Effect of light and darkness on the growth and development of downy mildew pathogen Hyaloperonospora arabidopsidis

Disease development in plants requires a susceptible host, a virulent pathogen, and a favourable environment. Oomycete pathogens cause many important diseases and have evolved sophisticated molecular mechanisms to manipulate their hosts. Day length has been shown to impact plant‐oomycete interactions but a need exists for a tractable reference system to understand the mechanistic interplay between light regulation, oomycete pathogen virulence, and plant host immunity. Here we present data demonstrating that light is a critical factor in the interaction between Arabidopsis thaliana and its naturally occurring downy mildew pathogen Hyaloperonospora arabidopsidis (Hpa). We investigated the role of light on spore germination, mycelium development, sporulation and oospore formation of Hpa, along with defence responses in the host. We observed abundant Hpa sporulation on compatible Arabidopsis under day lengths ranging from 10 to 14 hours. Contrastingly, exposure to constant light or constant dark suppressed sporulation. Exposure to constant dark suppressed spore germination, mycelial development and oospore formation. Interestingly, exposure to constant light stimulated spore germination, mycelial development and oospore formation. A biomarker of plant immune system activation was induced under both constant light and constant dark. Altogether, these findings demonstrate that Hpa has the molecular mechanisms to perceive and respond to light and that both the host and pathogen responses are influenced by the light regime. Therefore, this pathosystem can be used for investigations to understand the molecular mechanisms through which oomycete pathogens like Hpa perceive and integrate light signals, and how light influences pathogen virulence and host immunity during their interactions

Left Ventricular Dysfunction in Patients Receiving Cardiotoxic Cancer Therapies Are Clinicians Responding Optimally?

ObjectivesThe purpose of this study was to examine treatment practices for cancer therapy-associated decreased left ventricular ejection fraction (LVEF) detected on echocardiography and whether management was consistent with American College of Cardiology/American Heart Association guidelines.BackgroundPatients treated with anthracyclines or trastuzumab are at risk of cardiotoxicity. Decreased LVEF represents a Class I indication for drug intervention according to American College of Cardiology/American Heart Association guidelines.MethodsPatients receiving anthracycline or trastuzumab at Stanford University from October 2005 to October 2007 and who had undergone echocardiography before and after receiving an anthracycline or trastuzumab were identified. Chart review examined chemotherapy regimens, cardiac risk factors, imaging results, concomitant medications, and cardiology consultations.ResultsEighty-eight patients received therapy with an anthracycline or trastuzumab and had a pre-treatment and follow-up echocardiogram. Ninety-two percent were treated with anthracyclines, 17% with trastuzumab after an anthracycline, and 8% with trastuzumab without previous treatment with anthracycline. Mean baseline LVEF was 60%, with 14% having a baseline <55%. Forty percent had decreased LVEF (<55%) after anthracycline and/or trastuzumab treatment. Of these patients, 40% received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, 51% beta-blocker therapy, and 54% cardiology consultation. Of patients with asymptomatic decreased LVEF, 31% received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, 35% beta-blocker therapy, and 42% cardiology consultation. Of those with symptomatic decreased LVEF, 67% received angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, 100% beta-blocker therapy, and 89% cardiology consultation.ConclusionsMany cancer survivors are not receiving treatment consistent with heart failure guidelines. There is substantial opportunity for collaboration between oncologists and cardiologists to improve the care of oncology patients receiving cardiotoxic therapy

PRELIMINARY STUDY OF WATER INJECTION ON THE COMBUSTION AND EMISSIONS CHARACTERISTICS IN A HCCI ETHANOL ENGINE

Our dependence on fossil fuels coupled with concerns about harmful emissions have motivated researchers to look for renewable fuels that have clean combustion and for advanced combustion modes. In this context, homogeneous charge compression ignition (HCCI) is an emerging technology which offers an alternative to conventional spark ignition and compression ignition engines and can operate on renewable fuels. Low temperature combustion, which can result in low NOx emissions with high indicated efficiency, is the more important characteristic of this combustion mode. It’s main problem is the combustion timing control due to lack of direct ignition control, once HCCI flame initiation is based on charge thermal state. Thus, controlled auto-ignition (CAI) combustion mode has been proposed. Several methods were proposed for combustion phasing control, between them, the injection of water in the intake manifold. This work investigated the influence of water injection in the intake runner of an ethanol HCCI cylinder from a converted three-cylinder diesel generator set, in which two cylinders operated on conventional diesel combustion and one diesel cylinder provided recycled exhaust gas for the one cylinder running on ethanol HCCI combustion. The water injection was used to control the CA50 combustion parameter. The results show that water injection is an efficient strategy to control the combustion timing, since the reactivity of the mixture can be controlled. The results at 400 and 600 kPa of IMEP and 1800 rpm indicated a good combustion stability, high efficiency and low emissions characteristics. The highest indicated fuel conversion efficiency found was 36.9% for 600 kPa of IMEP and 8 CAD of CA50. However, for 200 kPa of IMEP the combustion was unstable, the indicated efficiency was deteriorated and indicted CO emissions was high

