bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasound criteria and CA 125 as predictive variables of ovarian cancer in women with adnexal tumors
Authors: Hartman C. A. , Juliato C. R. T. , Sarian L. O. , Toledo M. C. , Jales R. M. , Morais S. S. , Pitta D. D. , Marussi E. F. , Derchain S.
Published: May 2012

Objectives

To evaluate the capacity to predict malignancy in women with adnexal tumors using CA 125 measurement and ultrasound criteria.

Methods

This was a cross‐sectional study including 103 women with a total of 110 adnexal tumors. CA 125 level was measured in a sample of peripheral blood. Lesions were classified by ultrasound, using standardized predetermined criteria, as benign (B) or malignant (M). Those that could not be classified by these criteria were assessed subjectively. Histopathologic examination of surgical specimens was used as the gold standard.

Results

Of 110 tumors, 79 (71.8%) were benign and 31 (28.2%) were malignant on histopathology. Ultrasound criteria could be applied to 91 (82.7%) tumors, resulting in a sensitivity of 90%, specificity of 87%, positive predictive value (PPV) of 69% and negative predictive value (NPV) of 97%. In tumors not classifiable according to ultrasound criteria, subjective sonographic assessment gave a sensitivity of 67%, specificity of 80%, PPV of 75% and NPV of 73%. At a cut‐off point of 37.4 U/mL, CA 125 had a sensitivity of 69%, a specificity of 87.8%, a PPV of 69% and a NPV of 88% for detection of malignancy. When CA 125 was associated with age and ultrasound criteria in a logistic regression model, the sensitivity and specificity increased in the subset of sonographically malignant tumors.

Conclusion

The majority of tumors were correctly classified using ultrasound criteria. CA 125 alone performed worse than did ultrasound in discriminating malignant from benign adnexal tumors. CA 125 measurement contributed to the diagnosis of malignancy, improving overall specificity, only in sonographically malignant tumors. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Chapter 7: Grading a Body of Evidence on Diagnostic Tests
Authors: Singh Sonal , Chang Stephanie M. , Matchar David B. , Bass Eric B.
Published: May 2012

INTRODUCTION

Grading the strength of a body of diagnostic test evidence involves challenges over and above those related to grading the evidence from health care intervention studies. This chapter identifies challenges and outlines principles for grading the body of evidence related to diagnostic test performance.

CHALLENGES

Diagnostic test evidence is challenging to grade because standard tools for grading evidence were designed for questions about treatment rather than diagnostic testing; and the clinical usefulness of a diagnostic test depends on multiple links in a chain of evidence connecting the performance of a test to changes in clinical outcomes.

PRINCIPLES

Reviewers grading the strength of a body of evidence on diagnostic tests should consider the principle domains of risk of bias, directness, consistency, and precision, as well as publication bias, dose response association, plausible unmeasured confounders that would decrease an effect, and strength of association, similar to what is done to grade evidence on treatment interventions. Given that most evidence regarding the clinical value of diagnostic tests is indirect, an analytic framework must be developed to clarify the key questions, and strength of evidence for each link in that framework should be graded separately. However if reviewers choose to combine domains into a single grade of evidence, they should explain their rationale for a particular summary grade and the relevant domains that were weighed in assigning the summary grade.
Consilience in sarcopenia of cirrhosis
Authors: Dasarathy Srinivasan
Published: May 2012

Cirrhosis is the consequence of progression of many forms of necro‐inflammatory disorders of the liver with hepatic fibrosis, hepatocellular dysfunction, and vascular remodeling. Reversing the primary hepatic disorder, liver transplantation, and controlling the complications are the major management goals. Since the former options are not available to the majority of cirrhotics, treating complications remains the mainstay of therapy. Sarcopenia and/or cachexia is the most common complication and adversely affects survival, quality of life, development of other complications of cirrhosis, and outcome after liver transplantation. With the increase in number of cirrhotic patients with hepatitis C and nonalcoholic fatty liver disease, the number of patients waiting for a liver transplantation is likely to continue to increase above the currently estimated 72.3/100,000 population. One of the critical clinical questions is to determine if we can treat sarcopenia of cirrhosis without transplantation. No effective therapies exist to treat sarcopenia because the mechanism(s) of sarcopenia in cirrhosis is as yet unknown. The reasons for this include the predominantly descriptive studies to date and the advances in our understanding of skeletal muscle biology and molecular regulation of atrophy and hypertrophy not being translated into the clinical practice of hepatology. Satellite cell biology, muscle autophagy and apoptosis, and molecular signaling abnormalities in the skeletal muscle of cirrhotics are also not known. Aging of the cirrhotic and transplanted population, use of mTOR inhibitors, and the lack of definitive outcome measures to define sarcopenia and cachexia in this population add to the difficulty in increasing our understanding of hepatic sarcopenia/cachexia and developing treatment options. Recent data on the role of myostatin, AMP kinase, impaired mTOR signaling resulting in anabolic resistance in animal models, and the rapidly developing field of nutriceuticals as signaling molecules need to be evaluated in human cirrhotics. Finally, the benefits of exercise reported in other disease states with sarcopenia may not be safe in cirrhotics due to the risk of gastrointestinal variceal bleeding due to an increase in portal pressure. This article focuses on the problems facing both muscle biologists and hepatologists in developing a comprehensive approach to sarcopenia in cirrhosis.
Food choices in the presence of ‘healthy’ and ‘unhealthy’ eating partners
Authors: Robinson Eric , Higgs Suzanne
Published: May 2012

