Testing a theoretical framework for the environment-species abundance paradigm: a new approach to the Abundant Centre Hypothesis

The linkage between environment, a species' fitness and its abundance is central to the theory of evolution. So far, all studies of this linkage have been heuristic and empirical due to an inability to determine fitness either experimentally (independent of abundance) or theoretically (from species-environment interaction). One category of such studies involves the Abundant Centre Hypothesis which posits that a species' abundance rises to a maximum at the centre of its range. We argue that the confusing mix of results from ACH studies arises from ignoring the central premise that the abundance distribution cannot be independent of the environment. First, we employed a theoretical framework to identify an environmental context (an elevational transect; 200-2800 m in the eastern Himalayas) likely to favour ACH. We then improved upon some previously identified conceptual and methodological shortcomings of ACH studies. Using systematically collected bird data (245 species; 15867 records) from that transect we found that the community average abundance profile is symmetric, as expected by ACH. Notwithstanding which, the abundance profiles of individual species showed a small degree of asymmetry which was correlated with elevation. This elevational dependence may be due to the hard elevational limits at the lower and upper ends of the mountain, as expected from theoretical considerations. We also showed that the average abundance profile shape is close to gaussian, while ruling out uniform and inverted-quadratic shapes. This work demonstrates that selecting a particular category of environmental contexts can help in integrating theoretical tools into a field dominated by empirical studies. Such a union should spur the development of more detailed and testable theoretical models for better insights in an important field.

Features of formation somatic pathologies under chronic exposure to hydrofluoride in the manufacture of titanic alloys

Introduction. Most studies on the morbidity of workers with fluorine compounds are devoted to occupational medicine at aluminium industry enterprises. The aim of the study is to identify the exposure, gender and evolutionary features of the formation of general somatic morbidity associated with chronic occupational exposure to hydrofluoride in the production of titanium alloys. Materials and methods. The analysis of the prevalence of chronic pathology according to the medical examination of 562 workers in contact with hydrofluoride and the incidence of temporary disability according to 29949 disability sheets in comparison with non-exposed persons of the same enterprise is given. Results. With an increase in the degree of harmfulness of working conditions, there was an augmentation increase in the risk of developing pathology of the respiratory organs, eyes, musculoskeletal system, arterial hypertension and hypercholesterolemia. In the working conditions of Class 3.1, an increased prevalence of diseases of the nervous and genitourinary systems with a moderate degree of occupational conditionality was revealed (relative risks (RR) 1.6 and 2.0, respectively, р < 0.05), class 3.2 - a high degree of professional conditionality of respiratory diseases (RR = 2.8). When working in harmful working conditions, there was an average degree of occupational conditionality of nervous system diseases in women (RR = 1.9) and a small degree of arterial hypertension in men (RR = 1.2). The prevalence of general somatic pathology in all age groups was higher than in non-exposed persons of the same age. Conclusion. Hydrofluoride in the production of titanium alloys was proved to be a trigger contributing to the formation of the pathology of the respiratory, circulatory, digestive, ear, eyes, skin, blood, musculoskeletal, nervous, endocrine, and genitourinary systems.

Room-Temperature Synthesis of Ni and Pt-Co Alloy Nanoparticles Using a Microreactor

Metal nanoparticles (NPs) are key materials used in a broad range of industries. Among the various synthetic routes of NPs, liquid-phase chemical reactions are promising because of their versatility in reaction conditions as well as their potential productivity. However, because the synthesis of NPs involves not only chemical reactions but also nucleation and growth processes, which are typically higher-order reactions in terms of the concentration, a small degree of nonuniformity in the concentration during mixing of reaction solutions can easily result in a wide size distribution of the resultant particles. A typical solution to this problem is to slow the rate of reactions compared with that of mixing; however, as a result, the synthetic processes often require long reaction periods and complex procedures. In this study, we applied a microreactor with excellent mixing performance to NP synthesis to simplify and intensify the processes. We synthesized nickel and platinum-cobalt alloy NPs as model materials. For the Ni NP synthesis, we demonstrated that the quick mixing provided by the microreactor enabled the precise control of the residence time, and consequently, monodispersed Ni NPs with an average size of 3.8 nm were synthesized. For the Pt-Co bimetallic system, the microreactor successfully produced Pt-Co alloy NPs, while batch-type synthesis with weaker mixing intensity resulted in a bimodal mixture of larger Pt NPs and smaller Co NPs. For both Ni and Pt-Co, monodispersed NPs were synthesized by simply mixing the reaction solutions in the microreactor at room temperature. These results demonstrate that the mixing process plays a key role in NP synthesis, and application of a microreactor enables the establishment of a facile and robust synthetic process.

Investigation of Shear Flow in a Planar Cylindrical Hybrid Geometry for Rheo-NMR Applications

<p>Materials which exhibit peculiar behaviour due to applied mechanical deformations are abundant in everyday life. Rheo-NMR is an established technique which has been used to study these responses for the past three decades by combining methodologies from rheometry and nuclear magnetic resonance (NMR). The technique enhances standard rheological studies of bulk properties, such as viscosity and elasticity, by applying the tools of NMR (e.g. spectroscopy, diffusion, relaxometry, imaging, and velocimetry) to matter under deformation. This allows for the exploration of molecular origins and / or local responses within the material which lead to the macroscopic behaviour. These materials are deformed (most commonly sheared) inside geometric housings with a NMR experiment running in parallel. For complex material studies it is desirable for these geometries to provide a simple homogeneous deformation. In reality, all standard rheometry geometries have inhomogeneity characteristics. In fact there is evidence to suggest that some material responses may be influenced by a small degree of deviation from pure homogeneity. This makes it harder to isolate any inherent material behaviour due to a magnitude or rate of deformation from the specific characteristics of how the deformation was applied. This contribution reports on the continued design and method development of a novel geometry for rheo-NMR - a planar cylindrical hybrid (PCH) shear geometry. The geometry includes planar sections with the aim to provide planar Couette flow, a simple truly homogeneous shear profile. It comprises of two parallel sections of planar flow connected by two semi-circular sections of circular flow to give a closed flow path in the shape of a racetrack. Shear is applied by rotating a band around the inner section like a conveyor belt. The purpose of the PCH geometry is to study the complex responses of materials under shear in this atypical shear environment. A paragon of a model system for exploring the novel geometry is a shear banding wormlike micelle (WLM) solution. It has a well documented nonlinear response to steady shear and previous work demonstrated that the curvature of a standard concentric cylinder geometric housing influenced the observed WLM’s rheological response. Strikingly, what was discovered by this thesis research was that there was no visible appearance of this material separating into bands in the planar (or cylindrical) regions in the PCH geometry when probed with an NMR velocity encoded imaging experiment. The more Newtonian-like response of the complex material differs from the intriguing curved flow profile seen for an actual Newtonian sample (which additionally evolves over the planar region) meaning the WLM’s response is still complex in nature. From these findings it is clear that geometry did not impart the homogeneous planar Couette flow for a Newtonian sample. However it has introduced a new deformation environment to study complex materials, acting completely differently to the geometries typically used in rheo-NMR and rheometry. Implications of this and motivation for work study are discussed.</p>

Investigation of Shear Flow in a Planar Cylindrical Hybrid Geometry for Rheo-NMR Applications

