| 1. |
- Allentoft, Morten E., et al.
(författare)
-
100 ancient genomes show repeated population turnovers in Neolithic Denmark
- 2024
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625, s. 329-337
-
Tidskriftsartikel (refereegranskat)abstract
- Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales1–4. However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution5–7. Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet (13C and 15N content), mobility (87Sr/86Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use.
|
|
| 2. |
- Allentoft, Morten E., et al.
(författare)
-
Population genomics of post-glacial western Eurasia
- 2024
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 625:7994, s. 301-311
-
Tidskriftsartikel (refereegranskat)abstract
- Western Eurasia witnessed several large-scale human migrations during the Holocene1–5. Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes—mainly from the Mesolithic and Neolithic periods—from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a ‘great divide’ genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 bp, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 bp, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a ‘Neolithic steppe’ cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.
|
|
| 3. |
- Becker-Larsen, Astrid, et al.
(författare)
-
"Organizing for excellence" : stress-recovery states in the Danish national orienteering team during a training camp and the 2015 World Championship
- 2017
-
Ingår i: Sport psychology: Linking theory to practice. - 9788491482826 ; , s. 639-640
-
Konferensbidrag (refereegranskat)abstract
- Elite level athletes are under considerable pressure to perform, why energy management is a natural part of the life of elite athletes. Energy management is particularly important during periods of high demand on their resources, such as during training camps and competitions, which are often intense and do not allow sufficient time for recovery. Research on recovery has mainly focused on individual physical and physiological strategies. In the 2015 World Championship, the Danish national orienteering team was the best nation, winning four gold medals. In the present study we examined: (a) the stress-recovery states of the Danish orienteers during a three-week preparatory training camp and the following 2015 World Championship, and (b) their perceived sources of stress and recovery during the two events. The study was designed as mixed-method with the RESTQ-sport questionnaire, semi-structured interviews, and a coach’s journal as the data sources used longitudinally during the camp and the championship. Results revealed: (a) well-balanced stress-recovery states among all athletes during the entire period; and (b) perceived sources of stress and recovery classified into organizational, social, personal, and athletic. The athletes themselves stated that their well-balanced stress-recovery states positively affected their learning, well-being, and performance. The organizational strategies played a key role in reducing athletes’ unnecessary stress and in facilitating individual recovery. We suggest that “organizing for excellence”, keeping in mind athletes' energy management, is a special task for coaches and managers when preparing for camps and competitions.
|
|
| 4. |
- Becker-Larsen, Astrid, et al.
(författare)
-
“Organizing for Excellence” : Stress-Recovery States in the Danish National Orienteering Team during a Training Camp and the 2015 World Championship
- 2017
-
Ingår i: Scandinavian Sport Studies Forum. - Malmö : Malmö University. - 2000-088X. ; 8, s. 87-111
-
Tidskriftsartikel (refereegranskat)abstract
- Elite athletes push themselves physically and psychologically to their limits in order to develop as athletes and to deliver top performances. To succeed, the athletes must manage their energy. This is particularly important in the periods of high demand on the athletes’ resources (Kellmann, Altenburg, Lormes, & Steinacker, 2001). These include training camps and competitions, because such events are generally intense and likely to induce increased stress, and their schedules often do not allow sufficient time for recovery (Elbe & Kellmann, 2007; Foster, Snyder, & Welsh, 1999). In 2015, the Danish national orienteering coach decided, as a new initiative, to include a three-week training camp in their preparation for the World Championship. The coach was aware that such a long period of intense focus on orienteering would require efficient energy management in the athletes. Therefore, the coach supported the research team in this study aimed at monitoring the athletes’ stress-recovery states during the preparatory camp and the World Championship, with further exploration of the athletes’ perceived sources of stress and recovery during the same period. From a research perspective, the present study is exclusive because of monitoring world-class athlete-participants during their preparation and participation in their most important event. From an applied perspective, searching for efficient processes for energy management during long-term training camps and competitions might become a frontier for improvement of athletes’ preparation and performance.
|
|
| 5. |
- Becker-Larsen, Astrid, et al.
