A comparison of denoising methods for X-ray fluoroscopic images

Fluoroscopic images exhibit severe signal-dependent quantum noise, due to the reduced X-ray dose involved in image formation, that is generally modelled as Poisson-distributed. However, image gray-level transformations, commonly applied by fluoroscopic device to enhance contrast, modify the noise statistics and the relationship between image noise variance and expected pixel intensity. Image denoising is essential to improve quality of fluoroscopic images and their clinical information content. Simple average filters are commonly employed in real-time processing, but they tend to blur edges and details. An extensive comparison of advanced denoising algorithms specifically designed for both signal-dependent noise (AAS, BM3Dc, HHM, TLS) and independent additive noise (AV, BM3D, K-SVD) was presented. Simulated test images degraded by various levels of Poisson quantum noise and real clinical fluoroscopic images were considered. Typical gray-level transformations (e.g. white compression) were also applied in order to evaluate their effect on the denoising algorithms. Performances of the algorithms were evaluated in terms of peak-signal-to-noise ratio (PSNR), signal-to-noise ratio (SNR), mean square error (MSE), structural similarity index (SSIM) and computational time. On average, the filters designed for signal-dependent noise provided better image restorations than those assuming additive white Gaussian noise (AWGN). Collaborative denoising strategy was found to be the most effective in denoising of both simulated and real data, also in the presence of image gray-level transformations. White compression, by inherently reducing the greater noise variance of brighter pixels, appeared to support denoising algorithms in performing more effectively. © 2012 Elsevier Ltd. All rights reserved.

Increased risk of diabetes mellitus among persons with psychotic symptoms:results from the WHO World Health Survey

OBJECTIVE: To analyze with a symptom-based approach the relationship between psychosis and diabetes mellitus in the general population. METHOD: Nationally representative samples from the World Health Organization (WHO) World Health Survey, totaling 224,743 randomly selected adults 18 years and older from 52 countries worldwide, were interviewed to establish the presence of psychotic symptoms and diabetes mellitus. Presence of psychotic symptoms was established using questions pertaining to positive symptoms from the psychosis screening module of the Composite International Diagnostic Interview. Presence of diabetes was established with a response of "yes" to the question, "Have you ever been diagnosed with diabetes (high blood sugar)?" The World Health Survey was conducted between 2002 and 2004. RESULTS: An increasing number of psychotic symptoms was related to increasing likelihood of diabetes mellitus (OR = 1.27; 95% CI, 1.24-1.30). As compared to no symptoms, at least 1 psychotic symptom substantially elevated the risk (OR = 1.71; 95% CI, 1.61-1.81). In people with a lifetime diagnosis of schizophrenia or psychosis, the prevalence of diabetes was higher in those with current psychotic symptoms (7.3% vs 5.2%; OR = 1.65; 95% CI, 1.21-2.26), suggesting that the persistence of symptoms over time could play a central role. After controlling for different potential confounders, there was a clear increase in the probability of having diabetes as the number of psychotic symptoms increased. The relationship between psychotic symptoms and diabetes was tested with multiple mediation models and path analyses for categorical outcomes. Only body mass index appeared as a relevant mediator in a model with a good fit (ie, χ21 = 3.2, P = .0742; comparative fit index = 0.999). CONCLUSIONS: Psychotic symptoms are related to increased rates of diabetes mellitus in nonclinical samples, independent of several potential confounders-including a clinical diagnosis of psychosis or schizophrenia, previous antipsychotic treatment, depression, lifestyle, and individual or country socioeconomic status. The findings highlight the worldwide relevance of the problem and the importance of identifying the specific paths of this association.

Banking Contagion under Different Exchange Rate Regimes in CEE

The global crisis of 2008 caused both liquidity shortage and increasing insolvency in the banking system. The study focuses on credit default contagion in the Central and Eastern European (CEE) region, which originated in bank runs generated by non-performing loans granted to non-financial clients. In terms of methodology, the paper relies on one hand on review of the literature, and on the other hand on a data survey with comparative and regression analysis. To uncover credit default contagion, the research focuses on the combined impact of foreign exchange rates and foreign private indebtedness.

Banking Contagion under Different Exchange Rate Regimes in CEE

The global crisis of 2008 caused both liquidity shortage and increasing insolvency in the banking system. The study focuses on credit default contagion in the Central and Eastern European (CEE) region, which originated in bank runs generated by non-performing loans granted to non-financial clients. In terms of methodology, the paper relies on one hand on review of the literature, and on the other hand on a data survey with comparative and regression analysis. To uncover credit default contagion, the research focuses on the combined impact of foreign exchange rates and foreign private indebtedness.

