On birational transformations of Hilbert schemes of points on K3 surfaces

We classify the group of birational automorphisms of Hilbert schemes of points on algebraic K3 surfaces of Picard rank one. We study whether these automorphisms are symplectic or non-symplectic and if there exists a hyperk\"ahler birational model on which they become biregular. We also present new geometrical constructions of these automorphisms.Comment: Minor changes, some errors are corrected. 26 page

Developmental cell biology of the BRX pathway in hormonal regulation and root stem cell regeneration

Plants evolved innovative solutions to survive and disseminate during land colonization. The key to success was the development of several systems driven by the new needs in the terrestrial environment. The root architecture system functions to mechanically support the plant and anchor it in the soil, as well as to acquire water and minerals. Concomitantly, plants evolved a long distance transport system composed of xylem, which distributes water and minerals, and phloem (proto- and meta-phloem), which transports so-called sap. Phloem sap, charged in carbohydrates and signalling molecules, is transported from the above-ground source organs to sink organs, such as the root. The protophloem functions as the final conduit into the root apical meristem (RAM), unloading the sap into the developing root apex. The RAM exhibits specific domains in which each cell undergoes specific sequence of division and differentiation. Intersected gene networks, phytohormones and epigenetic markers allow the maintenance of this pattern and maintain the division/differentiation rate to ensure the optimal root growth. In Arabidopsis thaliana, BREVIS RADIX (BRX) counteracts the CLAVATA3/EMBRYO SURRONDING REGION 45 – BARELY ANY MERISTEM 3 (BAM3) module that inhibits protophloem development. The local hyperactivity of this module in brx loss- of-function mutants generates undifferentiated cells (so-called gaps) which interrupt protophloem differentiation and thereby transport, and lead to a pleiotropic root phenotype (i.e. a shorter primary root and a more branched root system). Here I show the effects of a weakened variant of the CLE45 ligand, in which the crucial glycine at position six is replaced by a threonine. CLE45G6T roots are morphologically similar to brx and display a stochastic occurrence of gaps. In order to dissect the protophloem development genetically, I screened for brx suppressors uncovering several unknown bam3 alleles. Likewise, among brx suppressors, deleterious mutations either in BIG BROTHER (BB) or in JUMONJI 14 (JMJ14) can partially rescue the impaired root growth. Both genes are expressed in the primary root, but their biological function in root development is largely unknown. Here I show that BB limits cell proliferation but not elongation. bb loss-of-function mutants exhibit enhanced meristematic cell number, but bb surprisingly has no longer root compared to wild type. Dissection of the root meristem revealed as well a considerable enhancement of cell density within the root stele. I deduce that bb radial cell proliferation might slow down the overall root growth. However, in sensitized genetic backgrounds, such as brx, the supernumerary cells counterbalance the reduced root length. My findings therefore reveal a general role for BB in limiting cell proliferation in Arabidopsis roots. Contrary to bb, jmj14 mutants display neither differences in cell number, nor in cell elongation. JMJ14, an H3K4 demethylase, might modulate gene expression and thus indirectly influence root growth in brx. In summary, I identified several second site suppressors of the brx, which enhance our understanding of protophloem development and of root development in general. -- Les plantes ont sélectionné des solutions innovantes pour survivre et se disséminer en milieu aérien. L’un des éléments-clés de ce succès est l’acquisition d’un système racinaire servant à la fois de support mécanique, pour ancrer la plante dans le sol, et aussi d’atout physiologique, permettant à la plante de puiser l’eau et les minéraux présents dans le sol. De manière concomitante, la plante a développé un système de transport longue distance composé du xylème, conduisant la sève brute, et du phloème (composé de proto et méta-phloème), conduisant la sève élaborée. Cette dernière, chargée en photoassimilats et autres molécules signal indispensables à la croissance, est transportée depuis les organes sources photosynthétiques vers les organes puits en cours de développement tel que la racine. Ainsi, le proto-phloème assure le transport ultime de sève élaborée où elle est déchargée au niveau du Méristème Apical Racinaire (MAR) en cours de développement. Chez Arabidopsis thaliana, BREVIS RADIX (BRX) inhibe CLAVATA3/EMBRYO SURROUNDING REGION 45 (CLE45) - BARELY ANY MERISTEM 3 (BAM3), module qui inhibe la différentiation du proto-phloème. L'hyperactivité locale de ce module dans les mutants brx, chez lesquels BRX n’est pas fonctionnel, génère des cellules indifférenciées (appelées gaps) qui interrompent la différenciation du protophloème et produisent ainsi un phénotype pléiotropique (c'est-à-dire une racine primaire plus courte et un système racinaire plus ramifié). Dans ce travail, je montre l’effet d’une version atténuée du peptide CLE45: le peptide CLE45G6T présentant la substitution d’une glycine par une thréonine en position six du peptide. Les plantes exprimant CLE45G6T présentent les mêmes défauts de développement que le mutant brx, à savoir une différentiation stochastique du phloème. Un «screen» suppresseur mené sur le mutant brx a permis l’identification de nombreux acteurs impliqués dans la différentiation du proto-phloème y compris des allèles inconnus de bam3. Ainsi, big brother (bb) et jumonji 14 (jmj14) permettent de rétablir partiellement la croissance racinaire chez brx. Ces deux gènes sont exprimés dans la racine mais leurs fonctions biologiques dans la racine sont peu décrites. Chez le mutant bb le nombre de cellules méristématiques est augmentée alors que la longueur de la racine ne l’est pas comparée à la forme sauvage. La prolifération cellulaire radiale chez bb pourrait ralentir la croissance racinaire globale. Cependant, chez des mutants affectés dans le développement tel que brx, ces cellules surnuméraires pourraient contrebalancer les défauts de croissance. Mes travaux montrent que BB limite la prolifération cellulaire dans la racine d’Arabidopsis mais n’affecte pas l’élongation cellulaire. Contrairement à bb, jmj14 ne présente pas de différence dans le nombre de cellules, ni dans l’élongation cellulaire. De par son activité de H3K4 demethylase, JMJ14 pourrait moduler l’expression de certains gènes et ainsi promouvoir indirectement la croissance racinaire chez brx. En résumé, j’ai identifié plusieurs mutations suppressives du mutant brx, nous permettant ainsi d’approfondir notre compréhension du phloème et du développement de la racine en général

