"Tell us something new!" : the response of planning and transport professionals to public health guidance on the built environment and physical activity

A large proportion of non-communicable disease can be attributed to modifiable risk factors such as poor nutrition and physical inactivity. We present data on planning and transport practitioners' perceptions and responses to government public health guidance aimed at modifying environmental factors to promote physical activity. This study was informed by questions on the role of evidence-based guidance, the views of professionals towards the guidance, the links between guidance and existing legislation and policy and the practicality of guidelines. A key informant 'snowball' sampling technique was used to recruit participants from the main professional planning organisations across England. Seventy-six people were interviewed in eight focus groups. We found that evidence-based public health guidance is a new voice in urban and town planning, although much of the advice is already reflected by the 'accepted wisdom' of these professions. Evidence-based health guidance could be a powerful driver affecting planning practice, but other legislated planning guidance may take priority for planning and transport professionals.

Effects of undoped and manganese-doped zinc oxide nanoparticles on the colour fading of dyed polyester fabrics

This paper describes the effects of applying coatings of an acrylic polymer containing nanoparticles of zinc oxide (ZnO) on the fading rate in artificial sunlight of polyester fabrics dyed with disperse dyes containing anthraquinone and benzopyran chromophores. Factors affecting the transparency and UV absorbance of the coatings are discussed. Removing the UV component of sunlight with ZnO nanoparticles markedly decreased the fading rate of the dyes, provided the polymer/ZnO film was not in direct contact with the fabric. When the treatment was applied directly to the fabrics, however, the protection against colour fading was different for the two dyes studied. Whereas the rate of colour fading of a benzopyran dye, of relatively low lightfastness, was decreased by the polymer-ZnO film, the treatment increased the fading rate of the dye of higher lightfastness, based on anthraquinone. This effect has been attributed to the generation of reactive oxygen species (ROS) when ZnO is exposed to UV. The effect of decreasing the photoactivity of ZnO by doping with manganese has been examined. For the benzopyran dye, the UV protection was greatly increased, whereas a much smaller improvement was found for the anthraquinone-based dye.

Dietary protein level interacts with ω-3 polyunsaturated fatty acid deficiency to induce hypertension

Background : Dietary ω-3 fatty acid deficiency can lead to hypertension in later life; however, hypertension is affected by numerous other dietary factors. We examined the effect of altering the dietary protein level on blood pressure in animals deficient or sufficient in ω-3 fatty acids.

Methods : Female rats were placed on one of four experimental diets 1 week prior to mating. Diets were either deficient (10% safflower oil; DEF) or sufficient (7% safflower oil, 3% flaxseed oil; SUF) in ω-3 fatty acids and contained 20 or 30% casein (DEF20, SUF20, DEF30, SUF30). Offspring were maintained on the maternal diet for the duration of the experiment. At 12, 18, 24, and 30 weeks, blood pressure was assessed by tail cuff plethysmography.

Results : At both 12 and 18 weeks of age, no differences in blood pressure were observed based on diet, however, by 24 weeks hypertension was evident in DEF30 animals; there were no blood pressure differences between the other groups. This hypertension in DEF30 group was increased at 30 weeks, with systolic, diastolic, and mean arterial pressure all elevated.

Conclusions : These results indicate that the hypertension previously attributed to ω-3 fatty acid deficiency is dependent on additional dietary factors, including protein content. Furthermore, this study is the first to plot the establishment of ω-3 fatty acid deficiency hypertension over time.

