The Semantics and Complexity of Succesor-free Nondeterministic Gödel's T

We develop a model for a successor-free nondeterministic flavour of Gödel’s T, which is built with particular consideration made to keep it as convenient to compute as possible, while still being adequate. We desire this convenience since we will use deterministic programs to compute the interpretation of nondeterministic programs, and from this establish a relationship between deterministic and nondeterminstic complexity classes

Assessment of Heavy Metals in Soils and Tuber Crops on Ex-Mining Land of Southern Perak, Malaysia

Large areas of ex-mining lands in Southern Perak, Malaysia, are used for the cultivation of vegetables, fruits and tuber crops due to the shortage of land for agricultural productions. These areas have been cultivated for more than 20 years. Recent studies have reported that ex-mining land used for the cultivation of tuber crops and some fruits were found to be contaminated by heavy metals. Heavy metals concentrations may be high due to the use of high amounts of organic fertilizers (chicken dung) and agrochemicals (fertilizers, pesticides). There is a growing concern and awareness amongst consumers that long term addition of fertilizers may accumulate heavy metals in soil and taken up by tuber crops grown in the ex-mining lands. Heavy metals are known to cause detrimental health effects to human. Thus, a study concerning heavy metals contamination on tuber crops cultivated on ex-mining lands had been conducted. iii Four major cultivation areas were selected for this study namely; Kg. Baharu Bikam, Tapah Road, Pekan Pasir and Kg. Baru Cold Stream. The farms in these areas were found to be the largest tuber crops production in southern Perak. In the cultivated areas, sampling sites were chosen where the tuber crops were ready for harvest. Each sampling site, 3 soil samples and tuber crops were sampled. The three soil samples from each point were combined to form a composite sample. The soils were collected by using a stainless steel auger. An hundred eighty soil samples were collected from the cultivated soils which is 60 soil samples for each 3 depths (0-20 cm, 20-40 cm and 40-60 cm). While only 60 soil samples were collected on topsoil (0-20 cm) from the uncultivated exmining lands. The uncultivated soils were collected for the determination of heavy metals and used as background values (control). An overall total of 240 soil samples were taken from the cultivated and uncultivated soils. The crops selected were tuber crops such as tapioca, yam bean, sweet potatoes and Chinese radish. For each sampling site, geographic coordinates were recorded using global positioning system (GPS). The soils were air-dried, crushed, sieved to pass 2 mm sieve and analysed for the texture, mineralogy, pH, total organic carbon (OC), cation exchangeable capacity (CEC), total heavy metals content (Pb, Ni, Zn, Cd and Cu) and available heavy metals extracted with three different extractants i.e. 0.1 N HCI, EDTA and DTPA. While heavy metals in tuber crops were extracted using dry-ashing method. The heavy metals (Pb, Ni, Zn, Cd and Cu) were determined by Atomic Absorption Spectrophotometer (AAS). From this study, it was found that, the uncultivated soils in the study areas can be categorized according to their texture i.e sand, sandy clay loam and sandy loam. Sand texture consists of 89.5 to 91.5% sand and very low clay content (7- 10%). Sandy clay loam texture consists of 15.5 to 1 8.4 % sand and very high in clay content which is 41.8 to 42 %. Sandy loam consists of 12 to 19.5 % clay, 70 to 75.5% of sand and 15.5 to 18 % of silt. The pH of topsoils in the cultivated ex-mining soils of southern Perak had a mean value of 6.08. The mean cation exchange capacity of the cultivated exmining soils was 0.77 cmo1,kg-' soil. The soils have a mean organic carbon content of 0.66 %. On the other hand, soils in the uncultivated lands have pH, CEC, OC, with the values of 4.56, 0.35 cmolJcg-' and 0.31 %, respectively. Generally, there is a significant increase at p5 0.05 of pH, OC and CEC in the cultivated soils. Mean concentration of Zn in the cultivated soil was the highest followed by Pb, Cu, Ni and Cd, with values of 15.84 mgkg-', 10.43 rngkg-', 4.20 mgkg-', 3.07 me', and 0.84 mgkg-', respectively. In the uncultivated soil, a similar trend in heavy metal concentrations was observed for Zn, Pb, Cu, Ni and Cd with mean values of 8.09 mgkg-', 5.78 mgkg-', 1 .I9 mgkg-', 1 .OO rngkg-' and 0.69 mgkg-', respectively. T-test analysis showed that metal concentrations in cultivated soils are significantly higher at p10.05 level than in uncultivated soil except for Cd. However, both levels are still below the critical heavy metal concentrations limits in agricultural soils of Peninsular Malaysia and the concentration ranges (using the 95th percentile), except for Cd. Total Pb and Cd concentration in soil were significantly positive correlated with available Pb using 0.1N HCl extractant (r = 0.41*, n= 60) available Cd using DTPA (r= 0.23*, n=60). On the other hand, total Ni in soil was significantly negative correlated with available Ni using DTPA (I=-0.38, n=60). Regardless of the extraction methods used (O.1N HCl, EDTA or DTPA), no significant correlation was found between total Cu and Zn in soil and available Cu and Zn. Correlation analysis between heavy metals in tuber crops with available heavy metals indicates that, there was no relationship between total heavy metals in the tuber crops and available heavy metals in soil using different extraction methods except for Zn and Cu, which have a negative correlation using 0.1 N HCI (r = -0.25*, n= 60) and DTPA (I-=-0.22*, n=60), respectively. Amongst all of the crops studied, Chinese radish, tapioca and sweet potato contains the highest concentration of 15.33 mgkg-' Zn, 0.85 mgkg-' Pb and 0.12 mgkg-I Cd, respectively. On the other hand, yam bean showed that the lowest concentration of Zn, Cd, Cu and Ni with values of 2.41 mgkg-', 0.07 mgkg-', 0.63 mgkg-' and 0.56 mgkg-I, respectively. Lead is significant higher at pi0.05 in yam bean than in sweet potato and Chinese radish. There is no significant difference in the concentrations of Cd in all tuber crops studied. Copper show significant higher in tapioca than in sweet potato followed by Chinese radish and yam bean. Zinc concentration is significantly higher in Chinese radish than in tapioca, sweet potato and yam bean, while Ni is significantly higher in Chinese radish than in yam bean. Results from this study show an increased concentration of heavy metals in Chinese radish followed by tapioca, sweet potato and yam bean, but the heavy metals levels of all the tuber crops studied were still below the Maximum Permissible Concentration (MPC) as stated in the Malaysia Food Act (1983) and Food Regulation (1 985). Spatial distribution map is usefkl to detect the spatial area, which are low, optimum or high in heavy metal concentration. Tapah Road areas have the highest concentration of heavy metals in all elements studied with Zn value of 17.41 mgkg-', followed by Pb, Cu, Ni and Cd. On the other hand, Kg. Baharu Bikam has the lowest concentration for all elements. Statistical analyses indicate that there is no significant difference at p10.05 of heavy metals content in soil among those areas. vi

