Efficient vasculature investment in tissues can be determined without global information

Cells are the fundamental building blocks of organs and tissues. Information and mass flow through cellular contacts in these structures is vital for the orchestration of organ function. Constraints imposed by packing and cell immobility limit intercellular communication, particularly as organs and organisms scale up to greater sizes. In order to transcend transport limitations, delivery systems including vascular and respiratory systems evolved to facilitate the movement of matter and information. The construction of these delivery systems has an associated cost, as vascular elements do not perform the metabolic functions of the organs they are part of. This study investigates a fundamental trade-off in vascularization in multicellular tissues: the reduction of path lengths for communication versus the cost associated with producing vasculature. Biologically realistic generative models, using multicellular templates of different dimensionalities, revealed a limited advantage to the vascularization of two-dimensional tissues. Strikingly, scale-free improvements in transport efficiency can be achieved even in the absence of global knowledge of tissue organization. A point of diminishing returns in the investment of additional vascular tissue to the increased reduction of path length in 2.5- and three-dimensional tissues was identified. Applying this theory to experimentally determined biological tissue structures, we show the possibility of a co-dependency between the method used to limit path length and the organization of cells it acts upon. These results provide insight as to why tissues are or are not vascularized in nature, the robustness of developmental generative mechanisms and the extent to which vasculature is advantageous in the support of organ function

Identification of a bet-hedging network motif generating noise in hormone concentrations and germination propensity in Arabidopsis

Plants have evolved to exploit stochasticity to hedge bets and ensure robustness to varying environments between generations. In agriculture, environments are more controlled, and this evolved variability decreases potential yields, posing agronomic and food security challenges. Understanding how plant cells generate and harness noise thus presents options for engineering more uniform crop performance. Here, we use stochastic chemical kinetic modelling to analyse a hormone feedback signalling motif in Arabidopsis thaliana seeds that can generate tunable levels of noise in the hormone ABA, governing germination propensity. The key feature of the motif is simultaneous positive feedback regulation of both ABA production and degradation pathways, allowing tunable noise while retaining a constant mean level. We uncover surprisingly rich behaviour underlying the control of levels of, and noise in, ABA abundance. We obtain approximate analytic solutions for steady-state hormone level means and variances under general conditions, showing that antagonistic self-promoting and self-repressing interactions can together be tuned to induce noise while preserving mean hormone levels. We compare different potential architectures for this ‘random output generator’ with the motif found in Arabidopsis, and report the requirements for tunable control of noise in each case. We identify interventions that may facilitate large decreases in variability in germination propensity, in particular, the turnover of signalling intermediates and the sensitivity of synthesis and degradation machinery, as potentially valuable crop engineering targets

AI solutions for human problems

Abstract Background Bronchiectasis is a chronic respiratory condition. Persistent bacterial colonisation in the stable state with increased and sometimes altered bacterial burden during exacerbations are accepted as key features in the pathophysiology. The extent to which respiratory viruses are present during stable periods and in exacerbations is less well understood. Methods This study aimed to determine the incidence of respiratory viruses within a cohort of bronchiectasis patients with acute exacerbations at a teaching hospital and, separately, in a group of patients with stable bronchiectasis. In the group of stable patients, a panel of respiratory viruses were assayed for using real time quantitative PCR in respiratory secretions and exhaled breath. The Impact of virus detection on exacerbation rates and development of symptomatic infection was evaluated. Results Routine hospital-based viral PCR testing was only requested in 28% of admissions for an exacerbation. In our cohort of stable bronchiectasis patients, viruses were detected in 92% of patients during the winter season, and 33% of patients during the summer season. In the 2-month follow up period, 2 of 27 patients presented with an exacerbation. Conclusions This pilot study demonstrated that respiratory viruses are commonly detected in patients with stable bronchiectasis. They are frequently detected during asymptomatic viral periods, and multiple viruses are often present concurrently

