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The engraved trails of rocks on the nearly flat, dry mud surface of Racetrack Playa, Death Valley National Park, have excited speculation about the movement mechanism since the 1940s. Rock movement has been variously attributed to high winds, liquid water, ice, or ice flotation, but has not been previously observed in action. We recorded the first direct scientific observation of rock movements using GPS-instrumented rocks and photography, in conjunction with a weather station and time-lapse cameras. The largest observed rock movement involved >60 rocks on December 20, 2013 and some instrumented rocks moved up to 224 m between December 2013 and January 2014 in multiple move events. In contrast with previous hypotheses of powerful winds or thick ice floating rocks off the playa surface, the process of rock movement that we have observed occurs when the thin, 3 to 6 mm, “windowpane” ice sheet covering the playa pool begins to melt in late morning sun and breaks up under light winds of ∼4-5 m/s. Floating ice panels 10 s of meters in size push multiple rocks at low speeds of 2-5 m/min. along trajectories determined by the direction and velocity of the wind as well as that of the water flowing under the ice.

Concepts: Scientific method, Water, Weather, Observation, Wind, Death Valley National Park, Death Valley, Racetrack Playa


Abstract Background: No prior study has empirically characterized the association between health risks and reading popular fiction depicting violence against women. Fifty Shades-a blockbuster fiction series-depicts pervasive violence against women, perpetuating a broader social narrative that normalizes these types of risks and behaviors in women’s lives. The present study characterized the association between health risks in women who read and did not read Fifty Shades; while our cross-sectional study design precluded causal determinations, an empirical representation of the health risks in women consuming the problematic messages in Fifty Shades is made. Methods: Females ages 18 to 24 (n=715), who were enrolled in a large Midwestern university, completed a cross-sectional online survey about their health behaviors and Fifty Shades' readership. The analysis included 655 females (219 who read at least the first Fifty Shades novel and 436 who did not read any part of Fifty Shades). Age- and race-adjusted multivariable models characterized Fifty Shades' readers and nonreaders on intimate partner violence victimization (experiencing physical, sexual and psychological abuse, including cyber-abuse, at some point during their lifetime); binge drinking (consuming five or more alcoholic beverages on six or more days in the last month); sexual practices (having five or more intercourse partners and/or one or more anal sex partner during their lifetime); and using diet aids or fasting for 24 or more hours at some point during their lifetime. Results: One-third of subjects read Fifty Shades (18.6%, or 122/655, read all three novels, and 14.8%, or 97/655, read at least the first novel but not all three). In age- and race-adjusted models, compared with nonreaders, females who read at least the first novel (but not all three) were more likely than nonreaders to have had, during their lifetime, a partner who shouted, yelled, or swore at them (relative risk [RR]=1.25) and who delivered unwanted calls/text messages (RR=1.34); they were also more likely to report fasting (RR=1.80) and using diet aids (RR=1.77) at some point during their lifetime. Compared with nonreaders, females who read all three novels were more likely to report binge drinking in the last month (RR=1.65) and to report using diet aids (RR=1.65) and having five or more intercourse partners during their lifetime (RR=1.63). Conclusions: Problematic depictions of violence against women in popular culture-such as in film, novels, music, or pornography-create a broader social narrative that normalizes these risks and behaviors in women’s lives. Our study showed strong correlations between health risks in women’s lives-including violence victimization-and consumption of Fifty Shades, a fiction series that portrays violence against women. While our cross-sectional study cannot determine temporality, the order of the relationship may be inconsequential; for example, if women experienced adverse health behaviors first (e.g., disordered eating), reading Fifty Shades might reaffirm those experiences and potentially aggravate related trauma. Likewise, if women read Fifty Shades before experiencing the health behaviors assessed in our study, it is possible that the book influenced the onset of these behaviors by creating an underlying context for the behaviors.

