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The aim of this investigation was to study castor, canola, and sesame vegetable oils in order to evaluate their potential use as lubricants in steel mechanical components. For this purpose, densities of each oil were evaluated using the pycnometer method, as well as their dynamic viscosities through a Brookfield DV-II rotational viscometer. Both properties were evaluated at temperatures of 25, 40 and 100 °C. Additionally, viscosity indexes were determined according to ASTM D 2270. These rheological properties were used to estimate the lubrication regime considering parameters of real contact conditions in mechanical components. Friction and wear analyses were carried out to investigate the behaviour of the vegetable oil as lubricants. Such tests were carried out at room temperature on a CSM tribometer with pin-on-disk configuration by using castor, canola and sesame oils as lubricants. AISI 4140 hardened steel against AISI 100Cr6 steel pin was used as a mechanical component. From the rheological study, it was observed that canola and sesame oils behave as dilatant fluids at the evaluated temperatures, while castor oil behaves like a Newtonian fluid at 25 and 40 °C. Castor oil showed the highest density value among oils studied, but it also exhibited the lowest value of viscosity index (271). Contrarily, sesame oil was the least dense, but it exhibited the highest viscosity index (545). On the other hand, the lubrication regime study showed that by using castor oil as a lubricant in the mechanical component (4140/100Cr6), the system worked in a mixed lubrication regime while by using canola and sesame oils the system operated in boundary lubrication conditions. Finally, the kinetic friction coefficients were different for each lubricant obtaining the lowest value with castor oil while the highest value of friction coefficient was exhibited by the sesame oil lubricant.
Options with extendable features have many applications in finance and these provide the motivation for this study. The pricing of extendable options when the underlying asset follows a geometric Brownian motion with constant volatility has appeared in the literature. In this paper, we consider holder-extendable call options when the underlying asset follows a mean-reverting stochastic volatility. The option price is expressed in integral forms which have known closed-form characteristic functions. We price these options using a fast Fourier transform, a finite difference method and Monte Carlo simulation, and we determine the efficiency and accuracy of the Fourier method in pricing holder-extendable call options for Heston parameters calibrated from the subprime crisis. We show that the fast Fourier transform reduces the computational time required to produce a range of holder-extendable call option prices by at least an order of magnitude. Numerical results also demonstrate that when the Heston correlation is negative, the Black–Scholes model under-prices in-the-money and over-prices out-of-the-money holder-extendable call options compared with the Heston model, which is analogous to the behaviour for vanilla calls.
One of the key factors to improve swine production sustainability is the use of agro-industrial by-products in feeds, such as olive by-products. However, it is necessary to assess its effects on the overall production process, including the animal and the environment. With this aim, an experiment was conducted to determine the effects of including a partially defatted olive cake (PDOC) in pig diets on growth performance, faecal microbiota, carcass quality and gas emission from the slurry. Two finishing diets were formulated, a control (C) diet and a diet with PDOC included at 120 g/kg. Eighty finishing male pigs Duroc-Danbred × (Landrace × Large White) of 60.4 ± 7.00 kg BW were divided between these two treatments. During the finishing period (60 to 110 kg BW, 55 days) average daily gain, average daily feed intake and feed conversion ratio were recorded. Faecal samples from the rectum of 16 animals per treatment were incubated for bacteria enumeration. At the end of finishing period, backfat thickness and loin depth (LD) were measured. Animals were slaughtered to obtain carcass weight and carcass composition parameters, and subcutaneous fat was sampled to analyse the fatty acid (FA) profile. In addition greenhouse gas and ammonia emissions were measured during pig slurry storage using the methodology of dynamic flux chambers. An initial slurry characterisation and biochemical methane potential (B0) were also determined. No significant differences between treatments were found in performance, carcass quality and microbial counts with the exception of LD, which was lower in PDOC compared with C animals (45.5 v. 47.5 mm, SEM: 0.62; P = 0.020). The FA profile of the subcutaneous fat did not differ between treatments, but the monounsaturated FA (MUFA) concentration was higher and the polyunsaturated FA was lower in the animals fed PDOC (50.9 v. 48.3, SEM: 0.48, P < 0.001; 17.6 v. 19.3, SEM: 0.30, P < 0.001 in mg/100 g of Total FA, for PDOC and C animals, respectively). The initial pig slurry characterisation only showed differences in ADF concentration that was higher (P < 0.05) in the slurry from PDOC treatment. Regarding gas emission, slurries from both treatments emitted similar amounts of ammonia (NH3), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as B0 values. The results obtained suggest that PDOC may be included in balanced pig diets at rates of up to 120 g/kg without negative effects on performance, carcass quality, gut microflora and slurry gas emission, while improving the MUFA concentration of subcutaneous fat.
