Gait termination : a review of experimental methods and the effects of aging and gait pathologies

The study of human gait has expanded and diversified to the extent that it is now possible to identify a substantive literature concerning a variety of gait tasks, such as gait initiation [Halliday SE, Winter DA, Frank JS, Patla AE, Prince F. The initiation of gait in young, elderly, and Parkinson's disease subjects. Gait Posture 1998;8:8–14; Mickelborough J, van der Linden ML, Tallis RC, Ennos AR. Muscle activity during gait initiation in normal elderly people. Gait Posture 2004;19:50–57], stepping over and across obstacles [Patla AE, Prentice SD, Robinson C, Newfold J. Visual control of locomotion: strategies for changing direction and for going over obstacles. J Exp Psych 1991;17:603–34; Chen, HC, Ashton-Miller JA, Alexander NB, Schultz AB. Effect of age and available response time on ability to step over an obstacle. J Gerontol 1994;49:227–33; Sparrow WA, Shinkfield AJ, Chow S, Begg RK. Gait characteristics in stepping over obstacles. Hum Mov Sci 1996;15:605–22; Begg RK, Sparrow WA, Lythgo ND. Time-domain analysis of foot–ground reaction forces in negotiating obstacles. Gait Posture 1998;7:99–109; Patla AE, Rietdyk S. Visual control of limb trajectory over obstacles during locomotion: effect of obstacle height and width. Gait Posture 1993;1:45–60] negotiating raised surfaces such as curbs and stairs [Begg RK, Sparrow WA. Gait characteristics of young and older individuals negotiating a raised surface: implications for the prevention of falls. J Gerontol Med Sci 2000;55A:147–54; Mcfayden BJ, Winter DA. An integrated biomechanical analysis of normal stair ascent and descent. J Biomech 1988;21:733–44]. In addition, increasing research interest in age-related declines in gait that might predispose individuals to falls has engendered a very extensive literature concerning ageing effects on gait. While rapid locomotor adjustments are common in the course of daily activities there has been no previous review of the findings concerning gait adaptations when walking is terminated both rapidly and unexpectedly. The aims of this review were first, to summarise the key research findings and methodological considerations from studies of termination. The second aim was to demonstrate the effects of ageing and gait pathologies on termination with respect to the regulation of step characteristics, lower-limb muscle activation patterns and foot–ground reaction forces.

Online banking vs. bricks & mortar - or a hybrid model? A preliminary investigation of Australian and Indian banks

Deregulation, innovations in mobile and wireless technologies and media convergence, together with the rapid diffusion of the Internet, have opened up strategic business opportunities in the financial sector. With deregulation removing entry barriers, an increasing number of online banks are threatening the market share of ‘bricks and mortar’ banks. To survive this competition, and to leverage the new opportunities of online and mobile banking facilitated by the Internet, many banks have adapted a hybrid, ‘clicks and mortar’ model, to increase their profitability while reducing transaction costs. In this paper, we report the results of a preliminary analysis based on a few major banks in Australia and India, two diverse economies, to reveal some interesting insights.

Effect of organic additives on the cycling performances of lithium metal polymer cells

Gel polymer electrolytes were prepared by immersing a porous poly(vinylidene fluoride-co-hexafluoropropylene) membrane in an electrolyte solution containing small amounts of organic additive. Three kinds of organic compounds, thiophene, 3,4-ethylenedioxythiophene and biphenyl, were used as a polymerizable monomeric additive. The organic additives were found to be electrochemically oxidized to form conductive polymer films on the electrode at high potential. By using the gel polymer electrolytes containing different organic additive, lithium metal polymer cells, composed of lithium anode and LiCoO2 cathode, were assembled and their cycling performance evaluated. Adding small amounts of a suitable polymerizable additive to the gel polymer electrolyte was found to reduce the interfacial resistance in the cell during cycling, and it thus exhibited less capacity fade and better high rate performance. Differential scanning calorimetric studies showed that the thermal stability of the fully charged LiCoO2 cathode was improved in the cell containing an organic additive.

Zwitterionic additives for electrochemical devices

Zwitterionic electrolytes such as N-methyl-N-(n-butanesulfonate) pyrrolidinium are added to electrolyte compositions such as polyelectrolytes, ionic liquid electrolytes and molecular solvent electrolytes (for example, lithium hexafluorophosphate) to improve conductivity of the ion species, such as lithium, in the electrolyte. This has application to lithium based energy storage devices such as batteries and supercapacitors.

Preparation and characterization on cellulose nanofiber film

In this study, cellulose nanofibers were obtained from wood pulp using a chemo-mechanical method and thin films were made of these cellulose nanofibers. The morphology of the films was studied by scanning electron microscopy (SEM). SEM image analysis revealed that the films were composed of cellulose nanofibers with an average diameter of around 32 nm. Other properties were also characterized, including the degree of crystallinity by X-ray diffraction, chemical bonding by infrared attenuated total reflectance analysis, and thermal properties by differential scanning calorimetry. The foldable, strong, and optically translucent cellulose nanofiber films thus obtained have many potential applications as micro/nano electronic devices, biosensors and filtration media, etc.

