bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature-induced variation in reproductive success: field and control experiments with the C4 grass Echinochloa crus-galli
Authors: Potvin Catherine
Published: June 2010

To examine the influence of weather patterns on the flowering of a C4 plant, 11 transplant gardens were sown with seeds of Echinochloa crus-galli var. crus-galli within and beyond the species range. Both the isolated effect of climate and the joint effect of competition and soil quality on the flowering of E. crus-galli were analyzed. Although vegetative growth was significantly more vigorous in the southernmost site, Echinochloa plants were able to grow actively even at high latitudes. Conversely, flowering decreased gradually from south to north. The maximum temperature in August was the best predictor of floral emergence. Data from controlled experiments confirmed that flowering of E. crus-galli was size independent, and temperature was shown to have an effect on biomass accumulation and allocation as well as on floral emergence. Plants grown in the coolest thermoperiod produced a small number of heavy seeds, whose germinability was superior to that of plants grown in the other temperature treatments. Finally, the results indicate that maternal families represent a significant source of variability for reproductive characteristics. The presence of genetic effects suggests that E. crus-galli has the potential for further evolution with regard to temperature. Key words: flowering, reproduction, low temperature, C4 plants, Echinochloa crus-galli.
Litter mass-loss rates in late stages of decomposition at some climatically and nutritionally different pine sites. Long-term decomposition in a Scots pine forest. VIII
Authors: Berg Björn , McClaugherty Charles , Johansson Maj-Britt
Published: June 2010

The patterns of some chemical changes and litter mass-loss rates were investigated for a variety of types of decomposing litter in pine forests under different climatic conditions and at sites with different nutrient status. A mixed deciduous forest was also compared. In initially chemically identical Scots pine needle litter incubated under different climatic conditions, the lignin concentration increased faster as a function of accumulated mass loss when the climatic conditions promoted a higher initial mass-loss rate. Also under artificially created conditions, e.g., after fertilization and irrigation, the same phenomenon occurred. Litter mass-loss rates decreased during decomposition as lignin concentrations increased. The relative decrease was significantly larger at sites with a climate that promoted an initially higher mass-loss rate. At the same lignin concentration, however, the mass-loss rate was significantly lower in drier and colder conditions, viz. climatic conditions that promote a lower initial mass-loss rate. Nevertheless, at very high lignin concentrations that lignin clearly dominated over climate as a rate-regulating factor. A possible consequence of this observation could be a higher rate of organic matter accumulation at sites that initially promote a high initial mass-loss rate for litter than at sites with conditions that give lower initial rates, at least for a given species of litter. Key words: litter, decomposition, lignin, chemical changes, climatic transect, effect of climate change.
Latitudinal distribution of cesium-137 fallout in 1990 on Saxifraga oppositofolia from Ellesmere Island, Canada
Authors: France R. L. , Svoboda J. , Taylor H. W.
Published: June 2010

During the first ski traverse of Ellesmere Island in spring 1990, purple saxifrage (Saxifraga oppositifolia) was collected at 10 sites from 76 to 82°N. Measured 137Cs levels in this cushion plant displayed a progressive decrease in activity north of 78°, reflecting past global patterns of radionuclide fallout. Lower 137Cs activity at the southern end of Ellesmere Island may reflect a northward shift of the distribution maximum since a previous latitudinal survey conducted in 1979–1980. Levels of 137Cs in three species of lichens were consistently higher than those for nearby saxifrage, possibly owing to the larger exposure to fallout for much of the year and the slower rate of lichen growth. In support of previous research, no 134Cs was detected, which indicated that Chernobyl fallout had not been deposited in significant quantities at these extreme northern latitudes. Specific activities in 1990 of saxifrage samples were compared with similar samples collected during 1979–1980 to derive an effective half-life of 6.2 ± 1.0 years for northern Ellesmere Island. Key words: cesium, fallout, Ellesmere Island, saxifrage, half-life.
THE GEANT4-DNA PROJECT
Authors: INCERTI S. , BALDACCHINO G. , BERNAL M. , CAPRA R. , CHAMPION C. , FRANCIS Z. , GUÈYE P. , MANTERO A. , MASCIALINO B. , MORETTO P. , NIEMINEN P. , VILLAGRASA C. , ZACHARATOU C.
Published: June 2010

The Geant4-DNA project proposes to develop an open-source simulation software based and fully included in the general-purpose Geant4 Monte-Carlo simulation toolkit. The main objective of this software is to simulate biological damages induced by ionizing radiations at the cellular and sub-cellular scale. This project was originally initiated by the European Space Agency for the prediction of the deleterious effects of radiations that may affect astronauts during future long duration space exploration missions. In this paper, the Geant4-DNA collaboration presents an overview of the whole on-going project, including its most recent developments that are available in the Geant4 toolkit since December 2009 (release 9.3), as well as an illustration example simulating the direct irradiation of a biological chromatin fiber. Expected extensions involving several research domains, such as particle physics, chemistry and cellular and molecular biology, within a fully interdisciplinary activity of the Geant4 collaboration are also discussed.
COLLABORATIVE OPTIMIZATION WITH DIMENSION REDUCTION
Authors: GAO ZHENXIAO , XIAO TIANYUAN , FAN WENHUI
Published: June 2010

