bluuebunny/crossref_metadata_2025 huggingface dataset:
An Unusual 2,3-Secotaraxerene and Other Cytotoxic Triterpenoids from Pleiocarpa pycnantha (Apocynaceae) Leaves Collected from Nigeria
Authors: Omoyeni Olubunmi , Meyer Mervin , Iwuoha Emmanuel , Green Ivan , Hussein Ahmed
Published: March 2014

Three known triterpenoids, namely ursolic acid (1), and the 27-E- and 27-Z-p-coumaric esters of ursolic acid (compounds 2, 3), were isolated together with a new triterpene 2,3-seco-taraxer-14-en-2,3-lactone [pycanocarpine (4)] from an ethanolic extract of Pleiocarpa pycnantha leaves. The structure of 4 was unambiguously assigned using NMR, HREIMS and X-ray crystallography. The cytotoxic activities of the compounds were evaluated against HeLa, MCF-7, KMST-6 and HT-29 cells using the WST-1 assay. Ursolic acid (1) displayed potent cytotoxic activity against HeLa, HT-29 and MCF-7 cells with IC50 values of 10, 10 and 20 µM respectively. The new compound 4 and its hydrolysed derivative 5 were selectively cytotoxic to the breast cancer cell line, MCF-7 with IC50 values 20 and 10 µM respectively. This is the first report on isolation of a 2,3-seco-taraxerene derivative from the Apocynaceae family and cytotoxic activityof P. pycnantha constituents.
Regioselective Electrophilic Aromatic Bromination: Theoretical Analysis and Experimental Verification
Authors: Li Hui-Jing , Wu Yan-Chao , Dai Jian-Hong , Song Yan , Cheng Runjiao , Qiao Yuanyuan
Published: March 2014

Electrophilic aromatic bromination is the most common synthetic method used to prepare aryl bromides, which are very useful intermediates in organic synthesis. To understand the experimental results in electrophilic aromatic brominations, ab initio calculations are used here for a tentative analysis of the positional selectivity. The calculated results agree well with the corresponding experimental data, and the reliability of the resulting positional selectivity was verified by the corresponding experimental data.
Spectral Aging Model Applied to Meteosat First Generation Visible Band
Authors: Decoster Ilse , Clerbaux Nicolas , Baudrez Edward , Dewitte Steven , Ipe Alessandro , Nevens Stijn , Blazquez Almudena , Cornelis Jan
Published: March 2014

The Meteosat satellites have been operational since the early eighties, creating so far a continuous time period of observations of more than 30 years. In order to use this data for climate data records, a consistent calibration is necessary between the consecutive instruments. Studies have shown that the Meteosat First Generation (MFG) satellites (1982–2006) suffer from in-flight degradation which is spectral of nature and is not corrected by the official calibration of EUMETSAT. Continuing on previous published work by the same authors, this paper applies the spectral aging model to a set of clear-sky and cloudy targets, and derives the model parameters for all six MFG satellites (Meteosat-2 to -7). Several problems have been encountered, both due to the instrument and due to geophysical occurrences, and these are discussed and illustrated here in detail. The paper shows how the spectral aging model is an improvement compared to the EUMETSAT calibration method with a stability of 1%–2% for Meteosat-4 to -7, which increases up to 6% for ocean sites using the full MFG time period.
Estimates of Minor Ocean Tide Loading Displacement and Its Impact on Continuous GPS Coordinate Time Series
Authors: Li Zhao , Jiang Weiping , Ding Wenwu , Deng Liansheng , Peng Lifeng
Published: March 2014

The site displacement due to ocean tidal loading is regarded as one of the largest uncertainties in precise geodetic positioning measurements, among which the effect of minor ocean tides (MOT), except for the 11 main tidal constituents, are sometimes neglected in routine precise global positioning system (GPS) data processing. We find that MOT can cause large vertical loading displacements with peak-to-peak variations reaching more than 8 mm at coastal/island stations. The impact of MOT on the 24-hour GPS solution is slightly larger than the magnitude of MOT loading itself, with peak-to-peak displacement variation at about 10 mm for the horizontal and 30 mm for the vertical components. We also find that the vertical velocity of all the selected stations in the Southwest Pacific was reduced by more than 10% after considering the MOT effect, while stations with weighted root mean square reduced data account for 62%, 59%, and 36% for the up, east, and north components respectively, in particular for most coastal/island stations. Furthermore, MOT correction could significantly reduce the annual signal of the global stacked east component, the near fortnightly and the long-term periodic signals in the up component. The power of some anomalous harmonics of 1.04 cycle per year is also decreased to some extent. These results further proved the benefits of MOT correction in precise GPS data processing.
Improving Data Quality with an Accumulated Reputation Model in Participatory Sensing Systems
Authors: Yu Ruiyun , Liu Rui , Wang Xingwei , Cao Jiannong
Published: March 2014

