Appraisal of scientific literature and understanding continues to grow in the domain of human performance. The effects of sex on concentric resistance training and power output are not well understood. Recent advancements in technology permit more precise measurements of force output and the kinematic changes elicited by training stress. A unique device in capturing kinematic performance output is Proteus Motion. The machine produces an external magnetic load through a protruding apparatus connected to a gyrosphere, which in turn captures concentric movement through all three planes of movement (sagittal, coronal, transversal). The aim of this study is to investigate power output discrepancies between the sexes in upper extremity concentric movements. After 5 training sessions females expressed significant increases in concentric bilateral bicep curl power by 22.4 ± 30.1 w (p=0.001) and bilateral tricep extensions by 34.1 ± 30.3 w (p<0.001). Male subjects improved mean and peak power between sessions 1-5 (p<0.001), while there was no significant improvement from sessions 5-8 (p>0.250). In horizontal and vertical exercises females and males shared similar power profiles in pull motions, but not push movements. Future studies investigating biological sex, and its influence on power output are needed.

Thesis (DPhil (Ancient Studies))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The compositional strategy, structure, and peak of the book Hebrews are heavily debated. Most scholars analyze Hebrews from only a Western linear approach. Other scholars like Vanhoye, Neeley, G.H. Guthrie, and Gelardini have suggested a chiastic perspective. Despite the insights gained from a chiastic approach, the linguistic analyses of Neeley and G.H. Guthrie posit linguistic peaks that appear incompatible with the chiastic peak of Vanhoye, Neeley, and Gelardini. Neeley, G.H. Guthrie, and Westfall claim to apply linguistic principles to the text, but with quite different conclusions. This study focuses on the form and function of the literary units and the relationship of these units to the overall book-level structure. Initial considerations include defining the individual literary units and determining the significance of lexical and syntactical recurrences within the pericopes. Such recurrences are important features for determining textual boundaries, transitions, and compositional patterns. Subsequently, this study evaluates literary units in relation to each other in light of book-level correspondences (syntactical and semantic) as a means of positing an overall structure and compositional strategy for the book of Hebrews. Unlike the linear study of Westfall, the relationships of non-sequential literary units are considered as well as sequential units (i.e., both linear and concentric patterns). In addition to the analysis of the form and function of chiastic and parallel literary units, this study also considers the rhetorical function and significance of the central placement of OT quotations within those structures. Although the OT quotations often occur in the center of the chiastic structures, imperativals (imperatives, prohibitive subjunctives, and hortatory subjunctives) do not generally occur in the chiastic centers, but in the outer components of the chiastic structures. Such a perspective is helpful for understanding where the author is placing emphasis as well as for clarifying the relationship between the epideictic (doctrinal) and deliberative (hortatory) sections. Contrary to G.H. Guthrie’s and Westfall’s emphases on the deliberative sections, this study contends that Hebrews contains a coherent concentric pattern (involving a central thematic peak, dual hortatory climaxes, and dual apexes) as part of an overall compositional strategy. This is not to suggest that the epideictic sections are more important than the explicit exhortations found in the deliberative sections, but that the hortatory essence of Hebrews is rooted in both the theological truth of Jesus’ role as the great high priest and the function of his everlasting sacrifice in the heavenly tabernacle. The author weaved these texttypes together to deliver an even more powerful call to faithfulness. This study also challenges Nauck’s assertion that Heb 4:14–10:31 is one integral section. One of the key elements of this challenge is the unique interpretation of Heb 5:1-10 as foreshadowing the topic found in Hebrews 7. Understanding the foreshadowing essence of Heb 5:1-10 opens the means of interpreting Heb 4:14-16 and 10:19-22 as hortatory bookends to the central theological sections of Hebrews as opposed to designating Nauck’s lexical parallels as an inclusio. / AFRIKAANSE OPSOMMING: Daar word hewig gedebatteer oor die komposisionele strategie, struktuur en piek van die Hebreër-boek. Die meeste geleerdes analiseer Hebreërs slegs vanuit ‘n Westerse liniêre benadering. Ander geleerdes soos Vanhoye, Neeley, G.H. Guthrie en Gelardini het ‘n chiastiese perspektief voorgestel. Ten spyte van die insigte wat ‘n chiastiese benadering opgelewer het, poneer die linguistiese analises van Neeley en G.H. Guthrie linguistiese pieke wat onversoenbaar met die chiastiese piek van Vanhoye, Neeley and Gelardini lyk. Neeley, G.H. Guthrie en Westfall maak daarop aanspraak dat hulle linguistiese beginsels op die teks toepas, maar met uiteenlopende gevolgtrekkings. Hierdie studie fokus op die vorm en funksie van die literêre eenhede in die Hebreërboek en die verhouding van hierdie eenhede tot die oorkoepelende boek-vlak struktuur. Aanvanklike oorwegings sluit die omskrywing van die individuele literêre eenhede en die bepaling van die belang van leksikale en sintaktiese herhalings binne die perikope in. Sulke herhalings is van groot belang om die tekstuele grense, oorgange en komposisionele patrone te bepaal. Daarna word die literêre eenhede in verhouding tot mekaar in die lig van boek-vlak (sintaktiese en semantiese) ooreenkomste gëevalueer in ‘n poging om ‘n oorkoepelende struktuur en komposisionele strategie vir die Hebreërs-boek te poneer. Anders as die liniêre studie van Westfall word die verhoudings tussen nie-opeenvolgende sowel as opeenvolgende eenhede in ag geneem (d.w.s. beide liniêre en konsentriese patrone). Benewens die vorm en funksie van chiastiese en parallele literêre eenhede word die retoriese funksie en belang van die sentrale stelling van OT aanhalings binne hierdie strukture ook in oënskou geneem. Hoewel die OT aanhalings dikwels in die kern van die chiastiese strukture voorkom, word bevelsvorme (imperatiewe, verbodsubjuntiewe en aansporende subjunktiewe) nie normaalweg in die chiastiese kern aangetref nie, maar in die buitenste komponente van ‘n chiastiese struktuur. Hierdie insig help ons verstaan waar die skrywer die nadruk plaas en bied ook klarigheid oor die verhouding tussen die epideiktiese (leerstellige) en deliberatiewe (aansporende) gedeeltes. In teenstelling met G.H. Guthrie en Westfall se nadruk op die deliberatiewe gedeeltes word in hierdie studie aangevoer dat Hebreërs ‘n koherente konsentriese patroon (met ‘n sentrale tematiese piek, tweevoudige aanporende klimakse en tweevoudige kruine) bevat as deel van ‘n oorkoepelende komposisionele strategie. Dit beteken nie dat die epideiktiese gedeeltes belangriker is as die eksplisiete aansporings in die deliberatiewe gedeeltes nie, maar wel dat die aansporende essensie van Hebreërs gewortel is in sowel die teologiese waarheid van Jesus se rol as groot hoëpriester asook in die funksie van sy ewigdurende offerande in die hemelse tabernakel. Die skrywer het die onderskeie tekstipes verweef om ‘n nog sterker oproep tot getrouheid te maak. Hierdie studie betwis ook Nauck se bewering dat Heb 4:14–10:31 een integrale gedeelte vorm. Een van die sleutelelemente van die kritiek is die unieke interpretasie dat Heb 5:1-10 die tema wat in Hebreërs 7 voorkom, voorafskadu. Insig in die voorafskaduende rol van Heb 5:1-10 bied die geleentheid om Heb 4:14-16 en 10:19- 22 as aansporende boekstutte vir die sentrale teologiese gedeeltes van Hebreërs te interpreteer instede daarvan om Nauck se leksikale parallele as inclusio te beskryf.

