1,667 research outputs found
Effectiveness of entomopathogenic nematodes in the control of Cydia pomonella larvae in Northern Italy
Since 2006, a large scale research on the effectiveness of entomopathogenic nematodes
(EPN) in the control of codling moth (CM), Cydia pomonella, overwintering larvae has
been performed on about 35 ha of pear orchards per year in Emilia-Romagna, Northern
Italy. Steinernema carpocapsae and Steinernema feltiae activity was checked after spray
applications of EPNs to the trunk and branches. In 2006, the treatment was applied either
in spring or in autumn at different doses, before CM pupation; in 2007 the EPN treatment
was applied only in autumn at 1.5 x 109 I.J. ha –1. Every year it was distributed by means of
a conventional mist blower. The larval mortality was assessed directly on sentinel larvae in
card boards on the trunks and indirectly on the eggs laid by the females of the first CM
generation in spring. Moreover, each year, a trial was performed applying only S.
carpocapsae on sentinel larvae with the aim of testing this nematode at suitable
temperatures but at different water volumes.
The CM sentinel larvae were effectively parasitized after autumnal EPN application.
Moreover, the egg assessment demonstrated a good decrease in CM population in spring
2007, when EPNs had been applied at the best weather conditions (t° 12-14 °C and rain)
in the previous autumn
Convolutional Goppa Codes
We define Convolutional Goppa Codes over algebraic curves and construct their
corresponding dual codes. Examples over the projective line and over elliptic
curves are described, obtaining in particular some Maximum-Distance Separable
(MDS) convolutional codes.Comment: 8 pages, submitted to IEEE Trans. Inform. Theor
Daily variability of Ceres' Albedo detected by means of radial velocities changes of the reflected sunlight
Bright features have been recently discovered by Dawn on Ceres, which extend
previous photometric and Space Telescope observations. These features should
produce distortions of the line profiles of the reflected solar spectrum and
therefore an apparent radial velocity variation modulated by the rotation of
the dwarf planet. Here we report on two sequences of observations of Ceres
performed in the nights of 31 July, 26-27 August 2015 by means of the
high-precision HARPS spectrograph at the 3.6-m La Silla ESO telescope. The
observations revealed a quite complex behaviour which likely combines a radial
velocity modulation due to the rotation with an amplitude of approx +/- 6 m/s
and an unexpected diurnal effect. The latter changes imply changes in the
albedo of Occator's bright features due to the blaze produced by the exposure
to solar radiation. The short-term variability of Ceres' albedo is on
timescales ranging from hours to months and can both be confirmed and followed
by means of dedicated radial velocity observations.Comment: 5 pag, 1fig, two tables, MNRAS Letters 201
The planet search programme at the ESO CES and HARPS. IV. The search for Jupiter analogues around solar-like stars
In 1992 we began a precision radial velocity (RV) survey for planets around
solar-like stars with the Coude Echelle Spectrograph and the Long Camera (CES
LC) at the 1.4 m telescope in La Silla (Chile). We have continued the survey
with the upgraded CES Very Long Camera (VLC) and HARPS, both at the 3.6 m
telescope, until 2007. The observations for 31 stars cover a time span of up to
15 years and the RV precision permit a search for Jupiter analogues. We perform
a joint analysis for variability, trends, periodicities, and Keplerian orbits
and compute detection limits. Moreover, the HARPS RVs are analysed for
correlations with activity indicators (CaII H&K and CCF shape). We achieve a
long-term RV precision of 15 m/s (CES+LC, 1992-1998), 9 m/s (CES+VLC,
1999-2006), and 2.8 m/s (HARPS, 2003-2009, including archive data), resp. This
enables us to confirm the known planets around Iota Hor, HR 506, and HR 3259. A
steady RV trend for Eps Ind A can be explained by a planetary companion. On the
other hand, we find previously reported trends to be smaller for Beta Hyi and
not present for Alp Men. The candidate planet Eps Eri b was not detected
despite our better precision. Also the planet announced for HR 4523 cannot be
confirmed. Long-term trends in several of our stars are compatible with known
stellar companions. We provide a spectroscopic orbital solution for the binary
HR 2400 and refined solutions for the planets around HR 506 and Iota Hor. For
some other stars the variations could be attributed to stellar activity. The
