In drylands,biocrusts play crucial roles in regulating ecosystem functions.The study was conducted in the hilly rangelands of the semi-arid northern Negev of Israel,where we assessed the visual,morphological,spectral,...In drylands,biocrusts play crucial roles in regulating ecosystem functions.The study was conducted in the hilly rangelands of the semi-arid northern Negev of Israel,where we assessed the visual,morphological,spectral,and soil properties of livestock trampling routes and inter-route spaces in northern and southern facing hillslopes.Overall,both hillslope aspects were visually similar,whereas the ground surface of the routes was brighter(74.4%were characterized as having a'light'color)than the inter-route spaces(86.8%were characterized as having a'dark'color).These observations were supported by morphological identification of biocrust composition,which was dominated by cyanobacteria(67%)in the routes,and by mixed cyanobacteria/moss(56%)in the inter-routes.Mean Normalized Difference Vegetation Index(NDVI)was 24%higher in the inter-routes,while the mean Brightness Index(BI)was 12%higher in the routes.At the same time,the mean Crust Index(CI)was identical in the two microhabitats.Soil quality index(SQI),calculated based on the(pedoderm)soil properties of the two microhabitats,was 6%greater in the inter-routes than in the routes.This study suggests that recurrent trampling exacerbates soil compaction and shearing along the routes,thus preventing the successional development of complex biocrust compositions.展开更多
A laboratory lysimeter experiment was conducted to investigate the effects of forage corn （Zea rncbys L.） stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation. The experimenta...A laboratory lysimeter experiment was conducted to investigate the effects of forage corn （Zea rncbys L.） stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation. The experimental treatments tested were soil exchangeable sodium percentage （ESP） levels of 1, 11, and 19, added corn stalk contents of 0 to 36 g kg^-1, and incubation durations of 30 and 60 days. The experimental results indicated that corn stalk application and incubation significantly increased CO2 partial pressure in soil profile and lowered pH value in soil solution, subsequently increased native CaCO3 mineral dissolution and electrolyte concentration of soil solution, and finally significantly contributed to reduction on soil sodicity level. The reclamation efficiency of calcareous sodic soils increased with the added corn stalk. When corn stalks were added at the rates of 22 and 34 g kg^-1 into the soil with initial ESP of 19, its ESP value was decreased by 56% and 78%, respectively, after incubation of 60 days and the leaching of 6.5 pore volumes （about 48 L of percolation water） with distilled water. Therefore, crop stalk application and incubation could be used as a choice to reclaim moderate calcareous sodic soils or as a supplement of phytoremediation to improve reclamation efficiency.展开更多
The role of female sex pheromones in natural selection, particularly as a means for species recognition to avoid the generation of hybrid offspring with low fitness, has been widely explored and is generally accepted ...The role of female sex pheromones in natural selection, particularly as a means for species recognition to avoid the generation of hybrid offspring with low fitness, has been widely explored and is generally accepted by scholars. However, the significance of sex pheromones in shaping mate choice （sexual selection） and in competition over breeding resources （social se- lection） has been largely ignored. The effect of sexual selection on sex pheromones as a sexually dimorphic signaling trait has been discounted because the amount of pheromone released by females is typically minute, while the role of sex pheromones in competition over breeding resources （other than mates） has not yet been considered. As a result of natural selection, variation in sex pheromones among females is expected to be low, and males are not expected to choose their mates among phero- mone-releasing conspecific females. Sexual selection, on the other hand, should drive the increase in pheromone variance among females, and males are expected to choose females based on this variation. Moreover, social selection resulting from more general social interactions, for example competition among females for breeding sites and food, should also promote variance among female sex pheromones. Here, we review the cttrrent evidence for each of the three selection processes acting on sex pheromones of female moths as an advertising trait. We suggest that the three selection types are not mutually exclusive but rather act together to promote different fimess components in diverse ecological situations展开更多
