412 research outputs found

    Serotonin drives a novel GABAergic synaptic current recorded in rat cerebellar purkinje cells: a lugaro cell to purkinje cell synapse

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    We recorded a novel fast GABAergic synaptic current in cerebellar Purkinje cells in rat brain slices using patch-clamp techniques. Because of a relatively low sensitivity to bicuculline, these currents can be recorded under conditions in which basket and stellate cell inputs are blocked. The observations that the novel synaptic currents occur spontaneously only in the presence of serotonin, and the specific limited positions in the slice from which they can be electrically evoked, suggest that the presynaptic cell is the Lugaro cell. Cell-attached recordings confirm that the Lugaro cell is the only interneuron in the cerebellar cortex with firing behavior consistent with the spontaneous activity recorded in Purkinje cells. The input shows a strong presynaptic modulation mediated by GABAA receptors, resulting in a dynamic range from almost 0 to >90% release probability. Modeling GABAA receptor responses to different GABA transients suggests that the relatively low sensitivity of the synaptic currents to bicuculline, compared with the higher affinity GABAA receptor antagonist SR-95531 (2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl) pyridazinium), is attributable to an unusually long GABA dwell time and/or high GABA concentration in the synaptic cleft. The significance of this novel input is discussed in relation to other GABAergic synapses impinging on Purkinje cells. We suggest that the release of GABA onto Purkinje cells from Lugaro cells would primarily occur during motor activity under conditions in which the activity of basket and stellate cells might be inhibited

    Serotonin drives a novel GABAergic synaptic current recorded in rat cerebellar purkinje cells: a lugaro cell to Purkinje cell synapse

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    We recorded a novel fast GABAergic synaptic current in cerebellar Purkinje cells in rat brain slices using patch-clamp techniques. Because of a relatively low sensitivity to bicuculline, these currents can be recorded under conditions in which basket and stellate cell inputs are blocked. The observations that the novel synaptic currents occur spontaneously only in the presence of serotonin, and the specific limited positions in the slice from which they can be electrically evoked, suggest that the presynaptic cell is the Lugaro cell. Cell-attached recordings confirm that the Lugaro cell is the only interneuron in the cerebellar cortex with firing behavior consistent with the spontaneous activity recorded in Purkinje cells. The input shows a strong presynaptic modulation mediated by GABAA receptors, resulting in a dynamic range from almost 0 to >90% release probability. Modeling GABAA receptor responses to different GABA transients suggests that the relatively low sensitivity of the synaptic currents to bicuculline, compared with the higher affinity GABAA receptor antagonist SR-95531 (2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl) pyridazinium), is attributable to an unusually long GABA dwell time and/or high GABA concentration in the synaptic cleft. The significance of this novel input is discussed in relation to other GABAergic synapses impinging on Purkinje cells. We suggest that the release of GABA onto Purkinje cells from Lugaro cells would primarily occur during motor activity under conditions in which the activity of basket and stellate cells might be inhibited

    Digital Technologies for Quality Assurance in the Construction Industry: Current Trend and Future Research Directions towards Industry 4.0

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    Despite the growing rich and fragmented literature focusing on quality assurance (QA) and Industry 4.0, the implementation of associated individual digital technologies has not been fully evaluated and synthesised to achieve adequate QA in the construction industry; hence, it has received limited focus. This study, thus, aimed to organise, evaluate, and synthesise the current literature on individual digital technology applications in QA in the construction industry and propose future research directions. A literature review approach was adopted for this study along with Deming’s cycle framework to address four research questions: (1) What is the status of the state-of-the-art in the literature? (2) What digital technologies have been applied for QA in the construction industry? (3) Which areas in QA processes have experienced digital technology applications, and what are the applications? (4) What are the limitations of the existing studies and future research directions of digital technologies for QA in the construction industry? The findings showed an increasing trend of research on digital technology for QA in construction since 2017. This cuts across 23 countries with six different research methods published across 18 different publication sources. Four categories of digital technologies were revealed to have been adopted for QA in construction based on the functionality of the technologies: data collection technologies, decision-oriented technologies, collaborative technologies, and transparency and security-related technologies. Evaluation with Deming’s cycle framework revealed that digital technologies have a high level of application at the “do” phase, improving the quality management process during construction towards achieving pre-stated quality requirements. This includes mostly collaborative technologies, consisting of BIM technologies. Limitations of the existing studies were further identified, and this led to five research directions: interoperability of technology development, integrated digital technologies for QA of prefabricated and modular construction, integrated digital technologies for QA of cross-border construction logistics and supply chain, digital innovation for sustainable QA, and moving beyond the technical solution. The study showed a significant contribution to both academia and the industry in the built environment

    Secondary tropical forests recover dung beetle functional diversity and trait composition

