bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoluminescence decay profiles of exciton‐exciton scattering in a ZnO thin film
Authors: Wakaiki Shuji , Ichida Hideki , Mizoguchi Kohji , Kim DaeGwi , Kanematsu Yasuo , Nakayama Masaaki
Published: December 2010

We have investigated the photoluminescence (PL) dynamics of a ZnO thin film under intense excitation conditions at 10 K. In the ZnO thin film, a PL band due to exciton‐exciton scattering, the so‐called P emission, appears. The optical‐Kerr‐gating method with the ultrashort gating time of 0.6 ps enabled us to obtain precise information of the temporal profiles including the peak energy, the bandwidth and the intensity of the P emission, at various detection energies. We have found that the decay time of the P emission gradually shortens with decreasing detection energy. The change in the decay time can be reasonably attributed to the photon‐like characteristics of the lower polariton branch that is the final state of the exciton‐exciton scattering. Furthermore, we have shown that the decay time of the P emission is phenomenologically determined by the group velocity of the final state although the origin of the long decay time remains to be elucidated (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theory of radiation force exerted on dye‐doped molecules irradiated by resonant laser
Authors: Kudo Tetsuhiro , Ishihara Hajime
Published: December 2010

We theoretically investigate how the resonant radiation force (RF) affects the laser trapping of a single molecule by comparing the RF exerted on the dye‐doped molecule and that on the non‐doped one. In this investigtion, we evaluate the inter‐particle radiation force (IRF) in the focal spot of the incident focused beam. The result indicates the possibility of the increase of molecular density through the IRF even in the linear response regime. We also investigate the nonlinear optical effect that greatly changes the characteristics of the RF. This result shows that the nonlinear optical effect cannot be neglected if the incident laser intensity is strong enough to trap a single molecule, and that the nonlinearity makes the resonant trapping more advantageous (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton spin alignment observed via Hanle effect in single quantum dots
Authors: Kaji R. , Adachi S. , Muto S.
Published: December 2010

Polarization properties of the exciton emissions from single InAlAs/AlGaAs quantum dots were investigated by using Hanle‐like measurement. The in‐plane exchange field drives the exciton spin precession even under zero external magnetic field and the polarization of emissions can be converted from circular to linear and vice versa.

Longitudinal applied magnetic field increases the conversion ratio up to the theoretical limit ∼50%, where the field strength is comparable to the exchange field. Finally, the effect of valence band mixing on the polarization conversion was discussed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A simple approximate method for free vibration analysis of framed tube structures
Authors: Kamgar R. , Rahgozar R.
Published: December 2010

A simple approximate method is developed for determining natural frequency of tall buildings. Timoshenko's beam model, which considers the influence of shear and flexural deformation, was used in modelling framed tube structures. In this paper, natural frequency and mode shape of framed tube structures were calculated based on the flexural and shear rigidities along with the effects of rotational inertia. Dynamic model of Timoshenko's beam can be obtained by writing equilibrium equations of forces acting on an infinite element. The solution of the dynamic model was obtained by first applying the separation of variables to time and space, followed by the assumption of harmonic motion in time, the steady state eigen system was obtained. Natural frequencies of framed tube structures were calculated by solving the eigenproblem. A numerical example has been presented to demonstrate the ease of application and accuracy of the proposed method. The structure's fundamental frequency was computed using ETABS V9.0.0 (Computer and Structures, Berkeley, California, USA) and compared with the result obtained from proposed method, which shows that the percentage of error was low and acceptable. The proposed method can be adopted as an alternative procedure to evaluate the natural frequency of framed tube in the preliminary stages of structural design. Copyright © 2010 John Wiley & Sons, Ltd.
Test description of steel X‐bracing system using low‐grade steel and internal oblique transverse stiffeners
Authors: Sabouri‐Ghomi S. , Ebadi P.
Published: December 2010

A sample of steel X‐braced frame was studied using laboratory tests by which system behaviour and its failure modes were driven. The braces were designed based on the idea of using low‐grade steel in lateral load resisting system. Therefore, stocky braces were used. A rigid central core at intersection point of braces was considered. Oblique transverse stiffeners were provided inside the braces' cross‐section for more lateral stiffness and reduction of system yield displacement. Intervals between stiffeners were determined to create guided local buckling before global buckling of braces and thus dissipate energy by accordion behaviour. The hysteresis and energy absorption diagrams were presented. The system ductility has also been calculated. The obtained results represent uniform and stable energy absorption and reasonable system ductility by using low‐grade steel, rigid central core and oblique transverse stiffeners. Copyright © 2010 John Wiley & Sons, Ltd.
Benzene Trisulfonic Acid (H3BTS) as Analogue of Trimesic Acid for Building Open Frameworks: The First Rare Earth Examples [La(BTS)(H2O)5] and [RE(BTS)(H2O)4] (RE = Nd, Sm, Eu)
Authors: Mietrach Andrea , Muesmann Thomas W. T. , Zilinski Christian , Christoffers Jens , Wickleder Mathias S.
Published: December 2010

