883 research outputs found
Brief announcement: passive and active attacks on audience response systems using software defined radios
Audience response systems, also known as clickers, are used at many academic institutions to offer active learning environments. Since these systems are used to administer graded assignments, and sometimes even exams, it is crucial to assess their security. Our work seeks to exploit and document potential vulnerabilities of clickers. For this purpose, we use software defined radios to perform jamming, sniffing and spoofing attacks on an audience response system in production, which provide different possible methods of cheating. The results of our study demonstrate that clickers are easily exploitable. We build a prototype and show that it is practically possible to covertly steal or forge answers of a peer or even an entire classroom, with high levels of confidence. Additionally, we find that the receivers software of the system lacks protection against unexpected answers, which allows our spoofer to submit any ASCII character and opens the receiver up to possible fuzzing attacks. As a result of this study, we discourage using clickers for high-stake assessments, unless they provide proper security protection..http://people.bu.edu/staro/SSS2017_Brief_v0.pdfhttp://people.bu.edu/staro/SSS2017_Brief_v0.pdfhttp://people.bu.edu/staro/SSS2017_Brief_v0.pdfAccepted manuscrip
Significance of KRAS/PAK1/Crk pathway in non-small cell lung cancer oncogenesis.
BackgroundKey effector(s) of mutated KRAS in lung cancer progression and metastasis are unknown. Here we investigated the role of PAK1/Crk axis in transduction of the oncogenic KRAS signal in non-small cell lung cancer (NSCLC).MethodsWe used NSCLC clinical specimens to examine the correlation among KRAS mutations (codon 12, 13 and 61); PAK1/Crk axis activation [p-PAK1(Thr423), p-Crk(Ser41)]; and adhesion molecules expression by immunohistochemistry. For assessing the role of proto-oncogene c-Crk as a KRAS effector, we inhibited KRAS in NSCLC cells by a combination of farnesyltransferase inhibitor (FTI) and geranylgeranyltransferase inhibitor (GGTI) and measured p-Crk-II(Ser41) by western blotting. Finally, we disrupted the signaling network downstream of KRAS by blocking KRAS/PAK1/Crk axis with PAK1 inhibitors (i.e., IPA-3, FRAX597 or FRAX1036) along with partial inhibition of all other KRAS effectors by prenylation inhibitors (FTI + GGTI) and examined the motility, morphology and proliferation of the NSCLC cells.ResultsImmunohistochemical analysis demonstrated an inverse correlation between PAK1/Crk phosphorylation and E-cadherin/p120-catenin expression. Furthermore, KRAS mutant tumors expressed higher p-PAK1(Thr423) compared to KRAS wild type. KRAS prenylation inhibition by (FTI + GGTI) completely dephosphorylated proto-oncogene c-Crk on Serine 41 while Crk phosphorylation did not change by individual prenylation inhibitors or diluent. Combination of PAK1 inhibition and partial inhibition of all other KRAS effectors by (FTI + GGTI) dramatically altered morphology, motility and proliferation of H157 and A549 cells.ConclusionsOur data provide evidence that proto-oncogene c-Crk is operative downstream of KRAS in NSCLC. Previously we demonstrated that Crk receives oncogenic signals from PAK1. These data in conjunction with the work of others that have specified the role of PAK1 in transduction of KRAS signal bring forward the importance of KRAS/PAK1/Crk axis as a prominent pathway in the oncogenesis of KRAS mutant lung cancer
Posterior sub-Tenon capsule anesthesia for photocoagulation treatment of diabetic retinopathy performed in an inner-city county hospital clinic setting
poster abstractProliferative diabetic retinopathy (PDR) is a blinding eye disease demanding prompt therapy. However, treatment with panretinal photocoagulation (PRP) can be painful thereby limiting its extent. In addition, compliance to diabetic eye visits remains poor particularly in inner cities. Therefore, it is imperative to optimize treatment during clinic visits. The purpose of this study is to present the effect of sub-Tenon (Sub-T) capsule lidocaine anesthesia on PRP treatment extent for PDR performed during the eye clinic visit. This is an IRB-approved retrospective review of initial 12 eyes (9 subjects) with PDR undergoing PRP treatment involving Sub-T anesthesia in the eye clinic. Sub-T capsule lidocaine anesthesia was delivered and PRP was immediately performed. Primary end point was extent of treatment (number of PRP laser spots) delivered. Comparison was made to PRP in prior sessions without Sub-T anesthesia. All subjects had active PDR and sometimes vitreous hemorrhage (VH) at time of treatment. Decision was made to offer Sub-T anesthesia due to intolerable pain from prior PRP treatments in all subjects. We observed all subjects were able to tolerate a significantly greater extent of PRP with Sub-T anesthesia even with presence of VH, oftentimes undergoing thousands of laser spots and capable to complete treatment in same clinic visit. By comparison, prior PRP treatments (without Sub-T anesthesia) were much less extensive sometimes involving only a few laser spots. We conclude that Sub-T anesthesia allows a tier of pain control for those not able to tolerate traditional PRP without anesthesia performed in the eye clinic. This new information suggests that certain patients undergoing PRP can be offered Sub-T anesthesia, and it will be important to define algorithm for selection of such individuals
