There is limited evidence of Aboriginal and Torres Strait Islander people attending cardiac rehabilitation (CR) programs despite high levels of heart disease. One key enabler for CR attendance is a culturally safe program. This study evaluates improving access for Aboriginal and Torres Strait Islander women to attend a CR program in a non-Indigenous health service, alongside improving health workforce cultural safety.An 18-week mixed-methods feasibility study was conducted, with weekly flexible CR sessions delivered by a multidisciplinary team and an Aboriginal and/or Torres Strait Islander Health Worker (AHW) at a university health centre. Aboriginal and Torres Strait Islander women who were at risk of, or had experienced, a cardiac event were recruited. Data was collected from participants at baseline, and at every sixth-session attended, including measures of disease risk, quality-of-life, exercise capacity and anxiety and depression. Cultural awareness training was provided for health professionals before the program commenced. Assessment of health professionals’ cultural awareness pre- and post-program was evaluated using a questionnaire (n = 18). Qualitative data from participants (n = 3), the AHW, health professionals (n = 4) and referrers (n = 4) was collected at the end of the program using yarning methodology and analysed thematically using Charmaz’s constant comparative approach.Eight referrals were received for the CR program and four Aboriginal women attended the program, aged from 24 to 68 years. Adherence to the weekly sessions ranged from 65 to 100%. At the program’s conclusion, there was a significant change in health professionals’ perception of social policies implemented to ‘improve’ Aboriginal people, and self-reported changes in health professionals’ behaviours and skills. Themes were identified for recruitment, participants, health professionals and program delivery, with cultural safety enveloping all areas. Trust was a major theme for recruitment and adherence of participants. The AHW was a key enabler of cultural authenticity, and the flexibility of the program contributed greatly to participant perceptions of cultural safety. Barriers for attendance were not unique to this population.Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR) 12618000581268, http://www.ANZCTR.org.au/ACTRN12618000581268.aspx, registered 16 April 2018.The flexible CR program in a non-Indigenous service provided a culturally safe environment for Aboriginal women but referrals were low. Importantly, the combination of cultural awareness training and participation in the program delivery improved health professionals’ confidence in working with Aboriginal people. The online version contains supplementary material available at 10.1186/s12872-021-02016-3. Cardiovascular disease (CVD) is diagnosed in almost half of Aboriginal and Torres Strait Islander people aged 55 years and over, and is the largest cause of premature death in this population . CVD is It is widely recognised that cardiac rehabilitation (CR) improves cardio-metabolic risk profiles, decreases hospital admissions, increases medication adherence and improves quality-of-life in those diagnosed with coronary heart disease –9. CardiDespite these barriers, CR programs have been implemented for Aboriginal and Torres Strait Islander populations, primarily in Aboriginal Medical Services (AMS) , 18. TheOne of the key enablers for Aboriginal and Torres Strait Islander CR attendance is the provision of a culturally safe program, preferably delivered within an AMS , 19. Cul(i)evaluate the feasibility of a centre-based women’s Aboriginal and Torres Strait Islander CR program in a non-Indigenous health setting.(ii)investigate a combination of strategies to improve cultural safety in a non-Indigenous healthcare setting.The aim of this study was to implement known enablers, including the provision of a culturally informed gender-specific program, to overcome common access barriers for participation in CR programs in a non-Indigenous health service for Aboriginal and Torres Strait Islander women. Specifically, the two distinct aims were to:The mixed methods cohort feasibility study was conducted from February to December 2018 at a University Health Clinic.Yeddung Gauar’, meaning ‘Good Heart’.The CR program draws on the idea of restorative healthcare, framed using restorative practices defined as “a philosophy, in action, that places respectful relationships at the heart of every interaction” . This reThe evidence-based enablers incorporated into this program included an AHW, provision of transport assistance, and exercise and education sessions delivered in a gender specific, culturally safe, structured, yet flexible CR program in a non-hospital setting –19.Environmental changes to support cultural safety included visual displays representing Aboriginal culture  within the University Health Clinics . AborigiThe CR program used a multidisciplinary team approach, including exercise physiologists, physiotherapists, dietitians, psychologists, pharmacists, supervised university health students and an AHW. The CR program was a 6-week rolling program, conducted once a week for 18-weeks (June-October 2018), consisting of 1-h exercise and 30-min education sessions. Attendance was flexible and participants were not required to attend 6-consecutive weeks, however, participants were encouraged to complete 6 sessions or more during the 18-week period. Participants were re-assessed after every sixth session attended and continued on in the program following this assessment for the remainder of the 18-weeks, if desired. The main aim of the individually tailored exercise sessions was to increase cardiovascular fitness, involving exercise at a moderate intensity . The eduFemale Aboriginal and Torres Strait Islander adults (≥ 18 years old) were eligible for inclusion in the CR program. Participants were included if they had stable heart disease and were receiving optimal medical treatment + / − revascularisation, had experienced a heart attack, or if they were at medium-to-high risk of developing heart disease according to the Absolute Risk Calculator , 38. If The program was advertised in local media  and on the internet  from April to September 2018. Participants could self-refer or be referred by a health professional. Additionally, members of the research team and the University Elder-in-residence contacted key stakeholders such as the local AMS, Aboriginal and Torres Strait Islander health services, general medical practices, Aboriginal community groups and local hospitals. The research team also attended local Aboriginal and Torres Strait Islander events to promote the program. All potential participants were approached by the AHW initially to assess eligibility, interest and ability to commit to participating in the rolling 6-week program.Initial assessments and collection of baseline measurements, including obtaining written consent, for all participants were conducted one week prior to the commencement of the program. Assessments were repeated every sixth session attended. Demographic and clinical information was recorded to describe the sample such as age, education level, relationship and employment status, health conditions and medication use.2); waist and the hip circumference; resting blood pressure; random point-of-care lipid and glucose measurements  one of the ladies would do her shopping on her own…You know, walking around the supermarket, and then stopping, having a rest, getting up, going, that’s an achievement.’ ‘I’ve really enjoyed coming to the program, I’ve learned a variety of things. How to maintain doing exercise with healthy recipes for cooking and stuff like that.’ Participants enjoyed implementing and maintaining the exercise and diet recommendations. There were positive outcomes, such as, being able to walk longer distances with less effort and cooking healthier foods at home, improving their diet.‘she’s never lost any weight with us so we knew that wasn’t going to happen quickly…So you’ve obviously stimulated her somehow to get her moving. The weight loss, the weight loss is something that doesn’t happen easy.’ One of the referrers found that a participant had lost weight which had not been achieved with multiple previous visits to their service.The AHW and health professionals reported participants felt empowered, they’d achieved something and it increased their personal motivation or self-efficacy. Participants, health professionals and the AHW all felt that the participants’ health literacy had increased and they were feeling more confident to question health professionals and seek advice on their health. Participants also enjoyed educating other family members about what they had learnt in the program.p = 0.04). No other significant changes were found. On average, participants agreed that the rate of Aboriginal people developing diabetes and presenting to hospital with heart disease was approximately 3–4 times more than non-Aboriginal people.Eighteen health professionals and administrative staff completed the cultural awareness questionnaire at baseline, before the cultural awareness training, and eleven at 18-weeks Table . Nine ba‘having her there was important for the participants…it was in a way bridging the gap. If she wasn’t there then the adherence to participants turning up may have been affected…I think it’s got to do with the respect or the trust that participants will have in accessing services.’ Participants and health professionals felt that the program increased the knowledge, skills and confidence of the health professionals in working with Aboriginal patients. Health professionals, the AHW and participants said the AHW involvement was crucial, they were seen as a navigator of the program for the Aboriginal women.‘I found that it was little bit different in the sense that you could be a little bit more open with them, because the more open that you actually are, the more open they are. So I found that I needed to just be in a way a little bit more casual in a way sometimes, because they’d ask questions and you’re just like, “Oh, that’s,” you know I wouldn’t normally speak about [my] family, because they are massive on family, but I would normally not speak about [my] family with clients… At first I was a bit hesitant, because obviously you know we were taught basically to keep it professional, so opening up in that sense was a little bit more vulnerable.’ The AHW suggested health professionals need to get to know Aboriginal people individually, to improve their interactions. Health professionals learnt to be more open, more casual and talk more freely about their family which they wouldn’t normally do in a patient interaction.‘I found the participants, it took a bit of time to actually warm up and I guess trust and build that rapport with them, and then once that developed then it was much easier to interact with them, and then for them to trust me with the program that I had recommended.’ Health professionals found it took time to gain the trust of the participants and build rapport.Health professionals said they needed to recognise their own culture and the culture of the patients, including allowing time for silence. They also found that analogies worked well, particularly connecting with the land.‘Yes, I think it just made me a little bit more comfortable. So not having a lot to do with Indigenous people, I just didn’t, you know it was a bit I thought, well do I say the wrong thing? But once I got to know them and realised that I didn’t have to be frightened about what I said, well you know I wasn’t… you know with any group you’re careful what you say, but I’ve certainly felt that I was, you know, able to… and once I’ve met them. So having that initial information and understanding of the background, and where, what’s influencing, you know, people’s behaviours, I thought that made it a lot more easier’ Health professionals reported that the cultural awareness training increased their confidence with interactions with Aboriginal and Torres Strait Islander people.‘maybe every one or two years have the opportunity to attend something like [cultural awareness training], because it’s kind of like first aid, you learn something new every time you go, no matter how much you’re like, oh, I’ve done this before.’ Health professionals, referrers and the AHW recommended that attendance at cultural awareness training sessions should be repeated and not completed once only, similar to other mandatory workplace training, and the AHW suggested that cultural awareness training alone was not enough.‘OK, I’ve done the mainstream program, well I was put into it, at a point. Because I missed an appointment, because something came up, some sorry business came up. And because I missed that appointment, they just cancelled the rest of the appointments.’  Referrers, the AHW and participants discussed participant’s previous negative experiences with institutions and health professionals, reporting feelings of shame, guilt and judgement.‘It was a relaxed environment. It wasn’t rigid. Like I’ve said before, there’s been in mainstream, when you go there, you feel like you’re carrying guilt for being sick in the services. So here was, we could come in, if we were a bit off, they left us to do what we had to do. Didn’t question us.’ ‘I mean people aren’t going to go to…like the shame and guilt, you know, we’re our own worst enemies, if we don’t turn up to something we feel guilty’ The flexibility of the program was greatly valued as this lessened the feeling of guilt if participants were unable to attend every week.‘I do think having a capacity for people to not feel like if you don’t attend for your six weeks you miss out…I think that works really well, but it also doesn’t necessarily lead to great buy-in if you know that you can just turn up at any time. So I don’t know if there’s a way to find that middle ground…’ Although some health professionals thought the flexibility of the program may not encourage consistency.‘you saw that real connectedness in just participants… that just made me realise that you’re actually working with a very connected community’ Health professionals and referrers felt they needed to recognise that they were working with individuals where family and community would always come first.Allowing children (< 18 years old) to attend the program was very valuable to health professionals and participants, allowing family sharing of both participants and health professionals and a personal connection.‘black faces’, and being Aboriginal and Torres Strait Islander specific was a positive. The program differed to a mainstream service and was not time limited.‘ [the] program was incredible, especially having Aboriginal women there supporting you, like [the AHW]… So even just having that space to yarn, it was good.’ Participants felt this was a safe and comfortable environment, with ‘I don’t think people really take that much notice of it. I think… I don’t know whether people are sort of used to seeing Aboriginal artworks around, and maybe they just don’t [notice it]… But it definitely needs to be acknowledged, that’s for sure.’ Some health professionals felt that a culturally safe space was provided by introducing Aboriginal and Torres Strait Islander flags and artwork but some health professionals did not notice this.‘if they’re not promoting it, is it really for our mob?’ Some referrers suggested that potential participants did not want to go to the AMS, while others felt that AMS endorsement was important. Elder guidance and endorsement of the program was viewed as very important.Referrers, participants and the AHW all agreed that cultural considerations are important, particularly taking into consideration that heart problems can occur in younger people in the Aboriginal community. The resources provided were thought to be culturally appropriate by the health professionals and referrers, although they were not tailored for all participants, particularly younger participants. Health professionals questioned whether the program needed to be gender specific, while the AHW, participants and referrers thought this was a positive for the program.The Yeddung Gauar program created a culturally safe space for Aboriginal women using a combination of strategies to address non-Indigenous health professionals’ knowledge, awareness, behaviours, skills and attitudes. Participants felt that the health service environment was comfortable and safe, where they were not judged, and lessened feelings of guilt connected with previous experiences within the mainstream healthcare system. Health professionals’ knowledge, skills and confidence in working with Aboriginal people improved following attendance at the cultural awareness training and involvement in the program. However, issues such as recruitment methods need to be addressed to increase community trust and referrals to similar programs.It is clear that cultural awareness training alone is not sufficient to improve cultural safety . This isThemes of relationship and trust building, and unconditional positive regard towards attendees, with no judgement were strong and contributed greatly to cultural safety, from the participants’ perspective. This may have contributed to the adherence to the program, with all participants attending > 65% of the sessions available to them, higher than other rates of attendance previously reported in Aboriginal specific CR programs . Health As part of the program non-Indigenous health professionals recognised how important family and community were to participants. Hence, non-Indigenous health professionals’ need to be cognisant that the Aboriginal definition of health (life-death-life) differs from the Western view of absence of disease. Aboriginal health means not just the physical well-being of an individual but refers to the social, emotional and cultural well-being of the whole Community in which each individual is able to achieve their full potential as a human being thereby bringing about the total well-being of their Community, with less focus on the individual .The known enablers to increase participation in CR for Aboriginal and Torres Strait Islander peoples that were utilised in this program such as the inclusion of an AHW, provision of transport and a culturally safe environment, and a gender-specific flexible program reinforced the value of such factors, with all them found to be major enablers for the Yeddung Gauar program, resulting in positive changes in health outcomes –19. ThesAn important learning from this research was that although included as an investigator in the study, the leadership of an Aboriginal Traditional Land-owner and Elder could have been utilised more effectively in the co-design, management and leadership within the program. A barrier to success was noted to be the traditional colonised and hierarchical approach to research and health systems that does not take into account the cultural connection to Country, and respect and leadership power that Traditional Land-owner Elders hold in their local community. It is critical to be aware of Aboriginal protocols so as not to offend Aboriginal people. It is vital not to diminish the role of Traditional Owners in understanding the diversity that exists across each of the Aboriginal nations and respecting the difference between knowledges held in each First nation. Non-Indigenous researchers must practice cultural humility to have success and be alert to the reality that Aboriginal and/or Torres Strait Islander Health Workers who are not from the same Country need support and guidance from Elders who are Traditional Owners to successfully engage with the Aboriginal community they are working within. Non-Indigenous researchers and health workers need to respect the Elders guidance and leadership for trust to grow. Elders are leaders who are respected and followed by their community and will actively encourage participation when actively engaged. Using approaches that ensure cultural sensitivity, respect and voice of Traditional Land-owner Elders to guide the work and ensure all team members are respected will enhance future programs. In the gifted words of the United Ngunnawal Elders who supported this project, “In this Journey we strive for unity. We do this by empowering people, creating confidence, self-esteem and room for difference, so we can work and laugh together, moving forward all the while” .Three of the research team are First Australians . Researchers from physiotherapy and nursing with experience in Indigenous health, cardiac rehabilitation and restorative practice have also been involved in this research. An important strength of this study is the deliberate privileging of Aboriginal and Torres Strait Islander voices at all levels of the research strategy, applying restorative healthcare practice principles, an ontologically appropriate strength-based approach for this study with foundations in First Nations practice , 55. TheThe Yeddung Gauar cardiac rehabilitation program enabled female Aboriginal and Torres Strait Islander participants to attend a gender-specific evidence-based cardiac rehabilitation program, for the primary and secondary prevention of heart disease. This program was effectively delivered in a non-Indigenous health service by engaging in strategies that improved health workforce cultural safety and resulted in positive health outcomes. Future programs in non-Indigenous health settings should employ similar strategies and cultural learnings to increase cultural safety, recognising the evidence-based enablers and barriers for cardiac rehabilitation attendance for both Indigenous and non-Indigenous Australians.Additional file1: Health professionals cultural awareness questionnaire.Additional file2: Yarning circle topic guide.Additional file3: Semi-structured interview topic guide.


