Aggregate Impact Research Articles

Cyberattacks, Operational Disruption, and Investment in Resilience Measures

With the increased frequency and magnitude of cyberattacks, policymakers and the private sector search for ways to counter this threat. One of the main initiatives suggested to achieve this goal is sharing cybersecurity-related information. Although the general belief is that information sharing can increase both industry profit and social welfare, it is unclear whether firms would voluntarily share such information. In this paper, we examine the incentives of firms to share cybersecurity-related information, how information sharing impacts investments in cyber resilience, and the aggregate impact on welfare. We find that firms only voluntarily share information in less competitive markets when the impact of the disruption is high. In all other cases, firms elect not to share information, despite potential welfare benefits. To facilitate information sharing, we investigate an exclusionary policy (i.e., sharing must be mutual) and demonstrate market conditions under which this policy incentivizes information sharing. However, when competition is intense, even the exclusionary policy is ineffective because it reduces industry profit. To inform stronger interventions, we examine firms being mandated to disclose their private cyberthreat information. We demonstrate that an opportunity does exist for such disclosure, particularly when the cost of investing in cyber resilience is high. However, policymakers must use caution with such a policy because applying this intervention when investment costs are not high leads to a steep reduction in welfare. This paper was accepted by D. J. Wu, information systems. Supplemental Material: The online appendix is available at https://doi.org/10.1287/mnsc.2022.00430 .

The Pathway to Startup Success: A Comprehensive Systematic Review of Critical Factors and the Future Research Agenda in Developed and Emerging Markets

Notwithstanding the benefits derived from successful startup firms in the contemporary entrepreneurial landscape, for many startup firms, the pathway to success is extremely challenging; unfortunately, the failure rate is globally high. The aim of this article is to review empirical contributions regarding startup firms and provide a comprehensive analysis of the factors influencing their success in developed and emerging markets. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search was undertaken within the Web of Science database, encompassing studies published between 2004 and 2024, which were analyzed. The PRISMA framework is preferred because it stands out from other guidelines due to its transparent and complete reporting and evidence-based recommendations. This work also employed aggregate impact estimation to rank the relative importance of each success factor regarding the success of startups. This article offers a comprehensive analysis of 24 success factors extracted from a systematic review of 48 empirical studies conducted on the subject. We prioritized each success factor according to their relative impact on the success of startup firms. These were classified as personal (entrepreneurial vision and leadership, adaptability, networking), organizational (team building, financial and resource management, innovation, strategy and marketing) and environmental factors (government support and dynamism of political, economic and cultural environment). The findings underscore the importance of a holistic approach that considers both internal and external factors in fostering startup success. However, it is essential to acknowledge that not all factors exert comparable effects on success; certain factors wield a substantial influence, whereas others demonstrate a significant yet lesser impact. Several conclusions and implications for startup founders, government policymakers and startup firm researchers are derived.

Multi-scale study on the crack resistance and energy dissipation mechanism of modified rubberized concrete

This study investigates the impact of rubber aggregates with different particle sizes, volume proportions, and pretreatment methods on the crack resistance and energy dissipation properties of rubberized concrete (RuC). The mechanisms of crack resistance and energy consumption are analyzed from macroscopic, mesoscopic, and microscopic perspectives using static and dynamic performance tests, digital image correlation (DIC), and scanning electron microscopy (SEM). These techniques reveal changes in crack patterns, interface transition zones, and pore characteristics. The findings demonstrate that rubber aggregates significantly slow crack propagation and enhance damping energy dissipation, with the volume content of rubber being the most critical factor. The inclusion of rubber aggregates introduces "cavity defects" into the concrete structure, which accounts for RuC's reduced strength compared to standard concrete while highlighting its advantages in vibration reduction and energy absorption. These insights are essential for advancing research on material modifications and microscopic numerical simulations, contributing to reduced carbon emissions.

Can Big Data Aggregation Help Businesses Save Energy and Reduce Emissions? Quasi-Natural Experiment in Big Data Comprehensive Test

Aggregating big data pieces is critical for increasing enterprise resource allocation efficiency, reducing energy usage, and lowering carbon emissions intensity. This research aims to investigate the impact of big data aggregation on energy efficiency and carbon emission intensity among Chinese enterprises. To this end, it employs primary financial data from Chinese listed companies from 2009 to 2021 and carbon emissions data disclosed in social responsibility reports, sustainable development reports, and environmental reports. The findings revealed that the aggregation of big data elements dramatically reduces the intensity of carbon emissions in firms in the pilot regions. The decrease effect is more effective in economically developed places and regions with higher degrees of digitization, particularly for organizations in high-energy-consuming industries, and it is more robust for small and non-state-owned businesses. The aggregation of big data elements mainly aids firms in pilot regions in lowering energy consumption and emissions by increasing technical innovation and energy usage efficiency. To create a new national competitive advantage, we should actively promote the gradual expansion of the comprehensive pilot zone for big data, advance the in-depth application of big data in environmental governance, and better capitalize on the dividends of big data aggregation.

