Transcriptomes of Plant Gametophytes Have a Higher Proportion of Rapidly Evolving and Young Genes than Sporophytes

eproductive traits in plants tend to evolve rapidly due to various causes that include plant-pollinator coevolution and pollen competition, but the genomic basis of reproductive trait evolution is still largely unknown. To characterize evolutionary patterns of genome wide gene expression in reproductive tissues in the gametophyte and to compare them to developmental stages of the sporophyte, we analyzed evolutionary conservation and genetic diversity of protein-coding genes using microarray-based transcriptome data from three plant species, Arabidopsis thaliana, rice (Oryza sativa), and soybean (Glycine max). In all three species a significant shift in gene expression occurs during gametogenesis in which genes of younger evolutionary age and higher genetic diversity contribute significantly more to the transcriptome than in other stages. We refer to this phenomenon as “evolutionary bulge” during plant reproductive development because it differentiates the gametophyte from the sporophyte. We show that multiple, not mutually exclusive, causes may explain the bulge pattern, most prominently reduced tissue complexity of the gametophyte, a varying extent of selection on reproductive traits during gametogenesis as well as differences between male and female tissues. This highlights the importance of plant reproduction for understanding evolutionary forces determining the relationship of genomic and phenotypic variation in plants

Understanding the role of the anode on the polarization losses in high-temperature polymer electrolyte membrane fuel cells using the distribution of relaxation times analysis

To investigate the role of the anode on the polarization losses of a High-Temperature Polymer Electrolyte Membrane Fuel Cell (HT-PEMFC), we analyzed impedance data using the Distribution of Relaxation Times (DRT) method. Thereby, we varied the operating conditions of the anode (humidification, nitrogen dilution, and carbon monoxide (CO) impurities) to study its impact on Nyquist plot and DRT spectrum. Humidification of the hydrogen was found to dilute phosphoric acid, which is visible in the DRT. Nitrogen dilution of the anode gas slightly increases the Mass Transport (MT) resistance. Furthermore, CO was added to anode gas fed and it impacts the impedance throughout the whole frequency range, specifically the medium and low-frequency range, typically assigned to ORR kinetics and oxygen MT. For a more detailed analysis of the impedance data, a reference electrode was employed to separate the overpotential caused by each electrode. The DRT spectrum of the anode exhibits only one peak at 1 kHz. In the presence of CO, a second peak arises corresponding to side-reactions occurring as the anodic half-cell potential increases. It was found that the cathode is affected by CO on the anode merely by the lowered cell potential and not by CO directly

Robotic lobectomy: tips, pitfalls and troubleshooting

The robotic approach in thoracic surgery has rapidly gained popularity in recent years. As with the introduction of any new technology, this warrants not only adaptation of the operative technique itself, but also the evolution of appropriate troubleshooting strategies. A selected number of helpful tips and technical procedural manoeuvres have been compiled to prevent intraoperative problems, as well as to overcome challenging situations that can arise during robotic lobectomies. In robotic surgery, as opposed to open surgery or video-assisted thoracic surgery, these tips serve an important purpose for the operating surgeon, as well as the entire surgical team involved in the procedure. All the assembled recommendations have proved their effectiveness and have been successfully used by the authors in many procedures. Furthermore, these manoeuvres have been found to be of great importance in the training and proctoring of thoracic surgeons, fellows and residents (bed-side assistants). This guide of clearly arranged tips and troubleshooting strategies offers surgeons a useful tool to overcome difficult situations in robotic lobectomy and preferably improve the reproducibility and safety of their procedure

Waste Management in Nepal: Characterization and Challenges to Promote a Circular Economy

open access articleIn Nepal, the informal sector is responsible for treating 15% of household waste. It is the only alternative to landfilling and open disposal; however, the current waste management system does not acknowledge informal recyclers aggravating various challenges and vulnerabilities that the sector already faces. This study identifies and validates for the first time the challenges of the informal waste sector while providing a granular understanding of the actors that shape waste management in the region. The study uses primary data collected over a period of 6 months in Kathmandu and Lalitpur, the first and third most populated areas in Nepal. The methods considered were semi-structured interviews, questionnaires, and a co-creation workshop with formal and informal actors. A novel characterization of waste management actors was conducted to identify two profiles namely cyclists and scavengers and question the formality of the collection centres. Findings suggest that the price volatility of recycled materials and the lack of treatment and absence of regulatory capacity are among the main challenges in promoting a circular economy from the informal sector. The recommendations to overcome these challenges are a series of policy reforms, such as an extended responsibility producer scheme and the review of the tax on recycled material transport. The main policy implication from the finding reveals that circular economy is already being promoted by the informal sector — a responsibility that should fall under the remit of the regional and national governments. The study concludes that integration is not only necessary to improve the conditions of informal workers but essential to developing a circular economy in Nepal

