scispace - formally typeset
Search or ask a question

Showing papers by "University of Wollongong published in 2007"


Journal ArticleDOI
TL;DR: The authors compared the predictive validity of single-item and multiple-item measures of attitude toward the ad (AAd) and attitude towards the brand (ABrand), which are two of the most widely measured constructs in marketing.
Abstract: This study compares the predictive validity of single-item and multiple-item measures of attitude toward the ad (AAd) and attitude toward the brand (ABrand), which are two of the most widely measured constructs in marketing. The authors assess the ability of AAd to predict ABrand in copy tests of four print advertisements for diverse new products. There is no difference in the predictive validity of the multiple-item and single-item measures. The authors conclude that for the many constructs in marketing that consist of a concrete singular object and a concrete attribute, such as AAd or ABrand, single-item measures should be used.

2,218 citations


Book Chapter
01 Jan 2007
TL;DR: Since the IPCC Third Assessment Report (TAR), our understanding of the implications of climate change for coastal systems and low-lying areas (henceforth referred to as "coasts") has increased substantially and six important policy-relevant messages have emerged as discussed by the authors.
Abstract: Since the IPCC Third Assessment Report (TAR), our understanding of the implications of climate change for coastal systems and low-lying areas (henceforth referred to as ‘coasts’) has increased substantially and six important policy-relevant messages have emerged. Coasts are experiencing the adverse consequences of hazards related to climate and sea level (very high confidence). Coasts are highly vulnerable to extreme events, such as storms, which impose substantial costs on coastal societies [6.2.1, 6.2.2, 6.5.2]. Annually, about 120 million people are exposed to tropical cyclone hazards, which killed 250,000 people from 1980 to 2000 [6.5.2]. Through the 20th century, global rise of sea level contributed to increased coastal inundation, erosion and ecosystem losses, but with considerable local and regional variation due to other factors [6.2.5, 6.4.1]. Late 20th century effects of rising temperature include loss of sea ice, thawing of permafrost and associated coastal retreat, and more frequent coral bleaching and mortality [6.2.5]. Coasts will be exposed to increasing risks, including coastal erosion, over coming decades due to climate change and sea-level rise (very high confidence). Anticipated climate-related changes include: an accelerated rise in sea level of up to 0.6 m or more by 2100; a further rise in sea surface temperatures by up to 3°C; an intensification of tropical and extratropical cyclones; larger extreme waves and storm surges; altered precipitation/run-off; and ocean acidification [6.3.2]. These phenomena will vary considerably at regional and local scales, but the impacts are virtually certain to be overwhelmingly negative [6.4, 6.5.3].

1,755 citations


Journal ArticleDOI
TL;DR: The professionals most likely to act as gatekeepers to mental health services for young people are school counsellors, general practitioners, and youth workers, and Internet‐based information and interventions are being used to engage young people in the help‐seeking process.
Abstract: • Despite the high prevalence of mental health problems and disorders that develop in adolescence and early adulthood, young people tend to not seek professional help. Young men and young people from Indigenous and ethnic minority groups tend to be those most reluctant to seek help. • Young people are more inclined to seek help for mental health problems if they: ae have some knowledge about mental health issues and sources of help; ae feel emotionally competent to express their feelings; and ae have established and trusted relationships with potential help providers. • Young people are less likely to seek help if they: ae are experiencing suicidal thoughts and depressive symptoms; ae hold negative attitudes toward seeking help or have had negative past experiences with sources of help; or ae hold beliefs that they should be able to sort out their own mental health problems on their own. • Young people may seek help through talking to their family and friends, with family being more important for younger adolescents, and friends and partners becoming more influential later on.

