bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of HVAC system runtime due to occupancy-controlled smart thermostats in contemporary multi-unit residential building suites
Authors: Stopps H , Touchie M F
Published: October 2019

Previous studies in single family homes have demonstrated a reduction in space conditioning energy demand through the use of occupancy-controlled smart thermostats. This technology has the potential to reduce space conditioning demand in multi-unit residential buildings (MURBs) as well, however no previous studies have tested the performance of smart thermostats in this building type. Field data were collected from 56 thermostats installed in two condominium buildings located in Toronto, Canada. Thermostats installed in each suite were operated using through three different control scenarios during the monitoring period: 1) a baseline scenario, where the thermostat is operated as a standard programmable thermostat, 2) an occupancy-based control scenario, and 3) a load-shifting control scenario. Baseline runtime data collected while the thermostats were operated as a standard programmable thermostat was used in combination with weather data and a supervised learning regression algorithm (Random Forest) to estimate the baseline runtime for each suite on days that the occupancy-based control strategy was running. When the estimated baseline runtime derived from the regression model was compared with the actual system runtime while the occupancy-based control strategy is running, an average reduction in suite HVAC system runtime of 17% was found.
Microstructure and blowing agent concentration analysis in accelerated aged polyurethane & polyisocyanurate insulation
Authors: Jelena Madzarevic , Umberto Berardi
Published: October 2019

Some closed cell foam insulation products show an increase in thermal conductivity at low temperatures. This reduction in thermal performance has been attributed to the diffusion of air and blowing agent through the foam and to the condensation of the blowing agent. Aging processes and polymer degradation further increase the thermal conductivity of foams. The initial cell structure plays a role in dictating the thermal performance and changes with foam aging which is rarely investigated. To understand the loss of thermal performance in closed cell foams, a microstructure and chemical characterization of pristine and aged samples was performed in this study. The aging behaviour was analyzed by SEM imaging and by measuring the blowing agent concentration in the foam. Changes in the polymer physical attributes were identified. This study also used gas chromatography and quantified changes in pentane concentration in aged polyisocyanurate foams. Results show that aged foams undergo change in their polymer appearance and cellular elongation. Gas chromatography quantified a decrease in blowing agent in the range of 11-85% for polyisocyanurate foams after aging.
Smart heat storage building material development with Loess and SSPCM for building energy saving
Authors: Yang Sungwoong , Park Ji Hun , Wi Seunghwan , Lee Jongki , Yun Beom Yeol , Kim Sumin
Published: October 2019

This experiment aimed at the development of energy efficient and sustainable building materials. The specimens were made using loess, styrene butadiene latex (SBL), shape stable phase change material (SSPCM) made from x-GnP and n-octadecane for mechanical and thermal performance improvement. Compressive strength test, FT-IR (Fourier-transform infrared spectroscopy) and dynamic thermal transfer experiment were performed. From the result of the compressive strength test, it was found that the addition of SBL increases the compressive strength and the addition of SSPCM reduces the compressive strength. FT-IR analysis revealed no chemical reaction between PCM and x-GnP, indicating only physical binding. As a result of the dynamic heat transfer analysis, peak temperature reduction was observed. According to energy analysis, storage capacity energy was improved and PCM 7.5 was the most energy efficient.
Development and performance evaluation of natural building materials with pyrolyzed agricultural by-products for carbon reduction and energy saving
Authors: Yang Sungwoong , Park Ji Hun , Wi Seunghwan , Lee Jongki , Yun Beom Yeol , Kim Sumin
Published: October 2019

Hwangtoh (Korean red clay) and Biochar were used to develop building materials for sustainable and energy-efficient buildings and propose environmentally and thermally superior materials. Rice husk, coconut shell, and bamboo were made of biochar through pyrolysis with complete oxygen limitation. The compressive strength test was carried out to analyze the thermal performance and the mechanical performance, and the thermal conductivity measurement was conducted in order to derive the physical property information for the thermal performance of the material. The microporous structure affecting the thermal conductivity and mechanical performance. Through the dynamic heat transfer experiment, the temperature changes of the biochar mixed specimens in the same heating environment were analyzed. Comprehensive considerations have shown that bamboo biochar is replaced by 10% by weight.
Energy consumption, thermal comfort and load match: study of a monitored nearly Zero Energy Building in Mediterranean climate
Authors: Erba Silvia , Pagliano Lorenzo , Charani Shandiz Saeid , Pietrobon Marco
Published: October 2019

Several definitions of Zero Energy Buildings (ZEB) exist in literature and different implementations of the term can be found in National laws/regulations. The differences among the Member States in nomenclature and definition of the main indicators often lead to incomparable results and difficulties in transfer and diffusion of technologies across the EU. The paper aims to investigate the topic of ZEB by clarifying the meaning of nearly ZEB and Net ZEB through the application of the definitions in a case study of a high-performance building (certified Passivhaus) located in Sicily, Italy. The house fulfils the requirements of nearly ZEB, according to Italian legislation, and satisfies the Net ZEB’s yearly balance between imported and exported energy. However, the use of shorter calculation time periods highlights the presence of a relatively large mismatch between the time of use and of renewable generation. Finally, the results of the thermal comfort analysis show the achievement of adaptive thermal comfort in summer thanks to the passive features of the building (mass, external thermal insulation, solar protections) and passive techniques for heat removal (night ventilation and ground exchange).
Green roof for zero energy buildings: a pilot project
Authors: Asdrubali Francesco , Evangelisti Luca , Guattari Claudia
Published: October 2019