(författare)
-
“Organizing for Excellence” : Stress-Recovery States in the Danish National Orienteering Team during a Training Camp and the 2015 World Championship
- 2017
-
Ingår i: Scandinavian Sport Studies Forum. - : Department of Sport Studies, Malmö University. - 2000-088X. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- Energy management is a natural part of the life of elite athletes. This is particularly important during periods of high demand on their resources, such as during training camps and competitions, which are often intense and do not allow sufficient time for recovery. In the 2015 World Championships, the Danish national orienteering team was the best nation, winning four gold medals. In the present study we examined: (a) the stress-recovery states of the Danish orienteers during a three-week preparatory training camp and the following 2015 World Championships, and (b) their perceived sources of stress and recovery during the two events. The study was designed as case study with the RESTQ-sport questionnaire, semi-structured interviews, and a coach’s journal as the data sources used longitudinally during the camp and the championships. Results revealed: (a) well-balanced stress-recovery states among all athletes during the entire period; and (b) perceived sources of stress and recovery classified into organizational, social, personal, and athletic. The organizational strategies played a key role in reducing athletes’ unnecessary stress and in facilitating individual recovery. We suggest that “organizing for excellence”, keeping in mind athletes’ energy management, is a special task for coaches and managers when preparing for camps and competitions.
|
|
| 6. |
- Biasin, Elisa, et al.
(författare)
-
Anisotropy enhanced X-ray scattering from solvated transition metal complexes
- 2018
-
Ingår i: Journal of Synchrotron Radiation. - 0909-0495. ; 25:2, s. 306-315
-
Tidskriftsartikel (refereegranskat)abstract
- Time-resolved X-ray scattering patterns from photoexcited molecules in solution are in many cases anisotropic at the ultrafast time scales accessible at X-ray free-electron lasers (XFELs). This anisotropy arises from the interaction of a linearly polarized UV-Vis pump laser pulse with the sample, which induces anisotropic structural changes that can be captured by femtosecond X-ray pulses. In this work, a method for quantitative analysis of the anisotropic scattering signal arising from an ensemble of molecules is described, and it is demonstrated how its use can enhance the structural sensitivity of the time-resolved X-ray scattering experiment. This method is applied on time-resolved X-ray scattering patterns measured upon photoexcitation of a solvated di-platinum complex at an XFEL, and the key parameters involved are explored. It is shown that a combined analysis of the anisotropic and isotropic difference scattering signals in this experiment allows a more precise determination of the main photoinduced structural change in the solute, i.e. the change in Pt - Pt bond length, and yields more information on the excitation channels than the analysis of the isotropic scattering only. Finally, it is discussed how the anisotropic transient response of the solvent can enable the determination of key experimental parameters such as the instrument response function.The analysis of time-resolved X-ray scattering patterns collected at an XFEL upon photoexcitation of a di-platinum complex in solution is described. The analysis quantitatively considers the anisotropy of the signal.
|
|
| 7. |
- Book Jr., Robert T., et al.
(författare)
-
Oatmeal is better than no meal : the career pathways of ten professional athletes from underserved communities in the United States
- 2021
-
Ingår i: International Journal of Sport and Exercise Psychology. - New York : Taylor & Francis. - 1612-197X .- 1557-251X. ; 19:4, s. 504-523
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to explore career pathways to athletic success in American professional athletes with low socioeconomic background. Ten African American professional male athletes, who met the criteria of playing at least one year in a professional league and spending their formative years in an American underserved community, participated in the study. Interviews inspired by the cultural praxis of athletes’ careers, lasted 68-137 minutes, and the transcripts were thematically analysed. Four career stages (childhood years, middle/high school years, college years, professional years) and three themes (context, challenges, coping) were visible in the career pathways of the participants. During the first stage the athletes’ athletic foundation was developed by participating in inexpensive, easy to access sports in unstructured sporting environments, while simultaneously relying upon the strength of a mother to keep them safe. An increased susceptibility to the dangers of environmental factors (e.g., drugs, gangs) during the middle/high school years made this period of time the most precarious for the athletes, but was also the most crucial for their athletic development. The college years were a time of “catching up,” whereby the athletes entered a whole new environment for which they were physically (e.g., underweight) and psycho-socially (e.g., racial integration) unprepared, but their hard work and the help of peers and coaches propelled them to success (i.e., professional contract). Finally, the results indicate that coping resources the athletes developed dealing with hardship were perceived as key factors enabling them to endure the difficulties of a professional career. © 2020 International Society of Sport Psychology.
|
|
| 8. |
- Book Jr, Robert T., et al.
