bluuebunny/crossref_metadata_2025 huggingface dataset:
Hierarchical Data Aggregation Using Compressive Sensing (HDACS) in WSNs
Authors: Xu Xi , Ansari Rashid , Khokhar Ashfaq , Vasilakos Athanasios V.
Published: February 2015

Energy efficiency is one of the key objectives in data gathering in wireless sensor networks (WSNs). Recent research on energy-efficient data gathering in WSNs has explored the use of Compressive Sensing (CS) to parsimoniously represent the data. However, the performance of CS-based data gathering methods has been limited since the approaches failed to take advantage of judicious network configurations and effective CS-based data aggregation procedures. In this article, a novel Hierarchical Data Aggregation method using Compressive Sensing (HDACS) is presented, which combines a hierarchical network configuration with CS. Our key idea is to set multiple compression thresholds adaptively based on cluster sizes at different levels of the data aggregation tree to optimize the amount of data transmitted. The advantages of the proposed model in terms of the total amount of data transmitted and data compression ratio are analytically verified. Moreover, we formulate a new energy model by factoring in both processor and radio energy consumption into the cost, especially the computation cost incurred in relatively complex algorithms. We also show that communication cost remains dominant in data aggregation in the practical applications of large-scale networks. We use both the real-world data and synthetic datasets to test CS-based data aggregation schemes on the SIDnet-SWANS simulation platform. The simulation results demonstrate that the proposed HDACS model guarantees accurate signal recovery performance. It also provides substantial energy savings compared with existing methods.
A Space-Efficient Streaming Algorithm for Estimating Transitivity and Triangle Counts Using the Birthday Paradox
Authors: Jha Madhav , Seshadhri C. , Pinar Ali
Published: February 2015

We design a space-efficient algorithm that approximates the transitivity (global clustering coefficient) and total triangle count with only a single pass through a graph given as a stream of edges. Our procedure is based on the classic probabilistic result,
the birthday paradox
. When the transitivity is constant and there are more edges than wedges (common properties for social networks), we can prove that our algorithm requires
O
(√
n
) space (
n
is the number of vertices) to provide accurate estimates. We run a detailed set of experiments on a variety of real graphs and demonstrate that the memory requirement of the algorithm is a tiny fraction of the graph. For example, even for a graph with 200 million edges, our algorithm stores just 40,000 edges to give accurate results. Being a single pass streaming algorithm, our procedure also maintains a real-time estimate of the transitivity/number of triangles of a graph by storing a minuscule fraction of edges.
Animal Models of Aging Research: Implications for Human Aging and Age-Related Diseases
Authors: Mitchell Sarah J. , Scheibye-Knudsen Morten , Longo Dan L. , de Cabo Rafael
Published: February 2015

Aging is characterized by an increasing morbidity and functional decline that eventually results in the death of an organism. Aging is the largest risk factor for numerous human diseases, and understanding the aging process may thereby facilitate the development of new treatments for age-associated diseases. The use of humans in aging research is complicated by many factors, including ethical issues; environmental and social factors; and perhaps most importantly, their long natural life span. Although cellular models of human disease provide valuable mechanistic information, they are limited in that they may not replicate the in vivo biology. Almost all organisms age, and thus animal models can be useful for studying aging. Herein, we review some of the major models currently used in aging research and discuss their benefits and pitfalls, including interventions known to extend life span and health span. Finally, we conclude by discussing the future of animal models in aging research.
Hepatitis B Virus-Related Glomerulonephritis: Not a Predominant Cause of Proteinuria in Korean Patients with Chronic Hepatitis B
Authors: Yoo Jeong-Ju , Lee Jeong-Hoon , Yoon Jung-Hwan , Lee Minjong , Lee Dong Hyeon , Cho Yuri , Jang Eun Sun , Cho Eun Ju , Yu Su Jong , Kim Yoon Jun , Lee Hyo-Suk
Published: February 2015

Background/Aims. Hepatitis B virus (HBV) can form immune complexes which may result in various types of glomerulonephritis (GN). However, proteinuria can occur because of other kidney diseases besides HBV-related GN (HBV-GN). The aim of this study is to elucidate the causes of proteinuria and report on the clinical outcomes of HBV-GN.Methods. We reviewed the medical records of patients positive for serum hepatitis B surface antigen who underwent renal biopsies due to proteinuria at a tertiary medical center in Korea.Results. A total of 55 patients were included. HBV-GN was diagnosed in 20 (36.4%) of the patients by confirming the presence of immune complexes (12 of 13 membranoproliferative glomerulonephritis, 7 of 8 membranous glomerulonephritis, and 1 of 13 immunoglobulin A nephropathy). Twenty-one patients had other types of GN. A total of 13 (65%) HBV-GN patients were treated with antiviral agents for a median of 11 months. However, the degrees of proteinuria were not significantly reduced in the antiviral intervention group when compared to the control group.Conclusions. Proteinuria can be caused by various glomerular diseases and HBV-GN accounts for one-third of total GN cases. Well-designed prospective study is needed to assess whether antiviral therapy against HBV infection may improve the prognosis of HBV-GN.
Formulation and Evaluation of Optimized Oxybenzone Microsponge Gel for Topical Delivery
Authors: Pawar Atmaram P. , Gholap Aditya P. , Kuchekar Ashwin B. , Bothiraja C. , Mali Ashwin J.
Published: February 2015

