Across two phylogeographic breaks: Quaternary evolutionary history of a mountain aspen (Populus rotundifolia) in the Hengduan Mountains

Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both.Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia,a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China.Demographic and migration hypotheses were tested using coalescent-based approaches.Limited historical gene flow was observed between the western and eastern groups of P.rotundifolia,but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line,manifesting in clear admixture and high genetic diversity in the central group.Wind-borne pollen and seeds may have facilitated the dispersal of P.rotundifolia following prevalent northwest winds in the spring.We also found that the Hengduan Mountains,where multiple genetic barriers were detected,acted on the whole as a barrier between the western and eastern groups of P.rotundifolia.Ecological niche modeling suggested that P.rotundifolia has undergone range expansion since the last glacial maximum,and demographic reconstruction indicated an earlier population expansion around 600 Ka.The phylogeographic pattern of P.rotundifolia reflects the interplay of biological traits,wind patterns,barriers,niche differentiation,and Quaternary climate history.This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.

Double-stranded DNA breaks and gene functions in recombination and meiosis

Meiotic 前期我是一个长、复杂的阶段。相应再结合是在 meiotic 前期期间发生在相应染色体之间的一个重要过程我。chiasmata 的形成，它一起保持相应染色体直到中期我到后期，我转移，为合适的染色体分离是批评的。最近的研究建议了 SPO11 蛋白质在产生被认为是相应再结合的起点的双 stranded DNA 裂缝(DSB ) 的地点在很多个有机体保存了功能。DSB 的这些地点处理要求 RecA 相当或相同的事物的功能，例如 RAD51， DMC1，和其它，由变异的研究建议了；因此，修理这些 meiotic DSB 的失败导致反常 chromosomal 引申，导致破坏成熟分裂。这些 RecA 相当或相同的事物的功能上的最近的发现改进了位于 meiotic 下面的机制的理解相应再结合。

Exposure to Long Magnetic Resonance Imaging Thermometry Does Not Cause Significant DNA Double-Strand Breaks on CF-1 Mice

The purpose of the study was to investigate if the high gradient strength and slew rate used for long MRI-thermometry monitoring could cause DNA double-stranded breaks (DSBs). To this end, an enzyme-linked immunosorbent assay (ELISA) was used to quantify γH2AX, a molecular marker for DSBs, in the blood of mice after a 6-hour exposure to magnetic resonance imaging (MRI). Fourteen CF-1 female mice were separated into 4 experimental groups: Untreated negative control, MRI-treated, MRI-Control, and exposed to ionizing radiation positive control. Untreated negative control was used as a baseline for ELISA to quantify γH2AX. MRI-treated consisted of a 6-hour continuous magnetic resonance imaging (MRI) echo planar imaging (EPI) sequence with a slew rate of 192 mT/m/s constituting a significantly longer imaging time than routine clinical imaging. MRI-control mice were maintained under the same conditions outside the MRI scanner for 6-hours. Mice in the irradiation group served as a positive control of DSBs and were exposed to either 2 Gy, 5 Gy or 10 Gy of ionizing radiation. DSBs in the blood lymphocytes from the treatment groups were analyzed using the γH2AX ELISA and compared. Total protein concentration in lysates was determined for each blood sample and averaged 1 ± 0.35 mg/mL. Irradiated positive controls were used to test radiation dose-dependency of the γH2AX ELISA assay where a linear dependency on radiation exposure was observed (r2 = 0.93) between untreated and irradiated samples. Mean and standard error mean of γH2AX formation were calculated and compared between each treatment group. Repeated measures 1-way ANOVA showed statistically significant differences between the means of irradiated controls and both the MRI-control and MRI-treated groups. There was no statistically significant difference between the MRI-treated samples and the MRI-control groups. Our results show that long MRI exposure at a high slew rate did not cause increased levels of γH2AX when compared to control mice, suggesting that no increase in DSBs was caused by the long MR thermometry imaging session. The novelty of this work contradicts other studies that have suggested MRI may cause DSBs;this work suggests an alternative cause of DNA damage.

