Mutation Testing as a Safety Net for Test Code Refactoring

Refactoring is an activity that improves the internal structure of the code without altering its external behavior. When performed on the production code, the tests can be used to verify that the external behavior of the production code is preserved. However, when the refactoring is performed on test code, there is no safety net that assures that the external behavior of the test code is preserved. In this paper, we propose to adopt mutation testing as a means to verify if the behavior of the test code is preserved after refactoring. Moreover, we also show how this approach can be used to identify the part of the test code which is improperly refactored

Grain Boundaries in Graphene on SiC(0001ˉ\bar{1}) Substrate

Grain boundaries in epitaxial graphene on the SiC(000$\bar{1}$) substrate are studied using scanning tunneling microscopy and spectroscopy. All investigated small-angle grain boundaries show pronounced out-of-plane buckling induced by the strain fields of constituent dislocations. The ensemble of observations allows to determine the critical misorientation angle of buckling transition $\theta_c = 19 \pm~2^\circ$. Periodic structures are found among the flat large-angle grain boundaries. In particular, the observed $\theta = 33\pm2^\circ$ highly ordered grain boundary is assigned to the previously proposed lowest formation energy structural motif composed of a continuous chain of edge-sharing alternating pentagons and heptagons. This periodic grain boundary defect is predicted to exhibit strong valley filtering of charge carriers thus promising the practical realization of all-electric valleytronic devices

Acute viral gastroenteritis in children hospitalized in Iksan, Korea during December 2010-June 2011

PurposeViral etiology is common in cases of children with acute diarrhea, and antibiotic therapy is usually not required. Therefore, it is important to determine the distribution of common viruses among children hospitalized with acute diarrhea.MethodsWe included 186 children who suffered from acute diarrhea and were hospitalized at the Wonkwang University Hospital Pediatric ward from December 1, 2010 to June 30, 2011 in this study. Stool samples were collected and multiplex reverse transcriptase polymerase chain reaction (multiplex RT-PCR) was used to simultaneously determine the viral etiology such as rotavirus, norovirus, astrovirus, or adenovirus.ResultsCausative viruses were detected in 72 of the 186 cases (38.7%). The mean age of the virus-positive cases was 1 year and 9 months (range, 1 month to 11 years). Rotavirus was detected in 50/186 (26.9%); norovirus, in 18/186 (9.7%); and astrovirus, in 3/186 cases (1.6%). Adenovirus was not detected in any of the cases. Proportions of norovirus genogroups I and II were 21.1% and 78.9%, respectively. Four of the 51 rotavirus-positive cases (7.8%) had received rotavirus vaccination at least once. The mean duration of diarrhea was 2.8 days (range, 1 to 10 days) and vomiting occurred in 39 of the 72 cases (54.2%).ConclusionViral etiology was confirmed in about one-third of the children with acute diarrhea, and the most common viral agent was rotavirus, followed by norovirus

Integrated Expression Profiling and Genome-Wide Analysis of ChREBP Targets Reveals the Dual Role for ChREBP in Glucose-Regulated Gene Expression

The carbohydrate response element binding protein (ChREBP), a basic helix-loop-helix/leucine zipper transcription factor, plays a critical role in the control of lipogenesis in the liver. To identify the direct targets of ChREBP on a genome-wide scale and provide more insight into the mechanism by which ChREBP regulates glucose-responsive gene expression, we performed chromatin immunoprecipitation-sequencing and gene expression analysis. We identified 1153 ChREBP binding sites and 783 target genes using the chromatin from HepG2, a human hepatocellular carcinoma cell line. A motif search revealed a refined consensus sequence (CABGTG-nnCnG-nGnSTG) to better represent critical elements of a functional ChREBP binding sequence. Gene ontology analysis shows that ChREBP target genes are particularly associated with lipid, fatty acid and steroid metabolism. In addition, other functional gene clusters related to transport, development and cell motility are significantly enriched. Gene set enrichment analysis reveals that ChREBP target genes are highly correlated with genes regulated by high glucose, providing a functional relevance to the genome-wide binding study. Furthermore, we have demonstrated that ChREBP may function as a transcriptional repressor as well as an activator

Acupuncture for the Treatment of Dry Eye: A Multicenter Randomised Controlled Trial with Active Comparison Intervention (Artificial Teardrops)

