Paranthropus boisei: Fifty Years of Evidence and Analysis

Paranthropus boisei is a hominin taxon with a distinctive cranial and dental morphology. Its hypodigm has been recovered from sites with good stratigraphic and chronological control, and for some morphological regions, such as the mandible and the mandibular dentition, the samples are not only relatively well dated, but they are, by paleontological standards, reasonably-sized. This means that researchers can trace the evolution of metric and nonmetric variables across hundreds of thousands of years. This paper is a detailed1 review of half a century’s worth of fossil evidence and analysis of P. boisei and traces how both its evolutionary history and our understanding of its evolutionary history have evolved during the past 50 years

ADDITIVE MANUFACTURING AND 3D PRINTING IN DENTISTRY

CAD / CAM techniques applied to solving dental problems demonstrate that there are many solutions available on the market to help the dentist individually perform the rehabilitation of a dental element to meet the specific needs of each patient. These manufacturing technologies close a digital workflow, potentially managed entirely by the dentist, which involves taking the impression of the oral cavity and the dental elements present through an intraoral scanner with the generation of a file on which to create the CAD project and to start extrapolating the file of the final work to be produced by subtractive or additive CAM. The 3D printing techniques allow to work easily with polymeric and ceramic materials, in order to create dental crowns that can satisfy practically all the needs encountered in the dental field. Leaving aside the techniques applied to polymers, this PhD project focuses on the applications of ceramic materials. This PhD thesis focuses on the design, study and implementation of 3D printing of ceramic supports specifically dedicated to the stabilization of dental implants. Through the development of a prototype of a 3D printer, it was possible to obtain the printing of ceramic products useful for the intended purpose

Experimental evaluation of the structural properties of innovative biomaterials

Double study on MTS 858 Minibionix . Development of a gripping system cooled with liquid nitrogen on samples of tendons and quantification of the effect of decellularization on their tensile biomechanical properties. Measurement of static and fatigue strength of dental implants with Rely X resin base and two types of shapes and materials: first an implant with crown in Lava Ultimate and then an implant with crown ia Lava Ultimate and abutment in Zirconi

An investigation relating to the design parameters of diaphragm mandrels

The aim of the present investigation was to establish the equations relating the deformations and the gripping pressure of diaphragm mandrels, as well as to simplify them, enabling their utilization by a designer. Diaphragm mandrels, to be used in lathe or finishing machining work, can be seen as revolution pieces constituted of an assemblage of elastic elements disposed around their revolution axis. The centering and gripping operations rely only on the elastic forces generated when those elements are elasticly deformed. The non-existence of metalic sliding parts distinguishes this type of mandrels from the usual types and assures an high degree of repeatability and accuracy during the machining operations. Four fundamental stages constitute the present work. Firstly, the preliminary design of the geometrical shape for the diaphragm mandrels has been developed in chapter 2. The second and third fundamental stages have been undertaken simultaneously. They are constituted of an theoretical and experimental analysis in view to obtain the equations earlier refered. This analysis has been undertaken firstly on two different types of Specimen, simulating the constituting elements of a diaphragm mandrel and finally on a third Specimen simulating an actual section of the mandrel. The first Specimen simulated the tapered parts of the mandrel, and the second type simulated the assemblage of those tapered parts and the holding part in between them. On pages 42, 71 and 126 are represented the first, the second and the third type of those Specimen, respectively. In chapter 3 is elaborated the theoretical analysis of the first type, in chapter 7 the second type and in chapter 11 the third type. Their experimental analysis is presented on chapter 4, 5 and 6 for the first type, on chapters 8, 9 and 10 for the second one and on the chapter 12, 13 and 14 for the third type. The theoretical analysis, based upon the energy method enabled the calculations of deformations, load forces and gripping pressure relationships, and from the experimental work the experimental values have been obtained and used to verify the accuracy of the theoretical analysis. Mechanical and electronic techniques have been used during the experiments and close correlation between the predicted results and the experimental ones have been obtained, this being stated in chapter 6, chapter 10 and chapter 14. Finally the third stage of this investigation has been related with the simplification of the theoretical expressions and their presentation in a tabled way providing their use by a designer to characterize the behaviour of a mandrel as well as to define its geometrical dimensions under a specific work situation, chapter 17 and 18

