Bidens pilosa L. (Asteraceae) control in sunflower with residual herbicides.

Abstract One of the most damaging species in sunflower crops in Brazil is the hairy beggartick (Bidens pilosa L). The large number of seeds, the various vegetative cycles during the year, the staggered germination and the scarcity of selective and effective herbicides to control this weed in sunflower are some of attributes that hinder the control of hairy beggartick populations. Two experiments were carried out to evaluate the control of hairy beggarticks, as well as sunflower tolerance to herbicides. The treatments were as follows: S-metolachlor (1,200 and 2,400 g ai ha-1), flumioxazin (60 and 120 g ai ha-1), and sulfentrazone (150 and 300 g ai ha-1) and two controls (weedy and weed-free check). The selectivity of the herbicides was higher at low doses. Flumioxazin and sulfentrazone caused injury to sunflowers at the highest doses and mainly in sandy soils. Although S-metolachlor did not cause visual symptoms of injury, the higher dose reduced sunflower yield. The herbicides sulfentrazone and flumioxazin provided satisfactory control of hairy beggartick plants in both types of soils. S-metolachlor presented medium control of hairy beggarticks in clay soil; however, its efficiency was slightly higher when applied in sandy soil. The most efficient herbicide for controlling hairy beggartick plants was flumioxazin, followed by sulfentrazone

Spitzer Observations of Transient, Extended Dust in Two Elliptical Galaxies: New Evidence of Recent Feedback Energy Release in Galactic Cores

Spitzer observations of extended dust in two optically normal elliptical galaxies provide a new confirmation of buoyant feedback outflow in the hot gas atmospheres around these galaxies. AGN feedback energy is required to prevent wholesale cooling and star formation in these group-centered galaxies. In NGC 5044 we observe interstellar (presumably PAH) emission at 8 microns out to about 5 kpc. Both NGC 5044 and 4636 have extended 70 microns emission from cold dust exceeding that expected from stellar mass loss. The sputtering lifetime of this extended dust in the ~1keV interstellar gas, ~10^7 yrs, establishes the time when the dust first entered the hot gas. Evidently the extended dust originated in dusty disks or clouds, commonly observed in elliptical galaxy cores, that were disrupted, heated and buoyantly transported outward. The surviving central dust in NGC 5044 and 4636 has been disrupted into many small filaments. It is remarkable that the asymmetrically extended 8 micron emission in NGC 5044 is spatially coincident with Halpha+[NII] emission from warm gas. A calculation shows that dust-assisted cooling in buoyant hot gas moving out from the galactic core can cool within a few kpc in about ~10^7 yrs, explaining the optical line emission observed. The X-ray images of both galaxies are disturbed. All timescales for transient activity - restoration of equilibrium and buoyant transport in the hot gas, dynamics of surviving dust fragments, and dust sputtering - are consistent with a central release of feedback energy in both galaxies about 10^7 yrs ago.Comment: 13 pages. Accepted by ApJ; minor typos correcte

Solving the Cooling Flow Problem of Galaxy Clusters by Dark Matter Neutralino Annihilation

Recent X-ray observations revealed that strong cooling flow of intracluster gas is not present in galaxy clusters, even though predicted theoretically if there is no additional heating source. I show that relativistic particles produced by dark matter neutralino annihilation in cluster cores provide a sufficient heating source to suppress the cooling flow, under reasonable astrophysical circumstances including adiabatic growth of central density profile, with appropriate particle physics parameters for dark matter neutralinos. In contrast to other astrophysical heat sources such as AGNs, this process is a steady and stable feedback over cosmological time scales after turned on.Comment: 4 pages, no figure. Accepted to Phys. Rev. Lett. A few minor revisions and references adde

New methods for the comprehensive analysis of bioactive compounds in Cannabis sativa L. (hemp)

Cannabis sativa L. is a dioecious plant belonging to the Cannabaceae family. The main phytochemicals that are found in this plant are represented by cannabinoids, flavones, and terpenes. Some biological activities of cannabinoids are known to be enhanced by the presence of terpenes and flavonoids in the extracts, due to a synergistic action. In the light of all the above, the present study was aimed at the multi-component analysis of the bioactive compounds present in fibre-type C. sativa (hemp) inflorescences of different varieties by means of innovative HPLC and GC methods. In particular, the profiling of non-psychoactive cannabinoids was carried out by means of HPLC-UV/DAD, ESI-MS, and MS2. The content of prenylated flavones in hemp extracts, including cannflavins A and B, was also evaluated by HPLC. The study on Cannabis volatile compounds was performed by developing a new method based on headspace solid-phase microextraction (HS-SPME) coupled with GC-MS and GC-FID. Cannabidiolic acid (CBDA) and cannabidiol (CBD) were found to be the most abundant cannabinoids in the hemp samples analysed, while f-myrcene and f-caryophyllene were the major terpenes. As regards flavonoids, cannflavin A was observed to be the main compound in almost all the samples. The methods developed in this work are suitable for the comprehensive chemical analysis of both hemp plant material and related pharmaceutical or nutraceutical products in order to ensure their quality, efficacy, and safety