Zonisamide (CI-912) and Cognition: Results from Preliminary Study

Nine patients with refractory partial seizures were evaluated in a pilot study of a new anticonvulsant compound, zonisamide (l,2-benzisoxazole-3-methane-sulfonamide; CI-912). Cognitive functioning was evaluated prior to treatment with zonisamide and repeated after 12 and 24 weeks of treatment with zonisamide. At minimum steady-state plasma concentrations >30 jjug/ml, zonisamide appeared to affect specific cognitive functions such as acquisition and consolidation of new information. Previously learned material, such as vocabulary, and psychomotor performance were not affected. Verbal learning was affected, while visual-perceptual learning was unimpaired. These cognitive effects were observed in the absence of the usual clinical signs and symptoms of toxicity. A linear relationship was found between impairment of cognitive abilities and the minimum plasma concentration (r = -0.73; p < 0.05). Findings also suggest the development of tolerance to the adverse cognitive effects. RESUMEN En un estudio piloto realizado para valorar la eficacia de la zonisamida (1,2-Bencisoxazol-melanosulfonamida [CI-912]), un nuevo compuesto anticonvulsive se han evaluado unos 9 pa-cientes con ataques parciales refractarios al tratamiento. Se de-terminÓ la capacidad cognitiva anterior al tratamiento y se re-pitio 12 y 24 semanas despuÉs del tratamiento con zonisamida. Con concentraciones plasmÁticas mÍnimas estables per encima de 30 mcg/ml, la zonisamida afectÓ las funciones cognitives especÍficas tales como la adquisiciÓn y consolidaciÓn de nueva informaciÓn. El material aprendido previamente, tal como el vo-cabulario, y las funciones psicomotoras no se afectaron. El aprendizaje verbal se modificÓ mientras que el aprendizaje visuo-perfectivo no se modificÓ. Estos efectos cognitivos se ob-servaron en ausencia de los habituales signos y sÍntomas clÍnicos de toxicidad. Se encontrÓ una relaciÓn lineal entre la alteraciÓn de las posibilidades cognitivas y la concentraciÓn plasmÁtica mÍnima (r = -0.73, p < 0.05). Estos hallazgos tambiÉn sugieren el desarrollo de una tolerancia a los efectos cognitivos adversos. ZUSAMMENFASSUNG 9 Patienten mit rezidivierenden Partial-AnfÄllen wurden in einer Pilotstudie mit einer neuen antiepileptischen Substanz: Zonisamide untersucht. Die kognitiven Funktionen wurden vor der Behandlung mit Zonisamide geprtÜft und nach 12 und 24 Therapiewochen mit Zonisamide wiederholt. Bei einem Min-destplasmaspiegel von 30 mcg/ml schien Zonisamide spezifische kognitive FÄhigkeiten wie Aufnahme und Speicherung neuer In-formationen zu beeintrÄchtigen. Vorher gelernte Inhalte wie sprachliche und psychomotorische Fertigkeiten wurden nicht beeinflußt. Verbales Lernen war ebenfalls betroffen, wÄhrend visuell, perzeptives Lernen nicht verschlechtert war. Diese BeeintrÄchtigung kognitiver Funktionen wurde bei fehlenden klinischen Intoxikationszeichen beobachtet. Eine lineare Bezie-hung zwischen Verschlechterung kognitiver FÄhigkeiten und Mindest-Plasmaspiegel konnte hergestellt werden (r = -0,73; p < 0,05). Allerdings lassen die Ergebnisse auch auf eine GewÖhnung an diese unerwÜnschten Nebenwirkungen schließen.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65995/1/j.1528-1157.1987.tb03624.x.pd

Digital Single-Cell Analysis of Plant Organ Development Using 3DCellAtlas

Diverse molecular networks underlying plant growth and development are rapidly being uncovered. Integrating these data into the spatial and temporal context of dynamic organ growth remains a technical challenge. We developed 3DCellAtlas, an integrative computational pipeline that semiautomatically identifies cell types and quantifies both 3D cellular anisotropy and reporter abundance at single-cell resolution across whole plant organs. Cell identification is no less than 97.8% accurate and does not require transgenic lineage markers or reference atlases. Cell positions within organs are defined using an internal indexing system generating cellular level organ atlases where data from multiple samples can be integrated. Using this approach, we quantified the organ-wide cell-type-specific 3D cellular anisotropy driving Arabidopsis thaliana hypocotyl elongation. The impact ethylene has on hypocotyl 3D cell anisotropy identified the preferential growth of endodermis in response to this hormone. The spatiotemporal dynamics of the endogenous DELLA protein RGA, expansin gene EXPA3, and cell expansion was quantified within distinct cell types of Arabidopsis roots. A significant regulatory relationship between RGA, EXPA3, and growth was present in the epidermis and endodermis. The use of single-cell analyses of plant development enables the dynamics of diverse regulatory networks to be integrated with 3D organ growth