Non-thermal inactivation of listeria spp. In a typical dry-fermented sausage : “Bergamasco” salami

Aim of the present study was the evaluation of the growth potential of Listeria spp. inoculated in the typical North Italian dry fermented sausage "Bergamasco" salami during its production. As it was necessary to carry out the challenge test in the production line of the industry, according to the guidelines of the European Reference Laboratory for Listeria monocytogenes, a non-pathogenic "surrogate" microorganism was used: for the inoculum, two strains of Listeria innocua (1 ATCC, 1 strain isolated from a similar substrate) were used. The inoculation of the samples occurred during grinding and mixing of the sausage mass, before the filling. To avoid cross-contamination, the control samples were produced before the contaminated ones. After the dripping, salamis were subjected to the normal production process (drying and maturation in five steps at specific temperatures and humidity rates). The inoculated products were subjected to the enumeration of Listeria spp. at T0 (day of inoculation) and at T4 (post-drying), and every 10 days during curing (T10, T20, T30, T40, T50, T60, T70, T80 and T90), as this salami is generally sold as whole piece with varying levels of curing (from T20 to T90). Since the product may be cut in half and vacuumpacked, at each of the times starting from T20, half salami was vacuum-packed and stored for 30 days at 12\ub0C, at the end of the which Listeria spp. enumeration was performed again. At all times and for each type of samples of each of the three batches, the enumeration of the natural microflora (Total Viable Count, lactic acid bacteria, Pseudomonas spp., Enterobacteriaceae) and the determination of water activity and pH were performed on control samples. The product was characterized by a high concentration of microflora (8-8.5 Log UFC/g), consisting mainly of lactic acid bacteria, added to the mixture at the beginning of the production process. The pH showed a decrease over time, expected for this type of products, due to the development of lactic acid bacteria (final pH: 5.42-5.55). The water activity reached values able to inhibit the development of Listeria spp. (final aw: 0.826-0.863). Listeria counts in the tested batches of "Bergamasco" salami showed the absence of significant growth in the product with a reduction of loads if compared to T0, between -0.59 and -1.04 Log CFU/g. Even in the samples subjected to vacuum packaging and storage at 12\ub0C, the absence of significant increase of lactic acid bacteria in the product was highlighted with further decrease of bacterial loads (-0.70/-0.79 Log CFU/g if compared to T20). Considering the worst case scenario (thus the batch with the highest growth potential), in the products stored in the curing room at 14-16\ub0C, at humidity of 80% and in the samples stored at 12\ub0C and vacuum packaged, the threshold indicated by the EURL Lm guidelines (+0.5 Log CFU/g) for the growth of Listeria spp. was not reached, allowing to classify "Bergamasco" salami in the category 1.3 of the EC Reg. 2073/2005 as "Ready-to-eat food unable to support the growth of Listeria monocytogenes"

