bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods for Model Calibration under High Uncertainty: Modeling Cholera in Bangladesh
Authors: Ryckman Theresa , Luby Stephen , Owens Douglas K. , Bendavid Eran , Goldhaber-Fiebert Jeremy D.
Published: July 2020

Background. Published data on a disease do not always correspond directly to the parameters needed to simulate natural history. Several calibration methods have been applied to computer-based disease models to extract needed parameters that make a model’s output consistent with available data. Objective. To assess 3 calibration methods and evaluate their performance in a real-world application. Methods. We calibrated a model of cholera natural history in Bangladesh, where a lack of active surveillance biases available data. We built a cohort state-transition cholera natural history model that includes case hospitalization to reflect the passive surveillance data-generating process. We applied 3 calibration techniques: incremental mixture importance sampling, sampling importance resampling, and random search with rejection sampling. We adapted these techniques to the context of wide prior uncertainty and many degrees of freedom. We evaluated the resulting posterior parameter distributions using a range of metrics and compared predicted cholera burden estimates. Results. All 3 calibration techniques produced posterior distributions with a higher likelihood and better fit to calibration targets as compared with prior distributions. Incremental mixture importance sampling resulted in the highest likelihood and largest number of unique parameter sets to better inform joint parameter uncertainty. Compared with naïve uncalibrated parameter sets, calibrated models of cholera in Bangladesh project substantially more cases, many of which are not detected by passive surveillance, and fewer deaths. Limitations. Calibration cannot completely overcome poor data quality, which can leave some parameters less well informed than others. Calibration techniques may perform differently under different circumstances. Conclusions. Incremental mixture importance sampling, when adapted to the context of high uncertainty, performs well. By accounting for biases in data, calibration can improve model projections of disease burden.
Regionalism With and Without Metropolitanism: Governance Structures of Rural and Non-Rural Regional Intergovernmental Organizations
Authors: Rickabaugh Jay
Published: July 2020

While prior scholarship has investigated many tools for regional governance across the rural-to-urban spectrum, the literature on regional organizations (councils of governments, planning district commissions, etc.) has been dominated by metropolitan regions. As a result, we know very little about the plethora of these regional organizations serving rural local governments. The omission of rural regions as a control variable from this conversation limits our ability to determine what traits are truly intergovernmental across this spectrum and what traits are specific to metropolitan and rural regions. Using a new, nationwide database of Regional Intergovernmental Organizations (RIGOs) and original governance documents, I present two unexpected empirical similarities between rural and non-rural RIGOs. First, I demonstrate that the quantity and relative dominance of the local governments within the territorial footprint of rural and non-rural RIGOs are nearly identical when population is held constant. Given the smaller populations within most rural RIGOs, this finding raises serious questions about how limited capacity is diffused and the need for multijurisdictional collaboration in rural areas. Second, I demonstrate that rural and non-rural RIGOs do not substantially differ in the way representational rights are apportioned to local governments on RIGO governing boards. Both rural and non-rural RIGOs similarly balance institutional membership with population proportionality in these collective choice arrangements. This evidence supports a broader intergovernmental hypothesis that an individual local government’s representational rights on a RIGO board are more likely to result from relative size differences among members than facets specific to a city–suburb dynamic.
Külpe’s Imageless But Visionary Idea: That Vivid Visual Images Are “Centrally Excited Sensations” Which Are Constructed From “Imageless Thoughts”
Authors: Kunzendorf Robert
Published: July 2020

In the current article, Section 1 begins with the reconsideration of Külpe’s late-nineteenth-century thesis that all problem solving is based on “imageless thoughts,” from which conscious images are constructed by vivid imagers but not by non-imagers. Section 2 proceeds by reconsidering Bühler’s refined thesis that conscious images are constructed from imageless rules, and by considering the present author’s auxiliary thesis that constructed images serve to test newly developed rules for parsing percepts and generating images. Section 3 concludes by reconsidering Külpe’s psychophysiological thesis that vivid visual images are “centrally excited sensations” which are centrifugally constructed on the retina, in accordance with generative rules in the cortex. Twentieth and twenty-first century evidence in support of these theses is summarized throughout the article, in the hope that Külpe’s visionary thoughts lead to further research and testing.
Postoperative risk of pancreatic fistula after distal pancreatectomy with or without spleen preservation
Authors: Mazzola Michele , Crippa Jacopo , Bertoglio Camillo L. , Andreani Sara , Morini Lorenzo , Sfondrini Stefano , Ferrari Giovanni
Published: July 2020

Introduction:

Outcomes after distal pancreatectomy with or without splenectomy are controversial. The present study aims to investigate differences in short-term and long-term outcomes between spleen-preserving distal pancreatectomy (SPDP) and distal pancreatectomy with splenectomy (DPS).

Methods:

In this retrospective review of consecutive patients undergoing distal pancreatectomy with or without splenectomy from January 2011 until December 2017 for benign disease, the primary endpoint was to compare postoperative pancreatic fistula (POPF). The secondary endpoint was to compare duration of surgery, intraoperative blood loss, postoperative complications, length of hospital stay, and long-term outcomes.

