Effect of culture conditions on conidia production and enhancement of environmental stress resistance of Esteya vermicola in solid-state fermentation

AIMS

Esteya vermicola is an endoparasitic fungus producing lunate conidia, which kill pine wood nematode (PWN), and PWN could cause pine wilt disease (PWD). The aims of this study were to increase production and confirm the resistance (temperature and UV irradiation) of lunate conidia, and further determine the effective concentrations of conidia infecting PWN.

METHODS AND RESULTS

In this study, rice was used as a carrier to absorb conidial suspension to propagate conidia. The optimal conditions for lunate conidia production were 25°C temperature, 9 days of culture time, 2 : 1 rice/distilled water ratio and 10% inoculum size. The germination rate of E. vermicola cultured on potato dextrose agar was influenced by UV irradiation, similar to growth on rice. Esteya vermicola cultured on rice under heat stress might be more suitable for application in the field. The concentration (1 × 10⁸ conidia per ml) to kill PWN had the highest infectivity among the four conidia concentrations tested after 3 days of inoculation.

CONCLUSIONS

This study showed a rice substrate-supported high-quality conidia production and the optimal infectivity concentration of E. vermicola.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results provide the necessary process of an economical and efficient biological control strategy against PWD.

Silence of lncRNA XIST represses myocardial cell apoptosis in rats with acute myocardial infarction through regulating miR-449

OBJECTIVE

To study the influences of long non-coding ribonucleic acid (lncRNA) X-inactive specific transcript (XIST) on rats with acute myocardial infarction (AMI), and its regulatory mechanism.

MATERIALS AND METHODS

A total of 30 Sprague-Dawley rats were randomly assigned into Sham group, Model group, and lncRNA XIST small interfering RNA (XIST siRNA) group. The AMI rat model was prepared through ligating the left anterior descending coronary artery. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular systolic diameter (LVDs), and left ventricular diastolic diameter (LVDd) of rats were determined using a color Doppler ultrasound system. Reverse transcription-polymerase chain reaction was performed to measure the expression levels of lncRNA XIST, microRNA (miR)-449, and Notch1 in rat heart tissues in each group. Pathological morphology of rat heart tissues in each group was observed via hematoxylin-eosin (HE) staining. Cell apoptosis in rat heart tissues was evaluated through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay.

RESULTS

Compared with those in Sham group, rats in Model group had significantly increased LVEDV, LVESV, LVDs, and LVDd. After transfection with lncRNA XIST siRNA, XIST level in rat heart tissues was remarkably declined in XIST siRNA group compared with that in Model group. According to HE staining results, the pathological injuries in rat heart tissues were greatly improved in XIST siRNA group compared with those in Model group. TUNEL staining results revealed that the apoptosis rate of cells in rat heart tissues in XIST siRNA group was markedly lower than that in Model group. Higher level of miR-449 and lower level of Notch1 were observed in rats of XIST siRNA group than those of Model group.

CONCLUSIONS

Knockdown of lncRNA XIST can repress the myocardial cell apoptosis in AMI model rats by downregulating miR-449 level.

Enhanced spatial resolution of Eljen-204 plastic scintillators for use in rep-rated proton diagnostics

A pixelated scintillator has been designed, fabricated, and tested using a laser-accelerated proton source for use in proton diagnostics at rep-rated laser facilities. The work presented here demonstrates the enhanced spatial resolution of thin, organic scintillators through a novel pixelation technique. Experimental measurements using laser-generated protons incident onto 130 μm-thick scintillators indicate a >20% reduction in the scintillator point spread function (PSF) for the detectors tested. The best performing pixelated detector reduced the ∼200 μm PSF of the stock material to ∼150 μm. The fabrication technique may be tailored to reduce the pixel size and achieve higher spatial resolutions.

Health in cities: Getting out and about as we age

Transportation influences health through its effects on people's access to goods, services, and life chance opportunities; social interactions; physical activity levels; air pollution exposures; and road injury risks. Given the ageing of populations, it is essential that decisions about land use and transportation systems are appropriate to meet the mobility needs of older people and support healthy ageing. Not all transportation options, however, may be accessible to older people. Factors that affect accessibility relate to the spatial and physical characteristics of places, personal and social contexts of individuals, and rules and norms underpinning planning and policy making.

This research aimed to understand how different parts and processes of urban systems interact to influence transportation options for older people. Using the Greater Sydney area as a case, we drew on key informant interviews and public policy documents to identify the considerations that inform planning and policy making as they pertain to the nature of cities and the opportunities of older people to get out and about. We compared and integrated these findings with peer-reviewed literature of similar urban growth areas.

Our analysis mapped the factors of the human-urban system that are central to enabling transportation mobility for older people, articulated their interrelationships, and identified the actors that influence them. Our results point to the involvement of actors from the public health, community development, transportation, and urban planning sectors at multiple levels of government. Each of these actors operate within their own remit to influence a part of the urban system relevant to older people's transportation, such as the zoning of land, the approval of housing developments, and the location of bus stops. However, these individual actions are constrained by others in the system. We interpret this complexity with a governance lens.

Key messages

Efforts to promote mobility in old age should move beyond ‘single solutions to single issues’ approaches toward those that reflect the complexity of cities and the ways that people move within them. For sustained realization of desired outcomes, age-friendly initiatives cannot occur in isolation, but rather must take into account the behaviours and dynamics of the urban system.

Hotspot parameter scaling with velocity and yield for high-adiabat layered implosions at the National Ignition Facility

This paper presents a study on hotspot parameters in indirect-drive, inertially confined fusion implosions as they proceed through the self-heating regime. The implosions with increasing nuclear yield reach the burning-plasma regime, hotspot ignition, and finally propagating burn and ignition. These implosions span a wide range of alpha heating from a yield amplification of 1.7-2.5. We show that the hotspot parameters are explicitly dependent on both yield and velocity and that by fitting to both of these quantities the hotspot parameters can be fit with a single power law in velocity. The yield scaling also enables the hotspot parameters extrapolation to higher yields. This is important as various degradation mechanisms can occur on a given implosion at fixed implosion velocity which can have a large impact on both yield and the hotspot parameters. The yield scaling also enables the experimental dependence of the hotspot parameters on yield amplification to be determined. The implosions reported have resulted in the highest yield (1.73×10^{16}±2.6%), yield amplification, pressure, and implosion velocity yet reported at the National Ignition Facility.

Impact of Localized Radiative Loss on Inertial Confinement Fusion Implosions

The impact to fusion energy production due to the radiative loss from a localized mix in inertial confinement implosions using high density carbon capsule targets has been quantified. The radiative loss from the localized mix and local cooling of the reacting plasma conditions was quantified using neutron and x-ray images to reconstruct the hot spot conditions during thermonuclear burn. Such localized features arise from ablator material that is injected into the hot spot from the Rayleigh-Taylor growth of capsule surface perturbations, particularly the tube used to fill the capsule with deuterium and tritium fuel. Observations, consistent with analytic estimates, show the degradation to fusion energy production to be linearly proportional to the fraction of the total emission that is associated with injected ablator material and that this radiative loss has been the primary source of variations, of up to 1.6 times, in observed fusion energy production. Reducing the fill tube diameter has increased the ignition metric χ_{no α} from 0.49 to 0.72, 92% of that required to achieve a burning hot spot.