Impact of protein aggregation on the immunogenicity of a human monoclonal antibody following pulmonary administration in mice

Spray drying is a widely employed method for generating dry powder formulations for inhalation. Yet, it presents substantial challenges when applied to therapeutic proteins due to stability issues. The formation of protein aggregates during the atomization and the heating steps can diminish protein activity and raise immunogenicity concerns. Here, we assessed the impact of varying levels of protein aggregates generated during spray-drying on the fate and the immunogenicity of the human monoclonal antibody NIP228 following intratracheal administration in mice. Aggregate-free rhodamine labelled NIP228 was spray-dried with or without 1% polysorbate 80 surfactant, resulting in the generation of powder formulations with associated low and high protein aggregate levels, respectively. Confocal imaging highlighted the presence of aggregates in the lungs for both powders but not for the solution, while flow cytometry analysis designated alveolar macrophages as the main immune cells taking up rhod-NIP228 in the lungs with very little involvement of dendritic cells and interstitial macrophages following a single dose administration. Notably, repeated intratracheal administration of the three formulations in mice did not impact the magnitude of the anti-drug antibody response in sera or broncho-alveolar lavages. The pulmonary route appeared to evoke a more robust immune response when compared to subcutaneous administration. Overall, the level of NIP228 aggregation in this study did not appear to be the primary driver of NIP228 immunogenicity following delivery to the lungs in mice, shedding new light on the interplay between protein aggregation and immunogenicity in the context of the pulmonary delivery of therapeutic proteins.

Correlation Between Strength and Durability of Sandstones from the Dumri Formation, Tinau Khola Area, West-Central Nepal

Strength and Durability indices are two significant geotechnical criteria that can describe rock fragments' strength and weathering resistance. The Dumri Formation is the youngest and thickest of the Tansen Group, Lesser Himalaya. A thick succession of medium-grained, bluish-grey quartzose sandstone and red-purple shale represents it. To assess the quality of the sandstones, different laboratory tests and analyses were made to characterize the physical and mechanical properties of the sandstones. Physical properties were greatly influenced by composition and texture. The intact rock strength was figured out by the point load strength index (PLSI) and Aggregate impact value (AIV). Rock durability against slaking was determined using the slake durability index (SDI) test. The strength and durability indices were correlated through regression analysis. Sandstones assessed were classified as lithic and feldspathic wacke. Sandstones exhibited high resistance to slaking and are extremely durable (SDI = 99.53-99.86%) under a two-cycle test. Sandstones are strong to very strong (PLSI = 5.28-8.92 MPa) and possess high impact resistance (AIV = 6-9%). The correlation between PLSI and SDI was found to be high (r=0.86). Similarly, a correlation between AIV and SDI was (r=0.98), and between AIV and PLSI was (r=0.86).

Impact of geopolymer aggregate on the mechanical properties and durability characteristics of concrete

This study examined the use of geopolymer aggregate (GPA), produced from slag and an alkaline solution, as a substitute for coarse aggregate in conventional concrete. The research aimed to evaluate how different proportions of GPA (25%, 50%, 75%, and 100% replacement) affect the durability and mechanical properties of concrete. A series of tests were conducted, including slump, compressive strength, flexural strength, chloride resistance, sulfate resistance, sorptivity, and water absorption. The results demonstrated significant improvements in concrete properties with the inclusion of GPA. The compressive strength of GPA concrete ranged from 31 to 38 MPa, showing a 10%–15% increase over that of standard concrete. Flexural strength improved by 6% at 7 days and 7.5% at 28 days compared to control mixes. Water absorption was reduced by 42.58%, and sorptivity decreased by 47.9% compared to ordinary aggregate concrete. GPA concrete also excelled in acid resistance, with a weight loss of 28.6% and a lower reduction in strength compared to traditional acidic aggregates. In sulfate resistance tests, GPA concrete showed a 31% reduction in both weight and strength loss. These results highlight the advantages of using GPA as an alternative to conventional coarse aggregates. GPA not only enhances the mechanical and durability properties of concrete but also presents a more sustainable option, contributing to reduced environmental impacts associated with traditional aggregate materials.

A "Wise" Intervention to Increase Hand Hygiene Compliance of Nurses in Acute Care Units in US Hospitals: A Multiple Baseline Interrupted Time-Series Evaluation.

