bluuebunny/crossref_metadata_2025 huggingface dataset:
Observation of new particle formation in subtropical urban environment
Authors: Cheung H. C. , Morawska L. , Ristovski Z. D.
Published: April 2011

Abstract. The aim of this study was to characterise the new particle formation events in a subtropical urban environment in the Southern Hemisphere. The study measured the number concentration of particles and its size distribution in Brisbane, Australia during 2009. The variation of particle number concentration and nucleation burst events were characterised as well as the particle growth rate which was first reported in urban environment of Australia. The annual average NUFP, NAitken and NNuc were 9.3×103, 3.7×103 and 5.6×103 cm−3, respectively. Weak seasonal variation in number concentration was observed. Local traffic exhaust emissions were a major contributor of the pollution (NUFP) observed in morning which was dominated by the Aitken mode particles, while particles formed by secondary formation processes contributed to the particle number concentration during afternoon. Overall, 65 nucleation burst events were identified during the study period. Nucleation burst events were classified into two groups, with and without particles growth after the burst of nucleation mode particles observed. The average particle growth rate of the nucleation events was 4.6 nm h−1 (ranged from 1.79–7.78 nm h−1). Case studies of the nucleation burst events were characterised including (i) the nucleation burst with particle growth which is associated with the particle precursor emitted from local traffic exhaust emission, (ii) the nucleation burst without particle growth which is due to the transport of industrial emissions from the coast to Brisbane city or other possible sources with unfavourable conditions which suppressed particle growth and (iii) interplay between the above two cases which demonstrated the impact of the vehicle and industrial emissions on the variation of particle number concentration and its size distribution during the same day.
Size-resolved and bulk activation properties of aerosols in the North China Plain
Authors: Deng Z. Z. , Zhao C. S. , Ma N. , Liu P. F. , Ran L. , Xu W. Y. , Chen J. , Liang Z. , Liang S. , Huang M. Y. , Ma X. C. , Zhang Q. , Quan J. N. , Yan P. , Henning S. , Mildenberger K. , Sommerhage E. , Schäfer M. , Stratmann F. , Wiedensohler A.
Published: April 2011

Abstract. Size-resolved and bulk activation properties of aerosols were measured at a regional/suburban site in the North China Plain (NCP), which is occasionally heavily polluted by anthropogenic aerosol particles and gases. A Cloud Condensation Nuclei (CCN) closure study is conducted with bulk CCN number concentration (NCCN) and calculated CCN number concentration based on the aerosol number size distribution and size-resolved activation properties. The observed CCN number concentration (NCCN-obs) are higher than those observed in other locations than China, with average NCCN-obs of roughly 2000, 3000, 6000, 10 000 and 13 000 cm−3 at supersaturations of 0.056, 0.083, 0.17, 0.35 and 0.70%, respectively. An inferred critical dry diameter (Dm) is calculated based on the NCCN-obs and aerosol number size distribution assuming homogeneous chemical composition. The inferred cut-off diameters are in the ranges of 190–280, 160–260, 95–180, 65–120 and 50–100 nm at supersaturations of 0.056, 0.083, 0.17, 0.35 and 0.7%, with their mean values 230.1, 198.4, 128.4, 86.4 and 69.2 nm, respectively. Size-resolved activation measurements show that most of the 300 nm particles are activated at the investigated supersaturations, while almost no particles of 30 nm are activated even at the highest supersaturation of 0.72%. The activation ratio increases with increasing supersaturation and particle size. The slopes of the activation curves for ambient aerosols are not as steep as those observed in calibrations with ammonium sulfate suggesting that the observed aerosols is an external mixture of more hygroscopic and hydrophobic particles. The calculated CCN number concentrations (NCCN-calc) based on the size-resolved activation ratio and aerosol number size distribution correlate well with the NCCN-obs, and show an average overestimation of 19%. Sensitivity studies of the CCN closure show that the NCCN at each supersaturation is well predicted with the campaign average of size-resolved activation curves. These results indicate that the aerosol number size distribution is critical in the prediction of possible CCN. The CCN number concentration can be reliably estimated using time-averaged, size-resolved activation efficiencies without accounting for the temporal variations.
Organic condensation: a vital link connecting aerosol formation to cloud condensation nuclei (CCN) concentrations
Authors: Riipinen I. , Pierce J. R. , Yli-Juuti T. , Nieminen T. , Häkkinen S. , Ehn M. , Junninen H. , Lehtipalo K. , Petäjä T. , Slowik J. , Chang R. , Shantz N. C. , Abbatt J. , Leaitch W. R. , Kerminen V.-M. , Worsnop D. R. , Pandis S. N. , Donahue N. M. , Kulmala M.
Published: April 2011

