bluuebunny/crossref_metadata_2025 huggingface dataset:
Delayed gangrene and amputation of penile glans after a religious circumcision in male child – A case report
Authors: Aiman Akram Syeda , Ansari Zuber , Akram Siddiqa
Published: March 2021

Circumcision is one of the most frequently performed surgical procedures in the world. Its complication rate is extremely low when performed by a trained surgeon, but the majority of circumcisions done for religious reasons in India, Africa, and Arab states are performed by traditional practitioners1 and have a high complication rate. We present the case of five-year-old boy who developed gangrene of the glans requiring amputation after such a procedure.
Comparing mental contrasting with implementation intentions against solution-focused and autonomous planning
Authors: Abdulla Adam , Woods Ruth
Published: March 2021

Research suggests that mental contrasting with implementation intentions (MCII) enhances commitment and goal attainment. However, most studies have used limited comparison conditions. The present study compared MCII against two other potentially effective approaches: autonomous planning (AP), and solution-focused planning (SFP). It was thought that condition would have an indirect effect on goal progress by affecting commitment. However, goal attainment expectancy was hypothesised to be a moderator such that MCII has positive effects when expectancy is high but negative effects when expectancy is low. Ninety-eight female students were randomly assigned to one of three conditions: 1) MCII, 2) AP, or 3) SFP. All students initially set themselves a goal for the coming week regarding personal projects. Mean commitment and goal progress were marginally higher in the MCII condition than in the AP and SFP conditions but the differences were not statistically significant and (as predicted) much smaller than in previous research. Expectancy did not appear to have a moderating effect. The apparent benefits of MCII were larger relative to AP than to SFP. Results suggest that MCII may sometimes be no more effective than other approaches to goal-setting and planning, particularly if they are evidence-based and carefully-designed. Implications for schools are addressed.
Stepping Outside the Echo Chamber: Is Intellectual Humility Associated With Less Political Myside Bias?
Authors: Bowes Shauna M. , Costello Thomas H. , Lee Caroline , McElroy-Heltzel Stacey , Davis Don E. , Lilienfeld Scott O.
Published: March 2021

In recent years, an upsurge of polarization has been a salient feature of political discourse in America. A small but growing body of research has examined the potential relevance of intellectual humility (IH) to political polarization. In the present investigation, we extend this work to political myside bias, testing the hypothesis that IH is associated with less bias in two community samples ( N1 = 498; N2 = 477). In line with our expectations, measures of IH were negatively correlated with political myside bias across paradigms, political topics, and samples. These relations were robust to controlling for humility. We also examined ideological asymmetries in the relations between IH and political myside bias, finding that IH–bias relations were statistically equivalent in members of the political left and right. Notwithstanding important limitations and caveats, these data establish IH as one of a small handful psychological features known to predict less political myside bias.
Visiting Migrants, Contesting Detention: An Overview of Community Visitation Programs and Advocacy for Immigrants inside U.S. Immigration Detention
Authors: Romero Luis A.
Published: March 2021

How do activists advocate for immigrants in U.S. immigration detention, given its closed and guarded structures? Providing advocacy for immigrants becomes difficult in detention as many people do not have the requisite skillset for legal advocacy, a prominent method in providing support to detained immigrants. In this article, I examine the Freedom for Immigrants’ Community Visitation Program (CVP) network, which organizes visits to detention sites, as one model by which people provide advocacy for detained immigrants. I base this on an analysis of CVP documents, websites, videos and reports, detained immigrant letters and statements, news stories, investigative reports, and secondary resources. Through this analysis, I find that CVPs organize volunteers by having a wide coverage of CVPs throughout the U.S. and manage visitation training programs. This allows volunteers to provide social and emotional support to detained migrants. Additionally, volunteers serve as advocates during instances of abuse occurring inside detention that may otherwise have remained invisible by rallying around detained migrants, as seen in the case of Laura Monterrosa. Visitation programs allow for an opening within the closed detention system for other people besides those living in its daily infrastructure and work to undo the complex detention system.
Family Visitation Patterns during Incarceration in Denmark
Authors: Anker Anne Sofie Tegner , Wildeman Christopher
Published: March 2021

While qualitative evidence has highlighted psychological benefits of visitation during incarceration, and quantitative evidence has linked visitation to better post-release outcomes for inmates, we know little about heterogeneity in visitation patterns and the factors shaping them. Using Danish administrative data on inmates incarcerated at least a year between 2004 and 2014 ( N = 5,441), we first examine average frequency and duration of family visits across the first year of incarceration and then describe five distinct visitation patterns using latent class analysis. Finally, we investigate what predicts visitation patterns.