Results:

Patients undergoing SPDP had a lower rate of POPF (13.6% vs 46.1%; p = 0.02). Patients undergoing SPDP (n = 22) were discharged earlier than patients undergoing DPS (n = 26) (8 [4–29] vs 12 [6.48] days; p = 0.003). No differences in other intraoperative and postoperative outcomes were found between groups.

Conclusion:

Patients undergoing SPDP developed fewer POPF and were discharged earlier compared to patients undergoing DPS.
HPV nonrelated endocervical adenocarcinoma in hereditary cancer syndromes
Authors: Carnevali Ileana , Di Lauro Eleonora , Pensotti Valeria , Sahnane Nora , Leoni Eleonora , Formenti Giorgio , Ghezzi Fabio , Sessa Fausto , Tibiletti Maria Grazia
Published: July 2020

Introduction:

The relationship between endocervical cancer and cancer susceptibility syndromes is not yet fully understood. We present 2 cases of endocervical cancer: 1 arising in a patient carrier with a pathogenic BRCA1 variant and the second detected in a Lynch syndrome family carrying the MSH2 germline pathogenic variant.

Case description:

Somatic analyses including loss of heterozygosity and fluorescent in situ hybridization demonstrated that the second hit in patient 1 is BRCA1-related. Mismatch repair somatic analyses in the second family demonstrated that the endocervical cancers of patient 2 and of her sister are MSH2-related. These data confirm the relationship between the pathogenesis of endocervical cancer and the presence of germline BRCA1 and MSH2 mutations.

Conclusions:

Our study confirms that gynecologic cancers including rare entities such as non–human papillomavirus–related endocervical cancer (NHPVA) are sentinels for inherited cancer syndromes. Endocervical cancer NHPVAs might be considered for cancer genetic counseling in order to improve cancer prevention. For this reason, the role of pathologists is particularly important for the correct identification of the cervical tumor site.
Impact of bedrock geochemistry on vegetation productivity depends on climate dryness in the Guizhou karst of China
Authors: Zhu Xinrong , Liu Hongyan , Wu Lu , Liang Boyi , Liu Feng , He Wengqi
Published: July 2020

The Guizhou karst area is one of the largest continuous areas of karst in the humid climate zone and is representative of karst landforms in China. Large portions of the karst system are characterized by extremely shallow soils underlain by weathered bedrock and water deficits are common. Although the distribution of ecosystem productivity is largely related to variations in the temperature and precipitation, the influence of the substrate in karst areas requires further exploration. We explored the relative importance of the bedrock geochemistry (characterized by the concentrations of Ca, Mg and Si) and climatic factors (temperature and precipitation) to explain the spatial variability in gross primary productivity (GPP) with various degrees of water deficit during the time period 2001–2015. Our results show that the impact of bedrock geochemistry is an important parameter in changing the original relationship between climate and the GPP. The bedrock geochemistry functioned as a “regulator” of the relation between climate and the GPP, which strengthened with decreasing climate favourability. The variations in GPP and surface water storage were significantly different when different elements (Ca, Mg or Si) were dominant. The Mg-rich regions showed the greatest annual variations in the GPP, whereas the Si-rich regions had the strongest surface water storage potential to support vegetation growth. The results of our study are important for systematically evaluating the effects of climate on vegetation productivity and provide a benchmark for global vegetation modelling predictions.
The influence of friendship on migraine in young adolescents: A social network analysis
Authors: Pan Yi-Ju , Chen Yu-Chun , Lu Shiang-Ru , Juang Kai-Dih , Chen Shih-Pin , Wang Yen-Feng , Fuh Jong-Ling , Wang Shuu-Jiun
Published: July 2020

Objective

The current study explored whether the chances of having migraine are influenced by a youth’s friendship with a migraineur.

Methods

The study was centered on a community-based non-referral cohort of eighth graders from two middle schools in Taiwan. Among the 642 recruited adolescent students, 610 (95%) (mean age 14.1 years, male ratio 51.2%) nominated three good friends and completed a validated headache questionnaire for migraine diagnosis at the follow-up survey 1 year later. To explore social influences on incident migraine, we used longitudinal statistical models to examine whether the development of migraine in one adolescent during the 1-year observational period was associated with that in his/her friends.

Results

Overall, 1700 social ties were established in the social network based on the reported lists of good friends. Randomization test for the homophily effect demonstrated that the students with migraine tended to cluster together in the social network even when those with incident migraine were also considered ( p = 0.003). Besides, when friendship choices were mutual, the relative risk of an adolescent becoming a migraineur was 3.26 (95% CI: 1.25–8.47, p = 0.015) if his/her friend became a migraineur (induction) during the 1-year observational period.