The ubiquity of mobile devices brings forth a sensing paradigm, participatory sensing, to collect and interpret sensory information from the environment. Participants join in multifarious sensing tasks and share their data. The sensing result can be obtained in light of shared data. It is not uncommon that some corrupted data is provided by participants, which makes sensing result unreliable accordingly. To address this nontrivial issue, we proposed the accumulated reputation model (ARM) to improve the accuracy of the sensing result. In ARM, participants’ reputation will be computed and accumulated based on their sensing data. The sensing data from reputable participants make higher contributions to the sensing result. ARM performs well on calculating accurate sensing results, even in extreme scenarios, where there are many inexperienced or malicious participants.
Group Inequality and Environmental Sustainability: Insights from Bangladesh and Kenyan Forest Commons
Authors: Matin Nilufar , Islam Mohammad , Mbuvi Musingo , Odit Bernard , Ongugo Paul , Syed Mohammad
Published: March 2014

The paper contributes to understanding the interactions of environmental and social dimensions of sustainability in situations of acute group inequalities. Using case studies of Mount Elgon in Kenya and Chittagong Hill Tracts in Bangladesh it shows the importance of ethnicity based inequalities in defining sustainability outcomes. The paper explores, first, the mechanisms through which dominant ethnic groups are able to exert influence on resource management at the expense of less powerful groups; and second, the consequences of ethnic inequalities for resource uses within ostensibly democratic systems. It combines information from social and political history with remote sensing data to explore causes, processes and patterns behind spatial trends in the study of forests. The paper concludes that efficacy of national democracy and its institutions in achieving positive environmental outcomes depends on the power relations among social groups, particularly in historically contested contexts. Further, environmental and social dimensions of sustainability cannot be treated separately and the issue of equity among groups, ethnic or otherwise, needs to be recognised in policies for sustainable development. The study points out the need for further research into integrating socio-political history with spatial data to better understand social and spatial distribution of policy impacts.
Review of Potential Characterization Techniques in Approaching Energy and Sustainability
Authors: LePoire David
Published: March 2014

Societal prosperity is linked to sustainable energy and a healthy environment. However, tough global challenges include increased demand for fossil fuels, while approaching peak oil production and uncertainty in the environmental impacts of energy generation. Recently, energy use was identified as a major component of economic productivity, along with capital and labor. Other environmental resources and impacts may be nearing environmental thresholds, as indicated by nine planetary environmental boundaries, many of which are linked to energy production and use. Foresight techniques could be applied to guide future actions which include emphasis on (1) energy efficiency to bridge the transition to a renewable energy economy; (2) continued research, development, and assessment of new technologies; (3) improved understanding of environment impacts including natural capital use and degradation; (4) exploration of GDP alternative measures that include both economic production and environmental impacts; and (5) international cooperation and awareness of longer-term opportunities and their associated potential scenarios. Examples from the U.S. and the international community illustrate challenges and potential.
Development of a Sustainable Process for the Solid-Liquid Extraction of Antioxidants from Oat
Authors: Orozco-Mena Raul , Salmerón-Ochoa Iván , Ortega-Rivas Enrique , Perez-Vega Samuel
Published: March 2014

This research paper studies the development of a sustainable process for the extraction of antioxidants from oat. Experimentation covered two factorials to evaluate significance among temperature, time, particle size and solvent. Total polyphenolic content (TPC) and oxygen radical absorbance capacity (ORAC) were the response variables. ANOVA was applied to find significance among variables and predict optimum conditions though a regression model. Extractions at different solid/solvent ratios were developed to study solvents’ solubility. Process simulation in Aspen Process Developer was carried out to evaluate energy cost, raw material cost, campaign time, and process mass intensity. Solvent and particle size showed significance as main effects, whereas temperature and time presented significance as interactions. From an industrial and sustainable perspective, ethanol (EtOH) in a 1/20 (w/v) ratio was the best choice since it presented the lowest cost for energy and raw material. It also showed the lowest process mass intensity (PMI), short campaign time, highest g extract/g oat, and a considerable antioxidant capacity.
Environmental Factors and Intermodal Freight Transportation: Analysis of the Decision Bases in the Case of Spanish Motorways of the Sea
Authors: López-Navarro Miguel
Published: March 2014

Today, there is widespread consensus about the notable, yet simultaneously growing, negative environmental impacts generated by the transportation sector. Experts working in a number of different fields consider the current situation to be unsustainable and possible measures to reduce emissions and foster sustainability are being encouraged. The European Commission has highlighted the need to shift away from unimodal road transport toward a greater use of intermodal transport through, for example, motorways of the sea, in light of the evidence that the former makes a significant contribution to increased CO2 emissions. However, although there is a general perception that sea transport is environmentally preferable to road transport, recent studies are beginning to question this assumption. Moreover, little research has been conducted to quantify environmental aspects and incorporate them into the decision-making processes involved in the modal shift. This study first reviews the existing literature to examine the extent to which environmental aspects are relevant in the modal choice in the case of short sea shipping and motorways of the sea. Related to this, the study also evaluates the role that different agents may play in making decisions about choice of mode, taking into consideration environmental aspects. Secondly, we use the values the European Commission provides to calculate external costs for the Marco Polo freight transport project proposals (call 2013) to estimate the environmental costs for several routes (a total of 72), comparing the use of road haulage with the intermodal option that incorporates the Spanish motorways of the sea. The results of this comparative analysis show that the intermodal option is not always the best choice in environmental terms. Consequently, the traditional environmental argument to justify this alternative must be used carefully.
PROSTATE DISEASES DIAGNOSIS IN POWER DOPPLER SONOGRAPHY
Authors: Chang Chuan-Yu , Tsai Yuh-Shyan , Chang Chuan-Wang , Fan Cheng-Min
Published: March 2014