The findings highlight that (a) there is substantial heterogeneity in the patterns of family visitation and (b) both individual-level and institution-level factors partially predict this heterogeneity. Parenthood, high pre-incarceration income, and long sentences were associated with high levels of visitation and being placed far from home and transferred between facilities were associated with a higher risk of receiving low or decreasing levels of visitation.
Satisfying Marital Relationship among Dual-Career Couples: A Validation Study
Authors: Ali Maheen Abid , Mahmood Zahid , Saleem Sadia
Published: March 2021

The aim of this study was to develop a culturally relevant scale of satisfying marriage for dual-career couples. In order to explore the phenomenology of satisfying marriage, 25 participants, 25–42 years of age, were interviewed and their responses were recorded. Responses were then collated and duplicate and vague items were discarded. The remaining responses were transformed into a four-point Likert scale to assess the content validity; 45 items constituted the Satisfying Marriage Scale (SMS). meaning] After expert validation by 13 experienced psychologists, the scale was administered to 250 married couples with age ranging from 21 years to 50 years (M = 31.40, SD = 6.27) to establish psychometric properties. meaning] SMS along with a demographic performa, Couple Satisfaction Index (CSI), and Multidimensional Scale of Perceived Social Support (MSPSS) were administered. Exploratory factor analysis (EFA) yielded three factors cooperation and coordination, mutual support, and mutual respect. The scale was found to have high internal consistency ( α = 0.95), and split-half reliability ( r = 0.81) with moderate levels of concurrent and construct validity. Results of the indigenous scale were further discussed in relevance to Pakistan’s cultural context.
Child Development Knowledge and Father Engagement: The Mediating Role of Parenting Self-efficacy
Authors: Connor Lisa A. , Stolz Heidi E.
Published: March 2021

Early father engagement is associated with numerous positive child outcomes including cognitive development, emotional regulation, and fewer problem behaviors. Various fathering programs attempt to encourage father engagement through teaching fathers about young children’s development and needs. This study examined 181 low-income fathers’ child development knowledge (self-perceived and objective) as predictors of father engagement (verbal stimulation, caregiving, and physical play) with infants. Additionally, parenting self-efficacy (PSE) was examined as a mediator. Results revealed that fathers’ self-perceived child development knowledge positively predicted engagement with infants (verbal stimulation and caregiving), but objective knowledge did not. PSE did not mediate the relationship between self-perceived knowledge and father engagement. These findings yield important implications for fathering research and interventions, suggesting that it may be particularly beneficial to increase fathers’ confidence in their ability to understand and meet their child’s needs rather than exclusively focusing on improving fathers’ knowledge of child development.
Exploring Normalization of Deviance among Perioperative Registered Nurses in the Operating Room
Authors: Wright M. Imelda , Polivka Barbara , Clark Paul
Published: March 2021

Normalization of deviance is a phenomenon in which individuals and teams deviate from what is known to be an acceptable performance standard until the adopted way of practice becomes normalized. In health care, this phenomenon erodes the safety culture, and it can be particularly concerning in high-risk work environments, such as the operating room (OR). The purposes of this study were to: (a) Explore the concept of normalization of deviance in the OR; (b) Identify reasons for normalization of deviance; and (c) Identify factors that protect against normalization of deviance.

This focused ethnographic study included a sample of 10 perioperative nurses who were interviewed. Our findings demonstrated that normalization exists in the OR. Reasons for normalization of deviance included productivity pressures, generalized complacency, complacency related to length of experience, social pressures, and negative acculturation. Factors that protect against normalization of deviance included nurse engagement and having supportive managerial relationships.
Percutaneous closure of native anterior mitral leaflet perforation under three-dimensional transesophageal echocardiography guidance
Authors: Chaturvedi Hemant , Rao Ravinder Singh
Published: March 2021

We are presenting a unique case of native anterior mitral leaflet (AML) perforation with severe mitral regurgitation leading to progressive dyspnea. Using real time three-dimensional transesophageal echocardiography, this case was accurately diagnosed and percutaneous closure has been done successfully with the device. Review of the literature showed successful transcatheter closure of AML perforation of only four cases, all post-operative status. So, it seems to be the first case of native AML perforation closure till date.
Associations between lifetime classic psychedelic use and markers of physical health
Authors: Simonsson Otto , Sexton James D , Hendricks Peter S
Published: March 2021

Background:

In recent years, there has been significant research on the mental health effects of classic psychedelic use, but there is very little evidence on how classic psychedelics might influence physical health.

Aims:

The purpose of the present study was to investigate the associations between lifetime classic psychedelic use and markers of physical health.

Methods:

Using data from the National Survey on Drug Use and Health (2015-2018) with 171,766 (unweighted) adults aged 18 or above in the United States, the current study examined the associations between lifetime classic psychedelic use and three markers of physical health (self-reported overall health, body mass index, and heart condition and/or cancer in the past 12 months) while controlling for a range of covariates.

