Millimeter Wave Communications

Millimeter wave (mmWave) technologies promise to revolutionize wireless networks by enabling multi-gigabit data rates. However, they suffer from high attenuation, and hence have to use highly directional antennas to focus their power on the receiver. Existing radios have to scan the space to find the best alignment between the transmitter’s and receiver’s beams, a process that takes up to a few seconds. This delay is problematic in a network setting where the base station needs to quickly switch between users and accommodate mobile clients. We present Agile-Link, the first mmWave beam steering system that is demonstrated to find the correct beam alignment without scanning the space. Instead of scanning, Agile- Link hashes the beam directions using a few carefully chosen hash functions. It then identifies the correct alignment by tracking how the energy changes across different hash functions. Our results show that Agile-Link reduces beam steering delay by orders of magnitude.National Science Foundation (U.S.

Achieving Successful Long-Term Recovery and Safety from a Catastrophe: The Federal Role

Our task, reflected in this report, was to assess the government’s role in achieving long-term, safe recovery of the Gulf coast communities from the catastrophic disaster of Hurricanes Katrina and Rita in the early fall of 2005. The focus is on its catastrophic nature and the ability of our society to deal with such. This report offers our analysis with a focus on the federal government, per the national policy interests of the Ford Foundation. A companion book from the research is under preparation; it will consider the same question with the state and local government focus added to the federal response

Molecular characterization of Prototheca strains isolated from Italian dairy herds.

One hundred sixty-one Prototheca spp. strains isolated from composite milk and barn-surrounding environmental samples (bedding, feces, drinking, or washing water, surface swabs) of 24 Italian dairy herds were characterized by genotype-specific PCR analysis. Overall, 97.2% of strains isolated from composite milk samples were characterized as Prototheca zopfii genotype 2, confirming its role as the main mastitis pathogen, whereas Prototheca blaschkeae was only sporadically isolated (2.8%). Regarding environmental sampling, 84.9% of isolates belonged to P. zopfii genotype 2, 13.2% to P. blaschkeae, and 1.9% to P. zopfii genotype 1. The data herein contradict previous hypotheses about the supposed exclusive role of P. zopfii genotype 2 as the causative agent of protothecal mastitis and, on the contrary, confirm the hypothesis that such pathology could be caused by P. blaschkeae in a few instances

Neural development features: Spatio-temporal development of the Caenorhabditis elegans neuronal network

The nematode Caenorhabditis elegans, with information on neural connectivity, three-dimensional position and cell linage provides a unique system for understanding the development of neural networks. Although C. elegans has been widely studied in the past, we present the first statistical study from a developmental perspective, with findings that raise interesting suggestions on the establishment of long-distance connections and network hubs. Here, we analyze the neuro-development for temporal and spatial features, using birth times of neurons and their three-dimensional positions. Comparisons of growth in C. elegans with random spatial network growth highlight two findings relevant to neural network development. First, most neurons which are linked by long-distance connections are born around the same time and early on, suggesting the possibility of early contact or interaction between connected neurons during development. Second, early-born neurons are more highly connected (tendency to form hubs) than later born neurons. This indicates that the longer time frame available to them might underlie high connectivity. Both outcomes are not observed for random connection formation. The study finds that around one-third of electrically coupled long-range connections are late forming, raising the question of what mechanisms are involved in ensuring their accuracy, particularly in light of the extremely invariant connectivity observed in C. elegans. In conclusion, the sequence of neural network development highlights the possibility of early contact or interaction in securing long-distance and high-degree connectivity

Evaluación del consumo eléctrico en el sector residencial de Mar del Plata : Aspectos económicos y ambientales

Este trabajo es continuación del trabajo presentado en AS ADES 2012 donde se analizó el consumo de energía eléctrica en el sector residencial de la ciudad de Mar del Plata a través de una encuesta y análisis de la facturación de electricidad. Esto permitió diagnosticar la situación y seleccionar las estrategias de ahorro más adecuadas. En este trabajo se realiza un análisis económico comparando la situación actual con una futura que supone reemplazar las lámparas actualmente utilizadas en las viviendas encuestadas por la tecnología LED, el impacto ambiental que representa desechar las lámparas utilizadas en una vivienda a la basura y cuál sería el beneficio si se las dispusiera adecuadamente, así como también el CO2 que se evitaría enviar a la atmósfera.This paper is a continuation of work presented in ASADES 2012 which analyzed the energy consumption in the residential sector of the city of Mar del Plata through a survey and analysis of electricity billing. This allowed diagnose the situation and select the most appropriate savings strategies. In this paper an economic analysis comparing the current situation with a future that involves replacing the lamps currently used in the houses surveyed by LED technology, the environmental impact is disposing of lamps used in a home in the trash and what the benefit if properly willed them and also avoid sending CO2 into the atmosphere.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Interfaz de monitoreo de un sistema fotovoltaico conectado a la red

En este trabajo se describe la implementación de una interfaz de monitoreo de un sistema foto voltaico conectado a la red desarrollado mediante LabVIEW 8.2, en el marco del proyecto IRESUD, implementado en la Facultad de Ingeniería de la ciudad de Mar del Plata. Tiene como objetivo ser utilizada para investigación, formación de recursos humanos, y disparador de inquietudes medioambientales relacionadas con la generación y uso de la energía eléctrica en el ámbito universitario y en la comunidad local. El sistema de adquisición consiste en un analizador de calidad de energía PQube comunicado o una computadora personal mediante Ethernet a través del protocolo Modbus TCP. El uso de las librerías Modbus y las herramientas de Web Server disponibles, permitieron generar fácilmente una aplicación web para mostrar en tiempo real las principales variables eléctricas de la instalación fotovoltaica. Dada su versatilidad el sistema puede ser replicable a otras instituciones.In this work the implementation of a monitoring interface of a networked PV system developed by LabVIEW 8.2, IRESUD under the project, implemented in the Faculty of Engineering of the city of Mar del Plata is disclosed. It aims to be used for research, training of human resources, and trigger environmental concerns related to the generation and use of electricity in the university and the local community. The acquisition system consists of a PQube power quality analyzer connected to PC via Ethernet Modbus TCP protocol. Using the Modbus libraries and tools available Web Server, allow easily generate a web application to display in real time the main electrical variables of the PV system. Given its versatility verified that the system can be replicated in other institutions.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

