Estimating the three-dimensional structure of canopy foliage based on the light measurements in a Betula ermanii stand

In order to more accurately evaluate the functional activity of forest stands by canopy production and evapotranspiration, we improved the methods for field measurements and statistical modeling to estimate foliage configuration (spatial distribution of leaves) while simultaneously reconstructing the three-dimensional photosynthetically active photon flux density (PPFD) distribution (PPFD pattern) in a forest canopy. By using a sensor (photodiode) array, a PPFD pattern was observed in summer 2002 under the canopy in an even-aged, pure stand of Japanese mountain birch Betula ermanii Cham. (17-years old) in Hokkaido, northern Japan. A Markov chain Monte Carlo (MCMC) sampling technique is developed such that a set of foliage configurations generated by the model referred to as the Gibbs foliage canopy (GFC) approximates the field-measured PPFD pattern. The posterior distribution of the foliage configurations is generated by the parallel tempering MCMC of eight independent series of foliage configurations. The GFC model generated the posterior distribution of the LAI estimates (mean 4.56) that appeared to be appropriate in comparison to other LAI estimates of the B. ermanii stand based on the indirect and nondestructive methods by LAI-2000 (LAI = 3.43) and litterfall traps (LAI = 5.56) because they could be under- and overestimated, respectively. Our evaluations of the canopy production and evapotranspiration rates suggest that the relationship between LAI and canopy functions was not very simple because it depended on the nonlinear functional forms of the leaf responses of photosynthesis and transpiration to PPFD. The current study demonstrates an application of MCMC techniques that can generate a set of possible structures of unobserved/unobservable objects based on the high-resolution dataset obtained by some indirect (or remote-sensing) methods.     

Role of sorbitol in manufacturing dried seafood from heated squid meat

SUMMARY: Japanese common squid meat was heat-treated at 80°C for 1 min, cured with 1.0 M sorbitol solution (pH 7.0) at 4°C for 18 h, and dried further at 30°C (60% relative humidity) for 16 h. Osmotic dehydration during the sorbitol curing process and slow moisture vaporization at the initial drying period were observed regardless of the heat denaturation of muscle protein. Simultaneously, lowering the amount of moisture vaporized in the falling rate of the drying period caused a shortening of the total drying time. Furthermore, the shear force of the dried product from heat-treated meat was kept at a lower value by sorbitol curing, although the suppression effect of sorbitol on the hardening of dried meat was lost by protein denaturation. These results are useful for understanding the role of sorbitol in reducing drying time and in eliminating excess hardening of dried squid products.     

Effect of EDTA alone and in combination with polygodial on the growth of Saccharomyces cerevisiae

The antifungal activity of ethylenediaminetetraacetic acid (EDTA) against Saccharomyces cerevisiae was significantly affected by various conditions such as inoculum size, pH, and metal ions (Mg(2+), Ca(2+)). EDTA was found to be effective against this yeast at the inoculum size of 10(5) colony forming units (CFU)/mL with the minimum inhibitory concentration of 400 mug/mL and the minimum fungicidal concentration of 6400 mug/mL, but it was not effective at 10(7) CFU/mL up to 6400 mug/mL. The fungicidal activity of EDTA against S. cerevisiae was significantly enhanced in combination with polygodial. Isobolograms, fractional inhibitory concentration, and fractional fungicidal concentration indices were used for evaluating the interaction between combined compounds. This synergistic effect is likely due to polygodial's destructive action on the cellular membrane, which facilitates the transmembrane transport of foreign compounds (EDTA) into yeast cells. Once inside the cells, EDTA forms chelation with divalent metals such as Mg(2+) and Ca(2+), which are required by various essential enzymes.     

Molecular design of antifungal agents

In a rational approach to the design of antifungal agents against Saccharomyces cerevisiae, a series of alkyl gallates (3,4,5-trihydroxybenzoates) were synthesized and assayed. Nonyl gallate (1) was found to be the most effective with a minimum fungicidal concentration (MFC) of 12.5 microg/mL (42 microM), followed by octyl gallate (2) with an MFC of 25 microg/mL (89 microM). These MFCs are little influenced by pH values. A time-kill curve study indicates that nonyl gallate exhibits fungicidal activity against S. cerevisiae at any growing stage. The antifungal activity of nonyl gallate is due primarily to its ability to act as a nonionic surface-active agent (surfactant). The length of the alkyl group is not a major contributor but plays a role in eliciting the activity to a large extent. As far as alkyl gallates are concerned, their antimicrobial spectra and potency depend largely on the hydrophobic portion of the molecules.     