In order to study the aerodynamic mechanism of the climbing flight based on the biological observation results, the kinematic parameters of the dragonfly during LAC and SAC are selected for analysis and numerical simulation. The results show that the climbing angle η and wing kinematics are related. There are considerable differences in wing kinematics during climbing with different η, while the wing kinematics are unchanged during climbing with similar η. With the increase in η, the phase difference (λ) between the forewing and the hind wing decreases and the amplitude of the positional angle (θmean) of the hind wing increases, while θmean of the forewing remains almost unchanged. Through numerical simulation of LAC and SAC, it can be found that during the climb with different η, the different wing kinematics have a significant influence on aerodynamic performance. During SAC, the increase in λ and the decrease in θmean of the hind wing weaken the aerodynamic disturbance of the forewing by the vortex wing of the hind wing, thus improving the flight efficiency.This study presents a detailed analysis of dragonflies’ climbing flight by integratinghigh-speed photogrammetry, three-dimensional reconstruction, and computational fluid dynamics. In this study, a dragonfly’s climbing flight is captured by two high-speed cameras with orthogonal optical axes. Through feature point matching and three-dimensional reconstruction, the body kinematics and wing kinematics of 22 dragonflies in climbing flight are accurately captured. Experimental results show that the climbing angles ( With the development and application of micro air vehicles (MAVs), the study of insect flight mechanisms has attracted more and more attention . InspireThe wing kinematics of dragonfly-like MAVs are based on the real flapping of dragonflies . The kinλ = 180°) when hovering, phased stroking (λ = 90°) when flying fast forward, and synchronized stroking (λ = 0°) when maneuvering. These observations provide a theoretical basis for the motion control of dragonfly-like MAVs. However, as a typical flying mode of dragonflies, especially in emergency escape or prey capture, systematic study on climbing has rarely been conducted. Dragonflies’ climbing flights were found in η) was 40° in Azuma’s observation and ranged from 11° to 81° in Wakeling’s observation. Both of them lacked detailed information on wing kinematics, and due to the small amount of flight samples, the distribution law of η cannot be statistically analyzed. So, how do the kinematic parameters of the body and wings change under different η, and what are the effects of these parameters on aerodynamic performance?By summarizing the observation results of free-flying dragonflies , consensη between 60° and 70°, and the SAC with η between 20° and 30°.  The kinematic parameters of the body and wings during LAC and SAC were analyzed and compared by using feature point matching and a three-dimensional reconstruction method. The aerodynamic characteristics during LAC and SAC were compared and studied by using a numerical simulation method, which provided guidance for the exploration of the bionic aerodynamic theory and the engineering application of MAV. The kinematics of wings extracted from LAC and SAC provides the data basis for flight control of tandem-wing MAVs.In this study, the kinematics and the aerodynamic mechanism of dragonfly climbing were investigated by analyzing the biological observation data and numerical simulation. Dragonflies were photographed by two high-speed cameras with orthogonal optical axes. Detailed body kinematics and wings kinematics during the climbing flight were obtained. According to the experimental results, it was found that the dragonfly’s climbing angle ranged from 10° to 80°. Two typical climbing statuses of dragonflies were selected for analysis in this study: the LAC with Pantala flavescens belongs to a widely distributed dragonfly family (Libellulidae) and is considered to be the most widespread dragonfly on the planet. The dragonflies measured in this experiment were collected from a pond at the main campus of Beihang University . The dragonflies were then transferred to the indoor laboratory in a dark container and were used in experiments on the day of capture. Following hypothermic anesthetization of individual dragonflies, the morphological parameters of their bodies and wings were measured, and black feature points were marked on the wings. As shown in −1, shutter speed 1 ms, resolution 1,280 × 1,024 pixels) were used to film the climbing flight of dragonflies within a glass observation box . In order to prevent the visual system of the dragonflies from being affected by the experimental equipment and the surrounding environment during flight, the observation box was made of transparent glass, and white curtains were used to separate the dragonflies from the surrounding environment without affecting the camera’s vision. The distribution of feature points is shown in ei . In this method, the continuum is regarded as discrete particles on a lattice. Particles move on the lattice and collide with each other according to specific rules. Through the statistics of particles and the motion characteristics, the macroscopic characteristics of fluid can be obtained.The fluid simulation was carried out using the commercial computational fluid dynamic (CFD) solver XFlow 2019, which solves the three-dimensional Boltzmann’s transport equation based on the lattice Boltzmann method (LBM). The LBM works on a spatial discretization named lattice, consisting of a Cartesian distribution of discrete points with a discrete set of velocity directions fi is the distribution function for particles with velocity ei at position R and time t, and Ωi is the collision operator that computes a post-collision state conserving mass and linear momentum. LBM schemes were classified as a function of the spatial dimensions d and the number of velocity distribution functions b, resulting in the notation DdQb. In the present method, the 27-velocity model (D3Q27), together with a central moment collision operator, was adopted to enhance the numerical stability. The governing equation of the flow field in continuum space is as follows:The Cartesian lattice is used and the meshing process is greatly simplified, which makes the lattice Boltzmann method (LBM) have advantages over conventional numerical methods in solving moving boundary conditions with complex surfaces.c × 40c × 30c in terms of average wing chord length (c). To resolve the near-wake vortex structures, the unsteady flow near the flapping wings was computed with a fine resolution of 0.01c and 200 time steps per cycle, and the total number of computational grid points was about 10.2 million. When further refinements to the domain and time step were applied, the variation in the mean total lift was less than 0.5%. The validation of the numerical method and detailed settings of the simulation are introduced in electronic A detailed description of this solver is given in λ is an important kinematic parameter for the interactions, which is defined as the phase lag between the forewing and the hind wing. We defined the phase difference λ as positive when the hind wing leads the forewing and negative when the forewing leads the hind wing. The climbing angle η is defined as the angle between the direction of average flight velocity V during climbing and the horizontal plane, and the pitch angle ε is defined as the angle between the dragonfly’s body longitudinal axis and the horizontal plane. The body posture of a dragonfly in flight can be represented by three Euler angles: pitch angle, yaw angle, and roll angle. Since the yaw angle and roll angle were approximately zero or 180° during the climb, the body posture can be described by ε. By analyzing the photo sequence, the trajectory of wing tip mark points during the stroke was obtained. Based on these points, a line can be determined by using the linear regression method. As a result, the flapping plane is defined based on the wing tip line and the root of the wing. The flapping plane angle βH is the angle between the flapping plane and the horizontal plane. L is the line joining the wing base and wing tip, and L’ is the projection of L onto the flapping plane. The position of the wing with respect to the flapping plane was determined by three Euler angles: the positional angle (θ), rotational angle (α), and deviation angle (δ), where θ is defined as the angle between the Z’-axis and L’, α is defined as the angle between the wing plane and the flapping plane, and δ is defined as the angle between L and L’.As shown in To ensure the validity of the experimental data, the photo sequences of climbing flight satisfied the following conditions: the flight process contains more than two wingbeats; the flight trajectory was approximately a straight climb; and dragonflies’ body rotation was negligible. Under these conditions, 22 climbing flight sequences were analyzed, with each sequence from a different dragonfly. The mass, body length, and wingspan of the dragonflies are shown in η between 10 and 80°. According to the distribution of η in These 22 climbing flight sequences were statistically analyzed. The results show that the dragonflies climb with θmean and αmean are the amplitude of the positional angle and rotational angle, respectively. θmin and αmin are the minimum positional angle and minimum rotational angle, respectively. θmax and αmax are the maximum positional angle and maximum rotational angle, respectively. According to the data in In this study, three groups of experimental data of LAC and SAC were selected for analysis, respectively. For these six cases [LAC cases marked as LD1 (ID = 4), LD2 (ID = 5), LD3 (ID = 6) in η is kept within a certain range. Therefore, the experimental data of two individuals (LD1 and SD1) were further analyzed to determine the climbing laws of dragonflies during LAC and SAC. LD1 was the fourth individual observed in the experiment, with a mass of 345 mg and a climbing angle of 67.5°. SD1 was the second observed individual with a mass of 334 mg and a climbing angle of 22.4°. As can be seen from f was about 28.5 Hz and λ was about 77°; for SD1, f was about 27.2 Hz and λ was about 102°. For LD1, θmean of both the forewing and the hind wing was more than 60°. For SD1, θmean of the forewing was 61.3°, while θmean of the hind wing was only 36°. Therefore, it can be concluded that with the increase in η, λ between the forewing and the hind wing decreases and θmean of the hind wing increases, while θmean of the forewing remains almost unchanged.It can be seen that during LAC or SAC, the kinematic parameters were almost the same. Therefore, it can be concluded that the kinematic parameters remain similar when η. The time courses of η and ε of LD1 and SD1 are shown in t = 0 is defined as the time when the dragonfly’s body enters the camera field of vision, and the positional coordinate of the dragonfly at this time is set as . Under these two conditions, η and ε fluctuated periodically with time, and the fluctuation period was roughly the same as the dragonfly’s flapping period. For LD1, the average η and ε were 67.5° and 65.2°, respectively. For SD1, the average η and ε were 22.4° and 13.5°, respectively. The displacement of the center of mass in the absolute coordinate system during the whole climbing flight process can be obtained by three-dimensional reconstruction of the photo sequences of LAC and SAC. As the yaw angle during the whole climb was almost zero, the displacement along the Z direction was negligible, and the kinematics of the center of mass during LAC and SAC are recorded in X direction and 0.161 m along the Y direction during the whole process. For SD1, the displacement was about 0.107 m in the X direction and 0.044 m in the Y direction. The velocity of the center of mass during climbing was obtained by taking the derivative of displacement with time in X-direction component was 0.28 m/s, and the Y-direction component was 1.10 m/s. For SD1, the average climbing speed was 1.00 m/s, the X-direction component is 0.86 m/s, and the Y-direction component was 0.50 m/s. The kinematics of the body posture were similar in other groups of LAC (LD2 and LD3) to those of LD1. The same phenomenon was observed during SAC. The average velocity was obtained by using the least square method. During LAC, the average acceleration in the horizontal direction (X direction) and vertical direction (Y direction) were −1.05 m/s2 and 1.02 m/s2, respectively. During SAC, the average horizontal acceleration and the average vertical acceleration were 0.26 m/s2 and 0.96 m/s2, respectively.