Homologues of archaeal rhodopsins in plants, animals and fungi: structural and functional predications for a putative fungal chaperone protein

AbstractThe microbial rhodopsins (MR) are homologous to putative chaperone and retinal-binding proteins of fungi. These proteins comprise a coherent family that we have termed the MR family. We have used modeling techniques to predict the structure of one of the putative yeast chaperone proteins, YRO2, based on homology with bacteriorhodopsins (BR). Availability of the structure allowed depiction of conserved residues that are likely to be of functional significance. The results lead us to predict an extracellular protein folding function and a transmembrane proton transport pathway. We suggest that protein folding is energized by a novel mechanism involving the proton motive force. We further show that MR family proteins are distantly related to a family of fungal, animal and plant proteins that include the human lysosomal cystine transporter (LCT) of man (cystinosin), mutations in which cause cystinosis. Sequence and phylogenetic analyses of both the MR family and the LCT family are reported. Proteins in both families are of the same approximate size, exhibit seven putative transmembrane α-helical spanners (TMSs) and show limited sequence similarity. We show that the LCT family arose by an internal gene duplication event and that TMSs 1–3 are homologous to TMSs 5–7. Although the same could not be demonstrated statistically for MR family members, homology with the LCT family suggests (but does not prove) a common evolutionary pathway. Thus, TMSs 1–3 and 5–7 in both LCT and MR family members may share a common origin, accounting for their shared structural features

Polymer-Based Systems for Advanced Optical Applications

Displays, in many different variations and for a multitude of uses, continue to be an evermore attractive area for industrial activity and academic development. Here, we address the development of polymer-based systems for application in advanced optical devices. More specifically, we report the fabrication and characterization of photoluminescent polarizers based on uniaxially oriented, conjugated polymers and their application in a new family of photoluminescent liquid-crystal displays with substantially increased brightness, contrast, and efficiency. In another development, we show that efficient 'color polarizers' can be produced on the basis of oriented polymer-inorganic nano-composites. It is anticipated that these polarizers enable the fabrication of another new family of LCDs in which multiple colors can be displayed on the same pixel

Focus, Vol. 1 No. 1

A literary magazine of student writing published by the Department of English of Stephen F. Austin State College.https://scholarworks.sfasu.edu/focus/1000/thumbnail.jp

Benefits of condensed tannins in forage legumes fed to ruminants:Importance of structure, concentration, and diet composition

Condensed tannins (CTs) account for up to 20% of the dry matter in forage legumes used as ruminant feeds. Beneficial animal responses to CTs have included improved growth, milk and wool production, fertility, and reduced methane emissions and ammonia volatilization from dung or urine. Most important is the ability of such forages to combat the effects of gastrointestinal parasitic nematodes. Inconsistent animal responses to CTs were initially attributed to concentration in the diet, but recent research has highlighted the importance of their molecular structures, as well as concentration, and also the composition of the diet containing the CTs. The importance of CT structural traits cannot be underestimated. Interdisciplinary research is the key to unraveling the relationships between CT traits and bioactivities and will enable future on-farm exploitation of these natural plant compounds. Research is also needed to provide plant breeders with guidelines and screening tools to optimize CT traits, in both the forage and the whole diet. In addition, improvements are needed in the competitiveness and agronomic traits of CT-containing legumes and our understanding of options for their inclusion in ruminant diets. Farmers need varieties that are competitive in mixed swards and have predictable bioactivities. This review covers recent results from multidisciplinary research on sainfoin (Onobrychis Mill. spp.) and provides an overview of current developments with several other tanniniferous forages. Tannin chemistry is now being linked with agronomy, plant breeding, animal nutrition, and parasitology. The past decade has yielded considerable progress but also generated more questions — an enviable consequence of new knowledge

Who will make the 'best' use of Africa's land? Lessons from Zimbabwe

Conflict over African land – between small holders and large industrial farmers and between domestic farmers and global agribusinesses – raises key questions about who will make the best use of African land and which farmers do most to decrease poverty and produce more food, industrial inputs, and exports. Zimbabwe has already gone through two major changes in land occupation, and thus provides an important test of what is the 'best' use of the land. Three measures of 'best' use have been cited in Zimbabwe: reward for military victory, poverty reduction, and agricultural production. Initial evidence indicates that commercial small holder production is a better use of the land than larger, more mechanised farming