938 citations


Journal ArticleDOI
TL;DR: The preparation and electrochemical performance of self-catalysis-grown SnO2 nanowires are reported on to determine their potential use as an anode material for lithium-ion batteries.
Abstract: One-dimensional (1D) nanostructured materials have received considerable attention for advanced functional systems as well as extensive applications owing to their attractive electronic, optical, and thermal properties. In lithium-ion-battery science, recent research has focused on nanoscale electrode materials to improve electrochemical performance. The high surface-to-volume ratio and excellent surface activities of 1D nanostructured materials have stimulated great interest in their development for the next generation of power sources. Materials based on tin oxide have been proposed as alternative anode materials with high-energy densities and stable capacity retention in lithium-ion batteries. Various SnO2-based materials have displayed extraordinary electrochemical behavior such that the initial irreversible capacity induced by Li2O formation and the abrupt capacity fading caused by volume variation could be effectively reduced when in nanoscale form. From this point of view, SnO2 nanowires can also be suggested as a promising anode material because the nanowire structure is of special interest with predictions of unique electronic and structural properties. Furthermore, the nanowires can be easily synthesized by a thermal evaporation method. However, in its current form, this method of manufacture of SnO2 nanowires has several limitations: it is inappropriate for mass production as high synthesis temperatures are required and there are difficulties in the elimination of metal catalysts that could act as impurities or defects. This results in reversible capacity loss or poor cyclic performance during electrochemical reactions. 12] The critical issues relating to SnO2 nanowires as anode materials for lithium-ion batteries are how to avoid the deteriorative effects of catalysts and how to increase production. Herein, we report on the preparation and electrochemical performance of self-catalysis-grown SnO2 nanowires to determine their potential use as an anode material for lithium-ion batteries. SnO2 nanowires have been synthesized by thermal evaporation combined with a self-catalyzed growth procedure by using a ball-milled evaporation material to increase production at lower temperature and prevent the undesirable effects of conventional catalysts on electrochemical performance. The self-catalysis-grown SnO2 nanowires show higher initial coulombic efficiency and an improved cyclic retention compared with those of SnO2 powder and SnO2 nanowires produced by Au-assisted growth. The self-catalysis growth method, which uses a ball-milled mixture of SnO and Sn powder as an evaporation source, is appropriate for obtaining SnO2 nanowires with high purity. The deposited products on the Si substrates contain almost 100% of the SnO2 nanowires formed. Observation with scanning electron microscopy (SEM) clearly shows a general view of randomly aligned SnO2 nanowires with diameters of 200–500 nm and lengths extending to several tens of micrometers (Figure 1a). Sn droplets at the tips of nanowires were observed and confirmed by energy dispersive X-ray (EDX)

851 citations


Journal ArticleDOI
TL;DR: The links between metabolic rate andmaximum life span of mammals and birds as well as the linking role of membrane fatty acid composition in determining the maximum life span are reviewed.
Abstract: Maximum life span differences among animal species exceed life span variation achieved by experimental manipulation by orders of magnitude. The differences in the characteristic maximum life span o...

789 citations


Journal ArticleDOI
18 Oct 2007-Nature
TL;DR: It is shown that by ∼164’kyr ago (±12 kyr) at Pinnacle Point (on the south coast of South Africa) humans expanded their diet to include marine resources, perhaps as a response to these harsh environmental conditions.
Abstract: Genetic and anatomical evidence suggests that Homo sapiens arose in Africa between 200 and 100 thousand years (kyr) ago, and recent evidence indicates symbolic behaviour may have appeared approximately 135-75 kyr ago. From 195-130 kyr ago, the world was in a fluctuating but predominantly glacial stage (marine isotope stage MIS6); much of Africa was cooler and drier, and dated archaeological sites are rare. Here we show that by approximately 164 kyr ago (+/-12 kyr) at Pinnacle Point (on the south coast of South Africa) humans expanded their diet to include marine resources, perhaps as a response to these harsh environmental conditions. The earliest previous evidence for human use of marine resources and coastal habitats was dated to approximately 125 kyr ago. Coincident with this diet and habitat expansion is an early use and modification of pigment, probably for symbolic behaviour, as well as the production of bladelet stone tool technology, previously dated to post-70 kyr ago. Shellfish may have been crucial to the survival of these early humans as they expanded their home ranges to include coastlines and followed the shifting position of the coast when sea level fluctuated over the length of MIS6.

788 citations


Journal ArticleDOI
TL;DR: This study demonstrates that the eyes-closed and eyes-open conditions provide EEG measures differing in topography as well as power levels, and should be recognised when evaluating EEG research, and considered when choosing eyes- Open or eyes- closed baseline conditions for different paradigms.

