243 research outputs found
Young in Class: Implications for Inattentive/Hyperactive Behaviour of Canadian Boys and Girls
Using data from the Statistics Canada National Longitudinal Survey of Children and Youth (NLSCY), this paper investigates the impact of school entry age on inattentive/hyperactive behaviours. We employ both a cross-provinces-time differences-in-differences approach, and a within-province regression discontinuity design. We find that being young in class causes greater inattentive/hyperactive behaviour, exacerbating any inattentive/hyperactive behavior exhibited prior to school entry. These results also also hold in sibling fixed effect models. Though we do not find gender differences in the effects, because boys are more likely to be inattentive/hyperactive at school entry, they are more affected. These effects persist into early adolescence
Technical challenges to surgical clipping of aneurysmal regrowth with coil herniation following endovascular treatment – a case report
In recent years, technical developments have made endovascular procedures attractive therapeutic options and enabled the endovascular surgeon to redefine the management of cerebral aneurysms. However, as the number of aneurysms undergoing endovascular therapy has grown, so has the number of patients with incompletely treated aneurysms who are presenting for further management. In cases of failure of endovascular treatment caused by either incomplete occlusion or regrowth of the aneurysm, a complementary treatment is often necessary. Surgical treatment of these patients is challenging. We present a case of a ruptured posterior cerebral artery aneurysm treated initially with endovascular coiling that left behind significant residual aneurysmal sac. Regrowth of the aneurysm documented on follow-up was treated surgically. At surgery, the coil was found to have herniated through the aneurysmal sac into the subarachnoid space, and the aneurysm was successfully clipped without removing the coils. We review the regrowth of aneurysms following endovascular therapy and potential problems and challenges of surgically managing these lesions
A pathway in quiescent cells that controls p27 Kip1 stability, subcellular localization, and tumor suppression
We have created two knock-in mouse models to study the mechanisms that regulate p27 in normal cells and cause misregulation of p27 in tumors: p27 S10A , in which Ser10 is mutated to Ala; and p27 CK − , in which point mutations abrogate the ability of p27 to bind cyclins and CDKs. These two mutant alleles identify steps in a pathway that controls the proteasomal degradation of p27 uniquely in quiescent cells: Dephosphorylation of p27 on Ser10 inhibits p27 nuclear export and promotes its assembly into cyclin-CDK complexes, which is, in turn, necessary for p27 turnover. We further show that Ras-dependent lung tumorigenesis is associated with increased phosphorylation on Ser10 and cytoplasmic mislocalization of p27. Indeed, we find that p27 S10A is refractory to Ras-induced cytoplasmic translocation and that p27 S10A mice are tumor resistant. Thus, phosphorylation of p27 on Ser10 is an important event in the regulation of the tumor suppressor function of p27
A review of duodenal metastases from squamous cell carcinoma of the cervix presenting as an upper gastrointestinal bleed
Upper gastrointestinal bleeding due to duodenal metastases is extremely uncommon. Extra-pelvic spread of squamous cell carcinoma (SCC) of the cervix to the small bowel is rare with only 6 reported cases in the English literature since 1981(PubMed, Medline)
Public policy action and CCC implementation: benefits and hurdles
Policy change continues to be an increasingly effective means of advancing the agenda of comprehensive cancer control. Efforts have moved progressively from describing how public policy can enhance the comprehensive cancer control agenda to implementation of public policy best practices at both the state and federal levels. The current political and economic contexts bring additional challenges and opportunities to the efforts surrounding comprehensive cancer control and policy. The purpose of this paper is to highlight recent policy successes, to illustrate the importance of policy as a means of advancing the comprehensive cancer control agenda, and to discuss continued policy action as we move forward in a time of healthcare reform and continuing economic uncertainty
Young in class: Implications for inattentive/hyperactive behaviour of Canadian boys and girls
Prioritizing Risks and Uncertainties from Intentional Release of Selected Category A Pathogens