Background. Oxybenzone, a broad spectrum sunscreen agent widely used in the form of lotion and cream, has been reported to cause skin irritation, dermatitis, and systemic absorption. Aim. The objective of the present study was to formulate oxybenzone loaded microsponge gel for enhanced sun protection factor with reduced toxicity. Material and Method. Microsponge for topical delivery of oxybenzone was successfully prepared by quasiemulsion solvent diffusion method. The effects of ethyl cellulose and dichloromethane were optimized by the 32 factorial design. The optimized microsponges were dispersed into the hydrogel and further evaluated. Results. The microsponges were spherical with pore size in the range of 0.10–0.22 µm. The optimized formulation possesses the particle size and entrapment efficiency of 72 ± 0.77 µm and 96.9 ± 0.52%, respectively. The microsponge gel showed the controlled release and was nonirritant to the rat skin. In creep recovery test it had shown highest recovery indicating elasticity. The controlled release of oxybenzone from microsponge and barrier effect of gel result in prolonged retention of oxybenzone with reduced permeation activity. Conclusion. Evaluation study revealed remarkable and enhanced topical retention of oxybenzone for prolonged period of time. It also showed the enhanced sun protection factor compared to the marketed preparation with reduced irritation and toxicity.
The Roles of SNF2/SWI2 Nucleosome Remodeling Enzymes in Blood Cell Differentiation and Leukemia
Authors: Prasad Punit , Lennartsson Andreas , Ekwall Karl
Published: February 2015

Here, we review the role of sucrose nonfermenting (SNF2) family enzymes in blood cell development. The SNF2 family comprises helicase-like ATPases, originally discovered in yeast, that can remodel chromatin by changing chromatin structure and composition. The human genome encodes 30 different SNF2 enzymes. SNF2 family enzymes are often part of multisubunit chromatin remodeling complexes (CRCs), which consist of noncatalytic/auxiliary subunit along with the ATPase subunit. However, blood cells express a limited set of SNF2 ATPases that are necessary to maintain the pool of hematopoietic stem cells (HSCs) and drive normal blood cell development and differentiation. The composition of CRCs can be altered by the association of specific auxiliary subunits. Several auxiliary CRC subunits have specific functions in hematopoiesis. Aberrant expressions of SNF2 ATPases and/or auxiliary CRC subunit(s) are often observed in hematological malignancies. Using large-scale data from the International Cancer Genome Consortium (ICGC) we observed frequent mutations in genes encoding SNF2 helicase-like enzymes and auxiliary CRC subunits in leukemia. Hence, orderly function of SNF2 family enzymes is crucial for the execution of normal blood cell developmental program, and defects in chromatin remodeling caused by mutations or aberrant expression of these proteins may contribute to leukemogenesis.
Tracheal Papilloma Treated with Cryotherapy and Interferon-α: A Case Report and Review of the Literature
Authors: Yıldırım Fatma , Türk Murat , Demircan Sedat , Akyürek Nalan , Yurdakul Ahmet Selim
Published: February 2015

Tracheal papilloma (TP) is characterized by papillomatous growth of the bronchial epithelium that involves the trachea as a response to Human Papilloma Virus (HPV) infection. A 40-year-old male, with 3-month history of progressive dyspnea was admitted to our hospital, and there were no any other respiratory symptoms. Physical examination was unremarkable. Chest computed tomography (CT) showed that there was a papillomatous mass at the distal trachea. The lesion occupied 80% of tracheal lumen. This patient received cryotherapy and mechanical debridement under general anesthesia and postoperative pathology showed endotracheal papillomatosis. Patient was treated with interferon-α(IFN-α) and he showed no recurrence at the 8th month of his therapy.
Meningitis, Clinical Presentation of Tetanus
Authors: Moniuszko Anna , Zajkowska Agata , Tumiel Ewa , Rutkowski Krzysztof , Czupryna Piotr , Pancewicz Sławomir , Rutkowski Ryszard , Zdrodowska Agnieszka , Zajkowska Joanna
Published: February 2015

Background. Tetanus is an acute disease caused by a neurotoxin produced byClostridium tetani. Tetanus immunization has been available since the late 1930s but sporadic cases still occur, usually in incompletely vaccinated or unvaccinated individuals.Case Report. An elderly previously vaccinated female contracted tetanus following foot injury. Clinically she presented with meningitis causing diagnostic and therapeutic delays.Why Should Physician Be Aware of This?Even in developed countries the differential diagnosis of meningitis, especially in the elderly, should include tetanus. Treatment in intensive care unit is required. General population might benefit from vaccine boosters and education on this potentially fatal disease.
Association of Polymorphisms of the Receptor for Advanced Glycation End Products Gene and Susceptibility to Sporadic Abdominal Aortic Aneurysm
Authors: Yao Ye , Zhuang Junli , Li You , Jing Bao , Li Hali , Li Jingbo , Shao Changgang , Li Keshen , Wang Haiyang
Published: February 2015

Accumulating evidence has suggested that receptor for advanced glycation end products (RAGE) is involved in the development and progression of human abdominal aortic aneurysms (AAAs). However, the association betweenRAGEgene polymorphisms and AAA has not yet been determined. The present study was aimed at analyzing the potential association between theRAGEgene polymorphisms and AAAs. A cohort of 381 patients and 436 age-matched healthy controls were genotyped to detect the threeRAGEpolymorphisms (−374 T/A, −429 T/C, and G82S) using SNaPshot. Our study demonstrated a significant difference in the genotype and allele frequencies of theRAGEG82S polymorphism between the AAA patients and the controls. Further stratification by gender and smoking status revealed that the presence of theRAGE82S allele confers a higher risk for developing AAA in men and smokers. Moreover, AAA patients with the variant 82S allele ofRAGEpresented with reduced serum soluble RAGE (sRAGE) production, and this decrease was more significant in men and smokers with AAA. Our study provides preliminary evidence that the 82S allele ofRAGEis a risk factor for AAA. This new piece of knowledge regarding RAGE may be clinically important for the prevention and therapy of AAAs.
Higher Mobility Scores in Patients with Cystic Fibrosis Are Associated with Better Lung Function
Authors: Thobani Aneesha , Alvarez Jessica A. , Blair Shaina , Jackson Kaila , Gottlieb Eric R. , Walker Seth , Tangpricha Vin
Published: February 2015