Objective: This study tested a 'wise' intervention (quick prompt of a specific psychological mec) in acute care hospital units to improve nurses' hand hygiene compliance (HHC). Design: A multiple baseline design in two medical-surgical teaching hospitals in the United States. Measurements: Hand hygiene data was collected using an electronic compliance monitoring system with sensors placed in doorways and on corresponding soap and alcohol-based hand rub dispensers. The outcome measure was the proportion of opportunities in which HH was undertaken by staff per week in each unit. Intervention: A quick-and-easy psychological prime to reinvigorate professional identity. Methods: Interrupted time series analysis using a quasi-Poisson regression model with statistical process control charts for each unit. Results: A statistically significant increase in HHC rates that was sustained for months post-intervention. However, the patterns by unit were not statistically significant once temporal trends were considered. Other factors, such as the unit type and the use of incentives could have impacted the results. Conclusions: These analyses suggest that the aggregate impact should not be taken as evidence of intervention effectiveness. This study therefore cannot be considered to have provided a strong foundation for use of a 'wise' intervention, despite its relatively small financial, logistical and psychological cost.

Sustainability assessment and impact of different recycled rubber aggregates on the performance of cement mortars

Sustainability assessment and impact of different recycled rubber aggregates on the performance of cement mortars

Impacts of Am Aggregation on the Bulk Properties of Mixed Oxides (U, Am)O2 from First Principles

Impacts of Am Aggregation on the Bulk Properties of Mixed Oxides (U, Am)O2 from First Principles

Impact of PVA-coated aggregate on concrete impermeability and creep characteristics under hydraulic pressure and development of a creep model

In marine engineering projects such as sea dikes, concrete must exhibit both exceptional impermeability and plastic deformation to prevent cracking and subsequent internal corrosion due to synergistic deformation with the foundation. This study enhances the interface transition zone (ITZ) and plastic deformation of concrete by applying a PVA film to the aggregate surface. We use nuclear magnetic resonance to investigate the internal pore distribution and conduct permeability tests to assess its impermeability. Utilizing a self-developed triaxial hydraulic creep apparatus, we tests the concrete's creep performance under hydraulic pressure. Compared with conventional waterproof concrete, the findings reveal that the PVA film on the aggregate surface significantly increases the water penetration pressure of the concrete and markedly enhances the momentary deformation and creep deformation under hydraulic pressure, significantly extending the time to creep. Furthermore, the study proposes a creep model incorporating a fractional derivative-based dashpot model, combined with the Burgers model. This research offers a novel approach and theoretical support for developing impermeable and plastic concrete suitable for marine engineering applications.

Budget impact analysis of baricitinib for treatment of alopecia areata: A Saudi hospital perspective

ObjectivesTo perform a budget impact analysis (BIA) of the adoption of baricitinib for the management of alopecia areata (AA) by a Saudi public sector payer. MethodsA BIA model was developed to calculate the expected financial impact under two scenarios: the baseline scenario, which reflects the current mix of treatments without baricitinib, and the projected scenario, in which baricitinib is adopted. The model assumed that patients with severe AA and those with mild-to-moderate AA who did not respond to other treatments were eligible for baricitinib treatment. The model input was based on published evidence, expert opinions, and the Saudi Expert Consensus Statement on the Diagnosis and Management of AA. ResultsAssuming a hypothetical total eligible population of 368 patients received different AA treatments over the 12-months study period. The aggregated 5-years cost in the baseline scenario was SR 5836616. Upon the introduction of baricitinib as an alternative treatment for severe AA, the projected aggregated budget impact was SR 7569120. Sensitivity analysis showed that the results were most sensitive to AA prevalence, percentage of severe AA, and predicted market share for baricitinib over the 5-year time horizon. ConclusionThe addition of baricitinib to formularies is likely to increase the cost impact from a government hospital perspective. However, this addition expands the treatment options for patients with AA and may result in improved outcomes. Future cost-effectiveness analyses are recommended to estimate the cost per incremental improvement in the outcomes.

