bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantifying retrieval uncertainties in the CM-SAF cloud physical property algorithm with simulated SEVIRI observations
Authors: Jonkheid B. J. , Roebeling R. A. , van Meijgaard E.
Published: February 2012

Abstract. The uncertainties in the cloud physical properties derived from satellite observations make it difficult to interpret model evaluation studies. In this paper, the uncertainties in the cloud water path (CWP) retrievals derived with the cloud physical properties retrieval algorithm (CPP) of the climate monitoring satellite application facility (CM-SAF) are investigated. To this end, a numerical simulator of MSG-SEVIRI observations was developed that calculates the reflectances at 0.64 and 1.63 μm for a wide range of cloud parameters, satellite viewing geometries and surface albedos. These reflectances are used as input to CPP, and the retrieved values of CWP are compared to the original input of the simulator. It is shown that the CWP retrievals are very sensitive to the assumptions made in the CPP code. The CWP retrieval errors are generally small for unbroken single-phase clouds with COT >10, with retrieval errors of ~3% for liquid water clouds to ~10% for ice clouds. When both liquid water and ice clouds are present in a pixel, the CWP retrieval errors increase dramatically; depending on the cloud, this can lead to uncertainties of 40–80%. CWP retrievals also become more uncertain when the cloud does not cover the entire pixel, leading to errors of ~50% for cloud fractions of 0.75 and even larger errors for smaller cloud fractions. Thus, the satellite retrieval of cloud physical properties of broken clouds and multi-phase clouds is complicated by inherent difficulties, and the proper interpretation of such retrievals requires extra care.
Long-term monitoring of atmospheric total gaseous mercury (TGM) at a remote site in Mt. Changbai area, northeastern China
Authors: Fu X. W. , Feng X. , Shang L. H. , Wang S. F. , Zhang H.
Published: February 2012

Abstract. Total gaseous mercury (TGM) was continuously monitored at a remote site (CBS) in the Mt. Changbai area, northeastern China biennially from 24 October 2008 to 31 October 2010. The overall mean TGM concentration was 1.60 ± 0.51 ng m−3, which is lower than those reported from remote sites in eastern, southwestern and western China, indicating a relatively low regional anthropogenic mercury (Hg) emission intensity in northeastern China. Measurements at a site in the vicinity (~1.2 km) of the CBS station during August 2005 and July 2006 showed a significantly higher mean TGM concentration of 3.58 ± 1.78 ng m−3. The divergent result was partially attributed to fluctuations in the regional surface wind system and moreover an effect of local emission sources. The temporal variation of TGM at CBS was obviously influenced by regional sources as well as long-range transported Hg. Regional sources, frequently contributing to episodical high TGM concentrations, were pinpointed as a large iron mining district in northern North Korea and two large power plants and urban areas to the southwest of the sampling site. Source areas in Beijing, Tianjin, southern Liaoning, Hebei, northwestern Shanxi and northwestern Shandong were found to contribute to elevated TGM observations at CBS via long-range transport. The diurnal pattern of TGM at CBS was mainly regulated by regional sources, likely as well as intrusion of air masses from the free troposphere during summer season. There are no discernible seasonal pattern of TGM at CBS, which mainly showed links with the patterns of regional air movements and long-range transport.
Lidar measurement of planetary boundary layer height and comparison with microwave profiling radiometer observation
Authors: Wang Z. , Cao X. , Zhang L. , Notholt J. , Zhou B. , Liu R. , Zhang B.
Published: February 2012

Abstract. Using the wavelet technology method and lidar measurements the atmospheric boundary layer height was derived above the city of Lanzhou (China) and its suburb rural area – Yuzhong. Furthermore, at Yuzhong, the average boundary layer height and entrainment zone thickness was derived in convective situations. Simultaneously the boundary layer height was derived from the microwave observations using a profiling radiometer and the parcel method. The results show that both data sets agree in strong convective situations. However, for weak convective situations the lidar measurements reveal boundary layer heights that are higher compared to the microwave observations, because a decrease of the thermal boundary layer height does not directly lead to a drop of aerosols in that altitude layer. Finally, the entrainment zone thicknesses are compared with theoretical predictions, and the results show some consistence between both data sets.
Ion resonance acceleration by dipolarization fronts: analytic theory and spacecraft observation
Authors: Artemyev A. V. , Lutsenko V. N. , Petrukovich A. A.
Published: February 2012

Abstract. In this paper, we consider the mechanism of ion acceleration by dipolarization fronts in the Earth's magnetotail. The statistics of dipolarization front observations by Interball-tail have been collected from 1995 to 1998 (51 events). We demonstrate that near dipolarization fronts bursts of energetic ions are often observed with an average energy of about 100–200 keV. We develop the analytical model of the ion resonance interaction with dipolarization fronts to describe the observed acceleration. We compare the model and the observations to estimate the width of fronts along the dawn-dusk direction, Ry. The mean value is ⟨ Ry ⟩ ~6 RE.
Improved modelling of atmospheric ammonia over Denmark using the coupled modelling system DAMOS
Authors: Geels C. , Andersen H. V. , Ambelas Skjøth C. , Christensen J. H. , Ellermann T. , Løfstrøm P. , Gyldenkærne S. , Brandt J. , Hansen K. M. , Frohn L. M. , Hertel O.
Published: February 2012