Eating with others has been shown to influence the amount of food eaten in a meal or snack. We examined whether choosing food in the presence of another person who is choosing either predominantly low-energy-dense or high-energy-dense foods affects food choices. A between-subjects laboratory-based study was used. A group of 100 young females selected a lunch-time meal from a buffet consisting of a range of high-energy-dense and low-energy-dense foods, in the presence of an ‘unhealthy’ eating partner (who chose predominantly high-energy-dense foods) or a ‘healthy’ eating partner (who chose predominantly low-energy-dense foods) or when alone. Participants in the ‘unhealthy’ eating partner condition were significantly less likely to choose and consume a low-energy-dense food item (carrots), than when choosing alone or in the presence of a ‘healthy’ eater. Choice of high-energy-dense food did not differ across the conditions, nor did the total energy consumed. These data suggest that social influences on food choice are limited in this context but the presence of an ‘unhealthy’ eating partner may undermine intentions to consume low-energy-dense foods.
Karyotype variations in Italian populations of the peach-potato aphid Myzus persicae (Hemiptera: Aphididae)
Authors: Rivi M. , Monti V. , Mazzoni E. , Cassanelli S. , Panini M. , Bizzaro D. , Mandrioli M. , Manicardi G.C.
Published: May 2012

In this study, we present cytogenetic data regarding 66 Myzus persicae strains collected in different regions of Italy. Together with the most common 2n = 12 karyotype, the results showed different chromosomal rearrangements: 2n = 12 with A1–3 reciprocal translocation, 2n = 13 with A1–3 reciprocal translocation and A3 fission, 2n = 13 with A3 fission, 2n = 13 with A4 fission, 2n = 14 with X and A3 fissions. A 2n = 12–13 chromosomal mosaicism has also been observed. Chromosomal aberrations (and in particular all strains showing A1–3 reciprocal translocation) are especially frequent in strains collected on tobacco plants, and we suggest that a clastogenic effect of nicotine, further benefited by the holocentric nature of aphid chromosomes, could be at the basis of the observed phenomenon.
Morphology and phylogeny ofReticulitermessp. (Isoptera, Rhinotermitidae) from Cyprus
Authors: Ghesini S. , Marini M.
Published: May 2012

Taxonomy and phylogeny of termites of the genusReticulitermesin central and eastern Mediterranean lands are poorly understood, partly due to insufficient sampling. This study aims to contribute to the knowledge of east Mediterranean termites by presenting morphological and molecular data onReticulitermesfrom Cyprus. Samples from 15 colonies were collected throughout the island. Qualitative and quantitative morphological characters were analyzed for alate and soldier castes. Partial sequences of the mitochondrial genes COII and 16S were used to evaluate genetic diversity of Cypriot colonies and to determine their phylogenetic relationships with taxa from central and eastern Mediterranean areas.

Cypriot alates have some morphological features in common with the IsraeliR. clypeatus: an enlarged postclypeus and a wide unpigmented margin of the eye. They are larger thanR. clypeatusbut smaller than western European species, such asR. banyulensis, R. lucifugus corsicusandR. grassei. For Cypriot soldiers, two size groups were identified, possibly in relation with the age of their mother colonies.

Phylogenetic analysis shows that, contrary to what might be expected, the samples with the highest affinity with Cypriot samples are not those from the nearby mainland (south Turkey, Israel), but from north-eastern Greece. Comprehensive sampling in the nearby mainland is lacking, so the possibility that populations exist it that region with an affinity towards CypriotReticulitermessp. cannot be ruled out. Together with samples from the Halkidiki peninsula, north-eastern Greece, northern Turkey and Crete, CypriotReticulitermesform a well-supported north-eastern Mediterranean clade.
Fossil-Fuel Futurity: Oil inGiant
Authors: WORDEN DANIEL
Published: May 2012

Giantis a sprawling narrative, centered around the Benedict family, Texas cattle ranchers, and Jett Rink, a nouveau riche oilman. Originally serialized inLadies'Home Journalin 1952, subsequently published as a novel, then adapted into George Stevens's 1956 film starring James Dean, Rock Hudson, and Elizabeth Taylor,Giantis a text that dramatizes the domestication and naturalization of the oil industry in the postwar United States while endorsing a multiracial vision of Texas. This essay explores howGiantultimately arrives at nationalistic pluralism after representing the radical changes brought about by the modern oil industry in the US, particularly the erosion of traditional class divisions as Jett Rink's oil wealth exceeds the Benedict's ranching wealth. The subsumption of oil into liberal pluralism marks what this essay names “fossil-fuel futurity,” an ideological configuration in which normative life is produced through the commodities and modes of transportation made available by fossil-fuel culture. The essay then putsGiantinto a broader context of narratives about oil in the postwar US, especially the television seriesDallas(1978–91) and the filmThere Will Be Blood(2007). In all three texts, oil culture becomes postwar US culture, saturating aesthetic, affective, and family relations. The challenge for us, then, is to imagine a mode of futurity that does not replicate the ideological valences of “fossil-fuel futurity.”
Economic History and Economic Policy
Authors: EICHENGREEN BARRY
Published: May 2012