Objective.The purpose of this study was to determine whether mobility and physical activity were associated with lung function in adults with cystic fibrosis (CF).Design.This was a prospective cohort observational study in an urban, academic, specialized care center. Participants were ambulatory, nonhospitalized adults with CF.Main Outcome Measures.Mobility was assessed monthly by the Life-Space Assessment (LSA) questionnaire and quarterly by pedometer. Lung function was assessed by spirometry.Results.Twenty-seven subjects participated. Subjects recorded mean pedometer steps of 20,213 ± 11,331 over three days and FEV1% predicted of 77.48% ± 22.60% over one year. The LSA score at enrollment was correlated with initial pedometer steps (r=0.42andP=0.03), and mean LSA score over one year was correlated with mean number of steps (r=0.51andP=0.007). LSA mobility and pedometer scores were correlated with FEV1% predicted at enrollment and throughout the study.Conclusions.Mobility and physical activity measured by LSA questionnaire and pedometer are positively associated with lung function in adults with CF. This study confirms the importance of mobility and physical activity and supports the utility of a simple office-based questionnaire as a measure of mobility in adults with CF.
Raman Spectroscopy Study of the Doping Effect of the Encapsulated Iron, Cobalt, and Nickel Bromides on Single-Walled Carbon Nanotubes
Authors: Kharlamova Marianna V.
Published: February 2015

In this contribution the modification of the electronic properties of single-walled carbon nanotubes (SWCNTs) filled with nickel bromide, cobalt bromide, and iron bromide was studied by Raman spectroscopy. The doping-induced alterations of the radial breathing mode (RBM) and G-mode in the Raman spectra of the filled SWCNTs were analyzed in detail. The observed shifts of the components of the Raman modes and changes of their profiles allowed concluding that the embedded compounds have an acceptor doping effect on the SWCNTs, and the doping level increases in the line with nickel bromide-cobalt bromide-iron bromide.
Effects of Hand Vibration on Motor Output in Chronic Hemiparesis
Authors: de Andrade Melo Sibele , Iancu Andreea , Dyer Joseph-Omer , Forget Robert
Published: February 2015

Background.Muscle vibration has been shown to increase the corticospinal excitability assessed by transcranial magnetic stimulation (TMS) and to change voluntary force production in healthy subjects.Objectives.To evaluate the effect of vibration on corticospinal excitability using TMS and on maximal motor output using maximal voluntary contraction (MVC) in individuals with chronic hemiparesis.Methodology.Nineteen hemiparetic and 17 healthy control subjects participated in this study. Motor evoked potentials (MEPs) and MVC during lateral pinch grip were recorded at first dorsal interosseous muscle in a single session before, during, and after one-minute trials of 80 Hz vibration of the thenar eminence.Results.In hemiparetic subjects, vibration increased MEP amplitudes to a level comparable to that of control subjects and triggered a MEP response in 4 of 7 patients who did not have a MEP at rest. Also, vibration increased the maximal rate of force production (dF/dtmax⁡) in both control and hemiparetic subjects but it did not increase MVC.Conclusion.Motor response generated with a descending cortical drive in chronic hemiparetic subjects can be increased during vibration. Vibration could be used when additional input is needed to reveal motor responses and to increase rate of force generation.
Effects of Students’ Effort Scores in a Structured Inquiry Unit on Long-Term Recall Abilities of Content Knowledge
Authors: Schmid Sarah , Bogner Franz X.
Published: February 2015

The influence of students’ investment and perception during participation in structured inquiry-based learning on their long-term retention was analyzed to gain more insights into the underlying reasons for long-term retention through structured inquiry learning. Therefore achievement was correlated to effort, lesson rating and perceived competence for learning (PCL), and subject grades. 126 ninth graders participating in a structured inquiry-based interdisciplinary Biology and Physics module were analyzed. Students’ knowledge was even measured four times: 2 weeks before, directly after, and six and 12 weeks after module participation. Effort, usefulness, and PCL were observed once, directly after module participation. The invested effort during the lesson correlated positively with the knowledge score measured six weeks and twelve weeks after the lesson. Thus, high effort individuals achieved high knowledge scores at the medium and the long-term measurement. Therefore, effort is a variable that seems to be linked to long-term achievement. Furthermore, Biology and Physics grades reflected individual abilities to acquire long-term knowledge, while a high preknowledge level did not. This result indicates learning strategies as possible core concept underlying individual achievement levels.
Dynamic Processes, Fixed Points, Endpoints, Asymmetric Structures, and Investigations Related to Caristi, Nadler, and Banach in Uniform Spaces
Authors: Włodarczyk Kazimierz , Plebaniak Robert
Published: February 2015

