Towards the mechanical characterization of abdominal wall by inverse analysis

The aim of this study is to characterize the passive mechanical behaviour of abdominal wall in vivo in an animal model using only external cameras and numerical analysis. The main objective lies in defining a methodology that provides in vivo information of a specific patient without altering mechanical properties. It is demonstrated in the mechanical study of abdomen for hernia purposes. Mechanical tests consisted on pneumoperitoneum tests performed on New Zealand rabbits, where inner pressure was varied from 0 mmHg to 12 mmHg. Changes in the external abdominal surface were recorded and several points were tracked. Based on their coordinates we reconstructed a 3D finite element model of the abdominal wall, considering an incompressible hyperelastic material model defined by two parameters. The spatial distributions of these parameters (shear modulus and non linear parameter) were calculated by inverse analysis, using two different types of regularization: Total Variation Diminishing (TVD) and Tikhonov (H1). After solving the inverse problem, the distribution of the material parameters were obtained along the abdominal surface. Accuracy of the results was evaluated for the last level of pressure. Results revealed a higher value of the shear modulus in a wide stripe along the craneo-caudal direction, associated with the presence of linea alba in conjunction with fascias and rectus abdominis. Non linear parameter distribution was smoother and the location of higher values varied with the regularization type. Both regularizations proved to yield in an accurate predicted displacement field, but H1 obtained a smoother material parameter distribution while TVD included some discontinuities. The methodology here presented was able to characterize in vivo the passive non linear mechanical response of the abdominal wall

Neanderthal selective hunting of reindeer? The case study of Abri du Maras (south-eastern France)

Fieldwork was supported by the Regional Office of Archaeology Rhône-Alpes, the French Ministry of Culture and Communication and the Ardèche Department through several scientific programs. M.G.Chacon, F. Rivals and E. Allué research are funded by ‘CERCA Programme/Generalitat de Catalunya’. Thanks to Jean-Jacques Hublin, Annabell Reiner and Steven Steinbrenner from the Max Planck Institute (MPI-EVA) for analytical support (isotope analysis). We are grateful to the two anonymous reviewers for their constructive remarks on this manuscript. The English manuscript was edited by L. Byrne, an official translator and native English speaker.Peer reviewedPostprin

Ageism and nursing students, past or reality?: a systematic review

Objective: This systematic review aimed to summarise and update existing knowledge about ageism among nursing students through the following research question: what is the perception and attitudes of ageism among student nurses? Design: A systematic review of longitudinal and cross-sectional studies of ageism in nursing students was carried out. Data sources: The literature search was conducted in the scientific databases Pubmed and Scopus in February 2021. Review methods: After the screening process, 22 studies meeting the selection criteria were selected; 8 more were identified after manually searching the selected paper' reference lists. A total of 30 studies were included in the review. The JBI Critical Appraisal Checklists for Analytical Cross-Sectional studies and for Cohort Studies were used to appraise the articles' quality. Results: There was large variability in the manifestation of ageism among student nurses, as well as in the instruments used for assessment. Most of the articles analysed attitudes towards old age, the majority of which were positive. Being a female student, being on the final year of study and having regular contact or cohabitation with an older adult were three of the main determinants in the expression of positive attitudes towards the elderly. Conclusions: Our findings suggest that student nurses generally have positive attitudes towards old age, although ageist beliefs and discriminatory behaviours were identified and should be studied in greater depth. Training programs for future care professionals have a responsibility to educate from a non-stereotypical perspective based on current societal needs

Risk factors for premature aging of placenta: comparative study of perinatal outcomes between grannum grade III placentas and grannum grade I-II placentas