θ, rotational angle α, and deviation angle δ can be well represented by the Fourier expansion series, including higher harmonics as follows ( follows :A(t)=A0λ of LAC (77°) was smaller than that of SAC (102°). θmean of the forewing (65°) and the hind wing (66°) were similar in LAC, while θmean of the forewing in SAC (64°) was much larger than that of the hind wing (36°). Average δ of the forewing and the hind wing in both cases was less than 2°.It can be seen from η and wing kinematics are related. With the increase in η, λ decreased and θmean of the hind wing increased, while θmean of the forewing remained almost unchanged. To analyze the aerodynamic influence of the variations of kinematic parameters in different climbing states, the aerodynamic performance of wing flapping in these two climbing statuses will be explored using numerical simulation in Definition of Kinematic Parameters.This section introduces the kinematic pattern of dragonflies’ bodies and wings in detail during LAC and SAC by analyzing the climbing photo sequences taken in the experiment. The results show that the climbing angle The geometric parameters and kinematic parameters of LD1 and SD1 were extracted from the aforementioned experimental observations, and the aerodynamic performance was simulated using numerical simulation tools. The instantaneous lift and thrust generated during flight of LD1 and SD1 were obtained by integrating the pressure and shear stress of each node on the wing surface. Based on the aerodynamic torque and kinematic laws of the wings, the instantaneous aerodynamic power was obtained. Since the wing flap was considered to be symmetric during flight, the aerodynamic force and flow field generated by the left and right wings can be regarded as identical. Therefore, the left forewing and the left hind wing were selected for flow field analysis.t = 0 represents the time when the dragonfly’s body enters the camera field of vision. As shown in Lmean and thrust Tmean were 1.90 and 0.07 mN, respectively. As shown in Lmean and Tmean were 1.83 and 0.38 mN, respectively.2. When the weight of SD1 was 335 mg, the angle between the net force and the horizontal plane was 22.3° and the average vertical acceleration was 0.94 m/s2. The relative differences between the direction of net force and the average vertical acceleration were within ±3%. Therefore, it can be concluded that the numerical simulation results were consistent with the experimental observations.When the weight of LD1 was 345 mg, the angle between the net force and the horizontal plane was 67.6° and the average vertical acceleration was 1.00 m/sT = 0 represents the start time of the forewing downstroke. As can be seen from T = 0.31, and lift peak of the hind wing appeared at T = 0.06 due to the phase difference. As can be seen from T = 0.76, and thrust peak of the hind wing at T = 0.57. The forewing contributed 40% of the whole lift, whereas the hind wing accounted for 60%. The hind wing’s lift peak (3.58 mN) and thrust peak (4.98 mN) were larger than the forewing’s lift peak (2.44 mN) and thrust peak (2.95 mN).T = 0.27 and T = 0.07, respectively, and the thrust peak of the forewing and the hind wing appeared at T = 0.77 and T = 0.57, respectively. The forewing contributed 53% of the whole lift, whereas the hind wing accounted for 47%. The lift peak of the hind wing (3.87 mN) was smaller than that of the forewing (4.51 mN), and the thrust peak of the hind wing (4.11 mN) was larger than that of the forewing (2.50 mN).Similarly, during SAC, the lift peak of the forewing and the hind wing appeared at θmean of the forewing (65°) and the hind wing (63°) was almost identical, and the surface area of the hind wing (383 mm2) was larger than that of the forewing (336 mm2), while in SAC, the hind wing generated less lift because θmean of the hind wing (36°) was smaller than that of the forewing (62°). During T = 0.07–0.31, both the forewing and the hind wing were in the middle of the downstroke and produced large lift. During T = 0.57–0.77, both the forewing and the hind wing were in the middle of the upstroke and produced large thrust. Therefore, dragonflies produced large aerodynamic forces in these two periods, which resulted in the peaks of total aerodynamic power in the corresponding periods, as shown in In LAC, the hind wing generated more lift because βbody was almost unchanged during different climbing statuses, which is similar to the results of βbody of the forewing and the hind wing was 65° and 66°, respectively; during SAC, βbody of the forewing and the hind wing was 64° and 67°, respectively. As shown in η = βbody-βH and βbody was almost unchanged, the large difference of η between LAC and SAC (67.5° and 22.4°) resulted in the significant difference in βH (−2.5° and 41.6°). Therefore, to get enough lift to counteract gravity, dragonflies employed different wing kinematics during LAC and SAC, which was the main reason for the different aerodynamic forces between the two statuses. Since the flapping plane during LAC was approximately parallel to the horizontal plane, the lift generated by the wing was positive during the downstroke and upstroke. The forewing flaps forward in the downstroke and flaps backward in the upstroke, resulting in negative thrust and positive thrust, respectively. During SAC, βH of the forewing was 41.6°, which causes a significant vertical upward displacement of the wing during the upstroke, resulting in negative lift during the early upstroke. Therefore, when climbing with different η, the law of lift generated by wings will change due to the variation of βH. During LAC, the wing generates lift during both upstroke and downstroke. During SAC, the wing generates negative lift during upstroke and positive lift during downstroke.In this experiment, the angle between the flapping plane and the body axis Q criterion. Based on the definition in Q is normalized by Q*= Q/2, and Q* below a certain negative threshold is indicative of a vortex-dominated region. Therefore, Q* = −0.2 was selected as the negative threshold.In order to explain the aerodynamic mechanism of the force peak and the force variation generated by wings during LAC and SAC, the three-dimensional vortex structure and two-dimensional vorticity slices along the spanwise were studied. The three-dimensional vortex structure was identified by the t = 115, 118, 122, and 125 ms during LAC, corresponding to the times of hind wing lift peak, forewing lift peak, hind wing thrust peak, and forewing thrust peak, respectively. As can be seen from r2 section is 5271 s−1. The radius of the second moment r2 is denoted by r2 = ∫Sr2·dS/S, where r is the radial distance from the wing root and S is the area of the wing. At t = 118 ms, the forewing is in the mid-downstroke, and a large and stable LEV is generated. The average vorticity of forewing LEV at r2 section is 4322 s−1. The smaller vorticity of the forewing is consistent with the fact that the peak lift of the forewing is smaller than that of the hind wing in Numerical Simulation. At this time, the hind wing is in the end of downstroke. The decrease of the flapping speed and the change of α led to the LEV breaking from the wingtip and losing the ability to generate lift. When t = 122 ms and T = 125 ms, the hind wing and the forewing are in the mid-upstroke, respectively, and the LEV attached to the lower surface of the wing is the main vortex structure generating thrust. When t = 122 ms, the average vorticity of hind wing LEV at r2 section is 4721 s−1; and when t = 125 ms, the average vorticity of forewing LEV at r2 section is 3942 s−1, which is consistent with the fact that the peak thrust of the forewing is smaller than that of the hind wing in Numerical Simulation.t = 74, 76.5, 80, and 82.5 ms during SAC, corresponding to the times of the hind wing lift peak, forewing lift peak, hind wing thrust peak, and forewing thrust peak, respectively. Similar to the flow fields of LAC, during the downstroke, LEV was generated on the leading edge of the wing and gradually developed and strengthened. With the downstroke of the wings, the vortex developed in the spanwise direction, and the LEV, wing-tip vortex (WTV) and trailing-edge vortex (TEV) formed a vortex ring, which generated most of the lift. During the upstroke, a stable LEV was generated on the lower surface of the wing. Due to the phase difference, the flapping of the forewing and the hind wing were not synchronized, which led to the movement of the wake into the vortex ring of the other wing, as shown in the black boxes of θmean of the hind wing (36°) was significantly smaller than that of the forewing (62°), resulting in a decrease in the flapping velocity and aerodynamic force of the hind wing. During downstroke, the average vorticity of hind wing LEV at r2 section at t = 75 ms was 2876 s−1, and the average vorticity of forewing LEV at r2 section at t = 76.5 ms was 4108 s−1, which means the strength of LEV generated by the hind wing decreases with θmean. Similarly, during upstroke, the average vorticity of hind wing LEV at the r2 section at t = 80 ms was 3041 s−1, and the average vorticity of forewing LEV at the r2 section at t = 82.5 ms is 4214 s−1, which explains why the hind wing produces less thrust during upstroke.