Zero Energy Buildings (ZEBs) and nearly Zero Energy Buildings (nZEBs) can be designed from scratch or they can be obtained after deep refurbishments of existing constructions. Both passive and active strategies are fundamental to achieve the ZEB or nZEB target. According to this, among passive systems, green roofs can be a viable solution because they allow to achieve energy savings, also reducing the urban heat island phenomenon. In this research, an innovative roof-lawn system was preliminary analyzed by installing several measurement instruments for obtaining information about thermal heat exchanges. Heat-flow meters, surface temperature and air temperature probes were installed, comparing the performance of the roof-lawn system with a nearby simple old roof, in order to quantify the two different behaviors from a thermal point of view.

The roof-lawn system revealed its advantages, showing a higher thermal inertia with no overheating and a lower thermal transmittance, as well as better indoor conditions for the occupants of the building. The study is the first step of a path which aims to design a more complex and complete system, also considering the structural part of the roof.
Assessment of technical-financial analysis of a zero energy building for Brazilian hot and temperate tropical climate
Authors: Domingos R M A , Gabriel E , Guarda E L A , Pereira F O R
Published: October 2019

The growing concern about energy consumption and environmental resources has led to research on sustainable approaches in construction. Efficient buildings have been built not only to attract new investments but also to take environmental considerations into account. Zero Energy Buildings; use a variety of passive strategies for energy efficiency and to decrease the use of heating, ventilation and air conditioning. These techniques impact directly on cost benefit and energy performance. The objective of this research is to identify efficient approaches for housing, considering the influence of climate, the energy generation, for two Brazilian cities. The cities climates area classified as Af (tropical climate) and Cfb (hot and temperate). The methodological procedures were divided into three stages: simulation to determine energy consumption in the efficient building; estimation of the balance between electric demand and generation by means of a building-integrated photovoltaics (BIPV); assessment of the life cycle cost of the net present value of BIPV. The results show that for the tropical climate the payback is 6.75 years and Internal Rate of Return (IRR) of 15.06% and for the temperate, payback is 10.25 years and IRR of 8.49%. These outcomes demonstrate that in hot climate payback happens in less time, due to the high incidence of solar radiation in the year.
Performance comparison between building insulating materials made of straw bales and EPS for timber walls
Authors: Evola Gianpiero , Cascone Stefano , Sciuto Gaetano , Parisi Chiara Baroetto
Published: October 2019

This paper studies the thermal and acoustic performance of straw bale walls used in timber-frame semi-detached houses recently built in Sicily (Southern Italy), and compares them to similar walls where expanded polystyrene (EPS) is adopted in place of the straw bales. In-situ measurements were carried out to analyse the acoustic performance of both wall typologies. The weighted Apparent Sound Reduction Index for the partition wall between two houses, as well as the weighted Standardized Level Difference for the façades were assessed based on the ISO Standards 16283. Moreover, the two insulating solutions were compared in relation to their steady and dynamic thermal performance. The results underline that the acoustic performance of the straw bale walls is far better than the walls adopting traditional EPS insulation. However, slight improvements are suggested to further increase the sound insulation properties of straw bales. On the other hand, EPS is a more effective thermal insulation even if straw bale walls comply with Italian standards. Finally, the dynamic performance of straw bales should be improved by increasing their density. Overall, the proposed straw bales used can be conveniently used in low-energy and n-ZEB buildings in warm and mild countries.
Dynamic simulation of cross-ventilated buildings with night-flush cooling in neighbourhood environment using integrated CFD-CFD-BES strategy
Authors: Zhang Ruijun , Mirzaei Parham A , Jones Benjamin M
Published: October 2019

Night flush cooling is an effective passive strategy to condition spaces and provide larger capacity to store heat. A common technique to quantify the benefit from this cooling strategy is using building energy simulation (BES) modelling, which, however, is weak in capturing the airflow patterns and convective heat transfer under the complex urban contexts. Therefore, dynamic coupling techniques of BES to computational fluid dynamics (CFD) are often used to improve the simulation performance of the night flush cooling strategies.

Nonetheless, dynamic coupling techniques always encounter a high computational cost to achieve accurate CFD calculations for naturally ventilated scenarios, as high-resolution grids are required to be prepared. Therefore, a framework of integration of a fine-resolution CFD grid (CFDf), a coarse-resolution CFD grid (CFDc) and BES is proposed in this work to study night-flush cooling. In this framework, the CFDf domain performs as the off-line module that generates the boundary conditions for the CFDc domain at its openings before the start of the iterative calculations. CFDc and BES domains are then performing a fully dynamic external coupling to achieve a convergence for the energy simulation using the updated convective heat transfer coefficient (CHTC) profiles at the exterior surfaces. A case study is investigated for a simple urban morphology in Los Angeles on a typical hot day. The results highlight an improvement in representation of the neighbourhood effect in energy calculations obtained in a feasible calculation run-time.
Occupant behaviour: a major issue for building energy performance
Authors: Laaroussi Y , Bahrar M , Elmankibi M , Draoui A , Si-Larbi A
Published: October 2019