In uniform spacesX, Dwith symmetric structures determined by theD-families of pseudometrics which define uniformity in these spaces, the new symmetric and asymmetric structures determined by theJ-families of generalized pseudodistances onXare constructed; using these structures the set-valued contractions of two kinds of Nadler type are defined and the new and general theorems concerning the existence of fixed points and endpoints for such contractions are proved. Moreover, using these new structures, the single-valued contractions of two kinds of Banach type are defined and the new and general versions of the Banach uniqueness and iterate approximation of fixed point theorem for uniform spaces are established. Contractions defined and studied here are not necessarily continuous. One of the main key ideas in this paper is the application of our fixed point and endpoint version of Caristi type theorem for dissipative set-valued dynamic systems without lower semicontinuous entropies in uniform spaces with structures determined byJ-families. Results are new also in locally convex and metric spaces. Examples are provided.
Effects of Transient Hypoxia versus Prolonged Hypoxia on Satellite Cell Proliferation and Differentiation In Vivo
Authors: Jash Sukanta , Adhya Samit
Published: February 2015

The microenvironment of the injury site can have profound effects on wound healing. Muscle injury results in ischemia leading to short-term local hypoxia, but there are conflicting reports on the role of hypoxia on the myogenic program in vivo and in vitro. In our rat model of mitochondrial restoration (MR), temporary upregulation of mitochondrial activity by a cocktail of organelle-encoded RNAs results in satellite cell proliferation and initiation of myogenesis. We now report that MR leads to a transient hypoxic response in situ. Inhibition of hypoxia by lowering mitochondrial O2consumption, either by respiratory electron transport inhibitors, or by NO-mediated inhibition of O2binding to cytochrome c oxidase, resulted in exacerbation of inflammation. Lentivirus-mediated knockdown of hypoxia-inducible factor 1α(HIF1α) or of Notch signaling components had a similar effect, and pharmacologic inhibition of HIF or Notch reduced the number of proliferating Pax7+cells. In contrast, a prolonged hypoxic response induced either by uncoupling of respiration from oxidative phosphorylation or through HIF stabilization by dimethyloxalylglycine (DMOG) had an immediate anti-inflammatory effect. Although significant satellite cell proliferation occurred in presence of DMOG, expression of differentiation markers was affected. These results emphasize the importance of transient hypoxia as opposed to prolonged hypoxia for myogenesis.
Prenatal Diagnosis of Concurrent Achondroplasia and Klinefelter Syndrome
Authors: Perez-Carbajo Esther , Zapardiel Ignacio , Sanfrutos-Llorente Luis , Cruz-Melguizo Sara , Martinez-Payo Cristina , Iglesias-Goy Enrique
Published: February 2015

Achondroplasia is the most frequent nonlethal skeletal dysplasia, with a prevalence of 1 : 5000 to 1 : 40,000 live births, and it is caused by a fibroblast growth factor receptor alteration. The combination of achondroplasia and Klinefelter syndrome is extremely rare and just four reports have been published in the literature, which were all diagnosed postnatally. We report the fifth case described of this uncommon association and its prenatal diagnosis. In cases of prenatal diagnosis of achondroplasia with additional suspicious morphological abnormalities, an invasive test such as amniocentesis must be carried out to assess the karyotype normality.
Myeloid-Derived Suppressor Cells: Paradoxical Roles in Infection and Immunity
Authors: Dai Jun , El Gazzar Mohamed , Li Guang Y. , Moorman Jonathan P. , Yao Zhi Q.
Published: February 2015

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature suppressor cells that are generated due to aberrant myelopoiesis under pathological conditions. Although MDSCs have been recognized for more than 20 years under the guise of different monikers, these particular populations of myeloid cells gained more attention recently due to their immunosuppressive properties, which halt host immune responses to growing cancers or overwhelming infections. While MDSCs may contribute to immune homeostasis after infection or tissue injury by limiting excessive inflammatory processes, their expansion may be at the expense of pathogen elimination and thus may lead to disease persistence. Therefore, MDSCs may be either damaging or obliging to the host by attenuating, for example, antitumor or anti-infectious immune responses. In this review, we recapitulate the biological and immunological aspects of MDSCs, including their generation, distribution, trafficking and the factors involved in their activation, expansion, suppressive functions, and interplay between MDSCs and regulatory T cells, with a focus on the perspectives of infection and inflammation.
Gallbladder Ejection Fraction Declines with Age in Patients Undergoing Cholecystectomy for Acalculous Biliary Symptoms But Has Low Accuracy in the Prediction of Gallbladder Pathology
Authors: Jones Aled , Shahtahmassebi Golnaz , Stell David
Published: February 2015

Background/Aims: Hepatobiliary Iminodiacetic Acid (HIDA) scan provides a technique to quantify gallbladder ejection fraction (EF) in patients suffering acalculous biliary colic (ACBC). We wished to evaluate the accuracy of EF in the prediction of gallbladder pathology in patients undergoing cholecystectomy. Methods: Data were retrieved from a database of patients referred for HIDA scan for ACBC, including EF and the pathological outcome of those undergoing cholecystectomy, and compared to normal values obtained from a review of related studies. Significant associations were demonstrated by chi-square, Mann-Whitney test, and linear regression. The predictive accuracy of different cut-offs of EF was demonstrated by the ROC curve analysis. Results: Of 83 patients referred for HIDA scan for ACBC, 41 underwent cholecystectomy. The median EF of this group (33%) was significantly lower than the composite normal median value from previous studies (56%). Thirty-two patients revealed evidence of gallbladder pathology. The EF declined with age (coefficient = -0.51, 95% CI = -0.99 to -0.33), but the median value did not differ between those with gallbladder pathology (34%) and those with normal gallbladders (29%). Conclusion/Discussion: Although an EF cut-off of 35% had the greatest accuracy in the prediction of pathology of those tested (0.56), the poor negative predictive value (23.5%) was a major contributor to its low accuracy. Although patients with ACBC have reduced gallbladder EF compared to the normal population, its quantitative assessment is of limited value in the prediction of gallbladder pathology.
National Trends, Complications, and Hospital Charges in Pediatric Patients with Chiari Malformation Type I Treated with Posterior Fossa Decompression with and without Duraplasty
Authors: Shweikeh Faris , Sunjaya Dharma , Nuno Miriam , Drazin Doniel , Adamo Mathew A.
Published: February 2015