Abstract. A local-scale Gaussian dispersion-deposition model (OML-DEP) has been coupled to a regional chemistry-transport model (DEHM) in the Danish Ammonia Modelling System, DAMOS. Thereby it has been possible to model the distribution of ammonia concentrations and depositions on a spatial resolution down to 400 m × 400 m for selected areas in Denmark. DAMOS has been validated against measured concentrations from the dense measuring network covering Denmark. Here measured data from 21 sites are included and the validation period covers 2–5 yr within the period 2005–2009. A standard time-series analysis (using statistic parameters like correlation and bias) show that the coupled model system captures the measured time-series better than the regional scale model alone. However, our study also shows that about 50% of the modelled concentration level at a given location originates from non-local emission sources. The local-scale model covers a domain of 16 km × 16 km and of the locally released ammonia (NH3) within this domain, our simulations at five sites, show that 14–27% of the locally emitted NH3 also deposit locally. These results underline the importance of including both high-resolution locale-scale modelling of NH3 as well as the regional scale component described by the regional model. The DAMOS system can be used as a tool in environmental management in relation to assessments of total nitrogen load of sensitive nature areas in intense agricultural regions. However, high spatio-temporal resolution in input parameters like NH3 emissions and land-use data are required.
Contributions of ectomycorrhizal fungal mats to forest soil respiration
Authors: Phillips C. L. , Kluber L. A. , Martin J. P. , Caldwell B. A. , Bond B. J.
Published: February 2012

Abstract. Distinct aggregations of fungal hyphae and rhizomorphs, or "mats" formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in Western Oregon to investigate whether there was an incremental increase in respiration from mat soils, and to estimate mat contributions to total soil respiration. We found that areas where Piloderma mats colonized the organic horizon often had higher soil surface flux than non-mats, with the incremental increase in respiration averaging 16 % across two growing seasons. Both soil physical factors and biochemistry were related to the higher surface flux of mat soils. When air-filled pore space was low (high soil moisture), soil CO2 production was concentrated into near-surface soil horizons where mats tend to colonize, resulting in greater apparent differences in respiration between mat and non-mat soils. Respiration rates were also correlated with the activity of chitin-degrading soil enzymes. This suggests that the elevated activity of fungal mats may be related to consumption or turnover of chitinous fungal cell-wall materials. We found Piloderma mats present across 57 % of the soil surface in the study area, and use this value to estimate a respiratory contribution from mats at the stand-scale of about 9 % of total soil respiration. The activity of EcM mats, which includes both EcM fungi and microbial associates, was estimated to constitute a substantial portion of total soil respiration in this old-growth Douglas-fir forest.
Measurement and modelling of evaporation from a coastal wetland in Maputaland, South Africa
Authors: Clulow A. D. , Everson C. S. , Mengistu M. G. , Jarmain C. , Jewitt G. P. W. , Price J. S. , Grundling P.-L.
Published: February 2012

Abstract. The contribution of freshwater supply from the Mfabeni Mire to Lake St. Lucia during dry periods is important to the survival of certain plant and animal species in the iSimangaliso Wetland Park. This freshwater supply is mainly dependent on the variability of the major components of the water balance, namely rainfall and total evaporation (ET). Attempts to quantify the water balance have been limited through uncertainties in quantifying ET from the Mfabeni Mire. Despite advances in evaporation measurement and modelling from wetlands, there still exists some doubt as to which methods are best suited to characterise wetland ET with most authors suggesting a combination of methods. In this study, the surface renewal (SR) method was successfully used to determine the long-term ET (12 months) from the Mfabeni Mire with calibration using eddy covariance during two window periods of approximately one week each. The SR method was found to be inexpensive, reliable and with low power requirements for unattended operation. The annual ET was lower (900 mm yr−1) than expected, due to cloud cover in summer and low atmospheric demand throughout the year, despite the available water and high windspeeds. Daily ET estimates were compared to the Priestley-Taylor results and a site specific calibration α = 1.0 was obtained for the site. The Priestley-Taylor results agreed well with the actual ET from the surface renewal technique (R2 = 0.96) throughout the 12 month period. A monthly crop factor (Kc) was determined for the standardised FAO-56 Penman-Monteith. However, Kc was variable in some months and should be used with caution for daily ET modelling. These results represent not only some of the first long-term measurements of ET from a wetland in Southern Africa, but also one of the few studies of actual ET in a subtropical peatland in the Southern Hemisphere. The study provides wetland ecologists and hydrologists with guidelines for the use of two internationally applied models for the estimation of wetland ET within a coastal, subtropical environment.
Understanding personal learning networks: Their structure, content and the networking skills needed to optimally use them
Authors: Rajagopal Kamakshi , Joosten-ten Brinke Desirée , Van Bruggen Jan , Sloep Peter B.
Published: February 2012

Networking is a key skill in professional careers, supporting the individual’s growth and learning. However, little is known about how professionals intentionally manage the connections in their personal networks and which factors influence their decisions in connecting with others for the purpose of learning. In this article, we present a model of personal professional networking for creating a personal learning network, based on an investigation through a literature study, semi-structured interviews and a survey.
Teenagers and social network sites: Do off-line inequalities predict their online social networks?
Authors: Ahn June
Published: February 2012

This study analyzes a data set of 701 U.S. teenagers (ages 12-18) that merges an online survey of social network site (SNS) preferences with administrative records from their public school districts. Using a multinomial logistic model, I examine whether offline divides across gender, ethnicity, socioeconomic status, self-esteem, and social capital predict teenagers’ membership into the popular SNSs, Facebook and Myspace. The results show that the characteristics of teens that use Facebook, Myspace, or both SNSs show distinct differences, which illuminate questions of digital divide and complex adolescent social practices as they relate to online participation. The study offers two main contributions by providing an analysis of: (a) teenage SNS users, a population that is less examined in the research literature of online communities; and, (b) the relationship between their off-line characteristics and online social networks.
Optical coherence tomography in tadalafil-associated retinal toxicity
Authors: Coscas Florence , Coscas Gabriel , Zucchiatti Ilaria , Bandello Francesco , Soubrane Gisele , Souïed Eric
Published: February 2012

Purpose

Tadalafil (Cialis) is a potent phosphodiesterase type 5 inhibitor that is widely used to treat erectile dysfunction. Phosphodiesterase-5 inhibitors have long been recognized to cause temporary and minor visual changes.

Methods

We report for the first time a case of visual disturbances due to reversible damage to the parafoveal photoreceptors following the use of tadalafil. The patient was examined using confocal scanning laser ophthalmoscopy combined with spectral domain optical coherence tomography (OCT).

Results

Spectral domain OCT of the right eye revealed a hyperreflective dense area and the appearance of a serous retinal detachment (SRD). The photoreceptors’ internal segment–outer segment (IS-OS) interface was thickened and markedly hyperreflective without distinguishable deposits. The increased hyperreflectivity of the IS-OS interface created a hyporeflective space behind which mimicked the appearance of a SRD. The use of tadalafil was discontinued and the patient examined 2 months later. Spectral domain OCT revealed disappearance of the dense area and the pseudo-SRD. The associated symptoms resolved rapidly with discontinuation of the drug.

Conclusions

Tadalafil use may be associated with reversible damage to the photoreceptors and corresponding visual symptoms.
Mechanical Analysis and Fabrication of a Penetrating Silicon Microprobe as an Artificial Optic Nerve Visual Prosthesis
Authors: Sui Xiaohong , Han Zhaolong , Zhou Dai , Ren Qiushi
Published: February 2012

Purpose

To investigate the mechanical response of a silicon microprobe while it penetrates the optic nerve.

Methods

The finite element method was adopted to analyze models of the mechanical aspects of the silicon microprobe, including the effects of dimensions, the buckling load, lateral load, and the interaction between the microprobe and the tissue of the optic nerve. The silicon microprobe was fabricated based on silicon-on-insulator (SOI) wafer by micro-electro-mechanical system (MEMS) processing techniques.

Results

The designed microprobe shank was 750 μm long and 110 μm wide with thickness of 15 μm. Lateral barbs were included so as to decrease the stress at stimulating-site regions. The microprobe could withstand a 50 MPa vertical load on the shank tip before buckling, but was more likely to be damaged by a lateral load rather than a vertical one. The silicon microprobe was successfully fabricated by MEMS processing techniques based on a four-inch SOI wafer. Mechanical analysis of the interactions between shank and optic nerve tissue showed that the maximum stress changed during the process of the microprobe insertion.

Conclusions

A silicon microprobe was designed as a potential visual prosthesis to be used for optic nerve stimulation. The mechanical issues were analyzed by means of the finite element method, and the implantable microprobe was fabricated based on a silicon-on-insulator wafer to maintain a uniform thickness.
Modulating Anti-MicroRNA-21 Activity and Specificity Using Oligonucleotide Derivatives and Length Optimization
Authors: Muñoz-Alarcón Andrés , Guterstam Peter , Romero Cristian , Behlke Mark A. , Lennox Kim A. , Wengel Jesper , EL Andaloussi Samir , Langel Ülo
Published: February 2012

MicroRNAs are short, endogenous RNAs that direct posttranscriptional regulation of gene expression vital for many developmental and cellular functions. Implicated in the pathogenesis of several human diseases, this group of RNAs provides interesting targets for therapeutic intervention. Anti-microRNA oligonucleotides constitute a class of synthetic antisense oligonucleotides used to interfere with microRNAs. In this study, we investigate the effects of chemical modifications and truncations on activity and specificity of anti-microRNA oligonucleotides targeting microRNA-21. We observed an increased activity but reduced specificity when incorporating locked nucleic acid monomers, whereas the opposite was observed when introducing unlocked nucleic acid monomers. Our data suggest that phosphorothioate anti-microRNA oligonucleotides yield a greater activity than their phosphodiester counterparts and that a moderate truncation of the anti-microRNA oligonucleotide improves specificity without significantly losing activity. These results provide useful insights for design of anti-microRNA oligonucleotides to achieve both high activity as well as efficient mismatch discrimination.
Impacts of Cropping Systems and Long-Term Tillage on Soil Microbial Population Levels and Community Composition in Dryland Agricultural Setting
Authors: Ng Justin P. , Hollister Emily B. , González-Chávez Ma. del Carmen A. , Hons Frank M. , Zuberer David A. , Aitkenhead-Peterson Jacqueline A. , Loeppert Richard , Gentry Terry J.
Published: February 2012

Few studies have used molecular methods to correlate the abundance of specific microbial taxonomic groups with changes in soil properties impacted by long-term agriculture. Community qPCR with 16S rRNA gene sequencing to examine the effects of long-term crop-management practices (no-till vs. conventional tillage, and continuous wheat (Triticum aestivum L.) vs. sorghum-wheat-soybean rotation (Sorghum bicolor L. Moench-Triticum aestivum L.-Glycine max L. Merr) on bacterial and fungal relative abundances and identify the dominant members of the soil microbial community. The qPCR assays revealed that crop rotation decreased bacterial copy numbers, but no-till practices did not significantly alter bacteria or fungi relative to conventional tillage. Cyanobacteria were more abundant while Actinobacteria were less numerous under continuous wheat. Acidobacteria and Planctomycetes were positively correlated with soil microbial biomass C and N. This study highlights ways cropping systems affect microbial communities and aids the development of sustainable agriculture.
Alone All Together—The Conundrum of Music Teacher Isolation and Connectedness
Authors: Sindberg Laura
Published: February 2012

Within the typical school structure, music teachers comprise a small number of the entire teaching staff. This can range from a single music teacher in an elementary school to three or more music teachers in a secondary school. Furthermore, it is not uncommon for music teachers to travel to multiple schools as part of their teaching assignment. Given the minority status of music teachers, it is possible that they experience feelings of professional isolation. This phenomenological study sought to examine the lived experience of professional isolation and connectedness among music teachers in an urban school district. The question guiding this inquiry was: How do public school music teachers perceive and describe their experience of professional isolation and connectedness? Four themes emerged from the data: emotional reactions, external factors, social factors, and awareness. Primary findings suggest that music teachers experience professional isolation to varying levels and the lived experience of isolation and connectedness, as portrayed by these teachers, is personally constructed and individually meaningful.
Socialization of Undergraduate Music Education Majors in a Professional Development Partnership Model
Authors: McClellan Edward R.
Published: February 2012

The purpose of this study was to examine music teacher education training models and model attributes that create the most effective environment in which undergraduate music education majors may construct their own professional identities unfettered by existing norms of the music technician profession, transcend tradition, and improve current music education practice. Research literature was examined to consider model design characteristics that affect undergraduate music education major socialization and identity orientation, learning that integrates learning theories with practice, and initial teaching is integrated with reflective practice. Through the collaborative university-school Professional Development Partnership model, a community of practice may empower undergraduate apprentice music teachers to think critically, develop creative independence in music teaching, construct beliefs about themselves as music teachers, and revise their principles regarding music teaching.
Correction of Posttraumatic Enophthalmos
Authors: Hazani Ron , Yaremchuk Michael J.
Published: February 2012

Management of posttraumatic enophthalmos can present as a challenge to the reconstructive surgeon, particularly in cases of late presentation. This article reviews the pertinent anatomy of the orbit, diagnostic modalities, indications for surgery, and surgical approaches as they relate to the treatment of posttraumatic enophthalmos. Internal orbital reconstruction has evolved to an elegant procedure incorporating various biologic or alloplastic implants, including anatomical pre-bent implants. Successful repair of late enophthalmos has been demonstrated in multiple recent studies and is likely related to the precision with which orbital anatomy can be restored.
Breast Reconstruction with Microvascular MS-TRAM and DIEP Flaps
Authors: Chang David W.
Published: February 2012

The free muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) and deep inferior epigastric perforator (DIEP) flaps involve transferring skin and subcutaneous tissue from the lower abdominal area and have many features that make them well suited for breast reconstruction. The robust blood supply of the free flap reduces the risk of fat necrosis and also enables aggressive shaping of the flap for breast reconstruction to optimize the aesthetic outcome. In addition, the free MS-TRAM flap and DIEP flap require minimal donor-site sacrifice in most cases. With proper patient selection and safe surgical technique, the free MS-TRAM flap and DIEP flap can transfer the lower abdominal skin and subcutaneous tissue to provide an aesthetically pleasing breast reconstruction with minimal donor-site morbidity.
Multiple Large Cysts Arising from Nevus Comedonicus
Authors: Jeong Hii-Sun , Lee Hye-Kyung , Lee Seung-Hyun , Kim Hyoung-Suk , Yi Sang-Yeop
Published: February 2012

Nevus comedonicus is a type of hamartoma that arises from a developmental anomaly of the mesodermal part of the pilosebaceous gland. In most cases of nevus comedonicus, an acne-like skin condition develops. Repeated inflammation can cause a morphological change to the cyst, papule, to abscess. We experienced a case of congenital nevus comedonicus, which led to the formation of large multiple cysts. A 50-year-old man was referred with a 12.5×10 cm lobulated mass on the posterior neck and upper back. The patient had a widespread presence of nevus comedonicus in the region ranging from the right superior chest to the posterior neck. The patient had a 30-year history of six prior excisions. A magnetic resonance imaging review led to a diagnosis of nevus comedonicus. Surgical treatment consisted of excision of the mass and wide excision for the patch type of nevus comedonicus around the neck. On histopathology, multiple masses were diagnosed as typical cysts containing keratinized tissue. The diffuse comedone lesions were diagnosed as nevus comedonicus. This case shows that large, multiple cysts can occur as a long-term complication of nevus comedonicus, and also highlights the importance of radical resection to prevent its further invagination.
Two Cases of Lower Body Contouring with a Spiral and Vertical Medial Thigh Lift
Authors: Kim Sang Wha , Han Hyun Ho , Seo Je Won , Lee Jung Ho , Oh Deuk Young , Ahn Sang Tae , Rhie Jong Won
Published: February 2012

