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81.
A number of improved cultivars of food legume crops have been developed and released in the tropics and the sub-tropics. Most
of these cultivars have been developed through conventional breeding approaches based on the development of crop varieties
under optimum soil fertility levels. Nevertheless, it is hardly possible to say that the varietal provisions made by the past
approach have been readily accepted, and properly utilized to boost productivity of food legumes grown by resource-poor farmers.
The approach itself did not fully appreciate the actual circumstances of the resource-poor farmers where marginal production
systems prevail and the poorest farmers could not afford to use cultivars developed under optimum soil fertility level. Therefore,
the limitations and strategic implications of past experiences made to develop crop cultivars need to be analyzed in order
to formulate better strategies and approaches in the future. The main purpose of this article is to review the efforts made,
the technical difficulties associated with the genetic improvement in food legumes as related to plant-nutrient relations,
causes of limited breeding success and thereby draw lessons useful to designing future breeding strategies. The scope of nutrient
deficiency stress and the approaches to breeding for plant-nutrient relations are discussed and the need for refining the
approach and better targeting of the breeding methodologies suggested. 相似文献
82.
In the United States, food banks served an estimated 46 million people in 2015. A combination of government policy reforms and political economic trends contributed to the rising numbers of individuals relying on private food assistance in the US, the United Kingdom and other high-income countries. Although researchers frequently map urban food environments, this project is one of the first to map private food assistance and potential need at the census-tract scale. We utilize Geographic Information Systems, demographic data, and food assistance locations to develop a rapid assessment tool that could support food banks, pantries, soup kitchens, and government agencies that seek to answer the question of whether people with the greatest need have food distribution sites in close proximity. We define access based on distance and then calculate potential food insecurity using either poverty rates or a food insecurity index. We apply these methods in a case study analysis of Santa Clara County, California. Our findings suggest that food assistance distribution locations match the areas of potential need in more than 80% of urban census tracts. However, there are several potentially underserved locations and populations that could benefit from new food assistance operations. The poverty and index-based approaches show significant spatial overlap in mapped areas of high food insecurity and low access. The poverty only approach produces a higher estimate of food insecurity rates, is easier to calculate, and draws attention to the need to address poverty as a root cause of hunger. 相似文献
83.
This article analyses motivations and attitudes of small-scale forest owners in the Czech Republic towards joining associations. The research is a follow-up to a field investigation performed within the National Forest Programme II for 2007–2013 in the Vyso?ina region in 2010. The present research was carried out in the Pilsen region in 2012 and the Central Bohemia region in 2015, applying the same method of investigation as in 2010—a questionnaire survey. The findings are based on the results of all three surveys and supported by the analysis of legal and forestry-related documents concerning financial subsidies for forest owners’ associations. The study has revealed reluctance of small-scale owners to join associations. Their lack of motivation is caused by insufficient funding from the government supporting the administration and management of associations. The reluctance also results from the request for associations to be legal entities, which most applicants do not meet as they are either not registered or are registered under unsuitable legal forms. Between 2011 and 2013, no contributions were paid by the government to associations, and no new small-scale forest owners’ associations were formed. To increase associations, we propose that the government should provide sufficient funding not only for the administration and management of associations but also for the process of establishing associations and initial investments. It is also necessary to make major innovations in legislature regarding the transition of ownerships to more convenient legal forms. 相似文献
84.
Majid Salehi Ahmad Vaez Mahdi Naseri-Nosar Saeed Farzamfar Arman Ai Jafar Ai Shima Tavakol Mehrdad Khakbiz Somayeh Ebrahimi-Barough 《Fibers and Polymers》2018,19(1):125-134
In the present study, naringin, a flavonoid isolated from the grape and citrus fruit species, was incorporated with poly(ε-caprolactone)/gelatin composite mats in order to develop a potential wound dressing. The composite mats were prepared by electrospinning of poly(ε-caprolactone)/gelatin (1:1 (w/w)) solution incorporated with 1.50 %, 3 % and 6 % (w/w) of naringin. The electrospun mats were evaluated regarding their morphology, contact angle, water-uptake capacity, water vapor transmission rate, tensile properties, drug release, cellular response and in vivo wound healing activity. The study showed that after 2 weeks, the full-thickness excisional wounds of Wistar rats treated with the naringin-loaded dressings achieved a wound closure of higher than 94 % and the dressing containing 6 % (w/w) naringin had almost 100 % wound closure. The sterile gauze, as the control group, showed nearly 86 % of wound closure after this period of time. Our results provided evidence that supports the possible applicability of naringin-loaded wound dressing for successful wound treatment. 相似文献
85.
