Synthesis and structure of tris(triphenyltin)benzene-1,3,5-tricarboxylate and its tri-DMSO adduct

The molecular structure of (Ph₃SnO₂C)₃C₆H₃ reveals distorted tetrahedral C₃O geometries for each tin atom. No intermolecular Sn...O associations occur between the molecules so that the trinuclear molecule may be considered monomeric. An increase in coordination number at tin is indicated by ¹¹⁹Sn NMR measurements conducted in d₆-DMSO solution and this has been confirmed by a structure analysis of (DMSO·Ph₃SnO₂C)₃C₆H₃·2 DMSO. In this structure, the tin atom geometries are distorted trigonal bipyramidal, existing within trans-C₃O₂ donor sets. Thus, while is it possible for the tin atoms to increase their coordination numbers in (Ph₃SnO₂C)₃C₆H₃, molecular aggregation to form polymeric arrays is precluded, most likely due to steric constraints.

Game geek's goss: linguistic creativity in young males within an online university forum (94/\/\3 933k’5 9055oneone)

In this paper the authors explore the use and adaptation of a language specifically developed for, and by, a community of young people who play computer games. Leet speak or 1337 5p34k, the language used by the participants in this study, incorporates symbols and numbers as substitutes for the letters contained in words. Described by the group as an ‘elite’ language or ‘leet speak’, the authors’ interest was captured by the derisive and ironic use of the language in an online forum for a tertiary first year unit of study. Rather than merely defining its participants within an elite cultural boundary, ‘leet speak’ is utilised ironically to unearth ‘wannabees’ (those seeking entrance and acceptance into the game world, generally 12 –16 year olds). Of particular fascination to the authors was that despite the clear self- demarcation of the group from the users of ‘leet speak’, and their insistence on its use solely by ‘newbs and wannabees’, the group continued to use the language to communicate with each other online. In this research, language defines the cultural group of games technology students in terms of the group’s continual subversion of the language’s very foundations whilst still using it to communicate. Perhaps most interesting was the group’s nonchalant admission that they perceived this to be the function of all languages ‘all languages are created purely for communication so dont [sic] have a cry about ppl been [sic] lazy’.

So far no good: the regulatory failure of criminal racial vilification laws in Australia

This article considers the efficacy of the two main legislative models in Australia which make racial vilification a crime. To this end, it considers whether the laws are compatible with the protection and promotion of freedom of speech; whether they sit comfortably within the existing criminal law frameworks; and whether the text of the offences is sufficiently clear and precise. It considers that the current models are fundamentally flawed and ought to be repealed, arguing, instead, for a particular kind of penalty enhancement statute.

µ- Calpain and calpain-3 are not autolyzed with exhaustive exercise in humans

µ-calpain and calpain-3 are Ca²⁺-dependent proteases found in skeletal muscle. Autolysis of calpains is observed using Western blot analysis as the cleaving of the full-length proteins to shorter products. Biochemical assays suggest that µ-calpain becomes proteolytically active in the presence of 2–200 µM Ca²⁺. Although calpain-3 is poorly understood, autolysis is thought to result in its activation, which is widely thought to occur at lower intracellular Ca²⁺ concentration levels ([Ca²⁺]i; ~1 µM) than the levels at which µ-calpain activation occurs. We have demonstrated the Ca²⁺-dependent autolysis of the calpains in human muscle samples and rat extensor digitorum longus (EDL) muscles homogenized in solutions mimicking the intracellular environment at various [Ca²⁺] levels (0, 2.5, 10, and 25 µM). Autolysis of calpain-3 was found to occur across a [Ca²⁺] range similar to that for µ-calpain, and both calpains displayed a seemingly higher Ca²⁺ sensitivity in human than in rat muscle homogenates, with ~15% autolysis observed after 1-min exposure to 2.5 µM Ca²⁺ in human muscle and almost none after 1- to 2-min exposure to the same [Ca²⁺]i level in rat muscle. During muscle activity, [Ca²⁺]i may transiently peak in the range found to autolyze µ-calpain and calpain-3, so we examined the effect of two types of exhaustive cycling exercise (30-s "all-out" cycling, n = 8; and 70% VO2 peak until fatigue, n = 3) on the amount of autolyzed µ-calpain or calpain-3 in human muscle. No significant autolysis of µ-calpain or calpain-3 occurred as a result of the exercise. These findings have shown that the time- and concentration-dependent changes in [Ca²⁺]i that occurred during concentric exercise fall near but below the level necessary to cause autolysis of calpains in vivo.