DNA Double-Strand Breaks,Potential Targets for HBV Integration

Hepatitis B virus(HBV)-induced hepatocellular carcinoma(HCC) is one of the most fre-quently occurring cancers.Hepadnaviral DNA integrations are considered to be essential agents which can promote the process of the hepatocarcinogenesis.More and more researches were designed to find the relationship of the two.In this study,we investigated whether HBV DNA integration occurred at sites of DNA double-strand breaks(DSBs),one of the most detrimental DNA damage.An 18-bp I-SceI homing endonuclease recognition site was introduced into the DNA of HepG2 cell line by stable DNA transfection,then cells were incubated in patients’ serum with high HBV DNA copies and at the same time,DSBs were induced by transient expression of I-SceI after transfection of an I-SceI expression vector.By using nest PCR,the viral DNA was detected at the sites of the break.It appeared that integra-tion occurred between part of HBV x gene and the I-SceI induced breaks.The results suggested that DSBs,as the DNA damages,may serve as potential targets for hepadnaviral DNA insertion and the integrants would lead to widespread host genome changes necessarily.It provided a new site to investi-gate the integration.

Adsorption dynamics of double-stranded DNA on a graphene oxide surface with both large unoxidized and oxidized regions

The adsorption dynamics of double-stranded DNA(dsDNA)molecules on a graphene oxide(GO)surface are important for applications of DNA/GO functional structures in biosensors,biomedicine and materials science.In this work,molecular dynamics simulations were used to examine the adsorption of different length dsDNA molecules(from 4 bp to24 bp)on the GO surface.The dsDNA molecules could be adsorbed on the GO surface through the terminal bases and stand on the GO surface.For short dsDNA(4 bp)molecules,the double-helix structure was partially or totally broken and the adsorption dynamics was affected by the structural fluctuation of short dsDNA and the distribution of the oxidized groups on the GO surface.For long dsDNA molecules(from 8 bp to 24 bp)adsorption is stable.By nonlinear fitting of the contact angle between the axis of the dsDNA molecule and the GO surface,we found that a dsDNA molecule adsorbed on a GO surface has the chance of orienting parallel to the GO surface if the length of the dsDNA molecule is longer than 54 bp.We attributed this behavior to the flexibility of dsDNA molecules.With increasing length,the flexibility of dsDNA molecules also increases,and this increasing flexibility gives an adsorbed dsDNA molecule more chance of reaching the GO surface with the free terminal.This work provides a whole picture of adsorption of dsDNA molecules on the GO surface and should be of benefit for the design of DNA/GO based biosensors.

Volatility spillovers,structural breaks and uncertainty in technology sector markets

This study uses the dynamic conditional correlation to investigate how technology subsector stocks interact with financial assets in the face of economic and financial uncertainty.Our results suggest that structural breaks have diverse effects on financial asset connectedness and that the level of bond linkage increases when the trend breaks.We see a growing co-movement between the technology sector and major financial assets when uncertainty is considered.Overall,our findings indicate that the connectedness response varies depending on the type of uncertainty shock.

Application of Artificially Induced Double-strand Breaks (DSB) and Triplex-forming Oligonucleotides (TFO) in the Improvement of Gene Targeting Efficiency

Gene targeting technology is an important means to investigate gene functions, but its efficiency of gene targeting is very low, especially for somatic cell targeting. Artificially induced double-strand breaks （DSB） and triplex forming oligonucleotide （TFO） are currently developed methods to improve the targeting efficiency. This paper summarized the basic principles, design ideas and application in gene targeting efficiency improvement of these two methods, analyzed and com- pared their characteristics, and finally proposed prospects for their future development.

Investigation of hydroxyl-terminated polybutadiene propellant breaking characteristics and mechanism impacted by submerged cavitation water jet

A submerged cavitation water jet(SCWJ)is an effective method to recycle solid propellant from obsolete solid engines by the breaking method.Solid propellant's breaking modes and mechanical process under SCWJ impact are unclear.This study aims to understand those impact breaking mechanisms.The hydroxyl-terminated polybutadiene(HTPB)propellant was chosen as the research material,and a self-designed test system was used to conduct impact tests at four different working pressures.The high-speed camera characterized crack propagation,and the DIC method calculated strain change during the impact process.Besides,micro and macro fracture morphologies were characterized by scanning electron microscope(SEM)and computed tomography(CT)scanning.The results reveal that the compressive strain concentration region locates right below the nozzle,and the shear strain region distributes symmetrically with the jet axis,which increases to 4% at first 16th ms,the compressive strain rises to 2% and 6% in the axial and transverse direction,respectively.The two tensile cracks formed first at the compression strain concentrate region,and there generate many shear cracks around the tensile cracks,and those shear cracks that develop and aggregate cause the cracks to become wider and cut through the tensile cracks,forming the tensile-shear cracks and the impact parts eventually fail.The HTPB propellant forms a breaking hole shaped conical after impact 10 s.The mass loss increases by 17 times at maximum,with the working pressure increasing by three times.Meanwhile,the damage value of the breaking hole remaining on the surface increases by 7.8 times while 2.9 times in the depth of the breaking hole.The breaking efficiency is closely affected by working pressures.The failure modes of HTPB impacted by SCWJ are classified as tensile crack-dominated and tensile-shear crack-dominated damage mechanisms.

