479 research outputs found
Speech production, dual-process theory, and the attentive addressee
This thesis outlines a model of Speaker-Addressee interaction that suggests some
answers to two linked problems current in speech production. The first concerns an
under-researched issue in psycholinguistics: how are decisions about speech content
â conceptualization â carried out? The second, a pragmatics problem, asks how
Speakers, working under the heavy time pressures of normal dialogue, achieve
optimal relevance often enough for successful communication to take place.
Links between these problems are discussed in Chapter 1; Chapter 2 reviews existing
research on speech production and dialogue. Chapter 3 presents the central claim of
my thesis: that the Addressee exerts a significant influence over the Speakerâs
decision-making at a level below the latterâs consciousness. Using evidence drawn
from psycholinguistics, developmental psychology and human-computer interaction,
Chapter 4 presents evidence to support this claim, demonstrating that a Speakerâs
performance can be decisively affected at a preconscious level by the degree of
attentiveness shown by the Addressee. Lack of attentiveness, in particular, appears to
damage speech production at the conceptualization level. I suggest, therefore, that
Speaker and Addressee are linked in a feedback loop: unless a Speaker achieves and
maintains relevance to an Addressee, the Addresseeâs interest will be lost, and this
will impair the Speakerâs production abilities and hence the communication process
itself.
Chapters 5 and 6 consider some automatic mechanisms that may help Speakers
dovetail their productions to Addressee need. These include the neural mechanisms
underlying face perception and social rejection; automatic aspects of theory of mind;
intuitive memory and inference systems of the type being explored in dual-process
theory; and connections between verbal performance and behavioural priming
currently being investigated. Chapter 7 summarizes the complete argument,
discusses its wider implications, and includes suggestions for further work
Spread of metals through an invertebrate food chain as influenced by a plant that hyperaccumulates nickel
Hyperaccumulation of metals in the shoot
system of plants is uncommon, yet taxonomically and geographically
widespread. It may have a variety of functions,
including defense against herbivores. This study investigated
the effects of hyperaccumulation on metal concentrations
across trophic levels. We collected plant material,
soil, and invertebrates from Portuguese serpentine outcrops
whose vegetation is dominated by the nickel hyperaccumulator
Alyssum pintodasilvae. Samples were analyzed for
nickel, chromium, and cobalt. Grasshoppers, spiders, and
other invertebrates collected from sites where A. pintodasilvae
was common had significantly elevated concentrations
of nickel, compared to nearby sites where this hyperaccumulator
was not found. Chromium and cobalt, occurring in
high concentrations in the serpentine soil but not accumulated
by A. pintodasilvae, were not elevated in the invertebrates.
Therefore, it appears likely that a flux of nickel to
herbivore and carnivore trophic levels is specifically facilitated
by the presence of plants that hyperaccumulate this
metal. The results may be relevant to the development of
phytoremediation and phytomining technologies, which use
plants to extract metals from the soil
A Locus for Hereditary Sensory Neuropathy with Cough and Gastroesophageal Reflux on Chromosome 3p22-p24
Hereditary sensory neuropathy type I (HSN I) is a group of dominantly inherited degenerative disorders of peripheral nerve in which sensory features are more prominent than motor involvement. We have described a new form of HSN I that is associated with cough and gastroesophageal reflux. To map the chromosomal location of the gene causing the disorder, a 10-cM genome screen was undertaken in a large Australian family. Two-point analysis showed linkage to chromosome 3p22-p24 (Zmax=3.51 at recombination fraction (Ξ) 0.0 for marker D3S2338). A second family with a similar phenotype shares a different disease haplotype but segregates at the same locus. Extended haplotype analysis has refined the region to a 3.42-cM interval, flanked by markers D3S2336 and D3S1266
Human Salmonella Typhi exposure generates differential multifunctional crossâreactive Tâcell memory responses against Salmonella Paratyphi and invasive nontyphoidal Salmonella
Objective
There are no vaccines for most of the major invasive Salmonella strains causing severe infection in humans. We evaluated the specificity of adaptive T memory cell responses generated after Salmonella Typhi exposure in humans against other major invasive Salmonella strains sharing capacity for dissemination.
Methods
T memory cells from eleven volunteers who underwent controlled oral challenge with wt S. Typhi were characterised by flow cytometry for crossâreactive cellular cytokine/chemokine effector responses or evidence of degranulation upon stimulation with autologous Bâlymphoblastoid cells infected with either S. Typhi, Salmonella Paratyphi A (PA), S. Paratyphi B (PB) or an invasive nontyphoidal Salmonella strain of the S. Typhimurium serovar (iNTSTy).
Results
Blood Tâcell effector memory (TEM) responses after exposure to S. Typhi in humans evolve late, peaking weeks after infection in most volunteers. Induced multifunctional CD4+ Th1 and CD8+ TEM cells elicited after S. Typhi challenge were crossâreactive with PA, PB and iNTSTy. The magnitude of multifunctional CD4+ TEM cell responses to S. Typhi correlated with induction of crossâreactive multifunctional CD8+ TEM cells against PA, PB and iNTSTy. Highly multifunctional subsets and T central memory and T effector memory cells that reâexpress CD45 (TEMRA) demonstrated less heterologous Tâcell crossâreactivity, and multifunctional Th17 elicited after S. Typhi challenge was not crossâreactive against other invasive Salmonella.
