801 research outputs found
A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: Implications for
Strong gravitational lensing provides an independent measurement of the
Hubble parameter (). One remaining systematic is a bias from the
additional mass due to a galaxy group at the lens redshift or along the
sightline. We quantify this bias for more than 20 strong lenses that have
well-sampled sightline mass distributions, focusing on the convergence
and shear . In 23% of these fields, a lens group contributes a 1%
convergence bias; in 57%, there is a similarly significant line-of-sight group.
For the nine time delay lens systems, is overestimated by 11%
on average when groups are ignored. In 67% of fields with total
0.01, line-of-sight groups contribute more convergence than
do lens groups, indicating that the lens group is not the only important mass.
Lens environment affects the ratio of four (quad) to two (double) image
systems; all seven quads have lens groups while only three of 10 doubles do,
and the highest convergences due to lens groups are in quads. We calibrate the
- relation: with a rms scatter of 0.34 dex.
Shear, which, unlike convergence, can be measured directly from lensed images,
can be a poor predictor of ; for 19% of our fields, is
. Thus, accurate cosmology using strong gravitational lenses
requires precise measurement and correction for all significant structures in
each lens field.Comment: 34 pages, 11 figures, accepted for publication in Ap
Ototoxicity from Combined Cisplatin and Radiation Treatment: An In Vitro Study
Objective. Combined cisplatin (CDDP) and radiotherapy is increasingly being used to treat advanced head and neck cancers. As both CDDP and radiation can cause hearing loss, it is important to have a better understanding of the cellular and molecular ototoxic mechanisms involved in combined therapy. Procedure.
The effects of CDDP, radiation, and combined CDDP-radiation on the OC-k3 cochlear cell line were studied using MTS assay, flow cytometry, Western blotting, and microarray analysis. Results. Compared to using CDDP or radiation alone, its combined use resulted in enhanced apoptotic cell death and apoptotic-related gene expression, including that of FAS. Phosphorylation of p53 at Ser15 (a marker for p53 pathway activation in response to DNA damage) was observed after treatment with either CDDP or radiation. However, posttreatment activation of p53 occurred earlier in radiation than in CDDP which corresponded to the timings of MDM2 and TP53INP1 expression. Conclusion. Enhanced apoptotic-related gene expressions leading to increased apoptotic cell deaths could explain the synergistic ototoxicity seen clinically in combined CDDP-radiation therapy. CDDP and radiation led to differential temporal activation of p53 which suggests that their activation is the result of different upstream processes. These have implications in future antiapoptotic treatments for ototoxicity
Distinct neuroanatomical and neuropsychological features of Down syndrome compared to related neurodevelopmental disorders: a systematic review
ObjectivesWe critically review research findings on the unique changes in brain structure and cognitive function characteristic of Down syndrome (DS) and summarize the similarities and differences with other neurodevelopmental disorders such as Williams syndrome, 22q11.2 deletion syndrome, and fragile X syndrome.MethodsWe conducted a meta-analysis and systematic literature review of 84 studies identified by searching PubMed, Google Scholar, and Web of Science from 1977 to October 2022. This review focuses on the following issues: (1) specific neuroanatomic and histopathological features of DS as revealed by autopsy and modern neuroimaging modalities, (2) language and memory deficits in DS, (3) the relationships between these neuroanatomical and neuropsychological features, and (4) neuroanatomic and neuropsychological differences between DS and related neurodevelopmental syndromes.ResultsNumerous post-mortem and morphometric neuroimaging investigations of individuals with DS have reported complex changes in regional brain volumes, most notably in the hippocampal formation, temporal lobe, frontal lobe, parietal lobe, and cerebellum. Moreover, neuropsychological assessments have revealed deficits in language development, emotional regulation, and memory that reflect these structural changes and are more severe than expected from general cognitive dysfunction. Individuals with DS also show relative preservation of multiple cognitive, linguistic, and social domains compared to normally developed controls and individuals with other neurodevelopmental disorders. However, all these neurodevelopment disorders exhibit substantial heterogeneity among individuals.ConclusionPeople with Down syndrome demonstrate unique neurodevelopmental abnormalities but cannot be regarded as a homogenous group. A comprehensive evaluation of individual intellectual skills is essential for all individuals with neurodevelopment disorders to develop personalized care programs
New interleukin-15 superagonist (IL-15SA) significantly enhances graft-versus-tumor activity.