The reaction of benzene 1,3,5‐trisulfonic acid (H3BTS) with the hydroxides RE(OH)3 (RE = La, Nd, Sm, Eu) in aqueous solution afforded the sulfonates [La(BTS)(H2O)5] and [RE(BTS)(H2O)4] (RE = Nd, Sm, Eu). Single crystal investigations were performed for the lanthanum and the europium compound, respectively. [La(BTS)(H2O)5] is triclinic [P$\bar{1}$, Z = 2, a = 783.18(6) pm, b = 1056.94(8) pm, c = 1082.38(8) pm, α = 114.860(2)°, β = 96.655(3)°, γ = 104.402(3)°] whereas [Eu(BTS)(H2O)4] exhibits monoclinic symmetry [P21/n, Z = 4, a = 767.61(5) pm, b = 1730.2(1) pm, c = 1134.06(8) pm, β = 108.375(8)°]. Despite these crystallographic differences, the structural features of the lanthanum and europium compounds are very similar. They show the metal ions connected by BTS anions to layers that are further linked by hydrogen bonds. Interestingly, only two of the three sulfonate groups are connected to rare earth ions, whereas the third remains uncoordinated and acts as acceptor within the hydrogen bonds. According to powder XRD measurements the neodymium and samarium sulfonates are isotypic with the europium compound. The thermal analyses of the compounds show the dehydration in a temperature range between 100 and 300 °C, whereas the decomposition of the organic ligands takes place at temperatures as high as 550 °C. Thus the anhydrous sulfonates are much more stable than comparable salts of trimesic acid. The residues of the thermal decompositions were identified by XRD experiments.
A case study applying process and project alignment methodology
Authors: Martins Paula Ventura , da Silva Alberto Rodrigues
Published: December 2010

Software Process Improvement (SPI) is one of the main software development challenges. However, SPI standards and models (CMMI, SPICE) have not been always adopted with success. The current problem is a lack of strategy to implement successfully these standards and models. To undertake this objective is essential observe real life experiences and detect process and project mutual relationships. Without this alignment it will not be possible to find out how process management is really important to achieve organization’s strategic objectives. This paper proposes a methodology that allows the definition, evaluation and improvement of an organization software development process. This proposal, called a Process and Project Alignment Methodology (ProPAM), allows the specification of an organization development process, as well process and project alignment. ProPAM presents the following life cycle: (1) process definition; (2) project definition considering a base process model; (3) project coordination and monitoring and (4) process improvement assessment. This paper also provides an overview of the action plan to be taken within the software organizations that intent to conduct a SPI initiative. This plan includes two distinct phases: (1) specify the development process and (2) analyze projects, starting an SPI effort. In order to evaluate ProPAM, a study case is undertaken. The case study is performed following the action plan and presents all the steps of the ProPAM. Final results show that, when the organization started using ProPAM, process and project alignment reduced project planning time and effort. ProPAM also introduced new organizational practices that result in a SPI program.
Adaptive complementary filtering algorithm for mobile robot localization
Authors: Neto Armando Alves , Macharet Douglas Guimarães , da Silva Campos Víctor Costa , Montenegro Campos Mario Fernando
Published: December 2010

As a mobile robot navigates through an indoor environment, the condition of the floor is of low (or no) relevance to its decisions. In an outdoor environment, however, terrain characteristics play a major role on the robot’s motion. Without an adequate assessment of terrain conditions and irregularities, the robot will be prone to major failures, since the environment conditions may greatly vary. As such, it may assume any orientation about the three axes of its reference frame, which leads to a full six degrees of freedom configuration. The added three degrees of freedom have a major bearing on position and velocity estimation due to higher time complexity of classical techniques such as Kalman filters and particle filters. This article presents an algorithm for localization of mobile robots based on the complementary filtering technique to estimate the localization and orientation, through the fusion of data from IMU, GPS and compass. The main advantages are the low complexity of implementation and the high quality of the results for the case of navigation in outdoor environments (uneven terrain). The results obtained through this system are compared positively with those obtained using more complex and time consuming classic techniques.
General detection model in cooperative multirobot localization
Authors: Odakura Valguima Victoria Viana Aguiar , da Costa Bianchi Reinaldo Augusto , Costa Anna Helena Reali
Published: December 2010

The cooperative multirobot localization problem consists in localizing each robot in a group within the same environment, when robots share information in order to improve localization accuracy. It can be achieved when a robot detects and identifies another one, and measures their relative distance. At this moment, both robots can use detection information to update their own poses beliefs. However some other useful information besides single detection between a pair of robots can be used to update robots poses beliefs as: propagation of a single detection for non participants robots, absence of detections and detection involving more than a pair of robots. A general detection model is proposed in order to aggregate all detection information, addressing the problem of updating poses beliefs in all situations depicted. Experimental results in simulated environment with groups of robots show that the proposed model improves localization accuracy when compared to conventional single detection multirobot localization.
Compulsory Flow Q-Learning: an RL algorithm for robot navigation based on partial-policy and macro-states
Authors: Silva Valdinei Freire da , Costa Anna Helena Reali
Published: December 2010