Parameter selection methods for variational image restoration

Vi undersøker diskrepansprinsippet og ein L-hyperflate-metode som automatiserte parametervalmetodar i støyfjerningsproblem for bilete. Å velje optimale regulariseringsparametrar er alltid utfordrande, og utfordringa er enda større for regulariseringsfunksjonar med fleire parametrar. Vi eksperimenterer med total generalisert variasjon, ei fleirparameterval-metode, og med einparametervalmetoden total variasjon. Total generalisert variasjon er kjent som ein god støyfjerningsmetode for bilete, sidan rekonstruksjonar med denne metoden ikkje har den stykkvis konstante eigenskapen kjent som "trappeeffekta", som er vanleg i rekonstruksjonar basert på total variasjon. Dei numeriske løysarane som er testa er basert på konveks optimeringsteori og ein Chambolle-Pock primal-dual-løysar. Eksperiment med einparametermetodar viser at diskrepansprinsippet presterer betre enn L-kurvemetoden for eit støyfjerningsproblem for eit RGB-bilete, når ein bruker total varisjon som regulariseringsfunksjon. For høge støynivå gjer ein ved bruk av diskrepansprinsippet nær optimale parameterval for total variasjon. Dei numeriske resultata viser at ein automatisert versjon av det balanserte diskrepansprinsippet med Broyden si metode som numerisk løysar presterer betre enn eksisterande parametervalalgortimar for einparametermetodar. For bilete med færre detaljar og overflater med nesten konstante intensitetar, forblir total variasjon ein betre metode. Testar av L-hyperoverflate-metoden antyder at det er vanskeleg å velje gode parametrar for total generalisert variasjon med denne metoden.We investigate the discrepancy principle and the L-hypersurface method as automated parameter selection methods for image denoising problems. Choosing optimal regularization parameters is always challenging, and the challenge is even bigger for multi-parameter regularization. We experiment with total generalized variation, a multi-parameter regularization functional, and the single-parameter regularization functional total variation. Total generalized variation is known to be a good multi-parameter regularization functional for image denoising, as its reconstructions avoids the piecewise constant property known as 'staircasing', which is commonly observed in total variation reconstructions. The numerical solvers we test are based on convex optimization theory and use a Chambolle-Pock primal-dual solver. Single-parameter choice experiments show that the discrepancy principle performs better than the L-curve method for a RGB-image denoising problem, using a total variation regularization functional. For high noise levels, the discrepancy principle makes an almost optimal parameter choice for total variation. The numerical results show that an automated balanced discrepancy principle with Broyden's method as numerical solver performs better than the existing parameter choice algorithms for single-parameter methods. For images with fewer details and surfaces with almost constant intensities, total variation remains a better method. Tests of the L-hypersurface method suggest difficulties with choosing good parameters for total generalized variation by the means of this method

Las Vegas Optic, 01-21-1913

https://digitalrepository.unm.edu/lvdo_news/2899/thumbnail.jp

A follow-up of patient reported outcomes in chronic plantar heel pain participants treated with Graston Technique: A mixed methods approach

Chronic Plantar Heel Pain (CPHP), commonly known as “plantar fasciitis,” is a condition that is estimated to affect 10% of the American population. A treatment for CPHP and other soft tissue overuse conditions that is increasing in popularity is the use of metal instruments for deep tissue massage for 10 minutes, twice a week for six weeks, called the Graston Technique. The purpose of this study is to longitudinally examine the foot pain and function of participants who received Graston Technique treatment approximately two years before this study. A mixed methods design where quantitatively, three self-reported survey instruments were utilized, and qualitatively, an interview regarding foot pain and function, as well as quality of life, was completed. This study is motivated by three research questions: (1) Will participants treated with Graston Technique for CPHP report a maintenance or decrease in pain levels two years posttreatment? (2) Will participants treated with Graston Technique for CPHP report a maintenance or improvement in functional outcomes two years posttreatment? (3) What are the lived experiences of participants treated with Graston Technique for CPHP? The findings of this case series design demonstrate that 13 out of 15 participants maintained or improved pain levels and functional outcomes near two years posttreatment. Qualitatively, 10 out of 15 of the participants described having foot pain at the cessation of treatment, with the pain subsiding a few months later. This could occur from the long-term mechanical changes that Graston Technique can impose on degenerated tissue, such as in CPHP. The findings support that Graston Technique may be an effective treatment for CPHP to maintain pain and functional levels two years after the treatment has ended

