59 research outputs found

    IS THERE A MARRIAGE OR PARENTHOOD INCOME PENALTY AMONG POLICE?: A CASE STUDY OF OCCUPATIONAL GENDER INEQUALITY IN THE PUBLIC SECTOR

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    Research has found an earnings advantage for married men as well as men with children. In contrast, married women and women with children often receive a much smaller wage premium, or even face a wage penalty. Most research on the marriage and motherhood income penalties has focused on the private labor market, tacitly assuming that the laws and regulations that govern public sector occupations will prevent this form of occupational gender inequality within these domains. Whether this is the case remains an empirical question. With increasing numbers of females entering the labor force, examining whether these forms of occupational gender inequality are present within public sector jobs has become more important. Using data from the Current Population Survey covering 41 years, I explore the gendered effects of marriage and parenthood on income inequality using police officers as a case study of a public-sector occupation. My analyses reveal that female police officers experience both marriage and motherhood income penalties, though the marriage penalty is partially explained by the stronger negative effect of motherhood on female police officers’ income. Furthermore, these analyses suggest that male officers enjoy stable marriage and fatherhood income advantages over time, but females continuously face a motherhood penalty. I conclude with a discussion of the implications of my findings for future research. Keywords: police officer, marriage penalty, motherhood penalty, income, gender inequalit

    A privacy-preserving fuzzy interest matching protocol for friends finding in social networks

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    Nowadays, it is very popular to make friends, share photographs, and exchange news throughout social networks. Social networks widely expand the area of people’s social connections and make communication much smoother than ever before. In a social network, there are many social groups established based on common interests among persons, such as learning group, family group, and reading group. People often describe their profiles when registering as a user in a social network. Then social networks can organize these users into groups of friends according to their profiles. However, an important issue must be considered, namely many users’ sensitive profiles could have been leaked out during this process. Therefore, it is reasonable to design a privacy-preserving friends-finding protocol in social network. Toward this goal, we design a fuzzy interest matching protocol based on private set intersection. Concretely, two candidate users can first organize their profiles into sets, then use Bloom filters to generate new data structures, and finally find the intersection sets to decide whether being friends or not in the social network. The protocol is shown to be secure in the malicious model and can be useful for practical purposes.Peer ReviewedPostprint (author's final draft

    Cost-effective secure e-health cloud system using identity based cryptographic techniques

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    Nowadays E-health cloud systems are more and more widely employed. However the security of these systems needs more consideration for the sensitive health information of patients. Some protocols on how to secure the e-health cloud system have been proposed, but many of them use the traditional PKI infrastructure to implement cryptographic mechanisms, which is cumbersome for they require every user having and remembering its own public/private keys. Identity based encryption (View the MathML sourceIBE) is a cryptographic primitive which uses the identity information of the user (e.g., email address) as the public key. Hence the public key is implicitly authenticated and the certificate management is simplified. Proxy re-encryption is another cryptographic primitive which aims at transforming a ciphertext under the delegator AA into another ciphertext which can be decrypted by the delegatee BB. In this paper, we describe several identity related cryptographic techniques for securing E-health system, which include new View the MathML sourceIBE schemes, new identity based proxy re-encryption (View the MathML sourceIBPRE) schemes. We also prove these schemes’ security and give the performance analysis, the results show our View the MathML sourceIBPRE scheme is especially highly efficient for re-encryption, which can be used to achieve cost-effective cloud usage.Peer ReviewedPostprint (author's final draft

    Material removal mode and friction behaviour of RB-SiC ceramics during scratching at elevated temperatures

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    Thermal assistance is considered a potentially effective approach to improve the machinability of hard and brittle materials. Understanding the material removal and friction behaviour influenced by deliberately introduced heat is crucial to obtain a high-quality machined surface. This paper aims to reveal the material removal and friction behaviours of RB-SiC ceramics scratched by a Vickers indenter at elevated temperatures. The material-removal mode, scratching hardness, critical depth of the ductile–brittle transition, scratching force, and friction are discussed under different penetration depths. The size effect of scratching hardness is used to assess the plastic deformation at elevated temperatures. A modified model is established to predict the critical depth at elevated temperatures by considering the changes in mechanical properties. The results reveal that the material deformation and adhesive behaviour enhanced the ductile-regime material removal and the coefficient of friction at elevated temperatures