occurrence of two Jupiter-mass planets in our sample is in line with the
estimate of 10% for the frequency of giant planets with periods smaller than 10
yr around solar-like stars. We have not detected a Jupiter analogue, while the
detections limits for circular orbits indicate at 5 AU a sensitivity for
minimum mass of at least 1 M_Jup (2 M_Jup) for 13% (61%) of the stars.Comment: 63 pages, 24 figures (+33 online figures), 13 Tables, accepted for
publication in A&A (2012-11-13
Evaluation of Hot-Melt Extrusion and Injection Molding for Continuous Manufacturing of Immediate-Release Tablets
The exploitation of hot-melt extrusion and injection molding for the manufacturing of immediate-release (IR) tablets was preliminarily investigated in view of their special suitability for continuous manufacturing, which represents a current goal of pharmaceutical production because of its possible advantages in terms of improved sustainability. Tablet-forming agents were initially screened based on processability by single-screw extruder and micromolding machine as well as disintegration/dissolution behavior of extruded/molded prototypes. Various polymers, such as low-viscosity hydroxypropylcellulose, polyvinyl alcohol, polyvinyl alcohol-polyethylene glycol graft copolymer, various sodium starch glycolate grades (e.g., Explotab\uae CLV) that could be processed with no need for technological aids, except for a plasticizer, were identified. Furthermore, the feasibility of both extruded and molded IR tablets from low-viscosity hydroxypropylcellulose or Explotab\uae CLV was assessed. Explotab\uae CLV, in particular, showed thermoplastic properties and a very good aptitude as a tablet-forming agent, starting from which disintegrating tablets were successfully obtained by either techniques. Prototypes containing a poorly soluble model drug (furosemide), based on both a simple formulation (Explotab\uae CLV and water/glycerol as plasticizers) and formulations including dissolution/disintegration adjuvants (soluble and effervescent excipients) were shown to fulfill the USP 37 dissolution requirements for furosemide tablets
Selective C–Cl bond oxidative addition of chloroarenes to a POP–rhodium complex
The C–Cl bond cis oxidative addition of 12 chloroarenes, including chlorobenzene, chlorotoluenes, chlorofluorobenzenes, and di- and trichlorobenzenes to RhH{xant(PiPr2)2} (1; xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) and the ability of the resulting rhodium(III) species to undergo reductive elimination reactions are reported. Complex 1 reacts with chlorobenzene to give RhHCl(C6H5){xant(PiPr2)2} (2), which eliminates benzene to afford RhCl{xant(PiPr2)2} (3). On the other hand, in the presence of potassium tert-butoxide (KOtBu), it undergoes dehydrodechlorination to yield Rh(C6H5){xant(PiPr2)2} (4). The reactions of 1 with 3- and 4-chlorotoluenes lead to RhHCl(C6H4-3-Me){xant(PiPr2)2} (5) and RhHCl(C6H4-4-Me){xant(PiPr2)2} (6), respectively. Treatment of the acetone solutions of both compounds with KOtBu also results in their dehydrodechlorination to give Rh(C6H4-3-Me){xant(PiPr2)2} (7) and Rh(C6H4-4-Me){xant(PiPr2)2} (8). Chlorofluorobenzenes undergo both C–Cl oxidative addition and C–H bond activation in a competitive manner. The amount of the C–H activation product increases as fluorine and chlorine are separated. Complex 1 reacts with o-chlorofluorobenzene to afford the C–Cl oxidative addition product RhHCl(C6H4-2-F){xant(PiPr2)2} (9). The reaction of 1 with m-chlorofluorobenzene leads to RhHCl(C6H4-3-F){xant(PiPr2)2} (10; 91%) and the C–H bond activation product Rh(C6H3-2-Cl-6-F){xant(PiPr2)2} (12; 9%), whereas p-chlorofluorobenzene gives a mixture of RhHCl(C6H4-4-F){xant(PiPr2)2} (13; 61%) and Rh(C6H3-3-Cl-6-F){xant(PiPr2)2} (15; 39%). The addition of KOtBu to the acetone solutions of 9, 10, and 13 produces the HCl abstraction and the formation of Rh(C6H4-2-F){xant(PiPr2)2} (16), Rh(C6H4-3-F){xant(PiPr2)2} (17), and Rh(C6H4-4-F){xant(PiPr2)2} (18). In contrast to o-chlorofluorobenzene, 1,2-dichlorobenzene reacts with 1 to give RhHCl(C6H4-2-Cl){xant(PiPr2)2} (19; 32%), Rh(C6H4-2-Cl){xant(PiPr2)2} (20; 51%) and Rh(C6H3-2,3-Cl2){xant(PiPr2)2} (22; 17%). The reactions of 1 with 1,3- and 1,4-dichlorobenzene lead to the respective C–Cl bond oxidative addition products RhHCl(C6H4-3-Cl){xant(PiPr2)2} (23) and RhHCl(C6H4-4-Cl){xant(PiPr2)2} (24), which afford Rh(C6H4-3-Cl){xant(PiPr2)2} (25) and Rh(C6H4-4-Cl){xant(PiPr2)2} (26) by dehydrodechlorination with KOtBu in acetone. Treatment of 1 with 1,2,3-, 1,2,4-, and 1,3,5-trichlorobenzenes leads to RhHCl(C6H3-2,3-Cl2){xant(PiPr2)2} (27), RhHCl(C6H3-3,4-Cl2){xant(PiPr2)2} (28), and RhHCl(C6H3-3,5-Cl2){xant(PiPr2)2} (29). The addition of KOtBu to acetone solutions of 27-29 affords 22, Rh(C6H3-3,4-Cl2){xant(PiPr2)2} (30) and Rh(C6H3-3,5-Cl2){xant(PiPr2)2} (31).Financial support from the MINECO of Spain (Projects CTQ2014-52799-P and CTQ2014-51912-REDC), the Diputacion General de Aragon (E-35), FEDER, and the European Social Fund is acknowledged.Peer reviewe
