TransverseDiff gravity is to scalar-tensor as unimodular gravity is to General Relativity

Transverse Diffeomorphism (TDiff) theories are well-motivated theories of gravity from the quantum perspective, which are based upon a gauge symmetry principle. The main contribution of this work is to firmly establish a correspondence between TransverseDiff and the better-known scalar-tensor gravity --- in its more general form ---, a relation which is completely analogous to that between unimodular gravity and General Relativity. We then comment on observational aspects of TDiff. In connection with this proof, we derive a very general rule that determines under what conditions the procedure of fixing a gauge symmetry can be equivalently applied before the variational principle leading to the equations of motion, as opposed to the standard procedure, which takes place afterwards; this rule applies to gauge-fixing terms without derivatives.Comment: 10 pages; amsart style; v3: version as appeared in JCAP, redaction improve

Mid-infrared imaging- and spectro-polarimetric subarcsecond observations of NGC 1068

We present sub-arcsecond 7.5$-$13 $\mu$m imaging- and spectro-polarimetric observations of NGC 1068 using CanariCam on the 10.4-m Gran Telescopio CANARIAS. At all wavelengths, we find: (1) A 90 $\times$ 60 pc extended polarized feature in the northern ionization cone, with a uniform $\sim$44$^{\circ}$ polarization angle. Its polarization arises from dust and gas emission in the ionization cone, heated by the active nucleus and jet, and further extinguished by aligned dust grains in the host galaxy. The polarization spectrum of the jet-molecular cloud interaction at $\sim$24 pc from the core is highly polarized, and does not show a silicate feature, suggesting that the dust grains are different from those in the interstellar medium. (2) A southern polarized feature at $\sim$9.6 pc from the core. Its polarization arises from a dust emission component extinguished by a large concentration of dust in the galaxy disc. We cannot distinguish between dust emission from magnetically aligned dust grains directly heated by the jet close to the core, and aligned dust grains in the dusty obscuring material surrounding the central engine. Silicate-like grains reproduce the polarized dust emission in this feature, suggesting different dust compositions in both ionization cones. (3) An upper limit of polarization degree of 0.3 per cent in the core. Based on our polarization model, the expected polarization of the obscuring dusty material is $\lesssim$0.1 per cent in the 8$-$13 $\mu$m wavelength range. This low polarization may be arising from the passage of radiation through aligned dust grains in the shielded edges of the clumps.Comment: 17 pages, 10 figures, accepted for publication at MNRA

Noncommutative Wess-Zumino-Witten actions and their Seiberg-Witten invariance

We analyze the noncommutative two-dimensional Wess-Zumino-Witten model and its properties under Seiberg-Witten transformations in the operator formulation. We prove that the model is invariant under such transformations even for the noncritical (non chiral) case, in which the coefficients of the kinetic and Wess-Zumino terms are not related. The pure Wess-Zumino term represents a singular case in which this transformation fails to reach a commutative limit. We also discuss potential implications of this result for bosonization.Comment: Version to appear in Nuclear Physics

A glass bead semi‑hydroponic system for intact maize root exudate analysis and phenotyping

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, and to measure root phenotype data using standard methods and the Digital imaging of root traits (DIRT) software. LC–MS/MS (Liquid Chromatography—Tandem Mass Spectrometry) and GC–MS (Gas Chromatography—Mass Spectrometry) targeted metabolomics platforms were used to detect and quantify metabolites in the root exudates. Phytohormones, some of which are reported in maize root exudates for the first time, the benzoxazinoid DIMBOA (2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one), amino acids, and sugars were detected and quantified. After validating the methodology using known concentrations of standards for the targeted compounds, we found that the choice of the exudate collection solution affected the exudation and analysis of a subset of analyzed metabolites. No differences between collection in water or CaCl2 were found for phytohormones and sugars. In contrast, the amino acids were more concentrated when water was used as the exudate collection solution. The collection in CaCl2 required a clean-up step before MS analysis which was found to interfere with the detection of a subset of the amino acids. Finally, using the phenotypic measurements and the metabolite data, significant differences between genotypes were found and correlations between metabolites and phenotypic traits were identified. Conclusions: A new plant growth system combining glass beads supported hydroponics with semi-automated drip irrigation of sterile solutions was implemented to grow maize plants and collect root exudates without disturbing or damaging the roots. The validated targeted exudate metabolomics platform combined with root phenotyping provides a powerful tool to link plant root and exudate phenotypes to genotype and study the natural variation of plant populations

A glass bead semi-hydroponic system for intact maize root exudate analysis and phenotyping