Reinforcement Learning is carried out on-line, through trial-and-error interactions of the agent with the environment, which can be very time consuming when considering robots. In this paper we contribute a new learning algorithm, CFQLearning, which uses macro-states, a low-resolution discretisation of the state space, and a partial-policy to get around obstacles, both of them based on the complexity of the environment structure. The use of macro-states avoids convergence of algorithms, but can accelerate the learning process. In the other hand, partial-policies can guarantee that an agent fulfils its task, even through macro-state. Experiments show that the CFQ-Learning performs a good balance between policy quality and learning rate.
Donor Conversion and Procurement Failure: The Fate of Our Potential Organ Donors
Authors: Branco Bernardino C. , Inaba Kenji , Lam Lydia , Salim Ali , Barmparas Galinos , Teixeira Pedro G. R. , Talving Peep , Demetriades Demetrios
Published: December 2010

Background

Donor availability remains the primary limiting factor for organ transplantation today. The purpose of this study was to examine the causes of procurement failure amongst potential organ donors.

Methods

After Institutional Review Board approval, all surgical intensive care unit (SICU) patients admitted to the LAC + USC Medical Center from 01/2006 to 12/2008 who became potential organ donors were identified. Demographics, clinical data, and procurement data were abstracted. In non‐donors, the causes of procurement failure were documented.

Results

During the 3‐year study period, a total of 254 patients were evaluated for organ donation. Mean age was 44.8 ± 18.7 years; 191 (75.2%) were male, 136 (53.5%) were Hispanic, and 148 (58.3%) were trauma patients. Of the 254 patients, 116 (45.7%) were not eligible for donation: 34 had multi‐system organ failure, 24 did not progress to brain death and had support withdrawn, 18 had uncontrolled sepsis, 15 had malignancy, 6 had human immunodeficiency virus or hepatitis B or C, and 19 patients had other contraindications to organ donation. Of the remaining 138 eligible patients, 83 (60.2%) did not donate: 56 because the family denied consent, 9 by their own choice. In six, next of kin could not be located, five died because of hemodynamic instability before organ procurement was possible, four had organs that could not be placed, and three had their organs declined by the organ procurement organization. The overall consent rate was 57.5% (n = 67). From the 55 donors, 255 organs were procured (yield 4.6 organs/donor).

Conclusions

Of all patients screened for organ donation, only a fifth actually donated. Denial of consent was the major potentially preventable cause of procurement failure, whereas hemodynamic instability accounted for only a small percentage of donor losses. With such low conversion rates, the preventable causes of procurement failure warrant further study.
Systematic review and meta‐analysis of biliary reconstruction techniques in orthotopic deceased donor liver transplantation
Authors: Paes‐Barbosa Fabio Colagrossi , Massarollo P. C. , Bernardo W. M. , Ferreira F. G. , Barbosa F. K. , Raslan M. , Szutan L. A.
Published: December 2010

Background

Biliary complications remain a major cause of morbidity and mortality in liver transplantation and the biliary anastomosis technique could increase this risk. The aim of this study was to compare the effects of biliary reconstruction techniques in orthotopic liver transplantation on the incidence of biliary complications.

Methods

A systematic review and meta‐analysis using the Medline‐PubMed, EMBASE, Scielo‐LILACS, and Cochrane Databases were performed comparing biliary reconstruction techniques in liver transplantation with regard to the occurrence of biliary complications. Number needed to treat (NNT) was calculated at a 95% confidence interval.

Results

Fifty‐seven articles were selected (3 randomized clinical trials, 6 clinical trials, and 48 historical cohort studies). There was a lower risk for biliary complications (NNT = 6) using end‐to‐end choledochocholedochostomy (EECC) without drainage compared with EECC with drainage. The biliary complication risk was lower (NNT = 4) for side‐to‐side choledochocholedochostomy (SSCC) with drainage compared with SSCC without drainage. No difference was found between EECC without drainage and SSCC with drainage.

Conclusions

According to our results, considering the highest level of evidence available in the literature, we suggest that biliary reconstruction in liver transplantation should be performed using EECC or SSCC, without drainage in the former, and with drainage in the latter.
Tissue damage with different surgical techniques in a porcine model of liver resection: implications for living‐donor liver transplantation?
Authors: Goralczyk Armin Dietmar , Obed Aiman , Große Beilage Angelika , Sattler Burckhardt , Füzesi Laszlo , Lorf Thomas
Published: December 2010

Background/purpose

For living‐donor liver transplantation (LDLT) it is of paramount importance to preserve as much viable liver tissue as possible to avoid postoperative complications in the donor and recipient. The depth of tissue damage caused by common surgical techniques for liver resection has not been studied so far.

Methods

Here we compared the depth of tissue damage and the immunohistochemical expression of heat shock protein (HSP) 70, a marker for tissue damage, in a porcine model of liver resection, to assess the effect of different surgical techniques, i.e., blunt dissection (BD), and dissection with an ultrasound aspirator (UA), an ultrasound scalpel (US), or a water‐jet (WJ).

Results

Analysis with linear mixed effects models (LME) showed significantly less tissue damage with BD and UA than with US and WJ (jointp value <0.001). Damage also increased within 6 h after surgery (p value = 0.004). Semiquantitative evaluation of HSP 70 showed increased expression after resection with US compared to all other resection methods (p value <0.001), indicating increased tissue damage with this method.

