bluuebunny/crossref_metadata_2025 huggingface dataset:
Neonatal intussusception: A rare but important condition to diagnose
Authors: Mak Oi‐Sze , Cheung Sing‐Tak , Tam Yuk‐Him , Sihoe Dart‐Yin , Chan Kin‐Wai , Mou Wai‐Cheung , Chong Hoi‐Man , Tsui Kwan‐Pok , Lee Kim‐Hung
Published: January 2010

Intussusception is one of the most common causes of intestinal obstruction in infancy but rarely occurs in the neonatal period. The presentation, pathology and management of neonatal intussusception are quite different from the usual childhood intussusception. Over a 2‐year period, we have managed three cases. We herein report our experience to highlight the diversity in presentation and management of neonatal intussusception.
First single incision transumbilical laparoscopic nephrectomy in Hong Kong
Authors: Cheng Chi‐Wai
Published: January 2010

Single port access procedure attempts to further enhance cosmetic benefits and reduce morbidity of minimally invasive surgery. A 47‐year‐old woman underwent a single incision transumbilical laparoscopic nephrectomy for her non‐functioning left kidney due to a full staghorn stone complicated by recurrent symptomatic urinary tract infection. The operation was successfully completed with three transumbilical ports (12 mm, 5 mm and 5 mm). Flexible grasper was used to facilitate dissection. Both 10 mm and 5 mm lens were used, the latter being required when instruments larger than 5 mm needed to be accommodated. The ureter was divided between Hem‐O‐Lok clips, whereas the renal vessels were controlled by vascular Endo‐GIA staplers. Specimen retrieval was made possible by connecting the three transumbilical ports. No extra‐umbilical incision was made. To my knowledge, this is the first case of single incision transumbilical laparoscopic nephrectomy ever carried out in Hong Kong.
Cerebral motor cortical mapping: Awake procedure is preferable to general anaesthesia
Authors: Chan Danny T.M. , Kan Patricia K.Y. , Lam Joseph M.K. , Zhu Xian‐Lun , Chan Yu‐Leung , Mak Henry K.F. , Wong Tammy Y.Y. , Poon Wai‐Sang
Published: January 2010

Objective:  To investigate the outcome of surgical resection of cerebral lesions near or at the motor cortex under general anaesthesia or in the awake condition.

Methods:  Patients undergoing motor cortical mapping for tumour surgery were recruited. Surgery was carried out according to the cortical mapping protocol of the centre. Tumour location, stimulation threshold, extent of resection and postoperative complications, including neurological deficits and seizure, were recorded. Results were categorized in the awake group and in the general anaesthesia (GA) group for analysis.

Results:  From February 2003 to July 2006, 28 patients suffering from brain tumour (24 glioma, two metastasis and two cavernoma) were indicated for motor cortical mapping to facilitate safe tumour removal.

Eight patients were in the GA group. Five tumours were subcortical lesions, whereas three were cortical lesions. There were 20 patients in the awake group. Three tumours were subcortical, whereas 17 were cortical lesions. The mean stimulation threshold was 10.75 mA (5–16 mA) in the GA group and 7.7 mA (4–12 mA) in the awake group. There were four early postoperative seizures, two transient (3‐month) deficits and four permanent deficits in the GA group. One early postoperative seizure, five transient deficits and no permanent deficits were recorded in the awake group. All the permanent deficits were associated with subcortical tumours and were in the GA group. Seventy five percent of the patients achieved radiological total removal and an average extent of resection of 94.15% was achieved in the awake group. Only 37.5% of patients achieved radiological total removal and the average of extent of resection was 64.1% in the GA group.

Conclusions:  General anaesthesia was associated with high postoperative permanent deficit despite the effort of motor cortical mapping. Higher rate of early postoperative seizure was also found in the GA group. Awake motor cortical mapping was safer and was associated with fewer complications. We suggest that awake motor cortical mapping is preferable to the general anaesthetic technique.
SENSORY ATTRIBUTES OF HADDOCK BALLS AFFECTED BY ADDED FISH PROTEIN ISOLATE AND FROZEN STORAGE
Authors: SHAVIKLO GHOLAM REZA , ARASON SIGURJON , THORKELSSON GUDJON , SVEINSDOTTIR KOLBRUN , MARTINSDOTTIR EMILIA
Published: January 2010

Fish protein isolate (FPI) made from haddock (Melanogrammus aeglefinus) cut‐offs by the pH‐shift process was added to haddock mince to make two groups of fried fish balls. The proportions (%) of mince to isolate were 100:0 (control group), 75:25 and 50:50. All groups were air packed and kept frozen at −18C. The sample groups were evaluated by sensory evaluation 1 day after processing and after 2, 4 and 8 weeks of storage at −18C. The results indicated that added FPI to mince and frozen storage affected the odor, flavor, texture and appearance of fish balls significantly, possibly because of chemical and biochemical changes of all groups. This study also revealed that most negative features are attributed to the groups containing 50% mince and 50% isolate. The results can be considered for product development of FPI.

