bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding and analysis of CAOS development in context: the case of China
Authors: Wang Zhelong , Jiang Ming , Gu Hong
Published: August 2008

Background

Computer‐assisted orthopaedic surgery (CAOS) has great advantages in precise determination of focus, planning an optimal surgical project and assuring the success of operation. In adopting CAOS, China is facing many problems, gaining experience and learning lessons.

Methods

A literature review of the current development of CAOS in China and case studies, including adopted CAOS systems, CAOS clinical applications in the orthopaedic field and emerging CAOS research in China was carried out. Experience and lessons gained through adopting CAOS in China are also illustrated and analysed.

Results and Discussion

In the course of investigating the current development of CAOS in China, existing problems were analysed, experience gained and lessons illustrated.

Conclusions

By summarizing the Chinese experience and lessons of adopting CAOS, we not only deliver an in‐depth understanding of present CAOS development and give advice for future CAOS development in China; this also has implications for other developing countries where CAOS development is burgeoning. Copyright © 2008 John Wiley & Sons, Ltd.
Carbon Nanotubes Conjugated to Tumor Lysate Protein Enhance the Efficacy of an Antitumor Immunotherapy
Authors: Meng Jie , Meng Jie , Duan Jinhong , Kong Hua , Li Li , Wang Chen , Xie Sishen , Chen Shuchang , Gu Ning , Xu Haiyan , Yang Xian‐Da
Published: August 2008

The biomedical applications of carbon nanotubes (CNTs) have attracted deep interest in recent years. Antitumor immunotherapy has the potential to improve the prognosis of cancer treatment but the efficacy of current immunotherapy generally needs further improvement. Multi‐walled CNTs conjugated to tumor lysate protein are investigated as to whether they would enhance the efficacy of an immunotherapy employing a tumor‐cell vaccine in a mouse model bearing the H22 liver cancer. The tumor cure rate is found to be markedly improved by CNTs conjugated to tumor lysate protein. The cellular antitumor immune reaction is also enhanced. Moreover, the observed antitumor immune response is relatively specific against the tumor intended for treatment. These findings suggest that CNTs may have a prospective role in the development of new antitumor immunotherapies.
Evaluation of modal incremental dynamic analysis, using input energy intensity and modified bilinear curve
Authors: Zarfam Panam , Mofid Massood
Published: August 2008

In this paper, a technique for the study of nonlinear performance of structures in different levels of earthquakes is developed. In this method, the Incremental Dynamic Analysis (IDA) curves are not achieved from nonlinear dynamic analysis of multi‐degree‐of‐freedom (MDF) structure. However, the procedure of constructing these curves is based on modelling of the entire structure with several single‐degrees‐of‐freedom (SDF) structures and evaluating them through the modal pushover analysis method. An innovative idea for approximating pushover curves that is based on error distribution is introduced in this investigation. Furthermore, the total input energy applied towards the SDF oscillator, which gets converted into MDF structure, is used as intensity measure to impose the different levels of scaled earthquakes.

This technique possesses all the advantages of the IDA method in studying the performance of structures in different levels of earthquake. In addition, it benefits from easy usage, high solving speed and less computational CPU time and in attendance with the modified bilinear curves. In this paper, six earthquake records have been applied over four different 4, 8, 12 and 16‐storey structures. The structural responses derived by this method, in the format of multi‐modal incremental curves, containing maximum displacement, drift, hinge rotation and hysteretic energy at the end of the earthquake, have been compared with the IDA method. Comparison of the results is found to have acceptable precision and reveals good agreement between two methods. Copyright © 2008 John Wiley & Sons, Ltd.
Sodium Cardanol Sulfonate Surfactant from Cashew Nut Shell Liquid
Authors: Peungjitton Passapan , Sangvanich Polkit , Pornpakakul Surachai , Petsom Amorn , Roengsumran Sophon
Published: August 2008

Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.
Sports in the Human Economy: “Leibesübungen,” Medicine, Psychology, and Performance Enhancement during the Weimar Republic
Authors: Hau Michael
Published: August 2008

In 1926, the President of the GermanReichCommittee for Physical Exercise (Deutscher Reichsausschuss für Leibesübungen, or DRAL) Theodor Lewald discussed the significance of sports for the German economy and national health in a presentation to the Berlin Chamber of Industry and Commerce. Lewald deplored the physical state of the German population as a consequence of the lost war. Two million of the physically and mentally strongest German men had been killed, while millions of German men, women, and children were permanently physically weakened as a result of starvation during the war and the allied hunger blockade after the armistice. To make matters worse, the hygienic benefits of military service that had guaranteed the physical strength and fitness of male youth had been lost. Prior to the war about 500,000 men had served in the German army or navy where they had learned regimens of cleanliness, order, and discipline. According to Lewald, by limiting the size of the German army to 100,000 men, the victorious allies had not only weakened Germany militarily, but they had also tried to paralyze Germany economically by permanently weakening the “strength of the German people” (deutsche Volkskraft).1
Echinococcus granulosus strain differentiation in Iran based on sequence heterogeneity in the mitochondrial 12S rRNA gene
Authors: Rostami Nejad M. , Nazemalhosseini Mojarad E. , Nochi Z. , Fasihi Harandi M. , Cheraghipour K. , Mowlavi G.R. , Zali M.R.
Published: August 2008

