ABSTRACT
Spaceflight and terrestrial spaceflight analogs can alter immune phenotypes. Macrophages are important immune cells that bridge the innate and adaptive immune systems and participate in immunoregulatory processes of homeostasis. Furthermore, macrophages are critically involved in initiating immunity, defending against injury and infection, and are also involved in immune resolution and wound healing. Heterogeneous populations of macrophage-type cells reside in many tissues and cause a variety of tissue-specific effects through direct or indirect interactions with other physiological systems, including the nervous and endocrine systems. It is vital to understand how macrophages respond to the unique environment of space to safeguard crew members with appropriate countermeasures for future missions in low Earth orbit and beyond. This review highlights current literature on macrophage responses to spaceflight and spaceflight analogs.
ABSTRACT
The recent acceleration of commercial, private and multi-national spaceflight has created an unprecedented level of activity in low Earth orbit, concomitant with the largest-ever number of crewed missions entering space and preparations for exploration-class (lasting longer than one year) missions. Such rapid advancement into space from many new companies, countries and space-related entities has enabled a 'second space age'. This era is also poised to leverage, for the first time, modern tools and methods of molecular biology and precision medicine, thus enabling precision aerospace medicine for the crews. The applications of these biomedical technologies and algorithms are diverse, and encompass multi-omic, single-cell and spatial biology tools to investigate human and microbial responses to spaceflight. Additionally, they extend to the development of new imaging techniques, real-time cognitive assessments, physiological monitoring and personalized risk profiles tailored for astronauts. Furthermore, these technologies enable advancements in pharmacogenomics, as well as the identification of novel spaceflight biomarkers and the development of corresponding countermeasures. In this Perspective, we highlight some of the recent biomedical research from the National Aeronautics and Space Administration, Japan Aerospace Exploration Agency, European Space Agency and other space agencies, and detail the entrance of the commercial spaceflight sector (including SpaceX, Blue Origin, Axiom and Sierra Space) into aerospace medicine and space biology, the first aerospace medicine biobank, and various upcoming missions that will utilize these tools to ensure a permanent human presence beyond low Earth orbit, venturing out to other planets and moons.
ABSTRACT
Evidence from the International Space Station suggests microbial populations are rapidly adapting to the spacecraft environment; however, the mechanism of this adaptation is not understood. Bacteriophages are prolific mediators of bacterial adaptation on Earth. Here we survey 245 genomes sequenced from bacterial strains isolated on the International Space Station for dormant (lysogenic) bacteriophages. Our analysis indicates phage-associated genes are significantly different between spaceflight strains and their terrestrial counterparts. In addition, we identify 283 complete prophages, those that could initiate bacterial lysis and infect additional hosts, of which 21% are novel. These prophage regions encode functions that correlate with increased persistence in extreme environments, such as spaceflight, to include antimicrobial resistance and virulence, DNA damage repair, and dormancy. Our results correlate microbial adaptation in spaceflight to bacteriophage-encoded functions that may impact human health in spaceflight.
Subject(s)
Adaptation, Physiological , Bacteria , Bacteriophages , Space Flight , Bacteria/virology , Bacteria/genetics , Bacteriophages/genetics , Bacteriophages/physiology , Prophages/genetics , Prophages/physiology , Humans , Virulence/genetics , Genome, Bacterial/geneticsABSTRACT
Illustration of life-histories of phages and plasmids through horizontal and vertical transmission (see Figure 1 for more information).
Subject(s)
Onions , Viruses , Onions/genetics , Gene Transfer, Horizontal , Plasmids , Viruses/genetics , Interspersed Repetitive SequencesABSTRACT
OBJECTIVE: This study aims to evaluate if there is any significant linguistic difference in LoR based on applicant's race/ethnicity. DESIGN: Retrospective review of applications to pediatric surgery fellowship at a single institution (2016-2020). Race was self-reported by applicants. LoR were analyzed via the Linguistic Inquiry and Word Count (LIWC) software program. SETTING: Johns Hopkins All Children's Hospital, St. Petersburg, Florida USA. A free-standing tertiary pediatric hospital. PARTICIPANTS: Pediatric surgery fellowship applicants from 2016 to 2020. RESULTS: A total of 1086 LoR from 280 applicants (52% female) were analyzed. Racial distribution was Caucasians 62.1%, Asian 12.1%, Hispanics 7.1%, multiracial 6.4% African Americans 5%, and other/unknown 7.1%. Letter writers were largely male (84%), pediatric surgeons (63%) and professors (57%). There was no difference in LoR word count across races. LoR for female multiracial candidates contained higher use of affiliation and negative emotion terms compared to Hispanic females (pâ¯=â¯0.002 and 0.048, respectively), and past focus terms when compared to Caucasian and Asian female applicants (p < 0.001 and pâ¯=â¯0.003, respectively). Religion terms were more common in LoR for Asian females when compared to Caucasian females (p < 0.001). CONCLUSION: This study demonstrates linguistic differences in LoR for pediatric surgery training programs based on applicant race/ethnicity. While differences are present, these do not suggest overt bias based on applicants race or ethnicity.
