4,645 research outputs found
Torque Expression of Contemporary Self-ligating Bracket Systems
Background: Self-ligating bracket systems in orthodontics have evolved over the years, but there is limited data regarding their ability to generate torque for efficient third-order tooth positioning.
Aim: To compare contemporary active self-ligating bracket systems against a passive self-ligating bracket system and a traditional twin bracket system in their ability to generate torque at different degrees and direction of wire rotation, in vitro.
Materials and Methods: Five bracket system groups of 0.022 inch slot size (twin bracket system Victory Series with elastic ligature [E-Vic]; passive self-ligating bracket system Damon Q [P-Dmn]; and active self-ligating bracket systems Speed [A-Spd], InOvation-R [A-Ovn] and Empower 2 Active[A-Emp]) were tested for torque expression utilizing a 0.019 x 0.025 inch stainless steel wire ligated into their slots. Single upper right central incisor brackets of each system were mounted using a specialized mounting jig, and a custom torque assembly fixed to an Instron materials testing machine was utilized to measure torque generated from -15 to +45 degrees of wire rotation. Ten clockwise and ten counterclockwise rotations were performed for each bracket system (n=20).
Results: Torque expression significantly varied between bracket systems with P-Dmn, E-Vic and A-Ovn generating the highest torque, and A-Spd and A-Emp the lowest, at most degrees of wire rotation. The direction of wire rotation had the largest effect on the A-Spd and A-Emp active bracket systems, whereby the counterclockwise rotation generated significantly more torque than the clockwise rotation tests.
Conclusions: All five bracket systems displayed different behaviors of torque expression when comparing degrees and direction of wire rotation. Understanding these differences in torque expression can help the clinician plan and provide treatment more efficiently
The first definitive Middle Jurassic atoposaurid (Crocodylomorpha, Neosuchia), and a discussion on the genus Theriosuchus
Atoposaurids were a clade of semiaquatic crocodyliforms known from the Late Jurassic to the latest Cretaceous. Tentative remains from Europe, Morocco, and Madagascar may extend their range into the Middle Jurassic. Here we report the first unambiguous Middle Jurassic (late Bajocian–Bathonian) atoposaurid: an anterior dentary from the Isle of Skye, Scotland, UK. A comprehensive review of atoposaurid specimens demonstrates that this dentary can be referred to Theriosuchus based on several derived characters, and differs from the five previously recognized species within this genus. Despite several diagnostic features, we conservatively refer it to Theriosuchus sp., pending the discovery of more complete material. As the oldest known definitively diagnostic atoposaurid, this discovery indicates that the oldest members of this group were small-bodied, had heterodont dentition, and were most likely widespread components of European faunas. Our review of mandibular and dental features in atoposaurids not only allows us to present a revised diagnosis of Theriosuchus, but also reveals a great amount of variability within this genus, and indicates that there are currently five valid species that can be differentiated by unique combinations of dental characteristics. This variability can be included in future broad-scale cladistics analyses of atoposaurids and closely related crocodyliforms, which promise to help untangle the complicated taxonomy and evolutionary history of Atoposauridae
Recommended from our members
Assessment of the nucleotide modifications in the high-resolution cryo-electron microscopy structure of the Escherichia coli 50S subunit.