Introduction: The placenta aging has been related with intrauterine fetal growth, low maternal age, Caucasian, multiparity, hypertensive states and smoking habit. Grannum P. classification is the most used for its assessment. The association between grade III placenta (G3P) and ex-smoking or smokeexposed pregnants has not been studied Main outcome: To asses if smoking, being an ex-smoker or a passive-smoker is a risk factor for developing grade III placenta, as well as if there is a smoking-free period of time to avoid the effect of smoking over placenta Material and methods: A retrospective case-control study of single pregnancies followed-up at the Obstetric Ultrasound Unit between January 2013 and January 2014. Placental grading according to Grannum classification was stablished through abdominal approach between 34-36 weeks of gestation and two groups were established: grade III placenta and grade I-II placenta (G1-2P) Maternal and paternal characteristics, type of delivery and perinatal outcomes were collected Results: Baseline characteristics were similar between the two groups. In G3P the incidence of hypertensive disease of pregnancy was higher(p=0,0107). The percentage was similar for premature birth, 1st and 5th minute Apgar, type of delivery and cesarean due to risk of loss of fetal wellbeing. A lower neonatal weight was found in G3P, at the same median days at delivery, with a mean difference of 148,156(p=0,008313. Regarding weight percentile, it was found a p35 in G3P and a p47,5 in G1- 2P(p=0,08235) 15% of the total pregnant were smokers. In G3P group it was found a higher frequency of smokers and ex-smokers since 1st trimester of pregnancy (p=0.0001), as well as pregnant non-smokers with an smoking partner(p=0,0001). There was an strong evidence for association between pregnant smokers and smoking partners(p=0,0001). No difference was found regarding to neonatal weight comparing smokers, ex-smokers and ex-smokers since 1st trimester of pregnancy. The length of pregnancy was lower between G3P pregnant smokers compared to G1-2P pregnant smokers, with a mean difference of 8 days (p=0,00091) Conclusions: There is a strong evidence for association between smoking during pregnancy, quitting smoking at the beginning of the pregnancy or being a passive smoker with development of G3P Some pregnant smokers don`t develop premature aging of placenta, it could be due to either other parameters or a later aging (data were collected between 34-36 weeks). The association between quitting smoking at the beginning of the pregnancy and not having a smoking partner reduces the risk of developing G3

The earliest evidence for Upper Paleolithic occupation in the Armenian Highlands at Aghitu-3 Cave

With its well-preserved archaeological and environmental records, Aghitu-3 Cave permits us to examine the settlement patterns of the Upper Paleolithic (UP) people who inhabited the Armenian Highlands. We also test whether settlement of the region between ∼39–24,000 cal BP relates to environmental variability. The earliest evidence occurs in archaeological horizon (AH) VII from ∼39–36,000 cal BP during a mild, moist climatic phase. AH VI shows periodic occupation as warm, humid conditions prevailed from ∼36–32,000 cal BP. As the climate becomes cooler and drier at ∼32– 29,000 cal BP (AH V-IV), evidence for occupation is minimal. However, as cooling continues, the deposits of AH III demonstrate that people used the site more intensively from ∼29–24,000 cal BP, leaving behind numerous stone artifacts, faunal remains, and complex combustion features. Despite the climatic fluctuations seen across this 15,000-year sequence, lithic technology remains attuned to one pattern: unidirectional reduction of small cores geared towards the production of bladelets for tool manufacture. Subsistence patterns also remain stable, focused on medium-sized prey such as ovids and caprids, as well as equids. AH III demonstrates an expansion of social networks to the northwest and southwest, as the transport distance of obsidian used to make stone artifacts increases. We also observe the addition of bone tools, including an eyed needle, and shell beads brought from the east, suggesting that these people manufactured complex clothing and wore ornaments. Remains of micromammals, birds, charcoal, pollen, and tephra relate the story of environmental variability. We hypothesize that UP behavior was linked to shifts in demographic pressures and climatic changes. Thus, by combining archaeological and environmental data, we gain a clearer picture about the first UP inhabitants of the Armenian Highlands

The global Alzheimer's Association round robin study on plasma amyloid β methods

Introduction: Blood-based assays to measure brain amyloid beta (Aβ) deposition are an attractive alternative to the cerebrospinal fluid (CSF)-based assays currently used in clinical settings. In this study, we examined different blood-based assays to measure Aβ and how they compare among centers and assays. Methods: Aliquots from 81 plasma samples were distributed to 10 participating centers. Seven immunological assays and four mass-spectrometric methods were used to measure plasma Aβ concentrations. Results: Correlations were weak for Aβ42 while Aβ40 correlations were stronger. The ratio Aβ42/Aβ40 did not improve the correlations and showed weak correlations. Discussion: The poor correlations for Aβ42 in plasma might have several potential explanations, such as the high levels of plasma proteins (compared to CSF), sensitivity to pre-analytical sample handling and specificity, and cross-reactivity of different antibodies. Different methods might also measure different pools of plasma Aβ42. We, however, hypothesize that greater correlations might be seen in future studies because many of the methods have been refined during completion of this study