Conclusion
Gaps in crossâreactive immune effector functions in human Tâcell memory compartments were highly dependent on invasive Salmonella strain, underscoring the importance of strainâdependent vaccination in the design of Tâcellâbased vaccines for invasive Salmonella
Promoting critically informed learning and knowing about occupation through conference engagements
As occupation-focused discussions and applications of critical theoretical perspectives increase, attention must also be paid to how different spaces of knowledge dissemination, exchange, and production support critically informed learning and knowing about occupation. This paper presents the reflections of a group of international scholars and lecturers whose shared interest in critical theoretical perspectives prompted the incremental co-development of a series of conference engagements. We describe how our group came together, what kinds of learning experiences we developed to promote and support engagement with critical theoretical perspectives, and what understandings we gained through ongoing critical reflexivity about those learning experiences. Our discussion addresses two problematics related to conferences as learning spaces: inclusion, and sustained engagement with epistemic communities and ideas that may form through critically oriented conference sessions. We also discuss how enacting critical pedagogies and principles of âunconferencingâ may better promote critically informed ways of learning and knowing occupation than typical conference structures. The paper ends with a call for continued integration of varied critically informed teaching and learning opportunities at conferences, as a means of further encouraging diverse types of knowledge production, sharing, and learning about occupation
Case report : typhoid fever complicated by ileal perforation in an urban slum of Dhaka, Bangladesh
Intestinal perforation is one of the most dangerous complications of typhoid fever and demands urgent hospitalization, diagnosis, and surgical management to reduce morbidity and prevent mortality. Here, we report a case of typhoidal intestinal perforation in a 19 year-old young man detected by passive surveillance during a cluster-randomized trial with Vi-tetanus toxoid conjugate vaccine (Typhoid Vaccine Acceleration Consortium: TyVAC) in an urban slum area in Mirpur, Dhaka, Bangladesh. The patient presented with a high-grade fever, lower abdominal pain, and vomiting and was admitted to a healthcare facility. Physical examination and preoperative investigations of the patient suggested a presumptive diagnosis of intestinal perforation, and the patient was transferred to a tertiary-level hospital for surgical management. A positive blood culture, intraoperative findings, and histopathology of an intestinal biopsy confirmed ileal perforation due to typhoid fever. This case report highlights the need for prompt diagnosis and appropriate pre- and postoperative management of patients who appear with the symptoms of typhoidal intestinal perforation. This report further demonstrates the importance of systematic surveillance and proper evaluation to determine the true incidence rate of typhoid fever and intestinal perforation in Bangladesh
Recommended from our members
Projecting Antarctic ice discharge using response functions from SeaRISE ice-sheet models
The largest uncertainty in projections of future sea-level change results from the potentially changing dynamical ice discharge from Antarctica. Basal ice-shelf melting induced by a warming ocean has been identified as a major cause for additional ice flow across the grounding line. Here we attempt to estimate the uncertainty range of future ice discharge from Antarctica by combining uncertainty in the climatic forcing, the oceanic response and the ice-sheet model response. The uncertainty in the global mean temperature increase is obtained from historically constrained emulations with the MAGICC-6.0 (Model for the Assessment of Greenhouse gas Induced Climate Change) model. The oceanic forcing is derived from scaling of the subsurface with the atmospheric warming from 19 comprehensive climate models of the Coupled Model Intercomparison Project (CMIP-5) and two ocean models from the EU-project Ice2Sea. The dynamic ice-sheet response is derived from linear response functions for basal ice-shelf melting for four different Antarctic drainage regions using experiments from the Sea-level Response to Ice Sheet Evolution (SeaRISE) intercomparison project with five different Antarctic ice-sheet models. The resulting uncertainty range for the historic Antarctic contribution to global sea-level rise from 1992 to 2011 agrees with the observed contribution for this period if we use the three ice-sheet models with an explicit representation of ice-shelf dynamics and account for the time-delayed warming of the oceanic subsurface compared to the surface air temperature. The median of the additional ice loss for the 21st century is computed to 0.07 m (66% range: 0.02â0.14 m; 90% range: 0.0â0.23 m) of global sea-level equivalent for the low-emission RCP-2.6 (Representative Concentration Pathway) scenario and 0.09 m (66% range: 0.04â0.21 m; 90% range: 0.01â0.37 m) for the strongest RCP-8.5. Assuming no time delay between the atmospheric warming and the oceanic subsurface, these values increase to 0.09 m (66% range: 0.04â0.17 m; 90% range: 0.02â0.25 m) for RCP-2.6 and 0.15 m (66% range: 0.07â0.28 m; 90% range: 0.04â0.43 m) for RCP-8.5. All probability distributions are highly skewed towards high values. The applied ice-sheet models are coarse resolution with limitations in the representation of grounding-line motion. Within the constraints of the applied methods, the uncertainty induced from different ice-sheet models is smaller than that induced by the external forcing to the ice sheets