The building sector in the world is responsible for nearly 36% of the final energy consumption and nearly 40% of total direct and indirect CO2 emissions. One of the most efficient strategies to reduce the energy consumption in buildings is the estimation and optimization of building energy performance. According to the International Energy Agency IEA-EBC[1], several factors influence the energy performance of buildings; one of the significant factors is the occupant behavior. Recently, there has been growing interest in this field. In this context, different methods have been proposed and developed especially when the traditional methods such as interview and survey are not efficient and sufficient to analyze and to predict the occupant behavior with better accuracy. The main objective of this study is to provide a clear definition of the occupant behavior, a review of current approaches to analyze the occupant behavior and presentation of our research that proposes the possibility of including the occupants as a part of the problem and a solution to the problem. This research is a part of a European project H2020 “Holistic Energy and Architectural Retrofit Toolkit (HEART)”.
Solar Strategies for net-zero energy housing in Canadian North
Authors: Ma L , Ge H , Thirunavukarasu A , Athienitis A
Published: October 2019

The North imports most of its energy for fuel and cost of fuel is much higher than the national average, consequently, cost for space heating relying on fuel is very high. The North has an abundance of solar energy available. With the growing concerns on climate change, the region desires to be less dependent on fossil fuels. Significant energy savings for little added cost in housing could be achieved by building high performing envelope systems and integrating solar design strategies. The objective of this paper is to investigate the potential of integrating solar design strategies in improving energy efficiency of housing suitable for the Canadian Northern climates through modelling by optimizing passive solar design and optimal use of thermal and electrical energy from Building Integrated Photovoltaic/Thermal system (BIPV/T) to achieve net-zero energy housing. A reference home with typical construction built in Northern region is modelled using EnergyPlus. The key solar design strategies and building envelope parameters are optimized to minimize energy consumption and maximize the energy production for the reference home. The parameters investigated include thermal resistance of building envelope components, window-wall ratios, thermal mass, night window shutters, shading schedules, and ventilation rates. The optimal use of thermal energy produced by BIPV/T system by integration with Heat Recovery Ventilation (HRV) and air-source Heat Pump (ASHP) is evaluated. Modelling results show that 43% energy saving can be achieved by optimizing the passive solar design and overheating can be eliminated by proper solar shading and natural ventilation. The integration of BIVP/T with HRV can reduce the frost cycle by 10.4%. These preliminary findings demonstrate the potential of integrating solar design strategies to reduce energy consumption and develop net-zero energy housing for the Canadian North.
DanBERA: A tool for Danish buildings energy renovation design and assessment
Authors: Jradi Muhyiddine , Andersen Sandra , Hagenau Morten
Published: October 2019

The paper presents the development and implementation of DanBERA tool for Danish buildings energy renovation design and assessment. Unlike the static tools used in the current building renovation market, DanBERA is based on dynamic energy performance simulations of case study buildings considering various building characteristics and specifications and taking into account the dynamic impact of occupancy and weather conditions. The tool uses a systematic and comprehensive renovation assessment methodology considering technical, economic and environmental impacts. A list of standard energy renovation measures is considered, targeting the building physical envelope upgrade in addition to energy systems performance improvement and installation of renewable energy systems. In addition, DanBERA provides a comprehensive assessment of various renovation measures and packages, yet using limited number of inputs including building type, indoor floor area, construction or last renovated year and location. The possibility of having a building ventilation system is also available. Four major building categories are included in the current version, single-story and two-story residential houses, residential apartments and office buildings. The tool implementation is demonstrated in the paper by considering 3 Danish case studies and reporting the renovation design and assessment results regarding energy consumption and indoor air quality.
Impact of electrical vehicle (EV) penetration on the cost-optimal building integrated photovoltaics (BIPV) at a small residential district in Sweden
Authors: Lovati Marco , Zhang Xingxing
Published: October 2019

Buildings are transforming into prosumers because of the intensive growth in photovoltaics (PV), electric vehicles (EV) and home batteries. To adapt such transformation trend, this paper optimizes the cost-optimal capacity and positions of building integrated photovoltaics (BIPV) in a small residential district in Sweden, by considering thermal-electricity loads, power sharing among neighbour buildings, and electrical storage. This study focuses on two optimization scenarios with two different objectives: (1) maximizing net present value (NPV) of the BIPV system, and (2) achieving 27% renewable energy sources (RES) (as set by EU Framework for climate and energy).The optimization is performed with varying penetration of EV demand. The results show that: in scenario (1) the increase in EVs enables larger BIPV capacity with slightly improved self-consumption and thus with a little more profit. In scenario (2) however the levelized cost of electricity (LCOE) of the self-consumed electricity sensibly increases with growing presence of EVs, leading to the decreased profit. In conclusion, three main factors were found that are negatively affecting the performance of BIPV in relation to the EVs in the Swedish residential sector: A low electricity price in summer, a prevalence of the EV load at night, and the absence of PV over-production in winter.
An evaluation of energy conservation measures for deteriorated single-family houses
Authors: An Sang Min , Kim Joo Han , Kim Sung Wan , Lee Kyung Hoi
Published: October 2019

