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Start Over Coverage 217-221

1. A characterization of C1,1 functions via lower directional derivatives

Creator:
Bednařík, Dušan and Pastor, Karel
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
second-order derivative, C 1,1 function, ℓ-stable function, and ˜ℓ-stability
Language:
English
Description:
The notion of ˜ℓ-stability is defined using the lower Dini directional derivatives and was introduced by the authors in their previous papers. In this paper we prove that the class of ˜ℓ-stable functions coincides with the class of C1,1 functions. This also solves the question posed by the authors in SIAM J. Control Optim. 45 (1) (2006), pp. 383–387.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

3. Leaf characteristics and gas exchange of the mangrove Laguncularia racemosa as affected by salinity

Creator:
Sobrado, M. A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
leaf succulence, net photosynthetic rate, nitrogen use efficiency, sodium accumulation, stomatal conductance, water use efficiency, and δ13C
Language:
Multiple languages
Description:
Under constant salinity we analysed the leaf characteristics of Laguncularia racemosa (L.) Gaertn. in combination with gas exchange and carbon isotopic composition to estimate leaf water-use efficiency (WUE) and potential nitrogen-use efficiency (NUE). NaCl was not added to the control plants and the others were maintained at salinities of 15 and 30 ‰ (S0, S15, and S30, respectively). Leaf succulence, sodium (Na), nitrogen (N), and chlorophyll (Chl) contents increased under salinity. Salinity had a negative impact on net photosynthetic rate (PN) and stomatal conductance (gs) at high and moderated irradiances. Potential NUE declined significantly (p<0.05) with salinity by 37 and 58 % at S15 and S30, respectively, compared to S0 plants. Conversely, compared to S0 plants, PN/gs increased under saline conditions by 12 % (S15) and 50 % (S30). Thus, WUE inferred from PN/gs was consistent with salinity improved short-term WUE. Long-term leaf WUE was also enhanced by salinity as suggested by significantly increased leaf δ13C with salinity. Improved WUE under salinity explains the eco-physiological success of mangrove species under increasing salinity. Conversely, decline in NUE may pose a problem for L. racemosa under hyper-saline environments regardless of N availability.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public