Diel cycling of the cosmopolitan abundant Pelagibacter virus 37‐F6: one of the most abundant viruses on earth

The spatiotemporal dynamics for marine viral populations has only recently been explored. However, nothing is known about temporal activities of the uncultured Pelagibacter virus vSAG 37‐F6, which was discovered by single‐virus genomics as potentially the most abundant marine virus. Here, we investigate the diel cycling of 37‐F6 virus and the putative SAR11 host using coastal and oceanic transcriptomic and viromic time‐series data from Osaka Bay and North Pacific Subtropical Gyre. Virus 37‐F6 and relatives displayed diel cycling of transcriptional activities synchronized with its putative host. In both virus and host, the lowest transcription rates were observed at 14:00–15:00, coinciding roughly with maximum solar irradiance, while higher transcriptional rates were detected during the night/early morning and afternoon. Diel abundance of free viruses of 37‐F6 in seawater roughly mirrored the transcriptional activities of both virus and host. In Osaka Bay, among viral relatives (genus level), virus 37‐F6 specifically showed the highest ratio of transcriptional activity to virome abundance, a proxy for viral transcriptional activity relative to free viral particle abundance. This high ratio suggests high infection rate efficiencies in vSAG 37‐F6 virus compared to viral relatives. Thus, time‐series data revealed temporal transcript activities in one of the most abundant viruses in Earth.This work has been supported by Spanish Ministry of Economy and Competitiveness to MMG (Ref. RTI2018-094248-B-100), Generalitat Valenciana to FMH (ACIF/2015/332), and Gordon and Betty Moore Foundation to MMG (grant 5334). Gordon and Betty Moore Foundation to EFD (3777) and Simons Foundation Grant #329108 (to EFD)

Localizing gravity on Maxwell gauged CP1 model in six dimensions

We shall consider about a 3-brane embedded in six-dimensional space-time with a negative bulk cosmological constant. The 3-brane is constructed by a topological soliton solution living in two-dimensional axially symmetric transverse subspace. Similar to most previous works of six-dimensional soliton models, our Maxwell gauged CP1 brane model can also achieve to localize gravity around the 3-brane. The CP1 field is described by a scalar doublet and derived from O(3) sigma model by projecting it onto two-dimensional complex space. In that sense, our framework is more effective than other solitonic brane models concerning with gauge theory. We shall also discuss about linear stability analysis for our new model by fluctuating all fields.Comment: 23 pages, 7 figures; references adde

TOI-2015b: A Warm Neptune with Transit Timing Variations Orbiting an Active mid M Dwarf

We report the discovery of a close-in ($P_{\mathrm{orb}} = 3.349\:\mathrm{days}$) warm Neptune with clear transit timing variations (TTVs) orbiting the nearby ($d=47.3\:\mathrm{pc}$) active M4 star, TOI-2015. We characterize the planet's properties using TESS photometry, precise near-infrared radial velocities (RV) with the Habitable-zone Planet Finder (HP) Spectrograph, ground-based photometry, and high-contrast imaging. A joint photometry and RV fit yields a radius $R_p~=~3.37_{-0.20}^{+0.15} \:\mathrm{R_\oplus}$, mass $m_p~=~16.4_{-4.1}^{+4.1}\:\mathrm{M_\oplus}$, and density $\rho_p~=~2.32_{-0.37}^{+0.38} \:\mathrm{g cm^{-3}}$ for TOI-2015b, suggesting a likely volatile-rich planet. The young, active host star has a rotation period of $P_{\mathrm{rot}}~=~8.7 \pm~0.9~\mathrm{days}$ and associated rotation-based age estimate of $1.1~\pm~0.1\:\mathrm{Gyr}$. Though no other transiting planets are seen in the TESS data, the system shows clear TTVs of super period $P_{\mathrm{sup}}~\approx~430\:\mathrm{days}$ and amplitude $\sim$$100\:\mathrm{minutes}$. After considering multiple likely period ratio models, we show an outer planet candidate near a 2:1 resonance can explain the observed TTVs while offering a dynamically stable solution. However, other possible two-planet solutions -- including 3:2 and 4:3 resonance -- cannot be conclusively excluded without further observations. Assuming a 2:1 resonance in the joint TTV-RV modeling suggests a mass of $m_b~=~13.3_{-4.5}^{+4.7}\:\mathrm{M_\oplus}$ for TOI-2015b and $m_c~=~6.8_{-2.3}^{+3.5}\:\mathrm{M_\oplus}$ for the outer candidate. Additional transit and RV observations will be beneficial to explicitly identify the resonance and further characterize the properties of the system.Comment: 28 pages, 15 figures, 6 tables. As submitted to AAS Journal

