Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
CBE Life Sci Educ ; 21(3): ar44, 2022 09.
Article in English | MEDLINE | ID: mdl-35759624

ABSTRACT

This study assesses the impacts of the Science program at Piedmont Virginia Community College and its flagship capstone research experience, Supervised Study, through psychosocial perceptions associated with persistence in science and through a comparative analysis of subsequent science bachelor's degree attainment. Supervised Study involves authentic, independent projects, a research methods course and learning community, and one-on-one faculty mentoring. The Persistence in the Sciences survey was used as a repeated-measures instrument in four semesters of Supervised Study. Positive trends were observed for self-efficacy, science identity, community values, and networking, while responses related to project ownership were mixed (n = 13). To contextualize these observations, transfer and bachelor's degree completion rates were analyzed. Students who earn an associate's degree in Science (n = 113 between 2012 and 2019) complete bachelor's degrees at high rates (66.4%). Moreover, they are two to four times more likely to major in physical and natural sciences than their science-oriented peers, who take many of the same courses, with the exception of Supervised Study. Notably, these comparison rates remain consistent between different demographic groups. These findings further describe a model for research at the community college level that supports persistence in undergraduate science for a broad group of students.


Subject(s)
Faculty , Students , Humans , Mentors , Surveys and Questionnaires , Universities
2.
Elife ; 102021 12 07.
Article in English | MEDLINE | ID: mdl-34874009

ABSTRACT

As part of the Reproducibility Project: Cancer Biology, we published Registered Reports that described how we intended to replicate selected experiments from 29 high-impact preclinical cancer biology papers published between 2010 and 2012. Replication experiments were completed and Replication Studies reporting the results were submitted for 18 papers, of which 17 were accepted and published by eLife with the rejected paper posted as a preprint. Here, we report the status and outcomes obtained for the remaining 11 papers. Four papers initiated experimental work but were stopped without any experimental outcomes. Two papers resulted in incomplete outcomes due to unanticipated challenges when conducting the experiments. For the remaining five papers only some of the experiments were completed with the other experiments incomplete due to mundane technical or unanticipated methodological challenges. The experiments from these papers, along with the other experiments attempted as part of the Reproducibility Project: Cancer Biology, provides evidence about the challenges of repeating preclinical cancer biology experiments and the replicability of the completed experiments.


Subject(s)
Biomedical Research/methods , Neoplasms , Reproducibility of Results , Animals , Cell Line , Humans , Mice
3.
Elife ; 52016 Feb 19.
Article in English | MEDLINE | ID: mdl-26894955

ABSTRACT

The Reproducibility Project: Cancer Biology seeks to address growing concerns about reproducibility in scientific research by conducting replications of selected experiments from a number of high-profile papers in the field of cancer biology. The papers, which were published between 2010 and 2012, were selected on the basis of citations and Altmetric scores (Errington et al., 2014). This Registered Report describes the proposed replication plan of key experiments from "Diverse somatic mutation patterns and pathway alterations in human cancers" by Kan and colleagues published in Nature in 2010 (Kan et al., 2010). The experiments to be replicated are those reported in Figures 3D-F and 4C-F. Kan and colleagues utilized mismatch repair detection (MRD) technology to identify somatic mutations in primary human tumor samples and identified a previously uncharacterized arginine 243 to histidine (R243H) mutation in the G-protein α subunit GNAO1 in breast carcinoma tissue. In Figures 3D-F, Kan and colleagues demonstrated that stable expression of mutant GNAO1(R243D) conferred a significant growth advantage in human mammary epithelial cells, confirming the oncogenic potential of this mutation. Similarly, expression of variants with somatic mutations in MAP2K4, a JNK pathway kinase (shown in Figures 4C-E) resulted in a significant increase in anchorage-independent growth. Interestingly, these mutants exhibited reduced kinase activity compared to wild type MAP2K4, indicating these mutations impose a dominant-negative influence to promote growth (Figure 4F). The Reproducibility Project: Cancer Biology is a collaboration between the Center for Open Science and Science Exchange and the results of the replications will be published in eLife.