Collaborative optimization (CO) method is widely used in solving multidisciplinary design optimization (MDO) problems, yet its computation requirement has been an obstacle to the applications, leading to doubts about CO's convergence property. The feasible domain of CO problem is first examined and it is proven that feasible domain remains the same during the CO formulation. So is the same with extreme points. Then based on contemporary research conclusion that the system-level optimization problem suffers from inherent computational difficulties, it is further pointed out that the employment of meta-heuristic optimization methods in CO could eliminate these difficulties. To make CO more computational feasible, a new method collaborative optimization with dimension reduction (CODR) is proposed. It focused on optimization dimension reduction and lets local copy of common shared design variables equal system shared design variables directly. Thus, the number of dimensions that CODR could reduce equal the number of common shared design variables. Numerical experiment suggests that CODR reduces computations greatly without losing of optimization accuracy.
A NOVEL ANALYTICAL METHOD TO INVESTIGATE EFFECT OF RADIATION ON FLOW OF A MAGNETO-MICROPOLAR FLUID PAST A CONTINUOUSLY MOVING PLATE WITH SUCTION AND BLOWING
Authors: RASHIDI MOHAMMAD MEHDI , ERFANI ESMAEEL
Published: June 2010

In this article, Differential Transform Method (DTM) and Padé approximants (DTM-Padé), are considered for finding analytical solutions of a magneto-micropolar flow past a continuously moving plate with suction and blowing and radiation effect. This technique is extended to give solutions for system of nonlinear ordinary differential equations with boundary conditions at infinity. The analytic solutions of the system of nonlinear ordinary differential equations are constructed in the ratio of two polynomials. Graphical results are presented to investigate influence of the radiation parameter, magnetic field parameter, Prandtl number, coupling constant parameter and the surface mass transfer parameter on velocity profiles, angular velocity profiles and temperature profiles. In addition, the numerical method is used to investigate the validity of this analytical method, an excellent agreement is observed between the solutions obtained from the DTM-Padé and numerical results. The results reveal that the DTM-Padé is very effective and convenient for solving engineering problems especially for boundary-layer problems.
GRID-INDEPENDENT METROPOLIS SAMPLING FOR VOLUME VISUALIZATION
Authors: TANAKA SATOSHI , HASEGAWA KYOKO , NAKATA SUSUMU , NAKAJIMA HIDEO , HATTA TAKUYA , NGANA FREDERIKA RAMBU , KAWAMURA TAKUMA , SAKAMOTO NAOHISA , KOYAMADA KOJI
Published: June 2010

We propose a method of sampling regular and irregular-grid volume data for visualization. The method is based on the Metropolis algorithm that is a type of Monte Carlo technique. Our method enables "importance sampling" of local regions of interest in the visualization by generating sample points intensively in regions where a user-specified transfer function takes the peak values. The generated sample-point distribution is independent of the grid structure of the given volume data. Therefore, our method is applicable to irregular grids as well as regular grids. We demonstrate the effectiveness of our method by applying it to regular cubic grids and irregular tetrahedral grids with adaptive cell sizes. We visualize volume data by projecting the generated sample points onto the 2D image plane. We tested our sampling with three rendering models: an X-ray model, a simple illuminant particle model, and an illuminant particle model with light-attenuation effects. The grid-independency and the efficiency in the parallel processing mean that our method is suitable for visualizing large-scale volume data. The former means that the required number of sample points is proportional to the number of 2D pixels, not the number of 3D voxels. The latter means that our method can be easily accelerated on the multiple-CPU and/or GPU platforms. We also show that our method can work with adaptive space partitioning of volume data, which also enables us to treat large-scale/complex volume data easily.
Palaeoenvironmental analysis of Archaean siliciclastic sedimentary rocks in the west–central Jack Hills belt, Western Australia with new constraints on ages and correlations
Authors: Eriksson Kenneth A. , Wilde Simon A.
Published: June 2010

Zircons with ages between 3.05 and 4.4 Ga and hosted in conglomerates and associated sandstones in the Jack Hills belt of Western Australia have been the subject of numerous studies but none, to date, has been concerned with understanding the depositional environments of the sedimentary rocks. Intact, 250 and 320 m thick stratigraphical sections include conglomerates and sandstones that are equivalent to those at the W74 discovery site that host the ancient zircons. Facies associations are compatible with a prograding fan delta depositional setting in which alluvial fans were sourced by proximal highlands, were built directly into a lake or sea and were characterized by high gradients and high flow velocities. Locally, the succession is capped by a 20–25 m thick interval of cross-bedded quartz arenite–gritstone with a similar U–Pb detrital zircon age spectrum to the W74 discovery site, suggesting that this facies association is of comparable age and genetically related to the underlying facies associations. The quartz arenite–gritstone facies association is interpreted to record transgressive tidal reworking of the fan delta. Similar sedimentary units, including areally extensive quartz arenite successions, are widely developed elsewhere in Western Australia and on other continents, indicating that stable continental crust was widespread by 3.0 Ga.
Early Devonian alkaline intrusive complex from the northern North China craton: a petrological monitor of post-collisional tectonics
Authors: Zhang Xiaohui , Zhang Hongfu , Jiang Neng , Zhai Mingguo , Zhang Yanbin
Published: June 2010