Enhancing textile production:Smartex exhibits groundbreaking solutions

Smartex,a trailblazing leader in textile industry innovation,was proud to announce its return to ITM 2024,showcasing unparalleled advancements in quality control and production efficiency.Building on the success of previous exhibitions at ITM 2022 and ITMA Milan 2023,Smartex emerges stronger than ever,presenting its complete Smartex System tailored to transform textile manufacturing.

Impacts of monsoon break events in the western North Pacific on the cross-equatorial flows over the Maritime Continent

本文利用ERA5逐日再分析资料,探讨了1979-2020年间西北太平洋季风中断事件对海洋性大陆越赤道气流的影响.合成结果表明,西北太平洋季风中断事件会造成高,低空越赤道气流减弱,即高层南风异常,低层北风异常,与此相关的环流异常表现为西北太平洋高层气旋,低层反气旋的斜压结构。特别的是,西北太平洋季风中断对高空越赤道气流的影响更为显著,92%的季风中断事件都导致高空越赤道气流减弱,而只有70%的事件造成低空越赤道气流减弱,这是由于低空越赤道气流同时还受到赤道中东太平洋海温异常的调控.

Comparison of DNA double-strand breaks induced by ^(16)O^(8+) in deproteinized DNA and intact cells

The yield of DNA double-strand breaks (DSBs) is sure to be influenced by theenvironment around DNA molecule. Inverse pulsed-field gel electrophoresis (PIGE) has beenapplied to compare the sensitivity of B16 cells and their DNA in DSBs induced by 75 MeV/u16O8+ beam. Results show that the percentages of DNA released from the plug(PR) in bothkinds of tile samples increase with the dose and approach a similar quasi-threshold of about81%. A simple new equation was presented to calculate the break level of DNA molecules.Within a certain dose, the relationship between the break level and the dose is linear. Theyield of DSBs in deproteinized DNA was 1.11 DSBs/100 Mbp/Gy, while that in intact cells was0.60DSBs/100Mbp/Gy. It is testified that deproteinized DNA is more sensitive to oxygen ionsirradiation than intact cells.

DETECTION OF STRAND BREAKS OF DNA IN HUMAN EARLY CHORIONIC VILLUS CELLS INDUCED BY DIAGNOSTIC ULTRASOUND USING ^(32)P-LABELED ALU HYBRIDIZATION

Objective To explore if strand breaks of DNA in human early chorionic villus cells in uterus were induced by diagnostic ultrasound and to evaluate the method used for detection of single-stranded breaks and double-stranded breaks in human DNA. Methods 60 normal pregnant women aged 20-30, who underwent artificial abortion during 6-8 weeks of gestation, were randomly divided into 2 experimental groups: All 30 cases were exposed to diagnostic ultrasound in uterus for 10 minutes, and 24 hours later chorionic villi were extracted; the other 30 cases were taken as the control group. Single-stranded DNA and double-stranded DNA in villus cells in all cases were isolated by the alkaline unwinding combined with hydroxylapatite chromatography, and were quantitatively detected using 32 P-labeled Alu probe for dot-blotting hybridization. Results There was no significant difference in quantity and percentage in single-stranded DNA and double-stranded DNA between 2 groups (P>0.05). 32 P-Alu probe could only hybridize with human DNA, and could detect DNA isolated from as few as 2.5×10 3 chorionic villus cells and 0.45ng DNA in human leukocytes. Conclusion The results suggested that there were no DNA strand damages in human chorionic villus cells when the uterus was exposed to diagnostic ultrasound for 10 minutes. The method,^(32)P-Alu probe for dot-blotting hybridization, was even more specific, sensitive and accurate than conventional approaches.

