Random Forest as a Predictive Analytics Alternative to Regression in Institutional Research

In institutional research, modern data mining approaches are seldom considered to address predictive analytics problems. The goal of this paper is to highlight the advantages of tree-based machine learning algorithms over classic (logistic) regression methods for data-informed decision making in higher education problems, and stress the success of random forest in circumstances where the regression assumptions are often violated in big data applications. Random forest is a model averaging procedure where each tree is constructed based on a bootstrap sample of the data set. In particular, we emphasize the ease of application, low computational cost, high predictive accuracy, flexibility, and interpretability of random forest machinery. Our overall recommendation is that institutional researchers look beyond classical regression and single decision tree analytics tools, and consider random forest as the predominant method for prediction tasks. The proposed points of view are detailed and illustrated through a simulation experiment and analyses of data from real institutional research projects. Accessed 3,712 times on https://pareonline.net from January 13, 2018 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Fast Estimation of Leakage Area in a Multizone Test Facility

The effects of building leakage on heat and mass transfer in buildings are difficult to model due to the difficulty in knowing crack size, shape, position, and number. Nevertheless, interest remains high in the estimation of crack areas in buildings because of the important effects cracks have on infiltration, indoor air quality, building energy performance, and because of interest in exploring mitigation/ventilation strategies. We show how a steady-state model is developed that can provide fast estimation of the crack areas for a test facility. The facility is then modeled in CONTAM to perform simulations and make prediction of overpressure values using the set of estimated crack areas determined from the above model. Comparisons are made between the CONTAM model predictions and experimental results in terms of overpressure, and good agreement is achieved. The experimental overpressure ranges from 3 Pa to 155 Pa, covering the normal range of overpressure in commercial and residential buildings. The method outlined in the present work can be extended to estimate crack areas of the openings in multizone pressurization tests. Further, this method holds promise in filling the knowledge gap of interzonal leakage in multizone buildings

Angiotensin II upregulates the expression of placental growth factor in human vascular endothelial cells and smooth muscle cells

<p>Abstract</p> <p>Background</p> <p>Atherosclerosis is now recognized as a chronic inflammatory disease. Angiotensin II (Ang II) is a critical factor in inflammatory responses, which promotes the pathogenesis of atherosclerosis. Placental growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family cytokines and is associated with inflammatory progress of atherosclerosis. However, the potential link between PlGF and Ang II has not been investigated. In the current study, whether Ang II could regulate PlGF expression, and the effect of PlGF on cell proliferation, was investigated in human vascular endothelial cells (VECs) and smooth muscle cells (VSMCs).</p> <p>Results</p> <p>In growth-arrested human VECs and VSMCs, Ang II induced PlGF mRNA expression after 4 hour treatment, and peaked at 24 hours. 10^-6mol/L Ang II increased PlGF protein production after 8 hour treatment, and peaked at 24 hours. Stimulation with Ang II also induced mRNA expression of VEGF receptor-1 and -2(VEGFR-1 and -2) in these cells. The Ang II type I receptor (AT₁R) antagonist blocked Ang II-induced PlGF gene expression and protein production. Several intracellular signals elicited by Ang II were involved in PlGF synthesis, including activation of protein kinase C, extracellular signal-regulated kinase 1/2 (ERK1/2) and PI3-kinase. A neutralizing antibody against PlGF partially inhibited the Ang II-induced proliferation of VECs and VSMCs. However, this antibody showed little effect on the basal proliferation in these cells, whereas blocking antibody of VEGF could suppress both basal and Ang II-induced proliferation in VECs and VSMCs.</p> <p>Conclusion</p> <p>Our results showed for the first time that Ang II could induce the gene expression and protein production of PlGF in VECs and VSMCs, which might play an important role in the pathogenesis of vascular inflammation and atherosclerosis.</p

Direct and negative regulation of the sycO-ypkA-ypoJ operon by cyclic AMP receptor protein (CRP) in Yersinia pestis