Biomechanics of the Golf Swing and Putting Stroke

Context: This thesis focused on two main areas of golf performance. Firstly, centre of pressure excursions influence on full golf swing performance, as despite golf coaching literature placing importance on weight transfer, literature into this mechanism is limited. Secondly, the area of the golf putt was examined; few studies have investigated the biomechanics into the putting stroke despite it being identified as the most important performance factor within golf. Areas of investigation were, centre of pressure excursions during the putting stroke, the impact point on golf ball and movement variability on performance outcomes being the ball roll kinematics. Aims: To examine biomechanical factors that influence golf performance. Centre of pressure excursion during the full golf swing and putting stroke were examined. Additionally, body segment kinematics and variability of rotations were correlated with putting performance outcomes. The impact point on the golf ball was considered as a mechanism that can cause variability of the kinematic ball roll. Subjects: All subjects used in this thesis were actively playing golf. Subjects were categorised using the golf handicap system. For studies assessing reliability, validity or isolating putter stroke kinematics a mechanical putting robot was used. Methods: Correlational research whereby no variables were manipulated was predominantly adopted throughout this thesis to establish relationships between biomechanical parameters and golf performance. Biomechanical parameters were assessed using the appropriate data collection and analysis techniques; this included the variability associated with segment rotations. Results: Significant differences were observed for the centre of pressure excursions along the mediolateral axis between three different golf clubs (full swing). For the putting stroke low handicap golfers demonstrated lower centre of pressure excursions along the anteroposterior axis in comparison to high handicap golfers, additionally, a large amount of inter-subject variability was observed for centre of pressure excursions. In regards to the impact point on the golf ball, significant associations were identified between impact variables and the performance measures horizontal launch angle and whether the ball was pushed or pulled, these results were not replicated with human participants. It was identified that the relationship between the centre of mass displacement and centre of pressure excursions is a complex one and that movement variability had a detrimental effect on the horizontal launch angle and therefore performance. Conclusions: The results from the full swing analysis of this thesis suggest that stance width may influence the amount of centre of pressure excursions that occur. For the golf putting stroke, golfers and coaches should reduce the amount of variability associated with the technique to improve performance. Regarding future scientific research, a combination of individual analysis accompanying group-based analysis should be utilised due to the large inter-subject differences observed

The Study and Replication of Plant Surfaces

The analysis and replication of surfaces which mimic the behaviour of plants is of importance as it can have a variety of applications. These applications, such as the collection of fog for drinking water, waterproof electronics, and antibiofouling devices have the potential to improve the day to day lives of millions of people. In this thesis the surfaces of multiple plants were analysed and replicated using a variety of techniques to better understand and replicate their wetting mechanisms. Also developed were a range of new analysis and replication techniques which have many potential applications in future projects. The wetting mechanism and surface of Xanthosoma sagittifolium was investigated through the use of analytical techniques such as scanning electron microscopy and time of flight secondary ion mass spectrometry, before being replicated using a nanoimprinting process. This led to the successful production, and testing, of replicas of the leaves of Xanthosoma sagittifolium. These techniques were also employed to aid in the analysis of other plant surfaces, such as that of Eremopyrum orientale and Phyllostachys aurea, and led to the development of a new technique by which plant surfaces could be analysed using time of flight secondary ion mass spectrometry without the need for a live specimen. Also developed was a new replication method employing 3D printing to replicate the surfaces of Phyllostachys aurea. The development of these techniques should prove useful in future analysis and replication of plant surfaces, particularly in countries where resources are limited, or where the plant of interest is in an isolated location

Demountable composite beams: Analytical calculation approaches for shear connections with multilinear load-slip behaviour

The work carried out throughout the thesis focused on the behaviour of demountable composite beams in order to facilitate the integration of steel-concrete composite construction into the concept of circular economy. There are several hindrances in the way of reuse when considering traditional composite structures. One of them is the method that the current construction practice applies for connecting the concrete deck to the steel beam. The traditionally applied welded studs are advantageous in the terms of structural performance; however, they do not provide the ability of dismounting. In order to overcome this issue, different demountable shear connection types were investigated that use pretensioned bolted connections. The investigations included laboratory experiments in the means of push-out tests and full-scale beam-tests. The experiments were complemented by numerical simulations and parametric studies. The experiments showed that the developed shear connections have highly a nonlinear load-slip behaviour. When these types of connections are applied in a composite beam, the nonlinearity of the shear connection causes a nonlinear load-deflection response already in the elastic phase. Analytical equations were derived for the description of the elastic properties of composite beams with nonlinear shear connection. For the calculation of the elastic deflections an iterative procedure was developed. This method is capable of capturing the nonlinear load-deflection response. With the developed iterative method, the elastic deflections can be determined with a similar accuracy by using spreadsheet calculations as by using nonlinear finite element simulations. Due to the highly nonlinear behaviour of the tested shear connections the basic assumptions of Eurocode 4 for the determination of the plastic moment resistance of composite beams with partial shear connection are not valid anymore. The code does not enable the use of equidistant shear connector spacing and the design needs to be conducted using fully elastic analysis. This would make the use of demountable shear connections complicated and uneconomic. In the face of these issues, the probability of the practical application of demountable and reusable composite structures would be very low. On the other hand, experiments and numerical simulations show that composite beams can develop plasticity even if a non-ductile shear connection is applied. In order to overcome these issues, a new calculation method was developed for the prediction of the plastic moment resistance of demountable composite beams. A simplified method was proposed based on the developed procedure by defining an effective shear resistance for the demountable shear connections. The effective shear resistance allows the current calculation method to be extended for demountable shear connections. In this way, the benefits of composite construction can be maintained while providing the possibility of reuse