Parasite strain characterization is essential for the establishment of a prevention and control strategy in any endemic area. The aim of this study was to characterize different Echinococcus granulosus isolates from Iran by using DNA sequences of the mitochondrial 12S rRNA gene. Thirty livers and lungs of cattle, sheep and goats naturally infected with E. granulosus were collected from abattoirs in northern and western Iran between June and October 2007. These samples yielded 18 fertile cysts which we used for the genetic work. We designed and tested two new primer pairs which specifically amplify portions of the mitochondrial 12S rRNA gene of the two strains (G1 and G6) of E. granulosus known to occur in Iran. One primer pair amplified a fragment of 259 base pairs (bp) from only the G1 strain. The second pair amplified a fragment of 676 bp from the G6 strain. The G1 genotype was identified in all fertile cyst samples, in agreement with previous studies in Iran. Ten of our samples and a single reference sample of the G6 strain were sequenced and compared with the G1 and G6 sequences deposited in GenBank.
Sealer's sledge excavated on Livingston Island, South Shetland Islands
Authors: Pearson Michael , Stehberg Ruben , Zarankin Andres , Senatore Maria Ximena , Gatica Carolina
Published: August 2008

Details are provided of a sledge, possibly of late nineteenth/early twentieth century provenance, discovered on Byers Peninsula, Livingston Island, South Shetland Islands, in 2007.
On moduli of smoothness ofk-monotone functions and applications
Authors: KOPOTUN KIRILL
Published: August 2008

Letkbe the set of allk-monotone functions on (−1, 1), i.e., those functionsffor which thekth divided differences [x0,. . .,xk;f] are nonnegative for all choices of (k+1) distinct pointsx0,. . .,xkin (−1, 1). We obtain estimates (which are exact in a certain sense) ofkth Ditzian–Totikq-moduli of smoothness of functions ink∩p(−1, 1), where 1 ≤q<p≤ ∞, and discuss several applications of these estimates.
Investigating learner preparedness for and usage patterns of mobile learning
Authors: Stockwell Glenn
Published: August 2008

While the use of mobile devices for language learning has sparked the interest of an increasing number of researchers in recent years (e.g., Aizawa & Kiernan, 2003; Thornton & Houser, 2005), our knowledge of learners' preferences for the mobile platform and their usage patterns remains limited. Are learners prepared to use mobile phones for performing language learning activities, or is there still a preference for desktop computer environments? Do learners make attempts to use mobile phones and then opt for a desktop computer instead? When and where do those learners who choose to use mobile phones use them, and why do they choose them? The current study investigated 75 learners of English at a Japanese university who were assigned vocabulary learning activities which they could choose to complete on either a mobile phone or desktop computer. It sought to determine their intentions to use mobile phones for language learning if other options were available, to compare this with their actual usage patterns, and to determine when and why learners used mobile phones. Learner attitudes and preferences were elicited through a post-survey, and usage patterns were determined through analysis of detailed server logs. The results are discussed in terms of the readiness of learners to undertake mobile-based language learning activities, and the issues having an effect on the establishment of the mobile phone as a language learning tool.
Seed germination of six coastal plant species of the Baltic region: effect of salinity and dormancy-breaking treatments
Authors: Necajeva Jevgenija , Ievinsh Gederts
Published: August 2008

Seed salinity tolerance and dormancy play important roles in germination behaviour. The effects of NaCl concentration and different dormancy-breaking treatments on germination were determined for six species growing on the coasts of the Baltic Sea or the Gulf of Riga: Juncus balticus, Triglochin maritima, Triglochin palustre, Anthyllis maritima, Linaria vulgaris and Linaria loeselii. Germination percentages were significantly reduced at NaCl concentrations >100 mM. Germination of J. balticus, T. maritima and T. palustre, but not that of A. maritima and L. vulgaris, recovered after seeds were rinsed with distilled water. Seeds of J. balticus were non-dormant; those of A. maritima had physical dormancy; and those of T. palustre, T. maritima, L. loeselii and L. vulgaris had non-deep to intermediate physiological dormancy, which was broken by cold stratification or gibberellic acid. The seeds of plants growing in habitats periodically exposed to sea water (coastal meadows) were characterized by greater salinity tolerance than seeds of plants growing in habitats less exposed to sea water (dunes).
Comparison of simple sequence repeat (SSR) and diversity array technology (DArT) markers for assessing genetic diversity in cassava (Manihot esculenta Crantz)
Authors: Hurtado P. , Olsen K. M. , Buitrago C. , Ospina C. , Marin J. , Duque M. , de Vicente C. , Wongtiem P. , Wenzel P. , Killian A. , Adeleke M. , Fregene M.
Published: August 2008

