Foliar calcium effects on quality and primary and secondary metabolites of white-fleshed ‘Lemonato’ peaches

‘Lemonato’ is a Greek peach melting-flesh white-flesh cultivar with high nutritional value highly appreciated by the consumers. This study aimed to evaluate the effect of pre-harvest foliar calcium application on fruit quality, primary metabolite profile, antioxidant activity, total phenolic content, and phenolic profile of the ‘Lemonato’ peach, clone ‘Stamatis’. The experiment was conducted for two years, 2019 and 2020, in two commercial orchards at Kato Lehonia and Agios Vlasios regions, central Greece, where the ‘Lemonato’ clone ‘Stamatis’ is traditionally cultivated. The treatments were organic calcium (Ca), calcium–silicate in nanoparticles (Ca–Si), and calcium chloride (CaCl2). Foliar application of the different Ca formulations, commonly used as a horticultural practice, were not effective at improving the fruit quality characteristics in this clone, which is characterized by fruit softening during ripening. The study revealed the sugars and organic acid composition and phenolic profile of the ‘Lemonato’ peach, clone ‘Stamatis’. Peach fruit quality, primary metabolites, and phenolic compounds of the two orchards showed a different response to organic Ca and Ca–Si, indicating that genetic or environmental factors may also be involved. A higher concentration of organic Ca and CaCl2 increased the peach fruit phenolic compounds content and the total antioxidant activity, improving the fruit nutritional qualit

Polarization of the Microwave Background in Reionized Models

I discuss the physics of polarization in models with early reionization. For sufficiently high optical depth to recombination the polarization is boosted on large scales while it is suppressed on smaller scales. New peaks appear in the polarization power spectrum, their position is proportional to the square root of the redshift at which the reionization occurs while their amplitude is proportional to the optical depth. For standard scenarios the rms degree of linear polarization as measured with a 7 degree FWHM antenna (like the one of the Brown University experiment) is $1.6\mu K$, $1.2 \mu K$, $4.8\times 10^{-2} \mu K$ for an optical depth of 1, 0.5 or 0 respectively. For a 1 degree FWHM antenna this same models give $2.7 \mu K$ , $1.8 \mu K$ and $0.77 \mu K$. Detailed measurement of polarization on large angular scales could provide an accurate determination of the epoch of reionization, which cannot be obtained from temperature measurements alone.Comment: 19 pages, 12 figures, Revised to match PRD accepeted version. Improved COBE normaliztion so some numerical results change slightl

Breakdown of the adiabatic limit in low dimensional gapless systems

It is generally believed that a generic system can be reversibly transformed from one state into another by sufficiently slow change of parameters. A standard argument favoring this assertion is based on a possibility to expand the energy or the entropy of the system into the Taylor series in the ramp speed. Here we show that this argumentation is only valid in high enough dimensions and can break down in low-dimensional gapless systems. We identify three generic regimes of a system response to a slow ramp: (A) mean-field, (B) non-analytic, and (C) non-adiabatic. In the last regime the limits of the ramp speed going to zero and the system size going to infinity do not commute and the adiabatic process does not exist in the thermodynamic limit. We support our results by numerical simulations. Our findings can be relevant to condensed-matter, atomic physics, quantum computing, quantum optics, cosmology and others.Comment: 11 pages, 5 figures, to appear in Nature Physics (originally submitted version

Depolarization of the cosmic microwave background by a primordial magnetic field and its effect upon temperature anisotropy

We estimate the depolarizing effect of a primordial magnetic field upon the cosmic microwave background radiation due to differential Faraday rotation across the last scattering surface. The degree of linear polarization of the CMB is significantly reduced at frequencies around and below 30 GHz $(B_* /10^{-2}{\rm Gauss})^{1/2}$, where $B_*$ is the value of the primordial field at recombination. The depolarizing mechanism reduces the damping of anisotropies due to photon diffusion on small angular scales. The $l\approx 1000$ multipoles of the CMB temperature anisotropy correlation function in a standard cold dark matter cosmology increase by up to 7.5\% at frequencies where depolarization is significant.Comment: Latex, 23 pages, 4 figures. Submitted to Phys. Rev.

