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1.
J Chiropr Educ ; 36(1): 43-49, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34320650

RESUMO

OBJECTIVE: This study explored self-reported experiences of alternate admission track plan (AATP) students who completed a chiropractic training program at a US chiropractic college. METHODS: Our institution conducted semistructured exit interviews with 16 graduating AATP students. Our consensus-drafted open-ended interview questions probed in-depth for these students' experience throughout the training program, with national board exams, their personal characteristics, their satisfaction with the training program generally, and with the AATP program specifically. We employed a content analysis to identify themes and patterns of responses across the blinded deidentified interview transcripts. We used a combination of deductive coding based on our interview guides, and inductive coding to identify newly emerging subthemes. RESULTS: Perceived facilitators of student success were strong commitment to chiropractic, cooperative, and supportive environment (eg, student study groups and a highly committed faculty), work ethic, and time management skills. Although many recommended that AATP entrants without science backgrounds take prerequisite courses in biology and chemistry, they also observed that a capable student could dedicate the time and effort to obtain the needed information via available college resources. CONCLUSION: Graduating AATP students were positive about the AATP program overall, and their preparation for national board exams and for clinical practice. They greatly valued the opportunity to accelerate their entrance into chiropractic college. A major limitation of this study is that the perspectives of AATP students who did not complete the doctor of chiropractic program are not represented in these interviews of graduating students.

2.
Sci Rep ; 9(1): 11440, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31391571

RESUMO

Lysenin is a pore-forming toxin, which self-inserts open channels into sphingomyelin containing membranes and is known to be voltage regulated. The mechanistic details of its voltage gating mechanism, however, remains elusive despite much recent efforts. Here, we have employed a novel combination of experimental and computational techniques to examine a model for voltage gating, that is based on the existence of an "effective electric dipole" inspired by recent reported structures of lysenin. We support this mechanism by the observations that (i) the charge-reversal and neutralization substitutions in lysenin result in changing its electrical gating properties by modifying the strength of the dipole, and (ii) an increase in the viscosity of the solvent increases the drag force and slows down the gating. In addition, our molecular dynamics (MD) simulations of membrane-embedded lysenin provide a mechanistic picture for lysenin conformational changes, which reveals, for the first time, the existence of a lipid-dependent bulge region in the pore-forming module of lysenin, which may explain the gating mechanism of lysenin at a molecular level.


Assuntos
Ativação do Canal Iônico/fisiologia , Metabolismo dos Lipídeos , Simulação de Dinâmica Molecular , Domínios Proteicos/fisiologia , Toxinas Biológicas/metabolismo , Colesterol/metabolismo , Lipídeos , Mutação , Fosfatidilcolinas/metabolismo , Engenharia de Proteínas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Esfingomielinas/metabolismo , Toxinas Biológicas/genética
3.
J Phys Oceanogr ; 47(6): 1-56, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29657336

RESUMO

Motivated by the substantial sensitivity of eddies in two-layer quasi-geostrophic (QG) turbulence models to the strength of bottom drag, this study explores the sensitivity of eddies in more realistic ocean general circulation model (OGCM) simulations to bottom drag strength. The OGCM results are interpreted using previous results from horizontally homogeneous, two-layer, flat-bottom, f-plane, doubly periodic QG turbulence simulations and new results from two-layer ß-plane QG turbulence simulations run in a basin geometry with both flat and rough bottoms. Baroclinicity in all of the simulations varies greatly with drag strength, with weak drag corresponding to more barotropic flow and strong drag corresponding to more baroclinic flow. The sensitivity of the baroclinicity in the QG basin simulations to bottom drag is considerably reduced, however, when rough topography is used in lieu of a flat bottom. Rough topography reduces the sensitivity of the eddy kinetic energy amplitude and horizontal length scales in the QG basin simulations to bottom drag to an even greater degree. The OGCM simulation behavior is qualitatively similar to that in the QG rough bottom basin simulations in that baroclinicity is more sensitive to bottom drag strength than are eddy amplitudes or horizontal length scales. Rough topography therefore appears to mediate the sensitivity of eddies in models to the strength of bottom drag. The sensitivity of eddies to parameterized topographic internal lee wave drag, which has recently been introduced into some OGCMs, is also briefly discussed. Wave drag acts like a strong bottom drag in that it increases the baroclinicity of the flow, without strongly affecting eddy horizontal length scales.

4.
Eur Phys J C Part Fields ; 74(7): 2945, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25814901

RESUMO

Flavour- and CP-violating electromagnetic or chromomagnetic dipole operators in the quark sector are generated in a large class of new physics models and are strongly constrained by measurements of the neutron electric dipole moment and observables sensitive to flavour-changing neutral currents, such as the [Formula: see text] branching ratio and [Formula: see text]. After a model-independent discussion of the relevant constraints, we analyze these effects in models with partial compositeness, where the quarks get their masses by mixing with vector-like composite fermions. These scenarios can be seen as the low-energy limit of composite Higgs or warped extra dimensional models. We study different choices for the electroweak representations of the composite fermions motivated by electroweak precision tests as well as different flavour structures, including flavour anarchy and [Formula: see text] or [Formula: see text] flavour symmetries in the strong sector. In models with "wrong-chirality" Yukawa couplings, we find a strong bound from the neutron electric dipole moment, irrespective of the flavour structure. In the case of flavour anarchy, we also find strong bounds from flavour-violating dipoles, while these constraints are mild in the flavour-symmetric models.

5.
Biophys Chem ; 184: 126-30, 2013 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-24075493

RESUMO

The pore-forming toxin lysenin self-inserts to form conductance channels in natural and artificial lipid membranes containing sphingomyelin. The inserted channels exhibit voltage regulation and hysteresis of the macroscopic current during the application of positive periodic voltage stimuli. We explored the bi-stable behavior of lysenin channels and present a theoretical approach for the mechanism of the hysteresis to explain its static and dynamic components. This investigation develops a model to incorporate the role of charge accumulation on the bilayer lipid membrane in influencing the channel conduction state. Our model is supported by experimental results and also provides insight into the temperature dependence of lysenin channel hysteresis. Through this work we gain perspective into the mechanism of how the response of a channel protein is determined by previous stimuli.


Assuntos
Ativação do Canal Iônico , Canais Iônicos/metabolismo , Modelos Biológicos , Toxinas Biológicas/metabolismo , Canais Iônicos/química , Bicamadas Lipídicas/metabolismo , Temperatura , Toxinas Biológicas/química
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