Statistical copolymers of 2-hydroxy-3-benzophenoxy propyl methacrylate (HBPPMA) and benzyl methacrylate (BzMA) in different feed ratios were synthesized by free radical copolymerization method at 60 °C in presence of AIBN initiator. The compositions of copolymer were estimated from 1H-NMR technique. The monomer reactivity ratios of HBPPMA and BzMA were calculated as r1 (rHBPPMA)=0.51±0.076 and r2 (rBzMA)=1.07±0.140 for Kelen-Tüdos method, and was estimated as r1=0.37±0.0006 and r2=0.64±0.0485 according to Fineman Ross equation. The average values estimated from the two methods showed that monomer reactivity ratio of benzyl methacrylate was a slightly high in comparison to HBPPMA. The copolymer system showed an azeotropic point, which is equal to M BzMA =m BzMA =0.43. DSC measurements showed that the Tg’s of poly(HBPPMA) and poly(BzMA) were 84 °C and 73 °C, respectively. The Tg in the copolymer system decreased with increase in benzyl methacrylate content. The decomposition temperature of poly(BzMA) and poly(HBPPMA) occurs in a single stage at about 207 °C and 260 °C, respectively. Those of HBPPMA-BzMA copolymer systems are between decomposition temperatures of two homopolymers. The dielectric constant, dielectric loss factor and electrical conductivity were investigated depend on the frequency of the copolymers. The highest dielectric constants depending on all the studied frequencies were recorded for the poly(HBPPMA) and the copolymer containing the highest HBPPMA unit. The dielectric constant for P(HBPPMA) and P(BzMA) at 1 kHz are 6.56 and 3.22, respectively. Also, those of copolymer systems were estimated between these two values. Similarly, poly(HBPPMA) and copolymers, which are prepared under the same conditions show the dissipation factor and conductivity as well. 相似文献
86.
Cynthia Yuri Ogawa Katsuyuki Hamasaki Shigeki Dan Shuichi Kitada 《Fisheries Science》2011,77(6):915-927
The fishery biology of mud crabs Scylla spp. was examined using baited traps and gill nets from September 2001 to August 2005 at Iriomote Island, Japan. To elucidate
the growth of the crabs, artificially produced S. serrata juveniles were released and recaptured at the study site. The sizes at which 50% of females and males of S. serrata reached sexual maturity (SM50) were estimated as an external carapace width (ECW) based on the morphology of the abdomen and the chela respectively. Two
species, S. serrata and S. olivacea, were identified in the area with S. serrata being the dominant species (>95% of the catch). Changes in the mean ECW and the results of the release and recapture experiments
suggested that the recruitment of young crabs to the fishery occurred from December/January to April/May. The SM50 of females and males occurred at 132.4 and 150.7 mm ECW respectively. The body size composition of S. serrata revealed that immature crabs comprised approximately 40 and 65% of the catch for females and males respectively. To maintain
a sustainable fishery for S. serrata, a minimum landing size based on the SM50 estimates should be implemented as a fishing regulation. 相似文献
87.
