Bridging the divide between cytokinesis and cell expansion

Two of the most fundamental processes in plant development are cytokinesis, by which new cells are formed, and cell expansion, by which existing cells grow and establish their functional morphology. In this review we summarize recent progress in understanding the pathways necessary for cytokinesis and cell expansion, including the role of the cytoskeleton, cell wall biogenesis, and membrane trafficking. Here, we focus on genes and lipids that are involved in both cytokinesis and cell expansion and bridge the divide between these two processes. In addition, we discuss our understanding of and controversies surrounding the role of endocytosis in both of these processes.     

Bridging the gap: How the National Core Arts Standards forge the divide between the arts and assessment-based learning

ABSTRACT

This article is a review and thematic analysis of the 2014 National Core Arts Standards (NCAS). Historically, there exists a gap between the arts and assessment-based educational practices. Thematic analysis of the NCAS reveals a policy striving to bridge the gap between the way arts educators envision arts in schools, and the current reality of assessment-based schooling in the United States. This policy could become the foundation for the recognition of the arts as academically rigorous subject matter, capable of existing and thriving in an assessment-oriented world; it remains to be seen as to how and if arts educators will use and adapt NCAS. Is the NCAS merely a symbolic policy or does it have the support behind it to be a material policy that truly creates change in the educational system?     

Conservation Genetic Resources for Effective Species Survival (ConGRESS): Bridging the divide between conservation research and practice

Policy makers and managers are increasingly called upon to assess the state of biodiversity, and make decisions regarding potential interventions. Genetic tools are well-recognised in the research community as a powerful approach to evaluate species and population status, reveal ecological and demographic processes, and inform nature conservation decisions. The wealth of genetic data and power of genetic methods are rapidly growing, but the consideration of genetic information and concerns in policy and management is limited by the currently low capacity of decision-makers to access and apply genetic resources. Here we describe a freely available, user-friendly online resource for decision-makers at local and national levels (http://congressgenetics.eu), which increases access to current knowledge, facilitates implementation of studies and interpretation of available data, and fosters collaboration between researchers and practitioners. This resource was created in partnership with conservation practitioners across the European Union, and includes a spectrum of taxa, ecosystems and conservation issues. Our goals here are to (1) introduce the rationale and context, (2) describe the specific tools (knowledge summaries, publications database, decision making tool, project planning tool, forum, community directory), and the challenges they help solve, and (3) summarise lessons learned. This article provides an outlook and model for similar efforts to build policy and management capacity.     

Phase separation in a sheared gelatin/maltodextrin mixture studied by small-angle light scattering

The influence of shear on the structure of a gelatin/maltodextrin mixture was investigated using small-angle light scattering both during phase separation and after phase separation was allowed to occur quiescently. In all cases, phase separation occurred via spinodal decomposition to form a droplet morphology, and a characteristic length scale was formed in the structure that was prevalent during shear, as well as in quiescent conditions. Below the critical shear rate for droplet breakup, shear accelerated the coarsening rate of the droplets. A transient regime of rapid hydrodynamic coarsening was present when shear was initiated after phase separation and at late times in all cases once the droplets attained a certain size. At the critical shear rate for droplet breakup (1 s(-1)), the rapid repetition of breakup and coarsening was postulated to occur, which enabled a microstructure consisting of elongated droplets with a narrow size distribution to form. When the shear rate enabled droplets to extend to such an extent that a percolated structure could form (10 s(-1)), then the structure was relatively stable and changed very slowly over time. At very high shear rates (100 s(-1)), droplet breakup was suppressed and a highly fibrillar morphology formed that was stable only while the system was under shear. Cessation of shear at high rates led to fiber breakup and the formation of many small droplets. For a given shear rate, the final microstructure appeared to be independent of the time that shear was started when the structure consisted of discrete droplets or fibers. When a percolated structure could form, however, the shear history appeared to be important.     

