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1.
Secondary metabolites of lichens can be involved in production of chelates with heavy metals. We hypothesized that parietin plays important role in protection of photobiont cells in Xanthoria parietina from an excess of cadmium ions. Two types of X. parietina lichen thalli, natural with presence of secondary metabolite parietin (p+) as well as without parietin (p−) were exposed to different doses of cadmium (up to 300 μmol g−1 dw). Based on determination of the total and intracellular Cd-accumulation, ergosterol and thiobarbituric acid reactive substances (TBARS) content did not show statistically significant differences in the response of both types of thalli (p+ and p−). However, a stronger toxic effect of the highest Cd-dose on photosynthetic pigment content and chlorophyll a fluorescence was observed in the parietin-depleted thalli. The protective role of parietin against Cd excess was better supported and concluded from the differences observed in the production of non-protein thiol compounds (cysteine, glutathione and phytochelatins) involved in Cd detoxification. In the p+ thalli Cys content was stable but GSH content slightly decreased in the studied Cd range, while in the p− thalli these compounds were completely absent at high Cd doses. At Cd doses higher than 37.5 μmol Cd g−1 dw, toxic to both types of X. parietina thalli, Cys and GSH contents were significantly higher in p+ than in p− thalli. Also, the photobiont partner in the p+ thalli was better protected of the metal exposition, and able to produce phytochelatins (PCs) over the whole range of metal, while in the p− thalli the production was completely inhibited at 75 μmol Cd g−1 dw and higher concentrations, together with the inhibition of cysteine (Cys) and reduced glutathione (GSH) production. The obtained results indicate that the parietin layer is a natural barrier decreasing Cd access to algal cells in X. parietina. Comparison of PCs production appeared to be the most sensitive marker for estimation of Cd availability to photobiont in the symbiotic system.  相似文献   

2.
Surveys of the distribution of the lichensXanthoria parietinaandRamalina duriaeiin Israel showed that environments with air pollution had no damaging effects onX. parietina, whereasR. duriaeihad disappeared from polluted environments: physiological studies supported this relative sensitivity. Investigations of possible defence mechanisms protectingX. parietinafrom the damaging effects of air pollution showed a multitude of possible protective systems. These included constitutive avoidance such as: efficient buffering capacity; a relatively high potassium content; and antioxidation by parietin, and induced tolerance such as: SO2oxidation to non-toxic sulphate; increased glutathione content; induced proline and arginine synthesis; and increased detoxification of active oxygen forms.  相似文献   

3.
Abstract:Thalli of the lichens Buellia frigida and Xanthoria elegans were collected from five different locations each 5–15 km apart in the Vestfold Hills, Princess Elizabeth Land, eastern Antarctica. A further collection was made from Mawson Station, Mac Robertson Land, eastern Antarctica, 660 km away. DNA was extracted from whole thalli and the ribosomal ITS region amplified by PCR using fungal specific primers. Resulting products were sequenced to gain an indication of whether or not variation was present within populations of lichen-forming fungi from continental Antarctica, and therefore of the availability of genetic resources to react to pressures such as climate change. Three genotypes ofB. frigida and two of X. elegans were detected in the Vestfold Hill collections. However, these differed by only one nucleotide position suggesting the presence of relatively little genetic variation, if the ITS region is indicative of the overall genome. Buellia frigida collected from Mawson Station had an identical ITS region sequence to the most common Vestfold Hills genotype, indicating that this species may have a low level of genetic variation across much of eastern Antarctica. In contrast, X. elegans collected from Mawson showed considerable genetic variation from the Vestfolds thalli, differing at 14·2% of nucleotide positions and had an identical ITS region sequence to an isolate from maritime Antarctica 4960 km away. Samples from the Vestfold Hills formed a distinct cluster in a phylogenetic analysis of ITS sequences from a worldwide collection of X. elegans isolates.  相似文献   

