2,103 research outputs found
Estimating the reproductive number, total outbreak size, and reporting rates for Zika epidemics in South and Central America
As South and Central American countries prepare for increased birth defects
from Zika virus outbreaks and plan for mitigation strategies to minimize
ongoing and future outbreaks, understanding important characteristics of Zika
outbreaks and how they vary across regions is a challenging and important
problem. We developed a mathematical model for the 2015 Zika virus outbreak
dynamics in Colombia, El Salvador, and Suriname. We fit the model to publicly
available data provided by the Pan American Health Organization, using
Approximate Bayesian Computation to estimate parameter distributions and
provide uncertainty quantification. An important model input is the at-risk
susceptible population, which can vary with a number of factors including
climate, elevation, population density, and socio-economic status. We informed
this initial condition using the highest historically reported dengue incidence
modified by the probable dengue reporting rates in the chosen countries. The
model indicated that a country-level analysis was not appropriate for Colombia.
We then estimated the basic reproduction number, or the expected number of new
human infections arising from a single infected human, to range between 4 and 6
for El Salvador and Suriname with a median of 4.3 and 5.3, respectively. We
estimated the reporting rate to be around 16% in El Salvador and 18% in
Suriname with estimated total outbreak sizes of 73,395 and 21,647 people,
respectively. The uncertainty in parameter estimates highlights a need for
research and data collection that will better constrain parameter ranges.Comment: 35 pages, 16 figure
An assessment of the sea breeze energy potential using small wind turbines in peri-urban coastal areas
From wind speed data recorded hourly at 2 m high during 18 years (1993-2010) in the Llobregat Delta (15 km south of Barcelona city; northeast of the Iberian Peninsula), wind speed distributions at 10 m high were computed for the whole year and for the sea breeze period (from March 1 to September 30, from 10 to 19 local time). Weibull probability density functions fitted to the distributions were used to assess the wind energy generated by two off-grid small wind turbines: the IT-PE-100 and the HP-600W. Results from FAST and AeroDyn simulation tools were compared with those obtained by applying measured wind speeds to manufacturer power curves. Using manufacturer data, the IT-PE-100 would deliver 132 kWh during the whole year (70 kWh during the sea breeze period). From the simulations, the IT-PE-100 would deliver 155 kWh during the whole year (80 kWh during the sea breeze period). It is concluded that the sea-breeze is an interesting wind energy resource for micro-generation, not only in the Mediterranean basin but in other areas of the world with similar wind regimes, and particularly in peri-urban coastal areas where large-scale wind farms cannot be implemented.Peer ReviewedPostprint (published version
Electric energy production with small scale wind turbines in Viladecans (Delta del Llobregat)
The objective of this project was to determine which of the two small scale wind turbines presented (IT-PE-100 and HP-600) was the most appropriate for the wind conditions of Viladecans (Delta del Llobregat). Firstly, a wind study was conducted in order to obtain the speed distribution, using Weibull probability density function, and showed a weighted average speed of 1.46 m/s. It was decided that the best way to choose one of the two turbines would be using Fast & Aerodyn simulation software, using the previously calculated wind speed distribution, to obtain the generator power curve for each case. For the IT-PE-100 model, we used already calculated Fast & Aerodyn files from other projects conducted at Universitat PolitĂšcnica de Catalunya (UPC), and only changed the wind files, to adequate the outputs to the Viladecans area. With that wind speed distribution, the software submitted a yearly income of 99.6kWh. For the HP-600, the Fast & Aerodyn files were had to be made from scratch. Since only one of the turbine blades was available for our study, it was decided to perform a 3D digitalization. That gave us a point cloud of the blade, which was converted into a CAD file using Rapidform, a reverse engineering software. With the CAD file we were able to perform a flow simulation along the blade, using SolidWorks, in order to obtain all the necessary aerodynamic parameters needed for the creation of the Fast & Aerodyn files. These files, along with the previously calculated wind speed distribution, were used as inputs in Fast & Aerodyn, which gave us a yearly income of 66kWh, which was to be expected, since this wind turbine model is thought to work at higher wind speeds. Therefore, it was concluded that the best option for the Viladecans area was the IT-PE-100 small scale wind turbine.Lâobjectiu dâaquest projecte Ă©s determinar quin dels dos aerogeneradors
proposats (
IT
-
PE
-
100
i HP
-
600) és el més apropiat per les condicions de v
ent a
Viladecans (Delta del Llobregat).