η, λ increased, and θmean of the hind wing decreased. In this section, the influence of wing kinematics will be explained by flow field analysis.The two typical climbing processes (LAC and SAC) of dragonflies have been observed and analyzed, and it was found that with the increase in θmean of the hind wing is conducive to the stable output of lift and meets the aerodynamic force required for LAC. By comparing η increased, in order to ensure maneuverability, θmean of the hind wing increased, which increased the size and strength of LEV. Since reducing λ can also produce greater aerodynamic force, which has been detailed in θmean of the hind wing and reduce λ during LAC for greater aerodynamic force.During LAC, the flight velocity has a large component in the vertical direction. This flight status needs to overcome gravity to do work and is similar to the maneuvering flight mode like preying and escaping from enemies. In maneuvering flight, it is necessary to ensure that sufficient aerodynamic force is generated. Therefore, the large λ enlarges the distance between the forewing and the hind wing, and the vortex ring generated by the hind wing has less influence on that of the forewing. Besides, the smaller θmean of the hind wing during SAC corresponds to the smaller vortex ring strength. These two factors weaken the aerodynamic disturbance of the forewing during SAC and improve the flight efficiency. The aerodynamic mechanism can also be obtained during the upstroke by comparing During SAC, the velocity has a large component in the horizontal direction. The aerodynamic force generated by the wings mainly overcomes air drag. In order to reduce energy consumption and improve endurance during cruise flight like SAC, dragonflies can reduce vorticity dissipation and flow separation by adjusting wing kinematics. The vortex ring generated in the mid-downstroke of the hind wing generates a low-pressure area above the upper surface of the wing, which interacts with the wake of the forewing. As can be seen from the black boxes in λ and decreasing θmean of the hind wing to efficiency improvement, efficiencies of flapping wings during LAC and SAC were calculated. The aerodynamic power Pa was obtained by calculating the products of torque Ma and angular velocity ω. And the power coefficient CP was calculated usingρ is the fluid density and the reference velocity Uref is the average velocity at the r2 section. The force coefficient CF is calculated usingF is the cycle-averaged aerodynamic force generated by the wing. The ratio of CF to CP is taken as a measure of efficiency, similar to the practice of In order to verify the contribution of increasing The influence of wing kinematics on aerodynamic performance can provide guidance for the control of MAVs. In maneuvering flight, the tandem-wing MAV can provide the required aerodynamic force by reducing the phase difference and increasing the amplitude of the positional angle of the hind wing. During cruising flight, efficiency can be improved by increasing the phase difference and decreasing the amplitude of the positional angle of the hind wing.η were concentrated at 60°–70° (LAC) and 20°–30° (SAC). By analyzing the kinematic parameters of the body and wings, it was found that during climbing, the angle between the flapping plane and the body axis was not affected by the climbing angle. It was also found that the climbing angle η and wing kinematics were related. There were considerable differences in wing kinematics during climbing with different η, while the wing kinematics were basically unchanged during climbing with similar η. With the increase in the climbing angle, the flapping frequency increased, the phase difference decreased, the amplitude of the hind wing positional angle decreased, and the positional angle of the forewing remained unchanged. To meet the need for lift, dragonflies balance gravity by adjusting the kinematics of their wings during different climbing statuses, which results in different aerodynamic variations.In this study, the photo sequences of 22 dragonflies during climbing were analyzed. It was found that the climbing angles Through numerical simulations of LD1 and SD1, it was found that a large aerodynamic force was generated during mid-downstroke and mid-upstroke, mainly by the vortex ring composed of LEV, WTV, and TEV. During LAC, the flapping plane was almost horizontal, and positive lift was generated in both the downstroke and the upstroke. During SAC, the angle between the flapping plane and the horizontal plane was 43.6°, resulting in positive lift during the downstroke and negative lift during the upstroke; and reduction of the hind wing positional angle leads to a decrease in vortex structure strength, resulting in an aerodynamic force generated by the hind wing that was less than that of the forewing.λ and the decrease in θmean of the hind wing weakened the aerodynamic disturbance of the forewing by the vortex ring of the hind wing, thus improving the flight efficiency. This aerodynamic mechanism can be used to improve flight efficiency in MAV design.During SAC, the increase in


Background: Preferentially expressed antigen in melanoma (PRAME) is a cancer testis antigen (CTA) identified in 1997 through analysis of the specificity of tumor-reactive T-cell clones derived from a patient with metastatic cutaneous melanoma. Although at first it seemed even more specific, various studies have shown that PRAME can also be expressed in the context of atypical lesions that do not correspond solely to the definition of malignant melanoma. Methods: A systematic review of English articles was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: 126 records were identified in the literature search, of which 9 were duplicates. After screening for eligibility and inclusion criteria, 53 publications were included. Conclusions: The advent of a new marker such as PRAME is surely a step forward not only in the diagnostic approach, but also in the immunotherapeutic approach to MM. However, various studies have shown that PRAME can also be expressed in the context of atypical lesions apart from MM and, for this reason, the diagnostic sensitivity and specificity (hence accuracy) are clearly lower. Further studies with larger case series will be necessary to understand better what possibilities are offered in terms of diagnostic reliability by PRAME. Despite advances in therapy and treatment, malignant melanoma (MM) continues to be a very aggressive skin cancer, with 324,635 new cases and 57,043 deaths worldwide in 2020, accounting for 1.7% of all cancers in the world population , and MITA systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search of PubMed, MEDLINE, and Web of Sciences (WoS) databases was performed until 22 February 2022 using the terms: preferentially expressed antigen in melanoma (PRAME) in combination with each of the following: melanoma, neoplasm, and immunohistochemistry. Only articles in English were selected. Eligible articles were assessed according to the Oxford Centre for Evidence-Based Medicine 2011 guidelines . Review An independent extraction of articles was performed by two investigators (G.C. and A.C.) according to the inclusion criteria. Disagreement was resolved by discussion between the two review authors. Because the study designs, participants, treatment measures, and reported outcomes varied markedly, we focused on describing the different approaches of the authors regarding the immunoexpression of PRAME in malignant melanoma, analyzing the techniques (mainly immunohistochemistry) used in the works examined. Finally, we analyzed the state of the art, imagining what the future perspectives may be.In total, 126 records were initially identified in the literature search, of which nine were duplicates. After screening for eligibility and inclusion criteria, 53 publications were ultimately included . Most ofSince its first description back in 1997 by Ideka et al. , PRAME hConsidering that in the biology of malignant transformation from dysplastic nevus to MM a series of genetic-molecular events occur, that alter the expression of various protein molecules ,32, LohmA study by Raghavan et al. investigated further and confirmed the usefulness of PRAME IHC for making differential diagnoses between melanocytic proliferations with intermediate histopathology and melanoma: they found that traumatized, mitotically-active, persistent and recurrent, and dysplastic nevi usually lacked PRAME expression altogether. As in the study by Lezcano et al. , the neeScherlfer et al. conducted a study on the relationship between clinical features, gene expression profile (GEP) class, and PRAME expression in uveal melanoma. There was no association between PRAME expression and clinical features . PRAME staining was not statistically associated with a higher TNM stage. However, it should be noted that the GEP class was associated with higher TNM staging and worsening of the GEP class was associated with positive PRAME status. PRAME expression was found to be associated with an increased risk of metastasis and a worse prognosis in all GEP classes.PRAME expression was associated with the largest basal diameter (LBD) and tumor volume. Notwithstanding, PRAME expression can appear at any stage of tumor progression and not only in advanced stages. These findings were in agreement with the already known strong association of LBD with GEP and metastatic risk . These dIn a cases series reported by Hovander et al. PRAME expression was studied in eight cases of oral malignant melanoma (OMM), a rare and very aggressive neoplasm with a high risk of metastasis. In this study, PRAME was positive in 83.2% of the OMMs analyzed . In a 20In this scenario, rising attention is being devoted to this marker, and new studies are being conducted in an attempt to increase experiences, report results, and find safer answers ,57,58,59In an elegant paper published in 2021, Lopez et al. described their pilot study on PRAME immunostaining of 24 lesions that are particularly difficult to diagnose: 24 lesions consisting of five cases of low-grade inactivated melanocytic tumor (BIMTs), seven cases of deep penetrating nevus (DPNs), and 12 combined nevi with conventional and DPN features (CDPNs). A total of five BIMTs were analyzed in regard to PRAME, and none had an immunoreactivity score greater than 1+, while all the BIMT cases scored higher than zero demonstrated a weak staining intensity. Of the remaining 19 cases, seven were DPNs and 12 were CDPNs. None of the DPN/CDPN cases demonstrated an immunoreactivity score greater than 2+, except for one CDPN. Of the DPN/CDPN cases scored higher than zero, only two demonstrated strong intensity, neither of which showed salient distinguishing morphologic features. None of the 24 cases examined demonstrated diffuse positivity (score: 4+). This work offered the authors a slightly greater confidence in the possibility of PRAME providing a practical diagnostic aid in the course of the diagnostic management of these particular lesions .In 2020, Leczano et al. demonstrated a high concordance between PRAME immunoexpression results and cytogenetic data, starting from ambiguous melanocytic lesions and difficult diagnostic categorization . In thisVery recently, in 2022, Krajisnik et al. published a paper where they evaluated the expression of the PRAME protein in a series of melanocytic lesions of the nail. In their work, 25 nail unit melanomas  and 32 control benign melanocytic lesions were retrospectively reviewed. PRAME nuclear staining was evaluated (similarly to other works in the literature) as a percentage and intensity labeling. All melanoma cases showed PRAME nuclear expression, which was usually widespread and strong. In samples with few cancer cells, staining was restricted to tumor cells, corresponding to the initial H&E imprint. All control cases were negative for PRAME expression. The expression of PRAME was useful in distinguishing between melanomas and other melanocytic lesions of the nail. This antibody has also been shown to be diagnostically valuable for detecting melanoma cells in small samples with minimal disease .PRAME expression in melanoma cells is regulated by many actors. Hypermethylation appears to downregulate the expression of PRAME , while dFrom a molecular point of view, mucosal melanomas are more similar to uveal melanoma than to cutaneous melanoma ,46,68.PRAME is expressed by melanoma and many different tumors: a higher expression is typical of advanced diseases and is associated with lymph node spread of the disease. Prognosis is poor when PRAME is overexpressed, indicating worse disease-free, progression-free, and metastasis-free prognosis, and worse overall survival .