Codes of ethics in large private sector Australian businesses

This thesis deals with codes of ethics in the top 500 companies operating in the private sector in Australia. We seek to answer two questions. First, can businesses adopt codes of ethics in a meaningful way, or are business ethics a contradiction in terms for profit seeking organisations in competitive markets? Second, to what extent do Australia’s top 500 private sector firms show commitment to codes of ethics? A number of ancillary questions are explored to form a picture of the current Australian situation and to compare it to the rest of the world, especially the US and Canada. Chapter 1 discusses these questions and the origins of the author’s interest in business ethics. This chapter develops a focus upon codes of ethics and their role in assisting to establish and maintain an ethical culture. The chapter looks at previous research on codes of ethics and demonstrates a lack of understanding in Australia on the subject and the need for research into it. Also included in Chapter 1 is the plan for the thesis. Chapters 2 to 4 review the literature upon which the thesis is based. In Chapter 2, the meaning of the terms ethics and business ethics are considered. Deontological and teleological approaches are distinguished and a (largely) teleological model of business ethics is developed. This chapter also asks whether business ethics are possible. The contention that ethics may be good for a business’s profit is explored in-depth and the conclusion is reached that ethics should be pursued for its inherent worth regardless of the economic benefit that can be attributed to it. A number of models of ethical decision making are discussed in Chapter 3 starting with Kohlberg and Kramer (1969). This discussion leads to the conclusion that organisations must create an ethical culture for staff if they require them to embrace ethical practices. If this is a correct conclusion, then the role of senior managers becomes critical in the process. Chapter 4 looks further at the role of senior managers, organisational culture and ethical/unethical behaviour in organisations. The conclusion is that senior managers do play an integral part in shaping the culture of an organisation. Their actions, either overtly or covertly, impact upon their staff and highlight behaviour that the organisation is or is not willing to tolerate. Sims (1991) proposed ten ways to foster an ethical culture and these ideas are set out and further explored through the work of other writers on management ethics. Finally, the link between ethics and strategic planning is examined. In Chapter 5 the methods used for empirical data gathering are described and justified. A number of factors that can lead us to consider a company’s ‘commitment’ to ethics are outlined. A survey of Australian companies was the primary means of data collection. Each question in the survey instrument is listed and explained. Also the survey response rate is reported, as are major demographic characteristics of respondents. Chapter 6 provides the research findings from the survey of the top 500 companies operating in the private sector in Australia. The research examines: i) the current Australian usage and implementation of codes of ethics; ii) the measures put in place in organisations in order to support a code; From this analysis conclusions are drawn about the ‘commitment’ of companies operating in Australia to codes of ethics. Australian companies are becoming aware of the potential of code usage. Companies operating in Australia that have codes appear to be good at implementing codes and examining staff performance in relation to codes. However, they lack the procedures that incorporate education and training and the implementation of the support mechanisms necessary to enhance employee understanding of the code. In Chapter 7, Australian codes are compared to American and Canadian codes for similarity and disparity. The assessment found that in all three countries codes are primarily concerned with company continuance. Australian codes do tend to be more socially oriented than in the other two countries and also less legalistic. Chapter 8 looks at 4 companies from the first survey that were asked for more in-depth information in a quest to determine current best practice in Australia. These organisations were chosen because they appeared, from the first survey instrument, to have put in place mechanisms to assist employees to better understand the code. The implication is that companies must make a conscious, positive effort to ensure that employees are considered in the process of ethical development. They should have input into the process, rather than just being directed to follow another management initiative. The final chapter summarises the research findings and looks at answers to the two major questions and the seven subordinate empirical questions posed at the start of the thesis. The conclusion reached is that companies operating in Australia appear to be moving towards establishing codes of ethics. Those who already have codes display a real commitment to them. The movement appears to be gathering momentum as more organisations see the value of incorporating ethical business practices into the every day workings of their individual companies. Generally, most Australian companies lag behind the rest of the world, but the pace-setting companies are defining their own best practice and achieving positive outcomes for themselves, their employees and other stakeholders.

