Exploring the tactile and thermal behaviour of rose petals for bio-inspired material design.

Rice is believed to show photosynthetic symmetry between adaxial and abaxial leaf sides. To verify this, we re-examined dorsoventral asymmetry in photosynthesis, chlorophyll fluorescence and anatomical traits in flag leaves of two Oryza sativa cultivars that differ in nitrogen (N) response and in leaf angle: 'Akenohoshi', a cultivar that can adapt to low-N (LN), with low leaf angle (more erect leaves), and 'Shirobeniya', a cultivar that is unable to adapt to LN, with higher leaf angle. Plants were grown under standard-N (SN) and LN conditions. LN leaves of both cultivars became more erect than SN, but LN Akenohoshi still had more erect ones than Shirobeniya. Contrary to results of previous studies, leaves of both cultivars showed an asymmetry in photosynthetic rate between adaxial and abaxial sides (higher on the adaxial side) under SN. SN leaves of both cultivars showed lower susceptibility to photoinhibition on the adaxial side than on the abaxial side. However, leaves of Akenohoshi showed less asymmetry in these traits under LN than under SN, whereas leaves of Shirobeniya had similar degrees of asymmetry in these traits under both SN and LN. Both cultivars also showed dorsoventral asymmetry in anatomical traits of mesophyll tissue regardless of N level, but the degree of asymmetry was lower in LN Akenohoshi. These data reveal that rice leaves exhibit dorsoventral asymmetry in photosynthetic and anatomical features, and that the degree of asymmetry varies with cultivar and N level. It is suggested that lower leaf angles (particularly in Akenohoshi) in the presence of LN represent a light acclimation to prevent photoinhibition.

Surface and internalized Escherichia coli O157:H7 on field-grown spinach and lettuce treated with spray-contaminated irrigation water.

Microscale mechanism of microstructure, micromorphology and Janus wettability of the banana leaf surface

Plant can absorb  pollutan.  Part of  plant  which  absorb  the  pollutan  were leaf. Plant can use as  pollotan  indicator  such  plant  which  growth aside  street.The  purpose  of  this  study were  to determine the number and distribution of stomatal of plants which grouth aside street at Ternate City. This research was a descriptive study. The data were collecting by couting the number of stomatal and its distribution by using replica and whole mount method. Such plants were used in this study were Ficus benjamina L,  Callophylum  inophyllum  L.,  Acacia crassicarpa, Samanea saman and Arecaceae. The result of this study showed a varies of stomatal number and  its distribution within five species plants Stomatal number on A. crassicarpa categorited into uncoonting both of  upper  adaxial and lower abaxial,   F. benjamina L. had  stomatal number very high at abaxial side than adaxial side, C. inophyllum L. had stomatal number on adaxial side higher than adaxial side in S. Saman, its stomatal number on adaxial side categorized uncoonting whereas adaxial side were low. The stomata number of Arecaceae were categorized moderate on abaxial side where as adaxial side were low. Stomatal distribution on F. benjamina L., C. inophyllum L., A. crassicarpa, S. saman were random wereas Arecaceae were aline.Â

Although mutations affecting dorsoventral patterning in plants have been known for centuries (Linnaeus 1749), the underlying mechanisms controlling this process have remained mysterious. Recent papers by Sawa et al. (1999b) and others have begun to shed light on this subject through the isolation and characterization of genes responsible for dorsoventrality. In plants, lateral organs and shoots are initiated from the flanks of the shoot apical meristem (SAM), a multilayered dome of self-organizing and self-perpetuating cells. Primordia emerge from the SAM with a characteristic asymmetry and identity that depend on both extrinsic and intrinsic factors (Fig. 1). For leaf primordia, this means having distinct upper and lower programs of growth and cellular differentiation so that cells in the upper half develop the appropriate epidermis, palisade mesophyll, and xylem strand, and cells in the bottom half develop a phloem strand, a spongy mesophyll, and appropriate epidermis. Organ shape and cell-type differences between the adaxial (upper) and abaxial (lower) sides of the mature leaf ensure that the plant puts the bulk of its light-gathering capacity toward the light. The asymmetry in the shape of most leaves is apparent from inception as they emerge as a crescent on the flank of the SAM, and this dorsoventrality is further accentuated by differential growth of the adaxial and abaxial sides. Early asymmetry is also revealed by adaxialand abaxial-specific expression of genes in incipient and young organ primordia (Fig. 1; see also Sawa et al. 1996). Dorsoventral patterning also occurs in lateral primordia that give rise to asymmetric shoots, such as the snapdragon flower, in which the upper and lower positioned petals and stamens differ. The dorsoventrality of this and other asymmetric lateral shoots is a result of the differences in the initiation and growth of organs on the adaxial and abaxial sides of the lateral SAM, and also to the asymmetry of the lateral SAM itself.