Long-term motor deficit in brain tumour surgery with preserved intra-operative motor-evoked potentials

Muscle motor-evoked potentials are commonly monitored during brain tumour surgery in motor areas, as these are assumed to reflect the integrity of descending motor pathways, including the corticospinal tract. However, while the loss of muscle motor-evoked potentials at the end of surgery is associated with long-term motor deficits (muscle motor-evoked potential-related deficits), there is increasing evidence that motor deficit can occur despite no change in muscle motor-evoked potentials (muscle motor-evoked potential-unrelated deficits), particularly after surgery of non-primary regions involved in motor control. In this study, we aimed to investigate the incidence of muscle motor-evoked potential-unrelated deficits and to identify the associated brain regions. We retrospectively reviewed 125 consecutive patients who underwent surgery for peri-Rolandic lesions using intra-operative neurophysiological monitoring. Intraoperative changes in muscle motor-evoked potentials were correlated with motor outcome, assessed by the Medical Research Council scale. We performed voxel-lesion-symptom mapping to identify which resected regions were associated with short- and long-term muscle motor-evoked potential-associated motor deficits. Muscle motor-evoked potentials reductions significantly predicted long-term motor deficits. However, in more than half of the patients who experienced long-term deficits (12/22 patients), no muscle motor-evoked potential reduction was reported during surgery. Lesion analysis showed that muscle motor-evoked potential-related long-term motor deficits were associated with direct or ischaemic damage to the corticospinal tract, whereas muscle motor-evoked potential-unrelated deficits occurred when supplementary motor areas were resected in conjunction with dorsal premotor regions and the anterior cingulate. Our results indicate that long-term motor deficits unrelated to the corticospinal tract can occur more often than currently reported. As these deficits cannot be predicted by muscle motor-evoked potentials, a combination of awake and/or novel asleep techniques other than muscle motor-evoked potentials monitoring should be implemented

Antagonistic peptide technology for functional dissection of CLE peptides revisited

Information collected using antagonistic peptide approaches can be very useful, but these approaches do not work in all cases and require insight on ligand-receptor interactions and peptide ligand structur

Recreational fisheries within the Portofino MPA and surrounding areas (Ligurian Sea, Western Mediterranean Sea)

In the Mediterranean Sea, recreational fishing is a popular activity and anglers catch a significant amount of fish which could represent more than 10% of the total harvesting in a littoral area. The Portofino Marine Protected Area, established in 1999 in the Ligurian Sea (North-Western Mediterranean), traditionally hosts a well-developed recreational fishery. Aim of this study has been to characterize the activities of the local anglers, analysing their annual harvesting within and around the Portofino MPA and the species composition of the catches. This was possible studying data from the mandatory anglers' logbooks, and through interviews and surveys at sea. In 2015, the 340 checked anglers fished, in average, 1 kg/day, on average, mainly by trolling or handlining systems. Each fisherman, during 25 (± 21) trips, fished approximately 25 kg/year, for a total harvesting of about 8-9 t/year. Seriola dumerili, with 230 kg/year, was the species most caught in terms of biomass. It was followed by Coryphaena hippurus (130 kg/year). In addition, the analysis of catches occurring during local fishing competitions organized off the MPA limits suggested a harvesting capacity for each angler varying between 0.7 and 1.1 kg/angler per day, depending on the used gear (handlining, trolling, spear-guns). Finally, 36% of the anglers claimed to hook often the hard bottom seabed, often losing nylon lines. Consequently, the Management Body of the Portofino MPA has been advised to suspend recreational fishing activities in the most busy areas for a period of two years, calling for a complete removal of the lost fishing gears

