bluuebunny/crossref_metadata_2025 huggingface dataset:
The clinical and functional significance of c-Met in breast cancer: a review
Authors: Ho-Yen Colan M , Jones J Louise , Kermorgant Stephanie
Published: April 2015

c-Met is a receptor tyrosine kinase that upon binding of its ligand, hepatocyte growth factor (HGF), activates downstream pathways with diverse cellular functions that are important in organ development and cancer progression. Anomalous c-Met signalling has been described in a variety of cancer types, and the receptor is regarded as a novel therapeutic target. In breast cancer there is a need to develop new treatments, particularly for the aggressive subtypes such as triple-negative and basal-like cancer, which currently lack targeted therapy. Over the last two decades, much has been learnt about the functional role of c-Met signalling in different models of breast development and cancer. This work has been complemented by clinical studies, establishing the prognostic significance of c-Met in tissue samples of breast cancer. While the clinical trials of anti-c-Met therapy in advanced breast cancer progress, there is a need to review the existing evidence so that the potential of these treatments can be better appreciated. The aim of this article is to examine the role of HGF/c-Met signalling in in vitro and in vivo models of breast cancer, to describe the mechanisms of aberrant c-Met signalling in human tissues, and to give a brief overview of the anti-c-Met therapies currently being evaluated in breast cancer patients. We will show that the HGF/c-Met pathway is associated with breast cancer progression and suggest that there is a firm basis for continued development of anti-c-Met treatment, particularly for patients with basal-like and triple-negative breast cancer.
Targeting PTEN-defined breast cancers with a one-two punch
Authors: Maggi Leonard B , Weber Jason D
Published: April 2015

With tremendous advances in sequencing and analysis in recent years, a wealth of genetic information has become available to identify and classify breast cancer into five main subtypes - luminal A, luminal B, claudin-low, human epidermal growth factor receptor 2-enriched, and basal-like. Current treatment decisions are often based on these classifications, and while more beneficial than any single treatment for all breast cancers, targeted therapeutics have exhibited limited success with most of the subtypes. Luminal B breast cancers are associated with early relapse following endocrine therapy and often exhibit a poor prognosis that is similar to that of the aggressive basal-like breast cancers. Identifying genetic components that contribute to the luminal B endocrine resistant phenotype has become imperative. To this end, numerous groups have identified activation of the phosphatidylinositol 3-kinase (PI3K) pathway as a common recurring event in luminal B cancers with poor outcome. Examining the pathways downstream of PI3K, Fu and colleagues have recreated a human model of the luminal B subtype of breast cancer. The authors were able to reduce expression of phosphatase and tensin homolog (PTEN), the negative regulator of PI3K, using inducible short hairpin RNAs. By varying the expression of PTEN, the authors effectively conferred endocrine resistance and recapitulated the luminal B gene expression signature. Using this system in vitro and in vivo, they then tested the ability of selective kinase inhibitors downstream of PI3K to enhance current endocrine therapies. A combination of fulvestrant, which blocks ligand-dependent and -independent estrogen receptor signaling, with protein kinase B inhibition was found to overcome endocrine resistance. These findings squarely place PTEN expression levels at the nexus of luminal B breast cancers and indicates that patients with PTEN-low estrogen receptor-positive tumors might benefit from combined endocrine and PI3K pathway therapies.
Synthesis, crystal structures and docking studies of 2,7-diphenyl-1,4-diazepan-5-one derivatives
Authors: Velusamy Maheshwaran , Sreenivasan Sethuvasan , Kandasamy Ravichandran , Subbu Ponnuswamy , Paramasivam Sugumar , Mondikalipudur Nanjappagounder Ponnuswamy
Published: April 2015

Background

1,4-Diazepine derivatives are the seven membered, nitrogen containing heterocyclic ring systems possessing a wide range of therapeutic applications. 1,4-Diazepines attracted the attention of chemists and druggists due to their biological and medicinal properties, such as antimicrobial, anti-HIV and anticancer activities. Herein, we report the preparation, crystal structure determined by X-ray crystallographic methods and docking of the molecules with the potential target protein NS5B RNA polymerase.

Results

The crystal structures and conformational studies of 1,4-diazepine [t-3, t-6-dimethyl-r-2,c-7-diphenyl-1,4-diazepan-5-one(DIAZ1)] and its nitroso derivative [t-3, t-6-dimethyl-1-nitroso-r-2,c-7-diphenyl-1,4-diazepan-5-one(DIAZ2)] are reported. The analyses of the molecules reveal that the seven membered diazepine ring systems adopt chair and boat conformations in compounds DIAZ1 & DIAZ2, respectively. In DIAZ2, the oxygen O2A is disordered over two positions with the refined occupancies of 0.792(7): 0.208(7) in the nitroso group. In both DIAZ1 & DIAZ2, the symmetry related molecules form a hetero/homo-dimer through N-H…O hydrogen bonds.

