bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving uncertainty estimation in urban hydrological modeling by statistically describing bias
Authors: Del Giudice D. , Honti M. , Scheidegger A. , Albert C. , Reichert P. , Rieckermann J.
Published: April 2013

Abstract. Hydrodynamic models are useful tools for urban water management. Unfortunately, it is still challenging to obtain accurate results and plausible uncertainty estimates when using these models. In particular, with the currently applied statistical techniques, flow predictions are usually overconfident and biased. In this study, we present a flexible and computationally efficient methodology (i) to obtain more reliable hydrological simulations in terms of coverage of validation data by the uncertainty bands and (ii) to separate prediction uncertainty into its components. Our approach acknowledges that urban drainage predictions are biased. This is mostly due to input errors and structural deficits of the model. We address this issue by describing model bias in a Bayesian framework. The bias becomes an autoregressive term additional to white measurement noise, the only error type accounted for in traditional uncertainty analysis in urban hydrology. To allow for bigger discrepancies during wet weather, we make the variance of bias dependent on the input (rainfall) or/and output (runoff) of the system. Specifically, we present a structured approach to select, among five variants, the optimal bias description for a given urban or natural case study. We tested the methodology in a small monitored stormwater system described by means of a parsimonious model. Our results clearly show that flow simulations are much more reliable when bias is accounted for than when it is neglected. Furthermore, our probabilistic predictions can discriminate between three uncertainty contributions: parametric uncertainty, bias (due to input and structural errors), and measurement errors. In our case study, the best performing bias description was the output-dependent bias using a log-sinh transformation of data and model results. The limitations of the framework presented are some ambiguity due to the subjective choice of priors for bias parameters and its inability to directly reduce the causes of bias. More experience with the application of this framework will lead to a greater prior knowledge for a bias formulation. Furthermore, propagation of input uncertainty and improvement to the model structure are expected to reduce the bias.
Ikaite crystal distribution in winter sea ice and implications for CO2 system dynamics
Authors: Rysgaard S. , Søgaard D. H. , Cooper M. , Pućko M. , Lennert K. , Papakyriakou T. N. , Wang F. , Geilfus N. X. , Glud R. N. , Ehn J. , McGinnis D. F. , Attard K. , Sievers J. , Deming J. W. , Barber D.
Published: April 2013

Abstract. The precipitation of ikaite (CaCO3 ⋅ 6H2O) in polar sea ice is critical to the efficiency of the sea ice-driven carbon pump and potentially important to the global carbon cycle, yet the spatial and temporal occurrence of ikaite within the ice is poorly known. We report unique observations of ikaite in unmelted ice and vertical profiles of ikaite abundance and concentration in sea ice for the crucial season of winter. Ice was examined from two locations: a 1 m thick land-fast ice site and a 0.3 m thick polynya site, both in the Young Sound area (74° N, 20° W) of NE Greenland. Ikaite crystals, ranging in size from a few μm to 700 μm, were observed to concentrate in the interstices between the ice platelets in both granular and columnar sea ice. In vertical sea ice profiles from both locations, ikaite concentration determined from image analysis, decreased with depth from surface-ice values of 700–900 μmol kg−1 ice (~25 × 106 crystals kg−1) to values of 100–200 μmol kg−1 ice (1–7 × 106 crystals kg−1) near the sea ice–water interface, all of which are much higher (4–10 times) than those reported in the few previous studies. Direct measurements of total alkalinity (TA) in surface layers fell within the same range as ikaite concentration, whereas TA concentrations in the lower half of the sea ice were twice as high. This depth-related discrepancy suggests interior ice processes where ikaite crystals form in surface sea ice layers and partly dissolve in layers below. Melting of sea ice and dissolution of observed concentrations of ikaite would result in meltwater with a pCO2 of <15 μatm. This value is far below atmospheric values of 390 μatm and surface water concentrations of 315 μatm. Hence, the meltwater increases the potential for seawater uptake of CO2.
Desert dust deposition on Mt. Elbrus, Caucasus Mountains, Russia in 2009–2012 as recorded in snow and shallow ice core: high-resolution "provenancing", transport patterns, physical properties and soluble ionic composition
Authors: Kutuzov S. , Shahgedanova M. , Mikhalenko V. , Lavrentiev I. , Kemp S.
Published: April 2013

Abstract. A record of dust deposition events between 2009 and 2012 on Mt. Elbrus, Caucasus Mountains derived from a snow pit and a shallow ice core is presented for the first time for this region. A combination of isotopic analysis, SEVIRI red-green-blue composite imagery, MODIS atmospheric optical depth fields derived using the Deep Blue algorithm, air mass trajectories derived using the HYSPLIT model and analysis of meteorological data enabled identification of dust source regions with high temporal (hours) and spatial (cf. 20–100 km) resolution. Seventeen dust deposition events were detected; fourteen occurred in March–June, one in February and two in October. Four events originated in the Sahara, predominantly in north-eastern Libya and eastern Algeria. Thirteen events originated in the Middle East, in the Syrian Desert and northern Mesopotamia, from a mixture of natural and anthropogenic sources. Dust transportation from Sahara was associated with vigorous Saharan depressions, strong surface winds in the source region and mid-tropospheric south-westerly flow with daily winds speeds of 20–30 m s−1 at 700 hPa level and, although these events were less frequent, they resulted in higher dust concentrations in snow. Dust transportation from the Middle East was associated with weaker depressions forming over the source region, high pressure centered over or extending towards the Caspian Sea and a weaker southerly or south-easterly flow towards the Caucasus Mountains with daily wind speeds of 12–18 m s−1 at 700 hPa level. Higher concentrations of nitrates and ammonium characterise dust from the Middle East deposited on Mt. Elbrus in 2009 indicating contribution of anthropogenic sources. The modal values of particle size distributions ranged between 1.98 μm and 4.16 μm. Most samples were characterised by modal values of 2.0–2.8 μm with an average of 2.6 μm and there was no significant difference between dust from the Sahara and the Middle East.
Análisis bibliométrico sobre la producción científica archivística en la Red de Revistas Científicas de América Latina y el Caribe (Redalyc) durante el período 2001-2011
Authors: Montilla Peña Leomar José
Published: April 2013

