bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidural space and regional anesthesia
Authors: De Andrés José , Reina Miguel Angel , Prats Alberto
Published: September 2009

Epidural fat provides sufficient cushion for the pulsatile movements of the dural sac, protects nerve structures, facilitates the movement of the dural sac over the periosteum of the spinal column during flexion and extension, and forms a pharmacologic reservoir of lipophilic substances. Root cuffs have a cellular component that affects the passage of substances injected epiduraly or near the intervertebral foramen, depending on the site of injection, preganglionar, postganglionar or ganglionar. We found fat inside root cuffs but not within the dural sac. Fat in this location may have affect kinetics of lipophilic drugs injected near nerve root cuffs. Ultrastructural morphology of the cellular component at preganglionar level may help explain unexpected subdural blockade after injection of local anesthetic via transforaminal route. Other morphological aspects of nerve root cuffs help to understand the function of the blood‐nerve barrier.

Based in this anatomical knowledge, we can speculate on the possible anesthetic implications of epidural fat in terms of the pharmacokinetics of drugs injected into the epidural space and the tasks of locating the epidural space and inserting an epidural catheter during anesthetic procedures.
Pain and rheumatology: An overview of the problem
Authors: Montecucco Carlomaurizio , Cavagna Lorenzo , Caporali Roberto
Published: September 2009

Actually pain is a very important health problem, affecting the majority of people, leading to a significant worsening of patients quality of life and being responsible for a large amount of both medical resources’ expenses and indirect costs. Between the different causes of pain, rheumatic conditions are predominant; in fact diseases such as osteoarthritis (OA), rheumatoid arthritis (RA), fibromyalgia (FM) and extra‐articular rheumatisms (EARs) are not only frequently observed, but are also invariably associated with pain occurrence. According to the wide range of rheumatic diseases described, pain expression is complex and not univocal, being influenced not only by the underlying disease, but also by other factors. Generally, 3 rhythms of pain presentation are described in rheumatic conditions: the “inflammatory” rhythm, characteristic of chronic arthritis, the “mechanic” one, characteristic of degenerative joint's diseases such as OA, and the “fibromyalgic” one, described in patients affected by FM; however also a true “neuropathic” pain may be present in these patients. This classification may be useful in the initial screening of the diseases potentially underlying to a painful syndrome, and in the follow‐up of patients once established the diagnosis. With this paper we describe the different aspect and the burden of pain in different rheumatic diseases.
Analysis of a population of patients who were referred to a second level pain center: Clinical and demographic characteristics
Authors: Bonezzi C. , Pitino E. , Allegri M.
Published: September 2009

Pain is the symptom that leads most patients to ask for medical intervention; if not controlled, pain may become a very costly item in the Italian Health Care system. Proper referral to a second level specialist pain center can extensively decrease the duration of a painful condition, prevent the onset of more pain and of the so‐called pain syndromes, and also reduce the improper use of analgesic drugs or pain surgery. Patients should be referred to a specialist pain center when their pain is uncontrolled.

In this observational study we analyzed the clinical and demographic data of a population referred for the first time to a specialist pain center (Fondazione Salvatore Maugeri, Pavia) in the year 2008 to define patient characteristics and to understand who makes referrals and after which kind of pharmacological and interventional treatment.

Our results indicate that in Italy patients are referred to a pain center very late, which increases the duration of pain syndromes and the cost of pain management.
A glycine hinge for tRNA‐dependent translocation of editing substrates to prevent errors by leucyl‐tRNA synthetase
Authors: Mascarenhas Anjali P. , Martinis Susan A.
Published: September 2009

Aminoacyl‐tRNA synthetases often rely on a proofreading mechanism to clear mischarging errors before they can be incorporated into newly synthesized proteins. Leucyl‐tRNA synthetase (LeuRS) houses a hydrolytic editing pocket in a domain that is distinct from its aminoacylation domain. Mischarged amino acids are transiently translocated ∼30 Å between active sites for editing by an unknown tRNA‐dependent mechanism. A glycine within a flexible β‐strand that links the aminoacylation and editing domains of LeuRS was determined to be important to tRNA translocation. The translocation‐defective mutation also demonstrated that the editing site screens both correctly and incorrectly charged tRNAs prior to product release.
On the eigenvalues of finite rank Bratteli–Vershik dynamical systems
Authors: BRESSAUD XAVIER , DURAND FABIEN , MAASS ALEJANDRO
Published: September 2009

In this article we study conditions to be a continuous or a measurable eigenvalue of finite rank minimal Cantor systems, that is, systems given by an ordered Bratteli diagram with a bounded number of vertices per level. We prove that continuous eigenvalues always come from the stable subspace associated with the incidence matrices of the Bratteli diagram and we study rationally independent generators of the additive group of continuous eigenvalues. Given an ergodic probability measure, we provide a general necessary condition for there to be a measurable eigenvalue. Then, we consider two families of examples, a first one to illustrate that measurable eigenvalues do not need to come from the stable space. Finally, we study Toeplitz-type Cantor minimal systems of finite rank. We recover classical results in the continuous case and we prove that measurable eigenvalues are always rational but not necessarily continuous.
Quality of life measures (EORTC QLQ-C30 and SF-36) as predictors of survival in palliative colorectal and lung cancer patients
Authors: Grande Gunn E. , Farquhar Morag C. , Barclay Stephen I.G. , Todd Christopher J.
Published: September 2009

Objective:

Self-reported health-related quality of life (HRQoL) is an important predictor of survival alongside clinical variables and physicians' prediction. This study assessed whether better prediction is achieved using generic (SF-36) HRQoL measures or cancer-specific (EORTC QLQ-C30) measures that include symptoms.

