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From foraging patterns in a single tree to social interactions across a home range, how primates use space is a key question in the field of primate behavioral ecology. Drawing on the latest advances in spatial analysis tools, this book offers practical guidance on applying geographic information systems (GIS) to central questions in primatology. An initial methodological section discusses niche modelling, home range analysis and agent-based modelling, with a focus on remote data collection. Research-based chapters demonstrate how ecologists apply this technology to study intensity of range use and travel routes, as well as to population-level questions; how GIS can help to assess the impact of logging, mining and hunting, as well as to inform primate conservation strategies. Offering best practice guidelines on cutting-edge technologies, this is an indispensable resource for any primatologist or student of animal behaviour.
In vitro maintenance of helminth parasites enables a variety of molecular, pharmaceutical and immunological analyses. Currently, the nutritional and environmental in vitro requirements of the equine ascarid parasite, Parascaris spp., have not been determined. Additionally, an objective method for assessing viability of Parascaris spp. intestinal stages does not exist. The purpose of this study was to ascertain the in vitro requirements of intestinal stages of Parascaris spp., and to develop a viability assessment method. A total of 1045 worms were maintained in a total of 212 cultures. Worms obtained from naturally infected foals at necropsy were immediately placed in culture flasks containing 200 mL of culture media. A variety of media types, nutrient supplementation and environmental conditions were examined. A motility-based scoring system was used to assess worm viability. Worms maintained in Roswell Park Memorial Institute-1640 had significantly better viability than any other media (P < 0.0001) and all media types supplemented with any of the nutrients examined (P < 0.0001). The use of a platform rocker also significantly improved viability (P = 0.0305). This is the first study to examine the requirements for maintaining Parascaris spp. intestinal stages in vitro and to evaluate their viability based on movement using an objective scoring system.
Mesophotic ecosystems have been relatively poorly studied in the Indo-Pacific and in particular within the Coral Triangle region. Here we used a mini-ROV to explore the changes in major benthic groups at two sites (~200 m apart) in the Wakatobi Marine National Park, SE Sulawesi, Indonesia spanning shallow water coral reefs (5 m) to deeper water mesophotic ecosystems (80 m). We found very similar patterns at both sites where coral cover peaked at 15 m, declined rapidly by 30 m, and was virtually absent at 50 m. As coral declined there was a marked increase in sponges, soft corals and other encrusting organisms (including ascidians, bryozoans, tubeworms, gorgonians and molluscs). Importantly, our results differ from most previous studies in other geographic locations where hard corals extend much deeper. It is unclear what drives this difference but it may be related to higher levels of turbidity and therefore reduced light penetration in the Wakatobi compared with other areas, which limits the vertical extent of coral development.
The effect of the nanofiller chemistry on the mechanical behaviour of thermoset polymer matrix nanocomposites is investigated. The interaction between a crosslinked polymer resin and the reinforcing nanofibers driven by their chemistry is revealed by molecular dynamics simulations. Specifically, crosslinked network systems of neat epoxy and epoxy-P(St-co-GMA) are modeled to discuss the effect of various molecular interactions as a function of temperature on a molecular basis. At 433K°, incorporation of single molecule of bonded P(St-co-GMA) and nonbonded P(St-co-GMA) lead to increase in Young’s modulus by 10% and 6%, respectively, compared to neat epoxy system.
Recent advances in fabricating controlled-morphology vertically aligned carbon nanotube (VA-CNTs) with ultrahigh volume fraction create unique opportunities for markedly improving the electromechanical performance of ionic polymer conductor network composite actuators (IPCNCs). Actuator experiments show that the continuous paths through inter-VA-CNT channels and low electrical conduction resistance due to the continuous CNTs in the composite electrodes of the IPCNC lead to fast ion transport and actuation speed (>10% strain/second). One critical issue in developing advanced actuator materials is how to suppress or eliminate unwanted strains generated under electric stimulation, which reduce the actuation efficiency and also the actuation strains. We observe that the VA-CNTs in the composite electrodes yields non-isotropic elastic modulus that suppresses the unwanted strain and markedly enhances the actuation strain (>8% strain under 4 volts). A transmission line model has been developed to understand the electrical properties of the actuator device.
Little is known about the prevalence or correlates of DSM-IV pathological gambling (PG).