Changing bodies, changing discourses : women's experiences of early menopause

Early menopause has been constructed by discourses of biological determinism as an untimely, but natural, failure of the female body. Medical discourses in particular have interpreted early menopause as a congenital irregularity and a rare anomaly of menopause at midlife. In this thesis I challenge the notion that early menopause is an innate imperfection related only to women’s age. I propose that early menopause is dependent upon the cultural interpretations of individual women and is constituted through the mercurial and multiple discourses of women who have this embodied experience. Moreover, I reveal that early menopause is a contemporary condition and that its location in history is inextricably bound to discourses of risk, naturalism and the self. Further I make the assumption that having an early menopause both affects and is an effect of women’s fertility, sexuality and subjectivity. I have drawn upon a broad range of sources to provide a sociological analysis of early menopause. Literature on early menopause is dominated by positivist discourses, yet many alternate discourses negotiate these influential constructions. I suggest here that the perception of early menopause as a natural fault is merely a construction by medical discourses and does not incorporate the dynamic discourses of early-menopausal women. Moreover, the restriction of early menopause to a genetic female failure excludes the majority of women who have an early menopause through iatrogenisis. This omission occurs through the failure of positivist discourses to accommodate diversity in discourses. Recent sociological and feminist studies have vindicated menopausal women. They have reconstructed menopause through notions of embodiment and have removed the veil of negativity used by the medical sciences to contain menopausal women (Komesaroff, Rothfield and Daly 1997). The visibility of menopausal women, however, remains connected to age. Menopause has been created as a predictable consequence of aging and as such has come to be synonymous with middle age. Nowadays, even men are said to experience menopause at midlife (Carruthers 1996). But early menopause is constituted within the discourses of women who have this experience. Medico-scientific discourses, based upon theories of genetic inevitability, disregard this perspective. Consequently early menopause is subsumed by naturalistic discourses that relate menopause to midlife. Such restraint reflects the unease created by menopause that does not coincide with prescribed life stages. Women's experiences of their changing bodies are largely unheard. Thus, women who have an early menopause are faced with a chasm of ‘cultural non-recognition’ (Fraser 1997). Conjointly with this discursive repression early-menopausal women face social imbalances that are transacted as both cause and consequence of early menopause. In particular the contemporary creation of early menopause is bound to the social and historical location of women as a group. Women are exploited by the institution of medicine, ‘exposure to environmental toxicity’ (Fraser 1997: 11) and commercialization as causes of early menopause. Yet the corporeal effects of practices of risk avoidance (Beck 1993), social practices (Shilling 1993) and Western consumerism (Lupton 1994) fail to be recognized. I address these problematics through a poststructural and feminist critique that assumes moments of commonality among women, while at the same time recognizes shifting and multiple differences (Nicholson 1999). I suggest here that early menopause falls into cultural misrecognition in Fraser's (1997) terms and argue that it is united concurrently with the gender injustice of androcentrism (Fraser 1997: 21). Fraser (1997: 16) suggests that it is only by relating these dual problematics that we are able to make sense of current dilemmas. Thus I have critiqued early menopause through a connection between individual embodied experiences of early menopause and early menopause as a modern phenomenon that is specific to women. I have attempted to unravel these arguments that simultaneously call to ‘... abolish gender differentiation and to valorize gender specificity’ (Fraser 1997: 21) while at the same time acknowledging their interconnectedness. An approach of merely combining women’s discourses with overarching social issues would be inadequate as not only do these problematics intersect but they also can be opposed. As Fraser (1997: 25) notes with her theory, redressing one aspect of cultural or social analysis can further imbalance another. For instance making visible the diversity and uniqueness of individual experiences of early menopause could detract from acknowledging the contemporary construction of early menopause through social inequality. Crucial to this understanding is a destabilizing of the binary construction of differences between the sexes that makes way for a reconstruction of early menopause through ‘sexual slippage’ (Matus 1995). In this thesis I look for a subtlety between the particular and the collective that views early menopause as concurrently a singular and changeable experience as well as imbedded in social practice. I suggest that these concepts are entwined as interactive effects of early menopause. Thus I have analyzed the bivalent problematics of the embodiment and social location of early menopause as imbricated, dynamic and unending discourses. From this perspective I reviewed the literature that was available on early menopause. In Chapter One I look to descriptions of early menopause and note that it has disappeared into a conglomeration of disparate, mostly medical, discourses that are contradictory. Nevertheless