<p>Materials which exhibit peculiar behaviour due to applied mechanical deformations are abundant in everyday life. Rheo-NMR is an established technique which has been used to study these responses for the past three decades by combining methodologies from rheometry and nuclear magnetic resonance (NMR). The technique enhances standard rheological studies of bulk properties, such as viscosity and elasticity, by applying the tools of NMR (e.g. spectroscopy, diffusion, relaxometry, imaging, and velocimetry) to matter under deformation. This allows for the exploration of molecular origins and / or local responses within the material which lead to the macroscopic behaviour. These materials are deformed (most commonly sheared) inside geometric housings with a NMR experiment running in parallel. For complex material studies it is desirable for these geometries to provide a simple homogeneous deformation. In reality, all standard rheometry geometries have inhomogeneity characteristics. In fact there is evidence to suggest that some material responses may be influenced by a small degree of deviation from pure homogeneity. This makes it harder to isolate any inherent material behaviour due to a magnitude or rate of deformation from the specific characteristics of how the deformation was applied. This contribution reports on the continued design and method development of a novel geometry for rheo-NMR - a planar cylindrical hybrid (PCH) shear geometry. The geometry includes planar sections with the aim to provide planar Couette flow, a simple truly homogeneous shear profile. It comprises of two parallel sections of planar flow connected by two semi-circular sections of circular flow to give a closed flow path in the shape of a racetrack. Shear is applied by rotating a band around the inner section like a conveyor belt. The purpose of the PCH geometry is to study the complex responses of materials under shear in this atypical shear environment. A paragon of a model system for exploring the novel geometry is a shear banding wormlike micelle (WLM) solution. It has a well documented nonlinear response to steady shear and previous work demonstrated that the curvature of a standard concentric cylinder geometric housing influenced the observed WLM’s rheological response. Strikingly, what was discovered by this thesis research was that there was no visible appearance of this material separating into bands in the planar (or cylindrical) regions in the PCH geometry when probed with an NMR velocity encoded imaging experiment. The more Newtonian-like response of the complex material differs from the intriguing curved flow profile seen for an actual Newtonian sample (which additionally evolves over the planar region) meaning the WLM’s response is still complex in nature. From these findings it is clear that geometry did not impart the homogeneous planar Couette flow for a Newtonian sample. However it has introduced a new deformation environment to study complex materials, acting completely differently to the geometries typically used in rheo-NMR and rheometry. Implications of this and motivation for work study are discussed.</p>

Experimental study of the flow structure in cross flows

This study investigates the development of flow and mixing processes in the stationary and impulsive transverse jets with a small degree and frequency of blowing pulsation. Velocity field measurements were carried out using the TR PIV technique. The fields of statistical moments are obtained. It is shown that when a cross flow is injected, the main flow is turbulized, while the rise of the pulsating jet depends on the outflow mode. It is shown that with an increase in the frequency of pulsations of the transverse jet, it is more strongly “pressed” against the lower wall, maximum values of the intensity of pulsations of the transverse velocity component exceed by more than 1.5 times the values of pulsations of the transverse component.

The effect of post-fixation olecranon lengthening on range of motion of the elbow: a cadaveric study

Background Principles of fixation of comminuted olecranon fractures include anatomical reduction of the articular surface and restoration of ulnohumeral joint motion. However, comminution sometimes may not permit anatomical fixation of fracture fragments, resulting in inadvertent olecranon lengthening after plate fixation. The aim of our study is to investigate the relationship between olecranon lengthening following plate fixation and loss of elbow extension. Materials and methods Transverse olecranon osteotomies were performed on 8 cadaveric elbows. The osteotomy sites were then fixed with olecranon plates. Lengthening of the osteotomy sites were simulated by placement of 2mm, 4mm, 6mm and 8mm blocks. Lateral view photographs of the elbows were taken after each degree of lengthening. These photographs were then printed and measurements of elbow extension were performed with a goniometer with average values taken. The measurements were tabulated and statistical analysis performed to determine the relationship between degree of elbow extension loss and amount of olecranon lengthening. Results Average values of each degree of lengthening (at 2mm, 4mm, 6mm and 8mm) were taken and compared with the baseline measurement (at 0mm). Cluster analysis showed that for every increment in osteotomy length of 2mm, there is a corresponding increase of 0.79° of elbow extension loss (p<0.01, 95% confidence level 0.55°-1.03°). Conclusion Lengthening of olecranon by increments of 2mm correlates positively with loss of elbow extension. This shows that inadvertent intra-operative olecranon lengthening post-fixation may result in limited range of motion. However, it is reassuring to know that the small degree of extension loss may not translate to functional limitation.

