Molecular and Genetic Regulation of Sensory Quality of Climacteric Fruit

The sensory quality of fruit has become a major criterion in making the purchasing decision by consumers. Breeding programs have mainly been directed, from the post-harvest stand point, towards improving shelf-life. Chance seedlings or mutants with improved agronomic traits and/or extended shelf-life have been used for introgressing the long shelf-life character and eventually improved sensory quality traits in commercial genotypes of apple, melon or tomato. Because the plant hormone ethylene plays a central role in both storability and ripening of climacteric fruit, the generation by biotechnology of ethylene-inhibited fruit has offered a powerful tool to better understand, at the molecular and genetic level, the interrelations between storability and sensory quality. In the melon, inhibition of ethylene synthesis results is a strong inhibition of the synthesis of aroma volatiles while the accumulation of sugars is not affected or is even improved. The softening of the flesh is strongly affected but not abolished. Mid or long shelf-life melons generated by classical breeding present the same behavior. The generation of recombinant inbred lines by crossing a typical climacteric melon (Cantaloupe Charentais of the cantalupensis group) with a non climacteric melon (PI161375 of the agrestis chinensis group) allowed to demonstrate that the climacteric character is conferred by 2 duplicated loci only, which are of great importance for the regulation of storability and sensory quality. Due to the importance of aroma volatiles in sensory quality and to the strong negative correlation between aroma production and ethylene synthesis, we have developed a research program aimed at isolating genes involved in the synthesis of aroma volatiles. We will report on the recent advances in the field with special emphasis on the characterization of genes responsible for the synthesis of esters, a family of compounds crucial for the flavor of many fruit

Thorium and uranium isotopes in a manganese nodule from the Peru basin determined by alpha spectrometry and thermal ionization mass spectrometry (TIMS): Are manganese supply and growth related to climate?

Thorium- and uranium isotopes were measured in a diagenetic manganese nodule from the Peru basin applying alpha- and thermal ionization mass spectrometry (TIMS). Alpha-counting of 62 samples was carried out with a depth resolution of 0.4 mm to gain a high-resolution230Thexcess profile. In addition, 17 samples were measured with TIMS to obtain precise isotope concentrations and isotope ratios. We got values of 0.06–0.59 ppb (230Th), 0.43–1.40 ppm (232Th), 0.09–0.49 ppb (234U) and 1.66–8.24 ppm (238U). The uranium activity ratio in the uppermost samples (1–6 mm) and in two further sections in the nodule at 12.5±1.0 mm and 27.3–33.5 mm comes close to the present ocean water value of 1.144±0.004. In two other sections of the nodule, this ratio is significantly higher, probably reflecting incorporation of diagenetic uranium. The upper 25 mm section of the Mn nodule shows a relatively smooth exponential decrease in the230Thexcess concentration (TIMS). The slope of the best fit yields a growth rate of 110 mm/Ma up to 24.5 mm depth. The section from 25 to 30.3 mm depth shows constant230Thexcess concentrations probably due to growth rates even faster than those in the top section of the nodule. From 33 to 50 mm depth, the growth rate is approximately 60 mm/Ma. Two layers in the nodule with distinct laminations (11–15 and 28–33 mm depth) probably formed during the transition from isotopic stage 8 to 7 and in stage 5e, respectively. The Mn/Fe ratio shows higher values during interglacials 5 and 7, and lower ones during glacials 4 and 6. A comparison of our data with data from adjacent sediment cores suggests (a) a variable supply of hydrothermal Mn to sediments and Mn nodules of the Peru basin or (b) suboxic conditions at the water sediment interface during periods with lower Mn/Fe ratios

Electromagnetic modeling and optimization of packaged photodetector modules for 100 Gbit/s applications

In this paper, we propose an accurate full 3D EM behavioral model of PD chips for the first time. The model, which is meshed at 130 GHz, runs for about 17 minutes on an Intel Core2 Duo CPU@3 GHz PC with 3.5 GB of RAM. The impact of various parameters in wire- bonding transitions for transmission characteristic is summarized in the Table I. When numbers of bonding wires are placed separately all through strips of CBCPWs as well as keeping an optimized gap of transitions, more than 10 GHz bandwidth improvement can be achieved compared the worst case. We also notice that optimization on bonding wires does not significantly improve the fast decay beyond 60 GHz. Further investigation and optimization of the transition is required including a redesign of the CBCPW

Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECRs) with a Fluorescence detector Array of Single-pixel Telescopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report first results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photomultiplier tube at the focal plane of a 1 m$^2$ Fresnel lens system taken from the prototype of the JEM-EUSO experiment. The FAST prototype took data for 19 nights, demonstrating remarkable operational stability. We detected laser shots at distances of several kilometres as well as 16 highly significant UHECR shower candidates.Comment: Accepted for publication in Astroparticle Physic

The U(1)-Higgs Model: Critical Behaviour in the Confinig-Higgs region

We study numerically the critical properties of the U(1)-Higgs lattice model, with fixed Higgs modulus, in the region of small gauge coupling where the Higgs and Confining phases merge. We find evidence of a first order transition line that ends in a second order point. By means of a rotation in parameter space we introduce thermodynamic magnitudes and critical exponents in close resemblance with simple models that show analogous critical behaviour. The measured data allow us to fit the critical exponents finding values in agreement with the mean field prediction. The location of the critical point and the slope of the first order line are accurately given.Comment: 21 text pages. 12 postscript figures available on reques

Astroclimatic Characterization of Vallecitos: A candidate site for the Cherenkov Telescope Array at San Pedro Martir

We conducted an 18 month long study of the weather conditions of the Vallecitos, a proposed site in Mexico to harbor the northern array of the Cherenkov Telescope Array (CTA). It is located in Sierra de San Pedro Martir (SPM) a few kilometers away from Observatorio Astron\'omico Nacional. The study is based on data collected by the ATMOSCOPE, a multi-sensor instrument measuring the weather and sky conditions, which was commissioned and built by the CTA Consortium. Additionally, we compare the weather conditions of the optical observatory at SPM to the Vallecitos regarding temperature, humidity, and wind distributions. It appears that the excellent conditions at the optical observatory benefit from the presence of microclimate established in the Vallecitos.Comment: 16 pages, 16 figures, Publication of the Astronomical Society of the Pacific, accepte

The bright optical flash from GRB 060117

We present a discovery and observation of an extraordinarily bright prompt optical emission of the GRB 060117 obtained by a wide-field camera atop the robotic telescope FRAM of the Pierre Auger Observatory from 2 to 10 minutes after the GRB. We found rapid average temporal flux decay of alpha = -1.7 +- 0.1 and a peak brightness R = 10.1 mag. Later observations by other instruments set a strong limit on the optical and radio transient fluxes, unveiling an unexpectedly rapid further decay. We present an interpretation featuring a relatively steep electron-distribution parameter p ~ 3.0 and providing a straightforward solution for the overall fast decay of this optical transient as a transition between reverse and forward shock.Comment: Accepted to A&A, 4 pages, corected few typos pointed out by X.F. W

Critical Behavior of the Three-Dimensional Ising Spin Glass

We have simulated, using parallel tempering, the three dimensional Ising spin glass model with binary couplings in a helicoidal geometry. The largest lattice (L=20) has been studied using a dedicated computer (the SUE machine). We have obtained, measuring the correlation length in the critical region, a strong evidence for a second-order finite temperature phase transition ruling out other possible scenarios like a Kosterlitz-Thouless phase transition. Precise values for the $\nu$ and $\eta$ critical exponents are also presented.Comment: RevTex; 12 pages plus 5 ps figures. Final version to be published in PR

Sequential loss of myelin proteins during Wallerian degeneration in the human spinal cord

Axons undergo Wallerian degeneration (WD) distal to a point of injury. In the lesioned PNS, WD may be followed by successful axonal regeneration and functional recovery. However, in the lesioned mammalian CNS, there is no significant axonal regeneration. Myelin-associated proteins (MAPs) have been shown to play significant roles in preventing axonal regeneration in the CNS. Since relatively little is known about such events in human CNS pathologies, we performed an immunohistochemical investigation on the temporal changes of four MAPs during WD in post-mortem spinal cords of 22 patients who died 2 days to 30 years after either cerebral infarction or traumatic spinal cord injury. In contrast to experimental studies in rats, the loss of myelin sheaths is greatly delayed in humans and continues slowly over a number of years. However, in agreement with animal data, a sequential loss of myelin proteins was found which was dependent on their location within the myelin sheath. Myelin proteins situated on the peri-axonal membrane were the first to be lost, the time course correlating with the loss of axonal markers. Proteins located within compact myelin or on the outer myelin membrane were still detectable 3 years after injury in degenerating fibre tracts, long after the disappearance of the corresponding axons. The persistence of axon growth-inhibitory proteins such as NOGO-A in degenerating nerve fibre tracts may contribute to the maintenance of an environment that is hostile to axon regeneration, long after the initial injury. The present data highlight the importance of correlating the well documented, lesion-induced changes that take place in controlled laboratory investigations with those that take place in the clinical domai