Method:

Fifty-four lung and 46 colorectal patients comprised the sample. Ninety-four died before study conclusion. EORTC QLQ-C30 and SF-36 scores and demographic and clinical information were collected at baseline. Follow-up was 5 years. Deaths were flagged by the Office of National Statistics. Cox regression survival analyses were conducted. Surviving cases were censored in the analysis.

Results:

Univariate analyses showed that survival was significantly associated with better EORTC QLQ-C30 physical functioning, role functioning, and global health and less dyspnea and appetite loss. For the SF-36, survival was significantly associated with better emotional role functioning, general health, energy/vitality, and social functioning. The SF-36 summary score for mental health was significantly related to better survival, whereas the SF-36 summary score for physical health was not. In the multivariate analysis, only the SF-36 mental health summary score remained an independent, significant predictor, mainly due to considerable intercorrelations between HRQoL scales. However, models combining the SF-36 mental health summary score with diagnosis explained a similar amount of variance (12%–13%) as models combining diagnosis with single scale SF-36 Energy/Vitality or EORTC QLQ-C30 Appetite Loss.

Significance of results:

HRQoL contributes significantly to prediction of survival. Generic measures are at least as useful as disease-specific measures including symptoms. Intercorrelations between HRQoL variables and between HRQoL and clinical variables makes it difficult to identify prime predictors. We need to identify variables that are as independent of each other as possible to maximize predictive power and produce more consistent results.
Validation of the Demoralization Scale in an Irish advanced cancer sample
Authors: Mullane Mary , Dooley Barbara , Tiernan Eoin , Bates Ursula
Published: September 2009

Objective:

This article presents a validation study of the Demoralization Scale, a 24-item, 5-point response questionnaire developed by Kissane et al. in 2004 to assess demoralization in advanced cancer patients.

Method:

One hundred Irish inpatients with advanced palliative cancer completed the Demoralization Scale and measures of depression, hopelessness, quality of life, and personal hopefulness.

Results:

Principal component analysis of the Demoralization Scale yielded four similar factors found by Kissane et al. (2004), namely, loss of meaning, dysphoria, disheartenment, and sense of failure. A new factor, the hopelessness factor, was also found in the current study. The reliability of the five factors was good, ranging from .72 to .93. Contrary to the findings of Kissane et al.'s (2004) study, divergent validity of the Demoralization Scale was not supported. Demoralized patients were significantly more likely to be depressed than those that did not score highly on the Demoralization Scale. In addition, this study found significantly lower levels of demoralization in general compared with Kissane et al.'s (2004) study.

Significance of results:

The results of the current study show that, in an Irish palliative care context, demoralization is not differentiated from depression. Additional factor analytic studies are needed to validate the Demoralization Scale.
Attitudes of Quebec doctors toward sedation at the end of life: An exploratory study
Authors: Blondeau Danielle , Dumont Serge , Roy Louis , Martineau Isabelle
Published: September 2009

Objective:

The induction of sedation at the end of life is a much debated practice and not very documented. The goal of this study was to explore the practice from both a clinical and ethical point of view.

Methods:

Data were collected through semistructured interviews with 19 Quebec physicians working in palliative care.

Results:

Doctors' first priority was their patients, not patients' families. Clinically, the therapeutic aim of sedation was strictly to relieve suffering on the part of the patient. Ethically, getting the patient's consent was imperative. The family's consent was only required in cases of incapacity. Generally, sedation and euthanasia were seen as two distinct practices.

Significance of the research:

There are still very few guidelines regarding end-of-life sedation in Québec, and its normative framework is more implicit than explicit. It should be noted that most of the respondents regarded sedation and euthanasia as two distinct practices.
Effect of temporal resolution on N2O emission inventories in Dutch fen meadows
Authors: Nol L. , Heuvelink G. B. M. , de Vries W. , Kros J. , Moors E. J. , Verburg P. H.
Published: September 2009

Most countries use a 1‐year‐resolution emission factor approach (Tier 1 or 2) to estimate terrestrial N2O emissions as part of their national greenhouse gas inventory. Little attention has so far been paid to the effect of the temporal resolution of the approach (e.g., day, season, and year) on N2O emission estimates. The effect of lumping temporal variation can be very large because of daily or seasonal variations of processes causing N2O emissions. Therefore, we compared annual N2O emissions from a model with daily time steps (DNDC) with those of a model with annual time steps (INITIATOR). Emissions were simulated for two intensively managed grassland plots in the Dutch fen meadow landscape. Annual N2O emissions from the investigated grasslands were sensitive to rainfall distribution within the year, especially to summer rainfall. We recommend that Tier 2 N2O emission estimates for intensively managed grasslands on peat soils in the temperate climate zone are adjusted for relative summer rainfall.
Sensitivity of remote sensing–derived phytoplankton productivity to mixed layer depth: Lessons from the carbon‐based productivity model
Authors: Milutinović Svetlana , Behrenfeld Michael J. , Johannessen Johnny A. , Johannessen Truls
Published: September 2009

