The evolution of networks of innovators within and across borders: Evidence from patent data

Recent studies on the geography of knowledge networks have documented a negative impact of physical distance and institutional borders upon research and development (R&D) collaborations. Though it is widely recognized that geographic constraints and national borders impede the diffusion of knowledge, less attention has been devoted to the temporal evolution of these constraints. In this study we use data on patents filed with the European Patent Office (EPO) for OECD countries to analyze the impact of physical distance and country borders on inter-regional links in four different networks over the period 1988-2009: (1) co-inventorship, (2) patent citations, (3) inventor mobility and (4) the location of R&D laboratories. We find the constraint imposed by country borders and distance decreased until mid-1990s then started to grow, particularly for distance. We further investigate the role of large innovation "hubs" as attractors of new collaboration opportunities and the impact of region size and locality on the evolution of cross-border patenting activities. The intensity of European cross-country inventor collaborations increased at a higher pace than their non-European counterparts until 2004, with no significant relative progress thereafter. Moreover, when analyzing networks of geographical mobility, multinational R&D activities and patent citations we cannot detect any substantial progress in European research integration above and beyond the common global trend

Networks of innovators within and across borders. Evidence from patent data

Recent studies on the geography of knowledge networks have documented a negative impact of physical distance and institutional borders upon research and development (R&D) collaborations. Though it is widely recognized that geographic constraints hamper the diffusion of knowledge, less attention has been devoted to the temporal evolution of these constraints. In this study we use data on patents filed with the European Patent Office (EPO) for 50 countries to analyze the impact of physical distance and country borders on inter-regional links in four different networks over the period 1988-2009: (1) co-inventorship, (2) patent citations, (3) inventor mobility and (4) the location of R&D laboratories. We find the constraint imposed by country borders and distance decreased until mid-1990s then started to grow, particularly for distance. The intensity of European cross-country inventor collaborations increased at a higher pace than their non-European counterparts until 2004, with no significant relative progress afterwards. Moreover, when analyzing networks of geographical mobility, multinational R&D activities and patent citations we do not depict any substantial progress in European research integration aside from the influence of common global trends

Polaronic conductivity in the photoinduced phase of 1T-TaS2

The transient optical conductivity of photoexcited 1T-TaS2 is determined over a three-order-of-magnitude frequency range. Prompt collapse and recovery of the Mott gap is observed. However, we find important differences between this transient metallic state and that seen across the thermally-driven insulator-metal transition. Suppressed low-frequency conductivity, Fano phonon lineshapes, and a mid-infrared absorption band point to polaronic transport. This is explained by noting that the photo-induced metallic state of 1T-TaS2 is one in which the Mott gap is melted but the lattice retains its low-temperature symmetry, a regime only accessible by photo-doping.Comment: 10 pages, 4 figure

Comparison of Organic and Conventional Crops at the Neely-Kinyon Long-term Agroecological Research Site

The Neely-Kinyon Long-term Agroecological Research (LTAR) site was established in 1998 to study the long-term effects of organic production in Iowa. Treatments at the LTAR site, replicated four times in a completely randomized design, include the following rotations: conventional Corn-Soybean (C-S), organic Corn-Soybean-Oats/Alfalfa (C-SO/A), organic Corn-Soybean-Oats/AlfalfaAlfalfa (C-S-O/A-A) and Corn-SoybeanCorn-Oats/Alfalfa (C-SB-C-O/A). On April 13, 2011, Badger oats were underseeded with BR Goldfinch alfalfa at a rate of 90 lb/acre and 15 lb/acre, respectively. Following harvest of the organic corn plots in 2010, winter rye was no-till drilled at a rate of 75 lb/acre on October 20, 2010

Adaptive Kayak Seating: The Tide Rider 360

The Adaptive Paddling Program at California Polytechnic State University has sponsored the construction of an adaptive kayak seat, the Tide Rider 360, to provide paddlers with disabilities sufficient trunk support while out on the water. In particular, this design focused on providing the least restrictive environment for all users while still providing sufficient lateral, neck, back, and hip support. This seat is intended for use in the quarterly Adaptive Paddling Program to allow people with disabilities to experience the joys of kayaking in the most comfortable and supportive environment possible. The following report details the background research, design development, manufacturing, and testing processes that went into designing this seat. It provides in-depth breakdowns on aspects such as the concept generation and material selection methods in order to prove that this kayak seat meets the requirements of the Adaptive Paddling Program. In particular, this seat was designed for use in marine environments with maximum levels of adjustability, support, and comfort. It was designed to fit to all different types of people in terms of weight, disability, and paddling ability. This kayak seat was manufactured out of aluminum tubing and joints, high density polyethylene sheets, and polyethylene foam. In addition to these materials, we added pre-manufactured wheelchair support components for the lateral supports, headrest, hip supports, and seat base. The total cost for the manufacturing of this prototype came out to be approximately $2100 and the final weight was just around 30 pounds. We conducted multiple levels of testing on the kayak seat, including a load test and in-pool assessment. Our load testing proved that the aluminum seat frame experiences minimal deflection and bending when subjected to a constant weight for an extended period of time. The in-pool testing verified that the seat is able to support a paddler while still allowing them a wide range of motion, if so desired. The prototype as is does have a few shortcomings, such as some hard to reach adjustment bolts, but the Adaptive Paddling Program still feels confident in the ability of this seat and the fulfillment of the preset requirements. We believe that with a few slight modifications to the seat back angle and some additional reach of the supports, this product would be able to change the lives of the participants in the Adaptive Paddling Program

Ubiquitin domain proteins in disease

The human genome encodes several ubiquitin-like (UBL) domain proteins (UDPs). Members of this protein family are involved in a variety of cellular functions and many are connected to the ubiquitin proteasome system, an essential pathway for protein degradation in eukaryotic cells. Despite their structural similarity, the UBL domains appear to have a range of different targets, resulting in a considerable diversity with respect to UDP function. Here, we give a short summary of the biochemical and physiological roles of the UDPs, which have been linked to human diseases including neurodegeneration and cancer

Population Inversion in Monolayer and Bilayer Graphene

The recent demonstration of saturable absorption and negative optical conductivity in the Terahertz range in graphene has opened up new opportunities for optoelectronic applications based on this and other low dimensional materials. Recently, population inversion across the Dirac point has been observed directly by time- and angle-resolved photoemission spectroscopy (tr-ARPES), revealing a relaxation time of only ~ 130 femtoseconds. This severely limits the applicability of single layer graphene to, for example, Terahertz light amplification. Here we use tr-ARPES to demonstrate long-lived population inversion in bilayer graphene. The effect is attributed to the small band gap found in this compound. We propose a microscopic model for these observations and speculate that an enhancement of both the pump photon energy and the pump fluence may further increase this lifetime.Comment: 18 pages, 6 figure