Allergic to the Twentieth Century: Intentional Communities and Therapeutic Landscapes in The Village and Safe

The concept of therapeutic landscapes has been used to explore diverse spaces and places of healing or wellness, from hospitals to gardens, libraries to smoking areas. A central strand of this work considers rural and/or natural landscapes as affording particular healing experiences. In this paper, I draw on this lineage of work alongside research into the formation of intentional communities in rural settings and the body of writing on representations of rural landscapes and country life. The two representations I analyse are films: The Village (M. Night Shyamalan, 2004) and Safe (Todd Haynes, 1995). In the former, an apparent settler village in rural Pennsylvania is revealed, in the film’s denouement, as an intentional community built as a retreat from the violence of contemporary urban life, guarded by Elders and a shared mythology about border-policing creatures. In Safe, the health hazards of modern suburban living, which lead the central character to develop multiple chemical sensitivity (MCS), can only be escaped by a similar retreat to a wilderness commune in the American desert. In both films, the spaces of rural life are constructed as therapeutic landscapes through their nostalgic, anti-modern withdrawal, and their protective boundary keeping

Disease concepts and treatment by tribal healers of an Amazonian forest culture

<p>Abstract</p> <p>Background</p> <p>The extensive medicinal plant knowledge of Amazonian tribal peoples is widely recognized in the scientific literature and celebrated in popular lore. Despite this broad interest, the ethnomedical systems and knowledge of disease which guide indigenous utilization of botanical diversity for healing remain poorly characterized and understood. No study, to our knowledge, has attempted to directly examine patterns of actual disease recognition and treatment by healers of an Amazonian indigenous culture.</p> <p>Methods</p> <p>The establishment of traditional medicine clinics, operated and directed by elder tribal shamans in two remote Trio villages of the Suriname rainforest, presented a unique investigational opportunity. Quantitative analysis of clinic records from both villages permitted examination of diseases treated over a continuous period of four years. Cross-cultural comparative translations were articulated of recorded disease conditions through ethnographic interviews of elder Trio shamans and a comprehensive atlas of indigenous anatomical nomenclature was developed.</p> <p>Results</p> <p>20,337 patient visits within the period 2000 to 2004 were analyzed. 75 disease conditions and 127 anatomical terms are presented. Trio concepts of disease and medical practices are broadly examined within the present and historical state of their culture.</p> <p>Conclusion</p> <p>The findings of this investigation support the presence of a comprehensive and highly formalized ethnomedical institution within Trio culture with attendant health policy and conservation implications.</p

Phagosomal Rupture by Mycobacterium tuberculosis Results in Toxicity and Host Cell Death

Survival within macrophages is a central feature of Mycobacterium tuberculosis pathogenesis. Despite significant advances in identifying new immunological parameters associated with mycobacterial disease, some basic questions on the intracellular fate of the causative agent of human tuberculosis in antigen-presenting cells are still under debate. To get novel insights into this matter, we used a single-cell fluorescence resonance energy transfer (FRET)-based method to investigate the potential cytosolic access of M. tuberculosis and the resulting cellular consequences in an unbiased, quantitative way. Analysis of thousands of THP-1 macrophages infected with selected wild-type or mutant strains of the M. tuberculosis complex unambiguously showed that M. tuberculosis induced a change in the FRET signal after 3 to 4 days of infection, indicating phagolysosomal rupture and cytosolic access. These effects were not seen for the strains M. tuberculosisΔRD1 or BCG, both lacking the ESX-1 secreted protein ESAT-6, which reportedly shows membrane-lysing properties. Complementation of these strains with the ESX-1 secretion system of M. tuberculosis restored the ability to cause phagolysosomal rupture. In addition, control experiments with the fish pathogen Mycobacterium marinum showed phagolysosomal translocation only for ESX-1 intact strains, further validating our experimental approach. Most importantly, for M. tuberculosis as well as for M. marinum we observed that phagolysosomal rupture was followed by necrotic cell death of the infected macrophages, whereas ESX-1 deletion- or truncation-mutants that remained enclosed within phagolysosomal compartments did not induce such cytotoxicity. Hence, we provide a novel mechanism how ESX-1 competent, virulent M. tuberculosis and M. marinum strains induce host cell death and thereby escape innate host defenses and favor their spread to new cells. In this respect, our results also open new research directions in relation with the extracellular localization of M. tuberculosis inside necrotic lesions that can now be tackled from a completely new perspective