Laser ablation inductively coupled plasma mass spectrometry zircon U–Pb dating and geochemical data document the Early Devonian Sandaogou alkaline complex (409 Ma) from the northern margin of the North China craton. The rock suite includes pyroxene syenite, quartz syenite and monzonite. These rocks exhibit high contents of K
2
O (5–13 wt%), strong enrichments in large ion lithophile elements and light REE, slightly negative Eu anomalies, and pronounced depletions in high field strength elements. They are characterized by moderate
87
Sr/
86
Sr
i
ratios of 0.7052–0.7071, low ε
Nd
(t) values of −12.7 to −17.9 and zircon ε
Hf
(t) values from −27.8 to −32.3. These geochemical features and quantitative isotopic modelling suggest that they might have been formed through simultaneous fractional crystallization and lower crustal assimilation of a metasomatized mantle-derived alkali basaltic magma. These trachytic rocks, together with the Middle Devonian alkaline rocks and mafic–ultramafic complex from neighbouring regions, constitute a linear post-collisional magmatic belt along the northern North China craton, possibly formed under a tectonic regime of slab breakoff. They serve not only as a magmatic milestone for marking the termination of Early Palaeozoic orogenic cycle around the northern North China craton, but also as a spatial tracer for locating the position of the potential ancient slab breakoff at the surface.

Supplementary material:

Analytical methods, mineral composition data, field and zircon cathodoluminescence (CL) photographs are available at
http://www.geolsoc.org.uk/SUP18403
.
Effects of Cretaceous plume and convergence, and Early Tertiary tectonomagmatic quiescence on the central and southern Levant continental margin
Authors: Segev Amit , Rybakov Michael
Published: June 2010

This study synthesizes geological and geophysical evidence concerning the structure and character of the central and southern Jurassic Levant continental margin during Cretaceous–Tertiary time. From the beginning of the Cretaceous and until Cenomanian time, the Levant margin was strongly affected by extensional tectonics, cyclical igneous activity and rifting coupled with thermal and vertical fluctuations. It is suggested here that during the Senonian–Maastrichtian convergence of Afro-Arabia and the Mesotethys, and the Tauride part of Eurasia, the Herodotus basin oceanic crust subducted along the Eratosthenes Arc, below the short-lived abandoned Levant back-arc basin. Such a plate configuration assumes regional shear zones, as follows: (1) between the Eratosthenes Arc from the south and the Kyrenia Arc from the north: the NW–SE Carmel–Azraq–Sirhan fault system; (2) between the Sinai and the African plates: the Suez fault system; (3) between the Mesotethys and the African plates: the northern Egypt–Sinai–Negev west–east transversal fault system. Distinct tectonomagmatic quiescence between Late Maastrichtian and Late Eocene time allowed thermal relaxation and subsidence of the Levant margin until the apparent achievement of local isostatic compensation and the consequent development of the longest transgression over the Afro-Arabian ramp.

Supplementary material:

Details on the construction of the Bouguer gravity map are available at
http://www.geolsoc.org.uk/SUP18404
.
Regional conductivity data used to reassess Early Palaeozoic structure in the Northern Ireland sector of the Southern Uplands–Down–Longford terrane
Authors: Beamish D. , Kimbell G.S. , Stone P. , Anderson T.B.
Published: June 2010

A high-resolution, airborne conductivity survey has proved spectacularly successful in delineating the zones of carbonaceous mudstone (Moffat Shale Group) that form the structural and stratigraphical base of various sandstone-dominated tracts within the Northern Ireland sector of the Southern Uplands–Down–Longford Ordovician–Silurian accretionary terrane. The anomalies associated with mudstone both at outcrop and concealed allow the major tract boundary faults to be plotted across large areas of poor exposure to reveal a large-scale regional swing in the strike of these faults from their prevalent ENE–WSW trend into a NE–SW orientation. The fault traces defined by the geophysical anomalies cut across those, deduced by extrapolation into an area of sparse bedrock exposure, that are illustrated on the current geological map. A substantial revision of the regional fault pattern is thus required. In places the major tract boundary faults appear to anastomose into strike-slip duplexes, suggesting transpression in the accretionary regime. However, the wholesale realignment of the strike trend is likely to have had a later, post-accretion origin, perhaps involving a releasing bend on a major, strike-parallel fault that controlled emplacement of the Newry granitoid pluton (425 Ma), and might also be associated with Au mineralization in Armagh and Monaghan.
A pulse in the planet: regional control of high-frequency changes in relative sea level by mantle convection
Authors: Lovell Bryan
Published: June 2010