Results:

Respondents who reported having tried a classic psychedelic at least once in their lifetime had significantly higher odds of greater self-reported overall health and significantly lower odds of being overweight or obese versus having a normal weight. The association between lifetime classic psychedelic use and having a heart condition and/or cancer in the past 12 months approached conventional levels of significance, with lower odds of having a heart condition and/or cancer in the past 12 months for respondents who had tried a classic psychedelic at least once.

Conclusion:

The results of the present study suggest that classic psychedelics may be beneficial to physical health. Future research should investigate the causal effects of classic psychedelics on physical health and evaluate possible mechanisms.
Validity of Surrogate Endpoints and Their Impact on Coverage Recommendations: A Retrospective Analysis across International Health Technology Assessment Agencies
Authors: Ciani Oriana , Grigore Bogdan , Blommestein Hedwig , de Groot Saskia , Möllenkamp Meilin , Rabbe Stefan , Daubner-Bendes Rita , Taylor Rod S.
Published: March 2021

Background

Surrogate endpoints (i.e., intermediate endpoints intended to predict for patient-centered outcomes) are increasingly common. However, little is known about how surrogate evidence is handled in the context of health technology assessment (HTA).

Objectives

1) To map methodologies for the validation of surrogate endpoints and 2) to determine their impact on acceptability of surrogates and coverage decisions made by HTA agencies.

Methods

We sought HTA reports where evaluation relied on a surrogate from 8 HTA agencies. We extracted data on the methods applied for surrogate validation. We assessed the level of agreement between agencies and fitted mixed-effects logistic regression models to test the impact of validation approaches on the agency’s acceptability of the surrogate endpoint and their coverage recommendation.

Results

Of the 124 included reports, 61 (49%) discussed the level of evidence to support the relationship between the surrogate and the patient-centered endpoint, 27 (22%) reported a correlation coefficient/association measure, and 40 (32%) quantified the expected effect on the patient-centered outcome. Overall, the surrogate endpoint was deemed acceptable in 49 (40%) reports ( k-coefficient 0.10, P = 0.004). Any consideration of the level of evidence was associated with accepting the surrogate endpoint as valid (odds ratio [OR], 4.60; 95% confidence interval [CI], 1.60–13.18, P = 0.005). However, we did not find strong evidence of an association between accepting the surrogate endpoint and agency coverage recommendation (OR, 0.71; 95% CI, 0.23–2.20; P = 0.55).

Conclusions

Handling of surrogate endpoint evidence in reports varied greatly across HTA agencies, with inconsistent consideration of the level of evidence and statistical validation. Our findings call for careful reconsideration of the issue of surrogacy and the need for harmonization of practices across international HTA agencies.
Locally advanced malignant solitary fibrous tumour successfully treated with conversion chemotherapy, operation and postoperative radiotherapy: a case report
Authors: Li Zhi-Ke , Liu Jie , Chen Chen , Yang Ke-Yi , Deng Yao-Tiao , Jiang Yu
Published: March 2021

Preoperative diagnosis of solitary fibrous tumour (SFT) may not provide a complete tumour picture and may be inaccurate. There is no standard treatment for locally advanced or metastasised malignant SFT (MSFT). Here, the case of a 17-year-old male patient with final pathology diagnosis of MSFT is reported. Preoperative biopsy pathology results suggested an Ewing sarcoma that was positive for CD99 antigen, vimentin, friend leukaemia integration 1 transcription factor, apoptosis regulator Bcl-2, and synaptophysin; and negative for CD34 antigen, S-100 protein (S-100), smooth muscle antigen, cytokeratin, and Wilms tumour 1 associated protein. The Ki67 positive rate was 8%, so the patient initially received eight cycles of conversion chemotherapy (vincristine, etoposide, ifosfamide and pirarubicin for one cycle, and vincristine, doxorubicin, and cyclophosphamide/ifosfamide and etoposide for 7 cycles in total). The tumour shrunk significantly and was surgically removed. The final pathology diagnosis was MSFT that was positive for CD99 and signal transducer and activator of transcription 6, and negative for CD34, tumour protein 63, S-100, desmin, and epithelial membrane antigen. Fluorescence in situ hybridization showed no gene translocation in EWS RNA binding protein 1, SS18 subunit of BAF chromatin remodelling complex or FUS RNA binding protein. The patient finally accepted adjuvant radiotherapy of 5600 cGy. Disease-free survival has been > 1 year, with no recurrence or metastasis detected to date. MSFT is rare and treatment for locally advanced or metastatic MSFT remains controversial. The efficacy of the present therapeutic strategy requires further research.
Rare submandibular gland metastasis of hepatocellular carcinoma: case report and review of the literature
Authors: Deng Sinan , Ruan Danping , He Jie
Published: March 2021