759 citations


Journal ArticleDOI
01 Dec 2007-Oikos
TL;DR: It is suggested that selection typically acts on maternal effects to maximise maternal rather than (or in addition to) offspring fitness, and many maternal effects will have an adaptive basis for mothers, regardless of whether these effects increase or decrease survival or reproductive success of individual offspring.
Abstract: Maternal effects have become an important field of study in evolutionary ecology and there is an ongoing debate regarding their adaptive significance. Some maternal effects can act to increase offspring fitness and are called 'adaptive maternal effects'. However, other maternal effects decrease offspring fitness and there is confusion regarding whether certain maternal effects are indeed adaptive or merely physiological inevitabilities. Here we suggest that the focus on the consequences of maternal effects for offspring fitness only and the use of 'snapshot' estimates of fitness have misdirected our effort to understand the evolution of maternal effects. We suggest that selection typically acts on maternal effects to maximise maternal rather than (or in addition to) offspring fitness. We highlight the importance of considering how maternal effects influence maternal fitness across a mother's lifetime and describe four broad types of maternal effects using an outcome-based approach. Overall, we suggest that many maternal effects will have an adaptive basis for mothers, regardless of whether these effects increase or decrease survival or reproductive success of individual offspring.

753 citations


Journal ArticleDOI
TL;DR: Gong et al. as discussed by the authors reported a new way of synthesizing hydrogels with a well-defined network structure and high mechanical strength, where a peroxidized MMS acts as both an initiator and a crosslinker.
Abstract: The industrial and biomedical applications of hydrogels made from either natural or synthetic sources are strongly limited by their poor mechanical properties. A normal structure (NS) hydrogel breaks under low stress because there are very few energy dissipation mechanisms to slow crack propagation. In addition, as their crosslinking points are distributed irregularly and the polymer chains between the crosslinking points have different lengths, the stress cannot be evenly distributed between the polymer chains, and crack initiation is facile. Many efforts have been focused on increasing the mechanical strength of hydrogels, but the robustness still remains unsatisfactory. In recent years, three kinds of novel hydrogels with unique structures and high mechanical strength have been developed. Topological (TP) gels have figure-ofeight crosslinkers that can slide along polymer chains. The gel swells to about 500 times its original weight and can be stretched to nearly 20 times its original length. The nanocomposite (NC) hydrogel is made from specific polymers with a water-swellable inorganic clay. Most of the macromolecules are grafted onto nanoparticles, indicating that the nanoparticle clay acts as a highly multifunctional crosslinking agent. We believe that the high mechanical strength of this material has its origin in the very high functionality of the rigid crosslinked points and the lack of short chains between crosslinked components, as every active chain has to stretch between nanoparticles. The extension degree of a chain before breakage is controlled by the relationship between its relaxed end-to-end distance and its contour length, which is low for short chains. When a short chain in an NS hydrogel breaks, its load is thrown onto just one or two other adjacent chains, which dramatically increases their load. Hence, multiple chain fractures occur, causing voids and microcracks. However, in an NC hydrogel with large, rigid crosslinking points, the load from a single broken chain will be spread over many other chains, and the material is less likely to form the microcracks and voids responsible for initiating bulk failure. Gong et al. have reported a new method of obtaining strong and tough hydrogels by making double-network (DN) materials with a high molar ratio of the second network to the first network. In this case, the first network is highly crosslinked and the second network is loosely crosslinked. These DN hydrogels demonstrate extremely high mechanical strength. By adding a third component to a DN gel, either a weakly crosslinked network or noncrosslinked linear chains, gels with high-strength and low-frictional coefficients were obtained. Macromolecular microspheres (MMSs) have become an important structure in polymeric materials. The hydrogel microspheres on the microor nanoscale are known as microgels or nanogels, respectively. They are usually environmentally sensitive and are mainly used in drug delivery and other biomedical applications. However, it is difficult to form bulk hydrogels (macrogels) with these microgels, and when formed, the macrogels do not exhibit high mechanical strength. Very little work has been done on incorporating other kinds of microspheres into bulk hydrogel structures, and the improvement in mechanical strength is far less than for the three hydrogels mentioned above. Here, we report a new way of synthesizing hydrogels with a novel, well-defined network structure and high mechanical strength. In this method, a peroxidized MMS acts as both an initiator and a crosslinker. The mechanism for the formation of the peroxide and the initiation of polymerization, as well as for the formation of a hydrogel, are proposed in Scheme 1. The new hydrogel is a macromolecular microsphere composite (MMC) hydrogel. When the MMS emulsion is irradiated with Co c-rays in oxygen, peroxides (POOR and POOH; here P is the macromolecule that comprises the MMS, and R is a short alkyl group) are formed on the surface and possibly, to a certain extent, in the inner part of the MMS. The formation of peroxides on the MMS was proven with iodometry, which is the common method used to verify their formation and determine the amount formed in the polymers. Potassium iodide and isopropyl alcohol were added to the irradiated MMS emulsion, and as the solution was heated and refluxed for 30 min, it gradually became yellow, which indicates the formation of I2 and further establishes the presence of peroxides on the MMS. The peroxides decomposed under heat to form the free radicals PO , OR , and OH . PO initiated the grafting of C O M M U N IC A TI O N