Conclusion

In this study, the crystal structures of two new 1,4-diazepines, namely t-3, t-6-dimethyl-r-2,c-7-diphenyl-1,4-diazepan-5-one and t-3, t-6-dimethyl-1-nitroso-r-2,c-7-diphenyl-1,4-diazepan-5-one were synthesized and characterized by X-ray crystallographic methods. The docking studies show that the compounds inhibit at the active site of the target protein and can be utilized as potential drug molecules. In both the compounds, N-H…O hydrogen bonds lead to dimer formation. In DIAZ2, additionally a couple of C-H…O interactions are noted between the molecules.
Physically motivated global alignment method for electron tomography
Authors: Sanders Toby , Prange Micah , Akatay Cem , Binev Peter
Published: April 2015

Electron tomography is widely used for nanoscale determination of 3-D structures in many areas of science. Determining the 3-D structure of a sample from electron tomography involves three major steps: acquisition of sequence of 2-D projection images of the sample with the electron microscope, alignment of the images to a common coordinate system, and 3-D reconstruction and segmentation of the sample from the aligned image data. The resolution of the 3-D reconstruction is directly influenced by the accuracy of the alignment, and therefore, it is crucial to have a robust and dependable alignment method. In this paper, we develop a new alignment method which avoids the use of markers and instead traces the computed paths of many identifiable ‘local’ center-of-mass points as the sample is rotated. Compared with traditional correlation schemes, the alignment method presented here is resistant to cumulative error observed from correlation techniques, has very rigorous mathematical justification, and is very robust since many points and paths are used, all of which inevitably improves the quality of the reconstruction and confidence in the scientific results.
A large-scale field study in eastern Siberia using novel time-domain electromagnetic technology
Authors: Davydycheva Sofia , Kaminsky Alexander , Rykhlinski Nikolai , Yakovlev Andrei
Published: April 2015

We evaluated the results of a large-scale commercial project that illustrated the capabilities of advanced time-domain electromagnetic (TDEM) technologies powered with integrated interpretation of geologic and geophysical data. To study the hydrocarbon prospectivity of a field in Eastern Siberia, we developed a survey design, and then acquired, processed, and interpreted the TDEM data from 30 profiles (total length 772 km) covering an area of approximately [Formula: see text]. The data were acquired using the conventional TDEM and a novel high-resolution version of TDEM, the focused-source electromagnetic method. We described the geologic framework, data acquisition methodologies, and key results obtained using integrated TDEM, seismic, and well-logging data. The interpretation was used to select well locations for additional exploratory drilling. Postsurvey drilling supported our interpretation. The presented case study demonstrates the value of TDEM in the exploration workflow.
Characterization and origin of the Silurian Wufeng-Longmaxi Formation shale multiscale heterogeneity in southeastern Sichuan Basin, China
Authors: Jiang Zhenxue , Tang Xianglu , Cheng Lijun , Li Zhuo , Zhang Yingying , Bai Yongqiang , Yuan Yuan , Hao Jin
Published: April 2015

Shale heterogeneity is important for micro- to macroscale-quality reservoir prediction. We evaluated the multiscale heterogeneity in shale based on thin-section observation, field emission scanning electron microscope observation, low-pressure [Formula: see text] adsorption analysis, mercury intrusion porosimetry, organic carbon analysis, and bulk chemical analysis by X-ray powder diffraction. We evaluated the results in which the heterogeneity of minerals and organic matter in shale was shown by disorderly and unsystematically distributed mineral grains, lamina, and rapid lithology at multiple scales. The random arrangement of minerals, seasonal climate changes, large changes of sedimentary environment, and the provenance supply was considered to be the origin of the heterogeneity from the micro- to the macroscale in shale. In addition, a multiscale heterogeneity distribution model of marine shale in southeastern Sichuan basin was established, which can be used to predict shale gas distribution from the micro- to the macroscale.
Enhancement of dynamic reservoir interpretation by correlating multiple 4D seismic monitors to well behavior
Authors: Yin Zhen , Ayzenberg Milana , MacBeth Colin , Feng Tao , Chassagne Romain
Published: April 2015

We have found that dynamic reservoir interpretation can be enhanced by directly correlating the seismic amplitudes from many repeated 4D seismic monitors to the field production and injection history from wells. This “well2seis” crosscorrelation was achieved by defining a linear relationship between the 4D seismic signals and changes in the cumulative fluid volumes at the wells. We also found that the distribution of the well2seis correlation attribute can reveal key reservoir connectivity features, such as the seal of faults, fluid pathways, and communication between neighboring compartments. It can therefore enhance dynamic reservoir description. Based on this enhanced interpretation, we have developed a workflow to close the loop between 4D seismic and reservoir engineering data. First, the reservoir model was directly updated using quantitative information extracted from multiple surveys, by positioning and placing known barriers or conduits to flow. After this process, a seismic-assisted history matching was applied using the well2seis attribute to honor data from the seismic and engineering domains, while remaining consistent with the fault interpretation. Compared to traditional history matching, that attempts to match individual seismic time-lapse amplitudes and production data, our approach used an attribute that condensed available data to effectively enhance the signal. In addition, the approach was observed to improve the history-matching efficiency as well as model predictability. The proposed methodology was applied to a North Sea-field, the production of which was controlled by fault compartmentalization. It successfully detected the communication pathways and sealing property of key faults that are known to be major factors in influencing reservoir development. After history matching, the desired loops were closed by efficiently updating the reservoir simulation model, and this was indicated by a 90% reduction in the misfit errors and 89% lowering of the corresponding uncertainty bounds.
Compaction-induced anisotropy and time-lapse AVO analysis
Authors: Islam Nayyer , Pennington Wayne D.
Published: April 2015

