2,746 research outputs found
A new integrated design framework for the facility layout problem
This thesis proposes a new integrated design framework for solving facility layout problems (FLP). The most popular existing framework, Muther\u27s Systematic Layout Planning (SLP) does not address the variety of design goals associated with facility layout problems and is highly manual and so time consuming to perform. Furthermore, the SLP framework does not help the designer select a modeling tool to use in developing design alternatives, either by defining what a requisite model would include, or explicitly suggesting ones from literature. With the advancements made in academic research and computational capabilities since the development of the SLP framework, a new framework was needed to better address varying design goals, and assist designers in the selection of appropriate models. The framework proposed here guides the designer through determination of model requirements to meet their design goals by framing the FLP in terms of Design Layers . In addition, it proposes candidate models (or methodologies) to generate analytically derived solutions for design goals such as construction of simple block layouts, or determination of input/output points and flow paths in order to create detailed block layouts. The models and methodologies proposed are shown to rapidly reach good candidate solutions to a wide range of design problems
A Multi-Institutional Study of Teaching Development Opportunities & Faculty Practice
To contextualize the myriad of teaching development efforts available to faculty, this large-scale multi-institution study of nearly 4,500 faculty broadens our understandings of who participates in teaching development practices, how their participation relates to their institutional environments, and how their participation connects to their use of effective teaching practices. Results show there are some notable trends by academic field, social identity, the type of courses taught, and institutional characteristics. The overview of professional development participation in this study gives strength to positive findings from smaller-scale research studies and provides a solid base for more specific studies of these practices
Pancreas preserving distal duodenectomy: a versatile operation for a range of infra-papillary pathologies
AIM
To investigate the range of pathologies treated by pancreas preserving distal duodenectomy (PPDD) and present the outcome of follow-up.
METHODS
Neoplastic lesions of the duodenum are treated conventionally by pancreaticoduodenectomy. Lesions distal to the major papilla may be suitable for a pancreas-preserving distal duodenectomy, potentially reducing morbidity and mortality. We present our experience with this procedure. Selective intraoperative duodenoscopy assessed the relationship of the papilla to the lesion. After duodenal mobilisation and confirmation of the site of the lesion, the duodenum was transected distal to the papilla and beyond the duodenojejunal flexure and a side-to-side duodenojejunal anastomosis was formed. Patients were identified from a prospectively maintained database and outcomes determined from digital health records with a dataset including demographics, co-morbidities, mode of presentation, preoperative imaging and assessment, nutritional support needs, technical operative details, blood transfusion requirements, length of stay, pathology including lymph node yield and lymph node involvement, length of follow-up, complications and outcomes. Related published literature was also reviewed.
RESULTS
Twenty-four patients had surgery with the intent of performing PPDD from 2003 to 2016. Nineteen underwent PPDD successfully. Two patients planned for PPDD proceeded to formal pancreaticoduodenectomy (PD) while three had unresectable disease. Median post-operative follow-up was 32 mo. Pathologies resected included duodenal adenocarcinoma (n = 6), adenomas (n = 5), gastrointestinal stromal tumours (n = 4) and lipoma, bleeding duodenal diverticulum, locally advanced colonic adenocarcinoma and extrinsic compression (n = 1 each). Median postoperative length of stay (LOS) was 8 d and morbidity was low [pain and nausea/vomiting (n = 2), anastomotic stricture (n = 1), pneumonia (n = 1), and overwhelming postsplenectomy sepsis (n = 1, asplenic patient)]. PPDD was associated with a significantly shorter LOS than a contemporaneous PD series [PPDD 8 (6-14) d vs PD 11 (10-16) d, median (IQR), P = 0.026]. The 30-d mortality was zero and 16 of 19 patients are alive to date. One patient died of recurrent duodenal adenocarcinoma 18 mo postoperatively and two died of unrelated disease (at 2 mo and at 8 years respectively).
