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

A step forward in tropical anthracology: understanding woodland vegetation and wood uses in ancient Sri Lanka based on charcoal records from Mantai, Kirinda and Kantharodai

The aim of this study is to present the anthracological results from three archaeological sites located in the North, North West and South East of Sri Lanka. The study is based on the observation and analysis of 1689 charcoal fragments using for support the reference collection of South Indian wood at the Institute of Archaeology ( UCL), Inside Wood (2004-onwards) and several wood anatomy atlases. Mantai (200 BCE-850 CE), an urban site, has yielded 25 taxa with significant presence of cf. Cocos nucifera among other taxa. Kantharodai (400-170- BCE), an urban site, has yielded 19 taxa from arid zones (Fabaceae, Rubiaceae), mangroves (Rhizophoraceae) and dune zones (cf. Cocos nucifera). Kirinda (500–900 CE), a fishing settlement, has yielded 24 taxa including Fabaceae (Dalbergia, Acacia) and Rubiaceae, belonging to dry deciduous forest and open savannas. This collective data set allows for the identification of discernible patterns related to the use of ecological interfaces between the forest and the open plains, used and actively managed by humans, and the possibility to identify if this changed with an increase in maritime trade and/or changes in agriculture over time. This study provides evidence of the differences in the vegetation present as well as use of wood fuel and other specific uses of wood for each site examined. It also sheds new light on tropical anthracology regarding quantification and accuracy in taxa identification

Integrated study of factors affecting fetal weight in singleton pregnancies. Nomogram and development of basic and advanced fetal growth customized models

We have performed a multivariate analysis to explore the influence on birth and ultrasound fetal weight estimation of traditional factors as biochemical data and maternal characteristics in combination with non- traditionally explored predictors as paternal height, Pregnancy-associated plasma protein A (PAPP-A), single umbilical artery or Free-beta Human Chorionic Gonadotropin (fß- HCG). The study was performed for a Spanish population (region of Aragon) in singleton pregnancies at term (37-42 weeks). Also, we have created a nomogram and in order to predict the occurrence of SGA (small for gestational age) and LGA (large for gestational age) cases we provide a multivariate predictive model of fetal weight that have been compared with other models in the prediction of ultrasound and birth weights. After study we have created a software application for automated calculation of percentile fetal weight, adjusting the variables when they were significant

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

Technical and cultural processes during the early Holocene in the NE of the Iberian Peninsula. The levels B and Bb of La Cativera (El Catllar, Tarragona)

[spa] Este trabajo presenta la estructura tecnológica observada en los niveles B y Bb (Boreal) de La Cativera, donde se observa una dualidad entre explotaciones laminares simplificadas y una producción de lascas cortas normalizadas. Una nueva datación inédita refuerza la posición cronológica de estos niveles pese a que las estrategias de talla de los mismos difieren significativamente de las documentadas en yacimientos sincrónicos. Los niveles B y Bb coinciden en el tiempo con los conjuntos del Mesolítico de Muescas y Denticulados, sin embargo el análisis tecnológico de la industria lítica lo pone en relación más directa con los conjuntos del Magdaleniense final y/o Epipaleolítico microlaminar propios del Tardiglaciar.[eng] This study presents the technological structure observed in levels B and Bb (Boreal) from La Cativera. A dual technological pattern is observed. For one side simplified blade exploitation is observed and for the other, a normalized short flake production is documented too. A new 14C data corroborates the chronological position of both levels despite showing technical schemes which significantly vary from those of synchronous sites. The B and Bb levels match in time with the so called Notched and Denticulate Mesolithic industries, however the observed knapping patterns present a major affinity with the Late Magdalenian or Epipalaeolithic Late Glacial knapping scheme

Procesos técnicos y culturales durante el Holoceno inicial en el noroeste de la Península Ibérica. Los niveles B y Bb de La Cativera (El Catllar, Tarragona)

This study presents the technological structure observed in levels B and Bb (Boreal) from La Cativera. A dual technological pattern is observed. For one side simplified blade exploitation is observed and for the other, a normalized short flake production is documented too. A new 14C data corroborates the chronological position of both levels despite showing technical schemes which significantly vary from those of synchronous sites. The B and Bb levels match in time with the so called Notched and Denticulate Mesolithic industries, however the observed knapping patterns present a major affinity with the Late Magdalenian or Epipalaeolithic Late Glacial knapping schemes.Este trabajo presenta la estructura tecnológica observada en los niveles B y Bb (Boreal) de La Cativera, donde se observa una dualidad entre explotaciones laminares simplificadas y una producción de lascas cortas normalizadas. Una nueva datación inédita refuerza la posición cronológica de estos niveles pese a que las estrategias de talla de los mismos difieren significativamente de las documentadas en yacimientos sincrónicos. Los niveles B y Bb coinciden en el tiempo con los conjuntos del Mesolítico de Muescas y Denticulados, sin embargo el análisis tecnológico de la industria lítica lo pone en relación más directa con los conjuntos del Magdaleniense final y/o Epipaleolítico microlaminar propios del Tardiglaciar

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

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

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

Biomechanical and morphological study of a new elastic mesh (Ciberlastic) to repair abdominal wall defects

The aim of this study was to conduct a preclinical evaluation of the behaviour of a new type of abdominal LW prosthesis (Ciberlastic), which was designed with a non-absorbable elastic polyurethane monofilament (Assuplus, Assut Europe, Italy) to allow greater adaptability to mechanical area requirements and higher bio-mimicking with the newly formed surrounding tissues. Our hypothesis was that an increase in the elasticity of the mesh filament could improve the benefits of LW prostheses. To verify our hypothesis, we compared the short- and long-term behaviour of Ciberlastic and Optilene® elastic commercial meshes by repairing the partially herniated abdomen in New Zealand White rabbits. The implanted meshes were mechanically and histologically assessed at 14 and 180 days post-implant. We mechanically characterized the partially herniated repaired muscle tissue and also determined mesh shrinkage at different post-implant times. This was followed by a histological study in which the tissue incorporation process was analysed over time. The new prosthesis designed by our group achieved good behaviour that was similar to that of Optilene®, one of the most popular LW prostheses on the market, with the added advantage of its elastic property. The mechanical properties are significantly lower than those of the polypropylene Optilene® mesh, and the new elastic mesh meets the basic mechanical requirements for positioning in the abdominal wall, which was also demonstrated by the absence of recurrences after implantation in the experimental model. We found that the growth of a connective tissue rich in collagen over the hernial defect and the proper deposit of the collagen fibres in the regenerated tissue substantially modified the original properties of the mesh, thereby increasing its biomechanical strength and making the whole tissue/mesh stiffer