Practical Flapping Mechanisms for 20cm-span Micro Air Vehicles
[[abstract]]In the body of research relevant to high-performance flapping micro air vehicles (MAV), development of light-weight, compact and energy-efficient flapping mechanisms occupies a position of primacy due to its direct impact on the flight performance and mission capability. Realization of such versatile flapping mechanism with additional ability of producing thrust levels that fulfill requirements of cruising forward flight and vertical take-off and landing (VTOL) conditions demand extensive design validation and performance evaluation. This paper presents a concerted approach for mechanism development of a 20 cm span flapping MAV through an iterative design process and synergistic fabrication options involving electrical-discharge-wire-cutting (EDWC) and injection molding. Dynamic characterization of each mechanism is done through high speed photography, power take-off measurement, wind tunnel testing and proof-of-concept test flights. The research outcome represents best-in-class mechanism for a 20 cm span flapping MAV with desirable performance features of extra-large flapping stroke up to 100°, minimal transverse vibrations and almost no phase lag between the wings.[[notice]]補æ£å®Œç•¢[[journaltype]]國外[[incitationindex]]SCI[[ispeerreviewed]]Y[[booktype]]紙本[[countrycodes]]US
Myelodysplastic/Myeloproliferative Neoplasms
Myeloid malignancies exemplified by acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and myeloproliferative neoplasms (MPNs) are all characterized by abnormal proliferation of stem cells. AML is characterized by proliferation of myeloid blasts that ultimately perturb normal bone marrow (BM) function and suppress hematopoiesis. The hallmarks of MDS are cytopenias (anemia, leukopenia, or thrombocytopenia), impaired differentiation in one or more of myeloid cell lines, and ineffective hematopoiesis (Tiu et al. 2011a). MPNs manifest with proliferation of one or more cell lines in the BM with accompanying BM fibrosis and extramedullary hematopoiesis (Fig. 1). When features of both MDS and MPN coexist in the same patient, the disease is called MDS/MPN overlap neoplasms. The recognition that some MDS patients have overlapping MPN features led to the coining of the term MDS/MPN overlap. This group was first described in 1997 at the clinical advisory meeting of the World Health Organization (WHO) (Harris et al. 1999) and later adapted in the 2001 WHO classification (Harris et al. 2001). As in the case of MDS and MPNs, MDS/MPN patients are also at risk for AML evolution. Within this overlapping class, four different disease entities were classified: Juvenile myelomonocytic leukemia (JMML), chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (BCR-ABL1 negative) (aCML), and MDS/MPN-unclassifiable (MDS/MPN-U), which also included the provisional disease category, refractory anemia with ring sideroblast associated with marked thrombocytosis (RARS-T). Of note, each of these disease entities has a defined natural history, influenced by a variety of factors such as BM blast counts, presence of concomitant diseases (e.g., systemic mastocytosis with associated clonal hematologic non-mast cell lineage disease [SM-AHNMD]), and different cytogenetic and epigenetic/molecular profile which may explain the clinicopathologic diversity of these diseases
Beta-Blocker Use Is Associated With Impaired Left Atrial Function in Hypertension
BACKGROUND: Impaired left atrial (LA) mechanical function is present in hypertension and likely contributes to various complications, including atrial arrhythmias, stroke, and heart failure. Various antihypertensive drug classes exert differential effects on central hemodynamics and left ventricular function. However, little is known about their effects on LA function.
METHODS AND RESULTS: We studied 212 subjects with hypertension and without heart failure or atrial fibrillation. LA strain was measured from cine steady-state free-precession cardiac MRI images using feature-tracking algorithms. In multivariable models adjusted for age, sex, race, body mass index, blood pressure, diabetes mellitus, LA volume, left ventricular mass, and left ventricular ejection fraction, beta-blocker use was associated with a lower total longitudinal strain (standardized beta=-0.21; P=0.008), and lower LA expansion index (standardized beta=-0.30; P \u3c 0.001), indicating impaired LA reservoir function. Beta-blocker use was also associated with a lower positive strain (standardized beta=-0.19; P=0.012) and early diastolic strain rate (standardized beta=0.15; P=0.039), indicating impaired LA conduit function. Finally, beta-blocker use was associated with a lower (less negative) late-diastolic strain (standardized beta=0.15; P=0.049), strain rate (standardized beta=0.18; P=0.019), and a lower active LA emptying fraction (standardized beta=-0.27; P\u3c 0.001), indicating impaired booster pump function. Use of other antihypertensive agents was not associated with LA function.