Academic achievement orientation of West Indian American parents and adolescents

Literature addressing academic achievement orientation of Black adolescents in the United States often depicts poor school related attitudes and adaptation patterns, low academic achievement, and deficient family backgrounds. However, some researchers maintained that certain Black immigrant groups possessed positive academic achievement orientations and exemplary academic achievements (Ogbu, 1991; Gibson, 1991; Vernez, & Abrahamse, 1996). In this study, I attempted to combine qualitative data from multiple sources (surveys, interviews, observations, literature, and document analysis), using standard case study methodology and the constant comparative method of analysis to understand the relationship that existed between the academic achievement orientation of a select group of West Indian American parents and adolescents in Broward County, Florida. The sub-sample of 11 families, comprising 15 adolescents and 13 parents, was selected through maximum variation sampling from a pool of 23 families. The findings were presented as a single composite case study. The participants possessed specific, longstanding educational and career goals for the children. The parents were deeply involved and were knowledgeable of their children's schools and academic progress. While mothers were the parents most actively involved in the schools, fathers were strong authoritative figures. Families evidenced a strong moral religious base with set rules of behavior, firm parenting practices, and established chains of authority. Family members emphasized education over material things; reading over audiovisual or social activities; family cohesion over individual wishes; and academics over extracurricular activities. The parents' strong positive academic achievement orientation was communicated to the children and reinforced by relatives, family friends, and others. In turn, the adolescents possessed positive school-related attitudes and attributional styles. While they admitted their parents were somewhat strict, they voluntarily complied with the rules and were highly motivated to succeed because they believed their parents deeply cared for them and that education leads to success and upward mobility. Each adolescent was pursuing an academic track and planning for college and specific profession. The findings support Ogbu's cultural ecological model (1991). I recommend these findings to teachers, counselors, administrators, parents, and others working with West Indian American families. ^

Domestic and foreign isolationism in an interdependent world

Since Plato's Republic and Aristotle's Politics established the basis for Western political thought almost 2500 years ago, the discipline of international relations has evolved substantially. However, most of the literature revolves around state interaction within the system, and there is little discussion of countries that opt out of the international states system and become isolationist. Given the interdependent nature of the modern international system, this study elaborates on domestic and foreign isolationism by expounding upon the reasons and consequences of states opting out of the international system. The empirical case studies utilized to explore isolationism are Albania, North Korea, and Burma. By empirically verifying the components, motivations, and consequences of isolationism in an interdependent world, this study provides insight into why and how states resist engagement with the global socioeconomic and political state system. ^ Using historical, comparative, and inductive analysis, this study explains why states choose to isolate themselves both domestically and internationally. Specifically, comparative historical analysis highlights isolationism as a concept and practice. This study maintains that extreme forms of self-imposed isolation in an interdependent international system, while perhaps serving the immediate interests of a ruling regime, harms the long-term national interests of the state and the populace. Although the leadership in an isolationist state gains a significant amount of power and control over the people within its borders, the state as a whole experiences profound negative effects. In the long term, a state loses power, stability, prestige, and suffers a decline in overall economic prosperity. ^ States that withdraw from the international system, therefore, provide insight into an unexplored area of international relations when considering notions of rationality, self-interest, power politics, cooperation, and alliances. In short, isolationism in an interdependent state system goes against the logic of the modern society/system of states, resulting in deleterious consequences to the wellbeing of the state. ^

Glacial North Atlantic: Sea surface conditions reconstructed by GLAMAP 2000

The response of the tropical ocean to global climate change and the extent of sea ice in the glacial nordic seas belong to the great controversies in paleoclimatology. Our new reconstruction of peak glacial sea surface temperatures (SSTs) in the Atlantic is based on census counts of planktic foraminifera, using the Maximum Similarity Technique Version 28 (SIMMAX-28) modern analog technique with 947 modern analog samples and 119 well-dated sediment cores. Our study compares two slightly different scenarios of the Last Glacial Maximum (LGM), the Environmental Processes of the Ice Age: Land, Oceans, Glaciers (EPILOG), and Glacial Atlantic Ocean Mapping (GLAMAP 2000) time slices. The comparison shows that the maximum LGM cooling in the Southern Hemisphere slightly preceeded that in the north. In both time slices sea ice was restricted to the north western margin of the nordic seas during glacial northern summer, while the central and eastern parts were ice-free. During northern glacial winter, sea ice advanced to the south of Iceland and Faeroe. In the central northern North Atlantic an anticyclonic gyre formed between 45° and 60°N, with a cool water mass centered west of Ireland, where glacial cooling reached a maximum of >12°C. In the subtropical ocean gyres the new reconstruction supports the glacial-to-interglacial stability of SST as shown by CLIMAP Project Members (CLIMAP) [1981]. The zonal belt of minimum SST seasonality between 2° and 6°N suggests that the LGM caloric equator occupied the same latitude as today. In contrast to the CLIMAP reconstruction, the glacial cooling of the tropical east Atlantic upwelling belt reached up to 6°-8°C during Northern Hemisphere summer. Differences between these SIMMAX-based and published U37[k]- and Mg/Ca-based equatorial SST records are ascribed to strong SST seasonalities and SST signals that were produced by different planktic species groups during different seasons.

Distribution of planktic foraminifera in surface sediments of the Atlantic Ocean

We present a data set of 738 planktonic foraminiferal species counts from sediment surface samples of the eastern North Atlantic and the South Atlantic between 87°N and 40°S, 35°E and 60°W including published Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) data. These species counts are linked to Levitus's [1982] modern water temperature data for the four caloric seasons, four depth ranges (0, 30, 50, and 75 m), and the combined means of those depth ranges. The relation between planktonic foraminiferal assemblages and sea surface temperature (SST) data is estimated using the newly developed SIMMAX technique, which is an acronym for a modern analog technique (MAT) with a similarity index, based on (1) the scalar product of the normalized faunal percentages and (2) a weighting procedure of the modern analog's SSTs according to the inverse geographical distances of the most similar samples. Compared to the classical CLIMAP transfer technique and conventional MAT techniques, SIMMAX provides a more confident reconstruction of paleo-SSTs (correlation coefficient is 0.994 for the caloric winter and 0.993 for caloric summer). The standard deviation of the residuals is 0.90°C for caloric winter and 0.96°C for caloric summer at 0-m water depth. The SST estimates reach optimum stability (standard deviation of the residuals is 0.88°C) at the average 0- to 75-m water depth. Our extensive database provides SST estimates over a range of -1.4 to 27.2°C for caloric winter and 0.4 to 28.6°C for caloric summer, allowing SST estimates which are especially valuable for the high-latitude Atlantic during glacial times.

Arquitetura, cidade e território no Brasil colonial: a contribuição dos carmelitas calçados da Bahia e Pernambuco (1580-1800)

This study investigates the religious group named 'shoe wearing carmelites' (or Calced Carmelites) from Brazil´s Order of Carmo, from 1580 until 1800, in the Capitaincy of Bahia de Todos os Santos (Recôncavo, city of Salvador and Sergipe) and in the Capitaincy of Pernambuco (Alagoas, Pernambuco and Itamaracá). The study does not include the religious group known as the 'Reformed' Carmelites from Goiana, Recife and Paraíba convents. The Order of Carmo is a religious order from the Roman Catholic Church, founded in the 12th century. By the 16th century they were split into 'Calced' and 'Discalced'. In 1580 the Calced ones came from Portugal to Brazil, built convents in urban areas and were able to acquire slaves, farms and other assets. As any other religious order, the Carmelites had their modus operandi. This work emphasizes the way they operated or acted in the city, either individually or in association with other Carmelite religious foundations elsewhere (networking). Their action affected, although indirectly, the building of some specific aspects of the architecture, the city and the territory in colonial Brazil. The main objective of this study is to demonstrate the impact of the Calced Carmelites from Bahia and Pernambuco upon the territory of colonial Brazil, which is analyzed according to three scales: 1) the region or interurban; 2) the city or intraurban; 3) the building or the architecture. The research employs the comparative method of analysis, especially for the architectural scale. The work demonstrates that although not acting as architects or urbanists, the Carmelites contributed to the formation of the colonial territory of Brazil, behaving as a well-articulated and hierarchized religious network, from an economic and social perspective. Moreover, they influenced the emergence and growth of several colonial urban nuclei, from Bahia to Pernambuco, mainly in the surroundings of their religious buildings. Finally, it is very clear this religious order’s contribution to colonial architecture, as it can be seen by the architectural characteristics of the convents and churches which have been analyzed, many of which still stand in a good state of conservation nowadays.

Relative abundance of anaerobic methanotrophic archaea in bacterial mat Cascadia margin off Oregon

The microbially mediated anaerobic oxidation of methane (AOM) is the major biological sink of the greenhouse gas methane in marine sediments (doi:10.1007/978-94-009-0213-8_44) and serves as an important control for emission of methane into the hydrosphere. The AOM metabolic process is assumed to be a reversal of methanogenesis coupled to the reduction of sulfate to sulfide involving methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) as syntrophic partners which were describes amongst others in Boetius et al. (2000; doi:10.1038/35036572). In this study, 16S rRNA-based methods were used to investigate the distribution and biomass of archaea in samples from sediments above outcropping methane hydrate at Hydrate Ridge (Cascadia margin off Oregon) and (ii) massive microbial mats enclosing carbonate reefs (Crimea area, Black Sea). Sediment samples from Hydrate Ridge were obtained during R/V SONNE cruises SO143-2 in August 1999 and SO148-1 in August 2000 at the crest of southern Hydrate Ridge at the Cascadia convergent margin off the coast of Oregon. The second study area is located in the Black Sea and represents a field in which there is active seepage of free gas on the slope of the northwestern Crimea area. Here, a field of conspicuous microbial reefs forming chimney-like structures was discovered at a water depth of 230 m in anoxic waters. The microbial mats were sampled by using the manned submersible JAGO during the R/V Prof. LOGACHEV cruise in July 2001. At Hydrate Ridge the surface sediments were dominated by aggregates consisting of ANME-2 and members of the Desulfosarcina-Desulfococcus branch (DSS) (ANME-2/DSS aggregates), which accounted for >90% of the total cell biomass. The numbers of ANME-1 cells increased strongly with depth; these cells accounted 1% of all single cells at the surface and more than 30% of all single cells (5% of the total cells) in 7- to 10-cm sediment horizons that were directly above layers of gas hydrate. In the Black Sea microbial mats ANME-1 accounted for about 50% of all cells. ANME-2/DSS aggregates occurred in microenvironments within the mat but accounted for only 1% of the total cells. FISH probes for the ANME-2a and ANME-2c subclusters were designed based on a comparative 16S rRNA analysis. In Hydrate Ridge sediments ANME-2a/DSS and ANME-2c/DSS aggregates differed significantly in morphology and abundance. The relative abundance values for these subgroups were remarkably different at Beggiatoa sites (80% ANME-2a, 20% ANME-2c) and Calyptogena sites (20% ANME-2a, 80% ANME-2c), indicating that there was preferential selection of the groups in the two habitats.

Paleotemperature and productivity reconstruction of sediment core D11957P on the Iberian Margin

Foraminifera counts and climatic assemblages from the Tore Seamount are used to approach the glacial and interglacial changes in temperature and productivity on the Iberian Margin over the last 225 kyr. Chronostratigraphy is based on Globigerinoides ruber and Globigerina bulloides oxygen isotopes and supported by foraminifera and carbonate stadial fluctuations. Foraminifera indicate cooling from late interglacial stage 5 to the beginning of Termination I (TI). Neogloboquadnna pachyderma-s reflects cold conditions during glacial stages 4-2. In contrast, glacial stage 6 is dominated by warmer N. pachyderma-d and dutertrei and a restricted arctic assemblage. Past sea surface temperatures confirm the general cooling, reaching 4.3°C (SIMMAX.28) during stage 2. Multiple productivity proxies such as organic carbon, productivity-related foraminifera, and delta13C constrain the changes observed. A productivity increase occurs after interglacial stage 5, enhanced from late glacial stage 3 to TI Present-day satellite-detected phytoplankton plumes off Portugal would have accounted in the past glacial stages for the general productivity increase over the Tore. On top of this, welldefined peaks of organic carbon and productivity-related foraminifera correspond with Heinrich events 1-4.

Matematik Öğretmeni Adaylarının Dörtgenleri Sınıflandırma Becerilerinin İncelenmesi

This study aimed to explore prospective teachers’ performance on recognizing quadrilaterals with their special cases and constructing a hierarchical classification of them. The participants consisted of 44 freshmen studying at a public university’s elementary school mathematics education department. Data was collected with a question form containing two questions at the first day of the geometry course taught in the second term of the first year. For quantifying the data of the first question, while students who identify the prototypes of quadrilaterals and their special cases were given 1 and 2 points for each correct answer respectively, -1 point was given for each incorrect answer. The similarity index was employed to quantify students’ concept maps. We investigated that students could detect the prototypes of the quadrilaterals but not their special cases. Additionally, the similarity index between majority of freshmen’ concept maps and the referent map was found as low or moderate.

An appraisal of adaptive management planning and implementation in ecological restoration: case studies from the San Francisco Bay Delta, USA

Adaptive management has been defined and redefined in the context of natural resource management, yet there are few examples of its successful application in ecological restoration. Although the 2009 Delta Reform Act now legally requires adaptive management for all restoration efforts in the Sacramento-San Joaquin Delta, in California, USA, projects in this region still encounter problems with implementation. We used a comparative case study analysis to examine adaptive management planning and implementation both in and around the Delta, assessing not only why adaptive management is not yet well implemented, but also what changes can be made to facilitate the adaptive management approach without sacrificing scientific rigor. Adaptive management seems to be directly and indirectly affected by a variety of challenges and convoluted by ambiguity in both planning documents and practitioner’s interpretations of the concept. Addressing these challenges and ambiguities at the project level may facilitate the adaptive management process and help make it more accessible to practitioners.