medical discourses offer ‘conclusive’ definitions of early menopause that are based on naturalistic views of the body (Shilling 1994). The determinants used are inconsistent and do not include women's discourses of early menopause. Thus, dominant medical discourses obscure women’s embodied experiences of early menopause and ignore the contemporary causes of early menopause. In Chapter Two I examine the causes of early menopause as a way of explaining the disparity between medical discourses and my anecdotal observations of early menopause as a fairly common contemporary occurrence. The relatively recent escalation in gynaecological surgery, especially hysterectomy, appears to account almost single-handedly for early menopause as a current phenomenon. Moreover, the extraordinary number of women who have their uterus removed at hysterectomy can be interpreted as a modern implementation of ancient anxieties. Women's sexuality has been constructed throughout history as problematic and this unease has been translated through women's bodies as dangerous and in need of control (Greer 1992). Thus social concerns which have evolved historically have emerged through the representation of a woman's uterus as an unseen, dark and mysterious risk (Beck 1993). Medical discourses define this risk and are able to negate the so-called dangers of women's sexuality through the surgical removal of their organs. Widespread negotiation of medical discourses is apparent, as hysterectomy in the modern Western world is the most common of all surgical operations (Hufnagel 1989). It is overwhelmingly the most common cause of early menopause as well. I examine also the historical condemnation of infertile women and how this anxiety has been transposed to the modern world through the commercialization of reproduction. Transactions of this social unease can cause early menopause. For instance the medical technology of in-vitro fertilization (I.V.F.) has been offered as a panacea for the infertility of early menopause but, paradoxically, can cause early menopause as well. Conception through technology has been normalized as a viable option for women who are unable to conceive and understandings of I.V.F. have moved into everyday discourse. Medical discourses have constructed fertility as a saleable item and infertile women expect that they can purchase this merchandise. Human eggs have become lucrative commodities that now are available in the market place. Egg ‘donation’ for I.V.F. programs can hasten the attrition rate of eggs and can cause early menopause in some pre-menopausal women (Rowland 1992: 24). Even the recycling of a woman’s uterus supposedly has become a possibility through the transferring of this ‘used’ organ at hysterectomy to a recipient woman who can use the other woman’s uterus as a ‘gestational garage’ (Rogers 1998). In this way women have been disembodied as mechanical systems with inter-changeable body parts and the potentially detrimental consequences of these commercial transactions are ignored. In addition I show how early menopause can be caused by the connection between the self and the social structure. Women's subjectivity is constituted through the cultural discourses available to them and these discourses affect social behaviour (Lupton 1995). For instance smoking and dieting have been identified as causes of early menopause. These activities have been related to the creation of women’s bodies as hetero-sexually desirable and are endemic to young women (Evans-Young 1995). This suggests that cultural causes of early menopause are transactions of sexual politics. Yet there is a paucity of literature that acknowledges the relationship between women’s subjectivity and early menopause. Thus the second chapter exposes a link between sexual politics and causes of early menopause through women's relationships with risk, naturalism and the self. In Chapter Three I deconstruct early menopause through theoretical considerations. I rely on an overarching poststructuralism that embraces the concept of fragmented plural discourses and the subjectivity of menopausal women as a continuous process (Komesaroff 1997: 61). I have woven these variables through broad feminist critiques (Leonard 1997). Through this eclectic approach I hoped to find some loose alignment between the corporeal, ontological and embodied dimensions of early menopause. The recurring themes of sexuality, fertility and subjectivity emerge through deconstructing discourses of sexual difference as immutable and non-negotiable; exposing ‘premature ovarian failure’ as a discursive construction that censures early-menopausal women; and acknowledging the discourses of individual women as unique, diverse and dynamic. I looked to a method of exposing some of these individual discourses and in Chapter Four I describe a critical research process aimed at understanding early menopause as a lived experience. In the remaining chapters I align these ontological arguments with an analysis of the discourses of women who had experienced or were experiencing an early menopause. This section partly relieves the ‘cultural non-recognition’ of the discourses of early-menopausal women. I recorded the narratives of fifty early-menopausal women through in-depth interviews and used this empirical data to direct the study. This data provides the opportunity to understand early menopause as an assortment of embodied experiences. For instance women’s experiences of age at commencement of menopause spanned over three and half decades. They did not reflect the age specifications prescribed by medical discourses. Rather women interpreted their experiences within their own discourses and determined their menopause as early based upon the expectations of their cultural