Conclusion

We suggest that in cases of liver resection for LDLT surgeons should reevaluate using US and WJ because of possible excessive tissue damage compared to BD and UA. Overall we advocate the use of BD as it requires no special equipment and, hence, has considerably higher cost‐effectiveness without compromising tissue preservation and clinical outcome and is readily available even in low‐tech environments.
Magnetic compression anastomosis for biliary obstruction: review and experience at Tokyo Medical University Hospital
Authors: Itoi Takao , Kasuya Kazuhiko , Sofuni Atsushi , Itokawa Fumihide , Tsuchiya Takayoshi , Kurihara Toshio , Ikeuchi Nobuhito , Takeuchi Mami , Nagano Takeshi , Iwamoto Hitoshi , Yamanouchi Eigoro , Shimazu Motohide , Tsuchida Akihiko
Published: December 2010

Background

Magnetic compression anastomosis (MCA) is a revolutionary, minimally invasive method of performing choledochoenterostomy or choledochocholedochostomy without using surgical techniques in patients with biliary stricture or obstruction. Herein, we describe a case series of MCA for severe biliary stricture or obstruction, which could not be treated with conventional therapies.

Patients and methods

Two patients with biliary obstruction were treated using MCA for choledochocholedochostomy and choledochoenterostomy at Tokyo Medical University Hospital and Tokyo Medical University Hachioji Medical Center. Endoscopically, a samarium–cobalt (Sm–Co) rare‐earth magnet was placed at the superior site of obstruction through the percutaneous transhepatic biliary drainage route and another Sm–Co magnet was placed at the inferior site of obstruction. A comprehensive computer‐aided literature search for MCA was performed up to September 2009 by using MEDLINE and EMBASE.

Results

MCA techniques enabled complete anastomosis in both cases without procedure‐related complications.

Conclusions

The MCA technique is a revolutionary method of performing choledochocholedochostomy and choledochoenterostomy interventionally in patients with biliary obstruction, for whom the conventional endoscopic procedure is not available, or in candidates who are deemed unsuitable for surgery.
Continuous dependence for NLS in fractional order spaces
Authors: Han Zheng , Cazenave Thierry , Fang Daoyuan
Published: December 2010

For the nonlinear Schrödinger equation

iu_{t} + \mathrm{\Delta }u + \lambda |u|^{\alpha }u = 0

in

\mathbb{R}^{N}

, local existence of solutions in

H^{s}

is well known in the

H^{s}

-subcritical and critical cases

0 < \alpha ⩽4/ (N−2s)

, where

0 < s < \mathrm{\min }\{N/ 2,1\}

. However, even though the solution is constructed by a fixed-point technique, continuous dependence in

H^{s}

does not follow from the contraction mapping argument. In this paper, we show that the solution depends continuously on the initial value in the sense that the local flow is continuous

H^{s}\rightarrow H^{s}

. If, in addition,

\alpha ⩾1

then the flow is locally Lipschitz.
Gradient flow of the Chapman–Rubinstein–Schatzman model for signed vortices
Authors: Serfaty Sylvia , Ambrosio Luigi , Mainini Edoardo
Published: December 2010

We continue the study of Ambrosio and Serfaty (2008) [4] on the Chapman–Rubinstein–Schatzman–E evolution model for superconductivity, viewed as a gradient flow on the space of measures equipped with the quadratic Wasserstein structure. In Ambrosio and Serfaty (2008) [4] we considered the case of positive (probability) measures, while here we consider general real measures, as in the physical model. Understanding the evolution as a gradient flow in this context gives rise to several new questions, in particular how to define a “Wasserstein” distance for signed measures. We generalize the minimizing movement scheme of Ambrosio et al. (2005) [3] in this context, we show the entropy argument of Ambrosio and Serfaty (2008) [4] still carries through, and derive an evolution equation for the measure which contains an error term compared to the Chapman–Rubinstein–Schatzman–E model. Moreover, we also show the same applies to a very similar dissipative model on the whole plane.
Healthcare Delivery in the U.S.A.: An Introduction
Authors: Bryan Dennis N.
Published: December 2010

Healthcare Delivery in the U.S.A.: An Introduction Margaret F. Schulte 2009, CRC Press 144 $49.95 softcover
101 Global Leadership Lessons for Nurses
Authors: Colopinto Kara L.
Published: December 2010

101 Global Leadership Lessons for Nurses Nancy Rollins Gantz 2010, Sigma Theta Tau International 680 $39.95 softcover
The Coaching Connection
Authors: Harvey Mary Kay
Published: December 2010

The Coaching Connection Paul Gorrell and John Hoover 2009, AMACOM 226 $29.95 hardcover
Value-Maximizing Managers, Value-Increasing Mergers, and Overbidding
Authors: Akdoğu Evrim
Published: December 2010