Hesperidin is a flavanone glycoside widely available for dietary intake in citrus fruits or citrus fruit derived products; however, exhaustive and reliable data are scarcely available for biological activity when it exerts protective health effects in humans. The principal intent of this work is to check binding domain and structural changes of human serum albumin (HSA), the primary carrier of flavonoids, in blood plasma association with hesperidin by employing molecular modeling, steady state and time-resolved fluorescence, and circular dichroism (CD) methods. From molecular modeling simulations, subdomains IIA and IIIA, which correspond to Sudlow's sites I and II, respectively, were earmarked to possess affinity for hesperidin, but the affinity of site I with flavanone is greater than that of site II. This corroborates the site-specific probe and hydrophobic 8-anilino-1-naphthalenesulfonic acid (ANS) displacement results placing the hesperidin at warfarin-azapropazone and indole-benzodiazepine sites. Steady state and time-resolved fluorescence manifested that static type, due to HSA-hesperidin complex formation (1.941 × 10(4) M(-1)), is the operative mechanism for the diminution in the tryptophan (Trp)-214 fluorescence. Moreover, via alterations in three-dimensional fluorescence and CD spectral properties, we can securely draw the conclusion that the polypeptide chain of HSA is partially destabilized after conjugation with hesperidin. We anticipate that this study can provide better knowledge of bioavailability such as absorption, biodistribution, and elimination, of hesperidin in vivo, to facilitate the comprehension of the biological responses to physiologically relevant flavanones. 相似文献
88.
To reduce reliance on scientific fertilizer due to rapid increase of fertilizer prices and environmental constraint, it necessary to improve crop productivity and soil fertility on sustainable basses. Utilization of “summer gap” through biochar and legumes have pleasant effects on improving crop productivity and soil fertility on long term basses. Two years’ field experiments were conducted on wheat and maize crops with “summer gap” utilization with legumes and biochar at research farm of agronomy, the University of Agriculture Peshawar during 2011–2013. Wheat-maize-wheat cropping system was followed with the adjustment of legumes in “summer gap” (land available after wheat harvest till maize sowing). Legumes i.?e. mung bean, cowpea and Sesbania with a fallow were adjusted in the “summer gap” with and without biochar application. Biochar was included at the rate of 0 and 50?t?ha-1 with four N levels of 0, 90, 120, 150 and 0, 60, 90, 120?kg?ha-1 to subsequent maize and wheat crops, respectively. In legumes’ experiment, biochar increased fresh and dry fodder yield in cowpea and Sesbania, grain and biological yields in mung bean. In maize experiments, biochar improved grain yield. Nitrogen application increased grain and biological yields. In wheat experiments with increasing nitrogen level enhanced biological and grain yields. It is concluded that use of biochar and legumes in “summer gap” improve overall farm productivity and soil fertility on sustainable basses. 相似文献
89.
Jianli Liu Baoqi Zuo Xianyi Zeng Philippe Vroman Besoa Rabenasolo Weidong Gao 《Fibers and Polymers》2011,12(7):963-969
Previous work has shown that the uniformity recognition of nonwoven can be considered as a special case of pattern recognition.
In this paper, a generalized frame for uniformity recognition based on computer vision and pattern recognition is introduced
briefly. To validate the proposed generalized frame, a case study id carried out in experiment. In the experiment section,
the uniformity recognition of nonwovens will be solved by unifying wavelet texture analysis, generalized Gaussian density
(GGD) model and learning vector quantization (LVQ) neural network. 625 nonwoven images of 5 different uniformity grades, 125
of each grade, are decomposed at four levels with five different wavelet bases of Symlets family. And wavelet coefficients
in each subband are independently modeled by the GGD model, while the scale and shape parameters of GGD model are extracted
using maximum likelihood (ML) estimator as features to train and test LVQ neural network. For comparison, two energy-based
features are also extracted from wavelet coefficients directly and jointly used as textural features. Experimental results
coming from 625 nonwoven samples indicate the GGD parameters are more expressive and powerful in characterizing textures than
the energy-based ones, especially when the number of decomposition levels is 4. 相似文献
90.
A new species of Microterys Howard (Hymenoptera: Encyrtidae), M. angustus Zu, Li & Wang sp. nov., is described from China as a parasitoid of Parthenolecanium corni (Bouché) (Hemiptera: Coccidae) on Acer saccharum Marsh. and Sophora japonica Linn.. 相似文献