Several molecular marker systems have been developed for assessing genetic diversity in crop germplasm collections. A trade-off often exists between the number of loci that can feasibly be sampled by a marker system and the amount of information provided by each locus. We compared the usefulness of two marker systems for revealing genetic diversity and population structure in cassava (Manihot esculenta Crantz): simple sequence repeats (SSRs) and diversity array technology (DArT) markers. DArTs survey many more loci per reaction than do SSRs; however, as bi-allelic, dominant markers, DArTs provide less polymorphism information per locus. Genetic differentiation was assessed in a randomly selected set of 436 cassava accessions, consisting of 155 African and 281 Latin American accessions. A genome-wide set of 36 SSR markers and a DArT array of approximately 1000 polymorphic clones were used to assess genetic diversity and differentiation. Cluster analyses were performed using principal coordinate analysis (PCoA). Results were compared with a priori expectations of genetic differentiation based on previous genetic analyses. Analyses of the two datasets generated broadly similar clustering patterns. However, SSRs revealed greater differentiation than DArTs, and more effectively recovered patterns of genetic differentiation observed in previous analyses (differentiation between Latin American and African accessions, and some geographical differentiation within each of these groups). These results suggest that SSR markers, while low throughput in comparison with DArTs, are relatively better at detecting genetic differentiation in cassava germplasm collections. Nonetheless, DArTs will likely prove useful in ‘orphan crop’ species, where alternative molecular markers have not been developed.
Ductile deformation of passive margins: A new mechanism for subduction initiation
Authors: Goren L. , Aharonov E. , Mulugeta G. , Koyi H. A. , Mart Y.
Published: August 2008

The onset of subduction at passive margins has been extensively investigated and debated. However, the force constellations and mechanisms that enable the development of a subduction system from a passive margin remain unclear. This study presents new insights into the conditions and processes by which lateral density differences between oceanic and continental lithospheres in passive margins may lead to initiation of a low‐angle subduction system. The presented study consists of (1) analytical calculations of flow fields generated in passive margins, and (2) analogue experiments of mature passive margins performed in a centrifuge. The analytical formulation predicts temporal and spatial evolution of an interface between the oceanic and continental lithospheres, and demonstrates that oceanic underthrusting may occur by rotation of this interface. The analogue experiments show that incipient subduction may develop by ductile deformation within the lithosphere, involving no sliding along the ocean‐continent interface, so that the frictional resistance between the plates need not be overcome. The force induced by the negative buoyancy of the oceanic plate with respect to the asthenosphere, is found to be in some cases irrelevant to subduction nucleation. Results of both the analogue experiments and the analytical calculation are compared to the south‐east Australian passive margin, and show an excellent fit to its geometry and stress distribution. The proposed mechanism is also applied to the only two cases of subduction of Atlantic tectonic system, the Lesser‐Antilles and the South Sandwich subduction systems.
Comprehensive data set of global land cover change for land surface model applications
Authors: Sterling Shannon , Ducharne Agnès
Published: August 2008

To increase our understanding of how humans have altered the Earth's surface and to facilitate land surface modeling experiments aimed to elucidate the direct impact of land cover change on the Earth system, we create and analyze a database of global land use/cover change (LUCC). From a combination of sources including satellite imagery and other remote sensing, ecological modeling, and country surveys, we adapt and synthesize existing maps of potential land cover and layers of the major anthropogenic land covers, including a layer of wetland loss, that are then tailored for land surface modeling studies. Our map database shows that anthropogenic land cover totals to approximately 40% of the Earth's surface, consistent with literature estimates. Almost all (92%) of the natural grassland on the Earth has been converted to human use, mostly grazing land, and the natural temperate savanna with mixed C3/C4 is almost completely lost (∼90%), due mostly to conversion to cropland. Yet the resultant change in functioning, in terms of plant functional types, of the Earth system from land cover change is dominated by a loss of tree cover. Finally, we identify need for standardization of percent bare soil for global land covers and for a global map of tree plantations. Estimates of land cover change are inherently uncertain, and these uncertainties propagate into modeling studies of the impact of land cover change on the Earth system; to begin to address this problem, modelers need to document fully areas of land cover change used in their studies.
Measuring suprathermal electron parameters in space plasmas: Implementation of the quasi‐thermal noise spectroscopy with kappa distributions using in situ Ulysses/URAP radio measurements in the solar wind
Authors: Zouganelis I.
Published: August 2008

We discuss the implementation of the quasi‐thermal noise spectroscopy using kappa velocity distribution functions for the electrons. The quasi‐thermal noise spectroscopy is a powerful tool for in situ space plasma diagnostics based on the analysis of the electrostatic field spectrum produced by the quasi‐thermal fluctuations of electrons. The electron parameters are obtained by fitting the voltage power spectrum calculated with a model of the particle velocity distribution to the voltage measured at the terminals of an electric antenna. In the present work, the model of spectrum due to the electrons is depending on only three parameters and computed by assuming that the electron velocity distribution is a generalized Lorentzian or “kappa” distribution. The three fitted parameters are thus the electron density, total temperature and kappa index of the distribution. We show for the first time that this model produces good quality fittings for solar wind measurements obtained by the radio receiver on Ulysses, which should enable to improve the accuracy of the measurement of the total electron temperature and give better information on the suprathermal electrons.
Estimation of Earth interior parameters from a Bayesian inversion of very long baseline interferometry nutation time series
Authors: Koot L. , Rivoldini A. , de Viron O. , Dehant V.
Published: August 2008

