A separated vortex ring underlies the flight of the dandelion.

Wind-dispersed plants have evolved ingenious ways to lift their seeds1,2. The common dandelion uses a bundle of drag-enhancing bristles (the pappus) that helps to keep their seeds aloft. This passive flight mechanism is highly effective, enabling seed dispersal over formidable distances3,4; however, the physics underpinning pappus-mediated flight remains unresolved. Here we visualized the flow around dandelion seeds, uncovering an extraordinary type of vortex. This vortex is a ring of recirculating fluid, which is detached owing to the flow passing through the pappus. We hypothesized that the circular disk-like geometry and the porosity of the pappus are the key design features that enable the formation of the separated vortex ring. The porosity gradient was surveyed using microfabricated disks, and a disk with a similar porosity was found to be able to recapitulate the flow behaviour of the pappus. The porosity of the dandelion pappus appears to be tuned precisely to stabilize the vortex, while maximizing aerodynamic loading and minimizing material requirements. The discovery of the separated vortex ring provides evidence of the existence of a new class of fluid behaviour around fluid-immersed bodies that may underlie locomotion, weight reduction and particle retention in biological and manmade structures.

Synthetic developmental biology: molecular tools to re-design plant shoots and roots.

Plant morphology and anatomy strongly influence agricultural yield. Crop domestication has strived for desirable growth and developmental traits, such as larger and more fruits and semi-dwarf architecture. Genetic engineering has accelerated rational, purpose-driven engineering of plant development, but it can be unpredictable. Developmental pathways are complex and riddled with environmental and hormonal inputs, as well as feedback and feedforward interactions, which occur at specific times and places in a growing multicellular organism. Rational modification of plant development would probably benefit from precision engineering based on synthetic biology approaches. This review outlines recently developed synthetic biology technologies for plant systems and highlights their potential for engineering plant growth and development. Streamlined and high-capacity genetic construction methods (Golden Gate DNA Assembly frameworks and toolkits) allow fast and variation-series cloning of multigene transgene constructs. This, together with a suite of gene regulation tools (e.g. cell type-specific promoters, logic gates, and multiplex regulation systems), is starting to enable developmental pathway engineering with predictable outcomes in model plant and crop species.

From passive to informed: mechanical mechanisms of seed dispersal.

Plant dispersal mechanisms rely on anatomical and morphological adaptations for the use of physical or biological dispersal vectors. Recently, studies of interactions between the dispersal unit and physical environment have uncovered fluid dynamic mechanisms of seed flight, protective measures against fire, and release mechanisms of explosive dispersers. Although environmental conditions generally dictate dispersal distances, plants are not purely passive players in these processes. Evidence suggests that some plants may enact informed dispersal, where dispersal-related traits are modified according to the environment. This can occur via developmental regulation, but also on shorter timescales via structural remodelling in relation to water availability and temperature. Linking interactions between dispersal mechanisms and environmental conditions will be essential to fully understand population dynamics and distributions.

Generating and characterizing single- and multigene mutants of the Rubisco small subunit family in Arabidopsis.

The primary CO2-fixing enzyme Rubisco limits the productivity of plants. The small subunit of Rubisco (SSU) can influence overall Rubisco levels and catalytic efficiency, and is now receiving increasing attention as a potential engineering target to improve the performance of Rubisco. However, SSUs are encoded by a family of nuclear rbcS genes in plants, which makes them challenging to engineer and study. Here we have used CRISPR/Cas9 [clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9] and T-DNA insertion lines to generate a suite of single and multiple gene knockout mutants for the four members of the rbcS family in Arabidopsis, including two novel mutants 2b3b and 1a2b3b. 1a2b3b contained very low levels of Rubisco (~3% relative to the wild-type) and is the first example of a mutant with a homogenous Rubisco pool consisting of a single SSU isoform (1B). Growth under near-outdoor levels of light demonstrated Rubisco-limited growth phenotypes for several SSU mutants and the importance of the 1A and 3B isoforms. We also identified 1a1b as a likely lethal mutation, suggesting a key contributory role for the least expressed 1B isoform during early development. The successful use of CRISPR/Cas here suggests that this is a viable approach for exploring the functional roles of SSU isoforms in plants.

Velocity of the falling dispersal units in Zelkova abelicea: remarkable evolutionary conservation within the relict tree genus.

