Opportunities for Sustainable Mining Pit Lakes in Australia

Abstract.  Due to operational and regulatory practicalities, pit lakes will continue to be common legacies of mine lease relinquishments. Unplanned or inappropriate management of these geographical features can lead to both short- and long-term liability to mining companies, local communities, and the nearby environment during mining operations or after lease relinquishment. However, the potential for pit lakes to provide benefit to companies, communities, and the environment is frequently unrecognised and yet may be a vital contribution to the sustainability of the open-cut mining industry. Sustainable pit lake management aims to minimise short and long term pit lake liabilities and maximise short and long term pit lake opportunities. Improved remediation technologies are offering more avenues for pit lakes resource exploitation than ever before, at the same time mining companies, local communities, and regulatory authorities are becoming more aware of the benefit these resources can offer.     

Sterol Carrier Protein-2/Sterol Carrier Protein-x/Fatty Acid Binding Protein-1 Ablation Impacts Response of Brain Endocannabinoid to High-Fat Diet

Brain endocannabinoids (EC) such as arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) primarily originate from serum arachidonic acid (ARA), whose level is regulated in part by a cytosolic ARA-binding protein, that is, liver fatty acid binding protein-1 (FABP1), not expressed in the brain. Ablation of the Fabp1 gene (LKO) increases brain AEA and 2-AG by decreasing hepatic uptake of ARA to increase serum ARA, thereby increasing ARA availability for uptake by the brain. The brain also expresses sterol carrier protein-2 (SCP-2), which is also a cytosolic ARA-binding protein. To further resolve the role of SCP-2 independent of FABP1, mice ablated in the Scp-2/Scp-x gene (DKO) were crossed with mice ablated in the Fabp1 gene (LKO) mice to generate triple knock out (TKO) mice. TKO impaired the ability of LKO to increase brain AEA and 2-AG. While a high-fat diet (HFD) alone increased brain AEA, TKO impaired this effect. Overall, these TKO-induced blocks were not attributable to altered expression of brain proteins in ARA uptake, AEA/2-AG synthesis, or AEA/2-AG degrading enzymes. Instead, TKO reduced serum levels of free ARA and/or total ARA and thereby decreased ARA availability for uptake to the brain and downstream synthesis of AEA and 2-AG therein. In summary, Scp-2/Scp-x gene ablation in Fabp1 null (LKO) mice antagonized the impact of LKO and HFD on brain ARA and, subsequently, EC levels. Thus, both FABP1 and SCP-2 participate in regulating the EC system in the brain.     

On the VC Dimension of Bounded Margin Classifiers

In this paper we prove a result that is fundamental to the generalization properties of Vapnik's support vector machines and other large margin classifiers. In particular, we prove that the minimum margin over all dichotomies of k n + 1 points inside a unit ball in R ⁿ is maximized when the points form a regular simplex on the unit sphere. We also provide an alternative proof directly in the framework of level fat shattering.     

Electronic Commerce — How to Get the Security Right?

Electronic Commerce is about Commerce. ‘Electronic’ is only to speed up matters and thus increases the turnover. But to some (in fact, most) security experts, the focus is on ‘Electronic’ rather than ‘Commerce’, which is only an excuse to build ‘very secure’ systems. As a result, many systems available today are too cumbersome (e.g. SET), and if we are not careful, we will waste a lot of resources before we get it right. In the following, we exhibit a number of bad designs for E-commerce and explain how E-commerce security should be implemented to meet the obvious user requirements: secure, yet flexible, mobile and user friendly. The most radical new proposal is the concept of a virtual smartcard for signing to meet these challenges we so far have failed to handle in a satisfactory manner.     

Program proving: Jumps and functions

Summary Proof methods adequate for a wide range of computer programs have been expounded in [1] and [2]. This paper develops a method suitable for programs containing functions, and a certain kind Of jump. The method is illustrated by the proof of a useful and efficient program for table lookup by logarithmic search.     

Program proving: Coroutines

Summary Proof methods adequate for a wide range of computer programs have been given in [1–6]. This paper develops a method suitable for programs which incorporate coroutines. The implementation of coroutines described follows closely that given in SIMULA [7, 8], a language in which such features may be used to great advantage. Proof rules for establishing the correctness of coroutines are given and the method is illustrated by the proof of a useful program for histogram compilation.     

