Nitrogen sensing and regulatory networks: it's about time and space.

A plant's response to external and internal nitrogen signals/status relies on sensing and signaling mechanisms that operate across spatial and temporal dimensions. From a comprehensive systems biology perspective, this involves integrating nitrogen responses in different cell types and over long distances to ensure organ coordination in real time and yield practical applications. In this prospective review, we focus on novel aspects of nitrogen (N) sensing/signaling uncovered using temporal and spatial systems biology approaches, largely in the model Arabidopsis. The temporal aspects span: transcriptional responses to N-dose mediated by Michaelis-Menten kinetics, the role of the master NLP7 transcription factor as a nitrate sensor, its nitrate-dependent TF nuclear retention, its "hit-and-run" mode of target gene regulation, and temporal transcriptional cascade identified by "network walking." Spatial aspects of N-sensing/signaling have been uncovered in cell type-specific studies in roots and in root-to-shoot communication. We explore new approaches using single-cell sequencing data, trajectory inference, and pseudotime analysis as well as machine learning and artificial intelligence approaches. Finally, unveiling the mechanisms underlying the spatial dynamics of nitrogen sensing/signaling networks across species from model to crop could pave the way for translational studies to improve nitrogen-use efficiency in crops. Such outcomes could potentially reduce the detrimental effects of excessive fertilizer usage on groundwater pollution and greenhouse gas emissions.

Filling the gaps on root hair development under salt stress and phosphate starvation using current evidence coupled with a meta-analysis approach.

Population expansion is a global issue, especially for food production. Meanwhile, global climate change is damaging our soils, making it difficult for crops to thrive and lowering both production and quality. Poor nutrition and salinity stress affect plant growth and development. Although the impact of individual plant stresses has been studied for decades, the real stress scenario is more complex due to the exposure to multiple stresses at the same time. Here we investigate using existing evidence and a meta-analysis approach to determine molecular linkages between two contemporaneous abiotic stimuli, phosphate (Pi) deficiency and salinity, on a single plant cell model, the root hairs (RHs), which is the first plant cell exposed to them. Understanding how these two stresses work molecularly in RHs may help us build super-adaptable crops and sustainable agriculture in the face of global climate change.

Spatiotemporal analysis identifies ABF2 and ABF3 as key hubs of endodermal response to nitrate.

Nitrate is a nutrient and a potent signal that impacts global gene expression in plants. However, the regulatory factors controlling temporal and cell type-specific nitrate responses remain largely unknown. We assayed nitrate-responsive transcriptome changes in five major root cell types of the Arabidopsis thaliana root as a function of time. We found that gene-expression response to nitrate is dynamic and highly localized and predicted cell type-specific transcription factor (TF)-target interactions. Among cell types, the endodermis stands out as having the largest and most connected nitrate-regulatory gene network. ABF2 and ABF3 are major hubs for transcriptional responses in the endodermis cell layer. We experimentally validated TF-target interactions for ABF2 and ABF3 by chromatin immunoprecipitation followed by sequencing and a cell-based system to detect TF regulation genome-wide. Validated targets of ABF2 and ABF3 account for more than 50% of the nitrate-responsive transcriptome in the endodermis. Moreover, ABF2 and ABF3 are involved in nitrate-induced lateral root growth. Our approach offers an unprecedented spatiotemporal resolution of the root response to nitrate and identifies important components of cell-specific gene regulatory networks.

Activity-Dependent Nr4a2 Induction Modulates Synaptic Expression of AMPA Receptors and Plasticity via a Ca2+/CRTC1/CREB Pathway.

