bluuebunny/crossref_metadata_2025 huggingface dataset:
Controllable Synthesis of Pt Functionalized Black Phosphorus (BP) Nanocomposite for High Performance NOx Gas Sensor
Authors: Liang Ying , Bi Hongmei
Published: March 2021

Compared with bulk material-based sensors, functional sensors fabricated with nanomaterials have many advantages, such as high sensitivity, multifunctional integration, low power-dissipation, and low cost. Black phosphorus (BP) is a two-dimensional (2D) crystal material, which has a
higher molecular adsorption energy, tunable direct band gap, high carrier mobility, ambipolar characteristics, and high current on/off ratio. In this paper, BP bulk was ground into powder, and then the powder was dispersed in dimethylformamide (DMF) to obtain two-dimensional BP nanosheets
solution. Afterwards, the black phosphorus nanosheets and H2PtCl6 solution were mixed to obtain the Pt functionalized BP nanocomposite by one-step reduction method. Pt nanoparticles were dispersed on the surface of BP nanosheets with highly uniform size. The Pt functionalized
BP nanocomposite exhibited a high response of 2.19 to 10 ppm NOx in a short period of 1.93 s at room temperature. The detection limit was as low as 30 ppb. The Pt functionalized BP nanocomposite will be useful for precise detection of NOx.
Effect of Short-Term Exposure to Titanium Dioxide Nanoparticles on Intestinal Absorption of Glucose by Ex Vivo Everted Rat Gut Sac Model
Authors: Wang Yun , Chen Zhangjian , Chen Shi , Zhuo Lin , Zhao Lin , Jia Guang
Published: March 2021

Titanium dioxide nanoparticles (TiO2 NPs) as food additives were widely found in various foodrelated products, especially in high-sugar foods. The daily intake of TiO2 NPs in the diet may therefore expose the small intestine to TiO2 NPs and affect its
physiological functions, including the absorption of nutrients. It is speculated that TiO2 may cause serious health hazards by increasing sugar uptake. To explore this possibility, transport of glucose from small intestine was studied using an everted gut sac model prepared from
small intestine of young healthy male SD rats. The translocation of TiO2 NPs and the morphological changes of small intestine were also observed after exposure of intestinal lumen to TiO2 NPs for 2 h. The results showed that TiO2 NPs can enter into enterocyte
but hardly cross the intestinal epithelium. No change on microstructure of gut epithelia and expression of glucose transporter was found, and there is no obvious impact on intestinal absorption and metabolism of glucose. These results suggest that short-term exposure to TiO2 NPs
has little influence on intestinal absorption of glucose. More attention should be paid to the chronic effect of dietary consumption of TiO2 NPs on nutrient absorption.
Advances in Land Surface Models and Indicators for Drought Monitoring and Prediction
Authors: Peters-Lidard Christa D. , Mocko David M. , Su Lu , Lettenmaier Dennis P. , Gentine Pierre , Barlage Michael
Published: March 2021

Millions of people across the globe are affected by droughts every year, and recent droughts have highlighted the considerable agricultural impacts and economic costs of these events. Monitoring the state of droughts depends on integrating multiple indicators that each capture particular aspects of hydrologic impact and various types and phases of drought. As the capabilities of land surface models and remote sensing have improved, important physical processes such as dynamic, interactive vegetation phenology, groundwater, and snowpack evolution now support a range of drought indicators that better reflect coupled water, energy, and carbon cycle processes. In this work, we discuss these advances, including newer classes of indicators that can be applied to improve the characterization of drought onset, severity, and duration. We utilize a new model-based drought reconstruction to illustrate the role of dynamic phenology and groundwater in drought assessment. Further, through case studies on flash droughts, snow droughts, and drought recovery, we illustrate the potential advantages of advanced model physics and observational capabilities, especially from remote sensing, in characterizing droughts.
Effects of MJO Vertically Tilted Structure on Its Phase Speed from the Moisture Mode Theory Perspective
Authors: Hu Feng , Li Tim
Published: March 2021

The effect of vertically tilted structure (VTS) of the MJO on its phase propagation speed was investigated through the diagnosis of ERA-Interim reanalysis data during 1979–2012. A total of 84 eastward propagating MJO events were selected. It was found that all MJO events averaged throughout their life cycles exhibited a clear VTS, and the tilting strength was significantly positively correlated to the phase speed. The physical mechanism through which the VTS influenced the phase speed was investigated. On the one hand, a stronger VTS led to a stronger vertical overturning circulation and a stronger descent in the front, which caused a greater positive moist static energy (MSE) tendency in situ through enhanced vertical MSE advection. The stronger MSE tendency gradient led to a faster eastward phase speed. On the other hand, the enhanced overturning circulation in front of MJO convection led to a stronger easterly/low pressure anomaly at the top of the boundary layer, which induced a stronger boundary layer convergence and stronger ascent in the lower troposphere. This strengthened the boundary layer moisture asymmetry and favored a faster eastward propagation speed.
Evaluation of Patterns in Access to Breast Cancer Care and Breast Cancer Presentation in a Safety Net Patient Population
Authors: Choe Erica , Park Hayoung , Hembrick Ma’at , Dauphine Christine , Ozao-Choy Junko
Published: March 2021

Background

While prior studies have shown the apparent health disparities in breast cancer diagnosis and treatment, there is a gap in knowledge with respect to access to breast cancer care among minority women.