context. Many of the women experienced changes attributed to menopause at midlife. It was not these changes that were significant to early-menopausal women it was how each woman translated these changes that provided meanings of early menopause. In Chapter Five I introduce the women through a table that connects the varying experiences of each woman. This profile shows that, in the main, the women’s experiences of early menopause were unexpected. I suggest that this is due to the disparity between early-menopausal women’s experiences and the current age and social norms of menopause. By bracketing the women into cohorts patterns emerged displaying differences between women who had menopause in their teens, twenties, thirties and forties. Adolescent women had intense feelings of abnormality and despair. Women who were in their twenties were less devastated by menopause than the younger women but described their sexuality and self-identity as changing. And although some women in their thirties were shocked or dismayed to have an early menopause others were ambivalent or happy. These women also described their sexuality and self-identity through changing discourses. A number of the women who were in their forties said that they were ‘too young for the menopause’ but were far less despondent than the younger women. It seemed that the greater the distance between age norms and social norms the more negatively women responded. Age norms that determine the social norms of women's lives through a ‘biological clock’ are constructed to reflect social values. But age is a social construction that changes over time. Thus it would appear that women’s changing bodies and changing discourses of early menopause are in the process of recreating age and social norms around menopause. In Chapter Six I draw upon women’s narratives that describe a connection between early menopause and sexuality. Yet the respondents were not unified in their constructions of sexuality. For instance a number of the women rejected the containment of their sexuality as absolute and defined in terms of bi-lateral hetero-sexual opposition. The discourses of these women constructed their sexuality as continuously flexible. Some early-menopausal women described this sexual mobility as an equivocal relationship between their sexuality, reproductive capacity and female organs. Other women articulated their sexuality as vacillating, ambiguous and unrepresentative of the so-called ‘true woman’. Several felt that they were not meant to have female reproductive organs at all. Nearly one third of the women had had their uterus removed at hysterectomy and the reproductive organs of two women were rudimentary. Women’s narratives showed that the social value of fertility influences constructions of early menopause. In Chapter Seven I record the contrast between the poignant responses of women who wished to have a baby of their own and other women who resisted discourses that entwine reproductivity with being a woman. For instance some women negotiated fertility through economic discourses of consumerism with the expectation that they could purchase conception as a commodity. Other women welcomed their early menopause as freedom from contraceptive concerns and others had no interest in reproduction at all. Thus discord arose through discourses that problematize early-menopausal women as non-reproductive and discourses that value variability. In addition many of the women’s accounts constructed their subjectivity as mobile, challenging the notion that discourses of the self are immutable. Chapter Eight presents narratives which suggest that the subjectivity of many women was altered continuously by early menopause. Yet some of the women rejected the construction of their subjectivity as unfluctuating. These contradictions reflect the uncertainties of the contemporary world. Nevertheless most respondents found that the tethering of menopause to constructions of midlife was incongruous with their own experiences. Many women refused to accept the label of social redundancy attached to middle-aged women. They moved their subjectivity beyond the reproductive body to a shifting and tractable identity of the self. This thesis demonstrates that the medical construction of early menopause as a rare and natural female flaw varies from women's experiences which suggest that early menopause is common and discursively constructed. This disparity has occurred through the privilege placed upon the construction of bodies as immutable and sexually static. This privileging has obscured the multi-dimensional causes of early menopause and given preference to a mono-causal theory. By exposing the variety of causes of early menopause the medical construction of women through a universal and unalterable body of reproduction is challenged. Moreover, women's discourses of early menopause demonstrate that the medical reduction of early menopause to a spontaneous bio-chemical malfunction has ignored the volatility of women’s embodied experiences. Women experience early menopause variously and through mercurial discourses. I suggest here that women's discourses of their experiences of early menopause reflect recurring and restructuring philosophical quandaries of fertility, sexuality and subjectivity. While there can be no representative claims made from this thesis it contributes to an understanding of the embodied experiences of early menopause. It provides an understanding of the creation of early menopause through social practices and goes part way to redressing the problematics of what Fraser terms ‘cultural non-recognition’. But, more importantly, it acknowledges early menopause as a variety of experiences where women interpret their changing bodies through changing discourses.