4.
Although salivary testosterone (T) is often used in clinical studies accuracy is mostly questionable. State of the art data for men is sparse and for women absent. Our objective was to perform a critical evaluation of salivary T (Sal-T) as a method for indirect assessment of serum T using state of the art methods. Saliva was collected via ‘Salivette’ and ‘passive drooling’ methods. Sal-T and free T in serum after equilibrium dialysis were measured by LC-MS/MSResultsEvaluation of Sal-T results versus free T by equilibrium dialysis (ED-T) for men gave: ‘Salivette’ Sal-T = 0.05 + 0.88x ED-T, r = 0.43; ‘passive drooling’ Sal-T = 0.17 + 0.91x ED-T r = 0.71. In women, correlation was comparable but values are higher than free T: ‘passive drooling’ Sal-T = 0.12 + 2.32x ED-T, r = 0.70. The higher than expected T values in saliva, appear to be explained by T binding to salivary proteins. Iso-electric focusing of saliva proteins, followed by fractionation and LC–MS/MS assay of T showed marked testosterone peaks at pH 5.3 and 8.4, providing evidence for T binding in saliva to proteins such as albumin and proline rich protein (PRP).ConclusionsPassive drooling is the collection method of choice for testosterone in saliva. Sal-T is not directly comparable to serum free T due to T binding to saliva proteins, which substantially affects the low Sal-T in women but not the higher Sal-T in healthy adult men.  相似文献   

5.
《Aquatic Botany》2005,81(4):315-325
Effects of irradiance and water flow on formation and growth of filamentous and spongy thalli of Codium fragile (Suringar) Hariot growing on vinylon threads were investigated at the laboratory culture. They showed clear differences in their irradiance and water flow requirements for their formation and growth. Spongy thalli were formed from the cultured filamentous thalli only at the high water flow velocity (10 cm s−1). Number of the spongy thalli remarkably increased with increasing irradiance because those at 10, 50 and 100 μmol m−2 s−1 reached 0, 2 and 76 thalli m−1, respectively, by 10 weeks of culture. In contrast, filamentous thalli were formed from the cultured spongy thalli at 0 and 3 cm s−1, and difference in irradiance had no effect on their formation. Growth of the spongy thalli greatly accelerated under the combination of the high irradiance and high water velocity (200 μmol m−2 s−1 and 10 cm s−1) because their relative growth rate in wet weight under the condition was two–four times higher than those at the other examined irradiances and water velocities. On the other hand, difference in water velocity had no effect on growth of the filamentous thalli under flowing water, and their growth decelerated at the high irradiance (200 μmol m−2 s−1). This demonstrates that water flow is a major factor controlling the formation of the spongy and filamentous thalli. The formation and growth of the spongy thalli surely occur under the combination of the high irradiance and fast flowing water. In contrast, the formation of the filamentous thalli occurs in the calm water, and their growth is inhibited under the high irradiance.  相似文献   

6.
《Journal of Asia》2014,17(4):837-844
Helicoverpa armigera (Hübner) is one of the most important pests of a wide range of agricultural crops worldwide. Resistance of 10 tomato cultivars (‘Primoearly,’ ‘Riogrand,’ ‘CaljN3,’ ‘Kingstone,’ ‘Earlyurbana,’ ‘Petomech,’ ‘EarlyurbanaY,’ ‘Mobil,’ ‘Imprial’ and ‘Petoearly’) to H. armigera was evaluated under laboratory conditions at 25 ± 1 °C, 60 ± 5% RH and a photoperiod of 16:8 (L:D) hours using age-stage, two-sex life table parameters. The larval period ranged from 19.96 on ‘Riogrand’ to 24.58 days on ‘Imprial.’ The insects reared on ‘Imprial’ had the longest total preoviposition period (44.80 days) and those reared on ‘Riogrand’ had the shortest one (35.44 days). The longest adult longevity for female and male was observed on ‘EarlyurbanaY’ (14.40 days) and ‘Kingstone’ (15.00 days), respectively. Using age-stage, two-sex life table, the value of the net reproductive rate (R0) varied from 7.8 on ‘Imprial’ to 186.9 offspring per individual on ‘Petomech.’ The lowest value of the intrinsic rate of increase (r) and finite rate of increase (λ) was on ‘Imprial’ (0.0410 and 1.0423 day 1, respectively) and the highest was on ‘Petomech’ (0.1274 and 1.1359 day 1, respectively). The mean generation time (T) on different cultivars varied from 39.9 to 48.2 days. The results revealed that ‘Petomech’ was the most susceptible (suitable) and ‘Imprial’ was the most resistant (unsuitable) cultivar to this pest among the tomato cultivars tested.  相似文献   

