Urban greenways planning. A vision plan for Milan (Italy)

Greenways are “green infrastructure” to link people and places (Fabos, 1995) and can be planned at different scales (from national to municipal) and for multiple purposes, “including ecological, recreational, cultural, aesthetic” (Ahern, 1995), “to provide people with access to open spaces close to where they live” (President\u27s Commission on Americans Outdoors, 1987), in order to “enhance both the environment and quality of life” (European Greenways Association, 2000). At the municipal scale, the urban greenways network can help to reshape the city, making it more livable; urban greenways represent “at once the parks for the 21st century and a part of the transportation infrastructure, providing for pleasant, efficient, healthful and environmentally-sound travel by foot, bicycle or skates” (New York City Department of City Planning, 1993). Turner (2006) reported the results of a research conducted in 2001 among the British local authorities, in which come out the different purpose of urban greenway planning: creating a coherent (green) network of public open spaces, creating a green transport network that confers a vital new use on public open spaces, contributing to the reintegration of planning for ‘town’ and ‘country’ in order to serve the needs of a new urban population seeking active recreation in the countryside. The most important benefits of greenways in urban areas are environmental protection, recreation, and alternative transportation. These benefits cannot be realized unless the greenway planners take a systematic approach to the delineation of greenway paths (Conine et al., 2004). Various methodologies for greenways planning that take into account the many factors in a cohesive manner have been developed for and successfully applied, such as those described in Flink and Searns (1993), Smith and Hellmund (1993), Fabos (1995), Tzolova (1995), Xiang (1996), Toccolini et al. (2004), Ribeiro and Barao (2006) and Toccolini et al. (2006). In the present study three significant experiences were analyzed more in depth: New York City (New York City Department of City Planning, 1993), Vancouver (City of Vancouver, 1995) and Brussels (Institut Bruxellois pour la Gestion de l’Environnement, 2001). There has always been a strong link between the city of New York and the Greenways; as a matter of fact it is right here where it was first conceived the first plan of the modern age concerning a network of urban greenways (in 1866, with the Parkways designed by Frederick Law Olmsted and Calvert Vaux). Over the years, the great metropolis has preserved this link and recently this link has led to a plan of Greenways for the city. The plan was proposed in 1993 by NYC Department of City Planning. The plan states that “greenways would be a system of bicycle-pedestrian pathways along natural and manmade linear spaces such as rail and highway rightsof- way, river corridors, waterfront spaces, parklands and, where necessary, city streets. They are at once the parks for the 21st century and a part of the transportation infrastructure, providing for pleasant, efficient, healthful and environmentally-sound travel by foot, bicycle or skates”. The plan concerns a system of about 570 km of greenways designed to create new opportunities from a recreational point of view, increase the mobility of cyclists and pedestrians and generally speaking was created to enhance the quality of life of NY citizens. The network of greenways brings advantages in many fields, such as citizens health, transportation, socializing development and recreational aspects. As a matter of fact, the plan for NY wants greenways to accomplish different tasks: ⎯ build new spaces that are easily reachable from home and work, through which it is possible to explore and appreciate the different metropolitan environments; ⎯ offer recreational advantages (sunbathing, staying outdoors, admiring the landscape, relax, getting in touch with nature, etc.); ⎯ improve people health (physical activities, outdoor sports); ⎯ provide an alternative, completion and integration with traditional means of transportation; ⎯ provide the possibility to decrease traffic and urban pollution; ⎯ build natural “buffer zones” to separate areas with different functions (residential areas, commercial areas, etc.); ⎯ represent a meeting place to socialize with other people

Suburban waterfront with ecological and recreational function: planning based on network analysis