Transcription factors have a pivotal role in synaptic plasticity and the associated modification of neuronal networks required for memory formation and consolidation. The nuclear receptors subfamily 4 group A (Nr4a) have emerged as possible modulators of hippocampal synaptic plasticity and cognitive functions. However, the molecular and cellular mechanisms underlying Nr4a2-mediated hippocampal synaptic plasticity are not completely known. Here, we report that neuronal activity enhances Nr4a2 expression and function in cultured mouse hippocampal neurons (both sexes) by an ionotropic glutamate receptor/Ca2+/cAMP response element-binding protein/CREB-regulated transcription factor 1 (iGluR/Ca2+/CREB/CRTC1) pathway. Nr4a2 activation mediates BDNF production and increases expression of iGluRs, thereby affecting LTD at CA3-CA1 synapses in acute mouse hippocampal slices (both sexes). Together, our results indicate that the iGluR/Ca2+/CREB/CRTC1 pathway mediates activity-dependent expression of Nr4a2, which is involved in glutamatergic synaptic plasticity by increasing BDNF and synaptic GluA1-AMPARs. Therefore, Nr4a2 activation could be a therapeutic approach for brain disorders associated with dysregulated synaptic plasticity.SIGNIFICANCE STATEMENT A major factor that regulates fast excitatory synaptic transmission and plasticity is the modulation of synaptic AMPARs. However, despite decades of research, the underlying mechanisms of this modulation remain poorly understood. Our study identified a molecular pathway that links neuronal activity with AMPAR modulation and hippocampal synaptic plasticity through the activation of Nr4a2, a member of the nuclear receptor subfamily 4. Since several compounds have been described to activate Nr4a2, our study not only provides mechanistic insights into the molecular pathways related to hippocampal synaptic plasticity and learning, but also identifies Nr4a2 as a potential therapeutic target for pathologic conditions associated with dysregulation of glutamatergic synaptic function.

Insights into molecular links and transcription networks integrating drought stress and nitrogen signaling.

Drought and the availability of nitrate, the predominant source of nitrogen (N) in agriculture, are major factors limiting plant growth and crop productivity. The dissection of the transcriptional networks' components integrating droght stress and nitrate responses provides valuable insights into how plants effectively balance stress response with growth programs. Recent evidence in Arabidopsis thaliana indicates that transcription factors (TFs) involved in abscisic acid (ABA) signaling affect N metabolism and nitrate responses, and reciprocally, components of nitrate signaling might affect ABA and drought gene responses. Advances in understanding regulatory circuits of nitrate and drought crosstalk in plant tissues empower targeted genetic modifications to enhance plant development and stress resistance, critical traits for optimizing crop yield and promoting sustainable agriculture.

Multiomics analyses reveal the central role of the nucleolus and its machinery during heat stress acclimation in Pinus radiata.

Global warming is causing rapid changes in mean annual temperature and more severe drought periods. These are major contributors of forest dieback, which is becoming more frequent and widespread. In this work, we investigated how the transcriptome of Pinus radiata changed during initial heat stress response and acclimation. To this end, we generated a high-density dataset employing Illumina technology. This approach allowed us to reconstruct a needle transcriptome, defining 12 164 and 13 590 transcripts as down- and up-regulated, respectively, during a time course stress acclimation experiment. Additionally, the combination of transcriptome data with other available omics layers allowed us to determine the complex inter-related processes involved in the heat stress response from the molecular to the physiological level. Nucleolus and nucleoid activities seem to be a central core in the acclimating process, producing specific RNA isoforms and other essential elements for anterograde-retrograde stress signaling such as NAC proteins (Pra_vml_051671_1 and Pra_vml_055001_5) or helicase RVB. These mechanisms are connected by elements already known in heat stress response (redox, heat-shock proteins, or abscisic acid-related) and with others whose involvement is not so well defined such as shikimate-related, brassinosteriods, or proline proteases together with their potential regulatory elements. This work provides a first in-depth overview about molecular mechanisms underlying the heat stress response and acclimation in P. radiata.

Feasibility Study of Experimental Protocol for the Time-Dependent Mechanical Response of Synthetic Tibia.

