Diffusion of Competing Innovations: The Effects of Network Structure on the Provision of Healthcare

Medical innovations, in the form of new medication or other clinical practices, evolve and spread through health care systems, impacting on the quality and standards of health care provision, which is demonstrably heterogeneous by geography. Our aim is to investigate the potential for the diffusion of innovation to influence health inequality and overall levels of recommended care. We extend existing diffusion of innovation models to produce agent-based simulations that mimic population-wide adoption of new practices by doctors within a network of influence. Using a computational model of network construction in lieu of empirical data about a network, we simulate the diffusion of competing innovations as they enter and proliferate through a state system comprising 24 geo-political regions, 216 facilities and over 77,000 individuals. Results show that stronger clustering within hospitals or geo-political regions is associated with slower adoption amongst smaller and rural facilities. Results of repeated simulation show how the nature of uptake and competition can contribute to low average levels of recommended care within a system that relies on diffusive adoption. We conclude that an increased disparity in adoption rates is associated with high levels of clustering in the network, and the social phenomena of competitive diffusion of innovation potentially contributes to low levels of recommended care.Innovation Diffusion, Scale-Free Networks, Health Policy, Agent-Based Modelling

Energy from waste: reuse of compost heat as a source of renewable energy

An in-vessel tunnel composting facility in Scotland was used to investigate the potential for collection and reuse of compost heat as a source of renewable energy. The amount of energy offered by the compost was calculated and seasonal variations analysed. A heat exchanger was designed in order to collect and transfer the heat. This allowed heated water of 47.3oC to be obtained. The temperature could be further increased to above 60oC by passing it through multiple tunnels in series. Estimated costs for installing and running the system were calculated. In order to analyse these costs alternative solar thermal and ground source heat pump systems were also designed. The levels of supply and economic performance were then compared. A capital cost of £11,662 and operating cost of £1,039 per year were estimated, resulting in a cost of £0.50 per kWh for domestic water and £0.10 per kWh for spatial heat. Using the heat of the compost was found to provide the most reliable level of supply at a similar price to its rivals

Modes of Information Flow

Information flow between components of a system takes many forms and is key to understanding the organization and functioning of large-scale, complex systems. We demonstrate three modalities of information flow from time series X to time series Y. Intrinsic information flow exists when the past of X is individually predictive of the present of Y, independent of Y's past; this is most commonly considered information flow. Shared information flow exists when X's past is predictive of Y's present in the same manner as Y's past; this occurs due to synchronization or common driving, for example. Finally, synergistic information flow occurs when neither X's nor Y's pasts are predictive of Y's present on their own, but taken together they are. The two most broadly-employed information-theoretic methods of quantifying information flow---time-delayed mutual information and transfer entropy---are both sensitive to a pair of these modalities: time-delayed mutual information to both intrinsic and shared flow, and transfer entropy to both intrinsic and synergistic flow. To quantify each mode individually we introduce our cryptographic flow ansatz, positing that intrinsic flow is synonymous with secret key agreement between X and Y. Based on this, we employ an easily-computed secret-key-agreement bound---intrinsic mutual information&mdashto quantify the three flow modalities in a variety of systems including asymmetric flows and financial markets.Comment: 11 pages; 10 figures; http://csc.ucdavis.edu/~cmg/compmech/pubs/ite.ht

Variabilidad polínica del género Agrostis en la Península Ibérica

Se estudian l os caracteres polínicos de 33 poblaciones pertenecientes a 8 especies del género Agrostis L. (Poaceae ) a microscopía óptica y electrónica de barrido . Se utilizan métodos estadísticos poniendo de manifiesto la vari abilidad de los parámetros P, E y RA , y se exponen l as diferencias exínicas de l as disti ntas espec i esThe pollen char acters for 33 populations of 8 species from the Iberi.an Península belonging to Agrostis L. ( Poaceae ) were examined both i n light microscopy and scanning e l ectron microscopy . The use of stadist i cal methods s hows the variabili ty of the P, E and RA parameters and the exine diferences between the species are show

Estudios taxonómicos en el género Salvia L., secciones Salvia y Aethiopis Bentham: palinología