PRACTICAL APPLICATIONS

Fish protein isolate from by‐products is a new source of fish protein to produce ready‐to‐eat or value‐added products. Little information has been published on product development about fish protein isolate and quality and sensory attributes of such products. Therefore, the results of this study could be useful for applying fish protein isolate to food systems.
Effect of UVA or UVB Irradiation on Cutaneous Lipids in Films or in Solution
Authors: Merle Chloé , Laugel Cécile , Baillet‐Guffroy Arlette
Published: January 2010

The barrier function of the skin is largely due to the stratum corneum which is essentially composed of lipids. Different external factors, such as UV irradiation, affect this skin layer and are responsible for a destabilization of the supramolecular organization of its constituted lipids. In this work, mass spectrometry and infrared spectroscopy are combined to study the correlation between the formation of oxidative compounds by UV irradiation and the lipid organization. Experiments were carried out on unsaturated lipids in film or solution form, exposed to UVA or UVB irradiation. UV exposure leads to the formation of oxygenated entities in the case of lipids with an unsaturated fatty acid moiety, resulting in a decrease in their packing which is greater when the lipids are in solution. The packing decrease is even greater following UVB irradiation.
Low‐light‐induced Violaxanthin De‐epoxidation in Shortly Preheated Leaves: Uncoupling from ΔpH‐dependent Nonphotochemical Quenching
Authors: Ilík Petr , Kotabová Eva , Špundová Martina , Novák Ondřej , Kaňa Radek , Strzałka Kazimierz
Published: January 2010

Plants protect themselves against excessive light by the induction of ΔpH‐dependent nonphotochemical quenching (qE) that is associated with de‐epoxidation of violaxanthin (V) to zeaxanthin (Z) in thylakoid membranes. In this work, we report that low light (12 μmol photons m−2 s−1) is sufficient for a marked stimulation of the V to Z conversion in shortly preheated wheat leaves (5 min, 40°C), but without a substantial increase in qE. Re‐irradiation of these leaves with high light led to a rapid induction of nonphotochemical quenching, implying a potential photoprotective role of low‐light‐induced Z in preheated leaves. On the contrary to low light conditions, preheated leaves exposed to high light behaved similar to nonheated leaves with respect to the V to Z conversion and qE induction. The obtained results indicate that low‐light‐induced lumen acidification in preheated leaves is high enough to activate V de‐epoxidation, but not sufficiently high to induce the formation of quenching centers.
PERSPECTIVE: Underutilized resources for studying the evolution of invasive species during their introduction, establishment, and lag phases
Authors: Marsico Travis D. , Burt Jennifer W. , Espeland Erin K. , Gilchrist George W. , Jamieson Mary A. , Lindström Leena , Roderick George K. , Swope Sarah , Szűcs Marianna , Tsutsui Neil D.
Published: January 2010

The early phases of biological invasions are poorly understood. In particular, during the introduction, establishment, and possible lag phases, it is unclear to what extent evolution must take place for an introduced species to transition from established to expanding. In this study, we highlight three disparate data sources that can provide insights into evolutionary processes associated with invasion success: biological control organisms, horticultural introductions, and natural history collections. All three data sources potentially provide introduction dates, information about source populations, and genetic and morphological samples at different time points along the invasion trajectory that can be used to investigate preadaptation and evolution during the invasion process, including immediately after introduction and before invasive expansion. For all three data sources, we explore where the data are held, their quality, and their accessibility. We argue that these sources could find widespread use with a few additional pieces of data, such as voucher specimens collected at certain critical time points during biocontrol agent quarantine, rearing, and release and also for horticultural imports, neither of which are currently done consistently. In addition, public access to collected information must become available on centralized databases to increase its utility in ecological and evolutionary research.
Governing Antarctica: Contemporary Challenges and the Enduring Legacy of the 1959 Antarctic Treaty
Authors: Dodds Klaus
Published: January 2010

This article considers the governance of the Antarctic in the light of the 50th anniversary of the Antarctic Treaty in December 2009. Created in the midst of the cold war, this treaty provided a mechanism for governing the Antarctic. Science and international collaboration were central to this new regime. Over the next five decades, the Antarctic Treaty System (ATS) expanded as new legal instruments were developed and entered into force including the Protocol on Environmental Protection. New issues such as fishing and tourism along with an expanded membership have transformed the politics of Antarctica. Current controversies involving illegal, unregulated and unreported fishing, the Law of the Sea and the creation of the ‘coastal state’, tourism and whaling will continue to provoke serious challenges for the governance of Antarctica.
Understanding the Global Dimensions of Policy
Authors: Koenig‐Archibugi Mathias
Published: January 2010

Beyond wide agreement that many areas of contemporary policy making are unintelligible if processes that transcend the boundaries of individual states are not taken into account, analysts often disagree on how various ‘global’ and ‘local’ factors interact to produce policies and policy outcomes. The disagreement stems in part from the use of different analytic lenses, and specifically from the choice between ‘state‐centric’ and ‘polycentric’ lenses. This article examines the fundamental assumptions of these general perspectives with regard to the polity, politics and policy dimensions of global policy making, and surveys some of the research questions and findings that resulted from their use. It concludes that scholars and policy makers should treat the two analytical lenses as complementary, as each of them stimulates the analyst to ask questions and look for entities and causal connections that the other lens may miss.

Policy Implications

 Analysts and policy makers need to be aware of the sometimes implicit assumptions underlying global policy studies.

 ‘State‐centric’ and ‘polycentric’ lenses provide complementary and valuable perspectives on the global dimensions of policy making.

