Changes in Continental Freshwater Discharge from 1948 to 2004

A new dataset of historical monthly streamflow at the farthest downstream stations for the world’s 925 largest ocean-reaching rivers has been created for community use. Available new gauge records are added to a network of gauges that covers ∼80 × 106 km2 or ∼80% of global ocean-draining land areas and accounts for about 73% of global total runoff. For most of the large rivers, the record for 1948–2004 is fairly complete. Data gaps in the records are filled through linear regression using streamflow simulated by a land surface model [Community Land Model, version 3 (CLM3)] forced with observed precipitation and other atmospheric forcings that are significantly (and often strongly) correlated with the observed streamflow for most rivers. Compared with previous studies, the new dataset has improved homogeneity and enables more reliable assessments of decadal and long-term changes in continental freshwater discharge into the oceans. The model-simulated runoff ratio over drainage areas with and without gauge records is used to estimate the contribution from the areas not monitored by the gauges in deriving the total discharge into the global oceans. Results reveal large variations in yearly streamflow for most of the world’s large rivers and for continental discharge, but only about one-third of the top 200 rivers (including the Congo, Mississippi, Yenisey, Paraná, Ganges, Columbia, Uruguay, and Niger) show statistically significant trends during 1948–2004, with the rivers having downward trends (45) outnumbering those with upward trends (19). The interannual variations are correlated with the El Niño–Southern Oscillation (ENSO) events for discharge into the Atlantic, Pacific, Indian, and global ocean as a whole. For ocean basins other than the Arctic, and for the global ocean as a whole, the discharge data show small or downward trends, which are statistically significant for the Pacific (−9.4 km3 yr−1). Precipitation is a major driver for the discharge trends and large interannual-to-decadal variations. Comparisons with the CLM3 simulation suggest that direct human influence on annual streamflow is likely small compared with climatic forcing during 1948–2004 for most of the world’s major rivers. For the Arctic drainage areas, upward trends in streamflow are not accompanied by increasing precipitation, especially over Siberia, based on available data, although recent surface warming and associated downward trends in snow cover and soil ice content over the northern high latitudes contribute to increased runoff in these regions. The results are qualitatively consistent with climate model projections but contradict an earlier report of increasing continental runoff during the recent decades based on limited records

A noval noninvasive targeted therapy for osteosarcoma: the combination of LIFU and ultrasound-magnetic-mediated SPIO/TP53/PLGA nanobubble

PurposeOsteosarcoma (OS) is the most common type of primary malignant bone tumor. Transducing a functional TP53 gene can effectively inhibit OS cell activity. Poly lactic acid-glycolic acid (PLGA) nanobubbles (NBs) mediated by focused ultrasound (US) can introduce exogenous genes into target cells in animal models, but this technique relies on the passive free diffusion of agents across the body. The inclusion of superparamagnetic iron oxide (SPIO) in microbubbles allows for magnetic-based tissue localization. A low-intensity-focused ultrasound (LIFU) instrument was developed at our institute, and different intensities of LIFU can either disrupt the NBs (RLI-LIFU) or exert cytocidal effects on the target tissues (RHI-LIFU). Based on these data, we performed US-magnetic-mediated TP53-NB destruction and investigated its ability to inhibit OS growth when combined with LIFU both in vitro and in vivo.MethodsSeveral SPIO/TP53/PLGA (STP) NB variants were prepared and characterized. For the in vitro experiments, HOS and MG63 cells were randomly assigned into five treatment groups. Cell proliferation and the expression of TP53 were detected by CCK8, qRT-PCR and Western blotting, respectively. In vivo, tumor-bearing nude mice were randomly assigned into seven treatment groups. The iron distribution of Perls’ Prussian blue-stained tissue sections was determined by optical microscopy. TUNEL-DAPI was performed to examine apoptosis. TP53 expression was detected by qRT-PCR and immunohistochemistry.ResultsSPIO/TP53/PLGA NBs with a particle size of approximately 200 nm were prepared successfully. For in vitro experiments, ultrasound-targeted transfection of TP53 overexpression in OS cells and efficient inhibition of OS proliferation have been demonstrated. Furthermore, in a tumor-bearing nude mouse model, RLI-LIFU-magnetic-mediated SPIO/TP53/PLGA NBs increased the transfection efficiency of the TP53 plasmid, resulting in apoptosis. Adding RHI-LIFU to the treatment regimen significantly increased the apoptosis of OS cells in vivo.ConclusionCombining LIFU and US-magnetic-mediated SPIO/TP53/PLGA NB destruction is potentially a novel noninvasive and targeted therapy for OS

Induction of ROS generation and NF-κB activation in MARC-145 cells by a novel porcine reproductive and respiratory syndrome virus in Southwest of China isolate

Each ORF gene nucleotide sequence of YN-2011

Online sensor information and redundancy resolution based obstacle avoidance for high DOF mobile manipulator teleoperation

