Airbnb Price Prediction with Sentiment Classification

Airbnb is an online platform that provides arrangements for short-term local home renting services. It is a challenging task for the house owner to price a rental home and attract customers. Customers also need to evaluate the price of the rental property based on the listing details. This paper demonstrates several existing Airbnb price prediction models using machine learning and external data to improve the prediction accuracy. It also discusses machine learning and neural network models that are commonly used for price prediction. The goal of this paper is to build a price prediction model using machine learning and sentiment analysis techniques to help hosts and customers to price the house and evaluate the offered price. Other than using only the numerical data to build the model, customer review is another factor that affects the house pricing. Sentiment analysis techniques, such as Textblob, are also introduced in this project. Compared with using the numerical score of sentiment analysis from customer reviews, we classify sentiments into three types: positive, neutral, and negative. We observe that using classified sentiments with Regression Tree provides a more accurate prediction result compared with using numerical sentiment scores

Pih1p-Tah1p puts a lid on hexameric AAA+ ATPases Rvb1/2p

Accepted author manuscriptThe Saccharomyces cerevisiae (Sc) R2TP complex affords an Hsp90-mediated and nucleotide-driven chaperone activity to proteins of small ribonucleoprotein particles (snoRNPs). The current lack of structural information on the ScR2TP complex, however, prevents a mechanistic understanding of this biological process. We characterized the structure of the ScR2TP complex made up of two AAA+ ATPases, Rvb1/2p, and two Hsp90 binding proteins, Tah1p and Pih1p, and its interaction with the snoRNP protein Nop58p by a combination of analytical ultracentrifugation, isothermal titration calorimetry, chemical crosslinking, hydrogen-deuterium exchange, and cryoelectron microscopy methods. We find that Pih1p-Tah1p interacts with Rvb1/2p cooperatively through the nucleotide-sensitive domain of Rvb1/2p. Nop58p further binds Pih1p-Tahp1 on top of the dome-shaped R2TP. Consequently, nucleotide binding releases Pih1p-Tah1p from Rvb1/2p, which offers a mechanism for nucleotide-driven binding and release of snoRNP intermediates.Ye

Inhibition of IRAK 1/4 alleviates colitis by inhibiting TLR4/ NF-κB pathway and protecting the intestinal barrier

Interleukin-1 receptor-associated kinase 1/4 (IRAK1/4) is the main kinase of the Toll-like receptor (TLR)-mediated pathway, considered a new target for treating inflammatory diseases. Studies showed a significant correlation between TLRs and inflammatory responses in ulcerative colitis (UC). Therefore, in this study, after inducing experimental colitis in mice with 3% dextran sulfate sodium (DSS), different concentrations of IRAK1/4 inhibitors were administered intraperitoneally. Then, the disease activity index was assessed, including the degree of pathological damage, by HE staining. Subsequently, while western blotting detected the TLR4/NF-κB pathway and intestinal barrier protein expression (Zonula-1, Occludin, Claudin-1, JAM-A), real-time polymerase chain reaction (RT-PCR) detected the mRNA expression levels of IRAK1/4 and mucin1/2. Furthermore, the expression levels of Zonula-1 and occludin were detected by immunofluorescence, including the plasma FITC-dextran 4000 concentration, to evaluate intestinal barrier permeability. However, ELISA measured the expression of inflammatory factors to reflect intestinal inflammation in mice. Investigations showed that the IRAK 1/4 inhibitor significantly reduced clinical symptoms and pathological DSS-induced colitis damage in mice and then inhibited the cytoplasmic and nuclear translocation of NF-κB p65, including the phosphorylation of IκBα and reduction in downstream inflammatory factor production. Therefore, we established that the IRAK1/4 inhibitor effectively improves colitis induced by DSS, partly by inhibiting the TLR4/NF-κB pathway, reducing inflammation, and maintaining the integrity of the colonic barrier

Fc galactosylation follows consecutive reaction kinetics and enhances immunoglobulin G hexamerization for complement activation

Fc galactosylation is a critical quality attribute for anti-tumor recombinant immunoglobulin G (IgG)-based monoclonal antibody (mAb) therapeutics with complement-dependent cytotoxicity (CDC) as the mechanism of action. Although the correlation between galactosylation and CDC has been known, the underlying structure–function relationship is unclear. Heterogeneity of the Fc N-glycosylation produced by Chinese hamster ovary (CHO) cell culture biomanufacturing process leads to variable CDC potency. Here, we derived a kinetic model of galactose transfer reaction in the Golgi apparatus and used this model to determine the correlation between differently galactosylated species from CHO cell culture process. The model was validated by a retrospective data analysis of more than 800 historical samples from small-scale and large-scale CHO cell cultures. Furthermore, using various analytical technologies, we discovered the molecular basis for Fc glycan terminal galactosylation changing the three-dimensional conformation of the Fc, which facilitates the IgG1 hexamerization, thus enhancing C1q avidity and subsequent complement activation. Our study offers insight into the formation of galactosylated species, as well as a novel three-dimensional understanding of the structure–function relationship of terminal galactose to complement activation in mAb therapeutics

Function-structure approach reveals novel insights on the interplay of Immunoglobulin G 1 proteoforms and Fc gamma receptor IIa allotypes

Human Fc gamma receptor IIa (FcγRIIa) or CD32a has two major allotypes with a single amino acid difference at position 131 (histidine or arginine). Differences in FcγRIIa allotypes are known to impact immunological responses such as the clinical outcome of therapeutic monoclonal antibodies (mAbs). FcγRIIa is involved in antibody-dependent cellular phagocytosis (ADCP), which is an important contributor to the mechanism-of-action of mAbs by driving phagocytic clearance of cancer cells. Hence, understanding the impact of individual mAb proteoforms on the binding to FcγRIIa, and its different allotypes, is crucial for defining meaningful critical quality attributes (CQAs). Here, we report a function-structure based approach guided by novel FcγRIIa affinity chromatography-mass spectrometry (AC-MS) assays to assess individual IgG1 proteoforms. This allowed to unravel allotype-specific differences of IgG1 proteoforms on FcγRIIa binding. FcγRIIa AC-MS confirmed and refined structure-function relationships of IgG1 glycoform interactions. For example, the positive impact of afucosylation was higher than galactosylation for FcγRIIa Arg compared to FcγRIIa His. Moreover, we observed FcγRIIa allotype-opposing and IgG1 proteoform integrity-dependent differences in the binding response of stress-induced IgG1 proteoforms comprising asparagine 325 deamidation. The FcγRIIa-allotype dependent binding differences resolved by AC-MS were in line with functional ADCP-surrogate bioassay models. The molecular basis of the observed allotype specificity and proteoform selectivity upon asparagine 325 deamidation was elucidated using molecular dynamics. The observed differences were attributed to the contributions of an inter-molecular salt bridge between IgG1 and FcγRIIa Arg and the contribution of an intra-molecular hydrophobic pocket in IgG1. Our work highlights the unprecedented structural and functional resolution of AC-MS approaches along with predictive biological significance of observed affinity differences within relevant cell-based methods. This makes FcγRIIa AC-MS an invaluable tool to streamline the CQA assessment of therapeutic mAbs

Implementation of High Time Delay Accuracy of Ultrasonic Phased Array Based on Interpolation CIC Filter

In order to improve the accuracy of ultrasonic phased array focusing time delay, analyzing the original interpolation Cascade-Integrator-Comb (CIC) filter, an 8× interpolation CIC filter parallel algorithm was proposed, so that interpolation and multichannel decomposition can simultaneously process. Moreover, we summarized the general formula of arbitrary multiple interpolation CIC filter parallel algorithm and established an ultrasonic phased array focusing time delay system based on 8× interpolation CIC filter parallel algorithm. Improving the algorithmic structure, 12.5% of addition and 29.2% of multiplication was reduced, meanwhile the speed of computation is still very fast. Considering the existing problems of the CIC filter, we compensated the CIC filter; the compensated CIC filter’s pass band is flatter, the transition band becomes steep, and the stop band attenuation increases. Finally, we verified the feasibility of this algorithm on Field Programming Gate Array (FPGA). In the case of system clock is 125 MHz, after 8× interpolation filtering and decomposition, time delay accuracy of the defect echo becomes 1 ns. Simulation and experimental results both show that the algorithm we proposed has strong feasibility. Because of the fast calculation, small computational amount and high resolution, this algorithm is especially suitable for applications with high time delay accuracy and fast detection

