Memoized Symbolic Execution

This paper introduces memoized symbolic execution (Memoise), a novel approach for more efficient application of forward symbolic execution, which is a well-studied technique for systematic exploration of program behaviors based on bounded execution paths. Our key insight is that application of symbolic execution often requires several successive runs of the technique on largely similar underlying problems, e.g., running it once to check a program to find a bug, fixing the bug, and running it again to check the modified program. Memoise introduces a trie-based data structure that stores the key elements of a run of symbolic execution. Maintenance of the trie during successive runs allows re-use of previously computed results of symbolic execution without the need for re-computing them as is traditionally done. Experiments using our prototype embodiment of Memoise show the benefits it holds in various standard scenarios of using symbolic execution, e.g., with iterative deepening of exploration depth, to perform regression analysis, or to enhance coverage

Acute myeloid leukemia in children in Pakistan: an audit

Objective: To see the clinical features and treatment of children with Acute Myeloid Leukemia (AML) in Pakistan. Setting: Tertiary referral at a specialist Hematology/Oncology center. Methods: Retrospective, chart-based review of children (less than 14 years) admitted to the hospital with a diagnosis of AML between January 1987 and August 1997. Results: A total of 23 patients were admitted. There were 18 males and 5 females. The mean age was 8 5 years. M3 was the commonest morphological subtype (43%). Twenty- two percent of the patients presented with hyperleucocytosis (TLC\u3e 100 x i09 /L) and 95% with an elevated LDH (\u3e548 lUlL). Pneumonia at presentation was seen in 29%. Of 23 patients 14 were evaluable for responses. Six patients died early (43%); 3 before starting the chemotherapy and 3 during the induction chemotherapy, 8/11 (73%) patients entered remission. The median survival was 9 months. Conclusion: The pediatric patients with acute myeloid leukemia present with advanced disease. There is a high early death rate (within 28 days of diagnosis). The long-term outcome was inferior to that reported in the literature (JPMA 52:247; 2002)

Novel heuristic for low-batch manufacturing process scheduling optimisation with reference to process engineering

YesScheduling is an important element that has a major impact on the efficiency of all manufacturing processes. It plays an important role in optimising the manufacturing times and costs resulting in energy efficient processes. It has been estimated that more than 75% of manufacturing processes occur in small batches. In such environments, processes must be able to perform a variety of operations on a mix of different batches. Batch-job scheduling optimisation is the response to such low batch manufacturing problems. The optimisation of batch-job process scheduling problem is still a challenge to researchers and is far from being completely solved due to its combinatorial nature. In this paper, a novel hybrid heuristic (HybH) solution approach for batch-job scheduling problem is presented with the objective of optimising the overall Makespan (Cmax). The proposed HybH is the combination of Index Based Heuristic (IBH) and the Finished Batch-Job (FBJ) process schedule. The heuristic assigns the first operation to a batch-job using IBH and the remaining operations on the basis FBJ process schedule. The FBJ process schedule gives priority to the batch-job with early finished operations, without violating the constraints of process order. The proposed HybH is explained with the help of a detailed example. Several benchmark problems are solved from the literature to check the validity and effectiveness of the proposed heuristic. The presented HybH has achieved batch-job process schedules which have outperformed the traditional heuristics. The results are encouraging and show that the proposed heuristic is a valid methodology for batch process scheduling optimisation

Optimization of glucose oxidase production by Aspergillus niger

The glucose oxidase was produced by fermentation using Aspergillus niger isolated from potato as producer organism and glucose as the carbon source (substrate). Maximum production of the enzyme (1.59 ìmoleHQMin-1ml-1) was achieved at 10% glucose concentration after 48 h of submerged fermentation. The pH for the optimal production of enzyme was found to be 5.5 (enzyme activity 1.56 ìmoleHQMin-1ml-1). Addition of urea (0.2%) and KH2PO4 (0.4%) into the fermentation medium increases enzyme activity (2.01 and 2.96 ìmoleHQMin-1ml-1, respectively) while MgSO4·7H2O was found to inhibit GOX production by A. niger.Key words: Glucose oxidase, Aspergillus niger, glucose oxidase

Outcome of adult patients with acute lymphoblastic leukaemia receiving the MRC UKALL XII protocol: a tertiary care centre experience