Primerament, es va dur a terme un estudi del vent, amb lâobjectiu dâobtenir la
distribuciĂł de velocitats fent servir la funciĂł de densitat de probabilitat de Weibull.
Aquesta distribuciĂł va resultar en una mitja pon
derada de velocitats de 1.46 m/s.
Es va decidir que la millor manera dâescollir una de les dues turbines seria fer
servir el software de simulaciĂł Fast & Aerodyn, fent servir com a inputs la
distribuciĂł de probabilitat del vent prĂšviament calculada, junta
ment amb arxius
de caracteritzaciĂł dels aerogeneradors, amb tal dâobtenir la corba de potĂšncia
per cada cas.
Pel model
IT
-
PE
-
100
es van fer servir arxius de Fast & Aerodyn ja generats,
extrets dâaltres projectes fets a la Universitat PolitĂšcnica de Catalu
nya (UPC).
Per tal dâadequar els resultats a lâĂ rea de Viladecans, nomĂ©s es van haver de
modificar els arxius relatius al vent. Amb aquests inputs, el software va reportar
una producciĂł energĂštica anual de 99.6kWh.
Amb el cas de lâaerogenerador HP
-
600, el
s arxius de Fast & Aerodyn van haver
de ser creats de forma Ăntegra. Degut a que nomĂ©s tenĂem a la nostra disposiciĂł
una de les pales de la turbina, es va decidir fer una digitalitzaciĂł en 3D
dâaquesta. Aquest procĂ©s ens va donar el nĂșvol de punts de la pa
la, que va ser
convertit a un arxiu de tipus CAD mitjançant el software dâenginyeria inversa
Rapidform. Important lâarxiu de CAD a SolidWorks, va ser possible fer una
simulaciĂł de flux al voltant de la pala, que ens va permetre obtenir tots els
parĂ metres
aerodinĂ mics necessaris per la creaciĂł dels inputs demanats per
Fast & Aerodyn. Aquests arxius, juntament amb la distribuciĂł de vents que va ser
calculada prĂšviament, ens van reportar una producciĂł energĂštica anual inferior
de 66.3kWh.
Per tant, es va con
cloure que la millor opciĂł per lâĂ rea de Viladecans era fer
servir lâaerogenerador
IT
-
PE
-
100
Building Capacity for Volunteerism and Social Support at Leeway, Inc., a Skilled Nursing Facility
Leeway Inc., a skilled nursing center in New Haven that cares for individuals with HIV/AIDS, was founded in 1995. Its continuum of care includes skilled nursing care, residential care, independent housing, and community case management. It provides a wide variety of care, which includes medical, behavioral, and nursing services, as well as mental health services and addiction treatment. One of Leewayâs priorities is to address the psychiatric disorders that many HIV/AIDS patients have, such as depression, anxiety, addiction, and substance-related disorders (Leeway, 2012). Among patients admitted to Leeway between October 1995 and December 1999, 25% had severe, long-term comorbid psychiatric disorders. Each year, the prevalence of psychiatric comorbid disorders has increased. Between 1996 and 1998, the prevalence of psychiatric comorbid disorders increased from 38% to 53%. This trend could be due to low discharge rates and longer lengths of stay among these individuals (Goulet, 2000). Leeway places a significant emphasis on creating a plan of care that addresses and manages these disorders (Leeway, 2012).
Some of the obstacles faced by the residents include social stigma, lack of engagement in their community, and lack of companionship. Moreover, the resident population is unique for several reasons, one of which is age. Leeway residents are younger than those at the typical nursing home facility, which introduces a variety of challenges to keep them engaged in activities. A current volunteer program has attempted to address many of these obstacles, but demonstrates the need for improvement. Residents reported differing levels of interest in both the frequency and structure of volunteer engagement. Staff also expressed the needs to balance the benefits and drawbacks of an individualized program, a âbuddyâ or more group activities facilitated by volunteers which would help increase companionship and engagement among residents. Residents also frequently expressed satisfaction with activities outside of the facility, which is one way in which the program could be expanded in the future.
