Using virtual worlds as collaborative environments for innovation and design: lessons learned and observations from case studies in architectural projects

In this paper we discuss observations and lessons learned in conducting architectural design projects in virtual worlds. By integrating a community of users in virtual worlds into a collaborative architectural design process, organisations can tap the community's creativity and intelligence through immersive technology. The paper provides an overview of the latest advances of information and communication technologies in immersive virtual environments and discusses some of the observations and lessons learned which should be taken into account in developing collaboration models for such activities. Here we propose four modes of collaboration, based on the choices for degree of openness and governance structure, which are illustrated by four case studies

CBCT Assessment of Root Dentine Removal by Gates-Glidden Drills and Two Engine-Driven Root Preparation Systems

Introduction: The aim of this study was to compare the dentine removing efficacy of Gates-Glidden drills with hand files, ProTaper and OneShape single-instrument system using cone-beam computed tomography (CBCT). Methods and Materials: A total of 39 extracted bifurcated maxillary first premolars were divided into 3 groups (n=13) and were prepared using either Gates-Glidden drills and hand instruments, ProTaper and OneShape systems. Pre- and post-instrumentation CBCT images were obtained. The dentin thickness of canals was measured at furcation, and 1 and 2 mm from the furcation area in buccal, palatal, mesial and distal walls. Data were analyzed using one-way ANOVA test. Tukey’s post hoc tests were used for two-by-two comparisons. Results: Gates-Glidden drills with hand files removed significantly more (P<0.001) dentine than the engine-driven systems in all canal walls (buccal, palatal, mesial and distal). There were no significant differences between OneShape and ProTaper rotary systems (P>0.05). Conclusion: The total cervical dentine removal during canal instrumentation was significantly less with engine-driven file systems compared to Gates-Glidden drills. There were no significant differences between residual dentine thicknesses left between the various canal walls.Keywords: Cone-Beam Computed Tomography; Maxillary First Premolar; Root Canal Preparation; Root Thicknes

Habitat Conditions of the Most Important Medicinal Plants from Lamiaceae Family in Mazandaran Province

The production and proper utilization of medicinal plants in natural habitats need to review and identify the natural conditions and climate of the habitat of these plants and separating them from harmful and poisonous plants. The current study was aimed to introduce and determine the distribution of medicinal plants from Lamiaceae family in Mazandaran province as well as the introduction of natural habitats in order to provide information for executive agencies and administrators of land use plan to be used for optimal utilization of potentials of natural resources. In this study, after collecting the documents, the aromatic and medicinal species (wild species) of Mazandaran province were identified and their distribution was investigated. According to the obtained results, the medicinal species of Lamiaceae family in Mazandaran province contain 23 species, belonging to 11 genera among which Stachys spp. with seven species is known as the riches genus in Lamiaceae family, distributed in an area of 16322 km2 in Mazandaran province. As a result of this study, the distributionmap of natural habitats, habitat conditions, life form, and utilizable organs of medicinal species belonging to Lamiaceae family in Mazandaran province have been provided. According to the rich flora of Mazandaran province, the results of this study could help in financing, planning, cultivation and production of medicinal plants at industrial levels. In addition, the production of herbal medicines could be used in pharmaceutical, medical and food industries

Review of the Energy and Social Impact of Bitcoin Mining and Transactions and Its Potential Use as a Productive Use of Energy (PUE) to Aid Equitable Investment in Solar Micro and Mini Grids Worldwide

Despite the climate commitments made by countries in the Paris Climate Agreement adopted in 2015, and reinforced during COP 21, world carbon emissions have increased in both 2021 and 2022. It is increasingly unlikely that the world can achieve the targeted 50% carbon reduction by 2030; the reduction approximately needed for reducing global temperature rise since the beginning of the industrial revolution to less than 1.5 deg. C. At the same time, the carbon intensive loads associated with bitcoin mining have grown, thereby contributing to growing worldwide carbon emissions. In this context, the role of cryptocurrency and particularly bitcoin is reviewed from energy and social perspectives. Revealed is the value of a truly neutral and secure currency to much of the world. Also revealed is a growing trend toward powering cryptocurrency miners with renewable energy. In this context, an opportunity for leveraging cryptocurrency, and particularly bitcoin, to fuel investment in solar micro- and mini grids. A number of cases are posed to demonstrate this potential throughout the world and at multiple scales. These include: i). existing microgrids with significant stranded energy to generate income which could be used to reduce the cost per kWh for the community; ii). new solar microgrids optimized to meet community load and mining operations; (iii) solar microgrid powered water purification systems in water scarce communities; (iv) dedicated solar powered bitcoin mining mini grids developed solely to create a funding stream for self-investment of communities for their benefit; and (v) numerous applications where bitcoin mining inclusion in micro- and mini grids can effectively seed microgrid development in places where such investment is not yet feasible. All of these projects are shown to be impact investment worthy

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

Investigating the effect of graphene oxide nanosheets on the barrier properties of high density polyethylene coated by layer-by-layer assembly method