Background: The treatment of type 1 Chiari malformation (CM-1) with posterior fossa decompression without (PFD) or with duraplasty (PFDD) is controversial. The authors analyze both options in a national sample of pediatric patients. Methods: Utilizing the Kids' Inpatient Database, CM-1 patients undergoing PFD or PFDD from 2000 through 2009 were analyzed. Results: 1,593 patients with PFD and 1,056 with PFDD were evaluated. The average age was 10.3 years, slightly younger in PFD (9.8 vs. 10.9 years, p = 0.001). PFDD patients were more likely White (81.2 vs 75.6%, p = 0.04) and less likely admitted emergently (8.4 vs. 13.8%, p = 0.007). They also underwent more reoperations (2.1 vs. 0.7%, p = 0.01), had more procedure-related complications (2.3 vs. 0.8%, p = 0.003), a longer length of stay (4.4 vs. 3.8 days, p = 0.001) and higher charges (USD 35,321 vs. 31,483, p = 0.01). Conclusions: This large national study indicates that PFDD is performed more often in Caucasians, less so emergently, and associated with significantly more complications and immediate reoperations, while PFD is more frequent in those with syringomyelia and more economical, requiring fewer hospital resources. Overall, PFD is more favorable for CM-1, though it would be prudent to conduct a prospective trial, as this analysis is limited by data on preoperative presentations and long-term outcomes.
Factors Influencing Survival after Pancreatoduodenectomy for Ductal Adenocarcinoma Depend on Patients' Age
Authors: Urbonas Kestutis , Gulbinas Antanas , Smailyte Giedrė , Pranys Darius , Jakstaite Aldona , Pundzius Juozas , Barauskas Giedrius
Published: February 2015

Background: It is supposed that a prolonged lifetime will be associated with increased incidence of PDAC among the elderly. Some studies show a tendency toward decreased survival in the elderly patients following pancreatoduodenectomy for PDAC. The aim of this study was to evaluate factors, influencing survival following pancreatoduodenectomy for PDAC in different age groups. Methods: Data of 251 patients after pancreatoduodenectomy for PDAC between 1999 and 2012 were analyzed. The Kaplan-Meier method and log-rank test were used to calculate survival and to compare differences between groups. The Cox proportional hazard model was applied to indentify independent prognosticators. Results: The overall median survival was 14.9 months. Postoperative morbidity was 25.5% with a 5.1% mortality rate. No significant differences in the overall morbidity (22.4 vs. 29.6%) or mortality (2.8 vs. 8.3%) rates were observed between different patients' age groups (<70 years and >70 years). Multivariate analysis revealed R1 resection (HR 1.76) and poor tumor differentiation (G3-G4) (HR 1.48) were independent negative factors for survival in patients <70 years. Lymph-node metastases (N1) - HR 4.89 and perineural invasion - HR 2.73 were independent prognosticators in the elderly. Conclusions: Our study highlighted different factors influencing long-term survival after pancreatoduodenectomy: R1 resection and poor tumor differentiation (G3-G4) were independent negative factors for survival in patients <70 years, while perineural invasion and lymph-node metastases result in worse survival among the elderly.
Warburg Effect or Reverse Warburg Effect? A Review of Cancer Metabolism
Authors: Xu Xiao Dong , Shao Shi Xiu , Jiang Hai Ping , Cao Yan Wei , Wang Yong Hua , Yang Xue Cheng , Wang You Lin , Wang Xin Sheng , Niu Hai Tao
Published: February 2015

Cancer is a major threat to human health. A considerable amount of research has focused on elucidating the nature of cancer from its pathogenesis to treatment and prevention. Tumor cell metabolism has been considered a hallmark of cancer. Cancer cells differ from normal cells through unlimited cell division, and show a greater need for energy for their rapid growth and duplication. Research on glycometabolism, as the key point of energy metabolism, has played a unique role. In the 1920s, Warburg found that cancer cells prefer to produce adenosine triphosphate (ATP) by glycolysis, which is a less efficient pathway compared to oxidative phosphorylation. This striking discovery, called ‘the Warburg effect', has influenced and guided the study of the mechanism and treatment of tumors for generations, but its causal relationship with cancer progression is still unclear. Some studies have now shown contradicting evidence and a new hypothesis, the reverse Warburg effect, has been put forward, in which cancer cells produce most of their ATP via glycolysis, even under aerobic conditions. In this review we discuss the new points concerning the energy metabolism of a tumor, as well as the current facts and perspectives.
Crianças e games na escola: entre paisagens e práticas
Authors: Fantin Monica
Published: February 2015

O artigo situa algumas paisagens teóricas e conceituais sobre os jogos tradicionais, eletrônicos e digitais a partir de referenciais dos estudos da infância, dos jogos e da cultura lúdica. Ao destacar as fronteiras que as crianças ultrapassam quando integram os diferentes tipos de jogos em seu repertório lúdico e cultural, o artigo reflete sobre os elementos comuns dos jogos e a especificidades dos games diante das novas práticas na cultura digital. Entre aprendizagens informais e contextos formais escolares, a diversidade que as experiências com jogos propiciam às crianças desafia a escola a construir outras práticas e assegurar mediações significativas, e diante da ambigüidade histórica entre jogo e educação, alguns destes desafios são problematizados no texto. Por fim, o artigo destaca possíveis cruzamentos entre as fronteiras conceituais e as práticas com games a partir de outros modos de ver a relação entre tecnologias e crianças nos cenários da mídia-educação.
Aportes para la educación inicial: saberes construidos por el Proyecto Pedagógico Educativo Comunitario
Authors: Pineda-Báez Nisme Yurany , Garzón-Rodríguez Juan Carlos , Bejarano-Novoa Diana Carolina , Buitrago-Rodríguez Nidya Esperanza
Published: February 2015