Massive weight loss results in skin excess, leading to an unsatisfying body contour. Various thigh lift procedures can correct flabby skin in the lower leg. We present a lower body contouring technique with a report on two patients. The procedure is determined by the body contour of the patient. As the skin excess in the thigh area tended to appear mostly on the medial side, a vertical medial thigh lift was considered. Moreover, for patients with a pear/guitar-shaped body contour, we added the spiral thigh lift for skin excess in the buttocks and the lateral thigh area. The extent of tissue to excise was determined by pinching the patient in a standing position. The inferior skin flap was fixed to non-movable tissue, which was helpful for lifting the tissue and preventing the widening of the scar. After the operation, a drain was kept for 3 to 4 days. A compressive garment was used after removing the drain. There were no complications. The patients were discharged 6 to 8 days after the operation. In conclusion, skin excess, especially in the lower body, can be corrected by a thigh lift combining several procedures, varying from person to person.
Unusual ribbon‐like periventricular heterotopia with congenital cataracts in a Japanese girl
Authors: Tsuburaya Rie , Uematsu Mitsugu , Kikuchi Atsuo , Hino‐Fukuyo Naomi , Kunishima Shinji , Kato Mitsuhiro , Haginoya Kazuhiro , Tsuchiya Shigeru
Published: February 2012

Periventricular heterotopia (PH), clumps of neurons mislocated beside the ventricle, is caused by failure to initiate migration during embryogenesis. We report on a 32‐month‐old Japanese girl with a unique subtype of PH, namely ribbon‐like PH. The patient presented with severe psychomotor developmental delay, intractable epilepsy, and congenital cataracts and developed West syndrome phenotype. Brain magnetic resonance imaging revealed a unique undulating form of PH, categorized as ribbon‐like PH, and other brain malformations including simplified gyri and dysgenesis of the corpus callosum. There was no evidence of prenatal TORCH infection or associated syndrome. Array‐based comparative genomic hybridization revealed no chromosomal rearrangements. Genetic analyses of the FLNA, DCX, ARX, LIS1, and TUBA1A genes showed no mutations. Although little is known about ribbon‐like PH, the clinical manifestations in our patient clearly differed from those in other reported patients. © 2012 Wiley Periodicals, Inc.
Third case of 8q23.3‐q24.13 deletion in a patient with Langer–Giedion syndrome phenotype without TRPS1 gene deletion
Authors: Pereza Nina , Severinski Srećko , Ostojić Saša , Volk Marija , Maver Aleš , Dekanić Kristina Baraba , Kapović Miljenko , Peterlin Borut
Published: February 2012

Langer–Giedion syndrome (LGS) is a contiguous gene syndrome caused by a hemizygous deletion on chromosome 8q23.3‐q24.11 involving TRPS1 and EXT1 genes. We report on a girl with LGS phenotype and a 7.5 Mb interstitial deletion at chromosome 8q23.3‐q24.13. Array‐comparative genomic hybridization (a‐CGH) revealed a deletion encompassing only the EXT1 and not the TRPS1 gene. Even though the deletion of TRPS1 and EXT1 genes is responsible for craniofacial and skeletal features of LGS, there have been previous reports of patients with LGS phenotype and 8q24 deletions leaving the TRPS1 gene intact. To our knowledge, this is the third such case. Our patient differs from previously reported LGS patients without TRPS1 gene deletion in that she has the typical LGS facial dysmorphism and skeletal abnormalities. However, the girl is of normal height and has only a mild developmental delay. Additionally, she has dyslalia and premature adrenarche classified as Tanner stage 3 premature pubarche which have not yet been described as features of LGS. We examine the molecular breakpoints and phenotypes of our patient and previously reported cases. © 2012 Wiley Periodicals, Inc.
Conducting stability of nickel‐coated graphite/methyl vinyl silicone rubber composites
Authors: Zou Hua , Yan Shani , Sun Yebin , Zhang Liqun , Tian Ming
Published: February 2012

In this study, conductive composites of methyl vinyl silicone rubber (MVQ) filled with nickel‐coated graphite (NCG) were prepared. The effects of the storage time, aging time, stretching, neutral‐salt spraying, and acid‐salt spraying on the electrical conductivity of NCG/MVQ were investigated. The results indicate that the values of the NCG/MVQ volume resistivity increased a little and were no greater than 0.1 Ω cm after long‐term storage, thermooxidative aging, stretching, and neutral‐salt spraying, respectively; this showed good conductive stability. The volume resistivity rose rapidly under acid‐salt spraying; this indicated poor conductive stability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Simultaneous determination of atractylenolide II and atractylenolide III by liquid chromatography–tandem mass spectrometry in rat plasma and its application in a pharmacokinetic study after oral administration of Atractylodes Macrocephala Rhizoma extract
Authors: Shi Yang‐yang , Guan Shu‐hong , Tang Ren‐neng , Tao Si‐jiao , Guo De‐an
Published: February 2012