Among the variations in the rotation of the Earth, the nutation is the most suitable for studying the Earth's internal structure. The nutation is mainly driven by the gravitational torque of the Moon, the Sun and the planets acting on its equatorial bulge. The Earth response to this external forcing is influenced by its internal structure. Because the gravitational forcing is known to a very good accuracy, the high precision nutation observations, using the very long baseline interferometry (VLBI) technique, allow to estimate Earth interior parameters. The nutational response of the nonrigid Earth to the gravitational forcing has previously been modeled by a semianalytic model which depends on parameters, related to the Earth interior, that are adjusted on the nutation observations. Those parameters are the dynamical ellipticities of the whole Earth and fluid core, compliances describing the deformability of the whole Earth and fluid core, and coupling constants related to the torques generated by the differential rotation of the mantle, fluid core and solid inner core. Most of the nutation models are frequency domain models so that, in previous studies, the time series of observations are processed before the fit in order to get data in the frequency domain. Because the parameters are fit only on the twenty dominant terms in the frequency domain, this fit leads to a loss of information. In this paper, we present a new fit procedure of the nutation model to the observations, which estimates the Earth's parameters directly from the time series of nutation data. This allows to use all the information of the time domain data and to account for the time variable uncertainties on the data (this time variability is due to the improvement of the measurement techniques). Rather than the linearized least squares method used in previous studies, we use a probabilistic (Bayesian) inversion method. This method does not rely on the assumption that the model is linear in its parameters, it is thus particularly well‐suited for the highly nonlinear nutation model. In addition, we include an additional parameter to allow for uncertainties in the nutation model itself. This parameter is estimated jointly with the geophysical parameters. As result, we obtain a probability distribution on the parameters. The numerical results are compared with those obtained from previous studies.
Seismic structure of the crust and the upper mantle beneath the Himalayas: Evidence for eclogitization of lower crustal rocks in the Indian Plate
Authors: Monsalve G. , Sheehan A. , Rowe C. , Rajaure S.
Published: August 2008

Variations in the seismic velocity structure of the Himalayan collision zone include significant differences between its north and south portions, with transitions in physical properties across the Greater Himalaya. We combined P‐ and S‐wave traveltimes from a temporary broadband seismic network in eastern Nepal and southern Tibet with arrival times at the permanent station network of the Department of Mines and Geology of Nepal to determine the seismic velocity structure across the Himalaya, using local earthquake tomography and traveltimes of regional earthquakes. The P‐to‐S velocity ratio (Vp/Vs) structure marks the difference between the Indian Plate and the overlying materials, with the Vp/Vs ratios being high for the former and low for the latter. We also found a significant increase in the uppermost mantle seismic velocities from south to north, reaching P‐wave velocities (Vp) over 8.4 km/s north of the Greater Himalaya. These high Vp values do not seem to be the result of biases due to anisotropy in the upper mantle beneath the Greater and Tethyan Himalayas. Instead, we suggest that rocks in the lower crust of the underthrusting Indian Plate undergo metamorphism to eclogite as they plunge to greater depth beneath the mountain range, explaining the high seismic velocities.
Hadley circulation signal in the tropical cyclone frequency over the western North Pacific
Authors: Zhou Botao , Cui Xuan
Published: August 2008

The relationship between the boreal spring (March–May) Hadley circulation (HC) and the following summer (June–September) tropical cyclone (TC) frequency expressed as the total number of TCs in the western North Pacific is investigated through using the observed data. Results show that the spring HC is negatively correlated to the summer TC frequency. Such a relationship can be explained by the changes of the atmospheric circulations related to anomalous spring HC. A strong spring HC is followed by the weaker East Asian monsoon, stronger vertical zonal wind shear, and reduced convection over the western North Pacific in summer, which are unfavorable for TC genesis, and vice versa. The potential mechanism of how the spring HC affects the summer atmospheric circulations is also preliminarily identified. It is found that sea surface temperature (SST) anomalies in the Indian Ocean and the South China Sea may play important roles, since an anomalous spring HC can excite simultaneous SST anomalies, which can persist to the following summer and in turn give rise to the atmospheric anomalies associated with TC activities. Thus the variation of the spring HC can be a potential indicator in predicting summer TC activities over the western North Pacific.
Forcing mechanism of the seasonally asymmetric quasi‐biennial oscillation secondary circulation in ERA‐40 and MAECHAM5
Authors: Peña‐Ortiz C. , Ribera P. , García‐Herrera R. , Giorgetta M. A. , García R. R.
Published: August 2008

