Social Media Does Not Elicit a Physiological Stress Response as Measured by Heart Rate and Salivary Cortisol Over 20-Minute Sessions of Cell Phone Use

The pervasive use of social media has raised concerns about its potential detrimental effects on physical and mental health. Others have demonstrated a relationship between social media use and anxiety, depression, and psychosocial stress. In light of these studies, we examined physiological indicators of stress (heart rate to measure autonomic nervous system activation and cortisol to assess activity of the hypothalamic-pituitary-adrenal axis) associated with social media use and investigated possible moderating influences of sex, age, and psychological parameters. We collected physiological data from 59 subjects ranging in age from 13 to 55 across two cell phone treatments: social media use and a pre-selected YouTube playlist. Heart rate was measured using arm-band heart rate monitors before and during cell phone treatments, and saliva was collected for later cortisol analysis (by enzyme immunoassay) before and after each of the two cell phone treatments. To disentangle the effects of cell phone treatment from order of treatment, we used a crossover design in which participants were randomized to treatment order. Our study uncovered a significant period effect suggesting that both heart rate and cortisol decreased over the duration of our experiment, irrespective of the type of cell phone activity or the order of treatments. There was no indication that age, sex, habits of social media use, or psychometric parameters moderated the physiological response to cell phone activities. Our data suggest that 20-minute bouts of social media use or YouTube viewing do not elicit a physiological stress response

Pleiades or Not? Resolving the Status of the Lithium-rich M Dwarfs HHJ 339 and HHJ 430

Oppenheimer et al. discovered two M5 dwarfs in the Pleiades with nearly primordial lithium. These stars are not low enough in mass to represent the leading edge of the lithium depletion boundary at Pleiades age (~125 Myr). A possible explanation for the enhanced lithium in these stars is that they are actually not members of the Pleiades but instead are members of a younger moving group seen in projection toward the Pleiades. We have used data from Gaia DR2 to confirm that these two stars, HHJ 339 and HHJ 430, are indeed not members of the Pleiades. Based on their space motions, parallaxes, and positions in a Gaia-based color–magnitude diagram, it is probable that these two stars are about 40 parsecs foreground to the Pleiades and have ages of ~25 Myr. Kinematically they are best matched to the 32 Ori moving group

A phase I, open-label, randomized crossover study to assess the effect of dosing of the MEK 1/2 inhibitor Selumetinib (AZD6244; ARRY-142866) in the presence and absence of food in patients with advanced solid tumors

<p><b>Purpose:</b> This Phase I study assessed whether food influences the rate and extent of selumetinib absorption in patients with advanced solid malignancies and determined the safety, tolerability, and pharmacokinetic (PK) profile of selumetinib and its active metabolite N-desmethyl-selumetinib in fed and fasted states.</p> <p><b>Methods:</b> A single dose of 75 mg selumetinib was to be taken with food on Day 1 followed by a single dose of 75 mg after fasting for at least 10 h on Day 8, or vice versa, followed by twice daily dosing of 75 mg selumetinib from Day 10. Plasma concentrations and PK parameters were determined on Days 1 and 8. Patients could continue to receive selumetinib for as long as they benefitted from treatment.</p> <p><b>Results:</b> In total, 31 patients were randomized to receive selumetinib; 15 to fed/fasted sequence and 16 to fasted/fed sequence. Comprehensive PK sampling was performed on 11 and 10 patients, respectively. The geometric least-squares means of C<sub>max</sub> and AUC for selumetinib were reduced by 62% (ratio 0.38 90% CI 0.29, 0.50) and 19% (ratio 0.81 90% CI 0.74, 0.88), respectively, under fed compared with fasting conditions. The rate of absorption (t<sub>max</sub>) of selumetinib (fed) was delayed by approximately 2.5 h (median). The food effect was also observed for the active metabolite N-desmethyl-selumetinib. Selumetinib was well tolerated.</p> <p><b>Conclusions:</b> The presence of food decreased the extent of absorption of selumetinib. It is recommended that for further clinical studies, selumetinib be taken on an empty stomach. Selumetinib demonstrated an acceptable safety profile in the advanced cancer population.</p&gt

The Ups and Downs in Women's Employment: Shifting Composition or Behavior from 1970 to 2010?