Water-saving irrigation methods have been increasingly used for vegetable cultivation in greenhouse or plastic film house. However, there is limited information concerning the effect of water-saving irrigation methods...Water-saving irrigation methods have been increasingly used for vegetable cultivation in greenhouse or plastic film house. However, there is limited information concerning the effect of water-saving irrigation methods on soil phosphorus （P） behavior. In this experiment, drip and subsurface irrigation methods were applied, with furrow irrigation method as control, in Mollic Gleysols. Soil P distribution throughout the depth was significantly affected by irrigation methods. Total, Olsen, organic and inorganic P contents were greater in the topsoil （0-10 and 10-20 cm） than in the subsoil （20-30, 30-40, 40-50 and 50-60 cm）. The Olsen P content throughout 0-60 cm layer under drip and subsurface irrigation treatments was lower than that under the furrow irrigation treatment. However, the total, organic and inorganic P contents from 20 to 60 cm under drip irrigation treatment were higher than or close to those under furrow irrigation treatment, but were lower under subsurface irrigation treatment than under furrow irrigation treatment. Under subsurface irrigation treatment, the contents of total, organic and inorganic P at the 0-10 cm layer were 78.0%, 1.3% and 3.7% greater than those at the 10-20 cm layer, respectively. But Olsen P content at the 10-20 cm layer was 5.7% larger than that at the 0-10 cm layer. These suggested that soil P behavior could be manipulated by soil water management to some extent. 在展开更多
Organ fibrosis and architectural remodeling can severely disrupt tissue function, often with fatal consequences. Fibrosis is the end result of chronic inflammatory reactions induced by a variety of stimuli, and the ke...Organ fibrosis and architectural remodeling can severely disrupt tissue function, often with fatal consequences. Fibrosis is the end result of chronic inflammatory reactions induced by a variety of stimuli, and the key cellular mediator of fibrosis comprises the myofibroblasts which, when activated, serve as the primary collagen-producing cells. Complex links exist between fibrosis, regeneration and carcinogenesis, and the concept that all organs contain common tissue fibrosis pathways that could be potential therapeutic targets is an attractive one. Because of the major impact of fibrosis on human health there is an unmet need for safe and effective therapies that directly target fibrosis. Halofuginone inhibits tissue fibrosis and regeneration, and thereby affects the development of tumors in various tissues along the gastrointestinal tract. The high efficacy of halofuginone in reducing the fibrosis that affects tumor growth and tissue regeneration is probably due to its dual role in inhibiting the signaling pathway of transforming growth factor β, on the one hand, and inhibiting the development of Th17 cells, on the other hand. At present halofuginone is being evaluated in a clinical trial for other fibrotic indication, and any clinical success in that trial would allow the use of halofuginone, also for all other fibrotic indications, including those of the gastrointestinal tract.展开更多
Potassium （K） affects a range of physiological processes in the plant and is a key factor controlling crop productivity and yield quality. Little information is available concerning effects of K nutrition on functio...Potassium （K） affects a range of physiological processes in the plant and is a key factor controlling crop productivity and yield quality. Little information is available concerning effects of K nutrition on function of cut flower plants. The present study was carried out to investigate the interaction between K and N nutrition, on flower quantity and quality of Ranunculus asiaticus L. The plants were supplied with three levels of K fertigation （60, 120, or 180 mg K L-1） under 50 mg N L-1 application, and at the intermediate level of 120 mg K L-1, to three levels of N applications （50, 100, or 150 mg N L-l）. The two lowest K treatments and the lowest N treatment excelled in flower production due to the lower incidence of stem-toppling, a disorder associated with localized Ca deficiencies in rapidly expanding tissues of the flower stem. Detrimental effects in terms of yield quality were apparent already under supply of 180 mg K L-1 and 50 mg N L-1, and were not associated with changes in osmotic potential, relative water content or membrane stability of the plant tissue, or with changes in mineral contents of the leaves other than reduced Ca under high N application. Our results suggest a low nutritional requirement of R. asiaticus L. for K and N, a lack of involvement of tissue water relations in the reduced flower quality under the application of high concentrations of K and N, and an induction of stem toppling under high application of N and K by reduced availability of Ca to the expanding tissue of the flower stem.展开更多
The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the...The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the understanding of sucrose metabolism in microspores and the supporting tissues. The aims of the present work were to 1) follow the changes in total and relative concentrations of sucrose, glucose, fructose and starch in the stamen parts and microspores up until anthesis, 2) follow the activities of sucrose-metabolism-related enzymes, in the anther walls fraction and microspores of the crop plant tomato. Sucrose was found to be partially cleaved in the filament, decreasing by more than twofold in the anther wall layers and the locular fluid, and to accumulate in the mature pollen grains, constituting 80% of total soluble sugars. Thus, sucrose was both the starting sugar, supporting microspore development, and the main carbohydrate accumulated at the end of the pollen-development program. The major invertase found to be active in both the anther wall layers and in maturing microspores was cell-wall-bound invertase. High fructokinase 2 and sucrose phosphate synthase activities during pollen maturation coincided with sucrose accumulation. The potential importance of sucrose accumulation during pollen dehydration phase and germination is discussed.展开更多
Seeds with colored testa (seed coat) contain high concentrations of polyphenolic compounds that exhibit high levels of antioxidant activity. Common processing procedures, such as cooking and baking, decrease the level...Seeds with colored testa (seed coat) contain high concentrations of polyphenolic compounds that exhibit high levels of antioxidant activity. Common processing procedures, such as cooking and baking, decrease the levels of these bioactive compounds and consequently, overall antioxidant activity. Here, the effects of baking and cooking processes were examined on total phenolic content (TPC), total flavonoid content (TFC) and ferric-reducing ability of plasma antioxidant activity (FRAP AA) of red and yellow quinoa seeds. Our results indicate that red quinoa seed contains significantly higher levels of TPC, TFC and FRAP AA than yellow quinoa seeds. In addition, cooked and baked quinoa seeds retain most of their TPC, TFC and FRAP AA in the final product. Thus, red quinoa seeds processed by these two methods might be considered a functional food, in addition to its traditional role of providing dietary proteins. Due to their high antioxidant activity, red quinoa seeds might also contribute significantly to the management and/or prevention of degenerative diseases associated with free radical damage.展开更多
文摘In drylands,biocrusts play crucial roles in regulating ecosystem functions.The study was conducted in the hilly rangelands of the semi-arid northern Negev of Israel,where we assessed the visual,morphological,spectral,and soil properties of livestock trampling routes and inter-route spaces in northern and southern facing hillslopes.Overall,both hillslope aspects were visually similar,whereas the ground surface of the routes was brighter(74.4%were characterized as having a'light'color)than the inter-route spaces(86.8%were characterized as having a'dark'color).These observations were supported by morphological identification of biocrust composition,which was dominated by cyanobacteria(67%)in the routes,and by mixed cyanobacteria/moss(56%)in the inter-routes.Mean Normalized Difference Vegetation Index(NDVI)was 24%higher in the inter-routes,while the mean Brightness Index(BI)was 12%higher in the routes.At the same time,the mean Crust Index(CI)was identical in the two microhabitats.Soil quality index(SQI),calculated based on the(pedoderm)soil properties of the two microhabitats,was 6%greater in the inter-routes than in the routes.This study suggests that recurrent trampling exacerbates soil compaction and shearing along the routes,thus preventing the successional development of complex biocrust compositions.
