bluuebunny/crossref_metadata_2025_split huggingface dataset:
Weighted simultaneous algebraic reconstruction technique for tomosynthesis imaging of objects with high‐attenuation features
Authors: Levakhina Y. M. , Müller J. , Duschka R. L. , Vogt F. , Barkhausen J. , Buzug T. M. 
Published: March 2013

Purpose:This paper introduces a nonlinear weighting scheme into the backprojection operation within the simultaneous algebraic reconstruction technique (SART). It is designed for tomosynthesis imaging of objects with high‐attenuation features in order to reduce limited angle artifacts.Methods:The algorithm estimates which projections potentially produce artifacts in a voxel. The contribution of those projections into the updating term is reduced. In order to identify those projections automatically, a four‐dimensional backprojected space representation is used. Weighting coefficients are calculated based on a dissimilarity measure, evaluated in this space. For each combination of an angular view direction and a voxel position an individual weighting coefficient for the updating term is calculated.Results:The feasibility of the proposed approach is shown based on reconstructions of the following real three‐dimensional tomosynthesis datasets: a mammography quality phantom, an apple with metal needles, a dried finger bone in water, and a human hand. Datasets have been acquired with a Siemens Mammomat Inspiration tomosynthesis device and reconstructed using SART with and without suggested weighting. Out‐of‐focus artifacts are described using line profiles and measured using standard deviation (STD) in the plane and below the plane which contains artifact‐causing features. Artifacts distribution in axial direction is measured using an artifact spread function (ASF). The volumes reconstructed with the weighting scheme demonstrate the reduction of out‐of‐focus artifacts, lower STD (meaning reduction of artifacts), and narrower ASF compared to nonweighted SART reconstruction. It is achieved successfully for different kinds of structures: point‐like structures such as phantom features, long structures such as metal needles, and fine structures such as trabecular bone structures.Conclusions:Results indicate the feasibility of the proposed algorithm to reduce typical tomosynthesis artifacts produced by high‐attenuation features. The proposed algorithm assigns weighting coefficients automatically and no segmentation or tissue‐classification steps are required. The algorithm can be included into various iterative reconstruction algorithms with an additive updating strategy. It can also be extended to computed tomography case with the complete set of angular data.
Whole-Genome Sequence of Mycobacterium intracellulare Clinical Strain MOTT-H4Y, Belonging to INT5 Genotype
Authors: Lee Hyungki , Kim Byoung-Jun , Kim Kijeong , Hong Seok-Hyun , Kook Yoon-Hoh , Kim Bum-Joon 
Published: March 2013

ABSTRACT

Here, we report the draft genome sequence of the
Mycobacterium intracellulare
clinical strain MOTT-H4Y, grouped previously into the INT5 genotype of the 5 genotypes of
M. intracellulare
.
HIV-Specific CD8+T Cells from Elite Controllers Are Primed for Survival
Authors: Yan Jiyu , Sabbaj Steffanie , Bansal Anju , Amatya Nilesh , Shacka John J. , Goepfert Paul A. , Heath Sonya L. 
Published: March 2013

ABSTRACTHIV-specific cytotoxic T lymphocytes (CTL) are preferentially primed for apoptosis, and this may represent a viral escape mechanism. We hypothesized that HIV-infected individuals that control virus to undetectable levels without antiretroviral therapy (ART) (elite controllers [EC]) have the capacity to upregulate survival factors that allow them to resist apoptosis. To address this, we performed cross-sectional and longitudinal analysis of proapoptotic (cleaved caspase-3) and antiapoptotic (Bcl-2) markers of cytomegalovirus (CMV) and HIV-specific CD8 T cells in a cohort of HIV-infected subjects with various degrees of viral control on and off ART. We demonstrated that HIV-specific CTL from EC are more resistant to apoptosis than those with pharmacologic control (successfully treated patients [ST]), despite similarin vivoconditions. Longitudinal analysis of chronically infected persons starting ART revealed that the frequency of HIV-specific T cells prone to death decreased, suggesting that this phenotype is partially reversible even though it never achieves the levels present in EC. Elucidating the apoptotic factors contributing to the survival of CTL in EC is paramount to our development of effective HIV-1 vaccines. Furthermore, a better understanding of cellular markers that can be utilized to predict response durability in disease- or vaccine-elicited responses will advance the field.
Porcine Reproductive and Respiratory Syndrome Virus Nsp1β Inhibits Interferon-Activated JAK/STAT Signal Transduction by Inducing Karyopherin-α1 Degradation
Authors: Wang Rong , Nan Yuchen , Yu Ying , Zhang Yan-Jin 
Published: March 2013