 Systematic data collection and analysis of nonstate mechanisms of policy making should be encouraged and supported.
G2 in G20: China, the United States and the World after the Global Financial Crisis
Authors: Garrett Geoffrey
Published: January 2010

The post‐global financial crisis world will be increasingly dominated by China and the United States. What the de facto G2 do, together, independently or in conflict, will increasingly define the global bounds of the possible. Both countries want to embed their bilateral diplomacy in the multilateralism of the G20. The problem for the emergent G2 in G20 global architecture is that economic relations between China and the US will be increasingly difficult to manage. The large economic imbalances between the two countries, in which China buys American debt and Americans buy Chinese goods, will endure. Before the crisis, the codependence these imbalances created was a source of stability in Sino–American relations. After the crisis, they will be a source of frustration and conflict, as the second half of 2009 showed. To manage economic relations between China and the US effectively, the G20 agenda will have to move from crisis management to strategic planning for the global economy. The G20 will also have to become more institutionalized, but in a way that resembles more a nonexecutive board of directors of a multinational firm than a management committee of C‐level executives.

Policy Implications

 The world will be characterized by a de facto China–US G2 after the financial crisis.

 Despite new commitments from both countries, large‐scale China–US economic imbalances will persist.

 Dueling protectionism and economic nationalism are the biggest potential medium‐term threats to China–US relations.

 Nesting the de facto G2 in the de jure G20 is the best hope for managing China–US tensions.

 The G20 should be institutionalized as the board of directors for overseeing the Bretton Woods system, not as a replacement for it.
Instability Control by Premixed Pilot Flames
Authors: Albrecht Peter , Bade Stefanie , Lacarelle Arnaud , Paschereit Christian Oliver , Gutmark Ephraim
Published: January 2010

Premixed flames of swirl-stabilized combustors (displaced half-cone) are susceptible to thermo-acoustic instabilities, which should be avoided under all operating conditions in order to guarantee a long service life for both stationary and aircraft gas turbines. The source of this unstable flame behavior can be found in a transition of the premix flame structure between two stationary conditions that can be easily excited by fuel fluctuations, coherent structures within the flow, and other mechanisms. Pilot flames can alleviate this issue either by improving the dynamic stability directly or by sustaining the main combustion process at operating points where instabilities are unlikely. In the present study, the impact of two different premixed pilot injections on the combustion stability is investigated. One of the pilot injector (pilot flame injector) was located upstream of the recirculation zone at the apex of the burner. The second one was a pilot ring placed at the burner outlet on the dump plane. A noticeable feature of the pilot injector was that an ignition device allowed for creating pilot premixed flames. The present investigation showed that these premixed pilot flames were able to suppress instabilities over a wider fuel/air ratio range than the conventional premixed pilot injection alone. Furthermore, it was possible to prevent instabilities and maintain the flame burning near the lean blowout when a percentage of the fuel was premixed with air and injected through the pilot ring. NOx emissions were significantly reduced.
Experimental Investigation of the Effect of Biodiesel Utilization on Lubricating Oil Degradation and Wear of a Transportation CIDI Engine
Authors: Sinha Shailendra , Agarwal Avinash Kumar
Published: January 2010

In the present experimental research work, rice-bran oil methyl ester (ROME) is derived through transesterification of rice-bran oil using methanol in the presence of sodium hydroxide catalyst. On the basis of previous research for performance, emission, and combustion characteristics, a 20% (v/v) blend of ROME (B20) was selected as optimum biodiesel blend. This experimental investigation was aimed to investigate the effect of biodiesel on wear of in-cylinder engine components. Endurance tests were conducted on a medium duty direct injection transportation diesel engine with B20. Tests were conducted under predetermined loading cycles in two phases: engine operating on mineral diesel (B00) and engine fueled with B20. After completion of these tests, engines were dismantled for observing the physical condition of various vital engine parts, e.g., piston rings, bearings, cylinder liner, and cylinder head. Physical measurements of these vital parts were also carried out to assess the wear of these parts. The physical wear of various parts except big end bearings (connecting rod bearing bore) were found to be lower in the case of B20 fueled engine. Wear metals in the lubricating oil samples drawn from the engines at regular intervals were investigated. Relatively lower wear concentrations of all wear metals except lead were found in the lubricating oil of B20 fueled engine. To quantify the wear of cylinder liners, surface parameters at different locations in the liner (top dead center, bottom dead center, and midstroke) were measured and compared. A qualitative analysis was also carried out by conducting surface profiles and scanning electron microscopy at the same locations.
Integration of Nuclear Energy Into Oil Sands Projects
Authors: Finan Ashley E. , Kadak Andrew C.
Published: January 2010

