Switchable multi-wavelength mode-locked Yb-doped fiber laser using a polarization maintaining 45°-tilted fiber gratings based Lyot filter

We demonstrate a multi-wavelength mode-locked Yb-doped fiber laser by incorporating a pair of polarization maintaining 45° tilted fiber gratings (PM-45°TFG) based Lyot filter. Thanks to the functions of the polarizer and the comb filtering introduced by the Lyot filter, dissipative soliton (DS) pulses centered at 1035.26 nm, 1044.93 nm, 1055.62 nm, 1066.11 nm and 1076.63 nm can be generated respectively by finely tuning the intracavity polarization controllers (PCs). Moreover, the laser also can operate in a multi-wavelength regime via appropriately adjusting the pump power and polarization orientation. The high nonlinearity induced by the long cavity length leads to the generation of h-shaped mode-locked pulse with a repetition rate of 566.27 kHz. In the absence of any disturbance, the laser can operate steadily, that can potentially be used in various fields including wavelength division multiplexing systems etc

Pump-controlled wavelength switchable dissipative soliton mode-locked Yb-doped fiber laser using a 45° tilted fiber grating

We demonstrate a pump-controlled wavelength switchable Yb-doped fiber laser (YDFL) by nonlinear polarization rotation (NPR) for the first time. The polarizer replaced by a 45° tilted fiber grating (45°-TFG) combines with a section of polarization maintaining fiber (PMF) to form a fiber-based birefringent filter. Stable dissipative soliton (DS) with center wavelength of 1068.39 nm is generated under the mode-locked threshold of 277 mW. The operating wavelength switching between 1046.51 nm and 1067.90 nm can be realized via increasing the pump power simply while keeping the polarization controllers (PCs) in a fixed state. The laser maintains stable mode-locking operation at each wavelength, which can be regarded as a type of multi-wavelength ultrafast light source with precise control and integration potential

PacBio But Not Illumina Technology Can Achieve Fast, Accurate and Complete Closure of the High GC, Complex Burkholderia pseudomallei Two-Chromosome Genome

Although PacBio third-generation sequencers have improved the read lengths of genome sequencing which facilitates the assembly of complete genomes, no study has reported success in using PacBio data alone to completely sequence a two-chromosome bacterial genome from a single library in a single run. Previous studies using earlier versions of sequencing chemistries have at most been able to finish bacterial genomes containing only one chromosome with de novo assembly. In this study, we compared the robustness of PacBio RS II, using one SMRT cell and the latest P6-C4 chemistry, with Illumina HiSeq 1500 in sequencing the genome of Burkholderia pseudomallei, a bacterium which contains two large circular chromosomes, very high G+C content of 68–69%, highly repetitive regions and substantial genomic diversity, and represents one of the largest and most complex bacterial genomes sequenced, using a reference genome generated by hybrid assembly using PacBio and Illumina datasets with subsequent manual validation. Results showed that PacBio data with de novo assembly, but not Illumina, was able to completely sequence the B. pseudomallei genome without any gaps or mis-assemblies. The two large contigs of the PacBio assembly aligned unambiguously to the reference genome, sharing >99.9% nucleotide identities. Conversely, Illumina data assembled using three different assemblers resulted in fragmented assemblies (201–366 contigs), sharing only 92.2–100% and 92.0–100% nucleotide identities to chromosomes I and II reference sequences, respectively, with no indication that the B. pseudomallei genome consisted of two chromosomes with four copies of ribosomal operons. Among all assemblies, the PacBio assembly recovered the highest number of core and virulence proteins, and housekeeping genes based on whole-genome multilocus sequence typing (wgMLST). Most notably, assembly solely based on PacBio outperformed even hybrid assembly using both PacBio and Illumina datasets. Hybrid approach generated only 74 contigs, while the PacBio data alone with de novo assembly achieved complete closure of the two-chromosome B. pseudomallei genome without additional costly bench work and further sequencing. PacBio RS II using P6-C4 chemistry is highly robust and cost-effective and should be the platform of choice in sequencing bacterial genomes, particularly for those that are well-known to be difficult-to-sequence

