Large Area Crop Inventory Experiment (LACIE). The boundary pixel study in Kansas and North Dakota

The author has identified the following significant results. The statistical mapping approach to handling boundary pixels can be used as a standard for objectively comparing the cluster based technique, the maximum likelihood estimate based technique, and multicategory labeling

Large Area Crop Inventory Experiment (LACIE). Phase 3 direct wheat study of North Dakota

The author has identified the following significant results. The green number and brightness scatter plots, channel plots of radiance values, and visual study of the imagery indicate separability between barley and spring wheat/oats during the wheat mid-heading to mid-ripe stages. In the LACIE Phase 3 North Dakota data set, the separation time is more specifically the wheat soft dough stage. At this time, the barley is ripening, and is therefore, less green and brighter than the wheat. Only 4 of the 18 segments studied indicate separation of barley/other spring small grain, even though 11 of the segments have acquisitions covering the wheat soft dough stage. The remaining seven segments had less than 5 percent barley based on ground truth data

Observations of one young and three middle-aged γ\gamma-ray pulsars with the Gran Telescopio Canarias

We used the 10.4m Gran Telescopio Canarias to search for the optical counterparts to four isolated $\gamma$-ray pulsars, all detected in the X-rays by either \xmm\ or \chan\ but not yet in the optical. Three of them are middle-aged pulsars -- PSR\, J1846+0919 (0.36 Myr), PSR\, J2055+2539 (1.2 Myr), PSR\, J2043+2740 (1.2 Myr) -- and one, PSR\, J1907+0602, is a young pulsar (19.5 kyr). For both PSR\, J1907+0602 and PSR\, J2055+2539 we found one object close to the pulsar position. However, in both cases such an object cannot be a viable candidate counterpart to the pulsar. For PSR\, J1907+0602, because it would imply an anomalously red spectrum for the pulsar and for PSR\, J2055+2539 because the pulsar would be unrealistically bright ($r'=20.34\pm0.04$) for the assumed distance and interstellar extinction. For PSR\, J1846+0919, we found no object sufficiently close to the expected position to claim a possible association, whereas for PSR\, J2043+2740 we confirm our previous findings that the object nearest to the pulsar position is an unrelated field star. We used our brightness limits ($g' \approx 27$), the first obtained with a large-aperture telescope for both PSR\, J1846+0919 and PSR\, J2055+2539, to constrain the optical emission properties of these pulsars and investigate the presence of spectral turnovers at low energies in their multi-wavelength spectra.Comment: 10 pages, 11 figures, accpted for publication in MNRA

MAIZE UNDER THE CLIMATE CHANGE IMPACT

Research into plant breeding always focused on increasing productivity potential in new developed plant varieties because this criterion ensures the economic efficiency of a crop and finally of the agricultural farm. Lately, however, due to the challenges of climate change, the stability of crop production is strongly affected because of the global warming. One of the most important crops for humankind is maize which becomes nowadays the most productive grain crop worldwide. Maintaining a high production of maize in the conditions of climate change remains a priority for researchers. In order to be able to make the most relevant decisions over a long period of time regarding the future of crop plants due to their importance for food security in the context of climate change, more and more researchers are using different modelling systems in crop science. A study based on the ‘Climex’ model indicates that the negative effects of global warming will limit maize cultivation in the countries between tropics of Capricorn and Cancer, but also will expand some areas from USA, Mexico, Brazil, China, Africa and Latin America, due to the cold stress reduction. Following the simulations performed until this moment, some measures that will be able to ensure large corn production in the near future despite climate change are breeding cultivars that start filling the grain as fast as possible, creating drought tolerant hybrids, improving irrigation technologies and not least, reconsider favourable areas for maize cultivation