An explanation for high-frequency cycles of sea level in non-glacial times has remained elusive, despite more than two centuries of research since Lavoisier's seminal observations were published in 1789. In the development of seismic stratigraphy in the 1970s, putatively global high-frequency changes in relative sea level (Vail third-order cycles) were attributed to an unknown eustatic mechanism, prompting a search for Mesozoic ice ages. Over the last decade, a regional mechanism of sea-level control has been developed from studies of the sedimentary record in high-quality oil-industry data. These geological studies have supported the geophysical prediction that significant regional control of sea level is exercised by mantle-induced vertical motions of the Earth's surface. These vertical motions can occur over time intervals from several tens of million years to less than a million years, with amplitudes of tens of metres or more even at the shorter intervals. The vertical motions are not confined to regions with major hotspots. There are two related controls of surface vertical motion: evolution of mantle-convection cells, and pulsing flow within each cell. The effects are evident in the sedimentary record of North Atlantic basins. Mantle convection provides an alternative, regional, mechanism to eustatic control for explaining medium-frequency to high-frequency sea-level cycles.
Structurally focused fluid flow during orogenesis: the Islay Anticline, SW Highlands, Scotland
Authors: Pitcairn Iain K. , Skelton Alasdair D.L. , Broman Curt , Arghe Fredrik , Boyce Adrian
Published: June 2010

Displacement of isotopic compositions at boundary layers across strata of contrasting composition is commonly used to investigate hydrothermal fluid flow during orogeny. This study investigates whether hydrothermal fluid flow was focused along the Islay Anticline, Islay, SW Highlands of Scotland, as shown in the axial zone of the neighbouring Ardrishaig Anticline. Four localities from the limb to the axial plane of the Islay Anticline were investigated for isotopic homogenization of metacarbonate units to silicate values. At Mull of Oa on the limb of the anticline, metacarbonate samples show limited isotopic resetting and the fluid flux is estimated to be <1 m
3
m
−2
. Within the axial zone of the Islay Anticline, metacarbonate units from Port a' Chotain and Bagh an Da Dhoruis show complete isotopic homogenization to silicate values indicating higher fluid fluxes. Fluid flow was enhanced along localized parasitic folds such as at Port an t-Sruthain, where metacarbonates have been isotopically reset, and there are abundant quartz–carbonate veins that precipitated during D
1
–D
2
deformation. Metamorphic fluid flow was higher in the axial zone of the Islay Anticline and in localized antiformal structures. Fluid fluxes are estimated to be considerably lower than at the neighbouring Ardrishaig Anticline.
Regional-scale Cretaceous albitization in the Pyrenees: evidence from
in situ
U–Th–Pb dating of monazite, titanite and zircon
Authors: Poujol Marc , Boulvais Philippe , Kosler Jan
Published: June 2010

Albitization is a common metasomatic process active in various geodynamic contexts. In the northern Pyrenees, there are several occurrences of albitites but, until now, only one occurrence has been dated (117 Ma, Ar–Ar dating). This paper presents new U–Th–Pb ages for several albitite occurrences throughout the Pyrenees to test whether they are contemporaneous and, if so, to specify the regional extent of the albitization event. Ages obtained from large euhedral titanite and monazite grains from distinct albitites are 110 ± 8 and 98 ± 2 Ma, respectively. The zircon U–Th–Pb isotopic system did not record this Cretaceous metasomatic event, even when grains were selected in metasomatically Zr-enriched rocks or in hydrothermal structures (millimetre-sized veins cross-cutting granitoids). We argue that the total time span of 20 Ma recorded by albitites corresponds to a long-lived hydrothermal system that was active during the rotation of Iberia around Europe, along the North Pyrenean Fault. Because albitization and talc mineralization have the same spatial and temporal distribution in the Pyrenees, we argue that these two metasomatic phenomena are two independent records of this single, regional-scale, long-lived hydrothermal system.
Upper crust reworking during gravitational collapse: the Bembibre–Pico Sacro detachment system (NW Iberia)
Authors: Gómez Barreiro Juan , Catalán José R. Martínez , Díez Fernández Rubén , Arenas Ricardo , Díaz García Florentino
Published: June 2010

The kinematics of the basal allochthon in the SW of the Órdenes Complex is analysed to constraint its evolution during collisional and postcollisional stages of the Variscan orogeny. Two distinct sequences have been identified in the basal allochthon of this sector: the upper and lower sequences, in close correlation with the subdivision of the basal allochthon in the Malpica–Tui Complex. Three main tectonic episodes have been established in the basal allochthon: a high-pressure event related to continental subduction, a mesozonal event of regional exhumation by thrusting and recumbent folding, and a regional-scale extensional episode that resulted in the development of the Bembibre–Pico Sacro detachment system. The Bembibre–Pico Sacro system rejuvenated pre-existing shear zones, whose weakness favoured the nucleation of the detachments. Shear zones associated with the detachments overprinted the previous tectonic fabrics under conditions ranging from lower amphibolite to greenschist facies, and with heterogeneously distributed ductile to brittle deformation. The detachment system is coeval with late orogenic collapse and widespread magmatism, and represents its upper crustal expression. It correlates with mid- and lower crustal flow and the development of gneiss domes at depth in such a way that the basal allochthon can be considered a rheological boundary between the more rigid allochthonous sequences above and the more viscous Schistose Domain and autochthon below.
The Plio-Quaternary magmatic feeding system beneath Gran Canaria (Canary Islands, Spain): constraints from thermobarometric studies
Authors: Aulinas M. , Gimeno D. , Fernandez-Turiel J.L. , Perez-Torrado F.J. , Rodriguez-Gonzalez A. , Gasperini D.
Published: June 2010

