41 research outputs found
A predictive model for fracture in human ribs based on in-vitro acoustic emission data
Purpose
The aim of this paper is to propose a fracture model for human ribs based on acoustic emission (AE) data. The accumulation of microcracking until a macroscopic crack is produced can be monitored by AE. The macrocrack propagation causes the loss of the structural integrity of the rib.
Methods
The AE technique was used in in vitro bending tests of human ribs. The AE data obtained were used to construct a quantitative model that allows an estimation of the failure stress from the signals detected. The model predicts the ultimate stress with an error of less than 3.5% (even at stresses 15% lower than failure stress), which makes it possible to safely anticipate the failure of the rib.
Results
The percolation theory was used to model crack propagation. Moreover, a quantitative probability-based model for the expected number of AE signals has been constructed, incorporating some ideas of percolation theory. The model predicts that AE signals associated with micro-failures should exhibit a vertical asymptote when stress increases. The occurrence of this vertical asymptote was attested in our experimental observations. The total number of microfailures detected prior to the failure is urn:x-wiley:00942405:media:mp15082:mp15082-math-0001 and the ultimate stress is urn:x-wiley:00942405:media:mp15082:mp15082-math-0002 MPa. A significant correlation (p < 0.0001) between urn:x-wiley:00942405:media:mp15082:mp15082-math-0003 and the predicted value is found, using only the first N = 30 micro-failures (correlation improves for N higher).
Conclusions
The measurements and the shape of the curves predicted by the model fit well. In addition, the model parameters seem to explain quantitatively and qualitatively the distribution of the AE signals as the material approaches the macroscopic fracture. Moreover, some of these parameters correlate with anthropometric variables, such as age or Body Mass Index. The proposed model could be used to predict the structural failure of ribs subjected to bending.Peer ReviewedPostprint (author's final draft
Impact of Biological Agents on Postsurgical Complications in Inflammatory Bowel Disease : A Multicentre Study of Geteccu
Background: The impact of biologics on the risk of postoperative complications (PC) in inflammatory bowel disease (IBD) is still an ongoing debate. This lack of evidence is more relevant for ustekinumab and vedolizumab. Aims: To evaluate the impact of biologics on the risk of PC. Methods: A retrospective study was performed in 37 centres. Patients treated with biologics within 12 weeks before surgery were considered "exposed". The impact of the exposure on the risk of 30-day PC and the risk of infections was assessed by logistic regression and propensity score-matched analysis. Results: A total of 1535 surgeries were performed on 1370 patients. Of them, 711 surgeries were conducted in the exposed cohort (584 anti-TNF, 58 vedolizumab and 69 ustekinumab). In the multivariate analysis, male gender (OR: 1.5; 95% CI: 1.2-2.0), urgent surgery (OR: 1.6; 95% CI: 1.2-2.2), laparotomy approach (OR: 1.5; 95% CI: 1.1-1.9) and severe anaemia (OR: 1.8; 95% CI: 1.3-2.6) had higher risk of PC, while academic hospitals had significantly lower risk. Exposure to biologics (either anti-TNF, vedolizumab or ustekinumab) did not increase the risk of PC (OR: 1.2; 95% CI: 0.97-1.58), although it could be a risk factor for postoperative infections (OR 1.5; 95% CI: 1.03-2.27). Conclusions: Preoperative administration of biologics does not seem to be a risk factor for overall PC, although it may be so for postoperative infections
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study
Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak.
Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study.
Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM.
Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide
Sloan Digital Sky Survey IV : mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z ~ 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z ~ 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
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Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing
three major spectroscopic programs. The Apache Point Observatory Galactic
Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky
Way stars at high resolution and high signal-to-noise ratio in the
near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA)
survey is obtaining spatially-resolved spectroscopy for thousands of nearby
galaxies (median redshift of z = 0.03). The extended Baryon Oscillation
Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas
distributions between redshifts z = 0.6 and 3.5 to constrain cosmology using
baryon acoustic oscillations, redshift space distortions, and the shape of the
power spectrum. Within eBOSS, we are conducting two major subprograms: the
SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray
AGN and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey
(TDSS), obtaining spectra of variable sources. All programs use the 2.5-meter
Sloan Foundation Telescope at Apache Point Observatory; observations there
began in Summer 2014. APOGEE-2 also operates a second near-infrared
spectrograph at the 2.5-meter du Pont Telescope at Las Campanas Observatory,
with observations beginning in early 2017. Observations at both facilities are
scheduled to continue through 2020. In keeping with previous SDSS policy,
SDSS-IV provides regularly scheduled public data releases; the first one, Data
Release 13, was made available in July 2016
Impact of Biological Agents on Postsurgical Complications in Inflammatory Bowel Disease: A Multicentre Study of Geteccu
Background: The impact of biologics on the risk of postoperative complications (PC) in inflammatory bowel disease (IBD) is still an ongoing debate. This lack of evidence is more relevant for ustekinumab and vedolizumab. Aims: To evaluate the impact of biologics on the risk of PC. Methods: A retrospective study was performed in 37 centres. Patients treated with biologics within 12 weeks before surgery were considered “exposed”. The impact of the exposure on the risk of 30-day PC and the risk of infections was assessed by logistic regression and propensity score-matched analysis. Results: A total of 1535 surgeries were performed on 1370 patients. Of them, 711 surgeries were conducted in the exposed cohort (584 anti-TNF, 58 vedolizumab and 69 ustekinumab). In the multivariate analysis, male gender (OR: 1.5; 95% CI: 1.2–2.0), urgent surgery (OR: 1.6; 95% CI: 1.2–2.2), laparotomy approach (OR: 1.5; 95% CI: 1.1–1.9) and severe anaemia (OR: 1.8; 95% CI: 1.3–2.6) had higher risk of PC, while academic hospitals had significantly lower risk. Exposure to biologics (either anti-TNF, vedolizumab or ustekinumab) did not increase the risk of PC (OR: 1.2; 95% CI: 0.97–1.58), although it could be a risk factor for postoperative infections (OR 1.5; 95% CI: 1.03–2.27). Conclusions: Preoperative administration of biologics does not seem to be a risk factor for overall PC, although it may be so for postoperative infections
I Congresso Ibero-Americano de Bibliotecas Escolares
Actas de la primera edición del I Congreso Iberoamericano de Bibliotecas Escolares, CIBES 2015, organizado por la Universidad Carlos III de Madrid (España), la Universidad Estatal Paulista (Brasil) y el Ayuntamiento de Getafe (España). Celebrado: 21 - 23 de octubre de 2015 en la Universidad Estatal Paulista (Marília) y 26 - 28 de octubre de 2015 en la Universidad Carlos III de Madrid (Getafe)Universidad Carlos III de Madrid (España)Universidad Estatal Paulista (Brasil)Ayuntamiento de Getafe (España)Dimensiones y visiones de la biblioteca escolar en una Educación por competencias: la
necesidad de una política estratégica / Miguel Ángel Marzal. -- Getafe ciudad educadora,
lectora y escritora: Bibliotecas escolares / Lourdes Muñoz Santiuste. -- Presente y
futuro: biblioteca escolar-CREA y proyectos interdisciplinares / Rosa Piquín. -- Cultura
en información: un reto esencial de la biblioteca escolar / Mónica Baró. -- Bibliotecas
escolares de Galicia: un mundo de oportunidades a favor de la Educación / Cristina Novoa.
-- 10 años de la Red de Bibliotecas Escolares de Extremadura (REBEX) / Casildo Macías
Pereira. -- Biblioteca Escolar y uso ético de la información para una Cultura de Paz / Ana
Barrero Tíscar. -- Dinamización de la Biblioteca Escolar Plumita durante el curso escolar
2014/15 / María Antonia Cano Cañada. -- Experiencia de la creación de una biblioteca
escolar / Susana Santos Martín. -- Grupo cooperativo Bibliotecas escolares en Red-Albacete
/ José Manuel Garrido Argandoña y Eva Leal Scasso. -- La BCREA "Juan Leiva". El fomento de
la lectura desde la web social / Andrés Pulido Villar. -- Proceso de implantación de una
herramienta de autoevaluación en la red de bibliotecas escolares de Extremadura (REBEX) /
Casildo Macías Pereira. -- La biblioteca escolar: abriendo fronteras / Lorena Verónica
Cabrera Orellana. -- O programa RBE e a avaliaçao das bibliotecas escolares: melhoria,
desenvolvimiento e innovaçao / Elsa Conde. -- Profesional de Biblioteconomía y
Documentación: esencial en la plantilla de la escuela / Pilar del Campo Puerta. -- Una
mirada activa al proceso educativo desde la biblioteca escolar / María Jesús Fontela
Fernández . -- Con otra mirada "La ilustración como vehículo de comunicación y aprendizaje
en las bibliotecas escolares" / Pablo Jurado Sánchez-Galán. -- Fingertips. Recriar a
biblioteca escolar na sala de aula / Rui Alfonso Mateus. -- Hablemos de libros. Cómo
transformar una clase de literatura en una comunidad de interpretación de textos /
Francisco César Díaz Rey. -- Inclusión social de familias inmigrantes a través de un
programa de aprendizaje de la lengua castellana / Ana Carmen Tolino Fernández-Henarejos.