Hepatocellular carcinoma (HCC), the most common primary hepatic tumor, metastasizes in more than 50% of cases. However, metastasis of HCC to the submandibular glands is very rare. HCC rarely metastasizes to the salivary glands; only six cases of metastasis to the parotid gland have been reported in the English-language literature. Moreover, only one case of metastasis of HCC to the submandibular glands has been reported to date, and the affected patient died of hepatic failure. This clinical report describes a 55-year-old man who had undergone two surgeries for liver cancer and subsequently presented with a 2-week history of a right submandibular mass. We performed dissection of the right submandibular triangle, and metastatic HCC of the submandibular gland was diagnosed. Although HCC metastases to the oral cavity have been reported, this is only the second case of HCC metastasis to the submandibular gland. Fine-needle aspiration biopsy is recognized as a simple, direct approach for morphologic diagnosis of salivary gland lesions; however, histological and immunohistochemical examination of the surgical specimen remains necessary.
rpoB gene mutations in rifampin-resistant Mycobacterium tuberculosis isolates from rural areas of Zhejiang, China
Authors: Zeng Mei-Chun , Jia Qing-Jun , Tang Lei-Ming
Published: March 2021

Objective

The aim was to analyze genetic mutations in the rpoB gene of rifampin-resistant Mycobacterium tuberculosis isolates (RIFR-MTB) from Zhejiang, China.

Methods

We prospectively analyzed RIFR-associated mutations in 13 rural areas of Zhejiang. Isolates were subjected to species identification, phenotype drug susceptibility testing (DST), DNA extraction, and rpoB gene sequencing.

Results

A total of 103 RIFR isolates were identified by DST (22 RIFR only, 14 poly-drug resistant, 49 multidrug resistant, 13 pre-extensively drug resistant [pre-XDR], and 5 extensively drug resistant [XDR]) from 2152 culture-positive sputum specimens. Gene sequencing of rpoB showed that the most frequent mutation was S450L (37.86%, 39/103); mutations P280L, E521K, and D595Y were outside the rifampicin resistance-determining region (RRDR) but may be associated with RIFR. Mutations associated with poly-drug resistant, pre-XDR, and XDR TB were mainly located at codon 445 or 450 in the RRDR.

Conclusions

The frequency of rpoB RRDR mutation in Zhejiang is high. Further studies are needed to clarify the relationships between RIFR and the TTC insertion at codon 433 in the RRDR and the P280L and D595Y mutations outside the RRDR.
Sonographic findings of hepatic venous gas in association with spontaneous rupture of a Klebsiella pneumoniae liver abscess: a case report
Authors: Zheng Haining , Gu Chenxing , Jiang Suzhen , Liu Xiaona , Wang Xiaoqing , Wen Chaoyang
Published: March 2021

Hepatic venous gas (HVG) is a very rare ultrasonic finding, and it is defined as abnormal accumulation of gas in the hepatic venous system. Various diseases can cause HVG, and femoral venous catheter is the most common cause. We, herein, present the case of a 79-year-old female patient with HVG that was caused by spontaneous rupture of a Klebsiella pneumoniae liver abscess. This was first found by bedside ultrasonography. On the basis of the blood culture results, imipenem–cilastatin and cefoperazone sulbactam were administered and the effect was acceptable. After 41 days of antibacterial and symptomatic treatment in the hospital, the patient had recovered well and was discharged. All of the previous reports on HVG have been summarized by thoroughly reviewing the previous published work. Overall, this is the first patient with HVG in association with spontaneous rupture of a K. pneumoniae liver abscess, and it might provide insights for future studies regarding the treatment of this disease.
Combined pulsed-dye laser and medical therapy for treatment of cutaneous sarcoidosis lesions: a case report
Authors: Dong Wenxin , Li Caixia , Shi Yu , Zhang Wei
Published: March 2021

Sarcoidosis is a systemic granulomatous disease of unknown etiology that most frequently occurs in the lungs. However, cutaneous lesions are often the primary sign. Cutaneous sarcoidosis is difficult to treat, although different therapies have been applied. We herein report a case in which cutaneous sarcoidosis was treated with pulsed-dye laser (PDL) therapy along with oral administration of acitretin and hydroxychloroquine; no topical medications were applied. All patient details are de-identified. The treatment areas gradually improved after several courses of PDL therapy. This case illustrates that PDL therapy can serve as an auxiliary treatment for cutaneous sarcoidosis.
Occupational performance coaching for stroke survivors delivered via telerehabilitation using a single-case experimental design
Authors: Kessler Dorothy , Anderson Nicole D , Dawson Deirdre R
Published: March 2021

Introduction

Sustaining a stroke has a devastating, long-term impact on participation in everyday life. Despite the recognition of participation as a key outcome of stroke rehabilitation, there are few effective interventions that address participation. Occupational performance coaching is a promising intervention designed to improve participation among stroke survivors. Delivery of occupational performance coaching using telerehabilitation could improve access. This study examined the feasibility, acceptability and potential efficacy of telerehabilitation occupational performance coaching.