Interleukin-15 (IL-15) is a potent cytokine that increases CD8+ T and NK cell numbers and function in experimental models. However, obstacles remain in using IL-15 therapeutically, specifically its low potency and short in vivo half-life. To help overcome this, a new IL-15 superagonist complex comprised of an IL-15N72D mutation and IL-15RαSu/Fc fusion (IL-15SA, also known as ALT-803) was developed. IL-15SA exhibits a significantly longer serum half-life and increased in vivo activity against various tumors. Herein, we evaluated the effects of IL-15SA in recipients of allogeneic hematopoietic stem cell transplantation. Weekly administration of IL-15SA to transplant recipients significantly increased the number of CD8+ T cells (specifically CD44+ memory/activated phenotype) and NK cells. Intracellular IFN-γ and TNF-α secretion by CD8+ T cells increased in the IL-15SA-treated group. IL-15SA also upregulated NKG2D expression on CD8+ T cells. Moreover, IL-15SA enhanced proliferation and cytokine secretion of adoptively transferred CFSE-labeled T cells in syngeneic and allogeneic models by specifically stimulating the slowly proliferative and nonproliferative cells into actively proliferating cells.We then evaluated IL-15SA\u27s effects on anti-tumor activity against murine mastocytoma (P815) and murine B cell lymphoma (A20). IL-15SA enhanced graft-versus-tumor (GVT) activity in these tumors following T cell infusion. Interestingly, IL-15 SA administration provided GVT activity against A20 lymphoma cells in the murine donor leukocyte infusion (DLI) model without increasing graft versus host disease. In conclusion, IL-15SA could be a highly potent T- cell lymphoid growth factor and novel immunotherapeutic agent to complement stem cell transplantation and adoptive immunotherapy
Pretravel plans and discrepant trip experiences among travelers attending a tertiary care centre family travel medicine clinic
Background International travel can expose travelers to a number of health risks. Pretravel consultation (PC) helps mitigate risk and prepare travelers for health concerns that might arise. The assessment of risk, mitigation strategies, and relevance of pretravel advice is dependent on how closely travelers adhere to their planned travel itinerary and activities. We determined the proportion of returned travelers whose completed travel experiences differed from their stated travel itineraries, and identified discrepancies that significantly altered the traveler\u27s health risk and would have required alternative counseling during their PC. Methods We conducted a prospective cohort study at the SickKids\u27 Family Travel Clinic between October 2014 and November 2015. Returned travelers who completed a post-travel survey were included. Pretravel consultation assessments and post-trip surveys were compared to identify discrepant trip experiences. Results A total of 389 travelers presented to the clinic for a PC during the study period and 302 (77.6%) were enrolled. Post-travel surveys were received from 119 (39.4%) participants, representing 101 unique itineraries. The median participant age was 36.3 years (IQR 26.6- 47.5) and there were 73 female travelers (61%). Most participants (n = 87,73%) were healthy as well as Canadian born (n = 84, 71%). A quarter of travelers were visiting friends and relatives (VFR) (n = 30, 25.2%). The vast majority of returned travelers (n = 109, 92%) reported discrepant trip experiences involving trip duration, countries visited, accommodations, environmental surroundings and/or activities. Almost two thirds of these individuals (n = 68, 62%) would have required alternative pretravel counseling. We did not identify any demographic or planned trip characteristics that predicted discrepant trip experiences requiring alternative pretravel counseling. Conclusions The majority of travelers reported discrepant trip experiences and the discrepancies often affected health risk. Therefore, clinicians should consider providing broader counselling during the PC as discrepancies from planned travel are common
Multi-center evaluation of analytical performance of the Beckman Coulter AU5822 chemistry analyzer
Objectives
Our three academic institutions, Indiana University, Northwestern Memorial Hospital, and Wake Forest, were among the first in the United States to implement the Beckman Coulter AU5822 series chemistry analyzers. We undertook this post-hoc multi-center study by merging our data to determine performance characteristics and the impact of methodology changes on analyte measurement.