Changes in monocyte subsets in volunteers who received an oral wild-type Salmonella Typhi challenge and reached typhoid diagnosis criteria
An oral Controlled Human Infection Model (CHIM) with wild-type S. Typhi was re-established allowing us to explore the development of immunity. In this model, ~55% of volunteers who received the challenge reached typhoid diagnosis criteria (TD), while ~45% did not (NoTD). Intestinal macrophages are one of the first lines of defense against enteric pathogens. Most organs have self-renewing macrophages derived from tissue-resident progenitor cells seeded during the embryonic stage; however, the gut lacks these progenitors, and all intestinal macrophages are derived from circulating monocytes. After infecting gut-associated lymphoid tissues underlying microfold (M) cells, S. Typhi causes a primary bacteremia seeding organs of the reticuloendothelial system. Following days of incubation, a second bacteremia and clinical disease ensue. S. Typhi likely interacts with circulating monocytes or their progenitors in the bone marrow. We assessed changes in circulating monocytes after CHIM. The timepoints studied included 0 hours (pre-challenge) and days 1, 2, 4, 7, 9, 14, 21 and 28 after challenge. TD participants provided extra samples at the time of typhoid diagnosis, and 48-96 hours later (referred as ToD). We report changes in Classical Monocytes -CM-, Intermediate Monocytes -IM- and Non-classical Monocytes -NCM-. Changes in monocyte activation markers were identified only in TD participants and during ToD. CM and IM upregulated molecules related to interaction with bacterial antigens (TLR4, TLR5, CD36 and CD206). Of importance, CM and IM showed enhanced binding of S. Typhi. Upregulation of inflammatory molecules like TNF-α were detected, but mechanisms involved in limiting inflammation were also activated (CD163 and CD354 downregulation). CM upregulated molecules to interact/modulate cells of the adaptive immunity, including T cells (HLA-DR, CD274 and CD86) and B cells (CD257). Both CM and IM showed potential to migrate to the gut as integrin α4ÎČ7 was upregulated. Unsupervised analysis revealed 7 dynamic cell clusters. Five of these belonged to CM showing that this is the main population activated during ToD. Overall, we provide new insights into the changes that diverse circulating monocyte subsets undergo after typhoid diagnosis, which might be important to control this disease since these cells will ultimately become intestinal macrophages once they reach the gut
The STRATAA study protocol: a programme to assess the burden of enteric fever in Bangladesh, Malawi and Nepal using prospective population census, passive surveillance, serological studies and healthcare utilisation surveys.
Introduction Invasive infections caused by Salmonella enterica serovar Typhi and Paratyphi A are estimated to account for 12â27âmillion febrile illness episodes worldwide annually. Determining the true burden of typhoidal Salmonellae infections is hindered by lack of population-based studies and adequate laboratory diagnostics.
The Strategic Typhoid alliance across Africa and Asia study takes a systematic approach to measuring the age-stratified burden of clinical and subclinical disease caused by typhoidal Salmonellae infections at three high-incidence urban sites in Africa and Asia. We aim to explore the natural history of Salmonella transmission in endemic settings, addressing key uncertainties relating to the epidemiology of enteric fever identified through mathematical models, and enabling optimisation of vaccine strategies.
Methods/design Using census-defined denominator populations of â„100â000 individuals at sites in Malawi, Bangladesh and Nepal, the primary outcome is to characterise the burden of enteric fever in these populations over a 24-month period. During passive surveillance, clinical and household data, and laboratory samples will be collected from febrile individuals. In parallel, healthcare utilisation and water, sanitation and hygiene surveys will be performed to characterise healthcare-seeking behaviour and assess potential routes of transmission. The rates of both undiagnosed and subclinical exposure to typhoidal Salmonellae (seroincidence), identification of chronic carriage and population seroprevalence of typhoid infection will be assessed through age-stratified serosurveys performed at each site. Secondary attack rates will be estimated among household contacts of acute enteric fever cases and possible chronic carriers.
Ethics and dissemination This protocol has been ethically approved by the Oxford Tropical Research Ethics Committee, the icddr,b Institutional Review Board, the Malawian National Health Sciences Research Committee and College of Medicine Research Ethics Committee and Nepal Health Research Council. The study is being conducted in accordance with the principles of the Declaration of Helsinki and Good Clinical Practice. Informed consent was obtained before study enrolment. Results will be submitted to international peer-reviewed journals and presented at international conferences.
Trial registration number ISRCTN 12131979.
Ethics references Oxford (Oxford Tropical Research Ethics Committee 39-15).
Bangladesh (icddr,b Institutional Review Board PR-15119).
Malawi (National Health Sciences Research Committee 15/5/1599).
Nepal (Nepal Health Research Council 306/2015)
- âŠ