Energy security and greenhouse gas reduction are thought to be two of the most urgent priorities for sustaining and improving the human condition in the near future. Few places pit the two goals so directly in opposition to one another as the Alberta oil sands. Here, Canadian natural gas is burned in massive quantities to extract oil from one of North America’s largest native sources of carbon-intensive heavy oil. However, this conflict need not continue. Nonemitting nuclear energy can replace natural gas as a fuel source in an economical and more environmentally sound way. This would allow for the continued extraction of transportation fuels without greenhouse gas emissions, while freeing up the natural gas supply for hydrogen feedstock and other valuable applications. Bitumen production in Alberta expanded dramatically in the past 5 years as the price of oil rose to record levels. This paper explores the feasibility and economics of using nuclear energy to power future oil sands production and upgrading activities, and puts forth several nuclear energy application scenarios for providing steam and electricity to in situ and surface mining operations. This review includes the Enhanced CANDU 6, the Advanced CANDU Reactor, and the pebble bed modular reactor. Based on reasonable projections of available cost information, steam produced using nuclear energy is expected to be less expensive than steam produced by natural gas at current natural gas prices and at prices above $6.50/MMBtu (CAD). For electricity production, nuclear energy becomes competitive with natural gas plants at gas prices of $10–13/MMBtu (CAD). Costs of constructing nuclear plants in Alberta are affected by higher local labor costs, which this paper took into account in making these estimates. Although a more definitive analysis of construction costs and project economics will be required to confirm these findings, there appears to be sufficient merit in the potential economics to support further study.
Identification of Squeeze Film Damper Force Coefficients From Multiple-Frequency Noncircular Journal Motions
Authors: Delgado Adolfo , San Andrés Luis
Published: January 2010

In rotor-bearing systems, squeeze film dampers (SFDs) provide structural isolation, reduce amplitudes of rotor response to imbalance, and in some instances, increase the system threshold speed of instability. SFDs are typically installed at the bearing supports, either in series or in parallel. In multispool engines, SFDs are located in the interface between rotating shafts. These intershaft dampers must ameliorate complex rotor motions of various whirl frequencies arising from the low speed and the high speed rotors. The paper presents experiments to characterize the forced response of an open ends SFD subject to dynamic loads with multiple frequencies, as in a jet engine intershaft damper. The test rig comprises of a stationary journal and a flexibly supported housing that holds the test damper and instrumentation. The open ends SFD is 127 mm in diameter, 25.4 mm film land length, and has a radial clearance of 0.125 mm. The damper is lubricated with ISO VG 2 oil at room temperature (24°C, feed pressure 31 kPa). In the experiments, two orthogonally positioned shakers deliver forces to the test damper that produce controlled amplitude motions with two whirl frequencies, one fixed and the other one varying over a specified range that includes the test system natural frequency. The test data collected, forces and motions versus time, are converted into the frequency domain for parameter identification. The identified viscous damping coefficients are strong functions of the amplitude of journal motion, lying within predictions from classical formulas for circular centered orbits and small amplitude motions about an eccentric journal position. The damper inertia coefficients agree well with predictions derived from a fluid flow model that includes the effect of the feed groove.
Gas Turbine Performance and Health Status Estimation Using Adaptive Gas Path Analysis
Authors: Li Y. G.
Published: January 2010

In gas turbine operations, engine performance and health status are very important information for engine operators. Such engine performance is normally represented by engine airflow rate, compressor pressure ratios, compressor isentropic efficiencies, turbine entry temperature, turbine isentropic efficiencies, etc., while the engine health status is represented by compressor and turbine efficiency indices and flow capacity indices. However, these crucial performance and health information cannot be directly measured and therefore are not easily available. In this research, a novel Adaptive Gas Path Analysis (Adaptive GPA) approach has been developed to estimate actual engine performance and gas path component health status by using gas path measurements, such as gas path pressures, temperatures, shaft rotational speeds, fuel flow rate, etc. Two steps are included in the Adaptive GPA approach, the first step is the estimation of degraded engine performance status by a novel application of a performance adaptation method, and the second step is the estimation of engine health status at component level by using a new diagnostic method introduced in this paper, based on the information obtained in the first step. The developed Adaptive GPA approach has been tested in four test cases where the performance and degradation of a model gas turbine engine similar to Rolls-Royce aero engine Avon-300 have been analyzed. The case studies have shown that the developed novel linear and nonlinear Adaptive GPA approaches can accurately and quickly estimate the degraded engine performance and predict the degradation of major engine gas path components with the existence of measurement noise. The test cases have also shown that the calculation time required by the approach is short enough for its potential online applications.
Which Came First?
Authors: Bentley-Lewis Rhonda
Published: January 2010

Researchers use Mendelian randomization to decipher directions of causality between obesity and inflammation.
Spatial characteristics of canopy disturbances in riparian old-growth hemlock – northern hardwood forests, Adirondack Mountains, New York, USA
Authors: Curzon Miranda T. , Keeton William S.
Published: January 2010

Gap dynamics in temperate, late-successional forests influence important riparian functions, including organic matter recruitment and light environments over streams. However, controls on gap dynamics specific to riparian forests are poorly understood. We hypothesized that (i) gaps are larger and more frequent nearer streams, (ii) gaps cluster at within-stand scales, and (iii) tree damage type and gap fraction vary among riparian landforms. All gaps within four 6–9 ha plots in riparian old-growth eastern hemlock ( Tsuga canadensis (L.) Carrière) – northern hardwood forest in the Adirondack Mountains, New York, USA, were mapped and measured. We recorded species, damage type, and diameter at breast height for gapmakers and dominant perimeter trees. Spatial distribution was assessed with Ripley’s K. Spatial autocorrelation in gap area and tree damage type were assessed using Moran’s I. Linear regression analysis defined relationships between proximity to streams and gap area and frequency. Expanded gap fraction ranged from 28.3% to 47.6%. Gaps were randomly distributed at scales ≤25 m and clustered at scales of 63–122 m. Distribution patterns were not consistent at other scales. Convergent and divergent landforms significantly influenced gap fraction, tree damage type, and species distributions. Positive correlations between convergent topography and gap area suggest an interaction between low-order riparian landforms and gap formation dynamics in late-successional forests.
Effect of thinning, fertilization with biosolids, and weather on interannual ring specific gravity and carbon accumulation of a 55-year-old Douglas-fir stand in western Washington
Authors: Kantavichai Rapeepan , Briggs David G. , Turnblom Eric C.
Published: January 2010

