328 research outputs found
Preventative approach to microbial control of capnodis tenebrionis by soil application of metarhizium brunneum and beauveria bassiana
Management of the Mediterranean flat-headed root-borer, Capnodis tenebrionis, is critical due to the larvae’s root localization. Neonate larvae can be exposed to natural enemies before penetrating the roots. Application of Metarhizium brunneum strain Mb7 and Beauveria bassiana strain GHA formulations on rice granules was investigated for their efficacy against C. tenebrionis larvae. Mb7 application, evaluated on apricot twigs, significantly and dose-dependently reduced colonization rates of neonates, with highest mortality at 108 conidia/g soil. Neonate susceptibility to Mb7 and GHA was evaluated on potted rootstocks (GF677 almond × peach, 2729 plum) planted in entomopathogenic fungi (EPF)-premixed soil (1.3–1.6 × 105 conidia/cm3 soil) or in EPF-free soil surface-treated with 5 g Mb7 fungal granules (1.25 × 109 conidia). Larval colonization rates were reduced 7.4-fold in 2729 by both fungi; only Mb7 completely prevented colonization of GF677 by larvae. Larvae inside plant galleries exhibited mycosis with EPF-treated soils and both fungi proliferated on larval frass. Mb7 conidia germinated in the rhizosphere of GF677, and conidia of both fungi remained viable throughout the trial. Galleria baiting technique was used on EPF-treated soil to evaluate EPF infectivity over time; Mb7 and GHA persisted 180 and 90 days post inoculation, respectively. The formulation (fungus-covered rice grains), delivery method (mixing with soil) and persistence (3–6 months) of Mb7 and GHA are feasible for potential field application to control C. tenebrionis
RoboTAP: Target priorities for robotic microlensing observations
Context. The ability to automatically select scientifically-important transient events from an alert stream of many such events, and to conduct follow-up observations in response, will become increasingly important in astronomy. With wide-angle time domain surveys pushing to fainter limiting magnitudes, the capability to follow-up on transient alerts far exceeds our follow-up telescope resources, and effective target prioritization becomes essential. The RoboNet-II microlensing program is a pathfinder project, which has developed an automated target selection process (RoboTAP) for gravitational microlensing events, which are observed in real time using the Las Cumbres Observatory telescope network.
Aims. Follow-up telescopes typically have a much smaller field of view compared to surveys, therefore the most promising microlensing events must be automatically selected at any given time from an annual sample exceeding 2000 events. The main challenge is to select between events with a high planet detection sensitivity, with the aim of detecting many planets and characterizing planetary anomalies.
Methods. Our target selection algorithm is a hybrid system based on estimates of the planet detection zones around a microlens. It follows automatic anomaly alerts and respects the expected survey coverage of specific events.
Results. We introduce the RoboTAP algorithm, whose purpose is to select and prioritize microlensing events with high sensitivity to planetary companions. In this work, we determine the planet sensitivity of the RoboNet follow-up program and provide a working example of how a broker can be designed for a real-life transient science program conducting follow-up observations in response to alerts; we explore the issues that will confront similar programs being developed for the Large Synoptic Survey Telescope (LSST) and other time domain surveys
TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844
Data from the newly-commissioned \textit{Transiting Exoplanet Survey
Satellite} (TESS) has revealed a "hot Earth" around LHS 3844, an M dwarf
located 15 pc away. The planet has a radius of and
orbits the star every 11 hours. Although the existence of an atmosphere around
such a strongly irradiated planet is questionable, the star is bright enough
(, ) for this possibility to be investigated with transit and
occultation spectroscopy. The star's brightness and the planet's short period
will also facilitate the measurement of the planet's mass through Doppler
spectroscopy.Comment: 10 pages, 4 figures. Submitted to ApJ Letters. This letter makes use
of the TESS Alert data, which is currently in a beta test phase, using data
from the pipelines at the TESS Science Office and at the TESS Science
Processing Operations Cente
TOI 540 b: A Planet Smaller than Earth Orbiting a Nearby Rapidly Rotating Low-mass Star
We present the discovery of TOI 540 b, a hot planet slightly smaller than
Earth orbiting the low-mass star 2MASS J05051443-4756154. The planet has an
orbital period of days ( 170 ms) and a radius of , and is likely terrestrial based on the observed
mass-radius distribution of small exoplanets at similar insolations. The star
is 14.008 pc away and we estimate its mass and radius to be and , respectively. The
star is distinctive in its very short rotational period of hours and correspondingly small Rossby number of 0.007 as
well as its high X-ray-to-bolometric luminosity ratio of based on a serendipitous XMM-Newton detection during a slew operation.