Objetivo. Analiza la producción científica archivística registrada en la hemeroteca de acceso libre Red de Revistas Científicas de América Latina y el Caribe (Redalyc). Método. Se aplicó un estudio bibliométrico con un muestreo que incluyó un análisis estadístico longitudinal desde el año 2001 hasta 2011. Se desarrollaron búsquedas avanzadas por palabras clave relacionadas a la archivística.Resultados. Se identificó que el año de mayor productividad fue el 2011 con un total de 19 publicaciones, siendo Biblios la revista que más ha publicado sobre archivística con 22 artículos, encontrándose que el 68,38% de la producción autoral son firmados por un solo autor.Conclusiones. En el decenio estudiado se registraron en Redalyc un total de 117 publicaciones referidas al área, existiendo un crecimiento gradual en los últimos años en la productividad científica archivística. Se identificó que los temas más comunes son: archivos como medio de acceso a la información, fuentes documentales.
Elaboración de una guía visual sobre experiencias en materia de conservación de colecciones en archivos y bibliotecas
Authors: Dobrecky Leticia Paula
Published: April 2013

Se presenta una propuesta para reunir imágenes sobre experiencias llevadas a cabo por archivos y bibliotecas en materia de conservación de colecciones que se encuentran disponibles en los sitios web de las instituciones. Para tal fin, se diseña una guía orientada a la identificación visual de las problemáticas relacionadas con dicha temática. Para ello, se inicia con la búsqueda y descripción de los materiales seleccionados hasta la difusión y publicación de la obra en el repositorio E-LIS. El análisis de los resultados permite establecer que si bien una de sus principales ventajas es la facilidad de consulta, aún falta incorporar mayor funcionalidad para la recuperación de la información. Se está comenzando a desarrollar un nuevo recurso en un entorno más dinámico para superar dicha limitación.
Perfil do gestor da informação em bibliotecas universitárias na Região Metropolitana do Recife
Authors: Rodrigues Anielma Maria Marques , Azevedo Alexander Willian
Published: April 2013

Objetivo. Trata-se de uma pesquisa bibliográfica de natureza descritiva com o objetivo de delinear o perfil do gestor da informação em bibliotecas universitárias do Recife e de sua Região Metropolitana. Método. Para alcançar o objetivo proposto foi realizado um levantamento bibliográfico, na área de ciência da informação, na qual foi possível contextualizar os atributos de competências dos profissionais da informação partir das abordagens qualitativas e quantitativas. Resultados. Os resultados obtidos apontam questões sobre: a) atividades executadas na rotina do profissional; b) habilidades que possuem para realizar suas tarefas; c) profissional; d) local de trabalho; e) formação acadêmica. Conclusões. Com as respostas obtidas é possível vislumbrar as diferentes competências do bibliotecário de acordo com sua atuação profissional e experiência pessoal.
Cemented Total Hip Arthroplasty in Rheumatoid Arthritis. A Systematic Review of the Literature
Authors: Zwartelé Rob , Pöll Ruud G.
Published: April 2013

Background

Cemented total hip arthroplasty (THA) in rheumatoid arthritis (RA) is allegedly associated with increased rates of infection, dislocation and aseptic loosening of cup and stem.

Method

Systematic review of the literature on clinical and radiological results of cemented THA in RA.

Results

Twenty-one case series and eight reports on four implant registries were included. The quality of most studies was judged to be poor. The reported rates of infection and dislocation in the case series were conflicting with a risk of bias due to under-registration. The registries proved unsuitable for providing reliable data on the incidence of these two complications. Increased rates of aseptic loosening were reported in 10 out of 20 case series on the cup and in six out of 19 on the stem. Nearly all of these were based on series implanted before 1980. None of the registries reported a significantly increased risk of aseptic loosening of cup or stem.

