Raman Spectroscopy of Amino Acid Crystals

In this chapter, we investigate the Raman spectra of proteinogenic amino acid crystals. Amino acids are fundamental organic molecules that compose polypeptides (a linear chain of amino acids) and proteins (folded polypeptides with specific functions) found in all living beings. Surprisingly, the number of these basic molecules is not more than 22 (20 of them commonly known as the standard amino acids, plus pyrrolysine and selenocysteine). They are defined as a molecule formed by an NH2 group, a COOH group, a lateral chain (the R group), and a hydrogen atom, all of them connected to a single carbon, the α-carbon. Interestingly, α-amino acids show chirality, i.e., they present different distributions of group of atoms around the α-carbon, being defined as l- and d-form. For amino acids and proteins found in the living beings, the l-form is the dominant form, although some exceptions have been discovered in the last decades. In this chapter, we present the Raman spectra of all standard amino acids and discuss the different kinds of vibrations found, comparing them. As complementary part of the work, we present results on vibrational properties of some amino acids using Raman spectroscopy when subjected to specific conditions, with variation in temperature or pressure. Finally, we present some perspectives as the investigation of purines, a group of molecules associated with the DNA molecule

Indicadores biofisicos de la Estructura Agroecological Principal (EAP) para el co-deseno de SAF cacao en dos zonas productora de Tumaco (Narino)

El co-diseño de sistemas agroforestales (SAF) implica entender la estructura y función de los sistemas, no solo a nivel productivo, sino también a nivel ecosistémico y cultural. Lo anterior, porque las decisiones que toman los agricultores, sobre cómo arreglar espacialmente los sistemas productivos, responden a motivaciones productivas y no productivas, las cuales se basan en la experiencia y evidencia empírica local. Sin embargo, estas decisiones pueden ser mejor orientadas a partir del análisis de información cartográfica, indicadores de paisaje y de aspectos socioculturales. En este trabajo, enmarcado en el programa rutas PDET para la estabilización territorial, se caracterizaron 100 unidades productivas agropecuarias (UPAs) de cacao en dos zonas productoras del municipio de Tumaco (Nariño). En el presente trabajo se exponen los resultados de cuatro indicadores biofísicos que han sido usados para el análisis de estructura agroecológica principal (EAP), como herramienta de co-diseño de los SAF cacao a nivel predial, pero también como instrumento de planificación a escala de paisaje. La conexión de las UPAs con la Estructura Ecológica Principal del Paisaje (CEEP) no muestra correlación con los diferentes parámetros de paisaje evaluados, sin embargo, si se identifica que UPAs cacaoteras con arboles de más de 10 años tienen mayor conectividad con el paisaje, en comparación con UPAs de cacao de menor edad. Además, son estás fincas en las que hay mayor porcentaje de uso del suelo (USC) con coberturas diversificadas (SAF cacao, áreas de barbecho y zonas de conservación) y mayor conectividad externa (CE) con setos y cercas vivas. La conectividad interna (CI) de las UPAs es baja, y es quizá el indicador biofísico que más impacta de manera negativa la EAP. De lo anterior se interpreta que, bajo el análisis de paisaje, si bien los componentes de los SAF de cacao por si solos contribuyen en la EAP, hay que implementar acciones que mejoren la conectividad interna y externa, además del establecimiento y ampliación de áreas de conservación, que contribuyan a mejorar la integración de las fincas cacaoteras con el paisaje

In vitro binding and survival assays of Leishmania parasites to peripherical blood monocytes and monocyte-derived macrophages isolated from dogs naturally and experimentally infected with Leishmania (Leishmania) chagasi

<p>Abstract</p> <p>Background</p> <p>There are a few works considering the characterization of canine monocyte-derived macrophages as well as a standardized procedure for isolation, culture, and infection of these cells with <it>Leishmania</it>. We have performed several modifications in order to improve the canine monocyte-derived macrophage cultures. In addition, we have done a comparative study between monocytes and monocyte-derived macrophages from dogs naturally and experimentally infected with <it>L. chagasi</it>.</p> <p>Results</p> <p>In the presence of exogenous serum, opsonized <it>Leishmania </it>promastigotes binds better to monocytes/macrophages than without serum. Otherwise, this binding occurs due to the strict correlation between the opsonized biologic particles with the third receptor of the complement (CR3-CD11b/CD18). In fact, our assays with CD11b confirmed the importance of this receptor for canine cells and the <it>L. chagasi </it>experimental system. Moreover, monocytes obtained from naturally infected dogs have shown a higher number of monocytes bounded to promastigotes. The experimental results regarding survival have shown that promastigote forms of opsonized <it>L. chagasi </it>were more infective, because we found higher numbers of promastigotes bound to the different cells. As a consequence, after forty-eight hours of binding, higher numbers of amastigotes appeared inside monocyte-macrophages.</p> <p>Conclusion</p> <p>These studies have given support to continue comparative studies involving canine monocytes, monocyte-derived macrophages and peritoneal macrophages. Since we have standardized the canine cell culture, we are looking forward to determining the phenotypic properties of these cells before and after <it>L. chagasi </it>infection using flow cytometry.</p

Domelito: jogo lúdico para auxiliar na compreensão da diabetes mellitus tipo I

A Diabetes mellitus tipo I é uma patologia crônica onde o pâncreas produz pouca ou nenhuma insulina e, normalmente, acomete crianças e adultos jovens. O desconhecimento da patologia pode gerar dificuldades da criança aderir ao tratamento, necessitando da participação da família para minimizar essa situação. Partindo do pressuposto que ações educativas ajudam na prevenção, manutenção e recuperação da sua saúde já que desencadeiam uma postura ativa do indivíduo, o presente trabalho tem como objetivo desenvolver um jogo para que as informações relacionadas aos hábitos alimentares e conceitos sobre controlar os níveis glicêmicos na forma de “dominó”. O jogo foi nomeado de “domelito” e poderá ser empregado em ações educativas de extensão junto à comunidade envolvendo crianças e familiares.

Lipophosphoglycans from \u3cem\u3eLeishmania amazonensis\u3c/em\u3e Strains Display Immunomodulatory Properties via TLR4 and Do Not Affect Sand Fly Infection

The immunomodulatory properties of lipophosphoglycans (LPG) from New World species of Leishmania have been assessed in Leishmania infantum and Leishmania braziliensis, the causative agents of visceral and cutaneous leishmaniasis, respectively. This glycoconjugate is highly polymorphic among species with variation in sugars that branch off the conserved Gal(β1,4)Man(α1)-PO4 backbone of repeat units. Here, the immunomodulatory activity of LPGs from Leishmania amazonensis, the causative agent of diffuse cutaneous leishmaniasis, was evaluated in two strains from Brazil. One strain (PH8) was originally isolated from the sand fly and the other (Josefa) was isolated from a human case. The ability of purified LPGs from both strains was investigated during in vitro interaction with peritoneal murine macrophages and CHO cells and in vivo infection with Lutzomyia migonei. In peritoneal murine macrophages, the LPGs from both strains activated TLR4. Both LPGs equally activate MAPKs and the NF-κB inhibitor p-IκBα, but were not able to translocate NF-κB. In vivo experiments with sand flies showed that both stains were able to sustain infection in L. migonei. A preliminary biochemical analysis indicates intraspecies variation in the LPG sugar moieties. However, they did not result in different activation profiles of the innate immune system. Also those polymorphisms did not affect infectivity to the sand fly

Is habitat fragmentation good for biodiversity?

Habitat loss is a primary threat to biodiversity across the planet, yet contentious debate has ensued on the importance of habitat fragmentation ‘per se’ (i.e., altered spatial configuration of habitat for a given amount of habitat loss). Based on a review of landscape-scale investigations, Fahrig (2017; Ecological responses to habitat fragmentation per se. Annual Review of Ecology, Evolution, and Systematics 48:1-23) reports that biodiversity responses to habitat fragmentation ‘per se’ are more often positive rather than negative and concludes that the widespread belief in negative fragmentation effects is a ‘zombie idea’. We show that Fahrig's conclusions are drawn from a narrow and potentially biased subset of available evidence, which ignore much of the observational, experimental and theoretical evidence for negative effects of altered habitat configuration. We therefore argue that Fahrig's conclusions should be interpreted cautiously as they could be misconstrued by policy makers and managers, and we provide six arguments why they should not be applied in conservation decision-making. Reconciling the scientific disagreement, and informing conservation more effectively, will require research that goes beyond statistical and correlative approaches. This includes a more prudent use of data and conceptual models that appropriately partition direct vs indirect influences of habitat loss and altered spatial configuration, and more clearly discriminate the mechanisms underpinning any changes. Incorporating these issues will deliver greater mechanistic understanding and more predictive power to address the conservation issues arising from habitat loss and fragmentation

Do cover crops compete with young grapevines for fertilizer nitrogen?

Vineyard soils of the Campanha Gaúcha region of Rio Grande do Sul are sandy and have low to medium organic matter content, displaying low natural ability to supply nitrogen (N). Therefore, maintenance of cover crops is essential or the protection of the soil surface from the impact of raindrops and water erosion. The application of nitrogen fertilizers is also necessary. However, cover crops can absorb part of the nitrogen applied in the soil, decreasing the availability to young vines, which may slow the growth of root and shoot, and thus, the beginning of grape production