687 research outputs found
On the prevalence of hierarchies in social networks
In this paper, we introduce two novel evolutionary processes for hierarchical networks referred to as dominance- and prestige-based evolution models, i.e., DBEM and PBEM, respectively. Our models are deterministic in nature which allows for closed-form derivation of equilibrium points for such type of networks, for the special case of complete networks. After deriving these equilibrium points, we are somewhat surprised in recovering the exponential and power-law strength distribution as the shared property of the resulting hierarchal networks. Additionally, we compute the network properties, Geodesic distance distribution and centrality closeness, for each model in closed form. Interestingly, these results demonstrate very different roles of hubs for each model, shedding the light on the evolutionary advantages of hierarchies in social networks: in short, hierarchies can lead to efficient sharing of resources and robustness to random failures. For the general case of any hierarchical network, we compare the estimations of tie intensities and node strengths using the proposed models to open-source real-world data. The prediction results are statistically compared using the KolmogorovāSmirnov test with the original data
Identification and Prioritization of Energy Consumption Optimization Strategies in the Building Industry Using the Hybrid SWARA-BIM Model
Energy consumption in buildings has become one of the most critical problems in all countries and principles of sustainability suggest that a satisfactory solution must be found to reduce energy consumption. This study aims to identify and prioritize energy consumption optimization strategies in buildings. Data collection consists of gather-ing primary data from the existing literature and secondary data from interviews, questionnaires, and simulations through building information modeling (BIM) tools. Twenty-nine strategies were identified and categorized into five groups according to their nature and ranked using one of the multiple criteria decision-making (MCDM) methods called the step-wise weight assessment ratio analysis (SWARA). A case study building in Shiraz, Iran, was simulated using BIM software, and the energy saving potential of the highest ranked strategies were obtained. According to the results, significant contributors to the energy consumption optimization were āUsing renewable energy resources,ā āUsing efficient insulation,ā and āUsing suitable materials,ā providing 100%, 35%, and 23% efficacy, respectively. The results obtained from this study can inform the building industryās key stakeholders regarding the best strategies to apply in order to reduce energy consumption and improve sustainability in the construction industry
Ambient betatron motion and its excitation by ghost lines in Tevatron
Transverse betatron motion of the Tevatron proton beam is measured and
analyzed. It is shown that the motion is coherent and excited by external
sources of unknown origins. Observations of the time varying ghost lines in the
betatron spectra are reported.Comment: 9 p
Heavy metal concentrations in the selected tissues of the Persian sturgeon, Acipenser persicus, from the southern coast of the Caspian Sea
Bioaccumulation of heavy metals including Cd, Pb, Cu and Zn in muscle, gill, liver, kidney and stomach in Acipenser persicus was studied. Fish were collected from the āIranian fishery zone 1ā located between Astara and Kiyahshahr. Samples (n=25) were collected from five stations in the study area during the autumn catch season in 2001. Samples were analyzed by wet digestion with hydrogen peroxide and nitric acid. Analyses were testified using spike method. A sample of bovine liver (CRM 185R) was tested to ascertain reliability of analyses. Digested samples were analyzed using Flame Atomic Absorption Spectrophotometer. The bioaccumulation pattern for Zn in different tissues studied was stomach>liver> kidney> gills>muscle tissue. The mean concentration of Zn in the stomach was 136.6Ā±10.70Ī¼g g-1 dry weight. Cu with the maximum concentration of 39.71Ā±8.85Ī¼g g-1 dry weight in liver showed a bioaccumulation pattern of liver>kidney>stomach>gills>muscle tissue. The bioaccumulation pattern for Pb was determined as gills>liver> kidney>stomach>muscle tissue. Maximum mean concentrations of Pb 6.87Ā±2.25Ī¼g g-1 dry weight belonged to gills. Bioaccumulation pattern for Cd in the different organs studied in A. persicus was kidney>liver>gills>stomach> muscle tissue. Maximum mean concentration of 5.1Ā±0.97Ī¼g g-1 dry weight belonged to kidneys and the minimum mean concentration of 0.05Ā±0.007Ī¼g g-1 dry weight belonged to muscle tissue. Concentration of the metals in the muscles samples were below the most guidelines for human consumption.
Concentrations for heavy metals were lower than the guidelines in some organs and were higher than that in the other organs studied. The observed concentrations do not pose health problems as these organs are not used for human consumption
Typing methods used in the molecular epidemiology of microbial pathogens: a how-to guide
Microbial typing is often employed to determine the source and routes of infections, confirm or rule out outbreaks, trace cross-transmission of healthcare-associated pathogens, recognize virulent strains and evaluate the effectiveness of control measures. Conventional microbial typing methods have occasionally been useful in describing the epidemiology of infectious diseases. However, these methods are generally considered too variable, labour intensive and time-consuming to be of practical value in epidemiological investigations. Moreover, these approaches have proved to be insufficiently discriminatory and poorly reproducible. DNA-based typing methods rely on the analysis of the genetic material of a microorganism. In recent years, several methods have been introduced and developed for investigation of the molecular epidemiology of microbial pathogens. Each of them has advantages and limitations that make them useful in some studies and restrictive in others. The choice of a molecular typing method therefore will depend on the skill level and resources of the laboratory and the aim and scale of the investigation. This study reviews the most popular DNA-based molecular typing methods used in the epidemiology of bacterial pathogens together with their advantages and limitations
Exosomal microRNAs in breast cancer and their potential in diagnosis, prognosis and treatment prediction
The significance of exosomal microRNAs (EmiRs) in breast cancer (BC) diagnosis has been widely addressed over
the past decades. However, little information is still available regarding these reliable biomarkersā impacts on BC
early diagnosis, prognosis, and treatment outcome predictions, but their great potential in spotting BC early and
their predictive essence in BC prognosis and treatment results are promising against this common cancer. The
present review focuses on the most recent findings and advancements of EmiRs applications in BC early diagnosis
and treatment prediction and identifies current helpful EmiRs that are widely used in this regard
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