Point X-ray sources in the SNR G 315.4-2.30 (MSH 14-63, RCW 86)

We report the results of a search for a point X-ray source (stellar remnant) in the southwest protrusion of the supernova remnant G 315.4-2.30 (MSH 14-63, RCW 86) using the archival data of the Chandra X-ray Observatory. The search was motivated by a hypothesis that G 315.4-2.30 is the result of an off-centered cavity supernova explosion of a moving massive star, which ended its evolution just near the edge of the main-sequence wind-driven bubble. This hypothesis implies that the southwest protrusion in G 315.4-2.30 is the remainder of a pre-existing bow shock-like structure created by the interaction of the supernova progenitor's wind with the interstellar medium and that the actual location of the supernova blast center is near the center of this hemispherical structure. We have discovered two point X-ray sources in the "proper" place. One of the sources has an optical counterpart with the photographic magnitude $13.38\pm0.40$, while the spectrum of the source can be fitted with an optically thin plasma model. We interpret this source as a foreground active star of late spectral type. The second source has no optical counterpart to a limiting magnitude $\sim 21$. The spectrum of this source can be fitted almost equally well with several simple models (power law: photon index $=1.87$; two-temperature blackbody: $kT_1 =0.11$ keV, $R_1 =2.34$ km and $kT_2 =0.71$ keV, $R_2 =0.06$ km; blackbody plus power law: $kT =0.07$ keV, photon index $=2.3$). We interpret this source as a candidate stellar remnant (neutron star), while the photon index and non-thermal luminosity of the source (almost the same as those of the Vela pulsar and the recently discovered pulsar PSR J 0205+6449 in the supernova remnant 3C 58) suggest that it can be a young "ordinary" pulsar.Comment: 7 pages, 6 figures,revised version accepted for publication in A&

On the origin of the system PSR B1757-24/SNR G5.4-1.2

A scenario for the origin of the system PSR B1757-24/supernova remnant (SNR) G5.4-1.2 is proposed. It is suggested that both objects are the remnants of a supernova (SN) that exploded within a pre-existing bubble blown-up by a runaway massive star (the SN progenitor) during the final (Wolf-Rayet) phase of its evolution. This suggestion implies that (a) the SN blast centre was significantly offset from the geometric centre of the wind-blown bubble (i.e. from the centre of the future SNR), (b) the bubble was surrounded by a massive wind-driven shell, and (c) the SN blast wave was drastically decelerated by the interaction with the shell. Therefore, one can understand how the relatively young and low-velocity pulsar PSR B1757-24 was able to escape from the associated SNR G5.4-1.2 and why the inferred vector of pulsar transverse velocity does not point away from the geometric centre of the SNR. A possible origin of the radio source G5.27-0.9 (located between PSR B1757-24 and the SNR G5.4-1.2) is proposed. It is suggested that G5.27-0.9 is a lobe of a low Mach number (\simeq 1.7) jet of gas outflowing from the interior of G5.4-1.2 through the hole bored in the SNR's shell by the escaping pulsar. It is also suggested that the non-thermal emission of the comet-shaped pulsar wind nebula originates in the vicinity of the termination shock and in the cylindric region of subsonically moving shocked pulsar wind. The role of magnetized wind-driven shells (swept-up during the Wolf-Rayet phase from the ambient interstellar medium with the regular magnetic field) in formation of elongated axisymmetric SNRs is discussed.Comment: 7 pages, accepted for publication in A&

Chemical characterization of non-psychoactive Cannabis sativa L. extracts, in vitro antiproliferative activity and induction of apoptosis in chronic myelogenous leukaemia cancer cells

In this study, extracts from non-psychoactive Cannabis sativa L. varieties were characterized by means of ultra high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) and their antiproliferative activity was assessed in vitro. The human chronic myelogenous leukaemia cell line K562 was chosen to investigate the mechanism of cell death. The effect on the cell cycle and cell death was analysed by flow cytometry. Proteins related to apoptosis were studied by western blotting. Mechanical properties of cells were assessed using the Micropipette Aspiration Technique (MAT). The results indicated that the cannabidiol (CBD)-rich extract inhibited cell proliferation of K562 cell line in a dose-dependent manner and induced apoptosis via caspase 3 and 7 activation. A significant decrease in the mitochondrial membrane potential was detected, together with the release of cytochrome c into the cytosol. The main apoptotic markers were not involved in the mechanism of cell death. The extract was also able to modify the mechanical properties of cells. Thus, this hemp extract and its pure component CBD deserve further investigation for a possible application against myeloproliferative diseases, also in association with other anticancer drugs

Preliminary results on the evolution of proglacial ponds in the deglaciating Alps

Deglaciation is one of the most evident effects of the ongoing climatic changes on the Alpine environment. One of its common consequences is the formation of new water bodies in the proglacial area, where proglacial lakes and ponds are increasingly relevant ecosystems for the mountain landscape. The EVERLAKE project focuses on a recent system of proglacial ponds that originated from the retreat of the Zufall/Cevedale Glacier (Plima catchment, Central/Eastern Italian Alps). The aims of the project are to: (i) provide a first hydroecological characterisation of these pond ecosystems from a physical, chemical and biological point of view; (ii) understand their evolutionary trend during the process of deglaciation, with a space-for-time substitution approach. Here, we present data collected during the ice-free season 2022, showing the seasonal development occurring in three ponds located along a gradient of distance from the Cevedale Glacier terminus (i.e., at 2700-2900 m a.s.l.). We monitored water level, temperature and electrical conductivity and assessed the origin of water through analyses of stable isotopes (δ2H, δ18O). Bathymetric measurements were performed to estimate the residence time of each waterbody. We also analysed basic water chemistry, concentrations of trace elements, benthic and planktonic chlorophyll-a and organic content. The biological communities of these poorly known aquatic ecosystems were characterised by adopting an integrated approach combining morphological observations of microalgae and 16S and 18S rRNA metabarcoding of eDNA from both benthic and planktonic samples. The ponds showed different ecological conditions related to their distance from the glacier margins

Antifungal Activity and DNA Topoisomerase Inhibition of Hydrolysable Tannins from Punica granatum L

Punica granatum L. (pomegranate) fruit is known to be an important source of bioactive phenolic compounds belonging to hydrolysable tannins. Pomegranate extracts have shown antifungal activity, but the compounds responsible for this activity and their mechanism/s of action have not been completely elucidated up to now. The aim of the present study was the investigation of the inhibition ability of a selection of pomegranate phenolic compounds (i.e., punicalagin, punicalin, ellagic acid, gallic acid) on both plant and human fungal pathogens. In addition, the biological target of punicalagin was identified here for the first time. The antifungal activity of pomegranate phenolics was evaluated by means of Agar Disk Diffusion Assay and minimum inhibitory concentration (MIC) evaluation. A chemoinformatic analysis predicted for the first time topoisomerases I and II as potential biological targets of punicalagin, and this prediction was confirmed by in vitro inhibition assays. Concerning phytopathogens, all the tested compounds were effective, often similarly to the fungicide imazalil at the label dose. Particularly, punicalagin showed the lowest MIC for Alternaria alternata and Botrytis cinerea, whereas punicalin was the most active compound in terms of growth control extent. As for human pathogens, punicalagin was the most active compound among the tested ones against Candida albicans reference strains, as well as against the clinically isolates. UHPLC coupled with HRMS indicated that C. albicans, similarly to the phytopathogen Coniella granati, is able to hydrolyze both punicalagin and punicalin as a response to the fungal attack. Punicalagin showed a strong inhibitory activity, with IC50 values of 9.0 and 4.6 µM against C. albicans topoisomerases I and II, respectively. Altogether, the results provide evidence that punicalagin is a valuable candidate to be further exploited as an antifungal agent in particular against human fungal infections

HPPD-Inhibiting herbicides alone or in tank-mix with Atrazine in elephant grass.

The interference imposed by weeds is one of the most important factors limiting elephant grass forage yield. Two experiments were carried out in 2015/2016 and 2017 to evaluate the selectivity and weed control of 4-hydroxyphenylpyruvate dioxygenase (HPPD)-inhibiting herbicides applied alone or in combination with atrazine in elephant grass. The treatments applied in the experiment conducted in Valença, Rio de Janeiro State, Brazil, were as follows: two rates of mesotrione (0.072 and 0.144 kg ha-1 + 0.5% v/v mineral oil - Assist®), two rates of tembotrione (0.075 and 0.100 kg ha-1 + 0.5% v/v mineral oil - Aureo®), atrazine + mesotrione (1.25 + 0.072 kg ha-1 + 0.5% v/v mineral oil - Assist®), atrazine + tembotrione (1.25 + 0.100 kg ha-1 + 0.5% v/v mineral oil - Aureo®), atrazine + mesotrione (1.25 + 0.072 kg ha-1), atrazine + tembotrione (1.25 + 0.100 kg ha-1) and two checks (weed-free check and weedy check). The same herbicide treatments and a check without application were applied in an experiment conducted in Coronel Pacheco, Minas Gerais State, Brazil. Two application rates of mesotrione with the addition of mineral oil or the tank mixture of atrazine plus mesotrione, with or without the addition of mineral oil, did not provide injuries capable to reduce elephant grass forage yield. Tembotrione was phytotoxic to elephant grass when applied with mineral oil. Atrazine plus tembotrione in a tank-mix, with or without mineral oil, were also phytotoxic to elephant grass. All treatments provided satisfactory weed control