Non-buckled vitrectomy for retinal detachment with inferior breaks and proliferative vitreoretinophathy

AIM: To investigate the efficacy of non-buckled vitrectomy with classical endotamponade agents in the treatment of primary retinal detachment (RD) complicated by inferior breaks and proliferative vitreoretinophathy (PVR). METHODS: A retrospective, consecutive and case series study of 40 patients with inferior break RD and PVR >= C1 was conducted. All patients underwent a standard 3-port 20-gauge pars plana vitrectomy (PPV) with gas or silicone oil tamponade without supplementary scleral buckling. The vitreous and all proliferative membrane were completely removed, and retinectomy was performed when necessary. The mean follow-up was 12.5 months. The primary and final anatomic success rate, visual acuity and complications were recorded and analyzed. RESULTS: Primary anatomic success rate was achieved in 35 of 40 eyes (87.5%) and the final anatomic success rate was 100%. The most common cause of redetachment was recurrent PVR. The best-corrected visual acuity (BCVA) at final follow-up was improved in 34 eyes (85%), remained stable in 1 eye (2.5%), and worsened in 5 eyes (12.5%). The mean visual acuity at final follow-up was improved significantly (P=0.000). CONCLUSION: This retrospective study provides evidence that vitrectomy without scleral buckling seemed to be an effective treatment for inferior break RD with PVR. With complete removal of vitreous and proliferative membranes and timing of retinectomy, the inferior breaks which complicated with PVR could be dosed successfully without additional sclera! buckling.

Selection of Multifractal Scaling Breaks andSeparation of Geochemical andGeophysical Anomaly

Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of functions within certain scale ranges The multifractalities can be estimated by applying multifractal modeling to the measures reflecting the characteristics of the physical processes such as the element concentration values analyzed in rock and soil samples and caused by the underlying mineralization processes and the other geological processes. The local and regional geological processes may result in geochemical patterns with distinct multifractalities as wall as variable scaling ranges. Separation of these multifractal measures on the basis of both the distinct multifractalities and the scaling ranges will be significant for both theoretical studies of multifractal modeling and its applications. Multifractal scaling breaks have been observed from various multifractal patterns. This paper introduces a technique for separating multifractal measures on the basis of scaling breaks. It has been demonstrated that the method is effective for decomposing geochemical and geophysical anomalies required for mineral exploration. A dataset containing the element concentration values of potassium and phosphorus in soil samples was employed for demonstrating the application of the method for studying the fertilizer and yield optimization in agriculture

Comparison of Densiron 68 and 1 000 cSt silicone oil in the management of rhegmatogenous retinal detachment with inferior breaks

AIM:To compare success rates and complications of Densiron 68 and 1000cSt silicone oil (SO) in the management of rhegmatogenous retinal detachment (RRD) with inferior breaks (IBs). METHODS:Totally 61 eyes of 61 consecutive patients with RRD with IBs were assigned to pars plana vitrectomy (PPV) with Densiron (n =31) or PPV with SO (n=30) in order of presentation. SO and Densiron removal was performed 3 months after initial surgery. Follow up visits were terminated 6 months after SO removal. ·RESULTS:With a single operation, the Densiron group showed 84% and SO 74% reattachment. With further surgery, both groups showed 90% reattachment. Complications such as cataract, raised intraocular pressure (IOP), inflammatory reaction, macular epiretinal membranes, and emulsification of SO were seen in both groups. CONCLUSION:Densiron and SO are found to have similar success rates and complications.

Missed retinal breaks in rhegmatogenous retinal detachment

AIM： To evaluate the causes and associations of missed retinal breaks（MRBs） and posterior vitreous detachment（PVD） in patients with rhegmatogenous retinal detachment（RRD）.METHODS： Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and191 patients were included for analysis of PVD,depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations.RESULTS： Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs（P =0.033） with the odds of missing a retinal break being1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy（PVR） and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae,pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD.Traumatic RRDs were rarely associated with PVD. CONCLUSION： Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD.