基金Project supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of Chinathe United States-Israel Binational Agricultural Research and Development Fund (No.452420)the Program for Changjiang Scholars and Innovative Research Team in University, China (No.IRT0657)
文摘A laboratory lysimeter experiment was conducted to investigate the effects of forage corn （Zea rncbys L.） stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation. The experimental treatments tested were soil exchangeable sodium percentage （ESP） levels of 1, 11, and 19, added corn stalk contents of 0 to 36 g kg^-1, and incubation durations of 30 and 60 days. The experimental results indicated that corn stalk application and incubation significantly increased CO2 partial pressure in soil profile and lowered pH value in soil solution, subsequently increased native CaCO3 mineral dissolution and electrolyte concentration of soil solution, and finally significantly contributed to reduction on soil sodicity level. The reclamation efficiency of calcareous sodic soils increased with the added corn stalk. When corn stalks were added at the rates of 22 and 34 g kg^-1 into the soil with initial ESP of 19, its ESP value was decreased by 56% and 78%, respectively, after incubation of 60 days and the leaching of 6.5 pore volumes （about 48 L of percolation water） with distilled water. Therefore, crop stalk application and incubation could be used as a choice to reclaim moderate calcareous sodic soils or as a supplement of phytoremediation to improve reclamation efficiency.
文摘The role of female sex pheromones in natural selection, particularly as a means for species recognition to avoid the generation of hybrid offspring with low fitness, has been widely explored and is generally accepted by scholars. However, the significance of sex pheromones in shaping mate choice （sexual selection） and in competition over breeding resources （social se- lection） has been largely ignored. The effect of sexual selection on sex pheromones as a sexually dimorphic signaling trait has been discounted because the amount of pheromone released by females is typically minute, while the role of sex pheromones in competition over breeding resources （other than mates） has not yet been considered. As a result of natural selection, variation in sex pheromones among females is expected to be low, and males are not expected to choose their mates among phero- mone-releasing conspecific females. Sexual selection, on the other hand, should drive the increase in pheromone variance among females, and males are expected to choose females based on this variation. Moreover, social selection resulting from more general social interactions, for example competition among females for breeding sites and food, should also promote variance among female sex pheromones. Here, we review the cttrrent evidence for each of the three selection processes acting on sex pheromones of female moths as an advertising trait. We suggest that the three selection types are not mutually exclusive but rather act together to promote different fimess components in diverse ecological situations
基金Supported by the Liaoning Provincial Education Commission,China(No.413101206)
文摘Water-saving irrigation methods have been increasingly used for vegetable cultivation in greenhouse or plastic film house. However, there is limited information concerning the effect of water-saving irrigation methods on soil phosphorus （P） behavior. In this experiment, drip and subsurface irrigation methods were applied, with furrow irrigation method as control, in Mollic Gleysols. Soil P distribution throughout the depth was significantly affected by irrigation methods. Total, Olsen, organic and inorganic P contents were greater in the topsoil （0-10 and 10-20 cm） than in the subsoil （20-30, 30-40, 40-50 and 50-60 cm）. The Olsen P content throughout 0-60 cm layer under drip and subsurface irrigation treatments was lower than that under the furrow irrigation treatment. However, the total, organic and inorganic P contents from 20 to 60 cm under drip irrigation treatment were higher than or close to those under furrow irrigation treatment, but were lower under subsurface irrigation treatment than under furrow irrigation treatment. Under subsurface irrigation treatment, the contents of total, organic and inorganic P at the 0-10 cm layer were 78.0%, 1.3% and 3.7% greater than those at the 10-20 cm layer, respectively. But Olsen P content at the 10-20 cm layer was 5.7% larger than that at the 0-10 cm layer. These suggested that soil P behavior could be manipulated by soil water management to some extent. 在
文摘Organ fibrosis and architectural remodeling can severely disrupt tissue function, often with fatal consequences. Fibrosis is the end result of chronic inflammatory reactions induced by a variety of stimuli, and the key cellular mediator of fibrosis comprises the myofibroblasts which, when activated, serve as the primary collagen-producing cells. Complex links exist between fibrosis, regeneration and carcinogenesis, and the concept that all organs contain common tissue fibrosis pathways that could be potential therapeutic targets is an attractive one. Because of the major impact of fibrosis on human health there is an unmet need for safe and effective therapies that directly target fibrosis. Halofuginone inhibits tissue fibrosis and regeneration, and thereby affects the development of tumors in various tissues along the gastrointestinal tract. The high efficacy of halofuginone in reducing the fibrosis that affects tumor growth and tissue regeneration is probably due to its dual role in inhibiting the signaling pathway of transforming growth factor β, on the one hand, and inhibiting the development of Th17 cells, on the other hand. At present halofuginone is being evaluated in a clinical trial for other fibrotic indication, and any clinical success in that trial would allow the use of halofuginone, also for all other fibrotic indications, including those of the gastrointestinal tract.