7.
Olive varieties ‘Koroneiki’, ‘Kalamata’, ‘Mastoidis’ and ‘Amigdalolia’ were employed in two experiments for 3 years to assess the effect of temperature on olive pollen germination and tube growth in relation to relative humidity and genotype. Pollen samples were subjected to pre-incubation at 10, 20, 30 or 40 °C in combination with decreased air relative humidity – 80, 40, 30 or 20%, respectively – for 24 h to simulate temperature stress that is observed during pollen dispersal; and subsequently in vitro cultured. In the second experiment, pollen was exposed at 15, 20, 25 and 30 °C for 24 h in vitro to evaluate pollen response in conditions of water and nutrients availability and to determine the optimum pollen germination and tube growth temperatures for each cultivar. The highest pre-incubation temperature treatment (40 °C) prevented pollen germination in ‘Koroneiki’ and ‘Mastoidis’, with the less affected varieties (‘Amigdalolia’ and ‘Kalamata’) having average germination percentages of only 7.6 and 2%, respectively. Pre-incubation at 30 °C had a negative impact on pollen germination in ‘Koroneiki’ (?65%), ‘Kalamata’ (?20%) and ‘Amigdalolia’ (?72%) compared to the control (20 °C). Pollen pre-incubation at 40 °C decreased significantly the pollen tube length in ‘Kalamata’ (?50%) and ‘Amigdalolia’ (?52%). In the second experiment, in vitro pollen germination increased after incubation at 25 °C for ‘Koroneiki’ (+6%), ‘Mastoidis’ (+52%), ‘Kalamata’ (+10%) and ‘Amigdalolia’ (+10%) compared to the control (20 °C). At 30 °C germination percentages for ‘Mastoidis’, ‘Kalamata’ and ‘Amigdalolia’ were 8, 6 and 14% higher, respectively, compared to the control (20 °C). Pollen tube length also increased with incubation temperature for all of the studied cultivars. Based on the cumulative stress response index (CSRI) that was calculated for high temperature stress the varieties were classified: ‘Mastoidis’ and ‘Kalamata’ as tolerant and ‘Koroneiki’ and ‘Amigdalolia’ as intermediate at 30 °C while all studied cultivars were sensitive at 40 °C. The observed strong genotype-differentiated response in high and low temperature stress could be exploited by plant breeders towards producing new tolerant olive varieties.  相似文献   

8.
《Inorganica chimica acta》2006,359(7):2159-2169
Single-crystal X-ray studies have defined the structures of a number of novel adducts of the form CuX:dpex (2:1), X = (pseudo-)halide, dpex = bis(diphenylpnicogeno)alkane, Ph2E(CH2)xEPh2, E = P, As, of diverse types, solvated with acetonitrile. CuBr:dpem (2:1)2. 2MeCN (E = both P, As) are tetranuclear, derivative of the familiar ‘step’ structure, while CuCl:dpph (MeCN solvate) and CuBr:dppe (MeCN solvate) yield one-dimensional polymers (i.e., x = 1, 2, 6 for dppx, x = m, e, h), as also does CuSCN:dpam (MeCN solvate). In CuI:dpsm:MeCN (3:1:2) (‘dpsm’ = Ph2Sb(CH2)SbPh2), CuI:dpsm (2:1)2 ‘step’ units are connected into an infinite ‘stair’ polymer by interspersed (MeCN)CuI linkers.  相似文献   