Abstract. Atmospheric aerosol particles influence global climate as well as impair air quality through their effects on atmospheric visibility and human health. Ultrafine (<100 nm) particles often dominate aerosol numbers, and nucleation of atmospheric vapors is an important source of these particles. To have climatic relevance, however, the freshly nucleated particles need to grow in size. We combine observations from two continental sites (Egbert, Canada and Hyytiälä, Finland) to show that condensation of organic vapors is a crucial factor governing the lifetimes and climatic importance of the smallest atmospheric particles. We model the observed ultrafine aerosol growth with a simplified scheme approximating the condensing species as a mixture of effectively non-volatile and semi-volatile species, demonstrate that state-of-the-art organic gas-particle partitioning models fail to reproduce the observations, and propose a modeling approach that is consistent with the measurements. We find that roughly half of the mass of the condensing mass needs to be distributed proportional to the aerosol surface area (thus implying that the condensation is governed by gas-phase concentration rather than the equilibrium vapour pressure) to explain the observed aerosol growth. We demonstrate the large sensitivity of predicted number concentrations of cloud condensation nuclei (CCN) to these interactions between organic vapors and the smallest atmospheric nanoparticles – highlighting the need for representing this process in global climate models.
Three-dimensional variations of atmospheric CO2: aircraft measurements and multi-transport model simulations
Authors: Niwa Y. , Patra P. K. , Sawa Y. , Machida T. , Matsueda H. , Belikov D. , Maki T. , Ikegami M. , Imasu R. , Maksyutov S. , Oda T. , Satoh M. , Takigawa M.
Published: April 2011

Abstract. Numerical simulation and validation of three-dimensional structure of atmospheric carbon dioxide (CO2) is necessary for quantification of transport model uncertainty and its role on surface flux estimation by inverse modeling. Simulations of atmospheric CO2 were performed using four transport models and two sets of surface fluxes compared with an aircraft measurement dataset of Comprehensive Observation Network for Trace gases by AIrLiner (CONTRAIL), covering various latitudes, longitudes, and heights. Under this transport model intercomparison project, spatiotemporal variations of CO2 concentration for 2006–2007 were analyzed with a three-dimensional perspective. Results show that the models reasonably simulated vertical profiles and seasonal variations not only over northern latitude areas but also over the tropics and southern latitudes. From CONTRAIL measurements and model simulations, intrusion of northern CO2 in to the Southern Hemisphere, through the upper troposphere, was confirmed. Furthermore, models well simulated the vertical propagation of seasonal variation in the northern free-troposphere. However, significant model–observation discrepancies were found in Asian regions, which are attributable to uncertainty of the surface CO2 flux data. The models consistently underestimated the north-tropics mean gradient of CO2 both in the free-troposphere and marine boundary layer during boreal summer. This result suggests that the north-tropics contrast of annual mean net non-fossil CO2 flux should be greater than 2.7 Pg C yr−1 for 2007.
A 6-year global climatology of occurrence of upper-tropospheric ice supersaturation inferred from the Atmospheric Infrared Sounder after synergetic calibration with MOZAIC
Authors: Lamquin N. , Stubenrauch C. J. , Gierens K. , Burkhardt U. , Smit H.
Published: April 2011

Abstract. Ice supersaturation in the upper troposphere is a complex and important issue for the understanding of cirrus cloud formation. Infrared sounders have the ability to provide cloud properties and atmospheric profiles of temperature and humidity. On the other hand, they suffer from coarse vertical resolution, especially in the upper troposphere and therefore are unable to detect shallow ice supersaturated layers. We have used data from the Measurements of OZone and water vapour by AIrbus in-service airCraft experiment (MOZAIC) in combination with Atmospheric InfraRed Sounder (AIRS) relative humidity measurements and cloud properties to develop a calibration method for an estimation of occurrence frequencies of ice supersaturation. This method first determines the occurrence probability of ice supersaturation, detected by MOZAIC, as a function of the relative humidity determined by AIRS. The occurrence probability function is then applied to AIRS data, independently of the MOZAIC data, to provide a global climatology of upper-tropospheric ice supersaturation occurrence. Our climatology is then related to high cloud occurrence from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and compared to ice supersaturation occurrence statistics from MOZAIC alone. Finally it is compared to model climatologies of ice supersaturation from the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF) and from the European Centre HAmburg Model (ECHAM). All the comparisons show good agreements when considering the limitations of each instrument and model. This study highlights the benefits of multi-instrumental synergies for the investigation of upper tropospheric ice supersaturation.
Ground-based and airborne in-situ measurements of the Eyjafjallajökull volcanic aerosol plume in Switzerland in spring 2010
Authors: Bukowiecki N. , Zieger P. , Weingartner E. , Jurányi Z. , Gysel M. , Neininger B. , Schneider B. , Hueglin C. , Ulrich A. , Wichser A. , Henne S. , Brunner D. , Kaegi R. , Schwikowski M. , Tobler L. , Wienhold F. G. , Engel I. , Buchmann B. , Peter T. , Baltensperger U.
Published: April 2011