Predation by Engytatus varians (Distant) adults on different development stages of the prey species Bactericera cockerelli (Sulcer) (egg, second, and third nymphal instars), Spodoptera exigua (Hübner) and Spodoptera frugiperda (J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicum L.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence of E. varians age on the predation capacity was also analysed. Engytatus varians females consumed significantly more B. cockerelli eggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly more S. exigua and S. frugiperda eggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instar S. exigua than males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar of S. frugiperda for both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed that E. varians has potential as a biological control agent for B. cockerelli and also for the Spodoptera species bioassayed.
This research communication addresses the hypothesis that in dual-purpose goats, exposure to 1 h of extra-light given from 16 to 17 h after dawn (pulse of light) in winter stimulates milk yield. One group of goats was maintained under natural short photoperiod (natural day; ND (n = 7)). Another group of lactating females was submitted to an artificial long-day photoperiod consisting of 16 h light and 8 h darkness (long days; LD (n = 7)). A third group of females received one single hour of extra-light 16 h after the fixed dawn (pulse of light; PL (n = 6)). Goats from LD and PL yielded 30% more milk than goats from ND. Mean percentages of fat, protein and lactose contents in milk did not differ between the 3 groups at any stage of lactation, but these components in grams/day were higher in goats from PL than in the others two groups within the first 45 d of lactation. In conclusion, dual-purpose lactating goats that started their lactation during natural short days, the daily exposition to a 1-h pulse of light is sufficient to stimulate milk yield compared to females maintained under natural short photoperiod.
All livestock animal species harbour complex microbial communities throughout their digestive tract that support vital biochemical processes, thus sustaining health and productivity. In part as a consequence of the strong and ancient alliance between the host and its associated microbes, the gut microbiota is also closely related to productivity traits such as feed efficiency. This phenomenon can help researchers and producers develop new and more effective microbiome-based interventions using probiotics, also known as direct-fed microbials (DFMs), in Animal Science. Here, we focus on one type of such beneficial microorganisms, the yeast Saccharomyces. Saccharomyces is one of the most widely used microorganisms as a DFM in livestock operations. Numerous studies have investigated the effects of dietary supplementation with different species, strains and doses of Saccharomyces (mostly Saccharomyces cerevisiae) on gut microbial ecology, health, nutrition and productivity traits of several livestock species. However, the possible existence of Saccharomyces which are indigenous to the animals’ digestive tract has received little attention and has never been the subject of a review. We for the first time provide a comprehensive review, with the objective of shedding light into the possible existence of indigenous Saccharomyces of the digestive tract of livestock. Saccharomyces cerevisiae is a nomadic yeast able to survive in a broad range of environments including soil, grass and silages. Therefore, it is very likely that cattle and other animals have been in direct contact with this and other types of Saccharomyces throughout their entire existence. However, to date, the majority of animal scientists seem to agree that the presence of Saccharomyces in any section of the gut only reflects dietary contamination; in other words, these are foreign organisms that are only transiently present in the gut. Importantly, this belief (i.e. that Saccharomyces come solely from the diet) is often not well grounded and does not necessarily hold for all the many other groups of microbes in the gut. In addition to summarizing the current body of literature involving Saccharomyces in the digestive tract, we discuss whether the beneficial effects associated with the consumption of Saccharomyces may be related to its foreign origin, though this concept may not necessarily satisfy the theories that have been proposed to explain probiotic efficacy in vivo. This novel review may prove useful for biomedical scientists and others wishing to improve health and productivity using Saccharomyces and other beneficial microorganisms.
This is a copy of the slides presented at the meeting but not formally written up for the volume.
As in vivo cellular imaging becomes the necessary norm for understanding cancer and other diseases, new non-toxic nanoprobes are going to be required to replace the high quality cadmium based nanoprobes in use today. We are developing less toxic probes based on two types of luminescent ceramic nanoparticles: naturally occurring fluorescent (NOF) mimics and Ln-based ceramic oxide materials. The NOF minerals of interest and that have demonstrated initial luminosity of sufficient brightness for use in cellular studies that include sphalerite, scheelite, manganoan and perovskite nanoparticles. For Ln-based materials we have shown that Ln-doped zincite will also luminesce enough to allow for quantification in cellular activity. Once formed, these probes are functionalized such that they can be delivered to desired cellular targets. Probe derivatization has focused on surface capping with functionalized poly(ethyleneglycol) molecules/lipids to yield water soluble NCs and polyarginine-based transporters for transmembrane delivery. The probes are being evaluated for their luminescent properties, as well as their non-toxicity and ability to report on cell-signaling events with various cell lines using multi-spectral, confocal microscopy, and other techniques. Preliminary interdisciplinary studies have validated the basic approaches for the synthesis of NOF nanoprobes and the bio-delivery and imaging of nanoparticles. Work to optimize the design, delivery, and imaging of these new nanoprobes is expected to achieve the NIH directed goal of increasing in the sensitivity and specificity of molecular probes for imaging. Details of the synthesis, functionalization and biological imaging using these probes will be presented. This work partially supported by the United States Department of Energy under contract number DE-AC04-94AL85000. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the United States Department of Energy and by the National Institutes of health through the NIH Roadmap for Medical Research, Grant #1 R21 EB005365-01. Information on this RFA (Innovation in Molecular Imaging Probes) can be found at http://grants.nih.gov/grants/guide/rfa-files/RFA-RM-04-021.html.