9.
《Aquatic Botany》2007,86(4):324-330
The green alga Caulerpa taxifolia was recorded at Malinska in 1994 and this actually represents the highest northern latitude (45°7′30″N) at which this invasive alga has been found in the world. The alga was widespread at four sites from which it was eradicated by suction pumps during 1996 and 1997. However, it immediately and intensively recolonized all but one site. Throughout 1998 and 1999 the renewed vegetation showed consistent seasonal patterns. The alga nearly disappeared in April and May while regenerating from over-wintering parts of the thalli in summer. The maximum development occurred in autumn and winter with values of biomass (around 200 g dry weight m−2) and frond number (around 2000 m−2) generally lower than those reported for the north-western Mediterranean. Values for the frond length (10–18 cm) were in the same range as those in the north-western basin. Throughout 1998 and 1999 the biomass was closely correlated to frond number and length (adjusted R2 = 0.90). During the following years C. taxifolia entered a phase of regression. The total colonized area, which amounted to several thousands of square metres in 1998, spontaneously declined in 2000 and 2001 so that only several thalli were found in 2004 during a detailed survey of the settlement. No major changes in winter seawater temperatures, ranging from 9.5 to 10.5 °C, were observed in the area from 1994 to 2004. Thus, other unknown processes could likely play a role on specific vegetation patterns of C. taxifolia in Malinska. Accordingly, it is difficult to explain why the still surviving thalli did not proliferate during the favourable summer–autumn period.  相似文献   

10.
A 2-year field experiment was performed with lachenalia (‘Namakwa’, ‘Ronina,’ ‘Rosabeth’ and ‘Rupert’) to study the effects of planting density on leaf formation, inflorescence quality and bulb production. Bulbs 6.0 cm in circumference were planted at a spacing of 2.0 × 5.0 cm, 3.0 × 7.0 cm and 5.0 × 10.0 cm, and cultivated in the open air in Polish conditions in 2009 and 2010. The spacing affected the number of leaves only in lachenalia ‘Namakwa’ in 2010. In the other cases, the bulbs formed 2–3 leaves. Plant height increased with the high-density treatment, but flower yield and the total time to the beginning of flowering were independent of planting density. The cultivars proved to differ in terms of the time of blooming: ‘Namakwa’ and ‘Ronina’ flowered earlier (after 63–73 days) than ‘Rosabeth’ and ‘Rupert’ (after 82–90 days). Plant arrangement had little effect on inflorescence length and the number of florets. Irrespective of the spacing, lachenalia ‘Rupert’ seemed to be the most floriferous — one bulb produced even 30 flowers. Lower planting density influenced advantageously the quality of bulbs (circumference and weight), without affecting their quantity (number of bulbs from one plant).  相似文献   

11.
Heat stress is a major factor limiting the growth of cool-season grasses in warm climatic regions by affecting many physiological processes, including protein metabolism. Protein degradation often occurs with increasing temperatures, but certain specific proteins such as heat shock proteins (HSPs) may be induced or enhanced in their expression under supraoptimal temperatures. The objectives of this study were to determine the critical temperature that causes protein induction or degradation in two Agrostis grass species differing in heat tolerance and to compare protein profiles between the two species under different temperature regimes. Plants of heat-tolerant Agrostis scabra and two cultivars of heat-sensitive Agrostis stolonifera (‘L-93’ and ‘Penncross’) were exposed to constant day/night temperatures of 20, 30, 35, 40, or 45 °C for 14 d. Leaf photochemical efficiency (Fv/Fm), chlorophyll and carotenoid contents, and soluble protein content declined with increasing temperatures. The decreases were the least severe for A. scabra, intermediate for ‘L-93’, and the most severe for ‘Penncross’, indicating interspecific and intraspecific variations in heat tolerance in Agrostis species. Protein degradation was observed at 30–45 °C in both cultivars of A. stolonifera, and at 40–45 °C in A. scabra.HSPs were induced or enhanced at 35–45 °C in ‘L-93’ and A. scabra, and at 40–45 °C in ‘Penncross’. Immunoblotting also revealed stronger expressions of HSP60 and HSP70 in A. scabra or ‘L-93’ than in ‘Penncross’ at 35–45 °C after 3 d. The results suggested the superior heat tolerance of Agrostis grass species and cultivars could be attributed to the early induction of HSPs, particularly small molecular weight (23 kDa), at a lower level of heat stress and the maintenance of protein thermostability, particularly high-molecular weight proteins (83 kDa and large units of Rubisco).  相似文献   