In order to detect early prostate cancer, physicians usually apply the ultrasound imaging to visualize prostate for diagnosis. However, the traditional gray-scale ultrasound images that obtained from transrectal ultrasound of the prostate are often limited in diagnosing prostate cancer because of cancer heterogeneity, which makes direct diagnosing on the image difficult. Power Doppler ultrasound images improve the diagnosis by providing extra information of blood flow. Previous study has shown that increased blood inflow exists in prostate cancer. It is not difficult to differentiate the malignancy from benign prostate diseases by inspecting Doppler spectrum at bilateral neurovascular bundle sites and using resistive index. Although it is effective; however, it is hand-held, time-consuming, and only limited in a small and static region, which might not represent the real status of the whole prostate. Therefore, this study proposed an integrated dynamic approach to estimate the resistive index of blood flow in regions of interest within or all over the whole prostate. Merits of the proposed approach include the follows: resistive index can be calculated in serial prostate frames; the calculation can be performed on integral prostate region; and the proposed approach shortened the time needed to complete the calculation on whole prostate. Experimental results show that dynamic resistive index is better than conventional resistive index, and comparable with Prostate specific antigen (PSA) test in diagnosing prostate cancer, indicating high performance of the proposed approach, which also reveals feasibility and effectively of it.
A General Framework of Algorithm-Based Fault Tolerance Technique for Computing Systems
Authors: Hamidi Hodjatollah
Published: March 2014

The Algorithm-Based Fault Tolerance (ABFT) approach transforms a system that does not tolerate a specific type of faults, called the fault-intolerant system, to a system that provides a specific level of fault tolerance, namely recovery. The ABFT philosophy leads directly to a model from which error correction can be developed. By employing an ABFT scheme with effective convolutional code, the design allows high throughput as well as high fault coverage. The ABFT techniques that detect errors rely on the comparison of parity values computed in two ways. The parallel processing of input parity values produce output parity values comparable with parity values regenerated from the original processed outputs and can apply convolutional codes for the redundancy. This method is a new approach to concurrent error correction in fault-tolerant computing systems. This chapter proposes a novel computing paradigm to provide fault tolerance for numerical algorithms. The authors also present, implement, and evaluate early detection in ABFT.
Technology-Related Risks in Virtual and Traditional Information Systems Projects
Authors: Reed April H.
Published: March 2014

Technology is important to software development projects; however, virtual projects are more dependent on technology than traditional co-located projects due to communication and collaboration needs. Two research studies in this chapter sought to determine whether seven technology-related risks pose a greater danger to virtual projects than traditional projects and to determine if technology-related risks have a high impact on project success. Results indicate that two technology-related risks exhibited a significantly greater impact on virtual IT projects: (1) inexperience with the company and its processes and (2) inadequate technical resources. Project managers need to be aware that traditional project risks can have a greater impact on virtual projects. Additionally, technology-related risks in the second study were found to have low levels of impact on project success. Results indicate in cases where a majority of team members are experienced with the application, development technology, and project technology, the risk of technology-related issues seems to lessen.
Student Mobility in Higher Education Explained by Cultural and Technological Awareness in Taiwan
Authors: Chang Dian-Fu
Published: March 2014

This chapter explores the factors that might influence the intention to study abroad and determines which requirement can be used to attract international students. Fuzzy statistics was used to determine the influencing factors related to student mobility in terms of outbound and inbound study. Exploring students' intentions to study abroad and their readiness may provide a better conception on the issue. The result reveals that study abroad is a better choice for many college students. Since the government provided a menu driven program for universities, various universities have been found to enhance their learning programs to attract more international students. The findings suggest that maintaining cheaper tuition, enhancing culture-related programs, and providing good environment and equipment will attract more international students. However, the factors influencing the international students coming vary in different countries.
An Intelligent System for Learning First Order Logic to Clause Form Conversion
Authors: Grivokostopoulou Foteini , Hatzilygeroudis Ioannis , Perikos Isidoros
Published: March 2014

In this chapter, the authors present an intelligent Web-based interactive system that aims at helping students in learning to convert First Order Logic (FOL) sentences into their Clause Form (CF) and provides feedback based on the student's actions. The system provides a step-by-step guidance and help during that process. It adapts its interface to the current step requirements. In addition, feedback is provided to the user-student upon request. The feedback is based on the errors made, which are detected by the system and classified in predefined categories. The system offers to the students the capability of trying the conversion of any FOL sentence of their own or choosing any of the pre-stored ones. The authors evaluated the system using two groups of undergraduate students (an experimental group and a control group). During the experiment, a pre-test and a post-test were used by both groups to collect the data. In addition, a questionnaire was given to the experimental group. Results are encouraging in that they revealed significantly better performance of the experimental group. Furthermore, the questionnaire results, concerning the system's usability and learning capabilities, have been quite satisfactory.
An Intelligent Decision Support System (IDSS) for Nutrition Therapy
Authors: Fahmi Ali , Dorostanian Amin , Rezazadeh Hassan , Ostadrahimi Alireza
Published: March 2014

