Traditional Construction Research Articles

Design, calibration and performance evaluation of a small-scale 3D printer for accelerating research in additive manufacturing in construction

3D printing in construction presents numerous advantages, such as geometric flexibility, potential cost and time savings, the incorporation of recycled and sustainable materials, and reduced waste, thereby reducing the construction sector's environmental impact. Despite these advantages, the widespread adoption of AM in construction faces hurdles, primarily due to the prohibitive costs of large-scale concrete printers — typically ranging from $180,000 to over $1 million — and technological constraints that impede research and development efforts within the construction sector. To address these challenges, our study focuses on designing, developing, calibrating and evaluating an affordable lab-scale 3D printer specifically tailored for cement-based materials, aiming to lower the entry barrier for AM research in construction. This paper presents a proof-of-concept for a simple, yet functional printing technology that meet the requirements for research studies. The study details the development process, from the conceptual design to the calibration of printing parameters. The development process included the assessment of preliminary extrusion system designs integrated with the motion systems of a fused deposition modeling 3D printer. Subsequently, material studies were carried out to determine optimal material mix compositions and ratios. A comprehensive calibration of printing parameters using statistical analysis was proposed to ensure consistent and quality printing. The printability and applicability of the proposed small-scale 3D printer were assessed by printing samples and testing their thermal properties. Cost analysis showed that the proposed 3D printer, costing $273, offers benefits compared to existing market alternatives. The study illustrates the potential of small-scale 3D printers to facilitate construction research and practices, thereby promoting the development of sustainable construction methods.

Development and application of artificial hydraulic lime for Chinese architectural heritage restorations

Lime is commonly employed in the restoration of historic buildings due to its strength properties, which align well with the demands of architectural heritage conservation. However, recent shortages in high-quality limestone raw materials and the commercial inclusion of finely ground limestone powder in hydrated lime powder have led to significant challenges. These include low initial strength, pronounced shrinkage and cracking, and poor resistance to frost. Although natural hydraulic lime (NHL) offers moderate strength, its high cost presents an obstacle to widespread use in architectural heritage restoration. Three types of artificial hydraulic lime (AHL) — AHL1, AHL2, and AHL3 — were prepared with the objective of low cost and easy scalability. These were formulated by incorporating white cement (WC), blast furnace slag powder (BFSP), heavy calcium carbonate powder (HCCP), and industrial-grade white sugar (WS) into industrial-grade hydrated lime powder (IHLP). To align the setting time of the AHLs with the requirements of traditional builders, WS was incorporated as a retarding agent. The addition of WC, BFSP, and HCCP to IHLP resulted in enhancements over IHLP in several key aspects: compressive strength, pore structure post-hardening, dry shrinkage rate, and frost resistance. This approach will enhance the restoration quality of architectural heritage in China, leading to fewer repeated repairs and significant savings in manpower and material costs. Ultimately, AHL2 was applied in the restoration of the Confucius Temple, proving its efficacy and alignment with traditional construction requirements. This research provides valuable theoretical and practical insights for enhancing the preservation of architectural heritage.

Construction of Virtual Simulation Experiment Platform for Intelligent Construction Based on Statistical Machine Learning System Modelling

In the construction of a virtual simulation experiment platform for intelligent construction, cutting-edge technologies converge to revolutionize traditional project management methodologies. By harnessing the power of virtual reality, statistical modeling, and machine learning, this platform empowers stakeholders to predict, optimize, and simulate construction projects with unprecedented accuracy and efficiency. This paper introduces the Virtual Statistical Machine Learning (VS-ML) platform and demonstrates its application in intelligent construction processes. Through comprehensive experimentation and simulation, the VS-ML platform accurately estimates construction project parameters, optimizes resource utilization, schedules tasks efficiently, and classifies project outcomes with high accuracy. Numerical results from our study showcase the platform's effectiveness in various aspects of construction project management. For instance, in construction projects estimation, scenarios ranging from Scenario 1 to Scenario 10 exhibit project durations between 100 to 150 days, cost estimates ranging from $470,000 to $550,000, and safety ratings varying from "Good" to "Excellent". Furthermore, labor efficiency and material waste estimations across scenarios demonstrate percentages ranging from 85% to 93% and 3% to 7%, respectively, with corresponding safety ratings. Additionally, task computations elucidate the durations, start dates, end dates, and resource allocations for individual tasks within construction projects. Lastly, classification results exhibit the predicted probabilities and class labels for samples, showcasing the platform's ability to accurately predict project outcomes. Overall, the findings underscore the potential of VS-ML in revolutionizing traditional construction practices through data-driven approaches, leading to improved project management, cost savings, and enhanced safety standards in the construction industry.