The development of postgraduate programs for physician assistants (PAs) began in 1973 and by 2020 there were approximately 72 programs spread across a broad range of medical and surgical disciplines. PA Post-graduate education programs are voluntary and available to American licensed PAs. Therefore, an assessment of the characteristics of PA post-graduate fellowships and residencies programs was initiated.A non-experimental, descriptive research study was designed to obtain information on the characteristics of PA postgraduate education programs in the US. The source of information was from surveyed members of the Association of Postgraduate Physician Assistant Programs (APPAP). Questions were drawn from consensus discussions. Directors of postgraduate programs that were operational in 2020 were eligible to participate.Seventy-two postgraduate program directors were invited to the survey and 34 program directors replied. These programs are geographically distributed across the US in 13 states. The respondents represent a wide range of medicine: surgery, emergency medicine, critical care, orthopaedics, hospitalist, psychiatry, oncology, primary care, pediatrics, and cardiology. Most programs are associated with an academic medical center and some institutions have more than one postgraduate specialty track. The curriculum includes bedside teaching, lectures, mentorship, assigned reading, procedures, simulation, and conferences. An average program length is 12 months and awards a certificate. Stipends for PA fellows are $50,000–80,000 (2020 dollars) and benefits include paid time off, health and liability insurance. About half of the programs bill for the services rendered by the PA. Over 90% of graduates are employed within 2 months of completing a PA postgraduate training program.A trend is underway in American medicine to include PAs in postgraduate education. PA postgraduate training occurs across a broad spectrum of medical and surgical areas, as well as diverse institutions and organizations overseeing these programs. Most PA postgraduate programs are in teaching hospitals where the PA resident or PA fellow also serves as a house officer alongside a categorical resident. This study sets the stage for more granular economic and social research on this growing phenomenon in American medicine.The online version contains supplementary material available at 10.1186/s12909-021-02613-y. Postgraduate education for American physician assistants (PAs) has been underway for half a century. Montefiore Hospital in New York introduced PAs as house officers on the surgery service in 1971 and began the first PA postgraduate fellowship program in 1973. Norwalk Hospital/Yale School of Medicine in 1976 was next . In the APPAP.org) website lists 72 programs spanning 32 tracks - some within the same institution [For 50 years a trend has been underway to adopt a postgraduate model of PA education . The AssPA education was established in the 1960s, due to limited access to healthcare services and physician supply. Spanning half a century the PA movement in 2020 numbered over 140,000 clinically active PAs and the 265 programs produce almost 10,000 graduates . This grTo set the stage for this project the medical school postgraduate pipeline has largely been constrained due to a federal policy in 1997 that restricted graduate medical education growth. National restriction on resident and fellow work hours per week has also limited the supply of house officers at a time of hospital expansion and consolidation . The med. To address this, a survey of PA postgraduate education programs was undertaken.Postgraduate PA programs have been insufficiently researched and more clarity is needed about this aspect of medical education . The notAPPAP.org). The APPAP website contains information on each program, the sponsoring institution, a contact, degree awarded, and class size. Additional information is gained through reaching the program’s website.A non-experimental, descriptive research study was designed to obtain aggregated information on the characteristics of PA postgraduate education programs in the U.S. The list of programs was drawn from the APPAP membership  initiative and considered an administrative project undertaking for continuous quality and process improvement. This project did not involve special populations. Additionally, this information can be found in the public domain and therefore the need for an institutional review board was not explored.In total 72 PA postgraduate programs directors were sent a set of questions along with an introduction for participation. Thirty-four program directors (47% rate of return), responded to the survey questions. On several occasions, the respondent opted to skip a question and the (per question response rates varied between 20 and 100%). Additionally, the survey also included several open-ended questions, which provided respondents the opportunity to give additional feedback. The 34 postgraduate programs are spread across the US in 13 states. Most programs are associated with an academic medical center. Because some directors oversee more than one specialty track within an institution, the total number of postgraduate programs represented in the answers varied.The majority (82%) of the 34 respondents represent a single-track program, meaning they provide postgraduate training in one discipline such as orthopaedics; 18% are multi-track programs. The disciplines most represented are surgical (39%), Emergency Medicine (33%), Critical Care (30%), and Orthopaedics (24%).  include nurse practitioners (NPs). The duration of most postgraduate PA education is 12 months (79%), with two at 18 months, and one two-year program. All award a certificate of completion. Some programs include research and award a postgraduate degree [).The techniques used by postgraduate programs in PA role development varies. The most common education delivery methods are case studies, bedside clinical teaching, in-person didactics, specialty rotations, grand rounds, online learning modules, simulation, and journal clubs Fig. .Fig. 2P Nearly all programs provide continuing medical education credits for maintenance of national certification and state licensure. Programs identified using electronic systems to deliver education (91%). All PAs must be licensed in the state where employed.Beyond a focus on the education about the particular medical or surgical specialty involved, the program incorporates a wide variety of skill development activities such as procedure training, professionalism and emotional intelligence, roles in team-based care, and interpersonal communication. Fig.  Nearly aEvaluations and assessments of PA fellows incorporate various methods. The more common techniques are one-on-one observations by a mentor or preceptor, instructor evaluations, through regular reviews with the program director or supervising  physician, completion of program requirements, and achieving clinical milestones Fig. .Fig. 4MAdministratively half (55%) of PA postgraduate programs reside in medical schools, with (40%) in health science colleges, and one (5%) in a nursing school. Three-quarters (76%) of the hospitals that sponsor PA postgraduate programs are affiliated with an academic medical center. The others are vertically integrated multi-hospital systems such as The Mayo Clinic (located in three states) (15%), community hospitals (6%), and one in an ambulatory clinic. Nearly all PA postgraduate programs (94%) credentialed and privileged the PA fellows similarly to other PAs and NPs in the organization. Almost all PA postgraduate programs (97%) award a certification of completion or a diploma (3%). The combined Army/Air Force – Baylor University program awards a Doctor of Science (DSc) for active-duty members and Arrowhead Orthopedics, in collaboration with University of Lynchburg, offers a Doctor of Medical Science (DMSc) track .fellows, but our program is HRSA grant-funded which is NP only and requires the name resident.”PAs in postgraduate training are referred to as “Fellows” (59%) or “Residents” (41%). One respondent commented, “We refer to them as Most programs (88%) draw on a national applicant pool with the remainder relying on regional or local applicants. All PAs accepted into a program are graduates of an accredited program and all are nationally certified by the National Commission on the Certification of Physician Assistants (NCCPA). Entry into a postgraduate PA program most commonly occurs within 2 years of graduation.Upon graduation from a postgraduate training program, the respondents reported that (96%) were employed within 2 months. When asked about the employment opportunity for graduates from the postgraduate programs, and (78%) reported the demand was “high.”.The majority of postgraduate programs (90%) reported that the chief administrator was a PA. One PA reported being a full-time administrator of multiple tracks, with the remainder varying from 4 h to 20 h a week of single-track programs (63%). Most (80%) of the PA administrators reported 5 years or more of clinical experience before assuming the program director role. In addition, a medical director was assigned to all PA postgraduate programs. The role of the medical director serves as the main medical supervisor of the PA fellow with involvement in educational assessment and program advocacy. The majority (76%) of physician medical directors are not allocated additional administrative time outside their clinical responsibilities. In most cases, physician supervision is a requirement of PA state licensure. A majority of programs have administrative support. Programs differed administratively by clinical department (38%), office of Graduate Medical Education (29%), office of ‘advanced practice’ (13%), medical group (13%), or other (7%). Figure 5The majority of costs associated with the PA postgraduate education were derived from the medical group (42%) or the hospital system (46%) with the remainder from graduate medical education or a private donor (12%). Also, 90% postgraduate programs reported that they do no pay an honorarium or stipend to clinical faculty to supervise postgraduate APP trainees in the clinical setting. Lastly, administrative costs to keep the program operational were not studied.PAs enrolled in postgraduate education are NCCPA-certified, licensed in the state where the program resides, and eligible for billing of their services. Billing is done by the hospital, medical group, or academic medical center and most (79%) reported billing for services provided by the PA fellow. Additionally, four program directors said they intended to begin billing for services rendered by their PAs. It should be noted that not all PA postgraduate programs bill for first assist services. Billing for these services typically requires an attestation from the surgeon that no qualified medical resident is available to assist with eligible operative cases. Medicare reimbursement for a PA/NP assisting in surgery is 13.6% of the primary surgeon’s allowable fee and some surgeries are ‘restricted’ from reimbursement.All programs provide a stipend for the PA fellow. The amount varied between $50,000–80,000 (2019 dollars). Omitted were the wages for federal employees  which are government scheduled and at a higher rate than civilian stipends. Employment benefits (not reported) include paid time off (2–4 weeks), health insurance, CME, liability