Boron Uptake, Translocation and Distribution in Oilseed rape (Brassica napus L.): Effect of Application Methods, Boron Status of Plants and Nitrogen Forms

Boron (B) is an essential micronutrient for vascular plants and its plant availability is reduced by soil liming, high soil pH, and drought periods during growth stages. This work, consisting of three independent hydroponics experiments, aimed at investigating the growth and physiological response of oilseed rape (Brassica napus L.) plants to B supply. In the first experiment, the influence of B supply on the growth and distribution of B in oilseed rape was investigated. The results showed that oilseed rape plants supplied with 0.25 µM B in the nutrient solution showed severe symptoms of B deficiency, which were not seen in the plants supplied with 1.0 µM B. The increasing B supply in the nutrient solution significantly increased the translocation factor, and hence increased B shoot to root ratio in oilseed rape plants. In the second experiment, the effects of continuous B resupply via roots and one-time foliar application leaves on growth and physiological response, the relative expression of specific genes involved in B absorption and transport in B-deficient oilseed rape were evaluated. It was found that continuous root resupply and one-time foliar resupply B to B-deficient plants partially retrieved B concentration in the leaves and dry matter production, with a corresponding increase in the net carbon assimilation, transpiration rate and sugar accumulation. The finding from this work provided evidence that the relative expression of BnaNIP5;1 and BnaBOR1;2 strongly upregulated in the roots and leaves of B-deficient oilseed rape plants. However, gene expression of BnaNIP5;1 and BnaBOR1;2 was upregulated only in roots, which could be attributed to the low B concentration in roots in the foliar-applied B treatments. The effects of foliar B resupply on the growth of oilseed rape suggest that dual resupply via roots and foliage is needed to achieve a complete growth recovery of the B deficiency in oilseed rape. In the third experiment, the mechanisms underlying the uptake and distribution of B in oilseed rape under different nitrogen forms were elucidated. The concentration of B in the oilseed rape was not affected by the N forms, whereas it depended on the levels of B supplied. Marginal B supply significantly decreased specific B uptake rates as well as B concentrations and accumulation in roots and shoots as compared to the high B supply. The NO3--fed plants showed reduced xylem B concentrations and accumulated relatively more B in roots than that recorded with other N forms. The relative expression of BnaNIP5;1 was upregulated in roots, while both BnaBOR1;2 and BnaNIP5;1 were upregulated in shoots in the NH4+-fed plants under marginal B supply. Nitrate nutrition led to up-regulation of BnaBOR1;2 and BnaNIP5;1 in roots only. Nitrate-induced alkalinization results in altered B distribution between roots and shoots due to a restriction of B transport, while NH4+-induced acidity can induce upregulation of B transport mechanisms, even though B concentrations do not indicate B deficiency

A see-saw scenario of an A4A_4 flavour symmetric standard model

A see-saw scenario for an $A_4$ flavour symmetric standard model is presented. The latter, compared with the standard model, has an extended field content adopting now an additional $A_4$ symmetry structure (along with the standard model symmetry). As before, the see-saw mechanism can be realized in several models of different types depending on different ways of neutrino mass generation corresponding to the introduction of new (heavy in general) fields with different symmetry structures. In the present paper, a general description of all these see-saw types is made with a more detailed investigation on type-I models, while for type-II and type-III models a similar strategy can be followed. As within the original see-saw mechanism, the symmetry structure of the standard model fields decides the number and the symmetry structure of the new fields. In a model considered here, the scalar sector consists of three standard-model-Higgs-like iso-doublets ($SU_L(2)$-doublets) forming together an $A_4$-triplet, and three iso-singlets transforming as three singlets (1,$1^{'}$ and $1^{''}$) of $A_4$. In the lepton sector, the three left-handed lepton iso-doublets form an $A_4$-triplet, while the three right-handed charged leptons are either $A_4$-singlets in one version of the model, or components of an $A_4$-triplet in another version. To generate neutrino masses through, say, the type-I see-saw mechanism, it is natural to add four right-handed neutrino multiplets, including one $A_4$-triplet and three $A_4$-singlets. For an interpretation, the model is applied to deriving some physics quantities such as neutrinoless double beta decay effective mass $|\langle m_{ee}\rangle|$, CP violation phase $\delta_{CP}$ and Jarlskog parameter $J_{CP}$, which can be verified experimentally.Comment: LaTeX, 31 pages, 12 figures, 6 tables. V3: some parts modifie