CMB Telescopes and Optical Systems

The cosmic microwave background radiation (CMB) is now firmly established as a fundamental and essential probe of the geometry, constituents, and birth of the Universe. The CMB is a potent observable because it can be measured with precision and accuracy. Just as importantly, theoretical models of the Universe can predict the characteristics of the CMB to high accuracy, and those predictions can be directly compared to observations. There are multiple aspects associated with making a precise measurement. In this review, we focus on optical components for the instrumentation used to measure the CMB polarization and temperature anisotropy. We begin with an overview of general considerations for CMB observations and discuss common concepts used in the community. We next consider a variety of alternatives available for a designer of a CMB telescope. Our discussion is guided by the ground and balloon-based instruments that have been implemented over the years. In the same vein, we compare the arc-minute resolution Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). CMB interferometers are presented briefly. We conclude with a comparison of the four CMB satellites, Relikt, COBE, WMAP, and Planck, to demonstrate a remarkable evolution in design, sensitivity, resolution, and complexity over the past thirty years.Comment: To appear in: Planets, Stars and Stellar Systems (PSSS), Volume 1: Telescopes and Instrumentatio

Detection of Polarization in the Cosmic Microwave Background using DASI

We report the detection of polarized anisotropy in the Cosmic Microwave Background radiation with the Degree Angular Scale Interferometer (DASI), located at the Amundsen-Scott South Pole research station. Observations in all four Stokes parameters were obtained within two 3.4 FWHM fields separated by one hour in Right Ascension. The fields were selected from the subset of fields observed with DASI in 2000 in which no point sources were detected and are located in regions of low Galactic synchrotron and dust emission. The temperature angular power spectrum is consistent with previous measurements and its measured frequency spectral index is -0.01 (-0.16 -- 0.14 at 68% confidence), where 0 corresponds to a 2.73 K Planck spectrum. The power spectrum of the detected polarization is consistent with theoretical predictions based on the interpretation of CMB anisotropy as arising from primordial scalar adiabatic fluctuations. Specifically, E-mode polarization is detected at high confidence (4.9 sigma). Assuming a shape for the power spectrum consistent with previous temperature measurements, the level found for the E-mode polarization is 0.80 (0.56 -- 1.10), where the predicted level given previous temperature data is 0.9 -- 1.1. At 95% confidence, an upper limit of 0.59 is set to the level of B-mode polarization with the same shape and normalization as the E-mode spectrum. The TE correlation of the temperature and E-mode polarization is detected at 95% confidence, and also found to be consistent with predictions. These results provide strong validation of the underlying theoretical framework for the origin of CMB anisotropy and lend confidence to the values of the cosmological parameters that have been derived from CMB measurements.Comment: 20 pages, 6 figure

Instrument, Method, Brightness and Polarization Maps from the 2003 flight of BOOMERanG

We present the BOOMERanG-03 experiment and maps of the Stokes parameters I, Q, U of the microwave sky obtained during a 14 day balloon flight in 2003. Three regions of the southern sky were surveyed: a deep survey (~ 90 square degrees) and a shallow survey (~ 750 square degrees) at high Galactic latitudes (both centered at RA ~ 5.5 h, dec ~ -45 deg) and a survey of ~ 300 square degrees across the Galactic plane at RA ~ 9.1 h, dec ~ -47 deg. All three surveys were carried out in three wide frequency bands centered at 145, 245 and 345 GHz, with an angular resolution of ~ 10'. The 145 GHz maps of Stokes I are dominated by Cosmic Microwave Background (CMB) temperature anisotropy, which is mapped with high signal to noise ratio. The measured anisotropy pattern is consistent with the pattern measured in the same region by BOOMERanG-98 and by WMAP. The 145 GHz maps of Stokes Q and U provide a robust statistical detection of polarization of the CMB when subjected to a power spectrum analysis. This amplitude of the polarization is consistent with that of the CMB in the $\Lambda$CDM cosmological scenario. At 145 GHz, in the CMB surveys, the intensity and polarization of the astrophysical foregrounds are found to be negligible with respect to the cosmological signal. At 245 and 345 GHz we detect ISD emission correlated to the 3000 GHz IRAS/DIRBE maps, and give upper limits for any other non-CMB component. We also present intensity maps of the surveyed section of the Galactic plane. These are compared to monitors of different interstellar components, showing that a variety of emission mechanisms is present in that region.Comment: see http://oberon.roma1.infn.it/boomerang/b2k and http://cmb.phys.cwru.edu/boomerang/ for a high resolution versio

Influence of Ambient Ozone Pollution on Olive Leaf Gas Exchange Irrigated with Saline Water