This is consistent with the X-ray emission being observed at a maximum value of
as predicted for the most rapidly rotating M
dwarfs. TOI 540 b may be an alluring target to study atmospheric erosion due to
the strong stellar X-ray emission. It is also among the most accessible targets
for transmission and emission spectroscopy and eclipse photometry with JWST,
and may permit Doppler tomography with high-resolution spectroscopy during
transit. This discovery is based on precise photometric data from TESS and
ground-based follow-up observations by the MEarth team.Comment: 18 pages, 7 figures. Accepted for publication in The Astronomical
Journa
Brain and ventricular volume in patients with syndromic and complex craniosynostosis
textabstractPurpose: Brain abnormalities in patients with syndromic craniosynostosis can either be a direct result of the genetic defect or develop secondary to compression due to craniosynostosis, raised ICP or hydrocephalus. Today it is unknown whether children with syndromic craniosynostosis have normal brain volumes. The purpose of this study was to evaluate brain and ventricular volume measurements in patients with syndromic and complex craniosynostosis. This knowledge will improve our understanding of brain development and the origin of raised intracranial pressure in syndromic craniosynostosis. Methods: Brain and ventricular volumes were calculated from MRI scans of patients with craniosynostosis, 0.3 to 18.3 years of age. Brain volume was compared to age matched controls from the literature. All patient charts were reviewed to look for possible predictors of brain and ventricular volume. Results: Total brain volume in syndromic craniosynostosis equals that of normal controls, in the age range of 1 to 12 years. Brain growth occurred particularly in the first 5 years of age, after which it stabilized. Within the studied population, ventricular volume was significantly larger in Apert syndrome compared to all other syndromes and in patients with a Chiari I malformation. Conclusions: Patients with syndromic craniosynostosis have a normal total brain volume compared to normal controls. Increased ventricular volume is associated with Apert syndrome and Chiari I malformations, which is most commonly found in Crouzon syndrome. We advice screening of all patients with Apert and Crouzon syndrome for the development of enlarged ventricle volume and the presence of a Chiari I malformation
Differential Adaptation of Human Gut Microbiota to Bariatric Surgery–Induced Weight Loss: Links With Metabolic and Low-Grade Inflammation Markers
International audienceOBJECTIVE Obesity alters gut microbiota ecology and associates with low-grade inflammation in humans. Roux-en-Y gastric bypass (RYGB) surgery is one of the most efficient procedures for the treatment of morbid obesity resulting in drastic weight loss and improvement of metabolic and inflammatory status. We analyzed the impact of RYGB on the modifications of gut microbiota and examined links with adaptations associated with this procedure. RESEARCH DESIGN AND METHODS Gut microbiota was profiled from fecal samples by real-time quantitative PCR in 13 lean control subjects and in 30 obese individuals (with seven type 2 diabetics) explored before (M0), 3 months (M3), and 6 months (M6) after RYGB. RESULTS Four major findings are highlighted: 1) Bacteroides/Prevotella group was lower in obese subjects than in control subjects at MO and increased at M3. It was negatively correlated with corpulence, but the correlation depended highly on caloric intake; 2) Escherichia coli species increased at M3 and inversely correlated with fat mass and leptin levels independently of changes in food intake; 3) lactic acid bacteria including Lacto-bacillus/Leuconostoc/Pediococcus group and Bifidobacterium genus decreased at M3; and 4) Faecalibacterium prausnitzii species was lower in subjects with diabetes and associated negatively with inflammatory markers at MO and throughout the follow-up after surgery independently of changes in food intake. CONCLUSIONS These results suggest that components of the dominant gut microbiota rapidly adapt in a starvation-like situation induced by RYGB while the F. prausnitzii species is directly linked to the reduction in low-grade inflammation state in obesity and diabetes independently of calorie intake. Diabetes 59:3049-3057, 201