Use of a Novel Polymer-Coated Steel as an Alternative to Traditional Can Manufacturing in the Food Industry

[EN] Metal containers (both food and beverage cans) are made from huge steel or aluminum coils that are transformed into two- or three-piece products. During the manufacturing process, the metal is sprayed on both sides and the aerosol acts as insulation, but unfortunately produces volatile organic compounds (VOCs). The present work presents a different way to manufacture these containers using a novel prelaminated two-layer polymer steel. It was experimentally possible to verify that the material survives all the involved manufacturing processes. Thus tests were carried out in an ironing simulator to measure roughness, friction coefficient and surface quality. In addition, two theoretical ironing models were developed: upper bound model and artificial neural network. These models are useful for packaging designers and manufacturers.Sellés, M.; Schmid, SR.; Sanchez-Caballero, S.; Ramezani, M.; Pérez Bernabeu, E. (2021). Use of a Novel Polymer-Coated Steel as an Alternative to Traditional Can Manufacturing in the Food Industry. Polymers. 13(2):1-15. https://doi.org/10.3390/polym13020222S11513

Surface tension of the isotropic-nematic interface

We present the first calculations of the pressure tensor profile in the vicinity of the planar interface between isotropic liquid and nematic liquid crystal, using Onsager's density functional theory and computer simulation. When the liquid crystal director is aligned parallel to the interface, the situation of lowest free energy, there is a large tension on the nematic side of the interface and a small compressive region on the isotropic side. By contrast, for perpendicular alignment, the tension is on the isotropic side. There is excellent agreement between theory and simulation both in the forms of the pressure tensor profiles, and the values of the surface tension.Comment: Minor changes; to appear in Phys. Rev.

Advanced interface models for metal forming simulations

Friction and heat transfer in metal forming simulations are usually restricted by software to be interface constants, a situation not reflected by the mechanics of real manufacturing processes. A better simulation approach is to use a micromechanics based method to estimate friction and heat transfer as evolutionary phenomenon. This paper presents a friction and heat transfer module for hot forging simulations. The friction model is based on a lubricant film thickness calculation using the Reynolds equation, and a calculation of the fractional contact area based on asperity flattening and roughening. Friction is then portioned between asperity and lubricant contacts. Heat transfer coefficients are calculated using a new model for heat conduction through asperity contact patches and lubricant that takes into account the restriction to heat flow at the contacts. The program is implemented as a user routine in a popular commercially available finite element code, DEFORM 2D.Schmid, SR.; Liu, J.; Sellés Cantó, MÁ.; Pasang, T. (2013). Advanced interface models for metal forming simulations. Computational Materials Science. 79:763-771. doi:10.1016/j.commatsci.2013.07.025S7637717

Integrating out strange quarks in ChPT

We study three flavour chiral perturbation theory in a limit where the strange quark mass is much larger than the external momenta and the up and down quark masses, and where the external fields are those of two-flavour chiral perturbation theory. In this case, the theory reduces to the one of SU(2)_L x SU(2)_R. Through this reduction, one can work out the strange quark mass dependence of the LECs in the two-flavour case. We present the pertinent relations at two-loop order for F,B and l_i.Comment: 14 pages, 3 figures, References added. Due to a typo in a form program, we missed a finite, scale independent part in l_7. Is now included. Version to appear in Phys.Lett.

Search for Solar Axions Produced in the p+d→3He+Ap + d \rightarrow\rm{^3He}+ A Reaction

A search for the axioelectric absorption of 5.5-MeV solar axions produced in the $p+d\rightarrow \rm{^3He}+\gamma(5.5 \rm{MeV})$ reaction was performed with two BGO detectors placed inside a low-background setup. A model independent limit on axion-photon and axion-nucleon couplings was obtained: $|g_{Ae}\times g_{AN}| \leq 3.2\times 10^{-9} (m_A=0)$. Constraints on the axion-electron coupling constant were obtained for axions with masses in the $(0.1-1.0)$ MeV range: $g_{Ae}\leq (1.8-9.0)\times 10^{-7}$. The solar positron flux from $A\rightarrow e^-+e^+$ decay was determined for axions with masses $m_A > 2m_e$. Using the existing experimental data on the interplanetary positron flux, a new constraint on the axion-electron coupling constant for axions with masses in the $(1.2-5.4)$ MeV range was obtained: $g_{Ae} \leq (1-5)\times 10^{-17}$.Comment: 6 pages, 5 figure