Some acquisitions can be viewed as the quickest means to obtain a scarce resource required for restructuring in response to an economic shock. Such acquisitions can give the acquirer a competitive edge and hurt its competitors. In this paper, I first show that if a firm will be adversely affected by a competitor’s acquisition, then it can rationally “overpay” for the target to avoid this outcome within a value-maximizing framework due to industry equilibrium effects. Next, I show that depending on the level of anticipation by the market, the magnitude of the cost of losing, and the competition between bidders, an acquirer can earn negative payoffs at the announcement of such an acquisition. Even though the merger is the best decision given the circumstances, negative returns incorporate the understanding that the target is a necessary resource to survive in this changing environment, losing it to a rival is costly, and there is a positive probability that the bidder may not win or win by paying more than the synergy value of the target. Finally, I extend the model to include 2 targets that become available sequentially to multiple bidders and show that when there are alternatives available for the target’s resources, overbidding subsides.
Player's Antarctic cigarette cards and the involvement of ‘Teddy’ Evans
Authors: Codling Rosamunde
Published: December 2010

During World War 1 John Player & Sons issued two series of cigarette cards, both entitled ‘Polar Exploration’. The first, probably issued in 1915, covered both Arctic and Antarctic subjects, but the second, issued in 1916, confined itself to the southern continent. Eight cards from the first series were derived from Shackleton's book The heart of the Antarctic. Commander E.R.G.R. ‘Teddy’ Evans, captain of R.F. Scott's vessel Terra Nova, was responsible for both the illustrations and texts of the cards in the second series.
David Geoffrey Dalgliesh
Authors: Stonehouse Bernard
Published: December 2010

David Geoffrey Dalgliesh, naval surgeon was born on 22 March 1922 to Kenneth and Ellen Dalgliesh. With three sisters and a younger brother he grew up in Sidcup, Kent, in semi-rural surroundings of gardens, fields and woodlands where he developed a lasting love of natural history. Aged nine he learnt woodwork, a manual skill that re-emerged later in his gift for surgery. He attended Merchant Taylor's School until 1939, taking the 1st MB examination in preparation for entering medical school. When World War II began in September 1939 he was of military age but compulsorily reserved as a future doctor. After a gap year as agricultural labourer, fire watcher and founder member of the Local Defence Volunteers (forerunner of the Home Guard), David joined St Thomas's Hospital Medical School in 1940. His early months of study coincided with the London blitz, in which every city hospital was fully involved and severely tested. Later he served in emergency dressing stations, set up in southern England to treat casualties returning from the Normandy invasion. On graduating MRCS and LRCP in 1946, David had gained an unusual but invaluable practical training in emergency medicine.
Macrobenthic communities of the north-western Ross Sea shelf: links to depth, sediment characteristics and latitude
Authors: Cummings V.J. , Thrush S.F. , Chiantore M. , Hewitt J.E. , Cattaneo-Vietti R.
Published: December 2010

In early 2004 the Victoria Land Transect project sampled coastal north-western Ross Sea shelf benthos at Cape Adare, Cape Hallett, Cape Russell and Coulman Island from 100–500 m deep. We describe the benthic macrofaunal assemblages at these locations and, to assess the use of seafloor sediment characteristics and/or depth measures in bioregionalizations, determine the extent to which assemblage compositions are related to measured differences in these factors. Percentages of fine sand and silt, the ratio of sediment chlorophyllato phaeophytin, and depth were identified as important explanatory variables, but in combination they explained only 17.3% of between-location differences in assemblages. Consequently, these variables are clearly not strong determinants of macrofaunal assemblage structure. Latitudeper sewas not a useful measure of community variability and change. A significant correlation between both number of individuals and number of taxa and sediment phaeophytin concentration across locations suggests that the distribution of the benthos reflects their response to seafloor productivity. A number of factors not measured in this study have probably influenced the structure and function of assemblages and habitats. We discuss the implications of the results to marine classifications, and stress the need to incorporate biogenic habitat complexity into protection strategies.
Population structure ofFriesea grisea(Collembola, Neanuridae) in the Antarctic Peninsula and Victoria Land: evidence for local genetic differentiation of pre-Pleistocene origin
Authors: Torricelli Giulia , Frati Francesco , Convey Peter , Telford Marco , Carapelli Antonio
Published: December 2010

Friesea griseais the only springtail species currently described from both East (Victoria Land) and West Antarctica (Antarctic Peninsula), although levels of genetic divergence between the two regions suggest the possibility of cryptic species. Determining the genetic structure of populations in the two regions is necessary in order to compare the effects of the different environmental conditions in the two regions, the different evolutionary histories of their inhabitants, and for assessing any influence of latitude in each region on genetic diversity. We analysed sequences of the mitochondrial COX1 and ATP6 genes from a total of 111 individuals for 17 sites (nine on the Antarctic Peninsula and eight in Victoria Land), to assess levels of genetic diversity. Both regions have their own unique sets of haplotypes, differing by about 20% of their nucleotide sequences. A similar number of haplotypes was found in the two regions, and within each we found two groups of populations sharing no haplotypes. In the Antarctic Peninsula, two, presumably ancestral, haplotypes are dominant in frequency. In Victoria Land, the Cape Hallett population showed a distinct set of haplotypes, genetically different from the southernmost populations, suggesting differentiation on pre-Pleistocene timescales.
Noetherian orders
Authors: PERDRY HERVÉ , SCHUSTER PETER
Published: December 2010