Species identification in the tropical lichen genus Phyllopsora is generally challenging and is based on ascospore morphology, vegetative dispersal units, thallus structure and secondary chemistry. As several type specimens are in poor condition and difficult to interpret, it is often unclear how these old names fit with the currently used taxonomy. In the present study, we aim to identify species boundaries in Phyllopsora s. str. supported by an integrative approach using multiple sources of evidence. We investigated a substantial amount of herbarium as well as freshly collected material and generated mtSSU and ITS sequence data from most of the described species, including several types. Species delimitation analyses are applied on the gene trees using mPTP and we construct a species tree of both markers with *BEAST, facilitating discussion of species delimitation and sister-relationships. Comparing morphology, chemistry and molecular data, we found that the mPTP analyses split established species repeatedly. Based on our integrative results, we exclude nine species from the genus, resurrect one (P. melanoglauca Zahlbr.), reduce two into synonymy with other Phyllopsora species and describe five as new to science: Phyllopsora amazonica Kistenich & Timdal (which shares the secondary chemistry (atranorin and terpenoid pattern) with P. halei chemotype 1, but differs, e.g., in having smaller areolae that are attached to a thinner, white prothallus, and in having more persistently marginate and less convex apothecia), Phyllopsora concinna Kistenich & Timdal (which shares the secondary chemistry (atranorin and parvifoliellin) with P. parvifoliella and P. rappiana, but differs from both in forming larger isidia, having a white prothallus, apothecial margin paler than the disc, and longer and broader ascospores), Phyllopsora furfurella Kistenich & Timdal (which is here segregated from P. furfuracea based on having a white prothallus and in containing skyrin in the hypothecium (K+ red)), Phyllopsora isidosa Kistenich & Timdal (which differs from P. byssiseda in forming a more crustose thallus with more delicate isidia, and from P. isidiotyla in forming somewhat coarser, less branched isidia) and Phyllopsora neotinica Kistenich & Timdal (a neotropical species here segregated from the now exclusively paleotropical P. chodatinica, differing in containing an unknown xanthone (not chodatin)). Lectotypes are designated for Biatora pyrrhomelaena Tuck., Lecidea leucophyllina Nyl., L. pertexta Nyl., and P. brachyspora Müll. Arg. In total, we accept 54 species in the genus Phyllopsora.
Venezuela has plunged into a humanitarian, economic, and health crisis of extraordinary proportions. This complex situation is derived from dismantling of structures at the institutional, legal, political, social, and economic level affecting the life and wellbeing of the entire population.
This study aims to assess the impact of Venezuela’s healthcare crisis on vector-borne and vaccine-preventable diseases and the spillover to neighboring countries.
Since October 2014, there is a paucity of official epidemiological information in Venezuela. An active search of published and unpublished data was performed. Venezuela and Latin America data were sourced from PAHO Malaria Surveillance and from Observatorio Venezolano de la Salud. Brazil and Colombian data were accessed via their respective Ministries of Health.
Economic and political mismanagement have precipitated a general collapse of Venezuela’s health system with hyperinflation rates above 45,000%, people impoverishment, and long-term shortages of essential medicines and medical supplies. In this context, the rapid resurgence of previously well-controlled diseases, such as vaccine-preventable (measles, diphtheria) and arthropod-borne (malaria, dengue) diseases has turned them into epidemics of unprecedented magnitudes. Between 2000-2015 Venezuela witnessed a 365% increase in malaria cases followed by a 68% increase (319,765 cases) in late 2017. The latest figures have surpassed 600,000 malaria cases with a prediction to reach 1 million by the end of 2018. Measles and diphtheria have recently re-emerged after a progressive interruption of the national immunization program, with vulnerable indigenous population being particularly affected. In response to Venezuela’s rapidly decaying situation, a massive population exodus is ongoing towards neighboring countries causing a spillover of diseases.
Action to halt the spread of vaccine-preventable diseases within Venezuela is a matter of urgency for the country and the region. Global and hemispheric health authorities should urge the Venezuelan government to allow establishing a humanitarian channel to bring relief.
The Centro de Laseres Pulsados in Salamanca, Spain has recently started operation phase and the first user access period on the 6 J 30 fs 200 TW system (VEGA 2) already started at the beginning of 2018. In this paper we report on two commissioning experiments recently performed on the VEGA 2 system in preparation for the user campaign. VEGA 2 system has been tested in different configurations depending on the focusing optics and targets used. One configuration (long focal length
cm) is for underdense laser–matter interaction where VEGA 2 is focused onto a low density gas-jet generating electron beams (via laser wake field acceleration mechanism) with maximum energy up to 500 MeV and an X-ray betatron source with a 10 keV critical energy. A second configuration (short focal length
cm) is for overdense laser–matter interaction where VEGA 2 is focused onto a
thick Al target generating a proton beam with a maximum energy of 10 MeV and temperature of 2.5 MeV. In this paper we present preliminary experimental results.
Poly (methyl methacrylate)/hydroxyapatite (PMMA/HAp) nanocomposites with HAp nanoparticles content of 12 wt.% were obtained by free-radical polymerization synthesis. Three different concentrations of benzoyl peroxide (PBO) of 3, 6, and 12 wt.% were studied. The results showed that the concentration of PBO has an effect on the performance of composites. In particular, the nanocomposite with the highest concentration of PBO presented the best mechanical and tribological behavior, as well as the lowest values of water absorption and porosity percent.
A new flower preserved in amber in sediments of Simojovel de Allende, México, is identified as an extinct member of Staphyleaceae, a family of angiosperms consisting of only three genera (Staphylea, Turpinia and Euscaphis), which has a large and abundant fossil record and is today distributed over the Northern Hemisphere. Staphylea ochoterenae sp. nov. is the first record of a flower for this group, which is small, pedicelled, pentamer, bisexual, with sepals and petals with similar size, dorsifixed anthers and superior ovary. Furthermore, the presence of stamens with pubescent filaments allows close comparison with extant flowers of Staphylea bulmada and S. forresti, species currently growing in Asia. However, their different number of style (one vs. three) and the apparent lack of a floral disc distinguish them from S. ochoterenae. The presence of Staphyleaceae in southern Mexico ca. 23 to 15My ago is evidence of the long history of integration of vegetation in low-latitude North America, in which some lineages, such as Staphylea, could move southwards from high latitudes of the Northern Hemisphere, as part of the Boreotropical Flora. In Mexico it grew in association with tropical elements, as suggested by the fossil record of the area.
The aim of this research was to investigate the influence of substrate roughness on the adhesion and tribological performance of thin TiN coatings obtained by physical vapor deposition. For that purpose, substrates of AISI H13 steel with surface finishes of 0.06, 0.28 and 0.90 μm in Ra were coated with TiN under the same coating conditions. The chemical composition of the steel, as well as that of the TiN coating, were obtained using EDS analysis. Adhesion tests were carried out following the procedure of BSi 1071-8 standard while hardness was evaluated by ASTM C 1327-03. On the other hand, dry sliding friction tests were conducted with a pin-on-disk tribometer, according to the ASTM G 99-05 standard. This study showed that the roughness of the coating increases as the substrate roughness increases. Regarding adhesion and hardness, all the samples showed an adhesion class 1 according to the standard and a hardness value of 14.51 GPa. Nevertheless, the highest substrate roughness produced the best adhesion. On the other hand, the lowest values for the friction coefficient and wear behavior were obtained by the sample with the lowest substrate roughness of 0.06 µm. In addition, it was found that friction and wear increase when the substrate roughness increases.
Traditional historical literature has stressed a generalised crisis throughout the world in the 17th century. First proposed for Europe with its numerous dynastic, religious and state conflicts, it has now been expanded to include Asia and the Middle East as well. It was also assumed that there was a significant crisis in the Americas, a theme which until recently has dominated the traditional literature. The claim that there was such a crisis was based on a series of classic studies by Earl J. Hamilton, Chaunu and Borah, among others. But new research has challenged this hypothesis and we will examine both these new studies as well as offering our own research findings on this subject.
Functional circuits of the human brain emerge and change dramatically over the second half of gestation. It is possible that variation in neural functional system connectivity in utero predicts individual differences in infant behavioral development, but this possibility has yet to be examined. The current study examines the association between fetal sensorimotor brain system functional connectivity and infant postnatal motor ability. Resting-state functional connectivity data was obtained in 96 healthy human fetuses during the second and third trimesters of pregnancy. Infant motor ability was measured 7 months after birth using the Bayley Scales of Infant Development. Increased connectivity between the emerging motor network and regions of the prefrontal cortex, temporal lobes, posterior cingulate, and supplementary motor regions was observed in infants that showed more mature motor functions. In addition, females demonstrated stronger fetal-brain to infant-behavior associations. These observations extend prior longitudinal research back into prenatal brain development and raise exciting new ideas about the advent of risk and the ontogeny of early sex differences.