Older adults' neuromuscular adaptations to resistence training and effects on challenging gait tasks

Community locomotion is threatened when older individuals are required to negotiate obstacles, which place considerable stress on the musculoskeletal system. The vulnerability of older adults during challenging locomotor tasks is further compromised by age-related strength decline and muscle atrophy. The first study in this investigation determined the relationship between the major muscle groups of the lower body and challenging locomotor tasks commonly found in the community environment of older adults. Twenty-nine females and sixteen males aged between 62 and 88 years old (68.2 ±6.5) were tested for the maximal voluntary contraction (MVC) strength of the knee extensors and 1-RM for the hip extensors, flexors, adductors, abductors, knee extensors and flexors and ankle plantar flexors. Temporal measurements of an obstacle course comprising four gait tasks set at three challenging levels were taken. The relationship between strength and the obstacle course dependent measures was explored using linear regression models. Significant associations (p≤0.05) between all the strength measures and the gait performances were found. The correlation values between strength and obstructed gait (r = 0.356-0.554) and the percentage of the variance explained by strength (R2 = 13%-31%), increased as a function of the challenging levels, especially for the stepping over and on and off conditions. While the difficulty of community older adults to negotiate obstacles cannot be attributed to a single causal pathway, the findings of the first study showed that strength is a critical requirement. That the magnitude of the association increased as a function of the challenging levels, suggests that interventions aimed at improving strength would potentially be effective in helping community older adults to negotiate environmental gait challenges. In view of the findings of the first study, a second investigation determined the effectiveness of a progressive resistance-training program on obstructed gait tasks measured under specific laboratory conditions and on an obstacle course mimicking a number of environmental challenges. The time courses of strength gains and neuromuscular mechanisms underpinning the exercise-induced strength improvements in community-dwelling older adults were also investigated. The obstructed gait conditions included stepping over an obstacle, on and off a raised surface, across an obstacle and foot targeting. Forty-three community-living adults with a mean age of 68 years (control =14 and experimental=29) completed a 24-week progressive resistance training program designed to improve strength and induce hypertrophy in the major muscles of the lower body. Specific laboratory gait kinetics and kinematics and temporal measures taken on the obstacle course were measured. Lean tissue mass and muscle activation of the lower body muscle groups were assessed. The MVC strength of the knee extensors and 1-RM of the hip extension, hip flexion, knee extension, knee flexion and ankle plantar flexion were measured. A 25% increase on the MVC of the knee extensors (p≤0.05) was reported in the training group. Gains ranging between 197% and 285% were recorded for the 1-RM exercises in the trained subjects with significant improvements found throughout the study (p≤0.05). The exercise-induced strength gains were mediated by hypertrophic and neural factors as shown by 8.7% and 27.7% increases (p≤0.05) in lean tissue mass and integrated electromyographic activity, respectively. Strength gains were accompanied by increases in crossing velocity, stride length and reductions in stride duration, stance and swing time for all gait tasks except for the foot targeting condition. Specific kinematic variables associated with safe obstacle traverse such as vertical obstacle heel clearance, limb flexion, horizontal foot placements prior to and at post obstacle crossing and landing velocities resulted in an improved crossing strategy in the experimental subjects. Significant increases in the vertical and anterior-posterior ground reaction forces accompanied the changes in the gait variables. While further long-term prospective studies of falls rates would be needed to confirm the benefits of lower limb enhanced strength, the findings of the present study provide conclusive evidence of significant improvements to gait efficiency associated with a systematic resistance-training program. It appears, however, that enhanced lower body strength has limited effects on gait tasks involving a dynamic balance component. In addition, due to the larger strength-induced increases in voluntary activation of the leg muscle compared to relatively smaller gains in lean tissue mass, neural adaptations appear to play a greater contributing role in explaining strength gains during the current resistance training protocol.

Mechanical properties of aged Mg-4Y-3RE alloy

This paper describes tensile properties of a peak-aged Mg-4Y·3RE alloy at room temperature to 823 K with 10^-5 - 10^-1 s^-1. The Mg alloy exhibited high strength (> 250 MPa) at room temperature to 473 K. However. the strength rapidly decreased at 573 K. It is suggested that a large decrease in strength at 573 K is attributed to grain boundary sliding. Also, elongation increased rapidly at 723 - 823 K. This is likely to arise from the relatively high strain rate sensitivity of about 0.3 due to the glide-controlled dislocation creep.

Nonisothermal Crystallization Behavior of Poly(m-xylene adipamide)/Montmorillonite Nanocomposites

This article reports the nonisothermal crystallization behavior of MXD6 and its clay nanocomposite system (MXD6/MMT) using differential scanning calorimetry (DSC). The DSC experimental data were analyzed by theoretical modeling of the crystallization kinetics using the Avrami, Ozawa, Jeziorny, and the combined Avrami―Ozawa semiempirical models. It has been determined that these models adequately described the crystallization behavior of the MXD6 nanocomposite at cooling rates below 20 °C/min, but there was a deviation from linear dependence at higher cooling rates. This was attributed to changes of both the free energy and the cooling crystallization function K(T) over the entire crystallization process, as well as possible relaxation effects leading to structural rearrangements. In addition, the activation energy determined using the differential isoconversional method of Friedman was also found to vary, indicating changes in both the free energy and crystallization mechanism. Despite the lack of a reliable theoretical model, the heterogeneous nucleating activity of the MMT nanoparticles was demonstrated and quantified using Dobreva's method (Φ = 0.71), and the crystallization rate for the nanocomposite system was found to be greater than pure MXD6 by up to 79% at 40 °C/min.