Multi-wavelength observations of 1RXH J173523.7-354013: revealing an unusual bursting neutron star
On 2008 May 14, the Burst Alert Telescope aboard the Swift mission triggered
on a type-I X-ray burst from the previously unclassified ROSAT object 1RXH
J173523.7-354013, establishing the source as a neutron star X-ray binary. We
report on X-ray, optical and near-infrared observations of this system. The
X-ray burst had a duration of ~2 h and belongs to the class of rare,
intermediately long type-I X-ray bursts. From the bolometric peak flux of
~3.5E-8 erg/cm^2/s, we infer a source distance of D<9.5 kpc. Photometry of the
field reveals an optical counterpart that declined from R=15.9 during the X-ray
burst to R=18.9 thereafter. Analysis of post-burst Swift/XRT observations, as
well as archival XMM-Newton and ROSAT data suggests that the system is
persistent at a 0.5-10 keV luminosity of ~2E35 (D/9.5 kpc)^2 erg/s. Optical and
infrared photometry together with the detection of a narrow Halpha emission
line (FWHM=292+/-9 km/s, EW=-9.0+/-0.4 Angstrom) in the optical spectrum
confirms that 1RXH J173523.7-354013 is a neutron star low-mass X-ray binary.
The Halpha emission demonstrates that the donor star is hydrogen-rich, which
effectively rules out that this system is an ultra-compact X-ray binary.Comment: Accepted for publication in MNRAS, 13 pages, 6 figures, 5 table
Extrasolar planets and brown dwarfs around A-F type stars V. A planetary system found with HARPS around the F6IV-V star HD 60532
Aims: In the frame of the search for extrasolar planets and brown dwarfs
around early-type stars, we present the results obtained for the F-type
main-sequence star HD 60532 (F6V) with HARPS.
Methods: Using 147 spectra obtained with HARPS at La Silla on a time baseline
of two years, we study the radial velocities of this star.
Results: HD 60532 radial velocities are periodically variable, and the
variations have a Keplerian origin. This star is surrounded by a planetary
system of two planets with minimum masses of 1 and 2.5 Mjup and orbital
separations of 0.76 and 1.58 AU respectively. We also detect high-frequency,
low-amplitude (10 m/s peak-to-peak) pulsations. Dynamical studies of the system
point toward a possible 3:1 mean-motion resonance which should be confirmed
within the next decade.Comment: 7 pages, 11 figures, accepted for publication in A&
Acquired Cold Urticaria: Clinical Features, Particular Phenotypes, and Disease Course in a Tertiary Care Center Cohort
BACKGROUND: Data about special phenotypes, natural course, and prognostic variables of patients with acquired cold urticaria (ACU) are scarce.
OBJECTIVES: We sought to describe the clinical features and disease course of patients with ACU, with special attention paid to particular phenotypes, and to examine possible parameters that could predict the evolution of the disease.
METHODS: This study was a retrospective chart review of 74 patients with ACU who visited a tertiary referral center of urticaria between 2005 and 2015.
RESULTS: Fourteen patients (18.9%) presented with life-threatening reactions after cold exposure, and 21 (28.4%) showed negative results after cold stimulation tests (classified as atypical ACU). Nineteen patients (25.7%) achieved complete symptoms resolution at the end of the surveillance period and had no subsequent recurrences. Higher rates of atypical ACU along with a lower likelihood of achieving complete symptom resolution was observed in patients who had an onset of symptoms during childhood (P < .05). In patients with atypical ACU, shorter disease duration and lower doses of antihistamines required for achieving disease control were detected (P < .05). Age at disease onset, symptom severity, and cold urticaria threshold values were found to be related to disease evolution (P < .05).
LIMITATIONS: This study was limited by its retrospective nature.
CONCLUSIONS: The knowledge of the clinical predictors of the disease evolution along with the clinical features of ACU phenotypes would allow for the establishment of an early and proper therapeutic strategy
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