671 citations


Journal ArticleDOI
01 Oct 2007-Obesity
TL;DR: This review focuses on the ability of different accelerometers to assess daily physical activity as compared with the doubly labeled water (DLW) technique, which is considered the gold standard for measuring energy expenditure under free‐living conditions.
Abstract: This review focuses on the ability of different accelerometers to assess daily physical activity as compared with the doubly labeled water (DLW) technique, which is considered the gold standard for measuring energy expenditure under free-living conditions. The PubMed Central database (U.S. NIH free digital archive of biomedical and life sciences journal literature) was searched using the following key words: doubly or double labeled or labeled water in combination with accelerometer, accelerometry, motion sensor, or activity monitor. In total, 41 articles were identified, and screening the articles' references resulted in one extra article. Of these, 28 contained sufficient and new data. Eight different accelerometers were identified: 3 uniaxial (the Lifecorder, the Caltrac, and the CSA/MTI/Actigraph), one biaxial (the Actiwatch AW16), 2 triaxial (the Tritrac-R3D and the Tracmor), one device based on two position sensors and two motion sensors (ActiReg), and the foot-ground contact pedometer. Many studies showed poor results. Only a few mentioned partial correlations for accelerometer counts or the increase in R(2) caused by the accelerometer. The correlation between the two methods was often driven by subject characteristics such as body weight. In addition, standard errors or limits of agreement were often large or not presented. The CSA/MTI/Actigraph and the Tracmor were the two most extensively validated accelerometers. The best results were found for the Tracmor; however, this accelerometer is not yet commercially available. Of those commercially available, only the CSA/MTI/Actigraph has been proven to correlate reasonably with DLW-derived energy expenditure.

655 citations


Journal ArticleDOI
TL;DR: The results reveal that a superior CRM capability can create positional advantage and subsequent improved performance and that to be most successful, CRM programs should focus on latent or unarticulated customer needs that underpin a proactive market orientation.
Abstract: The market enthusiasm generated around investment in CRM technology is in stark contrast to the naysaying by many academic and business commentators. This raises an important research question concerning the extent to which companies should continue to invest in building a CRM capability. Drawing on field interviews and a survey of senior executives, the results reveal that a superior CRM capability can create positional advantage and subsequent improved performance. Further, it is shown that to be most successful, CRM programs should focus on latent or unarticulated customer needs that underpin a proactive market orientation.