Design of heat-resilient housing in hot-arid regions

Extreme heat events in urban areas increasingly challenge the capacity of electrical distribution systems to serve building cooling equipment under peak loads and, when power is interrupted, the thermal response of buildings that can delay the onset of dangerously high indoor temperatures. The design of new buildings and their operation can mitigate the risks of intense heatwaves, but architects and planners face a myriad of choices about what measures to select, and how best to estimate their individual and collective performance. To aid the design and operation of heat-resilient buildings, this paper takes a multidisciplinary approach that is novel in two key aspects. First, it evaluates the individual and aggregated impact of factors associated with architectural and urban design, equipment technologies, and human behavior. Second, its valuation metrics include the magnitude of peak electrical load, appropriate for assessing active measures aimed at reducing peak power, and the time after a power outage for indoor temperatures to reach levels associated with heat stress, an indication of the efficacy of passive (no power) measures. The application of the method in the Middle East North Africa (MENA) region, where growing populations and demand for space cooling make it particularly relevant, relies on knowledge of building codes and local construction practice. Single-factor testing shows that pre-cooling produces the largest reduction in peak electrical load during a simulated four-day heatwave, followed by building adjacency, maximum temperature set point and equipment loads. A combination of all considered factors reduces peak power by 70% and shifts the reduced peak to a later hour. In response to a power outage, the incorporation of architectural factors (roof, wall and window thermal resistance above code minima, increased thermal mass, reduced glazing solar heat gain coefficient and window shading) reduces the time above a Heat Index of 28 °C (caution) in a week-long test period in which the power failure occurs at hour 40 from 119 to 53 h. The presented methodology applies broadly to other building types and to regions affected by very hot weather.

The Effect of the Ratio of Fly Ash to Alkaline Activator and the Molarity of NaOH on the Mechanical Properties of Fly Ash-Based Aggregates

The global demand for aggregates has escalated, leading to a decline in the availability of quality natural aggregates. In response, the cold bond pelletization (CBP) process emerged in the early 2000s as a novel approach to artificial aggregate production, utilizing dry powdered fly ash. This method involves agglomerating fly ash particles at room temperature in an inclined rotating pan to form pellets. However, the abstract lacks clarity in elucidating the significance of this approach. Our study investigates the mechanical properties of aggregates produced through the CBP method via experimental laboratory methods, focusing on variations in the ratio of fly ash to alkaline activator (FA/AA) and the molarity of Sodium Hydroxide (NaOH). Notably, we found that an effective molarity of 15 resulted in the lowest Aggregate Impact Value (AIV) percentage, indicating improved mechanical properties. Furthermore, we observed fluctuations in AIV values across different FA/AA ratios and NaOH molarities, suggesting nuanced effects on aggregate quality. Our findings underscore the importance of optimizing parameters in the CBP process for enhanced aggregate performance.

Comparative Analysis of the Strength of Concretes Made from Different Aggregates

The paper aimed to explore the replacement of river sand in concrete with iron fillings and sawdust at various percentages (10%, 20%, and 30%). The study used a 1:2:4 mix design and a water-cement ratio of 0.5. Wooden square cubes of dimensions 100 x 100 x 100 mm were employed, resulting in 42 concrete cubes. Tests were conducted to assess particle size distribution, specific gravity, bulk density, aggregate impact value, aggregate abrasion value, and compressive strength at 7th and 28th days of curing. Notably, after 7 days, compressive strength results showed that concrete with a 10% iron fillings replacement (18.5 N/mm²) had a higher average strength than concrete with 100% river sand (17.6 N/mm²). However, as the percentage of iron fillings increased to 20% (9.8 N/mm²) and 30% (7.1N/mm²), the compressive strength decreased. On the other hand, concrete with sawdust replacements at 10% (3.7 N/mm²), 20% (1.4 N/mm²), and 30% (0.5 N/mm²) exhibited significantly lower load-bearing capacity. These trends persisted at the 28th day, with the compressive strength decreasing with increasing percentages of iron fillings (10%: 20.3 N/mm², 20%: 11.2 N/mm², 30%: 11.6 N/mm²) and sawdust (10%: 3.4 N/mm², 20%: 2.3 N/mm², 30%: 1.4 N/mm²). The findings suggest that a low percentage of iron fillings can be used in combination with river sand to maintain load-bearing capacity, but sawdust or wood particles should be avoided as they adversely affect compressive strength. This research contributes valuable insights into the use of these materials in concrete mixtures.

Is the Modern Arctic Marginal Ice Zone More Susceptible to Summer Cyclones?

