Investigating hydrogen isotope variation during heating of n-Alkanes under limited oxygen conditions: implications for palaeoclimate reconstruction in archaeological settings

This paper reports on a series of heating experiments that focus on n-alkanes extracted from leaf, bark, and xylem tissues of the Celtis australis plant. These lipid biomarkers were analysed for their compound-specific hydrogen isotopic composition (δ2Hwax) under limited oxygen conditions at 150, 250, 350, and 450 °C. Our results reveal isotopic variations in wax lipids of different plant organs during short-term low-temperature combustion. We conclude that, in the absence of a detailed characterisation of the depositional environment in advance of sampling, δ2Hwax values in archaeological or otherwise highly anthropogenic environments should be interpreted cautiously. In addition, we observed that variation in δ2Hwax of leaves is minimal at temperatures ≤ 350 °C, highlighting the potential for δ2Hwax in thermally altered combustion substrates to yield palaeoclimate information, which could allow researchers to investigate links between archaeological and climatic records at a high spatial and temporal resolution.info:eu-repo/semantics/publishedVersio

El mango mangífera índica : manejo postcosecha

Manual de manejo de postcosecha del mango en el que se describen generalidades asociadas al cultivo, de mango, su origen, clasificación, variedades, manejo durante la cosecha y postcosecha, mercadeo y comercialización.Mango postharvest handling manual describing generalities associated with the cultivation, mango, its origin, classification, varieties, handling during harvest and postharvest, marketing and marketing.Generalidades -- Manejo de la cosecha -- Manejo de la postcosecha -- Fisiología de postcosecha de los frutos del mangonaDocumento producto del convenio entre el SENA y la Universidad Nacional de Colombia, programa de investigación "Manejo de postcosecha de frutas y hortalizas”70 página

Compound-specific carbon isotope analysis of short-chain fatty acids from pine tissues: characterizing paleo-fire residues and plant exudates

Different types of plant tissues and resin can account for the wax lipids found in sedimentary contexts and archaeological samples. Consequently, there is increasing research to characterize the fatty acid carbon isotope ratios of different plant anatomical parts and their plant exudates (resin). With the aim to explore isotopic differences between plant tissues, state of the fine organic matter, effect of thermal degradation, and to identify plant residues we measured the δ13C values of short-chain fatty acids (δ13C16:0 and δ13C18:0) in: i) dead and fresh (collected and immediately dried) pine needles and branches (Pinus canariensis) and pine resin from laboratory-controlled heating experiments and ii) sediment and charred pine tissue samples from a wild pine forest fire. Our results are compared to previously published experimental open-air fire experiments and pine-fuelled archaeological combustion features. We found that for both fatty acid types, there are differences in δ13C signatures among anatomical parts and initial moisture content. These data allow us to characterize the isotopic signature of pine tissue and the effect of degradation on isotopic biomarkers, as well as to estimate combustion temperatures in pine-fuelled anthropogenic fires.Grant project PALEOCHAR – 648871info:eu-repo/semantics/publishedVersio

Fuel sources, natural vegetation and subsistence at a high-altitude aboriginal settlement in Tenerife, Canary Islands: Microcontextual geoarchaeological data from Roques de García Rockshelter

High-altitude island environments, with their characteristic strong seasonal contrast and limited resources, are challenging contexts for human subsistence. However, although archaeological contexts in this kind of setting hold great potential to explore the diversity of human biological and cultural adaptations, such sites are rare. In this paper, we present the results of a microcontextual geoarchaeological study carried out at Rogues de Garcia Rockshelter, the highest altitude cave archaeological site in the Canary Islands (Spain). The site was inhabited by the aboriginal population of the island and has yielded a rich archaeological context derived from combustion activity. We carried out soil micromorphology to characterize site function and lipid biomarker analysis to investigate the natural and anthropogenic organic record. Our data indicate that the aboriginal groups that occupied the site kept goats with them (in the rockshelter) and probably used Juniperus turbinata (sabina) wood, a current distant fuel source. These results suggest that the aboriginal societies of Tenerife occupied the highlands regularly, taking their herds and firewood with them. Further research is necessary to explore the use and exploitation of fuel sources, the seasonality of these occupations and their differences with lowland sites.info:eu-repo/semantics/publishedVersio

