Product cones in dense pairs

LetM=〈M,<,+,...〉be an o-minimal expansion of an ordered group, andP⊆Ma dense set such thatcertain tameness conditions hold. We introduce the notion of aproduct conein ̃M=〈M,P〉, and prove: ifMexpands a real closed field, then ̃Madmits a product cone decomposition. IfMis linear, then it does not. Inparticular, we settle a question from [10]

Orthogonal Decomposition of Definable Groups

Orthogonality in model theory captures the idea of absence of non-trivial interactions between definable sets. We introduce a somewhat opposite notion of cohesiveness, capturing the idea of interaction among all parts of a given definable set. A cohesive set is indecomposable, in the sense that if it is internal to the product of two orthogonal sets, then it is internal to one of the two. We prove that a definable group in an o-minimal structure is a product of cohesive orthogonal subsets. If the group has dimension one, or it is definably simple, then it is itself cohesive. As an application, we show that an abelian group definable in the disjoint union of finitely many o-minimal structures is a quotient, by a discrete normal subgroup, of a direct product of locally definable groups in the single structures

Strategies for Controlled Placement of Nanoscale Building Blocks

The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others

Alterações morfológicas e acúmulo de compostos fenólicos em plantas de sorgo sob estresse de alumínio Changes in morfology and phenolics accumulation in sorghum (Sorghum bicolor (L.) Moench) plants under aluminum stress

Os efeitos do alumínio (Al+3) sobre a morfologia e o acúmulo de compostos fenólicos foram avaliados em duas cultivares de sorgo (Sorghum bicolor (L.) Moench) com tolerância diferencial ao Al+3. As plantas foram mantidas em solução nutritiva durante dez dias, na presença (185 mM) ou na ausência de Al+3. Os ápices radiculares foram coloridos com hematoxilina férrica, sendo a intensidade da coloração observada na presença do Al+3 muito próxima entre as cultivares, o que inviabiliza a aplicação desse teste, isoladamente, para discriminação entre o genótipo sensível e o tolerante ao Al+3. As análises da morfologia externa e interna dos ápices radiculares de plantas tratadas com Al+3 também foram muito similares entre as duas cultivares, não permitindo a utilização dessas características para seleção entre a cultivar sensível e a tolerante. O maior acúmulo de lignina e, principalmente, a menor produção de compostos fenólicos, observados na presença do Al+3 nas raízes das plantas da cultivar tolerante (BR006R), são parâmetros que possibilitam a discriminação das cultivares quanto à tolerância ao Al+3.<br>The Al+3 effects on the morphology and on the phenolics accumulation were evaluated in two sorghum cultivars exhibiting differential tolerance to Al+3. The plants were kept in nutrient solution, for ten days, in the presence (185 mM) or Al+3 absence. The root apexes were colored with ferric hematoxylin, and because the intensity of color development is very similar among evaluated cultivars, the use of this method as a selection parameter for Al+3-tolerance is not indicated. Analyses of superficial and internal morphology from tissues treated with Al+3 also expressed very similar alterations among the two cultivars, not allowing its use for selection between sensitive and Al+3-tolerant genotype. The higher lignin accumulation and, mainly, the lower phenolics production in roots of the BR006R cultivar in Al+3's presence, demonstrated the existence of differential tolerance among cultivars