In this research, an experimental biomechanics construct was developed to reveal the mechanics of distal tibial fracture by submitting synthetic tibiae to cyclic loading, resulting in a combined stress state due to axial compression and bending loads. The synthetic tibia was fixed at the knee but allowed to rotate in the coronal and sagittal planes at the ankle. The first three loading regimes lasted for 4000 cycles/each, and the final until ultimate failure. After 12k±80 cycles, the observed failure patterns closely resembled distal tibial fractures. The collected data during cyclic loading were fitted into a phenomenological model to deduce the time-dependent response of the synthetic tibiae. Images were also collected and analyzed using digital image correlation to deduce the full-field state of strain. The latter revealed that longitudinal strain contours extended in the proximal-distal direction. The transverse strain contours exemplified a medial-to-lateral distribution, attributed to the combined contributions of the Poisson's effect and the flexural deformation from axial and bending components of the applied load, respectively. The experimental construct, full-field characterization, and data analysis approaches can be extended to elucidate the effect of different fixation devices on the overall mechanical behavior of the bone and validate computational models in future research.

Risk Factors for Multiple Violations of Protective Orders in Intimate Partner Violence Against Women.

This study examined 1,134 cases of violence against women in intimate partner relationships with violations of protective orders in a monitoring period of up to 15 months. The dynamics of time and violence were analyzed in the cases of multiple violation versus one-time violation, with the objective of identifying and thus neutralizing the risk factors for this type of recidivism. The results showed that early violation, serious physical violence, death threats, as well as jealousy, harassment, and control are related to multiple violation. This article discusses the results in comparison with other research and proposes measures to avoid revictimizations.

Diagnosis and management of Abernethy syndrome.

Abernethy syndrome (AS or extrahepatic portosystemic shunt) is an uncommon congenital malformation consisting of agenesis or hypoplasia of the portal vein (PV) in such a way that splanchnic venous blood drains directly into the systemic circulation through aberrant communications, resulting in a portosystemic shunt that bypasses the liver AS is an underdiagnosed condition with unknown incidence and complication rate given that symptoms are usually absent. AS identification is increasingly common because of improved imaging techniques, hence prognostic implications and clinical management need be understood. This editorial reviews the natural history of AS and its diagnostic-therapeutic implications, illustrating the process with a series of cases from our institution.

Persistence of COVID-19 Symptoms and Quality of Life at Three and Twelve Months after Hospital Discharge.

Background and Objectives: Medical and public recognition of "long-COVID or post-COVID syndrome", as well as its impact on the quality of life (QoL), is required to better address the disease burden. Objectives: We aimed to describe the persistence of COVID-19 symptoms and QoL among patients at three and twelve months after their discharge from the hospital. Materials and Methods: We conducted an observational, prospective, and longitudinal analytic study from September 2021 to April 2022. To measure QoL, we used a validated version of the 36-item Short-Form Health Survey (SF-36). Results: We included 68 patients in the study. A total of 54 (79.4%) patients reported at least one persistent symptom at three months vs. 52 (76.4%) at twelve months (p = 0.804). Some persistent symptoms (myalgia, alopecia, and cough) decreased significantly at twelve months (50% vs. 30.9%, 29.4% vs. 13.2%, and 23.5% vs. 7.4%; respectively, p = 0.007); in contrast, other persistent symptoms (sleep-wake and memory disorders) were more frequent (5.9% vs. 32.4% and 4.4% vs. 20.6%; respectively, p = ≤0.001). Regarding QoL, a statistically significant improvement was observed in some scores over time, p = ≤0.037. At twelve months, dyspnea, myalgia, and depression were risk factors associated with a poor physical component summary (PCS), p = ≤0.027, whereas anxiety, depression, and fatigue were associated with a poor mental component summary (MCS), p = ≤0.015. Conclusion: As the proportion of persistent symptoms at twelve months is high, we suggest that patients must continue under long-term follow up to reclassify, diagnose, and treat new onset symptoms/diseases.

Cell surface receptor kinase FERONIA linked to nutrient sensor TORC signaling controls root hair growth at low temperature linked to low nitrate in Arabidopsis thaliana.