-- O desenvolvimento de atividades de mediação de leitura em biblioteca escolar: o caso da
biblioteca da Escola Sesc de Ensino Médio / Vagner Amaro. -- La biblioteca escolar.
Proceso de enseñanza-aprendizaje de padres a hijos / Ana Carmen Tolino Fernández-
Henarejos. -- Leo con y para los demás / Ismael Fernández Fernández, Ana María Moreno
Vicente y Ana Beatriz Vicente Pérez. -- Nanas y arrullo. Poesía a la deriva / Bernardo
Fuentes Navarrete y Carlos García-Romeral Pérez. -- Gestión y evaluación de servicios
bibliotecarios para personas con dislexia: una biblioteca escolar inclusiva desde una
perspectiva internacional / Carmen Jorge García-Reyes. -- Sueños lectores compartidos
hechos realidad: la biblioteca escolar del C.E.I.P-S.E.S-A.A “LA PAZ” de Albacete / Ana
Rosa Cabañero Tobarra, Juan Manuel Herráez, Eva Leal Scasso, María Marín Sánchez, Ana
Belén Medrano Martínez y María José Nortes Ruipérez. -- El programa biblioteca escuela en
Civican. La literatura como elemento motivador para la alfabetización informacional /
Villar Arellano Yanguas. -- La competencia digital en el diseño curricular: desde la
biblioteca al aula / Felicidad Campal García. -- O deselvomimento da pesquisa escolar por
meio da competência em informaçao / Luciane de Fátima Cavalcante Beckman y Marta Leandro
da Mata. -- Proyecto escolar de investigación documental "Te pillé leyendo" / José Manuel
Garrido Argandoña. -- Aprender com a Biblioteca Escolar: formar para as literacias / Paula
Correia y Isabel Mendinhos. -- Sucedió en el siglo XX / María Antonia Becerra Montalbán,
Ángel Bernabé Muñoz y Sofía Vaz Romero. -- El Club de lectura en la nube / Belén Benito
Blázquez y Ana Ordás García. -- Promover a leitura e a escrita na era digital:
prácticas nas bibliotecas escolares / María Raquel Ramos. -- A biblioteca escolar e o
desafío da interculturalidade: o projeto Ser + cidadao / María da Conceição Tomé. --
Cuando la competencia digital encontró a la alfabetización informacional o Mucho ruido y
pocas nueces / Felicidad Campal García. -- Hora de ler, un programa para el fomento de la
lectura en contexto educativo / Cristina Novoa. -- Hábitos de lectura para las
competencias en información y alfabetización en información en bibliotecas escolares de
Puerto Rico / Karen Denise Centeno Casillas. -- Repositorios digitales en las bibliotecas
escolares andaluzas: situación, modelos y herramientas para su creación / Dolores Olmos
Olmos y Andrés Pulido Villar. -- Trabajando las competencias clave con las aventuras de
Mozarito en Extremadura / María Teresa Carballosa González y María Esther Nieto Vidal. --
Análisis de modelos de evaluación de la web de la biblioteca escolar / Raúl Cremades
García. -- Emociónate con las historias: El bosque de las emociones e historias con mucho
teatro / Esther Luis Pérez y Ana María Peromingo Fernández. -- Biblioteca escolar de
innovación y continuación / E. María Guerrero Palacios y Silvia Mora Ramírez. -- Uso de
estándares y licencias para la creación y difusión de contenidos en las bibliotecas
escolares / José Luis Barreiro Cebey. -- La biblioteca escolar digital móvil / Javier
Fernández Delgado. -- Uso de aplicaciones móviles para el desarrollo de
la competencia lingüística. Proyecto Hansel App Gretel / Dolores Olmos Olmos. -- A memória
e a mediação segundo Vigotski / Leda Maria Araújo, Patricia Celia Santana, Sueli Bortolin
y Leticia Gorri Molina. -- Bibliotecas escolares como tema de estudo dos alunos de
graduação em blioteconomia do Instituto de Ensino Superior da FUNLEC: estado da arte /
Tiago Pereira Nocera y Rodrigo Pereira. -- Ações de mediação da leitura e da informação
em bibliotecas escolares: um olhar sobre as bibliotecas dos Colégios de Aplicação /
Tatyanne Christina Gonçalves Ferreira Valdez y Alberto Calil Júnior. -- Mediação
pedagógica numa biblioteca de escola pública em Londrina / Rovilson José da Silva, Teba
Silva Yllana y Sueli Bortolin. -- Utilização de categorias por cores em sistema de
biblioteca voltado ao público infanto-juvenil / Liliana Giusti Serra. -- Atividades de
ensino dos atos de leitura com crianças em risco social / Adriana Naomi Fukushima da Silva
y Dagoberto Buim Arena. -- Biblioteca escolar: espaço de significados entre
alunos, professores e bibliotecários / Rodrigo Barbosa Paulo, Marisa Xavier, Helen Castro
Casarin y Creuza Barbaroto. -- A Biblioteca Escolar no Contexto da Legislação e
do Processo Educativo / Eliane Lourdes da Silva Moro, Francisca Rosaline Leite Mota y
Raimundo Martins de Lima. -- O jornal impresso como fonte de informação: a importância da
formação de leitores críticos / Mariana Pícaro Cerigatto. -- Bibliotecas escolares no
estado do Rio Grande do Sul: a trajetória de realização dos fóruns gaúchos pela melhoria
das bibliotecas escolares / Eliane Lourdes da Silva Moro y Lizandra Brasil Estabel. -- O
acesso à informação dos usuários surdos na biblioteca escolar / André Luís Onório
Coneglian y Mayara Melo Santana. -- Aprendizagem coletiva de bibliotecários e a
competência de pesquisa dos docentes: o caso do Instituto Federal do Espírito Santo /
Maristela Almeida Mercandeli Rodrigues y Beatriz Quiroz Villardi. -- Biblioteca escolar:
atores, parâmetros e competências / Mavi Galante Mancera Dall´Acqua Carvalho y Claudio
Marcondes de Castro Filho. -- Estratégias de aprendizagem de escrita no
Ensino Fundamental II / Érika Christina Kohle. -- Bebês e livros: leitura nas bebetecas.
Kenia Adriana de Aquino Modesto Silva, Juliane Francischeti Martins Motoyama y Renata
Junqueira de Souza. -- Práticas alternativas para organização de acervos nos espaços de
leitura em ambientes escolares / Luciana Souza Gracioso, Ariovaldo Alves,
Débora Nascimento, Suelen Redondo, Tainara Torika Kiri de Castro, Elizabete Angelon y
Eduardo Barbosa. -- Reflexões sobre a modelagem e criação de uma Rede Virtual de Leitores
para Bibliotecas Escolares / Carla Floriana Martins y Raoni Guerra Rajão. -- Biblioteca
escolar: espaço de formação leitora? / Silvana Ferreira de Souza Balsan y Renata
Junqueira de Souza. -- “Se a Biblioteca Escolar é minha mãe, o Google é meu pai”:
representações da relação entre Biblioteca Escolar e Google no imaginário de
alunos do ensino técnico / Adriana Bogliolo Sirihal-Duarte, Maria L. Amorim Antunes y
Raquel Miranda Vilela Paiva. -- Desafios e propostas para a universalização das
bibliotecas escolares no Brasil e na Espanha / Rodrigo Pereira, Daniela Spudeit y Fernanda
de Sales. -- Bibliotecário educador: possibilidades de atuação no contexto da biblioteca
escolar / André Carlos da Silva, Valéria Martin Valls y Mariana de Paula Silva. -- Uma ONG
para Bibliotecas Escolares : estratégia para ampliar a igualdade e capacidade de acesso
e uso da informação e educação escolar de qualidade / Suelen Camilo Ferreira y Luciana de
Souza Gracioso. -- O aluno com deficência: o papel do bibliotecário na disponibilidade de
recursos acessíveis na biblioteca escolar / Adriano de Sales Coelho, Rosilene de Melo
Oliveira y Marcos Pastana Santos. -- Biblioteca digital virtual e o uso do tablete: uma
possibilidade de construção de novas práticas de leitura na escola / Barbara Cibelli da
Silva Monteagudo y Dagoberto Buim Arena. -- A importância da biblioteca na educação de
crianças de 0 a 3 anos / Yngrid Karolline Mendonça Costa y Cyntia Graziella Guizelim
Simões Girotto. -- Comportamento Informacional de adolescentes: a relação com bibliotecas
e escolas / Nelson Sebastian Silva-Jerez y Helen de Castro S. Casarin
Sloan Digital Sky Survey IV: mapping the Milky Way, nearby galaxies, and the distant universe
We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median ). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July