A complete framework of chronostratigraphic, petrographic, geochemical and thermobarometric data allows a reinterpretation of the evolution of the Plio-Quaternary volcanism in Gran Canaria. Bulk-rock and mineral chemistry has been used to define
P
–
T
crystallization paths, based on clinopyroxene–melt thermobarometry. Mafic magmas mainly crystallized at mantle depths (17–22 km) with secondary fractionation at crustal levels (1.5–8.0 km), suggesting multistage magma ascent. Crystallization of evolved magmas took place at crustal depths (3–15 km). The complexity of the magmatic plumbing system increased in the last 1 Ma, as shown by the presence of reverse zoned clinopyroxenes in the lavas, with green diopside–hedenbergite cores surrounded by brown diopsidic rims. Petrographic and chemical features of such clinopyroxenes support a xenocrystic origin of the green cores, related to magma mixing or mingling processes between pre-existing colder evolved magmas and new batches of hot basic magmas. The evolution of the magmatic feeding system beneath Gran Canaria was affected by the long-term uplift of the island as a result of lithospheric flexure caused by loading of the neighbouring island of Tenerife. This uplift favoured the generation of giant landslides and nesting of the recent volcanic activity (the last 1 Ma) within landslide basins. The association of rifts, giant landslides and nested volcanism with a higher degree of magmatic differentiation is proposed to constrain the plumbing system model.
First record of the Early Toarcian Oceanic Anoxic Event from the Southern Hemisphere, Neuquén Basin, Argentina
Authors: Al-Suwaidi A.H. , Angelozzi G.N. , Baudin F. , Damborenea S.E. , Hesselbo S.P. , Jenkyns H.C. , Manceñido M.O. , Riccardi A.C.
Published: June 2010

The first record of the Early Toarcian Oceanic Anoxic Event (
c
. 183 Ma) from the Southern Hemisphere is described from the Neuquén Basin, Argentina, identified chemostratigraphically on the basis of a relative increase in marine organic carbon and a characteristic negative carbon-isotope excursion (δ
13
C
org
) in bulk rock and fossil wood. The negative excursion of −6‰ in bulk organic carbon (falling to −31.3‰) crosses the boundary of the
tenuicostatum
–
hoelderi
Andean ammonite Zones, equivalent to the
tenuicostatum
–
falciferum
/
serpentinum
zones of Europe. These data indicate that the Early Toarcian Oceanic Anoxic Event was a global phenomenon.

Supplementary material:

A detailed stratigraphic log, chemostratigraphic data and nannofossil data are available at
http://www.geolsoc.org.uk/SUP18411
.
Privacy-preserving data publishing
Authors: Fung Benjamin C. M. , Wang Ke , Chen Rui , Yu Philip S.
Published: June 2010

The collection of digital information by governments, corporations, and individuals has created tremendous opportunities for knowledge- and information-based decision making. Driven by mutual benefits, or by regulations that require certain data to be published, there is a demand for the exchange and publication of data among various parties. Data in its original form, however, typically contains sensitive information about individuals, and publishing such data will violate individual privacy. The current practice in data publishing relies mainly on policies and guidelines as to what types of data can be published and on agreements on the use of published data. This approach alone may lead to excessive data distortion or insufficient protection.
Privacy-preserving data publishing
(PPDP) provides methods and tools for publishing useful information while preserving data privacy. Recently, PPDP has received considerable attention in research communities, and many approaches have been proposed for different data publishing scenarios. In this survey, we will systematically summarize and evaluate different approaches to PPDP, study the challenges in practical data publishing, clarify the differences and requirements that distinguish PPDP from other related problems, and propose future research directions.
Security Primitives for Reconfigurable Hardware-Based Systems
Authors: Huffmire Ted , Levin Timothy , Nguyen Thuy , Irvine Cynthia , Brotherton Brett , Wang Gang , Sherwood Timothy , Kastner Ryan
Published: June 2010

