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Original ArticleDaytime naps improve afternoon power and perceptual measures in elite rugby union athletes - A randomized cross-over trial
No full textDaytime napping are used by elite athletes in both training and match-day settings. Currently, there are limited interventional studies on the efficacy of napping on physical performance in elite team-sport athletes. Therefore, the objective was to investigate the effect of a daytime nap (<1 h) on afternoon performance of peak power, reaction time, subjective wellness, and aerobic performance in professional rugby union athletes. A randomised cross-over design was carried out amongst 15 professional rugby union athletes. Athletes performed nap (NAP) and no nap (CON) conditions on two occasions, separated by one week. Baseline testing of reaction time, subjective wellness, and 6-s peak power test on a cycle ergometer was completed in the morning, followed by 2 x 45-minute training sessions, after which athletes completed the NAP or CON condition at 1200h. Following the nap period, baseline measures were retested in addition to a 30-minute fixed intensity interval cycle and a 4-minute maximal effort cycling test. A significant group x time interaction was determined for 6-s peak power output (+157.6 W, p<0.01, d=1.53), perceived fatigue (-0.2 AU, p=0.01, d=0.37) and muscle soreness (-0.1 AU, p=0.04, d=0.75) in favor of the NAP condition. A significantly lower perceived exertion rating (-1.2 AU, p<0.01, d=1.72) was recorded for the fixed intensity session in favour of NAP. This study highlights that utilizing daytime naps between training sessions on the same day improved afternoon peak power and lower perceptions of fatigue, soreness, and exertion during afternoon training in professional rugby union athletes
Looking across languages: Anglocentrism, cross-linguistic experimental philosophy, and the future of inquiry about truth
Get PDFAnalytic debates about truth are wide-ranging, but certain key themes tend to crop up time and again. The three themes that we will examine in this talk are (i) the nature and behaviour of the ordinary concept of truth, (ii) the meaning of the truth predicate, and (iii) the nature of the property truth. We will start by offering a brief overview of the debates centering on these themes. We will then argue that cross-linguistic experimental philosophy has an indispensable yet underappreciated role to play in all of these debates. Recognising the indispensability of cross-linguistic experimental philosophy should compel philosophers to significantly revise the ways in which they inquire about truth. It should also prompt analytic philosophers more generally to consider whether similar revisions might be necessary elsewhere in the field
Optimized vitrification, cell cycle compatibility and volume of cytoplasts for bovine embryonic cloning
Get PDFCell transfer cloning is a promising method for multiplying elite alleles in a population. Together with gene editing, it can increase the genetic gain of livestock and support the adaptation of cattle to climate change. Embryos with superior genetics, including edited genes, can be expanded in vitro, and each single embryonic donor cell can be used in cell transfer to produce new embryos with a copy of those genes. Enucleated oocytes in metaphase II (MII cytoplasts) serve as recipient cells for the embryonic donors, supporting their reprogramming and development. Currently, the rate of healthy calves that can be produced from cloning with somatic cell donors is about 5% and the technology is associated with placental, fetal and neonatal abnormalities, referred to as the cloning syndrome. This is largely due to incomplete epigenetic reprogramming in somatic cells. The genome of a pluripotent embryo-derived donor is postulated to require less reprogramming to reach an embryonic state than a somatic donor, which could lead to improved embryo formation, increased numbers of healthy offspring and reduced animal welfare problems. These donors are also hypothesised to be more amenable to DNA editing. While the conditions for cytoplasts that receive somatic donors are well-researched, cytoplast conditions for embryo-derived donors remain to be optimised. The primary aim of this research project was to further the knowledge on bovine cell transfer methodology by trialling different treatments of cytoplasts that receive embryo-derived donors.
Blastocysts were produced through in vitro fertilization and plated to generate embryo-derived outgrowths as a source of donors for cloning. The zona pellucida was removed with assisted hatching techniques before plating. The rate of embryo-derived outgrowth formation after natural hatching without assistance was 80%. This was raised to 88% when mechanical zona pellucida dissection was performed on blastocysts before plating, while enzymatically removing the zona pellucida lowered the production of primary embryo outgrowthsto 36%. Donor outgrowths were arrested into mitosis by incubation in 500 nM nocodazole overnight before fusion with cytoplasts and activation with ionomycin and cycloheximide. Such chemically activated reconstructs had a 22% pseudo-polar body extrusion rate and blastocyst development was 7%. This was lower than blastocyst development in reconstructs without nocodazole-synchronization and with ionomycin and 6-dimethylaminopurine activation (13%). Non-synchronized donors were fused to cytoplasts that had received various treatments: aging and cooling, volume increases, and vitrification. Reconstructs were activated with ionomycin and 6-dimethylaminopurine. Embryos constructed with cytoplasts that had been aged and cooled to alter their MII state had lowered blastocyst development (4%) compared to embryos constructed with
cytoplasts that were not aged and cooled (15%). Increasing the volume of a MII cytoplast with embryo-derived donors did not significantly affect total blastocyst development (6%) compared to in control cytoplasts without altered volume (11%). Vitrified oocytes had a high survival rate after thawing (97%). Artificially activated zona-free vitrified oocytes were able to support development to the blastocyst stage, although this was at a lower rate (3%) than artificially activated fresh oocytes (22%). Vitrified cytoplasts had a high survival rate after thawing (92%) and were able to produce a blastocyst after cell transfer with somatic donors (2%). However, this blastocyst development occurred at a lower rate than with fresh cytoplasts and somatic donors (8%). The ability of vitrified cytoplasts to support the development of the embryo-derived donors to the blastocyst stage after cell transfer could not be proven.
Before proceeding to in vivo cloning trials, confirmation of blastocyst ploidy, and continued refinement of vitrification protocols, through trialling different reagents and concentrations, is required. Further data on the use of vitrified cytoplasts in double ECT is required to elucidate the role of reprogramming factors in cytoplasts on embryo-derived donors. Embryo transfer of the produced blastocysts will be the final measure of the effect of the cytoplast conditions trialled on overall cloning efficiency. Successful embryo transfer would accomplish the ultimate research aim of this project: to establish that bovine embryonic pluripotent stem cells can be successfully reprogrammed during cloning to produce blastocysts and then live offspring
Novel substituted hydroxyapatites
Get PDFHydroxyapatite (HAp) has been widely used as a bone replacement material for biomedical applications, in particular as a bone graft and coating for implants, because of its similarity in composition and crystal structure to natural bone.
The present study aims to develop of a novel method to prepare (unsubstituted and substituted) HAp by hydrolysis of monocalcium phosphate (MCP) using calcium hydroxide (Ca(OH)₂). Different techniques were used to characterize the prepared samples such as SEM, FTIR, XRD and ICP-MS. The presence of an apatitic phase in the sintered unsubstituted powders prepared by the hydrolysis of MCP/Ca(OH)₂ was confirmed by FTIR spectra, through detecting the fundamental vibrational modes of PO₄³⁻ group as well as by observation of the typical HAp lattice OH vibrations at 3572 and 631 cm⁻¹, so indicating formation of crystalline material. The XRD diffraction patterns of the sintered unsubstituted HAp powders were in a good agreement with the HAp patterns reported in the current literature, the standard HAp (reference card number 01-074-9780) as well as commercial HAp (Fluka) and showed the characteristic peaks of the HAp phase with a slight presence of the β-TCP phase that would have formed from the sintering process used to crystallise the HAp powders at 900 ˚C. The ICP-MS analyses of unsubstituted HAp powders showed that the Ca/P mole ratios of the unsubstituted HAp materials produced was 1.40, which is lower than the theoretical value of stochiometric HAp (1.67). This result can be ascribed to the substitution process of calcium ions by sodium ions in the HAp crystal lattice as a result of using sodium hydroxide to adjust pH in the reactions leading to the formation of HAp. The value of the (Ca+Na)/P when computed using elemental data obtained from the ICP-MS analyses was found to be 1.65 which is very close in value to of the value expected for stoichiometric HAp (1.67). SEM images showed that the sintered samples of unsubstituted HAp powders consist of particles with fine grains, spheroidal in shape associated with an irregular distribution of particle sizes. The degree of crystallinity and the numerical value of the crystallite size of the sintered unsubstituted HAp materials were 82.6% and 549.8 Å, respectively. The Rietveld refined values of lattice constants of the sintered unsubstituted HAp materials were a= 9.421±0.003 and c= 6.882±0.005 Å.
By means of the novel hydrolysis route (hydrolysis of MCP and Ca(OH)₂), three substituted “MHAp” materials were prepared with the following chemical formula: Ca₁₀₋ₓMₓ(PO₄)₆(OH)₂ (M=Zn, Sr and Cu, x=0.5, 1.0 and 1.5). FTIR spectra showed that there was:
• a presence of apatite phase in the prepared powders.
• a clear relation between the amount of M ions, and the intensities of OH⁻ vibration modes at 3572 cm⁻¹ (stretching) and 630 cm⁻¹.
• A clear shift of phosphate bands in the unsubstituted HAp at 572 and 604 cm⁻¹ to a lower wave number due to substitution of Sr²⁺ ions. This shift increases as the amount of Sr ions increases. Another shift of the OH librational band from 630 to 612 cm⁻¹ was also observed with an increase in the percentage of Sr²⁺ ions in the substituted HAp.
The phase purity, crystallinity, crystallite size and lattice parameters of the prepared MHAp materials varied with increasing substitution levels. SEM images showed that ZnHAp and CuHAp materials consisted of agglomerated crystals which are spheroidal in shape. Spheroidal particles were seen in 0.5 SrHAp and 1.0 SrHAp samples, but a combination of spheroidal and rod like particles was recorded in the case of the 1.5 SrHAp materials. The results of ICP-MS measurements displayed clearly the presence of these ions (Zn²⁺, Sr²⁺ and Cu²⁺ ions) in the HAp samples but did not offer explicit proof of substitution. The measured (actual) wt.% of Zn²⁺, Sr²⁺ and Cu²⁺ ions that that were detected by ICP-MS analysis was lower than the theoretical value indicating how difficult it is for the small ions such as Zn²⁺ and Cu²⁺as well as the large ions such as Sr²⁺to be introduced and hosted by the HAp sample.
Also, in the present study different systems of cationic substituted HAp, namely 1% RbHAp (1 wt.% Rb⁺), 1%EuHAp (1 wt.% Eu³⁺) and 1,3 and 5% ScHAp (1, 3 and 5 wt.% Sc³⁺), were prepared by using two different methods (precipitation and hydrolysis of MCP/Ca(OH)₂). The results of ICP-MS analysis showed that the presence of Rb⁺, Eu³⁺ and Sc³⁺ ions in the HAp crystal was very low. In the case of the Sc-substituted HAp, the level of substitution was negligible.
Various systems of anionic and co substituted HAp, namely 1, 3 and 5% NbHAp, 1% B₄O₇HAp, bromapatite, sulfoapatite and NaClHAp were also prepared by using different preparation methods (precipitation, hydrolysis of MCP/Ca(OH)₂ and ion exchange routes). There was found to be a reduction of the intensity of the stretching mode of the OH⁻ group at 3572 cm⁻¹ due to the replacement process of phosphate and/or hydroxyl groups by monovalent and bivalent ions( Br⁻, S²⁻ and B₄O₇²⁻).
The mechanical strength and the particle size of specific systems of unsubstituted HAp, substituted and co substituted HAp powders prepared by the hydrolysis process of MCP and Ca(OH)₂ were also studied. The results of the mechanical properties in the present investigation showed clearly that particle size plays a fundamental rule in the value of mechanical strength, since an enhancement in the mechanical strength was recorded because of the reduction in particle size that occurred in some preparations
A survey on compositional algorithms for verification and synthesis in supervisory control
Get PDFThis survey gives an overview of the current research on compositional algorithms for verification and synthesis of modular systems modelled as interacting finite-state machines. Compositional algorithms operate by repeatedly simplifying individual components of a large system, replacing them by smaller so-called abstractions, while preserving critical properties. In this way, the exponential growth of the state space can be limited, making it possible to analyse much bigger state spaces than possible by standard state space exploration. This paper gives an introduction to the principles underlying compositional methods, followed by a survey of algorithmic solutions from the recent literature that use compositional methods to analyse systems automatically. The focus is on applications in supervisory control of discrete event systems, particularly on methods that verify critical properties or synthesise controllable and nonblocking supervisors
Effects of solutions with high monovalent cation concentrations and high pH on soil properties
Get PDFThe effects of solutions with high monovalent cation concentrations and high pH on selected soil physical and chemical properties were investigated using a range of New Zealand soil types.
Some industries produce liquid wastes which are characterized by high pH and high monovalent cation concentrations. However, land treatment of these liquid wastes have been observed to cause adverse effects on soil properties, especially structural deterioration of the 0-10 cm depth of soil. To establish the mechanisms which cause the observed adverse effects, laboratory experiments were conducted to investigate the processes which occur when high pH solutions which contain monovalent cations (NaOH and KOH) are applied to soil. To isolate pH and cation effects, NaCl and KCl solutions were also used as treatments throughout this study. In addition to laboratory experiments, a field trial was conducted to examine the short term (12 months) effects of a surface applied amendment (gypsum, applied at 5 t ha⁻¹) on selected properties of a soil which had been irrigated with high pH dairy factory liquid wastes.
Single-step extraction experiments showed that hydroxide solutions dissolved organic carbon (OC) through the range of concentrations typically found in high pH liquid wastes (i.e. pH 10.5 - 13.5) and OC dissolution increased with increasing hydroxide concentration (i.e. increasing solution pH). Although NaOH dissolved more OC than KOH in the short term (after a single extraction), repeated treatment of soil with fresh hydroxide solution (using multi-step extractions) caused OC dissolution to increase though no cationic differences were measured in the longer term. In contrast to hydroxide solutions, chloride solutions dissolved minimal amounts of OC.
The saturated hydraulic conductivity (Kₛ) of the soils used in this study decreased over time when hydroxide solutions were used as influent solutions. Aggregate stability was also shown to decrease when soils were treated with hydroxide solutions. A two-stage process was proposed to explain the decrease in Kₛ when high pH solutions were applied to soil. First, OC is dissolved at the surface of the soil (i.e. 0-1 cm depth of soil) where the high pH solution is in contact with soil aggregates. The time required for dissolution to weaken aggregates being concentration dependent. Second, once a critical amount of OC had been removed, increased repulsion of soil particles (associated with increased negative charge on variable charge components in the soil due to increased pH) was thought to cause dispersion and deflocculation of clays and movement of the dislodged particles into pore spaces resulted in decreased Kₛ. In contrast to hydroxide solutions, aggregate stability was unaffected when soil was treated with chloride solutions and Kₛ was maintained or increased when chloride solutions were used as influent solutions. Decreasing the electrolyte concentration of the soil solution (by replacing the influent chloride solutions with distilled water) caused Kₛ to decrease, consistent with widely accepted diffuse double layer theory.
Cation exchange capacity (CEC) increased with increasing hydroxide concentration whereas chloride solutions had no effect on CEC. The increase in CEC in hydroxide-treated soil was attributed to negative sites being generated on components possessing variable charge characteristics. In general, higher exchangeable sodium percentage (ESP) and exchangeable potassium percentage (EPP) were found in hydroxide-treated soil compared to chloride-treated soil and were attributed to the new negative sites being counter-balanced by the monovalent cation present in the hydroxide solution (either Na⁺ or K⁺). Equations commonly used to predict ESP and EPP values from the composition of the soil solution (Richards, 1954) accurately predicted ESP and EPP in chloride-treated soil but did not accurately predict ESP or EPP in hydroxide-treated soil. These prediction equations do not take into account the increased total negative charge of the soil system and can therefore not be used to accurately predict ESP and EPP when high pH solutions are applied to soil.
The field trial showed that gypsum application increased infiltration rates in the irrigated soil by decreasing both the ESP and EPP of the soil and increasing the exchangeable Ca²⁺ concentration. Generally, gypsum did not affect any of the other measured properties (pH, OC, CEC, and bulk density) over the duration of the trial. In non-irrigated soil, the lack of effect of gypsum on any of measured soil properties was attributed to the high initial exchangeable Ca²⁺ concentration and low exchangeable Na⁺ and K⁺ concentrations compared to the irrigated soil.
It was concluded that for successful land treatment of liquid wastes with high monovalent cation concentrations and high pH, pH neutralisation of the liquid is essential to decrease the likelihood of OC dissolution and a build-up of negative charge on soil particles occurring. In addition, divalent cations should either be added to the liquid waste prior to disposal or should be applied to the soil in a relatively soluble form, in order to decrease the magnitude of problems associated with accumulation of monovalent cations on exchange sites. A conceptual model was proposed to describe the reactions that occur in soils when liquid wastes with high monovalent cation concentrations and high pH are applied using land treatment systems
Exporting as a dynamic process: a study of New Zealand specialist food exporters
Get PDFThe object of this study was to understand the export process by conducting case study research among New Zealand specialist food exporters. Past export research has used quantitative approaches to determine the influence of firm and environmental variables on quantitative measures of superior export performance. This approach has suggested that export processes are static and unidirectional; conceptualisations which contrast with the dynamic change that is apparent in firm export activities seen through export experience or even casual observation. It was in an effort to understand this changing export process that this study was undertaken.
Among the firm factors identified as influencing superior export performance are the perceptions of firm management. These perceptions change over time and those of export performance are specifically noted as influencing management perceptions. This study draws on these concepts of management perceptions and the role of strategy in the export process to ask “in which ways does export performance influence the export strategy process?” As a basis to frame and advance the study, the findings of past export research and its allusion to the role of performance perceptions were used to develop a research model.
The research question suggested an approach that would allow the researcher to get close to the research context; this was achieved using a methodology of phenomenology. To implement this research approach, case study, in a multiple case design, was used to gain insight into the perceptions of informants. The study was further facilitated by using the dynamic context provided by New Zealand specialist food exporters, from which eight case firms were selected using export and business criteria.
Interviews with management were the principal source of evidence. Evidence gathering was carried out concurrently with the analysis of evidence. This allowed earlier informant evidence to inform subsequent evidence gathering. Analysis used a variety of instruments to increase focus in case data, providing a basis for the development of the study’s findings. Consistency across cases in field work and analysis was underwritten by the use of a case study protocol and specialised computer software to maintain a case study data base.
Informant evidence indicated that export practitioners in case firms had a wider perception of export performance than past export research had suggested. These perceptions derive from streams of indicators of performance and contextual situations arising from export activities. The management perceptions that these indicators engender are applied in firm export strategy processes.
While the focus on export activity indicators varies according to firm organisational structure, the use of a range of indicators was a feature of all firms in the study.
These flows of indicator information and the perceptions and changes that they generated were part of a dynamic cycle of export activities. This process saw firm export strategy continuously reviewed, reformulated and implemented as it was adapted to address perceived changes in firm performance and context. These findings lead to the development of a conceptual model of a dynamic export process across case firms.
The dynamic export process identified in this study is a significant extension of past static cross-sectional conceptualisations of the export process. It suggests that export practitioners draw upon a wide range of export activity indicators to build perceptions of export outcomes and their export context. These perceptions inform and influence future export strategy and in turn, future export outcomes. This contribution to export research provides an understanding of the dynamic export process that is close to the reality of export practitioners. This understanding allows researchers, exporting firms and policy makers to conceptualise the export process in terms that are close to actual export practice. In addition, these exploratory findings of a dynamic export process provide a platform for further research to consider the application of this conceptualisation across exporting firms as a whole
Application of generalizability theory to evaluate the Kessler Psychological Distress Scale and distinguish between enduring and dynamic distress
Get PDFObjectives: Nowadays, the number of older people is increasing rapidly, both in absolute figures and as a proportion of the population, which makes the maintenance of psychological well-being among aging population imperative. Neuropsychological distress may promote cognitive impairment and impact on the health of older people, which makes accurate assessment of distress an important clinical and research issue. The Kessler Psychological Distress Scale (K-10) is a widely used instrument used to measure individual distress. However, the ability of K-10 to distinguish between enduring and dynamic distress symptoms, and the generalizability of its scores, have not been investigated in older populations using appropriate methodology. Method: Generalizability theory (G-theory) was applied to differentiate enduring and dynamic distress and examine the reliability of K-10 in a sample of 201 adults (43% males) aged 70 to 90 years old who participated in Sydney Memory and Ageing Study. The data were collected biennially over ten years. Results: The K-10 scale showed strong reliability (Ga=0.81, Gr=0.89) in assessing enduring distress and its assessment scores were generalizable across occasions and older adults. Most of distress symptoms represented by K-10 items were enduring. Limitations: Generalizability of these findings may be limited to older adults. Conclusions: The K-10 appears more suitable to evaluate enduring distress in aging populations over time, which is important for interventions targeting older adults’ mental health given its scores will likely capture enduring changes in neuropsychological health before and after interventions
Training parents to implement the Picture Exchange Communication System via telehealth and behavioural skills training
Get PDFResearch indicates that deficits in functional communication skills correlate with problem behaviour. Results from previous studies suggests that by teaching functional communication skills to an individual, it may be possible to replace problem behaviour with more socially appropriate means of communicating their needs and wishes. The primary aim of the current study was to investigate whether parents could be trained to implement the Picture Exchange Communication System (PECS) effectively with their adolescent son, Jack (pseudonym), who has an intellectual disability. The effectiveness of telehealth to administer PECS training was evaluated in conjunction with the use of behavioural skills training. Additionally, errors made by the parents in their use of PECS during training sessions where the researcher provided them with prompts were also examined. The secondary aim of the study was to investigate the effect of the aforementioned PECS training on the functional communication skills of Jack in the home environment. The most significant findings of the current study were that telehealth was a viable method of teaching PECS to parents, that parents made fewer errors for subsequent sessions within each phase, and that a greater number of errors were made in the role of communicative partner compared to physical prompter during Phase One. Results of the study also suggest that the intervention resulted in increased functional communication skills for Jack; namely the emergence of mands for particular toys and for making requests for the continuation of activities he enjoyed
Understanding outdoor education in South Korea: The perspectives of current leaders
No full textOutdoor education includes the provision of outdoor learning experiences to assist youth’s holistic development in relation to the outdoor environment. The formalised educational practice of outdoor education internationally derived mainly from the Western part of the world, with famous Western scholars and philosophers providing the root of the ideas and theories (Wurdinger, 1997). The practice is now widespread in different parts of the world, including South Korea. However, outdoor education in South Korea has not yet gone through systematic development (Lee, 2018). In-depth exploration to understand outdoor education through the eyes of current outdoor education leaders in South Korea and the key influences and social and cultural context that impacted the delivery of outdoor education is, therefore, timely. This study aims to understand outdoor education in South Korea, focussing on why and how outdoor education in South Korea has shaped as it is today.
This interpretive qualitative study was framed by critical realism and contextualism and used culturally responsive approaches to explore and highlight the perspectives and experiences of current outdoor leaders in Korea. One-on-one semi-structured interviews were conducted online with six current outdoor education leaders in South Korea from different backgrounds. Through thematic analysis, four main themes were identified. The first theme focused on learning outdoor education in South Korea, highlighting the challenges leaders face in learning and developing themselves as an OE leader. The second theme explored policies and regulation that impacts the operation and delivery of outdoor education. The third theme explored the perception of outdoor education from different parts of society, including parents, teachers, schools and organisations. Lastly, the final theme explored these current leaders' ideas and perceptions of the future of OE in South Korea. Given the interconnection of each challenge identified through the analysis of four themes, for OE to flourish in South Korea, there was the need for clarification of outdoor education, investment in the development of Korean-style outdoor education and changes in perception. The research concludes with areas for further study, limitations and a summary of the entire research