The origin of the Acheulean: the 1.7 million-year-old site of FLK West, Olduvai Gorge (Tanzania)

The appearance of the Acheulean is one of the hallmarks of human evolution. It represents the emergence of a complex behavior, expressed in the recurrent manufacture of large-sized tools, with standardized forms, implying more advance forethought and planning by hominins than those required by the precedent Oldowan technology. The earliest known evidence of this technology dates back to c. 1.7 Ma. and is limited to two sites (Kokiselei [Kenya] and Konso [Ethiopia]), both of which lack fauna. The functionality of these earliest Acheulean assemblages remains unknown. Here we present the discovery of another early Acheulean site also dating to c. 1.7 Ma from Olduvai Gorge. This site provides evidence of the earliest steps in developing the Acheulean technology and is the oldest Acheulean site in which stone tools occur spatially and functionally associated with the exploitation of fauna. Simple and elaborate large-cutting tools (LCT) and handaxes co-exist at FLK West, showing that complex cognition was present from the earliest stages of the Acheulean. Here we provide a detailed technological study and evidence of the use of these tools on the butchery and consumption of fauna, probably by early Homo erectus sensu lato

Shape invariance through Crum transformation

We show in a rigorous way that Crum's result on equal eigenvalue spectrum of Sturm-Liouville problems can be obtained iteratively by successive Darboux transformations. It can be shown that all neighbouring Darboux-transformed potentials of higher order, u_{k} and u_{k+1}, satisfy the condition of shape invariance provided the original potential u does. We use this result to proof that under the condition of shape invariance the n-th iteration of the original Sturm-Liouville problem defined through shape invariance is equal to the n-th Crum transformationComment: 26 pp, one more reference, J.-M. Sparenberg and D. Baye, J. Phys. A 28, 5079 (1995), has been added as Ref. 18 in the published version, which has 47 ref

Multi-isotopic study of the earliest medieval inhabitants of Santiago de Compostela (Galicia, Spain)

YesSantiago de Compostela is, together with Rome and Jerusalem, one of the three main pilgrimage and religious centres for Catholicism. The belief that the remains of St James the Great, one of the twelve apostles of Jesus Christ, is buried there has stimulated, since their reported discovery in the 9th century AD, a significant flow of people from across the European continent and beyond. Little is known about the practical experiences of people living within the city during its rise to prominence, however. Here, for the first time, we combine multi-isotope analysis (δ13C, δ15N, δ18Oap, δ13Cap, and 87Sr/86Sr) and radiocarbon dating (14C) of human remains discovered at the crypt of the Cathedral of Santiago to directly study changes in diet and mobility during the first three centuries of Santiago’s emergence as an urban centre (9th-12th centuries AD). Together with assessment of the existing archaeological data, our radiocarbon chronology broadly confirms historical tradition regarding the first occupation of the site. Isotopic analyses reveal that the foundation of the religious site attracted migrants from the wider region of the northwest corner of the Iberian Peninsula, and possibly from further afield. Stable isotope analysis of collagen, together with information on tomb typology and location, indicates that the inhabitants of the city experienced increasing socioeconomic diversity as it became wealthier as the hub of a wide network of pilgrimage. Our research represents the potential of multidisciplinary analyses to reveal insights into the origins and impacts of the emergence of early pilgrimage centres on the diets and status of communities within Christian medieval Europe and beyond.This project has been supported by a grant from the ‘la Caixa’ Banking Foundation (ID 100010434; Code: LCF/BQ/ES16/11570006). Patxi Pérez-Ramallo and Patrick Roberts would also like to thank the Max Planck Society for funding for this project. Patxi Pérez-Ramallo, Hannah Koon and Julia Beaumont would like to thank the University of Bradford for funding a support the first osteological and stable isotope analysis conducted in 2015. Two of the isotopic analyses and 14C dates have been carried out with funding from the Xunta de Galicia to the CulXeo Group (ED431B 2018/47) and to the research network ‘Cultural Heritage, archaeological and technical services’ (R2016/023). Open Access funding enabled and organized by Projekt DEAL