Methods

We performed a retrospective analysis of patients with newly diagnosed breast cancer from 2014 to 2016 to evaluate how patients presented and accessed cancer care services in our urban safety net hospital. Patient demographics, cancer stage, history of breast cancer screening, and process of referral to cancer care were collected and analyzed.

Results

Of the 202 patients identified, 61 (30%) patients were younger than the age of 50 and 75 (63%) were of racial minority background. Only 39% of patients with a new breast cancer were diagnosed on screening mammogram. Women younger than the age of 50 ( P < .001) and minority women ( P < .001) were significantly less likely to have had any prior screening mammograms. Furthermore, in patients who met the screening guideline age, more than half did not have prior screening mammograms.

Discussion

Future research should explore how to improve breast cancer screening rates within our county patient population and the potential need for revision of screening guidelines for minority patients.
Social spider optimization algorithm for tuning parameters in PD-like Interval Type-2 Fuzzy Logic Controller applied to a parallel robot
Authors: Humaidi Amjad J , Najem Huda T , Al-Dujaili Ayad Q , Pereira Daniel A , Ibraheem Ibraheem Kasim , Azar Ahmad Taher
Published: March 2021

This paper presents control design based on an Interval Type-2 Fuzzy Logic (IT2FL) for the trajectory tracking of 3-RRR (3-Revolute-Revolute-Revolute) planar parallel robot. The design of Type-1 Fuzzy Logic Controller (T1FLC) is also considered for the purpose of comparison with the IT2FLC in terms of robustness and trajectory tracking characteristics. The scaling factors in the output and input of T1FL and IT2FL controllers play a vital role in improving the performance of the closed-loop system. However, using trial-and-error procedure for tuning these design parameters is exhaustive and hence an optimization technique is applied to achieve their optimal values and to reach an improved performance. In this study, Social Spider Optimization (SSO) algorithm is proposed as a useful tool to tune the parameters of proportional-derivative (PD) versions of both IT2FLC and T1FLC. Two scenarios, based on two square desired trajectories (with and without disturbance), have been tested to evaluate the tracking performance and robustness characteristics of proposed controllers. The effectiveness of controllers have been verified via numerical simulations based on MATLAB/SIMULINK programming software, which showed the superior of IT2FLC in terms of robustness and tracking errors.
Montgomery and informed consent during Covid-19: Pneumatic retinopexy versus pars plana vitrectomy or scleral buckling for retinal detachment repair
Authors: Kiew G , Poulson AV , Newman DK , Alexander P , Snead MP
Published: March 2021

Recent reports suggest that the use of an outpatient-based procedure (pneumatic retinopexy, PR) for retinal detachment repair should be encouraged within the UK, especially in light of Covid-19 and possible restrictions/competing demands on access to operating theatres. It is therefore essential that patients receive comprehensive information about the risks and benefits of this approach compared with a formal surgical repair either by pars plana vitrectomy (PPV) and/or scleral buckling (SB). We report a retrospective case series of retinal detachments (RD) satisfying the strict selection criteria for PR but who were managed with formal surgery. Single-operation success rate for PPV/SB at six months follow-up was 93.8% in our study, higher than published primary success rates for PR (60–80%). When counselling patients for possible PR, the ease, speed and potentially reduced co-morbidity of an outpatient-based procedure needs to be balanced against its significantly higher failure rate in comparison with primary PPV/SB.
The Role of Death Anxiety and Self-Esteem in Suicide Attitudes
Authors: Kheibari Athena , Cerel Julie
Published: March 2021

The persistent stigmatization of suicide calls for a careful examination of the thought processes involved in perceptions of suicide. Hence, the present study is the first to apply terror management theory (TMT) and use experimental methods to examine whether reminders of death lead to increased stigma towards suicide and whether self-esteem moderates these stigmatized reactions. Consistent with the predicted effect of the death anxiety and self-esteem hypothesis, findings revealed that, for respondents with low self-esteem, thinking about their own death led to more stigma, less willingness to intervene, and allocated less money to a suicide prevention organization as compared to those who did not think about death. Findings from this study could have important implications for how we understand the psychological underpinnings of stigma and the role of death anxiety in hostile attitudes and decreased altruism – especially for mental health professionals working with individuals affected by suicide.
Locked Up and Locked Out: Client Perspectives on Personal Relationships While in Compulsory Drug Treatment
Authors: Petersson Frida J. M. , Berg Karin E. , Skårner Anette
Published: March 2021