PAH/PCB CONCENTRATIONS IN MUSSELS (MYTILUS GALLOPROVINCIALIS) FROM IZMIT BAY

Abstract PAH and PCB concentrations were determined in mussel samples collected from Izmit Bay at the east of marmara Sea. The samples were taken from ten points in spring season and analyzed by gas chromatography after ultrasonic extraction. Total PAH concentrations varied between 2.5-13.9 ng.g-wet wt., while the total PCB concentrations were between 4.2-140.7 ng.g-wet wt. The results indicates a considerable pollution problem in the bay, especially with respect to PCBs

Small RNA Inhibits Infection by Downy Mildew Pathogen Hyaloperonospora Arabidopsidis

Gene silencing exists in eukaryotic organisms as a conserved regulation of the gene expression mechanism. In general, small RNAs (sRNAs) are produced within the eukaryotic cells and incorporated into an RNA‐induced silencing complex (RISC) within cells. However, exogenous sRNAs, once delivered into cells, can also silence target genes via the same RISC. Here, we explored this concept by targeting the Cellulose synthase A3 (CesA3) gene of Hyaloperonospora arabidopsidis (Hpa), the downy mildew pathogen of Arabidopsis thaliana. Hpa spore suspensions were mixed with sense or antisense sRNAs and inoculated onto susceptible Arabidopsis seedlings. While sense sRNAs had no obvious effect on Hpa pathogenicity, antisense sRNAs inhibited spore germination and hence infection. Such inhibition of infection was not race‐specific, but dependent on the length and capping of sRNAs. Inhibition of infection by double stranded sRNA was more efficient than that observed with antisense sRNA. Thus, exogenous sRNA targeting conserved CesA3 could suppress Hpa infection in Arabidopsis, indicating the potential of this simple and efficient sRNA‐based approach for deciphering gene functions in obligate biotrophic pathogens as well as for R‐gene independent control of diseases in plants

DNA adducts in fish following an oil spill exposure

On 12 December 1999, one third of the load of the Erika tanker, amounting to about 10,000 t crude oil flowed into sea waters close to the French Atlantic Coast. This oil contained polycyclic aromatic compounds (PAC) that are known to be genotoxic. Genotoxic effects induce DNA adducts formation, which can thus be used as pollution biomarkers. Here, we assessed the genotoxic impact of the “Erika” oil spill by DNA adducts detection in the liver of immature fishes (Solea solea) from four locations of the French Brittany coasts. Two months after the spill, a high amount of DNA adducts was found in samples from all locations, amounting to 92–290 DNA adduct per 109 nucleotides. Then total DNA adduct levels decreased to reach about 50 adducts per 109 nucleotides nine months after the spill. In vitro experiments using human cell cultures and fish liver microsomes evidence the genotoxicity of the Erika fuel. They also prove the formation of reactive species able to create DNA adducts. Furthermore, in vitro and in vivo DNA adducts fingerprints are similar, thus confirming that DNA adducts are a result of the oil spill

The Early Social Cognition Inventory (ESCI): an examination of its psychometric properties from birth to 47 months

Social cognition refers to a broad range of cognitive processes and skills that allow individuals to interact with and understand others, including a variety of skills from infancy through preschool and beyond, e.g., joint attention, imitation, and belief understanding. However, no measures examine socio-cognitive development from birth through preschool. Current test batteries and parent-report measures focus either on infancy, or toddlerhood through preschool (and beyond). We report six studies in which we developed and tested a new 21-item parent-report measure of social cognition targeting 0–47 months: the Early Social Cognition Inventory (ESCI). Study 1 (N = 295) revealed the ESCI has excellent internal reliability, and a two-factor structure capturing social cognition and age. Study 2 (N = 605) also showed excellent internal reliability and confirmed the two-factor structure. Study 3 (N = 84) found a medium correlation between the ESCI and a researcher-administered social cognition task battery. Study 4 (N = 46) found strong 1-month test–retest reliability. Study 5 found longitudinal stability (6 months: N = 140; 12 months: N = 39), and inter-observer reliability between parents (N = 36) was good, and children’s scores increased significantly over 6 and 12 months. Study 6 showed the ESCI was internally reliable within countries (Australia, Canada, United Kingdom, United States, Trinidad and Tobago); parent ethnicity; parent education; and age groups from 4–39 months. ESCI scores positively correlated with household income (UK); children with siblings had higher scores; and Australian parents reported lower scores than American, British, and Canadian parents

Parents’ beliefs about their influence on children’s scientific and religious views: Perspectives from Iran, China and the United States

Parents in Iran, China and the United States were asked 1) about their potential influence on their children's religious and scientific views and 2) to consider a situation in which their children expressed dissent. The Iranian and US parents endorsed their influence on children's beliefs in both domains. By contrast, Chinese parents claimed more influence in the domain of science than religion. Most parents spoke of influencing their children via Parent-only mechanisms in each domain (e.g., discussion, teaching), although US parents did spontaneously note Multiple sources for the transmission of religious views (e.g., church, other influential adults). Parents proposed a similar stance towards children’s dissenting religious and scientific views. Chinese and US parents were more likely to express Supportive approaches and Iranian parents were more likely to express a Directive approach by comparison. The present research informs our understanding of the cultural transmission of views about science and religion