WITHDRAWN: From Debris to Innovation: Unveiling a New Frontier for Alkali-Activated Materials

Alkali-activated materials (AAMs) play a crucial role in addressing the environmental challenges of traditional construction binders by offering a lower carbon footprint alternative. Industrial by-products are utilized, reducing waste and energy consumption associated with lime and cement production. AAMs represent a sustainable innovation in the construction industry, promising significant reductions in CO2 emissions and resource utilization. This review aims to meticulously analyze the existing body of research on the potential of Construction and Demolition Waste (CDW) as an alternative precursor for producing AAMs. This review study introduces a novel angle by critically evaluating advancements in CDW processing techniques for AAM production, alongside assessing the environmental and mechanical outcomes. It pioneers bridging the gap between innovative recycling methods and sustainable construction practices. The ultimate goal is to synthesize findings into a comprehensive framework to guide future research toward optimizing CDW utilization in AAM production, thereby contributing to sustainable construction practices and the circular economy. This study stands out for its in-depth examination of CDW's role in mitigating the environmental impact of conventional construction materials, offering novel insights into the path toward sustainability in the construction industry. By critically assessing the latest advancements in CDW processing techniques and their environmental and mechanical implications, the study not only underscores the potential of CDW in revolutionizing the construction industry but also sets a new precedent in sustainability research. It bridges the crucial gap between theoretical innovation and practical application, offering actionable insights for optimizing CDW utilization in AAM production. This comprehensive analysis signifies a pivotal step towards integrating sustainable practices within the construction sector, advocating for a paradigm shift towards a circular economy that prioritizes resource efficiency and environmental stewardship.

The Guanxi mediating role linking organizational justice to contextual performance with age as a moderator.

Guanxi, a distinctive Chinese concept, reflects a shared vision of relationships and connections that include mutual understanding, trust, and a deep bond between individuals. Recognized for its potency in shaping the relationships that facilitate business undertakings and access to key resources, Guanxi is postulated as a potential mediator in the nexus between organizational justice and contextual work performance. The depth of Guanxi, intertwined with Chinese culture and values, may be perceived differently across age groups. Specifically, as Chinese millennials usually interact with global paradigms, generational disparities might emerge in valuing these traditional constructs. This study delves into how the dimensions of Guanxi-Ganqing (emotional connection), Renqing (reciprocity), and Xinren (loyalty)-mediate the relationship between organizational justice and contextual work performance, with chronological age as a moderator. The present study includes a convenience sample of 630 Chinese employees, aged 22-67 years, who participated in a quantitative online survey. The findings endorse the mediation role of Guanxi. The total influence of justice was found to be significant, as well as the indirect impacts, that were statistically salient. Although the age-moderated mediation was not wholly substantiated, the age-specific indirect effects of Renqing and Xinren did present significant variances between millennials and those above 42 years. The relevance of this study extends beyond the academic field, shedding light on the cultural dynamics at play within Chinese organizational settings. By unveiling the relationships between Guanxi, organizational justice, and performance, and by elucidating the age-specific variations therein, this research provides insights for organizational leaders and human resource professionals. Based on these findings, businesses can craft targeted interventions that capitalize on the strengths of Guanxi, ensuring fair practices and enhancing performance across diverse age groups. Further, recognizing the unique attributes and values of different generational cohorts can aid in fostering a harmonious, culturally attuned, and efficient workplace environment.