12.
《Journal of Asia》2020,23(4):942-949
The study focused on the ecological analysis of plant and soil nematode communities associated with vegetables-maize crop sequences in the eastern fringe of Kolkata at Dhapa from December 2011 to April 2014 at a monthly interval. Plant-parasitic nematodes like Pratylenchus zeae, Meloidogyne incognita, Hoplolaimus indicus, Helicotylenchus dihystera, Tylenchorhynchus brevilineatus, Rotylenchulus reniformis, and Criconemoides onoensis were observed in two major cropping sequences of chilli-amaranthus-maize-radish-cauliflower and amaranthus-maize-cabbage-chilli. Among them, R. reniformis was found to be the most prevalent genera with the highest relative prominence value (RPV) of 27.29 followed by P. zeae (20.30) and T. brevilineatus (16.70). The population dynamics of P. zeae revealed the lowest density of the nematode was recorded (26 per 200 cc of soil + 5 g of the root) in March and the highest (634) in September. The variation in the abundances of other PPNs was also noted, and that attributed to the crops in the crop sequence and weather conditions. Low numbers of R. reniformis was found in the maize rhizosphere. The saprozoic nematodes (SNs) maintained higher mean densities (1734/200 cc soil); they were recorded in high numbers in the rainy season as compared to other seasons. No significant differences in the Shannon diversity index (H′), evenness (J) were observed across the growing period. A significant relationship was found between nematode abundance and climatic variables observed. This study provides baseline information on nematodes associated with maize-based cropping system, population abundance, Mylonchulus-SNs relationships, and population fluctuation in response to environmental factors.  相似文献   

13.
Physical size has been critical in the evolutionary success of the genus Homo over the past 2.4 million-years. An acceleration in the expansion of savannah grasslands in Africa from 1.6 Ma to 1.2 Ma witnessed concomitant increases in physical stature (150–170 cm), weight (50–70 kg), and brain size (750–900 cm3). With the onset of 100,000 year Middle Pleistocene glacial cycles (“ice ages”) some 780,000 years ago, large-bodied Homo groups had reached modern size and had successfully dispersed from equatorial Africa, Central, and Southeast Asia to high-latitude localities in Atlantic Europe and North East Asia. While there is support for incursions of multiple Homo lineages to West Asia and Continental Europe at this time, data does not favour a persistence of Homo erectus beyond ~400,000 years ago in Africa, west and Central Asia, and Europe. Novel Middle Pleistocene Homo forms (780,000–400,000 years) may not have been substantially taller (150–170 cm) than earlier Homo (1.6 Ma–800,000 years), yet brain size exceeded 1000 cm3 and body mass approached 80 kg in some males. Later Pleistocene Homo (400,000–138,000 years) were ‘massive’ in their height (160–190 cm) and mass (70–90 kg) and consistently exceed recent humans. Relative brain size exceeds earlier Homo, yet is substantially lower than in final glacial H. sapiens and Homo neanderthalensis. A final leap in absolute and relative brain size in Homo (300,000–138,000 years) occurred independent of any observed increase in body mass and implies a different selective mediator to that operating on brain size increases observed in earlier Homo.  相似文献   