A review of the current treatment methods for posthaemorrhagic hydrocephalus of infants
Posthaemorrhagic hydrocephalus (PHH) is a major problem for premature infants, generally requiring lifelong care. It results from small blood clots inducing scarring within CSF channels impeding CSF circulation. Transforming growth factor – beta is released into CSF and cytokines stimulate deposition of extracellular matrix proteins which potentially obstruct CSF pathways. Prolonged raised pressures and free radical damage incur poor neurodevelopmental outcomes. The most common treatment involves permanent ventricular shunting with all its risks and consequences
Maternal distress and perceptions of infant development following extracorporeal membrane oxygenation and conventional ventilation for persistent pulmonary hypertension
Neurodevelopmental outcome and concurrent maternal distress were examined for infants who suffered persistent pulmonary hypertension at birth and were treated with either extracorporeal membrane oxygenation (ECMO) ( n = 19) or conventional ventilation (CV) ( n = 15). Mothers were asked to complete inventories assessing their infant's (mean age 8.74 months) developmental growth as well as their own psychological health. Relevant sociodemographic and treatment parameters were also entered into the analysis. The results indicated that ECMO and CV infants did not differ on developmental indices and impairment rates were 15–23% respectively, similar to previous reports, in addition, ECMO and CV mothers did not differ in their reports of psychological distress. Correlational analyses revealed that length of treatment for ECMO but not CV infants significantly predicted developmental delay and maternal distress. For CV mothers, maternal distress was associated with the perception of delayed language. The results are discussed in terms of the limited morbidity associated with ECMO and CV interventions and the possible role of a ‘vulnerable child syndrome’ in understanding the maternal-infant relationship following ECMO therapy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73367/1/j.1365-2214.1995.tb00410.x.pd
TOI-1235 b: A Keystone Super-Earth For Testing Radius Valley Emergence Models Around Early M Dwarfs
Small planets on close-in orbits tend to exhibit envelope mass fractions of either effectively zero or up to a few percent depending on their size and orbital period. Models of thermally driven atmospheric mass loss and of terrestrial planet formation in a gas-poor environment make distinct predictions regarding the location of this rocky/nonrocky transition in period–radius space. Here we present the confirmation of TOI-1235 b (P = 3.44 days, ), a planet whose size and period are intermediate between the competing model predictions, thus making the system an important test case for emergence models of the rocky/nonrocky transition around early M dwarfs (R s = 0.630 ± 0.015 , M s = 0.640 ± 0.016 ). We confirm the TESS planet discovery using reconnaissance spectroscopy, ground-based photometry, high-resolution imaging, and a set of 38 precise radial velocities (RVs) from HARPS-N and HIRES. We measure a planet mass of , which implies an iron core mass fraction of % in the absence of a gaseous envelope. The bulk composition of TOI-1235 b is therefore consistent with being Earth-like, and we constrain an H/He envelope mass fraction to be \u3c0.5% at 90% confidence. Our results are consistent with model predictions from thermally driven atmospheric mass loss but not with gas-poor formation, suggesting that the former class of processes remains efficient at sculpting close-in planets around early M dwarfs. Our RV analysis also reveals a strong periodicity close to the first harmonic of the photometrically determined stellar rotation period that we treat as stellar activity, despite other lines of evidence favoring a planetary origin ( days, ) that cannot be firmly ruled out by our data
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