bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulmonary sequestration of the left upper lobe associated with a bronchogenic cyst: Case report of an exceptional association
Authors: Barbut J. , Fernandez C. , Blanc F. , Dubus J.C. , Guys J.M. , de Lagausie P.
Published: December 2010

Intralobar pulmonary sequestration (ILPS) and bronchogenic cyst are rare congenital diseases. We present the first case of the association between an ILPS located in the upper lobe and a bronchogenic cyst. This association has been discovered antenatally in a girl. The cystic lesion has been shown by a fetal MRI and confirmed by a CT scan at 3 weeks of life. She underwent a left upper lobectomy by thoracoscopy at the age of 5 months. Postoperative course was uneventfull. This case confirms the congenital origin of pulmonary sequestration and shows the interest of an early surgery. Pediatr. Pulmonol. 2011; 46:509–511. © 2010 Wiley‐Liss, Inc.
Enhancing the performance of EWMA charts
Authors: Abbas Nasir , Riaz Muhammad , Does Ronald J. M. M.
Published: December 2010

Control charts are extensively used in processes and are very helpful in determining the special cause variations so that a timely action may be taken to eliminate them. One of the charting procedures is the Shewhart‐type control charts, which are used mainly to detect large shifts. Two alternatives to the Shewhart‐type control charts are the cumulative (CUSUM) control charts and the exponentially weighted moving average (EWMA) control charts that are specially designed to detect small and moderately sustained changes in quality. Enhancing the ability of design structures of control charts is always desirable and one may do it in different ways. In this article, we propose two runs rules schemes to be applied on EWMA control charts and evaluate their performance in terms of the Average Run Length (ARL). Comparisons of the proposed schemes are made with some existing representative CUSUM and EWMA‐type counterparts used for small and moderate shifts, including the classical EWMA, the classical CUSUM, the fast initial response CUSUM and EWMA, the weighted CUSUM, the double CUSUM, the distribution‐free CUSUM and the runs rules schemes‐based CUSUM. The findings of the study reveal that the proposed schemes are able to perform better than all the other schemes under investigation. Copyright © 2010 John Wiley & Sons, Ltd.
Reduced‐order design of high‐order sliding mode control system
Authors: Pan Yaodong , Kumar Krishna Dev , Liu Guangjun
Published: December 2010

To design an rth (r>2) order sliding mode control system, a sliding variable and its derivatives of up to (r − 1) are in general required for the control implementation. This paper proposes a reduced‐order design algorithm using only the sliding variable and its derivatives of up to (r − 2) as the extension of the second‐order asymptotic sliding mode control. For a linear time‐invariant continuous‐time system with disturbances, it is found that a high‐order sliding mode can be reached locally and asymptotically by a reduced‐order sliding mode control law if the sum of the system poles is less than the sum of the system zeros. The robust stability of the reduced‐order high‐order sliding mode control system, including the convergence to the high‐order sliding mode and the convergence to the origin is proved by two Lyapunov functions. Simulation results show the effectiveness of the proposed control algorithm. Copyright © 2010 John Wiley & Sons, Ltd.
The impact of science content and professional learning communities on science teaching efficacy and standards‐based instruction
Authors: Lakshmanan Aruna , Heath Barbara P. , Perlmutter Aaron , Elder Michael
Published: December 2010

This study examines the impact of standards‐based professional development on teacher efficacy and instructional practice of elementary and middle school science teachers. Professional development activities were conducted over a period of 3 years and included content courses as well as teacher involvement in professional learning communities. Teacher efficacy was assessed at five time points using the Science Teacher Efficacy Beliefs Instrument (STEBI), and instructional practice was evaluated at four time points with classroom observations using the Reformed Teaching Observation Protocol (RTOP). Results indicate that there was significant growth in teacher self‐efficacy but not in outcome expectancy. There was also significant growth in the extent to which teachers implemented inquiry‐based instruction in the classroom. Additionally, a positive correlation was observed between changes in self‐efficacy and changes in the use of inquiry‐based instructional practice. These results are discussed in terms of a model of teacher learning wherein changes in teacher beliefs and changes in classroom practice mutually influence each other, and also in terms of the impact of collaboration on teacher efficacy and practice. © 2010 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 534–551, 2011
Science student role: Evidence of social structural norms specific to school science
Authors: Shanahan Marie‐Claire , Nieswandt Martina
Published: December 2010

Sociocultural studies of science education have consistently recognized the dialectic nature of students' agency to create and author positions for themselves and the structural constraints that may influence them. This mixed‐methods study explores one particular aspect of these potential constraints: the possibility of a social structure specific to school science, using the concept of a science student role as an indicator. The first phase of the study was qualitative and exploratory, using open‐ended questionnaires and interviews to understand students' views of the expectations placed on them as science students (n = 95). The second phase was quantitative (using items developed from the qualitative analysis), with both exploratory and confirmatory elements (n = 157). Results suggest clear and explicit role understandings among these students, characterized by references to expectations of intelligence, experimental skill, scientific mindedness, and appropriate classroom behavior. The consistency of these expectations across genders, science teachers and schools provides evidence that there is an element of social structure specific to school science that needs to be considered in studies of student agency and identity. © 2010 Wiley Periodicals, Inc., Inc. J Res Sci Teach 48: 367–395, 2011
Supply chain collaboration: Impact on collaborative advantage and firm performance
Authors: Cao Mei , Zhang Qingyu
Published: December 2010

