El juego de la red de difusión

Es difícil encontrar herramientas de aprendizaje efectivas, entretenidas, realistas y asequibles. Al intentar explicar el análisis de redes y la difusión de la innovación a los estudiantes, se me ocurrió que se podría diseñar una actividad que los estudiantes pudieran hacer en clase para aprender los principios básicos. Por eso diseñé el juego de la red de difusión, fácilmente adaptable, que es instructivo en las lecciones que enseña, y que puede llevarse a cabo de múltiples formas

Influence network linkages across implementation strategy conditions in a randomized controlled trial of two strategies for scaling up evidence-based practices in public youth-serving systems.

BackgroundGiven the importance of influence networks in the implementation of evidence-based practices and interventions, it is unclear whether such networks continue to operate as sources of information and advice when they are segmented and disrupted by randomization to different implementation strategy conditions. The present study examines the linkages across implementation strategy conditions of social influence networks of leaders of youth-serving systems in 12 California counties participating in a randomized controlled trial of community development teams (CDTs) to scale up use of an evidence-based practice.MethodsSemi-structured interviews were conducted with 38 directors, assistant directors, and program managers of county probation, mental health, and child welfare departments. A web-based survey collected additional quantitative data on information and advice networks of study participants. A mixed-methods approach to data analysis was used to create a sociometric data set (n = 176) to examine linkages between treatment and standard conditions.ResultsOf those network members who were affiliated with a county (n = 137), only 6 (4.4%) were directly connected to a member of the opposite implementation strategy condition; 19 (13.9%) were connected by two steps or fewer to a member of the opposite implementation strategy condition; 64 (46.7%) were connected by three or fewer steps to a member of the opposite implementation strategy condition. Most of the indirect steps between individuals who were in different implementation strategy conditions were connections involving a third non-county organizational entity that had an important role in the trial in keeping the implementation strategy conditions separate. When these entities were excluded, the CDT network exhibited fewer components and significantly higher betweenness centralization than did the standard condition network.ConclusionAlthough the integrity of the RCT in this instance was not compromised by study participant influence networks, RCT designs should consider how influence networks may extend beyond boundaries established by the randomization process in implementation studies.Trial registrationNCT00880126

Studies towards the biomimetic synthesis of the stephacidin family of natural products and the concise and versatile synthesis of d,l-brevianamide B, C-12A-epi-malbrancheamide and structurally related analogs

2006 Fall.Includes bibliographical references.The total synthesis of stephacidin A, avrainvillamide and stephacidin B was envisioned to proceed through a biomimetic intramolecular Diels-Alder cylcoaddition. The Diels-Alder precursor was thought to come from the coupling of (L)-prolinamide with a α-ketoacid indole, which would subsequently form the requisite azadiene. While the desired α-ketoacid indole was not stable enough to be synthetically formed, a pseudo- α-ketoacid was successfully designed. The coupling of this vinyl ether carboxylic acid indole moiety with (L)-prolinamide provides an interesting intramolecular Diels-Alder (IMDA) precursor, which might prove to be a useful synthetic prototype for the IMDA. A similar coupling between a pseudo-α-ketoacid and (L)-prolinamide was applied to a different system of compounds, which led to a biomimetically-inspired intramolecular Diels-Alder reaction that diastereoselectively formed the characteristic bicyclo[2.2.2]diazaoctane core of the brevianamides. A concise synthesis of d,l-brevianamide B was successfully designed through a Fischer indole reaction of the key tricyclic IMDA cycloadduct and phenyl hydrazine. This IMDA / Fischer indole route to form the indolic bicyclo[2.2.2]diazaoctane core has proven to be a versatile method to access C-12a-epi-malbrancheamide and structurally related analogs for biological activity studies

Bridging, brokerage and betweenness

Valente and Fujimoto (2010) proposed a measure of brokerage in networks based on Granovetter’s classic work on the strength of weak ties. Their paper identified the need for finding node-based measures of brokerage that consider the entire network structure, not just a node’s local environment. The measures they propose, aggregating the average change in cohesion for a node’s links, has several limitations. In this paper we review their method and show how the idea can be modified by using betweenness centrality as an underpinning concept. We explore the properties of the new method and provide point, normalized, and network level variations. This new approach has two advantages, first it provides a more robust means to normalize the measure to control for network size, and second, the modified measure is computationally less demanding making it applicable to larger networks

Adolescent smoking networks: The effects of influence and selection on future smoking

Submitted in fulfillment of KU faculty's Open Access Policy.Peer influence and peer selection have both been linked to the smoking behavior of adolescents. The present investigation uses social network analysis methodology to explore the simultaneous effects of both processes on adolescent smoking and smoking susceptibility over two time periods. Results suggest the effects of friendship selection in 6th grade on smoking behavior in 7th grade were primarily direct. Selecting smokers as friends in 6th grade predicted both smoking and smoking susceptibility in 7th grade, and selecting susceptibles predicted future friendship selection and peer influence. Influence processes were indirectly related to smoking. Smokers' influence in 6th grade predicts the selection of smokers as friends in 7th grade. Smokers' influence also demonstrated a protective effect when ties were not reciprocated

Current Trends in Illegal Reentry Cases

As the Immigration and Naturalization Service (INS) begins removing more and more aliens, a growing number are reentering illegally after their removal. Many of those reentering do not realize that by doing so they are committing a crime. The case law in this area is quite complex and fraught with constitutional considerations. This article provides an overview of the crime of illegal reentry under Immigration and Nationality Act (INA) § 276

Compact pixel architecture for CMOS lateral flow immunoassay readout systems

A novel pixel architecture for CMOS image sensors is presented. It uses only one amplifier for both integration of the photocurrent and in-pixel noise cancelation, thus minimizing power consumption. The circuit is specifically designed to be used in readout systems for lateral flow immunoassays. In addition a switching technique is introduced enabling the use of column correlated double sampling technique in capacitive transimpedance amplifier pixel architectures without the use of any memory cells. As a result the reset noise which is crucial in these architectures can be suppressed. The circuit has been designed in a 0.35-μm CMOS technology and simulations are presented to show its performance

The Crystal and Molecular Structure and Absolute Configuration of (—)-(\u3ci\u3eS\u3c/i\u3e)-Warfarin

The crystal and molecular structure and the absolute configuration of (—)-(S)-warfarin, C19H1604, have been determined by X-ray crystallographic techniques. Crystals of (—)-(S)-warfarin are orthorhombic, space group P212121, with a=10·883 (3), b=9·562 (3), and c=14·902 (5) Å. Solution of the structure was by direct methods, and refinement by least-squares calculations led to a conventional R of 0·053 (Mo Kα data). The molecule crystallizes as the intramolecular hemiketal and thus may be described as (2S,4S)-2,3H-2-methyl-4-phenyl-5-oxobenzopyrano[3,4-e]dihydropyran-2-ol. The absolute configuration was confirmed by recollecting with Cu Kα radiation a group of reflect ions predicted to have the greatest observable Bijvoet differences based on the anomalous scattering of oxygen and the parameters from the refinement with Mo Kα data. A group of 51 Friedel pairs, 86% of which indicate the S enantiomer, gave a 17% decrease in the residual over the R enantiomer. Refinement of the imaginary part of the anomalous dispersion of oxygen gave a value of 0·037 for Δf