Noether classes of posets arise in a natural way from the constructively meaningful variants of the notion of a Noetherian ring. Using an axiomatic characterisation of a Noether class, we prove that if a poset belongs to a Noether class, then so does the poset of the finite descending chains. When applied to the poset of finitely generated ideals of a ring, this helps towards a unified constructive proof of the Hilbert basis theorem for all Noether classes.
Country characteristics and non-indigenous species
Authors: GREN ING-MARIE , THIERFELDER TOMAS , BERGLUND HELENA
Published: December 2010

This paper presents an econometric test of two hypotheses underlying the occurrence of non-indigenous species (NIS) at the global scale: openness of recipient nations which allows for international trade to act as a vector of NIS, and habitat fragmentation in recipient nations which facilitates establishment of introduced NIS. Explorative econometric methods have been utilised that combine the analysis of dimensionality with subset variable selection and multiple linear regression. Both NIS hypotheses are thereby supported, although slightly different in the cases of the mainland and island nations. It is concluded that expressions of openness have a larger impact on the number of NIS per unit territorial area in the mainland nations, whereas biota variables play a more dominant role in the case of the island nations. It is also concluded that different expressions of NIS occurrence affect the result, where NIS per area unit facilitates excellent explanatory performance.
The use of economic instruments for pollution control in Latin America: lessons for future policy design*
Authors: CAFFERA MARCELO
Published: December 2010

I review the few programs implemented in Latin America to control pollution with direct economic instruments and draw general lessons for the future implementation of these instruments in the region. The available evidence suggests that a combination of low capacities and political economy issues negatively affected the implementation of these programs. As a result, the capacity of the economic instruments to induce emission reductions cost effectively and their future political viability in these countries in the short- or medium-run may have been compromised. This present state of affairs provides more evidence in favor of the policy recommendation that Latin American countries should build local capacities before implementing direct economic instruments, than in favor of the alternative that these countries should adapt direct economic instruments to their institutional and political characteristics.
Variable Resolution Fluctuation Electron Microscopy on Cu-Zr Metallic Glass Using a Wide Range of Coherent STEM Probe Size
Authors: Hwang Jinwoo , Voyles P.M.
Published: December 2010

We report variable resolution fluctuation electron microscopy (VRFEM) measurements on Cu64.5Zr35.5metallic glass acquired using scanning transmission electron microscopy nanodiffraction using coherent probes 0.8 to 11 nm in diameter. The VRFEM results show that medium range atomic order structure of Cu64.5Zr35.5bulk metallic glass at the ∼1 nm scale has large fluctuations, but the structure becomes almost completely homogeneous at the 11 nm scale. We show that our experimental VRFEM data are consistent with two different models, the pair persistent model and the amorphous/nanocrystal composite model. We also report a new way to filter VRFEM data to eliminate the effect of specimen thickness gradient using high-angle annular dark field images as references.
Extended Depth of Field for High-Resolution Scanning Transmission Electron Microscopy
Authors: Hovden Robert , Xin Huolin L. , Muller David A.
Published: December 2010

Aberration-corrected scanning transmission electron microscopes (STEMs) provide sub-Angstrom lateral resolution; however, the large convergence angle greatly reduces the depth of field. For microscopes with a small depth of field, information outside of the focal plane quickly becomes blurred and less defined. It may not be possible to image some samples entirely in focus. Extended depth-of-field techniques, however, allow a single image, with all areas in focus, to be extracted from a series of images focused at a range of depths. In recent years, a variety of algorithmic approaches have been employed for bright-field optical microscopy. Here, we demonstrate that some established optical microscopy methods can also be applied to extend the ∼6 nm depth of focus of a 100 kV 5th-order aberration-corrected STEM (αmax = 33 mrad) to image Pt-Co nanoparticles on a thick vulcanized carbon support. These techniques allow us to automatically obtain a single image with all the particles in focus as well as a complimentary topography map.
High-Resolution Imaging of Kidney Vascular Corrosion Casts with Nano-CT
Authors: Wagner Roger , Van Loo Denis , Hossler Fred , Czymmek Kirk , Pauwels Elin , Van Hoorebeke Luc
Published: December 2010

A vascular corrosion cast of an entire mouse kidney was scanned with a modular multiresolution X-ray nanotomography system. Using an isotropic voxel pitch of 0.5 μm, capillary systems such as the vasa recta, peritubular capillaries and glomeruli were clearly resolved. This represents a considerable improvement over corrosion casts scanned with microcomputed tomography systems. The resolving power of this system was clearly demonstrated by the unique observation of a dense, subcapsular mat of capillaries enveloping the entire outer surface of the cortical region. Resolution of glomerular capillaries was comparable to similar models derived from laser scanning confocal microscopy. The high-resolution, large field of view and the three-dimensional nature of the resulting data opens new possibilities for the use of corrosion casting in research.
Profiling transboundary aerosols over Taiwan and assessing their radiative effects
Authors: Wang Sheng‐Hsiang , Lin Neng‐Huei , Chou Ming‐Dah , Tsay Si‐Chee , Welton Ellsworth J. , Hsu N. Christina , Giles David M. , Liu Gin‐Rong , Holben Brent N.
Published: December 2010

