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Ovule development is a key process for plant reproduction, helping to ensure correct seed production. Several molecular factors and plant hormones such as gibberellins are involved in ovule initiation and development. Gibberellins control ovule development by the destabilization of DELLA proteins, whereas DELLA activity has been shown to act as a positive factor for ovule primordia emergence. But the molecular mechanism by which DELLA acts in ovule primordia initiation remained unknown. In this study we report that DELLA proteins participate in ovule initiation by the formation of a protein complex with the CUC2 transcription factor. The DELLA protein GAI requires CUC2 to promote ovule primordia formation, through the direct GAI-CUC2 interaction in placental cells that would determine the boundary regions between ovules during pistil development. Analysis of GAI-CUC2 interaction and co-localization in the placenta supports this hypothesis. Moreover, molecular analysis identified a subset of the loci for which the GAI protein may act as a transcriptional co-regulator in a CUC2-dependent manner. The DELLA-CUC2 complex is a component of the gene regulatory network controlling ovule primordia initiation in Arabidopsis.

BACKGROUND: During the COVID-19 outbreak, most hospitals deferred elective surgical procedures to allow space for the overwhelming number of COVID-19 patient admissions, expecting a decrease in routine blood component requirements. However, because transfusion support needs of COVID-19 patients are not well known, its impact on hospital blood supply is uncertain. The objective of this study was to assess the effect of the COVID-19 pandemic on transfusion demand. STUDY DESIGN AND METHODS: Transfusion records during the peak of the COVID-19 pandemic (March 1-April 30, 2020) were reviewed in our center to assess changes in blood requirements. RESULTS: During this period 636 patients received a total of 2934 blood components, which reflects a 17.6% reduction in transfusion requirements with regard to the same period of 2019, and blood donations in Madrid dropped by 45%. The surgical blood demand decreased significantly during the outbreak (50.2%). Blood usage in the hematology and oncology departments remained unchanged, while the day ward demand halved, and intensive care unit transfusion needs increased by 116%. A total of 6.2% of all COVID inpatients required transfusion support. COVID-19 inpatients consumed 19% of all blood components, which counterbalanced the savings owed to the reduction in elective procedures. CONCLUSION: Although only a minority of COVID-19 inpatients required transfusion, the expected reduction in transfusion needs caused by the lack of elective surgical procedures is partially offset by the large number of admitted patients during the peak of the pandemic. This fact must be taken into account when planning hospital blood supply.

