Causes and consequences of dominance and diversity in grasslands

Understanding how species coexist and differ in abundance is central to ecology. Theory predicts competitively superior species should dominate systems and suppress diversity, yet many natural communities characterized by dominants are species rich. Understanding how shifts in dominance among species, and the inherent diversity of communities affect ecosystem function is a second central theme in ecology. For example, decreasing the number of species in local communities can reduce the ability of the community to respond to disturbance. These ideas have captured ecologists\u27 attention because anthropogenic pressures are causing many systems to lose species. In my dissertation I focused on processes that determine dominance and diversity and the consequences of changes in dominance and diversity on the ability of communities to respond to exotic invasion and disturbance. In chapter 1 I asked: does competitive ability correspond with large differences in plant species abundance found in field surveys of grasslands in western Montana? In a garden experiment I found that intraspecific competition appears to promote coexistence, but differences in abundance were not related to inherent interspecific competitive abilities in common garden experiments. In chapter 2 I asked: how important is competition relative to other mechanisms of coexistence, such as dispersal limitation and seed predation? Experimental manipulations of natural grassland communities showed that dispersal limitation caused a greater constraint on local diversity than competition from a single dominant species or from several common species. Seed predation, in contrast, did not influence diversity two years after the treatments were applied. In chapter 3 I asked: does invader impact on natives vary with disturbance and diversity? Burning a subset of experimentally invaded assemblages showed that the buffering effect of diversity on invader impact was lost after a form of disturbance that is commonly experienced by the native system. An important historical focus in plant ecology was on how species could coexist despite competition for limiting and shared resources, and in this context I found that competition did not correspond well with the ability of species to coexist or with the relative abundance of species. I also found that increasing native species diversity did not buffer the relative responses of natives and invaders to disturbance. Overall I found that by studying ecological processes together instead of in isolation we can gain a better understanding of the complexity of ecosystems

Traduire un essai sur la photographie. Approche contrastive des difficultés lexicales

Based on the analysis of the translation into Italian of an essay of the French historian of photography Clément Chéroux, Fautographie. Petite histoire de l’erreur photographique, the aim of this article is to insist on the importance of a lexical contrastive analysis when translating. An essay on photography belongs as to literature as to specialized texts so that the translation has to be precise towards the words of photography and also to the expressive choices of the author. Through the mistranslations picked out in the Italian edition, we intend to reaffirm the professionality required for any translation and also to minimize our critics stressing the cultural value of translating project

Therapist Self-Disclosure and Immediacy: A Qualitative Meta-Analysis

We review definitions and provide case examples of therapist self-disclosure (TSD) and immediacy (Im). We then present a qualitative meta-analysis of 21 studies that examined the subsequent process following TSD and Im in psychotherapy (excluding analogue and correlational studies). Across the 21 studies, the most frequent subsequent processes were enhanced therapy relationship, improved client mental health functioning, gains in insight, and overall helpfulness, suggesting that most often TSD and Im were followed by positive and beneficial therapeutic processes. In additional analyses, TSD was associated more often with improved mental health functioning, overall helpfulness, and enhanced therapy relationships, whereas Im was associated more often with clients opening up and being immediate. We also consider possible moderating variables, including client contributions and diversity issues. The article concludes with research-informed recommendations for judiciously using TSD and Im in practice

La promotion du patient comme partenaire de soin:: interventions infirmières : travail de Bachelor

Introduction : La relation infirmière-patient est une base fondamentale de la profession infirmière. Cependant, la place du patient n’a pas toujours été la même au cours de ces dernières années. L’approche du patient partenaire apporte une nouvelle vision de soins où l’on considère le patient comme un expert. Les soins qui lui sont prodigués sont les fruits de processus décisionnels partagés. La théorie de l’Human Caring de J. Watson a été utilisé comme ancrage disciplinaire dans ce travail. Méthodologie : Cette revue de littérature est basée sur l’analyse de six articles scientifiques sélectionnés dans les bases de données PubMed et Cinahl. La consultation des bases de données a été effectuée en sélectionnant l’option « All Fields ». Différents filtres ont été utilisés pour restreindre les recherches : Publication de moins de cinq ans, articles disponibles au complet (FULL), population adulte, filtres de langue : anglais, français, portugais, italien. Les critères d’exclusion concernaient essentiellement : la mauvaise population, le milieu de soin extra hospitalier et les articles ayant peu de lien ou ne traitant pas d’un sujet en rapport avec le patient partenaire

Discovery of Spiro-Piperidine Inhibitors and Their Modulation of the Dynamics of the M2 Proton Channel from Influenza A Virus

Amantadine has been used for decades as an inhibitor of the influenza A virus M2 protein (AM2) in the prophylaxis and treatment of influenza A infections, but its clinical use has been limited by its central nervous system (CNS) side effects as well as emerging drug-resistant strains of the virus. With the goal of searching for new classes of M2 inhibitors, a structure−activity relation study based on 2-[3-azaspiro(5,5)undecanol]-2-imidazoline (BL-1743) was initiated. The first generation BL-1743 series of compounds has been synthesized and tested by two-electrode voltage-clamp (TEV) assays. The most active compound from this library, 3-azaspiro[5,5]undecane hydrochloride (9), showed an IC50 as low as 0.92 ± 0.11 μM against AM2, more than an order of magnitude more potent than amantadine (IC50 = 16 μM). 15N and 13C solid-state NMR was employed to determine the effect of compound 9 on the structure and dynamics of the transmembrane domain of AM2 (AM2-TM) in phospholipid bilayers. Compared to amantadine, spiro-piperidine 9 (1) induces a more homogeneous conformation of the peptide, (2) reduces the dynamic disorder of the G34-I35 backbone near the water-filled central cavity of the helical bundle, and (3) influences the dynamics and magnetic environment of more residues within the transmembrane helices. These data suggest that spiro-piperidine 9 binds more extensively with the AM2 channel, thus leading to stronger inhibitory potency

Cigarette smoke extract induces differential expression levels of beta-defensin peptides in human alveolar epithelial cells

BACKGROUND: The damaging effects of cigarette smoke on the lungs are well known in terms of cancer risks. Additional molecular changes within the lung tissue can also occur as a result of exposure to cigarette smoke. The human β-defensin (hBD) class of antimicrobial peptides is the focus of our research. In addition to antimicrobial activity, β-defensins also have immunomodulatory functions. Over 30 previously unrecognized β-defensin genes have recently been identified in the human genome, many with yet to be determined functions. We postulated that altered β-defensin production may play a role in the pathogenesis observed in the lungs of smokers. Our hypothesis is that cigarette smoke exposure will affect the expression of β-defensins in human lung alveolar epithelial cells (A549). METHODS: We exposed A549 cells to cigarette smoke extract (CSE) and measured the changes in mRNA levels of several antimicrobial peptides by quantitative real-time PCR, and directly observed peptide expression in cells by immunofluorescence (IF) microscopy. RESULTS: We found that hBD3, hBD5, and hBD9 gene expression was upregulated in A549 cells exposed to CSE. HBD1, hBD8, hBD18 and LL-37 gene expression did not significantly change upon exposure to CSE. Expression of hBD3 and hBD4 peptides was visualized by IF. CONCLUSIONS: This differential expression suggests that hBD3, hBD5, and hBD9 may play a role in the changes to the lung tissue observed in smokers. Establishing differential β-defensin expression following CSE treatment will add to our understanding of the molecular response of the lung alveolar epithelium to cigarette smoke exposure