Mixed layer depth (MLD) has long been recognized as having an important influence on underwater light budget and, thus, net primary productivity (NPP) of phytoplankton. The depth‐ and wavelength‐integrated carbon‐based productivity model (DWI CbPM) is one of a few productivity algorithms that explicitly use information on MLD to estimate ocean NPP from remote sensing observations. This study evaluates the sensitivity of NPP estimates from the DWI CbPM to MLD input by using MLD fields from four different ocean models. Owing to the effect of MLD on light availability, the model NPP is generally inversely related to MLD, but the strength of this relationship is highly variable. In most of the ocean, it exhibits a seasonal character. In summer, NPP at middle and high latitudes can show substantial sensitivity to subtle changes in MLD, but is largely robust to strong MLD variability in winter. An opposite seasonal pattern is encountered in subtropical ocean gyres. A lack of seasonality is observed in tropical areas, among which only the equatorial Pacific displays strong response of NPP to small or moderate changes in MLD. We find that the spatial and temporal variability of the MLD‐NPP relationship can be explained by nonlinearity and light saturation/limitation thresholds indicated in the DWI CbPM, as well as the influence of surface irradiance (I0) and diffuse attenuation coefficient for downwelling light at 490 nm (Kd(490)). NPP is sensitive to varying MLD only if coincidental I0 and Kd(490) values are such that combined with the coexisting differences in MLD estimates, they have potential to give effective differences in light saturation/limitation of photosynthesis.
Randomly iterated search and statistical competency as powerful inversion tools for deformation source modeling: Application to volcano interferometric synthetic aperture radar data
Authors: Shirzaei M. , Walter T. R.
Published: September 2009

Modern geodetic techniques provide valuable and near real‐time observations of volcanic activity. Characterizing the source of deformation based on these observations has become of major importance in related monitoring efforts. We investigate two random search approaches, simulated annealing (SA) and genetic algorithm (GA), and utilize them in an iterated manner. The iterated approach helps to prevent GA in general and SA in particular from getting trapped in local minima, and it also increases redundancy for exploring the search space. We apply a statistical competency test for estimating the confidence interval of the inversion source parameters, considering their internal interaction through the model, the effect of the model deficiency, and the observational error. Here, we present and test this new randomly iterated search and statistical competency (RISC) optimization method together with GA and SA for the modeling of data associated with volcanic deformations. Following synthetic and sensitivity tests, we apply the improved inversion techniques to two episodes of activity in the Campi Flegrei volcanic region in Italy, observed by the interferometric synthetic aperture radar technique. Inversion of these data allows derivation of deformation source parameters and their associated quality so that we can compare the two inversion methods. The RISC approach was found to be an efficient method in terms of computation time and search results and may be applied to other optimization problems in volcanic and tectonic environments.
Inferring the coseismic and postseismic stress changes caused by the 2004 Mw = 6 Parkfield earthquake from variations of recurrence times of microearthquakes
Authors: Lengliné O. , Marsan D.
Published: September 2009

Kinematic models of coseismic stress, inverted from ground motion data, do not usually find good correlation between the location of aftershocks and high‐stress patches. In particular, numerous earthquakes are recorded in areas of the fault where the stress decreases. However, most of coseismic slip distributions have limited spatial resolution (typically not better than ∼1 km). Here we investigate the stress changes produced by the 2004 Mw = 6 Parkfield earthquake on and near its rupture zone, at the scale of magnitude 2 earthquake asperities (approximately tens of meters). After relocating earthquakes in this zone between 1984 and 2007, we form repeating, highly similar earthquake sequences and study how the quasiperiodicity of occurrence at each sequence, observed during the 20 years preceding the 2004 main shock, is perturbed by this event. We apply a simple model of the seismic cycle to infer the coseismic and postseismic stresses experienced by the repeatedly failing asperities. Despite being spatially sparse, these stress distributions have resolutions only limited by the typical scale of an asperity. We propose that the high spatial variability of the seismicity patterns following the Mw = 6 earthquake, results from an heterogeneous coseismic stress field. The emergence of the Omori‐Utsu law observed at large‐scale (greater than kilometers) at Parkfield is simply the outcome of averaging such quasi‐deterministic patterns over many sequences. The fact that the coseismic stress can significantly change over distances of the order of 100 m adds credence to the hypothesis that earthquake rupture is intrinsically very heterogeneous.
Latitude dependence of Martian pedestal craters: Evidence for a sublimation‐driven formation mechanism
Authors: Kadish Seth J. , Barlow Nadine G. , Head James W.
Published: September 2009

We report on the results of a survey to document and characterize pedestal craters on Mars equatorward of ∼60°N and 65°S latitude. The identification of 2696 pedestal craters reveals a strong latitude dependence, with the vast majority found poleward of 33°N and 40°S. This latitudinal extent is correlated with many climate indicators consistent with the presence of an ice‐rich substrate and with climate model predictions of where ice is deposited during periods of higher obliquity in the Amazonian. We have measured key physical attributes of pedestal craters, including the farthest radial extents of the pedestals, pedestal heights, and the circularity of the pedestal margins. In conjunction with the geographic distribution, our measurements strongly support a sublimation‐related formation mechanism. This is in contrast to previous hypotheses, which have relied on eolian deflation to produce the elevated plateaus. The identification of marginal pits on the scarps of some pedestal craters, interpreted to be sublimation pits, provide direct evidence for the presence of ice‐rich material underlying the armored surface of pedestal craters. On the basis of our findings, we propose a formation mechanism whereby projectiles impact into a volatile‐rich dust/snow/ice substrate tens to hundreds of meters thick overlying a dominantly fragmental silicate regolith. The area surrounding the resulting crater becomes armored. Pedestals extend to a distance of multiple crater radii, farther than typical ejecta deposits, necessitating an armoring mechanism that is capable of indurating the surface to a distance greater than the reach of the ejecta. Return to low obliquity causes sublimation of the volatile‐rich layer from the intercrater plains, lowering the elevation of the regional terrain. This yields generally circular pedestal craters elevated above the surrounding plains. As a result, the armored surfaces of pedestal craters have preserved a significant record of Amazonian climate history in the form of ice‐rich deposits.
A Comprehensive Data Portal for Global Climate Information
Authors: Diamond Howard J. , Lief Christina J.
Published: September 2009

The Global Observing Systems Information Center (GOSIC), initiated in 1997 at the request of the Global Climate Observing System (GCOS) Steering Committee (see http://www.wmo.int/pages/prog/gcos/ Publications/gcos‐39.pdf), responds to a need identified by the global climate observing community for easier and more effective access to observational climate data and information. GOSIC manages an online portal providing an entry point for users of climate‐related global observing systems data and information systems.

Following its initial development and implementation at the University of Delaware from 1997 to 2006, the U.S. National Oceanic and Atmospheric Administration's National Climatic Data Center (NCDC) assumed operational responsibility for GOSIC on behalf of the international climate observing and data user communities. The goal of GOSIC is to provide basic user services, including a description of the systems and their data as well as a tailored search capability that facilitates access to a worldwide set of observations and derived products. GOSIC's unique value is its ability to quickly link users, via a consistent and user‐friendly interface, to a wide range of data sets that reside at multiple data centers; the GOSIC portal (http://GOSIC.org) provides users with links to data, metadata, other search tools, and related climate‐observing information.
The Urgent Need for Improved Climate Models and Predictions
Authors: Goddard Lisa , Baethgen Walter , Kirtman Ben , Meehl Gerald
Published: September 2009

An investment over the next 10 years of the order of US$2 billion for developing improved climate models was recommended in a report (http://wcrp.wmo.int/documents/WCRP_WorldModellingSummit_Jan2009.pdf) from the May 2008 World Modelling Summit for Climate Prediction, held in Reading, United Kingdom, and presented by the World Climate Research Programme. The report indicated that “climate models will, as in the past, play an important, and perhaps central, role in guiding the trillion dollar decisions that the peoples, governments and industries of the world will be making to cope with the consequences of changing climate.”
Berkner Fellows at 2009 Joint Assembly
Authors: Fucugauchi Jaime Urrutia
Published: September 2009

Students and young scientists from economically depressed and developing countries who were this year's recipients of Berkner Travel Fellowships gathered for a reception on 26 May during the Joint Assembly in Toronto, Ontario, Canada. Joint Assembly, part of AGU's international collaboration program, was sponsored by eight societies: AGU; Canadian Geophysical Union; Geological Association of Canada; International Association of Hydrogeologists, Canadian National Chapter; Mineralogical Association of Canada; Society of Exploration Geophysicists; Mineralogical Society of America; and Geochemical Society.

Attendance and participation in the meeting by students and young researchers from different countries and research fields are major objectives of AGU and partner societies. Berkner Travel Fellowships provide fellows with financial support for meeting registration, travel, and subsistence while attending the meeting. Applicants must be under 36 years of age, a first author and presenter of an oral or poster abstract at Joint Assembly, and a permanent resident of a low‐income or lower‐middle‐income country.
Bottom pressure signals at the TAG deep‐sea hydrothermal field: Evidence for short‐period, flow‐induced ground deformation
Authors: Sohn Robert A. , Thomson Richard E. , Rabinovich Alexander B. , Mihaly Steven F.
Published: September 2009

Bottom pressure measurements acquired from the TAG hydrothermal field on the Mid‐Atlantic Ridge (26°N) contain clusters of narrowband spectral peaks centered at periods from 22 to 53.2 minutes. The strongest signal at 53.2 min corresponds to 13 mm of water depth variation. Smaller, but statistically significant, signals were also observed at periods of 22, 26.5, 33.4, and 37.7 min (1–4 mm amplitude). These kinds of signals have not previously been observed in the ocean, and they appear to represent vertical motion of the seafloor in response to hydrothermal flow ‐ similar in many ways to periodic terrestrial geysers. We demonstrate that displacements of 13 mm can be produced by relatively small flow‐induced pressures (several kPa) if the source region is less than ∼100 m below the seafloor. We suggest that the periodic nature of the signals results from a non‐linear relationship between fluid pore pressure and crustal permeability.
Dependence of bare soil albedo on soil moisture on the moraine of the Zongo glacier (Bolivia): Implications for land surface modeling
Authors: Gascoin S. , Ducharne A. , Ribstein P. , Lejeune Y. , Wagnon P.
Published: September 2009

Although the dependence of bare soil albedo on soil moisture is a familiar observation, it is not commonly represented in climate modeling. We investigate the impact of this dependence in a land surface model using meteorological data collected on the moraine of a Bolivian glacier. The relationship which is implemented to simulate albedo variations with soil moisture is deduced from a previous field study. The model is set up at the scale of the meteorological station plot to have the most accurate control on the model calibration and validation. A snow parameter is modified to account for the fact that the model was designed for larger cell sizes. Water content measurements are used to calibrate the parameter controlling the vertical water fluxes within the soil surface layer. This allows us to enhance the model's ability to capture the fast changes in surface soil moisture. The comparison of simulated ground heat flux and outgoing longwave radiations with observations shows that the model performs well despite the fact that all other parameters are set a priori on the basis of local properties of the surface. The results show that the dependence of bare soil albedo on soil moisture, which causes an increase in the net radiation, importantly influences the turbulent fluxes at the annual and monthly time scales. The mean annual evaporation is increased by 12%. As a consequence, this parameterization modifies the computed runoff, which is reduced by more than 5% during the rainy season.
Global atmospheric downward longwave radiation over land surface under all‐sky conditions from 1973 to 2008
Authors: Wang Kaicun , Liang Shunlin
Published: September 2009

In this article, we first evaluate two widely accepted methods to estimate global atmospheric downward longwave radiation (Ld) under both clear and cloudy conditions, using meteorological observations from 1996 to 2007 at 36 globally distributed sites, operated by the Surface Radiation Budget Network (SURFRAD), AmeriFlux, and AsiaFlux Projects. The breakdown of locations is North America (20 sites), Asia (12 sites), Australia (2 sites), Africa (1 site), and Europe (1 site). Latitudes for these sites range from 0° at the equator to ±50°; elevation ranges from 98 to 4700 m, and six different land cover types are represented (deserts, semideserts, croplands, grasslands, forests, and wetlands). The evaluation shows that the instantaneous Ld under all‐sky conditions is estimated with an average bias of 2 W m−2 (0.6%), an average standard deviation (SD) of 20 W m−2 (6%), and an average correlation coefficient (R) of 0.86. Daily Ld under all‐sky conditions is estimated with a SD of 12 W m−2 (3.7%) and an average R of 0.93. These results suggest that these two methods could be applied to most of the Earth's land surfaces. Accordingly, we applied them to globally available meteorological observations to estimate decadal variation in Ld. The decadal variations in global Ld under both clear and cloudy conditions at about 3200 stations from 1973 to 2008 are presented. We found that daily Ld increased at an average rate of 2.2 W m−2 per decade from 1973 to 2008. The rising trend results from increases in air temperature, atmospheric water vapor, and CO2 concentration.
Compact Reconnaissance Imaging Spectrometer for Mars investigation and data set from the Mars Reconnaissance Orbiter's primary science phase
Authors: Murchie Scott L. , Seelos Frank P. , Hash Christopher D. , Humm David C. , Malaret Erick , McGovern J. Andrew , Choo Teck H. , Seelos Kimberly D. , Buczkowski Debra L. , Morgan M. Frank , Barnouin‐Jha Olivier S. , Nair Hari , Taylor Howard W. , Patterson Gerald W. , Harvel Christopher A. , Mustard John F. , Arvidson Raymond E. , McGuire Patrick , Smith Michael D. , Wolff Michael J. , Titus Timothy N. , Bibring Jean‐Pierre , Poulet Francois
Published: September 2009

The part of the Compact Reconnaissance Imaging Spectrometer (CRISM) for Mars investigation conducted during the Mars Reconnaissance Orbiter's (MRO's) primary science phase was a comprehensive investigation of past aqueous environments, structure of the planet's crust, past climate, and current meteorology. The measurements to implement this investigation include over 9500 targeted observations of surface features taken at spatial resolutions of better than 40 m/pixel, monitoring of seasonal variations in atmospheric aerosols and trace gases, and acquisition of a 200 m/pixel map covering over 55% of Mars in 72 selected wavelengths under conditions of relatively low atmospheric opacity. Key results from these data include recognition of a diversity of aqueous mineral‐containing deposits, discovery of a widespread distribution of phyllosilicates in early to middle Noachian units, the first definitive detection of carbonates in bedrock, new constraints on the sequence of events that formed Hesperian‐aged, sulfate‐rich layered deposits, characterization of seasonal polar processes, and monitoring of the 2007 global dust event. Here we describe CRISM's science investigations during the Primary Science Phase, the data sets that were collected and their calibration and uncertainties, and how they have been processed and made available to the scientific community. We also describe the ongoing investigation during MRO's extended science phase.
Altered Brain Mitochondrial Metabolism in Healthy Aging as Assessed by in vivo Magnetic Resonance Spectroscopy
Authors: Boumezbeur Fawzi , Mason Graeme F , de Graaf Robin A , Behar Kevin L , Cline Gary W , Shulman Gerald I , Rothman Douglas L , Petersen Kitt F
Published: September 2009

A decline in brain function is a characteristic feature of healthy aging; however, little is known about the biologic basis of this phenomenon. To determine whether there are alterations in brain mitochondrial metabolism associated with healthy aging, we combined 13C/1H magnetic resonance spectroscopy with infusions of [1-13C]glucose and [2-13C]acetate to quantitatively characterize rates of neuronal and astroglial tricarboxylic acid cycles, as well as neuroglial glutamate–glutamine cycling, in healthy elderly and young volunteers. Compared with young subjects, neuronal mitochondrial metabolism and glutamate–glutamine cycle flux was ∼30% lower in elderly subjects. The reduction in individual subjects correlated strongly with reductions in N-acetylaspartate and glutamate concentrations consistent with chronic reductions in brain mitochondrial function. In elderly subjects infused with [2-13C]acetate labeling of glutamine, C4 and C3 differed from that of the young subjects, indicating age-related changes in glial mitochondrial metabolism. Taken together, these studies show that healthy aging is associated with reduced neuronal mitochondrial metabolism and altered glial mitochondrial metabolism, which may in part be responsible for declines in brain function.
High-Mobility Group Protein Box-1 and its Relevance to Cerebral Ischemia
Authors: Yang Qing-Wu , Wang Jing-Zhou , Li Jing-Cheng , Zhou Yu , Qi-Zhong  , Lu Feng-Lin , Xiang Jing
Published: September 2009

High-mobility group box-1 (HMGB1) was originally identified as a ubiquitously expressed, abundant, nonhistone DNA-binding protein. It has well-established functions in the maintenance of nuclear homeostasis. The HMGB1 can either be passively released into the extracellular milieu in response to necrotic signals or actively secreted in response to inflammatory signals. Extracellular HMGB1 interacts with receptors, including those for advanced glycation endproducts (RAGEs) as well as Toll-like receptor 2 (TLR2) and TLR4. The HMGB1 functions in a synergistic manner with other proinflammatory mediators and acts as a potent proinflammatory cytokine-like factor that contributes to the pathogenesis of diverse inflammatory and infectious disorders. Numerous reports point to HMGB1 as a novel player in the ischemic brain. This review provides an appraisal of the emerging roles of HMGB1 in cerebral ischemia injury, highlighting the relevance of HMGB1-blocking agents as potent therapeutic tools for neuroprotection.
Brain-Derived Neurotrophic Factor Enhances the Expression of the Monocarboxylate Transporter 2 through Translational Activation in Mouse Cultured Cortical Neurons
Authors: Robinet Camille , Pellerin Luc
Published: September 2009

MCT2 is the predominant neuronal monocarboxylate transporter allowing lactate use as an alternative energy substrate. It is suggested that MCT2 is upregulated to meet enhanced energy demands after modifications in synaptic transmission. Brain-derived neurotrophic factor (BDNF), a promoter of synaptic plasticity, significantly increased MCT2 protein expression in cultured cortical neurons (as shown by immunocytochemistry and western blot) through a translational regulation at the synaptic level. Brain-derived neurotrophic factor can cause translational activation through different signaling pathways. Western blot analyses showed that p44/p42 mitogen-activated protein kinase (MAPK), Akt, and S6 were strongly phosphorylated on BDNF treatment. To determine by which signal transduction pathway(s) BDNF mediates its upregulation of MCT2 protein expression, the effect of specific inhibitors for p38 MAPK, phosphoinositide 3-kinase (PI3K), mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK), p44/p42 MAPK (ERK), and Janus kinase 2 (JAK2) was evaluated. It could be observed that the BDNF-induced increase in MCT2 protein expression was almost completely blocked by all inhibitors, except for JAK2. These data indicate that BDNF induces an increase in neuronal MCT2 protein expression by a mechanism involving a concomitant stimulation of PI3K/Akt/mTOR/S6, p38 MAPK, and p44/p42 MAPK. Moreover, our observations suggest that changes in MCT2 expression could participate in the process of synaptic plasticity induced by BDNF.
Large reversible magnetocaloric effect caused by two successive magnetic transitions in ErGa compound
Authors: Chen J. , Shen B. G. , Dong Q. Y. , Hu F. X. , Sun J. R.
Published: September 2009

Intermetallic compound ErGa exhibits two successive magnetic transitions: spin-reorientation transition at TSR=15 K and ferromagnetic-paramagnetic transition at TC=30 K. Both transitions contribute greatly to the magnetic entropy change (ΔSM), each yielding a significant peak on their ΔSM-T curve and thus a considerable value of refrigerant capacity (RC) without hysteresis loss. For a magnetic field change of 5 T, the maximal values of −ΔSM are 21.3 J/kg K at TC and 16.5 J/kg K at TSR, with an RC value of 494 J/kg. Large reversible magnetocaloric effect and RC indicate the potentiality of ErGa as a candidate magnetic refrigerant at low temperatures.
Compressive ghost imaging
Authors: Katz Ori , Bromberg Yaron , Silberberg Yaron
Published: September 2009

We describe an advanced image reconstruction algorithm for pseudothermal ghost imaging, reducing the number of measurements required for image recovery by an order of magnitude. The algorithm is based on compressed sensing, a technique that enables the reconstruction of an N-pixel image from much less than N measurements. We demonstrate the algorithm using experimental data from a pseudothermal ghost-imaging setup. The algorithm can be applied to data taken from past pseudothermal ghost-imaging experiments, improving the reconstruction’s quality.
Low noise performance of passively mode locked quantum-dash-based lasers under external optical feedback
Authors: Merghem K. , Rosales R. , Azouigui S. , Akrout A. , Martinez A. , Lelarge F. , Duan G.-H. , Aubin G. , Ramdane A.
Published: September 2009

We report on a systematic investigation of the effect of external optical feedback on 17 GHz passively mode-locked two-section lasers based on InAs/InP quantum dashes emitting at 1.58 μm. Narrowing of mode-beating linewidth down to a record value of ∼500 Hz is demonstrated over a large operating range.
Current-controlled magnetoresistance in silicon in non-Ohmic transport regimes
Authors: Delmo Michael P. , Kasai Shinya , Kobayashi Kensuke , Ono Teruo
Published: September 2009

We show that the large positive magnetoresistance in nonmagnetic silicon devices can be controlled by a current applied in the non-Ohmic transport regime. The experimental results indicate that the carrier transport in this regime is dominated by the space-charge effect, where the magnetoresistance effect is greatly enhanced. We propose a device concept based on the space-charge-induced magnetoresistance effect in silicon that is controlled by both the current and the magnetic field, which looks similar to the characteristics of the field-effect transistors.
Giant reversible magnetocaloric effect in antiferromagnetic superconductor Dy0.9Tm0.1Ni2B2C compound
Authors: Li Lingwei , Nishimura Katsuhiko
Published: September 2009

The magnetic properties and magnetocaloric effect in antiferromagnetic superconductor Dy0.9Tm0.1Ni2B2C compound have been studied. The magnetic phase transition TM (∼9.2 K) occurs above the superconducting transition temperature Tc (∼4.5 K). A giant reversible magnetocaloric effect has been observed, which is related to a field-induced first order metamagnetic transition from antiferromagnetic to ferromagnetic state. The values of maximum magnetic entropy change (−ΔSMmax) reach 14.7 and 19.1 J kg−1 K−1 for the field change of 5 and 7 T with no obvious hysteresis loss around 13 K, respectively. These results indicated that Dy0.9Tm0.1Ni2B2C could be a promising candidate for magnetic refrigeration at low temperatures.
Nonlinear conductivity of electronic origin in self-doped LaMnO3+δ
Authors: Fisher B. , Genossar J. , Patlagan L. , Reisner G. M.
Published: September 2009

We report on electronic transport measurements on polycrystalline, nonmetallic samples of LaMnO3+δ, in the Ohmic and non-Ohmic regimes. The non-Ohmic regime has been investigated using single current pulses of short duration. The large nonlinearity of the pulsed I-V characteristics is probably of the same origin as that of the nonmetallicity of LaMnO3+δ, that is, disorder introduced by Mn vacancies. The dc I-V characteristics, under similar fields, show much larger nonlinearity and hysteresis, typical of self-heating in samples with activated conductivity.
Tunability of intersubband absorption from 4.5 to 5.3 μm in a GaN/Al0.2Ga0.8N superlattices grown by metalorganic chemical vapor deposition
Authors: Péré-Laperne N. , Bayram C. , Nguyen-Thê L. , McClintock R. , Razeghi M.
Published: September 2009

Intersubband (ISB) absorption at wavelengths as long as 5.3 μm is realized in GaN/Al0.2Ga0.8N superlattices grown by metalorganic chemical vapor deposition. By employing low aluminum content Al0.2Ga0.8N barriers and varying the well width from 2.6 to 5.1 nm, ISB absorption has been tuned from 4.5 to 5.3 μm. Theoretical ISB absorption and interband emission models are developed and compared to the experimental results. The effects of band offsets and the piezoelectric fields on these superlattices are investigated.
Combined effects of organic matter and pH on acute toxicity of cadmium to Paronychiurus kimi (Collembola): Development of response surface model
Authors: Son Jino , Mo Hyung-ho , Shin Key-il , Ryoo Mun Il , Cho Kijong
Published: September 2009

A second-order central composite design was employed to investigate the effect of organic matter (OM) content and soil acidity (pH) on the cadmium toxicity to Paronychiurus kimi (Lee), a collembolan species native to Korea. Two independent variables, OM and pH, were adjusted from 0 to 10% (in total dry wt) and 4.5 to 7.0, respectively. Cadmium concentrations tested were 10, 20, 40, 80, and 160 mg/kg dry soil. The toxic effects that cadmium exerted on P. kimi (28-day median lethal concentration (LC50s)) varied significantly with different combinations of OM content and pH. The second-order response surface model was appropriate for describing combined effects of OM and pH on the cadmium toxicity to P. kimi. Linear effects (OM and pH) were predominant contributors accounting for ≈70% of the total variance of cadmium toxicity to P. kimi. No significant quadratic (pH × pH) and interaction (OM × pH) effects were observed; therefore, the final second-order response surface model could be reduced as follows: 28-day LC50 of cadmium (mg/kg) = –94.87 + 26.69 × OM + 16.64 × pH – 1.82 × OM2. Validation of the developed response surface model using 4 soil media with different OM content and pH resulted in a significant correlation coefficient (R2 = 0.97) between predicted and observed 28-day LC50. Based on physico-chemical properties of the test media, developed models can be used to explain the variation of cadmium toxicities at various environmental conditions and may improve current environmental risk assessment procedures of metals.
Losses of nitrogen in surface runoff from a plantation horticulture farm in coastal Queensland, Australia
Authors: Stork Peter R. , Lyons David J. , Bell Michael J.
Published: September 2009

Surface losses of nitrogen from horticulture farms in coastal Queensland, Australia, may have the potential to eutrophy sensitive coastal marine habitats nearby. A case-study of the potential extent of such losses was investigated in a coastal macadamia plantation. Nitrogen losses were quantified in 5 consecutive runoff events during the 13-month study.
Irrigation did not contribute to surface flows. Runoff was generated by storms at combined intensities and durations that were 20–40 mm/h for >9 min. These intensities and durations were within expected short-term (1 year) and long-term (up to 20 years) frequencies of rainfall in the study area. Surface flow volumes were 5.3 ± 1.1% of the episodic rainfall generated by such storms. Therefore, the largest part of each rainfall event was attributed to infiltration and drainage in this farm soil (Kandosol). The estimated annual loss of total nitrogen in runoff was 0.26 kg N/ha.year, representing a minimal loading of nitrogen in surface runoff when compared to other studies.
The weighted average concentrations of total sediment nitrogen (TSN) and total dissolved nitrogen (TDN) generated in the farm runoff were 2.81 ± 0.77% N and 1.11 ± 0.27 mg N/L, respectively. These concentrations were considerably greater than ambient levels in an adjoining catchment waterway. Concentrations of TSN and TDN in the waterway were 0.11 ± 0.02% N and 0.50 ± 0.09 mg N/L, respectively. The steep concentration gradient of TSN and TDN between the farm runoff and the waterway demonstrated the occurrence of nutrient loading from the farming landscapes to the waterway. The TDN levels in the stream exceeded the current specified threshold of 0.2–0.3 mg N/L for eutrophication of such a waterway. Therefore, while the estimate of annual loading of N from runoff losses was comparatively low, it was evident that the stream catchment and associated agricultural land uses were already characterised by significant nitrogen loadings that pose eutrophication risks. The reported levels of nitrogen and the proximity of such waterways (8 km) to the coastline may have also have implications for the nearshore (oligotrophic) marine environment during periods of turbulent flow.
Characterising and improving the deteriorating trends in soil physical quality under banana
Authors: Rasiah V. , Armour J. D. , Moody P. W. , Pattison A. B. , Lindsay S. , Florentine S.
Published: September 2009

Deterioration in soil physical quality under intensive tillage practices is a norm rather than an exception. The objectives of this study were to (i) evaluate total porosity (TP) as an indicator parameter to assess the impact of banana cropping on compaction and infiltration in soils, and (ii) assess the effectiveness of different interrow grass-covers in minimising the deteriorating trends. Depth-incremented TP under banana rows and interrows from 4 sites, corresponding forest sites, and from 3 interrow grass-cover treatments were computed from bulk density measurements. The TP results show the compacted depth ranged from 0.35 to 0.45 m in banana rows and from 0.35 to 1.0 m in the interrows. The TP in 0.10 m depth increments decreased in the order: forest > rows > interrows, and was positively correlated with soil organic C (OC) and negatively with wheel traffic stress (WTS). The multiple regression analysis showed that 77% of the variability in TP was accounted for by clay + silt, OC, and WTS. We show that a threshold compaction index (DIt) of 0.81–0.83 can be estimated from TP regardless of the soil type. Depending on the soil type and the cultural practices followed, infiltration decreased from 0.75 mm/s in rainforest to 0.23 mm/s under banana in 1 soil type compared with 2.55 mm/s in forest and 0.85 mm/s under banana in another. After 18 months of interrow grass-covers we found the deterioration in TP was minimum under the indigenous grass-cover but not under the 2 improved species. We conclude the interrow grass-covers were effective in minimising WTS associated compaction and reduction in infiltration.
CAPS drives
trans
-SNARE complex formation and membrane fusion through syntaxin interactions
Authors: James Declan J. , Kowalchyk Judith , Daily Neil , Petrie Matt , Martin Thomas F. J.
Published: September 2009

Ca
2+
-dependent activator protein for secretion (CAPS) is an essential factor for regulated vesicle exocytosis that functions in priming reactions before Ca
2+
-triggered fusion of vesicles with the plasma membrane. However, the precise events that CAPS regulates to promote vesicle fusion are unclear. In the current work, we reconstituted CAPS function in a SNARE-dependent liposome fusion assay using VAMP2-containing donor and syntaxin-1/SNAP-25-containing acceptor liposomes. The CAPS stimulation of fusion required PI(
4
,
5
)P
2
in acceptor liposomes and was independent of Ca
2+
, but Ca
2+
dependence was restored by inclusion of synaptotagmin. CAPS stimulated
trans
-SNARE complex formation concomitant with the stimulation of full membrane fusion at physiological SNARE densities. CAPS bound syntaxin-1, and CAPS truncations that competitively inhibited syntaxin-1 binding also inhibited CAPS-dependent fusion. The results revealed an unexpected activity of a priming protein to accelerate fusion by efficiently promoting
trans
-SNARE complex formation. CAPS may function in priming by organizing SNARE complexes on the plasma membrane.