Conclusion

To the best of our knowledge, this is the first study to demonstrate that migraine may spread through social networks in young adolescents. Both homophily and induction effects are possibly contributory.
Relationship between Overconfidence and Risky Behavior among Ship Crew
Authors: Wang Ying , Shi Xin , Xu Dong
Published: July 2020

Human factors are a primary cause of maritime accidents. This paper explores the relationship between risky behavior and overconfidence among members of a ship crew. Data on confidence and risky behaviors were collected through experiments carried out on a navigation simulator and an associated questionnaire. Contingency table analysis and chi-square test were then performed to clarify the relationships between these variables. The results indicated that both overconfidence and underconfidence were potential causes of risky behaviors among crew members; the type of risky behavior undertaken was also found to be related to both overconfidence and underconfidence. Levels of confidence varied with individual characteristics such as age and sailing experience. The major findings were as follows. Crew members aged 25 years or younger were more likely to be overconfident; crew members with less sailing experience were more likely to be either highly overconfident or underconfident; highly overconfident and underconfident crew members were more prone to involvement in collisions; skill-based risky behaviors were most associated with underconfidence; rule-based risky behaviors were more likely to be exhibited by highly overconfident or underconfident crew members; knowledge-based risky behavior was primarily observed in highly overconfident crew members. This paper fills a current research gap by identifying the individual characteristics that induce risky behaviors, which will be beneficial in enabling the maritime sector to develop targeted interventions to prevent maritime accidents.
Stakeholders’ Ideas About Positive Aging for Latinos: A Conceptual Map
Authors: Piedra Lissette M. , Ridings John , Howe Melissa J. K. , Smith Jennifer L. , O’Brien Catherine , Howard Alexis , Conrad Kendon J.
Published: July 2020

Few studies explore the differences between diverse stakeholders’ understandings of what constitutes “positive aging” for Latino older adults. To address this gap, we worked with a 20-member steering committee (SC) of community stakeholders to collect concept mapping data from 38 scholars and community workers. We generated 90 statements related to positive aging from the literature and produced concept maps based on four different stakeholder groups’ ratings of them. All stakeholders prioritized “Financial Security,” but scholars marked “Spirituality” as least important whereas community workers rated it second highest. The design of programs for Latino older adults should reflect such differences.
The Clustering of Adverse Childhood Experiences in the Avon Longitudinal Study of Parents and Children: Are Gender and Poverty Important?
Authors: Lacey Rebecca E. , Howe Laura D. , Kelly-Irving Michelle , Bartley Mel , Kelly Yvonne
Published: July 2020

Previous research has demonstrated a graded relationship between the number of Adverse Childhood Experiences reported (an ACE score) and child outcomes. However, ACE scores lack specificity and ignore the patterning of adversities, which are informative for interventions. The aim of the present study was to explore the clustering of ACEs and whether this clustering differs by gender or is predicted by poverty. Data on 8,572 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC) were used. ALSPAC is a regionally representative prenatal cohort of children born between 1991 and 1992 in the Avon region of South-West England. ACEs included parental divorce, death of a close family member, interparental violence, parental mental health problems, parental alcohol misuse, parental drug use, parental convictions, and sexual, emotional, and physical abuse, between birth and 19 years. Latent class analysis was used to derive ACE clusters and associations between poverty, gender, and the derived classes tested using multinomial logistic regression. Five latent classes were identified: “Low ACEs” (55%), “Parental separation and mother’s mental health problems” (18%), “Parental mental health problems, convictions and separation” (15%), “Abuse and mental health problems” (6%), and “Poly adversity” (6%). Death of a close family member and sexual abuse did not cluster with other adversities. The clustering did not differ by gender. Poverty was strongly related to both individual ACEs and clusters. These findings demonstrate that ACEs cluster in specific patterns and that poverty is strongly related to this. Therefore, reducing child poverty might be one strategy for reducing ACEs.
Skills and Knowledge for Merchandising Professionals: The Case of the South African Apparel Retail Industry
Authors: Jacobs Bertha , Karpova Elena
Published: July 2020

This study explored skills and knowledge required for merchandising professionals to fulfill their roles and perform their responsibilities in the South African apparel retail industry. The apparel merchandising competency (AMC) framework was used as a theoretical foundation in this research. A phenomenological approach was followed to explore the perspective of professionals employed by South African retail companies. Semistructured, face-to-face, in-depth individual interviews were conducted with 16 merchandisers who had between 2 and 20 years of experience in the apparel industry. Atlas.ti software was used for data organization and analyses. Following the AMC framework, four topical areas emerged: (a) soft skills, (b) hard skills, (c) explicit knowledge, and (d) tacit knowledge. To fulfill their roles and perform their responsibilities, 8 soft skills, 7 hard skills, 10 explicit knowledge types, and 1 tacit knowledge type were identified as essential. Thick description of the findings using participant quotes and a graphical representation is presented.
The Exploration of the Modular System in Textile and Apparel Design
Authors: Chen Chanjuan , Lapolla Kendra
Published: July 2020

The aim of this design research is to explore modular shapes and interlocking systems for apparel design using research through practice approach. As a transformable design approach, modular design features small standardized units that can be independently combined in various configurations to create different forms and provide multiple functions. However, there has been little hands-on integration of methods for developing more fitted garment designs and incorporating visually appealing surfaces, such as prints, within a modular system. By adopting Bye’s description of a research through practice approach, the researchers for this study aimed to explore modular textile systems that would result in more fitted garments and aesthetically appealing surfaces. Through documenting and analyzing a range of data from the design process and outcome of four experimental designs, this study resulted in the development of advanced research through a Focused Knowledge Design Practice framework.
Essential Oil Use With Breast Imaging A Pilot Study
Authors: Weaver Cathrine , Yackzan Susan , Herron Rebecca , Nettro Alaina , Davies Claire
Published: July 2020