The seasonality of the quasi‐biennial oscillation (QBO) and its secondary circulation is analyzed in the European Reanalysis (ERA‐40) and Middle Atmosphere European Centre Hamburg Model (MAECHAM5) general circulation model data sets through the multitaper method‐singular value decomposition (MTM‐SVD). In agreement with previous studies, the results reveal a strong seasonal dependence of the QBO secondary circulation. This is characterized by a two‐cell structure symmetric about the equator during autumn and spring. However, anomalies strongly weaken in the summer hemisphere and strengthen in the winter hemisphere, leading to an asymmetric QBO secondary circulation characterized by a single‐cell structure displaced into the winter hemisphere during the solstices. In ERA‐40, this asymmetry is more pronounced during the northern than during the southern winter. These results provide the first observation of the QBO secondary circulation asymmetries in the ERA‐40 reanalysis data set across the full stratosphere and the lower mesosphere, up to 0.1 hPa. The MTM‐SVD reconstruction of the seasonal QBO signals in the residual circulation and the QBO signals in Eliassen Palm (EP) flux divergences suggest a particular mechanism for the seasonal asymmetries of the QBO secondary circulation and its extension across the midlatitudes. The analysis shows that the QBO modulates the EP flux in the winter hemispheric surf zone poleward of the QBO jets. The zonal wind forcing by EP flux divergence is transformed by the Coriolis effect into a meridional wind signal. The seasonality in the stratospheric EP flux and the hemispheric differences in planetary wave forcing cause the observed seasonality in the QBO secondary circulation and its hemispheric differences.
Seasonal statistical characteristics of aerosol optical properties at a site near a dust region in China
Authors: Zheng Youfei , Liu Jianjun , Wu Rongjun , Li Zhanqing , Wang Biao , Tamio Takamura
Published: August 2008

A ground‐based sky radiometer was used to measure direct and diffuse solar irradiances at Dunhuang, China from January 1999 to March 2001. The aerosol optical thickness (AOT), Angstrom exponent (α), volume size distributions, single scattering albedo and refractive index of aerosols were simultaneously retrieved using the “SKYRAD” inversion code and their seasonal variations and statistical characteristics were studied. The results reveal that during the study period, the AOT at Dunhuang varied seasonally, with the maximum AOT occurring in the spring and the minimum AOT occurring in the fall. The variation in α showed an opposite pattern, with a minimum in the spring and a maximum in the fall. A simple exponential function can express the relationship between AOT and α. The frequency distributions of AOT and α approximately follow a lognormal probability distribution and a normal probability distribution, respectively. The aerosol volume size distributions can be characterized by the sum of two lognormals distributions, and represent an accumulation mode with a radius of about 0.25 um, and a coarse mode with a radius of about 7.7 um. A pseudomode with a radius of about 1.69 um located between the accumulation mode and coarse mode is present in the springtime. The single scattering albedo showed a slight increasing trend with wavelength in spring, summer and autumn and a decreasing trend with wavelength in winter. The maximum value of the real part of the refractive index occurs at 400 nm, and the minimum value occurs at 875 nm for all seasons. Two Gaussian models were developed to describe the frequency distribution of the real part of the aerosol refractive index; the results indicate that the differences between the fits are greatest in the spring. The statistical characteristics of the frequency distributions of aerosol properties might provide a way to identify and estimate aerosol optical properties in areas located near dust regions.
Quantification of variability in bedform geometry
Authors: van der Mark C. F. , Blom A. , Hulscher S. J. M. H.
Published: August 2008

We analyze the variability in bedform geometry in laboratory and field studies. Even under controlled steady flow conditions in laboratory flumes, bedforms are irregular in size, shape, and spacing, also in case of well‐sorted sediment. Our purpose is to quantify the variability in bedform geometry. We use a bedform tracking tool to determine the geometric variables of the bedforms from measured bed elevation profiles. For each flume and field data set, we analyze variability in (1) bedform height, (2) bedform length, (3) crest elevation, (4) trough elevation, and (5) slope of the bedform lee face. Each of these stochastic variables is best described by a positively skewed probability density function such as the Weibull distribution. We find that, except for the lee face slope, the standard deviation of the geometric variable scales with its mean value as long as the ratio of width to hydraulic radius is sufficiently large. If the ratio of width to hydraulic radius is smaller than about ten, variability in bedform geometry is reduced. An exponential function is then proposed for the coefficients of variation of the five variables to get an estimate of variability in bedform geometry. We show that mean lee face slopes in flumes are significantly steeper than those in the field. The 95% and 98% values of the geometric variables appear to scale with their standard deviation. The above described simple relationships enable us to integrate variability in bedform geometry into engineering studies and models in a convenient way.
Climatology and summer energy and water balance of polygonal tundra in the Lena River Delta, Siberia
Authors: Boike Julia , Wille Christian , Abnizova Anna
Published: August 2008