Method

A single-case experimental design was used. Six community-dwelling stroke survivors received 10 sessions of telerehabilitation occupational performance coaching over 16 weeks. We examined the feasibility and acceptability of telerehabilitation occupational performance coaching, improvement in performance and satisfaction with identified goals.

Results

Telerehabilitation occupational performance coaching was feasible and acceptable to deliver; participants who started the intervention completed it and reported high satisfaction and a strong therapeutic relationship. All participants experienced technological issues that required resolution. Goal-performance and/or satisfaction improved for five of six participants. Sixty-four percent of goals showed trends for improvement and 43% showed significant improvements.

Conclusions

Findings support the feasibility and acceptability of telerehabilitation occupational performance coaching, along with its efficacy for improving performance and satisfaction with performance of goals. Further research is needed to prove the effectiveness of telerehabilitation occupational performance coaching and to determine who may benefit most.
Black feminist intersectionality is vital to group analysis: Can group analysis allow outsider ideas in?
Authors: Nayak Suryia
Published: March 2021

This is the transcript of a speech I gave at an Institute of Group Analysis (IGA) event on the 28th November 2020 about intersectionality and groups analysis. This was momentous for group analysis because it was the first IGA event to focus on black feminist intersectionality. Noteworthy, because it is so rare, the large group was convened by two black women, qualified members of the IGA—a deliberate intervention in keeping with my questioning of the relationship between group analysis and power, privilege, and position. This event took place during the Covid-19 pandemic via an online platform called ‘Zoom’. Whilst holding the event online had implications for the embodied visceral experience of the audience, it enabled an international attendance, including members of Group Analysis India.

Invitation to the event: ‘Why the black feminist idea of intersectionality is vital to group analysis’

Using black feminist intersectionality, this workshop explores two interconnected issues:

• Group analysis is about integration of parts, but how do we do this across difference in power, privilege, and position?

• Can group analysis allow outsider ideas in? This question goes to the heart of who/ what we include in group analytic practice—what about black feminism?

If there ‘cannot possibly be one single version of the truth so we need to hear as many different versions of it as we can’ (Blackwell, 2003: 462), we need to include as many different situated standpoints as possible. Here is where and why the black feminist idea of intersectionality is vital to group analysis.

On equality, diversity and inclusion, intersectionality says that the ‘problems of exclusion cannot be solved simply by including black [people] within an already established analytical structure’ (Crenshaw, 1989: 140). Can group analysis allow the outsider idea of intersectionality in?
YouTube to Teach Central Lines, The Expert vs Learner Perspective
Authors: King Daniel , Davison Danielle , Benjenk Ivy , Heinz Eric , Vaziri Khashayar , Hawkins Katrina , Yamane David
Published: March 2021

Purpose:

Instructional videos of medical procedures can be a useful guide for learners, demonstrating proper and safe technique. Open publishing sites such as YouTube are readily accessible, however the content is not peer reviewed and quality of videos vary greatly. Our aim was to evaluate a learner’s ability to interpret the quality of openly published content by comparing their rating of the most popular central line insertion videos on YouTube to expert evaluations.

Method:

YouTube search results for “central line placement” sorted by views or relevance compiled a list of the four most common videos. A fifth gold standard video, published by the New England Journal, was included, however was not found in the top results. Eleven expert practitioners from varying medical specialties (Critical Care, Surgery, Anesthesia, & Emergency Medicine) evaluated the 5 videos, utilizing a 22-item Likert scaled questionnaire emphasizing: preparation, sterility, anatomy, technique, & complications. Videos were compared as a composite average of the individual items on the survey. The highest, lowest, and 3rd ranked videos were evaluated by 45 residents (“learners”) in varying specialties (Internal Medicine, Emergency Medicine, Surgery, Anesthesia) and post graduate year (PGY). Learners assessed the videos using the same scale. A Welch T-test assessed statistical significance between the two groups. Subgroup analysis compared experts against different PGY and specialty cohorts.

Results:

The lowest scored video among the experts and learners was the most popular on YouTube, with 858,933 views at the time of inclusion. Though lowest in rank, this video was judged higher by learners than the experts (2.63/5 vs 2.18/5, P = 0.0029). The 3rd ranked video by experts with 249,746 views on YouTube, was also rated higher by learners (3.77/5 vs 3.45/5, P = 0.0084). The gold standard video by NEJM had 320,580 views and was rated highest by both the experts and learners (4.37/5 vs 4.28/5, P = 0.518). Subgroup analysis showed similar results with learners rating the videos overall better than experts, this was particularly true in the PGY-1 subgroup.