The study analyzes the heating energy performance and water use reduction of the deteriorated single-family house with energy conservation measures (ECMs) such as double-glazing window, internal insulation, high-efficiency boiler, LED lightings, and water-saving closet. The building energy consumption and savings of each energy conservation measure are analyzed using the DesignBuilder program. The payback period and life cycle cost are analyzed to verify the indices of the cost effectiveness. As a result, the refurbishment of the internal insulation system is identified to be the most effective measure to save energy and cost. The simultaneous consideration of thermal insulation and high-efficient boiler helps the low-income bracket among the single-family houses of the old downtown area to increase their residential improvement.
Bermuda’s Persistent Futures
Authors: Fosbury Timothy L
Published: October 2019

“Bermuda’s Persistent Futures” recovers Bermuda’s significance to the development of the settler colonial imaginations of early America. Following the 1609 wreck of the Sea Venture that began its settlement, English settlers insisted that Bermuda’s apparent lack of any previous Indigenous population, Spanish failures to account for its potential, and its proximity to England, North America, and the West Indies all made the 20-square-mile archipelago an anomalous and exceptional plantation in an emerging colonial system. Writers and officials seized upon Bermuda’s perceived uniqueness to position it as an isolated, vacant laboratory perfectly suited for uncovering what they believed had been waiting to be discovered—an America that was natural to England. Bermuda, in this sense, inspired a corpus of colonial fantasies about the hemisphere’s futures under a permanent English presence that was previously unimaginable to colonial writers. This essay focuses on Richard Norwood’s The Description of the Sommer Ilands, Once Called the Bermudas (1622–23) and J. Hector St. John de Crèvecoeur’s Lettres d’un cultivateur amèricain (1784) to reconstruct a Bermuda that persistently appeared to lead the way for the futures of American settlement.
Limited long-distance dispersal success in a Western European fairy shrimp evidenced by nuclear and mitochondrial lineage structuring
Authors: Rodríguez-Flores Paula C , Recuero Ernesto , Jiménez-Ruiz Yolanda , García-París Mario
Published: October 2019

Anostraca are known by their ability for long-distance dispersal, but the existence in several species of deep, geographically structured mtDNA lineages suggests their populations are subjected to allopatric differentiation, isolation, and prevalence of local scale dispersion. Tanymastix stagnalis is one of the most widespread species of Anostraca and previous studies revealed an unclear geographical pattern of mtDNA genetic diversity. Here, we analyze populations from the Iberian and Italian Peninsulas, Central Europe, and Scandinavia, with the aim to characterize the patterns of genetic diversity in a spatio-temporal framework using mtDNA and nuclear markers to test gene flow among close populations. For these aims we built a time-calibrated phylogeny and carried out Bayesian phylogeographic analyses using a continuous diffusion model. Our results indicated that T. stagnalis presents a deeply structured genetic diversity, including 7 ancient lineages, some of them even predating the Pleistocene. The Iberian Peninsula harbors high diversity of lineages, with strong isolation and recent absence of gene flow between populations. Dispersal at local scale seems to be the prevailing dispersal mode of T. stagnalis, which exhibits a pattern of isolation-by-distance in the Iberian Peninsula. We remark the vulnerability of most of these lineages, given the limited known geographic distribution of some of them, and the high risk of losing important evolutionary potential for the species.
Chlamydia trachomatis recruits protein kinase C during infection
Authors: Sah Prakash , Nelson Nicholas H , Shaw Jennifer H , Lutter Erika I
Published: October 2019

Chlamydia trachomatis is a significant pathogen with global and economic impact. As an obligate intracellular pathogen, C. trachomatis resides inside the inclusion, a parasitophorous vacuole, and depends on the host cell for survival and transition through a biphasic development cycle. During infection, C. trachomatis is known to manipulate multiple signaling pathways and recruit an assortment of host proteins to the inclusion membrane, including host kinases. Here, we show recruitment of multiple isoforms of protein kinase C (PKC) including active phosphorylated PKC isoforms to the chlamydial inclusion colocalizing with active Src family kinases. Pharmacological inhibition of PKC led to a modest reduction of infectious progeny production. PKC phosphorylated substrates were seen recruited to the entire periphery of the inclusion membrane. Infected whole cell lysates showed altered PKC phosphorylation of substrates during the course of infection. Assessment of different chlamydial species showed recruitment of PKC and PKC phosphorylated substrates were limited to C. trachomatis. Taken together, PKC and PKC substrate recruitment may provide significant insights into how C. trachomatis manipulates multiple host signaling cascades during infection.
New Bounds of Weyl Sums
Authors: Chen Changhao , Shparlinski Igor E
Published: October 2019

We augment the method of Wooley (2016) by some new ideas and in a series of results, improve his metric bounds on the Weyl sums and the discrepancy of fractional parts of real polynomials with partially prescribed coefficients. We also extend these results and ideas to principally new and very general settings of arbitrary orthogonal projections of the vectors of the coefficients $(u_1, \ldots , u_d)$ onto a lower-dimensional subspace. This new point of view has an additional advantage of yielding an upper bound on the Hausdorff dimension of sets of large Weyl sums. Among other technical innovations, we also introduce a “self-improving” approach, which leads to an infinite series of monotonically decreasing bounds, converging to our final result.
Factorizable Maps and Traces on the Universal Free Product of Matrix Algebras
Authors: Musat Magdalena , Rørdam Mikael
Published: October 2019