Root hairs (RH) are excellent model systems for studying cell size and polarity since they elongate several hundred-fold their original size. Their tip growth is determined both by intrinsic and environmental signals. Although nutrient availability and temperature are key factors for a sustained plant growth, the molecular mechanisms underlying their sensing and downstream signaling pathways remain unclear. We use genetics to address the roles of the cell surface receptor kinase FERONIA (FER) and the nutrient sensing TOR Complex 1 (TORC) in RH growth. We identified that low temperature (10°C) triggers a strong RH elongation response in Arabidopsis thaliana involving FER and TORC. We found that FER is required to perceive limited nutrient availability caused by low temperature. FERONIA interacts with and activates TORC-downstream components to trigger RH growth. In addition, the small GTPase Rho of plants 2 (ROP2) is also involved in this RH growth response linking FER and TOR. We also found that limited nitrogen nutrient availability can mimic the RH growth response at 10°C in a NRT1.1-dependent manner. These results uncover a molecular mechanism by which a central hub composed by FER-ROP2-TORC is involved in the control of RH elongation under low temperature and nitrogen deficiency.

An Easy Learning Approach to a Complex Surgical Technique: A Step-by-Step Site-Relapse Lateral Extended Endopelvic Resection (LEER).

Lateral pelvic sidewall involvement by gynecological tumors has been considered traditionally an absolute contraindication to curative resection.1 Moreover, the involvement of the pelvic sidewall at the time of relapse in cervical cancer after primary or adjuvant pelvic radiation occurs in 8.3% of patients.2,3 Laterally extended endopelvic resection (LEER), based on the ontogenetic compartment theory, provides a potential surgical option for patients for whom palliative therapy is the only alternative.4 This complex and ultraradical, surgical technique allows a high rate of complete resection in more than 70% of patients with gynecological cancers and lateral pelvic sidewall involvement. An adequate selection of patients and a deep knowledge of pelvic anatomy are crucial to obtain acceptable morbimortality rates and improved overall survival in this population.5 To deconstruct this complex procedure, we show a detailed step-by-step technique to facilitate the easy learning curve of this surgical technique. We review the Höckel original technique with different site-relapse adapted steps. We provide a pedagogical high-quality video (Video 1) and anatomical outline drawings (Fig. 1) to understand lateral pelvic wall anatomy and standardize this surgical technique. Our purpose is to bring this knowledge to gynecologists and pelvic surgeons in which pelvic lateral approach may be useful beyond gynecological oncologic surgery (Table 1).

Nitrate in 2020: Thirty Years from Transport to Signaling Networks.

Nitrogen (N) is an essential macronutrient for plants and a major limiting factor for plant growth and crop production. Nitrate is the main source of N available to plants in agricultural soils and in many natural environments. Sustaining agricultural productivity is of paramount importance in the current scenario of increasing world population, diversification of crop uses, and climate change. Plant productivity for major crops around the world, however, is still supported by excess application of N-rich fertilizers with detrimental economic and environmental impacts. Thus, understanding how plants regulate nitrate uptake and metabolism is key for developing new crops with enhanced N use efficiency and to cope with future world food demands. The study of plant responses to nitrate has gained considerable interest over the last 30 years. This review provides an overview of key findings in nitrate research, spanning biochemistry, molecular genetics, genomics, and systems biology. We discuss how we have reached our current view of nitrate transport, local and systemic nitrate sensing/signaling, and the regulatory networks underlying nitrate-controlled outputs in plants. We hope this summary will serve not only as a timeline and information repository but also as a baseline to define outstanding questions for future research.

Host-guest complexation of phthalimide-derived strigolactone mimics with cyclodextrins. Application in agriculture against parasitic weeds.

Parasitic weeds are noxious plants that damage crops of economic relevance, especially in Mediterranean and African countries. The strategy of suicidal germination was proposed to deal with this plague by using seed germination inducers that work as a pre-emergence herbicide and reduce the parasitic seed load before sowing. N-Substituted phthalimides with a furanone ring were found to be efficient in inducing the germination of Phelipanche ramosa and Orobanche cumana, two of the most problematic parasitic weeds of crops. However, the solubility of these compounds in water is low. A strategy for enhancing their aqueous solubility is the synthesis of host-guest complexes with cyclodextrins. Three bioactive phthalimide-lactones (PL01, PL04, and PL07) were selected and studied to form complexes of increased water solubility with α-, ß-, HP-ß-, and γ-cyclodextrin. The complexes obtained by the coprecipitation method, with increased aqueous solubility (up to 3.8 times), were studied for their bioactivity and they showed similar or slightly higher bioactivity than free phthalimide-lactones, even without the addition of organic solvents. A theoretical study using semiempirical calculations of molecular models including a solvation system confirmed the physicochemical empirical results. These results demonstrated that cyclodextrins can be used to improve the physicochemical and biological properties of parasitic seed germination inducers.