Microbial-based therapy of cancer: a new twist to age old practice

The use of bacteria in the regression of tumors has long been known. Various approaches for using bacteria in cancer therapy include the use of bacteria as sensitizing agents for chemotherapy, as delivery agents for cancer drugs and as agents for gene therapy. The tumor regression stimulated by infecting microorganisms has been attributed to activation of the immune system of the host. However, recent studies indicate that when tumor-harboring mice with defective immune systems are infected with certain microorganisms, the regression of the tumor is still observed, suggesting that there are other host factors contributing to the microbial associated regression of tumors. Since the use of live or attenuated bacteria for tumor regression has associated toxic effects, studies are in progress to identify a pure microbial metabolite or any component of the microbial cell that might have anti-cancer activity. It has now been demonstrated that a redox protein from Pseudomonas aeruginosa, a cupredoxin, can enter into human cancer cells and trigger the apoptotic cell death. In vivo, this cupredoxin can lead to the regression of tumor growth in immunodeficient mice harboring xenografted melanomas and breast cancer tumors without inducing significant toxic effects, suggesting that it has potential anti-cancer activity. This bacterial protein interacts with p53 and modulates mammalian cellular activity. Hence, it could potentially be used as an anti-cancer agent for solid tumors and has translational value in tumor-targeted or in combinational-biochemotherapy strategies for cancer treatments. Here, we focus on diverse approaches to cancer biotherapy, including bacteriolytic and bacterially-derived anti-cancer agents with an emphasis on their mechanism of action and therapeutic potential.

Flexible deterministic packet marking: an IP traceback system to find the real source of attacks

Internet Protocol (IP) traceback is the enabling technology to control Internet crime. In this paper, we present a novel and practical IP traceback system called Flexible Deterministic Packet Marking (FDPM) which provides a defense system with the ability to find out the real sources of attacking packets that traverse through the network. While a number of other traceback schemes exist, FDPM provides innovative features to trace the source of IP packets and can obtain better tracing capability than others. In particular, FDPM adopts a flexible mark length strategy to make it compatible to different network environments; it also adaptively changes its marking rate according to the load of the participating router by a flexible flow-based marking scheme. Evaluations on both simulation and real system implementation demonstrate that FDPM requires a moderately small number of packets to complete the traceback process; add little additional load to routers and can trace a large number of sources in one traceback process with low false positive rates. The built-in overload prevention mechanism makes this system capable of achieving a satisfactory traceback result even when the router is heavily loaded. The motivation of this traceback system is from DDoS defense. It has been used to not only trace DDoS attacking packets but also enhance filtering attacking traffic. It has a wide array of applications for other security systems.

Solvent diffusion in poly(ether ether ketone)/poly(ether imide) blends

Solvent uptake in thin, amorphous samples of poly(ether ether ketone), poly(ether imide) and a 50/50 blend has been measured as a function of temperature. Diffusion coefficients, percentage weight increase and apparent activation energies have been calculated. The 50/50 blend shows anomalous diffusion behaviour which may be attributed to specific interactions between the homopolymers and density changes on blending.

Alkalosis increases muscle K+ release, but lowers plasma [K+] and delays fatigue during dynamic forearm exercise