Conclusions

Considering the relatively frequent reports of increased infection rates in combination with the potential under-registration of complications, RA patients have to be considered to have a mild increased risk of postoperative infection. Case series and registries cannot answer the question of whether RA is a risk factor for dislocation as multivariate analysis is required. Increased rates of cup and stem failure due to aseptic loosening in RA patients are found in older but not in more recent studies.
Some Remarks on Bird's Brain and Behavior under the Constraints of Domestication
Authors: Mehlhorn Julia , Rehkämper Gerd
Published: April 2013

The relationship between domestication and evolution is still a matter of discussion. In this review, we present some arguments for the assumption that domestication could be seen as an evolutionary process including the possibility that new species might evolve. In course of domestication, many breeds have been developed which show numerous alterations in different parameters such as body size, coloring, habitat, behavior, and brain size and composition. Here, we would like to give an overview particularly about alterations and varieties in (brain) morphology and behavior in domestic poultry and argue that these alterations could be seen as adaptations to the man-made environment.
Lipids in Marine Ecosystems
Authors: Parrish Christopher C.
Published: April 2013

Lipids provide the densest form of energy in marine ecosystems. They are also a solvent and absorption carrier for organic contaminants and thus can be drivers of pollutant bioaccumulation. Among the lipids, certain essential fatty acids and sterols are considered to be important determinants of ecosystem health and stability. Fatty acids and sterols are also susceptible to oxidative damage leading to cytotoxicity and a decrease in membrane fluidity. The physical characteristics of biological membranes can be defended from the influence of changing temperature, pressure, or lipid peroxidation by altering the fatty acid and sterol composition of the lipid bilayer. Marine lipids are also a valuable tool to measure inputs, cycling, and loss of materials. Their heterogeneous nature makes them versatile biomarkers that are widely used in marine trophic studies, often with the help of multivariate statistics, to delineate carbon cycling and transfer of materials. Principal components analysis has a strong following as it permits data reduction and an objective interpretation of results, but several more sophisticated multivariate analyses which are more quantitative are emerging too. Integrating stable isotope and lipid data can facilitate the interpretation of both data sets and can provide a quantitative estimate of transfer across trophic levels.
Reducing Pesticide Drift by Considering Propeller Rotation Effects From Aerial Application Near Buffer Zones
Authors: Thomson Steven James , Womac Alvin R , Mulrooney Joseph E
Published: April 2013

Off-target drift of chemical from agricultural spraying can damage sensitive crops, destroy beneficial insects, and intrude on human and domestic animal habitats, threatening environmental quality. Reduction of drift from aerial application can be facilitated at the edge of a field by offsetting spray ½ or 1 boom width from the field edge or by switching off one boom. For single boom application (and especially when spraying in a cross wind), there is some question whether off-target drift of sprayed crop protection agent is influenced by which boom is spraying and if direction of propeller rotation has any effect. An experiment was conducted to determine the effect of propeller wash rotation on aerial spray drift from turbine-powered aircraft. Spray samplers were placed at three sample lines to collect drift fallout and air-entrained particles 104, 134, 195, and 317 meters downwind, perpendicular to the flight path. An aqueous mixture of malathion was applied from the aircraft through fifty hollow cone nozzles. Five total replications were conducted over two days. Each replication had four treatment combinations of actively spraying boom and airplane direction. Results showed that neither active boom nor boom location (upwind or downwind) was statistically significant for either sampling method at the 0.05 level. Blocking the study to account for weather differences increased statistical precision. Thus when analysis was limited to the second day of testing, propeller wash direction was significant at the 0.10 level for the fallout sheets (P = 0.0773), and at the 0.05 level for high volume (Hi-Vol) air samplers (P = 0.0200). Higher concentrations occurred when propeller wash spiraled downwind. Based on results of this study, recommendations for pilots spraying with a single boom near a boundary is to spray so that propeller wash rotation occurs upwind.
Synthesis and Crystal Structure of a Mn(II) Metal-Organic Framework Based on a Polydentate Schiff Base Ligand
Authors: Wang Jun Li , Li Hai Yan , Liu Chen Hong , Bai Yan
Published: April 2013

A Mn(II) metal-organic framework {[MnL2(NCS)2]·(H2O)4}n (1) with L=bis(pyridin-3-ylmethylene) biphenyl-2,20`-dicarbohydrazide has been synthesized and characterized by IR spectroscopy, elemental analysis, UV spectroscopy, thermogravimetric (TG) analysis, powder X-ray diffraction, and single-crystal X-ray structure determination. The Mn(II) atom has a distorted octahedral coordination environment with an N6 donor set from four ligands and two NCS- anions. The structure of 1exhibits a layer framework containing tetranuclear metallacyclic ring units [MnII
4L4] in the chair conformation. In addition, there are multiform O-H···O, C-H···O, N-H···O, and C-H···N hydrogen bonds and C-H···p interactions in a three-dimensional supramolecular network.
The Inclination Window for Low Earth Sun Synchronized Satellite Orbits
Authors: Cakaj Shkelzen , Kamo Bexhet , Malarić Krešimir
Published: April 2013

LEO (Low Earth Orbit) environmental satellites provide continuous coverage of Earth, supplying meteorological and oceanic observation data which are important in aerospace and maritime. The missions of such satellites are mainly based on photo imagery. For photo imagery, it is also important that the area observed from the satellite is treated under the same lighting conditions. This can be achieved by keeping the orbital plane position constant relative to the Sun due to the Earth’s motion around the Sun, defined as orbital Sun synchronization. The line of nodes defines the orientation of the satellite’s orbital plane in space. Nodal regression is defined as the shift of the orbit’s line of nodes over time, as Earth revolves around the Sun. Nodal regression is caused by the Earth’s oblateness. Nodal regression is a very useful feature, especially used to synchronize low Earth circular orbits with the Sun. Nodal regression depends on orbital attitude and orbital inclination angle. This paper provides an inclination window calculation for different attitudes in order to maintain orbital Sun synchronization.
Efficacy and Safety of Nonbiologic Immunosuppressants in the Treatment of Nonrenal Systemic Lupus Erythematosus: A Systematic Review
Authors: Pego‐Reigosa José M. , Cobo‐Ibáñez Tatiana , Calvo‐Alén Jaime , Loza‐Santamaría Estíbaliz , Rahman Anisur , Muñoz‐Fernández Santiago , Rúa‐Figueroa Íñigo
Published: April 2013

Objective

To analyze the efficacy and safety of nonbiologic immunosuppressants in the treatment of nonrenal systemic lupus erythematosus (SLE).