A synergistic process was developed to study the vertical distributions of aerosol optical properties and their effects on solar heating using data retrieved from ground‐based radiation measurements and radiative transfer simulations. Continuous MPLNET and AERONET observations were made at a rural site in northern Taiwan from 2005 to 2007. The aerosol vertical extinction profiles retrieved from ground‐based lidar measurements were categorized into near‐surface, mixed, and two‐layer transport types, representing 76% of all cases. Fine‐mode (Ångström exponent, α, ∼1.4) and moderately absorbing aerosols (columnar single‐scattering albedo ∼0.93, asymmetry factor ∼0.73 at 440 nm wavelength) dominated in this region. The column‐integrated aerosol optical thickness at 500 nm (τ500nm) ranges from 0.1 to 0.6 for the near‐surface transport type but can be doubled in the presence of upper layer aerosol transport. We utilize aerosol radiative efficiency (ARE, the impact on solar radiation per unit change of τ500nm) to quantify the radiative effects due to different vertical distributions of aerosols. Our results show that the ARE at the top of atmosphere (−23 W m−2) is weakly sensitive to aerosol vertical distributions confined in the lower troposphere. On the other hand, values of the ARE at the surface are −44.3, −40.6, and −39.7 W m−2 for near‐surface, mixed, and two‐layer transport types, respectively. Further analyses show that the impact of aerosols on the vertical profile of solar heating is larger for the near‐surface transport type than for the two‐layer transport type. The impacts of aerosol on the surface radiation and the solar heating profiles have implications for the stability and convection in the lower troposphere.
Extreme flood sensitivity to snow and forest harvest, western Cascades, Oregon, United States
Authors: Jones J. A. , Perkins R. M.
Published: December 2010

We examined the effects of snow, event size, basin size, and forest harvest on floods using >1000 peak discharge events from 1953 to 2006 from three small (<1 km2), paired‐watershed forest‐harvest experiments and six large (60–600 km2) basins spanning the transient (400–800 m) and seasonal (>800 m) snow zones in the western Cascades of Oregon. Retrospectively classified rain‐on‐snow events delivered 75% more water to soils than rain events. Peak discharges of >10 year rain‐on‐snow events were almost twice as high as rain peaks in large basins but only slightly higher in small basins. Peak discharges of >1 year rain‐on‐snow events increased slightly (10%–20%) after logging in small basins, but small basin peaks do not account for the magnitudes of large basin rain‐on‐snow peak discharges during >1 year floods. In extreme floods, despite very high infiltration capacity, high soil porosity, and steep hillslope gradients, prolonged precipitation and synchronous snowmelt produce rapid, synchronized hydrograph responses to small variations in maximum precipitation intensity. At the large basin scale, forest harvest may increase the area of snowpack and simultaneous snowmelt, especially in elevation zones normally dominated by rain and transient snow, thereby increasing large basin peaks without producing very large percent increases in small basin peaks. Further work is needed to describe water flow paths in melting snowpack, snow cover and the area experiencing snowmelt, synoptic peak discharges, and routing of flood peaks through the stream network during extreme rain‐on‐snow floods. The evolving structure of the forest on the landscape is a potentially very important factor influencing extreme rain‐on‐snow floods.
Remanence stability and magnetic fabric development in synthetic shear zones deformed at 500°C
Authors: Till J. L. , Jackson M. J. , Moskowitz B. M.
Published: December 2010

Shear experiments were performed on magnetite‐bearing calcite aggregates to examine magnetic fabric development and remanence stability in a deforming system using elevated temperature and pressure to encourage deformation by crystal‐plastic processes. Samples composed of 1 wt % pseudo‐single‐domain magnetite (1–2 μm) in a calcite matrix were created with either strong or weak initial fabrics and deformed in coaxial simple shear to strains up to γ = 1.5 at constant strain rates between 6 × 10−5 and 1 × 10−4 s−1 at 500°C and confining pressure of 300 MPa. Samples were given weak field thermal remanent magnetizations prior to deformation. Demagnetization of postdeformation remanence reveals that a primary remanent magnetization can withstand deformation at pressures and temperatures approximately equivalent to greenschist facies metamorphic conditions on laboratory time scales, but this stability is found to depend on the character of the predeformation fabric. The origin of secondary remanence components acquired during deformation is uncertain but is likely to partially result from thermal viscous remagnetization. Complete postdeformation remagnetization in initially anisotropic samples appears to involve a stress‐softening or piezoremanent magnetization mechanism. Postdeformation anisotropy measurements show progressive changes in magnetic fabric strength with strain. In the absence of a strong initial magnetic anisotropy, magnetic fabric intensity increases linearly as a function of strain; however, deformation that overprinted an existing fabric results in an apparent decrease of the initial anisotropy at low strains followed by rapid increases in magnetic fabric strength with increasing strain. Our results underscore the important role that initial fabric can play in determining the character of deformation fabrics.
Seasonal variation of turbulent diapycnal mixing in the northwestern Pacific stirred by wind stress
Authors: Jing Zhao , Wu Lixin
Published: December 2010

