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The application of three-dimensional (3D) printing in tissue engineering is becoming prominent nowadays. A big obstacle for this technology is the selection of proper ink material. Chitosan hydrogel is an established biocompatible material that can be used as tissue scaffolds, and it has the rheology necessary for processing via extrusion type 3D printer. However, chitosan still has degradation and swelling limitations. Hence, chitosan hydrogel blends were incorporated with cellulose particles and were prepared as ink material. The hydrogels were successfully synthesized via thermo-responsive sol-gel method. Fourier transform infrared spectroscopy (FT-IR) analysis showed that the gelation of hydrogels formed a semi-interpenetrating network of ionically crosslinked chitosan and cellulose particles. Rheological tests have shown that the hydrogels exhibited shear thinning property necessary for printing. However, high cellulose amounts caused clogging during printing, and the presence of water limited the structural rigidity of the printed product. Besides this, it was found that the addition of cellulose was able to increase swelling, decrease degradation rate, and decrease gelation time, but the effect is not significant for any of these three properties.

Animal movement has direct applications in spatial management and conservation planning, yet it is rarely taken into account for the design of natural protected areas. For instance, reef shark species are thought to benefit from marine protected area networks, even though their movement behaviour remains poorly characterized. Poor understanding of species' movements implies that the benefits of MPA networks for species' populations are still widely unknown. To understand the consequences of movement behaviour for protection, we modelled movements of three reef shark species' (Carcharhinus albimarginatus,C. amblyrhynchosandC. leucas) with distinct levels of reef association using real passive-acoustic telemetry data. The model simulates if individuals are protected or unprotected by their movements in a system of reef patches in a network of MPAs. Model parameters that control individuals' movements were estimated from acoustic telemetry data. To estimate benefits for species we monitored longevity and time spent in protected habitats across all scenarios of reef protection, fishing intensity (11 values for each) and protection of high or low suitability reefs (a reef-dependent factor that attracts sharks to reside in it) for populations of 1,000 individuals per species. The time individuals spent in protected reefs increased linearly with protection until it levelled off after 50%-80% of reefs protected (78%C. amblyrhynchos, 72%C. albimarginatusand 52% C. leucas, at 100% protection). Individuals' life span decreased exponentially with fishing intensity. Reef protection only mildly counteracted life span lost to fishing. Protecting highly suitable reefs increased time spent in protected reefs, optimal protection was reached at a lower number of reefs protected, and life expectancy was higher with protection of highly suitable reefs. Synthesis and applications. Our framework can be applied to many studies using passive-acoustic telemetry to track animal movements. Protected area networks benefit species highly attached to protected sites. To increase benefits of marine protected area networks for all species (with low and high degrees of reef attachment) we need to understand the use of reef-adjacent areas, dispersal routes and characterize reef suitability for multiple species.

Chronic hyperglycemia, oxidative stress and inflammation are key players in the pathogenesis of diabetic retinopathy (DR). In this work we study the role of phospholipase D (PLD) pathway in an in vitro model of high glucose (HG)-induced damage. To this end, we exposed human retinal pigment epithelium (RPE) cell lines (ARPE-19 and D407) to HG concentrations (16.5 or 33 mM) or to normal glucose concentration (NG, 5.5 mM) for 4, 24 or 72 h. Exposure to HG increased reactive oxygen species levels and caspase-3 cleavage and reduced cell viability after 72 h of incubation. In addition, short term HG exposure (4 h) induced the activation of early events, that involve PLD and ERK1/2 signaling, nuclear factor kappa B (NFκB) nuclear translocation and IκB phosphorylation. The increment in pro-inflammatory interleukins (IL-6 and IL-8) and cyclooxygenase-2 (COX-2) mRNA levels was observed after 24 h of HG exposure. The effect of selective pharmacological PLD1 (VU0359595) and PLD2 (VU0285655-1) inhibitors demonstrated that ERK1/2 and NFκB activation were downstream events of both PLD isoforms. The increment in IL-6 and COX-2 mRNA levels induced by HG was reduced to control levels in cells pre-incubated with both PLD inhibitors. Furthermore, the inhibition of PLD1, PLD2 and MEK/ERK pathway prevented the loss of cell viability and the activation of caspase-3 induced by HG. In conclusion, our findings demonstrate that PLD1 and PLD2 mediate the inflammatory response triggered by HG in RPE cells, pointing to their potential use as a therapeutic target for DR treatment. Fil: Tenconi, Paula Estefania. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Bermúdez, Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Oresti, Gerardo Martin. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Giusto, Norma Maria. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Salvador, Gabriela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina Fil: Mateos, Melina Valeria. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina

Snakebite causes more than 1.8 million envenoming cases annually and is a major cause of death in the tropics especially for poor farmers. While both social and ecological factors influence the chance encounter between snakes and people, the spatio-temporal processes underlying snakebites remain poorly explored. Previous research has focused on statistical correlates between snakebites and ecological, sociological, or environmental factors, but the human and snake behavioral patterns that drive the spatio-temporal process have not yet been integrated into a single model. Here we use a bottom-up simulation approach using agent-based modelling (ABM) parameterized with datasets from Sri Lanka, a snakebite hotspot, to characterise the mechanisms of snakebite and identify risk factors. Spatio-temporal dynamics of snakebite risks are examined through the model incorporating six snake species and three farmer types (rice, tea, and rubber). We find that snakebites are mainly climatically driven, but the risks also depend on farmer types due to working schedules as well as species present in landscapes. Snake species are differentiated by both distribution and by habitat preference, and farmers are differentiated by working patterns that are climatically driven, and the combination of these factors leads to unique encounter rates for different landcover types as well as locations. Validation using epidemiological studies demonstrated that our model can explain observed patterns, including temporal patterns of snakebite incidence, and relative contribution of bites by each snake species. Our predictions can be used to generate hypotheses and inform future studies and decision makers. Additionally, our model is transferable to other locations with high snakebite burden as well., Author summary Snakebite is a neglected tropical disease affecting millions, and a major cause of death of agricultural workers in the tropics. In this research, the authors have developed a simulation model that includes data for agricultural activity across the days and seasons, as well as snake behavioral patterns, and the times and locations humans and snakes meet. Using this model, they predicted observed seasonal snakebite patterns in Sri Lanka, and they successfully showed how these patterns vary between different agricultural activities, including seasonal rice cultivation, and rubber and tea harvests. The findings arising from this study demonstrate that different combinations of human and snake activity, including species and farming practice differences, are likely to generate differences in snakebite patterns across locations. This model could be applied to analyze and predict snakebite in tropical regions around the globe to help mitigate the problem.

Correlative estimates of fundamental niches are gaining momentum as an alternative to predict species’ abundances, particularly via the abundant niche-centroid hypothesis (an expected inverse relationship between species’ abundance variation across its range and the distance to the geometric centroid of its multidimensional ecological niche). The main goal of this review is to recapitulate what has been done, where we are now, and where should we move towards in regards to this hypothesis. Despite evidence in support of the abundance-distance to niche centroid relationship, its usefulness has been highly debated, although with little consideration of the underlying theory regarding the circumstances that might break down the relationship. We address some key points about the conditions needed to test the hypothesis in correlative studies, specifically in relation to nichecharacterization and configurations of the Biotic-Abiotic-Mobility (BAM) framework to illustrate the problem of unfilled niches. Using a created supraspecific modeling unit, we show that species for which only a portion of their fundamental niche is represented in their area of historical accessibility (M)—i.e., when the environmental equilibrium condition is violated—it is impossible to characterize their true niche centroid. Therefore, we strongly recommend to analyze this assumption prior toassess the abundant niche-centroid hypothesis. Finally, we discuss the potential of using modeling units above the species level for cases in which environmental conditions associated with species’ occurrences may not be sufficient to fully characterize their fundamental niches.