Facing uncertain environments, firms have strived to achieve greater supply chain collaboration to leverage the resources and knowledge of their suppliers and customers. The objective of the study is to uncover the nature of supply chain collaboration and explore its impact on firm performance based on a paradigm of collaborative advantage. Reliable and valid instruments of these constructs were developed through rigorous empirical analysis. Data were collected through a Web survey of U.S. manufacturing firms in various industries. The statistical methods used include confirmatory factor analysis and structural equation modeling (i.e., LISREL). The results indicate that supply chain collaboration improves collaborative advantage and indeed has a bottom‐line influence on firm performance, and collaborative advantage is an intermediate variable that enables supply chain partners to achieve synergies and create superior performance. A further analysis of the moderation effect of firm size reveals that collaborative advantage completely mediates the relationship between supply chain collaboration and firm performance for small firms while it partially mediates the relationship for medium and large firms.
Reassessment of Suicide Attempters at Home, Shortly After Discharge from Hospital
Authors: Verwey Bas , van Waarde Jeroen A. , Bozdağ Molla A. , van Rooij Iris , de Beurs Edwin , Zitman Frans G.
Published: December 2010

Background: Assessment of suicide attempters in a general hospital may be influenced by the condition of the patient and the unfavorable circumstances of the hospital environment. Aims: To determine whether the results of a reassessment at home shortly after discharge from hospital differ from the initial assessment in the hospital. Methods: In this prospective study, systematic assessment of 52 suicide attempters in a general hospital was compared with reassessment at home, shortly after discharge. Results: Reassessments at home concerning suicide intent, motives for suicide attempt, and dimensions of psychopathology did not differ significantly from the initial hospital assessment. However, patients’ motives for the suicide attempt had changed to being less impulsive and more suicidal, worrying was significantly higher, and self-esteem was significantly lower. A third of the patients had forgotten their aftercare arrangements and most patients who initially felt no need for additional help had changed their mind at reassessment. Conclusions: Results from this group of suicide attempters suggest that a brief reassessment at home shortly after discharge from hospital should be considered.
The Suicidal Process and Self-Esteem
Authors: Thompson Angus H.
Published: December 2010

Background: It has not been made clear whether self-esteem is associated with the severity of suicidal behavior. Aims: To test the association between responses to a self-esteem inventory and levels of suicidal behavior as conceptualized in the notion of the suicide process. Methods: Questions on the severity of suicidal behavior over the lifespan (death wishes, ideation, plans, and attempts), as well as a self-esteem inventory, were administered to 227 university undergraduates. Results: A negative relationship was found between the level of suicidality and self-esteem. As hypothesized, there were fewer cases in each succeeding level of seriousness of suicidal behavior. However, nearly all cases from any particular level were contained in the cohort of individuals who had displayed suicidal behavior at a less serious level. Conclusions: This suggests a possible progression through each of the stages of suicidal behavior, with very few cases showing a level of suicidal behavior that was not associated with a previous, less serious, form. It was hypothesized that early entry into the suicidal process may be indicated by low self-esteem, thus, allowing for a more timely preventive intervention.
Suicidal Ideation and Its Correlates in Prisoners
Authors: Zhang Jie , Grabiner Virginia E. , Zhou Yong , Li Ning
Published: December 2010

Background: Suicide is one of the leading causes of prisoners’ death, and, as a group, inmates have higher suicide rates than their community counterparts. However, the prevalence of suicidal ideation among Chinese inmates and their risks of suicide remain unknown. Aims: This study investigates the prevalence of suicidal ideation among Chinese incarcerated populations and its risk and protective factors. Methods: We randomly selected three types of prisoners (N = 690) and a sample of college students (n = 248) from four correction facilities and a police academy in China. A self-report questionnaire with standardized scales translated from the West was administered to the samples. Results: The prevalence of suicidal ideation among Chinese inmates is similar to that found among inmates in the West. The correlates of suicidal ideation for the Chinese inmates are also in line with what has been found in general populations. Conclusions: It is suggested that Chinese inmates have the same risk factors and protective factors for suicidal ideation as the general population in China. Suicide prevention in Chinese prisons can learn from and inform suicide prevention work for the general population.
Group velocity tomography of the Indo‐Eurasian collision zone
Authors: Acton C. E. , Priestley K. , Gaur V. K. , Rai S. S.
Published: December 2010

