Power-Assist Wheelchair Attachment

This senior design project sought to combine the best characteristics of manual and power wheelchairs by creating a battery-powered attachment to propel a manual wheelchair. The primary customer needs were determined to be affordability, portability, and travel on uneven surfaces. After the initial prototype, using a hub motor proved unsuccessful, so a second design was developed that consisted of a gear reduction motor and drive wheel connected to the back of the wheelchair by a trailing arm that could be easily attached/detached from the frame. The prototype of the second design succeeded in meeting most of the project goals related to cost, off-road capability, inclines, and range. Improvements can be made by reducing the attachment weight and improving user control of the device

Andesitic glaciovolcanic interactions at Tongariro and Ruapehu volcanoes, New Zealand

Glaciers that cap or flank volcanoes have a major control on the eruption style and distribution of volcanic material. Ancient deposits that were formed by the interaction of lava and ice inform our understanding of glaciovolcanic eruption dynamics, as well as the eruptive environment. To date, most studies have come from basaltic or rhyolitic volcanic areas covered by thick continental ice sheets (e.g., Iceland, North America and Antarctica). A primary aim of this thesis is to present new maps and emplacement models for previously undescribed proximal deposits from Tongariro and Ruapehu volcanoes, New Zealand; two mid-latitude, andesitic volcanoes where past and present ice has been in the form of waxing and waning alpine glaciers throughout the Late Pleistocene. The results presented here contribute to paleoenvironmental reconstructions for the central North Island of New Zealand, and support inferences about early edifice construction at both volcanoes. The mapped deposits include a variety of fragmental units, which have been sparsely documented from intermediate-composition volcanoes where coherent lava flows dominate. These unusual deposits have implications for the availability of meltwater and its effects during the deposition of voluminous fragmental andesite. At Tongariro volcano, many lithofacies were mapped, including a ≥ 100 m thick hyaloclastite deposit, ice-confined fractured lavas and channelised water-lain primary volcaniclastic deposits, all of which indicate the presence of water. The approximate ages of these deposits coincide with the variably cool last interglacial period (marine isotope stage 5) through the early stage of the last glacial period (marine isotope stage 4). A summit glacier of varying thickness is interpreted to have capped the edifice during this time, which produced and confined meltwater. The waterlain clastic deposits are interpreted as having originated from explosive eruptions into meltwater, which drained from the edifice along subglacial channels and deposited the eruption-fed tephra. These deposits have not yet been reported from andesitic interactions with other alpine glaciers. Their deposition along a high ridgeline is inferred to have been aided by confining ice that filled the adjacent valleys and prevented meltwater from flowing down the steep topography either side. Cool emplacement of these deposits in waterlain flows is supported by temperature determinations from paleomagnetic data. Randomly oriented magnetisation directions for lithic and possible juvenile clasts provide deposit temperature estimates of < 150 °C, which is strongly indicative of efficient mixing of tephra with water. On Ruapehu volcano, a ≥ 150 m thick and ≥ 1 km wide hydroclastic breccia deposit, analogous to submarine volcanic breccias, is exposed near the summit. The breccia is interpreted to have formed from non-explosive fragmentation by quenching and dynamic stressing of lava erupted into accumulated meltwater. The minimum age of the deposit coincides with the penultimate glacial period (marine isotope stage 6). The thickness of the glacier at that time is estimated to have been 150 m or more. Based on the emplacement models determined from field evidence, a new experimental technique was developed to investigate whether the thermal properties of andesitic lava control the availability of meltwater at the eruption site, a paucity of which has been called on for minimal evidence of andesite lava-water interaction. Preliminary data indicate that the thermal efficiency of andesite for ice melting is comparable with that of basalt and that meltwater production is not limited by a lower heat capacity. In addition, the experimental results show that heat transfer and meltwater production rates increase with applied force during dynamic lava-ice interaction. This effect should be taken into account when modelling the thermodynamics of a flowing or inflating lava that interacts with ice. Field mapping and experiments support inferences that retention of meltwater at the eruption site is probably the main control for the emplacement and preservation of fragmental material at andesitic volcanoes, which usually host ice-bounded lava flows controlled by meltwater drainage down steep slopes and where thick ice is hard to accumulate. At Tongariro and Ruapehu, it is likely that a composite arrangement of vents has existed at the edifices since early in their evolution, and allowed thick ice and meltwater to accumulate on steep topography during periods of ice advance

