Sampling Random Spanning Trees Faster than Matrix Multiplication

We present an algorithm that, with high probability, generates a random spanning tree from an edge-weighted undirected graph in $\tilde{O}(n^{4/3}m^{1/2}+n^{2})$ time (The $\tilde{O}(\cdot)$ notation hides $\operatorname{polylog}(n)$ factors). The tree is sampled from a distribution where the probability of each tree is proportional to the product of its edge weights. This improves upon the previous best algorithm due to Colbourn et al. that runs in matrix multiplication time, $O(n^\omega)$. For the special case of unweighted graphs, this improves upon the best previously known running time of $\tilde{O}(\min\{n^{\omega},m\sqrt{n},m^{4/3}\})$ for $m \gg n^{5/3}$ (Colbourn et al. '96, Kelner-Madry '09, Madry et al. '15). The effective resistance metric is essential to our algorithm, as in the work of Madry et al., but we eschew determinant-based and random walk-based techniques used by previous algorithms. Instead, our algorithm is based on Gaussian elimination, and the fact that effective resistance is preserved in the graph resulting from eliminating a subset of vertices (called a Schur complement). As part of our algorithm, we show how to compute $\epsilon$-approximate effective resistances for a set $S$ of vertex pairs via approximate Schur complements in $\tilde{O}(m+(n + |S|)\epsilon^{-2})$ time, without using the Johnson-Lindenstrauss lemma which requires $\tilde{O}( \min\{(m + |S|)\epsilon^{-2}, m+n\epsilon^{-4} +|S|\epsilon^{-2}\})$ time. We combine this approximation procedure with an error correction procedure for handing edges where our estimate isn't sufficiently accurate

Use of mifepristone for termination of intrauterine fetal demise (IUFD) in previously scarred uterus in later half of pregnancy (>20 weeks)

Background: Mifepristone has the potential to be used as an agent for induction of labour by increasing the uterine contractility and increasing the sensitivity of uterus to prostaglandins. The present study is an endeavor to study the effect of mifepristone alone to induce labour in scarred uterus and its risk benefit ratio.Methods: Total 39 patients with IUFD and previous uterine surgery were included in the study after their informed consent. All women in the study were given Tablet Mifepristone 200 mg orally, thrice a day, maximum 6 doses (Max -1200 mg) over a duration of 48 hours. Patients were monitored for vitals, the uterine contractions and any bleeding per vaginum. Next dose of drug was omitted if sufficient uterine contractions or cervical dilatation ≥2.5 cm achieved. Patients were shifted to the labour room after onset of active labour. Labour was augmented with oxytocin wherever required.Results: spontaneous labour occurred in 74.3% (29/39) women while operative (cesarean/ hysterotomy) delivery occurred in 17.9% (07/39). Mean induction (first dose of mifepristone) to delivery interval was 51.5 hrs in second trimester while 59.8 hrs in third trimester women. Oxytocin augmentation was done in 8 (20.5 %) women.Conclusions: The potential advantage of mifepristone over prostaglandins and oxytocin, is mainly in situations where they are contraindicated (i.e., scarred uterus). In this study authors found that with mifepristone only regimen is quite safe and effective, inducing spontaneous labour in 74.3% (29/39) women with IUFD and in reducing the operative (cesarean/ hysterotomy) delivery (17.9%)

The Dynamic Shift to Green Chemistry: Investigating the Spectral Behavior of Natural Deep Eutectic Solvents (NADES) and their Performance as MALDI-TOF Matrices

https://tigerprints.clemson.edu/csrp/1013/thumbnail.jp

Enhanced Anticancer Activity of Gemcitabine in Combination with Noscapine via Antiangiogenic and Apoptotic Pathway against Non-Small Cell Lung Cancer