We present results of a Rayleigh and Love wave group velocity dispersion study of the Indo‐Eurasian collision zone. Group velocity dispersion curves are measured and combined to produce dispersion maps for 10–70 s period Rayleigh waves from 4054 paths and for 15–70 s Love waves from 1946 paths. Group velocity maps benefit from the inclusion of data recorded at a large number of stations within India, an advantage over previous global studies. This has the largest impact at short periods as a result of the improved path length distribution. Synthetic tests are used to estimate resolution, which ranges from 3° to 5° on the continents for Rayleigh wave maps and from 5° to 7.5° for Love wave maps. Group velocities correspond well with known geological and tectonic features and show good correlation with sediment thickness at short periods. The cratons of the Indian Shield can be distinguished in the short‐period and midperiod group velocities. Group velocities are slow across Tibet until 70 s whereas the cratonic cores of the Indian Shield appear as a high velocity anomaly at 70 s. Dispersion curves extracted from the Rayleigh wave group velocity maps are inverted for shear wave velocity as a function of depth for profiles across India and Tibet. The relationship between shear velocity contours and the Moho indicated by receiver function studies has been used to obtain a first‐order estimate of crustal thickness across the collision zone. Results suggest a slow Tibetan midcrust and low sub‐Moho velocities beneath the central and northeastern Tibetan Plateau.
A seismic swarm and regional hydrothermal and hydrologic perturbations: The northern Endeavour segment, February 2005
Authors: Hooft Emilie E. E. , Patel Hemalinee , Wilcock William , Becker Keir , Butterfield David , Davis Earl , Dziak Robert , Inderbitzen Katherine , Lilley Marvin , McGill Paul , Toomey Douglas , Stakes Debra
Published: December 2010

The February 2005 swarm at the overlapping spreading center (OSC) on the northern end of the Endeavour segment is the first swarm on the Juan de Fuca Ridge recorded on a local seafloor seismic network. The swarm included several larger earthquakes and caused triggered seismicity and a hydrothermal response in the Endeavour vent fields as well as regional‐scale hydrologic pressure perturbations. The spatial and temporal pattern of over 6000 earthquakes recorded during this seismic sequence is complex. Small‐magnitude events dominate, and seismicity rates wax and wane, indicating a magmatic process. The main swarm initiates at the northern end of the Endeavour ridge. However, most of the moment release, including six strike‐slip events, occurs in the southwest Endeavour Valley, where the swarm epicenters generally migrate south. The main swarm is contemporaneous with a hydrologic pressure response at four sealed seafloor boreholes, ∼25–105 km away. We infer that the seismic sequence is driven by a largely aseismic magma intrusion at the northern Endeavour axis. Resulting stress changes trigger slip on tectonic faults and possibly dike propagation at the opposing limb of the Endeavour OSC in the southwest Endeavour Valley, consistent with the eventual decapitation of the Endeavour by the West Valley segment. Furthermore, 2.5 days after the start of the main swarm, seismicity is triggered beneath the Endeavour vent fields, and temperature increases at a diffuse vent in the Mothra field. We infer that this delayed response is due to a hydrologic pressure pulse that diffuses away from the main magma intrusion.
Probability density functions for passive scalars dispersed in random velocity fields
Authors: Dentz Marco , Tartakovsky Daniel M.
Published: December 2010

Spatial and temporal heterogeneity of ambient natural environments play a significant role in large scale transport phenomena. Uncertainty about spatio‐temporal fluctuations in system parameters (e.g., flow velocity) make deterministic predictions of macroscopic system states (e.g., solute concentration) elusive. Distributions of system states generally exhibit highly non‐Gaussian behavior, which cannot be captured solely by the corresponding mean and variance. Instead, these features of transport are described by the probability density function (PDF) of a system state, e.g., the PDF of concentration at a certain point in space and time. We study the PDF of a passive scalar that disperses in a random velocity field. We derive an explicit map between the velocity distribution and the scalar PDF, and obtain approximate solutions for the PDF of the normalized scalar. These solutions enable one to quantify explicitly the impact of dispersion on the evolution of the passive scalar PDF without recurrence to classical closure approximations used in mixing models.
Observations of the relationship between frequency sweep rates of chorus wave packets and plasma density
Authors: Macúšová E. , Santolík O. , Décréau P. , Demekhov A. G. , Nunn D. , Gurnett D. A. , Pickett J. S. , Titova E. E. , Kozelov B. V. , Rauch J.‐L. , Trotignon J.‐G.
Published: December 2010

Chorus emissions are generated by a nonlinear mechanism involving wave‐particle interactions with energetic electrons. Discrete chorus wave packets are narrowband tones usually rising (sometimes falling) in frequency. We investigate frequency sweep rates of chorus wave packets measured by the Wideband data (WBD) instrument onboard the Cluster spacecraft. In particular, we study the relationship between the sweep rates and the plasma density measured by the WHISPER active sounder. We have observed increasing values of the sweep rate for decreasing plasma densities. We have compared our results with results of simulations of triggered emissions as well as with estimates based on the backward wave oscillator model for chorus emissions. We demonstrate a reasonable agreement of our experimental results with theoretical ones.
H+ and O+ content of the plasma sheet at 15–19 Re as a function of geomagnetic and solar activity
Authors: Mouikis C. G. , Kistler L. M. , Liu Y. H. , Klecker B. , Korth A. , Dandouras I.
Published: December 2010

We have used the ion composition data from the CIS/CODIF instrument on the Cluster spacecraft to determine how the H+ and O+ contribution to the plasma sheet density changes as a function of geomagnetic conditions and solar activity. The Cluster spacecraft are in a polar orbit that cut through the equatorial plasma sheet at ∼19 Re downtail for the first 5 years of the mission. We have restricted the data set to apogee time periods, from 15 to 19 Re, in order to give the composition at a clear position, which can then be used, for example, as a boundary condition for models. The geomagnetic conditions are described using the Kp index, while the solar activity is represented by the use of F10.7 index. Functional forms for these dependencies are provided. The statistical study covers the years from 2001 to 2005, which covers solar maximum, and the declining stage of the solar cycle. We find, as expected, that the O+ density in this region depends strongly on both solar EUV and geomagnetic activity. In addition, we find that there is a gradient in the O+/H+ density ratio, from the 15 to 19 Re plasma sheet to the 6.6 Re plasma sheet, indicating that there is significant additional entry of O+ inside of 15 Re.
Geophysical properties within the San Andreas Fault Zone at the San Andreas Fault Observatory at Depth and their relationships to rock properties and fault zone structure
Authors: Jeppson Tamara N. , Bradbury Kelly K. , Evans James P.
Published: December 2010