On the role of cyclic unsaturated additives on the behaviour of lithium metal electrodes in ionic liquid electrolytes

Three cyclic vinyl based additives, based respectively on oxygen, sulphur and fluorine, are tested for their ability to improve the cycling of lithium in a hostile ionic liquid medium. Oxygen based vinylene carbonate is found to offer the best protection of the lithium metal whilst allowing very consistent lithium cycling to occur. The vinylene carbonate based system under study is, however, imperfect. Lithium metal is deposited in a dendritic morphology, and vinylene carbonate is rapidly consumed during lithium cycling if it is present in a small quantity. Our results suggest that ionic liquid systems critically relying on a small amount of additive to protect a lithium electrode are not viable for long cycle life secondary batteries. It is suggested that an ionic liquid which itself is lithium metal compatible be used instead.

ZWITTERIONIC ADDITIVES FOR ELECTROCHEMICAL DEVICES

Zwitterionic electrolytes such as N-methyl-N-(n-butanesulfonate) pyrrolidinium are added to electrolyte compositions such as polyelectrolytes, ionic liquid electrolytes and molecular solvent electrolytes (for example, lithium hexafluorophosphate) to improve conductivity of the ion species, such as lithium, in the electrolyte. This has application to lithium based energy storage devices such as batteries and supercapacitors.

Blend films of natural wool and cellulose prepared from an ionic liquid

Natural wool/cellulose blends were prepared in an ionic liquid green solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl) and the films were formed subsequently from the coagulated solutions. The wool/cellulose blend films show significant improvement in thermal stability compared to the coagulated wool and cellulose. Moreover, the blend films exhibited an increasing trend of tensile strength with increase in cellulose content in the blends which could be used for the development of wool-based materials with improved mechanical properties, and the elongations of the blends were considerably improved with respect to the coagulated films of wool and cellulose. It was found that there was hydrogen bonding interaction between hydroxyl groups of wool and cellulose in the coagulated wool/cellulose blends as determined by Fourier transform infrared (FTIR) spectroscopy. The ionic liquid was completely recycled with high yield and purity after the blend film was prepared. This work presents a green processing route for development of novel renewable blended materials from natural resource with improved properties.

Cellulose and hemicellulose digestion by herbivorous terrestrial crustaceans

Cellulose, the main component of plant cell walls, is insoluble and difficult to digest enzymatically. This research discovered that herbivorous land crabs have an efficient gastric mill in the stomach which disrupts this insoluble material, and a range of highly specialised enzymes that can then break down the cellulose.

Financial crisis, Social pathologies and 'generalised perversion' : questioning Zizek's diagnosis of the times

Slavoj Zizek's work has been highly influential in the formulation of an emerging consensus among Lacanian social researchers, that we live in a society of generalised perversion whose initial fruits are the corrosion of democracy and the recent financial crisis. This position rests upon a notion of modern subjectivity that connects ‘commodity fetishism’ with clinical perversion in a pathological configuration, so that social theoretical identification of crisis tendencies, evaluative language about moral problems and diagnostic categories from the Lacanian clinic can be combined in a single figure. In this article, we question the series of conceptual links that constitute this position, tracing them from Zizek’s critique in his short work on the global financial crisis and his broader restatement of this analysis in the recent Living in the End Times, through the moment of his announcement of the notion of ‘generalised perversion’ in The Ticklish Subject, all the way back to fundamental propositions outlined in his earliest work. Our argument progresses through three claims. First, we show in the evolution of this position that it leads Zizek to equivocate in his diagnosis of contemporary society between two mutually exclusive categories (‘psychosis’ and ‘perversion’), indicating an antinomy in his work that is resolved in favour of ‘generalised perversion’ on empirical, not logical, grounds. Secondly, we offer a critical resolution of the antinomy through a critique of what we argue is Zizek’s mistaken over-extension of psychoanalytic reason beyond its legitimate scope of application. Finally, we point to some of the political implications of the way that Zizek speculatively resolves his logical difficulties, by analysing the consequences of his claim that generalised social perversion - the problem to be solved - involves a dethroning of the communal ego ideal. A communitarian streak, implicit in the potential conflation of moral denunciation with psychoanalytic diagnosis that the rhetoric of ‘perversion’ invokes, runs through Zizek’s work on capitalism, we propose in conclusion.

Effects of additives on the cloud points of selected nonionic linear ethoxylated alcohol surfactants

Effects of various additives including inorganic salts, nonionic and ionic surfactants, water-soluble polymers and alcohols on the cloud points of three linear nonionic surfactants, Tergitol 15-S-7, Tergitol 15-S-9 and Neodol 25-7, were investigated. These surfactants are readily biodegradable and either linear primary or secondary ethoxylated alcohols. Cloud points of these surfactants were functions of their concentrations and concentrations of additives. The cloud points of nonionic surfactant mixtures lay in between the cloud points of individual component surfactants. Presence of two ionic surfactants, sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB), increased the cloud point of 1 wt% Tergitol 15-S-7 micellar solution dramatically when concentrations of ionic surfactants approaching their critical micelle concentration. Addition of water-soluble polymers decreased the cloud point, while addition of inorganic salts can either increase or decrease the cloud points. However, the effect of an alcohol additive on cloud point was dependent on its chain length or its water solubility. Interestingly, synergistic effects between sulfate or phosphate and pentanol on depression of cloud points of Tergitol 15-S-9 were discovered. A linear model predicting cloud points of Tergitol 15-S-X (X = 7, 9 and 12) surfactants and Neodol 25-X (X = 7, 9 and 12) surfactants were proposed with a correlation to logarithm of their ethylene oxide numbers.