Extracting Planet Mass and Eccentricity From TTV data

Most planet pairs in the Kepler data that have measured transit time variations (TTV) are near first-order mean-motion resonances. We derive analytical formulae for their TTV signals. We separate planet eccentricity into free and forced parts, where the forced part is purely due to the planets' proximity to resonance. This separation yields simple analytical formulae. The phase of the TTV depends sensitively on the presence of free eccentricity: if the free eccentricity vanishes, the TTV will be in phase with the longitude of conjunctions. This effect is easily detectable in current TTV data. The amplitude of the TTV depends on planet mass and free eccentricity, and it determines planet mass uniquely only when the free eccentricity is sufficiently small. We proceed to analyze the TTV signals of six short period Kepler pairs. We find that three of these pairs (Kepler-18,24,25) have TTV phase consistent with zero. The other three (Kepler-23,28,32) have small TTV phases, but ones that are distinctly non-zero. We deduce that the free eccentricities of the planets are small, < 0.01, but not always vanishing. Furthermore, as a consequence of this, we deduce that the true masses of the planets are fairly accurately determined by the TTV amplitudes, within a factor < 2. The smallness of the free eccentricities suggests that the planets have experienced substantial dissipation. This is consistent with the hypothesis that the observed pile-up of Kepler pairs near mean-motion resonances is caused by resonant repulsion. But the fact that some of the planets have non-vanishing free eccentricity suggests that after resonant repulsion occurred there was a subsequent phase in the planets' evolution when their eccentricities were modestly excited, perhaps by interplanetary interactions.Comment: final ApJ version (improved discussion

Comparison of short-term efficacy between unilateral biportal endoscopic lumbar interbody fusion and minimally invasive surgery transforaminal lumbar interbody fusion for lumbar spinal stenosis

Objective To compare the short-term efficacy of unilateral biportal endoscopic lumbar interbody fusion (ULIF) and minimally invasive surgery transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of lumbar spinal stenosis. Methods Clinical data of 87 patients with lumbar spinal stenosis from April 2020 to June 2022 were retrospectively analyzed. Among them, 43 cases were treated with ULIF (ULIF group) and 44 cases were treated with MIS-TLIF (MIS-TLIF group). The surgical time, intraoperative blood loss, postoperative ambulation time, drainage tube removal time, hospital stay, postoperative complications, visual analog scale (VAS) scores for back and leg pain, as well as Oswestry disability index (ODI) were compared between the two groups. Results Compared with the MIS-TLIF group, the ULIF group had a longer surgical time, with statistically significant difference (P＜0.05). There was no significant difference in intraoperative blood loss, postoperative ambulation time, drainage tube removal time and hospital stay between the two groups (P＞0.05). Two cases in the ULIF group and one case in the MIS-TLIF group experienced cerebrospinal fluid leakage postoperatively, but there were no other complications in either group. There was no statistically significant difference in the incidence of complications between the two groups (P＞0.05). Both groups were followed up for 12 months. The fusion rate in the ULIF group was significantly higher than that in the MIS-TLIF group at 6 months (81.4% vs 59.1%, χ2=5.163, P＜0.05) and 12 months (90.7% vs 68.2%, χ2=6.179, P＜0.05) after surgery. Conclusion For patients with lumbar spinal stenosis, ULIF can achieve similar efficacy to MIS-TLIF, while providing higher decompression efficiency, greater surgical instrument flexibility, and more thorough intervertebral space treatment. However, ULIF has a longer surgical time

A New Network-Based Strategy for Predicting the Potential miRNA-mRNA Interactions in Tumorigenesis

MicroRNA (miRNA) plays an important role in the degradation and inhibition of mRNAs and is a kind of essential drug targets for cancer therapy. To facilitate the clinical cancer research, we proposed a network-based strategy to identify the cancer-related miRNAs and to predict their targeted genes based on the gene expression profiles. The strategy was validated by using the data sets of acute myeloid leukemia (AML), breast invasive carcinoma (BRCA), and kidney renal clear cell carcinoma (KIRC). The results showed that in the top 20 miRNAs ranked by their degrees, 90.0% (18/20), 70.0% (14/20), and 70.0% (14/20) miRNAs were found to be associated with the cancers for AML, BRCA, and KIRC, respectively. The KEGG pathways and GO terms enriched with the genes that were predicted as the targets of the cancer-related miRNAs were significantly associated with the biological processes of cancers. In addition, several genes, which were predicted to be regulated by more than three miRNAs, were identified to be the potential drug targets annotated by using the human protein atlas database. Our results demonstrated that the proposed strategy can be helpful for predicting the miRNA-mRNA interactions in tumorigenesis and identifying the cancer-related miRNAs as the potential drug targets

Photometric Variability in the CSTAR Field: Results From the 2008 Data Set

The Chinese Small Telescope ARray (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18,145 targets within 20 deg2 CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes and classes of variability. The catalog of all these variables is presented along with the discussion of their statistical properties.Comment: 38 pages, 11 figures, 4 tables; Accepted for publication in ApJ

Insight Into the Pico- and Nano-Phytoplankton Communities in the Deepest Biosphere, the Mariana Trench

As photoautotrophs, phytoplankton are generally present in the euphotic zone of the ocean, however, recently healthy phytoplankton cells were found to be also ubiquitous in the dark deep sea, i.e., at water depths between 2000 and 4000 m. The distributions of phytoplankton communities in much deeper waters, such as the hadal zone, are unclear. In this study, the vertical distribution of the pico- and nano-phytoplankton (PN) communities from the surface to 8320 m, including the epipelagic, mesopelagic, bathypelagic, and hadal zones, were investigated via both 18S and p23S rRNA gene analysis in the Challenger Deep of the Mariana Trench. The results showed that Dinoflagellata, Chrysophyceae, Haptophyta, Chlorophyta, Prochloraceae, Pseudanabaenaceae, Synechococcaceae, and Eustigmatophyceae, etc., were the predominant PN in the Mariana Trench. Redundancy analyses revealed that depth, followed by temperature, was the most important environmental factors correlated with vertical distribution of PN community. In the hadal zone, the PN community structure was considerably different from those in the shallower zones. Some PN communities, e.g., Eustigmatophyceae and Chrysophyceae, which have the heterotrophic characteristics, were sparse in shallower waters, while they were identified with high relative abundance (94.1% and 20.1%, respectively) at the depth of 8320 m. However, the dinoflagellates and Prochloraceae Prochlorococcus were detected throughout the entire water column. We proposed that vertical sinking, heterotrophic metabolism, and/or the transition to resting stage of phytoplankton might contribute to the presence of phytoplankton in the hadal zone. This study provided insight into the PN community in the Mariana Trench, implied the significance of phytoplankton in exporting organic matters from the euphotic to the hadal zone, and also hinted the possible existence of some undetermined energy metabolism (e.g., heterotrophy) of phytoplankton making themselves adapt and survive in the hadal environment

Abundance and evolution of gas around Beta Pictoris

Recent observations have shown that carbon in the gas around beta Pictoris is more than 100 times over- abundant with respect to the solar abundance. Although it is thought that such an overabundance in carbon is crucial to retain the metal elements in the disk, its origin is however unclear. In this paper, we establish a simple analytical model to study gas the removal process and thus calculate the abundance of various elements in the gas disk around beta Pictoris. The gas removal rate is controlled by the inward flow from viscous accretion and the outward radiation-induced drift. If the disk viscosity (using classical alpha-disk model) is low, radiation drift dominates the gas loss, and carbon can become highly overabundant. In order to produce the observed overabundance of carbon, a low viscosity of alpha &lt; 10-3 and a gas production with solar abundance are preferred

A Neural Network Model for the Correlation between Sprinters&apos; Pre-competition Anxiety and Competition Performance

Abstract: Sprint is an important sporting event in track and field competition, in which, athletes&apos; pre-competition anxiety will greatly affect them in bringing into play their competence, which will then influence their final performance in the competition. For this reason, to study the correlation between sprinters&apos; pre-competition anxiety and their competition performance is of great significance in predicting athletes&apos; performance under difference anxiety state. After having analyzed domestic and foreign research achievements related with sport anxiety and sport performance, the study further applied CSAI-2 (1994) questionnaire to investigate athletes&apos; anxiety in sprint competition of a university sports meeting in Changsha. Moreover, based on neural network model, the study also constructed related models concerning athletes&apos; pre-competition anxiety and their competition performance. In addition, related curves concerning athletes&apos; pre-competition anxiety and specific performance are also formulated