insurance, and clothing/uniforms.If ARC-PA accreditation becomes available for your program will you pursue it?” Two-thirds (67%) said they would decline. Another two-thirds (68%) said they had discussed ARC-PA accreditation funding with their institution. The main reason for declining accreditation was cost (48%), as well as lack of support (18%), and other (joint PA/NP program or cost of multi-track programs). A plurality (37%) would be interested in applying for joint accreditation (not yet available) if it included NPs.Accreditation of PA postgraduate programs has been evolving in various forms since 2010 but the process was put in “abeyance” in 2014. One reason for suspension was that not all programs participated in accreditation, and none were bound by the accreditation process. The following survey question was about an accreditation process. ““There is an undeniable need for a JOINT accreditation process … as more programs are accepting NP and PA applicants.”To probe the reasons why programs have developed and remain operational, a series of questions were asked. Almost all agreed that recruitment and retention of postgraduate trainees are part of meeting workforce demands (83%), and retention of career staff (55%). Most program directors (76%) believed their program improved decision making and autonomy of PAs/NPs in the clinical setting. Additionally, (93%) of respondents believed their postgraduate program fostered interprofessional collaboration. Lastly, (34%) of respondents felt their postgraduate training program improved compliance with physician resident regulated work hours.This is the first study to describe the broad characteristics of postgraduate PA development in the United States. These findings shed light on the demographic, administrative, and educational aspects associated with PA postgraduate education. This information is of particular interest given the rising number of PA postgraduate programs and the desire for PA specialty training opportunities to support emerging and changing healthcare care needs. Additionally, the findings can be used to support PA postgraduate program development and expansion, continuous process improvement, and perhaps inform future policy decisions. The findings narrow the gap in the literature concerning post-graduate PA education and provides a springboard for further study on its perceived utility.In 2020, an estimated 200 enrollees have graduated from 72 programs . BecauseWhy did PA postgraduate programs develop and why do they remain operational? From the program director’s viewpoint, having a PA postgraduate program in clinical medicine and surgery provides the new PA an opportunity to focus on a specialty and receive intensive training in a structured and abbreviated period. Value for the employing hospital or medical practice is from providers who can also supplement the reduction in physician residency slots and limitations on resident work hours , 14. PAsAdministratively, adding a PA into an existing postgraduate training program is not likely to impact the ‘span of management’ for an attending physician. Adding another trainee at the margin appears to require little more in the human resource office or in department commitment . From thAs for the future, based on this census and survey project, half of the respondent programs have been operational for more than 10 years. Older programs include Montefiore Hospital , Norwalk Hospital/Yale Medical University (Burn/Surgery), The Army/Air Force-Baylor doctoral program  and Arrowhead Orthopedic Surgery PA Fellowship program. Most of the programs 74%) provide experience in the inpatient and outpatient settings. A growing number of institutions, such as The Mayo Clinic, have multiple postgraduate programs for PAs and NPs located on three campuses suggesting their demand is growing in large medical centers % provide. The VHAAll surveys have limitations and this one was no exception. The APPAP survey was lengthy (average 17 min), which may have contributed to response fatigue and a low rate of return (47%). Online surveys capture convenient samples that may or may not be representative ones with varying rates of survey responses that may lead to the potential for bias. In addition, several clinically focused educational programs were suspended, or activity restricted, during the COVID-19 pandemic. This may have affected the ability or interest of program personnel to complete the survey.One shortcoming is the limited information about NP postgraduate residencies in this census. The first NP residency began in 2007  and centAnother limitation is that it was a single-mode survey delivered by email invitation. No incentives were offered even though they can improve response rates in certain situations. The strength of this survey is its uniqueness in providing a contemporary overview of the characteristics of American clinical postgraduate education., grants) opportunities for postgraduate PA programs, assessing the career arc of PA/NP graduates, comparing postgraduate to on-the-job trainees, and assessing the opportunity cost of PA and NP postgraduate programs.The movement to enhance the graduate PA with additional clinical education began in 1973. A half century later, PA postgraduate programs remain a viable option for licensed PAs seeking specialty training in a variety of medical and surgical disciplines. Those most represented are surgery, emergency medicine, critical care, and orthopaedics. Most postgraduate programs are one year in length and utilize the PA as house officer alongside categorical residents. The 34 participating PA program directors in this APPAP member survey have several elements in common as they align with General Medical Education approved postgraduate programs and the PA is added at the margin of infrastructure. The prediction is that PA and NP postgraduate programs will grow as the shortfall in medical and surgical specialties worsens. As a source of readily available and reliable medical and surgical workforce their addition appears to be a necessity. Areas of needed research include return on investment for the sponsoring institution, external funding (i.e.Additional file 1.


Digital therapeutics are evidence-based therapeutic interventions driven by high-quality software programs for the treatment, prevention, or management of a medical disorder or disease. Many studies in the western population have shown the effectiveness of mobile app–based digital therapeutics for improving glycemic control in patients with type 2 diabetes (T2D). However, few studies have assessed similar outcomes in the South Asian population.This study aims to investigate the real-world effectiveness of the Wellthy CARE digital therapeutic for improving glycemic control among the South Asian population of Indian origin.1c (HbA1c). Secondary outcomes included the difference between preintervention and postintervention fasting blood glucose (FBG) and postprandial blood glucose (PPBG) levels; changes in BMI and weight at the completion of 16 weeks; and the association between program engagement and the changes in HbA1c, FBG, and PPBG levels.We analyzed deidentified data from 102 patients with T2D from India enrolled in a 16-week structured self-management program delivered using the Wellthy CARE mobile app. Patients recorded their meals, weight, physical activity, and blood sugar in the app, and they received lessons on self-care behaviors ; feedback provided by an artificial intelligence–powered chatbot; and periodic interactions with certified diabetes educators via voice calls and chats. The primary outcome of the program was a change in glycated hemoglobin A1c was –0.49% . Of all the patients, 63.7% (65/102) had improved HbA1c levels, with a mean change of −1.16% . The mean preintervention and postintervention FBG levels were 145 mg/dL  and 134 mg/dL  and PPBG levels were 188 mg/dL  and 166 mg/dL , respectively. The mean changes in BMI and weight were –0.47 kg/m2  and –1.32 kg , respectively. There was a stepwise decrease in HbA1c, FBG, and PPBG levels as the program engagement increased. Patients in the highest tertile of program engagement had a significantly higher reduction in HbA1c , FBG , and PPBG levels  than those in the lowest tertile.At the end of 16 weeks, the average change in HbA1c, FBG, and PPBG after 16 weeks. A higher level of participation showed improved glycemic control, suggesting the potential of the Wellthy CARE platform for better management of the disease.The use of the Wellthy CARE digital therapeutic for patients with T2D showed a significant reduction in the levels of HbA South Asians represent approximately one-fourth of the global population and are at a disproportionately higher risk of being diagnosed with type 2 diabetes (T2D). The global population of patients with diabetes was estimated to be 463 million in 2019 and is projected to reach 578 million by 2030, while that in South East Asia was 88 million in 2019 and is expected to reach 115 million by 2030 [Lifestyle management is a fundamental aspect of diabetes care and includes diabetes self-management education and support, medical nutrition therapy, physical activity, smoking cessation counseling, and psychosocial care. Behavioral and lifestyle interventions have been recognized as integral aspects of improving outcomes in these patients. An integrated self-management regimen requires patients to adhere to regular self-glucose monitoring, healthy eating, exercise, and regular physician and specialist visits . Self-moDespite robust evidence that lifestyle interventions in diabetes lead to a reduction in risk factors for cardiovascular diseases , self-ca1c (HbA1c) levels [Studies that have examined the effectiveness of diabetes education programs in improving glycemic control in Asian Indians have reported contrasting results depending on the region and intervention ,16. One ) levels . Traditi) levels ,18,19.The widespread adoption of mobile phone technologies in middle- and low-income countries underscores the potential for digital therapeutics to negotiate and overcome the practical roadblocks inherent to conventional physicians and in-clinic–based  interventions and education . Technol1c and blood sugar levels) and other health outcomes (weight) in patients with T2D after 16 weeks of the program.On the basis of the role of emerging evidence, we hypothesized that a digital therapeutic with an artificial intelligence (AI)–powered decision support system could enhance multiple behavior patterns  among South Asian patients with T2D. The aim of this study is to assess the real-world effect of the Wellthy CARE digital therapeutics platform on glycemic control , postprandial blood glucose (PPBG), BMI, and weight and program engagement measures in a convenience sample of adults with a self-reported diagnosis of T2D.We conducted an analysis of deidentified data for 102 patients with T2D on the Wellthy CARE mobile app. The analysis involved preintervention and postintervention assessment of HbA1c level of 6.5% or higher. User information was recorded on a web-based form, based on which the participants received a final decision on their eligibility to enroll.Participants were recruited through 2 channels: (1) a network of primary care clinics and diabetes centers through referrals from their treating physicians and (2) a social media campaign seeking participants for a smartphone-based diabetes