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Relic DNA confounds the results of DNA-based study on microeukaryotic succession in aquatic biofilms
No full textHigh-throughput sequencing has revolutionized the DNA sequence-based study of microbial community and diversity on an unprecedented scale. Relic DNA is widespread in the natural aquatic environment; however, the extent to which such DNA can bias the sequence-based analysis of living microeukaryotic communities is unclear. Here, we conducted a 30-day field-control experiment investigating biofilm succession of microeukaryotic communities on glass slides and polyurethane foam units (PFUs) in a subtropical urban reservoir, using DNA-based approach. The propidium monoazide (PMA) dye was used to distinguish living and relic DNA sequences. Our results showed that microeukaryotic community succession in biofilms was time and substratum dependent, which was correlated with changing environmental conditions, nutrients and microalgae. Most importantly, relic DNA has a significant influence on the estimation of beta diversity and turnover in community composition, importantly its presence masked the successional patterns of different microbial taxa. We found strong deterministic processes dominating microeukaryotic succession on glass slides and PFUs biofilms. Depending on substrate and the presence and absence of relic DNA sequences, contrasting community assembly mechanisms were observed. In the presence of relic DNA, our results showed that 0.53–3.15 % of dispersal limitation, and 13.16 % of homogeneous selection processes were overestimated, while 1.06–3.68 % of homogenizing dispersal, 2.11–10.53 % of undominated and 2.10–10.52 % of heterogeneous selection processes were underestimated. This study provides significant insights into the value of removing relic DNA when designing DNA-based studies to characterize microeukaryotic communities and raise questions about some ecological interpretations in molecular microbial ecology which have not accounted for the effects of relic DNA
Enhanced methane production during the anaerobic digestion of chicken manure through the addition of pristine and recovered biochar
No full textThis study investigates the impact of a 50:50 mixture of pristine and recovered biochar (CBC) on high-solids anaerobic digestion of chicken manure, comparing its performance with pristine biochar (PBC), recovered biochar (RBC), and a Control group. The experiment, conducted under mesophilic conditions using a 15% total solid content and 5% biochar dosage, showed that CBC treatment achieves the highest cumulative biogas production (314 mL g−1-VS) and the highest cumulative methane production o(112 mL g−1-VS) over 21 days. Further, digesters containing CBC exhibited the highest rate of COD removal (80.8%), surpassing digesters amended with PBC (71.1%), RBC (69.2%) and Control (57.8%). Although digesters amended with PBC showed a higher TAN adsorption capacity of 48 mg g−1 compared to the 32 mg g−1 of CBC, both TAN adsorption and the existing microbial population of 1.2 × 1014 microbes per gram, have allowed CBC to exhibit superior digester performance. These findings offer valuable insights for optimising anaerobic digestion processes and cutting operational costs in waste-to-energy projects incorporating biochar as an additive
Dynamic Mode Decomposition for soft tissue deformation modelling
No full textThis paper studies a new approach to dynamic modelling of soft tissue nonlinear deformation behavior based on dynamic model decomposition. This approach derives the deformation relationship between two continuous time points from correlated system snapshots. Subsequently, it constructs a reduced-order system by extracting most relevant information via thin-singular value decomposition to capture dynamic characteristics of the full-order deformation system. Unlike the existing methods which mainly rely on the establishment of complex constitutive equations for governing soft tissue deformation, the proposed method conducts tissue deformation directly from measured samples without involving constitutive governing equations. Simulation results show that the proposed method not only achieves real-time performance, but also sustains similar accuracy as the nonlinear finite element method
Environmental NGOs and Protected Area Conservation in Australia: The Political Consequences of Aligning with Private Interests
No full textThis article examines the political consequences of environmental nongovernment organization (ENGO) involvement in protected area conservation in Australia. Rapid growth of a nongovernment protected area (NGPA) estate this century has involved a range of individuals, communities, First Nations, and ENGOs, and has been closely tied to government policy and private finance. Although NGPA conservation achievements have been profound, there has been limited examination of what expanded nongovernment involvement, responsibility, and leadership mean for the practice and governance of nature conservation. Thematic analysis of twenty-four key informant interviews and selective gray literature identifies how financing, accountability, and partisan politics are emerging as key domains in shaping an NGPA estate that reflects a closer alignment with capital and market forces. ENGOs are playing a key role in crafting new political conditions for protected