Hydrocarbon reservoirs are often monitored using repeated seismic observations to track fluid movement and other changes. Here, we present a study of compaction-induced anisotropy in an unconsolidated overpressured sandstone reservoir from Teal South field in the Gulf of Mexico. Previous work at Teal South had demonstrated that the time-lapse observations could not be satisfied through models of fluid changes without strong pressure effects acting on the formation rock framework. However, those studies are not highly quantitative, and some minor inconsistencies appear on closer examination. We have examined the effect of the pressure-sensitivity of elastic moduli in the formation and carefully examined the offset-dependence of amplitudes in light of several rock-physics models, empirical and theoretical. The amplitude-variation-with-offset behavior for the interface between overlying shale and the hydrocarbon sand is best modeled under the assumption that this overpressured reservoir becomes anisotropic because it undergoes compaction during production, which reduces the reservoir pressure from highly overpressured to nearly normal for this depth. Although the results obtained here are only weakly constrained due to the limited offset ranges and low fold, this strongly suggests that anisotropic effects in poorly consolidated overpressured reservoirs undergoing primary depletion may in fact dominate over fluid effects after the bubble point has been reached.
Impacts of kerogen content and fracture properties on the anisotropic seismic reflectivity of shales with orthorhombic symmetry
Authors: Yang Li , Wu Xiaoyang , Chapman Mark
Published: April 2015

Shale often has strong intrinsic anisotropy, which can be described by transverse isotropy with a vertical axis of symmetry. When vertical fractures are present, shale is likely to exhibit orthorhombic symmetry. We used anisotropic rock-physics models to describe the orthorhombic properties of fractured shale, and we determined that composition and fracture properties had an impact on the azimuthal amplitude variations. Interpretation of azimuthal reflectivity variations was often performed under simplified assumptions. Although the Rüger equation was derived for weak anisotropy and for transverse isotropy with a horizontal axis of symmetry, our results indicated that the orthorhombic response can be well described by the Rüger equation. However, ambiguities could be introduced into the interpretation of parameters. We suggested that careful rock-physics modeling was important for interpreting the anisotropic seismic response of fractured shale.
Outcomes of Patients With Chronic Lymphocytic Leukemia and Richter's Transformation After Transplantation Failure
Authors: Rozovski Uri , Benjamini Ohad , Jain Preetesh , Thompson Philip A. , Wierda William G. , O'Brien Susan , Burger Jan A. , Ferrajoli Alessandra , Faderl Stefan , Shpall Elizabeth , Hosing Chitra , Khouri Issa F. , Champlin Richard , Keating Michael J. , Estrov Zeev
Published: April 2015

Purpose

Allogeneic stem-cell transplantation (SCT) induces long-term remission in a fraction of patients with high-risk chronic lymphocytic leukemia (CLL) or Richter's transformation (RT). Our purpose was to determine the outcomes of patients whose disease progressed after allogeneic SCT.

Patients and Methods

We retrospectively analyzed the outcomes of 72 patients (52 with CLL and 20 with RT) who underwent allogeneic SCT between 1998 and 2011 and had documented progression after transplantation. Twenty-two (31%) never had a response, and 50 (69%) had a response but experienced relapse after a median of 7 months (range, 2 to 85 months). Forty-eight patients who were receiving or were candidates to receive post-SCT cell-based therapies were not included in this analysis.

Results

The median age at time of transplantation was 58 years (range, 30 to 72 years). Sixty-two patients (86%) received more than two treatment regimens and 37 (51%) received more than three treatment regimens before SCT. Sixty-six patients (92%) had active disease at the time of transplantation. The 2- and 5-year survival rates were 67% and 38% (patients with CLL) and 36% and 0% (patients with RT). The patients who developed acute or chronic graft-versus-host disease had a longer overall survival (OS; P = .05). In a multivariable analysis, RT or low hemoglobin at the time of SCT predicted shorter OS. Chronic graft-versus-host disease and an initial response to SCT predicted longer OS.

Conclusion

Patients with CLL in whom allogeneic SCT fails may have a response to and benefit from salvage therapies, and their prognosis is relatively good.
Long-Term Pulmonary Function in Survivors of Childhood Cancer
Authors: Armenian Saro H. , Landier Wendy , Francisco Liton , Herrera Claudia , Mills George , Siyahian Aida , Supab Natt , Wilson Karla , Wolfson Julie A. , Horak David , Bhatia Smita
Published: April 2015

Purpose

This study was undertaken to determine the magnitude of pulmonary dysfunction in childhood cancer survivors when compared with healthy controls and the extent (and predictors) of decline over time.

Patients and Methods

Survivors underwent baseline (t1) pulmonary function tests, followed by a second comprehensive evaluation (t2) after a median of 5 years (range, 1.0 to 10.3 years). Survivors were also compared with age- and sex-matched healthy controls at t2.

