New views on old hands: the context of stencils in El Castillo and La Garma Caves (Cantabria, Spain)

Hand stencils are an intriguing feature of prehistoric imagery in caves and rockshelters in several parts of the world, and the recent demonstration that the oldest of those in Western Europe date back to 37 000 years or earlier further enhances their significance. Their positioning within the painted caves of France and Spain is far from random, but responds to the shapes and fissures in the cave walls. Made under conditions of low and flickering light, the authors suggest that touch—‘palpation’—as much as vision, would have driven and directed the locations chosen for these stencils. Detailed study of the images in two Cantabrian caves also allows different individuals to be distinguished, most of whom appear to have been female. Finally, the project reveals deliberate associations between the stencils and features on the cave walls

Segmented-block poly(ether amide)s containing flexible polydisperse polyethyleneoxide sequences and rigid aromatic amide moieties

We describe the synthesis and characterization of three novel aromatic diamines containing oxyethylene sequences of different lengths. These diamines were polymerized using the low-temperature solution polycondensation method with isophthaloyl chloride (IPC), terepthaloyl chloride (TPC), [1,1’-biphenyl]-4,4’-dicarbonyl dichloride (BDC), and 4,4′-oxybis(benzoyl chloride) (OBE), obtaining twelve poly(ether amide)s with short segments of polydisperse polyethyleneoxide (PEO) sequences in the polymer backbone. These polymers show reasonably high molecular mass materials (Mw > 12,000), and the relationship between their structure and properties has been carefully studied. Compared with conventional polyamides containing monodisperse PEO sequences, the polydispersity of the PEO segments within the structural units exerts a significant influence on the crystallinity, flexibility, solubility, and the thermal properties of the polymers. For instance, the all-para oriented polyamides (TPCP-A), with an average number of 8.2 ethylenoxide units per structural unit can be transformed conventionally (Tm = 259 °C) in comparison with thermally untransformable polymer with 2 ethylenoxide units (Tm = 425 °C)FEDER (Fondo Europeo de Desarrollo Regional), the Spanish Agencia Estatal de Investigación (PID2020-113264RB-I00/AEI/10.13039/501100011033) and (PID2019-108583RJ-I00/AEI/ 10.13039/501100011033), and the Consejería de Educación—Junta de Castilla y León (BU306P1

Planeación estratégica en el simulador de negocios para la industria de sensores

En el presente documento se ha incorporado el análisis y la toma de decisiones llevadas a cabo en el simulador de negocio Capstone. El simulador recrea un ambiente de negocios enfocado al mercado de sensores, en donde se toma el mando de una empresa llamada Erie, en la que a lo largo de ocho años se debe implementar una estrategia que tendrá que adaptarse a factores externos y que, por medio de diversas tácticas, buscará ser líder con respecto a la competencia.ITESO, A.C

Beneficios económicos de la cacería de lagarto (Caiman yacaré) en la Amazonía boliviana

El aprovechamiento legal del lagarto (Caiman yacare) representa una alternativa económica en las tierras bajas de la Amazonia boliviana. La cacería se enmarca en el Programa para la Conservación y Aprovechamiento Sostenible del Lagarto, que ya tiene vigencia durante más de una década. Sin embargo, son escasas las evaluaciones de los beneficios sociales, económicos y culturales que brinda el programa. En el presente trabajo se evalúa los beneficios económicos logrados por los cazadores de la comunidad campesina Bella Vista, situada en la provincia Iténez, antes de la elaboración del plan de manejo de lagarto de la zona sur del área protegida PD ANMI Iténez (2007), durante la fase de elaboración del plan (2008-2009) y después de su aprobación mediante Resolución Ministerial (2010). En este intervalo de tiempo los cupos aprovechados por los cazadores de Bella Vista subieron de 246 a 680 lagartos. Los beneficios económicos para los cazadores estuvieron determinados en mayor grado por las fluctuaciones en los precios ofertados por las empresas industriales que compran los chalecos. El valor económico en los mercados de un lagarto de aproximadamente 1.80 m de longitud bajó de aproximadamente 140 Bs (20 US$) a 70 Bs (10 US$) entre 2008 y 2010. El plan de manejo y el fortalecimiento organizativo de los cazadores han contribuido a mantener controlado el impacto a nivel local de la caída de los precios. Se presentan las estrategias de aprovechamiento sostenible de la especie en la región.A exploração legal do jacaré (Caiman yacare) representa urna alternativa económica em algumas regiões da Amazonia boliviana. A caça é parte do Programa de Conservação e Uso Sustentável do Jacaré, que está vigente por mais de urna década. No entanto, são escassas as avaliações dos beneficios sociais, económicos e culturais fomecidos pelo programa. O presente trabalho avalia os beneficios económicos obtidos pelos caçadores da comunidade rural Bella Vista, localizada na provincia Iténez, antes da elaboração do Plano de Manejo do Jacaré da zona sul da área protegida PD ANMI Iténez (2007), após a elaboração do plano (2008-2009) e depois da sua aprovação (2010). Neste período, a quota de explora9ao aumentou de 236 a 680. Os beneficios foram determinados em maior grau pelas oscila9óes nos preços oferecidos pelas empresas que compram peles de jacarés, variando, entre 2008 e 2010, de 140 Bs (20 US$) a 70 Bs (10 US$) para um jacaré de aproximadamente 1,80 m de comprimento. Graças ao plano de manejo e ao fortalecimento organizacional dos ca9adores, o impacto local do decréscimo dos pre90s tem sido controlado. Assim, são apresentadas as estratégias de exploração sustentável da espécie na região.The legal hunting of yacaré caiman (Calman yacare) represents an economic altemative in the lowlands of the Bolivian Amazon. Caiman hunting is implemented within the framework of the National Program for Conservation and Sustainable Use of Yacare Caiman, which has been in place for more than a decade. However, evaluations of the program’s social, economic and cultural benefits are scarce. This document evaluates the economic benefits gained by hunters from the farming community of Bella Vista, situated in the province of Iténez, department of Beni (northeast of the Bolivian Amazon) during three phases: before the elaboration of the caiman management plan in the area (Departmental Park Natural Area for Integrated Management PD ANMI Iténez) (2007), during its elaboration (2008-2009) and after plan approval (2010). Between 2007 and 2010 the hunting quota for the community increased from 246 to 680. The economic benefits are determined to a large extent by fluctuations in prices offered by the industrial tanneries. These prices decreased significantly between 2008 and 2010 thus being the main factor responsible for diminished benefits for local hunters. Between 2008 and 2010, the value of one caiman measuring 1.8 m decreased from 20 US$(140 Bs) to 10 US$ (70 Bs). The available data suggest that the management plan and the strengthening of local hunting organizations helped to buffer the negative tendency in prices. Sustainable hunting strategies for the yacare caiman in the region are presented

Mat thickness associated with Didymosphenia geminata and Cymbella spp. in the southern rivers of Chile

Didymosphenia geminata is a diatom that can alter aquatic systems. Several investigations have shown as chemical, and hydraulic factors have a great influence on the proliferation of D. geminata, but the study of other microalgae that could be associated with it has been poorly addressed. The objective of this study is to evaluate the relationship between mat thickness, D. geminata and another taxon that produces mucilage, Cymbella, while also considering physical and chemical factors. For this, two samples were taken, one in the spring of 2013 and the other in the autumn of 2014, from eight rivers in central-southern Chile-South America, where the benthic community was characterized, and the thickness of the mat was measured. The results show that the mat thickness on sites with the presence of both taxa is doubled, and while sites with D. geminata presence showed mat peak on autumn, sites with Cymbella spp. presence showed on spring. Also, higher values of mat thickness associated with low cell densities of D. geminata and intermediate cell densities of Cymbella spp. Finally, physicochemical variables that better explain mat thickness are phosphorus and water temperature. An alternation process of mucilage production may explain these results by these taxa strongly related to physicochemical variables. The present study contributes evidence about the relationship between mat thickness D. geminata and other microalgae contribution, and aquatic condition for this development

Estudio exploratorio de la variabilidad radial y apical del tamaño y frecuencia de los canales resiníferos en Pino radiata

En este trabajo se cuantifica la variabilidad radial y apical de los canales resiníferos de pino radiata (Pinus radiata) de 14 años.Se determinó la frecuencia y el tamaño de los canales resiníferos en muestras microtomadas usando un software comercial. Las muestras fueron extraídas de árboles en pie presentando tres niveles diferentes de resinación externa, es decir, moderada/leve, e intensa. Se evaluó la variabilidad de los canales resiníferos según la posición radial a tres diferentes alturas: base, DAP, y al comienzo de la copa del árbol.Los resultados muestran que la variación radial y apical del tamaño y la frecuencia de canales resiníferos aparece débilmente correlacionada con el nivel de intensidad de resinación observada en árboles en pie de pino radiata. AbstractRadial and apical variation in resin canals of radiata pine were studied. The frequency and size of resin canals were examined, using microscopic techniques from a commercial software. Wood samples from standing trees were taken, showing three different levels of external resin-bleeding intensity: moderate, light and intense. The variability of the resin canals were examined according to the radial position at three different heights ; bottom, breast height diameter and at the beginning of the tree top. The results show that the apical and radial variation of the size and frequency of resin canals appeared weakly correlated with the intensity level of the tree resin-bleeding of the standing radiata pine trees