We examine the relationships between borehole geophysical data and physical properties of fault‐related rocks within the San Andreas Fault as determined from data from the San Andreas Fault Observatory at Depth borehole. Geophysical logs, cuttings data, and drilling data from the region 3‐ to 4‐km measured depth of the borehole encompass the active part of the San Andreas Fault. The fault zone lies in a sequence of deformed sandstones, siltstone, shale, serpentinite‐bearing block‐in‐matrix rocks, and sheared phyllitic siltstone. The borehole geophysical logs reveal the presence of a low‐velocity zone from 3190 to 3410 m measured depth with Vp and Vs values 10–30% lower than the surrounding rocks and a 1–2 m thick zone of active shearing at 3301–3303 m measured depth. Seven low‐velocity excursions with increased porosity, decreased density, and mud‐gas kick signatures are present in the fault zone. Geologic data on grain‐scale deformation and alteration are compared to borehole data and reveal weak correlations and inverse relationships to the geophysical data. In places, Vp and Vs increase with grain‐scale deformation and alteration and decrease with porosity in the fault zone. The low‐velocity zone is associated with a significant lithologic and structural transition to low‐velocity rocks, dominated by phyllosilicates and penetratively foliated, sheared rocks. The zone of active shearing and the regions of low sonic velocity appear to be associated with clay‐rich rocks that exhibit fine‐scale foliation and higher porosities that may be a consequence of the fault‐related shearing of foliated and fine‐grained sedimentary rocks.
Subduction in the southern Caribbean: Images from finite‐frequency P wave tomography
Authors: Bezada M. J. , Levander A. , Schmandt B.
Published: December 2010

The eastern boundary of the Caribbean plate is marked by subduction of the Atlantic under the Lesser Antilles. The southeastern plate boundary is characterized by a strike‐slip margin, while different configurations of subduction of the southwest Caribbean under South America have been proposed. We investigate the slab geometry in the upper mantle using multiple‐frequency, teleseismic P wave tomography. Waveforms from P and PKPdf phases from 285 (Mb > 5.0) events occurring at epicentral distances from 30° to 90° and greater than 150° were bandpass filtered and cross‐correlated to obtain up to three sets of delay times for each event. The delay times were inverted using approximate first Fresnel zone sensitivity kernels. Our results show the subducting Atlantic slab, as well as a second slab in the west of the study area that we interpret as a subducting fragment of the Caribbean plate. Both slabs have steep dips where imaged and can be traced to depths greater than 600 km. These results are consistent with transition zone boundary topography as determined by receiver function analysis. The Atlantic slab extends continent‐ward south of the plate bounding strike‐slip margin. We interpret this extension as continental margin lithospheric mantle that is detaching from beneath South America and subducting along with the oceanic Atlantic slab. The steep subduction of the Caribbean occurs ∼500 km landward from the trench, implying an initial stage of shallow subduction as far to the east as the Lake Maracaibo‐Mérida Andes region, as has been inferred from intermediate depth seismicity.
A propagation model for the internal solitary waves in the northern South China Sea
Authors: Cai Shuqun , Xie Jieshuo
Published: December 2010

A two‐dimensional, regularized long‐wave equation model is developed to study the dynamic mechanisms of the propagation and evolution of the internal solitary waves (ISWs) in the northern South China Sea (SCS). It is shown that the bottom topography would cause the polarity reversal of ISWs, the change of the local wave crestline shape, and some diminution in wave amplitude; even if the ISWs are induced at the small sill channel along the Luzon Strait, they could propagate westward with their crestlines covering a large area in the latitudinal direction in the northern SCS. When there are two trains of ISWs propagating from the same source site with a time lag but different amplitudes of initial solitons, the latter train of ISWs with a larger amplitude may catch then swallow the former one with a smaller amplitude, and the wave amplitude of the merged ISW train decreases while the wave number increases. When there are two trains of ISWs propagating from the different source sites at the same time with the same amplitude of initial solitons, the crestlines of the two ISW trains may meet and a new leading soliton is induced at the connection point. Once the ISW trains collide with the island, before the island, a weak ISW train is reflected; behind the island, the former crestlines of the ISW train are torn by the island into two new trains, which may reconnect after passing around the island. The propagation direction, the wave amplitude, and the reconnection point of the new merged ISW train behind the island depend on the relative orientation of the original soliton source site to the island.
Analyzing the tidal‐related origin of subinertial flows through the Strait of Gibraltar
Authors: Bruno M. , Macías J. , González‐Vida J. M. , Vázquez A.
Published: December 2010