area conservation, where their role in neoliberal governance is not just service delivery, but statecraft and agenda setting. ENGOs are increasingly casting protected area conservation as apolitical, and thereby a bipartisan activity, driven by a “pragmatic” agenda that seeks to secure private financing for land ownership and management obligations. Frameworks of accountability to donors shape ENGO practices and conceptions of conservation through exposure to novel market mechanisms. As a result, ENGO operation permits limited space for plural, ideological, and structural debate about protected area conservation, the public interest, and the root causes of ecological crises to which it responds. The embrace of conservation led by nongovernment actors marks a substantive shift from the formative politics of ENGOs in Australia
A self-adapting woven net trap based on the evolution mechanism of orb-web topology
No full textThe development of structures that can adapt spontaneously to achieve desired functions in complex environments is crucial for new unmanned countermeasures, such as prey capture or net-recovery. Conventional structural optimization methods based on a singular net–like configuration may lead to functional limitations and fail to achieve specific objectives. In this study, we utilized an evolutionary algorithm that incorporated mechanical features and biological corrections to construct spider threads with advanced properties capable of efficient and reliable trapping behavior in arbitrary boundary conditions. We employed distinct thread types in different components, which achieved distinguished stiffness and strength that could not be accomplished by a single kind of thread. By assembling prestress reinforcement threads, we developed an orb-web-like trap that demonstrated effective trapping performance in experiments. The adaptive evolutionary method could be applied to design intelligent intercepting devices suited to particular functions and extreme environments, with wide application prospects in net-recovery system of UAV. Statement of significance: Structures that adapt spontaneously to perform desired functions in difficult environments are crucial for rising unmanned countermeasures. Conventional structural optimization methods based on a singular net–like configuration may lead to functional limitations and fail to achieve specific objectives. We used an evolutionary algorithm that combined mechanical features and biological corrections to create spider threads in arbitrary boundary circumstances in this work. The adaptive evolutionary method could be applied to design intelligent intercepting devices suited to particular functions and extreme environments, with wide application prospects in net-recovery system of UAV
Corruption, market structure, and industry competition in the Vietnamese construction sector
No full textThe Vietnamese construction sector is arguably the country’s industry most vulnerable to cor-ruption, leading to poor functioning of the sector. This analysis empirically investigates how cor-ruption affects competition in the construction industry, and how different market structures shape different types of corruption and its potentially different impacts. Our empirical models for industry competition are estimated on a panel of 33,045 year-observations using the Fractional Binomial Logit model. The findings demonstrate that corruption reduces competition, and that the effects of corruption depend on the type of corruption and market structure in which firms operate. We find evidence that corruption is characterized by collusion between local authorities and dominant firms in highly concentrated markets, leading to the persistent concentration of the sector in highly corrupt areas. In areas with lower corruption, corruption is characterized by bureaucratic holdups while lowered corruption increases industry competition. Petty corruption is observed in less corrupt areas while it does not affect industry competition. The finding suggests that promoting transparency in public procurement regulatory processes enhances industry competition and mitigates corruption risks associated with different market structures. Additionally, implementing reforms to ensure equitable access to reliable public reporting and services can facilitate a more concentrated yet efficient industry structure
Realization of flexible in-memory computing in a van der Waals ferroelectric heterostructure tri-gate transistor
No full textCombining logical function and memory characteristics of transistors is an ideal strategy for enhancing computational efficiency of transistor devices. Here, we rationally design a tri-gate two-dimensional (2D) ferroelectric van der Waals heterostructures device based on copper indium thiophosphate (CuInP2S6) and few layers tungsten disulfide (WS2), and demonstrate its multi-functional applications in multi-valued state of data, non-volatile storage, and logic operation. By co-regulating the input signals across the tri-gate, we show that the device can switch functions flexibly at a low supply voltage of 6 V, giving rise to an ultra-high current switching ratio of 107 and a low subthreshold swing of 53.9 mV/dec. These findings offer perspectives in designing smart 2D devices with excellent functions based on ferroelectric van der Waals heterostructures.[Figure not available: see fulltext.]