We relate factorizable quantum channels on $M_n({\mathbb{C}})$, for $n \ge 2$, via their Choi matrix, to certain matrices of correlations, which, in turn, are shown to be parametrized by traces on the unital free product $M_n({\mathbb{C}}) \ast _{\mathbb{C}} M_n({\mathbb{C}})$. Factorizable maps with a finite dimensional ancilla are parametrized by finite dimensional traces on $M_n({\mathbb{C}}) \ast _{\mathbb{C}} M_n({\mathbb{C}})$, and factorizable maps that approximately factor through finite dimensional $C^\ast $-algebras are parametrized by traces in the closure of the finite dimensional ones. The latter set of traces is shown to be equal to the set of hyperlinear traces on $M_n({\mathbb{C}}) \ast _{\mathbb{C}} M_n({\mathbb{C}})$. We finally show that each metrizable Choquet simplex is a face of the simplex of tracial states on $M_n({\mathbb{C}}) \ast _{\mathbb{C}} M_n({\mathbb{C}})$.
Claridge's Hotel puts out registration of trade mark by candle maker Claridge Candles
Authors: Shaw John
Published: October 2019

Claridge's Hotel Limited v (1) Claridge Candles Limited (2) Denise Shepherd [2019] EWHC 2003 (IPEC), Claim No: IP-2018-000160, 29 July 2019

Claridge's Hotel was successful in its claim to prevent the sale of CLARIDGE branded candles.
Refugees Hosting Other Refugees: Endurance and Maintenance of Care in Ouzaii (Lebanon)
Authors: Yassine Batoul , Al-Harithy Howayda , Boano Camillo
Published: October 2019

This article examines the socio-spatial mechanisms that emerge when refugees host other refugees. It argues that there is an underlying social infrastructure of care that impacts the refugees’ choice of destinations and modes of survival. When refugees host other refugees from close networks of relatives and neighbours, they create their own spatial clusters. In the process, the social infrastructure of care offers one mode of security to vulnerable refugees. Care as a concept and an approach is related to ideas of endurance and maintenance. It facilitates multiple dimensions, from space, to affection and to the everyday. It is able to reconfigure a life possible, life-enduring and a life meaningful in an urban setting. We focus on Ouzaii in Beirut, Lebanon. Ouzaii has been a destination for multiple displaced groups over different periods of time. Ouzaii currently hosts an approximate 10,000 Syrian refugees. They chose Ouzaii as their destination after they were helped by existing refugees who offered shelter and access to jobs. The resultant socio-spatial practices, flourishing businesses and leisurely facilities are evidence of successful social networks that form an infrastructure of care. They also play a role in the reconstitution of Ouzaii itself.

We conclude with reflections on how urban informality may offer refugees an alternative right to the city while allowing them to escape the gaze of the humanitarian-aid apparatus that can signify their vulnerability by reducing them to only being aid recipients. Instead, they form protective socio-spatial networks that have proved to be powerful in sustaining their livelihoods, guarding them from possible social discrimination or political threats.
78. Oral Norovirus Vaccination in Humans Induces Plasmablast B-Cell Expansion and Follicular T-Cell Activation Comparable to Natural Infection
Authors: Mateo Roberto , Lin Karen , Kolhatkar Nikita , Taylor David , Garg Shaily , Tucker Sean
Published: October 2019

Background

Norovirus (NoV) is a common cause of acute gastroenteritis, but no vaccines are currently licensed. Vaxart is developing an oral tableted NoV vaccine that induces both systemic and mucosal immune responses.

Methods

Two separate clinical studies were conducted to evaluate the safety and immunogenicity of an oral NoV vaccine and NoV infection. The first study investigated an oral tablet vaccine based on a recombinant adenovirus vector expressing NoV VP1 (rAd-VP1). In the second study, a controlled NoV infection (Norwalk virus) was performed using a strain isolated and purified from an infected subject. Serum and PBMCs were collected pre- and post-immunization/infection. Serum immune responses were assessed using IgG/IgA ELISAs and blocking titer (BT50) assays. Cellular immune responses were evaluated using antibody-secreting cell (ASC) assays to quantitate norovirus-specific B cells. Flow cytometry was used to analyze the phenotype of circulating B and T cells.

Results

The rAd-VP1 vaccine was well tolerated whereas most subjects (56%) in the controlled infection study had significant gastroenteritis 2–4 days post-inoculation. Subjects in cohorts vaccinated 28 days apart with 1 × 1010 or 1 × 1011 IUs showed the highest rises in serum IgG and IgA titers compared with those immunized 2 or 7 days apart with a 1 × 1010 IU vaccine dose. Subjects in the 1 × 1011 IU vaccine dose cohort had a 6-fold rise in serum IgA and 4-fold rise in BT50 titers, with mean IgA and IgG ASC values of 698 and 389 counts, respectively. In comparison, NoV-challenged subjects showed an average of 2,072 IgA and 886 IgG ASC counts. Remarkably, flow cytometry analysis revealed that activated B- and T-cell responses were similar post-vaccination and post-infection, with significant expansion of T follicular cells, plasmablasts, mucosal homing B cells, and preferential activation of IgA B cells.