Atractylenolide II (AII) and atractylenolide III (AIII) are the major active components in Atractylodes Macrocephala Rhizoma (AMR). In this study, a sensitive, rapid and selective liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the simultaneous determination of AII and AIII in rat plasma using loliolide as internal standard (IS). After protein precipitation with ethyl acetate, the analytes were injected into an LC‐MS/MS system for quantification. Chromatography was performed using a C18 column, eluting with water and acetonitrile (45:55, v/v) at 0.2 mL/min. All analytes including IS were monitored under positive ionization conditions by multiple reaction monitoring with an electrospray ionization source. The validated method was successfully applied to the pharmacokinetic study of AII and AIII in rat plasma after oral administration of AMR extract. The results provided a meaningful basis for evaluating the clinical applications of traditional Chinese medicine. Copyright © 2012 John Wiley & Sons, Ltd.
Simultaneous determination of lactate and pyruvate in human sweat using reversed‐phase high‐performance liquid chromatography: a noninvasive approach
Authors: Biagi Simona , Ghimenti Silvia , Onor Massimo , Bramanti Emilia
Published: February 2012

The simultaneous determination of lactate and pyruvate in sweat has been performed using reversed phase high‐performance liquid chromatography (RP‐HPLC) with UV detection at 220 nm. The calibration curves were linear in the investigated range 0.3 ‐ 350 mm of lactate, 0.003‐ 1 mm of pyruvate. The sensitivity was good with a limit of detection of 0.03 mm for lactate and 0.001 mm for pyruvate. Recoveries evaluated for the entire procedure were 102 ± 0.1 and 96 ± 0.1for lactate and pyruvate, respectively. The method was successfully applied to analysis of sweat in 8 athletes at rest (pilocarpine sweating) and during physical exercise. Copyright © 2012 John Wiley & Sons, Ltd.
Catalytic Hydrocracking—Mechanisms and Versatility of the Process
Authors: Weitkamp Jens
Published: February 2012

Hydrocracking of saturated hydrocarbons can proceed by means of four distinctly different mechanisms. On bifunctional catalysts comprising hydrogenation/dehydrogenation and Brønsted acid sites alkenes and carbocations occur as intermediates. The current mechanistic views of bifunctional hydrocracking of long‐chain n‐alkanes are discussed in detail with emphasis on the now widely accepted concept of ideal hydrocracking. Other mechanisms are hydrogenolysis and Haag–Dessau hydrocracking which proceed, respectively, on monofunctional metallic and acidic catalysts. Even without a catalyst, thermal hydrocracking occurs in chain reactions via radicals. The chemistry of hydrocracking naphthenes on bifunctional catalysts resembles that of alkanes. A peculiarity, however, is the pronounced reluctance of cyclic carbenium ions to undergo endocyclic β‐scissions. The effect manifests itself in the so‐called paring reaction, which, in turn, forms the basis for measuring the Spaciousness Index for characterizing the effective pore width of zeolitic catalysts. Hydrocracking on bifunctional catalysts is among the very important processes in modern petroleum refining. It is primarily used for converting heavy oils into diesel and jet fuel. Besides, hydrocracking is appreciated for its pronounced versatility: numerous process variants exist which help to meet specific requirements in refineries or petrochemical plants. Two recent developments are briefly discussed in this review, viz. the conversion of surplus aromatics, e.g., in pyrolysis gasoline, into a synthetic feedstock for steam crackers, and quality enhancement of diesel fuel by selective ring opening of polynuclear aromatics.
Particle Size Analysis with Absolute Precision
Authors: Witt Wolfgang , Stübinger Thomas , Köhler Ulrich , List Joachim , Jordan Jens
Published: February 2012

Größenstandards dienen von jeher dazu, verschiedenste Größenangaben miteinander vergleichen und ineinander umwandeln zu können. In der Partikelmesstechnik sind dennoch bis heute keine geeigneten Standards verfügbar, die bei hoher Genauigkeit eine Rückführung gemessener Partikelgrößenverteilungen auf das Urmeter gestatten. Eine absolute Qualifizierung von Messsystemen ist derzeit deshalb nur eingeschränkt möglich. Ausgehend von der Analyse der aktuellen Situation werden Überlegungen zur Schaffung eines geeigneten Standardmaterials vorgestellt. Über Mischungen von präzise qualifizierbaren, kugelförmigen, monodispersen Fraktionen sollen breite Verteilungen als Lattenzaunverteilungen erzeugt werden. Mithilfe von Simulationen wurden wesentliche Randparameter bestimmt und ein erstes Material hergestellt mit dem derzeit eine absolute Genauigkeit von ca. ±2 % erreicht wird.
Investigation of D2 Receptor–Agonist Interactions Using a Combination of Pharmacophore and Receptor Homology Modeling
Authors: Malo Marcus , Brive Lars , Luthman Kristina , Svensson Peder
Published: February 2012

