

Intact myelin, which normally surrounds axons, breaks down in Wallerian degeneration following axonal injury and during neurodegenerative diseases such as multiple sclerosis. Clearance of degenerated myelin by phagocytosis is essential since myelin impedes repair and exacerbates damage. CR3 (complement receptor-3) is a principal phagocytic receptor in myelin phagocytosis. We studied how tyrosine kinase Syk (spleen tyrosine kinase) and cofilin control phagocytosis of degenerated myelin by CR3 in microglia and macrophages. Syk is a non-receptor tyrosine kinase that CR3 recruits to convey cellular functions. Cofilin is an actin-depolymerizing protein that controls F-actin (filamentous actin) remodeling (i.e., disassembly and reassembly) by shifting between active unphosphorylated and inactive phosphorylated states.

Results

Syk was continuously activated during prolonged phagocytosis. Phagocytosis increased when Syk activity and expression were reduced, suggesting that normally Syk down regulates CR3-mediated myelin phagocytosis. Levels of inactive p-cofilin (phosphorylated cofilin) decreased transiently during prolonged phagocytosis. In contrast, p-cofilin levels decreased continuously when Syk activity and expression were continuously reduced, suggesting that normally Syk advances the inactive state of cofilin. Observations also revealed inverse relationships between levels of phagocytosis and levels of inactive p-cofilin, suggesting that active unphosphorylated cofilin advances phagocytosis. Active cofilin could advance phagocytosis by promoting F-actin remodeling, which supports the production of membrane protrusions (e.g., filopodia), which, as we also revealed, are instrumental in myelin phagocytosis.

Conclusions

CR3 both activates and downregulates myelin phagocytosis at the same time. Activation was previously documented. We presently demonstrate that downregulation is mediated through Syk, which advances the inactive phosphorylated state of cofilin. Self-negative control of phagocytosis by the phagocytic receptor can be useful in protecting phagocytes from excessive phagocytosis (i.e., “overeating”) during extended exposure to particles that are destined for ingestion.
The Majority of Dorsal Spinal Cord Gastrin Releasing Peptide is Synthesized Locally Whereas Neuromedin B is Highly Expressed in Pain- and Itch-Sensing Somatosensory Neurons
Authors: Fleming Michael S , Ramos Daniel , Han Seung Baek , Zhao Jianyuan , Son Young-Jin , Luo Wenqin
Published: July 2012

Background:

Itch is one of the major somatosensory modalities. Some recent findings have proposed that gastrin releasing peptide (Grp) is expressed in a subset of dorsal root ganglion (DRG) neurons and functions as a selective neurotransmitter for transferring itch information to spinal cord interneurons. However, expression data from public databases and earlier literatures indicate that Grp mRNA is only detected in dorsal spinal cord (dSC) whereas its family member neuromedin B ( Nmb) is highly expressed in DRG neurons. These contradictory results argue that a thorough characterization of the expression of Grp and Nmb is warranted.

Findings:

Grp mRNA is highly expressed in dSC but is barely detectable in DRGs of juvenile and adult mice. Anti-bombesin serum specifically recognizes Grp but not Nmb. Grp is present in a small number of small-diameter DRG neurons and in abundance in layers I and II of the spinal cord. The reduction of dSC Grp after dorsal root rhizotomy is significantly different from those of DRG derived markers but similar to that of a spinal cord neuronal marker. Double fluorescent in situ of Nmb and other molecular markers indicate that Nmb is highly and selectively expressed in nociceptive and itch-sensitive DRG neurons.

Conclusion:

The majority of dSC Grp is synthesized locally in dorsal spinal cord neurons. On the other hand, Nmb is highly expressed in pain- and itch-sensing DRG neurons. Our findings provide direct anatomic evidence that Grp could function locally in the dorsal spinal cord in addition to its roles in DRG neurons and that Nmb has potential roles in nociceptive and itch-sensitive neurons. These results will improve our understanding about roles of Grp and Nmb in mediating itch sensation.