In this paper, the authors have presented an expert system to support decision makers in nutrition therapy planning. This system is an extended version of a fuzzy decision support system for nutrition therapy. The presented expert system is equipped with an updated knowledge base component by using a set of rules. Also in order to deal with vagueness and uncertainty, fuzzy set theory could provide a suitable framework for data management, modelling and decision support. Therefore, fuzzy rules empower this system to be implemented more realistically. In addition, for developing knowledge management component, artificial neural network (ANN) is applied to survey the input data and information in the long term. The integration of ANN with the expert system provides the possibility for a set of novel rules to be generated and consequently adds new knowledge to the system.
Current State, Recent Advances and Perspectives of Development of Healthcare Information and Communication Technologies in Armenia
Authors: Chaltikyan Georgi , Avoyan Armen , Hovhannisyan Ruben , Saghatelyan Tatul , Aroyan Aleksandr
Published: March 2014

Armenia became an independent state after breakdown of the Soviet Union in 1991. After considerable derangements in the first independence decade, the country's healthcare system has seen some progress recently in terms of improving existing and developing new services, diversification of financing, with the introduction of public benefits, private domain and health insurance. The Information and Communication Technologies sector is one of the country's most dynamically developing and competitive industries. Despite that, Armenia has had modest achievements in eHealth and telemedicine so far. Centralized eHealth policy, administration and infrastructure are as yet absent, Health Information and Communication Technology (ICT) tools and applications are very slowly making their way into mainstream healthcare practices, and there are few regular telemedicine activities. Some revival of the field in the recent years is primarily related to consistent efforts by the authorities to develop eHealth, and the emergence of the national professional organization – Armenian Association of Telemedicine (AATM).
Morphological differentiation of two cichlid species in Sri Lanka using truss networks
Authors: Fernando GKAW , Amarasinghe US
Published: March 2014

Morphometric characterization using truss network systems has been widely used for fish identification and stock identification. In Sri Lanka, differentiation of Oreochromis mossambicus and O. niloticus, the two major species in reservoir fishery, using conventional morphometric characteristic and phenotypic variations is problematic, due to the reasons that both species share somewhat similar body shape characteristics and that the populations of the two species have mixed characteristics as a result of introgressive hybridization. In the present study, an attempt was made to employ truss network analysis to differentiate O. mossambicus and O. niloticus. Truss measurements of 100 specimens of O. mossambicus from Negombo lagoon and 100 specimens of O. niloticus from Baira lake were analyzed using principal component analysis (PCA). Before the analysis, two approaches of data transformation were employed to minimize to eliminate any size effect in the data set of truss measurements. It was concluded that the data standardization method using a geometric mean regression techniques on the logarithms of truss length and total length was more effective for morphometric differentiation of the two cichlid species than using ratio of truss length to standard length for data transformation. DOI: http://dx.doi.org/10.4038/sljas.v16i0.6705 Sri Lanka J. Aquat. Sci. 16 (2011): 01-10
B Cell Antigen Presentation in the Initiation of Follicular Helper T Cell and Germinal Center Differentiation
Authors: Barnett Lisa G. , Simkins Helen M. A. , Barnett Burton E. , Korn Lisa L. , Johnson Andy L. , Wherry E. John , Wu Gregory F. , Laufer Terri M.
Published: March 2014

High-affinity class-switched Abs and memory B cells are products of the germinal center (GC). The CD4+ T cell help required for the development and maintenance of the GC is delivered by follicular Th cells (TFH), a CD4+ Th cell subset characterized by expression of Bcl-6 and secretion of IL-21. The cellular interactions that mediate differentiation of TFH and GC B cells remain an important area of investigation. We previously showed that MHC class II (MHCII)–dependent dendritic cell Ag presentation is sufficient for the differentiation of a TFH intermediate (termed pre-TFH), characterized by Bcl-6 expression but lacking IL-21 secretion. In this article, we examine the contributions of MHCII Ag presentation by B cells to TFH differentiation and GC responses in several contexts. B cells alone do not efficiently prime naive CD4+ T cells or induce TFH after protein immunization; however, during lymphocytic choriomeningitis virus infection, B cells induce TFH differentiation despite the lack of effector CD4+ T cell generation. Still, MHCII+ dendritic cells and B cells cooperate for optimal TFH and GC B cell differentiation in response to both model Ags and viral infection. This study highlights the roles for B cells in both CD4+ T cell priming and TFH differentiation, and demonstrates that different APC subsets work in tandem to mediate the GC response.
Iddm30 Controls Pancreatic Expression of Ccl11 (Eotaxin) and the Th1/Th2 Balance within the Insulitic Lesions
Authors: Chao Gary Y. C. , Wallis Robert H. , Marandi Leili , Ning Terri , Sarmiento Janice , Paterson Andrew D. , Poussier Philippe
Published: March 2014

