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BCIT Citations Collection

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Phase change material's (PCM) impacts on the energy performance and thermal comfort of buildings in a mild climate
The current residential buildings are of light weight construction. As such, they tend to frequent indoor air temperatures fluctuations and have been proven detrimental for thermal comfort and mechanical system energy consumption. This is reflected in the energy consumption statistics for residential buildings. More than 62% of the building energy use is towards maintaining comfortable indoor conditions. Phase change materials (PCM); a latent heat thermal storage material, have the potential to increase the thermal mass of these buildings without drastically affecting the current construction techniques. In this paper, the potential of phase change materials is investigated through numerical and experimental studies. The field experimental study is conducted using twin side-by-side buildings exposed to the same interior and exterior boundary conditions, and EnergyPlus, after being benchmarked with the experimental results, is used for the numerical study. The numerical study is carried out for an existing residential apartment unit with particular emphasis on the effects of different design parameters such as orientation and window to wall ratio. Preliminary analyses of experimental data show that phase change materials are effective in stabilizing the indoor air by reversing the heat flow direction. In fact, the indoor air and wall temperature fluctuations are reduced by 1.4 °C and 2.7 °C respectively. Following, benchmarking of the numerical simulation shows confidence levels in predicting the interior conditions since discrepancies between experimental data and numerical data are within tolerance limits of the measuring device. Further, from the analysis of the numerical data, phase change material is effective in moderating the operative temperature but does not translate to significant thermal comfort improvement when evaluated over a night time occupancy regime in the summer. On the contrary, PCM is effective in lowering the heating energy demand by up to 57% during the winter condition., Peer reviewed article, Published. Received 1 October 2015, Revised 22 January 2016, Accepted 23 January 2016, Available online 29 January 2016.
Planning for climate action in British Columbia, Canada
Significant greenhouse gas (GHG) reductions from all sectors of human enterprise are necessary to avoid further effects and reduce the current effects of climate change. Agriculture and the global food system are estimated to contribute to one-third of all anthropogenic GHGs. In British Columbia, Canada, mandated GHG reduction targets and voluntary climate action programs are challenging local governments to include emission reduction targets, policies, and actions within official planning documents. At this early stage of GHG reductions, local government attention does not yet include agriculture but is directed toward the transportation, buildings, and waste management sectors. Given agriculture's contribution to GHG emissions and local government's engagement with GHG mitigation and food system planning, it seems reasonable to anticipate that over time, local governments should and will engage increasingly in reducing GHGs from agriculture. With the goal of advancing agriculture GHG mitigation by local governments, this paper reviews the jurisdictional powers governing agriculture and climate change within British Columbia. It examines how local governments can support mitigation within the sector through their roles in planning, policy, programming, and public engagement, and identifies potential research agenda items., Peer-reviewed article, Published. Submitted 18 April 2011 ; Revised 4 July 2011 and 1 August 2011 ; Accepted 2 September 2011 ; Published online 20 March 2012.
Precision of non-invasive temperature measurement by diffuse reflectance spectroscopy
Diffuse reflectance spectroscopy can be used as a noninvasive probe for measurement of temperature in real time. We have measured the precision of this technique to determine the temperature of Si and GaAs substrates during semiconductor processing. Our results show that the standard deviation of the noninvasive optical technique is less than 1.5 °C for GaAs and less than 2.0 °C for Si over the temperature range 25 °C≪T≪600 °C. This standard deviation compares favorably to that for a type‐K thermocouple used in the same measurements: s.d.≪1.5 °C. These results support the notion that noninvasive optical temperature measurement can be used in semiconductor processing with a precision approaching that of a thermocouple., Peer-reviewed article, Published.
