338 research outputs found
An Open Guide to Data Structures and Algorithms
This textbook serves as a gentle introduction for undergraduates to theoretical concepts in data structures and algorithms in computer science while providing coverage of practical implementation (coding) issues. The field of computer science (CS) supports a multitude of essential technologies in science, engineering, and communication as a social medium. The varied and interconnected nature of computer technology permeates countless career paths making CS a popular and growing major program. Mastery of the science behind computer science relies on an understanding of the theory of algorithms and data structures. These concepts underlie the fundamental tradeoffs that dictate performance in terms of speed, memory usage, and programming complexity that separate novice programmers from professional practitioners
Response to continuing 4-H youth development in SC during a pandemic: The SC 4-H@Home program
State mandates imposed by governors during COVID-19 affected extracurricular activities for children and youth. To continue providing 4-H programming during quarantine, Clemson Extension 4-H Youth Development Agents created the SC 4-H@Home program. Daily activities were developed that could be completed at-home using common household items and were delivered via email to registered participants. A survey was conducted at the conclusion of the program that included open- and closed-ended questions to gauge the effectiveness of the program. Results indicate that, overall, the SC 4-H@Home program was beneficial to youth and contributed to their education during the COVID-19 crisis
Organometallic 3-(1H-Benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines as Potential Anticancer Agents
Early detection of SARS-CoV-2 variants through dynamic co-mutation network surveillance
BackgroundPrecise public health and clinical interventions for the COVID-19 pandemic has spurred a global rush on SARS-CoV-2 variant tracking, but current approaches to variant tracking are challenged by the flood of viral genome sequences leading to a loss of timeliness, accuracy, and reliability. Here, we devised a new co-mutation network framework, aiming to tackle these difficulties in variant surveillance.MethodsTo avoid simultaneous input and modeling of the whole large-scale data, we dynamically investigate the nucleotide covarying pattern of weekly sequences. The community detection algorithm is applied to a co-occurring genomic alteration network constructed from mutation corpora of weekly collected data. Co-mutation communities are identified, extracted, and characterized as variant markers. They contribute to the creation and weekly updates of a community-based variant dictionary tree representing SARS-CoV-2 evolution, where highly similar ones between weeks have been merged to represent the same variants. Emerging communities imply the presence of novel viral variants or new branches of existing variants. This process was benchmarked with worldwide GISAID data and validated using national level data from six COVID-19 hotspot countries.ResultsA total of 235 co-mutation communities were identified after a 120 weeks' investigation of worldwide sequence data, from March 2020 to mid-June 2022. The dictionary tree progressively developed from these communities perfectly recorded the time course of SARS-CoV-2 branching, coinciding with GISAID clades. The time-varying prevalence of these communities in the viral population showed a good match with the emergence and circulation of the variants they represented. All these benchmark results not only exhibited the methodology features but also demonstrated high efficiency in detection of the pandemic variants. When it was applied to regional variant surveillance, our method displayed significantly earlier identification of feature communities of major WHO-named SARS-CoV-2 variants in contrast with Pangolin's monitoring.ConclusionAn efficient genomic surveillance framework built from weekly co-mutation networks and a dynamic community-based variant dictionary tree enables early detection and continuous investigation of SARS-CoV-2 variants overcoming genomic data flood, aiding in the response to the COVID-19 pandemic
Panax Quinquefolium Saponins Attenuate Myocardial Dysfunction Induced by Chronic Ischemia
Background/Aims: Previous studies in rat models of myocardial ischemia showed that Panax quinquefolium saponins (PQS) could attenuate ischemic/reperfusion injury, increase vessel density and improve cardiac function. In the current study, we examined whether PQS could attenuate myocardial dysfunction in a swine model of chronic myocardial ischemia (CMI). Methods: CMI was established in Bama mini-pigs by placing amroid constrictor on the left anterior descending artery (LAD). Starting from 2 months after the surgery, pigs randomly received PQS (30 mg/kg/day), atorvastatin (1.5 mg/kg/day), or no drug for one month (n=6). A group of pigs receiving sham surgery was included as an additional control. Glucose utilization was assessed with positron emission tomography-computer tomography (PET-CT). Cardiac function was assessed with echocardiography. Myocyte size, nuclear density, and arteriolar density were examined in tissue section obtained from the ischemia area. Potential molecular targets of PQS were identified using proteomic analysis with isobaric tags for relative and absolute quantitation (iTARQ) and network pharmacology. Results: In comparison to the sham controls, pigs implanted with ameroid constrictor had decreased ventricular wall motion, left ventricular ejection fraction (LVEF), and glucose utilization. PQS significantly increased cardiac function and glucose utilization. Arteriole density and myocyte nuclear density were increased. Myocyte diameter was decreased. PQS also attenuated the CMI-induced change of protein expression profile. The effects of atorvastatin were generally similar to that of PQS. However, PQS attenuated the reduction of left ventricular systolic WT induced by CMI more robustly than atorvastatin. Conclusion: The results from the current study supports the use of PQS in patients with coronary artery disease
