230 research outputs found
Enzymatic Activity in the Chorion for Hatching in the California Grunion
Leuresthes tenuis is a small, silverside fish that spawns on the beaches during some of the highest tides of the summer months. Of the many unique traits to the species including that the eggs develop fully out of water to the point of hatching competence but will not hatch until presented with an environmental cue, which causes them to hatch in less than a minute. The purpose of this study is to better understand the role of enzymes called chorionases, which act to break down the chorion (egg membrane). I hypothesize that the chorion begins to weaken in this species when it is hatching competent but before it receives the stimulus to hatch. Unlike most organisms, the grunion embryo reaches hatching competence when it is fully developed, once it reaches competence, it stalls development and waits for an environmental cue. Before this, the egg is not hatching competent and will not hatch even if the trigger is there. The fact that it hatches so quickly could be evidence that an enzyme is acting to break down the chorion and this is what I hypothesize causes hatching competence. Some related fish have two chorionases while some only have one. To see whether one or two enzymes act in hatching in the grunion, I made a solution of the hatching enzyme, concentrated it, ran both SDS-PAGE and native-PAGE gels to separate out the protein by size, and cut out and sent those bands away for sequencing. To test whether the egg weakens upon hatching competence, I measured change in diameter of eggs that were pressed under a weight. We found no significant difference in pliability between the two groups of eggs using this methodology. If there are two enzymes, one may be acting before the other. If there is only one enzyme, another mechanism is at play
Teacher Outcomes of an Intensive STEM-Focused Professional Learning Initiative: An Examination of Their Beliefs, Practices, and Perceptions
The purpose of this paper is to describe teacher outcomes from participating in an intensive science, technology, engineering, and mathematics (STEM) professional learning (PL) initiative for middle school science teachers in the United States. The initiative included intensive summer coursework and ongoing support (e.g., individual coaching, professional learning communities), and focused on enhancing teachersâ STEM instruction and their pedagogical content knowledge (PCK), with the ultimate goal of improving student outcomes.
In this mixed method study, we examine change across time in teachersâ beliefs, use of STEM instruction, and PCK. In general, we did not observe statistically significant change in teachersâ beliefs, use of STEM instruction, or PCK from the beginning to the end of Year 1. In follow-up focus groups, ten teachers described their perceptions of student outcomes of STEM instruction and identified tensions related to implementation. We offer implications intended to inform future work in the area of STEM PL
An Investigation of Student Performance, Student Satisfaction , and Learner Characteristics in Online Versus Face-to-Face Classes--RESEARCH
The purpose of this study was to investigate student performance, student satisfaction, and learner characteristics in online versus face-to-face delivery formats in accounting. Forty-four students, enrolled in either the face-to-face or online section of an accounting course, completed a survey assessing satisfaction, learning outcomes, and learner characteristics. Significant differences were found regarding satisfaction with learning and perception of the instructor. However, online learners displayed similar traits as their face-to-face counterparts. In addition, researchers compared pre-test / post-test, homework, quiz, and exam scores to determine if delivery method affected learning. A significant difference was found between face-to-face and online students in post-test performance. Overall, the results of this study suggest that students perform as well in an online course as they do in a traditional face-to-face classroom and learner characteristics are similar for both online students and face-to-face classroom students. Post-test results indicate that students in an online class do not retain the information as well as those in a face-to-face class. These results, like others, show that online instructors continue to face challenges in promoting student participation and interaction in the course and overall satisfaction with learning. There is a need to replicate this study in other online courses in different disciplines
Large-scale associations between the leukocyte transcriptome and BOLD responses to speech differ in autism early language outcome subtypes.
