Ranking Functions for Size-Change Termination II

Size-Change Termination is an increasingly-popular technique for verifying program termination. These termination proofs are deduced from an abstract representation of the program in the form of "size-change graphs". We present algorithms that, for certain classes of size-change graphs, deduce a global ranking function: an expression that ranks program states, and decreases on every transition. A ranking function serves as a witness for a termination proof, and is therefore interesting for program certification. The particular form of the ranking expressions that represent SCT termination proofs sheds light on the scope of the proof method. The complexity of the expressions is also interesting, both practicaly and theoretically. While deducing ranking functions from size-change graphs has already been shown possible, the constructions in this paper are simpler and more transparent than previously known. They improve the upper bound on the size of the ranking expression from triply exponential down to singly exponential (for certain classes of instances). We claim that this result is, in some sense, optimal. To this end, we introduce a framework for lower bounds on the complexity of ranking expressions and prove exponential lower bounds.Comment: 29 pages

Sponges from North Borneo and their bioactivity against human colorectal cancer cells

Sponges are major source of numerous cytotoxic compounds that are used for defence as well as adaptation to the environment. Numerous studies have discovered compounds from sponge extracts that were effective against a wide range of cancer cells. In this study, a total of 23 sponges comprising of 19 species were collected from Northeast Borneo. Sponges were treated and extracted using modified Folch extraction method, followed by cytotoxicity assay to determine their effectiveness against different colorectal cancer cells. Our results demonstrate that Monanchora clathrata, Dysidea sp., and Jaspis sp. possess different degrees of cytotoxicity against a wide range of human colorectal cancer cells. Monanchora clathrata (KDT07), Dysidea sp. (KDT09), and Jaspis sp. (KDT18) are among the demosponges which possess significant cytotoxicity against colorectal cancer cell lines, including HCT116, LoVo, SW480, and SW620. KDT08 and KDT21 which fall under the same genus Dysidea, possess insignificant cytotoxicity against colorectal cancer cells suggested environmental factors (symbiotic organisms) play a role in biosynthesizing bioactive compounds. Presented results suggested the importance of intensifying research on isolating and purifying natural products from marine sponges for useful applications

Efficient micropropagation of Dendrobium aurantiacum from shoot explant

Embryogenic tissue culture (seed tissue culture) is a common practice in plant industry to speed up and mass production. However, the culture method is not widely adopted in most of the orchid species. Micro-size orchid seeds are difficult to obtain and collect due to ambiguous seed maturation period. Most of orchid seeds have no endosperm and highly dependent on the specific fungi for germination and survival. Micropropagation from shoot culture with meristem tissue is potentially be another alternative for mass propagation of orchid. Therefore, this study examine the potential of micropropagation technique by shoot culture in orchid, Dendrobium aurantiacum (F. Muell.) F. Muell. This study reported an effective aseptic technique to develop sterilized D. aurantiacum tissue in vitro. The callus induction and regeneration from shoot explant by utilization of different plant growth regulator had been examined in this study. Among the treatments, 20% sodium hypochlorite with 15 mins sterilization period showed the highest sterilization efficiency on explants with only 16.7±5.8% of contamination occurred after two weeks and obtained highest survival rate 73.3±5.8% after one month. Callus formed in all combinations of plant hormone treatments. Media treated with 10 mg/L 2,4-D showed the highest callus induction rate but browning condition occur after 3 months of culture. Cell count on callus proliferation showed a significant difference (p < 0.05) between control and treatments. In conclusion, micropropagation of D. aurantiacum had been shortened almost 9-12 months required for nature germination

Fuzzy mathematical model for solving supply chain problem

In a real world application supply chain, there are many elements of uncertainty such as supplier performance, market demands, product price, operation time, and shipping method which increases the difficulty for manufacturers to quickly respond in order to fulfil the customer requirements. In this paper, the authors developed a fuzzy mathematical model to integrate different operational functions with the aim to provide satisfy decisions to help decision maker resolve production problem for all functions simultaneously. A triangular fuzzy number or possibilistic distribution represents all the uncertainty parameters. A comparison between a fuzzy model, a possibilistic model and a deterministic model is presented in this paper in order to distinguish the effectiveness of model in dealing the uncertain nature of supply chain. The proposed models performance is evaluated based on the operational aspect and computational aspect. The fuzzy model and the possibilistic model are expected to be more preferable to respond to the dynamic changes of the supply change network compared to the deterministic model. The developed fuzzy model seems to be more flexible in undertaking the lack of information or imprecise data of a variable in real situation whereas possibilistic model is more practical in solving an existing systems problem that has available data provided