Lineages, Sub-Lineages and Variants of Enterovirus 68 in Recent Outbreaks
Enterovirus 68 (EV68) was first isolated in 1962. Very few cases of EV68 infection were described over the ensuing 40 years. However, in the past few years, an increase in severe respiratory tract infections associated with EV68 has been reported. We identified two clusters of EV68 infection in South London, UK, one each in the autumn/winters of 2009 and 2010. Sequence comparison showed significant homology of the UK strains with those from other countries including the Netherlands, Japan and the Philippines, which reported EV68 outbreaks between 2008 and 2010. Phylogenetic analysis of all available VP1 sequences indicated the presence of two modern EV68 lineages. The 2010 UK strains belonged to lineage 2. Lineage 1 could be further divided into two sub-lineages: some Japanese and Dutch strains collected between 2004 and 2010 form a distinct sub-lineages (sub-lineage 1.1), whereas other strains from the UK, Japan, Netherlands and Philippines collected between 2008 and 2010 represent sub-lineage 1.2. The UK 2009 strains together with several Dutch and Japanese strains from 2009/2010 represents one variant (1.2.1), whereas those from the Philippines a second variant (1.2.2). Based on specific deletions and substitutions, we suggest rules for the assignment of lineages and sub-lineages. Molecular epidemiological analysis indicates rapid recent evolution of EV68 and this may explain the recent findings of a global resurgence of EV68. Continuous global monitoring of the clinical and molecular epidemiology of EV68 is recommended
Implementation of a standardized protocol to manage elderly patients with low energy pelvic fractures: can service improvement be expected?
Purpose: The incidence of low energy pelvic fractures (FPFs) in the elderly is increasing. Comorbidities, decreased bone-quality, problematic fracture fixation and poor compliance represent some of their specific difficulties. In the absence of uniform management, a standard operating procedure (SOP) was introduced to our unit, aiming to improve the quality of services provided to these patients. Methods: A cohort study was contacted to test the impact of (1) using a specific clinical algorithm and (2) using different antiosteoporotic drugs. Multivariate regression analysis was used to determine prognostic factors. Study endpoints were the time-to-healing, length-of-stay, return to pre-injury mobility, union status, mortality and complications. Results: A total of 132 elderly patients (≥65 years) admitted during the period 2012–2014 with FPFs were enrolled. High-energy fractures, acetabular fractures, associated trauma affecting mobility, pathological pelvic lesions and operated FPFs were used as exclusion criteria. The majority of included patients were females (108/132; 81.8%), and the mean age was 85.8 years (range 67–108). Use of antiosteoporotics was associated with a shorter time of healing (p = 0.036). Patients treated according to the algorithm showed a significant protection against malunion (p < 0.001). Also, adherence to the algorithm allowed more patients to return to their pre-injury mobility status (p = 0.039). Conclusions: The use of antiosteoporotic medication in elderly patients with fragility pelvic fractures was associated with faster healing, whilst the adherence to a structured clinical pathway led to less malunions and non-unions and return to pre-injury mobility state
A carotenoid-deficient mutant in Pantoea sp. YR343, a bacteria isolated from the Rhizosphere of Populus deltoides, is defective in root colonization
The complex interactions between plants and their microbiome can have a profound effect on the health and productivity of the plant host. A better understanding of the microbial mechanisms that promote plant health and stress tolerance will enable strategies for improving the productivity of economically important plants. Pantoea sp. YR343 is a motile, rod-shaped bacterium isolated from the roots of Populus deltoides that possesses the ability to solubilize phosphate and produce the phytohormone indole-3-acetic acid (IAA). Pantoea sp. YR343 readily colonizes plant roots and does not appear to be pathogenic when applied to the leaves or roots of selected plant hosts. To better understand the molecular mechanisms involved in plant association and rhizosphere survival by Pantoea sp. YR343, we constructed a mutant in which the crtB gene encoding phytoene synthase was deleted. Phytoene synthase is responsible for converting geranylgeranyl pyrophosphate to phytoene, an important precursor to the production of carotenoids. As predicted, the ΔcrtB mutant is defective in carotenoid production, and shows increased sensitivity to oxidative stress. Moreover, we find that the ΔcrtB mutant is impaired in biofilm formation and production of IAA. Finally we demonstrate that the ΔcrtB mutant shows reduced colonization of plant roots. Taken together, these data suggest that carotenoids are important for plant association and/or rhizosphere survival in Pantoea sp. YR343.Work at the University of Notre Dame was supported by DOE grant SC0006642 (RM) and by a subcontract from Oak Ridge National Laboratory (SP).http://www.frontiersin.orgam2016Microbiology and Plant Patholog
The DNA Methylation Inhibitor Zebularine Controls CD4+ T Cell Mediated Intraocular Inflammation
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