Retinal sensitivity loss in third-generation n-3 PUFA-deficient rats

A previous study conducted in guinea pigs suggested that ingestion of diets high in EPA and DHA may result in suboptimal retinal function. The aim of the present study was to evaluate retinal function in pigmented (Long-Evans) rats, raised to a third generation on diets that were either deficient in n-3 PUFA or adequate (with the addition of DHA). Electroretinographic assessment employed full-field white flash stimulation. Photoreceptor responses were evaluated in terms of peak amplitudes and implicit times (a-wave, b-wave), intensity-response functions (Naka-Rushton), and the parameters of a model of transduction (P3). Retinal phospholipid FA composition was measured by capillary GLC. DHA levels were reduced by 55% in n-3-deficient animals compared with the n-3-adequate group, whereas the levels of docosapentaenoic acid n-6 were 44 times higher in n-3-deficient animals. The level of arachidonic acid was marginally higher (12.8%) in n-6-adequate animals. The n-3-deficient animals exhibited significantly reduced retinal sensitivity (σ and S values were both affected by 0.29 log units) and increased b-wave implicit times compared with those fed the n-3-adequate diet. These data suggest that n-3 PUFA are required for development of retinal sensitivity, more so than other indices of retinal function assessed by current methods, such as maximal response amplitude. However, the benefit for retinal function of adding preformed DHA to diets already replete in n-3 PUFA remains unclear.

Not so easy being green?

Small and medium enterprises (SMEs) make up the bulk of modern economies. In Australia alone, there are about 951,000 small businesses in the private non-agricultural sector, employing 3.1 million people. For professional advisers and managers of these SMEs, the growing community concern for environmental issues will have quite an impact and SMEs are likely to find that ecological issues will become a big part of the daily management and strategic development of their firms. There are a few inherent problems standing in the way of greater environmental performance by Australia's SMEs. SMEs' lack of time and expertise is sometimes used as an excuse for inaction. But one way to get around this could be through outsourcing.

Sophistic 3.0 and the end of media relations

This paper looks at Web 2.0 as a new form of discursive art which may be changing human subjectivity - which may be producing new kinds of people. It casts the Web 2.0 era as the 'Third Sophistic' in comparison to the two other sophistics: (1) the period from the Ancient Greek Enlightenment when grammar, rhetoric and dialectic were invented by the original pre-Socratic sophists up until the times of Plato, Aristotle, and Isocrates; and (2) the Second Sophistic in the early centuries of the Common Era when 'epideictic,' that is subtle, artistic rhetoric was perfected. These sophistics marked alterations in the possibilities for human cultural expression and conception. Are we experiencing a 'Sophistic 3.0'? If so what are the likely consequences for contemporary discourse and its media?

Modeling of enzyme–substrate complexes for the metalloproteases MMP-3, ADAM-9 and ADAM-10

The matrix metalloproteases (MMPs) and the ADAMs (A Disintegrin And Metalloprotease domain) are proteolytic enzyme families containing a catalytic zinc ion, that are implicated in a variety of normal and pathological processes involving tissue remodeling and cancer. Synthetic MMP inhibitors have been designed for applications in pathological situations. However, a greater understanding of substrate binding and the catalytic mechanism is required so that more effective and selective inhibitors may be developed for both experimental and clinical purposes. By modeling a natural substrate spanning P4-P4‘ in complex with the catalytic domains, we aim to compare substrate-specificities between Stromelysin-1 (MMP-3), ADAM-9 and ADAM–10, with the aid of molecular dynamics simulations. Our results show that the substrate retains a favourable antiparallel beta-sheet conformation on the P-side in addition to the well-known orientation of the P'-region of the scissile bond, and that the primary substrate selectivity is dominated by the sidechains in the S1' pocket and the S2/S3 region. ADAM-9 has a hydrophobic residue as the central determinant in the S1' pocket, while ADAM-10 has an amphiphilic residue, which suggests a different primary specificity. The S2/S3 pocket is largely hydrophobic in all three enzymes. Inspired by our molecular dynamics calculations and supported by a large body of literature, we propose a novel, hypothetical, catalytic mechanism where the Zn-ion polarizes the oxygens from the catalytic glutamate to form a nucleophile, leading to a tetrahedral oxyanion anhydride transition state.