Recommendations and Products: 1. Advertise the volunteer positions as âCommunity Programming Volunteersâ to boost enrollment and encourage a sense of agency and investment, 2. Hire a volunteer coordinator to serve as a point of contact, summarize feedback for staff, lead new initiatives, and perform basic administrative tasks, 3. Divide the year into three terms, and hold one orientation session at the beginning of each term, 4. Replace the ad hoc system of volunteer applications, training, and feedback with concise online platforms that automatically feed into a central system of records, 5. Create a separate but converging program structure that allows for two screening and orientation processes for regular and sporadic volunteers, 6. Create a two-part schedule for volunteer sessions: a. Matching interested residents with regular volunteers based on interests. Residents and volunteer buddies will meet for a 10-20 minute check-in with the option of joining the group activities and b. Regular and sporadic volunteers engage in a group activity or game, 7. Implement a hybrid individualized-group volunteer program structure, 8. Provide volunteers with nametags, and 9. Connect with schools and colleges throughout New Haven to access new volunteer pools.https://elischolar.library.yale.edu/ysph_pbchrr/1050/thumbnail.jp
Efectos de la variaciĂłn del contenido de la resoluciĂłn ejecutoriada en la aprobaciĂłn de liquidaciĂłn de devengados, Condevilla, 2020
La presente investigaciĂłn denominada âEfectos de la variaciĂłn del contenido de la
ResoluciĂłn Ejecutoriada en la AprobaciĂłn de LiquidaciĂłn de Devengados,
Condevilla, 2020â; tuvo como objetivo analizar si la variaciĂłn del contenido de la
ResoluciĂłn ejecutoriada, genera algĂșn efecto sobre la aprobaciĂłn de liquidaciĂłn de
devengados Condevilla, 2020.
La metodologĂa empleada en el presente estudio fue de enfoque cualitativo y de
tipo bĂĄsico, contando con un diseño de teorĂa fundamentada. Aunado a ello, se
utilizĂł como instrumentos de recolecciĂłn de datos la guĂa de entrevista y la guĂa de
anĂĄlisis documental.
La conclusiĂłn a la cual se arribĂł fue que, una resoluciĂłn ejecutoriada que obligue
al demandado al pago por de la liquidaciĂłn de pensiones devengadas, no se puede
variar, siendo este el fin del trĂĄmite civil y el inicio de la investigaciĂłn a nivel penal
por el delito de OmisiĂłn a la Asistencia Familiar; sin embargo, al realizar dicho
reajuste, recĂĄlculo o variaciĂłn del monto aprobado por el Ăłrgano judicial, durante la
aplicaciĂłn del Principio de Oportunidad, se generan determinados efectos, como la
inseguridad e inestabilidad jurĂdica, perjudicando directamente a los alimentistas
In-situ approach for thermal energy storage and thermoelectricity generation on the Moon: Modelling and simulation
Human, tele-operated rovers, and surface infrastructures are now being actively considered for lunar polar exploration. Current approaches to energy provision consider, among others, hybrid direct energy/chemical technologies, such as solar photovoltaic arrays, batteries, and regenerative fuel cells. Due to the long period of darkness on the Moon and the challenges this poses to the aforementioned conventional energy generation and storage technologies, there is a need to assess the potential of In-Situ Resources Utilization (ISRU) methods to enable or supplement long duration missions. We present a computational model (MATLAB) of a Thermal Energy Storage (TES) system coupled to drive a heat engine (Thermoelectric Generator) to produce electricity. The TES medium designed is based off processed lunar regolith, an abundant material present on the surface of the Moon. The architecture has been optimized to provide a minimum electrical power of 36âŻW per unit after 66âŻh of polar night, but the modular nature of the model allows other ranges of parameter to be simulated. A trade-off between this ISRU-based concept and conventional approaches for energy production and storage was performed and ranked TES and thermoelectricity generation as the least appropriate option. This result is valuable in a period of enthusiasm towards ISRU. It shows that processes exploiting extraterrestrial materials instead of Earth supplies are not systematically attractive. Despite the non-favorable performances for the proposed concept, some perspectives for the TES system are given as well as potential model improvements such as the need to assess the use of a Stirling heat engine
The Biosurveillance Analytics Resource Directory (BARD): Facilitating the Use of Epidemiological Models for Infectious Disease Surveillance
