Simulating Flying Insects Using Dynamics and Data-Driven Noise Modeling to Generate Diverse Collective Behaviors

We present a biologically plausible dynamics model to simulate swarms of flying insects. Our formulation, which is based on biological conclusions and experimental observations, is designed to simulate large insect swarms of varying densities. We use a force-based model that captures different interactions between the insects and the environment and computes collision-free trajectories for each individual insect. Furthermore, we model the noise as a constructive force at the collective level and present a technique to generate noise-induced insect movements in a large swarm that are similar to those observed in real-world trajectories. We use a data-driven formulation that is based on pre-recorded insect trajectories. We also present a novel evaluation metric and a statistical validation approach that takes into account various characteristics of insect motions. In practice, the combination of Curl noise function with our dynamics model is used to generate realistic swarm simulations and emergent behaviors. We highlight its performance for simulating large flying swarms of midges, fruit fly, locusts and moths and demonstrate many collective behaviors, including aggregation, migration, phase transition, and escape responses

Genetic Variants at 1p11.2 and Breast Cancer Risk: A Two-Stage Study in Chinese Women

BACKGROUND: Genome-wide association studies (GWAS) have identified several breast cancer susceptibility loci, and one genetic variant, rs11249433, at 1p11.2 was reported to be associated with breast cancer in European populations. To explore the genetic variants in this region associated with breast cancer in Chinese women, we conducted a two-stage fine-mapping study with a total of 1792 breast cancer cases and 1867 controls. METHODOLOGY/PRINCIPAL FINDINGS: Seven single nucleotide polymorphisms (SNPs) including rs11249433 in a 277 kb region at 1p11.2 were selected and genotyping was performed by using TaqMan® OpenArray™ Genotyping System for stage 1 samples (878 cases and 900 controls). In stage 2 (914 cases and 967 controls), three SNPs (rs2580520, rs4844616 and rs11249433) were further selected and genotyped for validation. The results showed that one SNP (rs2580520) located at a predicted enhancer region of SRGAP2 was consistently associated with a significantly increased risk of breast cancer in a recessive genetic model [Odds Ratio (OR)  =  1.66, 95% confidence interval (CI)  =  1.16-2.36 for stage 2 samples; OR  =  1.51, 95% CI  =  1.16-1.97 for combined samples, respectively]. However, no significant association was observed between rs11249433 and breast cancer risk in this Chinese population (dominant genetic model in combined samples: OR  =  1.20, 95% CI  =  0.92-1.57). CONCLUSIONS/SIGNIFICANCE: Genotypes of rs2580520 at 1p11.2 suggest that Chinese women may have different breast cancer susceptibility loci, which may contribute to the development of breast cancer in this population

Cultural proximity, destination familiarity and tourists’ sense of away-from-home (SAFH)

Travel is about leaving home. Immersing in a non-daily environment spontaneously gives people a sense of away-from-home (SAFH) - a concept natively related to travel, but rarely discussed in prior studies. This study proposes this novel concept of SAFH building on the dualistic context of home and away to describe the emotive states people develop at a tourist destination, relative to their home environment. The components of SAFH, and the influences of cultural proximity, destination familiarity, and geographic distance on these senses, are investigated. A set of data (498 samples) was collected from domestic tourists from other regions of China visiting the city of Hangzhou. The findings indicate that tourists' SAFH comprises of five senses: Novelty, uncomfortableness, insecurity, situational uncontrollability, and emotional isolation. Tourists’ destination familiarity significantly influences their SAFH. The direct and indirect impacts of cultural proximity on the SAFH mainly exist in the long-haul travelling group. In conclusion, when travelling in a particular destination, tourists generate a sense of away-from-home which varies due to their different origins and familiarities with the destination

Optimization of tungsten particles spheroidization with different size in thermal plasma reactor based on numerical simulation

Micro-size tungsten particles have been prepared by radio-frequency (RF) thermal plasma reactor. SEM images show that spheroidization ratio of small particles is obviously lower than that of big particles. Numerical model has been founded to simulate the spheroidization system to explain this phenomenon based on FLEUNT software. The calculation results indicate that small particles are easy to diffuse and &#39;back-mix&#39;, which will urge small particles to escape from the high temperature area, while big particles are flowing straightly through the high temperature area, as a result that small particles cannot absorb enough heat and cannot be spheroidized well. The forces of diffusion and &#39;back-mixing&#39; are each radial velocity and axial velocity. With some calculations based on the change of each gas flow, it can be found that appropriate combinations of gas flow can improve the spheroidization ratio of small particles. (C) 2016 Elsevier B.V. All rights reserved.</p

Organization and evolution of climate responsive strategies, used in Turpan vernacular buildings in arid region of China

Under the global crisis of energy shortage and environmental pollution, the climate responsive strategies used in vernacular buildings have attracted much attention for their potential to reduce energy consumption and carbon emissions. However, the relationships between these traditional climatic strategies were not precisely perceived, which may cause the inapplicability of these strategies for contemporary rural houses. In this paper, taking the Turpan vernacular buildings in arid region of China, the climate responsive strategies of buildings in the most significant periods such as the Gaochang period (before 1318), the Khanate and Republican period (1318–1949), the Modern period (1949–2010), and the Contemporary period (2011–present) were summarized. In addition, two different types of climatic strategies organizations, namely multilayer spaces and integrated building envelopes, were identified based on the temperature difference measurement and comparative analysis. The assessment of thermal performance of the organizations was conducted by the methodology of software simulation. Furthermore, the applicability of the organizations in rural areas was discussed, and a new combined organization was proposed. Consequently, this study can contribute to provide the main approaches for climatically responsive rural houses

Effect of Coating Pre-Treatment on Surface Recrystallization of DD6 Single Crystal

Thermal barrier coatings (TBCs) are widely used to protect high-temperature components against harsh environments, such as extremely high temperatures. In this work, a second generation Ni-based single crystal superalloy (DD6) was treated in two ways: (1) via simple surface sandblasting under different pressures with no additional coating, and (2) through simple surface sandblasting under different pressures and then by applying NiCoCrAlYHf (HY5) coatings. The effects of pre-treatment (sandblasting) and the HY5 coating on the surface recrystallization of the alloy were thoroughly investigated. According to the results, both sandblasting pressure and the presence or absence of a coating significantly influence surface recrystallization. In particular, the critical sandblasting pressure for recrystallization increased the maximum recrystallization depth in both the coated and uncoated samples. Meanwhile, the recrystallization depth of the alloy with a coating was reduced compared to that without a coating. In addition, the number of recrystallized cells in the coated alloy was decreased, which indicated that the HY5 coating effectively reduced the degree of recrystallization