Urban fringe areas have multiple land uses and are places where sections of waterway, together with fragmented areas of natural vegetation, are often found passing through urban areas, transportation routes and gradually expanding rural areas. These overlapping functions are often the cause of an extremely disorderly landscape devoid of guiding connotative elements. In this context, the waterfront can be a guiding element for the redevelopment of the fringe areas between cities and the countryside. The purpose of this paper is the definition of a methodology for planning a suburban waterfront with an ecological function and bicycle paths for recreational use. The evaluation phases for resources and planning, conducted with tools for network analysis, have identified potential corridors based on current land uses and have addressed the issue of bicycle paths on an inter-municipal scale. The methodology is proposed for regional level planning and the validation of the method was achieved through its application to the stretch of the Lambro River between Monza Park and the city of Milan in the North of Italy

Using α-Helical Coiled-Coils to Design Nanostructured Metalloporphyrin Arrays

We have developed a computational design strategy based on the alpha-helical coiled-coil to generate modular peptide motifs capable of assembling into metalloporphyrin arrays of varying lengths. The current study highlights the extension of a two-metalloporphyrin array to a four-metalloporphyrin array through the incorporation of a coiled-coil repeat unit. Molecular dynamics simulations demonstrate that the initial design evolves rapidly to a stable structure with a small rmsd compared to the original model. Biophysical characterization reveals elongated proteins of the desired length, correct cofactor stoichiometry, and cofactor specificity. The successful extension of the two-porphyrin array demonstrates how this methodology serves as a foundation to create linear assemblies of organized electrically and optically responsive cofactors

Inside-out Ca2+ signalling prompted by STIM1 conformational switch

Store-operated Ca(2+) entry mediated by STIM1 and ORAI1 constitutes one of the major Ca(2+) entry routes in mammalian cells. The molecular choreography of STIM1–ORAI1 coupling is initiated by endoplasmic reticulum (ER) Ca(2+) store depletion with subsequent oligomerization of the STIM1 ER-luminal domain, followed by its redistribution towards the plasma membrane to gate ORAI1 channels. The mechanistic underpinnings of this inside-out Ca(2+) signalling were largely undefined. By taking advantage of a unique gain-of-function mutation within the STIM1 transmembrane domain (STIM1-TM), here we show that local rearrangement, rather than alteration in the oligomeric state of STIM1-TM, prompts conformational changes in the cytosolic juxtamembrane coiled-coil region. Importantly, we further identify critical residues within the cytoplasmic domain of STIM1 (STIM1-CT) that entail autoinhibition. On the basis of these findings, we propose a model in which STIM1-TM reorganization switches STIM1-CT into an extended conformation, thereby projecting the ORAI-activating domain to gate ORAI1 channels