Taste and smell : a unifying chemosensory theory

Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hear-ing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch.With the progress of natural sciences, information at molecular, anatomical, and neurobiological levelshas also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differenti-ation of these two senses has emerged, especially when considering species other than humans. In spite ofthis, conflicting information has been interpreted so that it could conform to the traditional differentia-tion. As a result, a confirmation bias is currently affecting scientific research on chemosensory systemsand is also hindering the development of a satisfactory narrative of the evolution of chemical communi-cation across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. Wethus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic,complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals havebecome signals that are crucially important to communication among and within cells, organs, and or-ganisms in a wide variety of environmental conditions

Taste and Smell: A Unifying Chemosensory Theory

Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hearing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch. With the progress of natural sciences, information at molecular, anatomical, and neurobiological levels has also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differentiation of these two senses has emerged, especially when considering species other than humans. In spite of this, conflicting information has been interpreted so that it could conform to the traditional differentiation. As a result, a confirmation bias is currently affecting scientific research on chemosensory systems and is also hindering the development of a satisfactory narrative of the evolution of chemical communication across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. We thus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic, complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals have become signals that are crucially important to communication among and within cells, organs, and organisms in a wide variety of environmental condition

Taste and Smell: A Unifying Chemosensory Theory

Since antiquity, the sense of smell (olfaction) is considered as a distance sense, just like sight and hear- ing. Conversely, the sense of taste (gustation) is thought to operate by direct contact, similarly to touch. With the progress of natural sciences, information at molecular, anatomical, and neurobiological levels has also contributed to the taste-smell dichotomy, but much evidence inconsistent with a sharp differenti- ation of these two senses has emerged, especially when considering species other than humans. In spite of this, conflicting information has been interpreted so that it could conform to the traditional differentia- tion. As a result, a confirmation bias is currently affecting scientific research on chemosensory systems and is also hindering the development of a satisfactory narrative of the evolution of chemical communi- cation across taxa. From this perspective, the chemosensory dichotomy loses its validity and usefulness. We thus propose the unification of all chemosensory modalities into a single sense, moving toward a synthetic, complex, and interconnected perspective on the gradual processes by which a vast variety of chemicals have become signals that are crucially important to communication among and within cells, organs, and or- ganisms in a wide variety of environmental conditions

Systematic versus on-demand early palliative care: results from a multicentre, randomised clinical trial

Background Early palliative care (EPC) in oncology has been shown to have a positive impact on clinical outcome, quality-of-care outcomes, and costs. However, the optimal way for activating EPC has yet to be defined. Methods This prospective, multicentre, randomised study was conducted on 207 outpatients with metastatic or locally advanced inoperable pancreatic cancer. Patients were randomised to receive ‘standard cancer care plus on-demand EPC’ (n = 100) or ‘standard cancer care plus systematic EPC’ (n = 107). Primary outcome was change in quality of life (QoL) evaluated through the Functional Assessment of Cancer Therapy – Hepatobiliary questionnaire between baseline (T0) and after 12 weeks (T1), in particular the integration of physical, functional, and Hepatic Cancer Subscale (HCS) combined in the Trial Outcome Index (TOI). Patient mood, survival, relatives' satisfaction with care, and indicators of aggressiveness of care were also evaluated. Findings The mean changes in TOI score and HCS score between T0 and T1 were −4.47 and −0.63, with a difference between groups of 3.83 (95% confidence interval [CI] 0.10–7.57) (p = 0.041), and −2.23 and 0.28 (difference between groups of 2.51, 95% CI 0.40–4.61, p = 0.013), in favour of interventional group. QoL scores at T1 of TOI scale and HCS were 84.4 versus 78.1 (p = 0.022) and 52.0 versus 48.2 (p = 0.008), respectively, for interventional and standard arm. Until February 2016, 143 (76.9%) of the 186 evaluable patients had died. There was no difference in overall survival between treatment arms. Interpretations Systematic EPC in advanced pancreatic cancer patients significantly improved QoL with respect to on-demand EPC