This qualitative study explores clients’ perspectives on their personal relationships while in compulsory drug treatment. Interviews with 31 participants (14 female and 17 male) were conducted at four compulsory treatment institutions for adults who use drugs in Sweden. Taken together, our study reveals that clients in general had to struggle to maintain social relationships due to strict restrictions on their interpersonal contact and communication. Feelings of isolation and anxiety characterized much of their relationships during the treatment period, with emotional withdrawal commonly described as a way to cope. Moreover, some participants expressed shame and guilt over the pain and suffering they had subjected their family members to through their drug use, feelings that put additional strain on the contact. The emotionally and socially significant relationships described by our interviewees provide links to other personal roles and settings than those prescribed by the institution. At the studied institutions, however, little attention was given to this relational dimension of the clients’ situation. Based on the results of the present study, possibilities for improvement of compulsory drug treatment are discussed.
Changes in Family Roles and Subjective Well-Being among Japanese Adults
Authors: Hara Yuko
Published: March 2021

Research in Western countries has demonstrated that marriage is associated with improved well-being, and parenthood with decreased well-being, for both men and women. However, less is known about whether the associations are universal for both genders across countries. Using nine waves of panel data and fixed effects models, this study examines the relationship between changes in family roles and subjective well-being of men and women in the highly gendered social context of Japan. Well-being was assessed across two domains: self-rated health and mental health. The results broadly support the protective effect theory, which posits that marriage itself has a positive effect on well-being; however, no association was observed between becoming a wife and self-rated health. Contrary to what previous research predicts, only men’s self-rated health negatively responds to transition to parenthood. These findings highlight the importance of country context and gender differences in the significance of family obligations.
Thymoma with a feeding vessel from coincident coronary–pulmonary artery fistulas
Authors: Matsuzaki Kanji , Imai Akito , Konishi Taisuke , Ichimura Hideo , Kobayashi Keisuke , Watanabe Yasunori
Published: March 2021

We report a rare case of a 68-year-old man with thymoma and coronary–pulmonary artery fistulas. The thymoma was 66 × 51 × 88 mm in size and accompanied by a feeding vessel originating from the coronary–pulmonary artery fistulas. We performed total thymectomy and resection of coronary–pulmonary artery fistulas at the same time, which has not been reported in the literature. The fistulas along with the left main trunk were successfully resected while temporarily transecting the main pulmonary artery. This strategy was a useful option for obtaining a good field of vision around the left main trunk behind the main pulmonary artery.
Assessing the Impacts of Weather on Pedestrian Signal Activity at 49 Signalized Intersections in Northern Utah
Authors: Runa Ferdousy , Singleton Patrick A.
Published: March 2021

A deeper understanding of how weather variables affect pedestrian volumes is important, as active travelers are an essential part of a sustainable transportation system. Pedestrian data are limited for investigating the impacts of weather on walking levels, with most studies having data at only a couple of locations. Pedestrian actuation data (from push-buttons at traffic signals) overcomes this limitation. The Utah Department of Transportation archives pedestrian push-button press data for use in its Automated Traffic Signal Performance Measures system. In this study, pedestrian actuation data was used as a proxy for walking activity and weather data was collected from the National Oceanic and Atmosphere Administration. Using 15 months of daily time series data in Cache County, the impacts of weather on pedestrian signal activity were examined at 49 signalized intersections, using a log-linear time series regression analysis with categorical step-wise weather variables. The findings revealed that snow depth had the most frequent negative effect on walking activity. Snowfall (> 0.6 in.) also tended to have negative impacts when significant. Very hot maximum temperatures (≥ 90°F) were associated with lower pedestrian activity at around one-third of signals. Very low minimum temperatures (< 20°F) were also associated with lower pedestrian activity. Precipitation had a negative effect on walking levels, but at only a few signals. The study’s key findings offer implications for multimodal transportation planning (winter maintenance, shade trees, etc.) and traffic signal operations.
Framings of Food Waste: How Food System Stakeholders Are Responsibilized in Public Policy Debate
Authors: Mesiranta Nina , Närvänen Elina , Mattila Malla
Published: March 2021

Food waste is a global sustainability issue that demands that multiple stakeholders participate in solving it. This article examines how different food system stakeholders are held responsible in the policy debate related to food waste reduction. The study adopts a framing approach, paying attention to the construction and negotiation of what is going on in the food waste–related public policy debate. The data consist of documents generated as a result of food policy development processes in Finland. The authors identify four framings—eco-efficiency, solidarity, safety, and appreciation—within which the issue of food waste is presented differently and different stakeholders responsibilized. The framings reveal the nature of food waste as a boundary object, a flexible and open-ended object that has different context-dependent meanings. The study extends marketing literature on responsibilization by investigating several stakeholders beyond consumers. Additionally, considering food waste a boundary object sheds light on how stakeholders, even those with conflicting interests, can debate policy measures collaboratively. Finally, the authors outline policy implications related to each framing.
Development of a novel meniscal sheet scaffold and its effectiveness for meniscal regeneration in a rabbit defect model
Authors: Ikeda Kuniaki , Otsuki Shuhei , Okuno Nobuhiro , Sezaki Shunsuke , Nakagawa Kosuke , Miyamoto Yuki , Okamoto Yoshinori , Wakama Hitoshi , Okayoshi Tomohiro , Neo Masashi
Published: March 2021