Design and methods
We independently completed performance validation studies including precision, linearity/analytical measurement range, method comparison, and reference range verification. Complete data sets were available from at least one institution for 66 analytes with the following groups: 51 from all three institutions, and 15 from 1 or 2 institutions for a total sample size of 12,064.
Results
Precision was similar among institutions. Coefficients of variation (CV) were 10% included direct bilirubin and digoxin. All analytes exhibited linearity over the analytical measurement range. Method comparison data showed slopes between 0.900-1.100 for 87.9% of the analytes. Slopes for amylase, tobramycin and urine amylase were 1.5, due to known methodology or standardization differences. Consequently, reference ranges of amylase, urine amylase and lipase required only minor or no modification.
Conclusion
The four AU5822 analyzers independently evaluated at three sites showed consistent precision, linearity, and correlation results. Since installations, the test results had been well received by clinicians from all three institutions
Community-Based OT Program Planning: A Virtual Level II Fieldwork Program Developed in Response to the Global Pandemic
The purpose of this article is to explain how an occupational therapy (OT) program in a university setting developed a virtual Level II community-based fieldwork program in response to the COVID-19 global pandemic. This virtual fieldwork program, guided by the PRECEDE-PROCEED Planning Model (PPM), was designed to help keep students on track with their academic goals while providing them with experiential learning that would increase their confidence in OT program planning and promote their professional development. Outcome measures for this study consisted of a pre-and post-fieldwork survey that asked participants to rank their self-perceived confidence in five distinct areas of community-based OT program development. Some portions of Section III in the Student’s Evaluation of the Fieldwork Experience (SEFWE) form were also used to examine students’ feedback after participating in this virtual fieldwork program. Retrospective data analysis of pre-post survey results showed improvements in students’ perceived confidence with certain aspects of OT program development in community settings. Within the core function of program development, occupation-based approaches to community-based programs can be used to inform, educate, and empower people and populations about important health issues while simultaneously offering students rich opportunities for professional development and identity. Dissemination of this information can be helpful to other OT professionals who are developing alternate fieldwork programs in response to the pandemic and beyond
Effectiveness of a Positive Youth Development Program for Secondary 1 Students in Macau: A Pilot Study
With the rapid change to society after the opening of the gaming licensure by the government and the potential attraction to youth caused by the casinos, a well-tested and comprehensive adolescent development program previously established in Hong Kong was adopted and modified to be used in Macau. It is expected to help our adolescents achieve positive growth and be better prepared for future challenges. The aim of this study is to examine the effectiveness of the modified positive youth development program for Secondary 1 Students in Macau. Specifically, two research questions will be asked: (1) How does the positive youth development program affect positive growth for youth in Macau?; and (2) Is youth growth related to different factors such as gender, age, family financial condition, and parents' marital status? A mixed research method with a quantitative approach using a pre- and post-test pre-experimental design, and a qualitative approach using a focus group for the participants is carried out. The study sample included 232 Secondary 1 Students in two schools. The objective outcome evaluation showed that, overall, 123 (53%) of the participants had significant improvement on the total scores of the Chinese Positive Youth Development Scale (CPYDS) and the two composite scores. However, there were some increases in the behavioral intention of alcohol drinking and participation in gambling activities. The “happiness of the family life” was found to have significant differences in the score of the CPYDS, which was shown to be the factor related to youth growth. The focus group interviews revealed that both positive and negative feedback was obtained from the discussion; however, the majority of the participants perceived benefits to themselves from the program. With reference to the principle of triangulation, the present study suggests that, based on both quantitative and qualitative evaluation findings, it should be concluded that there is positive evidence supporting the effectiveness of the Tier 1 Program of the Hong Kong Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes), which was adopted and modified for Macau. In addition, special attention should be paid to the behavioral intention of alcohol drinking and participation in gambling activities in the local context
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