Subject(s)
Breast Neoplasms/pathology , Mutation , Humans , Reproducibility of Results
4.
J Biol Chem ; 287(37): 31138-47, 2012 Sep 07.
Article in English | MEDLINE | ID: mdl-22815487

ABSTRACT

ADP ribosylation factors (Arfs) are small GTP-binding proteins known for their role in vesicular transport, where they nucleate the assembly of coat protein complexes at sites of carrier vesicle formation. Similar to other GTPases, Arfs require guanine nucleotide exchange factors to catalyze GTP loading and activation. One subfamily of ArfGEFs, the BRAGs, has been shown to activate Arf6, which acts in the endocytic pathway to control the trafficking of a subset of cargo proteins including integrins. We have previously shown that BRAG2 modulates cell adhesion by regulating integrin surface expression. Here, we show that, in addition to Arf6, endogenous BRAG2 also activates the class II Arfs, Arf4 and Arf5, and that surprisingly, it is Arf5 that mediates integrin internalization. We observed that cell spreading on fibronectin is enhanced upon inhibition of BRAG2 or Arf5 but not Arf6. Similarly, spreading in BRAG2-depleted cells is reverted by expression of a rapid cycling Arf5 mutant (T161A) but not by a corresponding Arf6 construct (T157A). We also show that BRAG2 binds clathrin and the AP-2 adaptor complex and that both BRAG2 and Arf5 localize to clathrin-coated pits at the plasma membrane. Consistent with these observations, depletion of Arf5, but not Arf6 or Arf4, slows internalization of ß1 integrins without affecting transferrin receptor uptake. Together, these findings indicate that BRAG2 acts at clathrin-coated pits to promote integrin internalization by activating Arf5 and suggest a previously unrecognized role for Arf5 in clathrin-mediated endocytosis of specific cargoes.


Subject(s)
ADP-Ribosylation Factors/metabolism , Clathrin/metabolism , Endocytosis/physiology , Guanine Nucleotide Exchange Factors/metabolism , Integrin alpha5beta1/metabolism , ADP-Ribosylation Factor 6 , ADP-Ribosylation Factors/genetics , Amino Acid Substitution , Cell Adhesion/physiology , Clathrin/genetics , Clathrin-Coated Vesicles/genetics , Clathrin-Coated Vesicles/metabolism , Gene Deletion , Guanine Nucleotide Exchange Factors/genetics , HeLa Cells , Humans , Integrin alpha5beta1/genetics , Mutation, Missense
5.
J Allergy Clin Immunol ; 111(1): 123-30, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12532107

ABSTRACT

BACKGROUND: Asthma and other atopic diseases are strongly hereditary. Although the mother might play a special role, the mechanisms for such an effect are not clear. OBJECTIVE: We sought to investigate the influence of maternal immune responses to cat and mite allergens on (1) maternal symptoms, (2) the development of immune responses in the infant, and (3) the development of allergic disease during the first 3 years of life. METHODS: In sera from 465 mothers and 424 infants (cord blood), as well as in sera from 230 of the children at age 2 to 3 years, total IgE and IgE antibodies were measured by using CAP testing; IgG and IgG4 antibodies for the cat allergen Fel d 1 were measured by means of radioimmunoprecipitation. RESULTS: In both mothers and children, approximately 15% of sera contained IgG antibodies to Fel d 1 without IgE antibodies to cat. The strongest predictor of the maternal IgG antibody response was exposure to greater than 8 microg of Fel d 1/g of dust. Thus approximately 70% of children living in a house with a cat had received IgG antibodies from their mothers. In many cases the infant received IgG and IgG4 antibodies to Fel d 1 from a nonallergic mother. Maternal IgE antibodies were consistently associated with asthma; by contrast, the IgG antibody was not independently related to asthma but was related to rhinitis in the mothers (odds ratio, 2.6; 95% CI, 1.1-6.2) and to eczema in children. At age 3 years, 13 of 230 sera contained IgE antibodies to mite, but only 5 had IgE antibodies to cat. CONCLUSIONS: A significant proportion (approximately 15%) of mothers and children exposed to high concentrations of cat (but not mite) allergens have serum IgG antibodies without IgE antibodies. This IgG antibody is freely transferred to the infant and might influence IgG antibody production in the child. The results indicate the importance of understanding the mechanisms of tolerance to cats and raise questions about the independent role of the mother in the inheritance of allergy.


Subject(s)
Allergens/immunology , Antigens, Dermatophagoides/immunology , Immunity, Maternally-Acquired/immunology , Animals , Antibody Formation , Cats/immunology , Child, Preschool , Fetal Blood/immunology , Humans , Immunization, Passive , Immunoglobulin E/blood , Risk Factors , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...