Integrated Assessment of Bearing Capacity and GHG Emissions for Foundation Treatment Piles Considering Stratum Variability

Foundation treatment piles are crucial for enhancing the bearing capacity and stability of weak foundations and are widely utilized in construction projects. However, owing to the complexity of geological conditions, traditional construction methods fail to meet the demand for low-carbon development. To address these challenges, this study introduced a comprehensive decision-making approach that considers the impact of stratum variability on greenhouse gas (GHG) emissions and pile bearing capacity from the design phase. During the design process, the GHG emissions and bearing capacities of deep cement mixing (DCM) and high-pressure jet grouting (HPJG) piles were quantitatively assessed by analyzing the environmental and performance impacts of foundation treatment piles related to materials, transportation, and equipment usage. The results suggest that the bearing capacity of piles in shallow strata is highly susceptible to stratum variability. Using piles with a diameter of 800 mm and a length of 20 m as an example, compared with DCM piles, HPJG piles demonstrated a superior bearing capacity; however, their total GHG emissions were 6.58% higher, primarily because of the extensive use of machinery during HPJG pile construction. The GHG emissions of foundation treatment piles in shallow strata were influenced more by geological variability than those in deep strata. Sensitivity analysis revealed that the pile diameter is a critical determinant of GHG emissions and bearing capacity. Based on the bearing capacity–GHG emission optimization framework, a foundation treatment strategy that integrates overlapping and spaced pile arrangements was introduced. This innovative construction method reduced the total GHG emissions by 22.7% compared with conventional methods. These research findings contribute to low-carbon design in the construction industry.

Multifunctional, High-Strength Electronic Skin Based on the Natural Sheepskin Fiber Network for Multifaceted Human Health Monitoring and Management.

Inspired by the animal skin fiber network, we developed an electronic skin (e-skin) utilizing natural sheepskin as the primary substrate. This innovative design addresses the limitations of conventional e-skins, including inadequate mechanical strength, overly complex artificial network construction, and limited health monitoring capabilities. This e-skin successfully retains the structure and properties of natural sheepskin while exhibiting exceptional mechanical strength (with a breaking strength of 4.01 MPa) and high elongation (with an elongation at a break of 304.8%). Moreover, it possesses various desirable attributes such as electrical conductivity, antibacterial properties, biocompatibility, and environmental stability. In addition, this e-skin has the advantage of diverse data collection (joint movement, bioelectricity, foot health detection, and speech disorder communication systems). Therefore, this e-skin breaks the traditional construction strategy and single-mode application and is expected to become an ideal material for building smart sensor devices.

Urban Livability and Vertical Inclusion: Exploring Mixed-Use Development Strategies in Khulna, Bangladesh

As urban populations expand and future needs evolve amidst limited land availability, rethinking traditional planning and construction approaches becomes imperative. Architect Frank Schlesinger advocates for urban environments that embrace mixed- use complexes, conceptualizing urban land as dynamic, three-dimensional blocks accommodating diverse functions above, at, and below ground levels. Shopping facilities, pivotal in urban landscapes, reflect regional and temporal variations in consumer behavior. Integrating public and private amenities is essential for cultivating a thriving urban ecosystem. However, rigid block structures in current city master plan to constrain diversity and livability, are exacerbated by inadequate setbacks that challenge urban identity. In Khulna, bustling daytime cores contrast with deserted evenings and holidays, reflecting segregated land uses that hinder societal inclusivity. Despite demand, office and commercial spaces often remain vacant. This study employs a mixed-method approach, combining quantitative surveys with qualitative methods such as interviews and observational studies. It aims to address critical local issues including land scarcity, traffic management, vertical development challenges, and the provision of sophisticated services to enhance urban comfort. By exploring innovative configurations of civic facilities, both horizontally and vertically, the study seeks to demonstrate how integrating functions can create cohesive and vibrant urban environments. Ultimately, the adoption of vertically integrated spaces holds promise for fostering inclusivity and sustainability in Khulna’s urban fabric.

Has the national ocean economic pilot project promoted blue economy development in China?