Post-transcriptional ribosomal RNA (rRNA) modifications are present in all organisms, but their exact functional roles and positions are yet to be fully characterized. Modified nucleotides have been implicated in the stabilization of RNA structure and regulation of ribosome biogenesis and protein synthesis. In some instances, rRNA modifications can confer antibiotic resistance. High-resolution ribosome structures are thus necessary for precise determination of modified nucleotides' positions, a task that has previously been accomplished by X-ray crystallography. Here, we present a cryo-electron microscopy (cryo-EM) structure of the Escherichia coli 50S subunit at an average resolution of 2.2 Ã… as an additional approach for mapping modification sites. Our structure confirms known modifications present in 23S rRNA and additionally allows for localization of Mg2+ ions and their coordinated water molecules. Using our cryo-EM structure as a testbed, we developed a program for assessment of cryo-EM map quality. This program can be easily used on any RNA-containing cryo-EM structure, and an associated Coot plugin allows for visualization of validated modifications, making it highly accessible
BioMeT and algorithm challenges: A proposed digital standardized evaluation framework
Technology is advancing at an extraordinary rate. Continuous flows of novel data are being generated with the potential to revolutionize how we better identify, treat, manage, and prevent disease across therapeutic areas. However, lack of security of confidence in digital health technologies is hampering adoption, particularly for biometric monitoring technologies (BioMeTs) where frontline healthcare professionals are struggling to determine which BioMeTs are fit-for-purpose and in which context. Here, we discuss the challenges to adoption and offer pragmatic guidance regarding BioMeTs, cumulating in a proposed framework to advance their development and deployment in healthcare, health research, and health promotion. Furthermore, the framework proposes a process to establish an audit trail of BioMeTs (hardware and algorithms), to instill trust amongst multidisciplinary users
Caltech Core-Collapse Project (CCCP) Observations of Type II Supernovae: Evidence for Three Distinct Photometric Subtypes
We present R-Band light curves of Type II supernovae (SNe) from the Caltech
Core Collapse Project (CCCP). With the exception of interacting (Type IIn) SNe
and rare events with long rise times, we find that most light curve shapes
belong to one of three distinct classes: plateau, slowly declining and rapidly
declining events. The last class is composed solely of Type IIb SNe which
present similar light curve shapes to those of SNe Ib, suggesting, perhaps,
similar progenitor channels. We do not find any intermediate light curves,
implying that these subclasses are unlikely to reflect variance of continuous
parameters, but rather might result from physically distinct progenitor
systems, strengthening the suggestion of a binary origin for at least some
stripped SNe. We find a large plateau luminosity range for SNe IIP, while the
plateau lengths seem rather uniform at approximately 100 days. As analysis of
additional CCCP data goes on and larger samples are collected, demographic
studies of core collapse SNe will likely continue to provide new constraints on
progenitor scenarios.Comment: Submitted to ApJ
Deliberative democracy and the politics of redistribution: the case of the Indian Panchayats
By examining evidence from India, where quotas for women in local government were introduced in 1993, this article argues that institutional reform can disturb hegemonic discourses sufficiently to open a window of opportunity where deliberative democratic norms take root and where, in addition to the politics of recognition, the politics of redistribution also operates
What are the ‘active ingredients’ of interventions targeting the public's engagement with antimicrobial resistance and how might they work?
Objectives. Changing public awareness of antimicrobial resistance (AMR) represents a global public health priority. A systematic review of interventions that targeted public AMR awareness and associated behaviour was previously conducted. Here, we focus on identifying the active content of these interventions and explore potential mechanisms of action.
Methods. The project took a novel approach to intervention mapping utilizing the following steps: (1) an exploration of explicit and tacit theory and theoretical constructs within the interventions using the Theoretical Domains Framework (TDFv2), (2) retrospective coding of behaviour change techniques (BCTs) using the BCT Taxonomy v1, and (3) an investigation of coherent links between the TDF domains and BCTs across the interventions.
Results. Of 20 studies included, only four reported an explicit theoretical basis to their intervention. However, TDF analysis revealed that nine of the 14 TDF domains were utilized, most commonly ‘Knowledge’ and ‘Environmental context and resources’. The BCT analysis showed that all interventions contained at least one BCT, and 14 of 93 (15%) BCTs were coded, most commonly ‘Information about health consequences’, ‘Credible source’, and ‘Instruction on how to perform the behaviour’.
Conclusions. We identified nine relevant TDF domains and 14 BCTs used in these interventions. Only 15% of BCTs have been applied in AMR interventions thus providing a clear opportunity for the development of novel interventions in this context. This methodological approach provides a useful way of retrospectively mapping theoretical constructs and BCTs when reviewing studies that provide limited information on theory and intervention content
Population screening for colorectal cancer means getting FIT:the past, present, and future of colorectal cancer screening using the fecal immunochemical test for hemoglobin (FIT)
Fecal immunochemical tests for hemoglobin (FIT) are changing the manner in which colorectal cancer (CRC) is screened. Although these tests are being performed worldwide, why is this test different from its predecessors? What evidence supports its adoption? How can this evidence best be used? This review addresses these questions and provides an understanding of FIT theory and practices to expedite international efforts to implement the use of FIT in CRC screening
- …