Journal ArticleDOI
TL;DR: In this article, the Lake−Thomas mechanism was used to fracture and unload only 1% of the bonds within the hydrogel network, leading to a decrease of up to 80% in the number of strands.
Abstract: Systematic loading and unloading experiments, in uniaxial tension and uniaxial compression, have been performed on a double-network hydrogel exhibiting a very high toughness. We observed a significant hysteresis during the first loading cycle that increased strongly with the applied maximum deformation. A large hysteresis was not observed during a second loading cycle, implying that the initial hysteresis can be attributed to the fracture of covalent bonds in the primary network. We report this type of dissipative mechanism for polymer gels for the first time. Assuming that the entire energy dissipated during the hysteresis cycle can be attributed to the fracture of network strands by a Lake−Thomas mechanism, our results suggest that the fracture and unloading of only 1% of the bonds within the network leads to a decrease of up to 80% of the number of strands. These results also demonstrate the very large degree of heterogeneity within the hydrogel network. If such a dissipative mechanism is active at the...

Journal ArticleDOI
TL;DR: Lean red meats are: • An excellent source of high biological value protein, vitamin B12, niacin, Vitamin B6, iron, zinc and phosphorus • A source of long-chain omega-3 polyunsaturated fats, riboflavin, pantothenic acid, selenium and possibly also vitamin D
Abstract: Lean red meats are: • An excellent source of high biological value protein, vitamin B12, niacin, vitamin B6, iron, zinc and phosphorus • A source of long-chain omega-3 polyunsaturated fats, riboflavin, pantothenic acid, selenium and possibly also vitamin D • Mostly low in fat and sodium • Sources of a range of endogenous antioxidants and other bioactive substances including taurine, carnitine, carnosine, ubiquinone, glutathione and creatine.

Journal ArticleDOI
TL;DR: This study suggests that despite the fact that lead and zinc were most likely bound as sulfide phases in deeper sediments, the metals maintain their bioavailability because of the continued cycling between pore waters and surface sediments due to physical mixing and bioturbation.

Journal ArticleDOI
TL;DR: How bacteriophage-encoded GAS DNase (Sda1), which facilitates the pathogen's escape from neutrophil extracellular traps, serves as a selective force for covRS mutation is described, providing a paradigm whereby natural selection exerted by the innate immune system generates hypervirulent bacterial variants with increased risk of systemic dissemination.
Abstract: Most invasive bacterial infections are caused by species that more commonly colonize the human host with minimal symptoms. Although phenotypic or genetic correlates underlying a bacterium's shift to enhanced virulence have been studied, the in vivo selection pressures governing such shifts are poorly understood. The globally disseminated M1T1 clone of group A Streptococcus (GAS) is linked with the rare but life-threatening syndromes of necrotizing fasciitis and toxic shock syndrome. Mutations in the GAS control of virulence regulatory sensor kinase (covRS) operon are associated with severe invasive disease, abolishing expression of a broad-spectrum cysteine protease (SpeB) and allowing the recruitment and activation of host plasminogen on the bacterial surface. Here we describe how bacteriophage-encoded GAS DNase (Sda1), which facilitates the pathogen's escape from neutrophil extracellular traps, serves as a selective force for covRS mutation. The results provide a paradigm whereby natural selection exerted by the innate immune system generates hypervirulent bacterial variants with increased risk of systemic dissemination.

Journal ArticleDOI
TL;DR: The Niah evidence demonstrates the sophisticated nature of the subsistence behavior developed by modern humans to exploit the tropical environments that they encountered in Southeast Asia, including rainforest.

Journal ArticleDOI
TL;DR: This review argues for shifting the focus towards food in order to better understand the nutrition-health interface by introducing the concept of food synergy to denote the action of the food matrix on human biological systems.
Abstract: The identification of nutrients and the study of their bioactivity were significant developments in the evolution of contemporary nutrition science. This review argues for shifting the focus towards food in order to better understand the nutrition-health interface. It begins by introducing the concept of food synergy (a perspective that more information can be obtained by looking at foods than at single food components) to denote the action of the food matrix (the composite of naturally occurring food components) on human biological systems. A proposal is then made for the means by which food-focused research might build the knowledge base for etiologic discovery and appropriate dietary advice. The diet-heart disease dilemma is put forward as an example of where a nutrient-based approach has limitations, and a summary of studies targeting food composition strengthens the case for a food-based approach. Finally, the argument is made that evidence from interventions points back to the central position of food in the relationship between nutrition and health, a position that begs for more whole food-based research.

