Scalable Hyperparameter Selection for Latent Dirichlet Allocation

Latent Dirichlet allocation (LDA) is a heavily used Bayesian hierarchical model used in machine learning for modeling high-dimensional sparse count data, for example, text documents. As a Bayesian model, it incorporates a prior on a set of latent variables. The prior is indexed by some hyperparameters, which have a big impact on inference regarding the model. The ideal estimate of the hyperparameters is the empirical Bayes estimate which is, by definition, the maximizer of the marginal likelihood of the data with all the latent variables integrated out. This estimate cannot be obtained analytically. In practice, the hyperparameters are chosen either in an ad-hoc manner, or through some variants of the EM algorithm for which the theoretical basis is weak. We propose an MCMC-based fully Bayesian method for obtaining the empirical Bayes estimate of the hyperparameter. We compare our method with other existing approaches both on synthetic and real data. The comparative experiments demonstrate that the LDA model with hyperparameters specified by our method outperforms models with the hyperparameters estimated by other methods. Supplementary materials for this article are available online.</p

Effect of perineum protection cooperated by two operators in the forceps-assisted vaginal delivery: a case-control study

Objective: To investigate the effect of unique skill of perineum protection in forceps delivery on the maternal and neonatal morbidity. Methods: A case-control study was conducted. Singleton pregnancies with forceps-assisted and normal vaginal deliveries were recruited. The maternal and neonatal complications were compared between forceps and normal deliveries. Results: Five hundred forty participants were included. The prevalence of maternal anal sphincter injury, postpartum hemorrhage, vaginal hematoma, cervical laceration, perineal wound infection, perineal wound dehiscence, dyspareunia, urinary incontinence, and anal incontinence were not significantly different between forceps and normal deliveries (p > .05). However, the rate of neonatal facial injury was higher in the forceps group (2.9% versus 0, p = .004). Conclusions: Cooperation according to the tension of perineum and labor process between obstetrician and midwife is important for perineum protection. Forceps-assisted delivery concentrating on perineum protection is an effective alternative in decreasing maternal morbidity.</p

Supplementary_figure_2 - High <i>BIRC7</i> Expression Might Be an Independent Prognostic Indicator of Poor Recurrence-Free Survival in Patients With Prostate Cancer

Supplementary_figure_2 for High BIRC7 Expression Might Be an Independent Prognostic Indicator of Poor Recurrence-Free Survival in Patients With Prostate Cancer by Yi Yang, Peng Sun, Wei Xu, and Wei Xia in Technology in Cancer Research & Treatment</p

Reactions of Boratabenzene Yttrium Complexes with KN(SiMe₃)₂: Salt Elimination and π-Ligand Displacement

Several solvent-free boratabenzene yttrium chlorides were synthesized and structurally characterized. Their reactions with KN(SiMe3)2 first gave boratabenzene yttrium amides; the latter reacted further with KN(SiMe3)2, which results in π-ligand displacement. The boratabenzene yttrium amides showed good catalytic activities for intramolecular hydroamination

Unusual Regioselectivity of Pd(0)-Catalyzed Coupling Reaction of Electron-Deficient Alkenyl Halides with Allenic/Propargylic Zinc Reagents. Highly Selective Synthesis of 6-Phenylhex-5-yn-2(or 3)-enoates/Enitrile and 4-Phenyl-6-substituted-hexa-2,4,5-trienoates

The Pd(0)-catalyzed coupling reaction of electron-deficient alkenyl halides with the organozinc formed by the subsequent treatment of 1-phenylalk-1-yne with n-BuLi and ZnBr2 with or without a catalytic amount of HgCl2 was studied. Both the allene-formation- and the alkyne-formation-type coupling reactions were observed with high regio- and stereoselectivity:  the reaction of 1-phenylprop-1-yne afforded 6-phenylhex-5-yn-2(or 3)-enoates and -enitriles, while the reaction of 1-phenylhex-1-yne formed 4-phenyl-6-substituted-hexa-2,4,5-trienoates. A plausible explanation for the regioselectivity was discussed. The double bonds in 6-phenylhex-5-yn-2-enoates were prone to migrate to the position conjugated with the carbon−carbon triple bonds to form 6-phenylhex-5-yn-3-enoates at higher temperature. The migration did not occur in absence of an excess amount of allenic/propargylic zinc reagent or at low temperature

Identification and Characterization of a Metalloprotein Involved in Gallium Internalization in <i>Pseudomonas aeruginosa</i>

Gallium nitrate (Ganite) is a potential drug for the treatment of Pseudomonas aeruginosa infection. CRISPR/Cas9-based gene mutagenesis studies reveal that siderophore pyochelin-facilitated uptake and an ABC transporter are two major Ga3+ internalization pathways in Pseudomonas aeruginosa (P. aeruginosa). Crystal structures reveal that Ga3+ and Fe3+ occupy exactly the same metal site of HitA, a periplasmic iron-binding protein of the ABC transporter system. The study provides a molecular basis for Ga3+ internalization by P. aeruginosa and facilitates gallium-based antimicrobial drug development