DEVELOPMENT OF AN AUTOMATIC WEIGHING PLATFORM FOR MONITORING BODYWEIGHT OF BROILER CHICKENS IN COMMERCIAL PRODUCTION

● An automatic weighing system for monitoring bodyweight of broilers was developed.● The new system was compared to the established live-bird sales weighing system data and tested in various conditions.● The system demonstrated superior accuracy and stability for commercial houses. Bodyweight is a key indicator of broiler production as it measures the production efficiency and indicates the health of a flock. Currently, broiler weight (i.e., bodyweight) is primarily weighed manually, which is time-consuming and labor-intensive, and tends to create stress in birds. This study aimed to develop an automatic and stress-free weighing platform for monitoring the weight of floor-reared broiler chickens in commercial production. The developed system consists of a weighing platform, a real-time communication terminal, computer software and a smart phone applet user-interface. The system collected weight data of chickens on the weighing platform at intervals of 6 s, followed by filtering of outliers and repeating readings. The performance and stability of this system was systematically evaluated under commercial production conditions. With the adoption of data preprocessing protocol, the average error of the new automatic weighing system was only 10.3 g, with an average accuracy 99.5% with the standard deviation of 2.3%. Further regression analysis showed a strong agreement between estimated weight and the standard weight obtained by the established live-bird sales system. The variance (an indicator of flock uniformity) of broiler weight estimated using automatic weighing platforms was in accordance with the standard weight. The weighing system demonstrated superior stability for different growth stages, rearing seasons, growth rate types (medium- and slow-growing chickens) and sexes. The system is applicable for daily weight monitoring in floor-reared broiler houses to improve feeding management, growth monitoring and finishing day prediction. Its application in commercial farms would improve the sustainability of poultry industry

The Mouse CircGHR Regulates Proliferation, Differentiation and Apoptosis of Hepatocytes and Myoblasts

The anterior pituitary gland of animals secretes growth hormone (GH) to bind to the growth hormone receptor (GHR) on the liver cell membrane through the blood circulation, thereby promoting the downstream gene insulin-like growth factor-1 (IGF1) expression, which is the canonical GH–GHR–IGF1 signaling pathway. Therefore, the amount of GHR and the integrity of its structure will affect animal growth and development. In the previous study, we found that the mouse GHR gene can transcribe a circular transcript named circGHR. Our group cloned the full-length of the mouse circGHR and analyzed its spatiotemporal expression profile. In this study, we further predicted the open reading frame of circGHR with bioinformatics, subsequently constructed a Flag-tagged protein vector and preliminarily verified its coding potential with western blot. Additionally, we found that circGHR could inhibit the proliferation of NCTC469 cells and has a tendency to inhibit cell apoptosis, while for C2C12 cells, it showed a tendency to inhibit cell proliferation and promote its differentiation. Overall, these results suggested that the mouse circGHR had the potential to encode proteins and affect cell proliferation, differentiation and apoptosis

Recent developments on natural fiber concrete: A review of properties, sustainability, applications, barriers, and opportunities

To reduce the carbon footprint of traditional concrete materials, natural fiber concrete is vital. This study systematically analyzed 196 peer-reviewed papers using the literature review method to understand fresh properties, mechanical properties, durability, thermal conductivity, sound absorption properties, sustainability, applications, barriers, and opportunities for natural fiber concrete. The findings indicate that natural fiber reduces the concrete cracking rate, increasing tensile strength. Although fibers enhance stress distribution within the concrete, increasing its stability, they reduce compressive strength. Additionally, 85.7% of natural fiber concretes exhibit considerable environmental benefits; however, 28.6% and 43% of the reviewed studies indicate effective economic and social sustainability, respectively. Moreover, this review demonstrates the following potential utilization: 60% in road pavements and 30% in residential buildings. However, natural fiber concrete is still predominantly utilized in the laboratory stage. The following perspective is noteworthy: this review summarizes the barriers that impede natural fiber concrete application and develops relevant recommendations

Research progress on "ammonia-hydrogen" green energy roadmap and storage & transportation technology of liquid ammonia

As a high-efficiency hydrogen energy carrier, ammonia has the significant advantages such as high energy density, low storage and transportation cost, high safety and carbon-free energy storage. It can effectively solve the problems of high-pressure storage and transportation of hydrogen energy, which is of great significance to open up a featured storage and transportation roadmap for hydrogen energy correponding to the characteristics of energy structure in China and achieve the goals of carbon peaking and carbon neutrality. Based on the fact that ammonia is easier to store and transport than hydrogen, the development status of ammonia-hydrogen green energy roadmap and the research progress of the transportation process system, safety technology and design standard of liquid ammonia pipeline relying on the roadmap were reviewed. In view of the problems that the safe pipeline transportation technology of liquid ammonia needs further research and the design experience of liquid ammonia pipeline is immature in China, the following 4 suggestions were proposed: (1) Studies should be conducted on the basic physical properties of liquid ammonia containing impurities and the phase change characteristics, as well as the thermo-hydraulic behaviors, of different pipeline transportation technologies through the combination of experiments and simulation methods. (2) The mature experience of oil and gas pipelines can be referred to liquid ammonia pipelines, but comprehensive fitness-for-service evaluation should be performed before transferring in-service oil and gas pipelines to liquid ammonia transportation ones, if any. (3) The leakage monitoring system should be improved based on the leakage and diffusion characteristics of liquid ammonia pipeline, and the effect of protection technologies should be verified and optimized. (4) The construction, operation and management standards of liquid ammonia pipelines should be improved from the perspectives of pipeline materials, equipment, safety and corrosion prevention, etc