En este estudio nuestro objetivo fue evidenciar los saberes y prácticas pedagógicas construidas en los 20 años de implementación del Proyecto Pedagógico Educativo Comunitario -Ppec-del Instituto Colombiano de Bienestar Familiar -ICBF-con la primera infancia. Se trata de la sistematización de 78 entrevistas que realizamos, en las que participaron 181 personas. Las categorías que nuclearon el proceso fueron la reconstrucción histórica del Ppec, la concepción, la intencionalidad, los saberes y prácticas pedagógicas y la operacionalización de la propuesta. En la génesis del Ppec se evidencia una forma de construcción de la política en diálogo con las prácticas, alimentada por la reflexión institucional y la revisión crítica de las discusiones de la época en torno al desarrollo infantil y social. Los saberes y las prácticas pedagógicas construidas con la primera infancia se caracterizan por ser participativas, significativas, contextuadas y humanizantes, constituyendo un tejido que se nutre además de los recursos comunitarios, del entorno y del medio ambiente, para constituirse en un proyecto de transformación social.
Calidad de vida de niños y niñas de estratos medios: estudio de caso
Authors: Mieles-Barrera María Dilia
Published: February 2015

Objetivos: Comprender las dimensiones y los aspectos relacionados con la calidad de vida; identificar percepciones, evaluaciones, aspiraciones, sentimientos y deseos de los niños y las niñas participantes relacionados con sus condiciones objetivas y subjetivas en la vida cotidiana; describir los aspectos identificados por niños y niñas como indicadores de bienestar o malestar. Alcance: Estudio pionero en la utilización de enfoque epistemológico cualitativo para la investigación en calidad de vida. Metodología: estudio de caso, técnicas participativas (taller lúdico reflexivo, mesa redonda, entrevista semiestructurada, grupos focales), tratamiento de la información con análisis temático. Resultados: los niños y niñas participantes asocian su calidad de vida con vivencias positivas y negativas derivadas de sus condiciones materiales de existencia, la familia, las amistades, la escuela, el reconocimiento público, los derechos, el uso de tecnologías y la satisfacción global. Conclusiones: la investigación permitió incorporar un abordaje más complejo e integral sobre la calidad de vida de la niñez, reafirmar la necesidad y las posibilidades de asumir a niños y niñas como sujetos de investigación per se, e identificar en cada una de las dimensiones las vivencias que les producen bienestar y malestar, como pistas que pueden dar origen a programas de promoción y prevención en las organizaciones sociales y estatales responsables del desarrollo de la niñez.
Construcción de imaginarios de la infancia y formación de educadoras de párvulos
Authors: Martínez-Núñez María Delia , Muñoz-Zamora Graciela
Published: February 2015

En las últimas décadas se ha instalado en nuestro país una racionalidad técnica respecto a la enseñanza universitaria, que no refleja una reflexión consistente e integral acerca de la infancia y el significado que esta adquiere en la formación de los educadores y educadoras de la primera infancia. En este artículo nos hemos propuesto como objetivo analizar las concepciones de infancia que predominan en los discursos y prácticas de las estudiantes de educación parvularia de la Universidad Metropolitana de Ciencias de la Educación. Utilizamos metodologías cualitativas, especialmente el análisis del discurso crítico y otras técnicas que nos permitieron adentrarnos en los imaginarios sobre la infancia. Nuestras conclusiones revelan los imaginarios sociales y la relevancia que estos tienen en la formación profesional y en la experiencia personal de las estudiantes.
La diversidad en la construcción de mundo de niños y niñas de dos culturas
Authors: Ibáñez-Salgado Nolfa
Published: February 2015

Asumiendo la concepción de diversidad como distintas construcciones de mundo, pretendo en este trabajo develar las lógicas que guían las interacciones en las que participan niños y niñas de dos culturas: cultura mayor y cultura mapuche. Comparo las interacciones habituales en el hogar de niños y niñas de clase media de Santiago, y de niños y niñas mapuche de comunidades rurales, y posteriormente en sus respectivas aulas. La metodología es cualitativa, de enfoque etnográfico. Los resultados muestran que las lógicas que guían la interacción en las familias de los niños y niñas mapuche son distintas y en algunos casos opuestas a las que imperan en la escuela, que la diversidad no es acogida pedagógicamente por el profesorado, y que aprendizajes previos de los niños y niñas mapuche se invisibilizan en el aula.
Resignificando la protección. Los sistemas de protección de derechos de niños y niñas en Argentina
Authors: Villalta Carla , Llobet Valeria
Published: February 2015

Este trabajo analiza las principales tensiones que emergen cuando se pretende adecuar la protección de la infancia provista por el Estado a un enfoque de derechos. Para ello, a partir de los resultados de una investigación desarrollada en las provincias argentinas de Mendoza y San Juan se indagan las formas en que la protección de la infancia es resignificada. Desde una perspectiva que desplaza la mirada desde las normas y reglamentaciones hacia las prácticas y disputas concretas, el objetivo es analizar los esquemas interpretativos a partir de los cuales distintos agentes instrumentan medidas de protección, y cómo a partir de ellos, y de las pujas y conflictos interinstitucionales, los sentidos dados a la protección son construidos, reapropiados y/o contestados.
Activation of Nuclear Factor Erythroid 2–Related Factor 2 Coordinates Dimethylarginine Dimethylaminohydrolase/PPAR-γ/Endothelial Nitric Oxide Synthase Pathways That Enhance Nitric Oxide Generation in Human Glomerular Endothelial Cells
Authors: Luo Zaiming , Aslam Shakil , Welch William J. , Wilcox Christopher S.
Published: February 2015

