Interactive Narrative Pedagogy as a Heuristic for Understanding Supervision in Practice-led Research

This paper addresses the disciplinary and methodological specificity of the PhD in practice-led research and advocates an interactive narrative pedagogy inspired by the psychoanalytic teachings of Lacan. It sets into motion an innovative engagement among the fields of Psychoanalysis, Writing and Pedagogy in order to consider the possibilities that transference offers supervisors and candidates in two specific environments, i.e. an on-campus setting equipped with infrastructure resources and an off-campus setting devoid of such resources. I argue that an ethical handling of the transference promotes creativity and benefits the community at large

Impact evaluation of rural road projects

Very few of the (many) aid-financed rural road projects in developing countries have been the subject of rigorous impact evaluations. Assessing the welfare impacts of rural roads poses a number of problems, with implications for data collection and evaluation methods. This paper surveys the problems and discusses some practical implementation issues related specifically to conducting an impact evaluation of a rural roads project that is assigned to some geographic areas but not to others.rural roads, poverty, evaluation, development planning,

Muscle inactivation of mTOR causes metabolic and dystrophin defects leading to severe myopathy

Mammalian target of rapamycin (mTOR) is a key regulator of cell growth that associates with raptor and rictor to form the mTOR complex 1 (mTORC1) and mTORC2, respectively. Raptor is required for oxidative muscle integrity, whereas rictor is dispensable. In this study, we show that muscle-specific inactivation of mTOR leads to severe myopathy, resulting in premature death. mTOR-deficient muscles display metabolic changes similar to those observed in muscles lacking raptor, including impaired oxidative metabolism, altered mitochondrial regulation, and glycogen accumulation associated with protein kinase B/Akt hyperactivation. In addition, mTOR-deficient muscles exhibit increased basal glucose uptake, whereas whole body glucose homeostasis is essentially maintained. Importantly, loss of mTOR exacerbates the myopathic features in both slow oxidative and fast glycolytic muscles. Moreover, mTOR but not raptor and rictor deficiency leads to reduced muscle dystrophin content. We provide evidence that mTOR controls dystrophin transcription in a cell-autonomous, rapamycin-resistant, and kinase-independent manner. Collectively, our results demonstrate that mTOR acts mainly via mTORC1, whereas regulation of dystrophin is raptor and rictor independent.

Cancer cell–derived microparticles bearing P-selectin glycoprotein ligand 1 accelerate thrombus formation in vivo

Recent publications have demonstrated the presence of tissue factor (TF)-bearing microparticles (MPs) in the blood of patients suffering from cancer. However, whether these MPs are involved in thrombosis remains unknown. We show that pancreatic and lung cancer cells produce MPs that express active TF and P-selectin glycoprotein ligand 1 (PSGL-1). Cancer cell-derived MPs aggregate platelets via a TF-dependent pathway. In vivo, cancer cell-derived MPs, but not their parent cells, infused into a living mouse accumulate at the site of injury and reduce tail bleeding time and the time to occlusion of venules and arterioles. This thrombotic state is also observed in mice developing tumors. In such mice, the amount of circulating platelet-, endothelial cell-, and cancer cell-derived MPs is increased. Endogenous cancer cell-derived MPs shed from the growing tumor are able to accumulate at the site of injury. Infusion of a blocking P-selectin antibody abolishes the thrombotic state observed after injection of MPs or in mice developing a tumor. Collectively, our results indicate that cancer cell-derived MPs bearing PSGL-1 and TF play a key role in thrombus formation in vivo. Targeting these MPs could be of clinical interest in the prevention of thrombosis and to limit formation of metastasis in cancer patients.

Netrin-1 acts as a survival factor for aggressive neuroblastoma

Neuroblastoma (NB), the most frequent solid tumor of early childhood, is diagnosed as a disseminated disease in >60% of cases, and several lines of evidence support the resistance to apoptosis as a prerequisite for NB progression. We show that autocrine production of netrin-1, a multifunctional laminin-related molecule, conveys a selective advantage in tumor growth and dissemination in aggressive NB, as it blocks the proapoptotic activity of the UNC5H netrin-1 dependence receptors. We show that such netrin-1 up-regulation is a potential marker for poor prognosis in stage 4S and, more generally, in NB stage 4 diagnosed infants. Moreover, we propose that interference with the netrin-1 autocrine loop in malignant neuroblasts could represent an alternative therapeutic strategy, as disruption of this loop triggers in vitro NB cell death and inhibits NB metastasis in avian and mouse models.

Staphylococcus aureus synthesizes adenosine to escape host immune responses

Staphylococcus aureus infects hospitalized or healthy individuals and represents the most frequent cause of bacteremia, treatment of which is complicated by the emergence of methicillin-resistant S. aureus. We examined the ability of S. aureus to escape phagocytic clearance in blood and identified adenosine synthase A (AdsA), a cell wall-anchored enzyme that converts adenosine monophosphate to adenosine, as a critical virulence factor. Staphylococcal synthesis of adenosine in blood, escape from phagocytic clearance, and subsequent formation of organ abscesses were all dependent on adsA and could be rescued by an exogenous supply of adenosine. An AdsA homologue was identified in the anthrax pathogen, and adenosine synthesis also enabled escape of Bacillus anthracis from phagocytic clearance. Collectively, these results suggest that staphylococci and other bacterial pathogens exploit the immunomodulatory attributes of adenosine to escape host immune responses.