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    Secondary forests dominate some human‐modified tropical biomes, and this is expected to increase via both abandonment of marginal agricultural land as well as forest and landscape restoration programmes. A key question is whether promoting the recovery and protection of secondary tropical forests will return invertebrate functional diversity and associated functional traits. Dung beetles are ideal for assessing functional diversity as they play vital roles in several ecosystem functions, including seed dispersal, nutrient cycling and bioturbation. We examined how taxonomic and functional diversity, and the functional trait composition of native dung beetle species recovers in naturally regenerating secondary forests in comparison to both cattle pastures and primary forest in the Colombian Choco‐Andes, a global hotspot of threatened biodiversity. Using a space‐for‐time approach, we found that taxonomic and functional diversity recovered to levels comparable to primary forest within approximately 30 years of secondary forest regrowth. Functional richness and FD, measures of the diversity of traits present in a community, were similar in secondary and primary forest, but significantly lower in pasture. Rolling dung beetle species were positively associated with forest habitats, particularly primary, while dwelling species were more common in pasture. Thus, the functional trait composition of secondary forests was more similar to primary forest than to pasture. The ability of secondary forests to rapidly accumulate primary‐forest dung beetle functional diversity, and a representative suite of functional traits, provides an opportunity to protect biodiversity and ecosystem functioning, especially in regions where marginal agricultural land allows cost‐effective conservation actions

    Insights into The Push Factors of Innovation Adoption of Professional Services Firms: The Case of Ghanaian Quantity Surveying Firms (QSF)

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    Construction industry is a universal driver of an economy but it is largely affected by its reluctance to innovate. This paper aims to identify the drivers of innovation adoption in Ghanaian Quantity surveying firms by looking at related previous literatures. The study adopted Quantitative research approach with census sampling technique, where questionnaires were sent to and retrieved from the top management of Quantity Surveying firms in Ghana. The study then adopted the use of mean score ranking, and hypothesis (H) was tested to check the significance level of all the push factors using One Sample Wilcoxon Signed rank test. 29 out of 43 questionnaires were retrieved from the quantity surveying firms (QSFs) at a response rate of 67.44%. Mean score ranking analysis clearly display that technological capability has the power to drive innovations in Quantity surveying (QS) firms. One Sample Wilcoxon Signed rank test concluded that effective information gathering is not important to the Quantity Surveying firms because it had a significant level of 0.384, which is greater than 0.05. Therefore, this research study has discovered that, programmes promoting access to technology is the main driver of technological capability towards innovations in professional service firms. The finding of this study is valuable to the Quantity Surveying firms as well as the other professionals in the construction industry as well as innovation policy makers and stakeholders, as it will help invest in technological capabilities including programmes promoting access to technology with the aim of driving innovations in the professional service firms

    Underlying Indicators For Measuring Smartness Of Buildings In The Construction Industry

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    Purpose: The introduction of the Smart Buildings Technology (SBT) concept (which incorporates elements of the Zero Energy Buildings (NZEB) concept) could be a measure in ensuring efficient energy consumption and high performance in buildings. Smart buildings provide solutions to improve building efficiency, and reduce energy consumption, carbon emissions and concomitant energy costs. In order to adopt SBT in the construction industry, it is important to identify the indicators of smartness of buildings, even though such may differ from region to region or even country to country. However, there have been inefficient studies identifying the indicators of smartness of buildings, especially in developing countries such as Ghana. This study investigates the underlying indicators for measuring the smartness of buildings in the construction industry. Methodology: An overarching post-positivist and empirical epistemological design was adopted for this research to analyse primary quantitative data. Data was collected via a structured questionnaire survey with 227 respondents including project managers and construction design teams in Ghana. The mean ranking analysis and one sample t-test were employed to analyse the data. Findings: Research findings revealed that the level of knowledge of smart building indicators is averagely high in the Ghanaian construction industry. With regards to the indicators of smart building, ‘sensors implementation to manage light level, air quality, temperature, fire alarm and smoke detector’ is regards as the most significant measure of smart buildings in the Ghanaian construction industry. Also, ‘remote implementation monitors building conditions and occupancy’, ‘implementation of any software that can talk to legacy equipment from many different manufactures’ and ‘data analytic’ are statistically insignificant in measuring smartness of buildings. Practical Implication: Practically, policy makers and practitioners can use the study’s results as blueprint guidance to appreciate and utilise the idea of smartness of buildings because it can improve building performance therefore, promoting the adoption of SBTs. To the body of knowledge, this study has identified the significant indicators for measuring the smartness of buildings, which can further influence SBTs adoption. Originality: Using the results, a model consisting of significant indicators for measuring building smartness was developed to help improve building performance. Recommendation: The study recommends future research to evaluate the awareness level of Smart Building Technologies (SBTs) by construction professionals and identify barriers to its adoption

    Insurable and non-insurable risks in complex project deals: case of the Ghanaian construction industry