    Characterization of hardness, elastic modulus and fracture toughness of RB-SiC ceramics at elevated temperature by Vickers test

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    In this paper, mechanical properties of RB-SiC ceramics, such as hardness, elastic modulus and fracture toughness, are characterized through indentation technique using a Vickers indenter at elevated temperatures ranging from room temperature to1200 °C realized by laser heating. The indentation size effect, load-displacement curves and relationship between crack length and applied load are studied in order to determine hardness, elastic modulus and fracture toughness accurately. The results show that the Meyer's index and Vickers hardness decrease with the increase temperature. It indicates that the permanent plastic deformation of RB-SiC ceramics is mainly responsible for the indentation size effect and the reduction of hardness at elevated temperature. Both material softening and plastic deformation will contribute to the indentation creep at elevated temperature as shown in the load-displacement curves. The elastic modulus decreases with the increase of temperature due to increase of contact depth as a result of less elastic recovery. In the indentation test for calculating fracture toughness, only radial-median cracks are identified by the relationship between crack length and applied load at all temperatures, although the fracture mode observed at the indent corner changes from transgranular at room temperature to intergranular at elevated temperature. As more energy is consumed by intergranular facture and cracking-healing takes place due to oxidation, only short crack length appears in the indentation test which implies an increase of fracture toughness with the increase of temperature. However, this tendency has an exception at the highest temperature of 1200 °C. This is because the free Si softening in RB-SiC specimen fails to resist crack propagation at extremely high temperature. Consequently, the crack length increases again which leads to the increase of the calculating fracture toughness at the highest temperature. These variations of hardness, elastic modulus and fracture toughness with temperatures will account for the possible change of material removal regimes occurred in some thermal-involved hybrid machining of RB-SiC ceramics

    Molecular cloning and expression analysis of adiponectin and its receptors (AdipoR1 and AdipoR2) in the hypothalamus of the Huoyan goose during different stages of the egg-laying cycle

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    Multiple amino acid sequence alignment of the Huoyan goose adiponectin protein with other vertebrate species. The colour black denotes 100 % conserved sequences, and the colour grey indicates non-conservative sequences. Gaps (−) were introduced to maximize the alignment. Sequences for the alignment were obtained from GenBank (accession numbers are in brackets): Anas platyrhynchos (ADA68839.1); Ovis aries (AHV91023.1); Canis lupus familiaris (BAD15362.1); Felis catus (BAF52934.1); Gallus (AAX40986.1); Homo sapiens (NP_004788.1); Meleagris gallopavo (XP_010714799.1); Mus musculus (NP_033735.3); and Sus scrofa (ABQ95350.1). (TIFF 3483 kb

    Surface and subsurface damage of reaction-bonded silicon carbide induced by electrical discharge diamond grinding

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    Reaction-bonded silicon carbide (RB-SiC) ceramic, one of the best candidates for large optical mirrors, is difficult to machine because of its high hardness and brittleness. A hybrid process called electrical discharge diamond grinding (EDDG) exhibits potential for improving the machinability of RB-SiC by combining electrical discharge machining (EDM) and diamond grinding. However, this hybrid process leads to damages that differ from those in conventional processes owing to the simultaneous actions of EDM and diamond grinding. In the present study, surface and subsurface damages induced by the interactions between EDM and diamond grinding during the EDDG of RB-SiC were examined. The effect of the discharge energy was considered. The surface and subsurface topographies and microstructures were characterized via scanning electron microscopy, Raman spectroscopy, and transmission electron microscopy. The EDM and grinding zones exhibited distinctive surface topographies and different dominant material removal mechanisms. An increase in the discharge energy facilitated ductile removal of the material and decomposition of SiC. Thus, a thinner subsurface damage layer was obtained compared with that in the less-thermally affected zone. The decomposed C and material migration tended to increase with the discharge energy. Owing to the interactions between EDM and diamond grinding, the subsurface was a mixture of amorphous/crystalline C, polycrystalline/nanocrystalline SiC, and a crystalline SiC matrix