Androgenic and Estrogenic Response of Green Mussel Extracts from Singapore’s Coastal Environment Using a Human Cell-Based Bioassay

In the last decade, evidence of endocrine disruption in biota exposed to environmental pollutants has raised serious concern. Human cell-based bioassays have been developed to evaluate induced androgenic and estrogenic activities of chemical compounds. However, bioassays have been sparsely applied to environmental samples. In this study we present data on sex hormone activities in the green mussel, Perna viridis, in Singapore’s coastal waters. P. viridis is a common bioindicator of marine contamination, and this study is a follow-up to an earlier investigation that reported the presence of sex hormone activities in seawater samples from Singapore’s coastal environment. Specimens were collected from eight locations around the Singapore coastline and analyzed for persistent organic pollutants (POPs) and heavy metals. Tissue extracts were then screened for activities on androgen receptors (ARs) and estrogen receptors (ER-α and ER-β) using a reporter gene bio-assay based on a HeLa human cell line. Mussel extracts alone did not exhibit AR activity, but in the presence of the reference androgenic hormone dihydrotestosterone (DHT), activities were up to 340% higher than those observed for DHT alone. Peak activities were observed in locations adjacent to industrial and shipping activities. Estrogenic activities of the mussel extract both alone and in the presence of reference hormone were positive. Correlations were statistically investigated between sex hormone activities, levels of pollutants in the mussel tissues, and various biological parameters (specimen size, sex ratio, lipid and moisture content). Significant correlations exist between AR activities, in the presence of DHT, and total concentration of POPs (r = 0.725, p < 0.05)

Predicting the catalytic sites of isopenicillin N synthase (IPNS) related non-haem iron-dependent oxygenases and oxidases (NHIDOX) through a structural superimposition and molecular docking approach

Isopenicillin N synthase (IPNS) related Non-haem iron-dependent oxygenases and oxidases (NHIDOX) demonstrated a striking structural conservativeness, even with low protein sequence homology. It is evident that these enzymes have an architecturally similar catalytic centre with active ligands lining the reactive pocket. Deacetoxycephalosporin C synthase (DAOCS), isopenicillin N synthase (IPNS), deacetylcephalosporin C synthase (DACS), clavaminate synthase 1 and 2 (CAS1 and 2) are important bacterial enzymes that catalyze the formation of β-lactam antibiotics belonging to this enzyme family. Most plant enzyme members within this subfamily namely flavonol synthase (FLS), leucoanthocyanidin dioxygenase (LDOX), anthocyanidin synthase (ANS), 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO), gibberellin 20-oxidase (G20O), desacetoxyvindoline-4-hydroxylase (D4H), flavanone 3β-hydroxylase (F3H), and hyoscyamine 6β-hydroxylase (H6H) are involved in catalyzing the biosyntheses of plant secondary metabolites. With the advancement of protein structural analysis software, it is possible to predict the catalytic sites of protein that shared a structural resemblance. By exploiting the superimposition model of DAOCS-IPNS, DAOCS-IPNS-CAS, G20O-LDOX, FLS-LDOX, ACCO-LDOX, D4H-LDOX, F3H-LDOX and H6H-LDOX model; a computational protocol for predicting the catalytic sites of proteins is now made available. This study shows that without the crystallized or nuclear magnetic resonance (NMR) structures of most NHIDOX enzyme, the plausible catalytic sites of protein can be forecasted using this structural bioinformatics approach.Keywords: Enzyme, catalytic sites, isopenicillin N synthase, ligand

Chfr is linked to tumour metastasis through the downregulation of HDAC1

Chfr is a ubiquitin ligase that functions in the mitotic checkpoint by delaying entry into metaphase in response to mitotic stress. It has been suggested that Chfr is a tumour suppressor as Chfr is frequently silenced in human cancers. To better understand how Chfr activity relates to cell-cycle progression and tumorigenesis, we sought to identify Chfr-interacting proteins using affinity purification combined with mass spectrometry. Histone deacetylase 1 (HDAC1), which represses transcription by deacetylating histones, was newly isolated as a Chfr-interacting protein. Chfr binds and downregulates HDAC1 by inducing its polyubiquitylation, both in vitro and in vivo. Ectopic expression of Chfr in cancer cells that normally do not express it results in downregulation of HDAC1, leading to upregulation of the Cdk inhibitor p21^(CIP1/WAF1) and the metastasis suppressors KAI1 and E-cadherin. Coincident with these changes, cells arrest in the G1 phase of the cell cycle and become less invasive. Collectively, our data suggest that Chfr functions as a tumour suppressor by regulating HDAC1

