Differential Priors for Elastic Nets

The elastic net and related algorithms, such as generative topographic mapping, are key methods for discretized dimension-reduction problems. At their heart are priors that specify the expected topological and geometric properties of the maps. However, up to now, only a very small subset of possible priors has been considered. Here we study a much more general family originating from discrete, high-order derivative operators. We show theoretically that the form of the discrete approximation to the derivative used has a crucial influence on the resulting map. Using a new and more powerful iterative elastic net algorithm, we confirm these results empirically, and illustrate how different priors affect the form of simulated ocular dominance columns

Sensibilidade de cultivares de soja (Glycine max) aos herbicidas diclosulam e flumetsulam Soybean (Glycine max) cultivars sensibility to the herbicides diclosulam and flumetsulam

O objetivo deste trabalho foi verificar, no campo, no município de Londrina-PR, a resposta de 12 cultivares de soja em relação aos herbicidas diclosulam e flumetsulam aplicados e incorporados em Latossolo Roxo distrófico (80,84 % de argila, pH 5,4 e matéria orgânica 3,07 %). As cultivares foram: 'FT-Guaira', 'Embrapa-48', 'Ocepar-14', 'BR-16', 'Embrapa-4', 'Ocepar-13', 'BR-36', 'FT10-Princesa', 'FT-2000', 'FTAbyara', 'BR-37' e 'RS7- Jacuí'. O diclosulam foi utilizado nas doses de 35 g/ha (normal) e 70 g/ha (dobrada); e o flumetsulam nas doses de 120 g/ha (normal) e 240 g/ha (dobrada); também foi utilizada a mistura de diclosulam + flumetsulam (20 + 100 g/ha); e imazaquin à 150 g/ha. Nas doses normais utilizadas dos dois herbicidas não foi possível distinguir nenhuma cultivar suscetível. Em dose dobrada do diclosulam os rendimentos das cultivares 'FT-Guaira', 'Embrapa 4' e 'BR-37 ' foram reduzidos em 20,9 %, 11,8 % e 11,0 % respectivamente, em relação à testemunha. O flumetsulam à 240 g/ha e sua mistura com diclosulam também reduziu o rendimento destas cultivares, mais o da 'Ocepar-14'. A maioria das cultivares teve o estande reduzido, nas doses dobradas dos dois herbicidas, mas também sem significância. Somente o estande da cultivar 'Embrapa-48' não foi afetado, ao contrário da 'RS-7 Jacuí'. A altura de plantas foi menor em relação à testemunha no tratamento com flumetsulam à 240 g/ha. Na maioria das cultivares o peso da biomassa seca de nódulos foi menor nas doses dobradas, e em algumas também o peso por unidade de nódulos. A biomassa seca da parte aérea e da raiz não foram reduzidas.<br>The objective of the present paper was to check the behaviour of 12 different soybean cultivars in relation to the tolerance to the herbicides flumetsulam and diclosulam applied on a soil classified as Latossolo Roxo distrófico (80,87% of clay, pH of 5,4 and 3,07 of organic matter) in Londrina - PR. The cultivars were: 'FTGuaira', 'Embrapa-48', 'Ocepar-14', 'BR-16', 'Embrapa-4', 'Ocepar-13', 'BR-36', 'FT 10- Princesa', 'FT-2000', 'FT-Abyara', 'BR-37' and 'RS 7-Jacuí'. Diclosulam was used in the rates of 35 g/ha (normal rate) and 70 g/ha (double rate) and flumetsulam in the rates of 120 g and 240 g/ha (normal and double rate respectively). It was also used a mix of diclosulam and flumetsulam (20 + 100 g/ha) and imazaquin at 150 g/ha. At the normal rates of both herbicides it was not poss to find any difference in suscetibily of the cultivars. At double rates of diclosulam the yields of 'FT-Guaira', 'Embrapa-4'and 'BR-37' were reduced in 20,9%, 11,8% and 11,0%, respectively, in relation to the check. Flumetsulam at 240 g/ha and its mix with diclosulam also reduced the yields of these cultivars, plus "Ocepar-14'. The major of the cultivars showed a reduced stand at the double rates of the both herbicides, but without significance. Only the stand of 'Embrapa- 48' was not affected, contrary to 'RS 7-Jacuí'. The plant height was reduced by flumetsulam at 240 g/ha. In all cultivars the nodule dry biomass was reduced in double rates, and in some of them the weight per unit of nodule. The dry biomass of aerial port and roots werw nor reduced