This study examined and compared the acute effects of ballistic and nonballistic concentric-only half-squats (COHSs) on squat jump performance. Fifteen resistance-trained men performed a squat jump 2 minutes after a control protocol or 2 COHSs at 90% of their 1 repetition maximum (1RM) COHS performed in a ballistic or nonballistic manner. Jump height (JH), peak power (PP), and allometrically scaled peak power (PPa) were compared using three 3 × 2 repeated-measures analyses of variance. Statistically significant condition × time interaction effects existed for JH (p = 0.037), PP (p = 0.041), and PPa (p = 0.031). Post hoc analysis revealed that the ballistic condition produced statistically greater JH (p = 0.017 and p = 0.036), PP (p = 0.031 and p = 0.026), and PPa (p = 0.024 and p = 0.023) than the control and nonballistic conditions, respectively. Small effect sizes for JH, PP, and PPa existed during the ballistic condition (d = 0.28–0.44), whereas trivial effect sizes existed during the control (d = 0.0–0.18) and nonballistic (d = 0.0–0.17) conditions. Large statistically significant relationships existed between the JH potentiation response and the subject's relative back squat 1RM (r = 0.520; p = 0.047) and relative COHS 1RM (r = 0.569; p = 0.027) during the ballistic condition. In addition, large statistically significant relationship existed between JH potentiation response and the subject's relative back squat strength (r = 0.633; p = 0.011), whereas the moderate relationship with the subject's relative COHS strength trended toward significance (r = 0.483; p = 0.068). Ballistic COHS produced superior potentiation effects compared with COHS performed in a nonballistic manner. Relative strength may contribute to the elicited potentiation response after ballistic and nonballistic COHS.