Purpose: To examine the following variables related to essential oil use: familiarity, enjoyment, influence on relaxation, intention for future use, and acceptance among women undergoing breast-imaging procedures. Design: A descriptive, exploratory study. Method: An investigator-designed questionnaire was used to gather demographic information and study variables ( N = 51). Data on age and scheduled procedure were collected. Data collected on essential oils included choice, anxiety, acceptance, familiarity, relaxation response, enjoyment with use, and intention to use in the future. Acceptance of essential oils was derived from the prompt included on the questionnaire “please tell us the reason you accepted the Essential Oil today.” Findings: Enjoyment with essential oils was high 97.9% ( n = 48), 76% ( n = 38) were familiar with their use, a majority 94% ( n = 48) of participants experienced some degree of relaxation following their use, and 94% ( n = 46) would continue their use in the future. Acceptance of essential oils was based largely on familiarity with their use. Conclusions: A majority of participants in this study enjoyed essential oils, were familiar with their use, experienced relaxation following use, and intended to use them in the future when undergoing breast-imaging procedures.
Reflexive Self-Identity and Work: Working Women, Biographical Disruption and Agency
Authors: Trusson Diane , Trusson Clive , Casey Catherine
Published: July 2020

The article examines how women workers reflexively shape their self-identities and work identities following a significant biographical disruption incurred by breast cancer diagnosis and treatment. Based on interviews with 22 women navigating their post-diagnosis life course, the article addresses participants’ challenges in their relationships with paid employment, their responses and self-identity narratives. It finds that women strive to revise and innovate their self-identity and work identity in the midst of personal and social constraints in working life. They craft their cancer disruptive experiences into new developments of who they are, and want to be, as persons and as workers. Multiple intersectional features of participants’ work-related self-identity are identified, including reassessment of priorities, capabilities and workplace relations.
When strategic uninformed abstention improves democratic accountability
Authors: Kato Gento
Published: July 2020

The recent development in formal studies of elections produced two sets of findings that question the custom to treat voter information as a prerequisite for competent democratic decision-making. One argues that uninformed abstention is an effective strategy to approximate informed electoral outcome, and another suggests that uninformed voters may motivate strategic political elites to improve accountability. This article bridges and extends these two findings by analyzing strategic incentives in the comprehensive voting model with abstention and its connection with electoral accountability. The proposed model offers a contextual explanation for two contrasting logic in uninformed abstention, delegation and discouragement, and shows that uninformed voting with abstention sometimes improves accountability. Furthermore, uninformed abstention is more effective in generating democratically preferred outcome under delegatory than discouraged context. The results make a significant addition to the existing accountability literature by providing a more general mechanism by which less voter information improves policy outcomes.
Strategic candidacy for political compromise in party politics
Authors: Ishihara Akifumi
Published: July 2020

We study political competition among parties with policy-motivated candidates and demonstrate two-party competition where one of them has no chance of winning in the general election. If there are multiple candidates in a party, then the party can nominate the representative contingent on who are the rivals in the general election. Given that the winning party takes such a strategy, the opponent party is willing to run even with no chance of winning the general election since policy compromises can be induced from the winning party. We further demonstrate that introducing primary elections into the nomination process may induce more ideological polarization or more moderation.
Cults of personality, preference falsification, and the dictator’s dilemma
Authors: Crabtree Charles , Kern Holger L , Siegel David A
Published: July 2020

We offer a novel rational explanation for cults of personality. Participation in a cult of personality is psychologically costly whenever it involves preference falsification, with the costs varying across individuals. We highlight two characteristics associated with lower individual costs of preference falsification: (i) loyalty to the regime and (ii) unscrupulousness. Different characteristics might serve the regime better in different roles. Using a simple formal screening model, we demonstrate that one’s participation in a cult of personality improves the dictator’s personnel decisions under a wide variety of circumstances. Decisions are most improved when subordinates’ characteristics that better enable cult participation are correspondingly valued by dictators. Dictators who can manipulate the costs that cult participants pay find it easiest to ensure that correspondence. Our model also highlights the importance to dictators of not believing their own propaganda, and their need to offer increasingly extreme acts of cult participation as old acts become normalized.
New soluble, transparent and heat-resistant poly(ether amide)s based on 10,10-bis[4-(4-aminophenoxy)-3-methylphenyl]-9(10H)-anthrone
Authors: Li Juan , Zhong Ming , Sang Xiao-Yan , Huang Zhen-Zhong
Published: July 2020