High degrees of freedom (DOF) mobile manipulators provide more flexibility than conventional manipulators. They also provide manipulation operations with a mobility capacity and have potential in many applications. However, due to high redundancy, planning and control become more complicated and difficult, especially when obstacles occur. Most existing obstacle avoidance methods are based on off-line algorithms and most of them mainly focus on planning a new collision-free path, which is not appropriate for some applications, such as teleoperation and uses many system resources as well. Therefore, this paper presents an online planning and control method for obstacle avoidance in mobile manipulators using online sensor information and redundancy resolution. An obstacle contour reconstruction approach employing a mobile manipulator equipped with an active laser scanner system is also introduced in this paper. This method is implemented using a mobile manipulator with a seven-DOF manipulator and a four-wheel drive mobile base. The experimental results demonstrate the effectiveness of this method. © 2013 Zhang et al.; licensee InTech.Link_to_subscribed_fulltex

Phase separating binary fluids under oscillatory shear

We apply lattice Boltzmann methods to study the segregation of binary fluid mixtures under oscillatory shear flow in two dimensions. The algorithm allows to simulate systems whose dynamics is described by the Navier-Stokes and the convection-diffusion equations. The interplay between several time scales produces a rich and complex phenomenology. We investigate the effects of different oscillation frequencies and viscosities on the morphology of the phase separating domains. We find that at high frequencies the evolution is almost isotropic with growth exponents 2/3 and 1/3 in the inertial (low viscosity) and diffusive (high viscosity) regimes, respectively. When the period of the applied shear flow becomes of the same order of the relaxation time $T_R$ of the shear velocity profile, anisotropic effects are clearly observable. In correspondence with non-linear patterns for the velocity profiles, we find configurations where lamellar order close to the walls coexists with isotropic domains in the middle of the system. For particular values of frequency and viscosity it can also happen that the convective effects induced by the oscillations cause an interruption or a slowing of the segregation process, as found in some experiments. Finally, at very low frequencies, the morphology of domains is characterized by lamellar order everywhere in the system resembling what happens in the case with steady shear.Comment: 1 table and 12 figures in .gif forma

NtMYB4 and NtCHS1 Are Critical Factors in the Regulation of Flavonoid Biosynthesis and Are Involved in Salinity Responsiveness

High levels of salinity induce serious oxidative damage in plants. Flavonoids, as antioxidants, have important roles in reactive oxygen species (ROS) scavenging. In the present study, the tobacco R2R3 MYB type repressor, NtMYB4, was isolated and characterized. The expression of NtMYB4 was suppressed by salinity. Overexpression of NtMYB4 reduced the salt tolerance in transgenic tobacco plants. NtMYB4 repressed the promoter activity of NtCHS1 and negatively regulated its expression. Rutin accumulation was significantly decreased in NtMYB4 overexpressing transgenic plants and NtCHS1 RNAi silenced transgenic plants. Moreover, high H2O2 and O2− contents were detected in both types of rutin-reduced transgenic plants under high salt stress. In addition, exogenous rutin supplementation effectively scavenged ROS (H2O2 and O2−) and improved the salt tolerance of the rutin-reduced transgenic plants. In contrast, NtCHS1 overexpressing plants had increased rutin accumulation, lower H2O2 and O2− contents, and higher tolerance to salinity. These results suggested that tobacco NtMYB4 acts as a salinity response repressor and negatively regulates NtCHS1 expression, which results in the reduced flavonoid accumulation and weakened ROS-scavenging ability under salt stress

Temporal and Spatial Expression of Muc1 During Implantation in Sows

Recent evidence points to an important role for Muc1 in embryo implantation. In this study, Real-time PCR and immunohistochemistry were used to study mRNA and protein levels at, and between, the attachment sites of the endometrium of Day 13, 18 and 24 pregnant sows. The results indicate that Muc1 mRNA expression was higher between attachment sites than at attachment sites during implantation and this effect was significant on Day 13 (P < 0.01) and 24 (P < 0.01). Intense Muc1 immunostaining was observed in luminal epithelium and stroma and the staining between attachment sites was stronger than at attachment sites on Days 13 and 18. Collectively, these results suggest the crucial role of Muc1 in successful implantation and embryo survival

The Overseeing Mother: Revisiting the Frontal-Pose Lady in the Wu Family Shrines in Second Century China

Located in present-day Jiaxiang in Shandong province, the Wu family shrines built during the second century in the Eastern Han dynasty (25–220) were among the best-known works in Chinese art history. Although for centuries scholars have exhaustively studied the pictorial programs, the frontal-pose female image situated on the second floor of the central pavilion carved at the rear wall of the shrines has remained a question. Beginning with the woman’s eyes, this article demonstrates that the image is more than a generic portrait (“hard motif ”), but rather represents “feminine overseeing from above” (“soft motif ”). This synthetic motif combines three different earlier motifs – the frontal-pose hostess enjoying entertainment, the elevated spectator, and the Queen Mother of the West. By creatively fusing the three motifs into one unity, the Jiaxiang artists lent to the frontal-pose lady a unique power: she not only dominated the center of the composition, but also, like a divine being, commanded a unified view of the surroundings on the lofty building, hence echoing the political reality of the empress mother’s “overseeing the court” in the second century during Eastern Han dynasty

Three-dimensional modelling of hydrodynamics and tidal flushing in Deep Bay

published_or_final_versiontocabstractCivil EngineeringMasterMaster of Philosoph