CONCLUSIONS: Beta-blocker use is significantly associated with impaired LA function in hypertension. This association could underlie the increased risk of atrial fibrillation and stroke seen with the use of beta-blockers (as opposed to other antihypertensive agents) demonstrated in recent trials
Gene expression and splicing alterations analyzed by high throughput RNA sequencing of chronic lymphocytic leukemia specimens.
BackgroundTo determine differentially expressed and spliced RNA transcripts in chronic lymphocytic leukemia specimens a high throughput RNA-sequencing (HTS RNA-seq) analysis was performed.MethodsTen CLL specimens and five normal peripheral blood CD19+ B cells were analyzed by HTS RNA-seq. The library preparation was performed with Illumina TrueSeq RNA kit and analyzed by Illumina HiSeq 2000 sequencing system.ResultsAn average of 48.5 million reads for B cells, and 50.6 million reads for CLL specimens were obtained with 10396 and 10448 assembled transcripts for normal B cells and primary CLL specimens respectively. With the Cuffdiff analysis, 2091 differentially expressed genes (DEG) between B cells and CLL specimens based on FPKM (fragments per kilobase of transcript per million reads and false discovery rate, FDR q < 0.05, fold change >2) were identified. Expression of selected DEGs (n = 32) with up regulated and down regulated expression in CLL from RNA-seq data were also analyzed by qRT-PCR in a test cohort of CLL specimens. Even though there was a variation in fold expression of DEG genes between RNA-seq and qRT-PCR; more than 90 % of analyzed genes were validated by qRT-PCR analysis. Analysis of RNA-seq data for splicing alterations in CLL and B cells was performed by Multivariate Analysis of Transcript Splicing (MATS analysis). Skipped exon was the most frequent splicing alteration in CLL specimens with 128 significant events (P-value <0.05, minimum inclusion level difference >0.1).ConclusionThe RNA-seq analysis of CLL specimens identifies novel DEG and alternatively spliced genes that are potential prognostic markers and therapeutic targets. High level of validation by qRT-PCR for a number of DEG genes supports the accuracy of this analysis. Global comparison of transcriptomes of B cells, IGVH non-mutated CLL (U-CLL) and mutated CLL specimens (M-CLL) with multidimensional scaling analysis was able to segregate CLL and B cell transcriptomes but the M-CLL and U-CLL transcriptomes were indistinguishable. The analysis of HTS RNA-seq data to identify alternative splicing events and other genetic abnormalities specific to CLL is an added advantage of RNA-seq that is not feasible with other genome wide analysis
Validation of a deep neural network-based algorithm supporting clinical management of adnexal mass
BackgroundConservative management of adnexal mass is warranted when there is imaging-based and clinical evidence of benign characteristics. Malignancy risk is, however, a concern due to the mortality rate of ovarian cancer. Malignancy occurs in 10–15% of adnexal masses that go to surgery, whereas the rate of malignancy is much lower in masses clinically characterized as benign or indeterminate. Additional diagnostic tests could assist conservative management of these patients. Here we report the clinical validation of OvaWatch, a multivariate index assay, with real-world evidence of performance that supports conservative management of adnexal masses.MethodsOvaWatch utilizes a previously characterized neural network-based algorithm combining serum biomarkers and clinical covariates and was used to examine malignancy risk in prospective and retrospective samples of patients with an adnexal mass. Retrospective data sets were assembled from previous studies using patients who had adnexal mass and were scheduled for surgery. The prospective study was a multi-center trial of women with adnexal mass as identified on clinical examination and indeterminate or asymptomatic by imaging. The performance to detect ovarian malignancy was evaluated at a previously validated score threshold.ResultsIn retrospective, low prevalence (N = 1,453, 1.5% malignancy rate) data from patients that received an independent physician assessment of benign, OvaWatch has a sensitivity of 81.8% [95% confidence interval (CI) 65.1–92.7] for identifying a histologically confirmed malignancy, and a negative predictive value (NPV) of 99.7%. OvaWatch identified 18/22 malignancies missed by physician assessment. A prospective data set had 501 patients where 106 patients with adnexal mass went for surgery. The prevalence was 2% (10 malignancies). The sensitivity of OvaWatch for malignancy was 40% (95% CI: 16.8–68.7%), and the specificity was 87% (95% CI: 83.7–89.7) when patients were included in the analysis who did not go to surgery and were evaluated as benign. The NPV remained 98.6% (95% CI: 97.0–99.4%). An independent analysis set with a high prevalence (45.8%) the NPV value was 87.8% (95% CI: 95% CI: 75.8–94.3%).ConclusionOvaWatch demonstrated high NPV across diverse data sets and promises utility as an effective diagnostic test supporting management of suspected benign or indeterminate mass to safely decrease or delay unnecessary surgeries
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