172 research outputs found

    Technology Media, Service Innovation and the Shaping of Executive Cognition

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    The upsurge of information and communication technology innovations around the world has induced the establishment of many technology enterprises, mostly small-medium, that focus on service innovation. Due to the materiality of technology to this enterprise genre, its executive is significantly shaped by technology media, but explanations of technological shaping are low. This paper seeks to address this gap through a study informed by critical realism and media ecology. It argues that executive cognition is shaped because ICT media and service innovation imperatives combine to generate executive internalizations; and it is shaped by service innovation driven internalizations of technology media functions. The paper also discusses theoretical, research and practical implications based on these arguments

    Facilitators and barriers to the successful implementation of pediatric antibacterial drug trials: Findings from CTTI's survey of investigators.

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    An urgent need exists to develop new antibacterial drugs for children. We conducted research with investigators of pediatric antibacterial drug trials to identify facilitators and barriers in the conduct of these trials. Seventy-three investigators completed an online survey assessing the importance of 15 facilitators (grouped in 5 topical categories) and the severity of 36 barriers (grouped in 6 topical categories) to implementing pediatric antibacterial drug trials. Analysis focused on the identification of key factors that facilitate the successful implementation of pediatric antibacterial drug trials and the key barriers to implementation. Almost all investigators identified two factors as very important facilitators: having site personnel for enrollment and having adequate funding. Other top factors were related to staffing. Among the barriers, factors related to parent concerns and consent were prominent, particularly obtaining parental consent when there was disagreement between parents, concerns about the number of blood draws, and concerns about the number of invasive procedures. Having overly narrow eligibility criteria was also identified as a major barrier. The survey findings suggest three areas in which to focus efforts to help facilitate ongoing drug development: (1) improving engagement with parents of children who may be eligible to enroll in a pediatric antibacterial drug trial, (2) broadening inclusion criteria to allow more participants to enroll, and (3) ensuring adequate staffing and establishing sustainable financial strategies, such as funding pediatric trial networks. The pediatric antibacterial drug trials enterprise is likely to benefit from focused efforts by all stakeholders to remove barriers and enhance facilitation

    Parents' perceived obstacles to pediatric clinical trial participation: Findings from the clinical trials transformation initiative.

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    Enrollment of children into pediatric clinical trials remains challenging. More effective strategies to improve recruitment of children into trials are needed. This study used in-depth qualitative interviews with parents who were approached to enroll their children in a clinical trial in order to gain an understanding of the barriers to pediatric clinical trial participation. Twenty-four parents whose children had been offered the opportunity to participate in a clinical trial were interviewed: 19 whose children had participated in at least 1 clinical trial and 5 who had declined participation in any trial. Each study aspect, from the initial explanation of the study to the end of the study, can affect the willingness of parents to consent to the proposed study and future studies. Establishing trust, appropriate timing, a transparent discussion of risks and benefits oriented to the layperson, and providing motivation for children to participate were key factors that impacted parents' decisions. In order for clinical trial accrual to be successful, parents' priorities and considerations must be a central focus, beginning with initial trial design. The recommendations from the parents who participated in this study can be used to support budget allocations that ensure adequate training of study staff and improved staffing on nights and weekends. Studies of parent responses in outpatient settings and additional inpatient settings will provide valuable information on the consent process from the child's and parent's perspectives. Further studies are needed to explore whether implementation of such strategies will result in improved recruitment for pediatric clinical trials

    A system of ODEs for a Perturbation of a Minimal Mass Soliton

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    We study soliton solutions to a nonlinear Schrodinger equation with a saturated nonlinearity. Such nonlinearities are known to possess minimal mass soliton solutions. We consider a small perturbation of a minimal mass soliton, and identify a system of ODEs similar to those from Comech and Pelinovsky (2003), which model the behavior of the perturbation for short times. We then provide numerical evidence that under this system of ODEs there are two possible dynamical outcomes, which is in accord with the conclusions of Pelinovsky, Afanasjev, and Kivshar (1996). For initial data which supports a soliton structure, a generic initial perturbation oscillates around the stable family of solitons. For initial data which is expected to disperse, the finite dimensional dynamics follow the unstable portion of the soliton curve.Comment: Minor edit

    Minimum follow-up time required for the estimation of statistical cure of cancer patients: verification using data from 42 cancer sites in the SEER database