The Use of Complementary and Alternative Medicine in a General Population in South Korea: Results from a National Survey in 2006

The purpose of this survey was to obtain information on the prevalence, costs, and patterns of use of complementary and alternative medicine (CAM) in a general population in the Republic of Korea. In 2006, we conducted nationwide and population-weighted personal interviews with 6,021 adults ranging from 30 to 69 yr of age; the final sample consisted of 3,000 people with a 49.8% response rate. In addition to their general socio-demographics, the respondents were asked about their use of CAM during the previous 12-month period, costs, sources of information, and reasons for use. The prevalence of use overall was 74.8%, while biologically based CAM therapies were the most likely type of use (65.4%). The median annual out-of-pocket expenditures for CAM therapies was about US$203. The primary reason for using CAM was for disease prevention and health promotion (78.8%). The main source of advice about CAM therapies use was most likely to be from family and friends (66.9%). Our study suggests that CAM use has been and continues to be very popular in South Korea. Conventional western medical doctors and governments should obtain more evidence and become more interested in CAM therapies

Influence of surgery involving tendons around the knee joint on ankle motion during gait in patients with cerebral palsy

Background Simultaneous motion of the knee and ankle joints is required for many activities including gait. We aimed to evaluate the influence of surgery involving tendons around the knee on ankle motion during gait in the sagittal plane in cerebral palsy patients. Methods We included data from 55 limbs in 34 patients with spastic cerebral palsy. Patients were followed up after undergoing only distal hamstring lengthening with or without additional rectus femoris transfer. The patients mean age at the time of knee surgery was 11.2 ± 4.7 years, and the mean follow-up duration was 2.2 ± 1.5 years (range, 0.9–6.0 years). Pre- and postoperative kinematic variables that were extracted from three-dimensional gait analyses were then compared to assess changes in ankle motion after knee surgery. Outcome measures included ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, peak ankle dorsiflexion during swing, and dynamic range of motion of the ankle. Various sagittal plane knee kinematics were also measured and used to predict ankle kinematics. A linear mixed model was constructed to estimate changes in ankle motion after adjusting for multiple factors. Results Improvement in total range of motion of the knee resulted in improved motion of the ankle joint. We estimated that after knee surgery, ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, peak ankle dorsiflexion during swing, and dynamic range of motion of the ankle decreased, respectively, by 0.4° (p = 0.016), 0.6° (p < 0.001), 0.2° (p = 0.038), and 0.5° (p = 0.006) per degree increase in total range of motion of the knee after either knee surgery. Furthermore, dynamic range of motion of the ankle increased by 0.4° per degree increase in postoperative peak knee flexion during swing. Conclusions Improvement in total knee range of motion was found to be correlated with improvement in ankle kinematics after surgery involving tendons around the knee. As motion of the knee and ankle joints is cross-linked, surgeons should be aware of potential changes in the ankle joint after knee surgery.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (NRF-2016R1C1B2008557), and was partly supported by the Technology Innovation Program funded By the Ministry of Trade, Industry and Energy (MOTIE) of Korea (10049785) and SNUBH research fund (grant no. 02-2012-018). No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article

What Are the Risk Factors Associated with Urinary Retention after Orthopaedic Surgery?

This study investigates the overall rate of urinary retention in a large cohort of unselected orthopaedic patients who had either general or regional anesthesia and defines the risk factors for postoperative urinary retention in that cohort of patients. A total of 15,681 patients who underwent major orthopaedic surgery with general or spinal/epidural anesthesia were included. Postoperative urinary retention was defined as any patient who required a postoperative consultation to the urologic department regarding voiding difficulty. Age at surgery, sex, type of surgery, medical history including hypertension and diabetes mellitus, and type of anesthesia were analyzed as potential predictor variables. There were 365 postoperative patients who required urology consults for urinary retention (2.3%). Older age at surgery (OR, 1.035; &lt; 0.0001), male sex (OR, 1.522; = 0.0004), type of surgery (OR, 1.506; = 0.0009), history of hypertension (OR, 1.288; = 0.0436), and history of diabetes mellitus (OR, 2.038; &lt; 0.0001) were risk factors for urinary retention after orthopaedic surgery. Advanced age, male sex, joint replacement surgery, history of hypertension, and diabetes mellitus significantly increased the risk of urinary retention. In patients with these risk factors, careful postoperative urological management should be performed