The relationship between the Reynolds number (Re) and discharge coefficients (C) was investigated through differential pressure flow meters. The focus of the study was directed toward very small Reynolds numbers commonly associated with pipeline transportation of viscous fluids. There is currently a relatively small amount of research that has been performed in this area for the Venturi, standard orifice plate, V-cone, and wedge flow meters. The Computational Fluid Dynamics (CFD) program FLUENT© was used to perform the research, while GAMBIT© was used as the preprocessing tool for the flow meter models created. Heavy oil and water were used separately as the two flowing fluids to obtain a wide range of Reynolds numbers with high precision. Multiple models were used with varying characteristics, such as pipe size and meter geometry, to obtain a better understanding of the C vs. Re relationship. All of the simulated numerical models were compared to physical data to determine the accuracy of the models. The study indicates that the various discharge coefficients decrease rapidly as the Reynolds number approaches 1 for each of the flow meters; however, the Reynolds number range in which the discharge coefficients were constant varied with meter design. The standard orifice plate does not follow the general trend in the discharge coefficient curve that the other flow meters do; instead as the Re decreases, the C value increases to a maximum before sharply dropping off. Several graphs demonstrating the varying relationships and outcomes are presented. The primary focus of this research was to obtain further understanding of discharge coefficient performance versus Reynolds number for differential producing flow meters at very small Reynolds numbers.

The main objective of the study was to investigate and simulate skeletal muscleforce production during and after isometric contractions, active muscle lengtheningand active muscle shortening. The motivation behind this work was to improve thedominant model of muscle force generation based on the theories of Hill from 1938. Effects of residual force enhancement and force depression were observed after concentric and eccentric contractions, and also during stretch-shortening cycles. It wasshown that this force modification is not related to lengthening/shortening velocity, butinstead the steady-state force after non-isometric contractions can be well describedby an initial isometric force to which a modification is added. The modification isevaluated from the mechanical work performed by and on the muscle during lengthvariations. The time constants calculated for isometric force redevelopment appearedto be in certain relations with those for initial isometric force development, an observation which extended our basis for muscle modelling. A macroscopic muscular model consisting of a contractile element, and paralleland series elastic elements was supplemented with a history component and adoptedfor mouse soleus muscle experiments. The parameters from the experiment analysis, particularly the force modification after non-isometric contractions and the timeconstants, were reproduced by the simulations. In a step towards a general implementation, the history modification was introduced in the muscluloskeletal model ofOpenSim software, which was then used for simulations of full body movements. / QC 20120525

Traumatic brain injury (TBI) is a severe condition and a major cause of death and disability. There is no pharmacological treatment available in clinical practice today and knowledge of brain injury mechanisms is of importance for development of neuroprotective drugs. The aims of the thesis were to get a better understanding of astrocyte reactions and immune responses, as well as behavioral changes after focal unilateral cortical contusion injury and diffuse bilateral central fluid percussion injury in rats and mice. In the focal injury models, the astrocyte reactions were generally restricted to the ipsilateral hemisphere. After diffuse TBI, vimentin and glial fibrillary acidic protein (GFAP) positive reactive astrocytes were bilaterally expressed in brain regions even distant from the injury site, including regions where axonal injury was seen. Early after diffuse TBI, there was a robust immune response, including activation of macrophages/microglia (Mac-2+) and infiltration of neutrophils (GR-1+) and T-cells (CD3+). In order to measure functional outcome, the recently established Multivariate Concentric Square Field™ (MCSF) test for complex behaviors, including risk taking and explorative strategies was used. The Morris water maze (MWM) was applied for testing learning and memory. The MCSF test revealed alterations in risk taking, risk assessment and exploratory behavior, in the mice subjected to focal injury whereas mice subjected to the diffuse injury showed a deviant stereotyped behavior. After focal injury mice showed a decreased ability to adapt to the arena in the second trial, when tested repeatedly in the MCSF test. Mice subjected to diffuse injury had an impaired memory but not learning, in the MWM test. Post-injury treatment with the anti-inflammatory anti-interleukin-1β (IgG2 a/k) antibody showed a positive effect on functional outcome in the diffuse injury model. Altogether, the results demonstrate that focal and diffuse TBI models produce differences in cellular reactions and behavioral outcome and that the immune response plays a key role in the pathology after brain injury.

