a new alkaloid (1) and two known compounds (2 and 3) were isolated from the blue-greenalga arthrospira platensis. their structures were determined on the basis of spectroscopic data.according to the obtained data and values in the literature, the compounds were concluded to beeckol.

Background: Divergent natural selection between ecologically different environments often drives speciation. An unanswered question concerns the importance of sexual selection in generating sexual isolation during this process. We illustrate that four distinct mechanisms can drive sexual isolation: (I) divergent sexual selection, (II) uniform sexual selection, (III) intrapopulation assortative ...

This paper introduces the first state-based formalization of isolation guarantees. Our approach is premised on a simple observation: applications view storage systems as black-boxes that transition through a series of states, a subset of which are observed by applications. Defining isolation guarantees in terms of these states frees definitions from implementation-specific assumptions. It makes...

Replicated systems are commonly used to provide highly available applications. In last years, these systems have been mostly based on the use of atomic broadcast protocols, and a wide range of solutions have been published. The use of these atomic broadcast-based protocols also has aided to develop recovery protocols providing fault tolerance to replicated systems. However, this research has be...

Mate recognition is critical to the maintenance of reproductive isolation, and animals use an array of sensory modalities to identify conspecific mates. In particular, olfactory information can be an important component of mate recognition systems. We investigated whether odor is involved in mate recognition in a sympatric benthic and limnetic species pair of three-spined sticklebacks (Gasteros...

A reduction of the computational complexity of bank of Kalman filters is proposed. The algorithm is focused in fault detection and isolation problems. It is shown that the orders of individual filters in the bank can be lower than the respective filtered process model order. The original model state variables are not estimated. Linear functions of noise samples are the newly estimated variables.

Reproductive isolation is essential for the process of speciation and much has been learned in recent years about the ecology and underlying genetics of reproductive barriers. But plant species are typically isolated not by a single factor, but by a large number of different preand postzygotic barriers, and their potentially complex interactions. This phenomenon has often been ignored to date. ...

Ecologically dependent reproductive isolation (EDRI) is the decrease in gene flow that occurs when adaptive divergence reduces the fitness of individuals that move between ecological environments. A particularly simple and perhaps almost universal mechanism contributing to EDRI is natural selection against migrants themselves (i.e. before any selection against their offspring). Here I use singl...

Hypotheses: Adaptation to different environments can drive the evolution of mating isolation and thereby contribute to ecological speciation. Adaptive divergence in nest characteristics, which could be one avenue to mating isolation, has received little attention. For it to be important, populations adapted to different environments should show genetic differences in nest characteristics. Organ...