Hypothesis: A nanocomposite layer including graphene nanosheets could be used to enhance the barrier properties of high density polyethylene through a layer-by-layer assembly method. Planar graphene nanoparticles help to decrease the gas permeability of polyethylene substrates by making a tortuous pathway for gas molecules transmittance.Methods: Two different methods were used to increase the barrier properties of high density polyethylene and the results were compared with each other. In the first method, a thin film of polymer nanocomposite including graphene oxide nanoparticles and polyvinyl alcohol was coated on the surface of high density polyethylene film using a film applicator. The effective variables in this method were the weight fraction of graphene oxide particles in polyvinyl alcohol and thickness of the nanocomposite layer. In the second method, a layer-by-layer assembly was used. Chitosan solution acted as a positive charge and graphene oxide suspension in water was utilized as a negative charge.Findings: In high density polyethylene samples coated by polyvinyl alcohol nanocomposite (10 micrometers), the oxygen transmittance rate decreased drastically to 3 cm3m2 bar. This decrease was expected due to the structure of polyvinyl alcohol and its inherent barrier properties. By adding graphene oxide into polyvinyl alcohol, the permeability values showed a slight decrease and reached 0.8 cm3 m2 bar.Statistical analysis based on the surface response method for the layer-by-layer method showed that permeability depends on pH, number of bilayers and graphene concentration. At high pH, the graphene oxide sheets take on a smoother and more stretched shape and are more likely to aggregate, which increases permeability

Guided tissue regeneration and platelet rich growth factor for the treatment of Grade II furcation defects: A randomized double-blinded clinical trial - A pilot study

Background: The treatment of furcation area defects remained as a challenging issue in periodontal treatments. Regeneration treatment of furcation defects is the most discussed periodontal treatment. Although not completely hopeless in prognosis, the presence of the furcation involvement significantly increases the chance of tooth loss. The current research was conductedeto compare theeadditive effect of combined guided tissue regeneration (GTR) and platelet-rich growth factor (PRGF) on the treatment of furcation bony defects. Materials and Methods: A randomized, triple-blinded, split-mouth study was designed. It included patients with a moderate to severe chronic periodontitis with bilateral Grade II furcation involvement of first or second mandibular molars. Each side of mouth was randomly allocated for the treatment with either Bio-Gide American Society of Anesthesiologists GTR or a PRGF or PRGF by itself. Plaque index, gingival index, vertical clinical attachment level, vertical probing depth, recession depth (REC), horizontal probing depth, fornix to alveolar crest (FAC), fornix to base of defect (FBD), furcation vertical component and furcation horizontal component (FHC) were recorded. The current research was conducted to compare the additive effect of combined GTR and PRGF on treatment of furcation bony defects. Altman's nomogram, Kolmogorov–Smirnov test, Friedman test, general linear model, repeated measures, and paired t-test were used as statistical analysis in this research. P < 0.05 was considered statistically significant. Results: Eight patients were finally enrolled for this study. Overly, general and specific clinical and furcation parameters were improved except REC that was deteriorated insignificantly and FAC improved not significantly. Intergroup comparison revealed better improvement of FHC in GTR/PRGF group (P = 0.02). Conclusion: A significant improvement in the Grade II furcation defects treated with either GTR or PRGF/GTR was noticed. Further large-scale trials are needed to reveal differences of mentioned treatment in more details

A comparison between conventional and digital radiography in root canal working length determination

Aim and Objectives: Obtaining a correct working length is necessary for successful root canal treatment. The aim of this study was to compare conventional and digital radiography in measuring root canal working length. Materials and Methods: In this in vitro study 20 mesio buccal canal from maxillary first molars with moderate and severe curvature and 20 canal form anterior teeth with mild curvature were chosen and their working length were measured with number 15 k file (Maillefer, DENTSPLY, Germany). Then for each canal five radiographies were taken, three conventional radiographies using three methods of processing: Manual, automatic, and monobath solution; in addition to two other digital radiographies using CCD and PSP receptors. Two independent observers measured working length in each technique. Finally, the mean of working length in each group was compared with real working length using a paired T-test. Also a one-way ANOVA test was used for comparing the two groups. The level of statistical significance was P < 0.05. Results: The results have shown that there was a high interobserver agreement on the measurements of the working length in conventional and digital radiography (P≤0.001). Also there was no significant difference between conventional and digital radiography in measuring working length (P > 0.05). Conclusion: Therefore it was concluded that the accuracy of digital radiography is comparable with conventional radiography in measuring working length, so considering the advantages of the digital radiography, it can be used for working length determination

In Vivo Comparative Evaluation of the Pomegranate (Punica granatum) Peel Extract as an Alternative Agent to Nystatin against Oral Candidiasis

Background: The pomegranate peel extract is a rich source of natural antioxidant and antimicrobial activity. The aim of the present investigation was to evaluate the in vivo antifungal activity of the pomegranate peel extract and to compare it with nystatin against oral candidiasis in Wistar rats. Methods: Thirty-five male Wistar rats, 6 to 8 weeks old and 220 to 250 g in weight, were used for animal studies. The rats were randomly divided into 7 groups. All the rats, except the control group, were immunosuppressed with cyclosporine (40 mg/kg/d) and hydrocortisone acetate (500 µg/kg/d). Then oral candidiasis was induced via the oral administration of a suspension of Candida albicans (ATCC 10231) (2×107 cell/mL) in PBS on the palate and tongue of the animals on days 3 and 5. Treatment was initiated by using 3 different concentrations of the pomegranate peel extract (125, 250, and 500 µg/mL/kg) and nystatin 100000 U/mL/kg by gavage daily. The statistical analysis was performed using the SPSS, version 22.0. In this study, generalized estimating equations were used for data analysis to determine the effects of the pomegranate peel extract and nystatin on oral candidiasis. Results: Regardless of the concentration of the pomegranate peel extract used for the treatment of oral candidiasis, a significant improvement was seen after 15 days of treatment. All the doses of the pomegranate peel were effective against candidiasis after 15 days; the pomegranate peel extract had no adverse effects following administration in the rats. Conclusion: Our results indicated that the pomegranate peel extract is a promising approach to oral candidiasis treatment, and it may serve as a natural alternative prospect due to its potency against oral candidiasis