This paper tracks factors contributing to the ups and downs in women’s employment from 1970 to 2010 using regression decompositions focusing on whether changes are due to shifts in the means (composition of women) or due to shifts in coefficients (inclinations of women to work for pay). Compositional shifts in education exerted a positive effect on women’s employment across all decades, while shifts in the composition of other family income, particularly at the highest deciles, depressed married women’s employment over the 1990s contributing to the slowdown in this decade. A positive coefficient effect of education was found in all decades, except the 1990s, when the effect was negative, depressing women’s employment. Further, positive coefficient results for other family income at the highest deciles bolstered married women’s employment over the 1990s. Models are run separately for married and single women demonstrating the varying results of other family income by marital status. This research was supported in part by an Upjohn Institute Early Career Research Award

A genetic history of the pre-contact Caribbean

Humans settled the Caribbean about 6,000 years ago, and ceramic use and intensified agriculture mark a shift from the Archaic to the Ceramic Age at around 2,500 years ago1,2,3. Here we report genome-wide data from 174 ancient individuals from The Bahamas, Haiti and the Dominican Republic (collectively, Hispaniola), Puerto Rico, Curaçao and Venezuela, which we co-analysed with 89 previously published ancient individuals. Stone-tool-using Caribbean people, who first entered the Caribbean during the Archaic Age, derive from a deeply divergent population that is closest to Central and northern South American individuals; contrary to previous work4, we find no support for ancestry contributed by a population related to North American individuals. Archaic-related lineages were >98% replaced by a genetically homogeneous ceramic-using population related to speakers of languages in the Arawak family from northeast South America; these people moved through the Lesser Antilles and into the Greater Antilles at least 1,700 years ago, introducing ancestry that is still present. Ancient Caribbean people avoided close kin unions despite limited mate pools that reflect small effective population sizes, which we estimate to be a minimum of 500–1,500 and a maximum of 1,530–8,150 individuals on the combined islands of Puerto Rico and Hispaniola in the dozens of generations before the individuals who we analysed lived. Census sizes are unlikely to be more than tenfold larger than effective population sizes, so previous pan-Caribbean estimates of hundreds of thousands of people are too large5,6. Confirming a small and interconnected Ceramic Age population7, we detect 19 pairs of cross-island cousins, close relatives buried around 75 km apart in Hispaniola and low genetic differentiation across islands. Genetic continuity across transitions in pottery styles reveals that cultural changes during the Ceramic Age were not driven by migration of genetically differentiated groups from the mainland, but instead reflected interactions within an interconnected Caribbean world1,8.This work was supported by a grant from the National Geographic Society to M. Pateman to facilitate analysis of skeletal material from The Bahamas and by a grant from the Italian ‘Ministry of Foreign Affairs and International Cooperation’ (Italian archaeological, anthropological and ethnological missions abroad, DGPSP Ufficio VI). D.R. was funded by NSF HOMINID grant BCS-1032255, NIH (NIGMS) grant GM100233, the Paul Allen Foundation, the John Templeton Foundation grant 61220 and the Howard Hughes Medical Institute.Peer reviewe