This paper estimates the impact of the national ocean economic pilot project on the blue economy (BE) development using panel data for 11 coastal regions in mainland China from 2005 to 2017. The study shows that the BE is composed of three levels: traditional advantageous industrial construction, emerging industrial development, and ecological protection, where they can merge an index system using the analytic hierarchy process-improved entropy weight method. Besides, this paper adopts heterogeneous timing difference-in-differences to find that the policy increased the BE in the pilot areas by an average of 0.025. This effect passed various robustness checks including the parallel trend hypothesis and placebo test. In addition, the policy can also mediate the BE by skill and capacity aggregation, optimization of transportation networks, and incentives for innovation, and their contributions were 21.5%,10.6%, and 10.6%. Moreover, this paper finds that the current BE work shows a preference for the economy over the ecosystem. For economic growth, pilots prefer traditional rather than emerging industries. In summary, this study recommends that multi-level governments should use a project-based management model for the BE, increase international cooperation and knowledge transfer to promote the integration of the knowledge economy and the BE and facilitate administrative reform to clarify the ecological responsibilities of marine management agencies.

Load bearing geopolymer from agro-waste and its energy-environmental- economic (E3) performance: Application through building information modeling

Agro-waste geopolymers are being significantly researched as sustainable substitutes to traditional construction materials for structural performance. However, a thorough assessment of their energy, environment, and economic (E3) performance is still questioned to facilitate in-situ building applications. This study first opts for a novel method of pressure catalysis for rice husk ash (RHA)-based geopolymers to enhance physico-mechanical performance with a low alkali activator dose. Afterward, the thermal conductivity of the optimized specimen was evaluated experimentally. Then, to assess its practical application, an E3 performance investigation was conducted on masonry brick/blocks as a pioneering approach for geopolymers. Distinct wall scenarios were simulated using Building Information Modeling (BIM) in a digital residential building. The experimental results showed that geopolymers with 50 % RHA, catalyzed under 20 MPa pressure, achieved 26.8 MPa compressive strength, lower density (1510 kg/m3), reduced water absorption (6.8 %), and 0.552 W/(m·K) thermal conductivity, outperforming traditional fired-clay brick and concrete block. The BIM analysis revealed that walls with RHA material had 53 % lower energy consumption and 30 − 41 % lesser CO2 emissions, respectively. Despite the higher cost, the RHA block has advantages as a masonry unit due to a high economic index. The significant energy and environmental gains suggest the potential for optimizing the production process of RHA-based geopolymer to enhance cost-effectiveness and amplify benefits.

A comparison of dislocation risk between dual mobility and traditional constructs used in proximal femoral replacement

BackgroundProximal femoral replacement (PFR) is a reconstruction technique after tumor resection or for revision of failed total hip arthroplasty (THA). However, despite acceptable long-term oncologic and functional outcomes, extensive soft tissue or bone loss increases the risk for prosthetic instability. Instability may depend on the construct chosen for reconstruction, with current options including bipolar, constrained, or dual mobility implants. Clinical studies comparing patient outcomes after PFR with these three different constructs are limited. MethodsThis study retrospectively examined a single tertiary academic institution's experience with PFR over a fifteen-year period. The medical records of patients who underwent PFR for indications such as tumor and failed THA with bone loss were reviewed. Patients were stratified into cohorts based on use of bipolar, constrained, or dual mobility implants. Patient demographics, disease characteristics, perioperative data, and data on prosthetic dislocations were recorded. ANOVA and chi-square testing was performed for continuous and categorical variables, respectively. The threshold for statistical significance was set to p < 0.05. Results106 patients were identified who underwent PFR. 46 underwent PFR with bipolar prosthesis (follow-up: 20 ± 24.57 months), 42 with constrained liner (follow-up: 30.45 ± 35.32 months), and 18 with dual mobility (follow-up: 15.38 ± 15.67 months). Only BMI (p = 0.036) and smoking history (P = 0.002) differed between groups. Dislocations occurred in 4 (8.7 %) patients who underwent reconstruction with bipolar prosthesis, compared to 8 (19.0 %) with constrained liner, and 3 (16.7 %) patients with dual mobility. Mean time to dislocation was significantly longer in dual mobility patients (P = 0.009). There were no differences in instances of early dislocation between groups (P = 00.238). ConclusionWhile study numbers are low, mean time to dislocation was significantly longer with dual mobility. Additional large-scale longitudinal studies are needed to fully elucidate the differences in outcomes amongst these three treatments.