Observations of three young gamma-ray pulsars with the Gran Telescopio Canarias

We report the analysis of the first deep optical observations of three isolated $\gamma$-ray pulsars detected by the {\em Fermi Gamma-ray Space Telescope}: the radio-loud PSR\, J0248+6021 and PSR\, J0631+1036, and the radio-quiet PSR\, J0633+0632. The latter has also been detected in the X rays. The pulsars are very similar in their spin-down age ($\tau \sim$40--60 kyrs), spin-down energy ($\dot{E} \sim10^{35}$ erg s$^{-1}$), and dipolar surface magnetic field ($B \sim 3$--$5\times10^{12}$ G). These pulsars are promising targets for multi-wavelength observations, since they have been already detected in $\gamma$ rays and in radio or X-rays. None of them has been detected yet in the optical band. We observed the three pulsar fields in 2014 with the Spanish 10.4m Gran Telescopio Canarias (GTC). We could not find any candidate optical counterpart to the three pulsars close to their most recent radio or {\em Chandra} positions down to $3 \sigma$ limits of $g'\sim27.3$, $g'\sim27$, $g'\sim27.3$ for PSR\, J0248+6021, J0631+1036, and J0633+0632, respectively. From the inferred optical upper limits and estimated distance and interstellar extinction, we derived limits on the pulsar optical luminosity. We also searched for the X-ray counterpart to PSR\, J0248+6021 with \chan\ but we did not detect the pulsar down to a 3$\sigma$ flux limit of $5 \times 10^{-14}$ erg cm$^{-2}$ s$^{-1}$ (0.3--10 keV). For all these pulsars, we compared the optical flux upper limits with the extrapolations in the optical domain of the $\gamma$-ray spectra and compared their multi-wavelength properties with those of other $\gamma$-ray pulsars of comparable age.Comment: 12 pages, 5 figures, accepted for publication in MNRA

SAX J1808.4-3658, an accreting millisecond pulsar shining in gamma rays?

We report the detection of a possible gamma-ray counterpart of the accreting millisecond pulsar SAX J1808.4-3658. The analysis of ~6 years of data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope (Fermi-LAT) within a region of 15deg radius around the position of the pulsar reveals a point gamma-ray source detected at a significance of ~6 sigma (Test Statistic TS = 32), with position compatible with that of SAX J1808.4-3658 within 95% Confidence Level. The energy flux in the energy range between 0.6 GeV and 10 GeV amounts to (2.1 +- 0.5) x 10-12 erg cm-2 s-1 and the spectrum is well-represented by a power-law function with photon index 2.1 +- 0.1. We searched for significant variation of the flux at the spin frequency of the pulsar and for orbital modulation, taking into account the trials due to the uncertainties in the position, the orbital motion of the pulsar and the intrinsic evolution of the pulsar spin. No significant deviation from a constant flux at any time scale was found, preventing a firm identification via time variability. Nonetheless, the association of the LAT source as the gamma-ray counterpart of SAX J1808.4-3658 would match the emission expected from the millisecond pulsar, if it switches on as a rotation-powered source during X-ray quiescence.Comment: 8 pages, 4 figures, accepted by MNRA

Bioefficiency of Chromolaena odorata (Linn.) on hematological and lipid profiles in sublethal cyanide poisoning in male wistar rats

Chromolaena odorata is an invasive plant which is acclaimed to have cyanide remediation potential from contaminated sites. This examination means to decide the impact of ethanol concentrates of C. odorata (ECO), sodium thiosulphate and a mix of both on hematological parameters and blood lipid profile of rodents presented to potassium cyanide. (KCN). A sum of thirty five male Wistar rats partitioned into seven groups of five units were used. KCN Group rats were administered with KCN alone. Rats in 100ECO, 150ECO, 200ECO groups were administered with 100, 150 and 200 mg/kg body weight of ECO respectively. Rats under Na2sS2O3 and Na2S2O3+ECO groups were administered 200 mg/kg sodium thiosulphate and sodium thiosulphate with ECO at 200 mg/kg respectively. The trial was done in about a month. Toward the finish of the investigation, the packed cell volume (PCV), hemoglobin level (Hb), Red blood cells (RBC) and white blood cells (WBC) were resolved utilizing known biochemical methodology. The outcomes demonstrated a noteworthy increment (p ? 0.05) in PCV, Hb, RBC and WBC level of remedial groups when contrasted with the cyanide group. Total cholesterol (TC), and triglyceride (TG) were altogether lower while HDL-cholesterol was fundamentally expanded in all the treated groups when contrasted and the untreated group given cyanide alone. However, no significant difference in LDL-cholesterol was indicated in all therapeutic groups compared with the cyanide group. The study revealed that C. odorata at the tested doses was able to improve the hematological parameters and lipid profile in cyanide exposed rats