Cardiac Strain Imaging Using Multi-Perspective Ultrafast Ultrasound

The heart is a complex organ with a high level of deformation occurring in different directions. Ultrasound imaging has proven to be a valuable tool to quantify these deformations. However, strain is not always measured accurately in vital parts of the heart when only using a single probe, even at a high frame rate, because of the anisotropic spatial resolution and contrast. Therefore, a multi-perspective ultrafast ultrasound (US) strain imaging method was developed, aiming at investigating improvements in strain while operating two probes at different relative angles. In an ex-vivo experiment of a beating porcine heart, parasternal short axis views of the left ventricle (LV) were acquired by two phased array probes with different relative angles (30°–75°) at a frame rate of 170 frames per second (FPS). A fully automatic registration algorithm was developed to register the image datasets for all cases. Next, radio frequency (RF) based strain imaging was performed. Axial displacements were compounded based on the unit axial vectors of the dual probes to improve motion tracking and strain estimation. After performing multi-perspective strain imaging, compounded radial and circumferential strain both improve compared to single probe strain imaging. While increasing the inter-probe angle from 30° to 75°, the mean tracking error (ME), mean drift error (MDE) and strain variability (SV) decreased, and signal-to-noise ratio (SNRe) increased for both strain components. For the largest angle (75°), large reductions in ME (−42%), MDE (−50%) and SV (−48%) were observed. The SNRe increased by 253 and 39% for radial and circumferential strain, respectively, and strain curves revealed less noise for each region. In summary, a multi-perspective ultrafast US strain imaging method was introduced to improve cardiac strain estimation in an ex-vivo beating porcine heart setup

Polar Lipid Composition of Biodiesel Algae Candidates <i>Nannochloropsis oculata</i> and <i>Haematococcus pluvialis</i> from Nano Liquid Chromatography Coupled with Negative Electrospray Ionization 14.5 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Algae lipids contain long-chain saturated and polyunsaturated fatty acids. The lipids may be transesterified to generate biodiesel fuel. Here, we compare polar lipid compositions for two microalgae, <i>Nannochloropsis oculata</i> and <i>Haematococcus pluvialis</i>, that are prospective lipid-rich feedstock candidates for an emerging biodiesel industry. Online nano liquid chromatography coupled with negative electrospray ionization 14.5 T Fourier transform ion cyclotron resonance mass spectrometry ((−)­ESI FT-ICR MS) with newly modified ion optics provides ultrahigh mass accuracy and resolving power to identify hundreds of unique elemental compositions. Assignments are confirmed by isotopic fine structure for a polar lipid extract. Collision-induced-dissociation (CID) MS/MS provides additional structural information. <i>H. pluvialis</i> exhibits more highly polyunsaturated lipids than does <i>N. oculata</i>

High frame rate multi-perspective cardiac ultrasound imaging using phased array probes

Ultrasound (US) imaging is used to assess cardiac disease by assessing the geometry and function of the heart utilizing its high spatial and temporal resolution. However, because of physical constraints, drawbacks of US include limited field-of-view, refraction, resolution and contrast anisotropy. These issues cannot be resolved when using a single probe. Here, an interleaved multi-perspective 2-D US imaging system was introduced, aiming at improved imaging of the left ventricle (LV) of the heart by acquiring US data from two separate phased array probes simultaneously at a high frame rate. In an ex-vivo experiment of a beating porcine heart, parasternal long-axis and apical views of the left ventricle were acquired using two phased array probes. Interleaved multi-probe US data were acquired at a frame rate of 170 frames per second (FPS) using diverging wave imaging under 11 angles. Image registration and fusion algorithms were developed to align and fuse the US images from two different probes. First- and second-order speckle statistics were computed to characterize the resulting probability distribution function and point spread function of the multi-probe image data. First-order speckle analysis showed less overlap of the histograms (reduction of 34.4%) and higher contrast-to-noise ratio (CNR, increase of 27.3%) between endocardium and myocardium in the fused images. Autocorrelation results showed an improved and more isotropic resolution for the multi-perspective images (single-perspective: 0.59 mm × 0.21 mm, multi-perspective: 0.35 mm × 0.18 mm). Moreover, mean gradient (MG) (increase of 74.4%) and entropy (increase of 23.1%) results indicated that image details of the myocardial tissue can be better observed after fusion. To conclude, interleaved multi-perspective high frame rate US imaging was developed and demonstrated in an ex-vivo experimental setup, revealing enlarged field-of-view, and improved image contrast and resolution of cardiac images