BACKGROUND:The aim of this investigation was to evaluate the anticancer activity of Noscapine (Nos) and Gemcitabine (Gem) combination (NGC) against non-small cell lung cancer (NSCLC) and to elucidate the underlying mechanism of action. METHODS:Isobolographic method was used to calculate combination index values from cytotoxicity data. In vitro antiangiogenic and apoptotic activity of Nos, Gem and NGC was evaluated. For in vivo studies, female athymic Nu/nu mice were xenografted with H460 tumors and the efficacy of Nos, Gem, or NGC was determined. Protein expressions by immunohistochemical staining were evaluated in harvested tumor tissues. RESULTS:The CI values (<0.59) were suggestive of synergistic behavior between Nos and Gem. NGC treatment showed significantly inhibited tube formation and increased percentage of apoptotic cells. NGC, Gem and Nos treatment reduced tumor volume by 82.9±4.5 percent, 39.4±5.8 percent and 34.2±5.7 percent respectively. Specifically, NGC treatment decreased expression cell survival proteins; VEGF, CD31 staining and microvessel density and enhanced DNA fragmentation and cleaved caspase 3 levels compared to single agent treated and control groups. CONCLUSION:Nos potentiated the anticancer activity of Gem in an additive to synergistic manner against lung cancer via antiangiogenic and apoptotic pathways. These findings suggest potential benefit for use of NGC chemotherapy for treatment of lung cancer

Cutaneous manifestations of COVID-19: Report of three cases and a review of literature

Background: Various cutaneous manifestations have been observed in patients with COVID-19 infection. However, overall similarities in the clinical presentation of these dermatological manifestations have not yet been summarized. Objective: This review aims to provide an overview of various cutaneous manifestations in patients with COVID-19 through three case reports and a literature review. Methods: A literature search was conducted using PubMed, OVID, and Google search engines for original and review articles. Studies written in the English language that mentioned cutaneous symptoms and COVID-19 were included. Results: Eighteen articles and three additional cases reported in this paper were included in this review. Of these studies, 6 are case series and 12 are case report studies. The most common cutaneous manifestation of COVID-19 was found to be maculopapular exanthem (morbilliform), presenting in 36.1% (26/72) patients. The other cutaneous manifestations included: a papulovesicular rash (34.7%, 25/72), urticaria (9.7%, 7/72), painful acral red purple papules (15.3%, 11/72) of patients, livedo reticularis lesions (2.8%, 2/72) and petechiae (1.4%, 1/72). Majority of lesions were localized on the trunk (66.7%, 50/72), however, 19.4% (14/72) of patients experienced cutaneous manifestations in the hands and feet. Skin lesion development occurred before the onset of respiratory symptoms or COVID-19 diagnosis in 12.5% (9/72) of the patients, and lesions spontaneously healed in all patients within 10 days. Majority of the studies reported no correlation between COVID-19 severity and skin lesions. Conclusion: Infection with COVID-19 may result in dermatological manifestations with various clinical presentations, which may aid in the timely diagnosis of this infection

Use of Xpert MTB/RIF in Decentralized Public Health Settings and Its Effect on Pulmonary TB and DR-TB Case Finding in India

Background Xpert MTB/RIF, the first automated molecular test for tuberculosis, is transforming the diagnostic landscape in high-burden settings. This study assessed the impact of up-front Xpert MTB/RIF testing on detection of pulmonary tuberculosis (PTB) and rifampicin-resistant PTB (DR-TB) cases in India. Methods This demonstration study was implemented in 18 sub-district level TB programme units (TUs) in India in diverse geographic and demographic settings covering a population of 8.8 million. A baseline phase in 14 TUs captured programmatic baseline data, and an intervention phase in 18 TUs had Xpert MTB/RIF offered to all presumptive TB patients. We estimated changes in detection of TB and DR-TB, the former using binomial regression models to adjust for clustering and covariates. Results In the 14 study TUs, which participated in both phases, 10,675 and 70,556 presumptive TB patients were enrolled in the baseline and intervention phase, respectively, and 1,532 (14.4%) and 14,299 (20.3%) bacteriologically confirmed PTB cases were detected. The implementation of Xpert MTB/RIF was associated with increases in both notification rates of bacteriologically confirmed TB cases (adjusted incidence rate ratio [aIRR] 1.39; CI 1.18-1.64), and proportion of bacteriological confirmed TB cases among presumptive TB cases (adjusted risk ratio (aRR) 1.33; CI 1.6-1.52). Compared with the baseline strategy of selective drug-susceptibility testing only for PTB cases at high risk of drug-resistant TB, Xpert MTB/RIF implementation increased rifampicin resistant TB case detection by over fivefold. Among, 2765 rifampicin resistance cases detected, 1055 were retested with conventional drug susceptibility testing (DST). Positive predictive value (PPV) of rifampicin resistance detected by Xpert MTB/RIF was 94.7% (CI 91.3-98.1), in comparison to conventional DST. Conclusion Introduction of Xpert MTB/RIF as initial diagnostic test for TB in public health facilities significantly increased case-notification rates of all bacteriologically confirmed TB by 39% and rifampicin-resistant TB case notification by fivefold