<p>Abstract</p> <p>Background</p> <p>Pathogenic yersiniae, including <it>Y. pestis</it>, share a type III secretion system (T3SS) that is composed of a secretion machinery, a set of translocation proteins, a control system, and six Yop effector proteins including YpkA and YopJ. The cyclic AMP receptor protein (CRP), a global regulator, was recently found to regulate the laterally acquired genes (<it>pla </it>and <it>pst</it>) in <it>Y. pestis</it>. The regulation of T3SS components by CRP is unknown.</p> <p>Results</p> <p>The <it>sycO</it>, <it>ypkA </it>and <it>yopJ </it>genes constitute a single operon in <it>Y. pestis</it>. CRP specifically binds to the promoter-proximate region of <it>sycO</it>, and represses the expression of the <it>sycO-ypkA-yopJ </it>operon. A single CRP-dependent promoter is employed for the <it>sycO-ypkA-yopJ </it>operon, but two CRP binding sites (site 1 and site 2) are detected within the promoter region. A CRP box homologue is found in site 1 other than site 2. The determination of CRP-binding sites, transcription start site and core promoter element (-10 and -35 regions) promotes us to depict the structural organization of CRP-dependent promoter, giving a map of CRP-promoter DNA interaction for <it>sycO-ypkA-yopJ</it>.</p> <p>Conclusion</p> <p>The <it>sycO-ypkA-yopJ </it>operon is under the direct and negative regulation of CRP in <it>Y. pestis</it>. The <it>sycO-ypkA-yopJ </it>promoter-proximate regions are extremely conserved in <it>Y. pestis</it>, <it>Y. pseudotuberculosis </it>and <it>Y. enterocolitica</it>. Therefore, data presented here can be generally applied to the above three pathogenic yersiniae.</p

Resting-state functional magnetic resonance imaging reveals brain remodeling after Tuina therapy in neuropathic pain model

Tuina, a method of traditional Chinese manual manipulation, is an effective alternative therapy for neuropathic pain (NP), but its analgesic mechanism remains unclear. In this study, we used resting-state functional magnetic resonance imaging (R-fMRI) to explore the analgesic mechanism of Tuina in an NP rat model. After undergoing surgery to induce chronic compression of the dorsal root ganglion (CCD), one group of rats underwent Tuina at the ipsilateral BL40 acupoint once a day for 10 min during the 25 days following surgery while another group did not. Behavioral tests were performed at baseline, on the third day following surgery, and once a week for the next 4 weeks. R-fMRI was performed at baseline and 7 days and 28 days following surgery. Behavioral testing revealed that the Tuina group presented a significant response improvement to mechanical and thermal nociception stimuli compared to the untreated group 2 weeks following CCD surgery. Interestingly, rats submitted to Tuina presented higher measures of spontaneous neuronal activity in basal forebrain region, primary somatosensory cortex barrel field, dentate gyrus, secondary somatosensory cortex, striatum, descending corticofugal pathways, and globus pallidum of the left hemisphere 4 weeks after the CCD surgery compared to rats having undergone CCD only. In addition, on the 28th day, the ALFF signals of the left dentate gyrus, left secondary somatosensory cortex, left striatum, and bilateral primary cingulate cortex were significantly increased while those in the right dentate gyrus and bilateral periaqueductal gray were significantly decreased compared to those on the 7th day. Correlation analysis showed that the ALFF values of the left descending corticofugal pathways and globus pallidum had a positive correlation with mechanical withdrawal threshold and paw withdrawal thermal latency tests. Altogether, these results indicate that NPP induced by CCD surgery affects the plasticity of the cerebral cortex, and that Tuina alleviate pain behavior by promoting cortical remodeling

Mutual exclusivity of hyaluronan and hyaluronidase in invasive group A Streptococcus

A recent analysis of group A Streptococcus (GAS) invasive infections in Australia has shown a predominance of M4 GAS, a serotype recently reported to lack the antiphagocytic hyaluronic acid (HA) capsule. Here, we use molecular genetics and bioinformatics techniques to characterize 17 clinical M4 isolates associated with invasive disease in children during this recent epidemiology. All M4 isolates lacked HA capsule, and whole genome sequence analysis of two isolates revealed the complete absence of the hasABC capsule biosynthesis operon. Conversely, M4 isolates possess a functional HA-degrading hyaluronate lyase (HylA) enzyme that is rendered nonfunctional in other GAS through a point mutation. Transformation with a plasmid expressing hasABC restored partial encapsulation in wild-type (WT) M4 GAS, and full encapsulation in an isogenic M4 mutant lacking HylA. However, partial encapsulation reduced binding to human complement regulatory protein C4BP, did not enhance survival in whole human blood, and did not increase virulence of WT M4 GAS in a mouse model of systemic infection. Bioinformatics analysis found no hasABC homologs in closely related species, suggesting that this operon was a recent acquisition. These data showcase a mutually exclusive interaction of HA capsule and active HylA among strains of this leading human pathogen