Proteomic analysis of the effects of aged garlic extract and its FruArg component on lipopolysaccharide-induced neuroinflammatory response in microglial cells
Aged garlic extract (AGE) is widely used as a dietary supplement, and is claimed to promote human health through anti-oxidant/anti-inflammatory activities with hypolipidemic, antiplatelet and neuroprotective effects. Prior studies of AGE have mainly focused on its organosulfur compounds, with little attention paid to its carbohydrate derivatives, such as N-α-(1-deoxy-D-fructos-1-yl)-L-arginine (FruArg). The goal of this study is to investigate actions of AGE and FruArg on antioxidative and neuroinflammatory responses in lipopolysaccharide (LPS)-activated murine BV-2 microglial cells using a proteomic approach. Our data show that both AGE and FruArg can significantly inhibit LPS-induced nitric oxide (NO) production in BV-2 cells. Quantitative proteomic analysis by combining two dimensional differential in-gel electrophoresis (2D-DIGE) with mass spectrometry revealed that expressions of 26 proteins were significantly altered upon LPS exposure, while levels of 20 and 21 proteins exhibited significant changes in response to AGE and FruArg treatments, respectively, in LPS-stimulated BV-2 cells. Notably, approximate 78% of the proteins responding to AGE and FruArg treatments are in common, suggesting that FruArg is a major active component of AGE. MULTICOM-PDCN and Ingenuity Pathway Analyses indicate that the proteins differentially affected by treatment with AGE and FruArg are involved in inflammatory responses and the Nrf2-mediated oxidative stress response. Collectively, these results suggest that AGE and FruArg attenuate neuroinflammatory responses and promote resilience in LPS-activated BV-2 cells by suppressing NO production and by regulating expression of multiple protein targets associated with oxidative stress., Peer-reviewed article, Published. Received: May 16, 2014; Accepted: October 24, 2014; Published: November 24, 2014.
Protracted myelin clearance hinders central primary afferent regeneration following dorsal rhizotomy and delayed neurotrophin-3 treatment
Regeneration within or into the CNS is thwarted by glial inhibition at the site of a spinal cord injury and at the dorsal root entry zone (DREZ), respectively. At the DREZ, injured axons and their distal targets are separated by degenerating myelin and an astrocytic glia limitans. The different glial barriers to regeneration following dorsal rhizotomy are temporally and spatially distinct. The more peripheral astrocytic barrier develops first, and is surmountable by neurotrophin-3 (NT-3) treatment; the more central myelin-derived barrier, which prevents dorsal horn re-innervation by NT-3-treated axons, becomes significant only after the onset of myelin degeneration. Here we test the hypothesis that in the presence of NT-3, axonal regeneration is hindered by myelin degeneration products. To do so, we used the Long Evans Shaker (LES) rat, in which oligodendrocytes do not make CNS myelin, but do produce myelin-derived inhibitory proteins. We show that delaying NT-3 treatment for 1 week in normal (LE) rats, while allowing axonal penetration of the glia limitans and growth within degenerating myelin, results in misdirected regeneration with axons curling around presumptive degenerating myelin ovoids within the CNS compartment of the dorsal root. In contrast, delaying NT-3 treatment in LES rats resulted in straighter, centrally-directed regenerating axons. These results indicate that regeneration may be best optimized through a combination of neurotrophin treatment plus complete clearance of myelin debris., Peer-reviewed article, Published. Received 3 June 2006, Revised 8 September 2006, Accepted 8 September 2006, Available online 22 November 2006.
Quantification of pyrrolizidine alkaloids in North American plants and honey by LC-MS
Pyrrolizidine alkaloids (PAs) are a class of naturally occurring compounds produced by many flowering plants around the World. Their presence as contaminants in food systems has become a significant concern in recent years. For example, PAs are often found as contaminants in honey through pollen transfer. A validated method was developed for the quantification of four pyrrolizidine alkaloids and one pyrrolizidine alkaloidN-oxide in plants and honey grown and produced in British Columbia. The method was optimised for extraction efficiency from the plant materials and then subjected to a single-laboratory validation to assess repeatability, accuracy, selectivity, LOD, LOQ and method linearity. The PA content in plants ranged from1.0 to 307.8 µg/g with repeatability precision between 3.8 and 20.8% RSD. HorRat values were within acceptable limits and ranged from 0.62 to 1.63 for plant material and 0.56–1.82 for honey samples. Method accuracy was determined through spike studies with recoveries ranging from 84.6 to 108.2% from the raw material negative control and from 82.1–106.0 % for the pyrrolizidine alkaloids in corn syrup. Based on the findings in this single-laboratory validation, this method is suitable for the quantitation of lycopsamine, senecionine, senecionineN-oxide, heliosupine and echimidine in common comfrey (Symphytum officinale), tansy ragwort (Senecio jacobaea), blueweed (Echium vulgare) and hound’s tongue (Cynoglossum officinale)and for PA quantitation in honey and found that PA contaminants were present at low levels in BC honey., Peer-reviewed article, Published. Received 4 June 2015; accepted 20 September 2015.