基金Supported by the Chief Scientist Fund of the Israeli Ministry of Agriculture, and the Israeli Flower Council (No.300487)
文摘Potassium （K） affects a range of physiological processes in the plant and is a key factor controlling crop productivity and yield quality. Little information is available concerning effects of K nutrition on function of cut flower plants. The present study was carried out to investigate the interaction between K and N nutrition, on flower quantity and quality of Ranunculus asiaticus L. The plants were supplied with three levels of K fertigation （60, 120, or 180 mg K L-1） under 50 mg N L-1 application, and at the intermediate level of 120 mg K L-1, to three levels of N applications （50, 100, or 150 mg N L-l）. The two lowest K treatments and the lowest N treatment excelled in flower production due to the lower incidence of stem-toppling, a disorder associated with localized Ca deficiencies in rapidly expanding tissues of the flower stem. Detrimental effects in terms of yield quality were apparent already under supply of 180 mg K L-1 and 50 mg N L-1, and were not associated with changes in osmotic potential, relative water content or membrane stability of the plant tissue, or with changes in mineral contents of the leaves other than reduced Ca under high N application. Our results suggest a low nutritional requirement of R. asiaticus L. for K and N, a lack of involvement of tissue water relations in the reduced flower quality under the application of high concentrations of K and N, and an induction of stem toppling under high application of N and K by reduced availability of Ca to the expanding tissue of the flower stem.
文摘The formation of mature and fertile pollen grains, taking place inside the anther, depends on supply of assimilates, in the form of sucrose, provided mainly by the leaves. Data is limited, however, with respect to the understanding of sucrose metabolism in microspores and the supporting tissues. The aims of the present work were to 1) follow the changes in total and relative concentrations of sucrose, glucose, fructose and starch in the stamen parts and microspores up until anthesis, 2) follow the activities of sucrose-metabolism-related enzymes, in the anther walls fraction and microspores of the crop plant tomato. Sucrose was found to be partially cleaved in the filament, decreasing by more than twofold in the anther wall layers and the locular fluid, and to accumulate in the mature pollen grains, constituting 80% of total soluble sugars. Thus, sucrose was both the starting sugar, supporting microspore development, and the main carbohydrate accumulated at the end of the pollen-development program. The major invertase found to be active in both the anther wall layers and in maturing microspores was cell-wall-bound invertase. High fructokinase 2 and sucrose phosphate synthase activities during pollen maturation coincided with sucrose accumulation. The potential importance of sucrose accumulation during pollen dehydration phase and germination is discussed.
文摘Seeds with colored testa (seed coat) contain high concentrations of polyphenolic compounds that exhibit high levels of antioxidant activity. Common processing procedures, such as cooking and baking, decrease the levels of these bioactive compounds and consequently, overall antioxidant activity. Here, the effects of baking and cooking processes were examined on total phenolic content (TPC), total flavonoid content (TFC) and ferric-reducing ability of plasma antioxidant activity (FRAP AA) of red and yellow quinoa seeds. Our results indicate that red quinoa seed contains significantly higher levels of TPC, TFC and FRAP AA than yellow quinoa seeds. In addition, cooked and baked quinoa seeds retain most of their TPC, TFC and FRAP AA in the final product. Thus, red quinoa seeds processed by these two methods might be considered a functional food, in addition to its traditional role of providing dietary proteins. Due to their high antioxidant activity, red quinoa seeds might also contribute significantly to the management and/or prevention of degenerative diseases associated with free radical damage.