Modes of antifungal action of (2E)-alkenals against Saccharomyces cerevisiae

A series of aliphatic (2E)-alkenals from C(5) to C(14) were tested for their antifungal activity against Saccharomyces cerevisiae ATCC 7754. (2E)-Undecenal (C(11)) was found to be the most effective with the minimum fungicidal concentration (MFC) of 6.25 microgram/mL, followed by (2E)-decenal (C(10)) with an MFC of 12.5 microgram/mL. The time-kill curve study showed that (2E)-undecenal was fungicidal against S. cerevisiae at any growth stage, and this activity was not influenced by pH values. The (2E)-alkenals inhibited glucose-induced acidification by inhibiting the plasma membrane H(+)-ATPase. The primary antifungal action of medium-chain (C(9)-C(12)) (2E)-alkenals against S. cerevisiae comes from their ability to function as nonionic surface-active agents (surfactants), disrupting the native membrane-associated function nonspecifically. Hence, the antifungal activity of (2E)-alkenals is mediated by biophysical processes, and the maximum activity can be obtained when the balance between the hydrophilic and hydrophobic portions becomes the most appropriate.     

Quantitative trait loci for soil-penetrating ability of roots in durum wheat

Increasing root penetration (RP) ability into hard soil is important to improve drought resistance in durum wheat. Traits related to RP ability were evaluated in 110 recombinant inbred lines (RILs) derived from a cross between 'Jennah Khetifa' and 'Cham1' using paraffin-Vaseline (PV) discs. QTL analyses were made for the number of roots penetrating the PV disc (PVRN), total number of seminal and crown roots (TRN), RP index (PVRN/TRN) and root dry weight (DW). 'Jennah Khetifa' had higher PVRN, RP index and root DW values than 'Cham1', and the RILs showed significant differences for these traits. Two closely-linked markers, Xgwm617a and Xgwm427b , on the long arm of chromosome 6A were associated with PVRN and RP index. For root DW, a QTL was linked to marker Xgwm11 on chromosome 1B. Alleles of 'Jennah Khetifa' were associated with increased PVRN, RP index and root DW. No QTL was detected for TRN in this mapping population. The absence of co-located QTLs suggested that RP ability was controlled separately from TRN and root DW. Although the population size and number of replications were small, this study helps in understanding the complexity of root growth and the potential of marker-assisted selection for selecting genotypes with high RP ability in durum wheat populations.     

Development of genomic and EST-SSR markers in radish (Raphanus sativus L.)

Radish (Raphanus sativus L.) belongs to Brassicaceae family and is a close relative of Brassica. This species shows a wide morphological diversity, and is an important vegetable especially in Asia. However, molecular research of radish is behind compared to that of Brassica. For example, reports on SSR (simple sequence repeat) markers are limited. Here, we designed 417 radish SSR markers from SSR-enriched genomic libraries and the cDNA data. Of the 256 SSR markers succeeded in PCR, 130 showed clear polymorphisms between two radish lines; a rat-tail radish and a Japanese cultivar, ‘Harufuku’. As a test case for evaluation of the present SSRs, we conducted two studies. First, we selected 16 SSRs to calculate polymorphism information contents (PICs) using 16 radish cultivars and four other Brassicaceae species. These markers detected 3–15 alleles (average = 9.6). PIC values ranged from 0.54 to 0.92 (average = 0.78). Second, part of the present SSRs were tested for mapping using our previously-examined mapping population. The map spanned 672.7 cM with nine linkage groups (LGs). The 21 radish SSR markers were distributed throughout the LGs. The SSR markers developed here would be informative and useful for genetic analysis in radish and its related species.     

Granulomatous nephritis and meningoencephalomyelitis caused by Halicephalobus gingivalis in a pony gelding

A ten-year-old Shetland pony gelding showed low appetite, ataxia, peculiar swaying, clouding of consciousness, and ultimately died. At necropsy, multiple coalescing granulomatous foci were detected in the kidneys, and small necrotic lesions were found in the cerebellum. Histologic examination of the renal tissue sections revealed extensive granuloma, and Halicephalobus gingivalis-like nematodes were seen. Similar nematodes were found in the granulomatous or necrotic lesions of the renal lymph nodes and cerebellum, and were also frequently detected in cerebrospinal meningovascular lesions. Morphologic features together with partial ribosomal RNA gene sequences of the nematodes in the lesions revealed that they were H. gingivalis. The present results indicated that H. gingivalis caused granulomatous nephritis and meningoencephalomyelitis in this pony gelding.