Effect of Sterol Carrier Protein-2 Expression on Sphingolipid Distribution in Plasma Membrane Lipid Rafts/Caveolae

Although sphingolipids are highly important signaling molecules enriched in lipid rafts/caveolae, relatively little is known regarding factors such as sphingolipid binding proteins that may regulate the distribution of sphingolipids to lipid rafts/caveolae of living cells. Since early work demonstrated that sterol carrier protein-2 (SCP-2) enhanced glycosphingolipid transfer from membranes in vitro, the effect of SCP-2 expression on sphingolipid distribution to lipid rafts/caveolae in living cells was examined. Using a non-detergent affinity chromatography method to isolate lipid rafts/caveolae and non-rafts from purified L-cell plasma membranes, it was shown that lipid rafts/caveolae were highly enriched in multiple sphingolipid species including ceramides, acidic glycosphingolipids (ganglioside GM1); neutral glycosphingolipids (monohexosides, dihexosides, globosides), and sphingomyelin as compared to non-raft domains. SCP-2 overexpression further enriched the content of total sphingolipids and select sphingolipid species in the lipid rafts/caveolae domains. Analysis of fluorescence binding and displacement data revealed that purified human recombinant SCP-2 exhibited high binding affinity (nanomolar range) for all sphingolipid classes tested. The binding affinity decreased in the following order: ceramides > acidic glycosphingolipid (ganglioside GM1) > neutral glycosphingolipid (monohexosides, hexosides, globosides) > sphingomyelin. Enrichment of individual sphingolipid classes to lipid rafts/caveolae versus non-rafts in SCP-2 expressing plasma membranes followed closely with those classes most strongly bound to SCP-2 (ceramides, GM1 > the neutral glycosphingolipids (monohexosides, dihexosides, and globosides) > sphingomyelin). Taken together these data suggested that SCP-2 acts to selectively regulate sphingolipid distribution to lipid rafts/caveolae in living cells.     

Unknown malcode detection and the imbalance problem

The recent growth in network usage has motivated the creation of new malicious code for various purposes. Today’s signature-based antiviruses are very accurate for known malicious code, but can not detect new malicious code. Recently, classification algorithms were used successfully for the detection of unknown malicious code. But, these studies involved a test collection with a limited size and the same malicious: benign file ratio in both the training and test sets, a situation which does not reflect real-life conditions. We present a methodology for the detection of unknown malicious code, which examines concepts from text categorization, based on n-grams extraction from the binary code and feature selection. We performed an extensive evaluation, consisting of a test collection of more than 30,000 files, in which we investigated the class imbalance problem. In real-life scenarios, the malicious file content is expected to be low, about 10% of the total files. For practical purposes, it is unclear as to what the corresponding percentage in the training set should be. Our results indicate that greater than 95% accuracy can be achieved through the use of a training set that has a malicious file content of less than 33.3%.     

Female Mice are Resistant to Fabp1 Gene Ablation-Induced Alterations in Brain Endocannabinoid Levels

Although liver fatty acid binding protein (FABP1, L‐FABP) is not detectable in the brain, Fabp1 gene ablation (LKO) markedly increases endocannabinoids (EC) in brains of male mice. Since the brain EC system of females differs significantly from that of males, it was important to determine if LKO differently impacted the brain EC system. LKO did not alter brain levels of arachidonic acid (ARA)‐containing EC, i.e. arachidonoylethanolamide (AEA) and 2‐arachidonoylglycerol (2‐AG), but decreased non‐ARA‐containing N‐acylethanolamides (OEA, PEA) and 2‐oleoylglycerol (2‐OG) that potentiate the actions of AEA and 2‐AG. These changes in brain potentiating EC levels were not associated with: (1) a net decrease in levels of brain membrane proteins associated with fatty acid uptake and EC synthesis; (2) a net increase in brain protein levels of cytosolic EC chaperones and enzymes in EC degradation; or (3) increased brain protein levels of EC receptors (CB1, TRVP1). Instead, the reduced or opposite responsiveness of female brain EC levels to loss of FABP1 (LKO) correlated with intrinsically lower FABP1 level in livers of WT females than males. These data show that female mouse brain endocannabinoid levels were unchanged (AEA, 2‐AG) or decreased (OEA, PEA, 2‐OG) by complete loss of FABP1 (LKO).