10,10-Bis[4-(4-aminophenoxy)-3-methylphenyl]-9(10 H)-anthrone, as a new aromatic diamine, was synthesized from 9(10 H)-anthrone by three-step procedure. Low-temperature polycondensation of this diamine with various aromatic dicarboxylic acid dichlorides produced a series of new cardo poly(ether amide)s with moderate to high inherent viscosities of 0.86–1.43 dL g−1 while the weight-average and number-average molecular weights were in the range of 48,600–59,800 and 29,800–35,600 g mol−1, respectively. All the polymers were readily soluble in polar solvents such as N, N-dimethylacetamide (DMAc), N, N-dimethylformamide, N-methyl-2-pyrrolidinone, dimethyl sulfoxide, and pyridine, and afforded transparent, flexible, and strong films upon casting from DMAc solvent. These polymers had glass transition temperatures of 254–297°C, 10% weight loss temperatures of 493–505°C, and char yields of 61–64% at 800°C in nitrogen. All polymers were amorphous and their films exhibited tensile strength of 80.7–101.4 MPa, elongation at break of 8.0–12.8%, and tensile modulus of 1.9–2.6 GPa. These polymers had low moisture uptake in the range of 2.13–4.02% and high transparency with an ultraviolet–visible absorption cutoff wavelength in the 322–375 nm range.
Synthesis of multielement phosphazene derivative and the study on flame-retardant properties of epoxy resin
Authors: Wang Lurong , Yang Baoping , Guo Yongliang , Zhang Yabin , Wang Niannian , Li Fuchong , Yu Hailong , Cui Jinfeng , Guo Junhong , Mu Bo , Tian Li
Published: July 2020

Herein, we have successfully synthesized phosphorus/nitrogen/silicon tri-elements compound phosphazene derivative hexa-[4-( N-(3-(triethoxysilyl)propyl)acetamide)phenoxy]cyclotriphosphazene (HNTPC) from hexachlorotriphosphazenitrile, methyl 4-hydroxybenzoate, and 3-triethoxysilylpropylamine, and it was used as an additive flame retardant in epoxy resin (EP). Then, the thermal stability and flame retardancy of the composite (HNTPC/EP) were tested. Thermogravimetric analysis showed that the presence of HNTPC made EP matrix decompose at a relatively low temperature, thus promoted the formation of a stable coke layer and protected the matrix from fire. Therefore, the amount of carbon residue was markedly increased at 800°C, indicating an outstanding condensed phase flame-retardant effect. Furthermore, various combustion test data manifested that the addition of HNTPC could significantly improve the flame-retardant performance of EP. In addition, the sample could pass the vertical burning tests (UL-94) V-1 grade when the addition amount was 10% and the limiting oxygen index value was 32.6%, the peak heat release rate and total heat release rate decreased by 40.0% and 21.5%, respectively. Besides, the results of scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy also showed that HNTPC can promote the formation of carbon layer and improved the flame-retardant property of EP. Finally, the condensed phase and gas phase synergistic flame-retardant mechanism of HNTPC was proposed.
Dielectric, thermally conductive, and heat-resistant polyimide composite film filled with silver nanoparticle-modified hexagonal boron nitride
Authors: Li Ruiyi , Lv Xiuwei , Yu Juan , Wang Xiaodong , Huang Pei
Published: July 2020

In this study, silver–polydopamine–hexagonal boron nitride (h-BN@Ag) particles were prepared using mussel chemistry and reducibility of catechol. The modified method was simple and eco-friendly. In addition, we prepared h-BN@Ag/polyimide (PI) composite films via in situ polymerization, the scraper method, and thermal imidization. Owing to the good dispersion of the h-BN@Ag filler particles in the PI matrix and the bridging role of the Ag nanoparticles, the thermal conductivities of the h-BN@Ag/PI composite films were higher than that of the pure PI film. The thermal conductivity of the h-BN@Ag/PI film with the filler content of 10 wt% was 0.382 W (m·K)−1, which was 108% higher than that of pure PI films (0.184 W (m·K) −1). Furthermore, the composite films presented extremely low dielectric permittivity and loss tangent. Moreover, the heat resistance index of the composite films (304.6°C) was higher than that of pure PI (294.3°C). Thus, h-BN@Ag/PI composite films could be promising electronic packaging materials.
Formulation of SiO2/oil nanolubricant for metal forming using hydrodynamic cavitation
Authors: Pang Hao , Ngaile Gracious
Published: July 2020

A novel hydrodynamic cavitation–based dispensing process was developed to disperse SiO2 nanoparticles into the base oil, and the effects of process parameters on dispersity and tribological properties of SiO2/oil nanolubricants were studied using the dynamic laser scattering and ring compression tests. With this process, nanolubricants with fine nanoparticles (139–1240 nm) were formulated. A mean particle size reduction of 78% was achieved in 60 min. This process can be scaled up for mass production with relative ease. The formulated SiO2/oil nanolubricants exhibited better tribological performance over that of base oil. Lubrication mechanisms of the SiO2/oil nanolubricant in metal forming were ascertained through analysis of the dispersity of nanolubricants and characterization of dents appearing on the surface of the deforming material. The study revealed the importance of formulating nanolubricants with specific particle size distribution that relate to the surface morphology of the deforming material. In this study, a nanolubricant with particle size of 3.6 μm exhibited better lubrication on ring samples with dent depth of 4.7 μm, implying that most nanoparticles were encapsulated in the dents facilitating hydrostatic lubrication.
Multi-domain integrated modeling and verification for the ball screw feed system in machine tools
Authors: Mei Zaiwu , Chen Liping , Ding Jianwan
Published: July 2020