Genomic Insights into the Formation of Human Populations in East Asia

厦门大学人类学研究所、厦门大学生命科学学院细胞应激生物学国家重点实验室王传超教授课题组与哈佛医学院David Reich教授团队合作，联合全球43个单位的85位共同作者组成的国际合作团队通过古DNA精细解析东亚人群形成历史。研究人员利用古DNA数据检验了东亚地区农业和语言共扩散理论，综合考古学、语言学等证据，该研究系统性地重构了东亚人群的形成、迁徙和混合历史。这是目前国内开展的东亚地区最大规模的考古基因组学研究，此次所报道的东亚地区古人基因组样本量是以往国内研究机构所发表的样本量总和的两倍，改变了东亚地区尤其是中国境内考古基因组学研究长期滞后的局面。 该研究是由王传超教授团队与哈佛医学院（David Reich教授）、德国马普人类历史科学研究所（Johannes Krause教授）、复旦大学现代人类学教育部重点实验室（李辉教授和金力院士）、维也纳大学进化人类学系（Ron Pinhasi副教授）、南洋理工大学人文学院（Hui-Yuan Yeh助理教授）、俄罗斯远东联邦大学科学博物馆（Alexander N Popov研究员）、西安交通大学（张虎勤教授）、蒙古国国家博物馆研究中心、乌兰巴托国立大学考古系、华盛顿大学人类学系、台湾成功大学考古所、加州大学人类学系等全球43个单位的85位共同作者组成的国际合作团队联合完成的。厦门大学人类学研究所、厦门大学生命科学学院细胞应激生物学国家重点实验室为论文第一完成单位。厦门大学人类学研究所韦兰海副教授、胡荣助理教授、郭健新博士后、何光林博士后和杨晓敏硕士参与了研究工作。The deep population history of East Asia remains poorly understood due to a lack of ancient DNA data and sparse sampling of present-day people1,2. We report genome-wide data from 166 East Asians dating to 6000 BCE-1000 CE and 46 present-day groups. Hunter-gatherers from Japan, the Amur River Basin, and people of Neolithic and Iron Age Taiwan and the Tibetan plateau are linked by a deeply-splitting lineage likely reflecting a Late Pleistocene coastal migration. We follow Holocene expansions from four regions. First, hunter-gatherers of Mongolia and the Amur River Basin have ancestry shared by Mongolic and Tungusic language speakers but do not carry West Liao River farmer ancestry contradicting theories that their expansion spread these proto-languages. Second, Yellow River Basin farmers at ～3000 BCE likely spread Sino-Tibetan languages as their ancestry dispersed both to Tibet where it forms up ～84% to some groups and to the Central Plain where it contributed ～59-84% to Han Chinese. Third, people from Taiwan ～1300 BCE to 800 CE derived ～75% ancestry from a lineage also common in modern Austronesian, Tai-Kadai and Austroasiatic speakers likely deriving from Yangtze River Valley farmers; ancient Taiwan people also derived ～25% ancestry from a northern lineage related to but different from Yellow River farmers implying an additional north-to-south expansion. Fourth, Yamnaya Steppe pastoralist ancestry arrived in western Mongolia after ～3000 BCE but was displaced by previously established lineages even while it persisted in western China as expected if it spread the ancestor of Tocharian Indo-European languages. Two later gene flows affected western Mongolia: after ～2000 BCE migrants with Yamnaya and European farmer ancestry, and episodic impacts of later groups with ancestry from Turan.We thank David Anthony, Ofer Bar-Yosef, Katherine Brunson, Rowan Flad, Pavel Flegontov,Qiaomei Fu, Wolfgang Haak, Iosif Lazaridis, Mark Lipson, Iain Mathieson, Richard Meadow,Inigo Olalde, Nick Patterson, Pontus Skoglund, Dan Xu, and the four reviewers for valuable comments. We thank Naruya Saitou and the Asian DNA Repository Consortium for sharing genotype data from present-day Japanese groups. We thank Toyohiro Nishimoto and Takashi Fujisawa from the Rebun Town Board of Education for sharing the Funadomari Jomon samples, and Hideyo Tanaka and Watru Nagahara from the Archeological Center of Chiba City who are excavators of the Rokutsu Jomon site. The excavations at Boisman-2 site (Boisman culture), the Pospelovo-1 site (Yankovsky culture), and the Roshino-4 site (Heishui Mohe culture) were funded by the Far Eastern Federal University and the Institute of History,Archaeology and Ethnology Far Eastern Branch of the Russian Academy of Sciences; research on Pospelovo-1 is funded by RFBR project number 18-09-40101. C.C.W was funded by the Max Planck Society, the National Natural Science Foundation of China (NSFC 31801040), the Nanqiang Outstanding Young Talents Program of Xiamen University (X2123302), the Major project of National Social Science Foundation of China (20&ZD248), a European Research Council (ERC) grant to Dan Xu (ERC-2019-ADG-883700-TRAM) and Fundamental Research Funds for the Central Universities (ZK1144). O.B. and Y.B. were funded by Russian Scientific Foundation grant 17-14-01345. H.M. was supported by the grant JSPS 16H02527. M.R. and C.C.W received funding from the ERC under the European Union’s Horizon 2020 research and innovation program (grant No 646612) to M.R. The research of C.S. is supported 30 by the Calleva Foundation and the Human Origins Research Fund. H.L was funded NSFC (91731303, 31671297), B&R International Joint Laboratory of Eurasian Anthropology (18490750300). J.K. was funded by DFG grant KR 4015/1-1, the Baden Württemberg Foundation, and the Max Planck Institute. Accelerator Mass Spectrometry radiocarbon dating work was supported by the National Science Foundation (NSF) (BCS-1460369) to D.J.K. and B.J.C. D.R. was funded by NSF grant BCS-1032255, NIH (NIGMS) grant GM100233, the Paul M. Allen Frontiers Group, John Templeton Foundation grant 61220, a gift from Jean-Francois Clin, and the Howard Hughes Medical Institute. 该研究得到了国家自然科学基金“中国东南各族群的遗传混合”、国家社科基金重大项目“多学科视角下的南岛语族的起源和形成研究”、厦门大学南强青年拔尖人才支持计划A类、中央高校基本科研业务费等资助