Methods

We conducted a sensitive literature search in Medline, Embase, and the Cochrane Central Register of Controlled Trials up to October 2011. The selection criteria were studies including adult patients with SLE, a treatment intervention with nonbiologic immunosuppressants, a placebo or active comparator group, and outcome measures assessing efficacy and/or safety. Meta‐analyses, systematic reviews, clinical trials, and cohort studies were included. The quality of each study was evaluated using Jadad's scale and the Oxford Levels of Evidence.

Results

In total, 158 of the 2,827 initially found articles were selected for detailed review; 65 studies fulfilled the predetermined criteria. Overall, the studies were low quality, with only 11 randomized controlled trials (RCTs). Cyclophosphamide demonstrated efficacy for neuropsychiatric SLE, preventing relapses with an additional steroid‐sparing effect, although its use was associated with cumulative damage, development of cervical intraepithelial neoplasia, and ovarian failure. Other immunosuppressants (azathioprine, methotrexate, leflunomide, mycophenolate mofetil, and cyclosporin A) demonstrated efficacy in reducing nonrenal activity and flares with a steroid‐sparing effect, although only on occasion in non–placebo‐controlled RCTs of small numbers of patients.

Conclusion

Several immunosuppressants demonstrated their safety and efficacy in nonrenal SLE. A specific drug for each particular manifestation cannot be recommended, although cyclophosphamide may be used in more severe cases, and methotrexate may be the first option in most cases of moderately active SLE. High‐quality RCTs of larger numbers of patients are needed.
Purification of flue gas by ionic liquids: Carbon monoxide capture in [bmim][Tf2N]
Authors: Raeissi Sona , Florusse Louw J. , Peters Cor J.
Published: April 2013

Knowledge of the solubility of carbon monoxide in ionic liquids is important for investigating the potential use of ionic liquids in reactions and gas separations. There is very limited information available on the capacity of ionic liquids to capture CO. The solubility of CO in 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide was investigated experimentally up to temperatures and pressures of 460 K and 10 MPa, respectively. The solubility was shown to be only slightly temperature‐dependent, and the P–T diagram for a constant composition mixture is concave‐downward with a peak in pressure. By comparing the single‐gas solubility results of CO with various other gases in the same ionic liquid, it seems that ionic liquids can potentially be used as gas‐separating media. However, although the single‐gas solubilities vary considerably among some gases, further studies on mixed (multicomponent) gases should be carried out as the presence of other components can influence the solubility of each gas component. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3886–3891, 2013
Intragenic ILRAPL1 deletion in a male patient with intellectual disability, mild dysmorphic signs, deafness, and behavioral problems
Authors: Barone Chiara , Bianca Sebastiano , Luciano Daniela , Di Benedetto Daniela , Vinci Mirella , Fichera Marco
Published: April 2013

Intellectual disability affects approximately 2% of the population, with affected males outnumbering affected female, partly due to disturbances involving X‐linked genes. To date >90 genes associated with X‐linked intellectual disability have been identified and, among these, IL1RAPL1 (interleukin 1 receptor accessory protein‐like 1), was first described and mapped to Xp21.3‐22.1 in 1999. Intragenic deletions of IL1RAPL1, only rarely identified, have mostly been associated with nonspecific intellectual disability (IDX) and autism spectrum disorder. Array‐CGH analysis performed in our patient with intellectual disability, mild dysmorphic signs and changes in behavior identified a 285 Kb deletion in chromosome Xp21.3‐21.2, with breakpoints lying in IL1RAPL1 gene intron 2 and intron 3. This is the first patient reported in literature with deletion of only exon 3 of IL1RAPL1 gene. Our patient also exhibits bilateral progressive neurosensorial deafness, which has not been previously associated with IL1RAPL1 mutations. © 2013 Wiley Periodicals, Inc.
Palmo‐Plantar hyperkeratosis, intellectual disability, and spastic paraplegia in two maternal half brothers: Further evidence for an X‐linked inheritance
Authors: Isidor Bertrand , Lefebvre Tiphaine , Barbarot Sébastien , Perrier Julie , Mercier Sandra , Péréon Yann , Le Caignec Cédric , David Albert
Published: April 2013

In 1983, Fitzsimmons et al. reported four brothers with an unrecognized disorder characterized by intellectual disability, spastic paraplegia, and palmo‐plantar hyperkeratosis (OMIM 309500). In this report, we describe a family in which two males, maternal half‐brothers, had learning disabilities. Both patients also showed spasticity in the lower limbs and palmo‐plantar hyperkeratosis. The mother of the affected boys had learning difficulties but did not show any dermatological symptoms. This report confirms that the association of features reported by Fitzsimmons et al. is a distinct entity and further suggests an X‐linked mode of inheritance. © 2013 Wiley Periodicals, Inc.
12q24.33 deletion: Report of a patient with intellectual disability and review of the literature
Authors: Kehrer Martin , Singer Sylke , Grasshoff Ute , Schäferhoff Karin , Bonin Michael , Riess Olaf , Schöning Martin , Tzschach Andreas
Published: April 2013