The EpsE Flagellar Clutch Is Bifunctional and Synergizes with EPS Biosynthesis to Promote Bacillus subtilis Biofilm Formation

Many bacteria inhibit motility concomitant with the synthesis of an extracellular polysaccharide matrix and the formation of biofilm aggregates. In Bacillus subtilis biofilms, motility is inhibited by EpsE, which acts as a clutch on the flagella rotor to inhibit motility, and which is encoded within the 15 gene eps operon required for EPS production. EpsE shows sequence similarity to the glycosyltransferase family of enzymes, and we demonstrate that the conserved active site motif is required for EPS biosynthesis. We also screen for residues specifically required for either clutch or enzymatic activity and demonstrate that the two functions are genetically separable. Finally, we show that, whereas EPS synthesis activity is dominant for biofilm formation, both functions of EpsE synergize to stabilize cell aggregates and relieve selective pressure to abolish motility by genetic mutation. Thus, the transition from motility to biofilm formation may be governed by a single bifunctional enzyme

The Spatial Architecture of Bacillus subtilis Biofilms Deciphered Using a Surface-Associated Model and In Situ Imaging

The formation of multicellular communities known as biofilms is the part of bacterial life cycle in which bacteria display cooperative behaviour and differentiated phenotypes leading to specific functions. Bacillus subtilis is a Gram-positive bacterium that has served for a decade as a model to study the molecular pathways that control biofilm formation. Most of the data on B. subtilis biofilms have come from studies on the formation of pellicles at the air-liquid interface, or on the complex macrocolonies that develop on semi-solid nutritive agar. Here, using confocal laser scanning microcopy, we show that B. subtilis strains of different origins are capable of forming biofilms on immersed surfaces with dramatically protruding “beanstalk-like” structures with certain strains. Indeed, these structures can reach a height of more than 300 µm with one undomesticated strain from a medical environment. Using 14 GFP-labeled mutants previously described as affecting pellicle or complex colony formation, we have identified four genes whose inactivation significantly impeded immersed biofilm development, and one mutation triggering hyperbiofilm formation. We also identified mutations causing the three-dimensional architecture of the biofilm to be altered. Taken together, our results reveal that B. subtilis is able to form specific biofilm features on immersed surfaces, and that the development of these multicellular surface-associated communities involves regulation pathways that are common to those governing the formation of pellicle and/or complex colonies, and also some specific mechanisms. Finally, we propose the submerged surface-associated biofilm as another relevant model for the study of B. subtilis multicellular communities

Puesta en marcha y estudio de la operación en campo de microinversores de potencia para aplicaciones fotovoltaicas

En este trabajo se estudia el sistema asociado a la operación y monitoreo de dos micro-inversores de potencia, desarrollados por el Laboratorio de Instrumentación y Control de la Universidad Nacional de Mar del Plata y Lytron SA. Cada microinversor inyecta a la red la energía generada por un panel fotovoltaico de 290 Wp. Ambos paneles, cada uno con su respectivo micro-inversor, se encuentran emplazados en la azotea de la Facultad. Además, se realiza una comparativa del desempeño de los micro-inversores individuales frente al de inversores de mayor potencia que inyectan actualmente la energía generada por arreglos de 6 paneles fotovoltaicos de las mismas características. Los mismos forman parte de la planta piloto de la Facultad, que integra el proyecto IRESUD. Se describe el tratamiento de los datos de irradiancia a fin de estimar el recurso solar en el plano de los paneles fotovoltaicos. Se presentan los datos de recurso y producción obtenidos durante tres semanas en el mes de abril. Luego, se toman como objeto de comparación dos días típicos, uno nublado y el otro soleado, relevando curvas de recurso y producción de los sistemas solares bajo estudio. Finalmente, se concluye que este tipo de inversores tiene un rendimiento aproximado al de los inversores convencionales, dejando en evidencia que el precio por unidad de potencia sería el factor determinante al momento de la elección del inversor que adoptará un sistema fotovoltaico.This paper studies the system involved in the operation and monitoring of two micro-inverters, developed by the Laboratorio de Instrumentación y Control of the Facultad de Ingeniería of the Universidad Nacional de Mar del Plata and Lytron SA. Each micro-inverter delivers to the grid the power generated by single photovoltaic panels with 290 Wp. Both, panels and micro-inverters, are settled in the roof of the building of the engineering school. Also, a comparison is made of the performance between individual inverters with others of higher power, of which the latter are injecting power from arrays of six identical photovoltaic panels. They are part of the photovoltaic solar plant of the engineering school, integrating the IRESUD project. Is described the data treatment of solar irradiance which aim to estimate the solar resource in the tilted plane of the panels. Resource and production data from three weeks of April are shown. Then, two typical days, one cloudy and one sunny, are taken as object of comparison displaying trends of resource and production from the solar systems under study. Finally, it is concluded that this type of inverters has an approximate performance to conventional inverters, manifesting that the price per watt peak unit would be the main factor for choosing the inverter which makes up a photovoltaic system.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism