Interference-Aware Deployment for Maximizing User Satisfaction in Multi-UAV Wireless Networks

In this letter, we study the deployment of Unmanned Aerial Vehicle mounted Base Stations (UAV-BSs) in multi-UAV cellular networks. We model the multi-UAV deployment problem as a user satisfaction maximization problem, that is, maximizing the proportion of served ground users (GUs) that meet a given minimum data rate requirement. We propose an interference-aware deployment (IAD) algorithm for serving arbitrarily distributed outdoor GUs. The proposed algorithm can alleviate the problem of overlapping coverage between adjacent UAV-BSs to minimize inter-cell interference. Therefore, reducing co-channel interference between UAV-BSs will improve user satisfaction and ensure that most GUs can achieve the minimum data rate requirement. Simulation results show that our proposed IAD outperforms comparative methods by more than 10% in user satisfaction in high-density environments.Comment: 5 pages, 3 figures, to appear in IEEE Wireless Communications Letter

EFFECT OF DIFFERENT RUNNING SPEED ON VERTICAL OSCILLATION AND STRIDE

The main purpose of this study was to investigate the effect of different running speed (3.5±O.3 and 4.9±O.2 m/si on vertical oscillation of the center of gravity and stride. Ten male elite running players served as subjects. A camera (60Hz) was to collect the parameters during running. From this research, the t-Test is used to analyze the parameters of the kinematics in different running speed. Results indicated that different running speed would not affect the vertical oscillation of human body center of gravity. In addition, a significant difference (p< .05) was found in the same speed of different step, but no significance was found in different running speed of the same step. The duration of the stance phase in lower speed for about 38.34% of the stride and the swing phase for 61.66%, in higher speed for about 32.11 % and 67.89%

Recycling Nonmagnetic Material from De-sulferization Slag as Coarse Aggregate through Cold-Pressing Technique

Every year there was approximately 500,000 tons of de-sulferization slag generated in Taiwan, but the recycling amount was very slightly. A new approach, the cold-pressing technique that incorporates the principles of the cement chemistry and composite material was developed to recycle innocuous resources (e.g. construction residual soil, granite and lime sludge, and sediment, etc.) as recycling coarse aggregate. Even this technique also has successfully been applied to recycle stainless steel reductive slag with low volume stability. This paper aims to show that using cold-pressing technique can recycle nonmagnetic material from de-sulferization slag as coarse aggregate. Herein the cement-based composite is regarded as concrete. Particularly, the mixture proportions with a low cement amount of 100 kg/m3 and more than 70% (by weight) of nonmagnetic material from de-sulferization were designed. The test results show that the specific gravity of recycling coarse aggregate is about 1.67 in the OD state; the absorption capacity is 27.65%; the dry loose density (i.e. unit weight) is about 1,106 kg/m3; and other characteristics conform to ASTM C33. Therefore the cold-pressing technique is a new and practicable approach to recycle nonmagnetic material from de-sulferization slag in future

Pleural Effusion after Percutaneous Radiofrequency Ablation for Hepatic Malignancies

AbstractBackground and AimsRadiofrequency ablation (RFA) can play an important role in the treatment of primary or metastatic liver tumors. Currently, percutaneous RFA is generally regarded as a safe, effective, and minimally invasive procedure. This study aimed to evaluate the presence and course of pleural effusion after monopolar RFA.MethodsFrom October 2008 to July 2013, a total of 54 patients (28 male and 26 female, mean age 65.2) treated with monopolar RFA were included in our study. 47 patients were diagnosed with hepatocellular carcinoma, 4 patients with hepatic metastasis, and 3 patients had other diagnoses. There were a total of 115 sessions of treatment and 199 liver tumors to be treated (1.73 ± 1.02 tumors treated per session). The tumor size ranged from 0.8 cm to 5.0 cm (mean 2.31 cm, standard deviation 1.04 cm). Thereafter, a follow-up ultrasound was performed within 24 hours subsequent to ablation to evaluate the presence of pleural effusion. The degree of pleural effusion was assessed by chest X-ray.ResultsFifteen (13.0%) treatment sessions in 14 patients showed right-sided pleural effusion after ablations. One patient had a large amount of effusion, while other patients manifested a minimal to small amount of effusion. There were 5 patients that experienced delayed resolution of pleural effusion; one patient (0.87%) had a minimal amount of pleural effusion even after one month. Overall, there was no pneumothorax, or periprocedural morality. Age, gender, tumor numbers, tumor sizes, and complete ablation of target tumors were similar among groups presenting with or without pleural effusion. Tumor locations associated with S78 segments abutting the diaphragm or right lobe of the liver were not associated with development of pleural effusion. Only the duration of ablation time had a marginal trend toward significance (p = 0.051).ConclusionsThe transient appearance of right-sided pleural effusion after percutaneous RFA for hepatic malignancies was not infrequent. However, refractory pleural effusion was rare

T-Analyst: a program for efficient analysis of protein conformational changes by torsion angles