Conclusion

The phenotype of activated B and T cells induced post-immunization was similar to that induced post-infection, suggesting that an oral vaccine can induce comparable adaptive immune responses without the substantial adverse clinical events that occur from natural infection. Future work in dose ranging will aide in the development of a safe and efficacious oral NoV vaccine.

Disclosures

All Authors: No reported Disclosures.
81. Azithromycin-Nonsusceptible Salmonella Newport Infections Associated with Mexican-style Soft Cheese and Beef—the United States, 2018–2019
Authors: Plumb Ian D , Tecle Selam , Schwensohn Colin , Schneider Zachary , Gieraltowski Laura , Freiman Jennifer , Cote Andrea , Noveroske Douglas , Dessai Uday , Jain Seema , Brandenburg Joshua , Chen Jessica , Tagg Kaitlin A , Bumpus-White Porscha , Shah Hazel , Francois Watkins Louise , Francois Watkins Louise , Wise Matthew E , Friedman Cindy R , Friedman Cindy R
Published: October 2019

Background

Azithromycin is a recommended oral agent for treating nontyphoidal Salmonella (NTS), when antibiotics are indicated. Azithromycin nonsusceptibility among NTS is <1% in the United States. CDC, FSIS, and state health departments investigated an outbreak of azithromycin-nonsusceptible Salmonella serotype Newport infections to determine sources.

Methods

We classified isolates as the outbreak strain if they were within 11 alleles by core genome multilocus sequence typing. We defined a case as infection with the outbreak strain during June 2018–February 2019. After stratifying by gender and ethnicity, we compared food exposures ≤7 days before illness onset with those reported by healthy persons in the Foodborne Diseases Active Surveillance Network population survey (2006–2007). We used broth microdilution to determine antimicrobial susceptibility.

Results

We identified 218 case patients from 31 states; 49 of 176 (28%) were hospitalized and 2 died. Overall, 65% (121/187) were Hispanic, and 41% (70/169) visited Mexico in the 7 days before illness onset. Among travelers to Mexico, 71% (23/32) reported eating Mexican-style soft cheese; 16/23 (70%) recalled obtaining the cheese in Mexico. Among nontravelers, the proportion who ate Mexican-style soft cheese (30%, 18/60) was similar to that reported by healthy persons, whereas the proportion who consumed beef (91%, 60/66) was higher than reported by healthy persons (P = 0.04). The outbreak strain was detected in a sample of soft cheese obtained in Mexico, and in a cecal sample from a steer and a beef sample that was collected at FSIS-regulated establishments in the United States. Isolates were resistant to ampicillin and trimethoprim–sulfamethoxazole, nonsusceptible to azithromycin, and showed decreased susceptibility to ciprofloxacin.

Conclusion

This is the first documented outbreak of azithromycin-nonsusceptible Salmonella infections in the United States. Two food vehicles—soft cheese obtained in Mexico, and beef obtained in the United States—were epidemiologically and genetically associated with this outbreak. Further investigation is warranted to determine the routes of entry, prevalence, and spread of azithromycin-nonsusceptible Salmonella in US and Mexican cattle.

Disclosures

All Authors: No reported Disclosures.
90. Fecal Microbiota Transplantation in Metastatic Melanoma Patients Resistant to Anti-PD-1 Treatment
Authors: Youngster Ilan , Baruch Erez , Katz Lior , Lahat Adi , Brosh-Nissimov Tal , Schachter Jacob , Koren Omry , Markel Gal , Boursi Ben
Published: October 2019

Background

Most metastatic melanoma patients treated with Programed cell Death (PD)-1 blockers fail to achieve a durable response. The gut microbiota profoundly affects host immunity, and fecal microbiota transplantations (FMT) have been shown to enhance anti-PD-1 effectiveness in murine models. We report initial safety and efficacy results from the first patients treated in a Phase I study of FMT and re-induction anti-PD-1 therapy in anti-PD-1 refractory metastatic melanoma.

Methods

FMT donors were two metastatic melanoma patients who achieved a durable complete response to treatment. FMT recipients were metastatic melanoma patients who failed at least one anti-PD-1 line of treatment. FMT was conducted by both colonoscopic and oral administration, followed by anti-PD-1 re-treatment. Each recipient underwent pre- and post-treatment stool sampling, tissue biopsy of both gut and tumor, and total body imaging.

Results

Five patients with treatment-resistant metastatic melanoma were recruited. No FMT-related or immunotherapy-related adverse events were observed. To assess engraftment of the new microbiota, recipients were paired with their respective donors and stool 16S rDNA gene sequence analysis was performed. Sequencing results demonstrated post-FMT compositional dissimilarity (Unweighted UniFrac, P = 0.04, FDR q = 0.22) between the two recipient–donor groups. Specific taxonomic dynamics included post-FMT increased abundance of Paraprevotellaceae, previously associated in descriptive studies with responsiveness to treatment, and significant reductions in abundance of β-proteobacteria, previously associated with reduced response to treatment. Immunohistochemical stains of biopsies demonstrated an increased post-FMT infiltration of antigen presenting cells (CD68+) in the gut (paired T-test, P = 0.008) and in the tumor (P = 0.0076). Post-treatment intra-tumoral CD8+ T-cell infiltration was also increased. Three patients had a partial or complete response to treatment post-FMT.