This study evaluated the biomechanical strength of a novel two-layer meniscal sheet scaffold (MSS) consisting of polyglycolic acid and poly-Llactic acid/caprolactone and investigated meniscal healing using wrapping treatment for meniscal defect model in a rabbit. The ultimate failure load of the MSS was determined using a tensile testing machine, in vitro. A 2-mm cylindrical defects were created at the medial meniscus of rabbit knees (n = 40). Each knee was assigned to one of two groups. The defect group was not treated and the MSS group underwent wrapping treatment with MSS. Menisci were harvested at 2, 4, 8, and 12 weeks post-implantation. The regenerated meniscus and defect size were evaluated using macrophotographs. Ishida scores for regenerated tissue were determined using Safranin-O/Fast Green staining. Immunohistochemical analysis of Ki-67 for cell proliferation, anti-type I and II collagen antibodies for structure of the regenerated tissue was elucidated. Medial femoral cartilage was stained with Safranin-O/Fast Green and evaluated with Osteoarthritis Research Society International (OARSI) scores. The strength of MSS was maintained over 90% from initial time point to 4 weeks after hydrolysis and over 60% of the strength remained at 8 weeks. The surface area of the meniscus was larger and the defect size smaller in the MSS group than in the defect group at 8 and 12 weeks. Ishida scores revealed that the MSS group improved significantly compared to that of the defect group at all postsurgery time points evaluated. Ki-67 positive cell ratio was significantly higher in the MSS group. OARSI score of the defect group was significantly higher and the defect group showed progressive degeneration in the articular cartilage from 8 to 12 weeks. Overall, wrapping meniscus defects with MSS was useful for accelerating meniscal healing from an early stage and beneficial for tissue regeneration and promoting extracellular matrix maturation.
The Endemic Amid the Pandemic: Seeking Help for Violence Against Women in the Initial Phases of COVID-19
Authors: Sorenson Susan B. , Sinko Laura , Berk Richard A.
Published: March 2021

During the first months of the COVID-19 pandemic, governments instituted a series of measures to control the spread of the virus. The measures were widely believed to increase women’s risk of violent victimization, most of which is by an intimate partner. We examined help-seeking during this period in a large U.S. city and used an interrupted time series analysis to assess the effects of three government interventions on domestic violence and sexual assault hotline calls and on “911” calls regarding domestic violence, assault, and rape. Declaration of an emergency appeared to reduce victim calls to the rape crisis hotline and the few “911” calls about rape. School closure was associated with a reduction in “911” calls about assault and rape and victim calls to the domestic violence hotline. Implementation of stay-at-home orders was associated with a gradual increase in domestic violence hotline calls. Although “911” calls regarding assault fell by nearly half, calls to police for domestic violence were unchanged. In sum, there was a decrease in help-seeking for sexual assault and assault in general but not for domestic violence during the initial phases of the COVID-19 outbreak. The analysis underscores the importance of distinguishing between the violence itself, calls to police, and calls to helplines when claims are made about changes over time in violence against women. The opportunities and constraints for each can differ widely under usual circumstances, circumstances that were altered by public health interventions related to the pandemic.
Self-silencing Mediates the Relationship Between Rejection Sensitivity and Intimate Partner Violence
Authors: Inman Elizabeth M. , London Bonita
Published: March 2021

Intimate partner violence, including physical, psychological, and sexual violence, affects over one-third of Americans and is particularly common among college students. Previous work has found links between rejection sensitivity and aggressive or hostile behavior (i.e., perpetration) in intimate relationships, but this construct has only been tested as a predictor of violence in an all-male sample. A related body of work has found relationships between self-silencing and rejection sensitivity, and between self-silencing and both hostile and ingratiating behavior. The purpose of this study was to bridge these related literatures and examine the relationship between rejection sensitivity and intimate partner violence experiences and the role of self-silencing as a possible mediator. To test these relationships, we collected survey data from a sample of college students ( N = 410) at a large university in the northeast United States. Using mediation analyses, we found that rejection sensitivity predicted intimate partner violence victimization (i.e., being the target of violence) through self-silencing. Similarly, rejection sensitivity predicted intimate partner violence perpetration (i.e., being violent toward one’s partner) through self-silencing. Neither gender nor race significantly moderated either path of the models. Implications of this study include incorporating individual difference variables in intimate partner violence research and programming.
Sexual Assault Victimization: Latinx Identity as a Protective Factor for Sexual Minorities
Authors: Gilmore Amanda K. , Walsh Kate , López Cristina , Fortson Kennicia , Oesterle Daniel W. , Salamanca Nashalys K. , Orchowski Lindsay M. , Davis Kelly Cue
Published: March 2021