Results

Median age at cancer diagnosis was 16.5 years (range, 0.2 to 21.9 years), and time from diagnosis to t2 was 17.1 years (range, 6.3 to 40.1 years). Compared with odds for healthy controls, the odds of restrictive defects were increased 6.5-fold (odds ratio [OR], 6.5; 95% CI, 1.5 to 28.4; P < .01), and the odds of diffusion abnormalities were increased 5.2-fold (OR, 5.2; 95% CI, 1.8 to 15.5; P < .01). Among survivors, age younger than 16 years at diagnosis (OR, 3.0; 95% CI, 1.2 to 7.8; P = .02) and exposure to more than 20 Gy chest radiation (OR, 5.6; 95% CI, 1.5 to 21.0; P = .02, referent, no chest radiation) were associated with restrictive defects. Female sex (OR, 3.9; 95% CI, 1.7 to 9.5; P < .01) and chest radiation dose (referent: no chest radiation; ≤ 20 Gy: OR, 6.4; 95% CI, 1.7 to 24.4; P < .01; > 20 Gy: OR, 11.3; 95% CI, 2.6 to 49.5; P < .01) were associated with diffusion abnormalities. Among survivors with normal pulmonary function tests at t1, females and survivors treated with more than 20 Gy chest radiation demonstrated decline in diffusion function over time.

Conclusion

Childhood cancer survivors exposed to pulmonary-toxic therapy are significantly more likely to have restrictive and diffusion defects when compared with healthy controls. Diffusion capacity declines with time after exposure to pulmonary-toxic therapy, particularly among females and survivors treated with high-dose chest radiation. These individuals could benefit from subsequent monitoring.
Preparation of Y3+- and La3+-doped ZIF-8 Crystals and the Fluorescence Sensing of Amines
Authors: Lin Yunfeng , Wang Chongqing , Pan Yichang , Xiang Long , Liu Yan
Published: April 2015

Y3+- and La3+-doped zeolitic imidazolate frameworks-8 (ZIF-8) crystals were first successfully prepared by hydrothermal synthesis. As-synthesized crystals were investigated by X-ray diffraction, field-emission scanning electron microscope, fluorescence spectrometric titration, and gas adsorption measurement. The Y3+-doped ZIF-8 crystals were found to be highly sensitive to amines (ethylamine, diethylamine, and triethylamine), providing a novel candidate for the sensitive and rapid detection of amines.
Experience in Macroeconomic Analysis and Forecasting of Employment and Labour Market in RF Economy
Authors: Королев  , Korolev I. , Единак  , Edinak E. , Долгова  , Dolgova I. , Коровкин  , Korovkin A.
Published: April 2015

The paper deals with the methods and approaches of analysis and forecasting of labor resources dynamics and its structure. Predictive and analytical tools to study the current and future dynamics of the labor demand and labor supply in the Russian economy taking in account the process of labor force demand and its supply adjustment are offered. Opportunities for further development and improvement of methods and approaches are discussed.
Fundamental Approaches to a System of Professional Standards for the Oil and Gas Industry
Authors: Иванов  , Ivanov P. , Кашина  , Kashina M.
Published: April 2015

The system of professional standards will allow the industry Nai more adequately and optimally meet their needs in the labor force. The paper describes the main approaches to the formation of professionaltion standards, establish certain principles and industry specific, which formed the basis of professional standards projects.
Internal Control in the Bank: Development Prospects
Authors: Кириллов  , Kirillov R.
Published: April 2015

In the article justified the need for creating a modern concept of internal control by the example of the banking

sector. The author considers the definition of internal control and its key components, tracing the history of

the development of this concept in various international instruments and research of various authors. The

essence and the current content of the internal control is exposed, identified approaches to its assessment,

performance criteria and development prospects of the banking sector companies.
ECG of the month
Authors: Regan Claire , Regan Martin
Published: April 2015

Clare Regan and Martin Regan present an ECG for you to analyse.
Research Roundup
Authors: Cope Graham F
Published: April 2015

In this section, Graham Cope presents a synopsis of a selection of recently published articles of interest to nurses working in the field of cardiovascular nursing. The aim of this roundup is to provide a brief overview of the research papers selected. A full reference is provided for those who wish to take a look at the research in further detail
Postoperative atrial fibrillation: a care study
Authors: Hill Corinne , Bowden Tracey
Published: April 2015

This care study outlines the pharmacological and non-pharmacological interventions that can be used in the prevention, detection and treatment of postoperative atrial fibrillation (POAF). It examines the impact of POAF, the predisposing risk factors and potential postoperative triggers. The theory behind nursing and medical care given to a patient suffering from POAF is discussed, including the need for preoperative patient education, effective assessment, timely treatment and the interventions needed to limit both the adverse effects of treatment and the complications associated with POAF. It also considers the theory behind rate vs. rhythm control treatment strategy and the use of amiodarone for the effective management of POAF.
Ablation of atrial fibrillation: pain relief by visualisation
Authors: Nørgaard Marianne Wetendorff , Pedersen Preben Ulrich , Bjerrum Merete
Published: April 2015

Marianne Wetendorff Nørgaard et al present an overview of both quantitative and qualitative studies investigating the effectiveness of visualisation as a form of pain relief in ablation for atrial fibrillation
Coronary artery bypass graft
Authors: Mendes Aysha
Published: April 2015

This section presents a concise overview of the treatments and clinical procedures regularly carried out in the field of cardiovascular care. This ‘back-to-basics’ article aims to refresh nurses' knowledge on correct practice, as well as introduce students and junior nurses to procedures
Binge drinking and cognitive impairment in young people
Authors: Thayanukulvat Claire , Harding Tracey
Published: April 2015

Aims and objectives:

To investigate the links between the binge pattern of drinking and the development of cognitive impairment in young adults in the UK. To determine from the findings whether cognitive impairment is an additional public health concern manifesting from this form of alcohol misuse and its relevance to nursing practice.

