Band-edge-induced Bragg diffraction in two-dimensional photonic crystals

Two-dimensional photonic crystals composed of two orthogonal volume diffraction gratings have been photogenerated in photopolymers. When the read beam is set at the Bragg angle, the diffraction efficiency of the transmission grating is strongly enhanced at the band edge of the reflection grating recorded in the material. Such a device provides Bragg operation and enhancement of the diffraction efficiency of the thin diffraction grating together with good wavelength selectivity. Such advantages could be interesting for optical signal processing

The Poplar-Poplar Rust Interaction: Insights from Genomics and Transcriptomics

Poplars are extensively cultivated worldwide, and their susceptibility to the leaf rust fungus Melampsora larici-populina leads to considerable damages in plantations. Despite a good knowledge of the poplar rust life cycle, and particularly the epidemics on poplar, the perennial status of the plant host and the obligate biotrophic lifestyle of the rust fungus are bottlenecks for molecular investigations. Following the completion of both M. larici-populina and Populus trichocarpa genome sequences, gene families involved in poplar resistance or in rust fungus virulence were investigated, allowing the identification of key genetic determinants likely controlling the outcome of the interaction. Specific expansions of resistance and defense-related genes in poplar indicate probable innovations in perennial species in relation with host-pathogen interactions. The genome of M. Larici-populina contains a strikingly high number of genes encoding small secreted proteins (SSPs) representing hundreds of candidate effectors. Transcriptome analyses of interacting partners in compatible and incompatible interactions revealed conserved set of genes involved in poplar defense reactions as well as timely regulated expression of SSP transcripts during host tissues colonisation. Ongoing functional studies of selected candidate effectors will be achieved mainly on the basis of recombinant protein purification and subsequent characterisation

A case report of liver transplantation following a biliopancreatic diversion: A friendly cohabitation?

Abstract Today, bariatric surgery has become the main therapeutic means to fight against the escalating increase in obesity, worldwide. Besides that, non-alcoholic steatohepatitis has inflated its indication for liver transplantation. Liver transplant surgeons are prone to face more and more patients with such background. Here, we described the first case of liver transplantation for hepatocellular carcinoma in a patient with previous history of biliopancreatic diversion with duodenal switch. Biliopancreatic diversion with duodenal switch is nowadays an uncommon bariatric surgery but use to be a second stage surgery following sleeve gastrectomy. Liver transplantation can be challenging as such bariatric procedure reshape the digestive anatomy and can also be responsible for malnutrition. Without such complication and in a center specialized in bariatric surgery and liver transplantation, such cases can be successful and should not alarm liver transplant surgeons. In our case, the bariatric anatomy was conserved, and the liver transplantation was successful, without difficulty of the post-operative immunosuppressive treatment. However, long term follow-up showed an exacerbation of the sarcopenia level and establish even more the need for an association of a well-planned physical and nutritional rehabilitation in the peri-operative period in such candidate

The Tertiary relict tree Zelkova abelicea (Ulmaceae): distribution, population structure and conservation status on Crete

Relict species provide a unique opportunity to understand past and recent biogeographical and evolutionary processes. Zelkova abelicea (Ulmaceae), which is endemic to the island of Crete (Greece), is one of the most prominent Tertiary relict trees of the Mediterranean region. We collected distribution, threat and population structure data by reviewing literature and herbaria and through field surveys at 14 study plots throughout the range of the species. The present distribution of Z. abelicea is extremely fragmented. Although the total estimated number of individuals is relatively high, the populations are dominated by dwarf, severely browsed, non-flowering individuals. The population structure is asymmetric. At most, 5% of a plot's trees are large and fruit-bearing. The asymmetric structure is particularly pronounced in isolated and small populations. Based on its limited geographical range, the fragmented spatial pattern, and data on distribution and population structure, our study confirms that Z. abelicea is a threatened species (IUCN category Endangered). Our research aim is to promote the development of new approaches for the improvement of conservation strategies for Tertiary relict trees characterized by major local disjunction

Results ofstandard stapler closure of pancreatic remnanat after distal spleno-pancreatectomy for adenocarcinoma

Background/Aim: The purpose of this study was to evaluate the results of stapled closure of the pancreatic remnant after cold-knife section of the pancreatic isthmus and distal pancreatectomy for adenocarcinoma. Methods: A retrospective evaluation of 57 consecutive patients undergoing distal spleno-pancreatectomy for adenocarcinoma was performed. The pancreatic isthmus was systematically straight-sectioned with a cold knife, and the remnant was stapled close without additional stitches or adjuncts. The study’s main endpoints were postoperativemortality, the occurrence of a pancreatic fistula, the need for a re-operation, the postoperative length of stay in the hospital, the rate of re-admission, and late survival. Results: Postoperative mortality was absent. Seventeen patients (29.8%) presented a pancreatic fistula of grade A in seven cases (41.2%), grade B in eight cases (47.1%), and grade C in two cases (11.8%). Re-operation was required in the two patients (3.5%) with grade C fistula in order to drain an intra-abdominal abscess. The mean postoperative length of stay in the hospital was 15 days (range, 6–62 days). No patient required re-admission. Twenty-nine patients (50.8%) were alive and free from disease, respectively, 12 patients (21.1%) at 12 months, 13 patients (22.8%) at 60 months, and four patients (7.0%) at 120 months from the operation. The remaining patients died of metastatic disease 9–37 months from the operation. Lastly, disease-related mortality was 49.1%. Conclusion: Stapler closure of the pancreatic remnant allows good postoperative results, limiting the formation of pancreatic fistula to the lower limit of its overall reported incidence