T-Analyst is a user-friendly computer program for analyzing trajectories from molecular modeling. Instead of using Cartesian coordinates for protein conformational analysis, T-Analyst is based on internal bond-angle-torsion coordinates in which internal torsion angle movements, such as side-chain rotations, can be easily detected. The program computes entropy and automatically detects and corrects angle periodicity to produce accurate rotameric states of dihedrals. It also clusters multiple conformations and detects dihedral rotations that contribute hinge-like motions. Correlated motions between selected dihedrals can also be observed from the correlation map. T-Analyst focuses on showing changes in protein flexibility between different states and selecting representative protein conformations for molecular docking studies. The program is provided with instructions and full source code in Perl

A Variant of Fibroblast Growth Factor Receptor 2 (Fgfr2) Regulates Left-Right Asymmetry in Zebrafish

Many organs in vertebrates are left-right asymmetrical located. For example, liver is at the right side and stomach is at the left side in human. Fibroblast growth factor (Fgf) signaling is important for left-right asymmetry. To investigate the roles of Fgfr2 signaling in zebrafish left-right asymmetry, we used splicing blocking morpholinos to specifically block the splicing of fgfr2b and fgfr2c variants, respectively. We found that the relative position of the liver and the pancreas were disrupted in fgfr2c morphants. Furthermore, the left-right asymmetry of the heart became random. Expression pattern of the laterality controlling genes, spaw and pitx2c, also became random in the morphants. Furthermore, lefty1 was not expressed in the posterior notochord, indicating that the molecular midline barrier had been disrupted. It was also not expressed in the brain diencephalon. Kupffer's vesicle (KV) size became smaller in fgfr2c morphants. Furthermore, KV cilia were shorter in fgfr2c morphants. We conclude that the fgfr2c isoform plays an important role in the left-right asymmetry during zebrafish development

The C-Terminus of Histone H2B Is Involved in Chromatin Compaction Specifically at Telomeres, Independently of Its Monoubiquitylation at Lysine 123

Telomeric heterochromatin assembly in budding yeast propagates through the association of Silent Information Regulator (SIR) proteins with nucleosomes, and the nucleosome array has been assumed to fold into a compacted structure. It is believed that the level of compaction and gene repression within heterochromatic regions can be modulated by histone modifications, such as acetylation of H3 lysine 56 and H4 lysine 16, and monoubiquitylation of H2B lysine 123. However, it remains unclear as to whether or not gene silencing is a direct consequence of the compaction of chromatin. Here, by investigating the role of the carboxy-terminus of histone H2B in heterochromatin formation, we identify that the disorderly compaction of chromatin induced by a mutation at H2B T122 specifically hinders telomeric heterochromatin formation. H2B T122 is positioned within the highly conserved AVTKY motif of the αC helix of H2B. Heterochromatin containing the T122E substitution in H2B remains inaccessible to ectopic dam methylase with dramatically increased mobility in sucrose gradients, indicating a compacted chromatin structure. Genetic studies indicate that this unique phenotype is independent of H2B K123 ubiquitylation and Sir4. In addition, using ChIP analysis, we demonstrate that telomere structure in the mutant is further disrupted by a defect in Sir2/Sir3 binding and the resulting invasion of euchromatic histone marks. Thus, we have revealed that the compaction of chromatin per se is not sufficient for heterochromatin formation. Instead, these results suggest that an appropriately arrayed chromatin mediated by H2B C-terminus is required for SIR binding and the subsequent formation of telomeric chromatin in yeast, thereby identifying an intrinsic property of the nucleosome that is required for the establishment of telomeric heterochromatin. This requirement is also likely to exist in higher eukaryotes, as the AVTKY motif of H2B is evolutionarily conserved

The Role of Oligomerization and Cooperative Regulation in Protein Function: The Case of Tryptophan Synthase

The oligomerization/co-localization of protein complexes and their cooperative regulation in protein function is a key feature in many biological systems. The synergistic regulation in different subunits often enhances the functional properties of the multi-enzyme complex. The present study used molecular dynamics and Brownian dynamics simulations to study the effects of allostery, oligomerization and intermediate channeling on enhancing the protein function of tryptophan synthase (TRPS). TRPS uses a set of α/β–dimeric units to catalyze the last two steps of L-tryptophan biosynthesis, and the rate is remarkably slower in the isolated monomers. Our work shows that without their binding partner, the isolated monomers are stable and more rigid. The substrates can form fairly stable interactions with the protein in both forms when the protein reaches the final ligand–bound conformations. Our simulations also revealed that the α/β–dimeric unit stabilizes the substrate–protein conformation in the ligand binding process, which lowers the conformation transition barrier and helps the protein conformations shift from an open/inactive form to a closed/active form. Brownian dynamics simulations with a coarse-grained model illustrate how protein conformations affect substrate channeling. The results highlight the complex roles of protein oligomerization and the fine balance between rigidity and dynamics in protein function

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data