PREMISE: Seed dispersal is extremely important for the recovery and restoration of forest communities. Relict tree genus Zelkova possesses a unique dispersal mechanism: mature fruits fall with the entire twig, and the dried leaves that are still attached function as a drag-enhancing appendage, carrying the fruits away from the parent tree. This singular adaptation has never been investigated in Z. abelicea. METHODS: Drop tests with dispersal units and individual fruits of Z. abelicea were performed in controlled conditions to measure their dispersal velocity and to define their flight mode. RESULTS: Zelkova abelicea uses both slowly falling dispersal units with chaotic motion, as well as fast falling individual fruits using a straight path. The falling velocity of Z. abelicea dispersal units is 1.53 m s-1 , which is virtually identical to that of the East Asiatic Z. serrata (1.51 m s-1 ). In contrast, the falling velocity of individual fruits was 2.74 m s-1 (Z. serrata: 5.36 m s-1 ). CONCLUSIONS: Members of the genus Zelkova, growing today in distant regions, show remarkable evolutionary conservation of the velocity and flight mechanics of their dispersal units. This is surprising because the Mediterranean and East Asiatic Zelkova species have been separated at least 15-20 mya. Zelkova abelicea, although growing in the Mediterranean with completely different forest structure and composition, still uses the same dispersal mechanism. The dispersal capacity of the genus Zelkova is less efficient than that of other wind dispersed trees, and it presumably evolved for short-distance ecological spread and not for long-distance biogeographical dispersal.

Genome-wide identification of physically clustered genes suggests chromatin-level co-regulation in male reproductive development in Arabidopsis thaliana.

Co-expression of physically linked genes occurs surprisingly frequently in eukaryotes. Such chromosomal clustering may confer a selective advantage as it enables coordinated gene regulation at the chromatin level. We studied the chromosomal organization of genes involved in male reproductive development in Arabidopsis thaliana. We developed an in-silico tool to identify physical clusters of co-regulated genes from gene expression data. We identified 17 clusters (96 genes) involved in stamen development and acting downstream of the transcriptional activator MS1 (MALE STERILITY 1), which contains a PHD domain associated with chromatin re-organization. The clusters exhibited little gene homology or promoter element similarity, and largely overlapped with reported repressive histone marks. Experiments on a subset of the clusters suggested a link between expression activation and chromatin conformation: qRT-PCR and mRNA in situ hybridization showed that the clustered genes were up-regulated within 48 h after MS1 induction; out of 14 chromatin-remodeling mutants studied, expression of clustered genes was consistently down-regulated only in hta9/hta11, previously associated with metabolic cluster activation; DNA fluorescence in situ hybridization confirmed that transcriptional activation of the clustered genes was correlated with open chromatin conformation. Stamen development thus appears to involve transcriptional activation of physically clustered genes through chromatin de-condensation.

A physico-genetic module for the polarisation of auxin efflux carriers PIN-FORMED (PIN).

Intracellular polarisation of auxin efflux carriers is crucial for understanding how auxin gradients form in plants. The polarisation dynamics of auxin efflux carriers PIN-FORMED (PIN) depends on both biomechanical forces as well as chemical, molecular and genetic factors. Biomechanical forces have shown to affect the localisation of PIN transporters to the plasma membrane. We propose a physico-genetic module of PIN polarisation that integrates biomechanical, molecular, and cellular processes as well as their non-linear interactions. The module was implemented as a discrete Boolean model and then approximated to a continuous dynamic system, in order to explore the relative contribution of the factors mediating PIN polarisation at the scale of single cell. Our models recovered qualitative behaviours that have been experimentally observed and enable us to predict that, in the context of PIN polarisation, the effects of the mechanical forces can predominate over the activity of molecular factors such as the GTPase ROP6 and the ROP-INTERACTIVE CRIB MOTIF-CONTAINING PROTEIN RIC1.

Implementation of Intravenous Drip Infusion Therapy with Peripheral Venous Catheters and the Incidence of Related Complications in Home-Based Medical Care Settings in Japan.