Enhancing the context-aware FOREX market simulation using a parallel elastic network model

[EN] Foreign exchange (FOREX) market is a decentralized global marketplace in which different participants, such as international banks, companies or investors, can buy, sell, exchange and speculate on currencies. This market is considered to be the largest financial market in the world in terms of trading volume. Indeed, the just-in-time price prediction for a currency pair exchange rate (e.g., EUR/USD) provides valuable information for companies and investors as they can take different actions to improve their business. The trading volume in the FOREX market is huge, disperses, in continuous operations (24 h except weekends), and the context significantly affects the exchange rates. This paper introduces a context-aware algorithm to model the behavior of the FOREX Market, called parallel elastic network model (PENM). This algorithm is inspired by natural procedures like the behavior of macromolecules in dissolution. The main results of this work include the possibility to represent the market evolution of up to 21 currency pair, being all connected, thus emulating the real-world FOREX market behavior. Moreover, because the computational needs required are highly costly as the number of currency pairs increases, a hybrid parallelization using several shared memory and message passing algorithms studied on distributed cluster is evaluated to achieve a high-throughput algorithm that answers the real-time constraints of the FOREX market. The PENM is also compared with a vector autoregressive (VAR) model using both a classical statistical measure and a profitability measure. Specifically, the results indicate that PENM outperforms VAR models in terms of quality, achieving up to 930xspeed-up factor compared to traditional R codes using in this field.This work was jointly supported by the Fundación Séneca (Agencia Regional de Ciencia y Tecnología, Región de Murcia) under Grant 20813/PI/18 and by the Spanish MEC and European Commission FEDER under Grants TIN2016-78799-P and TIN2016-80565-R (AEI/FEDER, UE).Contreras, AV.; Llanes, A.; Herrera, FJ.; Navarro, S.; López-Espin, JJ.; Cecilia-Canales, JM. (2020). Enhancing the context-aware FOREX market simulation using a parallel elastic network model. The Journal of Supercomputing. 76(3):2022-2038. https://doi.org/10.1007/s11227-019-02838-1S20222038763Bahrepour M, Akbarzadeh-T MR, Yaghoobi M, Naghibi-S MB (2011) An adaptive ordered fuzzy time series with application to FOREX. Expert Syst Appl 38(1):475–485Bank for International Settlements. https://www.bis.org/ . Accessed 13 Feb 2013Bhattacharyya S, Pictet OV, Zumbach G (2002) Knowledge-intensive genetic discovery in foreign exchange markets. IEEE Trans Evolut Comput 6(2):169–181Bank of International Settlements (2016) Triennial central bank survey: foreign exchange turnover in April 2016, BaselCaporale GM, Gil-Alana L, Plastun A (2017) Searching for inefficiencies in exchange rate dynamics. Comput Econ 49(3):405–432De Grauwe P, Markiewicz A (2013) Learning to forecast the exchange rate: two competing approaches. J Int Money Finance 32:42–76Fama E (1970) Efficient capital markets: a review of theory and empirical work. J Finance 25(2):383–417Fama EF (1965) The behavior of stock-market prices. J Bus 38(1):34–105Fama EF (1970) Efficient capital markets: a review of theory and empirical work. J Finance 25(2):383–417Fuglebakk E, Reuter N, Hinsen K (2013) Evaluation of protein elastic network models based on an analysis of collective motions. J Chem Theory Comput 9(12):5618–5628Hanssens DM, Parsons LJ, Schultz RL (2003) Market response models: econometric and time series analysis, vol 12. Springer, New YorkKamruzzaman J, Sarker RA (2003) Forecasting of currency exchange rates using ANN: a case study. In: Proceedings of the 2003 International Conference on Neural Networks and Signal Processing, 2003, vol 1. IEEE, pp 793–797Kamruzzaman J, Sarker RA, Ahmad I (2003) SVM based models for predicting foreign currency exchange rates. In: Third IEEE International Conference on Data Mining, 2003. ICDM 2003, IEEE, pp. 557–560Karplus M, McCammon JA (2002) Molecular dynamics simulations of biomolecules. Nat Struct Mol Biol 9(9):646–652Kleen A (2015) Intel PMU profiling tools. https://github.com/andikleen/pmu-tools/tree/d70840ba . Accessed 15 Mar 2019Kuo RJ, Chen C, Hwang Y (2001) An intelligent stock trading decision support system through integration of genetic algorithm based fuzzy neural network and artificial neural network. Fuzzy Sets Syst 118(1):21–45LeBaron B, Arthur WB, Palmer R (1999) Time series properties of an artificial stock market. J Econ Dyn Control 23(9):1487–1516Li Q, Chen Y, Wang J, Chen Y, Chen H (2017) Web media and stock markets: a survey and future directions from a big data perspective. IEEE Trans Knowl Data Eng 30:381–399Luetkepohl H (2009) Econometric analysis with vector autoregressive models. In: Belsley DA, Kontoghiorghes EJ (eds) Handbook of computational econometrics. Wiley, New York, pp 281–319Makovskỳ P (2014) Modern approaches to efficient market hypothesis of FOREX—the central European case. Proc Econ Finance 14:397–406Meade N (2002) A comparison of the accuracy of short term foreign exchange forecasting methods. Int J Forecast 18(1):67–83Meese RA, Rogoff K (1983) Empirical exchange rate models of the seventies: do they fit out of sample? J Int Econ 14(1–2):3–24Mockus J, Raudys A (2010) On the efficient-market hypothesis and stock exchange game model. Expert Syst Appl 37(8):5673–5681Nassirtoussi AK, Aghabozorgi S, Wah TY, Ngo DCL (2014) Text mining for market prediction: a systematic review. Expert Syst Appl 41(16):7653–7670Neely C, Weller P, Dittmar R (1997) Is technical analysis in the foreign exchange market profitable? A genetic programming approach. J Financial Quant Anal 32(4):405–426Pincak R (2013) The string prediction models as invariants of time series in the FOREX market. Phys A: Stat Mech Appl 392(24):6414–6426Samuelson PA (2016) Proof that properly anticipated prices fluctuate randomly. In: The World Scientific Handbook of Futures Markets, pp 25–38Sarantis N, Stewart C (1995) Structural, VAR and BVAR models of exchange rate determination: a comparison of their forecasting performance. J Forecast 14(3):201–215Schmidhuber J (2015) Deep learning in neural networks: an overview. Neural Netw 61:85–117Sims CA (1980) Macroeconomics and reality. Econ: J Econ Soc. 48:1–48Ţiţan AG (2015) The efficient market hypothesis: review of specialized literature and empirical research. Proc Econ Finance 32:442–449Yao J, Tan CL (2000) A case study on using neural networks to perform technical forecasting of FOREX. Neurocomputing 34(1):79–9

Gamma rays from microquasars Cygnus X-1 and Cygnus X-3

Gamma-ray observations of microquasars at high and very-high energies can provide valuable information of the acceleration processes inside the jets, the jet-environment interaction and the disk-jet coupling. Two high-mass microquasars have been deeply studied to shed light on these aspects: Cygnus X-1 and Cygnus X-3. Both systems display the canonical hard and soft X-ray spectral states of black hole transients, where the radiation is dominated by non-thermal emission from the corona and jets and by thermal emission from the disk, respectively. Here, we report on the detection of Cygnus X-1 above 60 MeV using 7.5 yr of Pass8 Fermi-LAT data, correlated with the hard X-ray state. A hint of orbital flux modulation was also found, as the source is only detected in phases around the compact object superior conjunction. We conclude that the high-energy gamma-ray emission from Cygnus X-1 is most likely associated with jets and its detection allow us to constrain the production site. Moreover, we include in the discussion the final results of a MAGIC long-term campaign on Cygnus X-1 that reaches almost 100 hr of observations at different X-ray states. On the other hand, during summer 2016, Cygnus X-3 underwent a flaring activity period in radio and high-energy gamma rays, similar to the one that led to its detection in the high-energy regime in 2009. MAGIC performed comprehensive follow-up observations for a total of about 70 hr. We discuss our results in a multi-wavelength context.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC 2017), Bexco, Busan, Korea (arXiv:1708.05153

Reconstructing formation processes at the Canary Islands indigenous site of Belmaco Cave (La Palma, Spain) through a multiproxy geoarchaeological approach

The indigenous populations of La Palma (Canary Islands), who arrived on the island from Northwest Africa ca. 2000 years B.P., were predominantly pastoralists. Yet, many aspects of their subsistence economy such as the procurement, management, and use of wild plant resources remain largely unknown. To explore this, we studied the 600–1100-year-old archaeological site of Belmaco Cave, which comprises a stratified sedimentary deposit representative of a fumier. Here, we present a high-resolution, multiproxy geoarchaeological study combining soil micromorphology, lipid biomarker analysis, X-ray diffraction, μ-X-ray diffraction, μ-X-ray fluorescence, Fourier transform infrared spectroscopy, and μ-Fourier transform infrared spectroscopy, to characterize formation processes and explore plant sources. Recurrent goat/sheep habitation and maintenance activities are represented by interstratified layers of unburned dung, charcoal-rich sediment, and dung ash. Lipid biomarker data show a herd diet mainly composed of herbaceous plants, which is key to understanding the mobility of indigenous shepherds. Our results also revealed an unusual suite of authigenic minerals including hazenite, aragonite, and sylvite, possibly formed through diagenetic processes involving interaction between ash, dung, urine, volcanogenic components, and bacterial activity, coupled with arid and alkaline conditions. Our study shows the potential of a multiproxy approach to a fumier deposit in a volcanogenic sedimentary context.publishedVersio

Micro-contextual identification of archaeological lipid biomarkers using resin-impregnated sediment slabs

Characterizing organic matter preserved in archaeological sediment is crucial to behavioral and paleoenvironmental investigations. This task becomes particularly challenging when considering microstratigraphic complexity. Most of the current analytical methods rely on loose sediment samples lacking spatial and temporal resolution at a microstratigraphic scale, adding uncertainty to the results. Here, we explore the potential of targeted molecular and isotopic biomarker analysis on polyester resin-impregnated sediment slabs from archaeological micromorphology, a technique that provides microstratigraphic control. We performed gas chromatography-mass spectrometry (GC-MS) and gas chromatography-isotope ratio mass spectromety (GC-IRMS) analyses on a set of samples including drill dust from resin-impregnated experimental and archaeological samples, loose samples from the same locations and resin control samples to assess the degree of interference of polyester resin in the GC-MS and Carbon-IRMS signals of different lipid fractions (n-alkanes, aromatics, n-ketones, alcohols, fatty acids and other high polarity lipids). The results show that biomarkers within the n-alkane, aromatic, n-ketone, and alcohol fractions can be identified. Further work is needed to expand the range of identifiable lipid biomarkers. This study represents the first micro-contextual approach to archaeological lipid biomarkers and contributes to the advance of archaeological science by adding a new method to obtain behavioral or paleoenvironmental proxies.This study has been funded by an ERC-Paleochar Consolidator Grant Project (ERC-2014-CoG-648871-PALEOCHAR). Archaeological research at El Salt is currently funded by the Spanish Ministry of Science and Innovation (Project PID2019-107113RB-I00) and was funded by the Spanish Ministry of Economy, Industry and Competitiveness (Project HAR2015-68321-P) when sampling for this study took place. Additional financial support for El Salt fieldwork is from the Cultural Heritage Department of the Valencia Government and the Archaeological Museum Camil Visedo Moltó of Alcoy. Research at the Axlor site is funded by the Spanish Ministry of Science and Innovation (Project PID2019-107260GB-I00, PID2019-107113RB-I00). Research at Crvena Stijena is funded by the Montenegrin Ministry of Culture, the Montenegrin Academy of Sciences, the United States National Science Foundation (NSF-BCS 1758285), and the University of Minnesota’s Office of the Vice President of Research Grant-in-Aid program. Research at Cape Esperberg is funded by a collaborative grant from the US National Science Foundation (ARC-1523160, ARC-1523205, ARC-1523059, ARC-1523079) and from the Archeology Commission of the French Ministry of Foreign Affairs

ROBOT MÓVIL MECX1 PARA LA DETECCIÓN DE PERSONAS EMPLEANDO MEMORIAS ASOCIATIVAS ALFA-BETA

ResumenEn presente trabajo de investigación propone emplear a las Memorias Asociativas Alpha-Beta (AMαβ) en la detección automática del cuerpo humano a partir de imágenes RGB-3D capturadas por el robot MECX1, las AMαβ son entrenadas con vectores característicos extraídos de dos tipos de imágenes, las imágenes positivas contienen personas bajo diferentes poses, distancias e iluminación, mientras que las imágenes negativas contienen objetos que el robot puede encontrar en su entorno de navegación. El rendimiento de las AMαβ es evaluado en dos pruebas, en la primera se determina la capacidad para recordar los vectores previamente aprendidos, los resultados muestran que la memoria fue capaz de recordar al 100% las formas de cuerpos humanos, así como de los  objetos con los que fue entrenada, en la segunda prueba se evalúa su capacidad para clasificar vectores que no aprendió anteriormente, obteniéndose una tasa de precisión promedio de 95.1%. Para la validación de los resultados y separación de los conjuntos de entrenamiento y prueba se empleó el método de K-fold-cross-validation.Palabra(s) Clave: cuerpo humano, detección, forma humana, memorias asociativas, reconocimiento. MECX1 MOBILE ROBOT FOR THE DETECTION OF PEOPLE USING ASSOCIATIVE MEMORIES ALPHA-BETA AbstractIn the present work, we propose to use Alpha-Beta Associative Memories (AMαβ) in the automatic detection of the human body from RGB-3D images captured by the robot MECX1, the AMαβ are trained with characteristic vectors extracted from two types of images, positive images contain people under different poses, distances and illumination, while negative images contain objects that the robot can find in its navigation environment. The performance of the AMαβ is evaluated in two tests, the first one determines the ability to remember previously learned vectors, the results show that memory was able to remember 100% human body forms as well as objects with the ones that were trained, in the second test we evaluated the memory capacity to classify vectors that were not previously learned, obtaining an average accuracy rate of 95.1%, K-fold-cross-validation method was used for the validation of the results and separation of the training and test sets.Keywords: associative memories, detection, human body, human shape

Características geoquímicas de los sedimentos superficiales de la Bahía de Panamá

Se cuantificó de manera puntual la composición porcentual de cada textura granulométrica así como los parámetros estadísticos texturales y los niveles de concentración de metales (Cu, Cd, Zn y Pb) en los sedimentos superficiales de 15 puntos de colecta de la Bahía de Panamá. Los resultados indican que la textura predominante es la arenosa, siendo las fracciones abundantes la arena fina (AF) > arena media (AM) > arena gruesa (AG). No se encontró uniformidad en el tamaño de grano en los distintos depósitos sedimentarios. El 58.3% de los sedimentos son mal clasificados y el 41.7% muy mal clasificados. Se diferenciaron sedimentos leptokúrticos (Costa del Este, Rampa, Naos), muy leptokúrticos (Santo Tomás), extremadamente leptokúrticos (Panamá Vieja) mesokúrticos (Matasnillo). Los porcentajes de materia orgánica en la Bahía de Panamá resultaron bajos, entre 0,13 y 1,23%. Las concentraciones de Cu variaron desde 17 µg.g-1 hasta 45 µg.g-1. El Cd mostró concentraciones que oscilaron entre 0.13 a 0.58ug. g-1. cuyo El contenido de Zn fluctuó entre 27 y 73 g.g-1. El Pb varió entre 19 y 433 ug.g1. Los metales no mostraron correlación significativa con la materia orgánica, excepto el Cd (r = 0,40). En general la distribución de la materia orgánica no condicionó la distribución de los metales traza en los sedimentos superficiales de la Bahía. Los metales trazas se acumularon preferiblemente en sedimentos finos, menores de 125 µm (>3Φ). Existen claras evidencias que el ecosistema se encuentra muy impactado por Pb