Conclusion:

The most popular central line insertion video was the worst rated by both experts and learners. Learners rated all the videos better than the expert. YouTube videos demonstrating medical procedures including central line insertion should come from peer reviewed sources if they are to be incorporated into educational curriculum.
Adolescent Peers and Prevention: Network Patterns of Sexual Violence Attitudes and Bystander Actions
Authors: Banyard Victoria , A. Waterman Emily , M. Edwards Katie , Valente Thomas W.
Published: March 2021

Peer sexual violence is a significant social problem that affects adolescents and can lead to negative mental health and developmental consequences. Peers are a significant source of influence for adolescent behavior. For example, recent studies show training teens to be bystanders can be an effective prevention strategy to reduce peer violence and harassment. Peers can also promote risky behaviors including substance use and violence. The current study examined how sexual violence-specific risk and protective attitudes (e.g., denial of peer sexual violence and positive peer prevention norms) and behaviors (alcohol use and bystander actions to prevent peer sexual violence) clustered within peer networks cross-sectionally and over time. Participants were 1,499 7th−10th graders who took surveys during an academic year and who reported having opportunity to take action as bystanders to peer sexual violence. Participants took surveys 6 months apart online in schools. Questions included nomination of best friends to capture information about peer networks. Social network analyses indicated that there was weak but significant clustering of positive prevention attitudes such as bystander denial and marginal clustering on reactive bystander behaviors to address sexual assault. For comparison, alcohol use and academic grades were analyzed and found to also cluster in networks in these data. These findings suggest that for early adolescents, peer bystander training may be influential for some key bystander attitudes and reactive sexual violence prevention behaviors as individual behaviors are not independent of those of their friends.
An Intergenerational Exploration of Breastfeeding Journeys Through the Lens of African American Mothers and Grandmothers
Authors: Muse Mary M. , Morris Jerome E. , Dodgson Joan E.
Published: March 2021

Background

Many individuals comprise a nursing mother’s social support network. Grandmothers within African American families, historically, have played a vital role in the transmission of culture. Understanding intergenerational perspectives within African American families related to infant feeding and scholarship about breastfeeding is critical, given the breastfeeding patterns among African American women.

Research aim

To describe intergenerational perspectives within African American families, where the mother has successfully breastfed.

Methods

A prospective, cross-sectional, qualitative design using semi-structured interviews was used. African American nursing mothers and maternal grandmothers ( N = 14) residing in the Metro–St. Louis area, who reflected economic and educational diversity, were recruited. Inductive and iterative data analysis, framed by Black Feminist Theory allowed for emerging patterns reflecting the participants’ voices.

Results

Three of the six (50%) grandmother participants had breastfed. The majority of the mother participants were married ( n = 5; 62.5%) and had a college degree ( n = 4; 50.0%) or a high school diploma ( n = 1; 12.5%); and four (50.0%) had received the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Three patterns emerged: (a) intergenerational connections; (b) changes in breastfeeding experiences over time; and (c) going with the flow (referring to the choice to work within the constraints of one’s circumstances). Grandmothers supported mothers’ breastfeeding decisions; grandmothers who had breastfed benefited from the updated information the mothers provided; and grandmothers who did not breastfeed acquired new breastfeeding knowledge, which informed the ways they supported the mothers.

Conclusion

The intergenerational perspectives surrounding breastfeeding within African American families participating in this study offer future research directions.
Being a Deliveroo Rider: Practices of Platform Labor in Nijmegen and Berlin
Authors: Timko Peter , van Melik Rianne
Published: March 2021

On-demand delivery platforms have become a common feature of urban economies across the globe. Noted for their hyper-outsourced, “lean” business models and reliance on independent contractors, these companies evade traditional employer obligations while still controlling workers through complex algorithmic management techniques. Using food delivery platform Deliveroo as a case-study, this paper investigates the diverse array of practices that on-demand workers carry out in order to enact this new platform labor arrangement in different spatial contexts. One of us conducted an auto-ethnographic project, working as a Deliveroo Rider in Nijmegen and Berlin for a period of nine months. Additionally, we interviewed 13 fellow platform workers. The findings reveal the motley, contingent, and conditional ways in which on-demand labor comes together on the ground. The paper concludes with discussing the uneven distribution of these practices across locations and social groups, and the sometimes contradictory impacts they have on the structure of platform labor.
An exploration into the opportunities and constraints for career progression into leadership roles for School Business Managers in the state sector in England
Authors: Marchant Josephine
Published: March 2021

Drawing on data from 116 survey responses by School Business Managers, and 7 semi-structured interviews with education professionals carried out between October 2017 and February 2018, this article reports on findings from a research project focussing on the opportunities and constraints for career progression into leadership roles for School Business Managers (SBMs) in the state sector in England. The article considers the differing roles and responsibilities of SBMs, how leadership is perceived in schools, the visibility of the SBM role, career aspirations of the SBMs who were surveyed, and the perceived constraints to progression to leadership roles. Analysis of the data was carried out using an inductive research approach using mixed methods. Snowballing was used to obtain a meaningful sample size for survey responses. Interviewees were chosen on the basis of judgement sampling. The sampling design for the survey and the interviews was one of non-probability. Findings suggest that leadership roles for SBMs do exist but that there are considerable constraints to these being achieved, not least the lack of appetite amongst SBMs to do so.
Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites
Authors: Ouyang Yuting , Zhang Qiu , Liu Xiukun , Hong Ruan , Xu Xu , Lu Shaorong , Li Yuqi
Published: March 2021