Marketing timber is shifting from logs, lumber, and veneer measured volumetrically to include carbon storage and energy that are based on dry mass. Conversion between volume and dry mass relies on accurate estimates of wood specific gravity (SG). We measured width and SG of growth rings and their earlywood and latewood components with X-ray densitometry on trees from controlled, thinned, biosolid fertilized, and combined treatments applied to a 55-year-old Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) stand. We developed models to predict interannual SG from climate and treatment effects and compared 20 year changes in dry mass and carbon storage with estimates from biomass equations and from the Wood Handbook average SG. Thinning increased latewood width but did not affect ring SG. Biosolid fertilization increased earlywood and latewood width and decreased ring SG 8% by decreasing earlywood SG, latewood SG, and latewood percentage. SG decreased with increased July soil moisture deficit; alternatively, SG increased with increased July total precipitation. Warmer mean March–May or August–November temperatures also increased SG. Because of the effects on SG, dry mass and carbon storage changes differed from volume changes produced by the treatments. Dry mass estimates using the average Wood Handbook SG or those calculated from biomass equations were inconsistent between treatments, with errors up to 50%.
Stem form and compression wood formation in young Pinus radiata trees
Authors: Lachenbruch Barbara , Droppelmann Fernando , Balocchi Claudio , Peredo Miguel , Perez Erika
Published: January 2010

The crooked stems of some individuals of radiata pine ( Pinus radiata D. Don) can hinder volume recovery and wood quality. To infer causes of crookedness and to learn how lean angle affects compression wood (CW) formation we studied 5-year-old trees in southern Chile. Eight initially straight and eight initially crooked trees were tethered initially to angles of 15° or 30° or were left untethered for 131 days (48 trees total). There were no significant differences between straight and crooked trees in the extent of CW in pretreatment wood or in the relationship between stem angle and CW extent. Crooked trees, however, righted themselves more quickly than did straight trees at angles <15°, a result that supports the overcompensation hypothesis for the development of crooked stems. Stem angle had a complex effect on CW extent. In 2- to 3-year-old wood there was no meaningful effect of angle on CW extent. One-year-old wood produced less CW at stem angles <10° than at stem angles >10°, but above or below that threshold, there was no meaningful effect of angle on CW extent. The intertree differences in CW extent, as well as the correlation of leader CW extent with bole CW in the best individuals, suggests that CW assays could be used for early screening for wood quality.
Spatiotemporal variability in tree and stand mortality caused by spruce budworm outbreaks in eastern Quebec
Authors: Bouchard Mathieu , Pothier David
Published: January 2010

We evaluated spruce budworm ( Choristoneura fumiferana (Clem.)) outbreak effects in nine study areas (60–86 ha each) located in the boreal forest of eastern Quebec (Canada). In each area, spruce budworm outbreak effects were measured from vegetation plots, dominant canopy and understory tree age structures, retrospective analysis of aerial photographs, defoliation records, and host tree growth reductions (dendrochronology). Large-scale synchronous outbreaks were detected across the region around the years 1880, 1915, 1950, and 1980. Overall, contrarily to what was expected for a region where host species (balsam fir ( Abies balsamea (L.) Mill.), Picea spp.) content is relatively high, these spruce budworm outbreaks seemed to have a relatively minor influence on stand dynamics, with the exception of the most recent outbreak (1980). This outbreak resulted in major stand mortality in the southern part of the region and favored the establishment of extensive tracts of young even-aged stands with few residual mature trees. This very abrupt increase in outbreak severity compared with earlier outbreaks, perhaps due to climatic or random factors, suggests that historical trends in successive outbreak severity should be extrapolated very cautiously and that the study of several outbreak cycles is needed to establish a range of natural variability that can be used to develop an ecosystem forest management strategy.
A COPULA-BASED CORRELATION MEASURE AND ITS APPLICATION IN CHINESE STOCK MARKET
Authors: WEN FENGHUA , LIU ZHIFENG
Published: January 2010

In this paper, a copula-based correlation measure is proposed to test the interdependence among stochastic variables in terms of copula function. Based on a geometric analysis of copula function, a new derivation method is introduced to derive the Gini correlation coefficient. Meantime theoretical analysis finds that the Gini correlation coefficient tends to overestimate the tail interdependence in the case of stochastic variables clustering at the tails. For this overestimation issue, a fully new correlation coefficient called Co is developed and extended to measure the tail interdependence. Empirical study shows that the new correlation coefficient Co can effectively solve the overestimation issue, which implies that the proposed new correlation coefficient is more suitable to describe the interdependence among stochastic variables than the Gini correlation coefficient.
A GAME THEORETIC OPTIMIZATION MODEL BETWEEN PROJECT RISK SET AND MEASURE SET
Authors: ZHAO LINDU , JIANG YIPING
Published: January 2010