The effects of tidal dynamics on subinertial flows through the Strait of Gibraltar are analyzed. As found in previous studies, an empirical orthogonal function analysis of subinertial currents at the Camarinal Sill yields two dominant oscillation modes. The first mode presents a barotropic character and rather irregular fluctuations and it has been related to meteorological forcing. The second mode is baroclinic and presents a clear deterministic behavior with time that seems to be related to tidal forcing. Against the hypothesis proposed in previous studies stating that tidal mixing cycles explain the second mode, we show, by using a one‐dimensional numerical model of two‐layer immiscible shallow water, that the origin of this mode may basically be related to nonlinear interactions among the main semidiurnal tidal constituents through the advective terms in the momentum balance and other nonlinear terms in the volume conservation equations. That mode is also crucial to understanding the vertical shear time variations of the horizontal currents. In particular, it minimizes the differences in the maximum shear between neap and spring tides.
Extinction‐to‐backscatter ratios of Saharan dust layers derived from in situ measurements and CALIPSO overflights during NAMMA
Authors: Omar Ali , Liu Zhaoyan , Vaughan Mark , Thornhill Kenneth , Kittaka Chieko , Ismail Syed , Hu Yongxiang , Chen Gao , Powell Kathleen , Winker David , Trepte Charles , Winstead Edward , Anderson Bruce
Published: December 2010

We determine the extinction‐to‐backscatter (Sa) ratios of dust using (1) airborne in situ measurements of microphysical properties, (2) modeling studies, and (3) the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) observations recorded during the NASA African Monsoon Multidisciplinary Analyses (NAMMA) field experiment conducted from Sal, Cape Verde during August to September 2006. Using CALIPSO measurements of the attenuated backscatter of lofted Saharan dust layers, we apply the transmittance technique to estimate dust Sa ratios at 532 nm and a two‐color method to determine the corresponding 1064 nm Sa. This method yielded dust Sa ratios of 39.8 ± 1.4 and 51.8 ± 3.6 sr at 532 and 1064 nm, respectively. Second, Sa at both wavelengths is independently calculated using size distributions measured aboard the NASA DC‐8 and estimates of Saharan dust complex refractive indices applied in a T‐Matrix scheme. We found Sa ratios of 39.1 ± 3.5 and 50.0 ± 4 sr at 532 and 1064 nm, respectively, using the T‐Matrix calculations applied to measured size spectra. Finally, in situ measurements of the total scattering (550 nm) and absorption coefficients (532 nm) are used to generate an extinction profile that is used to constrain the CALIPSO 532 nm extinction profile and thus generate a stratified 532 nm Sa. This method yielded an Sa ratio at 532 nm of 35.7 sr in the dust layer and 25 sr in the marine boundary layer consistent with a predominantly sea‐salt aerosol near the ocean surface. Combinatorial simulations using noisy size spectra and refractive indices were used to estimate the mean and uncertainty (one standard deviation) of these Sa ratios. These simulations produced a mean (± uncertainty) of 39.4 (±5.9) and 56.5 (±16.5) sr at 532 and 1064 nm, respectively, corresponding to percentage uncertainties of 15% and 29%. These results will provide a measurements‐based estimate of the dust Sa for use in backscatter lidar inversion algorithms such as CALIOP (Cloud‐Aerosol Lidar With Orthogonal Polarization).
Exploring summertime organic aerosol formation in the eastern United States using a regional‐scale budget approach and ambient measurements
Authors: Murphy Benjamin N. , Pandis Spyros N.
Published: December 2010

We present a new method for estimating the overall organic aerosol (OA) formation rate at the regional scale using a chemical transport model (CTM), PMCAMx‐2008, and an extensive set of measurements (Speciation Trends Network, Interagency Monitoring of Protected Visual Environments, Pittsburgh Air Quality Study, Southeastern Aerosol Research and Characterization) for the eastern United States. PMCAMx‐2008 takes into account up‐to‐date OA formation theory including primary OA evaporation, updated secondary OA (SOA) yields from traditional volatile organic precursor gases and multigenerational oxidation chemistry (aging) of vapors from anthropogenic sources, which lowers the volatility of the OA distribution over time. An overall OA formation rate of 22 ± 5 ktons d−1 is consistent with available measurements for this summer time period. We perform an extensive sensitivity analysis of uncertain OA model processes to demonstrate the relationship between the estimated total OA production rate and model performance. Perturbing, within reasonable limits, emissions of volatile precursors, SOA yields from isoprene oxidation, and the solubility of organic vapors produces model predictions for total OA that deviate little from the base case performance. The fractional error and fractional bias vary by less than 6% and 13%, respectively. These cases also result in total OA formation rates within 5 ktons d−1 of the base case. Neglecting chemical aging of anthropogenic OA components results in OA levels significantly lower than the observations everywhere, while aging biogenic SOA with the same parameters used for the base case anthropogenic SOA aging results in overpredictions in both the South and Midwest United States. Aging biogenic and anthropogenic SOA together with a reduced aging reaction rate results in reasonable model performance and an OA formation rate of ∼23 ktons d−1. This suggests that even though uncertainties in the OA aging mechanism and other important parameters may lead to uncertainties in the contributions of specific OA formation pathways, the proposed approach may be used to infer upper and lower limits on the total OA mass formation rate.
Airborne pollen in three European cities: Detection of atmospheric circulation pathways by applying three‐dimensional clustering of backward trajectories
Authors: Makra László , Sánta Tamás , Matyasovszky István , Damialis Athanasios , Karatzas Kostas , Bergmann Karl‐Christian , Vokou Despoina
Published: December 2010