A critical review on methods for time-dependent structural reliability
No full textWith increasing recognition of randomness and time-variance of variables in structural assessment, time-dependent reliability (TdR) methods have gained popularity among researchers and practitioners. This paper critically reviews commonly used TdR methods, with focuses on analytical solutions, hybrid solutions and simulation solutions. Through this review and analysis, research challenges for TdR methods are identified and future research directions are proposed. It is found that Rice formula-based solutions are accurate but have limited solutions, hybrid solutions are efficient but affected by non-Gaussianity and nonlinearity of limit state functions, and simulation solutions are robust but time-consuming for complex structure systems. It is also found that the effectiveness of TdR methods depends highly on the complexity of limit state functions and types of stochastic processes involved, in particular, the stationarity, Gaussianity and correlation. The contribution of this review is that different TdR methods are elucidated and future research directions are proposed
The role of polymer modification in mitigating ‘sunburn’ damage on asphalt roads
No full textAsphalt roads suffer from ageing throughout their service life due to exposure to ultraviolet light (UV). The aim of this study is to determine the role of polymers such as ethylene vinyl acetate (EVA), styrene butadiene styrene (SBS) and crumb rubber from end-of-life tyres (CR) in protecting bitumen against the damage caused by UV radiations when roads are exposed to sunlight. One unmodified bitumen and four polymer-modified commercial binders were exposed to a filtered xenon-arc light for 10, 20 and 30 days before being tested. Overall, SBS modified binders were less damaged by UV exposure, followed by CR and EVA modified binders. More specifically, SBS provided the best cracking resistance to the binder after ageing compared to conventional unmodified bitumen, followed by CR. EVA did not improve the cracking resistance of the binder. A deep chemical analysis of the photo-oxidation mechanism of polymer-modified binders revealed that SBS is more effective in reducing the formation of carbonyls and aromatics in aged bitumen compared to CR and EVA. The 3D network formed by SBS polymer chains in bitumen was found to be more resistant to oxidation than CR and EVA chains, hence providing a superior UV resistance to SBS-modified binders. Overall, CR seems to provide a sustainable alternative to conventional polymers since using CR for bitumen modification would reduce landfilling of tyres while increasing roads service life and reducing maintenance costs
P53 and TLR4 expression are prognostic markers informing progression free survival of advanced stage high grade serous ovarian cancer
No full textObjective: New prognostic biomarkers, and bio-signatures, are urgently needed to facilitate a precision medicine-based approach to more effectively treat patients with high-grade serous ovarian cancer (HGSC). In this study, we analysed the expression patterns of a series of candidate protein biomarkers. Methods: The panel of markers which included MyD88, TLR4, MAD2, PR, OR, WT1, p53, p16, CD10 and Ki67 was assessed using immunohistochemistry in a tissue microarray (TMA) cohort of n = 80 patients, composed of stage 3–4 HGSCs. Each marker was analysed for their potential to predict both overall survival (OS) and progression-free survival (PFS). Results: TLR4 and p53 were found to be individually predictive of poorer PFS (Log Rank, p = 0.017, p = 0.030 respectively). Cox regression analysis also identified high p53 and TLR4 expression as prognostic factors for reduced PFS (p53; HR=1.785, CI=1.036–3.074, p = 0.037 and TLR4; HR=2.175, CI=1.112–4.253, p = 0.023). Multivariate forward conditional Cox regression analysis, examining all markers, identified a combined signature composed of p53 and TLR4 as prognostic for reduced PFS (p = 0.023). Conclusion: Combined p53 and TLR4 marker assessment may help to aid treatment stratification for patients diagnosed with advanced-stage HGSC