This study was conducted to investigate and compare the thermal properties of two varieties: Tympanotonus fuscatus and Pachymelania aurita of Periwinkle in Nigeria. The thermal properties, namely; specific heat capacity,Cp, thermal conductivity, k, thermal diffusity,, thermal absorptivity, and thermal effusivity, of Periwinkle samples were determined. The mean thermal conductivity of T. fuscatus was found to be 0.085±0.00015 W/m.K at temperatures of 308 – 373 K, while that of P. aurita was 0.0952±0.00056 W/m.K at the same temperature range.The average specific heat capacity value of T. fuscatus was found to be 2403.663±3.4379 J/kg.K at temperature of 308 – 373 K lower than that of P. aurita having a mean value of 2832.314±1.7385 J/kg.K at the same temperature. The mean thermal diffisivity of T. fuscatus was found to be 2.6553×10-8 m2/s while that of P. aurita was found to be 5.6790×10-8 m2/s. The average values for thermal absorptivity and effusivity of T. fuscatus and P. aurita were obtained as 81.085m-1; 525.084 W.s1/2/m2K and 55.441 m-1; 396.952 W.s1/2/m2K, respectively. The results shown that average thermal absorptivity and effusivity values were higher in T. fuscatus than P. aurita. A Tukey pairwise comparison analysis carried out on the mean values of these thermal properties of T. fuscatus and P. aurita revealed that there is statistically significant difference at <5% between the thermal properties of the two varieties of periwinkle samples. These data would help us in predicting and controlling the heat flux during the design of periwinkle processing equipment.

New methods and instruments developed for measurement of rock thermal properties (thermal conductivity, thermal diffusivity, volumetric heat capacity, and coefficient of linear thermal expansion) have provided a sharp increase in the quality of experimental data for reservoirs and surrounding formations. Optical scanning technology primarily provides numerous high-precision, nondestructive, noncontact measurements of thermal conductivity and diffusivity directly on full cores, core plugs, and nonconsolidated rock samples and enables determination of thermal property tensor components and the recording of thermal property variations along cores. The instrument for simultaneous determination of thermal conductivity, diffusivity at formation temperature (up to 250 degC), and three-component pressure (pore, confining axial, and lateral) enables measurements at formation conditions to study thermal property variations during the heating of reservoirs and oil production in thermal enhanced oil recovery (EOR). The instrument for measurements of the coefficient of linear thermal expansion at temperatures up to 250 degC within every temperature interval of 20 degC provides measurements on core plugs that account for rock anisotropy. Application of the new techniques to study more than 8,000 cores from 17 Russian oil-gas and heavy oil fields provided a representative thermal property database for sedimentary rocks saturated by brine, oil, and gas, accounting for rock anisotropy and inhomogeneity as well as formation pressure and temperature. New correlations between thermal and other physical properties were established. The new experimental data demonstrated that previous information on thermal reservoir properties often needs to be significantly corrected. The new instruments provided detailed information on the spatial and temporal variations in the thermal reservoir properties during thermal EOR. Authors used this to construct detailed 4D reservoir models for estimation of reservoir thermal regime, thermal losses, and heat and mass transfer within reservoirs, enabling better design and optimization of thermal methods of EOR.

대두의 자엽 절편을 이용한 부정근 형성과 품종 반응을 비교하였다. 품종별 부정근 형성 양상은 직접적인 부정근 형성 품종과 callus형성이 동시에 이루어지는 품종들로 구분되었으며, callus 형성이 많은 품종에서는 부정근 형성수가 적었다. 자엽 절편에서의 부정근 형성은 절편의 향축면 치상시에만 부정근이 형성되었고, 배축면과 향축면이 동시에 치상될 경우에도 향축면에서만 부정근이 형성되며, 절편의 배축이 존재하였던 방향에서만 부정근이 형성되는 방향성이 존재하였다. 부정근 형성시 자엽 절편 내 탄수화물은 형성초기보다 형성이 가장 많은 유기 4일에 가장 많이 관찰되었으며 ,형성된 부정근의 생장이 이루어지는 7일 이후에는 관찰되지 않았다. The patterns of adventitious root formation from cotyledons for each cultivar of soybeans were compared. The results of adventitious root formation in cultivars are classified as two groups; the first group showed the direct adventitious root formation, and the second group resulted in the callus and adventitious root formation. The cultivars that have much callus formation had less the adventitious root formation. The adventitious root formation in the cotyledonary explants was occured only at the inoculation of adaxial side. When adaxial and abaxial side was inoculated simultaneously, the adventitious roots were formed at the adaxial side. Thus, it suggests that there must be direction to some extent. Starch in the cotyledonary explants were more abundant at the 4 days after induction than at the early stage of the adventitious root formation, but the starch was not observed after 7 days, that the growth stage of adventitious roots.