The long‐range transport of particulates can substantially contribute to local air pollution. The importance of airborne pollen has grown due to the recent climate change; the lengthening of the pollen season and rising mean airborne pollen concentrations have increased health risks. Our aim is to identify atmospheric circulation pathways influencing pollen levels in three European cities, namely Thessaloniki, Szeged, and Hamburg. Trajectories were computed using the HYSPLIT model. The 4 day, 6 hourly three‐dimensional (3‐D) backward trajectories arriving at these locations at 1200 UT are produced for each day over a 5 year period. A k‐means clustering algorithm using the Mahalanobis metric was applied in order to develop trajectory types. The delimitation of the clusters performed by the 3‐D function “convhull” is a novel approach. The results of the cluster analysis reveal that the main pathways for Thessaloniki contributing substantially to the high mean Urticaceae pollen levels cover western Europe and the Mediterranean. The key pathway patterns for Ambrosia for Szeged are associated with backward trajectories coming from northwestern Europe, northeastern Europe, and northern Europe. A major pollen source identified is a cluster over central Europe, namely the Carpathian basin with peak values in Hungary. The principal patterns for Poaceae for Hamburg include western Europe and the mid‐Atlantic region. Locations of the source areas coincide with the main habitat regions of the species in question. Critical daily pollen number exceedances conditioned on the clusters were also evaluated using two statistical indices. An attempt was made to separate medium‐ and long‐range airborne pollen transport.
Different impacts of two types of Pacific Ocean warming on Southeast Asian rainfall during boreal winter
Authors: Feng Juan , Wang Lin , Chen Wen , Fong Soi Kun , Leong Ka Cheng
Published: December 2010

The impacts of conventional El Niño‐Southern Oscillation (ENSO) and ENSO Modoki on wintertime Southeast Asian rainfall and related mechanisms are studied using the method of partial regression and correlation and numerical simulations of a simple baroclinic model. Results show that the Southeast Asian rainfall associated with these two kinds of ENSO exhibits different spatial distributions. In the case of El Niño, wet conditions are observed over south China, and dry conditions are seen over the Philippines, Borneo, Celebes, and Sulawesi. In contrast, for El Niño Modoki, the negative rainfall anomalies around the Philippines are weaker and are located more northward compared to the El Niño counterpart. The different Southeast Asian rainfalls that are related to ENSO and ENSO Modoki are attributed to the different anomalous Walker circulation and low‐level anticyclone around the Philippines. Both the Philippine anticyclone and the descending branch center of the Walker circulation over the western North Pacific occupy a smaller domain and are located more northward during El Niño Modoki than during El Niño. All of these factors favor the difference in the Southeast Asian rainfall anomalies between the two events. Numerical experiments also suggest that the different low‐level atmospheric responses are mainly induced by different diabatic cooling over the western North Pacific related to El Niño and El Niño Modoki.
Mars without the equilibrium rotational figure, Tharsis, and the remnant rotational figure
Authors: Matsuyama I. , Manga M.
Published: December 2010

We use a revised partitioning of the planet figure into equilibrium and nonequilibrium contributions that takes into account the presence of an elastic lithosphere to study the Martian gravity field and shape. The equilibrium contribution is associated with the present rotational figure, and the nonequilibrium contribution is dominated by Tharsis and a remnant rotational figure supported by the elastic lithosphere that traces the paleopole location prior to the formation of Tharsis. We calculate the probability density functions for Tharsis' size and location, the paleopole location, and the global average thickness of the elastic lithosphere at the time Tharsis was emplaced. Given the observed degree‐3 spherical harmonic gravity coefficients, the expected Tharsis center location is 258.6 ± 4.2°E, 9.8 ± 0.9°N, where the uncertainties represent the 90% confidence interval. Given this Tharsis center location and the observed degree‐2 spherical harmonic gravity coefficients, the expected paleopole location prior to the emplacement of Tharsis is 259.5 ± 49.5°E, 71.1−14.4+17.5°N, and the expected elastic lithospheric thickness at the time of loading is 58−32+34km. Our estimated paleopole colatitude implies 18.9−17.5+14.4°of true polar wander (TPW) driven by the emplacement of Tharsis, in disagreement with previous studies that invoke large TPW. The remnant rotational figure is visible in both the nonequilibrium degree‐2 geoid (areoid) without Tharsis and the nonequilibrium degree‐2 topography without Tharsis. The remnant rotational figure is also visible in the total nonequilibrium geoid without Tharsis, but it is not visible in the total nonequilibrium topography without Tharsis due to the strong signal of the north‐south dichotomy. Shorter wavelength geological features become significantly more visible in the geoid with the removal of the long wavelength contributions of the equilibrium rotational figure, Tharsis, and the remnant rotational figure. Removal of the equilibrium rotational figure and Tharsis from the topography reveals a better defined north‐south dichotomy boundary.
Role of discharge variability on pseudomeandering channel morphodynamics: Results from laboratory experiments
Authors: Visconti F. , Camporeale C. , Ridolfi L.
Published: December 2010