The autoimmune diabetic syndrome of the BioBreeding diabetes–prone (BBDP) rat is a polygenic disease that resembles in many aspects human type 1 diabetes (T1D). A successful approach to gain insight into the mechanisms underlying genetic associations in autoimmune diseases has been to identify and map disease-related subphenotypes that are under simpler genetic control than the full-blown disease. In this study, we focused on the β cell overexpression of Ccl11 (Eotaxin), previously postulated to be diabetogenic in BBDR rats, a BBDP-related strain. We tested the hypothesis that this trait is genetically determined and contributes to the regulation of diabetes in BBDP rats. Similar to the BBDR strain, we observed a time-dependent, insulitis-independent pancreatic upregulation of Ccl11 in BBDP rats when compared with T1D-resistant ACI.1u.lyp animals. Through linkage analysis of a cross-intercross of these two parental strains, this trait was mapped to a region on chromosome 12 that overlaps Iddm30. Linkage results were confirmed by phenotypic assessment of a novel inbred BBDP.ACI-Iddm30 congenic line. As expected, the Iddm30 BBDP allele is associated with a significantly higher pancreatic expression of Ccl11; however, the same allele confers resistance to T1D. Analysis of islet-infiltrating T cells in Iddm30 congenic BBDP animals revealed that overexpression of pancreatic Ccl11, a prototypical Th2 chemokine, is associated with an enrichment in Th2 CD4+ T cells within the insulitic lesions. These results indicate that, in the BBDP rat, Iddm30 controls T1D susceptibility through both the regulation of Ccl11 expression in β cells and the subsequent Th1/Th2 balance within islet-infiltrating T lymphocytes.
Humoral Immunity and CD4+ Th1 Cells Are Both Necessary for a Fully Protective Immune Response upon Secondary Infection with Brucella melitensis
Authors: Vitry Marie-Alice , Hanot Mambres Delphine , De Trez Carl , Akira Shizuo , Ryffel Bernhard , Letesson Jean-Jacques , Muraille Eric
Published: March 2014

Brucella spp are intracellular bacteria that cause brucellosis, one of the most common zoonoses in the world. Given the serious medical consequences of this disease, a safe and effective human vaccine is urgently needed. Efforts to develop this vaccine have been hampered by our lack of understanding of what constitutes a protective memory response against Brucella. In this study, we characterize the cells and signaling pathways implicated in the generation of a protective immune memory response following priming by the injection of heat-killed or live Brucella melitensis 16M. Using a panel of gene-deficient mice, we demonstrated that during a secondary recall response, both the Brucella-specific humoral response and CD4+ Th1 cells must act together to confer protective immunity in the spleen to B. melitensis infection. Humoral protective immunity is induced by the inoculation of both heat-killed and live bacteria, and its development does not require T cells, MyD88/IL-12p35 signaling pathways, or an activation-induced deaminase–mediated isotype switch. In striking contrast, the presence of memory IFN-γ–producing CD4+ Th1 cells requires the administration of live bacteria and functional MyD88/IL-12p35 pathways. In summary, our work identifies several immune markers closely associated with protective immune memory and could help to define a rational strategy to obtain an effective human vaccine against brucellosis.
#Indignación en Andalucía: origen y andadura inicial del movimiento 15-M
Authors: Peña Ramos José
Published: March 2014

El presente artículo exploratorio pretende realizar una aproximación inicial al origen, la evolución inmediata y los efectos del Movimiento 15-M, concretamente en Andalucía. En primer lugar, se establece un breve marco teórico-conceptual de referencia. En segundo lugar, se contextualiza este movimiento en el plano internacional, y se establecen sus principales características. En tercer lugar, se aborda el movimiento en el ámbito andaluz. En cuarto lugar, se analiza su impacto sobre la opinión pública andaluza. Y finalmente se aportan unas conclusiones.
Entre la necesidad y el no reconocimiento: la valoración de la dimensión temporal en las estrategias familiares para la contratación de cuidadoras domésticas inmigrantes en España y Chile
Authors: Acosta Elaine
Published: March 2014

El artículo tiene por objeto analizar el sentido que se le atribuye al recurso tiempo en la conformación de las estrategias familiares para la contratación de cuidadoras inmigrantes en el ámbito doméstico y las percepciones de las mujeres inmigrantes cuidadoras sobre el uso del tiempo en la definición y gestión de sus condiciones laborales. Para el análisis se han seleccionado los casos de España y Chile, que representan dos sociedades de destino de flujos migratorios altamente feminizados que tienen una alta concentración de mujeres inmigrantes en el sector doméstico y de cuidados. El análisis está basado en los resultados de una investigación más amplia recientemente finalizada. La información primaria de carácter cualitativo se obtuvo de la aplicación de 67 entrevistas en profundidad realizadas a distintos tipos de actores involucrados en la relación social de cuidado: mujeres inmigrantes cuidadoras, empleadores/as, personas receptoras de cuidado, en las dos sociedades de destino mencionadas. Los resultados finales indican que el recurso tiempo no solo es escaso, sino que está desigualmente distribuido para satisfacer las necesidades de cuidado en las familias. Se trata de desigualdades múltiples que se comportan de manera diferenciada en cada destino migratorio
La cooperación transfronteriza en la región del Trifinio y la difusión de modelos europeos de gobernanza de las fronteras en América Latina
Authors: Celata Filippo , Coletti Raffaella , Sanna Venere Stefania
Published: March 2014