    Spatial Heterogeneity Can Lead to Substantial Local Variations in COVID-19 Timing and Severity

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    Standard epidemiological models for COVID-19 employ variants of compartment (SIR) models at local scales, implicitly assuming spatially uniform local mixing. Here, we examine the effect of employing more geographically detailed diffusion models based on known spatial features of interpersonal networks, most particularly the presence of a long-tailed but monotone decline in the probability of interaction with distance, on disease diffusion. Based on simulations of unrestricted COVID-19 diffusion in 19 U.S cities, we conclude that heterogeneity in population distribution can have large impacts on local pandemic timing and severity, even when aggregate behavior at larger scales mirrors a classic SIR-like pattern. Impacts observed include severe local outbreaks with long lag time relative to the aggregate infection curve, and the presence of numerous areas whose disease trajectories correlate poorly with those of neighboring areas. A simple catchment model for hospital demand illustrates potential implications for health care utilization, with substantial disparities in the timing and extremity of impacts even without distancing interventions. Likewise, analysis of social exposure to others who are morbid or deceased shows considerable variation in how the epidemic can appear to individuals on the ground, potentially affecting risk assessment and compliance with mitigation measures. These results demonstrate the potential for spatial network structure to generate highly non-uniform diffusion behavior even at the scale of cities, and suggest the importance of incorporating such structure when designing models to inform healthcare planning, predict community outcomes, or identify potential disparities

    GCF2-Net: global-aware cross-modal feature fusion network for speech emotion recognition

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    Emotion recognition plays an essential role in interpersonal communication. However, existing recognition systems use only features of a single modality for emotion recognition, ignoring the interaction of information from the different modalities. Therefore, in our study, we propose a global-aware Cross-modal feature Fusion Network (GCF2-Net) for recognizing emotion. We construct a residual cross-modal fusion attention module (ResCMFA) to fuse information from multiple modalities and design a global-aware module to capture global details. More specifically, we first use transfer learning to extract wav2vec 2.0 features and text features fused by the ResCMFA module. Then, cross-modal fusion features are fed into the global-aware module to capture the most essential emotional information globally. Finally, the experiment results have shown that our proposed method has significant advantages than state-of-the-art methods on the IEMOCAP and MELD datasets, respectively

    Preparation of nano-selenium from chestnut polysaccharide and characterization of its antioxidant activity

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    Chestnut is widely cultivated and has high nutritional value due to its richness in polysaccharides. In order to improve the antioxidant activity of chestnut polysaccharide, chestnut polysaccharide (CP) was extracted by ultrasonic-assisted water extraction and alcohol precipitation and purified by cellulose DEAE-52 exchange and Sephadex G-100 chromatography in this study. CP isolates were characterized by I2-KI reaction, three-strand helical structure analysis, infrared spectrum analysis, and nuclear magnetic resonance detection. The results showed that CP is a pyrylan sugar with triple helical structure and connected by α-glycosidic bonds, with sugar residues 1,4-α-D-Glcp, 1,6-α-D-Galp, 1,5-α-L-Araf, 1,4-α-L-Rhap, and 1,4-β-D-Glcp in the CP backbone. After purification, the branching structure, rod, and spherical structure were significantly increased, with reduced lamellar structure. The in vitro scavenging rates of CP at 10 mg·mL−1 against DPPH, hydroxyl radicals, and ABTS were 88.95, 41.38, and 48.16%, respectively. The DPPH free radical scavenging rate of purified polysaccharide fraction CP-1a was slightly enhanced, and the other rates showed a small decrease. Selenized chestnut polysaccharide (CP-Se) was prepared using nano-selenium method. The selenization method was optimized and stable Se-CP was obtained. When the concentration was 5 mg·mL−1, Se-CP had significantly higher scavenging abilities 89.81 ± 2.33, 58.50 ± 1.60, and 40.66 ± 1.91% for DPPH, hydroxyl radical, and ABTS radicals, respectively, than those of CP. The results of this study provide insight into the effects purification and selenization of chestnut polysaccharide on antioxidant activity, and also provide a theoretical basis for the development of chestnut polysaccharide for use in functional foods or health products
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