Abstract. The volcanic aerosol plume resulting from the Eyjafjallajökull eruption in Iceland in April and May 2010 was detected in clear layers above Switzerland during two periods (17–19 April 2010 and 16–19 May 2010). In-situ measurements of the airborne volcanic plume were performed both within ground-based monitoring networks and with a research aircraft up to an altitude of 6000 m a.s.l. The wide range of aerosol and gas phase parameters studied at the high altitude research station Jungfraujoch (3580 m a.s.l.) allowed for an in-depth characterization of the detected volcanic aerosol. Both the data from the Jungfraujoch and the aircraft vertical profiles showed a consistent volcanic ash mode in the aerosol volume size distribution with a mean optical diameter around 3 ± 0.3 μm. These particles were found to have an average chemical composition very similar to the trachyandesite-like composition of rock samples collected near the volcano. Furthermore, chemical processing of volcanic sulfur dioxide into sulfate clearly contributed to the accumulation mode of the aerosol at the Jungfraujoch. The combination of these in-situ data and plume dispersion modeling results showed that a significant portion of the first volcanic aerosol plume reaching Switzerland on 17 April 2010 did not reach the Jungfraujoch directly, but was first dispersed and diluted in the planetary boundary layer. The maximum PM10 mass concentrations at the Jungfraujoch reached 30 μg m−3 and 70 μg m−3 (for 10-min mean values) during the April and May episode, respectively. Even low-altitude monitoring stations registered up to 45 μg m−3 of volcanic ash related PM10 (Basel, Northwestern Switzerland, 18/19 April 2010). The flights with the research aircraft on 17 April 2010 showed one order of magnitude higher number concentrations over the northern Swiss plateau compared to the Jungfraujoch, and a mass concentration of 320 (200–520) μg m−3 on 18 May 2010 over the northwestern Swiss plateau. The presented data significantly contributed to the time-critical assessment of the local ash layer properties during the initial eruption phase. Furthermore, dispersion models benefited from the detailed information on the volcanic aerosol size distribution and its chemical composition.
Determination of tropospheric vertical columns of NO2 and aerosol optical properties in a rural setting using MAX-DOAS
Authors: Halla J. D. , Wagner T. , Beirle S. , Brook J. R. , Hayden K. L. , O'Brien J. M. , Ng A. , Majonis D. , Wenig M. O. , McLaren R.
Published: April 2011

Abstract. Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements were performed in a rural location of southwestern Ontario during the Border Air Quality and Meteorology Study. Slant column densities (SCDs) of NO2 and O4 were determined using the standard DOAS technique. Using a radiative transfer model and the O4 SCDs, aerosol optical depths were determined for clear sky conditions and compared to OMI, MODIS, AERONET, and local PM2.5 measurements. This aerosol information was input to a radiative transfer model to calculate NO2 air mass factors, which were fit to the measured NO2 SCDs to determine tropospheric vertical column densities (VCDs) of NO2. The method of determining NO2 VCDs in this way was validated by comparison to composite VCDs derived from aircraft and ground-based measurements of NO2. The new VCDs were compared to VCDs of NO2 determined via the satellite instruments SCIAMACHY and OMI, for overlapping time periods. The satellite-derived VCDs were higher by 50%, with a mean positive error of 0.5–0.9 × 1015 molec cm−2. This last finding is different from previous studies whereby MAX-DOAS geometric VCDs were higher than satellite determinations, albeit for urban areas with higher VCDs. An effective boundary layer height, BLeff, is defined as the ratio of the tropospheric VCD and the ground level concentration of NO2. Variations of BLeff can be linked to time of day, source region, stability of the atmosphere, and the presence or absence of elevated NOx sources. In particular, a case study is shown where a high VCD and BLeff were observed when an elevated industrial plume of NOx and SO2 was fumigated to the surface as a lake breeze front impacted the measurement site. High BLeff values (~1.9 km) were observed during a regional smog event when high winds from the SW and high convection promoted mixing throughout the boundary layer. During this event, the regional line flux of NO2 through the region was estimated to be greater than 112 kg NO2 km−1 h−1.
Reliability of autoregressive error models as post-processors for probabilistic streamflow forecasts
Authors: Morawietz M. , Xu C.-Y. , Gottschalk L.
Published: April 2011

Abstract. In this study, the reliability of different versions of autoregressive error models as post-processors for probabilistic streamflow forecasts is evaluated. Rank histograms and reliability indices are used as performance measures. An algorithm for the construction of confidence intervals to indicate ranges of reliable forecasts within the rank histograms is presented. To analyse differences in performance of the post-processors, scatter plots of the standardized residuals of the error models are generated to assess the homoscedacity of the residuals with respect to streamflow. A problem of distorted impressions may appear when such plots are generated with a regular x-scale. The problem is analysed with both synthetic and real data, and a rank scaled x-axis is proposed to remedy the problem. The results of the study reveal large differences in the reliability of the post-processors. Versions with empirical distribution functions are clearly superior to those with standard normal distribution, but for validations with independent data their rank histograms still lie outside of the confidence bands for reliable forecasts.
Origin of the moisture feeding the Heavy Precipitating Systems over Southeastern France
Authors: Duffourg F. , Ducrocq V.
Published: April 2011