Polyspecific snake antivenom: manufacturing method development and toxicity profiling using an invertebrate model

Snakebite envenoming (SBE) presents unmet challenges particularly in Sub-Saharan Africa (SSA). Almost all SBE in SSA is due to bites by snakes belonging to the Elapidae and Viperidae families. Antivenom is highly effective in treating SBE. However, there is unprecedented shortage of antivenoms in SSA. This requires a significant increase in production of high quality and cost-effective polyspecific antivenoms against the most clinically relevant snake species within the Elapidae and Viperidae families. A manufacturing process was developed to produce equine-derived whole IgG and F(ab’)2 polyvalent antivenoms against ten snake species belonging to the Bitis, Dendroaspis, Echis and Naja genera. Ion exchange chromatography was used to isolate IgG(T) from the rest of the equine IgG subclasses. The binding capacity of the IgG(T)-enriched and IgG(T)-depleted antivenoms was characterised using immunological assays. Galleria mellonella and Vero cell assays were developed to assess snake venom toxicity and antivenom efficacy. The F(ab’)2 antivenom produced in this study demonstrated excellent stability, physicochemical and immunological properties comparable to the original Fav- AfriqueTM product which was terminated in 2014. The IgG(T) subclass accounts for the majority of equine IgG isotype in hyperimmune horse plasma. However, the IgG(T)-depleted antivenom had a higher binding capacity and better venom toxin recognition pattern compared to the IgG(T)-enriched antivenom. The G. mellonella larval model exhibited a statistically significant difference in toxicity profiles between the viper and elapid snake species. Additionally, the larval model was able to differentiate the antivenom efficacy in protecting toxicity induced by the viper and elapid venoms. This supports the implementation of this model as a strong candidate to reduce or replace the current in vivo preclinical tests for snake venom toxicity and antivenom efficacy. Likewise, a dose-and species-dependent cytotoxicity effect was observed in Vero cells treated with viper and elapid venoms. Thus, the sensitivity of Vero cell cytotoxicity assays supports its inclusion as a quality control assay for antivenom