ABSTRACT
Porcine reproductive and respiratory syndrome virus (PRRSV) inhibits the interferon-mediated antiviral response. Type I interferons (IFNs) induce the expression of IFN-stimulated genes by activating phosphorylation of both signal transducer and activator of transcription 1 (STAT1) and STAT2, which form heterotrimers (interferon-stimulated gene factor 3 [ISGF3]) with interferon regulatory factor 9 (IRF9) and translocate to the nucleus. PRRSV Nsp1β blocks the nuclear translocation of the ISGF3 complex by an unknown mechanism. In this study, we discovered that Nsp1β induced the degradation of karyopherin-α1 (KPNA1, also called importin-α5), which is known to mediate the nuclear import of ISGF3. Overexpression of Nsp1β resulted in a reduction of KPNA1 levels in a dose-dependent manner, and treatment of the cells with the proteasome inhibitor MG132 restored KPNA1 levels. Furthermore, the presence of Nsp1β induced an elevation of KPNA1 ubiquitination and a shortening of its half-life. Our analysis of Nsp1β deletion constructs showed that the N-terminal domain of Nsp1β was involved in the ubiquitin-proteasomal degradation of KPNA1. A nucleotide substitution resulting in an amino acid change from valine to isoleucine at residue 19 of Nsp1β diminished its ability to induce KPNA1 degradation and to inhibit IFN-mediated signaling. Interestingly, infection of MARC-145 cells by PRRSV strains VR-2332 and VR-2385 also resulted in KPNA1 reduction, whereas infection by an avirulent strain, Ingelvac PRRS modified live virus (MLV), did not. MLV Nsp1β had no effect on KPNA1; however, a mutant with an amino acid change at residue 19 from isoleucine to valine induced KPNA1 degradation. These results indicate that Nsp1β blocks ISGF3 nuclear translocation by inducing KPNA1 degradation and that valine-19 in Nsp1β correlates with the inhibition.
The pH of Activation of the Hemagglutinin Protein Regulates H5N1 Influenza Virus Replication and Pathogenesis in Mice
Authors: Zaraket Hassan , Bridges Olga A. , Russell Charles J. 
Published: March 2013

ABSTRACT

After receptor binding and internalization during influenza virus entry, the hemagglutinin (HA) protein is triggered by low pH to undergo irreversible conformational changes that mediate membrane fusion. To investigate how mutations that alter the activation pH of the HA protein influence the fitness of an avian H5N1 influenza virus in a mammalian model, we infected C57BL/6J or DBA/2J mice and compared the replication and virulence of recombinant A/chicken/Vietnam/C58/04 (H5N1) HA-Y23
1
H mutant, wild-type, and HA-H24
1
Q and HA-K58
2
I mutant viruses that have HA activation pH values of 6.3, 5.9, 5.6, and 5.4, respectively. The HA-Y23
1
H mutant virus was highly susceptible to acid inactivation
in vitro
and was attenuated for growth and virulence in mice, suggesting that an H5N1 HA protein triggered at pH 6.3 is too unstable for the virus to remain fit. Wild-type and HA-H24
1
Q viruses were similar in pathogenicity and grew to similar levels in mice, ducks, and cell cultures derived from both avian and mammalian tissues, suggesting that H5N1 HA proteins triggered at pH values in the range of 5.9 to 5.6 broadly support replication. The HA-K58
2
I mutant virus had greater growth and virulence in DBA/2J mice than the wild type did, although the mutant virus was highly attenuated in ducks. The data suggest that adaptation of avian H5N1 influenza virus for infection in mammals is supported by a decrease in the HA activation pH to 5.4. Identification of the HA activation pH as a host-specific infectivity factor is expected to aid in the surveillance and risk assessment of currently circulating H5N1 influenza viruses.
A Radar Analysis of Urban Snowfall Modification in Minneapolis–St. Paul
Authors: Perryman Nyssa , Dixon P. Grady 
Published: March 2013