Functional Characterization of Antibodies against Neisseria gonorrhoeae Opacity Protein Loops

Background: The development of a gonorrhea vaccine is challenged by the lack of correlates of protection. The antigenically variable neisserial opacity (Opa) proteins are expressed during infection and have a semivariable (SV) and highly conserved (4L) loop that could be targeted in a vaccine. Here we compared antibodies to linear (Ab linear) and cyclic (Abcyclic) peptides that correspond to the SV and 4L loops and selected hypervariable (HV2) loops for surface-binding and protective activity in vitro and in vivo. Methods/Findings: AbSV cyclic bound a greater number of different Opa variants than AbSV linear, including variants that differed by seven amino acids. Antibodies to the 4L peptide did not bind Opa-expressing bacteria. Ab SV cyclic and Ab HV2 cyclic, but not AbSV linear or AbHV2 linear agglutinated homologous Opa variants, and AbHV2BD cyclic but not AbHV2BD linear blocked the association of OpaB variants with human endocervical cells. Only AbHV2BD linear were bactericidal against the serum resistant parent strain. Consistent with host restrictions in the complement cascade, the bactericidal activity of Ab HV2BD linear was increased 8-fold when rabbit complement was used. None of the antibodies was protective when administered vaginally to mice. Antibody duration in the vagina was short-lived, however, with,50 % of the antibodies recovered 3 hrs postadministration. Conclusions: We conclude that an SV loop-specific cyclic peptide can be used to induce antibodies that recognize a broad spectrum of antigenically distinct Opa variants and have agglutination abilities. HV 2 loop-specific cyclic peptides elicite

New universal ITS2 primers for high-resolution herbivory analyses using DNA metabarcoding in both tropical and temperate zones

DNA metabarcoding is a rapidly growing technique for obtaining detailed dietary information. Current metabarcoding methods for herbivory, using a single locus, can lack taxonomic resolution for some applications. We present novel primers for the second internal transcribed spacer of nuclear ribosomal DNA (ITS2) designed for dietary studies in Mauritius and the UK, which have the potential to give unrivalled taxonomic coverage and resolution from a short-amplicon barcode. In silico testing used three databases of plant ITS2 sequences from UK and Mauritian floras (native and introduced) totalling 6561 sequences from 1790 species across 174 families. Our primers were well-matched in silico to 88% of species, providing taxonomic resolution of 86.1%, 99.4% and 99.9% at the species, genus and family levels, respectively. In vitro, the primers amplified 99% of Mauritian (n = 169) and 100% of UK (n = 33) species, and co-amplified multiple plant species from degraded faecal DNA from reptiles and birds in two case studies. For the ITS2 region, we advocate taxonomic assignment based on best sequence match instead of a clustering approach. With short amplicons of 187–387 bp, these primers are suitable for metabarcoding plant DNA from faecal samples, across a broad geographic range, whilst delivering unparalleled taxonomic resolution

Is the abundance of Faecalibacterium prausnitzii relevant to Crohn's disease?

Reports that bacteria within the Firmicutes phylum, especially the species Faecalibacterium prausnitzii, are less abundant in Crohn’s disease (CD) patients and supernatants from cultures of this bacterium are anti-inflammatory prompted the investigation of the possible correlations between the abundance of F.prausnitzii and the response to treatment in patients with gut diseases and healthy controls. In a randomized, double-blind trial, faeces were collected from healthy volunteers, and from patients with active CD, ulcerative colitis (UC) and irritable bowel syndrome before and after treatment. The levels of F. prausnitzii DNA in faecal suspensions were determined by PCR. Treatment by an elemental diet was effective, resulting in decreases in both the Harvey and Bradshaw index (P<0.001) and the concentrations of serum C-reactive protein (P<0.05). The total levels of F. prausnitzii in faecal samples from CD patients at presentation were lower than those in the other groups both before and after the treatment. There was no correlation between F. prausnitzii abundance and the severity of CD before treatment. Clinical improvement unexpectedly correlated with a significant decrease in the abundance of F. prausnitzii, especially the A2-165 subgroup (P<0.05). Our data suggest that a paucity of F. prausnitzii in the gastrointestinal microbial communities is likely to be a minor aetiological factor in CD: recovery following elemental diet is attributed to lower levels of gut flora