A quantitative study of cotyledon positioning in conifer development
The number of cotyledons in angiosperm monocots and dicots is tightly constrained. But in the gymnosperm Pinaceae (pine family), which includes many of the conifers, cotyledon number ( nc) can vary widely, commonly from 2 to 12. Conifer cotyledons form in whorled rings on a domed embryo geometry. We measured the diameter of embryos and counted the cotyledons to determine the radial positioning of the whorl and the circumferential spacing between cotyledons. Results were similar between Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco), Sitka spruce ( Picea sitchensis (L.) H.Karst .), and larch ( Larix × leptoeuropaea, synonymous with L. × marschlinsii Coaz), indicating a common mechanism for cotyledon positioning in conifers. Disrupting transport of the growth regulator auxin (with 1- N-naphthylphthalamic acid (NPA)) led to cup-shaped embryos, indicating that whorl (ring) formation is separable from cotyledon patterning within the ring. NPA inhibits cotyledon outgrowth, but not the spacing (distance) between cotyledons. The NPA effect is direct; it does not operate indirectly on embryo size. These results support a hierarchical model for cotyledon positioning in conifers, in which a first stage (not requiring auxin transport) sets the whorl position, constraining the second stage (which requires auxin transport) to form cotyledons within this whorl. Similarly, recent studies in Arabidopsis have shown that different components of complex developmental patterns can have different transport properties; this aspect of patterning may be shared across plants., Peer-reviewed article, Published. Received 27 November 2015. Accepted 8 April 2016.
Raphe-spinal neurons display an age-dependent differential capacity for neurite outgrowth compared to other brainstem-spinal populations
Functional regeneration of brainstem–spinal pathways occurs in the developing chick when the spinal cord is severed prior to embryonic day (E) 13. Functional spinal cord regeneration is not observed in animals injured after E13. This developmental transition from a permissive to a restrictive repair period may be due to the formation of an extrinsic inhibitory environment preventing axonal growth, and/or an intrinsic inability of mature neurons to regenerate. Here, we investigated the capacity of specific populations of brainstem–spinal projection neurons to regrow neurites in vitro from young (E8) versus mature (E17) brainstem explants. A crystal of carbocyanine dye (DiI) was implanted in ovo into the E5 cervical spinal cord to retrogradely label brainstem–spinal projection neurons. Three or 12 days later, discrete regions of the brainstem containing DiI-labeled neurons were dissected to produce explant cultures grown in serum-free media on laminin substrates. The subsequent redistribution of DiI into regenerating processes permitted the study of in vitro neurite outgrowth from identified brainstem–spinal neurons. When explanted on E8, i.e., an age when brainstem–spinal neurons are normally elongating through the spinal cord and are capable of in vivo functional regeneration, robust neurite outgrowth was observed from all brainstem populations, including rubro-, reticulo-, vestibulo-, and raphe–spinal neurons. In contrast, when explanted on E17, robust neurite outgrowth was seen only from raphe-spinal neurons. Neurite outgrowth from raphe-spinal neurons was 5-hydroxy-tryptamine immunoreactive. This study demonstrates that in growth factor-free environments with permissive growth substrates, neurite outgrowth from brainstem–spinal neurons is dependent on both neuronal age and phenotype., Peer-reviewed article, Published. Received 22 February 2000; Accepted 25 May 2000; Available online 25 May 2002.
Real-time control of a video game with a direct brain-computer interface
Mason and Birch have developed a direct brain–computer interface for intermittent control of devices such as environmental control systems and neuroprotheses. This EEG-based brain switch, named the LF-ASD, has been used in several off-line studies, but little is known about its usability with real-world devices and computer applications. In this study, able-bodied individuals and people with high-level spinal injury used the LF-ASD brain switch to control a video game in real time. Both subject groups demonstrated switch activations varying from 30% to 78% and false-positive rates in the range of 0.5% to 2.2% over three 1-hour test sessions. These levels correspond to switch classification accuracies greater than 94% for all subjects. The results suggest that subjects with spinal cord injuries can operate the brain switch to the same ability as able-bodied subjects in a real-time control environment. These results support the findings of previous studies., Peer-reviewed article, Published.