Abstract. In the Northwestern Mediterranean region, large amounts of precipitation can accumulate over the coasts in less than a day. The present study aims at characterising the origin and the pathways of the moisture feeding such heavy precipitation. The ten Heavy Precipitating Events (HPEs) that occurred over the French Mediterranean region during the autumns of 2008 and 2009 are simulated with the non-hydrostatic research numerical model Meso-NH at 2.5 km, 10 km and 40 km horizontal resolution. Using eulerian on-line passive tracers, high-resolution simulations (2.5 km horizontal resolution) show that the heavy precipitating systems are fed by a south-southwesterly to easterly low-level moist flow. It is typically 1000 m deep and remains almost unchanged all along an event. This low-level feeding flow crosses the most northwestern part of the Mediterranean in 5 to 10 h. Larger-scale simulations (40 km and 10 km horizontal resolution) show that the moisture of the low-level feeding flow is provided by both evaporation of the Mediterranean Sea within the last 2 days before the HPE triggering and transport from remote sources in the lower half of the troposphere over more than 3 to 4 days. Local Mediterranean moisture is gained along the air mass low-level progress towards the Northwestern Mediterranean basin following two main branches along the Spanish coast and west of Sardinia. The Mediterranean Sea is the main moisture source when anticyclonic conditions prevail during the last 3 or 4 days before the HPE. When cyclonic conditions prevail before the HPE, the relative contribution of local and remote sources is more balanced. Remote moisture comes most of the time from the Atlantic Ocean. African tropical moisture is a less frequent but larger remote source.
Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere
Authors: Fijałkowska-Lichwa L. , Przylibski T. A.
Published: April 2011

Abstract. The authors investigated short-time changes in 222Rn activity concentration occurring yearly in two underground tourist facilities with limited air exchange with the atmosphere. One of them is Niedźwiedzia (Bear) Cave in Kletno, Poland – a natural space equipped with locks ensuring isolation from the atmosphere. The other site is Fluorite Adit in Kletno, a section of a disused uranium mine. This adit is equipped with a mechanical ventilation system, operated periodically outside the opening times (at night). Both sites are situated within the same metamorphic rock complex, at similar altitudes, about 2 km apart. The measurements conducted revealed spring and autumn occurrence of convective air movements. In Bear Cave, this process causes a reduction in 222Rn activity concentration in the daytime, i.e. when tourists, guides and other staff are present in the cave. From the point of view of radiation protection, this is the best situation. For the rest of the year, daily concentrations of 222Rn activity in the cave are very stable. In Fluorite Adit, on the other hand, significant variations in daily 222Rn activity concentrations are recorded almost all year round. These changes are determined by the periods of activity and inactivity of mechanical ventilation. Unfortunately this is inactive in the daytime, which results in the highest values of 222Rn activity concentration at the times when tourists and staff are present in the adit. Slightly lower concentrations of radon in Fluorite Adit are recorded in the winter season, when convective air movements carry a substantial amount of radon out into the atmosphere. The incorrect usage of mechanical ventilation in Fluorite Adit results in the most unfavourable conditions in terms of radiation protection. The staff working in that facility are exposed practically throughout the year to the highest 222Rn activity concentrations, both at work (in the adit) and at home (outside their working hours). Therefore, not very well considered solution for the ventilation system not only does not prevent radioactive exposure of the staff, but can even increase it. The authors have also observed comparable characteristics of the annual patterns of 222Rn activity concentration changes in underground spaces and residential buildings situated in the same or similar climatic zones.
Stochastic index model for intermittent regimes: from preliminary analysis to regionalisation
Authors: Rianna M. , Russo F. , Napolitano F.
Published: April 2011

Abstract. In small and medium-sized basins or in rivers characterized by intermittent discharges, with low or negligible/null observed values for long periods of the year, the correct representation of the discharge regime is important for issues related to water management and to define the amount and quality of water available for irrigation, domestic and recreational uses. In these cases, only one index as a statistical metric is often not enough; it is thus necessary to introduce Flow Duration Curves (FDC). The aim of this study is therefore to combine a stochastic index flow model capable of reproducing the FDC record period of a river, regardless of the persistence and seasonality of the series, with the theory of total probability in order to calculate how often a river is dry. The paper draws from preliminary analyses, including a study to estimate the correlation between discharge indicators Q95, Q50 and Q1 (discharges exceeding 95%, 50% or 1% of the time, respectively) and some fundamental characteristics of the basin, as well as to identify homogeneous regions in the target area through the study of several geo-morphological features and climatic conditions. The stochastic model was then applied in one of the homogeneous regions that includes intermittent rivers. Finally, the model was regionalized by means of regression analysis in order to calculate the FDC for ungauged basins; the reliability of this method was tested using jack-knife validation.
Literature-based Resurrection of Neglected Medical Discoveries
Authors: Swanson Don R.
Published: April 2011

It is possible to find in the medical literature many articles that have been neglected or ignored, in some cases for many years, but which are worth bringing to light because they report unusual findings that may be of current scientific interest. Resurrecting previously published but neglected hypotheses that have merit might be overlooked because it would seem to lack the novelty of "discovery" -- but the potential value of so doing is hardly arguable. Finding neglected hypotheses may be not only of great practical value, but also affords the opportunity to study the structure of such hypotheses in the hope of illuminating the more general problem of hypothesis generation.
Simultaneous Blood Temperature Control and Blood Volume Control Reduces Intradialytic Symptoms
Authors: Veljančicć Ljubiša , Popović Jovan , Radović Milan , Ahrenholz Peter , Ries Wolfgang , Frenken Leon , Wojke Ralf
Published: April 2011

Purpose

Intra-dialytic morbid events (IME; e.g. hypotension, cramps, headaches) are frequent complications during hemodialysis (HD), known to be associated with ultrafiltration-induced hypovolemia and body temperature changes. Feedback control of blood volume adjusts the ultrafiltration rate in order to keep the blood volume above the patient's individual limit; feedback control of blood temperature maintains the mean arterial blood temperature at the individual pre-dialytic level. Each of these methods reduces the frequency of IME.