Subject(s)
Internship and Residency , Specialties, Surgical , Humans , Male , Female , Child , Personnel Selection , Language , LinguisticsABSTRACT
OBJECTIVE: We analyzed the prevalence and type of bias in letters of recommendation (LOR) for pediatric surgical fellowship applications from 2016-2021â¯using natural language processing (NLP) at a quaternary careâ¯academic hospital. DESIGN: Demographics were extracted from submitted applications. Theâ¯Valence Aware Dictionary forâ¯sEntimentâ¯Reasoning (VADER) modelâ¯was used to calculate polarity scores. The National Research Councilâ¯dataset was used for emotion and intensity analysis. â¯The Kruskal-Wallis H-testâ¯was used to determine statistical significance.⯠SETTING: This study took place at a single, academic, free standing quaternary care children's hospital with an ACGME accredited pediatric surgery fellowship. PARTICIPANTS: Applicants to a single pediatric surgery fellowship were selected for this study from 2016 to 2021. A total of 182 individual applicants were included and 701 letters of recommendation were analyzed. RESULTS: Black applicants had the highest meanâ¯polarityâ¯(most positive), while Hispanicâ¯applicants had the lowest. â¯Overall differences between polarity distributions were not statistically significant.â¯â¯ The intensity of emotions showed that differences in "anger" were statistically significant (p=0.03).⯠Mean polarity was higher for applicants that successfully matched in pediatric surgery. DISCUSSION: This study identified differences in LORs based on racial and gender demographics submitted as part of pediatric surgical fellowship applications to a single training program. The presence of bias in letters of recommendation can lead to inequities in demographics to a given program. While difficult to detect for humans, natural language processing is able to detect bias as well as differences in polarity and emotional intensity. While theâ¯types of emotions identified in this study are highly similar among race and gender groups, the intensity of these emotionsâ¯revealed differences,â¯with "anger" being most significant. CONCLUSION: From this work, it can be concluded thatâ¯bias in LORs, as reflected asâ¯differences in polarity,â¯which is likely a result of the intensity of the emotions being used and not the types of emotions being expressed.â¯â¯ Natural language processing shows promise in identification of subtle areas of bias that may influence an individual's likelihood of successful matching.
Subject(s)
Internship and Residency , Specialties, Surgical , Child , Humans , Fellowships and Scholarships , Natural Language Processing , Bias, Implicit , Personnel SelectionABSTRACT
BACKGROUND: Gender bias in letters of recommendation (LOR) has been reported for candidate selection in academic medicine, typically with females frequently described with communal terms (e.g. helpful, kind, interpersonal) and males described more with agentic terms (e.g. assertive, intellectual, ambitious). This study examined the presence of linguistic gender differences in LOR for Pediatric Surgery Fellowship. METHODS: LOR submitted to a single pediatric surgery fellowship program between 2014 and 2018 were retrospectively reviewed and analyzed using a previously validated Linguistic Inquiry and Word Count Software (LIWC) program. Descriptive statistics and bivariate analysis were employed in our analysis. Multivariable logistic regression models were built to assess independent association of LIWC variables with applicant gender, LOR writer gender, and applicant-writer gender concordance. RESULTS: 1264 LOR from 325 applicants (51% female) were analyzed. Of the letter writers, 83% were male, 57% were professors, and 7.6% were Pediatric Surgery Fellowship Program Directors. The overall median average word count was 518 words, with no significant difference in LOR word count between applicant genders. Compared to male applicants, female applicants were described significantly more with work words (e.g. excellent, work; p = 0.04). Male LOR writers used authentic words (e.g. honest, humble; p = 0.006) and home words (e.g. family, house; p = 0.04) significantly more than female LOR writers. There were no significant differences in the use of agentic and communal words between genders. CONCLUSION: While there are linguistic differences in LOR for candidates in the Pediatric Surgery match based on gender, previously described overt gender bias was not seen in this study. Interestingly, female candidates were described more with work words, like excellent; a reversal of previously described gender bias in academic medicine. These findings may be due to the unique interpersonal and multidisciplinary skills required in pediatric surgery and may represent a unique form of gender bias that warrants further study.