Tomography of the Solar Corona with the Metis Coronagraph I: Predictive Simulations with Visible-Light Images

The Solar Orbiter/Metis coronagraph records full-Sun visible-light polarized brightness (pB-) images of the solar corona. This work investigates the utility of a synoptic observational program of Metis for tomographic reconstruction of the three-dimensional (3D) distribution of the electron density of the global solar corona. During its lifetime, the mission’s distance to the Sun will range over ≈0.3−1.0AU, while its solar latitude will span ≈ ± 33 ∘. The limitations that this orbital complexity poses on tomographic reconstructions are explored in this work. Using the predicted orbital information of Solar Orbiter and 3D-MHD simulations of the solar corona using the Alfvén Wave Solar atmosphere Model (AWSoM), time series of synthetic MetispB-images were computed and used as data to attempt tomographic reconstruction of the model. These numerical experiments were implemented for solar-minimum and solar-maximum conditions. In both cases, images were synthesized from three orbital segments, corresponding to extreme geometrical conditions of observation by Metis: aphelion, perihelion, and maximum solar latitude. The range of heights that can be reconstructed, the required data-gathering period, and the accuracy of the reconstruction, are discussed in detail for each case. As a general conclusion, a Metis synoptic observational program with a cadence of at least four images day−1 provides enough data to attempt tomographic reconstructions during the whole lifetime of the mission, a requirement well within the two- to three-hour cadence of the current synoptic program. This program will allow implementation of tomography experimenting with different values for the cadence of the time series of images used to feed reconstructions. Its cadence will also provide continuous opportunities to select images avoiding highly dynamic events, which compromise the accuracy of tomographic reconstructions.Fil: Vasquez, Alberto Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Nuevo, Federico Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Frassati, Federica. Istituto Nazionale di Astrofisica; ItaliaFil: Bemporad, Alessandro. Istituto Nazionale di Astrofisica; ItaliaFil: Frazin, Richard A.. University of Michigan; Estados UnidosFil: Romoli, Marco. Università degli Studi di Firenze; ItaliaFil: Sachdeva, Nishtha. University of Michigan; Estados UnidosFil: Manchester, Ward B.. University of Michigan; Estados Unido

Two new novel point mutations localized upstream and downstream of the HMG box region of the SRY gene in three Indian 46,XY females with sex reversal and gonadal tumour formation

The Y chromosome-specific gene SRY is one of the key genes involved in human sex determination. The SRY gene encodes a testis-specific transcription factor that plays a key role in sexual differentiation; development in males; is located on the distal region of the short arm of the Y chromosome. Mutations in SRY gene result in XY sex reversal; pure gonadal dysgenesis. SRY expression initiates a network of gene activity that transforms the undifferentiated gonad; genital ridge into testis. Mutations in the SRY gene have been considered to account for only 0-5% of 46;XY gonadal dysgenesis cases; whereas the majority of the remaining cases may have mutation(s) in the SRY regulatory elements or other genes involved in the sex differentiation pathway. Patients both with gonadal dysgenesis; Y-chromosome presence are at high risk of developing gonadoblastoma. Using PCR; single strand conformational polymorphism (SSCP); automated DNA sequencing; we analysed the mutations in the SRY gene in three 46;XY sex reversal patients. Two patients demonstrated nucleotide substitution (A→G) within the open reading frame just outside; upstream of the conserved DNA-binding motif called the high-mobility group (HMG) box; replacing glutamine at codon 57 with arginine. Altered SSCP patterns were also observed in these patients. Histological examination of gonads in patient revealed the formation of gonadoblastoma. Patient demonstrated A→T substitution which replaces serine at codon 4 with cysteine; just outside but downstream of the HMG box. Results suggest the involvement of SRY gene in sex reversal which further supports the relationship between SRY alterations; gonadal dysgenesis and/or primary infertility