“The lessons of history” were widely invoked in 2008/09 as analysts and policymakers sought to make sense of the global financial crisis. Specifically, analogies with the early stages of the Great Depression of the 1930s were widely drawn. Building on work in cognitive science and literature on foreign policy making, this article seeks to account for the influence of this particular historical analogy and asks how it shaped both perceptions and the economic policy response. It asks how historical scholarship might be better organized to inform the process of economic policymaking. It concludes with some reflections on how research in economic history will be reshaped by the crisis.
Inequality of Wealth in the Ottoman Empire: War, Weather, and Long-Term Trends in Eighteenth-Century Kastamonu
Authors: COŞGEL METIN M. , ERGENE BOĞAÇ A.
Published: May 2012

This article offers a quantitative analysis of wealth inequality in the Ottoman Empire, employing data from probate inventories (terekes) of eighteenth-century Kastamonu, a town located in northern Anatolia. Extracting information on wealth levels and personal characteristics of individuals, we estimate aggregate measures of wealth inequality, namely the Gini coefficient, the coefficient of variation, and the wealth shares of the wealthiest 10 and 25 percent of estates. We use regression analysis to identify the time trend of wealth inequality and determine how warfare, significant weather events, macroeconomic variables, and shifts in population characteristics affected it.
Democratic Dividends: Stockholding, Wealth, and Politics in New York, 1791–1826
Authors: HILT ERIC , VALENTINE JACQUELINE
Published: May 2012

Using newly collected data, this article compares the wealth and status of New York City households who owned corporate stock to the general population both in 1791, when there were only two corporations in the state, and in 1826, when there were hundreds. The results indicate that although corporate stock was held principally by the city's elite merchants in both periods, share ownership became more widespread over time among less affluent households. In particular, later corporations were owned and managed by investors who were less wealthy than the stockholders of corporations created in earlier, less democratic periods.
Crisis and Bankruptcy: The Mediating Role of State Law, 1920–1932
Authors: HANSEN MARY ESCHELBACH , HANSEN BRADLEY A.
Published: May 2012

The onset of the Great Depression did not spark a surge in personal bankruptcy. For debtors in default, state garnishment law played a significant role in the decision to file for bankruptcy. Only states that made it easy to garnish a debtor's wages experienced significant increases in bankruptcy as a consequence of the Depression.
Magnetic resonance imaging features of large endolymphatic sac compartments: audiological and clinical correlates
Authors: Connor S E J , Siddiqui A , O'Gorman R , Tysome J R , Lee A , Jiang D , Fitzgerald-O'Connor A
Published: May 2012

Objectives:

(1) To study the prevalence and characteristics of large endolymphatic sac internal compartments on thin-section T2- and T2*-weighted magnetic resonance imaging, and to relate these to other large endolymphatic sac magnetic resonance imaging features, and (2) to correlate the compartment imaging features, endolymphatic sac size and labyrinthine anomalies with the patients' clinical and audiological data.

Method:

Magnetic resonance imaging studies for 38 patients with large endolymphatic sac anomalies were retrospectively reviewed in a tertiary referral centre. Endolymphatic sac compartment presence, morphology and imaging signal were assessed. Endolymphatic sac size and labyrinthine anomalies were also recorded. Endolymphatic sac compartments and other imaging features were correlated with clinical and audiological data.

Results:

Compartments were present in 57 per cent of the imaged endolymphatic sacs, but their presence alone did not correlate with other imaging features or clinical data. The endolymphatic sac : internal auditory meatus signal ratio was associated with a history of sudden or fluctuating hearing loss. Hearing loss correlated with opercular and extraosseous endolymphatic sac size measurements. A larger midpoint intraosseous endolymphatic sac size was associated with clear fluid loss at cochlear implantation.

Conclusion:

The magnetic resonance imaging characteristics of large endolymphatic sac compartments have been defined. The endolymphatic sac size and distal compartment signal should be recorded, as these provide prognostic information and assist the planning of appropriate interventions.
Traditional Electricity Systems in Spain: Fensa (1927-1991)
Authors: Garrués-Irurzun Josean
Published: May 2012

Because the literature of European economic history has paid little attention to traditional electricity systems, the interest in studyingFensalies in analysing the different types of companies, which helped to shape the development of the Spanish electricity sector prior to its present oligopolistic structure. This case provides insight into two issues. First, we learn about the behaviour of the second-generation companies (those that based their production on a controlled hydropower regime), which, despite their limited size, made their commercial specialisation (supplying the dynamic industrial market of Guipúzcoa) their main comparative advantage. Second, we analyse the behaviour of those companies which at this time, as distribution companies and/or subsidiaries of the large Spanish companies (Iberduero), were an instrument of the policy of integrating regional markets.
An arrow in the Achilles' heel of sustainability and wealth accounting
Authors: Smulders Sjak
Published: May 2012

How sustainable is the growth pattern of a national economy? At first, answering this question seems almost impossible, since this would require knowing what happens and what can happen in the future. One needs to assess whether the investments we make today will be sufficient to provide future generations with the means to cope with imminent disasters like the exhaustion of minerals and vital resources, or other problems like increasing population pressure and climate change. One also needs to assess which combination of investment leads to the desired result. If entrepreneurs, managers and households already have problems in finding out what is the best mix of investment for them in their micro-environment, how can we answer the aggregate question that needs so much more information?
Interlingual influence in bilingual speech: Cognate status effect in a continuum of bilingualism
Authors: AMENGUAL MARK
Published: May 2012