Meteorological and soil temperature and moisture data for the period 1998–2005 are presented from a long term monitoring station in the central Lena River Delta at 72°N, 126°E. The investigation site, Samoylov Island, is situated in the zone of continuous permafrost and is characterized by wet polygonal tundra. The summer energy and water balance of the tundra was analyzed for the dry year 1999 and the wet year 2003. The summer water balance of the tundra was found to be mainly controlled by precipitation. The partitioning of the available energy was controlled by precipitation via the soil moisture regime, and by the synoptic weather conditions via radiation and the advection of maritime cold or continental warm air masses. In 2003, regular high precipitation resulted in a constant recharge of polygonal ponds. Of the available energy, 61% were partitioned into latent heat flux and 17% into ground heat flux; hence, the tundra behaved like a typical wetland. In 1999, low precipitation resulted in a loss of polygonal pond waters and a drying of upper soil layers. This led to lower latent heat flux (31% of available energy), higher ground heat flux (29%), and a considerably higher soil thaw depth compared to 2003. Surface and subsurface water flow had a significant influence on the tundra water balance. In 2003, the formation of new surface flow channels through thermo‐erosion was observed, which is expected to have a strong and lasting influence on the hydrologic system of the tundra.
Late Tertiary faulting along the coastal plain of Israel
Authors: Steinberg J. , Gvirtzman Z. , Gvirtzman H. , Ben‐Gai Y.
Published: August 2008

This study documents a 70‐km long and 200–400 m high step at the base of the Pliocene section in the Israeli coastal plain. Depositional explanations for this lineament, such as a buried shelf edge or reef front, are very unlikely; whereas a fault scarp explanation is supported by seismic profiles and geological cross sections. The eastern elevated side of the fault was eroded before its burial, though a quantitive distinction between this erosion, earlier truncations, and original hiatuses, is not possible at this stage. Sediments covering the fault scarp constrain its age to Late Miocene and/or Early Pliocene. The presence of such a fault along the Israeli coastal plain may also shed light on numerous post‐Mid‐Cretaceous faults previously documented along the coastal plain, but never explained. In a wider perspective, the fault described here along with other documented processes indicate that in the Late Tertiary tectonism along the Levant continental margin resumed after a long passive history. This renewed activity is coeval with the Africa‐Arabian breakup and the Red Sea‐ Suez rifting. In particular, the fault described here is coeval with plate reorganization and vertical motions along the Dead Sea transform and possibly along the Cypriot Arc during the Late Miocene‐Early Pliocene.
University Camp Increases Student Interest in Science
Authors: White Michael A. , Turner Melissa , Litizzette Larry , Taylor Matthew J.
Published: August 2008

NASA, the U.S. National Science Foundation (NSF), and many other funding agencies are trying to increase student interest in science, technology, engineering, and mathematics careers. While rare experimental efforts have shown that factors such as small class size [Finn et al., 2001], community service [Markus et al., 1993], and targeted training [Zohar and Nemet, 2002] may improve student performance, the outcome of many educational activities is unclear or anecdotal [U.S. Department of Education, 2007].

With support from the NASA New Investigator Program in Earth Science (NIP), we used a statistical assessment to determine that participation in a summer science camp at Utah State University (USU), consisting of an 8‐week research experience, increased students' interest in science careers and fostered their intention to pursue activities likely to lead to a science career. Our results indicate that science‐based opportunities for high school students have beneficial effects and that broader research on the topic may be justified. In conducting our assessment, we also learned some valuable lessons that although perhaps familiar to science education specialists, may be useful and novel for AGU members interested in similar research.
Understanding Slow Slip, Tremor, and Quakes: Aseismic Slip, Tremor, and Earthquakes Workshop; Sidney, British Columbia, Canada, 25–28 February 2008
Authors: Gomberg Joan , Trehu Anne M. , Roeloffs Evelyn , Dragert Herb
Published: August 2008

The frequent occurrence and importance of slow slip and tremor have only recently become apparent, owing largely to advances in seismic and geodetic monitoring. At some plate boundaries, slow slip relaxes a significant fraction of accumulated tectonic stress. The radiation of seismic waves as tremor, which often accompanies the geodetically detected slow slip, arises from underlying physical processes that are poorly understood but appear to differ from those governing earthquake‐generated waves.

To further understanding of aseismic slip, tremor, and earthquakes, more than 52 participants contributed to a workshop with the goals of improving research coordination, assessing the earthquake hazard implications, and identifying ways to capitalize on the education and outreach opportunities these phenomena present.
Effect of dust absorption on the electron avalanche process occurring within Martian dust storms
Authors: Jackson Telana L. , Farrell William M. , Delory Greg T. , Nithianandam Jeyasingh
Published: August 2008

Martian dust devils and storms are believed to generate and maintain large‐scale E‐fields which may be strong enough to create a weakly ionized plasma in the low pressure CO2 atmosphere. Previous studies of the electron development included a determination of the avalanching electron growth via electron impact ionization with CO2 at electron energy levels above 14 eV. Townsend's first coefficient defining the path length for impact ionization was calculated as a function of driving electric field. Such calculations demonstrated the growth of the electron avalanche but did not include any electron loss processes. Herein, we consider the effect of such a loss process: electron absorption by dust grains. The inclusion of electron‐dust absorption has a moderating effect, controlling electron avalanche growth. A critical E‐field to initiate the avalanche is derivable, with fields below ∼7 kV/m quenching the process but above 7 kV/m fully capable of stimulating electron growth in the storm.
An autocorrelation method to detect low frequency earthquakes within tremor
Authors: Brown Justin R. , Beroza Gregory C. , Shelly David R.
Published: August 2008