Journal ArticleDOI
TL;DR: This article examined the distinctiveness of three "positive thinking" variables (self-esteem, trait hope, and positive attributional style) in predicting future high school grades, teacher-rated adjustment, and students' reports of their affective states.

Journal ArticleDOI
TL;DR: It is proposed that iodothyronines are normal constituents of biological membranes in vertebrates and may be better thought of as 'vitamone'-like molecules than traditional hormonal messengers.
Abstract: The thyroid hormones are very hydrophobic and those that exhibit biological activity are 3',5',3,5-L-tetraiodothyronine (T4), 3',5,3-L-triiodothyronine (T3), 3',5',3-L-triiodothyronine (rT3) and 3,5',-L-diiothyronine (3,5-T2). At physiological pH, dissociation of the phenolic -OH group of these iodothyronines is an important determinant of their physical chemistry that impacts on their biological effects. When non-ionized these iodothyronines are strongly amphipathic. It is proposed that iodothyronines are normal constituents of biological membranes in vertebrates. In plasma of adult vertebrates, unbound T4 and T3 are regulated in the picomolar range whilst protein-bound T4 and T3 are maintained in the nanomolar range. The function of thyroid-hormone-binding plasma proteins is to ensure an even distrubtion throughout the body. Various iodothyronines are produced by three types of membrane-bound cellular deiodinase enzyme systems in vertebrates. The distribution of deiodinases varies between tissues and each has a distinct developmental profile. Thyroid hormones. (1) the nuclear receptor mode is especially important in the thyroid hormone axis that controls plasma and cellular levels of these hormones. (2) These hormones are strongly associated with membranes in tissues and normally rigidify these membranes. (3) They also affect the acyl composition of membrane bilayers and it is suggested that this is due to the cells responding to thyroid-hormone-induced membrane rigidificataion. Both their immediate effects on the physical state of membranes and the consequent changes in membrane composition result in several other thyroid hormone effects. Effects on metabolism may be due primarily to membrane acyl changes. There are other actions of thyroid hormones involving membrane receptors and influences on cellular interactions with the extracellulara matrix. The effects of thyroid hormones are reviewed and appear to b combinations of these various modes of action. During development, vertebrates show a surge in T4 and other thyroid hormones, as well as distinctive profiles in the appearance of the deiodinase enzymes and nuclear receptors. Evidence from the use of analogues supports multiple modes of action. Re-examination of data from th early 1960s supports a membrane action. Findings from receptor 'knockout' mice supports an important role for receptors in the development of the thyroid axis. These iodothyronines may be better thought of as 'vitamone'-like molecules than traditional hormonal messengers.

Journal ArticleDOI
TL;DR: The geomorphology and morphostratigraphy of numerous worldwide sites reveal the relative movements of sea level during the peak of the last interglaciation (Marine Isotope Stage (MIS) 5e, assumed average duration between 13072 and 11972 ka) as discussed by the authors.

Journal ArticleDOI
TL;DR: This paper explored the phenomenon of bubble wrapping children to appease the anxieties of some middle class parents, and pointed out the negative impact of this on children's independent mobility and environmental play.
Abstract: Children in middle class Australia, and many western countries around the world experience restricted opportunities to engage in free play in their neighbourhood streets and parks. The impact of this has been a drastic decrease in children's independent mobility and environmental play. Recent research has focused on the physical environment of neighbourhoods' in an attempt to understand how they might be designed to encourage children's play and increase their environmental learning. This paper explores these same issues but from a different perspective. That is, to explain some of the changes in childhood environmental behaviours I explore children and parent relationships, in particular, the phenomena of ‘bubble‐wrapping’ children to appease the anxieties of some middle class parents. I acknowledge when making these claims that parenting is a complex and highly individual enterprise with many variables, therefore this paper is only seeking to draw attention to a broad pattern of behaviour of a select gr...