Mediterranean ecosystems are increasingly threatened by disturbances such as wildfires. These disturbances are expected to shift the selective pressures that determine trait-dependent community assembly. In addition, the stochasticity in species assembly may decrease because of the introduction of strong selection regimes or may increase because of random variation in recruitment. However, these changes in the selection profile and stochasticity in disturbed communities have seldom been evaluated. We examined the relative roles of wildfire disturbance, local conditions and successional dynamics on the assembly of aquatic macroinvertebrate communities. We used the theory of community assembly by trait selection (CATS) to identify traits under selection and to estimate their dependence on wildfire disturbance and environmental gradients. We took advantage of a natural wildfire that partially burned a Mediterranean system of temporary ponds, which were surveyed before and after the wildfire, creating a natural before-after-control-impact design. Before the wildfire, the burned and unburned ponds did not show differences in the selected traits. After the wildfire event, species with larger body sizes and scrapers were favoured in the burned ponds, while collectors and active dispersers were underrepresented. Nonetheless, local environmental conditions and successional dynamics had greater relevance in the selection of traits than the wildfire. This suggests that assembly mechanisms were largely determined by seasonal successional changes regardless of wildfire disturbance. Finally, the relevance of the analysed traits diminished during the hydroperiod, suggesting more stochastic assemblages and/or a replacement in the set of selected traits. Despite the prominent role of seasonal succession over wildfire, this disturbance was associated with a change in the selection strength over specific traits related with feeding strategies and species life histories. Both hydroperiod and wildfire highlighted a strong role of trait-mediated processes (i.e. niche assembly). Therefore, the predicted increase in the frequency and intensity of wildfires is likely to result in community functional shifts. Furthermore, stochasticity was also important for community assembly, particularly from the middle towards the end of the hydroperiod. Our results evidenced the strong relevance of successional changes in trait-mediated assembly mechanisms and its interplay with wildfire disturbance in temporary pond communities.Els efectes de les pertorbacions com ara els incendis són cada cop més freqüents en els ecosistemes mediterranis. Aquestes pertorbacions poden generar un canvi en els mecanismes de selecció sobre algunes espècies amb determinades característiques o trets biològics. Així, aquests canvis poden suposar un augment en la importància de la selecció d'uns determinats trets o, per contra, afavorir processos més estocàstics. De fet, l'efecte d'una pertorbació sobre aquests mecanismes i els canvis que comporten en la comunitat animal han estat poc estudiats. En aquest estudi s'ha analitzat el paper que juguen a l'hora de determinar l'estructura de les comunitats de macroinvertebrats aquàtics, els efectes d'un incendi, les condicions ambientals i les seves pròpies dinàmiques de successió. Per tal d'analitzar-ho, s'ha utilitzat la teoria de la selecció de trets en la generació de comunitats (CATS de les sigles en anglès) per identificar els principals trets afectats per la selecció i estimar-ne la relació amb l'incendi i els diversos gradients ambientals. Casualment s'havien mostrejat un conjunt d'estanys temporanis mediterranis un any abans que un incendi els afectes. Això va permetre comparar l'abans i el després de l'incendi, així com estanys cremats i no cremats. Abans d'aquesta pertorbació, els estanys cremats i no cremats no mostraven diferències en la selecció de determinats trets biològics de la fauna de macroinvertebrats. En canvi, després de la pertorbació, als estanys afectats per l'incendi les espècies de majors dimensions i els brostejadors es van veure afavorits mentre que els recol·lectors i els dispersors actius van tenir-hi una menor presència. Tanmateix, les condicions ambientals de cada lloc i els canvis lligats a la successió temporal de la comunitat mostraven una major importància en determinar la selecció de trets que no pas l'efecte de incendi. Aquest fet denota que tot i l'impacte de l'incendi, les condicions ambientals i els canvis al llarg del temps seguien essent els principals determinants de les comunitats estudiades. Finalment, al llarg de l'hidroperíode la rellevància de la selecció de trets analitzats va anar disminuint, cosa que suggereix un augment dels processos més estocàstics i/o un canvi en el conjunt de trets seleccionats. Tot i el rol dominant dels canvis estacionals sobre els generats per l'incendi, aquesta pertorbació va tenir un impacte en les forces de selecció per a alguns caràcters concrets relacionats amb l'alimentació i els cicles de vida d'algunes espècies. Consegüentment, tant els canvis al llarg de l'hidroperíode com els deguts a l'incendi subratllen una forta predominança de la selecció per trets en els estanys temporanis (mecanismes de nínxol). També cal destacar el paper i l'augment de processos més estocàstics, especialment a mesura que avança l'hidroperíode. En conseqüència, l'augment previst de la freqüència i la intensitat dels incendis pot induir canvis en el funcionament de les comunitats estudiades. Aquest estudi vol posar de manifest el paper dominant dels canvis lligats a la successió i com aquests canvis interactuen amb els generats per un incendi determinant les comunitats dels estanys temporanis, fortament influenciades per mecanismes de nínxol.