Methods

In a randomized clinical trial the simultaneous application of both feedback controls was investigated for the first time. In 15 weeks, each patient went through 3 study phases: an observational screening phase, a standard phase (STD), and a blood temperature- and blood volume-control phase (CTL). Patients with at least 5 sessions with IME out of 15 sessions in the screening phase were eligible for the study and randomized either into sequence STD-CTL or CTL-STD.

Results

26 patients completed the study according to protocol, and 778 HD treatments were analyzed. The general treatment parameters were similar in both study phases: treatment duration (STD: 244 min, CTL: 243 min, NS), pre-dialytic weight (STD: 72.3 kg, CTL: 72.2 kg, NS), and weight loss due to ultrafiltration (STD: 3.26 kg, CTL: 3.15 kg, NS). The proportion of HD treatments with IME was 32.8% during STD and 18.0% during CTL (p=0.024).

Conclusions

The frequency of HD sessions with IME was significantly reduced by 45% compared to standard HD in this randomized clinical trial by use of individualized HD treatments with simultaneous feedback control of blood volume and blood temperature.
Giant Splenic Artery Aneurysm: Case Report
Authors: Ali Sadaf , Verma Vibha , R Sastry , Wani Imtiaz
Published: April 2011

Splenic artery aneurysm is the third most common location of intra-abdominal aneurysms. Giant splenic artery aneurysm is rarely seen and is at a high risk of rupture. Location and size of the splenic artery aneurysm determine the likelihood of rupture. A case of giant splenic artery aneurysm in a 35-year-old woman is reported. She presented with upper gastrointestinal bleeding. She had splenomegaly and extrahepatic hepatic portal hypertension. Angiography confirmed a giant splenic artery aneurysm measuring 8 × 10 centimeters, located in middle and distal two-thirds of the splenic artery. Surgical treatment in the form of in toto excision of aneurysm with splenectomy and devascularization was performed.
Positive Solutions for Boundary Value Problem of Nonlinear Fractional -Difference Equation
Authors: El-Shahed Moustafa , Al-Askar Farah M.
Published: April 2011

We investigate the existence of multiple positive solutions to the nonlinear -fractional boundary value problem ,
,
by using a fixed point theorem in a cone.
Hopf Bifurcation Analysis in a Tabu Learning Neuron Model with Two Delays
Authors: Li Yingguo
Published: April 2011

We consider the nonlinear dynamical behavior of a tabu leaning neuron model with two delays. By choosing the sum of the two delays as a bifurcation parameter, we prove that Hopf bifurcation occurs in the neuron. Some numerical examples are also presented to verify the theoretical analysis.
The Dark Matter Halo Density Profile, Spiral Arm Morphology, and Supermassive Black Hole Mass of M33
Authors: Seigar Marc S.
Published: April 2011

We investigate the dark matter halo density profile of M33. We find that the HI rotation curve of M33 is best described by an NFW dark matter halo density profile model, with a halo concentration of and a virial mass of . We go on to use the NFW concentration of M33, along with the values derived for other galaxies (as found in the literature), to show that correlates with both spiral arm pitch angle and supermassive black hole mass.
On the Cosmic Ray-Induced Ionization Rate in Molecular Clouds
Authors: Yeghikyan Ararat G.
Published: April 2011

The transformation of the energy dependence of the cosmic ray proton flux in the keV to GeV region is investigated theoretically when penetrating inside molecular clouds ( mag). The computations suggest that energy losses of the cosmic ray particles by interaction with the matter of the molecular cloud are principally caused by the inelastic (electronic) interaction potential; the transformed energy distribution of energetic protons is determined mainly by the column density of the absorbing medium. A cutoff of the cosmic ray spectrum inside clouds by their magnetic fields is also phenomenologically taken into account. This procedure allows a determination of environment-dependent ionization rates of molecular clouds. The theoretically predicted ionization rates are in good agreement with those derived from astronomical observations of absorption lines in the spectrum of the cloud connected with the Herbig Be star LkH 101.
Clinical Challenges of Primary Diffuse Large B-Cell Lymphoma of the Dura: Case Report and Literature Review
Authors: Said Rabih , Rizk Sanaa , Dai Qun
Published: April 2011

Primary dural lymphoma is a rare disease with more indolent clinical behavior compared to primary central nervous system lymphoma. The majority of the reported cases were indolent marginal zone lymphoma subtype with more predilections to the spine. Herein, we are presenting a case of intracranial, diffuse large B-cell lymphoma of the dura that was diagnosed and treated at our institution. We are presenting the challenges in the treatment based on a review of the literature.
Anatomy as the backbone of an integrated first year medical curriculum: Design and implementation
Authors: Klement Brenda J. , Paulsen Douglas F. , Wineski Lawrence E.
Published: April 2011