Journal ArticleDOI
TL;DR: A ternary composite of CNT/polypyrrole/hydrous MnO 2 is prepared by in situ chemical method and its electrochemical performance is evaluated by using cyclic voltammetry (CV), impedance measurement and constant-current charge/discharge cycling techniques as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the effect of the capital structure on the performance of Jordanian companies and found that the short-term debt to total assets (STDTA) level has a significantly positive effect on the market performance measure (Tobin's Q).
Abstract: This study is to investigate the effect which capital structure has had on corporate performance using a panel data sample representing of 167 Jordanian companies during 1989-2003. Our results showed that a firm’s capital structure had a significantly negative impact on the firm’s performance measures, in both the accounting and market’s measures. We also found that the short-term debt to total assets (STDTA) level has a significantly positive effect on the market performance measure (Tobin’s Q). The Gulf Crisis 1990-1991 was found to have a positive impact on Jordani an corporate performance while the out break of Intifadah in the West Bank and Gaza in September 2000 had a negative impact on corporate performance.

Journal ArticleDOI
06 Jul 2007-Science
TL;DR: Broad continuity of Middle Paleolithic technology across the YTT event suggests that hominins persisted regionally across this major eruptive event.
Abstract: The Youngest Toba Tuff (YTT) eruption, which occurred in Indonesia 74,000 years ago, is one of Earth's largest known volcanic events. The effect of the YTT eruption on existing populations of humans, and accordingly on the course of human evolution, is debated. Here we associate the YTT with archaeological assemblages at Jwalapuram, in the Jurreru River valley of southern India. Broad continuity of Middle Paleolithic technology across the YTT event suggests that hominins persisted regionally across this major eruptive event.

Journal ArticleDOI
TL;DR: In this paper, a model study of carbon monoxide for 1988-1997 using the GEOS-Chem 3-D model driven by assimilated meteorological data, with time-varying emissions from biomass burning and from fossil fuel and industry, overhead ozone columns, and methane.
Abstract: [1] We present a model study of carbon monoxide for 1988–1997 using the GEOS-Chem 3-D model driven by assimilated meteorological data, with time-varying emissions from biomass burning and from fossil fuel and industry, overhead ozone columns, and methane. The hydroxyl radical is calculated interactively using a chemical parameterization to capture chemical feedbacks. We document the inventory for fossil fuels/industry and discuss major uncertainties and the causes of differences with other inventories that give significantly lower emissions. We find that emissions hardly change from 1988 to 1997, as increases in Asia are offset by decreases elsewhere. The model reproduces the 20% decrease in CO at high northern latitudes and the 10% decrease in the North Pacific, caused primarily by the decrease in European emissions. The model compares well with observations at sites impacted by fossil fuel emissions from North America, Europe, and east Asia suggesting that the emissions from this source are reliable to 25%, and we argue that bottom-up emission estimates are likely to be too low rather than too high. The model is too low at the seasonal maximum in spring in the southern tropics, except for locations in the Atlantic Ocean. This problem may be caused by an overestimate of the frequency of tropical deep convection, a common problem in models that use assimilated meteorological data. We argue that the yield of CO from methane oxidation is near unity, contrary to some other studies, based on removal rates of intermediate species.

Journal ArticleDOI
TL;DR: In this paper, a comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and formation to take place simultaneously at low temperatures, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in Jc.
Abstract: A comparative study of pure, SiC, and C doped MgB2 wires has revealed that the SiC doping allowed C substitution and MgB2 formation to take place simultaneously at low temperatures. C substitution enhances Hc2, while the defects, small grain size, and nanoinclusions induced by C incorporation and low-temperature processing are responsible for the improvement in Jc. The irreversibility field (Hirr) for the SiC doped sample reached the benchmarking value of 10 T at 20 K, exceeding that of NbTi at 4.2 K. This dual reaction model also enables us to predict desirable dopants for enhancing the performance properties of MgB2.

Journal ArticleDOI
TL;DR: The influence of membrane fouling on the retention of pharmaceutically active compounds (PhACs) by three nanofiltration membranes was investigated in this study and it was hypothesised that such influence was governed by three distinctive mechanisms: modification of the membrane charge surface, pore restriction, and cake enhanced concentration polarisation.