Sexual assault victimization is an experience that impacts many college students, and rates differ based on ethnicity and sexual minority status. However, little is known about the impact of the intersectionality of Latinx and sexual minority identities on sexual assault severity among college students. The current study examined past year sexual assault victimization severity based on sexual orientation and Latinx identities among a random sample of college students ( n = 506). Further, factors associated with past year sexual assault victimization severity were examined among sexual minority participants ( n = 170). Among all college students, identifying as a cisgender woman, sexual minority, or having a more severe sexual assault history was associated with higher past year sexual assault victimization severity. Further, among sexual minorities, identifying as Latinx or having fewer drinks per week were associated with less severe past year sexual assault victimization. Although preliminary, this finding suggests a need for future research to examine potential cultural factors associated with Latinx populations that may serve as protective factors for sexual assault victimization among college students.
Maternal Worry About Infant Weight and its Influence on Artificial Milk Supplementation and Breastfeeding Cessation
Authors: DiTomasso Diane , Wambach Karen Ann , Roberts Mary B. , Erickson-Owens Debra A. , Quigley Aimee , Newbury Jessica M.
Published: March 2021

Background

Maternal worry about infant weight has inconsistently been reported as a breastfeeding barrier. Weight monitoring is a critical tool to assess adequacy of infant feeding. Yet, little is known about the intensity of maternal worry about infant weight or associated breastfeeding outcomes.

Research aims

To examine (1) the frequency and intensity of maternal worry about infant weight; (2) the relationship between worry about weight and use of artificial milk; and 3) the relationship between worry about weight and breastfeeding cessation.

Methods

A prospective cross-sectional design was used. A questionnaire was completed by women in the United States ( N = 287) from 12 web-based maternal support groups.

Results

Sixty-three percent of women ( n = 182) had some worry about infant weight. Participants breastfeeding for the first time had more worry ( p = .035). Participants still breastfeeding had less worry about weight compared to those who had stopped (67%, n = 147 vs. 41%, n = 28). Exclusive breastfeeding participants had less worry ( p < .001) compared to those who supplemented with artificial milk. Increased worry was associated with the use of artificial milk within 1 week of birth ( p < .001) and early breastfeeding cessation ( p < .001).

Conclusions

Worry about weight is a significant breastfeeding barrier. It is associated with first time breastfeeding, less exclusive breastfeeding, use of artificial milk, and earlier breastfeeding cessation. Lactating mothers need anticipatory guidance about expected neonatal weight changes and interventions to help relieve worry about infant weight.
Does Social Media Engagement Translate to Civic Engagement Offline?
Authors: Piatak Jaclyn , Mikkelsen Ian
Published: March 2021

People increasingly engage in politics on social media, but does online engagement translate to offline engagement? Research is mixed with some suggesting how one uses the internet maters. We examine how political engagement on social media corresponds to offline engagement. Using data following the 2016 U.S. Presidential Election, we find the more politically engaged people are on social media, the more likely they are to engage offline across measures of engagement—formal and informal volunteering, attending local meetings, donating to and working for political campaigns, and voting. Findings offer important nuances across types of civic engagement and generations. Although online engagement corresponds to greater engagement offline in the community and may help narrow generational gaps, this should not be the only means to promote civic participation to ensure all have a voice and an opportunity to help, mobilize, and engage.
Flow behavior of skewed vortex generators on a backward-facing ramp
Authors: Cheawchan Atcha-uea , Wen Yiming , Teo Zhen Wei , Ng Bing Feng , New Tze How
Published: March 2021

The impact of skewness angle on the effectiveness of vortex generators (VGs) and the behavior of streamwise vortices on flow separation behind a backward-facing ramp (BFR) with a sharp transition were experimentally investigated using surface oil flow visualizations, planar and stereoscopic particle image velocimetry measurements. Counter/corotating streamwise vortices were generated by a set of boundary layer-type rectangular VG located upstream of the BFR that comprised a flat- and 30-inclined sections with different skewness angles of 10°, 20°, and 30°. Local Reynolds number based on the VG location was Rex ≈ 3 × 106. Results show that the reattachment length was reduced by ∼45% when the VG was located five times its height ahead of the transition. Additionally, the behavior of the vortex core generated by the left vane displayed strong dependence on the skewness angle, whereby its vorticity magnitude and vortex instability increase with the skewness angle. Circulation magnitude and vortex radius of the left vortex core are also observed to be physically larger and less stable. In contrast, the vortex core produced by the right vane displays opposite behavior as the skewness angle increases. Lastly, the vortex core location is observed to fluctuate more in the vertical direction than horizontal direction.
Aerodynamics of a half-rotating wing in hovering flight: An integrated study
Authors: Li Qian , Yuan Jiwei , Shen Huan , Deng Jiaguo , Jakobi Timothy R , Ravi Sridhar , Wang Xiaoyi , Ji Aihong
Published: March 2021