The first hominin of Europe

The earliest hominin occupation of Europe is one of the most debated topics in palaeoanthropology. However, the purportedly oldest of the Early Pleistocene sites in Eurasia lack precise age control and contain stone tools rather than human fossil remains(1-5). Here we report the discovery of a human mandible associated with an assemblage of Mode 1 lithic tools and faunal remains bearing traces of hominin processing, in stratigraphic level TE9 at the site of the Sima del Elefante, Atapuerca, Spain(6-8). Level TE9 has been dated to the Early Pleistocene ( approximately 1.2 - 1.1 Myr), based on a combination of palaeomagnetism, cosmogenic nuclides and biostratigraphy. The Sima del Elefante site thus emerges as the oldest, most accurately dated record of human occupation in Europe, to our knowledge. The study of the human mandible suggests that the first settlement of Western Europe could be related to an early demographic expansion out of Africa. The new evidence, with previous findings in other Atapuerca sites ( level TD6 from Gran Dolina(9-13)), also suggests that a speciation event occurred in this extreme area of the Eurasian continent during the Early Pleistocene, initiating the hominin lineage represented by the TE9 and TD6 hominins.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62855/1/nature06815.pd

Atlas de las praderas marinas de España

Knowledge of the distribution and extent of seagrass habitats is currently the basis of management and conservation policies of the coastal zones in most European countries. This basic information is being requested through European directives for the establishment of monitoring programmes and the implementation of specific actions to preserve the marine environment. In addition, this information is crucial for the quantification of the ecological importance usually attributed to seagrass habitats due to, for instance, their involvement in biogeochemical cycles, marine biodiversity and quality of coastal waters or global carbon budgets. The seagrass atlas of Spain represents a huge collective effort performed by 84 authors across 30 Spanish institutions largely involved in the scientific research, management and conservation of seagrass habitats during the last three decades. They have contributed to the availability of the most precise and realistic seagrass maps for each region of the Spanish coast which have been integrated in a GIS to obtain the distribution and area of each seagrass species. Most of this information has independently originated at a regional level by regional governments, universities and public research organisations, which explain the elevated heterogeneity in criteria, scales, methods and objectives of the available information. On this basis, seagrass habitats in Spain occupy a total surface of 1,541,63 km2, 89% of which is concentrated in the Mediterranean regions; the rest is present in sheltered estuarine areas of the Atlantic peninsular regions and in the open coastal waters of the Canary Islands, which represents 50% of the Atlantic meadows. Of this surface, 71.5% corresponds to Posidonia oceanica, 19.5% to Cymodocea nodosa, 3.1% to Zostera noltii (=Nanozostera noltii), 0.3% to Zostera marina and 1.2% to Halophila decipiens. Species distribution maps are presented (including Ruppia spp.), together with maps of the main impacts and pressures that has affected or threatened their conservation status, as well as the management tools established for their protection and conservation. Despite this considerable effort, and the fact that Spain has mapped wide shelf areas, the information available is still incomplete and with weak precision in many regions, which will require an investment of major effort in the near future to complete the whole picture and respond to demands of EU directives.Versión del edito

A Middle Palaeolithic wooden digging stick from Aranbaltza III, Spain

Aranbaltza is an archaeological complex formed by at least three open-air sites. Between 2014 and 2015 a test excavation carried out in Aranbaltza III revealed the presence of a sand and clay sedimentary sequence formed in floodplain environments, within which six sedimentary units have been identified. This sequence was formed between 137±50 ka, and includes several archaeological horizons, attesting to the long-term presence of Neanderthal communities in this area. One of these horizons, corresponding with Unit 4, yielded two wooden tools. One of these tools is a beveled pointed tool that was shaped through a complex operational sequence involving branch shaping, bark peeling, twig removal, shaping, polishing, thermal exposition and chopping. A use-wear analysis of the tool shows it to have traces related with digging soil so it has been interpreted as representing a digging stick. This is the first time such a tool has been identified in a European Late Middle Palaeolithic context; it also represents one of the first well-preserved Middle Palaeolithic wooden tool found in southern Europe. This artefact represents one of the few examples available of wooden tool preservation for the European Palaeolithic, allowing us to further explore the role wooden technologies played in Neanderthal communities