The present study investigates voice onset times (VOTs) to determine if cognates enhance the cross-language phonetic influences in the speech production of a range of Spanish–English bilinguals: Spanish heritage speakers, English heritage speakers, advanced L2 Spanish learners, and advanced L2 English learners. To answer this question, lexical items with considerable phonological, semantic, and orthographic overlap (cognates) and lexical items with no phonological overlap with their English translation equivalents (non-cognates) were examined. The results indicate that there is a significant effect of cognate status in the Spanish production of VOT by Spanish–English bilinguals. These bilinguals produced /t/ with longer VOT values (more English-like) in the Spanish production of cognates compared to non-cognate words. It is proposed that the exemplar model of lexical representation (Bybee, 2001; Pierrehumbert, 2001) can be extended to include bilingual lexical connections by which cognates facilitate phonetic interference in the bilingual mental lexicon.
Hyperactivity induced by the dopamine D2/D3 receptor agonist quinpirole is attenuated by inhibitors of endocannabinoid degradation in mice
Authors: Luque-Rojas María Jesús , Galeano Pablo , Suárez Juan , Araos Pedro , Santín Luis J. , de Fonseca Fernando Rodríguez , Calvo Eduardo Blanco
Published: May 2012

The present study was designed to investigate the effect of pharmacological inhibition of endocannabinoid degradation on behavioural actions of the dopamine D2/D3 receptor agonist quinpirole in male C57Bl/6J mice. In addition, we studied the effects of endocannabinoid degradation inhibition on both cocaine-induced psychomotor activation and behavioural sensitization. We analysed the effects of inhibition of the two main endocannabinoid degradation enzymes: fatty acid amide hydrolase (FAAH), using inhibitor URB597 (1 mg/kg); monoacylglycerol lipase (MAGL), using inhibitor URB602 (10 mg/kg). Administration of quinpirole (1 mg/kg) caused a temporal biphasic response characterized by a first phase of immobility (0–50 min), followed by enhanced locomotion (next 70 min) that was associated with the introduction of stereotyped behaviours (stereotyped jumping and rearing). Pretreatment with both endocannabinoid degradation inhibitors did not affect the hypoactivity actions of quinpirole. However, this pretreatment resulted in a marked decrease in quinpirole-induced locomotion and stereotyped behaviours. Administration of FAAH or MAGL inhibitors did not attenuate the acute effects of cocaine. Furthermore, these inhibitors did not impair the acquisition of cocaine-induced behavioural sensitization or the expression of cocaine-induced conditioned locomotion. Only MAGL inhibition attenuated the expression of an already acquired cocaine-induced behavioural sensitization. These results suggest that pharmacological inhibition of endocannabinoid degradation might exert a negative feedback on D2/D3 receptor-mediated hyperactivity. This finding might be relevant for therapeutic approaches for either psychomotor disorders (dyskinesia, corea) or disorganized behaviours associated with dopamine-mediated hyperactivity.
Current state of knowledge: the canine gastrointestinal microbiome
Authors: Hooda Seema , Minamoto Yasushi , Suchodolski Jan S. , Swanson Kelly S.
Published: May 2012

Gastrointestinal (GI) microbes have important roles in the nutritional, immunological, and physiologic processes of the host. Traditional cultivation techniques have revealed bacterial density ranges from 104to 105colony forming units (CFU)/g in the stomach, from 105to 107CFU/g in the small intestine, and from 109to 1011CFU/g in the colon of healthy dogs. As a small number of bacterial species can be grown and studied in culture, however, progress was limited until the recent emergence of DNA-based techniques. In recent years, DNA sequencing technology and bioinformatics have allowed for better phylogenetic and functional/metabolic characterization of the canine gut microbiome. Predominant phyla include Firmicutes, Bacteroidetes, Fusobacteria, Proteobacteria, and Actinobacteria. Studies using 16S ribosomal RNA (rRNA) gene pyrosequencing have demonstrated spatial differences along the GI tract and among microbes adhered to the GI mucosa compared to those in intestinal contents or feces. Similar to humans, GI microbiome dysbiosis is common in canine GI diseases such as chronic diarrhea and inflammatory bowel diseases. DNA-based assays have also identified key pathogens contributing to such conditions, including variousClostridium,Campylobacter,Salmonella, andEscherichiaspp. Moreover, nutritionists have applied DNA-based techniques to study the effects of dietary interventions such as dietary fiber, prebiotics, and probiotics on the canine GI microbiome and associated health indices. Despite recent advances in the field, the canine GI microbiome is far from being fully characterized and a deeper characterization of the phylogenetic and functional/metabolic capacity of the GI microbiome in health and disease is needed. This paper provides an overview of recent studies performed to characterize the canine GI microbiome.
Isotopic characterization of aerosol organic carbon components over the eastern United States
Authors: Wozniak Andrew S. , Bauer James E. , Dickhut Rebecca M. , Xu Li , McNichol Ann P.
Published: May 2012