This study introduces a new quasi-flapping wing driving mechanism based on a half-rotating mechanism which is capable of pure rotational flapping rather than the more traditional oscillatory flapping method. Lift models for half-rotating wing (HRW) aircraft in hovering flight are proposed based on the kinematics of a HRW prototype and the flow characteristics near the surface of its wing. Alongside further analytical expressions for lift based on kinematic extractions, computational models and a novel lift validation mechanism are used to reinforce the aerodynamic characteristics of the HRW in hovering flight. The aerodynamics of the HRW are experimentally assessed for different wing layouts and wing materials. Results indicate that the flow field generated by the motion of the wing arranged symmetrically on both sides of the body interfere with each other, causing the average lift coefficient of the paired-wing HRW to be less than that of the single-wing HRW. The average lift coefficient of the flexible wing is larger than that of the rigid wing. In addition, the average lift of the flexible wing increases with increasing flexural compliance within a particular range. Lift forces in different flight conditions are calculated using derived formulas alongside representative computational models, through which the derivation of lift variation for the HRW in hovering flight is validated. The theoretical lift curves show reasonable agreement with numerical simulation results in terms of the time course over one stroke cycle. The mechanisms of the HRW for generation and shedding of vortices in hovering flight are further revealed in computed flow field characteristics results. The velocity vectors of the flow field between the HRW and the symmetrically rotating wing indicate that the HRW with asymmetric rotation can generate lift force effectively. The velocity difference between the wing and the fluid is the key factor influencing the structure of generated vortices. In detailed three-dimensional (3D) vortex flows, our computational fluid dynamics study shows that a horseshoe-shaped vortex is first generated in the early downstroke. The horseshoe-shaped vortex subsequently grows into a doughnut-shaped vortex ring, with a jet stream appearing in its core which forms the downwash. The doughnut-shaped vortex ring eventually elongates into a long arc-shaped wake vortex ring. A large increasing lift force is generated during the upstroke, most likely due to the stable distal attached vortices; and in accordance with this, downwash becomes evident in the vortex ring during the downstroke.
Fast cooperative angular trajectory planning for multiple on-orbit service spacecraft based on the Bezier shape-based method
Authors: Fan Zichen , Huo Mingying , Qi Ji , Xu Song , Sun Kang , Qi Naiming
Published: March 2021

In this article, a fast cooperative obstacle avoidance angular trajectory planning method is presented for multiple on-orbit service (OOS) spacecraft, which can obtain the spatial angular trajectories of multiple spacecraft in a considerably short time. For multiple OOS spacecraft equipped with the manipulator, under the constraints of the maximum control moment, multiple obstacles, dynamics, and geometry, the Bezier shape-based (SB) method is used to rapidly generate the cooperative obstacle avoidance attitude angular trajectories of all OOS spacecraft at the same time. The superiority of the proposed method is proved by comparing the results of Bezier SB method and the finite Fourier series (FFS) SB method under the same initial conditions. To further verify the effectiveness of the proposed method, the results of the Bezier method are substituted into the Gauss pseudospectral method (GPM) as the initial values to further optimize the angular trajectories in the simulation. Simulation results show that compared with the FFS SB method, the Bezier SB method can use shorter computation time to get the results of spacecraft attitude movement faster; compared with GPM, Bezier SB method only uses about 2% of computation time to get the results of movement time difference of only 2%. The method proposed in this article can be applied to complex space OOS missions, which requires multiple OOS spacecraft to rapidly realize the space obstacle avoidance attitude maneuver to complete cooperative operation missions.
Investigation on the influence of the structure parameters of blade tip recess on the performance of axial flow compressor
Authors: Yan Song , Chu WuLi
Published: March 2021

As one of the important components of an aero engine, the compressor plays an important role in improving the performance of the aero engine. The blade tip recess (BTR) has great potential and advantages in improving the performance of the compressor. It is very important to clarify the influence of the structure parameters of the BTR on the performance of the compressor. In this study, the two-dimensional results of the BTR were analyzed by using the method of variance analysis, and the two-dimensional calculation results of the BTR were used to guide the design of the BTR of axial flow compressor rotor. In the NASA Rotor 35, the influence rules of the structure parameters of BTR on the recess effect that was basically the same as the two-dimensional conditions. The optimization of the rotor BTR structure parameters may be achieved by the two-dimensional calculation. The flow field analysis showed the BTR can retard the growth rate of the blockage area of the leading edge of blade tip by weakening the tip clearance leakage flow intensity that delayed the occurrence of blade tip blockage and improved the aerodynamic stability of the rotor.
Electrical conductivity and rheological properties of carbon black based conductive polymer composites prior to and after annealing
Authors: Gao Qingsen , Liu Jingguang , Liu Xianhu
Published: March 2021