Dimethylarginine dimethylaminohydrolase (DDAH) degrades asymmetric dimethylarginine, which inhibits nitric oxide (NO) synthase (NOS). Nuclear factor erythroid 2–related factor 2 (Nrf2) is a transcriptional factor that binds to antioxidant response elements and transcribes many antioxidant genes. Because the promoters of the human DDAH-1 and DDAH-2, endothelial NOS (eNOS) and PPAR-γ genes contain 2 to 3 putative antioxidant response elements, we hypothesized that they were regulated by Nrf2/antioxidant response element. Incubation of human renal glomerular endothelial cells with the Nrf2 activator
tert
-butylhydroquinone (20 μmol·L
−1
) significantly (
P
<0.05) increased NO and activities of NOS and DDAH and decreased asymmetric dimethylarginine. It upregulated genes for hemoxygenase-1, eNOS, DDAH-1, DDAH-2, and PPAR-γ and partitioned Nrf2 into the nucleus. Knockdown of Nrf2 abolished these effects. Nrf2 bound to one antioxidant response element on DDAH-1 and DDAH-2 and PPAR-γ promoters but not to the eNOS promoter. An increased eNOS and phosphorylated eNOS (P-eNOSser-1177) expression with
tert
-butylhydroquinone was prevented by knockdown of PPAR-γ. Expression of Nrf2 was reduced by knockdown of PPAR-γ, whereas PPAR-γ was reduced by knockdown of Nrf2, thereby demonstrating 2-way positive interactions. Thus, Nrf2 transcribes HO-1 and other genes to reduce reactive oxygen species, and DDAH-1 and DDAH-2 to reduce asymmetric dimethylarginine and PPAR-γ to increase eNOS and its phosphorylation and activity thereby coordinating 3 pathways that enhance endothelial NO generation.
Time-Dependent Effects of Aspirin on Blood Pressure and Morning Platelet Reactivity
Authors: Bonten Tobias N. , Snoep Jaapjan D. , Assendelft Willem J.J. , Zwaginga Jaap Jan , Eikenboom Jeroen , Huisman Menno V. , Rosendaal Frits R. , van der Bom Johanna G.
Published: February 2015

Aspirin is used for cardiovascular disease (CVD) prevention by millions of patients on a daily basis. Previous studies suggested that aspirin intake at bedtime reduces blood pressure compared with intake on awakening. This has never been studied in patients with CVD. Moreover, platelet reactivity and CVD incidence is highest during morning hours. Bedtime aspirin intake may attenuate morning platelet reactivity. This clinical trial examined the effect of bedtime aspirin intake compared with intake on awakening on 24-hour ambulatory blood pressure measurement and morning platelet reactivity in patients using aspirin for CVD prevention. In this randomized open-label crossover trial, 290 patients were randomized to take 100 mg aspirin on awakening or at bedtime during 2 periods of 3 months. At the end of each period, 24-hour blood pressure and morning platelet reactivity were measured. The primary analysis population comprised 263 (blood pressure) and 133 (platelet reactivity) patients. Aspirin intake at bedtime did not reduce blood pressure compared with intake on awakening (difference systolic/diastolic: −0.1 [95% confidence interval, −1.0, 0.9]/−0.6 [95% confidence interval, −1.2, 0.0] mm Hg). Platelet reactivity during morning hours was reduced with bedtime aspirin intake (difference: −22 aspirin reaction units [95% confidence interval, −35, −9]). The intake of low-dose aspirin at bedtime compared with intake on awakening did not reduce blood pressure of patients with CVD. However, bedtime aspirin reduced morning platelet reactivity. Future studies are needed to assess the effect of this promising simple intervention on the excess of cardiovascular events during the high risk morning hours.
Cys18-Cys137 Disulfide Bond in Mouse Angiotensinogen Does Not Affect AngII-Dependent Functions In Vivo
Authors: Wu Congqing , Xu Yinchuan , Lu Hong , Howatt Deborah A. , Balakrishnan Anju , Moorleghen Jessica J. , Vander Kooi Craig W. , Cassis Lisa A. , Wang Jian-an , Daugherty Alan
Published: February 2015

Renin cleavage of angiotensinogen (AGT) releases angiotensin I (AngI) in the initial step of producing all angiotensin peptides. It has been suggested recently that redox regulation of a disulfide bond in AGT involving Cys18-Cys137 may be important to its renin cleavage efficiency in vivo. The purpose of this study was to test this prediction in a mouse model by comparing AngII production and AngII-dependent functions in mice expressing wild-type AGT versus a mutated form of AGT lacking the disulfide bond. Wild-type (hepAGT+/+) and hepatocyte-specific AGT-deficient (hepAGT−/−) littermates were developed in an low-density lipoprotein receptor −/− background. hepAGT+/+ mice were injected intraperitoneally with adeno-associated viral (AAV) vector containing a null insert. hepAGT−/− mice were injected with AAV containing a null insert, wild-type AGT or Cys18Ser and Cys137Ser mutated AGT. Two weeks after AAV injection, mice were fed a Western diet for 12 weeks. Administration of AAV containing either form of AGT led to similar plasma AGT concentrations in hepAGT−/− mice. High plasma renin concentrations in hepAGT−/− mice were suppressed equally by both forms of AGT, which were accompanied by comparable increases of plasma AngII concentrations similar to hepAGT+/+ mice. AAV-driven expression of both forms of AGT led to equivalent increases of systolic blood pressure and augmentation of atherosclerotic lesion size in hepAGT−/− mice. These measurements were comparable to systolic blood pressure and atherosclerotic lesions in hepAGT+/+ mice. These data indicate that the Cys18-Cys137 disulfide bond in AGT is dispensable for AngII production and AngII-dependent functions in mice.
Astrocyte Overexpression of Heme Oxygenase-1 Improves Outcome After Intracerebral Hemorrhage
Authors: Chen-Roetling Jing , Song Wei , Schipper Hyman M. , Regan Christopher S. , Regan Raymond F.
Published: February 2015