Utilizando microscopía óptica y microscopio electrónico de barrido se han estudiado los caracteres polinices de 31 poblaciones de 6 especies, 8 subespecies y 3 variedades de la Península Ibér ic ~ y Norte de Africa pertenecientes a Salvia L. sect . Salvia y sect. Aethiopis Bentham. Se ha observado que este género , como l a mayoría de la fami l ia Lamiaceae es estenopal ino, no obstante, los caracteres de la exina permiten diferenciar parcialmente ambas seccionesThe pollen characters of 6 species , 8 subspecies and 3 varieties from 31 populat ions belonging to Salvia L. sect. Sal via and sect. Aethiopis Bentharn from t he Iberian Peninsula and N Africa, were examined both wi th light and scanni ng electron micrqscopy . The resul ts show that t he genus, like the most of the family Larniaceae, is stenopalynous . However , sexine characters can be used to dis t inguish each section

Estudio palinológico del género Scorzonera L. (Asteraceace) en la Península Ibérica

Se estudian 72 poblaciones pertenecientes a 10 especies del género Scorzonera L. representadas en la Península Ibéri ca , tanto al microscopio óptico como al microscopio electrónico de barrido, poniéndose de manifiesto la variación cuant i tativa de ciertos parámetros escogidos , así como el polimor fismo morfológi co. Se confecciona una c l ave de determinación para las especies, atendiendo a sus caracteres polínicos72 popu lations of 10 species of genus Scorzoner a L. from the Iberian Peninsula , have been studied, both in light microscopy and in scanning electron microscopy . These resul ts demonstrate the quanti tati ve variation of' the· measurements se l ected as wel l as the morphologi cal polymorphism . A key using pollen characters has be en mad

Análisis florístico de las sierras de María y Orce (provincias de Almería y Granada, España)

11 páginas, 4 tablas y 3 figuras[EN]We carried out a floristic analysis of the María and Orce mountain ranges, situated in the north of Almería and Granada provinces, respectively, in a región of continentalized climate with a climatic irregularity of 37.5%. The biological spectrum was compared with other peninsular and north african áreas. Being a montane zone, the dominant biotype is hemicryptophytic, but a relatively high proportion of therophytes is also present, which indicates a southeast semiarid peninsular influence. Data obtained from analysis of floristic elements present (mediterranean, 51 %; iberian, 18.5 %; ibero-northafrican, 10.3 %; etc.) allow these mountain ranges to be characterized as an área of conjunction between diverse floras, specifically betic (central and eastern andalusian), eastern peninsular (taxa of the southeastern and eastern peninsular regions which may also be present in the central or southern peninsular regions), and Murcia-Almerian (southeast semiarid). The área possesses 6 local endemics: Brassica repanda (Willd.) DC. subsp. almeriensis Gómez-Campo, Nepeta hispanica Boiss. & Reuter in Boiss, subsp. hispanica, Sideritis stachydioidesV/iWk., Sideritis x sagredoi O. Socorro, J. Molero, M. Casares & F. Pérez Raya, Centaurea mariana Nyman and Centaurea Xpüfontiana Fernández Casas & Susanna. The distribution of taxa in bioclimatic belts was also studied. There was a predominance of those taxa which occur in both the mesomediterranean and the supramediterranean. Analysis of the degree of conservation of the flora according to the categories of the IUCN (25.7 % of the flora was found to be threatened to a certain degree) indicates that 85.7 % of threatened taxa are present in the supra- and oromediterranean. Lastly, we give the distribution of floristic elements according to the bioclimatic belts, noting that the endemics of most limited range are present in the summit zones, with the exception of the Almenan endemics, whose área of distribution is the basal belt of the semiarid Murcia-Almerian región.[ES]La idea de evaluar la importancia de las áreas naturales, bien sea para su conservación o para otros fines, ha evolucionado en época reciente y ha encontrado una amplia aplicación (MARGULES & USHER, 1981; GOLDSMITH, 1983). La evaluación de áreas naturales implica factores subjetivos y objetivos que, a menudo, no pueden separarse fácilmente (ROOME, 1984). SMITH & THEBERGE (1986) analizaron los criterios usados en 22 sistemas de evaluación, encontrando que los más utilizados son los de rareza y singularidad, seguidos del de diversidad. En este trabajo se realiza un análisis florístico de las sierras de María y Orce, tomando como base el estudio de CUETO (1989). Dichas sierras están situadas al norte de las provincias de Almería y Granada, respectivamente; constituyen un núcleo montano con una altura media de 1326 m, que alcanza los 2045 m de altitud en el pico María. Ocupan un área virtual sobre el plano de 202,14 km2. Por su situación geográfica, presentan un clima continental, que se suaviza algo en las vertientes sur, como consecuencia de la influencia del Mediterráneo. La irregularidad climática es del 37,5% (MONTERO & GONZÁLEZ REBOLLAR, 1983); esto favorece la existencia de una flora rica y variada, puesto que los cambios de clima propician la presencia de táxones que se desarrollan dentro de límites climáticos muy diversos. Las precipitaciones anuales en la zona oscilan entre los 340 y los 640 mm; las mínimas se presentan en el extremo noroccidental del área, lo cual indica la influencia de la depresión de Orce, mientras que las máximas se recogen en las cotas superiores de la Sierra de María. Las temperaturas medias anuales se sitúan entre los 7 °C de las cumbres de la Sierra de Maria y los 12 °C que se alcanzan en el extremo noroccidental y en las zonas bajas de la vertiente sur de ambas sierras.Estación Experimental de Zonas Áridas, C.S.I.C. General Segura, 1.04001 Almería. Departamento de Biología Vegetal, Facultad de Ciencias. Fuentenueva, s/n. 18001 Granada. Centro de Ciencias Medioambientales, C.S.I.C. Serrano, 115 duplicado. 28006 Madrid.Peer reviewe