Saberes digitales: una aproximación desde las voces de los estudiantes

The second decade of the new century is about to end. In educational matters, it could be affirmed that many learning has left us the insertion of technologies in the classroom in these years, at all levels schoolchildren without exception. However, it could also be ensured that challenges in the short term arising from the current revolution social and technological, which on many occasions has left us without Enough spaces to reflect on its progress and implications It is interesting and challenging how the training processes in these last 20 years, when technologies of information and communications (ICT) have evolved step by step accelerated. Interesting, on the one hand, since one of the most important contributions important of the ICT is to act as large portals with access to the world, which both students, teachers and researchers open daily to understand the progress of their areas of knowledge and use tools that allow establishing better connectivity networks for the learning. Challenging, on the other hand, due to changes in paradigm that is being built around what has been understood for years regarding what the training process requires in terms of planning, didactic strategies, use of learning resources and the evaluation, to mention the main

HIV Risks and Seroprevalence Among Mexican American Injection Drug Users in California

Latinos in the United States are an ethnically diverse group disproportionately affected by HIV/AIDS. We describe HIV seroprevalence, HIV risk behaviors and utilization of health services among Mexican American injection drug users (IDUs) in California (n = 286) and compare them to White (n = 830) and African American (n = 314) IDUs. Study participants were recruited from syringe exchange programs (n = 24) in California. HIV seroprevalence among Mexican Americans (0.5%) was dramatically lower than Whites (5%) and African Americans (8%). Mexican Americans reported fewer sex-related risks than Whites and African Americans though injection-related risks remained high. Compared to Whites, Mexican Americans were more likely to participate in drug treatment during a 6 month period (AOR 1.5, 95% CI 1.1, 2.0) but less likely to receive any health care (AOR 0.6, 95% CI 0.5, 0.8). Exploring cultural and structural factors among Mexican American IDUs may offer new insights into how to maintain low rates of HIV seroprevalence and reduce barriers to health care utilization

Differential Effects of Migration and Deportation on HIV Infection among Male and Female Injection Drug Users in Tijuana, Mexico

HIV prevalence is rising, especially among high risk females in Tijuana, Baja California, a Mexico-US border city situated on major migration and drug trafficking routes. We compared factors associated with HIV infection among male and female injection drug users (IDUs) in Tijuana in an effort to inform HIV prevention and treatment programs. IDUs aged ≥18 years were recruited using respondent-driven sampling and underwent testing for HIV, syphilis and structured interviews. Logistic regression identified correlates of HIV infection, stratified by gender. Among 1056 IDUs, most were Mexican-born but 67% were born outside Tijuana. Reasons for moving to Tijuana included deportation from the US (56% for males, 29% for females), and looking for work/better life (34% for females, 15% for males). HIV prevalence was higher in females versus males (10.2% vs. 3.5%, p = 0.001). Among females (N = 158), factors independently associated with higher HIV prevalence included younger age, lifetime syphilis infection and living in Tijuana for longer durations. Among males (N = 898), factors independently associated with higher HIV prevalence were syphilis titers consistent with active infection, being arrested for having ‘track-marks’, having larger numbers of recent injection partners and living in Tijuana for shorter durations. An interaction between gender and number of years lived in Tijuana regressed on HIV infection was significant (p = 0.03). Upon further analysis, deportation from the U.S. explained the association between shorter duration lived in Tijuana and HIV infection among males; odds of HIV infection were four-fold higher among male injectors deported from the US, compared to other males, adjusting for all other significant correlates (p = 0.002). Geographic mobility has a profound influence on Tijuana's evolving HIV epidemic, and its impact is significantly modified by gender. Future studies are needed to elucidate the context of mobility and HIV acquisition in this region, and whether US immigration policies adversely affect HIV risk

Under the Skin of a Lion: Unique Evidence of Upper Paleolithic Exploitation and Use of Cave Lion (Panthera spelaea) from the Lower Gallery of La Garma (Spain)

ABSTRACT: Pleistocene skinning and exploitation of carnivore furs have been previously inferred from archaeological evidence. Nevertheless, the evidence of skinning and fur processing tends to be weak and the interpretations are not strongly sustained by the archaeological record. In the present paper, we analyze unique evidence of patterned anthropic modification and skeletal representation of fossil remains of cave lion (Panthera spelaea) from the Lower Gallery of La Garma (Cantabria, Spain). This site is one of the few that provides Pleistocene examples of lion exploitation by humans. Our archaeozoological study suggests that lion-specialized pelt exploitation and use might have been related to ritual activities during the Middle Magdalenian period (ca. 14800 cal BC). Moreover, the specimens also represent the southernmost European and the latest evidence of cave lion exploitation in Iberia. Therefore, the study seeks to provide alternative explanations for lion extinction in Eurasia and argues for a role of hunting as a factor to take into account