Pilot Study of Zonisamide (1,2-Benzisoxazole-3-methanesulfonamide) in Patients with Refractory Partial Seizures

A new anticonvulsant compound, zonisamide (1,2 benzioxazole-methanesulfonamide), was studied in 10 adults with medically refractory partial seizures. Following a single oral dose of 400 mg, peak plasma levels occurred an average of 2.8 h after dosing, and the mean clearance from plasma was 2.34 L/h. Whole blood concentrations were high than plasma concentrations because of red blood cell binding. steady-state plasma concentrations were high than predicted from a linear kinetic model. In most patients, seizure frequency was reduced after zonisamide was substituted for a standard antiepileptic drug. Dose-related reversible side effects in the central nervous and gastrointestinal system were observed. Most patients tolerated doses between 5.2 and 12.5 mg/kg/day. RÉSUMÉ Un nouveau produit anticonvulsivant, le zonisamide (1,2 benziosoxazole-methylsulfonamide) a ÉtÉ administrÉÀ 10 adultes atteints de crises partielles non contrÔlÉes par le traitement mÉdical. AprÈs une dose unique orale de 400 mg, le pic du taux plasmatique survient en moyenne 2 h 1/2 aprÉs l'ingestion, et la clairance plasmatique moyenne est de 2,34 litres par heure. les concentrations sanguines totales sont plus ÉlevÉes que les concentrations plasmatiques, en raison de la liaison aux globules rouges, les concentrations plasmatiques À l'État d'equilibre sont plus ÉlevÉes que celles que l'on peut dÉdurie d'un modÈle de cinÉtique linÉaire. Chez la plupart des patients, la frÉquence des crises a ÉtÉrÉduite par la substitution du zonisamide au traitement antiÉpileptique standard. Des effets secondaires doses-dÉpendants et rÉversibles ont ÉtÉ observÉs au niveau du systÈme nerveux central et du tube digestif. La plupart des patients ont tolÉrÉ des doses entre 5,2 et 12,5 mg/kg de poids par jour. RESUMEN En 10 adultos con ataques parciales refractarios a1 tratamiento mÉdico, se ha estudiado la acciÓn de un nuevo compuesto anticonvulsivo, la zonisamida (1,2 benzisoxazol-metanosulfonamida). Tras la ingestiÓn de una sola dosis oral de 400 mg., se alcanzaron los niveles pico en plasma en un promedio de 2.8 horas desputs de la dosis y el aclaramiento medio del plasma fuÉ de 2, 34 litros/hora. Las concentraciones en sangre fueron mÁs altas que las plasmÁticas debido a que la medicaciÓn se ligaba a los hematies. Las concentraciones plasmÁticas estables fueron mÁs altas que las previsibles de un modelo cinÉtico lineal. En la mayorÍa de los pacientes la frecuencia de los ataques se redujo despuÉs de cambiar la medicaciÓn antiepilÉptica standard por la zonisamida. TambiÉn se observaron los efectos colaterales sobre el tracto gastrointestinal y el sistema nervioso central que estaban relacionadas con la dosis y eran reversibles. La mayor parte de los pacientes tolerÓ dosis que oscilaban entre 5.2 y 12.5 mg/kg/dÍa. ZUSAMMENFASSUNG Ein neues Antikonvulsivum, Zonisamid (1,2 Benzisoxazol-Methansulfonamid) wurde bei 10 Envachsenen mit therapieresistenten PartialanfÄllen gesucht. Nach einer oralen Einzeldosis von 400 mg wurden Plasmaspitzenwerte im Durchschnitt nach 2, 8 Stunden erreicht. Die mittlere Clearance aus dem Plasma betrug 2, 34 L/Stunde. Ganzblutkonzentrationen waren hÖher als Plasmakonzentrationen aufgrund der Bindung an die roten BlutkÖrperchen. Die steady-state Plasmakonzentrationen waren hÖher als bei einem linearen kinetischen Modell zu envarten. Bei den meisten Patienten konnte die Anfallsfrequenz nach Substitution eines Standardantiepileptikums durch Zonisamid reduziert werden. Es bestanden dosisabhÄngige, reversible, zentral-nervÖse und gastrointestinale Nebenwirkungen. Die meisten Patienten tolerierten Dosen zwischen 5, 2 und 12, 5 mg/kg/Tag.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65938/1/j.1528-1157.1985.tb05407.x.pd