In Australia, the cane toad Rhinella marina and chytrid fungus Batrachochytrium dendrobatidis (Bd) are examples of invasive species that have had dramatic impacts on native fauna. However, little is known about the interaction between Bd and cane toads. We aimed to explore the interaction of these 2 species in 3 parts. First, we collated data from the literature on Bd infection in wild cane toads. Second, we tested the susceptibility of recently metamorphosed cane toads to Bd infection. Finally, we modelled the distribution of the 2 species in Australia to identify where they overlap and, therefore, might interact. Through our data collation, we found that adult cane toads are infrequently infected and do not carry high infection burdens; however, our infection experiment showed that metamorphs are highly susceptible to infection and disease, but resistance appears to increase with increasing toad size. Niche modelling revealed overlapping distributions and the potential for cane toads to be affected by chytridiomycosis in the wild. While Bd can cause mortality in small juveniles in the laboratory, warm microhabitats used by wild toads likely prevent infection, and furthermore, high mortality of juveniles is unlikely to affect the adult populations because they are highly fecund. However, to demonstrate the impact of Bd on wild cane toad populations, targeted field studies are required to assess (1) the overall impact of chytridiomycosis on recruitment especially in cooler areas more favourable for Bd and (2) whether cane toad juveniles can amplify Bd exposure of native amphibian species in these areas.

Disease risk mapping is important for predicting and mitigating impacts of bat-borne viruses, including Hendra virus (Paramyxoviridae:Henipavirus), that can spillover to domestic animals and thence to humans. We produced two models to estimate areas at potential risk of HeV spillover explained by the climatic suitability for its flying fox reservoir hosts, Pteropus alecto and P. conspicillatus. We included additional climatic variables that might affect spillover risk through other biological processes (such as bat or horse behaviour, plant phenology and bat foraging habitat). Models were fit with a Poisson point process model and a log-Gaussian Cox process. In response to climate change, risk expanded southwards due to an expansion of P. alecto suitable habitat, which increased the number of horses at risk by 175–260% (110,000–165,000). In the northern limits of the current distribution, spillover risk was highly uncertain because of model extrapolation to novel climatic conditions. The extent of areas at risk of spillover from P. conspicillatus was predicted shrink. Due to a likely expansion of P. alecto into these areas, it could replace P. conspicillatus as the main HeV reservoir. We recommend: (1) HeV monitoring in bats, (2) enhancing HeV prevention in horses in areas predicted to be at risk, (3) investigate and develop mitigation strategies for areas that could experience reservoir host replacements. Electronic supplementary material The online version of this article (10.1007/s10393-018-1322-9) contains supplementary material, which is available to authorized users.

Understanding environmental factors driving spatiotemporal patterns of disease can improve risk mitigation strategies. Hendra virus (HeV), discovered in Australia in 1994, spills over from bats (Pteropus sp.) to horses and thence to humans. Below latitude - 22°, almost all spillover events to horses occur during winter, and above this latitude spillover is aseasonal. We generated a statistical model of environmental drivers of HeV spillover per month. The model reproduced the spatiotemporal pattern of spillover risk between 1994 and 2015. The model was generated with an ensemble of methods for presence-absence data (boosted regression trees, random forests and logistic regression). Presences were the locations of horse cases, and absences per spatial unit (2.7 × 2.7 km pixels without spillover) were sampled with the horse census of Queensland and New South Wales. The most influential factors indicate that spillover is associated with both cold-dry and wet conditions. Bimodal responses to several variables suggest spillover involves two systems: one above and one below a latitudinal area close to - 22°. Northern spillovers are associated with cold-dry and wet conditions, and southern with cold-dry conditions. Biologically, these patterns could be driven by immune or behavioural changes in response to food shortage in bats and horse husbandry. Future research should look for differences in these traits between seasons in the two latitudinal regions. Based on the predicted risk patterns by latitude, we recommend enhanced preventive management for horses from March to November below latitude 22° south.

The Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae), is an invasive species and a vector of numerous human pathogens, including chikungunya, dengue, yellow fever, and Zika viruses. This mosquito had been reported from 36 geographic locations in Mexico by 2005, increasing to 101 locations by 2010 and 501 locations (spanning 16 states) by 2016. Here we modeled the occupied niche for Ae. albopictus in Mexico to characterize the environmental conditions related to its presence, and to generate updated environmental suitability maps. The predictors with the greatest contribution to characterizing the occupied niche for Ae. albopictus were NDVI and annual mean temperature. We also estimated the environmental suitability for Ae. albopictus in regions of the country where it has not been documented yet, by means of: 1) transferring its occupied niche model to these regions and 2) modeling its fundamental niche using global data. Our models will help vector control and public health institutions to identify areas where Ae. albopictus has not yet been recorded but where it may be present. We emphasize that most of Mexico has environmental conditions that potentially allow the survival of Ae. albopictus, which underscores the need for systematic mosquito monitoring in all states of the country.

Introducción y objetivo:Se presenta para su discusión un raro tumor faringoesofágico que debuta de forma dramática e inusual, tratado con cirugía exclusivamente, estando el paciente asintomático tras dos años de seguimiento.Material y Método:Se trata de un paciente de 57 años sin antecedentes médicos de interés que es trasladado al Servicio de Urgencias por hematemesis tras un vómito durante ingesta alcohólica, seguida de disfonía y disnea.Al ingreso se intenta una endoscopia digestiva que tuvo que ser interrumpida por empeoramiento de la disnea con desaturación grave de O2, que precisó una traqueotomía de urgencia. En una faringoscopia directa se descubre una masa ocupando toda la hipofaringe.Se solicitó una TC cervicotorácica y, por imposibilidad para la deglución, se colocó sonda nasogástrica para alimentación. Resultados:TC: Gran masa en oro e hipofaringe y esófago cervical, con oclusión completa de su luz, sugestivo de lipoma de gran tamaño.Ante este hallazgo se realiza una faringotomía lateral extirpando un tumor de la transición faringoesofágica, siendo el resultado anatomopatológico de Liposarcoma Bien Diferenciado tipo Fusocelular.Se realizó un estudio de extensión con Tc toraco-abdominal y PET-Tc descartando enfermedad metastática.No se realizó ningún otro tratamiento, siendo decanulado y reiniciando deglución una semana después. Tras dos años de seguimiento el paciente está asintomático.Conclusiones:El liposarcoma es un tumor faringoesofágico poco frecuente, teniendo en este paciente una presentación atípica, con una hematemesis y disnea severa de aparición súbita estando previamente asintomático. Este comportamiento sugiere un lento crecimiento descendente por el esófago, haciéndose patente el tumor con el vómito que lo elevó hacia la faringe, donde ocasionó la clínica urgente que motivó su traslado a nuestro Servicio.

Rat spermatogenic cells contain sphingomyelins (SMs) and ceramides (Cers) with very long-chain PUFAs (VLCPUFAs) in nonhydroxylated (n-V) and 2-hydroxylated (h-V) forms. How these atypical species distribute among membrane fractions during differentiation was investigated here using a detergent-free procedure to isolate a small light raft-like low-density fraction and a large heavy fraction, mostly derived from the plasma membrane of spermatocytes, round spermatids, and late spermatids. The light fraction contained cholesterol, glycerophospholipids (GPLs), and SM with the same saturated fatty acids in all three stages. In the heavy fraction, as PUFA increased in the GPL and VLCPUFA in SM from spermatocytes to spermatids, the concentration of cholesterol was also augmented. The heavy fraction had mostly n-V SM in spermatocytes, but accumulated h-V SM and h-V Cer in spermatids. A fraction containing intracellular membranes had less SM and more Cer than the latter, but in both fractions SM and Cer species with h-V increased over species with n-V with differentiation. This accretion of h-V was consistent with the differentiation-dependent expression of fatty acid 2-hydroxylase (Fa2h), as it increased significantly from spermatocytes to spermatids. The non-raft region of the plasma membrane is thus the main target of the dynamic lipid synthesis and remodeling that is involved in germ cell differentiation.