Project risk management, as a subjective and dynamic decision method of avoiding project risk, plays an important role in selecting appropriate control measures (i.e. measure set) to handle multiple emerging risks (i.e. risk set). This paper focuses on the multi-risk control problem under the condition of finite risk management resources. Based on the description of a Multi-HUB network and a collaboration mechanism within project risk management system, a multi-risk control system is formulated as a non-cooperative complete information game model between the project risk set and the measure set. In the proposed model, each risk within the risk set is described as a player in the game, who is competing with other players for the allocation of risk control resources that are available in limited quantities within a given measure set. Then an efficient algorithm is proposed to solve the allocation solution based on Nash equilibrium, and an experiment is presented to illustrate the effectiveness of the proposed game model. The proposed modeling and solution methods can be used to support decision-making in project risk management.
QUANTUM LIE SYSTEMS AND INTEGRABILITY CONDITIONS
Authors: CARIÑENA JOSÉ F. , DE LUCAS JAVIER
Published: January 2010

The theory of Lie systems has recently been applied to Quantum Mechanics and additionally some integrability conditions for Lie systems of differential equations have also recently been analyzed from a geometric perspective. In this paper we use both developments to obtain a geometric theory of integrability in Quantum Mechanics and we use it to provide a series of non-trivial integrable quantum mechanical models and to recover some known results from our unifying point of view.
TWISTED SYMMETRIES AND INTEGRABLE SYSTEMS
Authors: GAETA GIUSEPPE , CICOGNA GIAMPAOLO
Published: January 2010

Symmetry properties are at the basis of integrability. In recent years, it appeared that so-called twisted symmetries are as effective as standard symmetries in many respects (integrating ODEs, finding special solutions to PDEs). Here we discuss how twisted symmetries can be used to detect integrability of Lagrangian systems which are not integrable via standard symmetries.
Shedding light on the enigma of myocardial lipotoxicity: the involvement of known and putative regulators of fatty acid storage and mobilization
Authors: Brindley David N. , Kok Bernard P. C. , Kienesberger Petra C. , Lehner Richard , Dyck Jason R. B.
Published: January 2010

Excessive fatty acid (FA) uptake by cardiac myocytes is often associated with adverse changes in cardiac function. This is especially evident in diabetic individuals, where increased intramyocardial triacylglycerol (TG) resulting from the exposure to high levels of circulating FA has been proposed to be a major contributor to diabetic cardiomyopathy. At present, our knowledge of how the heart regulates FA storage in TG and the hydrolysis of this TG is limited. This review concentrates on what is known about TG turnover within the heart and how this is likely to be regulated by extrapolating results from other tissues. We also assess the evidence as to whether increased TG accumulation protects against FA-induced lipotoxicity through limiting the accumulations of ceramides and diacylglycerols versus whether it is a maladaptive response that contributes to cardiac dysfunction.
Treatment with an SSRI antidepressant restores hippocampo-hypothalamic corticosteroid feedback and reverses insulin resistance in low-birth-weight rats
Authors: Buhl Esben S. , Jensen Thomas Korgaard , Jessen Niels , Elfving Betina , Buhl Christian S. , Kristiansen Steen B. , Pold Rasmus , Solskov Lasse , Schmitz Ole , Wegener Gregers , Lund Sten , Petersen Kitt Falck
Published: January 2010

Low birth weight (LBW) is associated with type 2 diabetes and depression, which may be related to prenatal stress and insulin resistance as a result of chronic hypothalamic-pituitary-adrenal (HPA) axis hyperactivity. We examined whether treatment with a selective serotonin reuptake inhibitor [escitalopram (ESC)] could downregulate HPA axis activity and restore insulin sensitivity in LBW rats. After 4–5 wk of treatment, ESC-exposed LBW (SSRI-LBW) and saline-treated control and LBW rats (Cx and LBW) underwent an oral glucose tolerance test or a hyperinsulinemic euglycemic clamp to assess whole body insulin sensitivity. Hepatic phospho enolpyruvate carboxykinase (PEPCK) mRNA expression and red skeletal muscle PKB Ser473phosphorylation were used to assess tissue-specific insulin sensitivity. mRNA expression of the hypothalamic mineralocorticoid receptor was fivefold upregulated in LBW ( P < 0.05 vs. Cx), accompanied by increased corticosterone release during restraint stress and total 24-h urinary excretion ( P < 0.05 vs. Cx), whole body insulin resistance ( P < 0.001 vs. Cx), and impaired insulin suppression of hepatic PEPCK mRNA expression ( P < 0.05 vs. Cx). Additionally, there was a tendency for reduced red muscle PKB Ser473phosphorylation. The ESC treatment normalized corticosterone secretion ( P < 0.05 vs. LBW), whole body insulin sensitivity ( P < 0.01) as well as postprandial suppression of hepatic mRNA PEPCK expression ( P < 0.05), and red muscle PKB Ser473phosphorylation ( P < 0.01 vs. LBW). We conclude that these data suggest that the insulin resistance and chronic HPA axis hyperactivity in LBW rats can be reversed by treatment with an ESC, which downregulates HPA axis activity, lowers glucocorticoid exposure, and restores insulin sensitivity in LBW rats.
IVGTT glucose minimal model covariate selection by nonlinear mixed-effects approach
Authors: Denti Paolo , Bertoldo Alessandra , Vicini Paolo , Cobelli Claudio
Published: January 2010