Rivers experience a wide range of discharges. It is nowadays acknowledged that is not realistic to assume that the morphology of a river is influenced by only a single formative discharge. Rather, it is the full range of flows that are able to move sediments and erode banks that affect the fluvial morphology. Thus, the channel morphology emerges from the interactions between different competent discharges. A goal that has still not been completely achieved in geomorphology is the understanding of the role of discharge variability on river morphological processes. In this paper, we present the results of an experimental investigation concerning the impact of the sequencing of two competent discharges on a self‐forming pseudomeandering pattern. The inception of the pattern, the bar dynamics, and the bend erosion are investigated. A comparison of the experiments performed with steady and unsteady discharges has indicated the key role of the discharge variability in promoting and sustaining the pseudomeandering channel. These experimental findings shed light on some important morphological processes (bar deformation, low‐flow channel incision, and triggering of the bend inception) that are affected by discharge variations to a great extent, in agreement with some field studies and conceptual models.
High‐resolution dimethyl sulfide and dimethylsulfoniopropionate time series profiles in decaying summer first‐year sea ice at Ice Station Polarstern, western Weddell Sea, Antarctica
Authors: Tison J.‐L. , Brabant F. , Dumont I. , Stefels J.
Published: December 2010

High‐resolution profiles of ice dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) concentrations were measured together with a suite of ancillary physical and biological properties during a time series of decaying summer‐level first‐year sea ice throughout December 2004 during the Ice Station Polarstern drift experiment (western Weddell Sea, Antarctica). Ice DMSP and DMS concentrations were always maximum at the bottom of the ice sheet (636–2627 and 292–1430 nM, respectively) where the highest chlorophyll a levels were also found (15–30 μg L−1). Throughout the observation period, the autotrophic surface community (32–205 μg C L−1) was dominated by Phaeocystis sp. while the bottom community (1622–3830 μg C L−1) mainly consisted of pennate diatoms. This illustrates that, although being known for lower DMSP‐to‐chlorophyll a ratios than Phaeocystis sp., diatoms dominated the overall DMSP production because of their much larger biomass. Decreasing DMSP concentrations and increasing DMS‐to‐DMSP ratios in the bottom layers with time suggested active DMSP‐to‐DMS conversion in a slowly degrading environment. Drastic temporal brine volume and brine salinity changes associated with the decaying sea ice cover are shown to directly impact (1) the migration of DMSP and DMS through the brine network, (2) the DMSP‐to‐DMS conversion processes within the ice interior, and (3) the physiological response of the ice algae. First‐order flux estimates show that decaying summer‐level first‐year sea ice alone can significantly contribute to the regional sulfur budget of the Weddell Sea with an estimated average loss rate of 5.7 μmol DMS(P) m−2 d−1) toward the atmosphere and the ocean.
Lead identification and docking studies of metastatic protein human mitogen activated protein kinase kinase4
Authors: Meduru Harika , Pradhan Dibyabhaba , Munikumar Manne , Umamaheswari Amineni
Published: December 2010

Human dual specificity mitogen-activated protein kinase kinase 4 (MAP2K4) is a direct activator of MAP kinases in response to various environmental stresses or mitogenic stimuli. Upon phosphorylation, MAP2K4 has been shown to activate MAPK8, MAPK9 and MAPK14/p38 but not MAPK1/ERK2 or MAPK3/ERK1. Over expression of MAP2K4 causes carcinogenic effects, such as ovarian cancer, colorectal cancer, prostate cancer and pancreatic cancer. Our present study was carried out to design a potent drug molecule against MAP2K4 to control over expression. As there is no experimentally determined structure for MAP2K4, the homology modeling technique of Modeller9v7 was implemented to generate a MAP2K4 3D model based on the co-crystal structure of MAP2K6 (PDB ID: 3FME) with staurosporine. Twenty such models obtained were accessed through DOPE score, PROCHECK, ProSA and the highly reliable model was further optimized for virtual screening in Maestro v9.0 applying OPLS2001 force field. MAP2K4 specific inhibitors such as staurosporine, genistein and cayanidin were selected and screened against one million entries of the Ligand.Info Meta-Database, to generate an in house library of 1151 analogs. LigPrep was used to generate multiple conformations of the in-house ligands. In an effort to ensure good ADMET properties of the selected ligands Lipinski filter and reactive filter was applied. The strategic computational docking using Glide v5.5 ranked 10 lead molecules with good binding affinity with MAP2K4. Among ten lead molecules Lead ‘1’, Lead ‘2’, Lead ‘3’ had higher binding affinity than the published inhibitors. The scores for Lead ‘1’ -8.75, Lead ‘2’ -8.54, Lead ‘3’ -7.96 and scores for published inhibitors are STAUROSPORINE: -6.55; GENISTEIN: -6.42 and CAYANIDINE: -6.24. So Lead ‘1’ with the lowest docking score (-8.75kcal/mol) is the best ligand for protein functional activity inhibition. Lead ‘1’ directly binds to the MAP2K4 protein by forming strong hydrogen bonds with LYS-131, LEU-180, LYS-231, ASP-229. So we can consider that the lead ‘1’ molecule can act as a potent inhibitor for MAP2K4.
Docking studies to explore novel lead molecules for human Spleen tyrosine kinase involved in chronic lymphocytic leukemia
Authors: Kadaari Naveen , Pradhan Dibyabhaba , Munikumar Manne , Umamaheswari Amineni
Published: December 2010

B-cell chronic lymphocytic leukemia (CLL) is the most prevalent B-cell malignancy in adults. Despite advances in treatment, the disease remains incurable, warranting further efforts to identify novel molecular targets and inhibitors. Spleen tyrosine kinase (SYK) plays a pivotal role for B-lymphocyte development and maturation in the B-cell receptor (BCR) signaling pathway and hence represents a potential therapeutic target for CLL. The present study is directed towards finding novel inhibitors of SYK through ligand based virtual screening. The co-crystal structure of SYK was investigated to locate active site residues (Glu-449, Ala-451 Arg-498, Asn-499, Ser-511, and Asp-512). Five SYK specific published inhibitors (Gleevec, staurosporine, Bay61-3606, R-406 and p5c) were explored against more than one million entries of the Ligand.Info metadatabase to create an in-house library of 1957 structural analogs. Ligand dataset was prepared using LigPrep and filtered based on Lipinski’s rule of five and reactive group constraints. Docking using Computational Glide v5.5 from lesser to higher stringency towards minor steric classes were applied subsequently to the prepared ligand dataset against a grid around the centroid of the SYK active site. Fifteen lead molecules with good binding affinity to SYK were identified and compared with binding affinities and orientations of five published inhibitors. Apigenin (-10.05 Kcal/mol) and Glafenine (-9.72 Kcal/mol) endeavored better binding affinities, hydrogen bonding network and Van der Waal interactions with active site residues compared to published inhibitors. Thus, Apigenin and Glafenine would be valuable for designing a novel inhibitor against CLL, if synthesized and tested in vitro and in vivo.
The myotubularin family of lipid phosphatases in disease and in spermatogenesis
Authors: Mruk Dolores D. , Cheng C. Yan
Published: December 2010

The MTM (myotubularin)/MTMR (myotubularin-related) protein family is comprised of 15 lipid phosphatases, of which nine members are catalytically active. MTMs are known to play a fundamental role in human physiology as gene mutations can give rise to X-linked myotubular myopathy or Charcot–Marie–Tooth disease, which manifest in skeletal muscle or in peripheral neurons respectively. Interestingly, studies have shown MTMR2 and MTMR5, two MTM family members, to be highly expressed in the testis, particularly in Sertoli and germ cells, and knockout of either gene resulted in spermatogenic defects. Other studies have shown that MTMR2 functions in endocytosis and membrane trafficking. In the testis, MTMR2 interacts and co-localizes with c-Src/phospho-Src-(Tyr416), a non-receptor protein tyrosine kinase that regulates the phosphorylation state of proteins at the apical ES (ectoplasmic specialization), a unique type of cell junction found between Sertoli cells and elongating/elongated spermatids. In the present review, we highlight recent findings that have made a significant impact on our understanding of this protein family in normal cell function and in disease, with the emphasis on the role of MTMs and MTMRs in spermatogenesis. We also describe a working model to explain how MTMR2 interacts with other proteins such as c-Src, dynamin 2, EPS8 (growth factor receptor pathway substrate 8) and ARP2/3 (actin-related protein 2/3) at the apical ES and the apical TBC (tubulobulbar complex; tubular-like invaginations that function in the disassembly of the apical ES and in the recycling of its components) to regulate spermiation at late stage VIII of the seminiferous epithelial cycle.
D-dimensional Bose gases and the Lambert W function
Authors: Tanguay J. , Gil M. , Jeffrey D. J. , Valluri S. R.
Published: December 2010

The applications of the Lambert W function (also known as the W function) to D-dimensional Bose gases are presented. We introduce two sets of families of logarithmic transcendental equations that occur frequently in thermodynamics and statistical mechanics and present their solution in terms of the W function. The low temperature T behavior of free ideal Bose gases is considered in three and four dimensions. It is shown that near condensation in four dimensions, the chemical potential μ and pressure P can be expressed in terms of T through the W function. The low T behavior of one- and two-dimensional ideal Bose gases in a harmonic trap is studied. In 1D, the W function is used to express the condensate temperature, \documentclass[12pt]{minimal}\begin{document}$T_C$\end{document}TC, in terms of the number of particles N; in 2D, it is used to express μ in terms of T. In the low T limit of the 1D hard-core and the 3D Bose gas, T can be expressed in terms of P and μ through the W function. Our analysis allows for the possibility to consider μ, T, and P as complex variables. The importance of the underlying logarithmic structure in ideal quantum gases is seen in the polylogarithmic and W function expressions relating thermodynamic variables such as μ, T, and P.
Water sprints uphill on glass
Authors: Vorobyev A. Y. , Guo Chunlei
Published: December 2010

As a material, glass has been widely used in traditional fluidic devices and more recently in micro- and nanofluidic devices, and its wetting properties are crucially important in these applications. In this work, by using a high-intensity femtosecond laser structuring technique, we create a unique surface pattern on glass that transfer a regular glass surface to superwicking. As a result, water defies the gravity and sprints vertically uphill along the structured glass surface at an unprecedented velocity of 3.8 cm/sec. Our study shows that the dynamics of this fast self-propelled water flow follows a square root of time dependence.