Outcomes and factors influencing survival in cirrhotic cases with spontaneous rupture of hepatocellular carcinoma: a multicenter study

<p>Abstract</p> <p>Background</p> <p>Spontaneous rupture is rare complication of hepatocellular carcinoma (HCC) with high mortality rate in cirrhotic cases. The aim of this study was to determine the factors influencing prognosis in cases of spontaneously ruptured HCC and to investigate the outcomes of the treatments employed, especially transcatheter arterial embolization (TAE).</p> <p>Methods</p> <p>A retrospective multicenter study was conducted in 48 cirrhotic patients with spontaneous rupture of HCC. Conservative treatment was employed in 32 patients (ConT group) and TAE was performed in 16 patients (TAE group).</p> <p>Results</p> <p>The median survival time (MST) in the ConT group was only 13.1 days and the survival rate was extremely poor: 59.4% at 7 days, 37.5% at 14 days, and 6.3% at 30 days. On the other hand, the MST in the TAE group was 244.8 days and the survival rate was 87.5% at 1 month, 56.3% at 3 months, 23.4% at 12 months, and 15.6% at 24 months. According to the results of univariate analyses, factors associated with poor hepatic function and poor suitability for TAE was important determinants of short-term death (less than 3 weeks) among the patients (<it>p </it>< 0.05). On the other hand, among the patients in whom initial TAE was successfully performed (<it>n </it>= 15), a multivariate analysis showed that a maximum tumor size not exceeding 7 cm was the only independent factor determining long-term survival (<it>p </it>= 0.0130).</p> <p>Conclusion</p> <p>Despite the inherent limitations of this retrospective study, TAE appears to be a useful treatment strategy for cirrhotic patients with spontaneous HCC rupture, as it yielded a longer survival period compared with conservative treatment in patients with ruptured HCC. Among the patients with ruptured HCC in whom initial TAE was successfully performed, the maximum tumor size was an important factor influencing survival.</p

Manipulation of Signaling Thresholds in “Engineered Stem Cell Niches” Identifies Design Criteria for Pluripotent Stem Cell Screens

In vivo, stem cell fate is regulated by local microenvironmental parameters. Governing parameters in this stem cell niche include soluble factors, extra-cellular matrix, and cell-cell interactions. The complexity of this in vivo niche limits analyses into how individual niche parameters regulate stem cell fate. Herein we use mouse embryonic stem cells (mESC) and micro-contact printing (µCP) to investigate how niche size controls endogenous signaling thresholds. µCP is used to restrict colony diameter, separation, and degree of clustering. We show, for the first time, spatial control over the activation of the Janus kinase/signal transducer and activator of transcription pathway (Jak-Stat). The functional consequences of this niche-size-dependent signaling control are confirmed by demonstrating that direct and indirect transcriptional targets of Stat3, including members of the Jak-Stat pathway and pluripotency-associated genes, are regulated by colony size. Modeling results and empirical observations demonstrate that colonies less than 100 µm in diameter are too small to maximize endogenous Stat3 activation and that colonies separated by more than 400 µm can be considered independent from each other. These results define parameter boundaries for the use of ESCs in screening studies, demonstrate the importance of context in stem cell responsiveness to exogenous cues, and suggest that niche size is an important parameter in stem cell fate control