Background:

Young adults in the UK are participating in binge drinking; a ‘harmful’ form of alcohol misuse. Morbidity and mortality associated with alcohol misuse is already a public health concern.

Design:

Literature review.

Method:

Multiple database searches were undertaken, which revealed three case-control studies. The studies all investigated the binge pattern of drinking as well as meeting the following inclusion criteria; primary research published from 2005 onwards, used a human sample, participants were aged 18 to 24 and cognitive function was tested.

Results:

The quantitative data found cognitive impairment present in young adult binge drinkers, specifically in regions of the frontal lobe, temporal lobe and hippocampus. Individually the studies did not pose strong enough evidence to generalise findings. However, collectively the core findings along with previous studies can validate the link between binge drinking and cognitive impairment.

Conclusion:

Nurse-led alcohol misuse screening and brief intervention is the most effective public health prevention strategy. It is important for nurses to keep abreast of current evidence to better inform their practice and the information they provide to their service users. This review emphasises the need for nurses to routinely screen young adults and address the associated risk to cognitive function when participating in harmful drinking.
Left-Wing Politics in Turkey: Its Development and Problems
Authors: Şenol Durgun
Published: April 2015

This article examines the process of development of the political left since its inception in Turkey in a context when the republic was established as a nation state and 1917 October Revolution. It looks at how the movement has been transformed with the collapse of the Soviet Union and with the changes in domestic politics. The historical process of the Turkish left is divided into three eras: The first from the beginning of the republic to the 1960s; the second from 1960 to 1980; and the third from 1980 to the present day. In this era, the left has not had that organized structure and influence as in the second era.
Liberals and Muslims: Philosophy and Conquest
Authors: Shiraz Dossa
Published: April 2015

The liberal claim to decency is flimsy. In fact, the liberal norm is indecency. The Muslim case is symptomatic of this reality. The suffering of Muslims is extensive in liberal locales. The threat to Muslim security is intrinsic in liberal theory. It is the liberal genre of exclusion. In this article, I unravel anti-Muslim antipathy in Kant, Mill, and Montesquieu (KMM). I dissect their specious claims about the Muslims and the Orient. I stress KMM's formative influence on liberal academe. I conclude with the criticism of liberal Jewish attacks on Muslims/Arabs/Palestinians.
Exclusionary and Non-Consensual Transitions Versus Inclusive and Consensual Democratizations: The Cases of Egypt and Tunisia
Authors: Inmaculada Szmolka
Published: April 2015

The article analyzes the democratic transitions in Tunisia and Egypt, after the so-called “Arab Spring.” The working hypothesis is that the model of transition influences the result of democratization processes. The article is organized in three sections. The first one puts forward a theoretical and methodological framework, which includes a definition and classification of political regimes, a typology of the processes of political change and suggests models of democratic transition. Second, the models of transition in Tunisia and Egypt are compared in terms of four analytical dimensions: leadership of the transition, competition and interaction between political actors, consensus over the transition process, and the popular mobilization and the participation of the civil society. The third section assesses the outcomes of the research and concludes that the exclusion of political forces and the intervention of non-accountable actors can determine the result of democratic transitions (Egypt). In contrast, the agreements between political actors and the concessions of a predominant party can bring about a successful transition, even in a polarized scenario (Tunisia).
Narrating Arab American History: The Peddling Thesis
Authors: Charlotte Karem Albrecht
Published: April 2015

Alixa Naff's book Becoming American: The Early Arab Immigrant Experience is a foundational text for Arab American studies. Becoming American centered the voices of first- and second-generation Arab Americans through Naff's extensive use of oral histories. In large part due to Naff's work, pack peddling has had a central place in Arab American historical narratives as being the key to the early Syrian immigrants' integration into US society. This article shows how the claim that peddling facilitated assimilation is dependent upon certain ideological currents regarding race, class, gender, and sexuality. Then, I situate Naff's work within the context of US immigration history and liberal multiculturalism. I revisit the importance of Naff's work in order to show how the study of race, gender, class, and sexuality is crucial for understanding early Arab American history.
Algoritmo de optimización basado en enjambres de partículas con comportamiento de vorticidad y búsqueda individual y grupal
Authors: Espitia Cüchango Helbert Eduardo , Sofrony Esmeral Jorge Iván
Published: April 2015

En este documento se realiza la propuesta de un algoritmo de optimización basado en un enjam­bre de partículas con características de vorticidad, donde se considera una búsqueda grupal asociada al punto medio del enjambre y una búsqueda in­dividual dada por la mejor posición de cada indi­viduo. Con la búsqueda grupal se espera lograr la convergencia de todo el enjambre, mientras que la búsqueda individual permite una mejor explo­ración del espacio de búsqueda. El algoritmo pre­senta fases de convergencia y exploración dadas por el modelo seleccionado, el cual se encuentra basado en el comportamiento de un enjambre de individuos. Para establecer el desempeño del al­goritmo se emplea un conjunto de funciones de prueba en dos dimensiones.
Evaluación y diagnóstico de pasivos ambientales mineros en la Cantera Villa Gloria en la localidad de Ciudad Bolívar, Bogotá D.C.
Authors: García Ubaque César Augusto , García Vaca María Camila , Agudelo Rodríguez Carlos Fernando
Published: April 2015