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, and to measure root phenotype data using standard methods and the Digital imaging of root traits (DIRT) software. LC–MS/MS (Liquid Chromatography—Tandem Mass Spectrometry) and GC–MS (Gas Chromatography—Mass Spectrometry) targeted metabolomics platforms were used to detect and quantify metabolites in the root exudates. Phytohormones, some of which are reported in maize root exudates for the first time, the benzoxazinoid DIMBOA (2,4-Dihydroxy-7-methoxy-1,4-benzoxazin-3-one), amino acids, and sugars were detected and quantified. After validating the methodology using known concentrations of standards for the targeted compounds, we found that the choice of the exudate collection solution affected the exudation and analysis of a subset of analyzed metabolites. No differences between collection in water or CaCl2 were found for phytohormones and sugars. In contrast, the amino acids were more concentrated when water was used as the exudate collection solution. The collection in CaCl2 required a clean-up step before MS analysis which was found to interfere with the detection of a subset of the amino acids. Finally, using the phenotypic measurements and the metabolite data, significant differences between genotypes were found and correlations between metabolites and phenotypic traits were identified. Conclusions: A new plant growth system combining glass beads supported hydroponics with semi-automated drip irrigation of sterile solutions was implemented to grow maize plants and collect root exudates without disturbing or damaging the roots. The validated targeted exudate metabolomics platform combined with root phenotyping provides a powerful tool to link plant root and exudate phenotypes to genotype and study the natural variation of plant populations

Wind-induced Cross-Strait Sea Level Variability in the Strait of Gibraltar using Coastal Altimetry and In-Situ Measurements

In this work, we retracked altimeter waveforms of ESA satellites. ERS2 RA and Envisat RA2 from descending track 0360 over the eastern side of the Strait of Gibraltar using the Adaptive Leading Edge Subwaveform ALES retracker

Relationship Between Jump Capacity and Performance in BMX Cycling

The objective of this study is to assess the relationship between the results obtained on different vertical jump tests and the top score recorded during a BMX (Bicycle Moto-Cross) test and the rider''s performance. To do so, 10 BMX pilots participated in this study; 5 regarded as the elite group (EG) (age: 18.8 +/- 3.7, weight: 68.4 +/- 8.5 kg, height: 174 +/- 9 cm and previous BMX experience: 8 +/- 3.8 years) and 5 regarded as the recreational group (RG) (age: 19.8 +/- 4.8, weight: 69.2 +/- 11.7 kg, height: 170 +/- 9 cm, previous BMX experience: 4.2 +/- 1.3 years). Vertical jump capacity was obtained using the Bosco protocol, i.e. vertical squat jump (SJ), vertical countermovement jump (CMJ), drop jump (DJ) and repetitive jump (RJ), and time in race in a BMX circuit was determined. The results indicate a direct relationship between the time used to complete the circuit and the height of the jump reached in SJ (r: -.801; p:.017), CMJ (r : -.798; p :.018) and DJ (r : -.782; p:.022). This all suggests that assessing jump capacity using the Bosco test may be a useful tool for assessing BMX performance

Experimental aspects of SU(5)xU(1) supergravity

We study various aspects of $SU(5)\times U(1)$ supergravity as they relate to the experimental verification or falsification of this model. We consider two string-inspired, universal, one-parameter, no-scale soft-supersymmetry-breaking scenarios, driven by the $F$-terms of the moduli and dilaton fields. The model is described in terms of the supersymmetry mass scale (\ie, the chargino mass $m_{\chi^\pm_1}$), $\tan\beta$, and the top-quark mass. We first determine the combined effect on the parameter space of all presently available direct and indirect experimental constraints, including the LEP lower bounds on sparticle and Higgs-boson masses, the $b\to s\gamma$ rate, the anomalous magnetic moment of the muon, the high-precision electroweak parameters $\epsilon_1,\epsilon_b$ (which imply m_t\lsim180\GeV), and the muon fluxes in underground detectors (neutrino telescopes). For the still-allowed points in $(m_{\chi^\pm_1},\tan\beta)$ parameter space, we re-evaluate the experimental situation at the Tevatron, LEPII, and HERA. In the 1994 run, the Tevatron could probe chargino masses as high as 100 GeV. At LEPII the parameter space could be explored with probes of different resolutions: Higgs boson searches, selectron searches, and chargino searches. Moreover, for m_t\lsim150\GeV, these Higgs-boson searches could explore all of the allowed parameter space with \sqrt{s}\lsim210\GeV.Comment: latex, 36 pages, 25 figures (not included). Figures are available via anonymous ftp from hplaa02.cern.ch (/pub/lopez) as either 33 ps files (Easpects*.ps, 8.1MB) or one uuencoded file (AllFigures.uu, 3.7MB