14.
《Journal of Asia》2022,25(3):101961
Understanding local geographical variation in vector density and bionomics related to virus transmission are critical for planning effective vector control programs to control dengue virus transmission. This study investigated the prevalence and resting behaviour of Aedes aegypti and Ae. albopictus in three dengue high-risk areas in the Colombo District, Sri Lanka. Monthly sampling of resting adult mosquitoes was conducted from August 2019 to February 2020. Thirty-seven percent of the households (289/776) harboured Aedes mosquitoes, and 603 Aedes mosquitoes were collected. The proportion of Ae. aegypti was higher in the overall collection during the collection period (94% [569/603]), and 62% (352/569) were females. Significant monthly variations in Ae. aegypti were observed with respect to the indices: number of females per surveyed house (F/SH; p = 0.001), number of females per Aedes positive house (F/PH; p = 0.029), adult house index (AHI; p = 0.001), adult density (AD; p = 0.005) and resting ratio (RR; p = 0.001). AHI, AD, and RR had statistically significant positive correlations with monthly rainfall (p = 0.001, p = 0.011, and p = 0.002 respectively) and one-month lagged dengue cases (p = 0.002, p = 0.005, and p < 0.001 respectively). A statistically significantly higher proportion of Ae. aegypti females were caught resting indoors (N = 309, 88%) than outdoors (N = 43, 12%; p < 0.001). The most common resting areas were bedrooms (51%) & living/dining rooms (37%), and places were under or on furniture (47%) & hangings (34%) for Ae. aegypti. Conversely, 74% of female Ae. albopictus were collected outdoors. Results of this study could have strong implications to improve vector surveillance and control by early detection of dengue to detect outbreaks and minimization of disease transmission.  相似文献   

15.
《Endocrine practice》2016,22(7):786-790
Objective: To determine the relationship between the R577X polymorphism of the α-actinin-3 (ACTN3), which may play a role in the individual differences observed in the effects of exercise on health benefits and antiatherogenic markers (i.e., high-density lipoprotein cholesterol [HDL-C] and adiponectin) in athletes.Methods: Seventy-six male rugby players (mean age 19.8 years) were enrolled in this study. Genomic DNA was extracted from peripheral blood samples, and restriction fragment length polymorphism-polymerase chain reactions were conducted to assess ACTN3 genotypes. Body mass index (BMI), waist circumference, serum lipids including HDL-C, and adiponectin levels were measured. Current smoking and alcohol intake habits were evaluated with a questionnaire. All of the parameters were compared between 2 groups displaying frequently observed genotypes: one group consisting of patients having either the R/R or R/X genotype and a second group with the X/X genotype.Results: The frequency of the X allele was 0.55 and the distribution of the genotypes was 35.5% (n = 27) for X/X, 39.5% (n = 30) for R/X, and 25.0% (n = 19) for R/R. Serum HDL-C and adiponectin levels were significantly higher in X/X genotype compared to the R/R or R/X genotype (HDL-C 1.6 ± 0.3 [SD] vs. 1.4 ± 0.2 mmol/L; P<.01, adiponectin 8.8 ± 2.6 vs. 6.9 ± 2.3 μg/mL; P<.01), even after adjustments for confounders (P<.01).Conclusion: There may be a relationship between the ACTN3 genotype and HDL-C and adiponectin levels in rugby players. This may be useful information when determining the individual responses of antiatherogenic markers to exercise.Abbreviations:ACTN3 = α-actinin-3BMI = body mass indexCVD = cardiovascular diseaseHDL-C = high-density lipoprotein cholesterolLDL-C = low-density lipoprotein cholesterolR = arginine (R) at amino acid position 577 of the ACTN3 proteinTC = total cholesterolTG = triglycerideX = truncation at amino acid position 577 of the ACTN3 protein  相似文献   