Introduction:Acute lymphoblastic leukaemia (ALL) is a heterogeneous group of lymphoid neoplasm resulting from the proliferation of malignant lymphoid cells. We aimed to study the outcome of adult Patients with ALL receiving the Medical Research Council UKALL XII protocol. Methods: This was a retrospective study conducted at Aga Khan University Hospital from January 2001 to December 2008. The medical records of all adult Patients were reviewed and analysed for clinical, morphological and immunological features at presentation and impact on treatment outcomes. Multivariate analysis and survival studies were performed using Kaplan-Meier statistics. Results: The total number of Patients was 54, with a male to female ratio of 3.4:1 and a median age of 28 years. Common presenting symptoms were fever (n is 49) and bleeding (n is 14). 38 Patients had haemoglobin less than 10 gms/dl, 21 had white blood cell (WBC) count of 50 x 10E9/L or more, and 35 had lactate dehyrogenase more than 1,000 IU. Morphologically, FAB-L2 was the commonest subtype, with 38 Patients with B-ALL and eight with T-ALL. Multivariate analysis showed that age above 30 years, male gender, WBC count above 50 x 10E9/L and T-ALL subtype were independent risk factors for poor survival. 46 (85 percent) Patients achieved complete remission. The median survival was 12.3 months. At the end of five years, 16 Patients were alive, two were alive with disease and 14 were in complete remission. Conclusion: Overall survival and relapse rates in our study were comparable to those reported internationally

Cardiovascular risk factors in school children from low middle income families in Karachi, Pakistan

Serum levels of total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and trigly cerides (TG) were determined on 239 school children aged 5-19 years belonging to lower middle class families. The mean TC, LDL-C, HDL-C and TG ranged from 3.70-4.37 mmol/L, 2.17- 2.70 mmol/L, 0.94-1.14 mmol/L, 1.07-1.26 mmol/L respectively. In general, girls had higher TC, LDL-C and HDL-C levels. There was no significant difference in the TG levels between boys and girls. Thirty-three percent of the girls and 22% of the boys had TC level _4.4 mmol/L, the level at which dietary intervention is recommended for children. Fifty-three percent of the girls and 37% of the boys bad TG levels _ than the 90th percentile of the levels for children of similar age and sex in North America. The HDL-C levels were low with 37% of the girls and 44% of boys having values _ the lath percentile of levels for North American children. The mean daily intake of cholesterol ranged from 241 mg to 364 mg/day. Except for the 5-9 year olds, boys had a higher cholesterol intake than girls (P\u3c0.005). Twenty-two percent of the boys and 32% of the girls were overweight but weight status was significantly associated with elevated TC levels only in the boys (P \u3c0.05). Activity level was not significantly related to TC levels but girls who were active had significantly higher HDL-C levels than girls who were sedentary (P \u3c0.02). Family history of cardiovascular disease was significantly associated with elevated cholesterol levels in girls (P \u3c0.05). The results show that the prevalence of cardiovascular risk factors in these school children is relatively high even though they belong to lower middle class families in a developing countr

Carmen: Software Component Model Checker

International audienceThe challenge of model checking of isolated software components becomes more and more relevant with the boom of component-oriented technologies [20]. An important issue here is how to verify an open model representing an isolated software component (also referred as the missing environment problem in [17]). In this paper, we propose on-the-fly simulation of the component environment to address the issue. We employ behavior protocols [18] and a system coordinating two model checkers: Java PathFinder [4] and BPChecker [15]. This approach allows us to enclose the model represent- ing the behavior of a given component and consequently to exhaustively verify the model. Our solution was implemented as the Carmen tool [1]. We demonstrate scalability of our approach on real-life examples and show that, in comparison with the COMBAT model checker [17], we bring better performance, and also exhaustive and correct verification

Luminescent, sorptive and antibacterial potential of bismuth-organic framework

Metal organic frameworks are formed by the three-dimensional linkage of metal cores and organic linkers. In this work, bismuth-based metal organic framework (Bi-MOF) has been synthesized by using 5-hydroxyisophthalic acid (H2HIA) as linker via hydrothermal method. The said MOF was structurally characterized by UV/Vis, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), 1H NMR, energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA) and X-ray diffraction technique. This MOF showed highly porous structure with surface area 1096 m2/g as determined by BET analysis. A model batch adsorption experiment was performed to evaluate the efficiency of methylene blue (MB) dye removal from aqueous media. It was found that monolayer adsorption capacity calculated from the Langmuir isotherm was 0.6240 mg/g. Bi-MOF was also screened for its antibacterial and luminescent behavior.                     KEY WORDS: Bismuth, Metal-organic Frameworks, Luminescence, Sorption   Bull. Chem. Soc. Ethiop. 2021, 35(1), 119-128. DOI: https://dx.doi.org/10.4314/bcse.v35i1.1