Carbon isotopic signatures (δ13C, Δ14C) of aerosol particulate matter total organic carbon (TOC) and operationally defined organic carbon (OC) components were measured in samples from two background sites in the eastern U.S. TOC and water‐soluble OC (WSOC)δ13C values (−27 to −24‰) indicated predominantly terrestrial C3 plant and fossil derived sources. Total solvent extracts (TSE) and their aliphatic, aromatic, and polar OC components were depleted in δ13C (−30 to −26‰) relative to TOC and WSOC. Δ14C signatures of aerosol TOC and TSE (−476 to +25‰) suggest variable fossil contributions (∼5–50%) to these components. Aliphatic OC while comprising a small portion of the TOC (<1%), was dominated by fossil‐derived carbon (86 ± 3%), indicating its potential utility as a tracer for fossil aerosol OC inputs. In contrast, aromatic OC contributions (<1.5%) contained approximately equal portions contemporary (52 ± 8%) and fossil (48 ± 8%) OC. The quantitatively significant polar OC fraction (6–25% of TOC) had fossil contributions (30 ± 12%) similar to TOC (26 ± 7%) and TSE (28 ± 9%). Thus, much of both of the fossil and contemporary OC is deduced to be oxidized, polar material. Aerosol WSOC consistently showed low fossil content (<8%) relative to the TOC (5–50%) indicating that the majority of fossil OC in aerosol particulates is insoluble. Therefore, on the basis of solubility and polarity, aerosols are predicted to partition differently once deposited to watersheds, and these chemically distinct components are predicted to contribute in quantitatively and qualitatively different ways to watershed carbon biogeochemistry and cycling.
In situ observations of soil minerals and organic matter in the early phases of prescribed fires
Authors: Kavouras Ilias G. , Nikolich George , Etyemezian Vic , DuBois David W. , King James , Shafer David
Published: May 2012

We examined the chemical composition of aerosol samples collected during a prescribed fire at a Great Basin Desert site in the context of samples collected from controlled combustion of vegetation clippings from the same site and resuspension of soil samples obtained prior to and after the burn event. We observed a distinct difference in the composition of organic carbon resuspended soil dust after the burn, reflecting changes caused by the heating of the soil. The relative abundances of minerals and organic carbon fractions in aerosols collected during the first period of the burn were identical to those measured in soil dust. For aerosol samples collected for the remaining two periods of the burn event, the profiles of both minerals and organic carbon matched quite well those observed for vegetation combustion. Reconstruction of aerosol samples collected during the burn event showed that vegetation combustion dominated emissions but mineral soil dust may account for about 10% of PM10emissions (reconstructed) during the early stages of the fire. A large fraction of emissions during the first two hours was also unaccounted mainly because of the insufficient conversion of organic carbon to organic mass. The abundance of heavier non‐volatile organics in soil dust suggested the presence of humic/fulvic acids that exhibit higher OM‐to‐OC ratios and thus, account for a proportion of the unaccounted emissions. These findings indicated that soil dust may be released into the air during a fire event, probably due to the enhanced turbulent mixing near the burn front.
Effects of non‐Gaussian copula‐based hydraulic conductivity fields on macrodispersion
Authors: Haslauer C. P. , Guthke P. , Bárdossy A. , Sudicky E. A.
Published: May 2012

This is an application of a spatial copula model that is fitted to a real world data set. The copula model allows modeling of pure spatial dependence independently of the marginal distribution. Using non‐Gaussian copula models it is demonstrated that the spatial dependence structure of the Borden aquifer is significantly non‐Gaussian—despite the fact that the Borden aquifer is commonly thought of as a relatively homogeneous porous medium with a small variance of hydraulic conductivity. In addition to evaluating the spatial dependence structure of the Borden hydraulic conductivity data set using copulas, goal of this study is to explore if the structure of the hydraulic conductivity field influences a physical property, such as plume evolution as evaluated by second spatial central moments of concentration fields. For this comparison, two types of hydraulic conductivity fields were fitted to the Borden hydraulic conductivity data set: one with a Gaussian and the other with a non‐Gaussian type of dependence. These two types of hydraulic conductivity fields were constructed such that their second‐order spatial moments are identical, and hence they cannot be distinguished by semivariogram‐based geostatistics. This paper illustrates that the spatial dependence structure of the Borden hydraulic conductivity data set is significantly non‐Gaussian. Despite the fact that Borden is a relatively homogeneous porous medium, and despite the fact that both types of spatial fields are not distinguishable by their variograms, the solute transport characteristics based on these two types of isotropic fields differ significantly in two‐dimensional settings. The difference is less pronounced in three‐dimensions with anisotropy. It is postulated that non‐Gaussian spatial dependence of hydraulic conductivity and a more skewed marginal distribution of hydraulic conductivity will have significant implications in the other more heterogeneous aquifers.
GPS velocity and strain fields in Sicily and southern Calabria, Italy: Updated geodetic constraints on tectonic block interaction in the central Mediterranean
Authors: Palano M. , Ferranti L. , Monaco C. , Mattia M. , Aloisi M. , Bruno V. , Cannavò F. , Siligato G.
Published: May 2012