An accurate dynamic model for the computer numerical control machine tool feed system is of great significance to improve the machining accuracy. However, the accurate dynamic model of the feed system is difficult to be established because its dynamic characteristics not only depend on the performance of subsystems, such as mechanical, electrical, and control, but also on the interaction between them. In order to solve this problem, a modular modeling method based on a non-causal connection is proposed in this article, and the multi-domain seamless integrated model for the ball screw feed system is established. First, the feed system is decomposed by modularization, and the interface models in each domain are defined. Then all the subsystems are modeled strictly, and the nonlinear characteristics of each subsystem are analyzed. Finally, the multi-domain seamless integrated model of the ball screw feed system is established by the non-causal connection of subsystem models, and the experiment is carried out to validate the system model. The experimental results show that the multi-domain seamless integrated model of the ball screw feed system established in this article can accurately reflect the dynamic characteristics of the real physical system, and has high prediction accuracy for the dynamic following error. It is of great significance to further study the multi-domain coupling characteristics and compensation control methods of the machine tool system.
Performance-threshold-based resilience analysis of system of systems by considering dynamic reconfiguration
Authors: Chen Zhiwei , Zhao Tingdi , Jiao Jian , Chu Jiayun
Published: July 2020

In recent years, system of systems resilience has been widely studied. System of systems has obvious resilience properties when considering dynamic reconfiguration in the following four parts: avoidance, survival, adaption and recovery. System of systems can be downgraded and recovered by reconfiguring resources to keep the performance output enough to satisfy the threshold under internal failure or external shocks. In other words, because of dynamic reconfiguration, system of systems has obvious characteristics of resilience. In this study, first, a new resilience model for systems and system of systems based on the performance threshold is proposed. Second, military system of systems is decomposed hierarchically, including system of systems–level, platform-level and system-level top-down, respectively. Third, a radar network of military system of systems is taken as a typical case. A performance model for a radar network under internal or external shocks is established based on the linear-Gauss-Poisson process in system of systems, and its parameters are discussed in detail. Finally, a typical 5-node radar network of formation air defense military system of systems is taken as an example to demonstrate proposed models and methods. The reliability and resilience loss are achieved by considering internal failure or external shocks, which can serve as a reference for evaluating and improving the effectiveness of system of systems.
Rapid CO2 laser processing technique for fabrication of micro-optics and micro-structures on fused silica materials
Authors: Zhao Linjie , Cheng Jian , Yin Zhaoyang , Yang Hao , Liu Qi , Tan Chao , Liao Wei , Chen Mingjun , Yuan Xiaodong
Published: July 2020

Micro-optics and micro-structures play important roles in the field of optics. A multi-step processing strategy with the combination of various processing technologies has been applied to fabricate micro-optics and micro-structures. However, the multi-step processing method is complex and expensive. In this work, a rapid CO2 laser processing technique is proposed to fabricate micro-optics and micro-structures on fused silica materials. First, high-power and short-pulse CO2 laser is used to achieve rapid prototyping of micro-optics and micro-structures with pre-designed geometry on fused silica. In this step, a maximum material removal rate of 1.53 mm3/min could be achieved with surface roughness better than 100 nm. Then, using the same CO2 laser source with reduced laser power density, the initially processed fused silica surface could be smoothed to improve the surface quality. By simulating the CO2 laser interaction with fused silica material, the formation mechanism of smooth surface is revealed, and the processing parameters for achieving smooth silica surface are proposed. The surface roughness of finally processed silica surface could reach 10.8 nm. Finally, as an application example of the processed two-step CO2 laser processing method, a micro-structure with special hexagonal shape on fused silica optics is successfully processed. The proposed rapid CO2 laser processing technique for the fabrication of micro-optics and micro-structures on fused silica materials can be realized with only one equipment, which can not only ensure the processing accuracy and efficiency but also reduce the processing cost.
New construction of cycloidal gear unit made of plastics
Authors: Biernacki Krzysztof
Published: July 2020

Cycloidal gears constitute the main working unit of the fluid power gerotor machine. The paper presents a way of increasing the load-carrying capacity of cycloidal unit made of plastic. The aim has been reached through design and material modifications. As a result of those modifications, a design concept of the cycloidal gear system, which is different from the structures previously produced, has been created. The introduced modifications are based on the theoretical analysis of stress and deformations that occur in cycloidal gears during their operation. The analysis was conducted by means of the finite element method. Although the main focus was on analyzing the mechanism behind the deformations, an attempt was also made at extending the application scope for finite element method. The analysis by means of finite element method has been conducted for plastic and steel at the same time. This is result of showed design in which plastics and steel form the construction together one integral part. As a result of the analysis, the maximum value of the working pressure at which hydraulic gerotor machines with plastic cycloidal gears can work was determined. Thanks to the use of the finite element method one can point out the way of introduction of plastics in hydraulic machines construction.
“This Is What a Mechanic Sounds Like”: Children’s Vocal Control Reveals Implicit Occupational Stereotypes
Authors: Cartei Valentina , Oakhill Jane , Garnham Alan , Banerjee Robin , Reby David
Published: July 2020

