bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Pacific and Atlantic sea surface temperatures on interannual and decadal variations of GRACE land water storage in tropical South America
Authors: de Linage Caroline , Kim Hyungjun , Famiglietti James S. , Yu Jin‐Yi
Published: September 2013

We analyze 10 years of Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage anomalies (TWSAs) over tropical South America along with seven climate indices linked to equatorial Pacific and tropical Atlantic oceans sea surface temperatures (SSTs) using a multichannel singular spectrum analysis and lagged cross correlations. We focus on the interannual, nonlinear modes of covariability between TWSAs and SSTs. By comparing the relative distributions of the leading modes, we identify teleconnections between TWSAs, Pacific and Atlantic SSTs at different time periods. Thus, the northern and northeastern regions of tropical South America are mainly influenced by Pacific SSTs, while the central and western Amazon regions are more influenced by Atlantic SSTs. The former regions are more sensitive to central Pacific SSTs than to eastern Pacific SSTs. A quasi‐biennial mode explains the largest part (27%) of the residual, interannual cross covariance and is found both in the El Niño–Southern Oscillation and in the Atlantic meridional mode. A trend‐like mode explains the second largest part (24%) of the residual cross covariance and may be caused by the following: (1) the decadal variability in the North Pacific climate, as expressed by the negative trend in the Pacific decadal oscillation and by increased water storage in northern and northeastern South America, (2) the melting of Andean glaciers in Peru and Bolivia due to man‐induced increase in land surface temperatures, and (3) the land use/cover changes after deforestation leading to increased runoff and groundwater recharge, expressed by increased water storage in southern Amazon regions.
Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran
Authors: Landgraf A. , Zielke O. , Arrowsmith J. R. , Ballato P. , Strecker M. R. , Schildgen T. F. , Friedrich A. M. , Tabatabaei S. H.
Published: September 2013

The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a “simple” to a “composite” state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex.
Aluminium–phosphate interactions in the rhizosphere of two bean species: Phaseolus lunatus L. and Phaseolus vulgaris L
Authors: Mimmo Tanja , Ghizzi Massimiliano , Cesco Stefano , Tomasi Nicola , Pinton Roberto , Puschenreiter Markus
Published: September 2013

BACKGROUND

Plants differ in their response to high aluminium (Al) concentrations, which typically cause toxicity in plants grown on acidic soils. The response depends on plant species and environmental conditions such as substrate and cultivation system. The present study aimed to assess Al–phosphate (P) dynamics in the rhizosphere of two bean species, Phaseolus vulgaris L. var. Red Kidney and Phaseolus lunatus L., in rhizobox experiments.

RESULTS

Root activity of the bean species induced up to a sevenfold increase in exchangeable Al and up to a 30‐fold decrease in extractable P. High soluble Al concentrations triggered the release of plant‐specific carboxylates, which differed between soil type and plant species. The results suggest that P. vulgaris L. mitigates Al stress by an internal defence mechanism and P. lunatus L. by an external one, both mechanisms involving organic acids.

CONCLUSION

Rhizosphere mechanisms involved in Al detoxification were found to be different for P. vulgaris L. and P. lunatus L., suggesting that these processes are plant species‐specific. Phaseolus vulgaris L. accumulates Al in the shoots (internal tolerance mechanism), while P. lunatus L. prevents Al uptake by releasing organic acids (exclusion mechanism) into the growth media. © 2013 Society of Chemical Industry
High‐speed and low‐voltage write addressing of plasma display panels by use of extremely weak discharge
Authors: Yoshita Mao , Shiga Tomokazu
Published: September 2013

Although the priming effect shortens address period and reduces address voltage, it is difficult to use the priming effect for the conventional write addressing method because the ramp reset pulses provide little priming effect. An extremely weak discharge for priming has been incorporated with write addressing method. The extremely weak discharge is generated by priming pulse applied just prior to the scan pulse. In the 4‐in‐diagonal test panel containing Ne + 10%Xe mixture gas, infrared emission intensity of the discharge is 900 times smaller than that of sustain discharge. Therefore, there is no degradation of dark room contrast ratio. Because the priming discharge generates a very small amount of charges, there is little reduction in the amount of wall charge accumulated during reset period. Namely, increase in address voltage can be avoided. Although the discharge intensity is extremely low, it provides sufficient priming particles for high‐speed and low‐voltage addressing. When priming pulse voltage is 70 V and width is 10 µs, the address discharge delay is reduced to less than half. When the scan voltage margin is 10 V, the data voltage is reduced to 17 V, which is 20 V lower than that of conventional method.
Mechanical and corrosion behaviors of 25Cr–5.3Ni–2.8Mo–0.15N duplex stainless steel castings affected by annealing process
Authors: Li J. , Guo J. , Lu C.‐Y. , Jia P.‐G. , Wu S.‐H.
Published: September 2013

Stress relief annealing treatment is generally applied to keep the dimension stability and tolerance during machining process for casting. However, this process might depress properties of duplex stainless steel (DSS) castings used for sea water circulating pumps in power plants. In this paper, the microstructure and composition analysis of the 25Cr–5.3Ni–2.8Mo–0.15N DSS cast samples affected by stress relief annealing treatment were investigated by SEM and EDS. Meanwhile, uniaxial tensile test, Charpy impact test, and Brinell hardness test were also applied to research the strength, impact toughness, and hardness. Furthermore, the corrosion resistance of 25Cr–5.3Ni–2.8Mo–0.15N cast DSS was also determined by potentiodynamics polarization curves and cyclic voltammety. Brittle sigma phase precipitation has been observed in stress relief annealed samples by SEM and domain elements distribution, especially for samples annealed at 650 °C, comparing to the solidification solution treated sample. The strength and hardness of DSS sample stress relief annealed increased significantly, however, the elongation and toughness is depressed comparing to the solidification solution treated samples. Furthermore, the results of electrochemical measurements showed that annealing treatment at 650 °C significantly depresses the corrosion resistance of DSS. Therefore, stress relief annealing process of casting samples shall be considered especially due to its brittle transformation and depression of corrosion resistance.
A comprehensive approach based on SVM to model pitting corrosion behaviour of EN 1.4404 stainless steel
Authors: Jiménez‐Come M. J. , Turias I. J. , Ruiz‐Aguilar J. J. , Trujillo F. J.
Published: September 2013

Potentiodynamic polarisation tests have been widely used to evaluate pitting corrosion behaviour of stainless steels. This technique involves two principal steps: the interpretation of the polarisation curve and the microscopic analysis of the material surface. Therefore, analysing the influence of all possible environmental conditions on pitting corrosion behaviour can be complex. To deal with this problem, automatic models based on Bayes classifier (BC) and support vector machines (SVMs) techniques are presented in this work. The principal environmental variables involved in pitting corrosion: chloride ion concentration, pH and temperature are considered. Based on the obtained results related to precision and accuracy terms, SVMs models using linear or radial basis function kernels outperform models based on Bayes theory. In addition, ROC analysis reveals that SVMs models using linear kernel is the best option providing maximum values of sensitivity and specificity. These results reflect the validity of the presented model to be applied in the automatic determination of the corrosion state of austenitic stainless steel as function of environmental conditions, not requiring the use of polarisation tests.
AlN formation in Fe‐Al alloys in N2‐O2 atmospheres
Authors: Bott J. H. , Yin H. , Zhu J. , Sridhar S.
Published: September 2013

The reheating of high aluminum content transformation‐induced plasticity (TRIP) and light‐weight steels in a nitrogen‐rich atmosphere has been shown to cause development of subsurface aluminum nitride precipitates in addition to internal and external oxides. It is important to understand how these nitrides and oxides form and their consequences for the quality of steel products. This study looks at model iron‐aluminum (up to 8 wt.% aluminum) alloys and uses confocal laser scanning microscopy, XRD, SEM‐EDS, and TEM to study the effect of various conditions on the growth and development of these precipitates in a subsurface oxygen‐depleted region. It was found that nitrides formed when bulk aluminum content was below 8 wt.% when oxygen was sufficiently depleted due to the internal oxidation. In the samples containing 1 wt.% aluminum, the depth of the internal oxide and nitride zones were in agreement with the model proposed by Meijering. Increasing aluminum content to 3 and 5 wt.% had the effects of modifying the surface‐oxide scale composition and increasing its continuity, which gradually decreased the internal precipitation zones with increasing aluminum content. In samples containing 8 wt.% aluminum, a thick continuous oxide sale formed and completely prevented nitrogen and oxygen penetration into the bulk of the sample, thus preventing the formation of any internal precipitates.
Quantitative wearable sensors for objective assessment of Parkinson's disease
Authors: Maetzler Walter , Domingos Josefa , Srulijes Karin , Ferreira Joaquim J. , Bloem Bastiaan R.
Published: September 2013

There is a rapidly growing interest in the quantitative assessment of Parkinson's disease (PD)‐associated signs and disability using wearable technology. Both persons with PD and their clinicians see advantages in such developments. Specifically, quantitative assessments using wearable technology may allow for continuous, unobtrusive, objective, and ecologically valid data collection. Also, this approach may improve patient‐doctor interaction, influence therapeutic decisions, and ultimately ameliorate patients' global health status. In addition, such measures have the potential to be used as outcome parameters in clinical trials, allowing for frequent assessments; eg, in the home setting. This review discusses promising wearable technology, addresses which parameters should be prioritized in such assessment strategies, and reports about studies that have already investigated daily life issues in PD using this new technology. © 2013 International Parkinson and Movement Disorder Society
On some notions of convergence forn‐tuples of operators
Authors: Alpay Daniel , Colombo F. , Sabadini I.
Published: September 2013

The aim of this paper is to show that we can extend the notion ofconvergence in the norm‐resolvent senseto the case of several unbounded noncommuting operators (and to quaternionic operators as a particular case) using the notion ofS‐resolvent operator. With this notion, we can define bounded functions of unbounded operators using theS‐functional calculus forn‐tuples of noncommuting operators. The same notion can be extended to the case of theF‐resolvent operator, which is the basis of theF‐functional calculus, a monogenic functional calculus forn‐tuples of commuting operators. We also prove some properties of theF‐functional calculus, which are of independent interest. Copyright © 2013 John Wiley & Sons, Ltd.
Homoclinic solutions for second‐order discrete Hamiltonian systems with asymptotically quadratic potentials
Authors: Chen Huiwen , He Zhimin
Published: September 2013

In this paper, we study the existence of infinitely many homoclinic solutions for the second‐order self‐adjoint discrete Hamiltonian system , where , and are unnecessarily positive definites for all . By using the variant fountain theorem, we obtain an existence criterion to guarantee that the aforementioned system has infinitely many homoclinic solutions under the assumption that W(n,x) is asymptotically quadratic as | x | → + ∞ . Copyright © 2013 John Wiley & Sons, Ltd.
Validation of claims‐based algorithms for identification of high‐grade cervical dysplasia and cervical cancer
Authors: Kim Seoyoung C. , Gillet Victoria G. , Feldman Sarah , Lii Huichuan , Toh Sengwee , Brown Jeffrey S. , Katz Jeffrey N. , Solomon Daniel H. , Schneeweiss Sebastian
Published: September 2013

Background

High‐grade cervical dysplasia or cervical intraepithelial neoplasia grade 2 or worse has been widely used as a surrogate endpoint in cervical cancer screening or prevention trials.

Methods

To identify high‐grade cervical dysplasia and cervical cancer, we developed claims‐based algorithms that incorporated a combination of diagnosis and procedure codes using the billing data in an electronic medical records database and assessed the validity of the algorithms in an independent administrative claims database. We calculated the positive predictive value (PPV) with the 95% confidence interval (CI) of each algorithm, using new cytologic or pathologic diagnosis of cervical intraepithelial neoplasia 2 or 3, carcinoma in situ, or cervical cancer as the gold standard.

Results

Having ≥1 diagnosis code for high‐grade cervical dysplasia or cervical cancer had a PPV of 57.1% (95%CI, 54.7–59.5%). By requiring ≥2 diagnoses for high‐grade cervical dysplasia or cervical cancer, separated by 7–30 days, the PPV increased to 60.2% (95%CI, 53.9–66.1%). At least two diagnoses and a procedure code within a month from the first diagnosis date yielded a PPV of 80.7% (95%CI, 73.6–86.2%). The algorithms had greater PPVs in identifying prevalent high‐grade cervical dysplasia or cervical cancer. Overall, the PPVs of these algorithms were similar or slightly lower in the external claims data than in the sample used to derive the algorithms.

Conclusions

Use of ≥2 diagnosis codes in combination with a procedure code appears to be a valid tool for studying high‐grade cervical dysplasia and cervical cancer in both electronic medical record and administrative claims databases. Copyright © 2013 John Wiley & Sons, Ltd.
Development of a Liver‐Targeting Gold–PEG–Galactose Nanoparticle Platform and a Structure–Function Study
Authors: Ding Ya , Liang Juan‐Juan , Geng Dong‐Dong , Wu Di , Dong Lei , Shen Wen‐Bin , Xia Xing‐Hua , Zhang Can
Published: September 2013

For the specific liver parenchymal cell delivery, a series of short heterobifunctional poly(ethylene glycol) (PEG) derivatives containing dimercapto and galactose (Gal) terminals is synthesized for the preparation of gold conjugates. The Gal density on the surface of all gold conjugates can be well controlled and the prepared gold conjugates are stable in various media, even in the presence of serum. For the liver targeting and reflectance imaging applications, the structure–function relationships of this platform, including the influence of the PEG molecular weight and the Gal ligand coverage of hybrid particles on the cytotoxicity and cellular recognition of tumor cells in vitro and on their liver‐targeting ability in small animals, are studied. Biocompatibility results show that HepG2 cells are more sensitive than HeLa cells to gold conjugates. Cellular uptake studies demonstrate that a lower PEG molecular weight, a higher Gal density, or a higher gold concentration can increase the cellular uptake efficiency of these hybrid particles in HepG2 cells when the other parameters are constant. The results reveal the importance of parameter modulation for the design and control of nanoprobes and the gold conjugates with short PEG chains and a high Gal density are a potential vector for active‐targeting therapy.
Introduction and annealing of primary defects in proton‐bombarded n‐GaN
Authors: Schmidt Matthias , de Meyer Hannes , Johan Janse van Rensburg Pieter , Ernst Meyer Walter , Danie Auret Francois
Published: September 2013

We report on in situ space charge spectroscopy measurements on low‐temperature proton‐bombarded n‐type gallium nitride thin film samples. The scope of this study was to investigate the introduction and annealing dynamics of radiation‐induced lattice damage. Using optical excitation allowed for the detection of electronic defect states in the entire GaN bandgap and to detect unstable primary defects that would have been invisible in thermal space charge spectroscopic measurements. The introduction of compensating acceptor‐like primary defects by the bombardment was observed and manifested as a decrease in the sample capacitance. After the bombardment the concentrations of deep‐levels and acceptor states were monitored by deep‐level transient spectroscopy and photo‐capacitance measurements while the temperature was increased. It was found that annealing and reactions of primary bombardment‐induced defects occurs even below room‐temperature which might account for the radiation‐hardness of GaN.
Nowcasting severe convection in the Alpine region: the COALITION approach
Authors: Nisi L. , Ambrosetti P. , Clementi L.
Published: September 2013

The purpose of the operationally oriented system named the Context and Scale Oriented Thunderstorm Satellite Predictors Development (COALITION) is automatically to detect severe thunderstorms early in their development and consequently help weather forecasters to increase lead times when issuing severe weather warnings. This new object‐oriented system integrates data provided by different sources. Data from theMeteosatSecond Generation Rapid Scan Service, weather radar and numerical weather prediction, as well as climatology, are utilized by the system. One of its primary purposes is to use all the best operationally available information about convective processes and to integrate it into a heuristic model. Furthermore the orographic forcing, which is often neglected in heuristic nowcasting models, is taken into account and included in the system as an additional convective triggering mechanism. This is particularly important for areas characterized by complex orography like the Alpine region. The COALITION algorithm merges evolving thunderstorm properties with selected predictors. The forecast evolution of the storm is the result of the interaction between convective signatures and surrounding storm environment. Eight different ‘object‐environment’ interactions are analyzed in eight modules, providing ensemble nowcasts of thunderstorm attributes (satellite‐ and radar‐based) for the following 60 min. All ensemble nowcasts are then combined through a weighting and thresholding scheme and the results are summarized into a single graphical map in order to facilitate user interpretation. The COALITION nowcast system has an update frequency of 5 min. The output highlights the cells having a high probability of severe thunderstorm development within the next 30 min. Verification statistics confirm that COALITION is able to nowcast the intensity of developing convective cells with sufficient skill up to a lead time of about 20 min.
Multiple time scales in multi‐state models
Authors: Iacobelli Simona , Carstensen Bendix
Published: September 2013

In multi‐state models, it has been the tradition to model all transition intensities on one time scale, usually the time since entry into the study (‘clock‐forward’ approach). The effect of time since an intermediate event has been accommodated either by changing the time scale to time since entry to the new state (‘clock‐back’ approach) or by including the time at entry to the new state as a covariate. In this paper, we argue that the choice of time scale for the various transitions in a multi‐state model should be dealt with as an empirical question, as also the question of whether a single time scale is sufficient. We illustrate that these questions are best addressed by using parametric models for the transition rates, as opposed to the traditional Cox‐model‐based approaches. Specific advantages are that dependence of failure rates on multiple time scales can be made explicit and described in informative graphical displays.

Using a single common time scale for all transitions greatly facilitates computations of probabilities of being in a particular state at a given time, because the machinery from the theory of Markov chains can be applied. However, a realistic model for transition rates is preferable, especially when the focus is not on prediction of final outcomes from start but on the analysis of instantaneous risk or on dynamic prediction.

We illustrate the various approaches using a data set from stem cell transplant in leukemia and provide supplementary online material in R. Copyright © 2013 John Wiley & Sons, Ltd.
Physiological and Subjective Responses after Psychosocial Stress in Chinese Hepatitis B Patients
Authors: Zhao Xiansheng , Zhao Li , Lai Yinyan , Jiang Suwen , Shen Xueyong , Liu Sheng
Published: September 2013

Compared with healthy participants, Chinese patients with hepatitis B (HB) experience more psychosocial stress. The present study provided the first examination of physiological and subjective responses to stress in Chinese HB patients. A standard psychosocial stressor, the Trier Social Stress Test (TSST), was administered to 26 Chinese HB patients and 24 healthy control participants. Cortisol concentrations were measured in blood samples collected before and after the stressor. Self‐reported emotional responses and cardiovascular measures were examined before and after the TSST. Depression and anxiety were assessed using Hospital Anxiety and Depression Scale. Chinese HB patients exhibited higher cortisol response to the stressor than healthy control participants. Compared with healthy participants, Chinese HB patients showed higher levels of anxiety, depression and nervousness, and lower levels of calmness after the TSST. HB patients reported more negative life events in the previous 6 months and obtained higher adversity scores, as compared with control participants. Significant correlations were obtained between adversity scores and change cortisol secretion after TSST in HB patients, but not in healthy participants. This study firstly demonstrates that physiological and subjective responses to psychosocial stress among Chinese HB patients were different from that in healthy control participants. Copyright © 2013 John Wiley & Sons, Ltd.
A lean and mean strategy: a data migration industrial study
Authors: Razavian Maryam , Lago Patricia
Published: September 2013

Many companies have legacy assets to be integrated or modernized. Like today's software developments, migration projects are faced with steadily increasing demands for efficiency: migration has to be carried out faster, better, and cheaper. At the same time, migration complexity increases, and migration projects remain challenging despite the companies' extensive experience.

To cope with such efficiency demands, companies need a well‐defined migration strategy. In previous work, we have defined such a migration strategy called lean and mean strategy. In this paper, following technical action research, we apply our migration strategy, and evaluate it, in two large industrial case studies in the field of data migration. The use of the strategy in our case studies reveals the benefits of lean and mean strategy for meeting the efficiency demands. Copyright © 2013 John Wiley & Sons, Ltd.
Impact analysis in the presence of dependence clusters using Static Execute After in WebKit
Authors: Schrettner Lajos , Jász Judit , Gergely Tamás , Beszédes Árpád , Gyimóthy Tibor
Published: September 2013

Impact analysis based on code dependence can provide opportunities to identify parts of the software affected by a change. Because changes usually have far reaching effects in programs, effective and efficient impact analysis is vital. Static Execute After (SEA) is a relation on procedures that is efficiently computable and accurate enough to be a candidate for the use in impact analysis in practice. To assess the applicability of SEA in terms of capturing real defects, we present results on integrating it into the build system of WebKit, a large, open source software system, and on related experiments. We show that a large number of real defects can be captured by impact sets computed by SEA, albeit many of them are large. We demonstrate that this is not an issue in applying it to regression test prioritization, but generally it can be an obstacle in the path to efficient use of impact analysis. We believe that the main reason for large impact sets is the formation of dependence clusters in code. As apparently dependence clusters cannot be easily avoided in the majority of cases, we focus on determining the effects these clusters have on impact analysis and regression test prioritization. Copyright © 2013 John Wiley & Sons, Ltd.
Rethinking the Structural Architecture of the College Classroom
Authors: Hagopian Kevin Jack
Published: September 2013

This chapter provides a structural architecture for reducing ego‐based conflict in the college classroom.
Navigating the Paradox of Student Ego
Authors: Knowlton Dave S.
Published: September 2013

If professors are to appropriately affirm Millennial students' egos, then those professors must understand the distinctions between ego entitlement and ego engagement.
The Syllabus: A Place to Engage Students' Egos
Authors: Canada Mark
Published: September 2013

A well‐crafted syllabus can serve as an initial point of engagement for the Millennial student.
Affirming Ego through Out‐of‐Class Interactions: A Practitioner's View
Authors: Knowlton Heather M.
Published: September 2013

This chapter discusses the opportunities created by out‐of‐class interactions. These interactions allow for ego‐engaged exchanges between students and professors.
Domestic ships as a potential pathway of nonindigenous species from the Saint Lawrence River to the Great Lakes
Authors: Adebayo Abisola A. , Zhan Aibin , Bailey Sarah A. , MacIsaac Hugh J.
Published: September 2013

Ballast water moved by transoceanic vessels has been recognized globally as a predominant vector for the introduction of aquatic nonindigenous species (NIS). In contrast, domestic ships operating within confined geographic areas have been viewed as low risk for invasions, and are exempt from regulation in consequence. We examined if the St. Lawrence River could serve as a source of NIS for the Laurentian Great Lakes by surveying ballast water carried by domestic vessels and comparing biological composition in predominant St. Lawrence River—Great Lakes port-pairs in order to determine the likelihood that NIS could be transported to, and survive in, the Great Lakes. Thirteen potential invaders were sampled from ballast water, while 26 taxa sampled from St. Lawrence River ports are not reported from the Great Lakes. The majority of NIS recorded in samples are marine species with low potential for survival in the Great Lakes, however two euryhaline species (copepodOithona similis, and amphipodGammarus palustris) and two taxa reported from brackish waters (copepodMicrosetella norvegicaand decapodCancer irroratus) may pose a risk for invasion. In addition, four marine NIS were collected in freshwater samples indicating that at least a subset of marine species have potential as new invaders to the Great Lakes. Based on results from this study, the ports of Montreal, Sorel, Tracy and Trois Rivières appear to pose the highest risk for new ballast-mediated NIS from the St. Lawrence River to the Great Lakes.
Soil CO2 efflux and soil carbon balance of a tropical rubber plantation
Authors: Satakhun Duangrat , Gay Frédéric , Chairungsee Naruenat , Kasemsap Poonpipope , Chantuma Pisamai , Thanisawanyangkura Sornprach , Thaler Philippe , Epron Daniel
Published: September 2013

Natural rubber is a valuable source of income in many tropical countries and rubber trees are increasingly planted in tropical areas, where they contribute to land‐use changes that impact the global carbon cycle. However, little is known about the carbon balance of these plantations. We studied the soil carbon balance of a 15‐year‐old rubber plantation in Thailand and we specifically explored the seasonal dynamic of soil CO2 efflux (FS) in relation to seasonal changes in soil water content (WS) and soil temperature (TS), assessed the partitioning of FS between autotrophic (RA) and heterotrophic (RH) sources in a root trenching experiment and estimated the contribution of aboveground and belowground carbon inputs to the soil carbon budget. A multiplicative model combining both TS and WS explained 58 % of the seasonal variation of FS. Annual soil CO2 efflux averaged 1.88 kg C m−2 year−1 between May 2009 and April 2011 and RA and RH accounted for respectively 63 and 37 % of FS, after corrections of FS measured on trenched plots for root decomposition and for difference in soil water content. The 4‐year average annual aboveground litterfall was 0.53 kg C m−2 year−1 while a conservative estimate of belowground carbon input into the soil was much lower (0.17 kg C m−2 year−1). Our results highlighted that belowground processes (root and rhizomicrobial respiration and the heterotrophic respiration related to belowground carbon input into the soil) have a larger contribution to soil CO2 efflux (72 %) than aboveground litter decomposition.
Disruption of pro‐oxidant and antioxidant systems with elevated expression of the ubiquitin proteosome system in the cachectic heart muscle of nude mice
Authors: Hinch E. C. A. , Sullivan-Gunn M. J. , Vaughan V. C. , McGlynn M. A. , Lewandowski Paul A.
Published: September 2013

Background

Current research into the mechanisms of organ atrophy associated with cancer cachexia have centred on the loss of skeletal muscle, as it is one of the most profound physical changes of the disease. However, many patients with cancer cachexia also experience significant atrophy of the heart. The mechanisms causing cardiac tissue wastage in cancer cachexia are largely unknown. However, it is believed to involve a number of molecular interactions between the tumour and host. Increased levels of oxidative stress have been found in cancer cachectic skeletal muscle and has been linked to the activation of the ubiquitin proteosome system (UPS). The aim of the current study was to examine the role of oxidative stress and the UPS in the hearts of mice with cancer cachexia.

Methods

Oxidative damage to DNA (8‐OH‐2dG), mRNA levels of the ROS‐producing enzymes NADPH oxidase (NOX), and xanthine oxidase (XDH), the antioxidant enzyme superoxide dismutase (SOD) and key components of the UPS was measured in the heart of mice with cancer cachexia. Protein expression levels of NOX enzyme subunits and SOD enzyme activity was also measured in the same heart samples.

Results

8‐OH‐2dG levels were 1.5‐fold higher in the heart of mice with cancer cachexia, and this was associated with a 1.7‐fold lower level of NOX2 mRNA and twofold higher XDH mRNA in the same hearts. Cancer cachexia was also associated with a 1.5‐fold lower level of SOD activity in the heart. Accompanying these pro‐ and antioxidant differences was a significantly higher level of mRNA for the key UPS elements MURF‐1 (4.3=fold) and MAFbx (3.8‐fold) in the hearts of mice with cancer cachexia.

Conclusions

The current study demonstrated that cardiac atrophy of cachectic mice is associated with oxidative damage to DNA in the myocardium. The higher levels of XDH mRNA in cachectic hearts suggest that xanthine oxidase may have an important role to play in producing oxidative stress. It appears that the combination of higher XDH expression and lower SOD enzyme activity are key contributors to oxidative stress and cardiac tissue damage in cancer‐induced cardiac atrophy. Oxidative stress in the myocardium as with skeletal muscle may also induce increased expression of the E3 ligases MURF‐1 and MAFbx as seen in this study.

Electronic supplementary material

The online version of this article (doi:10.1007/s13539‐013‐0116‐8) contains supplementary material.
Brief report: Youth pathways out of homelessness – Preliminary findings
Authors: Kidd Sean A. , Karabanow Jeff , Hughes Jean , Frederick Tyler
Published: September 2013

While there exists an extensive body of knowledge regarding the risks associated with youth homelessness, very little work has addressed the process of exiting street contexts. This paper reports baseline findings from an ongoing longitudinal study assessing factors associated with a successful transition out of homelessness. Fifty‐one formerly homeless youth who obtained stable housing in the past 2 months to 2 years participated in this study which took place in two Canadian urban centres. Findings include poorer functioning across all domains for youth residing in housing contexts without supports, a lack of relationship between psychological and behavioural aspects of community integration, and the central role of self‐concept in mental health and quality of life. These findings suggest the need for ongoing support for youth exiting street spaces and social contexts, with attention to the importance of self‐concept and psychological aspects of community integration.
Pre-emptive virology screening in the pediatric hematopoietic stem cell transplant population
Authors: Evers Patrick D
Published: September 2013

BACKGROUND AND OBJECTIVES:

Pediatric patients undergoing hematopoietic stem cell transplant (HSCT) are at a uniquely high risk of cytomegalovirus (CMV) and Epstein–Barr virus (EBV) infections. The pre-emptive treatment model whereby asymptomatic post-transplant patients are routinely screened with treatment initiated if found viremic has recently been shown to be superior in terms of patient mortality when compared to deferring laboratory assessment and treatment until symptoms emerge. This study analyzes the cost-effectiveness of the pre-emptive therapy model in patient care dollars per quality-adjusted life years (QALY).

PATIENTS AND METHODS:

Utilization and outcome data were compiled as a retrospective cohort study of 96 pediatric patients receiving HSCT at University of California Los Angeles Pediatric Hematology/Oncology Department between the years 2006 and 2010. Two-decision tree models were constructed for each the preemptive model and the deferred model wherein costs and probability assumptions were based on either previously published literature or calculated from this study cohort.

RESULTS:

The pre-emptive model resulted in a five-year survival of 71%, during which time 4% of patients were found to be EBV viremic, while 33% were found to be CMV viremic. The average actual cost of EBV/CMV virology screening per patient in the cohort following the pre-emptive model was $9699 while the expected cost following the deferred model was $19,284. This results in an incremental cost effectiveness ratio illustrating pre-emptive model cost-savings of $2367/QALY.

CONCLUSION:

These results support the financial viability and prudence of scheduled screening for subclinical viremia for achieving optimal outcomes in a cost-effective manner in the pediatric HSCT population.
Two-layer shallow-water dam-break solutions for gravity currents in non-rectangular cross-area channels
Authors: Ungarish Marius
Published: September 2013

We consider the propagation of a high-Reynolds-number gravity current in a horizontal channel along the horizontal coordinate $x$. The bottom and top of the channel are at $z= 0, H$, and the cross-section is given by the quite general $- {f}_{1} (z)\leq y\leq {f}_{2} (z)$ for $0\leq z\leq H$. We develop a two-layer shallow-water (SW) formulation, and we implement it for the solution of the dam-break problem. The dependent variables are the position of the interface, $h(x, t)$, and the velocity (averaged over the area of the current), $u(x, t)$. The non-rectangular cross-section geometry enters the formulation via $f(h)$ and integrals of $f(z)$ and $zf(z)$, where $f(z)= {f}_{1} (z)+ {f}_{2} (z)$ is the width of the channel. For a given geometry $f(z)$, the free input parameters of the lock-release problem are: (i) the height ratio $H/ {h}_{0} $ of ambient to lock; and (ii) the density ratio of ‘light’ to ‘heavy’ fluids, $R$. We show that the dam-break problem is amenable to solution by the method of characteristics, but various complications (internal jumps, critical restrictions) appear when the return flow in the ambient is significant; these features are not captured by a one-layer shallow-water model. The role of the non-standard geometry in the detection and calculation of the internal and reflected jumps, and on the dam-break flow field, is elucidated. The methodology is illustrated for Boussinesq flow in typical geometries: power-law ($f(z)= b{z}^{\alpha } $, where $b, \alpha $ are positive constants), trapezoidal and circle (full or sector); we solved for full-depth ($H= 1$) and part-depth ($H\gt 1$) lock-release configurations. The approach seems to work well: in all the tested cases, the solution was obtained with simple mathematical and numerical tools (a Runge–Kutta integrator and a secant-method solver); the insights are compatible with our previous understanding of the problem; and the standard (rectangular) case is recovered in the appropriate limit (i.e. when the side-boundaries of the trapezium cross-section are vertical or far apart). A comparison of the speed of propagation with available experiments is also presented, and the agreement is satisfactory. The present solution is a significant generalization of the classical two-layer gravity–current dam-break problem. The classical formulation for a rectangular (or laterally unbounded) channel is now just a particular case, $f(z)= $ const., in the wide domain of cross-sections covered by the new model.
VARIATIONS ON A THEOREM OF DAVENPORT CONCERNING ABUNDANT NUMBERS
Authors: JENNINGS EMILY , POLLACK PAUL , THOMPSON LOLA
Published: September 2013

Let$\sigma (n)= {\mathop{\sum }\nolimits}_{d\mid n} d$be the usual sum-of-divisors function. In 1933, Davenport showed that$n/ \sigma (n)$possesses a continuous distribution function. In other words, the limit$D(u): = \lim _{x\rightarrow \infty }(1/ x){\mathop{\sum }\nolimits}_{n\leq x, n/ \sigma (n)\leq u} 1$exists for all$u\in [0, 1] $and varies continuously with$u$. We study the behaviour of the sums${\mathop{\sum }\nolimits}_{n\leq x, n/ \sigma (n)\leq u} f(n)$for certain complex-valued multiplicative functions$f$. Our results cover many of the more frequently encountered functions, including$\varphi (n)$,$\tau (n)$and$\mu (n)$. They also apply to the representation function for sums of two squares, yielding the following analogue of Davenport’s result: for all$u\in [0, 1] $, the limit$$\begin{eqnarray*}\tilde {D} (u): = \lim _{R\rightarrow \infty }\frac{1}{\pi R} \# \biggl\{ (x, y)\in { \mathbb{Z} }^{2} : 0\lt {x}^{2} + {y}^{2} \leq R\text{ and } \frac{{x}^{2} + {y}^{2} }{\sigma ({x}^{2} + {y}^{2} )} \leq u\biggr\}\end{eqnarray*}$$exists, and$\tilde {D} (u)$is both continuous and strictly increasing on$[0, 1] $.
DIRECTIONAL MAXIMAL OPERATORS AND RADIAL WEIGHTS ON THE PLANE
Authors: SAITO HIROKI , TANAKA HITOSHI
Published: September 2013

Let $\Omega $ be the set of unit vectors and $w$ be a radial weight on the plane. We consider the weighted directional maximal operator defined by $$\begin{eqnarray*}{M}_{\Omega , w} f(x): = \sup _{x\in R\in \mathcal{B} _{\Omega }}\frac{1}{w(R)} \int \nolimits \nolimits_{R} \vert f(y)\vert w(y)\hspace{0.167em} dy,\end{eqnarray*}$$ where ${ \mathcal{B} }_{\Omega } $ denotes the set of all rectangles on the plane whose longest side is parallel to some unit vector in $\Omega $ and $w(R)$ denotes $\int \nolimits \nolimits_{R} w$. In this paper we prove an almost-orthogonality principle for this maximal operator under certain conditions on the weight. The condition allows us to get the weighted norm inequality $$\begin{eqnarray*}\Vert {M}_{\Omega , w} f\mathop{\Vert }\nolimits_{{L}^{2} (w)} \leq C\log N\Vert f\mathop{\Vert }\nolimits_{{L}^{2} (w)} ,\end{eqnarray*}$$ when $w(x)= \vert x\hspace{-1.2pt}\mathop{\vert }\nolimits ^{a} $, $a\gt 0$, and when $\Omega $ is the set of unit vectors on the plane with cardinality $N$ sufficiently large.
Not just any old pile of dirt: evaluating the use of artificial nesting mounds as conservation tools for freshwater turtles
Authors: Paterson James E. , Steinberg Brad D. , Litzgus Jacqueline D.
Published: September 2013

The viability of freshwater turtle populations is largely dependent on the survivorship of reproducing females but females are frequently killed on roads as they move to nesting sites. Installing artificial nesting mounds may increase recruitment and decrease the risk of mortality for gravid females by enticing them to nest closer to aquatic habitats. We evaluated the effectiveness of artificial nesting mounds installed in Algonquin Park, Canada. Artificial mounds were monitored for 2 years to determine if turtles would select them for nest sites. We also simulated turtle paths from wetlands to nests to determine the probability that females would encounter the new habitat. A transplant experiment with clutches ofChrysemys pictaandChelydra serpentinaeggs compared nest success and incubation conditions in the absence of predation between artificial mounds and natural sites. More turtles than expected used the artificial mounds, although mounds comprised a small proportion of the available nesting habitat and the simulations predicted that the probability of females encountering mounds was low. Hatching success was higher in nests transplanted to artificial mounds (93%) than in natural nests (56%), despite no differences in heat units. Greater use than expected, high hatching success, and healthy hatchlings emerging from nests in artificial mounds suggest promise for their use as conservation tools.
The heptachordal basis of hexachordal theory: on the semiotics of musical notation in the Middle Ages
Authors: MENGOZZI STEFANO
Published: September 2013

By all appearances, the advent of a full-fledged hexachordal system in the late thirteenth century marked the culmination of a radical reconceptualisation of diatonic space that had begun over two centuries earlier with Guido of Arezzo's introduction of the syllables ut re mi fa sol la as an aid to sight-singing. An early witness of the new diatonic configuration is Johannes de Garlandia's Introductio musicae planae (c.1275), which presents the three proprietates per b quadro, per natura and per b molle as a fundamental articulation of the gamut that is necessary for conveying the intervallic distances between the diatonic pitches.

A contextual evaluation of the theory of the proprietates, however, indicates that the hexachordal parsing of the gamut was not meant to establish the major sixth as the regulative paradigm of diatonic space (i.e. as a normative scale), but was rather in line with the earlier understanding of the ut-la syllables as an optional aid for singing. The development of hexachordal theory was in fact an implicit confirmation of the heptachordal structure of the gamut that had been in place since around the year 1000 (and arguably earlier), when the cycle of seven A–G letters was first used to label the constituent pitches of the octave.
Large Feedback Arc Sets, High Minimum Degree Subgraphs, and Long Cycles in Eulerian Digraphs
Authors: HUANG HAO , MA JIE , SHAPIRA ASAF , SUDAKOV BENNY , YUSTER RAPHAEL
Published: September 2013

A minimum feedback arc set of a directed graph G is a smallest set of arcs whose removal makes G acyclic. Its cardinality is denoted by β(G). We show that a simple Eulerian digraph with n vertices and m arcs has β(G) ≥ m2/2n2+m/2n, and this bound is optimal for infinitely many m, n. Using this result we prove that a simple Eulerian digraph contains a cycle of length at most 6n2/m, and has an Eulerian subgraph with minimum degree at least m2/24n3. Both estimates are tight up to a constant factor. Finally, motivated by a conjecture of Bollobás and Scott, we also show how to find long cycles in Eulerian digraphs.
DELIVERY AT THE LIMITS OF VIABILITY
Authors: AIKEN CATHERINE E. , BROCKELSBY JEREMY C.
Published: September 2013

Delivery of the infant at the limits of viability is a complex challenge for the obstetrician. Despite the best efforts of obstetricians to prolong gestation beyond 23–24 weeks, there may be compelling reasons to intervene in an ongoing pregnancy for maternal benefit (for example in severe pre-eclampsia or placental abruption) or delivery may be considered for foetal reasons. However, the majority of deliveries at the limits of viability will be the consequence of spontaneous pre-term labour, leaving the obstetrician with the difficult and time-pressured decisions regarding which, if any, interventions may be of benefit to foetal or maternal outcome. In most European countries, the rate of pre-term birth continues to rise, making such clinical scenarios increasingly common.
FABRICATING INTIMACY: READING THE DRESSING ROOM IN VICTORIAN LITERATURE
Authors: Puri Tara
Published: September 2013

The Victorian novel is dominated by heroines, its narrative driven by their impulses and their irrepressible physicality. These women possess a strong visual presence that is intrinsically bound with the way in which they choose to dress themselves, with authorial attention consistently focusing on the elements of their clothing. The body was a highly visible, and more significantly, a readable cultural symbol in the Victorian period, with its signifying ability vitally linked to the clothes that adorned it. Clothes have often been employed in literary metaphors – words as the clothing of thought, clothes as a masking of the real, and so on. In his long poem In Memoriam, A.H.H., Tennyson succinctly deploys the quiet grief contained in the idea of widow's weeds, bringing together the expressivity of both clothes and words, when he writes: “In words, like weeds, I'll wrap me o'er, / Like coarsest clothes against the cold” (stanza 5, ll. 9–10). But in the realist Victorian novel, clothes become even more pertinent, offering a useful descriptive device that is pivotal to the creation of a believable, legible character. The awareness of clothing as something that has potential for both restriction of identity as well as expression of it permeates much of Victorian writing, with numerous novels rendering visible the construction of a coherent selfhood through clothing.