PURPOSE The objective of this study was to characterize the Best Medical Canada microMOSFET detectors for their application in in vivo dosimetry for high-dose-rate brachytherapy (HDRBT) with 192 Ir. We also developed a mathematical model to correct dependencies under the measurement conditions of these detectors. METHODS We analyzed the linearity, reproducibility, and interdetector variability and studied the microMOSFET response dependence on temperature, source-detector distance, and angular orientation of the receptor with respect to the source. The correction model was applied to 19 measurements corresponding to five simulated treatments in a custom phantom specifically designed for this purpose. RESULTS The detectors (high bias applied in all measurements) showed excellent linearity up to 160 Gy. The response dependence on source-detector distance varied by (8.65 ± 0.06)% (k = 1) for distances between 1 and 7 cm, and the variation with temperature was (2.24 ± 0.05)% (k = 1) between 294 and 310 K. The response difference due to angular dependence can reach (10.3 ± 1.3)% (k = 1). For the set of measurements analyzed, regarding angular dependences, the mean difference between administered and measured doses was -4.17% (standard deviation of 3.4%); after application of the proposed correction model, the mean difference was -0.1% (standard deviation of 2.2%). For the treatments analyzed, the average difference between calculations and measures was 4.7% when only the calibration coefficient was used, but it is reduced to 0.9% when the correction model is applied. CONCLUSION Important response dependencies of microMOSFET detectors used for in vivo dosimetry in HDRBT treatments, especially the angular dependence, can be adequately characterized by a correction model that increases the accuracy of this system in clinical applications.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant breakthrough infections in nursing home residents following vaccination with Comirnaty (R) COVID-19 vaccine were characterized. In total, 201 participants (median age, 87 years; range, 64-100; 133 female) from two nursing homes in the Valencian community (Spain) were included. SARS-CoV-2-Spike (S) antibody responses were determined by a lateral flow immunocromatography (LFIC) assay and by quantitative electrochemiluminescent assay in LFIC-negative participants. SARS-CoV-2-S-IFN gamma T cells were enumerated by flow cytometry in 10 participants. Nasopharyngeal SARS-CoV-2 RNA loads were quantified by real-time polymerase chain reaction assays. Vaccine breakthrough COVID-19 due to the Delta variant occurred in 39 residents (median age, 87 years; range, 69-96; 31 female) at a median of 6.5 months after vaccination (nine requiring hospitalization). Breakthrough infections occurred at a higher rate (p < 0.0001) in residents who had not been previously infected with SARS-CoV-2 (naive) (33/108; 18%) than in those with prior diagnosis of SARS-CoV-2 infection (experienced) (6/93; 6.4%), and were more likely (p < 0.0001) to develop in residents who tested negative by LFIC (20/49) at 3 months after vaccination as compared to their LFIC-positive counterparts (19/142). Among LFIC-negative residents, a trend towards lower plasma anti-RBD antibody levels was noticed in those developing breakthrough infection (p = 0.16). SARS-CoV-2 RNA loads in nasopharyngeal specimens were lower in SARS-CoV-2-experienced residents (p < 0.001) and in those testing positive by LFIC (p = 0.13). The frequency of SARS-CoV-2-S-reactive T cells at 3 months was similar in LFIC-negative residents with (n = 7) or without (n = 3) breakthrough infection. Prior history of SARS-CoV-2 infection and detection of S-reactive antibodies by LFIC at 3 months is associated with a lower risk of Delta-variant breakthrough infection in nursing home residents at midterm after Comirnaty (R) COVID-19 vaccination.

Disturbances, such as wildfires, are one of the main drivers of biodiversity dynamics, and their frequency and intensity are expected to increase due to global change. Such disturbances generate a mosaic of affected and unaffected patches that change landscape structure and, consequently, metacommunity networks. Therefore, to fully understand the consequences of such disturbances, a landscape perspective is required. In 2012, a wildfire burned 13 000 hectares in the NE Iberian Peninsula affecting a pond macroinvertebrate metacommunity. Communities were highly resilient to this disturbance, recovering after one hydroperiod. Their resilience was related to dispersal, being lower in species with weak dispersal abilities than those with strong dispersal abilities. This suggested that the metacommunity network played a major role in defining system resilience. In this context, we introduced a theoretical analysis based on this network in which we evaluated metacommunity resilience across several gradients of disturbance size and intensity incorporating species dispersal ability. Our study supports the empirical observation of a highly resilient metacommunity but also reveals that increased disturbance regimes might lead to a collapse of this resilience. Disturbance size and intensity interacted to determine the community recovery rate, which was high when both variables were low. Nevertheless, the transition from high to low resilience was sharp and depended on species dispersal. Diversity recovery was mostly driven by disturbance intensity, abruptly collapsing with its rise. This response highlighted the qualitative difference in the effect of size and intensity. These results not only illustrate the mechanisms shaping the studied metacommunity but also more generally stress the strong role of metacommunity mechanisms and landscape structure in biodiversity resilience. Finally, this study highlights the importance of using theoretical approaches rooted in empirical data to determine metacommunity dynamics and the need to preserve and build connected and heterogeneous landscapes to address future disturbance scenarios Financial support was provided by Ministerio de Economia y Competitividad (CGL2011-23907 and CGL2016-76024-R [AEI/FEDER/UE]), the Generalitat de Catalunya (ref. 2017 SGR 548) and to the European Commission, PONDERFUL Horizon 2020 project (H2020-LC-CLA-2019-2). AIB thanks the support provided by Comisión Sectorial de Investigación Científica-UdelaR (CSIC I+D-2016). MA thanks support of Fondo Clemente Estable (FCE_1_2014_1_104763). Finally, DC-M thanks the financial support by a PhD grant (FPU014/06783) and a mobility grant (EST16/00854) from Ministerio de Educación, Cultura y Deporte