Profiles of potential density obtained from CTD measurements along the northwestern Pacific section at 137°E are used to estimate both mean and seasonal variations of turbulent diapycnal mixing based on both a Thorpe‐scale method and a finescale parameterization method. In general, away from the bottom, the estimated mean value along this section is about O(10−4 m2/s), indicating much stronger mixing in the Northwestern Pacific than in the stratified mid‐latitude interior ocean. It is further found that the diffusivity can even exceed 10−4 m2/s around the rough topography. The turbulent diapycnal mixing in the upper ocean also displays a distinct seasonal variation with the amplitude decreasing with depth, bearing a statistically significant correlation with surface wind stress forcing. Our study here provides evidence for the important role of energy input from wind stress in sustaining the deep ocean mixing.
PCAIM joint inversion of InSAR and ground‐based geodetic time series: Application to monitoring magmatic inflation beneath the Long Valley Caldera
Authors: Lin Yu‐nung Nina , Kositsky Andrew P. , Avouac Jean‐Philippe
Published: December 2010

This study demonstrates the interest of using a Principal Component Analysis‐based Inversion Method (PCAIM) to analyze jointly InSAR and ground‐based geodetic time series of crustal deformation. A major advantage of this approach is that the InSAR tropospheric biases are naturally filtered out provided they do not introduce correlated or high amplitude noise in the input times series. This approach yields source models which are well‐constrained both in time and space due to the temporal resolution of the ground‐based geodetic data and the spatial resolution of the InSAR data. The technique is computationally inexpensive allowing for the inversion of large datasets. To demonstrate the performance of this approach, we apply it to the 1997–98 magmatic inflation event in the Long Valley Caldera, California.
Recent widening of the tropical belt from global tropopause statistics: Sensitivities
Authors: Birner Thomas
Published: December 2010

Several recent studies have shown evidence for a widening of the tropical belt over the past few decades. One line of evidence uses statistics of the tropopause height to distinguish between tropics and extratropics and defines tropical edge latitudes as those latitudes at which the number of days per year with tropopause heights greater than 15 km exceeds a certain threshold (typically 200 days/yr). This definition involves two somewhat arbitrary thresholds. Here the sensitivity of the resulting widening trend of the tropical belt to these thresholds is investigated using four different reanalysis data sets. Widening trends are found to be particularly sensitive to changes in the tropopause height threshold. Ways to objectively determine appropriate thresholds to define tropical edge latitudes based on tropopause statistics are presented. Trend estimates for the width of the tropical belt from different reanalysis data sets are found to be mostly inconsistent with each other despite consistent seasonal and interannual variations.
Assessment of apparent nonstationarity in time series of annual inflow, daily precipitation, and atmospheric circulation indices: A case study from southwest Western Australia
Authors: Bates Bryson C. , Chandler Richard E. , Charles Stephen P. , Campbell Edward P.
Published: December 2010

The southwest region of Western Australia has experienced a sustained sequence of low annual inflows to major water supply dams over the past 30 years. Until recently, the dominant interpretation of this phenomenon has been predicated on the existence of one or more sharp breaks (change or jump points), with inflows fluctuating around relatively constant levels between them. This paper revisits this interpretation. To understand the mechanisms behind the changes, we also analyze daily precipitation series at multiple sites in the vicinity and time series for several indices of regional atmospheric circulation that may be considered as drivers of regional precipitation. We focus on the winter half‐year for the region (May to October) as up to 80% of annual precipitation occurs during this “season”. We find that the decline in the annual inflow is in fact more consistent with a smooth declining trend than with a sequence of sharp breaks, the decline is associated with decreases both in the frequency of daily precipitation occurrence and in wet‐day amounts, and the decline in regional precipitation is strongly associated with a marked decrease in moisture content in the lower troposphere, an increase in regionally averaged sea level pressure in the first half of the season, and intraseasonal changes in the regional north‐south sea level pressure gradient. Overall, our approach provides an integrated understanding of the linkages between declining dam inflows, declining precipitation, and changes in regional atmospheric circulation that favor drier conditions.
The Combination of Genetic Variations in the PRDX3 Gene and Dietary Fat Intake Contribute to Obesity Risk
Authors: Hiroi Masako , Nagahara Yuka , Miyauchi Rie , Misaki Yasumi , Goda Toshinao , Kasezawa Nobuhiko , Sasaki Satoshi , Yamakawa‐Kobayashi Kimiko
Published: December 2010

Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the antioxidant capacity of the cell. This imbalance and an excess of ROS induce tissue/cellular damage, which are implicated in chronic inflammation disorders such as obesity, insulin resistance, and metabolic syndromes. Peroxiredoxins (Prxs) are the most abundant and ancient cellular antioxidant proteins that help to control intracellular peroxide levels and ROS‐dependent signaling. Of the six mammalian isoforms, Prx III is specifically localized in mitochondria. In this study, we detected novel associations between genetic variations of the PRDX3 gene and BMI and obesity risk in the general Japanese population. In addition, these associations were observed only in the subjects with high dietary fat intake, but not in the subjects with low dietary fat intake. These findings indicate that the interaction between genetic variations in the PRDX3 gene and dietary fat intake is important for modulation of BMI and obesity risk.