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.
Experimental and numerical investigation of a supersonic inlet with double S-bend diffuser
Authors: Zhang Jinsheng , Yuan Huacheng , Wang Yunfei , Huang Guoping
Published: March 2021

Design of a supersonic inlet with double S-bend diffuser was developed. Numerical simulation and wind tunnel experiment were carried out to investigate the aerodynamic performance and variable geometric rules of the inlet. The result indicates that the variable geometry scheme adopted solves the contradiction between starting performance at low Mach number and aerodynamic performance at high Mach number. The inlet works normally and stably over a wide speed range. At design point, the total pressure recovery coefficient reaches 0.47. In addition, two different kinds of inlets with double S-bend diffuser and single S-bend diffuser were studied. Compared with the double S-bend diffuser, the total pressure recovery coefficient of the single S-bend diffuser is higher at low Mach number (Ma0 < 3) and lower at high Mach number (Ma0 > 3). With the increase of backpressure, shock train mainly moves upstream along the low-energy flow region in the diffuser. For the double S-bend diffuser, shock train will first move along the lower corner and then along the upper corner. For the single S-bend diffuser, it will only move along the upper corner. The strong secondary flow of the double S-bend is the main reason for the above phenomenon.
Design of finite-time guidance law based on observer and head-pursuit theory
Authors: Zhu Chenqi
Published: March 2021

In order to improve the guiding accuracy in intercepting the hypersonic vehicle, this article presents a finite-time guidance law based on the observer and head-pursuit theory. First, based on a two-dimensional model between the interceptor and target, this study applies the fast power reaching law to head-pursuit guidance law so that it can alleviate the chattering phenomenon and ensure the convergence speed. Second, target maneuvers are considered as system disturbances, and the head-pursuit guidance law based on an observer is proposed. Furthermore, this method is extended to a three-dimensional case. Finally, comparative simulation results further verify the superiority of the guidance laws designed in this article.
Evaluation of pilot and quadcopter performance from open-loop mission-oriented flight testing
Authors: Zahed Muhammad Junayed Hasan , Fields Travis
Published: March 2021

Unmanned aircraft systems (UAS) have experienced tremendous growth through both commercial (i.e., toys and videography) and defense avenues. The rapid expansion, particularly in the consumer market, has outpaced regulatory bodies. Certification to commercially operate such vehicles currently requires the successful completion of a knowledge examination, without the need to physically operate a vehicle. The focus of the work presented herein is on quantifying the pilot and multi-rotor performance in an attempt to provide quantitative metrics that can be used to establish training and certification for pilots and aircraft. Test pilots were categorized based on their experience level, and the quadrotor unmanned aircraft was categorized based on the flight control mode. Cross-track command (CTC) and path error (PE) were calculated as potential time-domain metrics to quantify pilot and quadcopter performance. Individual binary logistic regression models were developed to identify the pilot experience level (PEL) and UAV control level (UCL) from the decision tree outcomes. A verification test case was included to evaluate the established regression models. Results show that the models can evaluate pilot and quadcopter performance individually, which can be used to develop the pilot training curriculum and/or evaluate pilot effectiveness in specific flight scenarios.
Trajectory shaping guidance law design using constraint-combining multiplier
Authors: Seo Min-Guk , Lee Chang-Hun , Kim Tae-Hun
Published: March 2021

A new design method for trajectory shaping guidance laws with the impact angle constraint is proposed in this study. The basic idea is that the multiplier introduced to combine the equations for the terminal constraints is used to shape a flight trajectory as desired. To this end, the general form of impact angle control guidance (IACG) is first derived as a function of an arbitrary constraint-combining multiplier using the optimal control. We reveal that the constraint-combining multiplier satisfying the kinematics can be expressed as a function of state variables. From this result, the constraint-combining multiplier to achieve a desired trajectory can be obtained. Accordingly, when the desired trajectory is designed to satisfy the terminal constraints, the proposed method directly can provide a closed form of IACG laws that can achieve the desired trajectory. The potential significance of the proposed result is that various trajectory shaping IACG laws that can cope with various guidance goals can be readily determined compared to existing approaches. In this study, several examples are shown to validate the proposed method. The results also indicate that previous IACG laws belong to the subset of the proposed result. Finally, the characteristics of the proposed guidance laws are analyzed through numerical simulations.
Numerical study on the airfoil self-noise of three owl-based wings with the trailing-edge serrations
Authors: Li Dian , Liu Xiaomin , Wang Lei , Hu Fujia , Xi Guang
Published: March 2021