The effect of annealing on the electrical and rheological properties of polymer (poly (methyl methacrylate) (PMMA) and polystyrene (PS)) composites filled with carbon black (CB) was investigated. For a composite with CB content near the electrical percolation threshold, the formation of conductive pathways during annealing has a significant impact on electrical conductivity, complex viscosity, storage modulus and loss modulus. For the annealed samples, a reduction in the electrical and rheological percolation threshold was observed. Moreover, a simple model is proposed to explain these behaviors. This finding emphasizes the differences in network formation with respect to electrical or rheological properties as both properties belong to different physical origins.
A Collaborative Indigenous–non-Indigenous Partnership Approach to Understanding Participant Experiences of a Community-Based Healthy Lifestyles Program
Authors: Wild Cervantée E. K. , Rawiri Ngauru T. , Cormack Donna M. , Willing Esther J. , Hofman Paul L. , Anderson Yvonne C.
Published: March 2021

We describe the approach of an Indigenous–non-Indigenous research partnership in the context of a qualitative study which aimed to understand barriers and facilitators to engagement in a community-based healthy lifestyles program in Aotearoa/New Zealand. Informed by Kaupapa Māori research principles and by “Community-Up” research values, this collaborative approach between the mixed Māori–non-Māori research team effectively engaged with Māori and non-Māori families for in-depth interviews on participant experience, including with non-service users. “Community-Up” research principles allowed for a respectful process which upheld the mana (status, dignity) of the interview participants and the research team. Challenges included maintaining flexibility in our conceptions of ethnicity to reflect the complexity of modern family life in Aotearoa/New Zealand. We were committed to ongoing communication, awareness, and attention to the relationships that formed the basis of our research partnership, which allowed effective navigation of challenges and was critical to the study’s success.
Palliative Care Education During COVID-19: The MERI Center for Education in Palliative Care at UCSF/Mt. Zion
Authors: Rabow Michael W. , Keyssar Judith Redwing , Long Judith , Aoki Maki , Kojimoto Gayle
Published: March 2021

In the setting of the COVID-19 pandemic as well as the recognition of systemic racism in our institutions, the symptom management, emotional/psychological support and advance care planning at the core of palliative care—once considered “an extra layer of support” —have been revealed as instrumental to individuals, families, communities, and countries facing the threat of the global pandemic. In this article, we outline the primary palliative care education efforts of one palliative care education center (The MERI Center at UCSF/Mt Zion campus) and detail the critical adjustments necessary and opportunities found in the COVID crisis.
Quantitative Analysis of Deltoid Ligament Degradation in Patients With Chronic Ankle Instability Using Computed Tomographic Images
Authors: Ikuta Yasunari , Nakasa Tomoyuki , Sumii Junichi , Nekomoto Akinori , Adachi Nobuo
Published: March 2021

Background:

Rotational ankle instability (RAI) is associated with the faster onset of severe ankle osteoarthritis via dysfunction of the anterior talofibular ligament, calcaneofibular ligament, and deltoid ligament. No specific clinical examination is available for RAI, and diagnostic imaging has limitations in evaluating ligament degradation. This study investigated the deltoid ligament degeneration using Hounsfield unit (HU) values on computed tomography (CT) images.

Methods:

Patients were enrolled in this retrospective analysis if they had undergone magnetic resonance imaging (MRI) and CT scans of the ankle. The chronic ankle instability (CAI) group comprised 20 ankles with CAI (9 men, 11 women; mean age, 28.7 years) and the control group comprised 28 ankles (16 men, 12 women, mean age, 41.3 years). The average HU values of the deep posterior tibiotalar ligament (dPTL) that constitutes the deltoid ligament were measured on coronal CT images, and MRI results were used as a reference. All patients were subdivided based on the MRI findings of dPTL injury such as fascicular disruption, irregularity, and the loss of striation.

Results:

A strong negative correlation was identified between age and HU values for all patients (Spearman ρ = −0.63; P < .001). The mean HU values of the dPTL for participants aged <60 years were 81.0 HU for the control group (21 ankles) and 69.5 HU for the CAI group ( P = .0075). No significant differences in the HU values were observed for the dPTL among the MRI subgroups.

Conclusion:

In addition to the conventional imaging examination such as stress radiographs and MRI, HU measurements of CT images could be useful for quantitatively and noninvasively evaluating degenerative changes in the deltoid ligament for CAI patients to assist the diagnosis of RAI.