Accretion Product Formation from Ozonolysis and OH Radical Reaction of alpha-Pinene : Mechanistic Insight and the Influence of Isoprene and Ethylene

alpha-Pinene (C10H16) represents one of the most important biogenic emissions in the atmosphere. Its oxidation products can significantly contribute to the secondary organic aerosol (SOA) formation. Here, we report on the formation mechanism of C-19 and C-20 accretion products from alpha-pinene oxidation, which are believed to be efficient SOA precursors. Measurements have been performed in a free-jet flow system. Detection of RO2 radicals and accretion products was carried out by recent mass spectrometric techniques using different ionization schemes. Observed C-10-RO2 radicals from alpha-pinene ozonolysis were O,O-C10H15(O-2)(x)O-2 with x = 0, 1, 2, 3 and from the OH radical reaction HO-C10H16(O-2)(alpha)O-2 with alpha = 0, 1, 2. All detected C 20 accretion products can be explained via the accretion reaction RO2 + R'O-2 -> ROOR' + O-2 starting from the measured C-10-RO2 radicals. We speculate that C-19 accretion products are formed in an analogous way assuming CH2O elimination. Addition of isoprene (C5H8), producing C-5-RO2 radicals, leads to C-15 accretion products formed via cross-reactions with C-10-RO2 radicals. This process is competing with the formation of C-19/C-20 products from the pure alpha-pinene oxidation. A similar behavior has been observed for ethylene additives that form C-12 accretion products. In the atmosphere, a complex accretion product spectrum from self- and cross-reactions of available RO2 radicals can be expected. Modeling atmospheric conditions revealed that C-19/C-20 product formation is only reduced by a factor of 1.2 or 3.6 in isoprene-dominated environments assuming a 2- or 15-fold isoprene concentration over alpha-pinene, respectively, as present in different forested areas.Peer reviewe

Comparison of Attachment Styles, Family Functioning and Locus of Control in Individuals with and without Alcohol Use Disorder

This study aims to examine the variables of attachment styles , family functioning, and locus of control in individuals with and without alcohol use disorder. The 54 participants, including 51 male and 3 females with alcohol use disorder between the ages of 18-60s were chosen from the outpatients of xx service, the attendants of xx meetings, and the people referred by them. The control group consisted of 60 participants who were similar to the study group in terms of age and gender variables, without alcohol use disorder and psychological disorder. Data were collected through a questionnaire including Sociodemographic Data Form, Michigan Alcoholism Screening Test (MAST), Experiences in Close Relationships - Revised (ECR -R), Family Assessment Device (FAD), and Rotter’s Locus of Control Scale (LCS). In the results of the study, it was found that the participants with alcohol use disorder had a significantly higher ECR-R anxiety and avoidance score, and LCS score than the control group. Participants with the alcohol use disorder had a considerably lower FAD score than the control group. Finally, the effects of the applied scales on alcohol addiction are analyzed and it was concluded that the scores of FAD and LCS had a statistically significant effect on alcohol addiction. Accordingly, an increase in the FAD score by one unit reduces the alcohol addiction risk by %95, while an increase in the LCS score by one unit increases the alcohol addiction risk by %31

The visual development of hand-centered receptive fields in a neural network model of the primate visual system trained with experimentally recorded human gaze changes.

Neurons have been found in the primate brain that respond to objects in specific locations in hand-centered coordinates. A key theoretical challenge is to explain how such hand-centered neuronal responses may develop through visual experience. In this paper we show how hand-centered visual receptive fields can develop using an artificial neural network model, VisNet, of the primate visual system when driven by gaze changes recorded from human test subjects as they completed a jigsaw. A camera mounted on the head captured images of the hand and jigsaw, while eye movements were recorded using an eye-tracking device. This combination of data allowed us to reconstruct the retinal images seen as humans undertook the jigsaw task. These retinal images were then fed into the neural network model during self-organization of its synaptic connectivity using a biologically plausible trace learning rule. A trace learning mechanism encourages neurons in the model to learn to respond to input images that tend to occur in close temporal proximity. In the data recorded from human subjects, we found that the participant's gaze often shifted through a sequence of locations around a fixed spatial configuration of the hand and one of the jigsaw pieces. In this case, trace learning should bind these retinal images together onto the same subset of output neurons. The simulation results consequently confirmed that some cells learned to respond selectively to the hand and a jigsaw piece in a fixed spatial configuration across different retinal views

A Self-Organizing Model of the Visual Development of Hand-Centred Representations

We show how hand-centred visual representations could develop in the primate posterior parietal and premotor cortices during visually guided learning in a self-organizing neural network model. The model incorporates trace learning in the feedforward synaptic connections between successive neuronal layers. Trace learning encourages neurons to learn to respond to input images that tend to occur close together in time. We assume that sequences of eye movements are performed around individual scenes containing a fixed hand-object configuration. Trace learning will then encourage individual cells to learn to respond to particular hand-object configurations across different retinal locations. The plausibility of this hypothesis is demonstrated in computer simulations