Previous publications have summarized that three special morphological structures of owl wing could reduce aerodynamic noise under low Reynolds number flows effectively. However, the coupling noise-reduction mechanism of bionic airfoil with trailing-edge serrations is poorly understood. Furthermore, while the bionic airfoil extracted from natural owl wing shows remarkable noise-reduction characteristics, the shape of the owl-based airfoils reconstructed by different researchers has some differences, which leads to diversity in the potential noise-reduction mechanisms. In this article, three kinds of owl-based airfoils with trailing-edge serrations are investigated to reveal the potential noise-reduction mechanisms, and a clean airfoil based on barn owl is utilized as a reference to make a comparison. The instantaneous flow field and sound field around the three-dimensional serrated airfoils are simulated by using incompressible large eddy simulation coupled with the FW-H equation. The results of unsteady flow field show that the flow field of Owl B exhibits stronger and wider-scale turbulent velocity fluctuation than that of other airfoils, which may be the potential reason for the greater noise generation of Owl B. The scale and magnitude of alternating mean convective velocity distribution dominates the noise-reduction effect of trailing-edge serrations. The noise-reduction characteristic of Owl C outperforms that of Barn owl, which suggests that the trailing-edge serrations can suppress vortex shedding noise of flow field effectively. The trailing-edge serrations mainly suppress the low-frequency noise of the airfoil. The trailing-edge serration can suppress turbulent noise by weakening pressure fluctuation.
Robust tracking for hypersonic vehicles subjected to mismatched uncertainties via fixed-time sliding mode control
Authors: Guo Jianguo , Yang Shengjiang , Guo Zongyi
Published: March 2021

This article investigates the robust tracking issue for the longitudinal dynamics of hypersonic vehicles subjected to mismatched uncertainties, and a novel sliding mode control approach is proposed to achieve the fixed-time convergence of tracking errors and satisfactory robustness against mismatched uncertainties. Establishing the control-oriented hypersonic vehicle model as velocity and altitude subsystems with mismatched uncertainties, the article introduces the nonlinear finite-time disturbance observer technique to estimate the uncertainties precisely. With the estimated uncertainties from the observer, the fixed-time sliding mode control is presented to track the velocity and altitude references. Consequently, the effect of the mismatched disturbances can be eliminated and the tracking performance can be improved. The stability of the closed-loop system is also analyzed. Numerical simulation results demonstrate the validity and superiority of the proposed control.
Aerodynamic design optimization of a hypersonic rocket sled deflector using the free-form deformation technique
Authors: Dang Tianjiao , Li Bingfei , Hu Dike , Sun Yachuan , Liu Zhen
Published: March 2021

An aerodynamic design optimization of a hypersonic rocket sled deflector is presented using the free-form deformation (FFD) technique. The objective is to optimize the aerodynamic shape of the hypersonic rocket sled deflector to increase its negative lift and enhance the motion stability of the rocket sled. The FFD technique is selected as the aerodynamic shape parameterization method, and the continuous adjoint method based on the gradient method is used to search the optimization in the geometric shape parameter space; the computational fluid dynamics method for a hypersonic rocket sled is employed. An automatic design optimization method for the deflector is carried out based on the aerodynamic requirements of the rocket sled. The optimization results show that the optimized deflector meets the design requirement of increasing the negative lift under the constraint of drag. By improving the pressure distribution on the surface of the deflector, the negative lift is increased by 7.39%, which confirms the effectiveness of the proposed method.
When war came home: air-raid shock in World War I
Authors: Linden Stefanie Caroline
Published: March 2021

During World War I, civilians became a target of the war machine. Air raids transformed the lives of those not involved in active combat and blurred the lines between the home front and the war front. This paper argues that the experience of air raids in World War I was comparable to the combat stress at the Western Front. The author bases her argument on contemporary publications in medical journals, measures taken by British authorities to prevent air-raid shock, and contemporary case records. The narratives of air-raid shock – similarly to those of shell-shocked soldiers – reflect the feelings of terror and loss of control, and demonstrate the profound effect these experiences could have on individuals’ mental health.
Estimating the role of urban development in environment quality: Evidence from G7 countries
Authors: Katircioglu Setareh
Published: March 2021

This study investigates the role of urbanization in carbon dioxide (CO2) emission in the case of the Group of Seven (G7) countries, except Germany. The conventional environmental Kuznets curve (EKC) was revised by augmenting and controlling for urbanization for this purpose. The results of this study confirm the long-term effects of urbanization on CO2 emission in the selected G7 countries. Only France and Italy seem to manage environmental issues when promoting urbanization; this is because urban development exerts negative effects on the climate levels in these two countries, while it generates positive impacts in the case of the other G7 countries. The inverted U-shaped and revised EKC is also successfully confirmed for only France and Italy among the others.