En la región del Trifinio se concentran algunas de las experiencias más avanzadas de cooperación transfronteriza de América Latina. Dichas experiencias son promovidas por las instituciones europeas y se han inspirado fuertemente en el modelo europeo de gobernanza de las regiones transfronterizas. Al mismo tiempo, este modelo no ha sido simplemente trasladado de la Unión Europea a la América Latina, sino que también se ha adaptado a las condiciones del contexto y a las características específicas de los procesos de reterritorialización e integración macrorregional que tienen lugar en la región y, más en general, en América Latina. A la luz del debate relativo a la europeización, el artículo pretende mostrar cómo el potencial y los límites de este tipo de iniciativas pueden ser adecuadamente comprendidos solo a través del balance que se crea, caso por caso, entre contaminación transnacional y adaptación local, y entre la transferencia de modelos y narrativas (que son típicos de la Unión Europea), y la apropiación de estos por parte delos actores locales
An in Silico Approach for Characterization of an Aminoglycoside Antibiotic-Resistant Methyltransferase Protein from Pyrococcus furiosus (DSM 3638)
Authors: Oany Arafat Rahman , Jyoti Tahmina Pervin , Ahmad Shah Adil Ishtiyaq
Published: March 2014

Pyrococcus furiosus is a hyperthermophilic archaea. A hypothetical protein of this archaea, PF0847, was selected for computational analysis. Basic local alignment search tool and multiple sequence alignment (MSA) tool were employed to search for related proteins. Both the secondary and tertiary structure prediction were obtained for further analysis. Three-dimensional model was assessed by PROCHECK and QMEAN6 programs. To get insights about the physical and functional associations of the protein, STRING network analysis was performed. Binding of the SAM (S-adenosyl-1-methionine) ligand with our protein, fetched from an antibiotic-related methyltransferase (PDB code: 3P2K: D), showed high docking energy and suggested the function of the protein as methyltransferase. Finally, we tried to look for a specific function of the proposed methyltransferase, and binding of the geneticin bound to the eubacterial 16S rRNA A-site (PDB code: 1MWL) in the active site of the PF0847 gave us the indication to predict the protein responsible for aminoglycoside antibiotic resistance.
Line bundles and the Thom construction in noncommutative geometry
Authors: Beggs Edwin , Brzeziński Tomasz
Published: March 2014

The idea of a line bundle in classical geometry is transferred to noncommutative geometry by the idea of a Morita context. From this we construct

\mathbb{Z}

- and

\mathbb{N}

-graded algebras, the

\mathbb{Z}

-graded algebra being a Hopf–Galois extension. A non-degenerate Hermitian metric gives a star structure on this algebra, and an additional star operation on the line bundle gives a star operation on the

\mathbb{N}

-graded algebra. In this case, we carry out the associated circle bundle and Thom constructions. Starting with a C*-algebra as base, and with some positivity assumptions, the associated circle and Thom algebras are also C*-algebras. We conclude by examining covariant derivatives and Chern classes on line bundles after the method of Kobayashi and Nomizu.
Bost–Connes systems associated with function fields
Authors: Neshveyev Sergey , Rustad Simen
Published: March 2014

With a global function field

K

with constant field

\mathbb{F}_q

, a finite set

S

of primes in

K

and an abelian extension

L

of

K

, finite or infinite, we associate a C*-dynamical system. The systems, or at least their underlying groupoids, defined earlier by Jacob using the ideal action on Drinfeld modules and by Consani–Marcolli using commensurability of

K

-lattices are isomorphic to particular cases of our construction. We prove a phase transition theorem for our systems and show that the unique KMS

_\beta

-state for every

0<\beta\le1

gives rise to an ITPFI-factor (ITPFI stands for “infinite tensor product of finite type I factors”) of type III

_{q^{-\beta n}}

, where

n

is the degree of the algebraic closure of

\mathbb{F}_q

in

L

. Therefore for

n=+\infty

we get a factor of type III

_0

. Its flow of weights is a scaled suspension flow of the translation by the Frobenius element on Gal

(\bar{\mathbb{F}}_q/\mathbb{F}_q)

.
Bioconectores: ¿Son realmente eficaces en la reducción de las bacteriemias relacionadas con el catéter permanente para hemodiálisis?
Authors: Crehuet Rodríguez Isabel , Bernárdez-Lemus María Albina , Ramírez Crehuet Marta , Méndez Briso-Montiano Pilar , Ruiz-Zorrilla López Carlos
Published: March 2014

Uno de los mayores problemas que presentan los catéteres venosos centrales tunelizados para hemodiálisis son las infecciones, por su gravedad y los elevados costes que generan. Por ello, es importante su prevención, ya que, además, el número de catéteres ha aumentado considerablemente en los últimos años.
Objetivos: Realizamos este estudio en nuestra unidad para analizar:
• Eficacia de unos conectores con sistema cerrado (TEGO®) en la prevención de bacteriemia relacionada con el catéter.
• Incidencia de Staphylococcus aureus y gérmenes causantes más frecuentes.
Material y método: Se realizó un estudio retrospectivo, comparativo y transversal durante 800 días, que dividimos en dos periodos iguales. En los primeros 400 se aplicó el protocolo de la unidad a 24 pacientes y en los 400 días siguientes se aplicó el mismo protocolo más los conectores anteriormente citados a 25. En ambos periodos, 19 fueron los mismos pacientes.
Resultados: En el primer periodo se contabilizaron 4 infecciones en 7062 días de catéter y en el segundo 2 infecciones en 8622 días de catéter.
Índice de bacteriemia en ambos periodos: 0,56/1000 y 0,23/1000 respectivamente.
Ninguna infección se produjo por Staphylococcus aureus, siendo el germen más frecuente Staphylococcus coagulasa negativo.
Conclusión: Nuestra conclusión es que los conectores fueron eficaces en la prevención de las bacteriemias ya que redujeron notablemente nuestros, ya bajos, índices de las mismas.
La adherencia terapéutica en el paciente trasplantado renal
Authors: Ruiz Calzado María Rocío
Published: March 2014