A survey of highly cited studies on plant pathogen effectors during the last two decades (2000-2020)

Plant effector biology is a research area that describes how plant-associated organisms modulate host structures and function to promote colonization by using small molecules (effectors). In this article, we analyzed 249 highly cited publications focused on plant pathogen effectors (i.e., Highly Influential studies on plant Pathogen Effectors; thereafter HIPEs) published between 2000 and 2020. This analysis identifies countries, organizations, and journals that contributed HIPEs, and reveals the evolution of research trends, model molecules, and model organisms over the last two decades. We notably show an increasing proportion of studies focused on effectors of biotrophic and hemibiotrophic fungi upon time. Our snapshot of the highly influential plant effector biology papers may help new comers in the field to gain an analytical understanding of this research area

Unprecedented change in the position of four radio sources

Astrometric positions of radio-emitting active galactic nuclei (AGNs) can be determined with sub-milliarcsec accuracy using very long baseline interferometry (VLBI). The usually small apparent proper motion of distant extragalactic targets allow us to realize the fundamental celestial reference frame with VLBI observations. However, long-term astrometric monitoring may reveal extreme changes in some AGN positions. Using new VLBI observations in 2018-2021, we show here that four extragalactic radio sources (3C48, CTA21, 1144+352, 1328+254) have a dramatic shift in their positions by 20-130 milliarcsec over two decades. For all four sources, the apparent positional shift is caused by their radio structure change.Comment: Accepted for publication in MNRA

WRINKLED1 and ACYL‐COA:DIACYLGLYCEROL ACYLTRANSFERASE1 regulate tocochromanol metabolism in Arabidopsis

Photosynthetic organisms such as plants, algae and some cyanobacteria synthesize tocochromanols, a group of compounds that encompasses tocopherols and tocotrienols and that exhibits vitamin E activity in animals. While most vitamin E biosynthetic genes have been identified in plant genomes, regulatory genes controlling tocopherol accumulation are currently unknown.We isolated by forward genetics Arabidopsis enhanced vitamin E (eve) mutants that overaccumulate the classic tocopherols and plastochromanol-8, and a tocochromanol unknown in this species. We mapped eve1 and eve4, and identified the unknown Arabidopsis tocochromanol by using a combination of analytical tools. In addition, we determined its biosynthetic pathway with a series of tocochromanol biosynthetic mutants and transgenic lines.eve1 and eve4 are two seed lipid mutants affecting the WRINKLED1 (WRI1) and ACYL-COA:DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1) genes, respectively. The unknown tocochromanol is 11′-12′ γ-tocomonoenol, whose biosynthesis is VITAMIN E 1 (VTE1) - and VTE2-dependent and is initiated by the condensation of homogentisate (HGA) and tetrahydrogeranylgeranyl pyrophosphate.This study identifies the first two regulatory genes, WRI1 and DGAT1, that control the synthesis of all tocochromanol forms in seeds, and shows the existence of a metabolic trade-off between lipid and tocochromanol metabolisms. Moreover, it shows that Arabidopsis possesses a tocomonoenol biosynthetic pathway that competes with tocopherol synthesis

Do living ex situ collections capture the genetic variation of wild populations? A molecular analysis of two relict tree species, Zelkova abelica and Zelkova carpinifolia

Botanic gardens and arboreta, particularly in regions where iconic relict trees naturally occur, play a vital role in the conservation of these species. Maintaining well-managed living ex situ collections of rare and threatened relict tree species provides an immediate insurance policy for the future species conservation. The aim of this research was to investigate the origin, representativeness and genetic diversity of relict trees kept in botanic gardens and arboreta. We used as a model two ecologically and biogeographically distinct members of the prominent relict genus Zelkova (Ulmaceae), which survived the last glaciation in disjunct and isolated refugial regions: Z. carpinifolia in Transcaucasia and Z. abelicea endemic to Crete (Greece) in the Mediterranean. Our study revealed substantial differences in the genetic diversity and the origin of living ex situ collections of the two investigated taxa. The living ex situ collections of Z. carpinifolia have relatively high representativeness compared with the global genetic variability of natural stands identified in a previous study. In contrast, Z. abelicea, which possesses an extraordinarily high genetic variability in natural populations, is clearly underrepresented in botanic garden collections. Moreover, all Z. abelicea trees investigated in this study most probably originated from a single region, the Levka Ori in western Crete. Thus, the ex situ conservation of Z. abelicea requires major planning and coordination efforts, including the establishment of well-documented collections in botanic gardens in Greece and especially on Crete. New living ex situ collections should be created using plant material collected from all of the mountain regions where Z. abelicea still occurs. Our study highlights the need for re-evaluating the existing living ex situ collections of trees and the development of new strategies for future conservation efforts in botanic gardens and arboreta. The coordination of conservation efforts between gardens must be enhanced to prioritize actions for the most threatened relict tree species