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe

Endocrine correlates of social and reproductive behaviours in a group-living Australian Passerine, the White-Browed Babbler

To investigate the evolutionary rationale for the seemingly altruistic behaviours commonly seen in cooperatively breeding Australian passerines, I examined alloparental behaviour in the White-browed Babbler Pomatostomus superciliosus (WBBA). Toward this end, I analysed behavioural, hormonal, and genetic factors in both free-living and captive WBBAs. Studies of free-living birds examined social and reproductive behaviours and hormonal correlates to reproduction. With captive birds, I performed both observations and manipulative experiments focusing on intragroup social structure, social behaviours, and the endocrine correlates to such structure and behaviours. The WBBA was selected as a study species as they live in sedentary, year-round social groups that engage in cooperative breeding. Field work was conducted in Back Yamma State Forest, in the central west region of New South Wales, Australia. In this population of WBBAs, groups included many close genetic relatives, and neighboring groups also shared several related individuals. There were multiple breeding pairs within most groups, and reproductive behaviours between breeding pairs were similar to those of many biparentally breeding songbirds. However, nest defense and postfledgling care were undertaken by large cooperative groups. In free-living WBBAs, plasma levels of testosterone (T), estradiol (E2), progesterone (P), prolactin (Prl), and corticosterone (B) were measured, and laparotomies were performed to ascertain gonadal condition. Endocrine profiles in WBBAs were similar to those reported for a number of passerines and likely reflected physiological changes necessary for breeding, such as spermatogenesis and ovulation. Males� T profiles resembled those of some polygynous passerines, in that plasma T levels rose after the completion of the female partners� clutch. This may reflect the possibility for extra-pair copulations in WBBA groups with multiple breeding females. There was some indication that WBBAs� endocrine system may have been fine-tuned to support alloparental behaviour. In adult males that chaperoned fledglings and juveniles, elevated plasma Prl titres may have facilitated alloparental care. Furthermore, elevated plasma P levels in some adult females may have been related to non-breeding behaviour and perhaps also to care of post-fledging young. Unlike many temperate zone species, many WBBAs maintained recrudesced gonads for much of the year, reflecting their extended (if not perpetual) breeding season. Studies on captive WBBAs were conducted in aviaries at the University of Wollongong. Extensive observations were undertaken to investigate intragroup social structure and associated allofeeding behaviour. Despite an absence of aggression, intragroup social structure appeared stratified and was maintained by ritualised behaviours and vocalisations. In particular, allofeeding behaviour appeared to act as an important social signal within groups, indicating high social standing of the feeder and low social status of the receiver. Plasma levels of B and Prl were measured and compared to social factors, but I found no hormonal correlates to WBBA social status or behaviour in groups with stable social structures. To further examine the relationship between the endocrine system and social behaviours and structure, manipulative experiments were carried out on captive WBBAs. Removal of group members from socially stable groups elicited no overt aggression, and exchange of members between groups elicited little aggressive behaviour; however, both experiments resulted in significant social restructuring. Nevertheless, I found no significant hormonal correlates (T, E2, and B were measured) to social instability caused by these perturbations. Another social behaviour, roost nest building, was correlated with elevated plasma T and E2 levels, in some months of the year but not others. Field and captive studies of the WBBA supported hypotheses suggesting that (1) alloparental behaviours evolved via kin selection mechanisms and (2) alloparental behaviours are important signals of quality used to help select mates and/or attract collaborators. In WBBAs alloparental behaviours seem to be either directed toward kin or co-opted as a means of advertising social status