management program. Patients expressed interest in participating in the program either by (1) calling a telephone number provided on the program recruitment handout or (2) filling out a preregistration form linked to the social media campaign where they voluntarily provided their mobile numbers. Patients who expressed interest in participating in the program received a screening phone call from the program staff members, explaining the program. Those who confirmed their willingness to participate underwent a screening interview (based on inclusion and exclusion criteria) to assess their eligibility. Preexisting T2D status was based on a combination of a self-reported diagnosis and a preintervention HbAEligible patients were invited to download the mobile app from the Google Play Store using a unique link sent to them via SMS or text messages. On the mobile app, participants were then instructed to set up their unique account with their phone number and a one-time password sent to them. After the account set up, patients were requested to provide informed consent for their participation in the program and the use of their deidentified data for clinical research purposes.The inclusion criteria for enrollment were as follows:1c >6.5%)Male or female adult patients aged 18 years or above at the time of enrollment, with a self-reported diagnosis of T2D  smartphone with an active internet connection and the person should be comfortable in reading English content on the phoneNo history of a major surgical procedure during the previous 6 months or plan for any major surgical procedure in the next 6 monthsAbsence of any medical condition that prevented them from walking for 15 minutes to 30 minutes a dayThe exclusion criteria for enrollment were as follows:Diagnosis of type 1 diabetes, gestational diabetes mellitus, maturity-onset diabetes of young, or any other forms of diabetesUndergoing hemodialysis for chronic kidney diseaseHistory of any serious heart-related event such as a heart attack or stroke in the past 1 yearPregnant, nursing, or planning for a pregnancy in the next 6 monthsParticipants were not compensated for participation but were enrolled in the program at no cost. Informed consent for using their deidentified data for clinical research was obtained from each participant before enrollment in the program. Participation in the program was voluntary, and refusal to grant consent for the use of their deidentified data for research did not affect the participants’ enrollment in the program or the quality of care administered to them. This work involved only secondary analyses of deidentified data; hence, no ethics clearance was obtained. The program did not use any investigational product, and all physical assessments and education were used as usual customary care. No change in treatment was made, and patient care was provided according to the normal clinical standards.conversation experience by an AI-powered chatbot that provided educational, behavioral, and motivational messaging specific to the data entered and in the context of the patient’s previous clinical, lifestyle, and behavioral data.The program was a 16-week structured lifestyle coaching delivered through the Wellthy CARE digital therapeutic consisting of the Wellthy CARE mobile app for Android smartphones, a web portal for health coaches to visualize patient data and communicate with them, and an AI-powered decision support system enabled across the platform . The WelThe program adopted a digital persuasion model that focused on improving the patients’ motivation, reducing the difficulty in performing a particular task, and then delivering appropriate triggers to the patients to take action. This was done through short culturally relevant content delivered in multiple formats such as informative lessons, videos, and protips along with quizzes and storyboards to reinforce the information and simple tasks to prompt actions. Patients could optionally enroll for challenges that required them to repeat an action multiple times during a specific period to enable skill formation. The program adopted a gamified approach to building skills and rewarded patients with virtual trophies as they completed the lessons, tasks, and challenges. A secure messaging system on the Wellthy CARE app was used by patients to communicate directly with their personal health coach at their own convenience.virtual diabetes educators who regularly reviewed patient data, providing personalized feedback during each interaction, and also responded to patient queries. All patients received a voice call at the start of the program. Health coaches could supplement automated messages with electronic messages sent to patients via a secure messaging system. Health coach messages were based on longitudinal data trends, providing weekly and monthly summaries to patients on their performance. About 50% of patients made voice calls to or received voice calls from the health coach during the program, in addition to communicating over the messaging system. This was an incremental and supportive program for the existing standard of care recommended by the treating physician.Health coaches were 1c test was performed before and after the completion of the intervention by an independent pathological laboratory that reported the values directly.A total of 102 participants completed and logged data during the 16 weeks on the Wellthy CARE platform. The participants self-reported their age, gender, height, and weight in the Wellthy CARE mobile app. All patients received a Gluco One (Dr Morepen) glucose meter and strips. The HbA1c level at the completion of the program (16 weeks). Secondary objectives included the difference between the mean preintervention and postintervention FBG and PPBG levels in participants who reported more than one blood sugar reading; change in BMI and weight in participants that reported more than one weight log; and association between program engagement, measured as the total number of interactions with the health coach and the AI-powered chatbot, and the change in HbA1c, FBG, and PPBG levels. In addition, we assessed the differences among patients who had an improvement of ≥0.4% in HbA1c (responders) and those who did not (nonresponders).The primary outcome of this study was the change in HbAt tests analysis for continuous variables and paired t tests for comparing preintervention and postintervention values for continuous variables. P values <.05 were considered statistically significant.Statistical analysis was performed using R software . The results were analyzed to identify program starters  and program completers . Baseline characteristics were compared between subgroups using chi-square tests or Fisher exact test for categorical variables and 2-sample two-tailed 1c among all patients was −0.49%  had a decrease of 0.5% or more and 27.5% (28/102) had a decrease of 1% or more; moreover, 29.4% (30) of the patients had a follow-up HbA1c level less than or equal to 7%. Among those with a baseline HbA1c level ≥7.5%, the mean change was −0.57% .The mean change in HbA1c levels was assessed after 16 weeks of the program. There was a stepwise decrease in HbA1c levels as the program engagement level increased  and the middle tertile of program engagers reduced their HbA1c levels by 0.76% (95% CI −1.33 to −0.18); however, those in the highest tertile of program engagers significantly reduced their HbA1c levels by 0.84% as compared with patients in lowest tertile .The relationship between program engagement and changes in HbAncreased . Among t1c levels and those who did not were grouped as nonresponders. The mean change in HbA1c among responders  was −1.34% (95% CI −1.07% to −1.60%), and that among nonresponders  was 0.43%  and PPBG  values (Among patients who reported more than one blood sugar reading (51/102), there was a significant difference between the mean preintervention and postintervention FBG  values .P=.02, highest vs lowest) and PPBG by 22.03 mg/dL  among the nonresponders  than the mean preintervention PPBG of 206 mg/dL among nonresponders , and the mean BMI reduction in males and females was −0.38 kg/m2  and −0.73 kg/m2 , respectively. The change in mean weight was −1.32 kg , and the mean weight change in males and females was −1.11 kg  and −2.00 kg , respectively.There was a significant change in BMI  and in wP=.005) among the nonresponders. There was no significant difference in the mean preintervention weight between responders and nonresponders.The responders reduced their weight by −2.36 kg  as compared with −0.26 kg  and reduce weight in patients of South Asian origin with T2D after a duration of 16 weeks of the program. Patients who used the digital therapeutic for 16 weeks reduced their HbA1c levels by 0.49% (n=102), FBG by 11 mg/dL (n=51), PPBG by 21 mg/dL (n=51), weight by 1.32 kg (n=59), and BMI by 0.47 kg/m2 (n=59). Patients with the highest engagement significantly reduced their HbA1c levels by 0.84%, FBG by 21.4 mg/dL, and PPBG by 22.03 mg/dL. There was a higher reduction in HbA1c, FBG, and PPBG levels as program engagement increased.This study assessed the effectiveness of the Wellthy CARE digital therapeutics platform to improve glycemic control  used for the selection of participants and reliance on self-reported disease biomarkers. The program was conducted for a short duration, and we did not independently quantify the effect of other behavioral and lifestyle measures on glycemic outcomes. This analysis can prove to be beneficial in providing important insights, especially when comparing the results of the Wellthy CARE platform with other digital therapeutics platforms. Real-world data helped in the study of people outside a controlled set of conditions. This increased the variability in the study; however, such studies have shown to be very helpful for the evaluation of new technologies. A variation in the number of male and female participants was noted, which was an undesirable bias due to social, economic, or other factors. The loss of data during follow-up also limited the scope of the study. However, the reporting for HbA1c levels, positive relationship of mobile app engagement with improvement in glycemic control, good rate of retention, and successful data collection contributed to its strength. The other strengths were that the app was implemented with the support of the same developmental processes and core support team that were involved in the development phase.The strength of this work was its design, which enabled us to closely simulate real-world implementations. The effectiveness of the intervention in documenting meaningful changes in HbA1c, FBG, and PPBG values with greater levels of engagement, suggesting the feasibility, acceptance, and value of using a digital therapeutic in resource-constrained countries of South Asia. The study findings can be explored further to evaluate the long-term acceptability, cost-effectiveness, and durability of the principal findings and its feasibility to be applied to a larger, culturally similar population.This work is one of the first to report the real-world effectiveness of a digital therapeutic that was a structured, behavioral, and self-management intervention delivered using a mobile-enabled app and an AI-powered decision support system—Wellthy CARE in improving glycemic control among South Asians with T2D. The intervention demonstrated incremental reduction in HbA