Deletions of chromosome band 12q24.33 are rare. We report on a 17‐year‐old male patient with intellectual disability but no major malformations or dysmorphic features in whom a de novo interstitial 660 kb deletion in 12q24.33 was detected by SNP array analysis. This deletion was secondary to a translocation t(12;14)(q24.3;q13)dn that also led to a small deletion in 14q21.1 and a small duplication in 2p23.1. The deletion overlaps with two previously published larger deletions in patients who suffered from intellectual disability, obesity, and polycystic kidney disease, indicating that haploinsufficiency of one or several of the genes in the deleted interval of the patient reported here causes intellectual deficits, but not obesity or renal problems. The 14 RefSeq genes that are harbored by this deletion include P2RX2, which had previously been proposed as a candidate gene for intellectual disability. Thus, the patient reported here broadens our knowledge of the phenotypic consequences of deletions in 12q24.33 and facilitates genotype–phenotype correlations for chromosome aberrations of this region. © 2013 Wiley Periodicals, Inc.
Anal atresia, coloboma, microphthalmia, and nasal skin tag in a female patient with 3.5 Mb deletion of 3q26 encompassing SOX2
Authors: Salem Nabeel J.M. , Hempel Maja , Heiliger Katrin‐Janine , Hosie Stuart , Meitinger Thomas , Oexle Konrad
Published: April 2013

A full term female newborn presented with prominent forehead, bilateral microphthalmia, iris coloboma and cataract, wide intercanthal distance, large, low‐set and protruding ears, skin tag at the left nasal nostril, imperforate anus with rectovestibular fistula, and postnatal growth delay with brachymicrocephaly. A marker chromosome was not detectable and the copy number of 22q11 was normal. However, array CGH revealed a 3.5 Mb microdeletion of chromosome region 3q26.32–3q26.33 (chr. 3: 178,598,162–182,114,483; hg19) which comprised the SOX2 gene. While SOX2 haploinsufficiency is known to cause microphthalmia and coloboma, it has not been described before in patients with anal atresia. © 2013 Wiley Periodicals, Inc.
Partial tetrasomy 14 associated with multiple malformations
Authors: Winberg Johanna , Lagerstedt Robinson Kristina , Naess Karin , Lesko Nicole , Wibom Rolf , Liedén Agne , Anderlid Britt‐Marie , Graff Caroline , Nordenskjöld Agneta , Nordgren Ann , Gustavsson Peter
Published: April 2013

We report on an 8‐year‐old female patient with multiple malformations including bilateral cleft lip and palate, coloboma, and craniosynostosis. She presented with severe intellectual disability, seizures, and gastrointestinal dysfunction. Mitochondrial investigations in a muscle biopsy revealed reduced activity in complex I of the mitochondrial respiratory chain. Chromosome analysis and fluorescent in situ hybridization (FISH) studies showed an isodicentric marker chromosome 14 that was identified in all cells analyzed in peripheral blood lymphocytes and cultured fibroblasts. Parental chromosome studies were normal. To further characterize the marker chromosome and determine its origin, we performed array‐based comparative genomic hybridization (CGH) and polymorphic marker analysis with quantitative fluorescent PCR (QF‐PCR). The combined results from cytogenetic and array‐CGH analyses showed tetrasomy 14p13q13.1 and results from the QF‐PCR point to formation of the marker chromosome in the maternal meiosis. Isodicentric chromosomes involving partial 14q have previously been reported in four cases; however, this is the first patient with tetrasomy 14p13q13.1 in non‐mosaic form surviving beyond infancy. © 2013 Wiley Periodicals, Inc.
Constitutional telomeric association (Y;7) in a patient with a female phenotype
Authors: Beneteau Claire , Baron Sabine , David Albert , Jossic Frédérique , Poulain Damien , Schmitt Sébastien , Leclair Marc‐David , Piloquet Philippe , Le Caignec Cédric
Published: April 2013

Telomeric associations (TAs) are fusions between two telomeres of two different chromosomes without visible loss of chromosomal material. Constitutional telomeric associations are rare chromosomal anomalies. We report on the cytogenetic and molecular analyses of a TA involving chromosomes Y and 7 in a child with a female phenotype. Prenatal cytogenetic analysis showed a 45,X chromosome complement in all cells. No fetal abnormality was identified at ultrasound examinations and the pregnancy went to term. During childhood, the proband had gonadal dysgenesis but no other phenotypic manifestations of Turner syndrome. Molecular genetic analyses showed the presence of genomic DNA of the SRY gene without any mutation. Karyotyping and fluorescent in situ hybridization (FISH) analyses on blood showed two cell lines: one cell line with a TA involving chromosomes Y and 7 [46,X,tas(Y;7)(p11.32;q36.3)] and a second cell line with a 45,X pattern. A human pantelomeric repeat TTAGGG probe hybridized to the junction of the TA within the derivative chromosome. FISH and array comparative genomic hybridization (aCGH) analyses demonstrated that tas(Y;7) occurred without detectable loss of any sequence at the derivative chromosome. SNP array analysis excluded an uniparental isodisomy of chromosome 7. Knowing more about TAs will help geneticists to deliver accurate genetic counseling. © 2013 Wiley Periodicals, Inc.
The sherds of conquistadors: a petrological study of ceramics from Graciosa Bay and Pamua, Solomon Islands
Authors: Kelloway Sarah J. , Gibbs Martin , Craven Steven
Published: April 2013