Morehouse School of Medicine chose to restructure its first year medical curriculum in 2005. The anatomy faculty had prior experience in integrating courses, stemming from the successful integration of individual anatomical sciences courses into a single course called Human Morphology. The integration process was expanded to include the other first year basic science courses (Biochemistry, Physiology, and Neurobiology) as we progressed toward an integrated curriculum. A team, consisting of the course directors, a curriculum coordinator, and the Associate Dean for Educational and Faculty Affairs, was assembled to build the new curriculum. For the initial phase, the original course titles were retained but the lecture order was reorganized around the Human Morphology topic sequence. The material from all four courses was organized into four sequential units. Other curricular changes included placing laboratories and lectures more consistently in the daily routine, reducing lecture time from 120 to 90 minute blocks, eliminating unnecessary duplication of content, and increasing the amount of independent study time. Examinations were constructed to include questions from all courses on a single test, reducing the number of examination days in each block from three to one. The entire restructuring process took two years to complete, and the revised curriculum was implemented for the students entering in 2007. The outcomes of the restructured curriculum include a reduction in the number of contact hours by 28%, higher or equivalent subject examination average scores, enhanced student satisfaction, and a first year curriculum team better prepared to move forward with future integration. Anat Sci Educ 4:157–169, 2011. © 2011 American Association of Anatomists.
β NO Turns and Helices Induced by β2‐Aminoxy Peptides: Synthesis and Conformational Studies
Authors: Jiao Zhi‐Gang , Chang Xiao‐Wei , Ding Wei , Liu Guo‐Jun , Song Ke‐Sheng , Zhu Nian‐Yong , Zhang Dan‐Wei , Yang Dan
Published: April 2011

Herein, we report an efficient route for the asymmetric synthesis of β2‐aminoxy acids as well as experimental and theoretical studies of conformations of peptides composed of β2‐aminoxy acids. The nine‐membered‐ring intramolecular hydrogen bonds, namely, β NO turns, are generated between adjacent residues in those peptides, in accordance with our computational results. The presence of two consecutive homochiral β NO turns leads to the formation of β NO helical structures in solution, although both helical (composed of two β NO turns of the same handedness) and reverse‐turn (composed of two β NO turns with opposite handedness) structures are of similar stability, as suggested by theoretical studies. Nevertheless, two slightly different conformations, with the same handedness, of β2‐aminoxy monomers have been observed in the solid state and in solution according to our X‐ray and 2D NOESY studies.
Origins and distribution of nerves to the female urinary bladder: New anatomical findings in the sex differences
Authors: Yamaguchi Kumiko , Kobayashi Mayumi , Kato Tomoyasu , Akita Keiichi
Published: April 2011

The development of nerve‐sparing procedures is important in preventing bladder dysfunction following radical hysterectomy. In this study, we dissected 14 halves of 7 female pelvises (age range: 46–86 years; mean age: 74 years) to examine the origins, courses, and distributions of nerve branches to the bladder in females in detail, and 6 halves of 3 male pelvises (age range: 71–85 years, mean age: 78 years) to compare with the female specimens. Nerve branches to the bladder originated mainly from the inferior hypogastric plexus, but independent direct branches running along the ureter from the hypogastric nerve were also distributed particularly to the trigone in all female specimens. We classified these independent branches into four types according to their relationship to the ureter. In males the numbers of the independent branches were small and they were difficult to find. The present observations indicate that nerve distribution patterns to the bladder differ between females and males. In nerve sparing procedures for radical hysterectomy, the area between the ureter and the hypogastric nerve is important. Clin. Anat. 24:880–885, 2011. © 2011 Wiley‐Liss, Inc.
Going Full Circle: Phase‐Transition Thermodynamics of Ionic Liquids
Authors: Preiss Ulrich , Verevkin Sergey P. , Koslowski Thorsten , Krossing Ingo
Published: April 2011

We present the full enthalpic phase transition cycle for ionic liquids (ILs) as examples of non‐classical salts. The cycle was closed for the lattice, solvation, dissociation, and vaporization enthalpies of 30 different ILs, relying on as much experimental data as was available. High‐quality dissociation enthalpies were calculated at the G3 MP2 level. From the cycle, we could establish, for the first time, the lattice and solvation enthalpies of ILs with imidazolium ions. For vaporization, lattice, and dissociation enthalpies, we also developed new prediction methods in the course of our investigations. Here, as only single‐ion values need to be calculated and the tedious optimization of an ion pair can be circumvented, the computational time is short. For the vaporization enthalpy, a very simple approach was found, using a surface term and the calculated enthalpic correction to the total gas‐phase energy. For the lattice enthalpy, the most important constituent proved to be the calculated conductor‐like screening model (COSMO) solvation enthalpy in the ideal electric conductor. A similar model was developed for the dissociation enthalpy. According to our assessment, the typical error of the lattice enthalpy would be 9.4 kJ mol−1, which is less than half the deviation we get when using the (optimized) Kapustinskii equation or the recent volume‐based thermodynamics (VBT) theory. In contrast, the non‐optimized VBT formula gives lattice enthalpies 20 to 140 kJ mol−1 lower than the ones we assessed in the cycle, because of the insufficient description of dispersive interactions. Our findings show that quantum‐chemical calculations can greatly improve the VBT approaches, which were parameterized for simple, inorganic salts with ideally point‐shaped charges. In conclusion, we suggest the term “augmented VBT”, or “aVBT”, to describe this kind of theoretical approach.
Towards a Fully Synthetic MUC1‐Based Anticancer Vaccine: Efficient Conjugation of Glycopeptides with Mono‐, Di‐, and Tetravalent Lipopeptides Using Click Chemistry
Authors: Cai Hui , Huang Zhi‐Hua , Shi Lei , Zhao Yu‐Fen , Kunz Horst , Li Yan‐Mei
Published: April 2011