BACKGROUND/AIMS: Home-based medical care is rapidly expanding in Japanese health care settings. We aimed to clarify the implementation status of drip injection with peripheral venous catheters (PVCs) and the incidence of related complications. METHODS: We investigated the number of patients who required intravenous drip infusion therapy at home. We also examined the incidence rate of PVC-related complications and their statistical correlation with patients' characteristics. RESULTS: Of 139 patients, 30 (21.6%) received intravenous drip infusion therapy through PVCs at home. Patients' activities of daily living (bed-ridden) and the presence of underlying disease (terminal cancer) were significantly correlated with the requirement for drip infusion therapy (p < 0.0001 and p < 0.0001, respectively). A high incidence of PVC-related complications (75%: 15 out of 20 patients) was observed. More than 50% of patients experienced multiple needling due to difficulty in securing venous access. CONCLUSIONS: This is the first report to reveal the relatively high incidence of PVC-related complications in home-based medical care settings. Safer vascular devises should be incorporated for more stable intervention.

Regulation of the KNOX-GA gene module induces heterophyllic alteration in North American lake cress.

Plants show leaf form alteration in response to changes in the surrounding environment, and this phenomenon is called heterophylly. Although heterophylly is seen across plant species, the regulatory mechanisms involved are largely unknown. Here, we investigated the mechanism underlying heterophylly in Rorippa aquatica (Brassicaceae), also known as North American lake cress. R. aquatica develops pinnately dissected leaves in submerged conditions, whereas it forms simple leaves with serrated margins in terrestrial conditions. We found that the expression levels of KNOTTED1-LIKE HOMEOBOX (KNOX1) orthologs changed in response to changes in the surrounding environment (e.g., change of ambient temperature; below or above water) and that the accumulation of gibberellin (GA), which is thought to be regulated by KNOX1 genes, also changed in the leaf primordia. We further demonstrated that exogenous GA affects the complexity of leaf form in this species. Moreover, RNA-seq revealed a relationship between light intensity and leaf form. These results suggest that regulation of GA level via KNOX1 genes is involved in regulating heterophylly in R. aquatica. The mechanism responsible for morphological diversification of leaf form among species may also govern the variation of leaf form within a species in response to environmental changes.

Mechanical Stress Induces Remodeling of Vascular Networks in Growing Leaves.

Differentiation into well-defined patterns and tissue growth are recognized as key processes in organismal development. However, it is unclear whether patterns are passively, homogeneously dilated by growth or whether they remodel during tissue expansion. Leaf vascular networks are well-fitted to investigate this issue, since leaves are approximately two-dimensional and grow manyfold in size. Here we study experimentally and computationally how vein patterns affect growth. We first model the growing vasculature as a network of viscoelastic rods and consider its response to external mechanical stress. We use the so-called texture tensor to quantify the local network geometry and reveal that growth is heterogeneous, resembling non-affine deformations in composite materials. We then apply mechanical forces to growing leaves after veins have differentiated, which respond by anisotropic growth and reorientation of the network in the direction of external stress. External mechanical stress appears to make growth more homogeneous, in contrast with the model with viscoelastic rods. However, we reconcile the model with experimental data by incorporating randomness in rod thickness and a threshold in the rod growth law, making the rods viscoelastoplastic. Altogether, we show that the higher stiffness of veins leads to their reorientation along external forces, along with a reduction in growth heterogeneity. This process may lead to the reinforcement of leaves against mechanical stress. More generally, our work contributes to a framework whereby growth and patterns are coordinated through the differences in mechanical properties between cell types.

Integration of transport-based models for phyllotaxis and midvein formation.

The plant hormone auxin mediates developmental patterning by a mechanism that is based on active transport. In the shoot apical meristem, auxin gradients are thought to be set up through a feedback loop between auxin and the activity and polar localization of its transporter, the PIN1 protein. Two distinct molecular mechanisms for the subcellular polarization of PIN1 have been proposed. For leaf positioning (phyllotaxis), an "up-the-gradient" PIN1 polarization mechanism has been proposed, whereas the formation of vascular strands is thought to proceed by "with-the-flux" PIN1 polarization. These patterning mechanisms intersect during the initiation of the midvein, which raises the question of how two different PIN1 polarization mechanisms may work together. Our detailed analysis of PIN1 polarization during midvein initiation suggests that both mechanisms for PIN1 polarization operate simultaneously. Computer simulations of the resulting dual polarization model are able to reproduce the dynamics of observed PIN1 localization. In addition, the appearance of high auxin concentration in our simulations throughout the initiation of the midvein is consistent with experimental observation and offers an explanation for a long-standing criticism of the canalization hypothesis; namely, how both high flux and high concentration can occur simultaneously in emerging veins.

Protein complex formation and intranuclear dynamics of NAC1 in cancer cells.