AbstractA better understanding of urban snowfall climatology will help to mitigate winter weather hazards in highly populated cities, such as Minneapolis–St. Paul, Minnesota. Winter road maintenance accounts for roughly 25% of Minnesota Department of Transportation maintenance budgets, and state and local agencies spend more than $2.3 billion on snow and ice control operations annually. Urban snowfall has also been shown to enhance health problems and increase mortality rates. Further research on urban snowfall climatology is needed to more accurately diagnose urban regions susceptible to such winter health risks. The winter urban heat island effect has been suggested to reduce snowfall downwind of city centers because of localized energy and moisture flux variations, but previous research lacks spatial detail since it is primarily based on sparse surface observations. This project utilizes radar data for two studies—a 25-event snowfall composite and an individual-event analysis of 13 snow-only events—occurring from 1995 to 2012 and passing over the Minneapolis–St. Paul urban area to quantify the change in radar reflectivity values as a proxy for snowfall intensity downwind of the city. Results show that for the summed maximum composite event snowfall was significantly decreased downwind of the urban region; however, the highest maximum composite event, as well as 4 of the 13 individual snowfall events evaluated, did not have significantly decreased snowfall downwind of the city center, with the highest maximum composite and two of the three individual events having increased reflectivity values downwind. Analysis of related atmospheric variables for events with increased downwind reflectivity suggests that atmospheric instability and convergence may play a critical role in urban snowfall modification.
An Experimental Evaluation of Four Face-to-Face Teaching Strategies
Authors: Wood David , Wood Heather , Middleton David 
Published: March 2013

This study tests a number of predictions about the effectiveness of four different strategies for teaching three to four year old children how to master a difficult construction task. These strategies were derived from previous studies of mother-child and experimenter-child interactions in an assisted learning situation. One strategy the 'contingent approach' was based primarily on theoretical considerations and when used in earlier work as a basis for describing and evaluating maternal teaching it enabled us to predict how well children taught by their mothers would do with a task after instruction. The three other strategies are idealised versions of the teaching methods used by less successful mothers-as-teachers. On the basis of our analysis of effective instruction it is possible to predict how well children taught by these four different techniques by a trained instructor should perform after instruction. The present study largely confirms these predictions. In so doing, it strengthens the supposition that it was maternal behaviour in the earlier work which influenced the children's task abilities and it also corroborates various hypotheses about the essential nature of effective face-to-face instruction.
Behavioral Factors, Life Changes, and the Development of Vital Exhaustion and Depression in Myocardial Infarction Patients
Authors: Falger Paul R. J. 
Published: March 2013

Epidemiological studies on psychosocial precursors of myocardial infarction (MI) in middle-aged subjects suggest that in the year prior to MI, psychological phenomena of 'vital exhaustion and depression' may be an equally important diagnostic measure as manifestations of chest pain, and other cardiac symptoms. A self-administered psychological survey the 'Maastricht Questionnaire' (MQ) was constructed in order to measure the prodromal phenomena of 'vital exhaustion and depression'. In this paper, several retrospective and longitudinal studies on MI patients and controls are commented on in which the MQ was employed. Since these studies as such cannot explain why an association exists, a retrospective investigation in a sample of 136 healthy middle-aged men was undertaken. In this study, the interrelationships between the Type A coronary-prone behavior pattern, exposure to stressful life changes over a two year period, and the association with the MQ were explored. Coronary-prone behavior was assessed through the Jenkins Activity Survey (JAS), exposure to stressful life changes through our Middle Adulthood Life Changes Questionnaire (MALC), which is described in full. It is demonstrated that manifestations of 'vital exhaustion and depression' are associated in particular with life changes in the Home & Social domain on the MALC, and with Type A coronary-prone behavior. The latter is associated also in particular with life changes connoting work involvement and conflict proneness in the Work & Career domain on the MALC. The extended MALC, now covering the whole human life span, and the MQ are current employed in a case-control study on MI patients, neighborhood and hospital controls in order to explore further the ontogenetic factors that may be conducive to the development of 'vital exhaustion and depression', and subsequent MI. Methodological considerations for extending the MALC are discussed, together with an illustrative case history on a MI patient from this study.
Applied Developmental Psychology: Tasks, Problems, Perspectives
Authors: Montada Leo 
Published: March 2013