[EN] The NOOT-BOP-COCH-LIKE (NBCL) genes are orthologs of Arabidopsis thaliana BLADE-ON-PETIOLE1/2. The NBCLs are developmental regulators essential for plant shaping, mainly through the regulation of organ boundaries, the promotion of lateral organ differentiation and the acquisition of organ identity. In addition to their roles in leaf, stipule and flower development, NBCLs are required for maintaining the identity of indeterminate nitrogen-fixing nodules with persistent meristems in legumes. In legumes forming determinate nodules, without persistent meristem, the roles of NBCL genes are not known. We thus investigated the role of Lotus japonicus NOOT-BOP-COCH-LIKE1 (LjNBCL1) in determinate nodule identity and studied its functions in aerial organ development using LORE1 insertional mutants and RNA interference-mediated silencing approaches. In Lotus, LjNBCL1 is involved in leaf patterning and participates in the regulation of axillary outgrowth. Wild-type Lotus leaves are composed of five leaflets and possess a pair of nectaries at the leaf axil. Legumes such as pea and Medicago have a pair of stipules, rather than nectaries, at the base of their leaves. In Ljnbcl1, nectary development is abolished, demonstrating that nectaries and stipules share a common evolutionary origin. In addition, ectopic roots arising from nodule vascular meristems and reorganization of the nodule vascular bundle vessels were observed on Ljnbcl1 nodules. This demonstrates that NBCL functions are conserved in both indeterminate and determinate nodules through the maintenance of nodule vascular bundle identity. In contrast to its role in floral patterning described in other plants, LjNBCL1 appears essential for the development of both secondary inflorescence meristem and floral meristem., This work was supported by the CNRS and by the grants ANR-14-CE19-0003 (NOOT) from the Agence National de la Recherche (ANR) to PR. This work has benefited from the facilities and expertise of the Servicio de Microscopia Electronica Universitat Politecnica de Valencia (Spain, http://www.upv.es/entidades/SME/) and of the IMAGIF Cell Biology Unit of the Gif campus (France, www.imagif.cnrs.fr) which is supported by the Conseil General de l'Essonne. The authors thank Dr Mathias Brault from the Institute of Plant Sciences Paris-Saclay (France) for providing the pFRN: RNAi plasmid, A. rhizogenes ARqua1 strain and control GUS:RNAi construction, and Dr Simona Radutoiu from the University of Aarhus (Denmark), for providing the Na-Borate/TRIZOL RNA extraction protocol. We are grateful to Dr Cristina Ferrandiz from the Instituto de Biologia Molecular y Celular de Plantas (Spain) for help in interpreting the identity of the meristems in the SEM pictures and Professor Frederique Guinel from the University of Wilfrid Laurier (Canada) for help in interpreting the identity of L. japonicus nodule vascular tissues. We thank Dr Julie Hofer from the University of Auckland (New Zealand), for manuscript revision and English language polishing.

Spanish Government, Grant/Award Number: BES-2010-038486; Generalitat Valenciana, Grant/Award Number: BEST/2017/029 and APOSTD/2016/044

The socio-economic relevance of domesticated animals during the Early Neolithic in the Iberian Peninsula is indisputable, yet we essentially know little about the way they were managed. Among domesticated animals, pig (Sus domesticus) was a common food source and previous studies have shown the potential of stable isotopes for assessing variability in pig diet in relation to husbandry practices. Nevertheless, this approach has never been applied to the earliest pigs in the Iberian Peninsula. We analyzed the carbon and nitrogen stable isotope composition of pig bone collagen from several Early Neolithic sites in the NE Iberian Peninsula. While pig δ13C values were similar across different populations, there were significant differences in δ15N values between sites. These are attributed to different pig husbandry systems, which may reflect distinct social and spatial organization and interaction with environmental conditions during the Early Neolithic in this region.