In this study, we explored the use of variation in sex-related cues of the voice to investigate implicit occupational stereotyping in children. Eighty-two children between the ages of 5 and 10 years took part in an imitation task in which they were provided with descriptions of nine occupations (three traditionally male, three traditionally female, and three gender-neutral professions) and asked to give voices to them (e.g., “How would a mechanic say . . . ?”). Overall, children adapted their voices to conform to gender-stereotyped expectations by masculinizing (lowering voice pitch and resonance) and feminizing (raising voice pitch and resonance) their voices for the traditionally male and female occupations, respectively. The magnitude of these shifts increased with age, particularly in boys, and was not mediated by children’s explicit stereotyping of the same occupations. We conclude by proposing a simple tool based on voice pitch for assessing levels of implicit occupational-gender stereotyping in children.
Association of MBL-2 gene polymorphisms with systemic lupus erythematosus: an updated meta-analysis and trial sequential analysis
Authors: Mahto Harishankar , Pati Abhijit , Sahu Sushil K , Sharma Hanuman Prasad , Padhi Archana , Panda Aditya K
Published: July 2020

Objectives

Mannose-binding lectin (MBL), an essential innate immune molecule, enhances the opsonization process and activates the complement system. Genetic variations at the promoter and coding region of the MBL-2 gene have been associated with susceptibility to systemic lupus erythematosus (SLE); however, reports remained inconsistent. The present study performs a meta-analysis of published peer-reviewed articles to draw a definitive conclusion.

Materials and Methods

Published peer-reviewed articles on the association of MBL-2 gene polymorphisms and SLE were screened on various databases such as PubMed (Medline), ScienceDirect, and Google Scholar. A total of 23 eligible articles were included in the present study, comprising 3074 SLE patients and 3985 controls. Genotype and/or allele data for MBL-2 polymorphisms (A > B, A > C, A > D, A > O, Y > X and H > L) were extracted and analyzed by Comprehensive Meta-Analysis software (CMA V3.1).

Results

The overall analysis revealed a significant association of MBL-2 (A > O) polymorphism with a predisposition to SLE in allele contrast ( p = 0.000; OR = 1.261), homozygous ( p = 0.005; OR = 1.482), heterozygous ( p = 0.004; OR = 1.247), dominant ( p = 0.000; OR = 1.303) and recessive ( p = 0.025; OR = 1.356) genetic comparison model. Similar results were also observed in the comparison of allele and the dominant genetic model of MBL-2 (A > B) polymorphism in overall (allele: p = 0.000, OR = 1.46, dominant: p = 0.001, OR = 1.31) and in the Asian cohorts (allele: p = 0.007, OR = 1.43, dominant: p = 0.008, OR = 1.32). Interestingly, MBL-2 (Y-221X) polymorphism exhibited protection against the development of SLE in heterozygous ( p = 0.005, OR = 0.619) and dominant genetic comparison ( p = 0.01, OR = 0.672) models.

Conclusions

MBL-2 variants (A > O and A > B) are associated with predisposition to SLE. Conversely, promoter polymorphism (Y-221X) offers protection against SLE development.
Infections in hospitalized children with newly diagnosed systemic lupus erythematosus in underresourced areas
Authors: Rianthavorn Pornpimol , Prurapark Pattareeya
Published: July 2020

Background

The administration of induction immunosuppressive therapy to children with newly diagnosed systemic lupus erythematosus (SLE) and concurrent infections can lead to unfavourable outcomes. This study was conducted to describe characteristics of infections occurring before the initiation of immunosuppressants in hospitalized children with newly diagnosed SLE in underresourced areas.

Methods

Medical records of paediatric patients with the diagnosis of SLE, who were admitted to a university-based hospital from 2002 to 2018, were reviewed. Only patients younger than 18 years of age with newly diagnosed SLE were included in the study. The primary outcome was infection before the administration of immunosuppressants. Logistic regression analysis was used to determine factors associated with infection and adjusted odds ratio (OR). The diagnostic accuracy of CRP was assessed.

Results

Infections were confirmed in 52/124 (41.9%) children. Pathogens were identified in 24 (46.2%) patients with bacterial predominance. The most common site was respiratory infections (36.5%). Fever and serosal involvement were more prevalent in patients with infection. Serum CRP levels were significantly higher in patients with infection than in those without infection (median 5.5 mg/L (interquartile range (IQR) 3.6–76.3 mg/L) vs. 3.5 mg/L (IQR 3.0–3.6 mg/L), p = 0.004). When a positive CRP level of >5 mg/L was used, positive CRP was found with a higher prevalence in patients with infection and was independently associated with infection (adjusted odds ratio (OR) = 28.6, 95% confidence interval (CI) 2.3–350.6; p = 0.009). Patients with infection had a longer hospital stay than patients without infection (median 20 days (IQR 13–25 days) vs. 15 days (IQR 9–24 days), p = 0.04). Sensitivity, specificity, positive predictive value and negative predictive value with 95% CI of CRP >5 mg/L were 62.5% (35.4–84.8%), 88.9% (65.3–98.6%), 80.3% (51.0–94.1%) and 76.6% (63.1–86.3%), respectively.