Phlebotominae Sand Flies in Paraguay. Abundance Distribution in the Southeastern Region

From September 1993 to August 2001, 7,190 phlebotomine were collected with CDC light trap in an endemic area for human leishmaniasis, in the departments of Misiones and Itapúa, Paraguay. Eleven species were identified: Lutzomyia neivai (93.7%), L. whitmani (4.1%), and L. fischeri, L. shannoni, L. migonei, L. misionensis, L. cortelezzii, L. pessoai, L. alphabetica, Brumptomyia avellari and B. guimaraesi (less than 1%). The last three species are new records for the country. The biodiversity and phlebotomine abundance were associated with the proximity to primary forest or gallery forest, but L. neivai was also found in peridomestic periurban environment. L. neivai was found throughout the year, and showed a period of higher activity from September to April (spring to fall) with a unimodal or bimodal pattern in relation to the annual rainy peaks during the summer. Background literature about phlebotomine from Paraguay has been reviewed.Fil: Salomón, Oscar Daniel. Ministerio de Salud de la Nación; ArgentinaFil: Rossi, Gustavo Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Cousiño, Blanca. Instituto de Investigaciones en Ciencias de la Salud; ParaguayFil: Spinelli, Gustavo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Limnología ; ArgentinaFil: Rojas de Arias, Antonieta. Instituto de Investigaciones en Ciencias de la Salud; ParaguayFil: López de Puerto, Delfin G.. Instituto de Investigaciones en Ciencias de la Salud; ParaguayFil: Ortiz, Arnaldo J.. Instituto de Investigaciones en Ciencias de la Salud; Paragua

Low-Income Engineering Students: Considering Financial Aid and Differential Tuition

This paper explores the relationship between tuition differentials and low-income students in Engineering fields at two public, research intensive universities. Although current reports indicate the need for increased participation within the Science, Technology, Engineering, and Mathematics (STEM) fields, rising tuition prices at the university and program levels may deter low-income students to enroll and persist within STEM, specifically Engineering. The findings reveal that increased costs due to tuition differentials policies are initially offset by financial aid, but over time costs increase, particularly for low-income students. The results highlight the need for comprehensive, time-sensitive financial aid packages that provide students opportunities to complete their postsecondary degrees, particularly in fields with higher tuition rates