A combined modeling approach was used to identify structural factors that underlie the structure–activity relationships (SARs) of full dopamine D2 receptor agonists and structurally similar inactive compounds. A 3D structural model of the dopamine D2 receptor was constructed, with the agonist (−)‐(R)‐2‐OH‐NPA present in the binding site during the modeling procedure. The 3D model was evaluated and compared with our previously published D2 agonist pharmacophore model. The comparison revealed an inconsistency between the projected hydrogen bonding feature (Ser‐TM5) in the pharmacophore model and the TM5 region in the structure model. A new refined pharmacophore model was developed, guided by the shape of the binding site in the receptor model and with less emphasis on TM5 interactions. The combination of receptor and pharmacophore modeling also identified the importance of His3936.55 for agonist binding. This convergent 3D pharmacophore and protein structure modeling strategy is considered to be general and can be highly useful in less well‐characterized systems to explore ligand–receptor interactions. The strategy has the potential to identify weaknesses in the individual models and thereby provides an opportunity to improve the discriminating predictivity of both pharmacophore searches and structure‐based virtual screens.
Melatonin receptors are anatomically organized to modulate transmission specifically to cone pathways in the retina of Xenopus laevis
Authors: Wiechmann Allan F. , Sherry David M.
Published: February 2012

Confocal image of the relative distribution of the Mel1b melatonin receptor (green) and the ON bipolar cell marker guanine nucleotide binding protein alpha, Go α (red) in the retina of Xenopus laevis. Mel1b receptor immunoreactivity is absent from the cell bodies of ON bipolar cells, identifying the Mel1b receptorimmunoreactive bipolar cells as OFF bipolar cells. The Journal of Comparative Neurology, Volume 520, Number 6, pages 1115–1127.
One‐Step Decatungstate‐Photomediated PEGylation of Single‐Walled Carbon Nanotubes
Authors: Ravelli Davide , Montanaro Sara , Tomasi Corrado , Galinetto Pietro , Quartarone Eliana , Merli Daniele , Mustarelli Piercarlo , Fagnoni Maurizio
Published: February 2012

A straightforward PEGylation of SWCNTs has been performed by photomediated addition of various PEG derivatives onto the nanotube surfaces. The reaction was promoted both by UV and by solar light and took place under very mild conditions using commercial PEGs as PEGylating agents. The process relies on the formation of α‐oxy radicals directly from PEGs by a photochemical hydrogen abstraction reaction mediated by a decatungstate salt. Actually, low‐molecular‐weight PEGs (e.g. PEG 200) added more efficiently than those having long polyethylene glycol chains (e.g. PEG 600). Interestingly, the functionalization caused a partial dissolution of the resulting CNTs in the reaction medium.
Prenatal cortisol exposure predicts infant cortisol response to acute stress
Authors: O'Connor Thomas G. , Bergman Kristin , Sarkar Pampa , Glover Vivette
Published: February 2012

Experimental animal findings suggest that early stress and glucocorticoid exposure may program the function of the hypothalamic–pituitary–adrenal (HPA) axis in the offspring. The extension of these findings to human development is not yet clear. A prospective longitudinal study was conducted on 125 mothers and their normally developing children. Amniotic fluid was obtained at, on average, 17.2 weeks gestation; infant behavior and cortisol response to a separation–reunion stress was assessed at 17 months. Amniotic fluid cortisol predicted infant cortisol response to separation–reunion stress: infants who were exposed to higher levels of cortisol in utero showed higher pre‐stress cortisol values and blunted response to stress exposure. The association was independent of prenatal, obstetric, and socioeconomic factors and child–parent attachment. The findings provide some of the strongest data in humans that HPA axis functioning in the child may be predicted from prenatal cortisol exposure. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 145–155, 2013
Efficient risk assessment of lifeline networks under spatially correlated ground motions using selective recursive decomposition algorithm
Authors: Lim Hyun‐Woo , Song Junho
Published: February 2012

For effective hazard mitigation planning and prompt‐but‐prudent post‐disaster responses, it is essential to evaluate the reliability of infrastructure networks accurately and efficiently. A nonsimulation‐based algorithm, termed as a recursive decomposition algorithm (RDA), was recently proposed to identify disjoint cut sets and link sets and to compute the network reliability. This paper introduces a ‘selective’ RDA, which preferentially identifies critical disjoint cut sets and link sets to calculate the probabilities of network disconnection events with a significantly reduced number of identified sets. To this end, the original RDA is improved by replacing the shortest path algorithm with an algorithm that identifies the most reliable path, and by using a graph decomposition scheme based on the probabilities associated with the subgraphs. The critical sets identified by the algorithm are also used to compute conditional probability‐based importance measures that quantify the relative importance of network components by their contributions to network disconnection events. This paper also introduces a risk assessment framework for lifeline networks based on the use of the selective RDA, which can consider both interevent and intraevent uncertainties of spatially correlated ground motions. The risk assessment framework and the selective RDA are demonstrated by a hypothetical network example, and the gas and water transmission networks of Shelby County in Tennessee, USA. The examples show that the proposed framework and the selective RDA greatly improve efficiency of risk assessment of complex lifeline networks, which are characterized by a large number of components, complex network topology, and statistical dependence between component failures. Copyright © 2012 John Wiley & Sons, Ltd.
Clinically relevant drug interactions in anxiety disorders
Authors: Muscatello Maria Rosaria , Spina Edoardo , Bandelow Borwin , Baldwin David S.
Published: February 2012

Objective

Certain drugs used in the treatment of patients with anxiety disorders can interact with other psychotropic drugs and with pharmacological treatments for physical illnesses. There is a need for an updated comparative review of clinically relevant drug interactions in this area.