Concepts: Domestic violence, Cross-sectional study, Alcoholism, Fiction, Novel


While assisted suicide (AS) is strictly restricted in many countries, it is not clearly regulated by law in Switzerland. This imbalance leads to an influx of people-‘suicide tourists’-coming to Switzerland, mainly to the Canton of Zurich, for the sole purpose of committing suicide. Political debate regarding ‘suicide tourism’ is taking place in many countries. Swiss medicolegal experts are confronted with these cases almost daily, which prompted our scientific investigation of the phenomenon. The present study has three aims: (1) to determine selected details about AS in the study group (age, gender and country of residence of the suicide tourists, the organisation involved, the ingested substance leading to death and any diseases that were the main reason for AS); (2) to find out the countries from which suicide tourists come and to review existing laws in the top three in order to test the hypothesis that suicide tourism leads to the amendment of existing regulations in foreign countries; and (3) to compare our results with those of earlier studies in Zurich. We did a retrospective data analysis of the Zurich Institute of Legal Medicine database on AS of non-Swiss residents in the last 5 years (2008-2012), and internet research for current legislation and political debate in the three foreign countries most concerned. We analysed 611 cases from 31 countries all over the world. Non-terminal conditions such as neurological and rheumatic diseases are increasing among suicide tourists. The unique phenomenon of suicide tourism in Switzerland may indeed result in the amendment or supplementary guidelines to existing regulations in foreign countries.

Concepts: Law, Switzerland, Suicide, Tourism, Suicide methods, Cantons of Switzerland, Zürich, Canton of Zürich


Without an approved vaccine or treatment, Ebola outbreak management has been limited to palliative care and barrier methods to prevent transmission. These approaches, however, have yet to end the 2014 outbreak of Ebola after its prolonged presence in West Africa. Here we show that a combination of monoclonal antibodies (ZMapp), optimized from two previous antibody cocktails, is able to rescue 100% of rhesus macaques when treatment is initiated up to 5 days post-challenge. High fever, viraemia and abnormalities in blood count and blood chemistry were evident in many animals before ZMapp intervention. Advanced disease, as indicated by elevated liver enzymes, mucosal haemorrhages and generalized petechia could be reversed, leading to full recovery. ELISA and neutralizing antibody assays indicate that ZMapp is cross-reactive with the Guinean variant of Ebola. ZMapp exceeds the efficacy of any other therapeutics described so far, and results warrant further development of this cocktail for clinical use.

Concepts: Immune system, Antibody, Macaque, Primate, Rhesus Macaque, Ebola, Viral hemorrhagic fever, Crab-eating Macaque


The aim of this study was to investigate the effectiveness of shoe inserts and plantar fascia-specific stretching vs shoe inserts and high-load strength training in patients with plantar fasciitis. Forty-eight patients with ultrasonography-verified plantar fasciitis were randomized to shoe inserts and daily plantar-specific stretching (the stretch group) or shoe inserts and high-load progressive strength training (the strength group) performed every second day. High-load strength training consisted of unilateral heel raises with a towel inserted under the toes. Primary outcome was the foot function index (FFI) at 3 months. Additional follow-ups were performed at 1, 6, and 12 months. At the primary endpoint, at 3 months, the strength group had a FFI that was 29 points lower [95% confidence interval (CI): 6-52, P = 0.016] compared with the stretch group. At 1, 6, and 12 months, there were no differences between groups (P > 0.34). At 12 months, the FFI was 22 points (95% CI: 9-36) in the strength group and 16 points (95% CI: 0-32) in the stretch group. There were no differences in any of the secondary outcomes. A simple progressive exercise protocol, performed every second day, resulted in superior self-reported outcome after 3 months compared with plantar-specific stretching. High-load strength training may aid in a quicker reduction in pain and improvements in function.

Concepts: Improve, Randomized controlled trial, Physical exercise, Exercise, Strength training, Outcome, Stretching, Plantar fasciitis


The valence of memories is malleable because of their intrinsic reconstructive property. This property of memory has been used clinically to treat maladaptive behaviours. However, the neuronal mechanisms and brain circuits that enable the switching of the valence of memories remain largely unknown. Here we investigated these mechanisms by applying the recently developed memory engram cell- manipulation technique. We labelled with channelrhodopsin-2 (ChR2) a population of cells in either the dorsal dentate gyrus (DG) of the hippocampus or the basolateral complex of the amygdala (BLA) that were specifically activated during contextual fear or reward conditioning. Both groups of fear-conditioned mice displayed aversive light-dependent responses in an optogenetic place avoidance test, whereas both DG- and BLA-labelled mice that underwent reward conditioning exhibited an appetitive response in an optogenetic place preference test. Next, in an attempt to reverse the valence of memory within a subject, mice whose DG or BLA engram had initially been labelled by contextual fear or reward conditioning were subjected to a second conditioning of the opposite valence while their original DG or BLA engram was reactivated by blue light. Subsequent optogenetic place avoidance and preference tests revealed that although the DG-engram group displayed a response indicating a switch of the memory valence, the BLA-engram group did not. This switch was also evident at the cellular level by a change in functional connectivity between DG engram-bearing cells and BLA engram-bearing cells. Thus, we found that in the DG, the neurons carrying the memory engram of a given neutral context have plasticity such that the valence of a conditioned response evoked by their reactivation can be reversed by re-associating this contextual memory engram with a new unconditioned stimulus of an opposite valence. Our present work provides new insight into the functional neural circuits underlying the malleability of emotional memory.