Bioclimatic Design Strategies For Housing in Areas Affected by Natural Events

Objective: The objective of this study was a housing design with bioclimatic criteria and construction technology with traditional materials to propose an appropriate solution for families that suffered damage from the 2017 earthquakes in Oaxaca, Mexico. Method: A climatic characterization of the site was carried out to obtain bioclimatic strategies for the housing design. Analysis methods were used to validate these strategies such as comfort triangles and Mahoney tables. The housing was designed considering the resulting strategies and prioritized passive ones. Results and conclusions: It was obtained that for the study area the main strategies for the housing design are natural cross ventilation, thermal inertia in walls and ceilings and solar radiation during the cold months. The study highlights the importance of implementing bioclimatic design strategies according to the climatic context that promote the improvement of the habitability level of housing. Implications of the research: The research contributes to the design of a sustainable housing model for families affected in their patrimony by the action of earthquakes in the study area considering the environmental conditions, in addition to promoting the conservation of traditional architecture and construction systems. Originality/value: In the area of sustainability and the environment, a housing design was proposed that adopts practices that minimize the environmental impact and ensures that the new houses are energy efficient and environmentally friendly and adapt to climate change.

Intangible cultural heritage based on finite element analysis: force analysis of Chinese traditional garden rockery construction

In traditional Chinese rockery stacking, the peculiarity of the materials and reliance on the personal experience of artisans during the construction process make it challenging to scientifically quantify the structural stress and use scientific methods to ensure the stability of rockery structures and the safety of the construction process. Therefore, the intangible cultural heritage of rockery stacking technology faces the problem of scientific structural inspection and risk estimation during the construction process. This study uses a finite element analysis to evaluate the structural stress of the rockery-stacking site to contribute to the sustainable development and protection of this intangible cultural heritage. After establishing a three-dimensional digital model, mechanical calculations are carried out for the overall structure of the rockery and its different parts. The analysis identifies three types of structural factors in artificial rockeries: contact, structure, and load. It also effectively and intuitively identifies the weak points in the rockery structures and provides an assessment of risks, offering valuable insights for risk prevention and for the construction and maintenance of the structures. These results contribute to the structural safety inspection of traditional Chinese rockery stacking and the structural evaluation of existing rockery heritage.

Research on Low-Carbon Design and Energy Efficiency by Harnessing Indigenous Resources through BIM-Ecotect Analysis in Hot Climates

In the face of contemporary challenges, such as economic instability, environmental degradation, and the urgent global warming crisis, the imperative of sustainability and energy efficiency has reached unparalleled significance. Sustainability encompasses not only the natural environment, but also extends to our immediate surroundings, including the built structures and the communities they serve. Embracing this comprehensive perspective, we embarked on a mission to conceive and construct a model house that harnesses state-of-the-art energy-efficient technologies. Our goal was to seamlessly integrate these features not only to meet our sustainability objectives, but also to mitigate environmental threats.This model embodies a harmonious fusion of indigenous resources, employing locally sourced stone and employing traditional construction techniques. Through this approach, we achieved significant reductions in carbon emissions and established a framework for passive cooling and heating systems. Moreover, the design is intrinsically attuned to its contextual surroundings, preserving the diverse tapestry of regional architectural styles. This study stands as a testament to the potential of innovative design and technology in shaping a sustainable future. The research employs a multi-dimensional approach, encompassing strategies of architectural design with a traditional planning approach, sustainable material selection, energy efficiency, and life cycle assessment across a diverse set of case studies. Building energy analysis is conducted through the application of BIM (Ecotect), providing insights into how BIM can adapt and thrive in various environments. Key findings underscore that thermal performance, minimizing energy loads, and reducing carbon emissions are pivotal aspects in designating a building as both green and energy efficient.