Adaptation of a Couple-Based HIV Intervention for Methamphetamine-Involved African American Men who have Sex with Men

In the U.S., incidence of HIV infection among men who have sex with men (MSM) has steadily increased since the 1990s. This points to a need for innovation to address both emerging trends as well as longer-standing disparities in HIV risk and transmission among MSM, such as the elevated rates of HIV/STIs among African American MSM and methamphetamine users. While couple-based sexual risk reduction interventions are a promising avenue to reduce HIV/STI transmission, prior research has been almost exclusively with heterosexual couples. We sought to adapt an existing, evidence-based intervention—originally developed and tested with heterosexual couples—for a new target population consisting of African American MSM in a longer-term same-sex relationship where at least one partner uses methamphetamine. The adaptation process primarily drew from data obtained from a series of focus groups with 8 couples from the target population. Attention is given to the methods used to overcome challenges faced in this adaptation process: limited time, a lead investigator who is phenotypically different from the target population, a dearth of descriptive information on the experiences and worldviews among the target population, and a concomitant lack of topical experts. We also describe a visualization tool used to ensure that the adaptation process promotes and maintains adherence to the theory that guides the intervention and behavior change. The process culminated with an intervention adapted for the new target population as well as preliminary indications that a couple-based sexual-risk reduction intervention for African American, methamphetamine-involved male couples is feasible and attractive

Network analysis of Arabidopsis mitochondrial dynamics reveals a resolved tradeoff between physical distribution and social connectivity

Mitochondria in plant cells exist largely as individual organelles which move, colocalize, and interact, but the cellular priorities addressed by these dynamics remain incompletely understood. Here, we elucidate these principles by studying the dynamic "social networks" of mitochondria in Arabidopsis thaliana wildtype and mutants, describing the colocalization of individuals over time. We combine single-cell live imaging of hypocotyl mitochondrial dynamics with individual-based modeling and network analysis. We identify an inevitable tradeoff between mitochondrial physical priorities (an even cellular distribution of mitochondria) and "social" priorities (individuals interacting, to facilitate the exchange of chemicals and information). This tradeoff results in a tension between maintaining mitochondrial spacing and facilitating colocalization. We find that plant cells resolve this tension to favor efficient networks with high potential for exchanging contents. We suggest that this combination of physical modeling coupled to experimental data through network analysis can shed light on the fundamental principles underlying these complex organelle dynamics. A record of this paper's transparent peer review process is included in the supplemental information. [Abstract copyright: Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

Superconducting resonators with voltage-controlled frequency and nonlinearity

Voltage-tunable superconductor-semiconductor devices offer a unique platform to realize dynamic tunability in superconducting quantum circuits. By galvanically connecting a gated InAs-Al Josephson junction to a coplanar waveguide resonator, we demonstrate the use of a wide-range gate-tunable superconducting element. We show that the resonant frequency is controlled via a gate-tunable Josephson inductance and that the non-linearity of the voltage-controlled InAs-Al junction is non-dissipative as is the case with conventional Al-AlO$_{x}$ junctions. As the gate voltage is decreased, the inductive participation of the junction increases up to $44\%$, resulting in the resonant frequency being tuned by over 2 GHz. Utilizing the wide tunability of the device, we demonstrate that two resonant modes can be adjusted such that they strongly hybridize, exhibiting an avoided level crossing with a coupling strength of 51 MHz. Implementing such voltage-tunable resonators is the first step toward realizing wafer-scale continuous voltage control in superconducting circuits for qubit-qubit coupling, quantum-limited amplifiers, and quantum memory platforms