In order to consider possible contributions of developmental psychology to the analysis and solution of practical problems a model of practical action is proposed comprising the following six steps or questions: (1) What is the phenomenon or the problem we have to deal with? (2) How did the phenomenon or problem come into existence? (3) What will be the outcome of further development if no action is taken to change the phenomenon or outcome. (4) What are possible goals for intervention? (5) How can the goals be achieved? (6) What is the outcome in terms of evaluation of prognosis, intervention or counselling? Within the framework of these six steps or questions available scientific knowledge as well as relevant methodological problems are discussed. Moreover, the relationships and differences between theory, basic research, applied research and practical application are analyzed, namely the problem of equivalence of concepts and measures, the problem of deduction of technologies from theory, the problem of falsification of theory by failures in its practical application and the problem of discrepancies in metatheoretical correspondence. The article closes with some recommendations concerning developmental research in relation to applications.
The Cumulative Deficit Hypothesis in the Light of Cross-Cultural Evidence
Authors: Saco-Pollitt Carmen , Pollitt Ernesto , Greenfield Daryl 
Published: March 2013

The cumulative deficit hypothesis proposes that under conditions of marked social and environmental deprivation growth and development deficits in children will augment as children grow older. This study assessed between group (cultures) differences in intra-group (age) changes in performance of 3 to 6-year-old children in a battery of tests (Discrimination Learning, Short-Term Memory and Oddity Learning) derived from a theoretical model relating attention, learning and memory processes. Subjects were selected from Cambridge, Massachusetts, and from two lowland villages in Guatemala. The two groups of children were exposed to markedly different environments and presented significant differences in health and nutrition status. The focus of the study is on whether the developmental trends observed within groups are different between groups. Age trends within samples were analyzed by breaking the age into three groups: 31 to 42, 43 to 54, and 55 to 66 months. In Cambridge changes in test performance as a function of age were present in all Discrimination Learning and Oddity Learning tasks; whereas in Guatemala there was no systematic evidence of an age improvement in learning. In both samples there were generally no age effects in the Memory tests. The evidence presented is in line with the notion of progressively increased risk, at least during the preschool period, among severely impoverished populations where the psychosocial and biophysical needs of children are not adequately met.
A Comparison of Complementary and Taxonomic Utilization: Significance of the Dependent Measure
Authors: Scott Marcia S. , Greenfield Daryl B. , Urbano Richard C. 
Published: March 2013

Preschool children's utilization of complementary relations (e.g., environmental associates such as bird-nest, dog-bone) and taxonomic relations (e.g., items related categorically such as two or more fruit) was compared using three response measures that varied the task demands placed on the child. These three response measures were: generating a related verbal response to a single picture study card; selecting the one of two choice pictures that was related to the study pictures; justifying the picture choice selected. For one set, the correct response was related taxonomically to the study picture. For the second set, a correct response formed a complementary pair with the study picture. Based on a conceptual analysis of the task, it was argued that picture choice would be less demanding for the child than justification of the picture choice which in turn would be less demanding than generating an appropriate pair. It was predicted that as task demands increased performance would decrease for both complementary and taxonomic pairing. More importantly, functionally and perceptually available complementary pairs should be maintained at progressively higher levels relative to more abstract and hierarchically related taxonomic pairs. In addition, as task demands increase, complementary intrusions should produce one source of systematic error in the taxonomic condition. The results supported these predictions.
MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures: a report from The International DLBCL Rituximab-CHOP Consortium Program
Authors: Hu Shimin , Xu-Monette Zijun Y. , Tzankov Alexander , Green Tina , Wu Lin , Balasubramanyam Aarthi , Liu Wei-min , Visco Carlo , Li Yong , Miranda Roberto N. , Montes-Moreno Santiago , Dybkaer Karen , Chiu April , Orazi Attilio , Zu Youli , Bhagat Govind , Richards Kristy L. , Hsi Eric D. , Choi William W. L. , Zhao Xiaoying , van Krieken J. Han , Huang Qin , Huh Jooryung , Ai Weiyun , Ponzoni Maurilio , Ferreri Andrés J. M. , Zhou Fan , Slack Graham W. , Gascoyne Randy D. , Tu Meifeng , Variakojis Daina , Chen Weina , Go Ronald S. , Piris Miguel A. , Møller Michael B. , Medeiros L. Jeffrey , Young Ken H. 
Published: March 2013