Assessing the Sustainability and Performance of Hempcrete

Aim: Traditional construction materials like cement, concrete, glass, asphalt, and steel require more energy in the manufacturing process, which results in high GHG emissions. Therefore, researchers from all over the world are focusing on solutions to tackle carbon emissions, with hempcrete emerging as a less polluting construction material. Hempcrete is a bio-composite comprising a woody core of hemp stem and hydrated lime. The objective of the study is to find out the physical and mechanical properties of hemp-lime concrete. Study Design: The present research paper is part of the ongoing study on hempcrete at G.B. Pant University of Agriculture &amp; Technology, Pantnagar, Uttarakhand, India. The present study chose an experimental research design. Methodology: The study presents its results in two parts: performance and sustainability. The first part investigates the performance of hempcrete in terms of its physical and mechanical characteristics. The researcher conducted numerous trials to fix mix designs, focusing on their workability. Cubes of size 10 cm were cast manually for five distinct mix designs. The second part of the paper examines the sustainability aspect of hemp-lime concrete via a relevant literature review. Results: During the specified time intervals of 28, 56, 84, and 112 days, the cubes exhibited a range in weight density from 506 to 674 kg/m3. In parallel, the compression test results demonstrated varying values, spanning from 0.510 Mpa to 0.810 Mpa across the same time points. Results show that there is a negative correlation between density and compressive strength and a positive correlation between density and water absorption rate. Conclusion: The results pertaining to weight density highlight the lightweight nature of hempcrete, to the extent that the cubes have the propensity to float in water. Due to its relatively low compressive strength values, hempcrete is deemed suitable for non-load-bearing applications within building construction.

Design of sustainable bituminous concrete pavement with cement–treated granular layers constructed on stabilized subgrade

Purpose Designing a sustainable bituminous concrete with long-term performance is a challenging problem. In addition, strength of the subgrade has a crucial impact on pavement design. This paper aims to concentrate on subgrade soil stabilization with granite dust powder (GDP) and crumb rubber powder (CRP) to improve the engineering properties of the soil. Further design of bituminous concrete pavement with cement-treated layers in base and subbase course layers was carried out with life cycle cost analysis and life cycle assessment for 1 km of a four-lane national highway. Design/methodology/approach Subgrade soil stabilized with GDP and CRP is characterized as per Indian Standards (IS)-2720 to determine the optimum dosage. Further, the mechanistic-empirical pavement design was carried out using Indian Road Congress-37 (2018), analyzed using IITPAVE software and validated with ANSYS software. The life cycle cost analysis is carried out using the net present value method, and the life cycle assessment is performed according to the cradle-to-grave approach. Findings A soil mix comprising 10% GDP and 2.5% CRP yielded a soaked California bearing ratio value of 6.58%. In addition, the design of bituminous concrete pavement with cement-treated granular layers showed a 26.9% reduction in life cycle cost and 59.4% reduction in total carbon footprint per kilometer compared to the pavement with traditional aggregate layers. Originality/value The research on subgrade stabilization with sustainable materials like GDP and CRP incorporating mechanistic empirical pavement design, life cycle cost analysis and life cycle assessment is limited. Overall, the study recommends the use of GDP and CRP to stabilize soil for subgrade application and incorporate cement-treated granular layers, which offer economic and environmental benefits compared to traditional pavement construction.

Evaluating social media in architecture, engineering, construction and operation industry: a Nigerian perspective on applications and benefits

PurposeIn several developing contexts, the delivery of Architecture, Engineering Construction and Operation (AECO) projects continually grapples with issues such as fragmented communication, a lack of transparency, safety and risk management concerns. These problems result from the use of traditional construction practices and insufficient technology integration. Therefore, there is a pressing need to enhance communication, transparency and collaboration within construction projects in these countries through the improved utilization of innovative tools. Consequently, this study empirically assesses both the application areas and the benefits associated with the adoption of social media within the Nigerian construction industry.Design/methodology/approachThis study employed a quantitative research approach that utilized a structured questionnaire to collect responses from construction professionals. The respondents were selected using a combination of purposive and snowball sampling techniques, resulting in a 75% response rate. Data analysis included mean score value (MSV), standard deviations and normality testing (Shapiro-Wilk) to assess data characteristics. The Kruskal-Wallis H-test was used for further analysis due to the ordinal nature of the data.FindingsThe findings of this study indicate that social media can be effectively used in project management, communication, safety management, as well as marketing and branding of AECO projects. The most significant benefits of using social media in construction activities include building trust and credibility, enhancing crisis communication and improving project collaboration.Originality/valueThis study introduces a fresh perspective by showcasing the transformative potential of social media, traditionally viewed as a communication tool, in addressing complex issues in construction project delivery. Consequently, the findings of this study can offer a paradigm shift in the way construction professionals, policymakers and industry stakeholders perceive and harness the capabilities of social media.