Data from the US National Comorbidity Survey Replication (NCS-R), a nationally representative US household survey, were used to assess lifetime gambling symptoms and PG along with other DSM-IV disorders. Age of onset (AOO) of each lifetime disorder was assessed retrospectively. AOO reports were used to study associations between temporally primary disorders and the subsequent risk of secondary disorders.
Most respondents (78.4%) reported lifetime gambling. Lifetime problem gambling (at least one Criterion A symptom of PG) (2.3%) and PG (0.6%) were much less common. PG was significantly associated with being young, male, and Non-Hispanic Black. People with PG reported first gambling significantly earlier than non-problem gamblers (mean age 16.7 v. 23.9 years, z=12.7, p<0.001), with gambling problems typically beginning during the mid-20s and persisting for an average of 9.4 years. During this time the largest annual gambling losses averaged US$4800. Onset and persistence of PG were predicted by a variety of prior DSM-IV anxiety, mood, impulse-control and substance use disorders. PG also predicted the subsequent onset of generalized anxiety disorder, post-traumatic stress disorder (PTSD) and substance dependence. Although none of the NCS-R respondents with PG ever received treatment for gambling problems, 49.0% were treated at some time for other mental disorders.
DSM-IV PG is a comparatively rare, seriously impairing, and undertreated disorder whose symptoms typically start during early adulthood and is frequently secondary to other mental or substance disorders that are associated with both PG onset and persistence.
Over the life span, the human body increasingly functions less efficiently. Skin wrinkles and sags; hair thins and turns grey; muscle mass and strength are more difficult to maintain; joints deteriorate; aerobic capacity and cardiac output decrease; the immune system becomes less responsive; visual and auditory acuity decline – and this is just a partial list. Faced with these changes, it is not surprising that many people dread growing old because they believe ageing portends losses in functional capacities and the enjoyable aspects of life. This chapter highlights the demographic realities of an ageing population, debunks some of the myths about age and physical functioning and summarizes research on the factors that promote successful ageing.
There is no doubt that the population of many western countries is ‘greying’. Average life expectancy in the US in 1900 was 47 years; today, it is closer to 76 years. Over two-thirds of people now live to at least age 65 (a three-fold increase from 1900). Furthermore, the fastest growing segment of the population is in the category over age 85 – 4% in 1900 to more than 10% today (e.g. US Department of Health and Human Services [DHHS], 1992; Volz, 2000).
Attitudes about ageing reflect many negative stereotypes about the intellectual prowess of our senior citizens (Center for the Advancement of Health, 1998). Are older people as cognitively deficient as is commonly assumed? Are they significantly less capable than middle-aged or younger adults of profiting from classroom instruction, solving everyday problems such as remembering to turn off the oven after removing a roast, or learning to operate such new technologies as computers, DVD players, or ATM machines?
Study of the abilities to learn, remember, and solve problems has a long history in psychology and is arguably the most thoroughly investigated aspect of adult development and ageing (Siegelman & Rider, 2003). One reason for this emphasis is that cognitive functioning in adulthood has so many important implications for the quality of ordinary people's lives. Furthermore, cognitive functioning can play a major role in how people feel about themselves as they age. Middle-aged adults occasionally claim that they have experienced a ‘senior moment’ after forgetting someone's name, their own telephone number, or a step in a well practiced procedure such as recording a programme on their VCR. Although such comments may be offered in a humorous light, they also may reflect a deep-seated concern that many middle-aged and older adults have about losing their memories (Whitbourne, 2005) (see ‘Dementias’).
Indeed, older adults have reasons for suspecting that their cognitive powers are declining.