Computing systems designed using reconfigurable hardware are increasingly composed using a number of different Intellectual Property (IP) cores, which are often provided by third-party vendors that may have different levels of trust. Unlike traditional software where hardware resources are mediated using an operating system, IP cores have fine-grain control over the underlying reconfigurable hardware. To address this problem, the embedded systems community requires novel security primitives that address the realities of modern reconfigurable hardware. In this work, we propose security primitives using ideas centered around the notion of “moats and drawbridges.” The primitives encompass four design properties: logical isolation, interconnect traceability, secure reconfigurable broadcast, and configuration scrubbing. Each of these is a fundamental operation with easily understood formal properties, yet they map cleanly and efficiently to a wide variety of reconfigurable devices. We carefully quantify the required overheads of the security techniques on modern FPGA architectures across a number of different applications.
Heartbeat of a nest
Authors: Ko Teresa , Ahmadian Shaun , Hicks John , Rahimi Mohammad , Estrin Deborah , Soatto Stefano , Coe Sharon , Hamilton Michael P.
Published: June 2010

We present a scalable end-to-end system for vision-based monitoring of natural environments, and illustrate its use for the analysis of avian nesting cycles. Our system enables automated analysis of thousands of images, where manual processing would be infeasible. We automate the analysis of raw imaging data using statistics that are tailored to the task of interest. These “features” are a representation to be fed to classifiers that exploit spatial and temporal consistencies. Our testbed can detect the presence or absence of a bird with an accuracy of 82%, count eggs with an accuracy of 84%, and detect the inception of the nesting stage within a day. Our results demonstrate the challenges and potential benefits of using imagers as biological sensors. An exploration of system performance under varying image resolution and frame rate suggest that an
in situ
adaptive vision system is technically feasible.
Dynamic sleep time control in wireless sensor networks
Authors: Ning Xu , Cassandras Christos G.
Published: June 2010

Idle listening is a major source of energy waste in wireless sensor networks. It can be reduced through Low-Power Listening (LPL) techniques in which a node is allowed to sleep for a significant amount of time. In contrast to conventional fixed sleep time policies, we introduce a novel dynamic sleep time control approach that further reduces control packet energy waste by utilizing known data traffic statistics. We propose two distinct approaches to dynamically compute the sleep time, depending on the objectives and constraints of the network. The first approach provides a dynamic sleep time policy that guarantees a specified average delay at the sender node resulting from packets waiting for the end of a sleep interval at the receiver. The second approach determines the optimal policy that minimizes total energy consumed. In the case where data traffic statistics are unknown, we propose an adaptive learning algorithm to estimate them online and develop corresponding sleep time computation algorithms. Simulation results are included to illustrate the use of dynamic sleep time control and to demonstrate how it dominates fixed sleep time methods. An implementation of our approach on a commercial sensor node supports the computational feasibility of the proposed approach.
Evaluating the multivariate visual quality performance of image-processing components
Authors: Radun Jenni , Leisti Tuomas , Virtanen Toni , Häkkinen Jukka , Vuori Tero , Nyman Göte
Published: June 2010

The estimation of image quality is a demanding task, especially when estimating different high-quality imaging products or their components. The challenge is the multivariate nature of image quality as well as the need to use naïve observers as test subjects, since they are the actual end-users of the products. Here, we use a subjective approach suitable for estimating the quality performance of different imaging device components with naïve observers—the interpretation-based quality (IBQ) approach. From two studies with 61 naïve observers, 17 natural image contents, and 13 different camera image signal processor pipelines, we determined the subjectively crucial image quality attributes and dimensions and the description of each pipeline's perceived image quality performance. We found that the subjectively most important image quality dimensions were color shift/naturalness, darkness, and sharpness. The first dimension, which was related to naturalness and colors, distinguished the good-quality pipelines from the middle- and low-quality groups, and the dimensions of darkness and sharpness described why the quality failed in the low-quality pipelines. The study suggests that the high-level concept naturalness is a requirement for high-quality images, whereas quality can fail for other reasons in low-quality images, and this failure can be described by low-level concepts, such as darkness and sharpness.
Neural modeling of flow rendering effectiveness
Authors: Pineo Daniel , Ware Colin
Published: June 2010

It has been previously proposed that understanding the mechanisms of contour perception can provide a theory for why some flow rendering methods allow for better judgments of advection pathways than others. In this article, we develop this theory through a numerical model of the primary visual cortex of the brain (Visual Area 1) where contour enhancement is understood to occur according to most neurological theories. We apply a two-stage model of contour perception to various visual representations of flow fields evaluated using the advection task of Laidlaw et al. In the first stage, contour
enhancement
is modeled based on Li's cortical model. In the second stage, a model of streamline
tracing
is proposed, designed to support the advection task. We examine the predictive power of the model by comparing its performance to that of human subjects on the advection task with four different visualizations. The results show the same overall pattern for humans and the model. In both cases, the best performance was obtained with an aligned streamline based method, which tied with a LIC-based method. Using a regular or jittered grid of arrows produced worse results. The model yields insights into the relative strengths of different flow visualization methods for the task of visualizing advection pathways.
Assessing Fit of Nontraditional Assistive Technologies
Authors: Randolph Adriane B. , Moore Jackson Melody M.
Published: June 2010