16.
The objective was to identify legume shrub species for development of agroforestry technologies based on seed and forage (leaves and twigs < 10 mm diameter) yield, and determinants of forage quality. Ten individual plants of Bituminaria bituminosa ‘Ecotypes 1’, B. bituminosa ‘Ecotypes 2’, Medicago citrina, and M. arborea from Spain; Colutea istria and Onobrychis aurantiaca from Syria; C. istria from Jordan; Chamaecytisus mollis from Morocco; and Coronilla glauca from France were randomly selected from plots established in a non-tropical dryland environment in northwest Syria in 2000. Five individual plants of each species were cut back to 0.5 m above ground in March 2004. Coppice regrowths were pruned in December 2004 and April 2005 to determine forage yield and proportion of forage in the total above ground biomass (PEFB). Forage samples were analyzed for concentrations of crude protein (CP), lignin(sa), acid detergent fibre (ADFom), neutral detergent fibre (aNDFom), in vitro organic matter (OM) digestibility (IVOMD), and in vitro 24 h gas production (IVGP24h). Matured seeds were hand harvested from the remaining five plants of each species to estimate seed yield. Forage (21–250 kg DM/ha) and seed (0–200 kg DM/ha) yields; PEFB (0.22–0.96); and concentrations of CP (85–115 g/kg DM), lignin(sa) (14–42 g/kg DM), ADFom (94–170 g/kg DM), aNDFom (122–217 g/kg DM), IVOMD (456–617 g/kg OM), and IVGP24h (27–42 ml 200 mg/DM) varied (P<0.05) among shrub species. The IVOMD and IVGP24h were positively correlated (r = 0.75, P<0.032), whereas IVOMD and IVGP24h were negatively correlated with ADFom, lignin(sa) and aNDFom. In terms of forage and seed yields and determinants of forage quality, C. istria from Jordan, M. arborea, B. bituminosa ‘Ecotype-2’, C. istria and O. aurantiaca have higher potential than C. mollis, C. glauca and B. Bituminosa ‘Ecotype-1’ for the development of agroforestry technologies in non-tropical dry areas.  相似文献   

17.
Rosa hybrida L. is an important commercial cut flower. The vase life of this flower is usually short due to vascular occlusion. We assessed the effect of Nano-Silver (NS) and S-carvone in prolonging the vase life of R. hybrida L. cv. ‘Avalanche’ and ‘Fiesta’. Hence, an experiment involving the treatment with NS at 0, 50, 100, and 200 mgL 1 and S-carvone at 0, 0.25, 0.5, and 0.75 mgL 1 with 10 replicates was conducted. Applying NS pulse treatments increased vase life, water uptake rate, and fresh weight and reduced the number of bacteria, water loss, stomatal conductance and transpiration rate. However, S-carvone treatments did not have a positive effect on the vase-life parameters of cut rose flowers. NS pulse treatments increased relative fresh weight (RFW), and water uptake rate (WUR) and decreased water loss (WL) (%) by 10, 89 and 31% for cultivar ‘Avalanche’, compared to the controls, respectively. Application of 200 mgL 1 NS led to the highest vase life (18 days) for roses. The results show that NS increased vase life by suppressing stomatal opening, decreasing transpiration from leaves and inhibiting bacterial proliferation.  相似文献   

18.
The hypothesis that central analgesia with reduced side effects is obtainable by occupying an ‘allosteric’ site in the MOR ligand binding domain requires the development of new ligands with peculiar pharmacological profile to be used as tools. New benzomorphan derivatives, analogues of LP1, a multitarget MOR agonist/DOR antagonist, were designed to examine in depth MOR ligand binding domain. Compound 5, bearing a diphenylic N-substituent on the benzomorphan nucleus, showed an affinity (Kiμ = 0.5 ± 0.2 nM) comparable to that of LP1 and a better selectivity versus DOR and KOR. It elicits antinociceptive effects in ex vivo (GPI) and in vivo. This new compound engages receptor amino acidic residues not reached by LP1 and by other established MOR ligands. Molecular modeling studies, conducted on 5 and on several reference compounds, allowed us to propose possible residues in the MOR ligand binding domain essential for their interactions with ‘orthosteric’ and ‘allosteric’ binding sites.  相似文献   