Population approaches, traditionally employed in pharmacokinetic-pharmacodynamic studies, have shown value also in the context of glucose-insulin metabolism models by providing more accurate individual parameters estimates and a compelling statistical framework for the analysis of between-subject variability (BSV). In this work, the advantages of population techniques are further explored by proposing integration of covariates in the intravenous glucose tolerance test (IVGTT) glucose minimal model analysis. A previously published dataset of 204 healthy subjects, who underwent insulin-modified IVGTTs, was analyzed in NONMEM, and relevant demographic information about each subject was employed to explain part of the BSV observed in parameter values. Demographic data included height, weight, sex, and age, but also basal glycemia and insulinemia, and information about amount and distribution of body fat. On the basis of nonlinear mixed-effects modeling, age, visceral abdominal fat, and basal insulinemia were significant predictors for SI (insulin sensitivity), whereas only age and basal insulinemia were significant for P2 (insulin action). The volume of distribution correlated with sex, age, percentage of total body fat, and basal glycemia, whereas no significant covariate was detected to explain variability in SG (glucose effectiveness). The introduction of covariates resulted in a significant shrinking of the unexplained BSV, especially for SI and P2 and considerably improved the model fit. These results offer a starting point for speculation about the physiological meaning of the relationships detected and pave the way for the design of less invasive and less expensive protocols for epidemiological studies of glucose-insulin metabolism.
A Modeling Study of the Effects of Membrane Afterhyperpolarization on Spike Interval Statistics and on ILD Encoding in the Lateral Superior Olive
Authors: Zhou Yi , Colburn H. Steven
Published: January 2010

The lateral superior olive (LSO) is the first nucleus in the ascending auditory pathway that encodes acoustic level information from both ears, the interaural level difference (ILD). This sensitivity is believed to result from the relative strengths of ipsilateral excitation and contralateral inhibition. The study reported here simulated sound-evoked responses of LSO chopper units with a focus on the role of the heterogeneity in membrane afterhyperpolarization (AHP) channels on spike interval statistics and on ILD encoding. A relatively simplified cell model was used so that the effects of interest could be isolated. Specifically, the amplitude and time constant of the AHP conductance within a leaky integrate-and-fire (LIF) cell model were studied. This extends the work of others who used a more physiologically detailed model. Results show that differences in these two parameters lead to both the distinctive chopper response patterns and to the level-dependent interval statistics as observed in vivo. In general, diverse AHP characteristics enable an enhanced contrast across population responses with respect to rate gain and temporal correlations. This membrane heterogeneity provides an internal, cell-specific dimension for the neural representation of stimulus information, allowing sensitivity to ILDs of dynamic stimuli.
Discovery of chicken microRNAs associated with lipogenesis and cell proliferation
Authors: Hicks Julie A. , Trakooljul Nares , Liu Hsiao-Ching
Published: January 2010

The primary function of microRNA (miRNA, a class of small regulatory RNA) is to regulate gene expression. Studies of miRNA in mammals suggest that many liver-associated miRNAs are expressed, with a wide range of functions. To characterize miRNA expressed in the avian liver, we created two small RNA libraries from embryonic chick livers at embryonic day (E)15 and E20, a time at which the embryo begins to grow rapidly and so its energy demands increase. It is of interest to examine miRNAs expressed at these developmental stages because miRNAs involved in regulating metabolic pathways and cell proliferation are likely to be identified. The small RNA libraries were sequenced with 454 Life Sciences deep sequencing. Of the 49,937 sequences obtained, 29,390 represented known chicken miRNAs and 1,233 reads represented homologous miRNAs that have not been previously identified in chickens. Additionally, 1,032 reads represented 17 potential novel miRNAs not previously identified in any species. To further investigate the possible functions of avian liver miRNAs we identified the potential targets of two differentially expressed novel miRNAs, nc-miR-5 and nc-miR-33. These two miRNAs were predicted to target metabolic genes, including the lipid metabolism-associated gene fatty acid synthase ( FAS), and genes involved in the control of cell proliferation, such as peroxisome proliferator-activated binding protein ( Pparbp) and bone morphogenetic protein 4 ( BMP4). Our findings demonstrate that a diverse group of miRNAs are expressed in developing avian livers. In addition, some of the identified miRNAs have been suggested to play a key role(s) in regulating metabolic pathways.
Mammary gene expression profiles during an intramammary challenge reveal potential mechanisms linking negative energy balance with impaired immune response
Authors: Moyes Kasey M. , Drackley James K. , Morin Dawn E. , Rodriguez-Zas Sandra L. , Everts Robin E. , Lewin Harris A. , Loor Juan J.
Published: January 2010