We present evidence linking vessel forms with ceramic wares resulting from the petrological analysis of 33 sherds from two sixteenth century Spanish colonial sites in the Solomon Islands. Our results expand the range of fabric types previously published, and comparative literature analyses support earlier studies suggesting probable ceramic origins in the Americas and Spain.
Synthesis and Properties of Isobicyclo‐DNA
Authors: Gerber Anna‐Barbara , Leumann Christian J.
Published: April 2013

We present the synthesis of the isobicyclo‐DNA building blocks with the nucleobases A, C, G and T, as well as biophysical and biological properties of oligonucleotides derived thereof. The synthesis of the sugar part was achieved in 5 steps starting from a known intermediate of the tricyclo‐DNA synthesis. Dodecamers containing single isobicyclo‐thymidine incorporations, fully modified A‐ and T‐containing sequences, and fully modified oligonucleotides containing all four bases were synthesized and characterized. Isobicyclo‐DNA forms stable duplexes with natural nucleic acids with a pronounced preference for DNA over RNA as complements. The most stable duplexes, however, arise by self‐pairing. Isobicyclo‐DNA forms preferentially B‐DNA‐like duplexes with DNA and A‐like duplexes with complementary RNA as determined by circular dichroism (CD) spectroscopy. Self‐paired duplexes show a yet unknown structure, as judged from CD spectroscopy. Biochemical tests revealed that isobicyclo‐DNA is stable in fetal bovine serum and does not elicit RNaseH activity.
Comparison of GA and DDE for optimizing coverage in indoor environment
Authors: Liao Shu‐Han , Chiu Chien‐Ching , Ho Min‐Hui
Published: April 2013

This paper presents a method for determining the required number and locations of transmitting antennas to optimize wireless propagation coverage in indoor ultra‐wideband communication system. In the coverage prediction model, we use the three‐dimensional ray‐tracing technique associated to a genetic algorithm and a dynamic differential evolution for optimizing the transmitting antennas location in an indoor environment. The ray‐tracing method is employed to calculate the field strength from one or more transmitting antennas, and the optimization algorithm is used to determine the required number and locations of these antennas to achieve optimized wireless coverage in the indoor environment. The combined three‐dimensional ray‐tracing and optimization algorithm was applied in the indoor environment to find the best location of the transmitting antennas by maximizing the power in the coverage area. The use of deployments to minimize the transmitting antennas and maximize the power in the coverage area was proposed. Obtained simulation results illustrate the feasibility of using the integrated ray‐tracing and optimization method to find the optimal transmitter locations in determining the optimized coverage of a wireless network. The dynamic differential evolution has better optimization results compared with the genetic algorithm. The investigated results can help communication engineers improve their planning and design of indoor wireless communication. Copyright © 2013 John Wiley & Sons, Ltd.
Ionospheric ripples excited by superimposed wave fronts associated with Rayleigh waves in the thermosphere
Authors: Kakinami Yoshihiro , Kamogawa Masashi , Watanabe Shigeto , Odaka Masatsugu , Mogi Toru , Liu Jann‐Yenq , Sun Yang‐Yi , Yamada Takuji
Published: April 2013

Coseismic ionospheric disturbances (CIDs) associated with the 2011 Tohoku earthquake off the Pacific coast (Mw 9.0, Tohoku EQ) were examined using total electron content and seismic wave data. A faster CID propagated at ~3.0 km/s only in the west‐southwest, while a slower CID propagated concentrically at 1.2 km/s or slower from the tsunami source area. Taking the propagation speed and oscillation cycle into account, the faster CID was associated with a Rayleigh wave, but the slower CID was associated with an acoustic or gravity wave. The north‐south asymmetry of the CID associated with the Rayleigh wave suggests that the Rayleigh wave did not act as a point source of the acoustic wave because a point source propagating in all directions must produce symmetric CID in all directions. Therefore, a superimposed wave front of acoustic waves was excited by the Rayleigh wave and produced the north‐south asymmetry of the faster CID due to the magnetic inclination effect, which is different from a well‐known north‐south asymmetry of CID excited at the epicenter. On the other hand, above and south of the tsunami source area, the CID with a period of 4 min was excited by a point source located at the tsunami source area because atmospheric waves propagating from a point source produce north‐south asymmetry in the resulting CID.
Cluster observations of hot flow anomalies with large flow deflections: 1. Velocity deflections
Authors: Wang Shan , Zong Qiugang , Zhang Hui
Published: April 2013