To evaluate the effects of acupuncture compared to a control group using artificial tears.multicenter randomised controlled trial (three local research hospitals of South Korea).150 patients with moderate to severe dry eye.Participants were randomly allocated into four weeks of acupuncture treatment (bilateral BL2, GB14, TE 23, Ex1, ST1, GB20, LI4, LI11 and single GV23) or to the artificial tears group (sodium carboxymethylcellulose).The ocular surface disease index (OSDI), tear film break-up time (TFBUT), Schirmer Ι test, visual analogue scale (VAS) for self-assessment of ocular discomfort, general assessment (by both acupuncture practitioners and participants) and quality of life (QOL) through the Measure Yourself Medical Outcome Profile-2 (MYMOP-2).There was no statistically significant difference between two groups for the improvement of dry eye symptoms as measured by OSDI (MD -16.11, 95% CI [-20.91, -11.32] with acupuncture and -15.37, 95% CI [-19.57, -11.16] with artificial tears; P = 0.419), VAS (acupuncture: -23.84 [-29.59, -18.09]; artificial tears: -22.2 [-27.24, -17.16], P = 0.530) or quality of life (acupuncture: -1.32 [-1.65, -0.99]; artificial tears: -0.96 [-1.32, -0.6], P = 0.42) immediately after treatment. However, compared with artificial tears group, the OSDI (acupuncture: -16.15 [-21.38, -10.92]; artificial tears: -10.76 [-15.25, -6.27], P = 0.030) and VAS (acupuncture: -23.88 [-30.9, -16.86]; artificial tears: -14.71 [-20.86, -8.55], P = 0.018) were significantly improved in the acupuncture group at 8 weeks after the end of acupuncture treatment. TFBUT measurements increased significantly in the acupuncture group after treatment.Acupuncture may have benefits on the mid-term outcomes related to dry eye syndrome compared with artificial tears.ClinicalTrials.gov NCT01105221

Arp2/3 Complex Regulates Asymmetric Division and Cytokinesis in Mouse Oocytes

Mammalian oocyte meiotic maturation involves oocyte polarization and a unique asymmetric division, but until now, the underlying mechanisms have been poorly understood. Arp2/3 complex has been shown to regulate actin nucleation and is widely involved in a diverse range of processes such as cell locomotion, phagocytosis and the establishment of cell polarity. Whether Arp2/3 complex participates in oocyte polarization and asymmetric division is unknown. The present study investigated the expression and functions of Arp2/3 complex during mouse oocyte meiotic maturation. Immunofluorescent staining showed that the Arp2/3 complex was restricted to the cortex, with a thickened cap above the meiotic apparatus, and that this localization pattern was depended on actin. Disruption of Arp2/3 complex by a newly-found specific inhibitor CK666, as well as by Arpc2 and Arpc3 RNAi, resulted in a range of effects. These included the failure of asymmetric division, spindle migration, and the formation and completion of oocyte cytokinesis. The formation of the actin cap and cortical granule-free domain (CGFD) was also disrupted, which further confirmed the disruption of spindle migration. Our data suggest that the Arp2/3 complex probably regulates oocyte polarization through its effect on spindle migration, asymmetric division and cytokinesis during mouse oocyte meiotic maturation

Stroke awareness decreases prehospital delay after acute ischemic stroke in korea

BACKGROUND: Delayed arrival at hospital is one of the major obstacles in enhancing the rate of thrombolysis therapy in patients with acute ischemic stroke. Our study aimed to investigate factors associated with prehospital delay after acute ischemic stroke in Korea. METHODS: A prospective, multicenter study was conducted at 14 tertiary hospitals in Korea from March 2009 to July 2009. We interviewed 500 consecutive patients with acute ischemic stroke who arrived within 48 hours. Univariate and multivariate analyses were performed to evaluate factors influencing prehospital delay. RESULTS: Among the 500 patients (median 67 years, 62% men), the median time interval from symptom onset to arrival was 474 minutes (interquartile range, 170-1313). Early arrival within 3 hours of symptom onset was significantly associated with the following factors: high National Institutes of Health Stroke Scale (NIHSS) score, previous stroke, atrial fibrillation, use of ambulance, knowledge about thrombolysis and awareness of the patient/bystander that the initial symptom was a stroke. Multivariable logistic regression analysis indicated that awareness of the patient/bystander that the initial symptom was a stroke (OR 4.438, 95% CI 2.669-7.381), knowledge about thrombolysis (OR 2.002, 95% CI 1.104-3.633) and use of ambulance (OR 1.961, 95% CI 1.176-3.270) were significantly associated with early arrival. CONCLUSIONS: In Korea, stroke awareness not only on the part of patients, but also of bystanders, had a great impact on early arrival at hospital. To increase the rate of thrombolysis therapy and the incidence of favorable outcomes, extensive general public education including how to recognize stroke symptoms would be important.ope

Constitutive activation of glycogen synthase kinase-3β correlates with better prognosis and cyclin-dependent kinase inhibitors in human gastric cancer