Docosapentaenoic acid (22:5n-3) : a review of its biological effects

This article summarizes the current knowledge available on metabolism and the biological effects of n-3 docosapentaenoic acid (DPA). n-3 DPA has not been extensively studied because of the limited availability of the pure compound. n-3 DPA is an elongated metabolite of EPA and is an intermediary product between EPA and DHA. The literature on n-3 DPA is limited, however the available data suggests it has beneficial health effects. In vitro n-3 DPA is retro-converted back to EPA, however it does not appear to be readily metabolised to DHA. In vivo studies have shown limited conversion of n-3 DPA to DHA, mainly in liver, but in addition retro-conversion to EPA is evident in a number of tissues. n-3 DPA can be metabolised by lipoxygenase, in platelets, to form ll-hydroxy-7,9,13,16,19- and 14-hydroxy-7,10,12,16,19-DPA. It has also been reported that n-3 DPA is effective (more so than EPA and DHA) in inhibition of aggregation in platelets obtained from rabbit blood. In addition, there is evidence that n-3 DPA possesses 10-fold greater endothelial cell migration ability than EPA, which is important in wound-healing processes. An in vivo study has reported that n-3 DPA reduces the fatty acid synthase and malic enzyme activity levels in n-3 DPA-supplemented mice and these effects were stronger than the EPA-supplemented mice. Another recent in vivo study has reported that n-3 DPA may have a role in attenuating age-related decrease in spatial learning and long-term potentiation. However, more research remains to be done to further investigate the biological effects of this n-3 VLCPUFA.

Channel estimation scheme for 3.9G wireless communication systems using RLS algorithm

Main challenges for a terminal implementation are efficient realization of the receiver, especially for channel estimation (CE) and equalization. In this paper, training based recursive least square (RLS) channel estimator technique is presented for a long term evolution (LTE) single carrier-frequency division multiple access (SC-FDMA) wireless communication system. This CE scheme uses adaptive RLS estimator which is able to update parameters of the estimator continuously, so that knowledge of channel and noise statistics are not required. Simulation results show that the RLS CE scheme with 500 Hz Doppler frequency has 3 dB better performances compared with 1.5 kHz Doppler frequency.

Questions of (re)production and legitimation : a second screening of 3 films on teacher-student relations

This study considers three Hollywood films that take, as their subject, a teacher-hero confronted with a 'problem' group of students and, as their narrative, the rehabilitation of these students and the resolution of their problems. Employing a Bourdieuian analysis, we attempt a second screening of these films on two levels: first, by stepping inside these celluloid classrooms, so to speak, and narrating a different text, one that is spoken from the position of students and which challenges each film's portrayal of good people achieving fine things; and secondly, by screening for gaps in their accounts of schooling, exposing their limited frames of reference and their legitimacy to speak on behalf of authentic classrooms. The first of these projects is undertaken as a way of challenging teachers and interested others to be wary of uncritical readings of popular images of teaching, whereas the second provides a beginning from which to consider how teachers' pedagogy and school curricula can be informed by a radical democratic view of education - how teachers might embrace the foreign.