Report on key points arising from visioning process on prosthetic and orthotic education done at the British Columbia Institute of Technology
The Prosthetics and Orthotics Department at the British Columbia Institute of Technology (BCIT) in Vancouver, Canada, has recently completed a visioning process which was done as part of a curriculum review. This report presents and discusses the key points emerging from the process. It is anticipated that the results of the visioning process will provide a basis for a major curriculum revision to the BCIT’s prosthetics and orthotics program. The intent of a curriculum review is to determine whether an educational program’s curriculum is current and relevant with respect to providing students with entry-level skills for the workforce. It involves examining the current scope of practice and competencies of the profession in question and then reflecting back on the curriculum to determine whether these competencies are being taught adequately. Visioning attempts to determine not what entry-level skills graduates require but, instead, what knowledge and skills students need to meet the challenges of the workplace approximately 10 to 15 years into the future., Peer-reviewed article, Published.
A review of the chemistry of the genus Crataegus
Since the 1800s, natural health products that contain hawthorn (Crataegus spp.) have been used in North America for the treatment of heart problems such as hypertension, angina, arrhythmia, and congestive heart failure. Traditionally, Native American tribes used hawthorn (Crataegus spp.) to treat gastrointestinal ailments and heart problems, and consumed the fruit as food. Hawthorn also has a long history of use in Europe and China for food, and in traditional medicine. Investigations of Crataegus spp. typically focus on the identification and quantification of flavonoids and anthocyanins, which have been shown to have pharmacological activity. The main flavonoids found in Crataegus spp. are hyperoside, vitexin, and additional glycosylated derivatives of these compounds. Reviewed herein are the botany, ethnobotany, and traditional use of hawthorn while focusing on the phytochemicals that have been reported in Crataegus species, and the variation in the described chemistry between individual species., Peer-reviewed article, Published. Received 4 July 2011; Revised 9 December 2011; Available online 17 May 2012.
Rho-kinase inhibition enhances axonal plasticity and attenuates cold hyperalgesia after dorsal rhizotomy
Dorsal rhizotomy results in primary deafferentation of the dorsal horn with concomitant sprouting of spared intraspinal monoaminergic axons. Because descending monoaminergic systems are thought to mitigate nociceptive transmission from the periphery and because dorsal rhizotomy can result in neuropathic pain, we sought to determine whether the rhizotomy-induced sprouting response could be further augmented. Because myelin-derived molecules mask endogenous plasticity of CNS axons and because myelin-inhibitory signaling occurs through the Rho-GTPase pathway, we inhibited Rho-pathway signaling after cervical dorsal rhizotomy in rats. An increase in the density of serotonergic- and tyrosine hydroxylase-positive fibers was seen in the dorsal horn 1 week after septuple rhizotomy, and axon density continued to increase for at least 1 month. One week after septuple rhizotomy, administration of intrathecal Y-27632, an antagonist of Rho-kinase (ROCK), increased the density of both fiber types over vehicle-treated controls. To examine behavioral effects of both cervical rhizotomy and ROCK inhibition, we examined responses to evoked pain: mechanical and thermal allodynia and cold hyperalgesia in the forepaw were examined after single, double, and quadruple rhizotomies of dorsal roots of the brachial plexus. The most notable behavioral outcome was the development of cold hyperalgesia in the affected forepaw after rhizotomies of the C7 and C8 dorsal roots. Application of Y-27632 both attenuated cold hyperalgesia and induced monoaminergic plasticity after C7/8 rhizotomy. Thus, inhibition of Rho-pathway signaling both promoted the sprouting of intact supraspinal monoaminergic fibers and alleviated pain after dorsal rhizotomy., Peer-reviewed article, Published. Received July 6, 2004; revised Oct. 3, 2004; accepted Oct. 18, 2004.

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