Case and statistical studies have been performed to investigate hot flow anomalies (HFAs) with large flow deflections using data from the Cluster‐C1 spacecraft from 2003 to 2009. We have selected 87 events with Vy or Vz in GSE coordinates larger than 200 km s−1. Observations of these HFAs indicate a “location‐dependent deflection”: Vy or Vz deflect to a positive value when the event is located in the positive Y or Z side relative to the subsolar point and to a negative value when it is located in the negative Y or Z side relative to the subsolar point. The amplitude of the deflection increases with increasing distance in Y or Z direction. The decrease in Vx at the event center is larger when the location is closer to the Sun‐Earth line. The location‐dependent deflection might be due to a near‐specular reflection of ions at the Earth's bow shock. The HFAs studied in this paper are close to the bow shock with the distance of the event location to the bow shock ranging from 0.03 to 3.51 RE, which might cause the reflected ions to remain as a coherent near‐specular reflected beam.
Intense solar near‐relativistic electron events at 0.3 AU
Authors: Lario David , Ho George C. , Roelof Edmond C. , Anderson Brian J. , Korth Haje
Published: April 2013

We study the two most intense electron events observed by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft during the rising phase of solar cycle 24. Both events occurred during intense periods of solar activity when sequences of coronal mass ejections (CMEs) emanated from the Sun. The first event occurred on 4 June 2011, when two successive CMEs, spaced by 15 h, were released from the same active region. A possible interpretation for this event is that the first CME, located beyond MESSENGER's heliocentric distance (R = 0.33 AU) at the time of the second CME, acted as a magnetic barrier for solar energetic particles (SEPs) accelerated during the second CME. Elevated electron intensities at MESSENGER resulted from particle confinement between the two CME‐driven shocks. This scenario is consistent with that proposed by Kallenrode and Cliver [2001a] to explain intense SEP events. The second event, observed by MESSENGER at R = 0.31 AU on 7 March 2012, belonged to a series of events generated by a single active region. A fast (>1500 km s−1) CME occurred 45 h before the onset of the main electron event. That implies that the prior CME‐driven shock was at such a distance that particle reflection from behind that shock might have not been sufficient to account for the initial onset of sunward‐directed electrons at MESSENGER, and additional mirroring and/or scattering processes closer to MESSENGER were necessary. Elevated intensities in this event are consistent with strong injection of SEPs from close to the Sun and particle reflection at some point in interplanetary space.
Production of very high potential differences by intracloud lightning discharges in connection with terrestrial gamma ray flashes
Authors: Mallios Sotirios A. , Celestin Sebastien , Pasko Victor P.
Published: April 2013

Terrestrial gamma‐ray flashes (TGFs) have been correlated with an early development stage of high altitude positive intracloud (+IC) flashes in which the negative leader propagates up toward the upper positive charge region, while the positive leader propagates down toward the lower negative charge region. The resultant bidirectional leaders develop electrical potential differences in the vicinity of their heads with respect to the ambient potential distribution created by the thundercloud charges. These potential differences are believed to be of essential importance for the generation of TGFs. Using electrostatic calculations and a three‐dimensional Cartesian fractal model, we quantify these potential differences produced in a developing +IC lightning discharge for given thunderstorm electric configurations. We present a case of a +IC lightning discharge in a realistic thunderstorm configuration that leads to a very high (∼300 MV) potential difference and show how a delay in the development of the negative leader with respect to the positive one in a bidirectional leader system can facilitate a high potential difference in the negative leader head region.
Direct observations of the role of convection electric field in the formation of a polar tongue of ionization from storm enhanced density
Authors: Thomas E. G. , Baker J. B. H. , Ruohoniemi J. M. , Clausen L. B. N. , Coster A. J. , Foster J. C. , Erickson P. J.
Published: April 2013

We examine the relationship of convection electric fields to the formation of a polar cap tongue of ionization (TOI) from midlatitude plumes of storm enhanced density (SED). Observations from the geomagnetic storm on 26–27 September 2011 are presented for two distinct SED events. During an hour‐long period of geomagnetic activity driven by a coronal mass ejection, a channel of high‐density F region plasma was transported from the dayside subauroral ionosphere and into the polar cap by enhanced convection electric fields extending to middle latitudes. This TOI feature was associated with enhanced HF backscatter, indicating that it was the seat of active formation of small‐scale irregularities. After the solar wind interplanetary magnetic field conditions quieted and the dayside convection electric fields retreated to higher latitudes, an SED plume was observed extending to, but not entering, the dayside cusp region. This prominent feature in the distribution of total electron content (TEC) persisted for several hours and elongated in magnetic local time with the rotation of the Earth. No ionospheric scatter from SuperDARN radars was observed within this SED region. The source mechanism (enhanced electric fields) previously drawing the plasma from midlatitudes and into the polar cap as a TOI was no longer active, resulting in a fossil feature. We thus demonstrate the controlling role exercised by the convection electric field in generating a TOI from midlatitude SED.
Two models of cross polar cap potential saturation compared: Siscoe‐Hill model versus Kivelson‐Ridley model
Authors: Gao Ye , Kivelson Margaret G. , Walker Raymond J.
Published: April 2013