Conclusions

Infections were common among hospitalized children with newly diagnosed SLE. Children with infections had a prolonged course of hospitalization. Positive CRP was associated with a predisposition towards infection. However, the diagnostic accuracy of CRP requires further validation in a larger study.
Characterization of Chilean patients with sporadic colorectal cancer according to the three main carcinogenic pathways: Microsatellite instability, CpG island methylator phenotype and Chromosomal instability
Authors: Wielandt Ana María , Hurtado Claudia , Moreno C Mauricio , Villarroel Cynthia , Castro Magdalena , Estay Marlene , Simian Daniela , Martinez Maripaz , Vial Maria Teresa , Kronberg Udo , López-Köstner Francisco
Published: July 2020

Molecular classification of colorectal cancer is difficult to implement in clinical settings where hundreds of genes are involved, and resources are limited. This study aims to characterize the molecular subtypes of patients with sporadic colorectal cancer based on the three main carcinogenic pathways microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and chromosomal instability (CIN) in a Chilean population. Although several reports have characterized colorectal cancer, most do not represent Latin-American populations. Our study includes 103 colorectal cancer patients who underwent surgery, without neoadjuvant treatment, in a private hospital between 2008 and 2017. MSI, CIN, and CIMP status were assessed. Frequent mutations in KRAS, BRAF, and PIK3CA genes were analyzed by Sanger sequencing, and statistical analysis was performed by Fisher’s exact and/or chi-square test. Survival curves were estimated with Kaplan–Meier and log-rank test. Based on our observations, we can classify the tumors in four subgroups, Group 1: MSI-high tumors (15%) are located in the right colon, occur at older age, and 60% show a BRAF mutation; Group 2: CIN-high tumors (38%) are in the left colon, and 26% have KRAS mutations. Group 3: [MSI/CIN/CIMP]-low/negative tumors (30%) are left-sided, and 39% have KRAS mutations; Group 4: CIMP-high tumors (15%) were more frequent in men and left side colon, with 27% KRAS and 7% presented BRAF mutations. Three percent of patients could not be classified. We found that CIMP-high was associated with a worse prognosis, both in MSI-high and MSI stable patients (p = 0.0452). Group 3 (Low/negative tumors) tend to have better overall survival compared with MSI-high, CIMP-high, and CIN-high tumors. This study contributes to understanding the heterogeneity of tumors in the Chilean population being one of the few characterizations performed in Latin-America. Given the limited resources of these countries, these results allow to improve molecular characterization in Latin-American colorectal cancer populations and confirm the possibility of using the three main carcinogenic pathways to define therapeutic strategies.
Effect of a Nurse-Led Protocol on Time to Treatment of Partial Occlusions in Central Venous Access Devices in Pediatric Oncology
Authors: Hunter Allison , Cunningham K. Shantel , Yuen Carol , Jensen Kristen , Afzal Arfan , Benzies Karen
Published: July 2020

Central venous access devices (CVADs) are the standard of care in pediatric oncology. Occlusion is a common complication that can lead to delays in therapy, readmission, and CVAD removal and reinsertion. Early treatment of partial occlusions using a standardized protocol may restore patency and increase life span of CVADs. The objective of this study was to develop and evaluate a nurse-led protocol to manage partial CVAD occlusions in pediatric oncology and autologous bone marrow transplant patients. The protocol enabled nurses to manage partially occluded CVADs by administering thrombolytic therapy following an algorithm and patient-specific standing order. The primary outcome was time from recognition of the partial occlusion to instillation of a thrombolytic. Secondary outcomes were thrombolytic dwell time, number of complete occlusions, and CVAD life span. We used a quasi-experimental, after-only, nonequivalent control group design to compare patients not exposed (retrospective cohort, n = 137) and patients exposed (prospective cohort, n = 101) to the nurse-led protocol. Mann–Whitney U tests were used to compare time to treatment, dwell time, and CVAD life span between cohorts, and χ2 was used to compare the proportion of occlusions classified as complete. Time to treatment was significantly lower in the prospective cohort ( M = 99.9 minutes) versus the retrospective cohort ( M = 483.7 minutes), U = 1366.50, p < .01, as was thrombolytic dwell time, U = 282.50, p < .01. Proportion of complete occlusions and CVAD life span did not differ between cohorts. The nurse-led protocol was effective to manage partial CVAD occlusions in pediatric oncology patients.
Paid Leave and Maternal Depressive Symptoms After Childbirth: The Moderating Role of Perceived Fairness of the Division of Household Labor
Authors: Hwang Woosang , Jung Eunjoo , Shaw Andrea V. , Mestad Renee , Lane Sandra D.
Published: July 2020

We examined whether using paid leave is directly linked to employed mothers’ depressive symptoms. In addition, we examined the moderating effect of employed mothers’ perceived fairness of division of household labor (housework and childcare) on the above association. We collected data from 92 employed mothers who were eligible to take paid leave and returned to the workplace after childbirth in Upstate New York State area. Using hierarchical regression analyses, we found that employed mothers’ paid leave use was not significantly associated with their levels of depressive symptoms. However, perceived fairness of division of household labor moderated the above association. Specifically, when employed mothers took paid leave, they reported lower levels of depressive symptoms than those who did not take leave when they perceived that the division of household labor was fair to them.