Abstract As Arctic sea ice melts, cyclones potentially enhance the mechanical and thermodynamic forces that influence the vulnerable ice edge. However, examples can be found in satellite observations and reanalyses where cyclones either locally increase or decrease ice within the marginal ice zone (MIZ). Two case studies with these opposing ice responses are presented. Guided by the tendencies during these events, 264 strong (minimum surface pressure below 984 mb) summer cyclones were sorted by prevailing wind direction and SST changes within the MIZ to quantify the net ice impacts in the present-day Arctic (2010–2019) and early satellite era (1982–1991). By tracking MIZ ice area from one week before the cyclone’s formation through two weeks after, we find cyclones that enhance southerly winds mostly decrease ice area, whereas enhanced northerlies generally increase ice area within the MIZ later in the season. Furthermore, early-summer storms tend to decrease MIZ ice area more than late-summer storms. A shift towards more frequent early-summer storms is observed from the 1980s to 2010s, resulting in almost two-thirds of recent storms decreasing area. Consequently, recent summer cyclones have more negative impacts, resulting in a decline of more than 40,000 km2 of MIZ ice area on average, whereas 1980s cyclones had little aggregate impact. Wind direction and SST trends partially reconcile the wide range of MIZ ice area changes due to cyclone passage, yet considerable variations in individual cyclones’ impacts remain even when controlling for these factors. These bulk diagnostics therefore only explain part of the complex ice-cyclone relationship.

Impacts of Soil Aggregation on Nitrogen Storage and Supply in Biomass Incorporated Sandy-Loam Acidic Soil

Impacts of Soil Aggregation on Nitrogen Storage and Supply in Biomass Incorporated Sandy-Loam Acidic Soil

Online bilateral matching methodology for anti-epidemic resources based on spatial transmission risk

This paper focuses on the online anti-epidemic resource allocation between demanders and suppliers considering the epidemic spatial spread. The spatial crowdsourcing with sharing platform is an effective way for anti-epidemic resource allocation, and a reasonable online matching strategy can improve the efficiency of resource utilization. The paper proposes online matching heuristic strategy (HSTRF-LRLUF strategy) and designs an online batch bilateral matching algorithm for anti-epidemic resources, which considers the impact of grid spatial aggregation and diffusion risk of emerging infectious diseases. The population distribution within grids and the commuting patterns between grids can provide decision support for selecting online matching strategies of anti-epidemic resources. A larger matching time window focusing on the spatial transmission risk (TR) of the epidemic can obtain better matching results. However, with a smaller matching time window, the decision makers can focus on spatial agglomeration risk (OR) or spatial diffusion risk (IR). The paper effectively combines the spatial crowdsourcing model with the anti-epidemic resource allocation to achieve the allocation of emergency resources to individuals. A combined anti-epidemic resource online matching heuristic strategies is designed from the spatial agglomeration risk and the spatial diffusion risk. Decision makers can dynamically adjust the online matching strategies of anti-epidemic resources by evaluating the spatial agglomeration risk, the spatial diffusion risk, and the overall spatial transmission risk based on the real-time spread of the epidemic and the supply of anti-epidemic resources.

Assessing the impact of recycled concrete aggregates and metakaolin on the mechanical properties of pervious concrete

Population growth and urban expansion have increased impervious surfaces, leading to environmental issues such as stormwater runoff and groundwater depletion. Traditional concrete, while durable, contributes to these problems. There is a need for sustainable construction materials that can address environmental challenges and reduce the consumption of natural resources. Pervious concrete, enhanced with recycled aggregates (RCA) and supplementary cementitious materials (SCMs) like metakaolin (MK) present a potential solution. This study aims to improve the mechanical and durability properties of pervious concrete by incorporating RCA and MK, assessing their effects on workability, density, porosity, permeability, compressive strength and flexural strength. The incorporation of RCA resulted in increased aggregate porosity compared to natural aggregates. Workability was assessed using the slump test, density was measured, and porosity and permeability were evaluated. The results showed that incorporation of RCA generally decreased workability, density and strength, while the addition of MK improved these properties by refining the microstructure. Specifically, mixes with 10% MK demonstrated better performance in terms of increased compressive and flexural strengths, improved density and reduced porosity. The ANN model showed high accuracy in predicting compressive and flexural strengths. The study concludes that RCA and MK can enhance the mechanical and durability properties of pervious concrete.

Inflation, Fiscal Policy, and Inequality: The Impact of the Post‐Pandemic Price Surge and Fiscal Measures on European Households

AbstractFollowing the inflation surge in the aftermath of the pandemic crisis, Euro Area governments adopted a large array of fiscal measures to cushion its impact on households. The inflationary shock and related fiscal measures affected households differently depending on their country, their consumption patterns, and their position in the income distribution. This paper uncovers the aggregate and distributional impact of this inflationary shock, as well as the impact of the government measures aimed at supporting households and containing prices. The analysis is carried out for 2022 and includes Germany, France, Italy, Spain, Portugal, and Greece. Our work confirms that the purchasing power and welfare of low‐income households was more severely affected than that of high‐income households. Fiscal measures contributed significantly to closing this gap, though with country differences. However, most fiscal measures were not particularly targeted at low‐income households, implying a low cost‐effectiveness in protecting the poorest in some countries.