En la ciudad de Bogotá la minería de extrac­ción de materiales para la construcción se intensificó desde el siglo XIX hasta principios del siglo XX (Secretaría Distrital de Ambien­te, 2007) y durante ese periodo, el crecimiento acelerado de la población, las imprecisiones técnicas de las operaciones mineras y una legislación que no contemplaba conceptos de cuidado del medio ambiente generaron numerosos pasivos ambientales, constituidos por las instalaciones mineras abandonadas o inactivas, áreas expuestas a remociones en masa que en la actualidad generan impactos negativos severos que afectan a la población y los ecosistemas. El objetivo de este artículo es emplear la metodología de evaluación del impacto ambiental Gómez Orea para diag­nosticar y analizar los pasivos ambientales presentes en la cantera Villa Gloria ubicada en la localidad de Ciudad Bolívar, y así de­terminar las posibles obras de mitigación que permitan darle un nuevo uso a esta zona, como: zonas verdes y/o áreas de recreación (Secretaría Distrital de Ambiente, 2007).
Cognición imitativa para un robot mediante una comunidad de replicadores neuro-meméticos
Authors: Sterpin Buitrago Dante Giovanni
Published: April 2015

Como herramienta de inteligencia artificial, la computación memética emplea modelos de ciertos elementos cerebrales, llamados neuro-memes, hipotéticamente implicados en la simbolización, diseminación y evolución de las características culturales en las sociedades humanas. Con la finalidad de simular el gran potencial evolutivo de los neuro-memes, recientemente se presentó el Perceptrón auto-supervisado (SSP) como replicador neuro-memético artificial, cuya capacidad de aprendizaje imitativo fue verificada al controlar un robot muy sencillo. Con respecto a dicha capacidad se observó una deficiencia aprehensiva cuando el imitador solamente observa la conducta libremente evidenciada por el instructor. Al atender dicha deficiencia se encontró la incapacidad de imitar una conducta con ciertas características. Considerando que el SSP es un modelo orientado al desarrollo de sistemas colectivos, en este artículo se presenta un sistema multi-agente compuesto por varios SSP, con el cual se solucionaron dichas dificultades encontradas en un SSP individual.
Extracción de reglas de clasificación sobre repositorio de incidentes de seguridad informática mediante programación genética
Authors: Carvajal Montealegre Carlos Javier
Published: April 2015

En este artículo se describe la obtención de reglas de clasificación sobre una colección de datos de incidentes de seguridad informática en un proceso de minería de datos, detallando el uso de la programación genética como un medio para modelar el comportamiento de los incidentes y representar las reglas en árboles de decisión. El proceso de extracción descrito incluye varios puntos, como la evaluación del enfoque de programación genética, la forma de representar a los individuos y la afinación de los parámetros del algoritmo para elevar el rendimiento. Se concluye con un análisis de los resultados y la descripción de las reglas obtenidas, considerando las posibles soluciones para minimizar la ocurrencia de los ataques informáticos. El artículo se basa en una parte de la tesis de grado Análisis de Incidentes de Seguridad Informática Mediante Minería de Datos, para Modelado de Comportamiento y Reconocimiento de Patrones (Carvajal, 2012).
Metamodels composition strategy for the model driven engineering context
Authors: Flórez Fernández Héctor Arturo
Published: April 2015

En enfoques de ingeniería basada en modelos (MDE), los metamodeladores usualmente tienen que crear un metamodelo basado en metamodelos existentes, en donde cada uno abstrae un dominio específico con el fin de abstraer un nuevo dominio, que incluye los elementos que se podrían tomar de los otros metamodelos ya creados. Este tipo de construcciones permite obtener ventaja de los conocimientos obtenidos en la construcción de los metamodelos previamente construidos. En este trabajo se presenta una propuesta para resolver la composición de metamodelos a través de un lenguaje de dominio específico (DSL). Este DSL es utilizado por metamodeladores, que son las personas que conocen los dominios abstraídos por los diferentes metamodelos y saben cómo combinar los metamodelos para generar uno nuevo. Además, se presenta un caso de estudio simple con el fin de demostrar el bajo nivel de complejidad del DSL.
Productividad en una celda de manufactura flexible simulada en promodel utilizando path networks type crane
Authors: Bernal Loaiza María Elena , Cock Sarmiento German , Restrepo Correa Jorge Hernán
Published: April 2015

Esta investigación se centra en el diseño de una simulación del proceso de una celda de manufactura flexible (FMC) de la Facultad de Ingeniería Industrial de la Universidad Tecnológica de Pereira, con el propósito de medir y elegir aquella alternativa de solución que mejore en mayor grado la productividad del sistema actual utilizando los resultados que proporciona el software Promodel. Para realizar lo anterior se utilizaron etapas de la simulación como definición del sistema, formulación del modelo, identificación de variables, recolección de datos, implementación e interpretación.Como resultado, se calculó la productividad teniendo en cuenta las variables del modelo y tiempo de la simulación, al mismo tiempo se interpretó la información de cada una de las locaciones, hallando el porcentaje de utilización y total de entidades para las locaciones con capacidad unitaria; para las locaciones con mayor capacidad se encuentra información referente al porcentaje de tiempo vacío, parcialmente ocupado, lleno y no disponible respecto del tiempo disponible. A diferencia de otras simulaciones, en este diseño en la parte de redes se utilizó el tipo de red Crane, asociado a los recursos del modelo. El cual facilita el desplazamiento de los brazos robots con las piezas que circulan a través del sistema.
Almost soliton duality
Authors: Maschler Gideon
Published: April 2015