Biodiversity and the divide between culture and nature

The term biodiversity may help us to reach beyond the nature–culture dualism that has a debilitating effect on conservation thinking. This, however, depends on how the term is actually used. The opportunity is that the term connects dialectically together biological entities and their conditions of reproduction and may, consequently, facilitate a shift from atomistic to processual thinking in ecology and conservation. Analogously, the term offers resources for analyzing the dynamic dependence of human activities on natural processes. Health offers a fruitful metaphor for evaluating the resilience and conditions of reproduction of ecosocial systems. On the other hand, problems and contradictions in the application of the term arise from too schematic a perception of the relationship between scientific knowledge and human, social agency. Science influences human agency primarily on the long term, by helping to form new perspectives on what it means to lead a human life. Conservation concerns have a great influence on such perspectives. However, an emphasis on crisis may be counterproductive: scientific arguments perform poorly in a crisis situation in which, instead, short-term interests of powerful social actors such as corporations, state agencies or professional groups may gain the upper hand.     

Rheological properties of mixtures of protein-polysaccharide-dynamic viscoelasticity of blend gels of acylated gelatin, kappa-carrageenan, and agarose

Complex Young's modulus of blend gels of gelatin and kappa-carrageenan or agarose has been measured in order to clarify the protein-polysaccharide interaction in biological systems. The mixture of gelatin and kappa-carrageenan showed phase separation in the intermediate volume fraction of gelatin, and it formed a homogeneous gel when the volume fraction of gelatin is very large or very small. Since the dynamic Young's modulus for blend gels of kappa-carrageenan and gelatin was larger than the calculated one from a theory for dispersed systems, some structural reinforcing must occur. The mixture of agarose and gelatin showed the inverse tendency. It was concluded that the role of electrolytic groups was dominant in dilute gels, while molecular entanglement became more important in concentrated gels.     

Mechanism and kinetics of phase separation in a gelatin/maltodextrin mixture studied by small-angle light scattering

Phase separation mechanisms and kinetics were studied using small-angle light scattering in a gelatin/maltodextrin system where phase separation could be studied in both liquid and gelled states. Nucleation and growth or spinodal decomposition occurred, depending on the quench depth. The transition between the two mechanisms occurred relatively sharply. The different mechanisms were distinguishable by the different behavior of the scattering function even though a peak was observed in both cases. Particular differences were the different evolution of the peak intensity and position, the absence of dynamic scaling of the nucleation and growth scattering function, and the final coarsening exponent of 1/3 that was measured when spinodal decomposition occurred but not for nucleation and growth. Gelation severely reduced the coarsening rate and initially placed the phase compositions far from their equilibrium values. Despite the loss of molecular mobility caused by gelation, the gelled systems did continue to evolve, albeit much more slowly than in the liquid case. Multiple coarsening rates were observed for some of the gelled samples, which were ascribed to the gradual movement of these systems toward the equilibrium compositions.     

Atul Butte discusses the divide between bioinformatics and the clinic

Atul Butte is an Assistant in Endocrinology and Informatics and Attending Physician at Children's Hospital, Boston, USA (http://www.chip.org), and is an Instructor in Paediatrics at Harvard Medical School (http://www.harvard.edu). He received his undergraduate degree in Computer Science from Brown University in 1991, and worked in several stints as a software engineer at Apple Computer and Microsoft Corporation. He graduated from the Brown University School of Medicine in 1995, during which he worked as a research fellow at National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK; http://www.niddk.nih.gov) through the Howard Hughes/NIH Research Scholars Program. He completed his residency in Paediatrics and Fellowship in Paediatric Endocrinology in 2001, both at Children's Hospital. During his research under Isaac Kohane (at Children's Hospital) he developed a novel methodology for analyzing large data sets of RNA expression, called Relevance Networks. His recent awards include the 2003 Emory University School of Medicine, Pathology Residents’ Choice Award, 2002 American Association for Clinical Chemistry Outstanding Speaker Award, 2002 Endocrine Society Travel Award based on presentation merit, 2001 American Association for Cancer Research Scholar-In-Training Award and the 2001 Lawson Wilkins Paediatric Endocrine Society Clinical Scholar Award.     

Bridging the gap between physics and biology.

The work is devoted to the historical development of physics and biology. Various aspects of their interactions are shown: antagonism, mutual penetration and a lot of bridges, built or being built between them. The gradual "evolution of the world picture" from going away of the "pre-scientific" animated Universe and the appearance of mechanicism and vitalism to the development of systems and field approaches is traced. The last part of the paper is concerned with some present-day works at the joint between physics and biology.