Level of Evidence:

Level III. case-control study.
Impact of Electronic Prescribing of Controlled Substances on Opioid Prescribing: Evidence From I-STOP Program in New York
Authors: Pylypchuk Yuriy , Parasrampuria Sonal , Smiley Carmen , Searcy Talisha
Published: March 2021

New York’s Internet System for Tracking Over-Prescribing (I-STOP) Act, requires prescribers in the state to electronically prescribe controlled substances (EPCS). We examine the effects of this mandate on prescribing patterns of opioids for Medicare Part D beneficiaries. Using 2014-2017 CMS Medicare Part D Prescriber Data, we apply a lagged dependent variable regression approach to identify the impact of I-STOP on the prescription of opioids. In the first year of implementation, the number of opioid prescriptions per prescriber decreased by 5.7 per year. The policy had a larger effect on the prescription of short-acting opioids and on prescribers prescribing medication for predominantly younger beneficiaries. Overall, I-STOP resulted in a reduction in the number of beneficiaries being prescribed opioids and in the number of opioid claims in the state of New York, suggesting positive implications for other states intending to curtail opioid overprescribing and misuse through the use of EPCS.
Interweaving in/on the Air: A Scripted Synthesis of Indigenous and Settler Knowledges for Environmental Protection in Resource Development
Authors: Takach Geo
Published: March 2021

The ever-rising threat of environmental catastrophe and the continuing displacement, dishonor, and attempted erasure of Indigenous Peoples and their traditional lands are linked by capitalism’s externalizing the costs of conquest, whether ecological or human. This work investigates efforts to address these intertwined issues of social, economic, and environmental justice through interweaving Indigenous and settler ways of knowing in resource-development projects in Canada. In seeking to dramatize the need for further informed and engaged public dialogue on how to redress the twin menaces of extractivism and colonization, this arts-based research unfolds as a script for a semi-satirical radio play or podcast. Here, our researcher seeks to explain research findings and advance environmental protection and decolonization on a radio talk show, only to be confronted by a skeptical host and a battery of opinionated guests reflecting real-world challenges to those two emancipatory goals. We close with a brief methodological reflection.
Social Media Preference and Condom Use Behaviors: An Analysis of Digital Spaces With Young African American Males
Authors: Burns Jade C. , Chakraborty Shawtaabdee , Saint Arnault Denise
Published: March 2021

Background. African American adolescents and young adults have an increased likelihood of engaging in risky sexual behaviors. With rising rates of sexually transmitted infections among this population, deeper consideration is now being focused on using social media to engage, educate, and improve sexual behavior in this group. Purpose. To determine why social media is useful and how it may affect the attitude, norms, and perceived behavioral control on condom use among young African American males (YAAMs) ages 18 to 21. Method. Group-depth interviews ( n = 41, mean age = 19, SD = 1.2) were conducted in metro Detroit to understand and describe the who, what, where, why, and how regarding social media use and preference among YAAMs) ages 18 to 21, and their condom use behaviors. Results. The most popular reasons for using social media were for educational purposes, entertainment, browsing the site, self-expression, seeking out or maintaining relationships with friends and family, and social justice. YouTube was stated as the easiest site to promote condom use education. YAAMs would seek out condom use education on social media sites if someone respected in the community or someone famous promoted condom use messages on the sites or if it was used to show where condoms were available for free or for purchase. Conclusion. Understanding how YAAMs use social media may help researchers design better questions to address disparities within this population. More important, it can help health care providers, families, and the community promote healthy behaviors and lifestyle changes among YAAMs.
Ideology, sense, and meaning: A theoretical-methodological approach
Authors: Coelho-Lima Fellipe , Varela Victor , Bendassolli Pedro F
Published: March 2021

This article discusses a theoretical-methodological approach aimed at overcoming some limitations of Marxism and cultural-historical psychology. The concepts of “ideology” proposed by Lukács and the “meaning-sense” by Vygotsky have been crisscrossed. The concept of ideology refers to ideas that have a social function of intervening in social conflicts by determining the praxes of individuals in their daily lives. Hence, ideology adopts language as a tool for its operationalization in the discourse. For Vygotsky, the smallest subdivision of a language is the word and, more specifically, its meaning. It transforms human thoughts into speech for communication and guidance of praxis. The appropriate meanings, present in the discourses, generate a process of re-elaboration in the sense by individuals through their experience ( perezhivanie). It is possible to approach both theoretical concepts by considering that meanings are elements that transmit ideologies from the social sphere to the individuals’ consciousness and influence their praxis. This understanding has methodological consequences and allows the use of meaning-senses as empirical elements for the analysis of ideology both in consciousness and daily life of individuals. This contributes to a discourse analysis that recognizes the dialectical feature of the individual–ideology relation.
Partisan bias in politicians’ perception of scandals
Authors: Schönhage Nanna Lauritz , Geys Benny
Published: March 2021

Do politicians perceive scandals differently when they implicate members of their own party rather than another party? We address this question using a between-subject survey experiment, whereby we randomly assign UK local councillors (N = 2133) to vignettes describing a major national-level scandal in their own party versus another party. Our results show that local politicians perceive a significantly larger impact of this national scandal on the national party image when it concerns their own party (relative to another party). When evaluating the same scandal’s impact on the local party image, no similar effect is observed. This suggests that local politicians tone down the local impact of a national scandal more when thinking about their own party. We suggest this derives from a form of motivated reasoning whereby politicians selectively focus on information allowing a more negative view of direct electoral opponents. These findings arise independent of the type of scandal under consideration.