Background: Aberrant regulation of glycogen synthase kinase-3 beta (GSK-3 beta) has been implicated in several human cancers; however, it has not been reported in the gastric cancer tissues to date. The present study was performed to determine the expression status of active form of GSK-3 beta phosphorylated at Tyr(216) (pGSK-3 beta) and its relationship with other tumor-associated proteins in human gastric cancers. Methods: Immunohistochemistry was performed on tissue array slides containing 281 human gastric carcinoma specimens. In addition, gastric cancer cells were cultured and treated with a GSK-3 beta inhibitor lithium chloride (LiCl) for immunoblot analysis. Results: We found that pGSK-3 beta was expressed in 129 (46%) of 281 cases examined, and was higher in the early-stages of pathologic tumor-node-metastasis (P < 0.001). The expression of pGSK-3 beta inversely correlated with lymphatic invasion (P < 0.001) and lymph node metastasis (P < 0.001) and correlated with a longer patient survival (P < 0.001). In addition, pGSK-3 beta expression positively correlated with that of p16, p21, p27, p53, APC, PTEN, MGMT, SMAD4, or KAl1 (P < 0.05), but not with that of cyclin D1. This was confirmed by immunoblot analysis using SNU-668 gastric cancer cells treated with LiCl. Conclusions: GSK-3 beta activation was frequently observed in early-stage gastric carcinoma and was significantly correlated with better prognosis. Thus, these findings suggest that GSK-3 beta activation is a useful prognostic marker for the early-stage gastric cancer.Hirakawa H, 2009, ONCOL REP, V22, P481, DOI 10.3892/or_00000460Dar AA, 2009, ONCOGENE, V28, P866, DOI 10.1038/onc.2008.434Holmes T, 2008, STEM CELLS, V26, P1288, DOI 10.1634/stemcells.2007-0600Wang Q, 2008, CELL DEATH DIFFER, V15, P908, DOI 10.1038/cdd.2008.2Takahashi-Yanaga F, 2008, CELL SIGNAL, V20, P581, DOI 10.1016/j.cellsig.2007.10.018Pan MH, 2007, J AGR FOOD CHEM, V55, P7777, DOI 10.1021/jf071520hShakoori A, 2007, CANCER SCI, V98, P1388, DOI 10.1111/j.1349-7006.2007.00545.xZheng HC, 2007, ANTICANCER RES, V27, P3561Saegusa M, 2007, J PATHOL, V213, P35, DOI 10.1002/path.2198Ma C, 2007, CANCER RES, V67, P7756, DOI 10.1158/0008-5472.CAN-06-4665Forde JE, 2007, CELL MOL LIFE SCI, V64, P1930, DOI 10.1007/s00018-007-7045-7Li YW, 2007, J BIOL CHEM, V282, P21542, DOI 10.1074/jbc.M701978200Ding QQ, 2007, CANCER RES, V67, P4564, DOI 10.1158/0008-5472.CAN-06-1788Kunnimalaiyaan M, 2007, MOL CANCER THER, V6, P1151, DOI 10.1158/1535-7163.MCT-06-0665Soto-Cerrato V, 2007, MOL CANCER THER, V6, P362, DOI 10.1158/1535-7163.MCT-06-0266Cao Q, 2006, CELL RES, V16, P671, DOI 10.1038/sj.cr.7310078Yang CH, 2006, PRECIS AGRIC, V7, P33, DOI 10.1007/s11119-005-6788-0Crew KD, 2006, WORLD J GASTROENTERO, V12, P354Mai W, 2007, ONCOLOGY-BASEL, V71, P297, DOI 10.1159/000106429Tan J, 2005, CANCER RES, V65, P9012, DOI 10.1158/0008-5472.CAN-05-1226Shakoori A, 2005, BIOCHEM BIOPH RES CO, V334, P1365, DOI 10.1016/j.bbrc.2005.07.041Farago M, 2005, CANCER RES, V65, P5792Ghosh JC, 2005, CLIN CANCER RES, V11, P4580Liao XB, 2003, MOL CANCER THER, V2, P1215Lee HS, 2003, J PATHOL, V200, P39, DOI 10.1002/path.1288Doble BW, 2003, J CELL SCI, V116, P1175, DOI 10.1242/jcs.00384Gotoh J, 2003, CARCINOGENESIS, V24, P435Goto H, 2002, ORAL ONCOL, V38, P549Lee HS, 2001, INT J CANCER, V91, P619D`Amico M, 2000, J BIOL CHEM, V275, P32649, DOI 10.1074/jbc.M000643200Endoh Y, 2000, J PATHOL, V191, P257Wu LY, 1998, J NATL MED ASSOC, V90, P410WOODGETT JR, 1984, BIOCHIM BIOPHYS ACTA, V788, P339