There is a variety of brain-based interface methods which depend on measuring small changes in brain signals or properties. These methods have typically been used for nontraditional assistive technology applications. Non-traditional assistive technology is generally targeted for users with severe motor disabilities which may last long-term due to illness or injury or short-term due to situational disabilities. Control of a nontraditional assistive technology can vary widely across users depending upon many factors ranging from health to experience. Unfortunately, there is no systematic method for assessing usability of nontraditional assistive technologies to achieve the best control. The current methods to accommodate users through trial-and-error result in the loss of valuable time and resources as users sometimes have diminishing abilities or suffer from terminal illnesses. This work describes a methodology for objectively measuring an individual’s ability to control a specific nontraditional assistive technology, thus expediting the technology-fit process.
ASSET queries
Authors: Chatziantoniou Damianos , Tzortzakakis Elias
Published: June 2010

Today's complex world requires state-of-the-art data analysis over truly massive data sets. These data sets can be stored persistently in databases or flat files, or can be generated in realtime in a continuous manner. An associated set is a collection of data sets, annotated by the values of a domain D. These data sets are populated using a data source according to a condition θ and the annotated value. An ASsociated SET (ASSET) query consists of repeated, successive, interrelated definitions of associated sets, put together in a column-wise fashion, resembling a spreadsheet document. We present DataMingler, a powerful GUI to express and manage ASSET queries, data sources and aggregate functions and the ASSET Query Engine (QE) to efficiently evaluate ASSET queries. We argue that ASSET queries: a) constitute a useful class of OLAP queries, b) are suitable for distributed processing settings, and c) extend the MapReduce paradigm in a declarative way.
Workshop on theory and practice of provenance event report
Authors: Cheney James
Published: June 2010

Provenance, or metadata about the creation, influences upon, or other history of objects or data, has attracted attention in a wide variety of contexts in computer science over the last few years. This event report describes a recent workshop on "Theory and Practice of Provenance", intended as a forum for presenting novel ideas about provenance and encouraging interaction among provenance researchers.
SIGMOD 2009 best demonstration competition
Authors: Jónsson Björn Pór
Published: June 2010

This report summarizes the best demonstration competition held during SIGMOD 2009. I first outline the evaluation process and then briefly describe the three best demonstrations. My conclusion is that the competition was a success and I hope that future demonstrations chairs will turn it into an established SIGMOD tradition.
Operating system development with ATS: work in progress
Authors: Danish Matthew , Xi Hongwei
Published: June 2010

Typical operating system design is marked by trade-offs between speed and reliability, features and security. Most systems are written in a low-level untyped programming language to achieve optimal hardware usage and for other practical reasons. But, this often results in CPU, memory, and I/O protection flaws due to mistakes in unverified code. On the other hand, fully verified systems are exceedingly hard to construct on any industrial scale. A high-level programming language, with an expressive type system suitable for systems programming, can help alleviate many of these problems without requiring the enormous effort of full verification.
Modular reasoning about invariants over shared state with interposed data members
Authors: Balzer Stephanie , Gross Thomas R.
Published: June 2010

Reasoning about object-oriented programs is difficult since such programs usually involve aliasing, and it is not easy to identify the ways objects can relate to each other and thus to confine a program's heap. In this paper, we address this problem in the context of a relationship-based programming language. In relationship-based programming languages, relationships are first-class citizens and allow a precise description of inter-object relationships. Relationships enforce a modularization discipline that is closer to the natural modularity inherent to many problem domains and that yields, as a result, program heaps that are DAGs. We further describe a mechanism, member interposition, that leverages the new modularization discipline and supports encapsulation of fields of shared objects. We have implemented the described modularization discipline and the mechanism of member interposition in the context of Rumer, a relationship-based programming language with support for contract specifications. We discuss the implications of member interposition for the modular verification of object invariants with an example. Relationships and interposed members provide an alternative to ownership type systems.
Resource typing in guru
Authors: Stump Aaron , Austin Evan
Published: June 2010

This paper presents a resource typing framework for the Guru verified-programming language, in which abstractions for various kinds of program resources can be defined. Implemented examples include reference-counted data, mutable arrays, and heap-allocated mutable aliased data. The approach enables efficient, type-safe programming with mutable and aliased data structures, with explicit deallocation (not garbage collection). We evaluate performance of the approach with two verified benchmarks, one involving mutable arrays, and another involving FIFO queues.
Free theorems for functional logic programs
Authors: Christiansen Jan , Seidel Daniel , Voigtländer Janis
Published: June 2010

Type-based reasoning is popular in functional programming. In particular, parametric polymorphism constrains functions in such a way that statements about their behavior can be derived without consulting function definitions. Is the same possible in a strongly, and polymorphically, typed functional logic language? This is the question we study in this paper. Logical features like nondeterminism and free variables cause interesting effects, which we examine based on examples and address by identifying appropriate conditions that guarantee standard free theorems or inequational versions thereof to hold. We see this case study as a stepping stone for a general theory, not provided here, involving the definition of a logical relation and other machinery required for parametricity arguments appropriate to functional logic languages.
Looking in the Mirror
Authors: Wagner Pat
Published: June 2010