En los pacientes con enfermedad renal crónica portadores de un trasplante renal, la adherencia al tratamiento es crucial para prevenir el rechazo, pérdida del injerto, y la morbilidad adicional.
Objetivo: conocer la producción científica actual de la adherencia al tratamiento de pacientes trasplantados de riñón y las variables que pueden influir.
Método: Se realizó una búsqueda en las bases de datos de Scielo, PubMed, The Chocrane, Science Direct y Google académico. Se incluyeron artículos científicos escritos en inglés y español. Se analizaron los artículos que trataban la adherencia al tratamiento inmunosupresor de pacientes trasplantados de riñón, excluyendo los pacientes pediátricos.
Resultados: La adherencia al tratamiento inmunosupresor por parte de estos pacientes es relativamente baja debido a la influencia de varios factores. La complejidad del tratamiento y el tiempo postrasplante, tienen una importante correlación negativa con la adherencia. El olvido u otras ocupaciones, se relaciona de forma significativa con la no adherencia no intencional por parte de los pacientes. Los grupos de edad con menos adherencia son los más jóvenes seguidos de los más mayores, y los más adherentes los adultos. En algunos países, la falta de adherencia se debe a que el elevado coste del tratamiento inmunosupresor corre por cuente del paciente.
Por otro lado, las variables que no parecen influir de forma concluyente, son: el estado civil o modo de vida, efectos secundarios, nivel socioeconómico y educativo, situación laboral, raza, creencias en la necesidad y factores psicológicos. Por último, la variable de género es claramente la única que no influye sobre la falta de adherencia, ya que una mayoría de estudios demuestran que no influyen frente a solo dos que consideran que los varones son los menos adherentes.
Conclusiones: los pacientes trasplantados de riñón presentan altos porcentajes de falta de adherencia al tratamiento, estando relacionados fundamentalmente la complejidad del tratamiento, el tiempo postrasplante, el olvido u otras ocupaciones y la edad (jóvenes y mayores).
Enhanced bacterial decomposition with increasing addition of autochthonous to allochthonous carbon without any effect on bacterial community composition
Authors: Attermeyer K. , Hornick T. , Kayler Z. E. , Bahr A. , Zwirnmann E. , Grossart H.-P. , Premke K.
Published: March 2014

Abstract. Dissolved organic carbon (DOC) concentrations – mainly of terrestrial origin – are increasing worldwide in inland waters. Heterotrophic bacteria are the main consumers of DOC and thus determine DOC temporal dynamics and availability for higher trophic levels. Our aim was to study bacterial carbon (C) turnover with respect to DOC quantity and chemical quality using both allochthonous and autochthonous DOC sources. We incubated a natural bacterial community with allochthonous C (13C-labeled beech leachate) and increased concentrations and pulses (intermittent occurrence of organic matter input) of autochthonous C (phytoplankton lysate). We then determined bacterial C consumption, activities, and community composition together with the C flow through bacteria using stable C isotopes. The chemical analysis of single sources revealed differences in aromaticity and low- and high-molecular-weight substance fractions (LMWS and HMWS, respectively) between allochthonous and autochthonous C sources. Both DOC sources (allochthonous and autochthonous DOC) were metabolized at a high bacterial growth efficiency (BGE) around 50%. In treatments with mixed sources, rising concentrations of added autochthonous DOC resulted in a further, significant increase in bacterial DOC consumption of up to 68% when nutrients were not limiting. This rise was accompanied by a decrease in the humic substance (HS) fraction and an increase in bacterial biomass. Changes in DOC concentration and consumption in mixed treatments did not affect bacterial community composition (BCC), but BCC differed in single vs. mixed incubations. Our study highlights that DOC quantity affects bacterial C consumption but not BCC in nutrient-rich aquatic systems. BCC shifted when a mixture of allochthonous and autochthonous C was provided simultaneously to the bacterial community. Our results indicate that chemical quality rather than source of DOC per se (allochthonous vs. autochthonous) determines bacterial DOC turnover.
Evaluation of modern and mid-Holocene seasonal precipitation of the Mediterranean and northern Africa in the CMIP5 simulations
Authors: Perez-Sanz A. , Li G. , González-Sampériz P. , Harrison S. P.
Published: March 2014

Abstract. We analyse the spatial expression of seasonal climates of the Mediterranean and northern Africa in pre-industrial (piControl) and mid-Holocene (midHolocene, 6 yr BP) simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Modern observations show four distinct precipitation regimes characterized by differences in the seasonal distribution and total amount of precipitation: an equatorial band characterized by a double peak in rainfall, the monsoon zone characterized by summer rainfall, the desert characterized by low seasonality and total precipitation, and the Mediterranean zone characterized by summer drought. Most models correctly simulate the position of the Mediterranean and the equatorial climates in the piControl simulations, but overestimate the extent of monsoon influence and underestimate the extent of desert. However, most models fail to reproduce the amount of precipitation in each zone. Model biases in the simulated magnitude of precipitation are unrelated to whether the models reproduce the correct spatial patterns of each regime. In the midHolocene, the models simulate a reduction in winter rainfall in the equatorial zone, and a northward expansion of the monsoon with a significant increase in summer and autumn rainfall. Precipitation is slightly increased in the desert, mainly in summer and autumn, with northward expansion of the monsoon. Changes in the Mediterranean are small, although there is an increase in spring precipitation consistent with palaeo-observations of increased growing-season rainfall. Comparison with reconstructions shows most models underestimate the mid-Holocene changes in annual precipitation, except in the equatorial zone. Biases in the piControl have only a limited influence on midHolocene anomalies in ocean–atmosphere models; carbon-cycle models show no relationship between piControl bias and midHolocene anomalies. Biases in the prediction of the midHolocene monsoon expansion are unrelated to how well the models simulate changes in Mediterranean climate.
Comment on "Streamflow input to Lake Athabasca, Canada" by Rasouli et al. (2013)
Authors: Peters D. L.
Published: March 2014