This thesis reports design and implementation of a MEMS based spiral channel dielectrophoretic separator for cytometry applications. Main objective of the thesis is to separate leukemia cells from healthy leukocytes with respect to the differences in their dielectric properties. A novel MEMS based dielectrophoretic separator with spiral channels and concentric 3D electrodes has been proposed. The proposed geometry decreased the footprint, which reduces the device cost, without degrading the separation and quantization performances. Concentric electrode geometry enables continuous electric-field application with simple voltage supplies. Theoretical explanation of the design has been presented and supported with finite element method simulations. Evolution of the design has been explained in conjunction with solutions to arising problems, chronologically. Comparisons of the proposed system with respect to the existing systems in the literature have been given. The devices are fabricated using a 3-mask process utilizing suspended parylene channel process. The experiments are realized with 1 &mu / m and 10 &mu / m polystyrene beads. The results show that 1 &mu / m particles have an average speed of 4.57 &mu / m/s with 1.06 &mu / m/s standard deviation, and 10 &mu / m particles have an average speed of 544 &mu / m/s with 105 &mu / m/s standard deviation. The speed variation coefficient for 1 &mu / m and 10 &mu / m beads can be calculated as 23% and 19%, respectively. The size accuracy of the device is &plusmn / 10%, while the resolution is 20%, that is, particles with radii different from each other by 20% can be separated. It is worthy to note that the experimental results almost match the simulation results.

The aim of the study: to determine and compare the low frequency fatigue of the legs’ muscles of 12–13 years old boys during the isometric and eccentric-concentric physical exercises. The objectives of the study: 1. To determine the exertion of low frequency fatigue during isometric exercises in boys. 2. To determine the exertion of low frequency fatigue during eccentric-concentric exercises in boys. 3. To compare the exertion of low frequency fatigue among isometric and eccentric-concentric exercises in boys. Subjects. Healthy boys (n = 6) aged 12–13 (12,4 ± 0,6) who do not participate in sports regularly but attend the classes of physical education twice a week. The rest period between the studies was three weeks. The tension was set up at 50 % MVS level. After that the values of the contractions and relaxations of the muscles were registered as follows: 1. The strength of muscle contraction caused by a single electric stimulus (Pt); 2. The strength of muscle contraction (P) caused by the following regiments of electrostimulation: 7 Hz (P7), 10 Hz (P10), 15 Hz (P15), 20 Hz (P20), and 100 Hz (P100) (the duration of the stimulation – 1 s, and the rest intervals between stimulations – 5 s); 3. Maximal voluntary strength (MVS) of muscle contractions (three trials every 3 minutes); 4. The workout (10 minutes of slow pedaling on the ergometer: the heart rate contractions from 110 to 130 times per minute); 5. Isometric workload: 18 times, each lasts 15 s, 40 % MVS contraction... [to full text]

Excessive and compulsive ethanol drinking is one of the most serious public health issues. Therefore, it is vital to increase the knowledge about risks and protection for alcohol use disorders (AUD) to optimize prevention and treatment strategies. Ethanol consumption commonly initiates during adolescence when extensive neuronal maturation and development also occurs. Early exposure to ethanol is a risk factor for AUD, but the effects of adolescent drinking and the basis for the individual susceptibility to AUD are not fully understood. The interactions between genotype and environmental factors determine the individual risk for AUD and this thesis aimed to examine the environmental impact. The specific aims were to investigate 1) how early-life conditions affect adolescent voluntary ethanol drinking, behavioural profiles, endogenous opioids and response to treatment with an opioid antagonist (naltrexone), and 2) whether alterations detected in the offspring may be mediated by variations in maternal behaviour. A rodent maternal separation (MS) model was used to mimic a protective and risk-inducing early-life environment, respectively, with the use of 15 min (MS15) or 360 min (MS360) of daily MS. The main findings were 1) the MS360, but not the MS15 rats, responded to naltrexone following adolescent ethanol drinking; all adolescent rats had a high voluntary ethanol intake independent of early environmental conditions whereas in the adult groups the MS360, but not the MS15 rats, increased their ethanol intake and preference over time; adolescent ethanol exposure resulted in higher dynorphin levels in hippocampus and higher Met-enkephalin-Arg6Phe7 in the amygdala, independently of rearing conditions, 2) behavioural profiling using the multivariate concentric square field™ test showed: the young MS360 rats had increased risk assessment and risk taking behaviour compared to the young MS15 rats; the young MS15 rats increased, whereas the young MS360 rats decreased, their risk assessment and risk taking behaviour over time; differences in pup-retrieval strategies where the MS360 dams retrieved some pups into a safe area but as compared to MS15 rats they left more pups in a risk area; increased risk assessment behaviour in the MS360 dams immediately after weaning. Taken together, early-life environmental conditions alter adult but not adolescent drinking, the response to naltrexone, and behaviour in dams and offspring. Adolescent rats consumed more ethanol independent of rearing conditions and displayed increased opioid levels in brain areas related to cognition and addiction.

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