We present an improved rendition of the geodetic velocity and strain fields in Sicily and southern Calabria obtained through the analysis of 18 years of GPS observations from continuous and survey station networks. The dense spatial coverage of geodetic data provides precise quantitative estimates of previously established first‐order active kinematic features, including: i) a narrow east‐west‐elongated belt of contraction (∼1–1.5 mm/yr) extending offshore northern Sicily from Ustica to Stromboli across the Aeolian Islands; ii) a narrow east‐west‐trending contractional belt located along the northern rim of the Hyblean Plateau in southern Sicily, with shortening at up to 4.4 mm/yr; iii) right motion (∼3.6 mm/yr) on the Aeolian‐Tindari‐Letojanni fault (ATLF) system, a main shear zone extending from the Aeolian Islands to the Ionian coast of Sicily, with significant transpression and transtension partitioned between discrete sectors of the fault; iv) transtension (∼1 mm/yr) across the Sicily Channel between Sicily and North Africa. We use geodetic observations coupled to geological constraints to better elucidate the interplay of crustal blocks revealed in the investigated area. In particular, we focus on the ATLF, which forms the primary boundary between the Sicilian and Calabrian blocks. The ATLF juxtaposes north‐south contraction between Sicily and the Tyrrhenian block with northwest‐southeast extension in northeastern Sicily and Calabria. Contraction between Sicily and Tyrrhenian blocks probably arises from the main Europe‐Nubia convergence, although Sicily has a component of lateral motion away from Nubia. We found that convergence is not restricted to the northern offshore, as commonly believed, but is widely accommodated between the frontal belt and the northern rim of the Hyblean foreland in southern Sicily. Geodetic data also indicate that active right shear on the ATLF occurs to the southeast of the mapped fault array in northern Sicily, suggesting the fault cuts through till the Ionian coast of the island. The small geodetic divergence between the Hyblean and Apulian blocks rimming on both sides the Calabria block and subjacent Ionian slab, coupled with marine geophysical evidences in the Ionian Sea lends credit to the proposed deep root of the ATLF and to a fragmentation of the Ionian domain.
Structural dissimilarity of large-scale structures in turbulent flows over wavy walls
Authors: Zenklusen Adrian , Kuhn Simon , von Rohr Philipp Rudolf
Published: May 2012

Turbulent flows over a wavy wall are investigated in channels with a wavy bottom and a flat top with different channel heights. Flow structures are determined from proper orthogonal decompositions of velocity fields measured with particle image velocimetry. Three different channel heights are considered, which are characterized by blockage ratios β (half channel height to wave amplitude ratio) 3.3, 6.7, and 10. Measurements are evaluated at comparable Reynolds numbers (Re) around 10 000. Structural similarity of large-scale structures, which is valid at β = 6.7 and 10, no longer holds at β = 3.3. Furthermore, characteristic regions of flows over wavy walls exhibit different locations in the case of the smallest channel height.
Dynamics in coarse-grained models for oligomer-grafted silica nanoparticles
Authors: Hong Bingbing , Chremos Alexandros , Panagiotopoulos Athanassios Z.
Published: May 2012

Coarse-grained models of poly(ethylene oxide) oligomer-grafted nanoparticles are established by matching their structural distribution functions to atomistic simulation data. Coarse-grained force fields for bulk oligomer chains show excellent transferability with respect to chain lengths and temperature, but structure and dynamics of grafted nanoparticle systems exhibit a strong dependence on the core-core interactions. This leads to poor transferability of the core potential to conditions different from the state point at which the potential was optimized. Remarkably, coarse graining of grafted nanoparticles can either accelerate or slowdown the core motions, depending on the length of the grafted chains. This stands in sharp contrast to linear polymer systems, for which coarse graining always accelerates the dynamics. Diffusivity data suggest that the grafting topology is one cause of slower motions of the cores for short-chain oligomer-grafted nanoparticles; an estimation based on transition-state theory shows the coarse-grained core-core potential also has a slowing-down effect on the nanoparticle organic hybrid materials motions; both effects diminish as grafted chains become longer.
Effect of textured electrodes with light-trapping on performance of polymer solar cells
Authors: Hu Ziyang , Zhang Jianjun , Zhao Ying
Published: May 2012

Textured electrodes with rough surface in combination with reflective back contacts provide efficient light-trapping by light scattering and multiple reflections to increase the path length of the light, and the resulting enhanced efficiency of organic photovolatics. In this paper, the effect of textured electrodes with different surface morphology on the performance of polymer solar cells was investigated. Two kinds of textured SnO2:F (FTO) electrodes possessing “V” (V-FTO) and “U” (U-FTO) topography, respectively, were used as the front electrodes of polymer solar cells. Due to the enhanced light absorption in active layer, the resultant cells with U-FTO and V-FTO showed 9% and 6% improvement in short current density (Jsc), respectively, compared with the flat FTO electrode. The U-FTO electrode was amenable to coating a conformal buffer layer and preferred to obtain high efficient cells. However, the enhanced Jsc of the V-FTO cells did not contribute to the improved efficiency for the decreased fill factor and open circuit voltage.
Adaptive properties of a liquid crystal cell with a microlens-profiled aligning surface
Authors: Reznikov M. , Reznikov Yu. , Slyusarenko K. , Varshal J. , Manevich M.
Published: May 2012

An array of electrically controlled adaptive microlenses produced as a liquid crystal cell with microlens-profiled aligning surface is presented. Measurements of microlens’ adaptivity are quantitatively explained by a proposed theoretical model. Details of microlens array production and characterization are presented along with the achievable electrically controlled focal length changes for nematic liquid crystals 5CB and ZLI-4801. Effects related to liquid crystal reorientation on the curved surface of the spherical lenses are discussed.
Enhanced magneto-thermoelectric power factor of a 70 nm Ni-nanowire
Authors: Mitdank R. , Handwerg M. , Steinweg C. , Töllner W. , Daub M. , Nielsch K. , Fischer S. F.
Published: May 2012