Gradient Ricci almost solitons were introduced by Pigola, Rigoli, Rimoldi and Setti [20]. They are defined as solitons except that the metric coefficient is allowed to be a smooth function rather than a constant. It is shown that any almost soliton is conformal to another almost soliton having a soliton function which is the negative of the original one. Uniqueness, and the case where both the source and target are solitons, are studied. Completeness of the target metric is also examined in the casewhere the source is Kähler and admits a special Kähler-Ricci potential in the sense of [10; 11].
Remarks on Kähler–Ricci solitons
Authors: Bedulli Lucio , Gori Anna
Published: April 2015

We prove that a compact complex manifold endowed with a Kähler-Ricci soliton cannot be isometrically embedded in a complex projective space ℂℙn in such a way that the Gauss map is rational, unless the metric is Einstein. This applies to hypersurfaces of complex compact homogeneous spaces canonically embedded in ℂℙn.We moreover obtain two curvature constraints for invariant Kähler-Ricci solitons on complex manifolds acted on by a compact Lie group with cohomogeneity one.
Geometric properties of semitube domains
Authors: Kosinski Łukasz , Warszawski Tomasz , Zwonek Włodzimierz
Published: April 2015

We study the geometry of semitube domains in ℂ2, in particular we extend the result of Burgués and Dwilewicz for semitube domains by dropping the smoothness assumption. We also prove various properties of non-smooth pseudoconvex semitube domains, obtaining a relation between pseudoconvexity of a semitube domain and the number of components of its vertical slices. Finally, we present an example of a non-convex domain in ℂn such that its image under arbitrary isometries is pseudoconvex.
Zwischen Leistungsvergleich und Qualitätsentwicklung. Ergebnisse des Round Table „Chancen und Risiken von Leistungsvergleichen für Bibliotheken“ im Herbst 2014
Authors: Bilo Albert , Brockmann Hanno
Published: April 2015

Leistungsvergleiche von Kommunen, Hochschulen und Bibliotheken haben nach wie vor Konjunktur, sind zugleich aber auch umstritten. Dies zeigt der aktuelle fachliche und überfachliche Diskurs. Bedarf es gezielter Modifikationen der bisherigen Messinstrumente oder hilft nur eine komplette Neuorientierung? Um einen Blick in die Zukunft von Leistungsvergleichen – insbesondere im Bibliotheksbereich – zu werfen, hat die gemeinsame Managementkommission des Deutschen Bibliotheksverbands und des Vereins Deutscher Bibliothekare am 15. und 16. September 2014 einen Round Table durchgeführt. Der vorliegende Beitrag liefert einen Überblick zu dieser Diskussionsrunde.
Bibliotheken auf dem Prüfstand
Authors: Porzberg Michael
Published: April 2015

Hochschulrankings bilden ein wichtiges Informationsinstrument für Studieninteressierte, Personalverantwortliche und Drittmittelgeber, um in vereinfachter Form die Leistung von Hochschulen durch Rangfolgen miteinander vergleichbar zu machen. Solche Rankings bilden zunehmend ein wichtiges Hilfsmittel, um das Erreichen von Effizienz- und Effektivitätszielen im Vergleich zu anderen Hochschulen zu verfolgen. Für Bibliotheken ist es wichtig, ihre Rolle in solchen Rankings korrekt einschätzen zu können und zu wissen, mit welchen Indikatoren bibliothekarische Leistungen in Hochschulrankings gemessen werden. Mit den so gewonnenen Erkenntnissen können Zielsysteme und Budgetverhandlungen optimiert werden.
Leistungsvergleiche als Instrument der Hochschulsteuerung: Ansätze, organisatorischer Kontext und Unterstützung des Steuerungshandelns
Authors: Oberschelp Axel , Jaeger Michael
Published: April 2015

Im Kontext des Steuerungsmodells des New Public Management treten Hochschulen zunehmend als organisationale Akteure in Erscheinung, die ihre Entwicklung selber steuern und dafür geeignete Instrumente benötigen. Mit Leistungsvergleichen sind in diesem Zusammenhang vielfältige Erwartungen verbunden und der z. T. hohe Verbreitungsgrad vergleichender Verfahren scheint deren Wirksamkeit zu bestätigen. In dem Beitrag werden die Stärken und Schwächen einzelner Instrumente hinsichtlich der Unterstützung des Steuerungshandelns an Hochschulen untersucht und vergleichend gegenübergestellt.
On the structure of quantum automorphism groups
Authors: Voigt Christian
Published: April 2015

We compute the K-theory of quantum automorphism groups of finite-dimensional

C
*

{C^{*}}

-algebras in the sense of Wang. The results show in
particular that the reduced

C
*

{C^{*}}

-algebras of functions on the quantum permutation groups

S
n
+

{S_{n}^{+}}

are pairwise non-isomorphic for different values of n.
Along the way we discuss some general facts regarding torsion in discrete quantum groups. In fact, the duals of quantum automorphism groups are the most basic examples of discrete quantum groups exhibiting genuine quantum torsion phenomena.
Applications of chelating resin for heavy metal removal from wastewater
Authors: Jiang Jun , Ma Xiao-Shuang , Xu Ling-Yun , Wang Li-Hua , Liu Gao-Yan , Xu Qing-Feng , Lu Jian-Mei , Zhang Yong
Published: April 2015