The cross polar cap potential is considered an instantaneous monitor of the rate at which magnetic flux couples the solar wind to the Earth's magnetosphere‐ionosphere system. Studies have shown that the cross polar cap potential responds linearly to the solar wind electric field under nominal solar wind conditions but asymptotes to the order of 200 kV for large electric field. Saturation of the cross polar cap potential is also found to occur in MHD simulations. Several mechanisms have been proposed to explain this phenomenon. Two well‐developed models are those of Siscoe et al. (2002), herein referred to as the Siscoe‐Hill model, and of Kivelson and Ridley (2008), herein referred to as the Kivelson‐Ridley model. In this study, we compare the mathematical formulas as well as the predictions of the two models with data. We find that the two models predict similar saturation limits. Their difference can be expressed in terms of a factor, which is close to unity during a saturation interval. A survey of the differences in the model predictions show that, on average, the potential of the Kivelson‐Ridley model is smaller than that of the Siscoe‐Hill model by 10 kV. Measurements of AMIE, DMSP, PC index, and SuperDARN are used to differentiate between the two models. However, given the uncertainties of the measurements, it is impossible to conclude that one model does a better job than the other of predicting the observed cross polar cap potentials.
Difference in seasonal and long‐term variations in geomagnetic Sq fields between geomagnetic Y and Z components
Authors: Takeda Masahiko
Published: April 2013

The amplitudes of geomagnetic solar quiet (Sq) fields in the Y (Sq(Y)) and Z (Sq(Z)) components were examined by the data obtained from several observatories for a period of more than 50 years. It was found that both Sq(Y) and Sq(Z) are strongly influenced by the solar activity and correlate fairly well with each other during all seasons. However, their seasonal variations are different. This is probably because Sq(Y) and Sq(Z) reflect the current intensity at different UTs, and different seasonal variations at different UTs lead to the difference in the seasonal variation of Sq(Y) and Sq(Z). The ratio of Sq(Z) to Sq(Y) is larger in winter than in summer at all observatories except for those in high geomagnetic latitudes. This difference is superficially attributed to the variation of the equivalent Sq current system, and probably significant part of the variation is due to interhemispheric field‐aligned currents driven by the Sq dynamo. On the other hand, long‐term variation in Sq(Z) at Honolulu was affected by the movement of the observatory in 1960, which illustrates the importance of induced currents in the ocean for the Sq field in the Z component.
Characteristics of global plasmaspheric TEC in comparison with the ionosphere simultaneously observed by Jason‐1 satellite
Authors: Lee H.‐B. , Jee G. , Kim Y. H. , Shim J. S.
Published: April 2013

We compared the global plasmaspheric total electron content (pTEC) with the ionospheric TEC (iTEC) simultaneously measured by Jason‐1 satellite during the declining phase of solar cycle 23 (2002–2009) to investigate the global morphology of the plasmaspheric density in relation to the ionosphere. Our study showed that the plasmaspheric density structures fundamentally follow the ionosphere, but there are also significant differences between them. Although the diurnal variations are very similar to each region, the plasmasphere shows much weaker variations, only approximately 1 TECU day‐night difference. By analyzing the day‐night differences in the plasmasphere, we found that the plasmaspheric contribution to the nighttime ionosphere does not increase with solar activity and the largest contribution occurs during June solstice. The plasmasphere shows similar seasonal variations to the ionosphere, except for the semiannual variation, which is essentially absent in the plasmasphere. There is also an important difference in the annual variation: although the annual variation in the ionosphere exists regardless of longitude, it occurs only at American sector in the plasmasphere. As solar activity increases to moderate level, the pTEC substantially enhances from approximately 2 to 4 TECU at the initial increase of solar activity below F10.7p = 100 and then quickly slows down while the iTEC almost linearly enhances. Although it is well known that magnetic storms are the major source of plasmaspheric density depletion, pTEC does not show this aspect of the plasmasphere probably due to the relatively small Kp values for high magnetic activity (Kp > 2.5) in the current study.
Dynamics of the foreshock compressional boundary and its connection to foreshock cavities
Authors: Omidi N. , Sibeck D. , Blanco‐Cano X. , Rojas‐Castillo D. , Turner D. , Zhang H. , Kajdič P.
Published: April 2013

We use several global hybrid (kinetic ions, fluid electrons) simulation runs for steady and time‐varying interplanetary magnetic field (IMF) conditions to examine the dynamics of the foreshock compressional boundary (FCB) and its connection to foreshock cavities. The results demonstrate that for steady IMF conditions, the FCB forms and evolves over a long period of time due to the dynamics of the bow shock and ion foreshock. Formation of the FCB is tied to the generation and nonlinear evolution of ULF waves associated with large‐amplitude fluctuations in magnetic field and density within the foreshock. As a result, even during steady IMF conditions, the transitions in the magnetic field strength and direction across an FCB evolve. Although the FCB itself is associated with increases in the magnetic field strength and density, these quantities are reduced on the turbulent side of the FCB as compared to the pristine solar wind. Hybrid simulations with time‐varying IMF have been performed to examine the relationship between the FCB and foreshock cavities generated under two possible scenarios. In the first scenario, a bundle of field lines connects to an otherwise quasi‐perpendicular bow shock and results in the formation of a finite‐sized foreshock region that travels with this bundle of field lines as it connects to different parts of the bow shock surface. Two FCBs bound the traveling foreshock region. In the second scenario, solar wind discontinuities cause the IMF cone angle (angle between the IMF and the solar wind flow direction) to vary and thereby modify the foreshock geometry and the position of the FCB. We demonstrate that structures similar to foreshock cavities bounded by FCBs form in both scenarios. We show that the two scenarios cannot be distinguished based on convecting or nonconvecting FCBs. We also demonstrate that depending on spacecraft location and the nature of the solar wind discontinuities, foreshock cavities may be bounded by an FCB on one side and a foreshock bubble on the other.