150 research outputs found
Improving Serial Imaging Protocols in Spontaneous Intracerebral Hemorrhage
There is no universally agreed upon protocol to image patient presenting with intra-parenchymal hemorrhage of non-traumatic etiology (sICH). At our institution, it is common practice for a patient to have 3 CT’s done within 24 hours. They are often at onset of symptoms or presentation, 6 hours post onset of symptoms, and finally 24 hours post bleed onset.
The goal of this project will be to assess the safety and efficacy of obtaining this repeat imaging in our patients in the hopes that limiting unnecessary CT head studies will decrease resource utilization, decrease patient radiation, expedite movement of stable patients out of the ICU and/or disposition
Sphenopalatine Artery Pseudoaneurysm Formation Following Facial Trauma: A case Report and Literature Review
Facial fractures, specifically orbitozygomatic and zygomaticomaxillary complex fractures, are well-documented and common injuries. Pseudoaneurysm formation following cerebrovascular blunt trauma is a rarely experienced complication with an incidence rate of less than 1% with only a few cases reported in the literature. Traumatic pseudoaneurysm formation of the sphenopalatine artery (SPA), the deepest branch of the maxillary artery, is extremely rare due to the deep location of the SPA and its protection from bony landmarks. In craniofacial trauma, pseudoaneurysm formation is not apparent on physical examination due to its deep location and usually presents as persistent nasal bleeding. SPA pseudoaneurysms can present as complications of surgical osteotomies, endoscopic sinus surgeries, facial trauma, or even as a progression of nasopharyngeal cancer. Endovascular embolization provides, safe, quick, and effective treatment while minimizing the morbidity of extensive surgical exposure. In this case report we describe a sphenopalatine artery pseudoaneurysm formation post trauma to provide insight to these rare entities and highlight the importance of early detection and treatment
A High Resolution Study of the HI-H2 Transition across the Perseus Molecular Cloud
To investigate the fundamental principles of H2 formation in a giant
molecular cloud (GMC), we derive the HI and H2 surface density (Sigma_HI and
Sigma_H2) images of the Perseus molecular cloud on sub-pc scales (~0.4 pc). We
use the far-infrared data from the Improved Reprocessing of the IRAS Survey and
the V-band extinction image provided by the COMPLETE Survey to estimate the
dust column density image of Perseus. In combination with the HI data from the
Galactic Arecibo L-band Feed Array HI Survey and an estimate of the local
dust-to-gas ratio, we then derive the Sigma_H2 distribution across Perseus. We
find a relatively uniform Sigma_HI ~ 6-8 Msun pc^-2 for both dark and
star-forming regions, suggesting a minimum HI surface density required to
shield H2 against photodissociation. As a result, a remarkably tight and
consistent relation is found between Sigma_H2/Sigma_HI and Sigma_HI+Sigma_H2.
The transition between the HI- and H2-dominated regions occurs at N(HI)+2N(H2)
~ (8-14) x 10^20 cm^-2. Our findings are consistent with predictions for H2
formation in equilibrium, suggesting that turbulence may not be of primary
importance for H2 formation. However, the importance of a warm neutral medium
for H2 shielding, an internal radiation field, and the timescale of H2
formation still remain as open questions. We also compare H2 and CO
distributions and estimate the fraction of "CO-dark" gas, f_DG ~ 0.3. While
significant spatial variations of f_DG are found, we do not find a clear
correlation with the mean V-band extinction.Comment: updated to match the final version published in April 201
Side-chain supramolecular polymers employing conformer independent triple hydrogen bonding arrays
Derivatives of thymine have been extensively used to promote supramolecular materials assembly. Such derivatives can be synthetically challenging to access and may be susceptible to degradation. The current article uses a conformer-independent acceptor-donor-acceptor array (ureidopyrimidine) which forms moderate affinity interactions with diamidopyridine derivatives to effect supramolecular blend formation between polystyrene and poly(methyl methacrylate) polymers obtained by RAFT which have been functionalized with the hydrogen bonding motifs
Genetic Population Structure in the Antarctic Benthos: Insights from the Widespread Amphipod, Orchomenella franklini
Currently there is very limited understanding of genetic population structure in the Antarctic benthos. We conducted one of the first studies of microsatellite variation in an Antarctic benthic invertebrate, using the ubiquitous amphipod Orchomenella franklini (Walker, 1903). Seven microsatellite loci were used to assess genetic structure on three spatial scales: sites (100 s of metres), locations (1–10 kilometres) and regions (1000 s of kilometres) sampled in East Antarctica at Casey and Davis stations. Considerable genetic diversity was revealed, which varied between the two regions and also between polluted and unpolluted sites. Genetic differentiation among all populations was highly significant (FST = 0.086, RST = 0.139, p<0.001) consistent with the brooding mode of development in O. franklini. Hierarchical AMOVA revealed that the majority of the genetic subdivision occurred across the largest geographical scale, with Nem≈1 suggesting insufficient gene flow to prevent independent evolution of the two regions, i.e., Casey and Davis are effectively isolated. Isolation by distance was detected at smaller scales and indicates that gene flow in O. franklini occurs primarily through stepping-stone dispersal. Three of the microsatellite loci showed signs of selection, providing evidence that localised adaptation may occur within the Antarctic benthos. These results provide insights into processes of speciation in Antarctic brooders, and will help inform the design of spatial management initiatives recently endorsed for the Antarctic benthos
Evaluating the pedagogical effectiveness of study preregistration in the undergraduate dissertation
Research shows that questionable research practices (QRPs) are present in undergraduate final-year dissertation projects. One entry-level Open Science practice proposed to mitigate QRPs is “study preregistration,” through which researchers outline their research questions, design, method, and analysis plans before data collection and/or analysis. In this study, we aimed to empirically test the effectiveness of preregistration as a pedagogic tool in undergraduate dissertations using a quasi-experimental design. A total of 89 UK psychology students were recruited, including students who preregistered their empirical quantitative dissertation (n = 52; experimental group) and students who did not (n = 37; control group). Attitudes toward statistics, acceptance of QRPs, and perceived understanding of Open Science were measured both before and after dissertation completion. Exploratory measures included capability, opportunity, and motivation to engage with preregistration, measured at Time 1 only. This study was conducted as a Registered Report; Stage 1 protocol: https://osf.io/9hjbw (date of in-principle acceptance: September 21, 2021). Study preregistration did not significantly affect attitudes toward statistics or acceptance of QRPs. However, students who preregistered reported greater perceived understanding of Open Science concepts from Time 1 to Time 2 compared with students who did not preregister. Exploratory analyses indicated that students who preregistered reported significantly greater capability, opportunity, and motivation to preregister. Qualitative responses revealed that preregistration was perceived to improve clarity and organization of the dissertation, prevent QRPs, and promote rigor. Disadvantages and barriers included time, perceived rigidity, and need for training. These results contribute to discussions surrounding embedding Open Science principles into research training
Design, synthesis and self-assembly of hydrogen bonding motifs for materials applications
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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