In Arabidopsis leaf primordia, the expression of HD-Zip III, which promotes tissue differentiation on the adaxial side of the leaf primordia, is repressed by miRNA165/166 (miR165/166). Small RNAs, including miRNAs, can move from cell to cell. In this study, HD-Zip III expression was strikingly repressed by miR165/166 in the epidermis and parenchyma cells on the abaxial side of the leaf primordia compared with those on the adaxial side. We also found that the MIR165A locus, which was expressed in the abaxial epidermis, was sufficient to establish the rigid repression pattern of HD-Zip III expression in the leaf primordia. Ectopic expression analyses of MIR165A showed that the abaxial-biased miR165 activity in the leaf primordia was formed neither by a polarized distribution of factors affecting miR165 activity nor by a physical boundary inhibiting the cell-to-cell movement of miRNA between the adaxial and abaxial sides. We revealed that cis-acting factors, including the promoter, backbone, and mature miRNA sequence of MIR165A, are necessary for the abaxial-biased activity of miR165 in the leaf primordia. We also found that the abaxial-determining genes YABBYs are trans-acting factors that are necessary for the miR165 activity pattern, resulting in the rigid determination of the adaxial-abaxial boundary in leaf primordia. Thus, we proposed a molecular mechanism in which the abaxial-biased patterning of miR165 activity is confined.

Four auxins (IAA, IBA, NAA and 2,4-D) and five cytokinins (2iP, zeatin,kinetin,BA and TDZ) were examined for their effects on direct somatic embryogenesis onleaf explantsof a sympodial orchid Oncidium 'Gower Ramsey’.On a hormone-freebasal medium, the percentages of embryo formation were 40%, 20%,5% and0% on leaf tips, adaxial sides, wound surfaces and abaxial sides of theleaf explants, respectively, and the average number of embryos per explant was5.6. Embryo formation on leaf explants was retarded by all four auxins tested,but promoted by all the cytokinins. The percentages of embryo formation werereduced to 20%, 5–10%, 0% and 0%,respectively, in the same parts of leaf explants when supplemented with lowdogsages of IAA (0.3–3 mg/l) on the basal medium.Furthermore, embryo formation was totally inhibited by 3 mg/l NAA,0.3–3 mg/l IBA and 2,4-D. The sequence of embryo formationonvarious location of leaf explants was altered by 0.3–1 mg/l2iP and 3 mg/l zeatin, and embryo formation on adaxial sides> leaf tips > woundsurfaces > abaxial sides. The highest percentage of embryoformation on leaf tips, adaxial sides and wound surfaces of explants were75%, 50% and 20% when supplemented with 1mg/lTDZ, 1 mg/l 2iP and 0.3 mg/l kinetin, respectively.The highest average number of embryo per explant (10.7) was found on a basalmedium containing 1 mg/l TDZ.

In the present work, the rear photoacoustic signal technique is used to determine thermal properties of human nails. The aging process of the human nail is analyzed through its thermal diffusivity and specific heat and using these results, thermal conductivity and thermal effusivity is determined. The study in vitro of this natural polymer showed a minimum for thermal properties to age about 20 years and an increase and possible saturation of them for ages over 50 years. The minimum value found for thermal diffusivity was close to 10x10(-4) cm2 s(-1) with saturation near 18x10(-4) cm2 s(-1). Thermal conductivity and effusivity presents the same behavior.

The evolution of thermal properties of copper samples, as a function of exposure time to a corroding atmosphere, is investigated in detail. The samples were exposed to a natural marine environment of the Yucatan Peninsula in Mexico and were analyzed without any additional pretreatment. The study is mainly based upon the measurements of thermal and optical properties of the sample, using the non-destructive photoacoustic technique. The thermal diffusivity was measured with a conventional open photoacoustic cell arrangement, whereas the thermal effusivity was determined using a new experimental configuration.

Summary Although not measurable at the field scale, thermal properties of reservoir rocks at depth are important for many applications. Motivated by the fact that field-scale elastic properties may be obtained from measurements at the surface, a new physics-based theoretical model has recently been developed to link thermal and elastic properties through their common dependences in rocks. The model aims to ultimately predict thermal properties from elastic ones. But verifying this model with existing datasets obtained from different rock samples measured under different experimental conditions proves to be challenging. New joint measurements of thermal and elastic properties acquired on reference sandstone samples at identical experimental conditions allow an improved assessment.

Substance metabolism, IAA and CTK signaling pathways regulating the origin of embryogenic callus during dedifferentiation and redifferentiation of cucumber cotyledon nodes

The epidermis of Argenteum mutant of Pisum sativum L. and Vicia faba L. was shown to be effective in protecting mesophyll photosynthesis from UV‐C irradiation (peak 254 nm; 1.5 W m−2). These plants were chosen because it is easy to peel the epidermis from both sides of the leaf in Argenteum and the abaxial side in Vicia. Chlorophyll a fluorescence induction was decreased to the same extent by UV‐C radiation in both leaf sides when the epidermis was removed. The fluorescence from the leaf with the epidermis inact was not affected. With irradiation of leaves with higher intensity (3.4 W m−2) of UV‐C, the variable fluorescence was decreased by UV‐C impinging on the abaxial side, but not the adaxial side in either of the plant species. A methanol extract from the mutant Pisum epidermis had a high absorbance in the UV region, and the absorbance was more than two‐fold larger in adaxial epidermis than in abaxial epidermis. These results indicate that the epidermal layer, which contains substances that have high UV absorbance, protects mesophyll photosynthesis against UV radiation.