On the energetic and magnetic stability of neutral and charged lithium clusters doped with one and two yttrium atoms.

DFT calculations were performed to study the effect on energetic and magnetic stability when clusters with up to 24 lithium atoms were doped with one and two atoms of yttrium. In this, the effect of the charge was considered. As a result, some stable structures were identified as possible magnetic superatoms, among them, the YLi12+ cluster with an icosahedron geometry with a spin magnetic moment of 4 bohr magnetons. The participation of yttrium in the electron density of the unpaired electrons providing magnetism in clusters was corroborated at the level of a density of states (DOS) calculation and a spin density calculation. In particular, in the Y2Li12+ superatom, it was found that the encapsulated yttrium atom participates with 35.02% and the second yttrium atom with 15.04%. These percentages, with a contribution from p orbitals, but to a greater extent by d orbitals. The complementation to these percentages is due to the participation of the s and p orbitals of the lithium atoms. In general, doping with a second yttrium atom allowed to obtain a greater amount of high magnetic moments, and considering charged clusters allowed to obtain also high magnetic moments.

Time intervals in the pathway to emergency cancer diagnosis.

Aim: Evidence on time-based metrics for cancers diagnosed through emergency presentation is lacking. We examined the duration of intervals from first symptoms to cancer diagnosis in the emergency versus primary care (PC) presentation route. Methods: Retrospective study of outpatients diagnosed with 15 solid cancers over 5 years. The outcome was the length of prediagnostic intervals by diagnostic route. Results: Median intervals in emergency presenters (n = 3167) were shorter than in PC presenters (n = 2215). However, intervals in emergency presenters with three or more prior PC consultations were similar to PC but remarkably longer than in those with one or two and no consultations. Conclusion: As we provide new interval measures for the emergency diagnostic pathway, results highlight the contribution of prior consultations to interval lengths.

Assessing the venous system: Correlation of mean systemic filling pressure with the venous excess ultrasound grading system in cardiac surgery.

BACKGROUND: Evaluation of the venous system has long been underestimated as an important component of the circulatory system. As systemic venous pressure increases, the perfusion pressure to the tissues is compromised. During initial resuscitation in cardiac surgery, excessive fluid administration is associated with increased morbidity and mortality. METHODS: We conducted a cross-sectional study of 60 consecutive adult patients who underwent cardiac surgery and in whom it was possible to obtain the venous excess ultrasound (VExUS) grading system and mean systemic filling pressure (Pmsf) in the postoperative period upon admission, at 24 and 48 h. We then determined the correlation between VExUS grading and Pmsf. RESULTS: On admission, patients with VExUS grading 0 predominated, with a progressive increase in venous congestion and an increase in Pmsf over the course of the first 48 h. There was a strong positive correlation between VExUS grading and the invasive measurement of Pmsf at 24 and 48 h after arrival. The presence of grade 2 or grade 3 venous congestion in the postoperative period poses an increased risk of developing acute kidney injury. CONCLUSION: The VExUS grading system indicates a high degree of systemic venous congestion in the first 48 h of the postoperative period after cardiac surgery and correlates with the Pmsf, which is the best surrogate of stressed circulatory volume.

Nutrient dose-responsive transcriptome changes driven by Michaelis-Menten kinetics underlie plant growth rates.