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    Purpose The purpose of this study is to investigate the insurable risks that impacted the operations on complex construction projects in developing countries using Ghana as a case study. Design/methodology/approach In this study, structured questionnaires were used to collect relevant information from the top management of construction and insurance firms in Ghana, comprising 50 industry professionals. The study adopted the χ2 and independent samples’ t test to interpret the responses from participants. Findings The study revealed the major risks that severely impacted the operations on complex construction projects, including strikes and labour disputes, long waiting time for approval of test samples, damages to property during construction, delay in payment to contractor for work done, poor construction method, pressure to deliver project on an accelerated schedule, labour shortage, permits delayed or take longer than expected, inaccurate materials estimating, change in weather pattern, low productivity of subcontractors and inadequate contractor experience. Practical implications The study is expected to contribute to increase in the awareness of the insurable risks and policies that project participants are exposed to, which will serve as a decision-making tool for contract formation. Originality/value This study assists in managing construction and insurance firms to note the major risk in managing a complex construction project. In addition to knowing the major risks identified, the study investigates the insurable risk by managing both construction and insurance firms

    Global hotspots of traded phylogenetic and functional diversity

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    Wildlife trade is a multibillion-dollar industry1 targeting a hyperdiversity of species2 and can contribute to major declines in abundance3. A key question is understanding the global hotspots of wildlife trade for phylogenetic (PD) and functional (FD) diversity, which underpin the conservation of evolutionary history4, ecological functions5 and ecosystem services benefiting humankind6. Using a global dataset of traded bird and mammal species, we identify that the highest levels of traded PD and FD are from tropical regions, where high numbers of evolutionary distinct and globally endangered species in trade occur. The standardized effect size (ses) of traded PD and FD also shows strong tropical epicentres, with additional hotspots of mammalian ses.PD in the eastern United States and ses.FD in Europe. Large-bodied, frugivorous and canopy-dwelling birds and large-bodied mammals are more likely to be traded whereas insectivorous birds and diurnally foraging mammals are less likely. Where trade drives localized extinctions3, our results suggest substantial losses of unique evolutionary lineages and functional traits, with possible cascading effects for communities and ecosystems5,7. Avoiding unsustainable exploitation and lost community integrity requires targeted conservation efforts, especially in hotspots of traded phylogenetic and functional diversity

    Secondary forest fragments offer important carbon‐biodiversity co‐benefits

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    Tropical forests store large amounts of carbon and high biodiversity, but are being degraded at alarming rates. The emerging global Forest and Landscape Restoration (FLR) agenda seeks to limit global climate change by removing carbon dioxide from the atmosphere through the growth of trees. In doing so, it may also protect biodiversity as a free co‐benefit, which is vital given the massive shortfall in funding for biodiversity conservation. We investigated whether natural forest regeneration on abandoned pastureland offers such co‐benefits, focusing for the first time on the recovery of taxonomic, phylogenetic and functional diversity of trees, including the recovery of threatened and endemic species richness, within isolated secondary forest fragments. We focused on the globally threatened Brazilian Atlantic Forest, where commitments have been made to restore one million hectares under FLR. Three decades after land abandonment, regenerating forests had recovered ~20% (72 Mg/ha−1) of the above‐ground carbon stocks of a primary forest, with cattle pasture containing just 3% of stocks relative to primary forests. Over this period, secondary forest recovered ~76% of taxonomic, 84% of phylogenetic and 96% of functional diversity found within primary forests. In addition, secondary forests had on average recovered 65% of threatened and ~30% of endemic species richness of primary Atlantic forest. Finally, we find positive relationships between carbon stock and tree diversity recovery. Our results emphasize that secondary forest fragments offer co‐benefits under FLR and other carbon‐based payments for ecosystem service schemes (e.g. carbon enhancements under REDD +). They also indicate that even isolated patches of secondary forest could help to mitigate climate change and the biodiversity extinction crisis by recovering species of high conservation concern and improving landscape connectivity

    Exploration of Latent Barriers Inhibiting Project Management Processes in Adopting Smart Building Technologies (SBTs) In the Developing Countries

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    Purpose: Whilst smart building technologies (SBTs) implementation ensures sustainability, their adoption is hampered by latent barriers, especially in project management processes. These latent barriers must be addressed in order to facilitate the successful and widespread adoption of SBTs. This study explores the significant latent barriers inhibiting the project management processes in adopting SBTs in developing countries. Methodology: A positivist research philosophy couched within a deductive approach was adopted to undertake a quantitative questionnaire survey of 227 project management and design team participants. Descriptive and inferential analytical tools (including a one sample T-test and exploratory factor analysis) were then adopted to interpret data collected. Findings: The results reveal that the “high cost of smart sustainable materials and equipment” is the major significant barrier hindering the adoption of SBTs in developing countries. Latent barriers were: “structure and time-related barriers”, “construction-related barriers” and “human, policy and cost-related barriers.” Originality: The study contributes novel insights into the prevailing nascent discourse on SBTs from the perspectives of construction project managers and design teams in developing countries, particularly. Furthermore, this is the first study that ascertains the significant barriers inhibiting project management processes in adopting SBTs in developing countries
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