Restoring the Soils of Nauru: Plants as Tools for Ecological Recovery

<p>The restoration of Nauru’s mined areas is fundamental to the future wellbeing of the people and ecosystems of Nauru. Extensive open cast phosphate mining on Nauru over the last 100 years has led to soil losses and landscape degradation to the extent that over 70% of this South-Western Pacific island state is now uninhabitable and almost all productive land has been lost. Significant landscape degradation has occurred and as a consequence the soils that remain are insufficient in volume and quality to achieve the Government’s restoration goals which support the long-term development of Nauru and the well-being of its people. The aim of this research is to evaluate aspects of cover-crop use as a means for soil restoration in Nauru. This research evaluates biomass production, phytoremediation potential, and germination success for a range of species in Nauruan soils. Field trials exploring biomass production and cadmium phytoextraction were performed, as was an experiment assessing the effects of cadmium on germination success. It was found that, in the circumstances assessed, biomass productivity was significantly determined by species, mulch use, soil type, and to a small degree – cadmium. Phytoextraction was significantly determined by tissue type. Germination success was not determined by soil cadmium, but soil type was a significant factor.</p>

Putting it to the Comic Book Fans: Is Auckland Libraries’ Comic Book/Graphic Novel and Manga Collection Meeting Customer Expectations?

<p><b>This study examines whether Auckland Libraries’ comic book/graphic novel and manga collection is meeting customer expectations and ascertains possible improvements that could be made.</b></p> <p>Methodology: The study predominantly used a quantitative approach to gather data through the use of self-completion questionnaires. A small degree of qualitative data was obtained from the questionnaire through open-ended questions. There was no recruiting of participants. The target population for this study included all Auckland Libraries customers, regardless of whether they frequently borrow from the comic book/graphic novel and manga collection or not.</p> <p>Results: The study found that participants were generally satisfied with the range of materials in the collection. However, it was commonly agreed amongst participants that Auckland Libraries could be doing more to showcase what was available. Areas identified for improvement include the organisation of the collection, its promotion and staff knowledge of the comic book/graphic novel and manga formats.</p> <p>Implications: This study recommends Auckland Libraries redesign cataloguing procedures for comic book/graphic novel and manga collection in order to introduce standardised organisation at each site. It also recommends Auckland Libraries take more promotional opportunities for the collection as well as the up-skilling of staff to assist with these.</p>

Putting it to the Comic Book Fans: Is Auckland Libraries’ Comic Book/Graphic Novel and Manga Collection Meeting Customer Expectations?

<p><b>This study examines whether Auckland Libraries’ comic book/graphic novel and manga collection is meeting customer expectations and ascertains possible improvements that could be made.</b></p> <p>Methodology: The study predominantly used a quantitative approach to gather data through the use of self-completion questionnaires. A small degree of qualitative data was obtained from the questionnaire through open-ended questions. There was no recruiting of participants. The target population for this study included all Auckland Libraries customers, regardless of whether they frequently borrow from the comic book/graphic novel and manga collection or not.</p> <p>Results: The study found that participants were generally satisfied with the range of materials in the collection. However, it was commonly agreed amongst participants that Auckland Libraries could be doing more to showcase what was available. Areas identified for improvement include the organisation of the collection, its promotion and staff knowledge of the comic book/graphic novel and manga formats.</p> <p>Implications: This study recommends Auckland Libraries redesign cataloguing procedures for comic book/graphic novel and manga collection in order to introduce standardised organisation at each site. It also recommends Auckland Libraries take more promotional opportunities for the collection as well as the up-skilling of staff to assist with these.</p>