Improvements in the tribological properties of pure aluminum and “aeronautical” alloy AA7075-T651 were obtained by oxygen-ion implantation [(0.7 to 5) × 1017 O/cm2, 30 keV] using our pulsed electron cyclotron resonance plasma source. This oxygen plasma source ion implantation process produced oxide nanoprecipitates that enhanced the hardness up to three times in the surface layer and caused reductions in the scratch depths and the friction coefficients by similar factors. A spectrum of tribological properties was obtained depending on temperature and ion dose. Temperature measurement and control were obtained through an integrated thermocouple and by changing the duty-cycle of the microwave source. The oxygen content and the depth-resolved chemical composition were measured and optimized using x-ray photoelectron spectroscopy (XPS) combined with Ar-ion etching. The tribological properties were investigated by (i) depth-sensing nanoindentation for hardness and Young's modulus, (ii) scratching and scratch-depth measurement via atomic force microscopy (AFM), and (iii) friction force measurements using AFM. Low-temperature (≤160°C) implantations with optimal O-ion doses produced, in both pure and alloyed Al, an approximately 50-nm-thick, smooth, and extremely fine-grained metal–alumina nanocomposite. The resulting surface was hard and stiff but nonbrittle and displayed high scratch resistance and low friction. High-temperature (~430°C) implantation had different effects on pure Al and AA7075. On pure Al, it produced a very hard but brittle Al2O3 layer for which yield points (displacement excursions) were observed at critical load values in the nanoindentation force–displacement curves. On AA7075, XPS chemical profiling revealed an effect of extreme Mg surface segregation and complete Al surface depletion; MgO crystallites formed a rather rough but surprisingly thick layer (>100 nm). The resulting AA7075 surface showed a hardness increase that was substantial but slightly smaller than that obtained at low temperature.
Aluminum and its alloys show poor tribological properties. Oxygen plasma source ion implantation is an emerging technology for the improvement of the surface mechanical properties of these materials. We found an optimum O ion dose, corresponding to 35 at.% O, for which we were able to obtain nanohardness enhancements by factors of 2× and 3× for pure and alloyed (AA7075) Al, respectively. Nanoscratch test results showed reductions in the scratch depths and the friction coefficients by nearly the same factors. It is also important to control the process temperature (∼160 °C). These improvements are due to the formation of a smooth, stiff, but nonbrittle metal–oxide (Al–Al2O3) nanocomposite.
The addition of carbon nanotubes (CNTs) to a polymer matrix is expected to yield improvements in both mechanical and electrical properties. The focus of this paper is to give a snapshot of our current work on CNT-filled thermoplastic polymer textile fibers and the enhancement of their electrical properties. The challenge is to determine the type and size of nanotubes that are most effective for a given application, and how they should be dispersed or modified to interact with the polymer. The objective of this work is to develop an understanding of how the processing methods and properties of nanotube polymer composites are related to the geometry of the nanotubes used, their orientation, and their loading fraction. It will then be possible to design desired composite properties by controlling the relevant process variables.
The research described in this paper primarily involves mesoscale simulations (dissipative particle dynamics) of packed assemblies of oriented CNTs suspended in a polymer matrix. Computer simulations have been carried out to study the effect of processing conditions, aspect ratio of CNTs and effect of electric field on electrical conductivity. The percolation threshold required to achieve an electrically conductive polymer-CNT fiber can be predicted for given set of process variables. The model predictions are compared with the predictions of classical percolation theory, and with experimental data from measurements of bulk resistivity from CNTs dispersed in thermoplastic polymers.
A range of multi-wall carbon nanotubes and carbon nanofibres were mixed with a polyamide-12 matrix using a twin-screw microextruder, and the resulting blends used to produce a series of reinforced polymer fibres. The aim was to compare the dispersion and mechanical properties achieved for nanofillers produced by different techniques. A high quality of dispersion was achieved for all the catalytically-grown materials and the greatest improvements in stiffness were observed using aligned, substrate-grown, carbon nanotubes. The use of entangled multi-wall carbon nanotubes led to the most pronounced increase in yield stress. The degrees of polymer and nanofiller alignment and the morphology of the polymer matrix were assessed using X-ray diffraction and calorimetry.
Latexes are dispersions of homopolymers and copolymers, usually in water. Uses of these latexes are many such as protective coatings and adhesives. In order to form a continuous film the polymer must have film forming properties such as a low glass transition temperature (Tg). Latexes are being designed such as one polymer in the core of the particle and a shell of another polymer or perhaps a series of shell layers. Microscopy has become a powerful tool in the examination of the morphology of the latex particles. Because of the use of low Tg polymers, sample preparation and examination by electron microscopy at temperatures above the Tg of the polymer causes the particles to become distorted and no longer representative of their true morphology. Low temperature methods therefore have become crucial in the field of latex microscopy.