(författare)
-
Sink or swim : career narratives of two African American athletes from underserved communities in the United States
- 2021
-
Ingår i: Qualitative Research in Sport, Exercise and Health. - Abingdon : Routledge. - 2159-676X .- 2159-6778. ; 13:6, s. 904-919
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to explore the career narratives of professional athletes from underserved communities in the United States. Two African American athletes (named Marcus and Imari for the study), who both met the criteria of playing at least one year in a professional league and spending their formative years in an underserved community, participated in this study. Life story interviews lasting about two hours were explored through the principles of narrative analysis, focusing on both content and structure. Each participant constructed a sink or swim narrative typology termed risk, descent, and gain that focused more on the environmental context in an underserved community than their athletic development, which opposes the performance narrative often depicted by professional athletes. Although the contextualised nature of risk manifested differently for Marcus and Imari, their life courses both reflected low points precipitated by risky decisions or circumstances followed by gainful moments ultimately culminating in professional contracts. The analysis also uncovered the realities and challenges associated with having the intersecting identity of being a poor, Black aspiring athlete in a racially charged atmosphere. Finally, the athletes’ perceptions of how their challenging formative development influenced their professional career pathway as well as the ramifications of sink or swim narratives in popular American culture are considered. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group.
|
|
| 9. |
- Book, Robert T., et al.
(författare)
-
“All they have seen is a model for failure:” Stakeholder’s perspectives on athletic talent development in American underserved communities
- 2022
-
Ingår i: Journal of Applied Sport Psychology. - Philadelphia : Routledge. - 1041-3200 .- 1533-1571. ; 34:6, s. 1037-1057
-
Tidskriftsartikel (refereegranskat)abstract
- This study explores the primary challenges faced and strategies implemented in underserved athletic talent development environments (UATDEs) in the United States and examines how developing within such environments impacts athletes once they reach the college and professional levels of sports. Thirteen stakeholders (M = 10, F = 3), who had significant experience working with professional and youth athletes from underserved communities, participated in the study. Unstructured interviews lasting slightly over an hour (M = 74 min) were analyzed using the principles of reflexive thematic analysis and the process uncovered two categories: shared features of school-based UATDEs in the United States and the ripple effects of trauma which were used to structure the findings. Within these two categories, primary themes were presented relating to the challenges observed and strategies implemented to overcome these obstacles in UATDEs as well as how developing within a UATDE can influence an athlete upon leaving the environment. The study found that stakeholders (i.e., administrators, coaches, etc.) who work within UATDEs must be aware of the inherent challenges that the environment creates and how to best support the athletes who require increased psychosocial developmental attention. Further, the same stakeholders also need to be supported in their work. Finally, when athletes from UATDEs leave the environment, stress-inducing traumatic events of their formative years may stay with them requiring that stakeholders at the university and professional levels provide support to those that need it as talent can suffer from trauma. Lay summary: This study explored the perceptions of stakeholders who work with athletes in or coming from American underserved communities. The consensus is that significant challenges exist for coaches working in such environments and athletes developing in these circumstances will likely carry emotional trauma with them during their life and athletic careers.Implications for practice Applied practitioners working in UATDEs must prioritize the psychosocial development of their athletes as much, if not more, than athletic development. Organizations, such as AASP and ISSP must educate (e.g., through conferences, seminars, webinars, etc.) stakeholders and coaches working in UATDEs of the potential challenges faced and resources required to excel in such environments. Applied practitioners in university and professional sport must understand that athletes coming from UATDEs will need additional and specialized support focused upon, for example, the transition to a new environment or managing the ripple effects of trauma. © 2021 Association for Applied Sport Psychology.
|
|
| 10. |
- Book, Robert T., et al.
(författare)
-
Empowering youth athletes against the odds : Successful talent-development environments in underserved communities
- 2019
-
Ingår i: Abstract book. ; , s. 321-321
-
Konferensbidrag (refereegranskat)abstract
- The research on the career pathways of professional athletes is well established in sport psychology, yet this field is lacking insight into the lives of athletes whose formative years were spent primarily in an American underserved community (Stambulova & Wyllemann, 2014). Using the Holistic Ecological Approach as a framework, this PhD project’s aim is to begin to understand how professional athletes were able to circumvent the environmental hardships and still reach the professional level of their chosen sport (Henriksen, 2010; Henriksen & Stambulova, 2017). This study involved in-depth, biographical interviews with N = 10 professional athletes who overcame significant adversity. Through the analysis of the data, many commonalities emerged. Key transitional and existential relationships, an understanding that sport was a way out of hardship and an ability to shift and persist through adversity, were key themes identified in the data. However, considering multi- and equifinality, no two lives are exactly the same and life stories can converge and diverge at many different junctions. Thus, this presentation will contain a brief summary of two athletes who overcame many of the same obstacles, reached a similar level in their sport, yet it is clear that their environment shaped them in drastically different ways.
|
|