A single polymorphic amino acid on Toxoplasma gondii kinase ROP16 determines the direct and strain-specific activation of Stat3

Infection by Toxoplasma gondii down-regulates the host innate immune responses, such as proinflammatory cytokine production, in a Stat3-dependent manner. A forward genetic approach recently demonstrated that the type II strain fails to suppress immune responses because of a potential defect in a highly polymorphic parasite-derived kinase, ROP16. We generated ROP16-deficient type I parasites by reverse genetics and found a severe defect in parasite-induced Stat3 activation, culminating in enhanced production of interleukin (IL) 6 and IL-12 p40 in the infected macrophages. Furthermore, overexpression of ROP16 but not ROP18 in mammalian cells resulted in Stat3 phosphorylation and strong activation of Stat3-dependent promoters. In addition, kinase-inactive ROP16 failed to activate Stat3. Comparison of type I and type II ROP16 revealed that a single amino acid substitution in the kinase domain determined the strain difference in terms of Stat3 activation. Moreover, ROP16 bound Stat3 and directly induced phosphorylation of this transcription factor. These results formally establish an essential and direct requirement of ROP16 in parasite-induced Stat3 activation and the significance of a single amino acid replacement in the function of type II ROP16.

Muscle inactivation of mTOR causes metabolic and dystrophin defects leading to severe myopathy

A single charged voltage sensor is capable of gating the Shaker K+ channel

We sought to determine the contribution of an individual voltage sensor to Shaker's function. Concatenated heterotetramers of Shaker zH4 Delta(6-46) wild type (wt) in combination with a neutral S4 segment Shaker mutant (mut) with stoichiometries 2wt/2mut and 1wt/3mut were studied and compared with the 4wt concatenated homotetramer. A single charged voltage sensor is sufficient to open Shaker conductance with reduced delay (<1 ms) and at more hyperpolarized voltages compared with 4wt. In addition, the wt-like slow inactivation of 1wt/3mut was almost completely eliminated by mutations T449V-I470C in its single wt subunit, indicating that the subunits bearing a neutral S4 were unable to trigger slow inactivation. Our results strongly suggest that a neutral S4 segment of Shaker's subunit is voltage insensitive and its voltage sensor is in the activated position (i.e., ready for pore opening), and provide experimental support to the proposed model of independent voltage sensors with a final, almost voltage-independent concerted step.

Incidence, Seasonality, Age Distribution, and Mortality of Pneumococcal Meningitis in Burkina Faso and Togo

Streptococcus pneumoniae causes a substantial proportion of meningitis cases in the African meningitis belt; however, few reports exist to quantify its burden and characteristics. We conducted population-based and sentinel hospital surveillance of acute bacterial meningitis among persons of all ages in Burkina Faso and Togo in 2002-2006. S. pneumoniae and other organisms were identified by culture, polymerase chain reaction, or detection of antigen in cerebrospinal fluid (CSF). Information was collected on 2843 patients with suspected acute bacterial meningitis. CSF specimens were collected from 2689 (95%) of the patients; of these 2689, 463 (17%) had S. pneumoniae identified, 234 (9%) had Haemophilus influenzae type b identified, and 400 (15%) had Neisseria meningitidis identified. Of the 463 cases of S. pneumoniae meningitis, 99 (21%) were aged <1 year, 71 (15%) were aged 1-4 years, 95 (21%) were aged 5-14 years, and 189 (41%) were aged >or=15 years (age was unknown for 9 [2%]). In Burkina Faso, the annual incidence rate of pneumococcal meningitis was 14 cases per 100,000 persons, with annual incidence rates of 77, 33, 10, and 11 cases per 100,000 persons aged <1 year, <5 years, 5-14 years, and >or=15 years, respectively. The case-fatality ratio for S. pneumoniae meningitis was 47% (range for age groups, 44%-52%), and 53% of deaths occurred among those aged >5 years. S. pneumoniae meningitis had an epidemic pattern similar to that of N. meningitidis meningitis. Of 48 isolates tested for serotype, 18 were from children aged <5 years; of these 18, 3 isolates (17%) each were serotypes 1, 2, and 5, and 5 isolates (28%) were serotype 6A. The 7-, 10-, and 13-valent pneumococcal conjugate vaccines would cover 6%, 39%, and 67% of serotypes identified among children aged <5 years, respectively. Of the 30 serotypes identified for patients aged >or=5 years, 18 (60%) were serotype 1, whereas no other serotype constituted >10%. The 7-, 10-, and 13-valent vaccines would cover 7%, 70%, and 77% of serotypes. Epidemic pneumococcal meningitis in the African meningitis belt countries of Burkina Faso and Togo is common, affects all age groups, and is highly lethal. On the basis of a modest number of isolates from a limited area that includes only meningitis cases, 7-valent pneumococcal conjugate vaccine might have only a limited and short-term role. By contrast, the proposed 10- and 13-valent vaccines would cover most of the identified serotypes. To better inform vaccine policy, continued and expanded surveillance is essential to document serotypes associated with pneumonia, changes in serotype distribution across time, and the impact of vaccine after vaccine introduction.