Key Points
DLBCL patients with MYC/BCL2 coexpression demonstrate inferior prognosis and high-risk gene expression signatures.
Adult-onset asthma: is it really different?
Authors: de Nijs Selma B. , Venekamp Lisette N. , Bel Elisabeth H. 
Published: March 2013

Asthma that starts in adulthood differs from childhood-onset asthma in that it is often non-atopic, more severe and associated with a faster decline in lung function.Understanding of the underlying mechanism of adult-onset asthma and identification of specific phenotypes may further our understanding of pathophysiology and treatment response, leading to better targeting of both existing and new approaches for personalised management. Pivotal studies in past years have led to sustained progress in many areas, ranging from risk factors for development, identification of different phenotypes, and introduction of new therapies.This review highlights and discusses literature on adult-onset asthma, with special focus on the differences from childhood-onset asthma, risk factors for development, phenotypes of adult-onset asthma and new approaches for personalised management.
Pentoxifylline and the proteasome inhibitor MG132 induce apoptosis in human leukemia U937 cells through a decrease in the expression of Bcl-2 and Bcl-XL and phosphorylation of p65
Authors: Bravo-Cuellar Alejandro , Hernández-Flores Georgina , Lerma-Díaz José Manuel , Domínguez-Rodríguez Jorge Ramiro , Jave-Suárez Luis F , De Célis-Carrillo Ruth , Aguilar-Lemarroy Adriana , Gómez-Lomeli Paulina , Ortiz-Lazareno Pablo Cesar 
Published: March 2013

Abstract

Background
In Oncology, the resistance of the cancerous cells to chemotherapy continues to be the principal limitation. The nuclear factor-kappa B (NF-κB) transcription factor plays an important role in tumor escape and resistance to chemotherapy and this factor regulates several pathways that promote tumor survival including some antiapoptotic proteins such as Bcl-2 and Bcl-XL. In this study, we investigated, in U937 human leukemia cells, the effects of PTX and the MG132 proteasome inhibitor, drugs that can disrupt the NF-κB pathway. For this, we evaluated viability, apoptosis, cell cycle, caspases-3, -8, -9, cytochrome c release, mitochondrial membrane potential loss, p65 phosphorylation, and the modification in the expression of pro- and antiapoptotic genes, and the Bcl-2 and Bcl-XL antiapoptotic proteins.

Results
The two drugs affect the viability of the leukemia cells in a time-dependent manner. The greatest percentage of apoptosis was obtained with a combination of the drugs; likewise, PTX and MG132 induce G1 phase cell cycle arrest and cleavage of caspases -3,-8, -9 and cytochrome c release and mitochondrial membrane potential loss in U937 human leukemia cells. In these cells, PTX and the MG132 proteasome inhibitor decrease p65 (NF-κB subunit) phosphorylation and the antiapoptotic proteins Bcl-2 and Bcl-XL. We also observed, with a combination of these drugs overexpression of a group of the proapoptotic genes BAX, DIABLO, and FAS while the genes BCL-XL, MCL-1, survivin, IκB, and P65 were downregulated.

Conclusions
The two drugs used induce apoptosis per se, this cytotoxicity was greater with combination of both drugs. These observations are related with the caspases -9, -3 cleavage and G1 phase cell cycle arrest, and a decrease in p65 phosphorylation and Bcl-2 and Bcl-XL proteins. As well as this combination of drugs promotes the upregulation of the proapoptotic genes and downregulation of antiapoptotic genes. These observations strongly confirm antileukemic potential.