Conclusion

FMT in metastatic melanoma patients seems to be safe and may alter recipient gut microbiota to resemble that of a responder donor. This alteration may result in intra-tumoral T-cell activity, and conferred clinical and radiological benefit in several recipients previously unresponsive to treatment.

Disclosures

All Authors: No reported Disclosures.
92. Incidence of Respiratory Syncytial Virus Infection among Hospitalized Adults, 2017–2019
Authors: Branche Angela , Saiman Lisa , Walsh Edward E , Falsey Ann R , Sieling William , Oberhardt Matthew , Zachariah Philip , Greendyke William G , Barrett Angela , Vargas Celibell , Alba Luis , Phillips Matthew R , Finelli Lyn
Published: October 2019

Background

Respiratory syncytial virus (RSV) infection has been increasingly recognized as an important cause of acute respiratory illness (ARI) and a trigger for exacerbation of underlying cardiopulmonary disease in adults. Incidence of hospitalized RSV infection remains uncertain as adults have not been systematically screened. Previous incidence estimates, derived primarily from modeling studies, have ranged from 84 to 190/100K population in adults >65 years of age. Accurate burden data are critical to inform RSV vaccine development for adults. We used active surveillance among hospitalized adults to determine population-based incidence rates of RSV infection.

Methods

Hospitalized adults ≥ 18 years old residing in the surveillance area with >2 ARI symptoms or exacerbation of underlying cardiopulmonary disease were screened for eligibility during October 2017–April 2018 and October 2018 to April 2019 in 3 hospitals in Rochester, NY and New York City. Respiratory specimens were tested for RSV using PCR assays. RSV incidence per 100,000 persons (per 2010 US Census data) was adjusted by percent market share for study hospitals in their catchment area.

Results

In total, 8,217 hospitalized adults residing in the surveillance area that met the surveillance case definition were tested for RSV; 768 (9.4%) were positive. Adults were aged 18–49 (12%), 50–64 (30%), and ≥65 years old (58%); 55% were female. RSV infection incidence varied from year 1 to year 2 and was highest in patients aged ≥65 years old (table).

Conclusion

This is the largest prospective RSV incidence study to date. Preliminary results indicate that the incidence of RSV infection may be higher than previously reported, especially in urban-dwelling adults >65 years of age. Results confirm the need for vaccines to prevent RSV infections in older adults.

Disclosures

All Authors: No reported Disclosures.
840. Clinical Failure Rates Associated with Hemin-induced Metronidazole Resistance in Clostridioides difficile
Authors: Gonzales-Luna Anne J , Shen Wan-Jou , Deshpande Aditi , Dotson Kierra M , Lancaster Chris , Hurdle Julian , Garey Kevin W
Published: October 2019

Background

Current guidelines suggest limiting metronidazole (MTZ) use due to increased treatment failures in patients with Clostridioides difficile infections (CDI). We hypothesized that an increase in the minimum inhibitory concentration (MIC) of MTZ to C. difficile may contribute to these poor response rates. The objective of this study was to examine clinical response rates in patients with CDI based on MTZ MIC and stratified by receipt of MTZ treatment.

Methods

Clostridioides difficile-positive stool samples collected from 2017 to 2018 as part of routine care at two hospital systems in Houston, Texas were collected for MIC determination at 24 h to MTZ by broth microdilution following incorporation of 5 mg/L of hemin. The primary outcome was initial clinical success by Day 7 of treatment in those with MICs ≥1 vs. <1. Results were stratified based on receipt of MTZ within 48 hours of diagnosis. Study objectives were tested using χ 2 and multivariable logistic regression analyses.

Results

A total of 235 C. difficile samples were included, of which 73 (31%) had an MTZ MIC ≥1. Overall, 72% received MTZ within the first 48 hours. Clinical success rates differed based on disease severity (77% in nonsevere, 64% in severe/fulminant; P = 0.03) and infecting ribotype (52% in RT 027, 75% in non-RT 027; P = 0.014). In patients with MTZ receipt, clinical success rates were higher in patients infected with strains with an MTZ MIC < 1 (76%) compared with those with an MIC ≥1 (60%; P = 0.031). The difference in initial clinical success was not different in those that did not receive MTZ (78% for MIC <1 vs. 65% for MIC ≥1, P = 0.28). After controlling for disease severity, treatment failure was higher in patients infected with strains with an MTZ MIC ≥1 and treated with MTZ (OR 2.1; 95% CI, 1.01–4.35; P = 0.048) but not for those with an MIC ≥1 treated with other therapies (OR 1.9; 95% CI, 0.62–5.6; P = 0.27).

Conclusion

This study provides the first preliminary evidence of an association between reduced metronidazole susceptibility and decreased clinical success rates. Larger studies are warranted to validate these findings.

Disclosures

All Authors: No reported Disclosures.
848. Low-Bioavailability vs. High-Bioavailability Oral Antibiotics for the Definitive Treatment of Enterobacteriaceae Bacteremia from Suspected Urine Source in Hospitalized Veterans
Authors: Sutton Jesse D , Chang Nai-Chung N , Stevens Vanessa W , Timbrook Tristan T , Spivak Emily S
Published: October 2019

Background

Limited and conflicting data exist evaluating low-bioavailability oral antibiotics (LOW) for definitive treatment of Enterobacteriaceae bacteremia (EB), and existing dogma limits their use. We compared outcomes for EB from a suspected urine source with LOW vs. high-bioavailability oral antibiotics (HIGH).

Methods

This was a retrospective cohort study across Veterans Affairs hospitals from 2006 to 2015. Inclusion criteria were monomicrobial EB and matching urine culture; receipt of active, empiric parenteral antibiotic(s); and conversion to a single oral LOW or HIGH between treatment day 2 and 6. Exclusion criteria were EB in the previous year, prior urologic abscess, or chronic prostatitis. HIGH included fluoroquinolones or trimethoprim-sulfamethoxazole. LOW included oral β-lactams. The primary outcome was all-cause 30-day mortality or recurrent EB. Patients were weighted using propensity-based overlap weights to make the groups more similar to each other at baseline. Log binomial regression models were used to estimate relative risks and risk differences.

Results

A total of 4,090 patients met inclusion criteria with 955 LOW and 3,135 HIGH. The median days of parenteral antibiotics before conversion to oral antibiotics were 4 (IQR 3, 5) in LOW and 4 (IQR 3, 4) in HIGH. The composite primary outcome occurred in 42 (4.4%) LOW and 94 (3.0%) HIGH. The adjusted relative risk (aRR) of the composite primary outcome with LOW was 1.28 (95% CI 0.86–1.89; risk difference [RD] 0.9%). Recurrent EB within 30-days occurred in 14 (1.5%) LOW and 12 (0.4%) HIGH (aRR 3.24, 95% CI, 0.46–22.8; RD 1.0%). Thirty-day mortality occurred in 29 (3.0%) LOW and 82 (2.6%) HIGH (aRR 1.0, 95% CI, 0.66–1.52; RD 0%). Similar outcomes were observed at 90 days.

Conclusion

There was no difference in the composite outcome of 30-day mortality and recurrent bacteremia comparing hospitalized patients who received LOW vs. HIGH for the definitive treatment of EB from a suspected urine source. While there was a nonsignificantly higher risk of 30-day recurrent EB with LOW, the absolute risk and risk difference were small, suggesting that definitive therapy with LOW may be considered. Future evaluation is needed to better understand risk factors for recurrent EB and which patients may fail LOW.

Disclosures

All Authors: No reported Disclosures.
885. HIV-1 Treatment Failure and Extensive Drug Resistance in Perinatally Infected Children Failing First-Line Antiretroviral Therapy in Western Kenya
Authors: Nyandiko Winstone , Holland Sabina , Vreeman Rachel , DeLong Allison , Manne Akarsh , Novitsky Vladimir , Coetzer Mia , Ngeresa Anthony , McAteer Carole , Aluoch Josephine , Orido Millicent , Sam Soya , Caliendo Angela , Ayaya Samuel , Hogan Joseph , Kantor Rami
Published: October 2019

Background

Understanding drug resistance in perinatally HIV-infected children (PHIC) when viral load (VL) monitoring is limited is critical for life-long antiretroviral use. Resistance data in PHIC in sub-Saharan Africa are limited. Though guidelines recommend PI-based first-line regimens in PHIC, many worldwide remain on NNRTI-based regimens. We examined treatment failure, resistance, and outcomes in Kenyan PHIC on first-line NNRTI-based therapy.

Methods

PHIC were enrolled in 2010–2013 at the Academic Model Providing Access to Healthcare in Eldoret, Kenya, a large program caring for >160,000 HIV patients; >15,000 PHIC. VL testing, not routinely available then, was done for all, and resistance testing was done in viremic PHIC. Clinical data were derived from medical records. Subtype and resistance interpretation were with Stanford Database tools. Associations between failure (>1,000 copies/mL) or resistance, and demographic, clinical or lab variables were evaluated with Fisher exact and Wilcoxon rank-sum tests.

Results

Of 482 PHIC enrolled, 52% were female, median age 8.4 years (range 1–15), median CD4% 28 (range 0–53), 79% on zidovudine (AZT)/abacavir (ABC)+lamivudine(3TC)+efavirenz (EFV)/nevirapine (NVP) for median 2.3 years. Treatment failure was seen in 31%, associated with low CD4% and count. Genotypes were available in 124, 47% female, median age 8.3 years (range 2–15), median CD4% 22 (range 0–45), 81% on AZT/ABC+3TC+EFV/NVP for median 2.5 years, median VL 7,515 copies/mL. Subtypes were A 76%, C 3%, D 15%, recombinants 6%. Reverse transcriptase mutations were in 93%; 93%-NNRTIs, median 2/patient, most common Y181C (44%); 89%-NRTIs, median 3/patient, most common M184V (85%); 89%-dual class, median 5/patient. Intermediate-high resistance to potential second-line drugs included 62% etravirine, 66% rilpivirine, and 19% tenofovir. Of 92/124 (74%) PHIC with follow-up data, 27% remained on NNRTI-based first-line (median CD4 count 461), of whom 24% had suppressed VL and 48% died; and 73% switched to PI-based second-line (median CD4 count 591), of whom 72% had suppressed VL and 6% died (P < 0.05 for both).

Conclusion

PHIC in western Kenya on NNRTI-based first-line regimens had high treatment failure rates and extensive drug resistance with poor clinical outcomes, demanding urgent interventions.

Disclosures

All Authors: No reported Disclosures.