Guest editorial : In Journal of networks, v.7 n.3

Networking of computing devices has been going through rapid evolution and thus continuing to be an ever expanding area of importance in recent years. New technologies, protocols, services and usage patterns have contributed to the major research interests in this area of computer science. The current special issue is an effort to bring forward some of these interesting developments that are being pursued by researchers at present in different parts of the globe. Our objective is to provide the readership with some insight into the latest innovations in computer networking through this. This Special Issue presents selected papers from the thirteenth conference of the series (ICCIT 2010) held during December 23-25, 2010 at the Ahsanullah University of Science and Technology. The first ICCIT was held in Dhaka, Bangladesh, in 1998. Since then the conference has grown to be one of the largest computer and IT related research conferences in the South Asian region, with participation of academics and researchers from many countries around the world. Starting in 2008 the proceedings of ICCIT are included in IEEExplore. In 2010, a total of 410 full papers were submitted to the conference of which 136 were accepted after reviews conducted by an international program committee comprising 81 members from 16 countries. This was tantamount to an acceptance rate of 33%. From these 136 papers, 14 highly ranked manuscripts were invited for this Special Issue. The authors were advised to enhance their papers significantly and submit them to undergo review for suitability of inclusion into this publication. Of those, eight papers survived the review process and have been selected for inclusion in this Special Issue. The authors of these papers represent academic and/or research institutions from Australia, Bangladesh, Japan, Korea and USA. These papers address issues concerning different domains of networks namely, optical fiber communication, wireless and interconnection networks, issues related to networking hardware and software and network mobility. The paper titled “Virtualization in Wireless Sensor Network: Challenges and Opportunities” argues in favor of bringing in different heterogeneous sensors under a common virtual framework so that the issues like flexibility, diversity, management and security can be handled practically. The authors Md. Motaharul Islam and Eui-Num Huh propose an architecture for sensor virtualization. They also present the current status and the challenges and opportunities for further research on the topic. The manuscript “Effect of Polarization Mode Dispersion on the BER Performance of Optical CDMA” deals with impact of polarization mode dispersion on the bit error rate performance of direct sequence optical code division multiple access. The authors, Md. Jahedul Islam and Md. Rafiqul Islam present an analytical approach toward determining the impact of different performance parameters. The authors show that the bit error rate performance improves significantly by the third order polarization mode dispersion than its first or second order counterparts. The authors Md. Shohrab Hossain, Mohammed Atiquzzaman and William Ivancic of the paper “Cost and Efficiency Analysis of NEMO Protocol Entities” present an analytical model for estimating the cost incurred by major mobility entities of a NEMO. The authors define a new metric for cost calculation in the process. Both the newly developed metric and the analytical model are likely to be useful to network engineers in estimating the resource requirement at the key entities while designing such a network. The article titled “A Highly Flexible LDPC Decoder using Hierarchical Quasi-Cyclic Matrix with Layered Permutation” deals with Low Density Parity Check decoders. The authors, Vikram Arkalgud Chandrasetty and Syed Mahfuzul Aziz propose a novel multi-level structured hierarchical matrix approach for generating codes of different lengths flexibly depending upon the requirement of the application. The manuscript “Analysis of Performance Limitations in Fiber Bragg Grating Based Optical Add-Drop Multiplexer due to Crosstalk” has been contributed by M. Mahiuddin and M. S. Islam. The paper proposes a new method of handling crosstalk with a fiber Bragg grating based optical add drop multiplexer (OADM). The authors show with an analytical model that different parameters improve using their proposed OADM. The paper “High Performance Hierarchical Torus Network Under Adverse Traffic Patterns” addresses issues related to hierarchical torus network (HTN) under adverse traffic patterns. The authors, M.M. Hafizur Rahman, Yukinori Sato, and Yasushi Inoguchi observe that dynamic communication performance of an HTN under adverse traffic conditions has not yet been addressed. The authors evaluate the performance of HTN for comparison with some other relevant networks. It is interesting to see that HTN outperforms these counterparts in terms of throughput and data transfer under adverse traffic. The manuscript titled “Dynamic Communication Performance Enhancement in Hierarchical Torus Network by Selection Algorithm” has been contributed by M.M. Hafizur Rahman, Yukinori Sato, and Yasushi Inoguchi. The authors introduce three simple adapting routing algorithms for efficient use of physical links and virtual channels in hierarchical torus network. The authors show that their approaches yield better performance for such networks. The final title “An Optimization Technique for Improved VoIP Performance over Wireless LAN” has been contributed by five authors, namely, Tamal Chakraborty, Atri Mukhopadhyay, Suman Bhunia, Iti Saha Misra and Salil K. Sanyal. The authors propose an optimization technique for configuring the parameters of the access points. In addition, they come up with an optimization mechanism in order to tune the threshold of active queue management system appropriately. Put together, the mechanisms improve the VoIP performance significantly under congestion. Finally, the Guest Editors would like to express their sincere gratitude to the 15 reviewers besides the guest editors themselves (Khalid M. Awan, Mukaddim Pathan, Ben Townsend, Morshed Chowdhury, Iftekhar Ahmad, Gour Karmakar, Shivali Goel, Hairulnizam Mahdin, Abdullah A Yusuf, Kashif Sattar, A.K.M. Azad, F. Rahman, Bahman Javadi, Abdelrahman Desoky, Lenin Mehedy) from several countries (Australia, Bangladesh, Japan, Pakistan, UK and USA) who have given immensely to this process. They have responded to the Guest Editors in the shortest possible time and dedicated their valuable time to ensure that the Special Issue contains high-quality papers with significant novelty and contributions.

Protonated melonate Ca[HC6N7(NCN)3]·7H2O – synthesis, crystal structure, and thermal properties

Calcium hydrogenmelonate heptahydrate Ca[HC6N7(NCN)3]·7H2O was obtained by metathesis reaction in aqueous solution. The structure of the molecular salt was elucidated by single-crystal X-ray diffraction. The crystal structure consists of alternating layers of planar monopronated melonate ions, Ca2+ and crystal water molecules. The anions of adjacent layers are staggered so that no π–π stacking occurs. The melonate entities are interconnected by hydrogen bonds within and between the layers. Ca[HC6N7(NCN)3]·7H2O was investigated by solid-state NMR and FTIR spectroscopy, TG and DTA measurements.

The M4 muscarinic antagonist MT-3 inhibits myopia in chick: evidence for site of action

It is well established that the broad-band muscarinic antagonist, atropine is effective at inhibiting the progression of myopia and does so by preventing the elongation of the vitreous chamber of the eye. However, uncertainty remains as to whether this effect occurs through a receptoral mechanism and, if so, which muscarinic receptor subtype mediates this effect. Previous work, in avian and mammalian models of myopia, implicates the M1 and M4 receptors as potential targets. The current study used physiologically relevant concentrations of highly selective muscarinic antagonists (MT-3 and MT-7) to further characterise the role of the M4 receptor in the control of myopia in the chick model of refractive development.

Fishy business : effect of omega-3 fatty acids on zinc transporters and free zinc availability in human neuronal cells

Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer's disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration.