11319 research outputs found
Sort by
Is brain function impaired in moderate sleep apnoea: Before and after six months of APAP
Get PDFThe physiological impact of severe levels of obstructive sleep apnoea and the benefits of treatment are well documented. Yet more of the population suffer sleep apnoea of moderate severity. However, we still have substantial gaps in our understanding on the physiological impact and treatment of people with sleep apnoea of moderate severity. Our study addressed whether moderate obstructive sleep apnoea (OSA) had an impact on cerebral blood flow, cognition, or microsleeps. It also explored the effect of 6–7 months of auto-titrating positive airway pressure (APAP) therapy on physiological measurements and quality-of-life in persons with moderate OSA.
Twenty-four patients aged 32–79 years (median age 59, 10 female), who had previously presented to the Christchurch Hospital Sleep Unit and subsequently diagnosed with sleep apnoea of moderate severity consented to our study. Following a Level II polysomnography to confirm their suitability to participate, thirteen of these participants, aged 43–79 years (median age 59, 4 female), were placed on APAP therapy, with instructions to use it for at least 4 hr per night for 70% or more of the nights. The remaining 11 participants aged 32–79 years (median age 62, 6 female), were placed in an untreated cohort. Placement in the treated cohort was dependent on order of presentation with those first recruited offered a place in the treated cohort. A third group of seven healthy controls aged 42–73 years (median age 62, 4 female) with an apnoea, hypopnea index (AHI) < 5 were recruited from a database of normal volunteers. The absence of sleep apnoea’s was confirmed by polysomnography in all seven participants. All three groups underwent an MRI ASL scan of cerebral perfusion, completed cognitive tests covering five cognitive domains – attention, executive functioning, memory, speed of processing, and visuospatial – and undertook a 30-minute task in which they were required to continuously track a constantly moving target for the purpose of detecting microsleeps. This behavioural data, along with video recordings of eye movement and closure, were visually rated to identify microsleeps. Finally, the Epworth sleepiness scale (ESS), Pittsburgh sleep quality index (PSQI), and Short-form 36 Health survey questionnaire (SF-36) were completed. All measurements were repeated after the intervention period of 6–7 months during which time the treated cohort received APAP therapy.
Global cerebral perfusion did not differ at baseline between participants with sleep apnoea of moderate severity and healthy controls (mean 49.26 ml/100g/min vs 48.73 respectively, p = .899, d = 0.06). Furthermore, global cerebral perfusion rates at follow-up for the treated cohort, were not significantly different to baseline (mean 51.64 vs 48.56, p = .150, d =0.42). Although a comparison of regional perfusion, as shown in the multi-sliced images, between the treated cohort, the untreated cohort, and the control group show a positive effect of change in the treated cohort over the other two, particularly in the right cerebral cortex/cingulate gyrus region and the right angular/supramarginal gyri, no statistically significant distinct regions of improved cerebral perfusion were identified.
The normalized and standardized composite cognitive score also did not differ at baseline between moderate OSA and healthy controls (median 0.26 vs 0.73, p = .166, d = -0.62). Repeat testing of cognition at the completion of 6–7 months of APAP therapy found no evidence of a difference between baseline and follow-up on total cognition (mean = 0.22 vs 0.36, p = .560, d = -0.17. However, despite memory showing a significant improvement (p = .001) there was a clear test-retest effect in all three groups.
Microsleep was also tested at baseline. Participants with moderate OSA (0–126 microsleeps, median 0) and healthy controls (0–2 microsleeps, median 0) displayed a similar propensity to microsleeps (p = .253, d = 2.1). No difference in microsleeps were observed between participants compliant with APAP treatment compared to their baseline result (median 0, range 0–5, vs. median 0, range 0–13, p = .344). Several markers of day-time sleepiness and quality of live improved in our treatment cohort: Epworth Sleepiness Scale (median 8 down from 11, p = .003, d =1.96), PSQI (mean 15.69 up from 14.23, p = .046, d = 0.94) and Minnesota Short Form 36 (mean 76.31 up from 66.09, p = .035, d = 0.93).
This research was unable to demonstrate any change in cerebral perfusion, cognition, or microsleeps following 6-7 months of APAP treatment. However, improvements in daytime sleepiness, sleep quality and quality of life are consistent with the observation that most participants who used APAP in this study wished to continue its use past its conclusion. This indicates a clinical benefit in treating moderate OSA not otherwise supported
Paul’s Use of the Remnant Concept in Romans 9-11 and its Interpretative Implications for Romans 11:26
Get PDFSitting at the climax of Romans 9-11 is one of the most hotly debated verses in the New Testament, Romans 11:26. Much of modern scholarship has interpreted “πᾶς Ἰσραὴλ σωθήσεται” (“All Israel will be saved,” 11:26) as referring in some way to the salvation of ethnic Jews. Some believe that all of the Jews of Israel will be saved because they are God’s people and God has a different plan for and relationship with Israel compared to the Gentiles. Others believe that Romans 11:26 speaks of the salvation of just the elect from within Israel throughout history. The majority position though, is that all Jews, regardless of any prior faith in Christ, will find salvation at the Parousia as Christ reveals himself to his people, just as he did to Paul on the Damascus Road. There is a small group of scholars, old and new, who understand Ἰσραήλ in Romans 11:26 to include both Jews and Gentiles.
In this thesis, I look at Paul’s use of the “remnant” in Romans 9-11 and how this idea of a remnant of faithful believers might help us find our way through the debate on 11:26. Paul draws on the Old Testament extensively in Romans 9-11, and in doing so leans on Isaiah’s concept of “the remnant.” It will be shown that Paul’s use of the remnant in Romans 9-11 makes it more likely than is usually recognized, that in Romans 11:26, Paul has the Gentiles on his mind, as well as Jews, when he says “πᾶς Ἰσραὴλ σωθήσεται.
Participation in science outreach and its impacts on programme presenters
Get PDFThis research investigates whether skills development, attitudes towards science, interest in lifelong learning about science, and the likelihood of future participation in science education and careers, are impacted by participation as a science outreach presenter. Local presenters are the heart of the operation team of Science Caravan, the most extensive science outreach programme in Thailand run by the National Science Museum (NSM). This programme involves students from local high schools or universities who volunteer to assist as presenters. About 8,000 presenters have helped visitors to be actively involved in science activities. However, little is known about the impact of presenting.
This study employed mixed methods; data were collected in two phases. Phase one involved three questionnaires. Two questionnaires were administered to current presenters (N = 690), pre-presenting survey (before training) and post-presenting survey at 12 locations of the Science Caravan tour between November 2017 and February 2018. Also, during the Science Caravan tour, 64 current presenters were observed to assess the improvement of science communication skills over their four days of presenting. An alumni survey was used to collect data from alumni presenters who had participated in the programme. This questionnaire was administered online from October 2017 to March 2018, and 726 alumni presenters responded. Phase two of data collection was performed a month after finishing at each location. This phase involved telephone follow-up interviews with 19 current presenters and 19 alumni presenters. Questionnaires, observations and interview data were analysed using a combination of descriptive statistics, non-parametric and parametric statistics, and thematic content analysis.There was significant impact of presenting on the students improved self-confidence and four essential skills: communication, problem-solving, critical thinking and interpersonal skills. Through a combination of training and immersive experience, presenters perceived substantial acquisition of science communication skills and understood some key elements of effective science communication. Direct observations over four days of presenting confirmed improved science communication skills.
The results demonstrate that while these presenters already possessed positive attitudes towards science, the brief experience of being Science Caravan presenters enhanced presenters’ science attitudes in all scales –with more positive attitudes in Self-concept in science, Value of science to society and Future participation in science, decreased Anxiety about science presenting. Moreover, presenting resulted in increased reported interest in life-long learning activities regarding science. This increase in life-long learning activities is related to students’ attitude and self-efficacy in science.
The impact on academic and career plans was directly linked to participants’ experience during their tenure in the programme. The results indicate that pre-existing participants’ interest in science-related aspirations was strengthened. The experience from the programme influenced presenters’ decisions about careers in different ways, such as inspiring aspiration, confirming interest in STEM, providing new information for possible STEM careers, and developing an appreciation of teaching. Self-concept, self-efficacy, education level, and interest in science-related activities are significant predictors of intentions of future participation in science.
Volunteer participation as a presenter in even short-duration events such as Science Caravan appears to be an effective model to offer skills development, foster a positive attitude towards science, increase interest in life-long learning activities and inspire young people to future involvement in science study or science-related careers
Preliminary Development of a PPAM Actuated Pediatric Prosthetic Ankle
Get PDFThe purpose of this research was to develop a preliminary design of a powered pediatric
prosthetic ankle. Previous research identified the health risk of improper gait cycle and the lack
of powered prosthetic ankle options for children. Costs for powered prosthetic ankles are too
high (upwards of $5000 NZD), the sizes are too large and the weight is too significant for a child
to benefit from. Current technologies for ankle joint actuation and materials for the prosthetic
structure were evaluated and a conclusion of utilizing PPAMs was chosen due to their ability to
generate the required 300 N of contraction force. CAD was used to model the structure of a
prosthetic ankle and evaluate the FOS of the different material combinations while under static
loading and fatigue simulations. HDPE and UHMWPE failed to withstand the simulations, while
the aluminum alloy and stainless steel showed minimal faults from the simulations. MatLab was
used to simulate the desired PPAM dimensions of 100 mm to determine the contraction force
and contraction percentage that can be generated by the PPAM. The smallest PPAM found in
research was 110 mm and showed promising results from their mathematical modeling. The
overall height of the prosthetic was no greater than 110 mm and the membrane length of the
PPAM was no greater than 100 mm, while successfully producing more than 300 N during
contraction. The results showed promising data that needs further development to allow the
benefits of this research to positively impact the lives of pediatric amputees
Analysis of Lateral Septal Activity during a Navigational Reward-Approach Task
No full textMotivation and the pursuit of reward involves the contribution of many brain regions including the hippocampus and ventral tegmental area (VTA). The lateral septum has been identified as a relay between the hippocampus and VTA, however, its exact influence on motivational and goal-directed behaviours is unclear. This experiment aimed to expand on the understanding of the lateral septum during these behaviours, focusing on lateral septal activity during a navigational reward-approach task. Specifically, the study aimed to determine whether there was anticipatory ramping pattern of the lateral septum activity as an animal approached a reward and whether hippocampal activity was related to this.
Rats were trained to run clockwise and anticlockwise circuits around a track to obtain a food reward at set locations. The two directions and two reward locations were used to help separate goal/approach effects and spatial/location effects. Local field potential (LFP) recordings were made from the CA1 layer of the hippocampus and from the lateral septum. Simultaneously, single-unit recordings were made from tetrodes positioned in the lateral septum. It was hypothesised that LFP activity from the hippocampus and the lateral septum would display coherence. Secondly, it was hypothesised that the hippocampal LFP signal would predominately lead the lateral septal signal, and that this lead will become stronger as the animal approaches the reward location, demonstrating the increasing hippocampal influence during this period. Lastly, it was hypothesised that identified lateral septal cells would increase their cell firing rate, in an anticipatory ramping pattern, as the animal moves toward the reward, potentially linking hippocampal spatial activity to motivational systems such as those in the VTA.
Data revealed coherence between the two LFP signals and a strong hippocampal lead was prominent in the LFP during the initial part of each circuit. Contrary to the hypothesis, however, the lateral septal lead increased as the animal approached the reward location. No evidence of a ramping pattern was found in the firing rate of lateral septal cells, with a more complex and non-linear pattern. Further analyses revealed a population level effect of differential cell firing between the first half of the track and the second half. Taken together, the results suggest that the activity of the lateral septum may be related to goal-directed behaviour, and that this activity is strongly influenced by the hippocampus. It is suggested that lateral septal activity may be used as a value signal to convey relevant information to connecting regions such as the hippocampus and VTA
Effect of Magnesium Concentration in Seawater on Marine Invertebrate Calcification
Get PDFVariation in seawater magnesium (Mg) and calcium (Ca) concentrations over the past 500 million years has influenced marine calcite composition. A local field study showed that present-day nearshore waters exhibited localized variation in [Mg], most likely due to freshwater mixing. This observation prompted investigation into how different water chemistries would affect the calcite of invertebrates. Artificial seawater was utilized to create multiple Mg/Ca conditions to carry out this research. A cost-effective yet robust methodology for artificial seawater suitable for invertebrate growth study was developed.
Blue mussels (Mytilus edulis), jingle oysters (Anomia trigonopsis), and blue tubeworms (Spirobranchus cariniferus) were grown for 50 days in artificial seawater with different Mg/Ca concentrations. Skeletal Mg/Ca growth responses were modeled from weight percentage of MgCO3 identified in new calcite growth. All three species were affected when Mg/Ca ratios were at the lowest level of 1.5. At seawater Mg/Ca = 1.5, blue mussel and jingle oyster had lower survival rates. However, the survival rates of blue mussels were not affected by Mg/Ca when held in a seawater with decreasing Mg/Ca levels over a 210-day dynamic treatment experiment. Low levels of Mg/Ca were antagonistic to populations of blue mussels only when abruptly treated and not when gradually introduced.
At Mg/Ca = 1.5, tubeworms precipitated calcite with lower amounts of MgCO3. Low Mg calcite produced by oysters and mussels was not influenced by decreased Mg concentration. Tubeworms became unable to regulate their calcification at low Mg concentrations and produced more brittle calcite. This supports a new model describing a tipping point at which active calcification strategies can be influenced to alter in a stepwise fashion. A species that actively regulates calcite precipitation can be influenced to create a calcite mineralogy with MgCO3 content significantly different than its normal weight percentage of Mg at a tipping point and become semi-active or passive in calcification regulation. The boundary of this tipping point seems to be species specific and is overlooked in experiments with few treatment conditions. Further study with more treatments in small increments would provide better resolution to focus on the exact moment of loss of calcification control
Release and bioactivity of PACA nanoparticles containing D-Lys6-GnRH for brushtail possum fertility control
No full textPoly(ethylcyanoacrylate) (PECA) nanoparticles containing the chemical sterilitant D-Lys6-GnRH were prepared by an in situ interfacial polymerization technique. Their potential as a peroral delivery system for biocontrol of the brushtail possum, a major pest species in New Zealand, was evaluated. Peptide release from resulting particles was studied in vitro in artificial gastric juice (AGJ), simulated intestinal fluids (SIF) and brushtail possum plasma. The nanoparticles released a small fraction of bioactive over 6 hours in AGJ and SIF (< 5%), whilst staying intact and retaining fractions of intact D-Lys6-GnRH. In contrast, 60% of D-Lys6-GnRH was released after 1 hour in possum plasma. The nanoparticles were also administered in vivo into the caecum of brushtail possums. A significant biological response, measured as an increase in plasma luteinizing hormone (LH), was evident 10 minutes after administration. This demonstrates not only that PECA nanoparticles were able to facilitate the uptake of D-Lys6-GnRH from the caecum into systemic circulation, but also that sufficient bioactive peptide reached the pituitary to exert a significant LH response following GnRH receptor mediated endocytosis. Hence, it can be concluded, that PECA nanoparticles comprise a promising formulation strategy for the peroral delivery of the chemical sterilitant D-Lys6-GnRH to the brushtail possum in New Zealand.Peer Reviewe
A Search for Face-Category Representation in Three Areas of the Avian Visual Forebrain
Get PDFVisual perception of the world around us is an essential part of life for almost all species. Past and current literature tells us that visual information is processed in a hierarchical fashion throughout the mammalian visual stream, and yet despite evidence to suggest that the avian visual system is as least as efficient, if not more so, than the mammalian visual system, how birds solve category and object representation in the absence of a cortex is still unknown. The aim of the current experiment was to determine whether birds also display category representation, with a focus on avian and human facial representation in three visual forebrain structures: entopallium (ENTO), mesopallium ventrolaterale (MVL) and the visual wulst (VW). We performed electrophysiological recordings from 14 pigeons during a passive visual looking task that presented birds with five categories of stimuli: human, human scrambled, pigeon, pigeon scrambled and sine gratings. We recorded from a total of 140 cells in ENTO, 121 in MVL and 96 in VW. We found no neurons that fired selectively to pigeon or human faces in either ENTO, MVL or VW. The MVL region did, however, display the highest proportion of category-preference and category-selective cells, suggesting that the region of the brain that may be responsible for categorisation and category-learning could lie within higher-order visual areas, compared to earlier visual areas such as ENTO and VW. The current failure to find face-selective cells (or face-patches) also highlights the need to consider alternative computational mechanisms that might underly visual recognition in non-mammalian species. The use of novel experimental techniques such a fMRI, eye-tracking and comprehensive receptive field mapping will be key in uncovering whether birds exhibit single-cells (or patches) selective for categories or objects, parallel to those found within the mammalian extra-striate cortex
To turn the key : the history of deaf education in New Zealand.
Get PDFOn the 10th March 1880, the Sumner School for the Deaf and Dumb was established. It was the first school for hearing impaired children in the world to be totally funded by the Government. In 1942, a further school was established in Auckland to cater for the hearing impaired children in the northern half of the North Island. During the 1960's and 1970's unit classes for hearing impaired children were developed in ordinary schools. As well, many children with hearing losses were educated in normal classrooms, often with specialist help.
In 1879 the Government sought an expert from England. The methods he brought to New Zealand at this time were innovative. They remained in favour for the next sixty years. In 1940 the Government again sought an expert from England. The principal chosen devoted thirty-three years to education in this specialist field.
The provision of education for hearing impaired children in New Zealand has not been without problems. The need for very small classes, highly competent specialist teachers, buildings to cope with wildly fluctuating rolls and satisfactory institutional care were but a few of the problems educationalists in this specialist field were forced to face. As well, children were often admitted at an advanced age and withdrawn at an early age. The provision of pre-school education proved particularly problematic. Some problems were resolved. The solution to others proved more elusive. The successes and failures of this educational enterprise are examined in the present thesis