Infectious diseases are transmitted when susceptible hosts are exposed to pathogen particles that can replicate within them. Among factors that limit transmission, the environment is particularly important for indirectly transmitted parasites. To try and assess a pathogens' ability to be transmitted through the environment and mitigate risk, we need to quantify its decay where transmission occurs in space such as the microclimate harbouring the pathogen. Hendra virus, a Henipavirus from Australian Pteropid bats, spills-over to horses and humans, causing high mortality. While a vaccine is available, its limited uptake has reduced opportunities for adequate risk management to humans, hence the need to develop synergistic preventive measures, like disrupting its transmission pathways. Transmission likely occurs shortly after virus excretion in paddocks; however, no survival estimates to date have used real environmental conditions. Here, we recorded microclimate conditions and fitted models that predict temperatures and potential evaporation, which we used to simulate virus survival with a temperature-survival model and modification based on evaporation. Predicted survival was lower than previously estimated and likely to be even lower according to potential evaporation. Our results indicate that transmission should occur shortly after the virus is excreted, in a relatively direct way. When potential evaporation is low, and survival is more similar to temperature dependent estimates, transmission might be indirect because the virus can wait several hours until contact is made. We recommend restricting horses' access to trees during night time and reducing grass under trees to reduce virus survival.

We describe herein computational studies on the unusual ability of Pd(PtBu3 )2 to catalyze formation of highly reactive acid chlorides from aryl halides and carbon monoxide. These show a synergistic role of carbon monoxide in concert with the large cone angle PtBu3 that dramatically lowers the barrier to reductive elimination. The tertiary structure of the phosphine is found to be critical in allowing CO association and the generation of a high energy, four coordinate (CO)(PR3 )Pd(COAr)Cl intermediate. The stability of this complex, and the barrier to elimination, is highly dependent upon phosphine structure, with the tertiary steric bulk of PtBu3 favoring product formation over other ligands. These data suggest that even difficult reductive eliminations can be rapid with CO association and ligand manipulation. This study also represents the first detailed exploration of all the steps involved in palladium-catalyzed carbonylation reactions with simple phosphine ligands, including the key rate-determining steps and palladium(0) catalyst resting state in carbonylations.

The sphingolipids (SLs) of rodent spermatogenic cells (spermatocytes, spermatids) and spermatozoa contain nonhydroxylated and 2-hydroxylated versions of very-long-chain (C26-C32) PUFAs (n-V and h-V, respectively) not present in Sertoli cells (SCs). Here, we investigated the expression of selected fatty acid elongases [elongation of very-long-chain fatty acid protein (Elovl)], with a focus on Elovl4, and a fatty acid 2-hydroxylase (Fa2h) in rat testes with postnatal development and germ cell differentiation. Along with Elovl5 and Elovl2, Elovl4 was actively transcribed in the adult testis. Elovl4 mRNA levels were high in immature testes and SCs, though the protein was absent. The Elovl4 protein was a germ cell product. All cells under study elongated [3H]arachidonate to tetraenoic and pentaenoic C24 PUFA, but only germ cells produced C26-C32 PUFAs. Spermatocytes displayed the highest Elovl4 protein levels and enzymatic activity. Fa2h mRNA was produced exclusively in germ cells, mostly round spermatids. As a protein, Fa2h was mainly concentrated in late spermatids, in the step of spermiogenesis in which they elongate and their heads change shape. The expression of Elovl4 and Fa2h thus correlate with the abundance of n-Vs and h-Vs in the SLs of rat spermatocytes and spermatids, respectively. Fil: Santiago Valtierra, Florencia Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Peñalva, Daniel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Luquez, Jessica Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Furland, Natalia Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Vásquez, Claudia. Pontificia Universidad Católica de Valparaíso. Facultad de Ciencias. Instituto de Química; Chile Fil: Reyes, Juan Guillermo. Pontificia Universidad Católica de Valparaíso. Facultad de Ciencias. Instituto de Química; Chile Fil: Aveldaño, Marta Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina Fil: Oresti, Gerardo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina

The scarcity of fossil fuels, in addition to environmental damage due to fossil fuel use and exploration, promotes research into alternative energy sources such as biofuels. Biodiesel has attracted considerable attention in recent years as an alternative to fossil fuels, since it is renewable, biodegradable and non-toxic. Biodiesel can be obtained from animal fat, vegetable oils including cooking oil. In this work, a method of producing biodiesel from seed cake waste from the edible Jatropha curcas L. plant was developed. Oil extraction using hexane gave the best oil quality. Transesterifications of approximately 95% were obtained by alkali or acid catalysis, and the obtained biodiesel products were successfully corroborated with NMR techniques. Since J. curcas is a non-toxic plant, the remaining de-oiled cake was tested for its nutritional properties. Nutritional analysis showed a content of 43% and 33% of protein and carbohydrate, respectively; suggesting that this waste can be used as an attractive protein and carbohydrate source for fermentation processes and/or for formulations for animal feeding. In conclusion, this work provides evidence that the oil from an edible and non-toxic species of J. curcas is an attractive option for biodiesel production with nutritional applications and negligible wasting.

Unique species of ceramide (Cer) with very-long-chain polyunsaturated fatty acid (VLCPUFA), mainly 28?32 carbon atoms, 4?5 double bonds, in nonhydroxy and 2-hydroxy forms (n-V Cer and h-V Cer, respectively), are generated in rat spermatozoa from the corresponding sphingomyelins during the acrosomal reaction. The aim of this study was to determine the properties of these sperm-distinctive ceramides in Langmuir monolayers. Individual Cer species were isolated by HPLC and subjected to analysis of surface pressure, surface potential, and Brewster angle microscopy (BAM) as a function of molecular packing. In comparison with known species of Cer, n-V Cer and h-V Cer species showed much larger mean molecular areas and increased molecular dipole moments in liquid expanded phases, which suggest bending and partial hydration of the double bonded portion of the VLCPUFA. The presence of the 2-hydoxyl group induced a closer molecular packing in h-V Cer than in their chain-matched n-V Cer. In addition, all these Cer species showed liquid-expanded to liquid-condensed transitions at room temperature. Existence of domain segregation was confirmed by BAM. Additionally, thermodynamic analysis suggests a phase transition close to the physiological temperature for VLCPUFA-Cers if organized as bulk dispersions. Fil: Peñalva, Daniel Alejandro. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentina Fil: Oresti, Gerardo Martin. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentina Fil: Dupuy, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones En Química Biológica de Córdoba (p); Argentina Fil: Antollini, Silvia Susana. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentina Fil: Maggio, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones En Química Biológica de Córdoba (p); Argentina Fil: Aveldaño, Marta Isabel. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentina Fil: Fanani, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones En Química Biológica de Córdoba (p); Argentina

As part of our daily routines, we continually move from one space to another. The existing conditions of the spaces we move through often impact the way we experience architecture. Whether we transition between spaces by walking, cycling, running, driving a car, or riding the train, we face many challenges on a daily basis. As it is crucial that designers understand how one single person or a group of people are able to move efficiently through the various spaces, my thesis research aimed at to exploring the following question: How can architecture enrich the experience of moving from one space to another, and bring people together into a shared space in a meaningful way? In response to the above question, I would like to research the ways in which mobility, in both vertical and horizontal dimensions, can create a positive and meaningful impact when bringing people together in a commercial-cultural type space. Therefore, my focus within this topic will be an exploration of how architecture may enrich this human experience, which should begin from the moment people arrive at the site, as this is a major space component of my project. Proceeding the moment we enter the first space of a building, and subsequently the different spaces within the building, and finally exiting the site. To accomplish the above aim, I have chosen to design a performing arts facility in which the main space will be an opera house in a metropolitan setting. Since the District of Columbia already has two such venues, I landed on the idea of providing the City of Alexandria with one of its very own. I propose The Alexandria Performing Arts Center, located on a waterfront site, that will include an opera house with a capacity of 1,400. The site is located at the Robinson Terminal North between Oronoco and Pendleton Street. Master of Architecture