CONCLUSION
PPDD is a versatile operation that can provide definitive treatment for a range of duodenal pathologies including adenocarcinoma
The Data Analysis Pipeline for the SDSS-IV MaNGA IFU Galaxy Survey: Emission-Line Modeling
SDSS-IV MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is the
largest integral-field spectroscopy survey to date, aiming to observe a
statistically representative sample of 10,000 low-redshift galaxies. In this
paper we study the reliability of the emission-line fluxes and kinematic
properties derived by the MaNGA Data Analysis Pipeline (DAP). We describe the
algorithmic choices made in the DAP with regards to measuring emission-line
properties, and the effect of our adopted strategy of simultaneously fitting
the continuum and line emission. The effect of random errors are quantified by
studying various fit-quality metrics, idealized recovery simulations and repeat
observations. This analysis demonstrates that the emission lines are well-fit
in the vast majority of the MaNGA dataset and the derived fluxes and errors are
statistically robust. The systematic uncertainty on emission-line properties
introduced by the choice of continuum templates is also discussed. In
particular, we test the effect of using different stellar libraries and simple
stellar-population models on the derived emission-line fluxes and the effect of
introducing different tying prescriptions for the emission-line kinematics. We
show that these effects can generate large ( 0.2 dex) discrepancies at low
signal-to-noise and for lines with low equivalent width (EW); however, the
combined effect is noticeable even for H EW 6~\AA. We provide
suggestions for optimal use of the data provided by SDSS data release 15 and
propose refinements on the \DAP\ for future MaNGA data releases.Comment: accepted on A
Two Sides of a Coin: Patterns of Student & Faculty Participation in High-Impact Practices
The higher education community continues to perpetuate high-impact practices as means for improving student success. Yet, challenges exist for assuring all students participate equitably in these beneficial educational experiences; one inhibiting factor may be a lack of faculty support. We examined the responses from 12,147 faculty and 28,504 seniors at 83 institutions to better understand the relationship between faculty who emphasize or participate in high-impact practices and students who do participate. Results indicate potential inequities in faculty participation in engaging students in high-impact practices. Faculty values of importance in participation relates to whether they participate reveling implications for future conversations about faculty hiring and development
Assessing the Faculty Role in High-Impact Practices
High-impact practices are effective educational practices leveraged to improve student outcomes, and often faculty members are key to their facilitation. This session examines faculty roles in emphasizing students’ participation and engaging students in these practices. We will share characteristics of faculty who encourage and partake in these activities with an emphasis on assessment practices for gathering more information about faculty experiences with high-impact practices. Attendees will have the opportunity to learn from one another through sharing their own challenges and successes in measuring faculty involvement in high-impact practices and how they cultivate a culture of high-impact experiences on campus
Trial of Ultrasound guided carpal tunnel release versus Traditional Open Release (TUTOR)
BACKGROUND: Carpal tunnel release (CTR) is a surgical treatment option for patients with carpal tunnel syndrome (CTS) symptoms that are unresponsive to conservative treatment. Most patients experience symptomatic relief after CTR regardless of the surgical technique. However, direct comparisons of the safety and effectiveness between CTR surgical techniques are limited. The purpose of this randomized controlled trial is to compare the safety and effectiveness of CTR with ultrasound guidance (CTR-US) versus mini-open CTR (mOCTR) in subjects with symptomatic CTS.
DESIGN AND METHODS: TUTOR (Trial of Ultrasound guided CTR versus Traditional Open Release) is a randomized controlled trial in which 120 subjects at up to 12 sites in the United States will be randomized (2:1) to receive CTR-US or mOCTR. The primary endpoint of the study is the percentage of patients who return to normal daily activities within 3 days of the procedure. Secondary endpoints of the study are median time to return to normal daily activities, percentage of patients who return to work within 3 days of the procedure, median time to return to work, Boston Carpal Tunnel Questionnaire Symptom Severity Scale (BCTQ-SSS) change score at 3 months, BCTQ Functional Status Scale (BCTQ-FSS) change score at 3 months, Numeric Pain Scale change score at 3 months, EuroQoL-5 Dimension 5-Level (EQ-5D-5L) change score at 3 months, and the incidence of device- or procedure-related adverse events at 3 months. Patient follow-up in this trial will continue for 1 year.
ETHICS AND DISSEMINATION: This study was approved by a central institutional review board and ongoing trial oversight will be provided by a data safety monitoring board (DSMB). The authors intend to report the results of this trial at medical conferences and peer-reviewed journals. The outcomes of TUTOR will have important clinical and economic implications for all stakeholders involved in treating patients with CTS.
STUDY REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov): NCT05405218.
LEVEL OF EVIDENCE: 1
Cautionary Tale of Using Tris(alkyl)phosphine Reducing Agents with NAD+-Dependent Enzymes
Protein biochemistry protocols typically include disulfide bond reducing agents to guard against unwanted thiol oxidation and protein aggregation. Commonly used disulfide bond reducing agents include dithiothreitol, β-mercaptoethanol, glutathione, and the tris(alkyl)phosphine compounds tris(2-carboxyethyl)phosphine (TCEP) and tris(3-hydroxypropyl)phosphine (THPP). While studying the catalytic activity of the NAD(P)H-dependent enzyme Δ1-pyrroline-5-carboxylate reductase, we unexpectedly observed a rapid non-enzymatic chemical reaction between NAD+ and the reducing agents TCEP and THPP. The product of the reaction exhibits a maximum ultraviolet absorbance peak at 334 nm and forms with an apparent association rate constant of 231–491 M−1 s−1. The reaction is reversible, and nuclear magnetic resonance characterization (1H, 13C, and 31P) of the product revealed a covalent adduct between the phosphorus of the tris(alkyl)phosphine reducing agent and the C4 atom of the nicotinamide ring of NAD+. We also report a 1.45 Å resolution crystal structure of short-chain dehydrogenase/reductase with the NADP+–TCEP reaction product bound in the cofactor binding site, which shows that the adduct can potentially inhibit enzymes. These findings serve to caution researchers when using TCEP or THPP in experimental protocols with NAD(P)+. Because NAD(P)+-dependent oxidoreductases are widespread in nature, our results may be broadly relevant
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