Innovation and Export of Vietnam’s SME Sector

Innovation has long been considered an important factor for creating and maintaining the competitiveness of nations and firms. The relationship between innovation and exporting has been investigated for many countries. However, there is a paucity of research in Vietnam with respect to this issue. In this paper we examine whether innovation performed by Vietnam’s small and medium enterprises (SMEs) enhances their exporting likelihood. Using the recently released Vietnam Small and Medium Enterprise Survey 2005, we find that innovation as measured directly by ‘new products’, ‘new production process’ and ‘improvement of existing products’ are important determinants of exports by Vietnamese SMEs.Vietnam; Export; Innovation; Small and Medium Enterprise

The sanctity of goddesses: an insight into the worship of Bà Tổ Cô in Northern Vietnam

In Vietnam, a country where religious expression is widespread, many gods and goddesses are commonly worshipped. Among those, Bà Tổ Cô (Family Goddess) is widely worshipped in the North of Vietnam due to her exceptional background as unmarried, young, and having spiritual roots, unlike other national and heroic figures. This article examines the sanctity of the Family Goddess by decoding the terms, worshippers, beliefs and practices, sacred encounters and supports. The research is a final result of decade-long field trips, archival study, and in-depth interviews with various stakeholders. The research findings show that the veneration of the Family Goddess in Northern Vietnam is a continuity of a long-standing tradition of worshipping female deities in Asia and thus emphasising the need to maintain this unique intangible heritage as a crucial part of Vietnamese cultural diversity

Model of neutrino effective masses

It is shown that an effective (nonrenormalizable) coupling of lepton multiplets to scalar triplets in the 331 model with sterile/exotic neutrinos, can be a good way for generating neutrino masses of different types. The method is simple and avoids radiative/loop calculations which, sometimes, are long and complicated. Basing on some astrophysical arguments it is also stated that the scale of SU(3)L symmetry breaking is at TeV scale, in agreement with earlier investigations. Or equivalently, starting from this symmetry breaking scale we could have sterile/exotic neutrinos with mass of a few keV's which could be used to explain several astrophysical and cosmological puzzles, such as the dark matter, the fast motion of the observed pulsars, the re-ionization of the Universe, etc

Combining content and social features in a deep learning approach to Vietnamese email prioritization

The email overload problem has been discussed in numerous email-related studies. One of the possible solutions to this problem is email prioritization, which is the act of automatically predicting the importance levels of received emails and sorting the user’s inbox accordingly. Several learning-based methods have been proposed to address the email prioritization problem using content features as well as social features. Although these methods have laid the foundation works in this field of study, the reported performance is far from being practical. Recent works on deep neural networks have achieved good results in various tasks. In this paper, the authors propose a novel email prioritization model which incorporates several deep learning techniques and uses a combination of both content features and social features from email data. This method targets Vietnamese emails and is tested against a self-built Vietnamese email corpus. Conducted experiments explored the effects of different model configurations and compared the effectiveness of the new method to that of a previous work

One-Time Foliar Application and Continuous Resupply via Roots Equally Improved the Growth and Physiological Response of B-Deficient Oilseed Rape

Oilseed rape (Brassica napus L.) is a high-boron (B)-demanding crop, and initially, normal growing plants might show B deficiency at advanced growth stages on soils with marginal B availability. Hence, we compared the effects of B resupply via roots and leaves on growth and physiological response, and relative expression of B transporters in B-deficient oilseed rape plants. Four-week-old plants initially grown with inadequate B (1 µM B for the first two weeks and 0.25 µM B for the next two weeks) were later grown either as such with 0.25 µM B, with 25 µM B in nutrient solution or foliar sprayed with 7 mL of 30, 60 and 150 mM B solution plant-1 as boric acid. Plants grown with 25 µM B in the nutrient solution from the beginning were included as adequate B treatment. Results showed that B resupply to B-deficient plants via roots and leaves (60 mM B) equally improved root and shoot dry matter, but not to the level of plants grown with adequate B supply. Foliar-applied 150 mM B proved toxic, causing leaf burn but not affecting dry matter. Resupply of B via roots increased B concentration in roots and leaves, while leaf-applied B did so only in leaves. Net carbon assimilation had a positive relationship with dry matter accumulation. Except for the highest foliar B level, B resupply via roots and leaves increased the accumulation of glucose, fructose and sucrose in leaves. Boron-deficient plants showed significant upregulation of BnaNIP5;1 in leaves and roots and of BnaBOR1;2 in roots. Boron resupply via roots reversed the B-deficiency-induced upregulation of BnaNIP5;1 in roots, whereas the expression of BnaBOR1;2 was reversed by both root and foliar B resupply. In leaves, B resupply by both methods reversed the expression of BnaNIP5;1 to the level of B-adequate plants. It is concluded that B resupply to B-deficient plants via roots and leaves equally but partially corrected B deficiency in B. napus grown in hydroponics