Recent studies have shown that deep tremor in the Nankai Trough under western Shikoku consists of a swarm of low frequency earthquakes (LFEs) that occur as slow shear slip on the down‐dip extension of the primary seismogenic zone of the plate interface. The similarity of tremor in other locations suggests a similar mechanism, but the absence of cataloged low frequency earthquakes prevents a similar analysis. In this study, we develop a method for identifying LFEs within tremor. The method employs a matched‐filter algorithm, similar to the technique used to infer that tremor in parts of Shikoku is comprised of LFEs; however, in this case we do not assume the origin times or locations of any LFEs a priori. We search for LFEs using the running autocorrelation of tremor waveforms for 6 Hi‐Net stations in the vicinity of the tremor source. Time lags showing strong similarity in the autocorrelation represent either repeats, or near repeats, of LFEs within the tremor. We test the method on an hour of Hi‐Net recordings of tremor and demonstrates that it extracts both known and previously unidentified LFEs. Once identified, we cross correlate waveforms to measure relative arrival times and locate the LFEs. The results are able to explain most of the tremor as a swarm of LFEs and the locations of newly identified events appear to fill a gap in the spatial distribution of known LFEs. This method should allow us to extend the analysis of Shelly et al. (2007a) to parts of the Nankai Trough in Shikoku that have sparse LFE coverage, and may also allow us to extend our analysis to other regions that experience deep tremor, but where LFEs have not yet been identified.
Origin of Jovian hiss in the extended Io torus
Authors: Wang Kaiti , Thorne Richard M. , Horne Richard B.
Published: August 2008

Plasma wave observations on Voyager, Ulysses, and Galileo have shown that whistler‐mode hiss at frequencies below one kHz is continuously present in the extended Io torus of Jupiter. Cyclotron resonant energies at frequencies below 1 kHz are extremely high (typically > MeV), and the Jovian resonant electron flux is too low to cause significant local wave amplification. We consequently explore the possibility that Jovian hiss could be generated elsewhere, and then propagate into the torus to form the observed hiss band. Based on previous studies of the properties and excitation region of Jovian chorus emissions, we demonstrate that whistler‐mode waves originating as discrete chorus emissions in the tenuous region from 10 to 15 RJ can refract and propagate inwards into the dense Io torus and there merge into a band of low‐frequency hiss. This proposed mechanism for the origin of Jovian hiss is analogous to the formation of plasmaspheric hiss at Earth.
Observations of relativistic electron precipitation from the radiation belts driven by EMIC waves
Authors: Rodger Craig J. , Raita Tero , Clilverd Mark A. , Seppälä Annika , Dietrich Sarah , Thomson Neil R. , Ulich Thomas
Published: August 2008

For some time theoretical modeling has shown that electromagnetic ion cyclotron (EMIC) waves should play an important role in the loss of relativistic electrons from the radiation belts, through precipitation into the atmosphere. Up to now there has been limited experimental evidence for relativistic electron precipitation driven by EMIC waves. In this paper we present case studies of events showing EMIC waves, observed by ground‐based pulsation magnetometers, which are linked to strong responses in a subionospheric precipitation monitor. This response is consistent with precipitation occurring near the plasmapause, where EMIC waves may resonate with relativistic electrons. At the same time there is only a weak response in a co‐located riometer chain, as expected for relativistic electron precipitation that penetrates deeply into the atmosphere.
Martian pedestal craters: Marginal sublimation pits implicate a climate‐related formation mechanism
Authors: Kadish Seth J. , Head James W. , Barlow Nadine G. , Marchant David R.
Published: August 2008

Pedestal craters on Mars are defined by an outward‐facing scarp forming a plateau perched tens of meters above the surrounding terrain. Their origin has been attributed to impact armoring of the surface and subsequent removal of inter‐crater terrain by either eolian deflation or sublimation of an ice‐rich substrate. We identified 2696 pedestal craters between ∼60°N and 60°S latitude; 98% are poleward of 33°N and 40°S. The majority of pedestal crater margins are smoothly sloped, but ∼3%, concentrated in Utopia Planitia and Malea Planum, display distinctive marginal pits. These pedestal crater scarps are anomalously tall (usually >80–100 m) and the pits resemble sublimation depressions seen on Earth and elsewhere on Mars, providing evidence for sublimation of volatiles in the scarp, where the armored surface has tapered. The pitted scarps provide insight into the origin of the general pedestal crater population, favoring formation via deposition of a volatile‐rich substrate, impact armoring, and sublimation of intervening volatiles. Crater densities and overlapping pedestal craters suggest multiple periods of emplacement and loss of these climate‐related, latitude‐dependent deposits throughout the Amazonian.
The influence of nonmigrating tides on the longitudinal variation of the equatorial electrojet
Authors: Lühr H. , Rother M. , Häusler K. , Alken P. , Maus S.
Published: August 2008