Impacts de l’heveaculture (Hévéa brasiliensis) sur les caracteristiques physico-chimiques des sols dans la Region de Kango (N-W, Gabon)

Cette étude a permis de déterminer les propriétés physico-chimiques des sols, les stocks de carbone, l’indice de dégradation des sols (IDS), le potentiel de séquestration de carbone (CSP) dans la région de Kango. Nous avons comparé des sols sous culture d’hévéa d’âges différents : 10 ans (n = 8) et 30 ans (n = 13), à ceux sous forêts (n = 5). Les sols ont été prélevés (n = 312) sur une profondeur de 0 à 120 cm avec un pas régulier de 20 cm. Les résultats d’analyses montrent que les sols des sites présentent une texture argileuse. Les sols sont très acides, le pH varie entre 4,34 ± 0,06 et 4,72 ± 0,08 avec des densités apparentes qui varient en moyenne entre 0,91 ± 0,09 g/cm3 et 1,13 ± 0,07 g/cm3. Les stocks de carbone diminuent (forêt : 61,41 ± 1,93 MgC/ha ; hévéa 10 ans : 34,14 ± 0,12 MgC/ha). L’IDS sous hévéas de 10 ans (-53,89 %) est plus impacté que ceux sous hévéas de 30 ans (-30,92 %). Le CSP des sols sous hévéas de 30 ans est 3 fois plus important que les sols sous hévéas de 10 ans.   English title: Impacts of rubber cultivation (<i>Hévéa brasiliensis</i>) on the physico-chemical characteristics of soils in the Kango Region (N-W, Gabon) This study made it possible to determine the physicochemical properties of soils, carbon stocks, the soil degradation index (SDI), the carbon  sequestration potential (CSP) in the Kango region. We compared soils under rubber tree cultivation of different ages: 10 years (n = 8) and 30 years (n = 13), with those under forests (n = 5). The soils were sampled (n = 312) to a depth of 0 to 120 cm with a regular step of 20 cm. The results of the analyzes show that the soils of the sites have a clay texture. The soils are very acidic, the pH varies between 4.34 ± 0.06 and 4.72 ± 0.08 with apparent densities which vary on average between 0.91 ± 0.09 g / cm3 and 1.13 ± 0 , 07 g / cm3. Carbon stocks are decreasing (forest: 61.41 ± 1.93 MgC / ha; 10-year-old rubber: 34.14 ± 0.12 MgC / ha). The IDS for 10-year-old rubber trees (-53.89%) is more affected than those for 30-year-old rubber trees (-30.92%). The CSP of soils under 30-year-old rubber trees is 3 times greater than soils under 10-year-old rubber trees

Gamma-ray signatures of cosmic ray acceleration, propagation, and confinement in the era of CTA

Galactic cosmic rays are commonly believed to be accelerated at supernova remnants via diffusive shock acceleration. Despite the popularity of this idea, a conclusive proof for its validity is still missing. Gamma-ray astronomy provides us with a powerful tool to tackle this problem, because gamma rays are produced during cosmic ray interactions with the ambient gas. The detection of gamma rays from several supernova remnants is encouraging, but still does not constitute a proof of the scenario, the main problem being the difficulty in disentangling the hadronic and leptonic contributions to the emission. Once released by their sources, cosmic rays diffuse in the interstellar medium, and finally escape from the Galaxy. The diffuse gamma-ray emission from the Galactic disk, as well as the gamma-ray emission detected from a few galaxies is largely due to the interactions of cosmic rays in the interstellar medium. On much larger scales, cosmic rays are also expected to permeate the intracluster medium, since they can be confined and accumulated within clusters of galaxies for cosmological times. Thus, the detection of gamma rays from clusters of galaxies, or even upper limits on their emission, will allow us to constrain the cosmic ray output of the sources they contain, such as normal galaxies, AGNs, and cosmological shocks. In this paper, we describe the impact that the Cherenkov Telescope Array, a future ground-based facility for very-high energy gamma-ray astronomy, is expected to have in this field of research.Comment: accepted to Astroparticle Physics, special issue on Physics with the Cherenkov Telescope Arra