What are the mistakes that even an experienced online trainer and educator can make? As resources for training and education collapse (time, budget, personnel), e-educators hunt for new efficiencies and shortcuts. However, we don't spend as much time as I think we should thinking about what we personally should be doing differently. I can't say I wasn't warned.
e-Learning Budgets Increase in the U.K.'s Voluntary Sector
Authors: Little Bob
Published: June 2010

A survey of learning technologies in the voluntary sector encompassing more than 80 charities, representing more than 50,000 staff and volunteers has found that the top four benefits of adopting learning technologies are: 1) improving flexibility of learning, 2) improving access to learning, 3) cutting costs and 4) increasing reach.
Cavity-Enhanced Direct Frequency Comb Spectroscopy: Technology and Applications
Authors: Adler Florian , Thorpe Michael J. , Cossel Kevin C. , Ye Jun
Published: June 2010

Cavity-enhanced direct frequency comb spectroscopy combines broad bandwidth, high spectral resolution, and ultrahigh detection sensitivity in one experimental platform based on an optical frequency comb efficiently coupled to a high-finesse cavity. The effective interaction length between light and matter is increased by the cavity, massively enhancing the sensitivity for measurement of optical losses. Individual comb components act as independent detection channels across a broad spectral window, providing rapid parallel processing. In this review we discuss the principles, the technology, and the first applications that demonstrate the enormous potential of this spectroscopic method. In particular, we describe various frequency comb sources, techniques for efficient coupling between comb and cavity, and detection schemes that utilize the technique's high-resolution, wide-bandwidth, and fast data-acquisition capabilities. We discuss a range of applications, including breath analysis for medical diagnosis, trace-impurity detection in specialty gases, and characterization of a supersonic jet of cold molecules.
Analysis of Water in Confined Geometries and at Interfaces
Authors: Fayer Michael D. , Levinger Nancy E.
Published: June 2010

The properties of water depend on its extended hydrogen bond network and the continual picosecond–time scale structural evolution of the network. Water molecules in confined environments with pools a few nanometers in diameter or at interfaces undergo hydrogen bond structural dynamics that differ drastically from the dynamics they undergo in bulk water. Orientational motions of water require hydrogen bond network rearrangement. Therefore, observations of orientational relaxation in nanoscopic water systems provide information about the influence of confinement and interfaces on hydrogen bond dynamics. Ultrafast infrared polarization- and wavelength-selective pump-probe experiments can measure the orientational relaxation of water and distinguish water at an interface from water removed from an interface. These experiments can be applied to water in reverse micelles (spherical nanopools). The results provide quantitative determination of the dynamics of water as a function of the size and nature of the confining structure.
Capillary Liquid Chromatography at Ultrahigh Pressures
Authors: Jorgenson James W.
Published: June 2010

Ultrahigh-pressure liquid chromatography (UHPLC) is a method of liquid chromatography utilizing sub-2-μm particles packed into capillary columns 25 to 100 cm long. Columns of this length packed with particles this fine require operation with pressures from 1,000 to 7,000 bar (15,000 to 100,000 psi). The advantages of this technique are high separation powers (theoretical plate counts from 100,000 to 300,000) and run times from a few minutes (isocratic) to a few hours (long gradients). This review discusses the background and theoretical basis of UHPLC, practical aspects of UHPLC hardware, examples of separations, future areas for research in UHPLC, and techniques that are both competitive with and complementary to UHPLC.
Chiral Separations
Authors: Stalcup A.M.
Published: June 2010

The main goal of this review is to provide a brief overview of chiral separations to researchers who are versed in the area of analytical separations but unfamiliar with chiral separations. To researchers who are not familiar with this area, there is currently a bewildering array of commercially available chiral columns, chiral derivatizing reagents, and chiral selectors for approaches that span the range of analytical separation platforms (e.g., high-performance liquid chromatography, gas chromatography, supercritical-fluid chromatography, and capillary electrophoresis). This review begins with a brief discussion of chirality before examining the general strategies and commonalities among all of the chiral separation techniques. Rather than exhaustively listing all the chiral selectors and applications, this review highlights significant issues and differences between chiral and achiral separations, providing salient examples from specific classes of chiral selectors where appropriate.
Single-Biomolecule Kinetics: The Art of Studying a Single Enzyme
Authors: Claessen Victor I. , Engelkamp Hans , Christianen, Peter C.M. , Maan Jan C. , Nolte Roeland J.M. , Blank Kerstin , Rowan Alan E.
Published: June 2010

The potential of single-enzyme studies to unravel the complex energy landscape of these polymeric catalysts is the next critical step in enzymology. From its inception in Rotman's emulsion experiments in the 1960s, the field of single-molecule enzymology has now advanced into the time-resolved age. Technological advances have enabled individual enzymatic turnover reactions to be observed with a millisecond time resolution. A number of initial studies have revealed the underlying static and dynamic disorder in the catalytic rates originating from conformational fluctuations. Although these experiments are still in their infancy, they may be able to relate the topography of the energy landscape to the biological function and regulation of enzymes. This review summarizes some of the experimental techniques and data-analysis methods that have been used to study individual enzyme molecules in search of a deeper understanding of their kinetics.