Computational design of membrane proteins

This article reviews the recent successes of computational protein design techniques applied to integral membrane proteins. This emerging area is still handicapped by significant difficulties in the experimental characterization of the stability and structure of the designed proteins. Nevertheless, by focusing on oligomeric complexes of single-span transmembrane (TM) peptides with detectable activity, the computational design of membrane proteins has already produced very exciting results. The 'take-home message' is that optimization of van der Waals packing and hydrogen bonding (both 'canonical' and weak Ca-HÁ Á ÁO bonds) can produce functional structures of remarkable stability and specificity in the membrane. Introduction Thanks to the development of fast sampling algorithms and the formulation of effective energy functions, computational protein design has made impressive advancements -such as enabling the design of artificial proteins with enzymatic activity [1] -and promises in the long term to create macromolecules with any desired activity and specificity for applications in research, biotechnology, and medicine. Since its early days, however, design has been primarily a tool for investigating the factors that govern the folding, the interactions, and the activity of proteins. In this capacity, design has been an important contributor to our understanding of integral membrane protein folding, a field that has yet to reach the level of maturity of its soluble counterpart. The advanced computational methods that have been developed for soluble proteins have begun to be applied to membrane proteins, but before the same level of success can be achieved, the technology needs to be adjusted to take into account an environment that is very different from bulk aqueous solution and in many ways more complex. Unlike methods such as molecular dynamics, in which the motions of all atoms -including the solvent -are evolved by simulating the fundamental interatomic forces, the computational methods used in protein design incorporate a number of simplifications and assumptions that are necessary to make the problem tractable. For example, the solvent can only be represented with implicit models, and the mobility of the main chain and the side chains is generally restricted or sampled at discrete intervals. Because of these simplifications, specialized energy functions become necessary Membrane protein folding: insertion Figures 1 and 2 illustrate the basic concepts of folding in the membrane. The primary driving force for folding in solution -the sequestration of nonpolar surface away from water -is spent to insert the hydrophobic transmembrane (TM) segments into the lipid bilayer (stage 1 in The stability of the insertion of TM domains in the bilayer is a long studied and well understood phenomenon Membrane protein folding: helix-helix association Figure 2 schematically summarizes the factors that are likely to contribute to the stability of the tertiary fold once the helices have been inserted in the bilayer. Overall, the two major factors that have emerged as contributors to membrane protein folding are van der Waals packing [15-17,18 ,19] and polar interactions. These include both 'canonical' hydrogen bonds (N and O donors) While the precise contribution of hydrogen bonding, van der Waals packing, and other factors is still under investigation, it is clear that they play an important role in the folding of membrane proteins. Further confirmation is provided by the success of recent computational design studies that have been based around these features, which is the topic of the following sections. Ca-HÁ Á ÁO C based design of antitransmembrane peptides A successful example of design performed around a stabilizing feature is of the CHAMP peptides (Computed Helical Anti-Membrane Protein), developed by DeGrado and colleagues as dominant-negative inhibitors of TM association against two closely related human integrins (a IIb b 3 and a v b 3 ) Design of an electron-transfer membrane protein based on polar interactions Very recently, we reported a functional membrane protein designed de novo with the objective of facilitating electron transfer across a lipid bilayer (called PRIME) Structural prediction of membrane proteins Protein structural prediction and protein design have different objectives but they share much of the underlying theoretical framework. Prediction and design have in common the ultimate aim of identifying the lowest energy state within their respective search spaces. Because of this commonality, similar methods and energy functions are applied to both problems, and it is therefore relevant here to discuss briefly the methodology introduced by a successful membrane structural prediction program, RosettaMembrane Conclusion So far the membrane protein design field has demonstrated its enormous potential by focusing on the areas in which the chances of success are most promising -the design of oligomeric complexes of single-span TM peptides with a detectable activity. The single-span TM helices -both natural and designed -have been a fertile ground for studying membrane helix association 464 Engineering and design Figure 4 Current Opinion in Structural Biolog

Tecniche per la valutazione della qualit\ue0 visuale del paesaggio rurale

L'articolo analizza le tecniche di valutazione della qualit\ue0 visuale del paesaggio basate sul giudizio formulato da un campione di intervistati sottoposti a test fotografico con particolare riferimento all'influenza dei cambiamenti stagionali sul giudizio di qualit\ue0 visuale espresso

Indicatori e modelli per lo sviluppo sostenibile del territorio e la valorizzazione del paesaggio. Ambito metropolitano: area nord-est di Milano

Le aree rurali in ambito metropolitano presentano caratteristiche e problematiche peculiari rispetto alle altre tipologie di aree rurali, in ragione loro localizzazione prossima alla citt\ue0\ua0. Le caratteristiche e le valenze di tali aree possono essere descritte in maniera sintetica e significativa attraverso l'utilizzo e la definizione di alcuni indicatori. Ci\uf2 anche al fine di effettuare confronti temporali e spaziali e di valutare gli effetti delle politiche sul territorio. Il presente lavoro \ue8 suddiviso in due momenti distinti. In un primo tempo sono stati individuati gli indicatori e sono stati raccolti i dati riguardanti il territorio in esame. In un secondo momento si \ue8 rivolta maggiore attenzione al livello comunale per individuare alternative spaziali allo sviluppo urbano e valutare quella in grado di rispondere meglio all'obiettvo generale. in tal senso viene utilizzato un approccio basato sull'integrazione tra metodi di analisi e valutazione delle risorse basati sull'impiego dello strumento GIS (EPP) con metodi di analisi multicriteriali basati sull'AHP (Analytic Hierarchy Process