Thermoelectric (TE) properties of a single nanowire (NW) are investigated in a microlab which allows the determination of the Seebeck coefficient S, the electrical conductivity σ, and a full ZT-characterization in the validity limit of the Wiedemann-Franz-law (ZT—figure of merit). A significant influence of the magnetization of a 70 nm diameter ferromagnetic Ni-NW on its power factor S2σ is observed. We detected a strong magnetothermopower effect (MTP) of about 10% and an anisotropic magnetoresistance (AMR) as a function of an external magnetic field B in the order of 1%. At T = 295 K and B = 0 T, we determined the absolute value of S = −(19 ± 2) μV/K. The thermopower S increases considerably as a function of B up to 10% at B = 0.5 T, and with a magnetothermopower of ∂S/∂B ≈ −(3.8 ± 0.5) μV/(KT). The AMR and MTP are related by ∂s/∂r ≈ −11 ± 1 (∂s = ∂S/S). Hence, the TE efficiency increases in a transversal magnetic field (B = 0.5 T) due to an enhanced power factor by nearly 20%.
Ultrafast formation of the benzoic acid triplet upon ultraviolet photolysis and its sequential photodissociation in solution
Authors: Yang Chunfan , Su Hongmei , Sun Xuezhong , George Michael W.
Published: May 2012

Time-resolved infrared (TR-IR) absorption spectroscopy in both the femtosecond and nanosecond time domain has been applied to examine the photolysis of benzoic acid in acetonitrile solution following either 267 nm or 193 nm excitation. By combining the ultrafast and nanosecond TR-IR measurements, both the excited states and the photofragments have been detected and key mechanistic insights were obtained. We show that the solvent interaction modifies the excited state relaxation pathways and thus the population dynamics, leading to different photolysis behavior in solution from that observed in the gas phase. Vibrational energy transfer to solvents dissipates excitation energy efficiently, suppressing the photodissociation and depopulating the excited S2 or S3 state molecules to the lowest T1 state with a rate of ∼2.5 ps after a delayed onset of ∼3.7 ps. Photolysis of benzoic acid using 267 nm excitation is dominated by the formation of the T1 excited state and no photofragments could be detected. The results from TR-IR experiments using higher energy of 193 nm indicate that photodissociation proceeds more rapidly than the vibrational energy transfer to solvents and C–C bond fission becomes the dominant relaxation pathway in these experiments as featured by the prominent observation of the COOH photofragments and negligible yield of the T1 excited state. The measured ultrafast formation of T1 excited state supports the existence of the surface intersections of S2/S1, S2/T2, and S1/T1/T2, and the large T1 quantum yield of ∼0.65 indicates the importance of the excited state depopulation to triplet manifold as the key factor affecting the photophysical and photochemical behavior of the monomeric benzoic acid.
Energy and force prediction for a nanosecond pulsed dielectric barrier discharge actuator
Authors: Wang Chin-Cheng , Roy Subrata
Published: May 2012

A three-species physical model is presented for dielectric barrier discharge (DBD) actuator under atmospheric pressure. The governing equations are solved for temporal and spatial distribution of electric potential and charge species using the finite element based multiscale ionized gas flow code. The plasma model is loosely coupled with compressible Navier-Stokes equations through momentum and energy source terms. Two cases of rf powered and nanosecond pulsed barrier discharge actuators are simulated. Based on the imparted time average electrohydrodynamic force and power deposition to the neutral gas, the nanosecond pulsed DBD actuator creates significant pressure variations within few microseconds. These results are in reasonable agreement with recently reported experimental shadow images.
Contributions of electron and phonon transport to the thermal conductivity of GdFeCo and TbFeCo amorphous rare-earth transition-metal alloys
Authors: Hopkins Patrick E. , Ding Manli , Poon Joseph
Published: May 2012

We experimentally investigate the electron and phonon contributions to the thermal conductivity of amorphous GdFeCo and TbFeCo thin films. These amorphous rare-earth transition-metal (RE-TM) alloys exhibit thermal conductivities that increase nearly linearly with temperature from 90 to 375 K. Electrical resistivity measurements show that this trend is due to an increase in the electron thermal conductivity over this temperature range and a relatively constant phonon contribution to thermal conductivity. We find that at low temperatures (∼90 K), the phonon systems in these amorphous RE-TM alloys contribute ∼70% to thermal conduction with a decreasing contribution as temperature is increased.
Low moment NiCr radio frequency magnetic films for multiferroic heterostructures with strong magnetoelectric coupling
Authors: Zhou Z. , Beguhn S. , Lou J. , Rand S. , Li M. , Yang X. , Li S. D. , Liu M. , Sun N. X.
Published: May 2012

