Crude oil is a complex mixture of hydrocarbons representing several classes of compounds. Some of these constituents significantly affect refinery processes and analysis procedures. ...Ultraviolet-visible (UV-vis) spectroscopy has received wide acceptance because of its broad scope, given that many active species in the spectrum of UV, and many more that with proper treatment, are able to form visible species in that spectrum. In this study two crude oils from different sources were analyzed without dilution C1-RC, in the coastal region and C2-RM of the maritime region of the Gulf of Mexico. Stages for obtaining calibration curves depending on the change in concentration of crude, starting from crude standard solutions and evaluating the repeatability of the method and the dispersion, were established. The results show three signals: (a) 230 nm corresponding to benzene compounds, (b) 260 nm to naphthenic compounds, and (c) 410 nm Soret band corresponding to the metal porphyrins. These species are found in asphaltenes, signals were evaluated individually for separate calibration curves, at concentrations between 10 and 90 mg L
−1
. The model equation of each curve based on the absorbance and concentration determination coefficient values for each compound are reported. It was possible to establish that the method developed is suitable for oil solutions at low concentrations.
The purpose of the study was to report the presence of the soft tick Otobius megnini (Duges) parasitizing a dog. Three specimens were collected during a routine consultation, and by morphological ...examination, identified as the ear tick. Physicians and public health authorities should be aware of the tick as part of differential diagnosis when earache is manifested by patients in close contact with animals and the posible incrimination of the parasite in harboring and transmitting pathogens.
Microplastics (MPs) are widespread in the water column of several aquatic ecosystems. Thus, the sampling methodology is considered as a basic factor influencing MPs abundance. In this baseline, a ...total of 67 investigations were chosen to conduct a quantitative analysis between two sampling methods: Trawl and bulk. The aim is to report a general overview of the MPs abundance and characteristic differences based on the sampling procedures and provide methodological recommendations. MPs abundance reported by bulk studies is 3500 higher than trawl studies. Furthermore, the morphological types and polymers abundances were statistically affected by the type of sampling tool. Conversely, MPs size ranges were significantly different between sampling procedures, suggesting that trawling underestimates the smaller MPs fractions. The analysis confirms that the sampling methods should be selected based on the research objectives. In this sense, it is recommended to combine both types of sampling procedures to obtain comprehensive data.
•Two surface water sampling methods, trawl and bulk, were quantitatively analyzed.•Bulk studies mostly report MP concentrations thousands of times higher than trawl.•Trawl studies report higher abundance of larger MPs (1–5 mm) than bulk methods.•The pros and cons of each methodology were discussed, and recommendations provided.
El Barrio de Magón en Cartago (Túnez) está formado por un excepcional grupo de viviendas de época púnica ubicadas junto a la muralla marítima de la ciudad. Sus características, enmarcadas en una ...cronología que se remonta hasta el siglo V a.C., convierten a este conjunto arqueológico es uno de los más relevantes del Mediterráneo centro-occidental de su época. Sin embargo, las importantes implicaciones económicas, sociales y políticas que se derivan de su construcción aún no han sido discutidas, 30 años después de su publicación final. Las síntesis históricas sobre Cartago que han aparecido desde entonces tampoco le han prestado la debida atención. El objetivo de este artículo es explorar algunas de las conclusiones históricas que desde la perspectiva cartaginesa local se pueden deducir de este gran proyecto urbanístico.
Many workers contribute to the success of animal welfare and study outcomes in biomedical research. However, the professional quality of life (ProQoL) of those who work with laboratory animals has ...not been explored in Spain. To this end, we adapted the ProQoL scale to the Spanish population working with laboratory animals. Participants were contacted by email and asked to complete an anonymous on-line questionnaire. The study comprised a total of 498 participants, 12.4% welfare officers/veterinarians, 19.5% caretaker/technicians, 13.9% principal investigators, 20.7% investigators, 13.6% research technicians, and 19.9% PhD students. The adapted scale revealed very good reliability and internal validity, providing information about two different subscales, compassion satisfaction and compassion fatigue. Animal-facility personnel showed higher total ProQoL and compassion-satisfaction scores than researchers; PhD students showed the lowest scores. Thus, our results indicate that job category is a contributing factor in perceived professional quality of life. We observed that compassion satisfaction is negatively associated with the perceived animal stress/pain. Participants reporting poorer compassion satisfaction also reported lower social-support scores. Overall, our ProQoL scale is a useful tool for analyzing the professional quality of life in the Spanish population, and may help to design future interventions to improve workplace wellbeing in Spain and other Spanish-speaking populations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The effect of cholesterol and ergosterol on supported lipid bilayers composed of 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and egg sphingomyelin (eSM) in a 1/1 M ratio was studied using ...atomic force microscopy. The addition of ergosterol or cholesterol to these membranes considerably modifies both the structure and the dynamics of the domains present in them. The height of the eSM enriched domains increases with concentration of both sterols, but more markedly with ergosterol. The height of the POPC enriched domains increases with concentration in a similar manner for both sterols. This effect is larger for eSM than for POPC when ergosterol, not cholesterol, is present. Domain coverage increases with both sterols at 5 mol% but decreases at 20 mol% and almost disappears at 40 mol%. The size of the eSM enriched domains decreases with sterol concentration, more markedly with cholesterol. Bilayer rupture forces show that overall stiffness increases with the addition of 5 mol% cholesterol, but only for the eSM enriched domains with ergosterol at the same concentration. At larger sterol concentrations the stiffness of both regions becomes reduced. At 40 mol% sterol concentration, both membranes present the same rupture force value. To gain mechanistic insight into these observations we performed Quantum Mechanical calculations and Molecular Dynamics simulations of the sterol molecules. We found that conformational freedom for the sterol molecules is quite different. This difference might be behind the observed phenomena. Finally, the different action of sterols on membrane properties is related to the sterol-dependent ionophoretic activity of polyene antibiotics.
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•Cholesterol and ergosterol have quite distinct effects on dynamics and morphology of membrane domains.•Ergosterol favors interaction with eSM enriched domains and has very marked effects on them.•Cholesterol affects both eSM and POPC enriched domains in a similar manner.•Both sterol inhibit domain formation with increasing concentration.•Molecular conformational differences of ergosterol and cholesterol are behind their effects on membrane structure.
The objective was to evaluate the production and nutritional composition of cassava (Manihot esculenta Crantz) meal under dierent organic fertilization rates. Twenty 10 10 m plots were planted with ...cassava and fertilized with 0.0, 0.5, 1.0 and 1.5 kg plant-1 of sugarcane lter cake (part of the waste left after processing). The variables measured were fresh and dry forage yield (FFY and DFY), fresh and dry tuber yield (FTY and DTY), meal yield (MY) and their nutritional composition. The results indicate that the organic fertilization signicantly increased the FFY, DFY, FTY, DTY and MY compared to the control. Applying 1.5 kg of organic fertilizer signicantly improved crude protein content (CP, 3.37%). Organic fertilization with 1.5 kg plant-1 of compost improved forage and tuber yield, and CP content.
The present research focuses on the understudied interface between syntax and gesture within the emerging field of the dialectal syntax of Spanish. In particular, a formal analysis of so-called ...lip-pointing in various Latin-American varieties of Spanish is developed. Evidence is provided for the availability of deictic adverbs realized as pointing gestures and, most importantly, gestural pronominals, that is to say, gestures which fulfill a nominal function. The discussion provides evidence for Jouitteau’s (2004, 2007) multi-channeled syntax hypothesis, which states that even in oral languages the externalization procedure may include a gestural component as part of their syntax.
El palacio es a la vez un tipo de edificio y una alegoría política. La definitiva importación al Mediterráneo Occidental de este tipo arquitectónico y de su lenguaje simbólico se consumó al tiempo ...que la República romana se transformaba en un Imperio. Pero antes de estos hechos hubo otras experimentaciones con elementos propios de la arquitectura palacial, tanto en ámbito público como privado, en Italia, Sicilia, en el Maghreb occidental y en la península ibérica. En este artículo se propone una definición razonada del término palacio que sirva para su uso analítico, se discute sobre el rol jugado por las grandes poleis mediterráneas, en especial Cartago, en la difusión de estos edificios y se aboga por considerar a las monarquías norteafricanas, aún no suficientemente atendidas por la investigación, como importantes vectores de transmisión de este tipo de arquitectura en el Mediterráneo occidental.
•Plant species richness in traditional agroforestry systems was positively related to the diversity of soil macro-arthropods.•Traditional agroforestry systems differ in their function and plant ...species richness.•The most abundant order of macro-arthropods was Hymenoptera, which represents almost 80% of the individuals collected.
A change in land use from forest to livestock and agriculture is generally linked to a potentially devastating effect on communities of flora and fauna. Tabasco is a state with the highest deforestation rate in the humid tropics of Mexico; more than 66% of its territory is currently occupied by livestock farming. Here, we evaluated the diversity of soil macro-arthropods and plant species richness in eight different, traditional agroforestry systems (AFS): family garden (FG), shade trees in plantations (ShTP), scattered trees in pastures (ScTP), living fences (LF), alley farming (AF), taungya systems (TG), slash and burn agriculture (SBA) and grazing plantations (GP). First, we recorded the biophysical information of the AFS, age and management of the system, richness of the plant community, and other general characteristics. Then, we collected of macro-arthropods in 49 plots of land in five sub-regions of Tabasco. We established ten pitfall traps in each plot during the dry season (March–May 2009). To compare the diversity of soil macro-arthropods among the AFS, we computed the species accumulation curves and calculated the diversity indexes. We found that the total plant richness varied among the AFS and ordered as FG (108), ShTP (106), ScTP (32), LF (38), AF (30), TG (16), SBA (0) and GP (2). We collected 42,269 individuals of arthropods, belonging to 15 orders in the eight AFS. The most abundant orders were Hymenoptera and Coleoptera, while the least abundant was Dermaptera. The SBA, FG, ShTP, and ScTP systems presented the higher diversity of macro-arthropods as shown by Shannon-Wiener index (H’) values. We also found a significant positive correlation (rs = 0.84) between macro-arthropod order diversity (H’) and plant species richness in the most common AFS. The study showed that the AFS with greater plant species richness are important agricultural production strategies that increase the diversity and conservation of soil macro-arthropods.
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