Impact of general practice endorsement on the social gradient in uptake in bowel cancer screening

This is a summary of independent research funded by the National Institute for Health. Research (NIHR)’s Programme Grants for Applied Research Programme (RP-PG-0609–10106

MIR21 drives resistance to Heat Shock Protein 90 inhibition in cholangiocarcinoma

Cholangiocarcinomas (CCA) are resistant to chemotherapy, so new therapeutic agents are needed. We performed a screen to identify small molecule compounds that are active against CCAs. Levels of microRNA 21 (MIR21 or miRNA21) are increased in CCAs. We investigated whether miRNA21 mediates resistance of CCA cells and organoids to HSP90 inhibitors

Complexity on Small Scales III: Iron and alpha Element Abundances in the Carina Dwarf Spheroidal Galaxy

We have obtained high-resolution spectroscopy of ten red giants in the Carina dwarf spheroidal (dSph) with UVES at the ESO/VLT. Here we present the abundances of O,Na,Mg,Si,Ca,Ti and Fe. By comparing the iron abundances [Fe/H] with calcium triplet (CaT) metallicities we show that the empirical CaT technique yields good agreement with the high-resolution data for [Fe/H]>-2 dex, but tends to deviate at lower metallicities. We identify two metal poor stars with iron abundances of -2.72 and -2.50 dex. These stars are found to have enhanced [alpha/Fe] ratios similar to those of stars in the Milky Way halo. However, the bulk of the Carina red giants are depleted in the [alpha/Fe] abundance ratios with respect to the Galactic halo at a given metallicity. One of our targets, with a [Fe/H] of -1.5 dex, is considerably depleted in almost all of the alpha-elements by ~0.5 dex compared to the solar values. Such a low [alpha/Fe] can be produced by stochastical fluctuations in terms of an incomplete mixing of single Type Ia and II SNe events into the ISM. Our derived element ratios are consistent with the episodic and extended SF in Carina known from its color-magnitude diagram. We find a considerable star-to-star scatter in the abundance ratios. This suggests that Carina's SF history varies with position within the galaxy, with incomplete mixing. Alternatively, the SF rate is so low that the high-mass stellar IMF is sparsely populated, as statistically expected in low-mass star clusters, leading to real scatter in the resultant mass-integrated yields. Both ideas are consistent with slow stochastic SF in dissolving associations, so that one may not speak of a single SF history at a detailed level (Abridged).Comment: 23 pages, 8 figures, accepted for publication in the A

Personalised profiling to identify clinically relevant changes in tremor due to multiple sclerosis

Background: There is growing interest in sensor-based assessment of upper limb tremor in multiple sclerosis and other movement disorders. However, previously such assessments have not been found to offer any improvement over conventional clinical observation in identifying clinically relevant changes in an individual's tremor symptoms, due to poor test-retest repeatability. Method: We hypothesised that this barrier could be overcome by constructing a tremor change metric that is customised to each individual's tremor characteristics, such that random variability can be distinguished from clinically relevant changes in symptoms. In a cohort of 24 people with tremor due to multiple sclerosis, the newly proposed metrics were compared against conventional clinical and sensor-based metrics. Each metric was evaluated based on Spearman rank correlation with two reference metrics extracted from the Fahn-Tolosa-Marin Tremor Rating Scale: a task-based measure of functional disability (FTMTRS B) and the subject's self-assessment of the impact of tremor on their activities of daily living (FTMTRS C). Results: Unlike the conventional sensor-based and clinical metrics, the newly proposed ’change in scale’ metrics presented statistically significant correlations with changes in self-assessed impact of tremor (max R2>0.5,p< 0.05 after correction for false discovery rate control). They also outperformed all other metrics in terms of correlations with changes in task-based functional performance (R2=0.25 vs. R2=0.15 for conventional clinical observation, both p< 0.05).Conclusions: The proposed metrics achieve an elusive goal of sensor-based tremor assessment: improving on conventional visual observation in terms of sensitivity to change. Further refinement and evaluation of the proposed techniques is required, but our core findings imply that the main barrier to translational impact for this application can be overcome. Sensor-based tremor assessments may improve personalised treatment selection and the efficiency of clinical trials for new treatments by enabling greater standardisation and sensitivity to clinically relevant changes in symptoms