Our objective was to compare mammary tissue gene expression profiles during a Streptococcus uberis ( S. uberis) mastitis challenge between lactating cows subjected to dietary-induced negative energy balance (NEB; n = 5) and cows fed ad libitum to maintain positive energy balance (PEB; n = 5) to better understand the mechanisms associated with NEB and risk of mastitis during the transition period. The NEB cows were feed-restricted to 60% of calculated net energy for lactation requirements for 7 days, and cows assigned to PEB were fed the same diet for ad libitum intake. Five days after feed restriction, one rear mammary quarter of each cow was inoculated with 5,000 cfu of S. uberis (O140J). At 20 h postinoculation, S. uberis-infected mammary quarters from all cows were biopsied for RNA extraction. Negative energy balance resulted in 287 differentially expressed genes (DEG; false discovery rate ≤ 0.05), with 86 DEG upregulated and 201 DEG downregulated in NEB vs. PEB. Canonical pathways most affected by NEB were IL-8 signaling (10 genes), glucocorticoid receptor signaling ( 13 ), and NRF2-mediated oxidative stress response ( 10 ). Among the genes differentially expressed by NEB, cell growth and proliferation ( 48 ) and cellular development ( 36 ) were the most enriched functions. Regarding immune response, HLA-A was upregulated due to NEB, whereas the majority of genes involved in immune response were downregulated (e.g., AKT1, IRAK1, MAPK9, and TRAF6). This study provided new avenues for investigation into the mechanisms relating NEB and susceptibility to mastitis in lactating dairy cows.
A single acute pharmacological dose of γ-hydroxybutyrate modifies multiple gene expression patterns in rat hippocampus and frontal cortex
Authors: Kemmel Véronique , Klein Christian , Dembélé Doulaye , Jost Bernard , Taleb Omar , Aunis Dominique , Mensah-Nyagan Ayikoe G. , Maitre Michel
Published: January 2010

γ-Hydroxybutyrate (GHB) is a natural brain neuromodulator that has its own enzymatic machinery for synthesis and degradation, release, and transport systems and several receptors that belong to the G protein-coupled receptor (GPCR) family. Targeting of this system with exogenous GHB is used in therapy to induce sleep and anesthesia and to reduce alcohol withdrawal syndrome. GHB is also popular as a recreational drug for its anxiolytic and mild euphoric effects. However, in both cases, GHB must be administered at high doses in order to maintain GHB concentrations in brain of ∼800–1,000 μM. These high concentrations are thought to be necessary for interactions with low-affinity sites on GABABreceptor, but the molecular targets and cellular mechanisms modulated by GHB remain poorly characterized. Therefore, to provide new insights into the elucidation of GHB mechanisms of action and open new tracks for future investigations, we explored changes of GHB-induced transcriptomes in rat hippocampus and prefrontal cortex by using DNA microarray studies. We demonstrate that a single acute anesthetic dose of 1 g/kg GHB alters a large number of genes, 121 in hippocampus and 53 in prefrontal cortex; 16 genes were modified simultaneously in both brain regions. In terms of molecular functions, the majority of modified genes coded for proteins or nucleotide binding sites. In terms of Gene Ontology (GO) functional categories, the largest groups were involved in metabolic processing for hippocampal genes and in biological regulation for prefrontal cortex genes. The majority of genes modified in both structures were implicated in cell communication processes. Western blot and immunohistochemical studies carried out on eight selected proteins confirmed the microarray findings.
Regulation of Chemokine Production via Oxidative Pathway in HeLa Cells
Authors: Kina Shinichiro , Nakasone Toshiyuki , Takemoto Hiroyuki , Matayoshi Akira , Makishi Shoko , Sunagawa Nao , Liang Feixin , Phonaphonh Thongsavanh , Sunakawa Hajime
Published: January 2010

Inflammation is associated with disease progression and, by largely unknown mechanisms, has been said to drive oncogenesis. At inflamed sites, neutrophils deploy a potent antimicrobial arsenal that includes proteinases, antimicrobial peptides, and ROS. Reactive oxygen species (ROSs) induce chemokines. In the present study, the concentrations of IL-8 in culture supernatants of HeLa cells treated with ROS were determined by enzyme-linked immunosorbent assay. We used -phenanthroline to deplete in order to investigate the mechanisms through which ROSs induce IL-8 secretion in our system. The iron chelator -phenanthroline effectively inhibited -induced ERK2 activation. Enzyme-linked immunosorbent assays showed that IL-8 protein secretion was elevated in ROS-treated HeLa cells. When was removed from these cells, IL-8 secretion was inhibited. Collectively, these results indicate that -mediated Erk pathway activation is an important signal transduction pathway in ROS-induced IL-8 secretion in epithelial cells.
The Application of Restriction Landmark Genome Scanning Method for Surveillance of Non-Mendelian Inheritance inF1Hybrids
Authors: Takamiya Tomoko , Hosobuchi Saeko , Noguchi Tomotsugu , Paterson Andrew H. , Iijima Hiroshi , Murakami Yasufumi , Okuizumi Hisato
Published: January 2010

We analyzed inheritance of DNA methylation in reciprocalF1hybrids (subsp.japonicacv. Nipponbare×subsp.indicacv. Kasalath) of rice (Oryza sativaL.) using restriction landmark genome scanning (RLGS), and detected differing RLGS spots between the parents and reciprocalF1hybrids.MspI/HpaII restriction sites in the DNA from these different spots were suspected to be heterozygously methylated in the Nipponbare parent. These spots segregated inF1plants, but did not segregate in selfed progeny of Nipponbare, showing non-Mendelian inheritance of the methylation status. As a result of RT-PCR and sequencing, a specific allele of the gene nearest to the methylated sites was expressed in reciprocalF1plants, showing evidence of biased allelic expression. These results show the applicability of RLGS for scanning of non-Mendelian inheritance of DNA methylation and biased allelic expression.