19.
《Small Ruminant Research》2007,70(1-3):55-61
Five groups of 20 infested skins with different ectoparasites and different levels of infestation and two groups of negative control skins from sheep and goats were examined for their corresponding defects at the pickled or wet blue stage of processing in tanneries. In addition, an analysis of skin defects was made from randomly selected processed skins at Kombolcha and Dessei tanneries. The prevalence of ‘ekek’ (cockle) at the pickled stage in Damalina ovis and Melophagus ovinus-infested sheep skins were 100 and 95%, respectively. Pickled goat skins affected by sarcoptic mange and Linognathus spp. were 100 and 0% positive for ‘ekek’ (cockle) lesion, respectively. The prevalence in control sheep and goat skins were 15 and 0%, respectively. There was a strong association (p < 0.05) between ‘ekek’ and infestation with M. ovinus and D. ovis in sheep and sarcoptic mange in goats. Follow-up of randomly selected 1000 pickled sheep skins and 1000 wet blue goat skins revealed that 71% of pickled sheep and 42% of wet blue goat skins had ‘ekek’ lesions. As the proportion of ‘ekek’ increased, the quality of graded skins decreased both in sheep and goats. Both on pickled sheep and wet blue goat skins, scratch and scars were found to have a strong association (p < 0.05) with ‘ekek’. The annual economic loses in 2002/2003 due to ‘ekek’ at the two tanneries was estimated to be 1.6 million USD for pickled sheep and 0.6 million USD for wet blue goat skins.  相似文献   

20.
《Aquatic Botany》2005,82(3):168-180
This study quantified the prevalence of holdfast aggregation (fusion of holdfasts) for the kelp Ecklonia radiata on subtidal reefs in southwestern Australia, and tested whether morphology, age, attachment or drag were different between kelps growing alone (solitary) or in aggregates. Wave-sheltered in-shore reefs consistently had fewer aggregates than wave-exposed off-shore reefs (15–20% versus 20–30%). On average, individual thalli from aggregates were longer (97.8 cm ± 2.2 S.E. versus 88.0 cm ± 2.0 S.E.) and had smaller holdfasts (32.9 g fresh wt ± 1.7 S.E. versus 45.8 g fresh wt ± 2.9 S.E.) than solitary thalli, whereas there were no significant differences in other morphological characters, including total biomass (805.1 g fresh wt ± 38.7 S.E. versus 831.5 g fresh wt ± 38.5 S.E.), stipe length (7.93 cm ± 0.47 S.E. versus 7.65 cm ± 0.40 S.E.) and stipe diameter (12.6 mm ± 0.23 S.E. versus 13.0 mm ± 0.25 S.E.). There was no difference in age between solitary (2.7–3.0 years) and aggregated (2.4–2.8 years) individuals. While the attachment force of whole aggregates (256.5 N ± 21.6 S.E.) was found to be significantly larger than attachment force for solitary individuals (162.5 N ± 12.9 S.E.), attachment areas were also larger for aggregates (90.7 cm2 ± 5.40 S.E. versus 64.3 cm2 ± 5.54 S.E.) and consequently there were no differences in attachment strength between aggregates (2.92 N cm−2 ± 0.26 S.E.) and solitary thalli (2.71 N cm−2 ± 0.22 S.E.). Aggregates had significantly smaller (17%) roughness factors (equivalent to drag coefficients) than solitary individuals and a negative relationship (r = −0.68) between roughness factors and biomass suggested that this was related to the scope for compaction and rearrangement of the thalli. Further, there was no relationship between roughness factors of solitary individuals and the aggregates they produced when combined, suggesting that roughness factors are not additive or multiplicative. The spatial distribution of holdfast aggregates, the morphological differences between solitary and aggregated individuals as well as their attachment and drag characteristics were all consistent with aggregation reducing the rate of fatal kelp dislodgment.  相似文献   

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