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    BACKGROUND: The present commonly used five-year survival rates are not adequate to represent the statistical cure. In the present study, we established the minimum number of years required for follow-up to estimate statistical cure rate, by using a lognormal distribution of the survival time of those who died of their cancer. We introduced the term, threshold year, the follow-up time for patients dying from the specific cancer covers most of the survival data, leaving less than 2.25% uncovered. This is close enough to cure from that specific cancer. METHODS: Data from the Surveillance, Epidemiology and End Results (SEER) database were tested if the survival times of cancer patients who died of their disease followed the lognormal distribution using a minimum chi-square method. Patients diagnosed from 1973–1992 in the registries of Connecticut and Detroit were chosen so that a maximum of 27 years was allowed for follow-up to 1999. A total of 49 specific organ sites were tested. The parameters of those lognormal distributions were found for each cancer site. The cancer-specific survival rates at the threshold years were compared with the longest available Kaplan-Meier survival estimates. RESULTS: The characteristics of the cancer-specific survival times of cancer patients who died of their disease from 42 cancer sites out of 49 sites were verified to follow different lognormal distributions. The threshold years validated for statistical cure varied for different cancer sites, from 2.6 years for pancreas cancer to 25.2 years for cancer of salivary gland. At the threshold year, the statistical cure rates estimated for 40 cancer sites were found to match the actuarial long-term survival rates estimated by the Kaplan-Meier method within six percentage points. For two cancer sites: breast and thyroid, the threshold years were so long that the cancer-specific survival rates could yet not be obtained because the SEER data do not provide sufficiently long follow-up. CONCLUSION: The present study suggests a certain threshold year is required to wait before the statistical cure rate can be estimated for each cancer site. For some cancers, such as breast and thyroid, the 5- or 10-year survival rates inadequately reflect statistical cure rates, and highlight the need for long-term follow-up of these patients

    Long-term survival rates of laryngeal cancer patients treated by radiation and surgery, radiation alone, and surgery alone : studied by lognormal and Kaplan-Meier survival methods

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    BACKGROUND: Validation of the use of the lognormal model for predicting long-term survival rates using short-term follow-up data. METHODS: 907 cases of laryngeal cancer were treated from 1973–1977 by radiation and surgery (248), radiation alone (345), and surgery alone (314), in registries of Connecticut and Metropolitan Detroit of the SEER database, with known survival status up to 1999. Phase 1 of this study used the minimum chi-square test to assess the goodness of fit of the survival times of those who died with disease to a lognormal distribution. Phase 2 used the maximum likelihood method to estimate long-term survival rates using short-term follow-up data. In order to validate the lognormal model, the estimated long-term cancer-specific survival rates (CSSR) were compared with the values calculated by the Kaplan-Meier (KM) method using long-term data. RESULTS: The 25-year CSSR were predicted to be 72%, 68% and 65% for treatments by radiation and surgery, by radiation alone, and by surgery alone respectively, using short-term follow-up data by the lognormal model. Corresponding results calculated by the KM method were: 72+/-3%, 68+/-3% and 66+/-4% respectively. CONCLUSIONS: The lognormal model was validated for the prediction of the long-term survival rates of laryngeal cancer patients treated by these different methods. The lognormal model may become a useful tool in research on outcomes

    The late radiotherapy normal tissue injury phenotypes of telangiectasia, fibrosis and atrophy in breast cancer patients have distinct genotype-dependent causes

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    The relationship between late normal tissue radiation injury phenotypes in 167 breast cancer patients treated with radiotherapy and: (i) radiotherapy dose (boost); (ii) an early acute radiation reaction and (iii) genetic background was examined. Patients were genotyped at single nucleotide polymorphisms (SNPs) in eight candidate genes. An early acute reaction to radiation and/or the inheritance of the transforming growth factor-β1 (TGFβ1 −509T) SNP contributed to the risk of fibrosis. In contrast, an additional 15 Gy electron boost and/or the inheritance of X-ray repair cross-complementing 1 (XRCC1) (R399Q) SNP contributed to the risk of telangiectasia. Although fibrosis, telangiectasia and atrophy, all contribute to late radiation injury, the data suggest that they have distinct underlying genetic and radiobiological causes. Fibrosis risk is associated with an inflammatory response (an acute reaction and/or TGFβ1), whereas telangiectasia is associated with vascular endothelial cell damage (boost and/or XRCC1). Atrophy is associated with an acute response, but the genetic predisposing factors that determine the risk of an acute response or atrophy have yet to be identified. A combined analysis of two UK breast cancer patient studies shows that 8% of patients are homozygous (TT) for the TGFβ1 (C-509T) variant allele and have a 15-fold increased risk of fibrosis following radiotherapy (95% confidence interval: 3.76–60.3; P=0.000003) compared with (CC) homozygotes

    Fibrocytes and the tissue niche in lung repair

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    Human fibrocytes are bone marrow-derived mesenchymal progenitor cells that express a variety of markers related to leukocytes, hematopoietic stem cells and a diverse set of fibroblast phenotypes. Fibrocytes can be recruited from the circulation to the tissue where they further can differentiate and proliferate into various mesenchymal cell types depending on the tissue niche. This local tissue niche is important because it modulates the fibrocytes and coordinates their role in tissue behaviour and repair. However, plasticity of a niche may be co-opted in chronic airway diseases such as asthma, idiopathic pulmonary fibrosis and obliterative bronchiolitis. This review will therefore focus on a possible role of fibrocytes in pathological tissue repair processes in those diseases
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