Alkalosis enhances human exercise performance, and reduces K⁺ loss in contracting rat muscle. We investigated alkalosis effects on K⁺ regulation, ionic regulation and fatigue during intense exercise in nine untrained volunteers. Concentric finger flexions were conducted at 75% peak work rate (-3 W) until fatigue, under alkalosis (Alk, NaHCO₃, 0.3 g kg⁻¹) and control (Con, CaCO₃) conditions, 1 month apart in a randomised, double-blind, crossover design. Deep antecubital venous (v) and radial arterial (a) blood was drawn at rest, during exercise and recovery, to determine arterio-venous differences for electrolytes, fluid shifts, acid–base and gas exchange. Finger flexion exercise barely perturbed arterial plasma ions and acid–base status, but induced marked arterio-venous changes. Alk elevated [HCO₃⁻] and P^CO2, and lowered [H+] (P < 0.05). Time to fatigue increased substantially during Alk (25 ± 8%, P < 0.05), whilst both [K⁺]_a and [K⁺]_v were reduced (P < 0.01) and [K⁺]_a-v during exercise tended to be greater (P= 0.056, n= 8). Muscle K⁺ efflux at fatigue was greater in Alk (21.2 ± 7.6 µmol min⁻¹, 32 ± 7%, P < 0.05, n= 6), but peak K⁺ uptake rate was elevated during recovery (15 ± 7%, P < 0.05) suggesting increased muscle Na⁺,K^+-ATPase activity. Alk induced greater [Na⁺]_a, [Cl⁻]_v, muscle Cl⁻ influx and muscle lactate concentration ([Lac⁻]) efflux during exercise and recovery (P < 0.05). The lower circulating [K⁺] and greater muscle K⁺ uptake, Na⁺ delivery and Cl⁻ uptake with Alk, are all consistent with preservation of membrane excitability during exercise. This suggests that lesser exercise-induced membrane depolarization may be an important mechanism underlying enhanced exercise performance with Alk. Thus Alk was associated with improved regulation of K⁺, Na⁺, Cl⁻ and Lac⁻.

How well does the index of receptivity to tobacco industry promotion discriminate between smoking and never smoking adolescents.

Tobacco advertising is often named as the culprit that causes children to start smoking (Lancaster & Lancaster, 2003). This belief can partly be attributed to the Index of Receptivity to Tobacco Industry Promotion (IRTIP) developed by Evans, Farkas, Gilpin, Berry, & Pierce (1995). IRTIP was later modified and used by Pierce, Choi, Gilpin, Farkas, & Berry (1998) in a longitudinal study that claimed to have found a causal link between advertising and adolescent cigarette trial. The model is advertised by the American National Cancer Institute (2004) as being able to measure the likelihood of an adolescent starting smoking. Because of Pierce’s causality claim and this endorsement, IRTIP has been widely adopted by tobacco-control researchers. Consequently, the results from IRTIP based surveys have played a central role in influencing tobacco control policy. Based on the logic that a model used to predict the chances of a non-smoker becoming a smoker should be able to distinguish between these two groups, discriminant analysis with dummy coded variables was used to validate IRTIP. The results show that while IRTIP classifies never-smokers well, it grossly misclassifies smokers. This leads to questions about the validity of the model and of studies using IRTIP.

Understanding exercise uptake and adherence for people with chronic conditions : a new model demonstrating the importance of exercise identity, benefits of attending and support

Understanding the factors influencing uptake and adherence to exercise for people with chronic conditions from different ages, genders and ethnicities is important for planning exercise services. This paper presents evidence supporting a new model of exercise uptake and adherence applicable to people with chronic conditions from diverse socio-demographic backgrounds. The study is based on 130 semistructured interviews with people with chronic conditions, including both those who did and those who did not attend exercise services, and supporters of those who attended. Analysis followed the guidelines of ‘framework analysis’. Results show that three factors were particularly important in influencing adherence behavior: (i) exercise identity, (ii) support and (iii) perceived benefits of attending. Social and cultural identities impacted on willingness to exercise, importance of exercise and perceived appropriateness of exercising. Having at least one supporter providing different types of support was associated with high levels of attendance. Those people who valued the social and psychological benefits of attending were more likely to be high attenders. The new model illustrates interaction between these three factors and discusses how these can be taken into account when planning exercise services for people with chronic conditions drawn from diverse socio-demographic groups.

Nanocrystalline titanium to mesoporous anatase with high bioactivity

In present study, the formation of bioactive anatase on bulk titanium (Ti) by hybrid surface mechanical attrition treatment (SMAT) is reported. A commercial pure Ti plate first underwent SMAT in a vacuum for 1 h to produce a nanocrystalline layer with a thickness of about 30 µm, and then the nanocrystalline Ti (30 nm) was transformed into mesoporous anatase with a grain size 10 nm by chemical oxidation and calcination. The mesoporous anatase showed excellent bioactivity while being soaked in simulated body fluid, which could be attributed to the unique nanostructure on the SMAT Ti surface.