The chelating resin was synthesized by free-radical copolymerization of iminodiacetic acid modified glycidyl methacrylate with a cross-linker N,N′-methylene biscarylamide at 70°C for removal of heavy metal ions from aqueous solutions. The equilibrium adsorption capacities of the chelating resin from their single-metal ion solutions were 3.28 mmol/g for Cd(II), 2.36 mmol/g for Cu(II), 1.71 mmol/g for Mn(II), 1.69 mmol/g for Ni(II), 1.41 mmol/g for Zn(II), 1.24 mmol/g for Co(II), 0.78 mmol/g for Cr(III) and 0.66 mmol/g for Pb(II). Their related absorption behaviors are discussed in this paper such as thermodynamic equilibrium, pH effect and the Langmuir and Freundlich model to evaluate the experimental data. According to the results, this resin could be used as a promising adsorbent for industrial wastewater disposal.
Alkaline leaching of zinc from low-grade oxide zinc ore using ammonium citrate as complexing agent
Authors: Li Shiwei , Ma Aiyuan , Yang Kun , Yin Shaohua , Zhang Libo , Peng Jinhui , Chen Weiheng , Xie Feng
Published: April 2015

In this study, the effect of ammonium citrate (AC) on the leaching of low grade zinc oxide ore in the 5
Homeostatic control of biological membranes by dedicated lipid and membrane packing sensors
Authors: Puth Kristina , Hofbauer Harald F. , Sáenz James P. , Ernst Robert
Published: April 2015

Biological membranes are dynamic and complex assemblies of lipids and proteins. Eukaryotic lipidomes encompass hundreds of distinct lipid species and we have only begun to understand their role and function. This review focuses on recent advances in the field of lipid sensors and discusses methodical approaches to identify and characterize putative sensor domains. We elaborate on the role of integral and conditionally membrane-associated sensor proteins, their molecular mechanisms, and identify open questions in the emerging field of membrane homeostasis.
Numerical Parametric Analysis of Bond Coat Thickness Effect on Residual Stresses in Zirconia-Based Thermal Barrier Coatings
Authors: Abbas Musharaf , Hasham Hasan Junaid , Baig Yasir
Published: April 2015

Numerical-based finite element investigation has been conducted to explain the effect of bond coat thickness on stress distribution in traditional and nanostructured yttria-stabilized zirconia (YSZ)-based thermal barrier coatings (TBC). Stress components have been determined to quantitatively analyze the mechanical response of both kinds of coatings under the thermal shock effect. It has been found that maximum radial tensile and compressive stresses that exist at thermally grown oxide (TGO)/bond coat interface and within TGO respectively decrease with an increase in bond coat thickness. Effect of bond coat thickness on axial tensile stresses is not significant. However, axial compressive stresses that exist at the edge of the specimen near bond coat/substrate interface decrease appreciably with the increase in bond coat thickness. Residual stress profile as a function of bond coat thickness is further explained for comparative analysis of both coatings to draw some useful conclusions helpful in failure studies of TBCs.
The Effects of Mechanical Properties on Fatigue Behavior of ECAPed AA7075
Authors: Kaya Hasan , Uçar Mehmet
Published: April 2015

In this study, the effects of equal channel angular pressing (ECAP) on high-cycle fatigue and fatigue surface morphology of AA7075 have been investigated at a constant temperature (483 K) and the “C” route for four passes at ECAP process. ECAPed and as-received specimens were tested by four-point bending fatigue device. Fatigue tests were carried out by using 100, 120 and 140 MPa strength values. ECAPed specimens were characterized for each pass with optical microscope (OM), scanning electron microscope (SEM), energy-dispersive spectroscope (EDS), transmission electron microscope (TEM), selected area electron diffraction (SAED) and hardness measurements. Fracture surfaces of the specimens were also characterized with SEM. The results show that the highest hardness values (137 HV) and the best fatigue life (5.4 × 107for 100 MPa) were measured in ECAPed four-pass sample. For this reason hardness values and fatigue life were increased with increasing number of severe plastic deformation (SPD) process.
Bullying and Zero-Tolerance Policies: The School to Prison Pipeline
Authors: Berlowitz Marvin J. , Frye Rinda , Jette Kelli M.
Published: April 2015

The centrality of zero-tolerance policies as a component of anti-bullying strategies is the focus of this paper. A review of the literature of social justice advocates, journalists, and scholars reveals that zero-tolerance policies tend to push students out of public schools into the criminal justice system in a pattern of institutional racism. This phenomenon has come to be labeled the “school to prison pipeline.” Interviews with teachers and administrators reveal that they see no alternative to their implementation of zero-tolerance policies, because they believe that violent behaviors manifested by racial minority students are grounded in cultural norms beyond the control of public educators. The authors conclude that the “school to prison pipeline” can only be ameliorated by a program of radical reform.
On the Fairness of the Multilateral Trading System
Authors: Brandi Clara
Published: April 2015

Three perspectives on international trade are present in current debates. From the first perspective, trade is regarded as a set of individual transactions among consenting parties and considerations of fairness and justice barely feature, if at all. The second perspective underlines the importance of background structures for trade, maintained by states, which gives rise considerations of fairness and justice. One prominent version of this perspective, for example as defended by Aaron James, views all trading states as having in principle equal claims to the gains from trade. A third perspective puts the focus on exploitation. In this special issue, Mathias