Design

Relevant literature on drug interactions with medications used in the treatment of anxiety disorders was identified through a search in MEDLINE and EMBASE.

Results

Drug interactions involving medications used to treat anxiety disorders may be pharmacokinetic, such as enzyme inhibition or induction in the cytochrome P450 system and transporter‐mediated drug interactions, or pharmacodynamic, such as additive effects in causing drowsiness or additive effects at neurotransmitter receptors. Certain selective serotonin reuptake inhibitors (fluoxetine, fluvoxamine, and paroxetine) are particularly liable to be potentially involved in untoward pharmacokinetic interactions.

Conclusions

The potential for drug interactions with medications used in anxiety disorders should be the cause of clinical concern, particularly in elderly individuals. However, the liability for harmful drug interactions may be anticipated, and the risk reduced. Although not all interactions are clinically relevant, careful monitoring of clinical response and possible interactions is essential. Copyright © 2012 John Wiley & Sons, Ltd.
Mothers' and Fathers' Parenting Quality and Toddlers' Interactive Behaviours in Dyadic and Triadic Family Contexts
Authors: Kwon Kyong‐Ah , Jeon Hyun‐Joo , Lewsader Joellen T , Elicker James
Published: February 2012

Based on a family systems perspective, this research examined the role of parental gender and family play context in parent–toddler interactions and how behaviours of family members influence each other. Sixty‐seven mostly White, middle‐class families consisting of a mother, father and toddler were videotaped in three separate sessions: mother–child, father–child and both parents–child at a university laboratory setting. The results indicated that there were significant main effects of both parent gender (mother versus father) and context (dyadic versus triadic) on parents' positive and negative parenting and children's engagement and negativity toward parents. Higher levels of mutual engagement between mothers and toddlers were associated with lower levels of fathers' positive parenting and children's engagement with fathers, when moving from the dyadic to the triadic play context. However, fathers' mutual engagement with toddlers was not associated with mothers' parenting quality and child interactive behaviours with mothers. There were also interaction effects of parent gender and context on parents' negative parenting and children's engagement and negativity toward parents. This study adds unique insights to the differences and similarities of parent–child dyadic and triadic interactions during toddlerhood. Copyright © 2012 John Wiley & Sons, Ltd.
Longitudinal Assessment of Sleep–Wake Regulation and Attachment Security with Parents
Authors: Zentall Shannon R. , Braungart‐Rieker Julia M. , Ekas Naomi V. , Lickenbrock Diane M.
Published: February 2012

The development of sleep–wake regulation occurs within the context of the infant–parent relationship. The present study investigated (1) patterns of change in night waking across infancy and attachment to parents and (2) if dependency, a characteristic of secure subgroup B4 and insecure‐resistant infants, accounted for differences in night waking. Forty‐six families reported on the number of infant night wakings at 7, 12, and 14 months of age. Attachment was measured at 12 (infant–mother) and 14 (infant–father) months. Findings suggest that infants with a secure (including the dependent‐secure, B4) pattern of attachment with mothers decreased in the number of night wakings over time, whereas infants with an insecure‐resistant pattern of attachment with mothers continued to wake at night into the second year. Attachment dependency did not account for differences in night waking. These findings are important to understanding the mechanism(s) underlying the relation between attachment and sleep–wake regulation. Copyright © 2012 John Wiley & Sons, Ltd.
Function biomedical informatics research network recommendations for prospective multicenter functional MRI studies
Authors: Glover Gary H. , Mueller Bryon A. , Turner Jessica A. , van Erp Theo G.M. , Liu Thomas T. , Greve Douglas N. , Voyvodic James T. , Rasmussen Jerod , Brown Gregory G. , Keator David B. , Calhoun Vince D. , Lee Hyo Jong , Ford Judith M. , Mathalon Daniel H. , Diaz Michele , O'Leary Daniel S. , Gadde Syam , Preda Adrian , Lim Kelvin O. , Wible Cynthia G. , Stern Hal S. , Belger Aysenil , McCarthy Gregory , Ozyurt Burak , Potkin Steven G.
Published: February 2012

This report provides practical recommendations for the design and execution of multicenter functional MRI (MC‐fMRI) studies based on the collective experience of the Function Biomedical Informatics Research Network (FBIRN). The study was inspired by many requests from the fMRI community to FBIRN group members for advice on how to conduct MC‐fMRI studies. The introduction briefly discusses the advantages and complexities of MC‐fMRI studies. Prerequisites for MC‐fMRI studies are addressed before delving into the practical aspects of carefully and efficiently setting up a MC‐fMRI study. Practical multisite aspects include: (i) establishing and verifying scan parameters including scanner types and magnetic fields, (ii) establishing and monitoring of a scanner quality program, (iii) developing task paradigms and scan session documentation, (iv) establishing clinical and scanner training to ensure consistency over time, (v) developing means for uploading, storing, and monitoring of imaging and other data, (vi) the use of a traveling fMRI expert, and (vii) collectively analyzing imaging data and disseminating results. We conclude that when MC‐fMRI studies are organized well with careful attention to unification of hardware, software and procedural aspects, the process can be a highly effective means for accessing a desired participant demographics while accelerating scientific discovery. J. Magn. Reson. Imaging 2012;36:39–54. © 2012 Wiley Periodicals, Inc.