The climatological model of the equatorial electrojet, EEJM‐1, derived from Ørsted, CHAMP and SAC‐C satellite measurements provides the opportunity to investigate the longitudinal variation of the current strength in detail. Special emphasis is put in this study on the effect of nonmigrating tides. We have found that the influence of the diurnal eastward‐propagating mode with wavenumber‐3, DE3, is particularly strong. In polar orbiting satellite observations the DE3 tidal signal appears as a four‐peaked longitudinal structure. We have put special emphasis in our analysis to isolate the DE3 contribution from other sources contributing to the wavenumber‐4 structure in satellite data. The amplitude of the DE3 signature in the EEJ not only peaks during equinox seasons, but is also strong around the June solstice. When looking at the modulation of the EEJ intensity the DE3 accounts for about 25% during the months of April through September. It is thus the dominant cause for longitudinal variations. During December solstice months the influence of DE3 is negligible. A secondary three‐peaked longitudinal pattern emerges during solstice seasons when the DE3 influence is removed. From the data available it is, however, not clear whether this pattern is related to any tidal drivers.
On the diurnal cycle of deep convection, high‐level cloud, and upper troposphere water vapor in the Multiscale Modeling Framework
Authors: Zhang Yunyan , Klein Stephen A. , Liu Chuntao , Tian Baijun , Marchand Roger T. , Haynes John M. , McCoy Renata B. , Zhang Yuying , Ackerman Thomas P.
Published: August 2008

The Multiscale Modeling Framework (MMF), also called “superparameterization”, embeds a cloud‐resolving model (CRM) at each grid column of a general circulation model to replace traditional parameterizations of moist convection and large‐scale condensation. This study evaluates the diurnal cycle of deep convection, high‐level clouds, and upper troposphere water vapor by applying an infrared (IR) brightness temperature (Tb) and a precipitation radar (PR) simulator to the CRM column data. Simulator results are then compared with IR radiances from geostationary satellites and PR reflectivities from the Tropical Rainfall Measuring Mission (TRMM). While the actual surface precipitation rate in the MMF has a reasonable diurnal phase and amplitude when compared with TRMM observations, the IR simulator results indicate an inconsistency in the diurnal anomalies of high‐level clouds between the model and the geostationary satellite data. Primarily because of its excessive high‐level clouds, the MMF overestimates the simulated precipitation index (PI) and fails to reproduce the observed diurnal cycle phase relationships among PI, high‐level clouds, and upper troposphere relative humidity. The PR simulator results show that over the tropical oceans, the occurrence fraction of reflectivity in excess of 20 dBZ is almost 1 order of magnitude larger than the TRMM data especially at altitudes above 6 km. Both results suggest that the MMF oceanic convection is overactive and possible reasons for this bias are discussed. However, the joint distribution of simulated IR Tb and PR reflectivity indicates that the most intense deep convection is found more often over tropical land than ocean, in agreement with previous observational studies.
Changes in Body Weight and Waist Circumference Affect Incident Hypercholesterolemia During 7 Years of Follow‐up
Authors: Williams Paul T.
Published: August 2008

Objective: To assess whether changes in total and regional adiposity affect the odds for becoming hypercholesterolemic.

Methods and Procedures: Changes in BMI and waist circumference were compared to self‐reported physician‐diagnosed hypercholesterolemia in 24,397 men and 10,023 women followed prospectively in the National Runners' Health Study.

Results: Incident hypercholesterolemia were reported by 3,054 men and 519 women during (mean ± s.d.) 7.8 ± 1.8 and 7.5 ± 2.0 years of follow‐up, respectively. Despite being active, men's BMI increased by 1.15 ± 1.71 kg/m2 and women's BMI increased by 0.96 ± 1.89 kg/m2. The odds for developing hypercholesterolemia increased significantly in association with gains in BMI and waist circumferences in both sexes. A gain in BMI ≥2.4 kg/m2 significantly (P < 0.0001) increased the odds for hypercholesterolemia by 94% in men and 129% in women compared to those whose BMI declined (40 and 76%, respectively, adjusted for average of the baseline and follow‐up BMI, P < 0.0001). A gain of ≥6 cm in waist circumference increased men's odds for hypercholesterolemia by 74% (P < 0.0001) and women's odds by 70% (P < 0.0001) relative to those whose circumference declined (odds increased 40% at P < 0.0001 and 49% at P < 0.01, respectively adjusted for average circumference). BMI and waist circumference at the end of follow‐up were significantly associated (P < 0.0001) with the log odds for hypercholesterolemia in both men (e.g., coefficient ± s.e.: 0.115 ± 0.011 per kg/m2) and women (e.g., 0.119 ± 0.019 per kg/m2) when adjusted for baseline values, whereas baseline BMI and circumferences were unrelated to the log odds when adjusted for follow‐up values.

Discussion: These observations are consistent with the hypothesis that weight gain acutely increases the risk for hypercholesterolemia.