Abstract. This comment paper addresses data and analysis issues in a paper entitled "Streamflow input to Lake Athabasca, Canada" by Rasouli et al. (2013). Analyses of observed and naturalized lake level data for Lake Athabasca are redone in this comment paper with corrected hydrometric data to provide northerners and researchers with the correct information for environmental assessments.
THE CHARACTER OF PLANAR TESSELLATIONS WHICH ARE NOT SIDE-TO-SIDE
Authors: Cowan Richard , Thäle Christoph
Published: March 2014

This paper studies stationary tessellations and tilings of the plane in which all cells are convex polygons. The focus is on the class of tessellations which are not side-to-side. The character of these tessellations is explored, with special attention paid to the relationship between edges of the tessellation and sides of the polygonal cells and to the combinatorial topology between the ‘adjacent’ geometric elements of the tessellation. Three new parameters, e0,e1 and e2 summing to unity, are introduced. These capture the essence of non side-to-side tessellations and play a role in understanding the adjacency of sides and cells. Examples illustrate the theory.
The lichen genus Stereocaulon (Schreb.) Hoffm. in Poland – a taxonomic and ecological study
Authors: Oset Magdalena
Published: March 2014

The monograph includes the results of research of the taxonomy, chemistry, ecology and distribution of Stereocaulon alpinum, S. botryosum, S. condensatum, S. dactylophyllum, S. evolutum, S. incrustatum, S. nanodes, S. paschale, S. pileatum, S. saxatile, S. subcoralloides, S. spathuliferum, S. taeniarum, S. tomentosum and S. vesuvianum in Poland. 1823 specimens from Polish and some European herbaria were examinated. The occurrance of S. spathuliferum has not been confirmed during this study, therefore its status in Poland remains unknown. During the study three lectotypes were designated. The lichenicolous fungi, Cercidospora stereocaulorum and Roselliniella stereocaulorum on Stereocaulon were also noted. A key to known Stereocaulon taxa in Poland, including S. spathuliferum is provided.
Sound Off! Staring Down Stereotypes
Authors: Lesser Lawrence M.
Published: March 2014

Stereotypes are encountered in many contexts in society and are often reflected in the humor of a community. Mathematics can be a powerful tool to help break down remaining harmful stereotypes in our society and build our capacity to pursue equity and justice.
Graphing Inequalities, Connecting Meaning
Authors: Switzer J. Matt
Published: March 2014

tudents often have difficulty with graphing inequalities (see Filloy, Rojano, and Rubio 2002; Drijvers 2002), and my students were no exception. Although students can produce graphs for simple inequalities, they often struggle when the format of the inequality is unfamiliar. Even when producing a correct graph of an inequality, students may lack a deep understanding of the relationship between the inequality and its graph. Hiebert and Carpenter (1992) stated that mathematics is understood “if its mental representation is part of a network of representations” and that the “degree of understanding is determined by the number and strength of the connections” (p. 67). I therefore developed an activity that allows students to explore the graphs of inequalities not presented as lines in slope-intercept form, thereby making connections between pairs of expressions, ordered pairs, and the points on a graph representing equations and inequalities.
The Circle Approach to Trigonometry
Authors: Moore Kevin C. , LaForest Kevin R.
Published: March 2014

A connected introduction of angle measure and the sine function entails quantitative reasoning.
Les facteurs prédisposant à la réussite éducative dès la petite enfance
Authors: Cantin Gilles , Bouchard Caroline , Bigras Nathalie
Published: March 2014

L’éducation à la petite enfance fait l’objet d’une attention de plus en plus grande dans la communauté scientifique. L’importance des apprentissages réalisés au cours de cette période est maintenant largement reconnue, notamment en regard de la réussite éducative des enfants. Dans cette perspective, au fil des dernières années, diverses conceptions au sujet de la préparation à l’école et à la vie ont balisé les travaux de recherche. Ces dernières années, une perspective écosystémique a été adoptée par nombre de chercheurs. Dans une telle perspective, divers facteurs tant proximaux que distaux sont à considérer pour comprendre, mais aussi mettre en place des interventions soutenant la réussite éducative. Ce texte introduit les divers articles regroupés dans ce numéro thématique portant sur les facteurs prédisposant à la réussite éducative dès la petite enfance. Il présente un survol de divers enjeux et travaux de recherche reconnus dans ce domaine afin de mettre la table en vue d’une réflexion approfondie sur cette problématique à la fois complexe et préoccupante.