Background and Purpose—

Heme oxygenase-1 (HO-1) catalyzes the rate-limiting reaction of heme breakdown and may have both antioxidant and pro-oxidant effects. In previous studies, HO-1 overexpression protected astrocytes from heme-mediated injury in vitro. In the present study, we tested the hypothesis that selective astrocyte overexpression of HO-1 improves outcome after intracerebral hemorrhage.

Methods—

Male and female transgenic mice overexpressing human HO-1 driven by the GFAP promoter (GFAP.HMOX1) and wild-type controls received striatal injections of autologous blood (25 μL). Blood–brain barrier disruption was assessed by Evans blue assay and striatal cell viability by methylthiazolyldiphenyl-tetrazolium bromide assay. Neurological deficits were quantified by digital analysis of spontaneous cage activity, adhesive removal, and elevated body swing tests.

Results—

Mortality rate for wild-type mice was 34.8% and was similar for males and females; all GFAP.HMOX1 mice survived. Striatal Evans blue leakage at 24 hours was 23.4±3.2 ng in surviving wild-type mice, compared with 10.9±1.8 ng in transgenics. Perihematomal cell viability was reduced to 61±4% of contralateral at 3 days in wild-type mice, versus 80±4% in transgenics. Focal neurological deficits were significantly reduced and spontaneous cage activity was increased in GFAP.HMOX1 mice.

Conclusions—

Selective HO-1 overexpression in astrocytes reduces mortality, blood–brain barrier disruption, perihematomal cell injury, and neurological deficits in an autologous blood injection intracerebral hemorrhage model. Genetic or pharmacological therapies that acutely increase astrocyte HO-1 may be beneficial after intracerebral hemorrhage.
Is There an Oil Weapon?: Security Implications of Changes in the Structure of the International Oil Market
Authors: Hughes Llewelyn , Long Austin
Published: February 2015

What is the relationship between oil and coercion? For decades states have worried that their dependence on oil gives producers a potential lever of coercion. The size, integration, and sophistication of the current oil market, however, are thought to have greatly attenuated, if not eliminated, the coercive potential of oil. The best way to analyze the current global oil market is by viewing it as a series of distinct market segments, from upstream production to midstream transport to downstream refining, with the potential for coercion varying across them. Oil-producing states do not have the greatest coercive potential in the international oil market. Instead, the United States remains the dominant presence, though its dominance has shifted from production—where it resided prior to World War II—to the maritime environment. These findings are significant for scholars’ and policymakers’ understanding of the relationship between oil and coercion. More generally, they suggest that studies of the potential for states to coerce others using economic instruments should take into account differences in the structure of markets for different goods.
Pakistan's Battlefield Nuclear Policy: A Risky Solution to an Exaggerated Threat
Authors: Sankaran Jaganath
Published: February 2015

Pakistan has introduced a new battlefield nuclear weapon, Nasr, into its arsenal. Nasr, a short-range ballistic missile, was first flight-tested in 2011. Pakistani leaders have declared that the weapon is meant to deter India from executing its Cold Start war doctrine. The doctrine was conceived by members of India's army and its strategic community in 2004 as a solution to perceived operational shortcomings of the army in responding to major terrorist incidents involving Pakistanis. It recommends the positioning of smaller army units at the international border with the capability to rapidly invade Pakistan and occupy narrow slices of territory, while denying Pakistan the ability to anticipate the attack and to immediately assemble a counterattack force. The Cold Start war doctrine, however, has since been publicly disavowed by the Indian government, and the Indian army has not reorganized or equipped its troops in a manner consistent with the doctrine. Further, the use of battlefield nuclear weapons inside Pakistan or near the densely populated border regions could potentially cause civilian casualties in the tens of thousands. These factors should dissuade Pakistan from deploying the Nasr missile.
Peasant, Revolutionary, Celebrity
Authors: Lionis Chrisoula
Published: February 2015

In the last decade, the international profile of Palestinian art has grown at an unprecedented rate. In the context of international exhibitions, the work of contemporary Palestinian artists is consistently framed as inherently political and is almost always discussed in terms of the conflict with Israel. This article examines the ways that a new generation of Palestinian artists have used their work to problematize the iconography of Palestinian nationalism developed by previous generations and the international framing of their work as inherently political. It considers the role of art in the development and dissemination of Palestinian nationalist iconography and maps the history of popular iconography to show the Nakba, the battle of Karameh and the Oslo Accords as events that each transformed Palestinian popular iconography. Examining the work of artists Khaled Hourani, Emily Jacir, Larissa Sansour and Monther Jawabreh, in this article I argue that contemporary art plays a significant role in subverting the trend of reducing the Palestinian experience to one of victimhood and loss.