Same-sex attracted youths: Suicide and related factors

Same-sex attracted youths comprise 10 percent to 11 percent of the secondary school population although not all of those who experience same-sex attraction will adopt a gay, lesbian, transgender or transsexual lifestyle. Most, if not all, will experience homophobia in one or more of its forms. Many of these young people will cope well with the heterocentric attitudes and prejudices prevalent in secondary schools and the wider community and make the transition into adulthood having learned how to mask their sexual preferences or develop effective coping mechanisms to deal with homophobia. Some will succumb to the pressures they experience and seek less ideal solutions that include drug use and promiscuity. Some will take their own lives. This article draws attention to the complications of same-sex attraction and argues for a school and community response that recognises and appreciates the positive contributions that diversity of sexual preference brings to any community.

Merleau-Ponty: uma ontologia do visível

This work discusses the ontology of the visible at the thought of Maurice Merleau-Ponty (1908-1961), which points to a depth and opacity of the perceived world that oppose transparency of geometric world thought by René Descartes (1596-1650). At first we approached the Cartesian discourse developed in Dioptrics Descartes, the first of three scientific discourses published in 1637, being introduced by the famous Discourse method. In this sense, this research discusses the mechanistic explanation that the modern philosopher has the vision, process comprising the formation of images on the retina and its communication to the brain, and the subsequent reading performed by an immaterial mind. Discusses the notion of image as a result of the interpretation of the spirit because, for Descartes, is not the eye that sees, but the spirit that reads and decodes the signals that the body receives the world. At another point, reflected on the criticism of the philosopher Maurice Merleau-Ponty at the thought of overflight present in Dioptrics Descartes. Therefore, it takes as its reference the third part of the book The Eye and the Spirit (1961), in which the intellectualist approach of vision is considered a failed attempt to move away from the visible to rebuild it from anywhere . In this sense, it reflects on a new ontology proposed by Merleau-Ponty thinking being without departing from the puzzles of the body and vision. Puzzles that show a promiscuity between the seer and the seen, between sentient and sensitive. Thus, this paper discusses how visibility was treated by the contemporary philosopher, not as something to be judged by the spirit to get a real nature of things, but as a manifestation of the same things. Finally, this research explores the ontology of the visible in merleaupontiano thought, an ontology that does not rebuild or appropriates visible by a thought of overflight, but what you do from your own visibility as compared original and constant with depth in the world.

Merleau-Ponty: uma ontologia do visível

This work discusses the ontology of the visible at the thought of Maurice Merleau-Ponty (1908-1961), which points to a depth and opacity of the perceived world that oppose transparency of geometric world thought by René Descartes (1596-1650). At first we approached the Cartesian discourse developed in Dioptrics Descartes, the first of three scientific discourses published in 1637, being introduced by the famous Discourse method. In this sense, this research discusses the mechanistic explanation that the modern philosopher has the vision, process comprising the formation of images on the retina and its communication to the brain, and the subsequent reading performed by an immaterial mind. Discusses the notion of image as a result of the interpretation of the spirit because, for Descartes, is not the eye that sees, but the spirit that reads and decodes the signals that the body receives the world. At another point, reflected on the criticism of the philosopher Maurice Merleau-Ponty at the thought of overflight present in Dioptrics Descartes. Therefore, it takes as its reference the third part of the book The Eye and the Spirit (1961), in which the intellectualist approach of vision is considered a failed attempt to move away from the visible to rebuild it from anywhere . In this sense, it reflects on a new ontology proposed by Merleau-Ponty thinking being without departing from the puzzles of the body and vision. Puzzles that show a promiscuity between the seer and the seen, between sentient and sensitive. Thus, this paper discusses how visibility was treated by the contemporary philosopher, not as something to be judged by the spirit to get a real nature of things, but as a manifestation of the same things. Finally, this research explores the ontology of the visible in merleaupontiano thought, an ontology that does not rebuild or appropriates visible by a thought of overflight, but what you do from your own visibility as compared original and constant with depth in the world.

Biosynthesis and mode of action of ribosomally synthesized and post-translationally modified antimicrobial peptides

One of the greatest sources of biologically active compounds is natural products. Often these compounds serve as platforms for the design and development of novel drugs and therapeutics. The overwhelming amount of genomic information acquired in recent years has revealed that ribosomally synthesized and post-translationally modified natural products are much more widespread than originally anticipated. Identified in nearly all forms of life, these natural products display incredible structural diversity and possess a wide range of biological functions that include antimicrobial, antiviral, anti-inflammatory, antitumor, and antiallodynic activities. The unique pathways taken to biosynthesize these compounds offer exciting opportunities for the bioengineering of these complex molecules. The studies described herein focus on both the mode of action and biosynthesis of antimicrobial peptides. In Chapter 2, it is demonstrated that haloduracin, a recently discovered two-peptide lantibiotic, possesses nanomolar antimicrobial activity against a panel of bacteria strains. The potency of haloduracin rivals that of nisin, an economically and therapeutically relevant lantibiotic, which can be attributed to a similar dual mode of action. Moreover, it was demonstrated that this lantibiotic of alkaliphile origin has better stability at physiological pH than nisin. The molecular target of haloduracin was identified as the cell wall peptidoglycan precursor lipid II. Through the in vitro biosynthesis of haloduracin, several analogues of Halα were prepared and evaluated for their ability to inhibit peptidoglycan biosynthesis as well as bacterial cell growth. In an effort to overcome the limitations of in vitro biosynthesis strategies, a novel strategy was developed resulting in a constitutively active lantibiotic synthetase enzyme. This methodology, described in Chapter 3, enabled the production of fully-modified lacticin 481 products with proteinogenic and non-proteinogenic amino acid substitutions. A number of lacticin 481 analogues were prepared and their antimicrobial activity and ability to bind lipid II was assessed. Moreover, site-directed mutagenesis of the constitutively active synthetase resulted in a kinase-like enzyme with the ability to phosphorylate a number of peptide substrates. The hunt for a lantibiotic synthetase enzyme responsible for installing the presumed dehydro amino acids and a thioether ring in the natural product sublancin, led to the identification and characterization of a unique post-translational modification. The studies described in Chapter 4, demonstrate that sublancin is not a lantibiotic, but rather an unusual S-linked glycopeptide. Its structure was revised based on extensive chemical, biochemical, and spectroscopic characterization. In addition to structural investigation, bioinformatic analysis of the sublancin gene cluster led to the identification of an S-glycosyltransferase predicted to be responsible for the post-translational modification of the sublancin precursor peptide. The unprecedented glycosyltransferase was reconstituted in vitro and demonstrated remarkable substrate promiscuity for both the NDP-sugar co-substrate as well as the precursor peptide itself. An in vitro method was developed for the production of sublancin and analogues which were subsequently evaluated in bioactivity assays. Finally, a number of putative biosynthetic gene clusters were identified that appear to harbor the necessary genes for production of an S-glycopeptide. An additional S-glycosyltransferase with more favorable intrinsic properties including better expression, stability, and solubility was reconstituted in vitro and demonstrated robust catalytic abilities.