Journal ArticleDOI
TL;DR: There are statistical artefacts associated with T-scores that have implications for how SF36V2 data are analysed and interpreted, and the proportions of cases within T-score deciles show there are important data distribution issues.
Abstract: The SF36 Version 2 (SF36V2) is a revision of the SF36 Version 1, and is a widely used health status measure. It is important that guidelines for interpreting scores are available. A population sample of Australians (n = 3015) weighted to achieve representativeness was administered the SF36V2. Comparisons between published US weights and sample derived weights were made, and Australian population norms computed and presented. Significant differences were observed on 7/8 scales and on the mental health summary scale. Possible causes of these findings may include different sampling and data collection procedures, demographic characteristics, differences in data collection time (1998 vs. 2004), differences in health status or differences in cultural perception of the meaning of health. Australian population norms by age cohort, gender and health status are reported by T-score as recommended by the instrument developers. Additionally, the proportions of cases within T-score deciles are presented and show there are important data distribution issues. The procedures reported here may be used by other researchers where local effects are suspected. The population norms presented may be of interest. There are statistical artefacts associated with T-scores that have implications for how SF36V2 data are analysed and interpreted.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the influence of fabrication conditions on the performance of magnetorheological elastomers (MR Elastomers) such as matrix type, external magnetic flux density, and temperature, plasticizer and iron particles.
Abstract: Magnetorheological Elastomers (MR Elastomers or MREs) are a kind of novel smart material, whose mechanical, electrical, magnetic properties are controllable under applied magnetic fields. They have attracted increasing attentions and broad application prospects. But conventional MREs are limited to wide applications because their MR effects and mechanical performances are not high enough. This paper aims to optimize the fabrication method and to fabricate good natural rubber based MREs with high modulus by investigating the influences of a variety of fabrication conditions on the MREs performances, such as matrix type, external magnetic flux density, and temperature, plasticizer and iron particles. Among these factors, the content of iron particles plays a most important contribution in shear modulus. When the iron particle weight fraction is 80% and the external magnetic flux density is 1 T, the field-induced increment of shear modulus reaches 3.6 MPa, and the relative MR effect is 133%. If the iron weight fraction increases to 90%, the field-induced increment of shear modulus is 4.5 MPa. This result has exceeded the best report in the literatures researching the MREs on the same kind of matrix. The dynamic performances of MREs were also experimentally characterized by using a modified Dynamic Mechanical Analyzer (DMA) system. The effects of strain amplitude and driving frequency on viscoelastic properties of MREs were analyzed.

Journal ArticleDOI
TL;DR: Sidestep cutting technique had a significant effect on loads experienced at the knee, such as foot wide, torso leaning in the opposite direction to the cut and torso rotating in the same direction as the cut, which place an athlete at higher risk of injury.
Abstract: Purpose: To identify the effect of modifying sidestep cutting technique on knee loads and predict what impact such change would have on the risk of noncontact anterior cruciate ligament injury. Methods: A force platform and motion-analysis system were used to record ground-reaction forces and track the trajectories of markers on 15 healthy males performing sidestep cutting tasks using their normal technique and nine different imposed techniques. A kinematic and inverse dynamic model was used to calculate the three-dimensional knee postures and moments. Results: The imposed techniques of foot wide and torso leaning in the opposite direction to the cut resulted in increased peak valgus moments experienced in weight acceptance. Higher peak internal rotation moments were found for the foot wide and torso rotation in the opposite direction to the cut techniques. The foot rotated in technique resulted in lower mean flexion/extension moments, whereas the foot wide condition resulted in higher mean flexion/extension moments. The flexed knee, torso rotated in the opposite direction to the cut and torso leaning in the same direction as the cut techniques had significantly more knee flexion at heel strike. Conclusion: Sidestep cutting technique had a significant effect on loads experienced at the knee. The techniques that produced higher valgus and internal rotation moments at the knee, such as foot wide, torso leaning in the opposite direction to the cut and torso rotating in the opposite direction to the cut, may place an athlete at higher risk of injury because these knee loads have been shown to increase the strain on the anterior cruciate ligament. Training athletes to avoid such body positions may result in a reduced risk of noncontact anterior cruciate ligament injures.