Heterogeneity in early language development in autism spectrum disorder (ASD) is clinically important and may reflect neurobiologically distinct subtypes. Here, we identified a large-scale association between multiple coordinated blood leukocyte gene coexpression modules and the multivariate functional neuroimaging (fMRI) response to speech. Gene coexpression modules associated with the multivariate fMRI response to speech were different for all pairwise comparisons between typically developing toddlers and toddlers with ASD and poor versus good early language outcome. Associated coexpression modules were enriched in genes that are broadly expressed in the brain and many other tissues. These coexpression modules were also enriched in ASD-associated, prenatal, human-specific, and language-relevant genes. This work highlights distinctive neurobiology in ASD subtypes with different early language outcomes that is present well before such outcomes are known. Associations between neuroimaging measures and gene expression levels in blood leukocytes may offer a unique in vivo window into identifying brain-relevant molecular mechanisms in ASD
Validation of a breast cancer assay for radiotherapy omission: an individual participant data meta-analysis
Background: There are currently no molecular tests to identify individual breast cancers where radiotherapy (RT) offers no benefit. Profile for the Omission of Local Adjuvant Radiotherapy (POLAR) is a 16-gene molecular signature developed to identify low risk cancers where RT will not further reduce recurrence rates. Methods: An individual participant data meta-analysis was performed in 623 cases of node-negative ER+/HER2-negative early breast cancer enrolled in three RT randomized trials for whom primary tumor material was available for analysis. A Cox proportional hazards model on time to locoregional recurrence (LRR) was used to test the interaction between POLAR score and RT.Results: 429 (69%) patientsâ tumors had a high POLAR score and 194 (31%) had a low score. Patients with high POLAR score had, in the absence of RT, a 10-year cumulative incidence of LRR: 20% (15%-26%) vs 5% (2%-11%) for those with a low score. Patients with a high POLAR score had a large benefit from RT (hazard ratio [HR] for RT vs no RT: 0.37 [0.23-0.60], p<0.001). In contrast, there was no evidence of benefit from RT for patients with a low POLAR score (HR: 0.92 [0.42-2.02], p = 0.832). The test for interaction between RT and POLAR was statistically significant (p = 0.022).Conclusions: POLAR is not only prognostic for locoregional recurrence but also predictive of benefit from radiotherapy in selected patients. Patients â„ 50 years with ER+/HER2-negative disease and a low POLAR score could consider omitting adjuvant RT. Further validation in contemporary clinical cohorts is required.<br/
Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.
BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities â„500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity â„500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500
Better Palliative Care for people with a Dementia: Summary of InterdisciplinaryWorkshop Highlighting Current Gaps and Recommendations for Future Research
Background: Dementia is the most common neurological disorder worldwide and is a life-limiting condition, but very often is not recognised as such. People with dementia, and their carers, have been shown to have palliative care needs equal in extent to those of cancer patients. However, many people with advanced dementia are not routinely being assessed to determine their palliative care needs, and it is not clear why this is so. Main body: An interdisciplinary workshop on "Palliative Care in Neurodegeneration, with a focus on Dementia", was held in Cork, Ireland, in May 2016. The key aim of this workshop was to discuss the evidence base for palliative care for people with dementia, to identify 'gaps' for clinical research, and to make recommendations for interdisciplinary research practice. To lead the discussion throughout the day a multidisciplinary panel of expert speakers were brought together, including both researchers and clinicians from across Ireland and the UK. Targeted invitations were sent to attendees ensuring all key stakeholders were present to contribute to discussions. In total, 49 experts representing 17 different academic and practice settings, attended. Key topics for discussion were pre-selected based on previously identified research priorities (e.g. James Lind Alliance) and stakeholder input. Key discussion topics included: i. Advance Care Planning for people with Dementia; ii. Personhood in End-of-life Dementia care; iii. Topics in the care of advanced dementia at home. These topics were used as a starting point, and the ethos of the workshop was that the attendees could stimulate discussion and debate in any relevant area, not just the key topics, summarised under iv. Other priorities. Conclusions: The care experienced by people with dementia and their families has the potential to be improved; palliative care frameworks may have much to offer in this endeavour. However, a solid evidence base is required to translate palliative care into practice in the context of dementia. This paper presents suggested research priorities as a starting point to build this evidence base. An interdisciplinary approach to research and priority setting is essential to develop actionable knowledge in this area
Dual targeting of p53 and c-MYC selectively eliminates leukaemic stem cells
e Glasgow and Manchester Experimental Cancer
Medicine Centres (ECMC), which are funded by CR-UK and the Chief Scientistâs Office (Scotland). We
acknowledge the funders who have contributed to this work: MRC stratified medicine infrastructure award
(A.D.W.), CR-UK C11074/A11008 (F.P., L.E.M.H., T.L.H., A.D.W.); LLR08071 (S.A.A., E.C.); LLR11017
(M.C.); SCD/04 (M.C.); LLR13035 (S.A.A., K.D., A.D.W., and A.P.); LLR14005 (M.T.S., D.V.); KKL690 (L.E.P.);
KKL698 (P.B.); LLR08004 (A.D.W., A.P. and A.J.W.); MRC CiC (M.E.D.); The Howat Foundation (FACS
support); Friends of Paul OâGorman (K.D. and FACS support); ELF 67954 (S.A.A.); BSH start up fund (S.A.A.);
MR/K014854/1 (K.D.)
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