Codon evolution in double-stranded organelle DNA: strong regulation of homonucleotides and their analog alternations

In our previous study, complete single DNA strands which were obtained from nuclei, chloroplasts and plant mitochondria obeyed Chargaff’s second parity rule, although those which were obtained from animal mitochondria deviated from the rule. On the other hand, plant mitochondria obeyed another different rule after their classification. Complete single DNA strand sequences obtained from chloroplasts, plant mitochondria, and animal mitochondria, were divided into the coding and non-coding regions. The non-coding region, which was the complementary coding region on the reverse strand, was incorporated as a coding region in the forward strand. When the nucleotide contents of the coding region or non-coding regions were plotted against the composition of the four nucleotides in the complete single DNA strand, it was determined that chloroplast and plant mitochondrial DNA obeyed Chargaff’s second parity rule in both the coding and non-coding regions. However, animal mitochondrial DNA deviated from this rule. In chloroplast and plant mitochondrial DNA, which obey Chargaff’s second parity rule, the lines of regression for G (purine) and C (pyrimidine) intersected with regression lines for A (purine) and T (pyrimidines), respectively, at around 0.250 in all cases. On the other hand, in animal mitochondrial DNA, which deviates from Chargaff’s second parity rule, only regression lines due to the content of homonucleotides or their analogs in the coding or non-coding region against those in the complete single DNA strand intersected at around 0.250 at the horizontal axis. Conversely, the intersection of the two lines of regression (G and A or C and T) against the contents of heteronucleotides or their analogs shifted from 0.25 in both coding and non-coding regions. Nucleotide alternations in chloroplasts and plant mitochondria are strictly regulated, not only by the proportion of homonucleotides and their analogs, but also by the heteronucleotides and their analogs. They are strictly regulated in animal mitochondria only by the content of homonucleotides and their analogs.

Maternal gene Ooep may participate in homologous recombination-mediated DNA double-strand break repair in mouse oocytes

DNA damage in oocytes can cause infertility and birth defects. DNA double-strand breaks （DSBs） are highly deleterious and can substantially impair genome integrity. Homologous recombination （HR）-mediated DNA DSB repair plays dominant roles in safeguarding oocyte quantity and quality. However, little is known regarding the key players of the HR repair pathway in oocytes. Here, we identified oocyte-specific gene Ooep as a novel key component of the HR repair pathway in mouse oocytes. OOEP was required for efficient ataxia telangiectasia mutated （ATM） kinase activation and Rad51 recombinase （RAD51） focal accumulation at DNA DSBs. Ooep null oocytes were defective in DNA DSB repair and prone to apoptosis upon exogenous DNA damage insults. Moreover, Ooep null oocytes exhibited delayed meiotic maturation. Therefore, OOEP played roles in preserving oocyte quantity and quality by maintaining genome stability. Ooep expression decreased with the advance of maternal age, suggesting its involvement in maternal aging.

An Improved Convolutional Neural Network Based Indoor Localization by Using Jenks Natural Breaks Algorithm

With the rapid growth of the demand for indoor location-based services(LBS), Wi-Fi received signal strength(RSS) fingerprints database has attracted significant attention because it is easy to obtain. The fingerprints algorithm based on convolution neural network(CNN) is often used to improve indoor localization accuracy. However, the number of reference points used for position estimation has significant effects on the positioning accuracy. Meanwhile, it is always selected arbitraily without any guiding standards. As a result, a novel location estimation method based on Jenks natural breaks algorithm(JNBA), which can adaptively choose more reasonable reference points, is proposed in this paper. The output of CNN is processed by JNBA, which can select the number of reference points according to different environments. Then, the location is estimated by weighted K-nearest neighbors(WKNN). Experimental results show that the proposed method has higher positioning accuracy without sacrificing more time cost than the existing indoor localization methods based on CNN.

Mechanical properties of double-stranded DNA biofilm with Gaussian distribution

In microcantilever-based label-free biodetection technologies, deflection changes induced by adsorptions of double-stranded DNA （dsDNA） molecules on Au-layer surface are greatly affected by the mechanical, thermal and electrical properties of DNA biofilm. In this paper, the elastic properties of dsDNA biofilm are studied. First, the Parsegian＇s empirical potential based on a mesoscopic liq- uid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders. Then, con- sidering a Gaussian distribution of DNA interaxial distance, the thought experiment method is used to derive an analyti- cal expression for Young＇s modulus of DNA biofilm with a stochastic packing pattern for the first time. Results show that Young＇s modulus of DNA biofilm is on the order of 10 MPa. These findings could provide a simple and effective method to evaluate the mechanical properties of soft biofilm on snbstrate.