Construction of Soviet traditions among the members of amateur folk ensemble (on the example of the song and dance ensemble «Uralskaya Ryabinushka»)

The article is devoted to the consideration of the process of reproduction of Soviet traditions in the space of organized amateur activity.Amateur folk ensembles are collectives founded in the Soviet period. Ensembles are continuing their activities at the moment on the basis of cultural and leisure institutions (houses, palaces of culture). Folk ensembles continue to construct Soviet traditions and behavioral patterns despite the absence of state ideology in Russia. The article presents the results of the author's qualitative research on the case study strategy. The research focuses on how Soviet cultural practices are reproduced in leisure organizations at present.

Asymmetric bulges within hairpin RNA transgenes influence small RNA size, secondary siRNA production and viral defence.

Small RNAs (sRNAs) are essential for normal plant development and range in size classes of 21-24 nucleotides. The 22nt small interfering RNAs (siRNAs) and miRNAs are processed by Dicer-like 2 (DCL2) and DCL1 respectively and can initiate secondary siRNA production from the target transcript. 22nt siRNAs are under-represented due to competition between DCL2 and DCL4, while only a small number of 22nt miRNAs exist. Here we produce abundant 22nt siRNAs and other siRNA size classes using long hairpin RNA (hpRNA) transgenes. By introducing asymmetric bulges into the antisense strand of hpRNA, we shifted the dominant siRNA size class from 21nt of the traditional hpRNA to 22, 23 and 24nt of the asymmetric hpRNAs. The asymmetric hpRNAs effectively silenced a β-glucuronidase (GUS) reporter transgene and the endogenous ethylene insensitive-2 (EIN2) and chalcone synthase (CHS) genes. Furthermore, plants containing the asymmetric hpRNA transgenes showed increased amounts of 21nt siRNAs downstream of the hpRNA target site compared to plants with the traditional hpRNA transgenes. This indicates that these asymmetric hpRNAs are more effective at inducing secondary siRNA production to amplify silencing signals. The 22nt asymmetric hpRNA constructs enhanced virus resistance in plants compared to the traditional hpRNA constructs.

Iliac Accessory Rod Technique for Rod Fracture Prevention in Long Fusion Constructs: 2-Dimensional Operative Video.

Implant-related complications in surgery for adult spinal deformity (ASD) account for roughly $1 billion US health care expenditures over 5 years, with a majority due to primary rod fracture.1,2 Traditional two-rod constructs have demonstrated rod fracture rates of up to 40%, with a median time to fracture of 3 years.3 Current supplementary rod techniques for decreasing rod fractures inadequately address the issue of increased strain across the lumbosacral junction.4 Here, we describe a novel four-rod technique using "iliac accessory rods," designed to mitigate rod fractures by reinforcing osteotomy levels and dispersing biomechanical stress across the lumbosacral junction. Compared with other supplementary rod techniques for ASD, iliac accessory rods anchor to independent iliac bolts.5 The added fixation points across the lumbosacral junction (4 iliac bolts total) substantially offloads stress on primary rods, most of which fracture near the lumbosacral junction.3 Additionally, connecting these rods to primary rods rostrally via side-to-side connectors, above the osteotomy levels, ensures mobile osteotomy segments are reinforced. Presented is a 78-year-old woman with ASD and worsening lower back pain, radiculopathy, and bilateral leg weakness who failed nonoperative management. She underwent T9 to bi-iliac instrumented fusion with L1-S1 posterior column osteotomies, L4-S1 transforaminal lumbar interbody fusions, and bilateral iliac accessory rod fixation. Postoperatively, she recovered well and had improvement in her symptoms. Imaging revealed correction of spinal alignment. The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image. Institutional Review Board approval was waived because of institutional exemption policy.