Magnetic/piezoelectric multiferroic heterostructures with a magnetic thin film on a piezoelectric slab provides a great opportunity to achieve a strong converse magnetoelectric coupling with great potential for voltage tunable magnetic devices. Efforts have been made in developing highly magnetostrictive RF magnetic materials with low magnetization using magnetic/piezoelectric heterostructures to generate large electric-field induced effective magnetic fields. In this work, we report on NiCr films having low magnetization and relatively large magnetostriction. Strong converse magnetoelectric coupling and large electric field tunable ferromagnetic resonance (FMR) bandwidths are achieved in layered NiCr/lead zirconate titanate (PZT) and NiCr/lead zinc niobate lead titanate (PZN-PT) multiferroic heterostructures. A large electric field induced effective magnetic field of 260 Oe for NiCr/PZT and 756 Oe for NiCr/PZN-PT was observed, corresponding to a giant magnetoelectric coupling coefficient of 13 Oe cm/kV in NiCr/PZT and 75.6 Oe cm/kV in NiCr/PZN-PT multiferroic heterostructures. A high voltage tunable FMR frequency range was observed, with fmax/fmin being 124 and 325% for NiCr/PZT and NiCr/PZN-PT. The strong converse magnetoelectric coupling of NiCr/PZT and NiCr/PZN-PT heterostructures provide great opportunities for electric field tunable RF magnetic devices.
A model for the frequency dispersion of the high-k metal-oxide-semiconductor capacitance in accumulation
Authors: Yao B. , Fang Z. B. , Zhu Y. Y. , Ji T. , He G.
Published: May 2012

High-frequency capacitance-voltage measurements have been made on metal-oxide-semiconductor capacitors by using single crystalline Er2O3 high-k gate dielectrics. Based on our analysis, it has been found that frequency dispersion of Er2O3 capacitance in accumulation decreases consistently with the increase of the frequency. A correction model is proposed to explain these frequency dispersion phenomena and the capacitance-frequency equations are obtained from the impedance expression of the equivalent circuit. Based on the simulated capacitance-frequency, it can be concluded that frequency dispersion of Er2O3 capacitance in accumulation originates from the existence of the parasitic resistances, the series resistances, and the formed SiOx interfacial layer.
Upper limit of two-dimensional hole gas mobility in strained Ge/SiGe heterostructures
Authors: Tanaka T. , Hoshi Y. , Sawano K. , Usami N. , Shiraki Y. , Itoh K. M.
Published: May 2012

High two-dimensional hole gas (2DHG) mobility (μ2DHG>10000cm2/Vs at T<100K) strained Ge/Si1−xGex structures with x=0.5 and 0.65 were fabricated, and temperature dependence of their 2DHG mobility was obtained experimentally by the mobility spectrum analysis of the conductivity under magnetic fields. The theoretically calculated 2DHG mobility was compared to experimental data to determine the effective deformation potentials for scattering by acoustic and optical phonons. Using empirically confirmed parameters, the upper theoretical limit of room temperature 2DHG mobility μ2DHG in strained Ge as a function of strain was calculated. The possibility to achieve μ2DHG>5000cm2/Vs at room temperature is presented.
Transformation of phosphorus in highly calcareous soils under field capacity and waterlogged conditions
Authors: Adhami E. , Ronaghi A. , Karimian N. , Molavi R.
Published: May 2012

The aim of the present study was to evaluate the transformation of applied inorganic phosphorus (P) in highly calcareous soils under two moisture regimes. The experimental design was a factorial combination of two rates of P (0 and 300 mg P kg–1 as KH2PO4) and two moisture regimes (field capacity, FC; waterlogged, WL) in a completely randomised design in duplicate with 20 surface soil samples. The fractionation sequence of inorganic P included successive extraction with NaHCO3, NH4 acetate buffer (NH4OAc), MgCl2, NH4F, NaOH–Na2CO3 (HC), Na citrate–bicarbonate–dithionite (CBD), and H2SO4 carried out 80 and 160 days after incubation. Recovery of applied P in each fraction was calculated as the difference between samples treated and untreated with P. Results indicated that NaHCO3-P decreased from 80 to 160 days, and the decrement was higher under WL than FC moisture regime. The NH4OAc-P was lower under WL than FC at 160 days, while P associated with free and crystalline Fe and Al oxides (NH4F-P, HC-P, CBD-P) was higher under WL than FC for both incubation periods. Oxalate-, citrate-, and citrate–ascorbate-extractable iron under FC and in conjunction with oxalate- and CBD-extractable aluminium and quinone- and hydroxylamine–hydrochloride-extractable manganese were the most influential factors regulating all P fractions. Results of the present study revealed that transformation of applied P into Al- and Fe-P fractions is not as low as previously reported in highly calcareous soils and that Al- and Fe-P oxides may be important in P transformation of these soils, especially in waterlogged condition.
Estimating nitrous oxide emissions from a dairy farm using a mechanistic, whole farm model and segregated emission factors for New Zealand
Authors: Vogeler Iris , Beukes Pierre , Romera Alvaro , Cichota Rogerio
Published: May 2012

Nitrous oxide (N2O) emissions from agriculture are generally estimated using default IPCC emission factors (EFs) despite the large variation in measured EFs. We used a classification and regression tree (CART) analysis to segregate measured EFs from direct emissions from urine patches and fertiliser and effluent applications, based on temporal and site-specific factors. These segregated EFs were linked to simulations from the DairyNZ Whole Farm Model to obtain N2O emissions for a typical pasture-based dairy farm in New Zealand. The N2O emissions from urine patches, dung pads, and fertiliser and effluent application, as well as from indirect sources, were aggregated to obtain total N2O emissions for the farm-scale. The results, based on segregated EFs, were compared with those obtained using New Zealand-specific EFs. On-farm N2O emissions based on these segregated EFs were 5% lower than those based on New Zealand-specific EFs. Improved farm management by avoiding grazing, effluent, and N fertiliser application during periods of high risk for N2O emissions, or by the use of mitigation technologies such as nitrification inhibitors, could reduce annual farm scale N2O emissions.