The membrane‐bound tumor‐associated glycoprotein MUC1 is aberrantly glycosylated in cancer cells compared with normal cells, and is therefore considered an attractive target for cancer immunotherapy. However, tumor‐associated glycopeptides from MUC1 do not elicit a sufficiently robust immune response. Therefore, antitumor vaccines were developed, which consist of MUC1 glycopeptides as the B epitopes and immune‐stimulating toll‐like receptor 2 (TLR 2) lipopeptide ligands. These fully synthetic vaccine candidates were prepared by solid‐phase synthesis of the MUC1 glycopeptides. The Pam3Cys lipopeptide, also synthesized on solid‐phase, was C‐terminally coupled to oligovalent lysine cores, which N‐terminally incorporate O‐propargyl oligoethylene glycol acyl side chains. The MUC1 glycopeptides and lipopeptide lysine constructs were then conjugated by click chemistry to give oligovalent synthetic vaccines. Oligovalent glycopeptide–lipopeptide conjugates are considered more immunogenic than their monovalent analogues.
CAFS: a novel lightweight cache‐based scheme for large‐scale intrusion alert fusion
Authors: Wen Sheng , Zhou Wei , Xiang Yang , Zhou Wanlei
Published: April 2011

In this paper, we present some practical experiences on implementing an alert fusion mechanism from our project. After investigation on most of the existing alert fusion systems, we found the current body of work alternatively weighed down in the mire of insecure design or rarely deployed because of their complexity. As confirmed by our experimental analysis, unsuitable mechanisms could easily be submerged by an abundance of useless alerts. Even with the use of methods that achieve a high fusion rate and low false positives, attack is also possible. To find the solution, we carried out analysis on a series of alerts generated by well‐known datasets as well as realistic alerts from the Australian Honey‐Pot. One important finding is that one alert has more than an 85% chance of being fused in the following five alerts. Of particular importance is our design of a novel lightweight Cache‐based Alert Fusion Scheme, called CAFS. CAFS has the capacity to not only reduce the quantity of useless alerts generated by intrusion detection system, but also enhance the accuracy of alerts, therefore greatly reducing the cost of fusion processing. We also present reasonable and practical specifications for the target‐oriented fusion policy that provides a quality guarantee on alert fusion, and as a result seamlessly satisfies the process of successive correlation. Our experiments compared CAFS with traditional centralized fusion. The results showed that the CAFS easily attained the desired level of simple, counter‐escapable alert fusion design. Furthermore, as a lightweight scheme, CAFS can easily be deployed and excel in a large amount of alert fusions, which go towards improving the usability of system resources. To the best of our knowledge, our work is a practical exploration in addressing problems from the academic point of view. Copyright © 2011 John Wiley & Sons, Ltd.
Multi‐Field Effect on the Electronic Properties of Silicon Nanowires
Authors: Zhang Ren Qin , Hou Chao , Gao Nan , Wen Zi , Jiang Qing
Published: April 2011

The quantum confinement and electronic properties of silicon nanowires (SiNWs) under an external strain field ε and an electric field E—as well as both (ε plus E)—are systematically investigated using density functional theory. These two fields exist in working environments of integrated circuits. It is found that both ε and E lead to a drop of the band gap Eg(ε,E) of the SiNWs. If both fields coexist, the interaction between ε and E causes that Eg(ε,E) becomes orientation‐dependent, which results from variations of both the conduction‐band minimum and the valence‐band maximum. The interaction is further illustrated by the density of states near the Fermi level and the eigenvalue of the highest occupied molecular orbital.
The Rate‐Determining Step is Dead. Long Live the Rate‐Determining State!
Authors: Kozuch Sebastian , Martin Jan M. L.
Published: April 2011

The concept of a rate‐determining step (RD‐Step) is central to the kinetics community, and it is basic knowledge even for the undergraduate chemical student. In spite of this, too many different definitions of the RD‐Step appear in the literature, all of them with drawbacks. This dilemma has been thoroughly studied by several authors in the attempt to “patch” the drawbacks and bring the RD‐Step to a correct physical meaning. Herein we review with simple models the most notable definitions and some challengers of the RD‐Step concept, to conclude with the deduction that there are no rate‐determining steps, only rate‐determining states.
Growth and characterization of a new langasite‐type single crystal Sr3NbAl1.5Ga1.5Si2O14
Authors: Zeng Yiming , Zheng Yanqing , Kong Haikuan , Xin Jun , Chen Hui , Tu Xiaoniu , Gao Pan , Shi Erwei
Published: April 2011