Concepts: Psychology, Neuroscience, Memory, Hippocampus, Neurogenesis, Granule cell, Classical conditioning, Fear conditioning



Liquid water has been known to occur beneath the Antarctic ice sheet for more than 40 years, but only recently have these subglacial aqueous environments been recognized as microbial ecosystems that may influence biogeochemical transformations on a global scale. Here we present the first geomicrobiological description of water and surficial sediments obtained from direct sampling of a subglacial Antarctic lake. Subglacial Lake Whillans (SLW) lies beneath approximately 800 m of ice on the lower portion of the Whillans Ice Stream (WIS) in West Antarctica and is part of an extensive and evolving subglacial drainage network. The water column of SLW contained metabolically active microorganisms and was derived primarily from glacial ice melt with solute sources from lithogenic weathering and a minor seawater component. Heterotrophic and autotrophic production data together with small subunit ribosomal RNA gene sequencing and biogeochemical data indicate that SLW is a chemosynthetically driven ecosystem inhabited by a diverse assemblage of bacteria and archaea. Our results confirm that aquatic environments beneath the Antarctic ice sheet support viable microbial ecosystems, corroborating previous reports suggesting that they contain globally relevant pools of carbon and microbes that can mobilize elements from the lithosphere and influence Southern Ocean geochemical and biological systems.

Concepts: Archaea, Bacteria, Organism, RNA, Ribosomal RNA, Water, Microorganism, Antarctica


Existing research on the extensive Chinese censorship organization uses observational methods with well-known limitations. We conducted the first large-scale experimental study of censorship by creating accounts on numerous social media sites, randomly submitting different texts, and observing from a worldwide network of computers which texts were censored and which were not. We also supplemented interviews with confidential sources by creating our own social media site, contracting with Chinese firms to install the same censoring technologies as existing sites, and–with their software, documentation, and even customer support–reverse-engineering how it all works. Our results offer rigorous support for the recent hypothesis that criticisms of the state, its leaders, and their policies are published, whereas posts about real-world events with collective action potential are censored.

Concepts: Scientific method, Sociology, Observation, People's Republic of China, Philosophy of science, Hypothesis, Political science, Tiananmen Square protests of 1989


The timing of Neanderthal disappearance and the extent to which they overlapped with the earliest incoming anatomically modern humans (AMHs) in Eurasia are key questions in palaeoanthropology. Determining the spatiotemporal relationship between the two populations is crucial if we are to understand the processes, timing and reasons leading to the disappearance of Neanderthals and the likelihood of cultural and genetic exchange. Serious technical challenges, however, have hindered reliable dating of the period, as the radiocarbon method reaches its limit at ∼50,000 years ago. Here we apply improved accelerator mass spectrometry (14)C techniques to construct robust chronologies from 40 key Mousterian and Neanderthal archaeological sites, ranging from Russia to Spain. Bayesian age modelling was used to generate probability distribution functions to determine the latest appearance date. We show that the Mousterian ended by 41,030-39,260 calibrated years bp (at 95.4% probability) across Europe. We also demonstrate that succeeding ‘transitional’ archaeological industries, one of which has been linked with Neanderthals (Châtelperronian), end at a similar time. Our data indicate that the disappearance of Neanderthals occurred at different times in different regions. Comparing the data with results obtained from the earliest dated AMH sites in Europe, associated with the Uluzzian technocomplex, allows us to quantify the temporal overlap between the two human groups. The results reveal a significant overlap of 2,600-5,400 years (at 95.4% probability). This has important implications for models seeking to explain the cultural, technological and biological elements involved in the replacement of Neanderthals by AMHs. A mosaic of populations in Europe during the Middle to Upper Palaeolithic transition suggests that there was ample time for the transmission of cultural and symbolic behaviours, as well as possible genetic exchanges, between the two groups.

Concepts: Human, Mass spectrometry, Neanderthal, Human evolution, Pleistocene, Upper Paleolithic, Mousterian, Middle Paleolithic