Nucleus accumbens-associated protein 1 (NAC1) is a cancer-related transcription regulator protein that is also involved in the pluripotency and differentiation of embryonic stem cells. NAC1 is overexpressed in various carcinomas including ovarian, cervical, breast, and pancreatic carcinomas. NAC1 knock-down was previously shown to result in the apoptosis of ovarian cancer cell lines and to rescue their sensitivity to chemotherapy, suggesting that NAC1 may be a potential therapeutic target, but protein complex formation and the dynamics of intranuclear NAC1 in cancer cells remain poorly understood. In this study, analysis of HeLa cell lysates by fast protein liquid chromatography (FPLC) on a sizing column showed that the NAC1 peak corresponded to an apparent molecular mass of 300-500 kDa, which is larger than the estimated molecular mass (58 kDa) of the protein. Furthermore, live cell photobleaching analyses with green fluorescent protein (GFP)-fused NAC1 proteins revealed the intranuclear dynamics of NAC1. Collectively our results demonstrate that NAC1 forms a protein complex to function as a transcriptional regulator in cancer cells.

Flowers under pressure: ins and outs of turgor regulation in development.

BACKGROUND: Turgor pressure is an essential feature of plants; however, whereas its physiological importance is unequivocally recognized, its relevance to development is often reduced to a role in cell elongation. SCOPE: This review surveys the roles of turgor in development, the molecular mechanisms of turgor regulation and the methods used to measure turgor and related quantities, while also covering the basic concepts associated with water potential and water flow in plants. Three key processes in flower development are then considered more specifically: flower opening, anther dehiscence and pollen tube growth. CONCLUSIONS: Many molecular determinants of turgor and its regulation have been characterized, while a number of methods are now available to quantify water potential, turgor and hydraulic conductivity. Data on flower opening, anther dehiscence and lateral root emergence suggest that turgor needs to be finely tuned during development, both spatially and temporally. It is anticipated that a combination of biological experiments and physical measurements will reinforce the existing data and reveal unexpected roles of turgor in development.

Microwave endometrial ablation at a frequency of 2.45 GHz for menorrhagia: analysis of treatment results at a single facility.

AIM: We aimed to evaluate the efficacy of microwave endometrial ablation at a frequency of 2.45 GHz in women with menorrhagia. This method has been attracting attention as an alternative to hysterectomy in the treatment of functional and organic menorrhagia. MATERIAL AND METHODS: We performed microwave endometrial ablation in 103 women with menorrhagia between August 2007 and October 2012. All patients had completed child bearing. We evaluated the efficacy of microwave endometrial ablation using a visual analog scale for menorrhagia, dysmenorrhea, and patient satisfaction. We also evaluated the incidence of hypermenorrhea recurrence, amenorrhea, and procedure complications in relation to patients' clinical factors, such as the presence of myoma, adenomyosis, uterine size, and type of bleeding. RESULTS: A total of 76 patients completed the evaluation period. Excessive menstruation improved from a preoperative mean visual analog score of 10, to 1.9 after treatment. Dysmenorrhea improved from a mean score of 4.2, to 1.3, and patient satisfaction had a mean score of 9.0. Hemoglobin levels improved from 10.1 g/dL preoperatively to 12.5 g/dL postoperatively. Four patients experienced recurrence of excessive menstruation. No related clinical factors could be identified for recurrence risk or the occurrence of postoperative infection. A total of 26 patients (34.2%) became amenorrheic; these patients were less likely to have myomata, intramural myomata, and myomata larger than 5 cm. CONCLUSIONS: Microwave endometrial ablation at a frequency of 2.45 GHz is an effective and safe treatment. It should be considered as a standard treatment for conservative therapy-resistant menorrhagia.

Mechanical control of morphogenesis at the shoot apex.

Morphogenesis does not just require the correct expression of patterning genes; these genes must induce the precise mechanical changes necessary to produce a new form. Mechanical characterization of plant growth is not new; however, in recent years, new technologies and interdisciplinary collaborations have made it feasible in young tissues such as the shoot apex. Analysis of tissues where active growth and developmental patterning are taking place has revealed biologically significant variability in mechanical properties and has even suggested that mechanical changes in the tissue can feed back to direct morphogenesis. Here, an overview is given of the current understanding of the mechanical dynamics and its influence on cellular and developmental processes in the shoot apex. We are only starting to uncover the mechanical basis of morphogenesis, and many exciting questions remain to be answered.

KRAS and MAPK1 gene amplification in type II ovarian carcinomas.