Synthesis and Structural Features of Boratabenzene Rare-Earth Metal Alkyl Complexes

A series of solvent-free boratabenzene rare-earth metal alkyl complexes (C5H5BR)2LnCH(SiMe3)2 (9: R = NEt2, Ln = Y; 10: R = NPh2, Ln = Y; 11: R = CH3, Ln = Y; 12: R = NPh2, Ln = Sm; 13: R = NPh2, Ln = Dy; 14: R = NEt2, Ln = Lu; 15: R = NPh2, Ln = Lu; 16: R = Me, Ln = Lu) were synthesized. The solid-state structures of 10, 13, and 15 were determined by single-crystal X-ray diffraction. The crystal structures of 10, 13, and 15 feature highly unsymmetrical coordination of the alkyl ligands and short Ln−C(alkyl) distances. The diamagnetic yttrium and lutetium alkyl complexes, 9−11 and 14−16, were characterized by (1H, 13C, 11B) NMR spectroscopy. The Ln−CαHα (1H NMR: δ 0.68−0.99 ppm) and Ln−CαHα (13C NMR: δ 33.9−39.1 ppm) resonances of these boratabenzene rare-earth metal alkyl complexes are rather downfield in comparison with those of the bis-Cp rare-earth metal alkyl complexes. 89Y NMR spectra of the boratabenzene yttrium alkyl complexes 9−11 and the Cp complex (C5H4Me)2YCH(SiMe3)2 were recorded. The 89Y NMR chemical shifts for 9, 10, and 11 are 176.1, 170.0, and 162.2 ppm, respectively, which are significantly downfield in comparison with that of (C5H4Me)2YCH(SiMe3)2 (44.0 ppm)

Table3_Bioinformatics analysis of the common targets of miR-223-3p, miR-122-5p, and miR-93-5p in polycystic ovarian syndrome.XLSX

Polycystic ovarian syndrome (PCOS) is one of the most common gynecological endocrine disorders. MicroRNAs (miRNAs) play extensive roles in the pathogenesis of PCOS and can serve as potential diagnostic markers. However, most studies focused on the regulatory mechanisms of individual miRNAs, and the combined regulatory effects of multiple miRNAs remain unclear. The aim of this study was to identify the common targets of miR-223-3p, miR-122-5p, and miR-93-5p; and assess the transcript levels of some of these targets in PCOS rat ovaries. Transcriptome profiles of granulosa cells from PCOS patients were obtained from the Gene Expression Omnibus (GEO) database to identify differentially expressed genes (DEGs). A total of 1,144 DEGs were screened, 204 of which were upregulated and 940 were downregulated. According to the miRWalk algorithm, 4,284 genes were targeted by all three miRNAs at the same time, and intersection with DEGs was used to obtain candidate target genes. A total of 265 candidate target genes were screened, and the detected target genes were subjected to Gene ontology (GO) and KEGG pathway enrichment, followed by PPI network analysis. Then, qRT-PCR was used to determine the levels of 12 genes in PCOS rat ovaries. The expressions of 10 of these genes were found to be consistent with our bioinformatics results. In conclusion, JMJD1C, PLCG2, SMAD3, FOSL2, TGFB1, TRIB1, GAS7, TRIM25, NFYA, and CALCRL may participate in the development of PCOS. Our findings contribute to the identification of biomarkers that may promote the effective prevention and treatment of PCOS in the future.</p

New ¹H NMR-Based Technique To Determine Epoxide Concentrations in Oxidized Oil

A new method to determine epoxide concentrations in oxidized oils was developed and validated using ¹H NMR. Epoxides derived from lipid oxidation gave signals between 2.90 and 3.24 ppm, well separated from the signals of other lipid oxidation products. To calibrate, soybean oils with a range of epoxide concentrations were synthesized and analyzed using ¹H NMR by taking the <i>sn</i>-1,3 glycerol protons (4.18, 4.33 ppm) as internal references. The ¹H NMR signals were compared to the epoxide content determined by titration with hydrogen bromide (HBr)–acetic acid solution. As expected, the signal response increased with concentration linearly (<i>R</i>² = 99.96%), and validation of the method gave results comparable to those of the HBr method. A study of the oxidative stability of soybean oil was performed by applying this method to monitor epoxides during thermal lipid oxidation. The epoxide content increased over time and showed a different trend compared to peroxide value (PV). A phenomenological model was suggested to model epoxides derived from lipid oxidation

S100B levels in human milk were closely correlated with BMI.

<p>The solid line represents the predicted regression line determined from measures analysis of human milk collected 3 days after birth. Pearson correlation coefficient (<i>r</i>) was 0.335. <i>P</i><0.05. n = 42.</p