This paper synthesizes available information on five Category A pathogens (Bacillus anthracis, Yersinia pestis, Francisella tularensis, Variola major and Lassa) to develop quantitative guidelines for how environmental pathogen concentrations may be related to human health risk in an indoor environment. An integrated model of environmental transport and human health exposure to biological pathogens is constructed which 1) includes the effects of environmental attenuation, 2) considers fomite contact exposure as well as inhalational exposure, and 3) includes an uncertainty analysis to identify key input uncertainties, which may inform future research directions. The findings provide a framework for developing the many different environmental standards that are needed for making risk-informed response decisions, such as when prophylactic antibiotics should be distributed, and whether or not a contaminated area should be cleaned up. The approach is based on the assumption of uniform mixing in environmental compartments and is thus applicable to areas sufficiently removed in time and space from the initial release that mixing has produced relatively uniform concentrations. Results indicate that when pathogens are released into the air, risk from inhalation is the main component of the overall risk, while risk from ingestion (dermal contact for B. anthracis) is the main component of the overall risk when pathogens are present on surfaces. Concentrations sampled from untracked floor, walls and the filter of heating ventilation and air conditioning (HVAC) system are proposed as indicators of previous exposure risk, while samples taken from touched surfaces are proposed as indicators of future risk if the building is reoccupied. A Monte Carlo uncertainty analysis is conducted and input-output correlations used to identify important parameter uncertainties. An approach is proposed for integrating these quantitative assessments of parameter uncertainty with broader, qualitative considerations to identify future research priorities
Cognitive neuroscience of delusions in aging
Assessments and clinical understanding of late-onset delusions in the elderly are inconsistent and often incomplete. In this review, we consider the prevalence, neurobehavioral features, and neuroanatomic correlations of delusions in elderly persons – those with documented cognitive decline and those with no evidence of cognitive decline. Both groups exhibit a common phenotype: delusions are either of persecution or of misidentification. Late-onset delusions show a nearly complete absence of the grandiose, mystical, or erotomanic content typical of early onset psychoses. Absent also from both elderly populations are formal thought disorders, thought insertions, and delusions of external control. Neuroimaging and behavioral studies suggest a frontotemporal localization of delusions in the elderly, with right hemispheric lateralization in delusional misidentification and left lateralization in delusions of persecution. We propose that delusions in the elderly reflect a common neuroanatomic and functional phenotype, and we discuss applications of our proposal to diagnosis and treatment
Enhancement of Rydberg-mediated single-photon nonlinearities by electrically tuned Förster resonances
We demonstrate experimentally that Stark-tuned Förster resonances can be used to substantially increase the interaction between individual photons mediated by Rydberg interaction inside an optical medium. This technique is employed to boost the gain of a Rydberg-mediated single-photon transistor and to enhance the non-destructive detection of single Rydberg atoms. Furthermore, our all-optical detection scheme enables high-resolution spectroscopy of two-state Förster resonances, revealing the fine structure splitting of high-n Rydberg states and the non-degeneracy of Rydberg Zeeman substates in finite fields. We show that the ∣50S1/2,48S1/2⟩↔∣49P1/2,48P1/2⟩ pair state resonance in 87Rb enables simultaneously a transistor gain G>100 and all-optical detection fidelity of single Rydberg atoms F>0.8. We demonstrate for the first time the coherent operation of the Rydberg transistor with G>2 by reading out the gate photon after scattering source photons. Comparison of the observed readout efficiency to a theoretical model for the projection of the stored spin wave yields excellent agreement and thus successfully identifies the main decoherence mechanism of the Rydberg transistor
Learning environments research in English classrooms
Although learning environments research has thrived for decades in many countries and school subjects, English classroom environment research is still in its infancy. This article paves the way for expanding research on English classroom environments by (1) reviewing the limited past research in English classrooms and (2) reporting the first study of English learning environments in Singaporean primary schools. For a sample of 441 grade 6 students, past research in other subjects was replicated in that a modified version of the What Is Happening In this Class? questionnaire was cross-validated, classroom environment was found to vary with the determinants of student sex and ethnicity, and associations emerged between students’ attitudes and the nature of the classroom environment
- …