An increase in nutrient dose leads to proportional increases in crop biomass and agricultural yield. However, the molecular underpinnings of this nutrient dose-response are largely unknown. To investigate, we assayed changes in the Arabidopsis root transcriptome to different doses of nitrogen (N)-a key plant nutrient-as a function of time. By these means, we found that rate changes of genome-wide transcript levels in response to N-dose could be explained by a simple kinetic principle: the Michaelis-Menten (MM) model. Fitting the MM model allowed us to estimate the maximum rate of transcript change (Vmax), as well as the N-dose at which one-half of Vmax was achieved (Km) for 1,153 N-dose-responsive genes. Since transcription factors (TFs) can act in part as the catalytic agents that determine the rates of transcript change, we investigated their role in regulating N-dose-responsive MM-modeled genes. We found that altering the abundance of TGA1, an early N-responsive TF, perturbed the maximum rates of N-dose transcriptomic responses (Vmax), Km, as well as the rate of N-dose-responsive plant growth. We experimentally validated that MM-modeled N-dose-responsive genes included both direct and indirect TGA1 targets, using a root cell TF assay to detect TF binding and/or TF regulation genome-wide. Taken together, our results support a molecular mechanism of transcriptional control that allows an increase in N-dose to lead to a proportional change in the rate of genome-wide expression and plant growth.

Feasibility of Cerebellar Measurements with Phased Array Sonography through the Anterior Fontanelle in Comparison to MRI.

OBJECTIVE: Cerebral sonography (CS) through the anterior fontanelle is a neonatal brain imaging method that has become an integral part of modern neonatal bedside care for both screening and diagnostic purposes. Premature infants with cognitive delay have a reduction in cerebellar size at term corrected age on magnetic resonance imaging (MRI). We aimed to determine the level of agreement between postnatal MRI and CS for cerebellar biometry and to determine the level of agreement within one and between different examiners. STUDY DESIGN: Cerebellar sonography and MRI measurements of the cerebellum from 30 term infants was assessed by Bland-Altman plots. Measurements between both modalities were compared using Wilcoxon's signed rank test. A p-value < 0.01 was considered statistically significant. Intraclass correlation coefficients (ICC) for intra- and interrater reliabilities of CS measurements were calculated. RESULTS: There was no statistically significant difference between CS and MRI for linear measurements, but the measurements of perimeter and surface area differed significantly between the two techniques. There was a systematic bias between both modalities for most measurements except for anterior-posterior (AP) width and vermis height (VH). For measurements that were not statistically different from MRI, we found excellent intrarater ICC for the AP width, VH, and cerebellar width. The interrater ICC was excellent for the AP width and VH, but poor for the transverse cerebellar width. CONCLUSION: With a strict imaging protocol, cerebellar measurements of the AP width and the VH can be used as an alternative to MRI for diagnostic-screening purposes in a neonatal department where multiple clinicians perform bedside CS. KEY POINTS: · Abnormal cerebellar growth and injuries affect neurodevelopmental outcome.. · Cerebral sonography through the anterior fontanelle is used for bedside imaging.. · Postnatal sonographic cerebellar measurements are not validated against MRI.. · Measuring vermis height and anterior-posterior width are reliable.. · Measuring transverse cerebellar width through anterior fontanelle is unreliable..

Personality Comparison between Lethal and Non-lethal Intimate Partner Violence Perpetrators and Their Victims.

Intimate partner violence against women (IPVAW) and femicide (intimate partner femicide, IPF), as a worldwide phenomenon, cannot be explained in a simple way. From an ecological point of view, there are individual factors contemplated. In the current studies, we consider personality as an individual factor to clarify what differentiates a non-lethal IPVAW situation from a femicide. Study 1 was designed to investigate the accuracy with which trained interviewers judged the personality of a group of IPVAW perpetrators during an interview. The target sample of study 1 was composed of 293 males who after being interviewed completed a measure of personality assessing the "Big Three" model of personality. The interviewers performed fairly accurate judgements about the personality of the target participants. Study 2 shows the differences in personality, using Eysenck's personality model, between the IPF and IPVAW perpetrators and their victims. The total sample study 2 was formed of 551 participants distributed among IPF perpetrators, IPVAW perpetrators, and the victims of both groups. Differences in proportions were observed between both groups of perpetrators as well as between each group and their respective victims. With these findings, we propose personality as a femicide risk factor that should be taken into consideration by police officers and other practitioners when receiving an IPVAW report.