Single crystals of Sr3NbAl1.5Ga1.5Si2O14 (SNAGS) with langasite structure have been successfully grown by Czochralski method. The X‐ray diffraction (XRD) verified that the as‐grown crystal was isostructural with A3BC3D2O14 structure and the lattice parameters were calculated as follows: a = 8.242 Å, c = 5.041 Å, V = 296.6 Å3. The piezoelectric coefficient d11 was 5.7pC/N, which was 2.47 times of α‐quartz (d11=2.31pC/N). The electric resistivity was up to 3.04×106 Ωcm at 700 °C for X‐cut sample. In addition, the transmission spectrum of the SNAGS crystal showed that it had a high transmittance (>80%) in the range of 350‐800 nm and exceeded 90% above 520 nm. These results suggest that the SNAGS crystals have potential applications in high‐temperature piezoelectric sensors and optical techniques. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gsx transcription factors repress Iroquois gene expression
Authors: Winterbottom Emily F. , Ramsbottom Simon A. , Isaacs Harry V.
Published: April 2011

We have previously shown that the Gsx family homeobox gene Gsh2 is part of the regulatory network specifying dorsoventral pattern of primary neurons in the developing amphibian embryo. Here, we investigate the role of Gsx transcription factors in regulating the transcription of Iroquois family homeobox genes in the amphibian neural plate. Iroquois genes are key regulators of neural patterning and their expression is coincident with that of the Gsx genes during open neural plate stages. We show that Gsx proteins repress Iroquois expression in the embryo and conversely, inhibition of Gsx activity with either antisense morpholino oligos or an anti‐morphic Gsx protein up‐regulates Iroquois expression. These data indicate that Gsx factors act as negative regulators of Iroquois gene expression in the amphibian neural plate and support a model in which the Gsx proteins promote neuronal differentiation by repressing the expression of known inhibitors of neuronal differentiation such as Iro3. Developmental Dynamics 240:1422–1429, 2011. © 2011 Wiley‐Liss, Inc.
Extraction of nucleic acids from bacterial spores using bead‐based mechanical lysis on a plastic chip
Authors: Geissler Matthias , Beauregard Julie A. , Charlebois Isabelle , Isabel Sandra , Normandin François , Voisin Benoît , Boissinot Maurice , Bergeron Michel G. , Veres Teodor
Published: April 2011

This paper describes an experimentally simple and efficient way of integrating bead‐based mechanical cell lysis on a plastic chip. The chip is fabricated from machined slides of poly(methylmethacrylate) and accommodates a metal disk along with solid microbeads in a designated lysis chamber. Magnetic actuation of the metal disk induces collisions and frictional forces within the lysis matrix causing cell disruption. The efficiency of nucleic acid extraction was investigated using spores of Bacillus atrophaeus subsp. globigii and the amount of genomic DNA in the lysates has been quantified by real‐time PCR. Compared to a standardized DNA extraction method based on BD GeneOhm™ Lysis Kit, the yield was dependent on the composition of the lysis matrix, including size and relative amount of microbeads, along with instrumental parameters, such as duration and frequency of agitation. The interplay of these parameters should allow for optimizing lysis protocols to faithfully disrupt any particular type of cell without affecting the genetic material to be extracted.
Extended biotic ligand model for prediction of mixture toxicity of Cd and Pb using single metal toxicity data
Authors: Jho Eun Hea , An Jinsung , Nam Kyoungphile
Published: April 2011

The combined toxic effects of Cd and Pb in the presence of different concentrations of Ca2+ were predicted using the biotic ligand model (BLM), with the parameters derived from the Cd-only and Pb-only toxicity data. The BLM-based toxic unit (TU) approach and the proposed BLM-based fmix approach were used for prediction. The predicted mixture toxic effects using the BLM-based fmix approach were closer to the observed mixture effects (root mean square error [RMSE] = 9.7 at 25 mM Ca2+) than that using the BLM-based TU approach (RMSE = 25.6 at 25 mM Ca2+). This can be attributed to the fact that the BLM-based TU approach only considers the competition between Ca2+ and Cd or Pb, whereas the BLM-based fmix approach considers both the competition between Cd and Pb and the competition between Ca2+ and Cd or Pb for biotic ligand sites. In addition, the parameters derived from the Cd-only and Pb-only solutions in the presence of the background Ca2+ concentration (0.025 mM) could be used to predict the mixture toxic effects at higher Ca2+ concentrations. The BLM-based fmix approach proposed in the current study suggests a new way of predicting the Cd–Pb mixture toxicity from the single metal toxicity data by adopting the fmix values. Environ. Toxicol. Chem. 2011; 30:1697–1703. © 2011 SETAC
An ALE mesh movement scheme for long‐term in‐flight ice accretion
Authors: Fossati M. , Khurram R. A. , Habashi W. G.
Published: April 2011

The rather irregular shapes that glaze ice may grow into while accreting over the surface of an aircraft represent a major difficulty in the numerical simulation of long periods of in‐flight icing. There is a constant need for remeshing: a wasteful procedure. In the framework of ALE formulations, a mesh movement scheme is presented, in which frame and elasticity analogies are loosely coupled. The resulting deformed mesh preserves the quality of elements, especially in the near‐wall region, where accurate prediction of heat flux and shear stresses is required. The proposed scheme handles mesh deformation in a computationally efficient manner by localizing the mesh deformation. The 2D problem of ice accretion over single and multi‐element airfoils is considered here as a numerical experiment. Experimentally measured glaze ice shapes were used to evaluate the performance of the present approach. Copyright © 2011 John Wiley & Sons, Ltd.