Epidemiological modeling for infectious disease is important for disease management and its routine implementation needs to be facilitated through better description of models in an operational context. A standardized model characterization process that allows selection or making manual comparisons of available models and their results is currently lacking. A key need is a universal framework to facilitate model description and understanding of its features. Los Alamos National Laboratory (LANL) has developed a comprehensive framework that can be used to characterize an infectious disease model in an operational context. The framework was developed through a consensus among a panel of subject matter experts. In this paper, we describe the framework, its application to model characterization, and the development of the Biosurveillance Analytics Resource Directory (BARD; http://brd.bsvgateway.org/brd/), to facilitate the rapid selection of operational models for specific infectious/communicable diseases. We offer this framework and associated database to stakeholders of the infectious disease modeling field as a tool for standardizing model description and facilitating the use of epidemiological models
Expedition 391 Preliminary Report : Walvis Ridge Hotspot: drilling Walvis Ridge, Southeast Atlantic Ocean, to test models of ridge hotspot interaction, isotopic zonation, and the hotspot reference frame
Hotspot tracks (quasilinear chains of seamounts, ridges, and other volcanic structures) provide important records of plate motions, as well as mantle geodynamics, magma flux, and mantle source compositions. The Tristan-Gough-Walvis Ridge (TGW) hotspot track, extending from the active volcanic islands of Tristan da Cunha and Gough through a province of guyots and then along Walvis Ridge to the Etendeka flood basalt province, forms one of the most prominent and complex global hotspot tracks. The TGW hotspot track displays a tight linear age progression in which ages increase from the islands to the flood basalts (covering ~135 My). Unlike Pacific tracks, which are simple chains of seamounts that are often compared to chains of pearls, the TGW track is alternately a steep-sided narrow ridge, an oceanic plateau, subparallel linear ridges and chains of seamounts, and areas of what appear to be randomly dispersed seamounts. The track displays isotopic zonation over the last ~70 My. The zonation appears near the middle of the track just before it splits into two to three chains of ridge- and guyot-type seamounts. The older ridge is also overprinted with age-progressive late-stage volcanism, which was emplaced ~30â40 My after the initial eruptions and has a distinct isotopic composition. The plan for Expedition 391 was to drill at six sites, three along Walvis Ridge and three in the seamount (guyot) province, to gather igneous rocks to better understand the formation of track edifices, the temporal and geochemical evolution of the hotspot, and the variation in paleolatitudes at which the volcanic edifices formed. After a delay of 18 days to address a shipboard outbreak of the coronavirus disease 2019 (COVID-19) virus, Expedition 391 proceeded to drill at four of the proposed sites: three sites on the eastern Walvis Ridge around Valdivia Bank, an ocean plateau within the ridge, and one site on the lower flank of a guyot in the Center track, a ridge located between the Tristan subtrack (which extends from the end of Walvis Ridge to the island of Tristan da Cunha) and the Gough subtrack (which extends from Walvis Ridge to the island of Gough). One hole was drilled at Site U1575, located on a low portion of the northeastern Walvis Ridge north of Valdivia Bank. At this location, 209.9 m of sediments and 122.4 m of igneous basement were cored. The latter comprised 10 submarine lava units consisting of pillow, lobate, sheet, and massive lava flows, the thickest of which was ~21 m. Most lavas are tholeiitic, but some alkalic basalts were recovered. A portion of the igneous succession consists of low-Ti basalts, which are unusual because they appear in the Etendeka flood basalts but have not been previously found on Walvis Ridge. Two holes were drilled at Site U1576 on the west flank of Valdivia Bank. The first hole was terminated because a bit jammed shortly after penetrating igneous basement. Hole U1576A recovered a remarkable ~380 m thick sedimentary section consisting mostly of chalk covering a nearly complete sequence from Paleocene to Late Cretaceous (Campanian). These sediments display short and long cyclic color changes that imply astronomically forced and longer term