Saline water is often available for irrigation and ambient ozone pollution is significant in the Mediterranean region. These two factors may negatively affect cultivated plant productivity. We studied the effects of a combination of these stress factors on leaf gas exchange of young olive trees, a major crop in the above region. Two-years-old 'Konservolea' and 'Kalamata' olive plants grafted on seedling rootstock were grown in sand: perlite mixture irrigated with half strength Hoagland's solution containing or not 100 mM NaCl. In open top chambers, the plants received outside air with ambient ozone or charcoal-filtered air from April to September. Leaf gas exchange parameters and chlorophyll fluorescence were measured periodically. High ozone concentrations from May to September able to damage plants (daylight mean ozone concentration >60 nL L(-1)) did not affect the olive leaf functions studied, showing that young olive trees are relatively resistant to ozone levels found around the Mediterranean region. Irrigation with 100 mM NaCl solution decreased stomatal conductance by around 45%, photosynthetic rate by more than 35% and Fv/Fm values below 0.75. Both studied olive cultivars showed similar behavior to salinity stress possibly due to the seedling rootstock on which both cultivars were grafted. The combination of salinity and ambient ozone stress did not result in any further effects to leaf gas exchange besides the ones from the salinity stress alone. (C) 2011 Friends Science Publisher

Preharvest AVG and kaolin and Postharvest 1-MCP application effects on advanced maturity peach quality and storage

Treatments to conserve quality for long-distance transportation were studied with advanced maturity 'Royal Glory' peaches and 'Caldesi 2000' nectarines. Kaolin (Surround) was applied at commercial rates 3 times every 10 days until harvest; AVG (ReTain) was also applied 10 days before anticipated harvest at 0.1% active ingredient + 0.01% surfactant; and 1250 μl L -1 1-MCP (SmartFresh) was applied immediately after harvest. Fruit quality was evaluated at harvest and after 1, 2 and 4 weeks storage in perforated PE bags at 2°C, 90-95% RH plus 1 day shelf life. Kaolin application had no effect on flesh firmness and overall fruit eating quality in both cultivars at harvest and during storage. Fruit from AVG treated trees were harder and had higher acidity than and similar soluble solids content (SSC) and flesh color to fruit from control trees at harvest. These effects disappeared after the 1st week of cold storage resulting in quality similar to control fruit from the 2nd week of storage. Postharvest 1-MCP application resulted in fruit harder than the control fruit at harvest and throughout the storage period with firmness able to withstand long distance transportation. 1-MCP treatment had no other effects on the organoleptic quality of these advanced maturity fruit throughout the 4 weeks cold storage. No chilling injury symptoms were observed at any time or treatment to an extent of degrading fruit quality

Deficit irrigation and reflective mulch effects on peach and nectarine fruit quality and storage ability

The effects of deficit irrigation and reflective mulch were studied as possible means to reduce irrigation water use and improve peach fruit quality and storage ability. 'Royal Glory' peach and 'Caldesi 2000' nectarine trees were drip irrigated close to ETc (control) or with 50% of ETc (deficit) during the last three weeks before anticipated harvest of tree-ripe fruit. Reflective Extenday® mulch was also applied on the tree row for almost a month before anticipated harvest at control or deficit irrigated trees. Fruit quality from the upper and lower parts of the tree was evaluated at harvest and after 2, 4 and 6 weeks at 2°C plus 1 day shelf life. Fruit quality included skin color, flesh firmness, specific conductivity and dry matter (DM), juice soluble solids content (SSC), acidity and total phenols (TP) and subjective evaluation of chilling injury (CI) symptoms (flesh leatheriness and browning). With storage time and in both cultivars, fruit skin only slightly changed, fruit flesh softened, specific conductivity, SSC, acidity and DM decreased and TP content and CI (mainly leatheriness) increased. With deficit irrigation or reflective mulch, the two cultivars behaved differently. Nectarines from deficit irrigated trees had improved quality but lower storage ability than fruit from control trees. Peaches from deficit irrigated trees had similar quality to control fruit except of higher SSC (mainly the fruit from the lower part of the canopy) and slightly higher CI. Nectarines from reflective mulched trees had better skin color, harder flesh, higher acidity and DM, similar SSC and TP and higher leatheriness incidence than fruit from control trees. Peaches from reflective mulched trees had the most advanced maturity fruit at harvest compared to the other treatments, and higher quality fruit but also lower storage ability than control fruit. In short, fruit quality of both cultivars studied was improved due to deficit irrigation or reflective mulching but their storage ability was reduced from these treatments