In this study, we examined the clinical significance of KRAS and MAPK1 amplification and assessed whether these amplified genes were potential therapeutic targets in type II ovarian carcinoma. Using fluorescence in situ hybridization, immunohistochemistry, and retrospectively collected clinical data, KRAS and MAPK1 amplifications were identified in 9 (13.2%) and 5 (7.4%) of 68 type II ovarian carcinoma tissue samples, respectively. Interestingly, co-amplification of KRAS and MAPK1 seemed to be absent in the type II ovarian carcinomas tested, except one case. Active phospho-ERK1/2 was identified in 26 (38.2%) out of 68 type II ovarian carcinomas and did not correlate with KRAS or MAPK1 amplification. There was no significant relationship between KRAS amplification and overall or progression-free survival in patients with type II ovarian carcinoma. However, patients with MAPK1 amplification had significantly poorer progression-free survival than patients without MAPK1 amplification. Moreover, type II ovarian carcinoma cells with concomitant KRAS amplification and mutation exhibited dramatic growth reduction following treatment with the MEK inhibitor PD0325901. These findings indicate that KRAS/MAPK1 amplification is critical for the growth of a subset of type II ovarian carcinomas. Additionally, RAS/RAF/MEK/ERK pathway-targeted therapy may benefit selected patients with type II ovarian carcinoma harboring KRAS/MAPK1 amplifications.

[Anesthetic management of total hysterectomy in a patient with pulmonary thromboembolism].

We report anesthetic management of a 38-year-old woman with pulmonary thromboembolism for total hysterectomy. She had been taking oral contraceptives for adenomyosis of the uterus. She had thrombi in the arteries from pulmonary trunk to bilateral main pulmonary arteries. Thrombolytic and anticoagulant therapies did not decrease the thrombi. Removal of the swollen uterus suspected to be the origin of the thrombi, rather than thromboembolectomy, was scheduled. Cannulation for percutaneous cardiopulmonary support was set up just in case of hemodynamic derangement, before the surgery. Cardiac contraction was evaluated with transesophageal echocardiography during the surgery. There was no untoward perioperative event. Pulmonary thromboembolectomy was not done because the postoperative CT revealed shrinkage of the pulmonary thrombi after anticoagulation treatment.

Engineering Themes in Plant Forms and Functions.

Living structures constantly interact with the biotic and abiotic environment by sensing and responding via specialized functional parts. In other words, biological bodies embody highly functional machines and actuators. What are the signatures of engineering mechanisms in biology? In this review, we connect the dots in the literature to seek engineering principles in plant structures. We identify three thematic motifs-bilayer actuator, slender-bodied functional surface, and self-similarity-and provide an overview of their structure-function relationships. Unlike human-engineered machines and actuators, biological counterparts may appear suboptimal in design, loosely complying with physical theories or engineering principles. We postulate what factors may influence the evolution of functional morphology and anatomy to dissect and comprehend better the why behind the biological forms.

Co-existence of malnutrition and sarcopenia and its related factors in a long-term nursing care facility: A cross-sectional study.

Objectives: Malnutrition and sarcopenia often co-exist in older patients. This condition, called co-MS, shows a worse prognosis than either condition alone but is often overlooked and undertreated. We aimed to clarify the prevalence of co-MS and its associated factors with a focus on prescription in a long-term nursing care facility in Japan. Methods: Patients aged >65 years who resided in a long-term nursing care facility in Hyogo, Japan, were recruited for this cross-sectional study, which was conducted from July 1 to July 30, 2022. Sarcopenia and malnutrition were diagnosed using the Asian Working Group for Sarcopenia and Global Leadership Initiative on Malnutrition criteria, respectively. Patients who met both criteria were classified as having co-MS. Potentially associated factors, including age, sex, length of stay, activities of daily living, comorbidity, oral function and hygiene, swallowing ability, and the number and type of prescriptions, were assessed. Results: The prevalence of sarcopenia was 92 % (72/78). All malnourished patients were sarcopenic (40.3 %) and were classified as having co-MS. Oral function and hygiene, swallowing ability, comorbidity, and the presence of potentially inappropriate medications showed significant associations in univariate analyses. Of particular note, potentially inappropriate medication was an independent factor in the multivariate analysis. Conclusions: Co-MS is prevalent in long-term nursing care facilities; thus, healthcare workers should pay attention to relevant factors to identify patients at risk of co-MS and to provide appropriate care and intervention.