paleoenvironmental changes. The igneous basement yielded 11 submarine lava units ranging from pillows to massive flows, which have compositions varying from tholeiitic basalt to basaltic andesite, the first occurrence of this composition recovered from the TGW track. These units are separated by seven sedimentary chalk units that range in thickness from 0.1 to 11.6 m, implying a long-term interplay of sedimentation and lava eruptions. Coring at Site U1577, on the extreme eastern flank of Valdivia Bank, penetrated a 154 m thick sedimentary section, the bottom ~108 m of which is MaastrichtianâCampanian (possibly Santonian) chalk with vitric tephra layers. Igneous basement coring progressed only 39.1 m below the sediment-basalt contact, recovering three massive submarine tholeiite basalt lava flows that are 4.1, 15.5, and >19.1 m thick, respectively. Paleomagnetic data from Sites U1577 and U1576 indicate that their volcanic basements formed just before the end of the Cretaceous Normal Superchron and during Chron 33r, shortly afterward, respectively. Biostratigraphic and paleomagnetic data suggest an eastâwest age progression across Valdivia Bank, becoming younger westward. Site U1578, located on a Center track guyot, provided a long and varied igneous section. After coring through 184.3 m of pelagic carbonate sediments mainly consisting of Eocene and Paleocene chalk, Hole U1578A cored 302.1 m of igneous basement. Basement lavas are largely pillows but are interspersed with sheet and massive flows. Lava compositions are mostly alkalic basalts with some hawaiite. Several intervals contain abundant olivine, and some of the pillow stacks consist of basalt with remarkably high Ti content. The igneous sequence is interrupted by 10 sedimentary interbeds consisting of chalk and volcaniclastics and ranging in thickness from 0.46 to 10.19 m. Paleomagnetic data display a change in basement magnetic polarity ~100 m above the base of the hole. Combining magnetic stratigraphy with biostratigraphic data, the igneous section is inferred to span >1 My. Abundant glass from pillow lava margins was recovered at Sites U1575, U1576, and U1578. Although the igneous penetration was only two-thirds of the planned amount, drilling during Expedition 391 obtained samples that clearly will lead to a deeper understanding of the evolution of the Tristan-Gough hotspot and its track. Relatively fresh basalts with good recovery will provide ample samples for geochemical, geochronologic, and paleomagnetic studies. Good recovery of Late Cretaceous and early Cenozoic chalk successions provides samples for paleoenvironmental study
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
GRB 081007 AND GRB 090424: THE SURROUNDING MEDIUM, OUTFLOWS, AND SUPERNOVAE
We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 09042We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 090424, two bursts detected by Swift. One of them, GRB 081007, also shows a spectroscopically confirmed supernova, SN 2008hw, which resembles SN 1998bw in its absorption features, while the maximum magnitude may be fainter, up to 0.7 mag, than observed in SN 1998bw. Bright optical flashes have been detected in both events, which allows us to derive solid constraints on the circumburst-matter density profile. This is particularly interesting in the case of GRB081007, whose afterglow is found to be propagating into a constant-density medium, yielding yet another example of a gamma-ray burst (GRB) clearly associated with a massive star progenitor which did not sculpt the surroundings with its stellar wind. There is no supernova component detected in the afterglow of GRB090424, likely because of the brightness of the host galaxy, comparable to the Milky Way. We show that the afterglow data are consistent with the presence of both forward- and reverse-shock emission powered by relativistic outflows expanding into the interstellar medium. The absence of optical peaks due to the forward shock strongly suggests that the reverse-shock regions should be mildly magnetized. The initial Lorentz factor of outflow of GRB081007 is estimated to be ?? ~ 200, while for GRB090424 a lower limit of ?? > 170 is derived. We also discuss the prompt emission of GRB081007, which consists of just a single pulse. We argue that neither the external forward-shock model nor the shock-breakout model can account for the prompt emission data and suggest that the single-pulse-like prompt emission may be due to magnetic energy dissipation of a Poynting-flux-dominated outflow or to a dissipative photosphere
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