bluuebunny/crossref_metadata_2025 huggingface dataset:
Aproximación al concejo de la ciudad de Santiago de Compostela y su configuración en la Edad Media. Un poder urbano en el señorío eclesiástico
Authors: Sánchez Sánchez Xosé M.
Published: April 2019

El estudio de la ciudad medieval de Santiago de Compostela viene marcado generalmente por el ámbito eclesiástico, materializado en su catedral, el episcopado y la peregrinación. Estos análisis han dejado ciertos segmentos necesitados de profundidad a la hora de definir las relaciones sociales y de poder político en una de las principales urbes peninsulares de señorío eclesiástico; es el caso, principalmente, del poder concejil y su relación con el poder feudal compostelano. Este artículo ofrece una aproximación y sistematización monográfica de la institución urbana en los siglos medievales, atendiendo principalmente a sus integrantes (justicias, notarios y guardianes del sello, a los que se añaden luego regidores y homes boos) en tiempos del concilium y del regimiento, y a las funciones que desarrolla, a saber: urbanismo; justicia; orden público; economía común; y abastecimiento y comercio.AbstractThe study of the medieval city of Santiago de Compostela is generally centred on the ecclesiastical sphere, characterized by its cathedral, the episcopacy and the pilgrimage route. This analysis has left certain segments of study in need of further research in order to define social and political relationships in one of the main Peninsular cities of ecclesiastical lordship. This is primarily the case of the town council and its relation to the main Compostelan feudal power. This article offers an initial examination of the urban institution in the later medieval period. The purpose is to unveil its structure after a brief look at its evolution up to the later Middle Ages. This analysis will focus on its members in the second half of the thirteenth century (justices, notaries and keepers of the seal); the materialization of power as viewed in the records of the first third of the fourteenth century with respect to a royal privilege negotiated by the prelate Berenguel de Landoira; and with the members of the town council in the fifteenth century and the consent of the regidores and procuradores. The analysis will conclude with a sketch of the main functions assumed by the institution, namely urbanism, justice, public order, economic issues, and supply and trade.
Los caminos de la repoblación segoviana en la Transierra entre los siglos XIII y XV. El privilegio de las alberguerías de 1273
Authors: Rodríguez Morales Jesús , González Agudo David
Published: April 2019

Los resultados de este estudio revelan la importancia de las ventas o alberguerías en la Repoblación segoviana al sur de la sierra de Guadarrama durante los siglos XIII-XV. La documentación archivística, que nos ha permitido identificar más de un 70 por ciento de estos establecimientos camineros, describe el trazado de varias vías antiguas de comunicación entre Segovia y sus extremos del Reino de Toledo. Las alberguerías segovianas se convertirían en un objetivo prioritario de la depredación señorial tardomedieval. Muchas ventas se vieron envueltas en disputas jurisdiccionales y fueron el origen de poblaciones modernas.AbstractThis study highlights the relevance of medieval inns (ventas or alberguerías) in the repopulation of Segovia’s southern plains beyond the Guadarrama mountain range, between the thirteenth and fifteenth centuries. Archival records have allowed us to identify 75 percent of these road hostels and describe several ancient routes between the city of Segovia and its southernmost limits in the kingdom of Toledo. Segovian inns would become a priority target for seigneurial abuse in the late Middle Ages. Most of these establishments were involved in jurisdictional disputes and were the origin of modern villages and towns.
Migraciones rurales en el paisaje meridional del Reino de Córdoba en el tránsito de la Edad Media a la Moderna
Authors: López Ríder Javier
Published: April 2019

Hasta el momento existen escasos estudios sobre los desplazamientos demográficos acaecidos en el Reino de Córdoba a fines de la Edad Media. Por ello, este artículo estudia los movimientos migratorios identificados en el marco rural de su zona meridional durante el siglo XV y principios del XVI. Primero se detallan las fuentes utilizadas, entre las que adquieren especial importancia los pleitos conservados en el Archivo General de Andalucía, Archivo Municipal de Córdoba y Real Chancillería de Granada, documentación novedosa que proporciona información inédita sobre el tema abordado. A continuación se plasman 510 casos de migraciones, estudiando su tipología y las causas que las motivaron, que ponen de manifiesto un marcado dinamismo poblacional a fines de la Edad Media en este ámbito territorial.AbstractThere are, as of yet, few studies on demographic movements in the kingdom of Cordoba at the end of the Middle Ages. Hence, this article will focus specifically on migratory movements identified in the southern area of its rural realm during the 15th  and early 16th centuries. Firstly, the written sources used will be identified, the most important of which are lawsuits kept in the Archivo General de Andalucía, the Municipal Archives of Cordoba and the archives of the Real Chancillería of Granada. These innovative records contain ill-known information regarding this topic. Secondly, a total of 510 migration cases are studied, a typology will be established, and the causes that led these groups to migrate will be identified. These cases support a distinct population dynamic at the end of the Middle Ages in this geographical area.
El linaje de Aza durante los siglos XIII y XIV: declive y resurgimiento
Authors: García Izquierdo Iván
Published: April 2019

El linaje de Aza fue un modesto grupo aristocrático castellano que adquirió cuotas de poder y cierta notoriedad durante algunas fases de su existencia. Historiográficamente su interés ha pasado un tanto desapercibido a ojos de los especialistas. De hecho, para la etapa comprendida entre los siglos XIII y XIV sólo contamos con un trabajo específico elaborado en época moderna por el genealogista Luis de Salazar y Castro, bastante cuestionable en algunas partes de su relato. Nuestra propuesta trata de acercarse a este grupo nobiliario en ese mismo intervalo temporal, con especial atención al trayecto que transcurre entre los reinados de Alfonso X y Alfonso XI, tratando de superar la mera concepción dinástica en base a dos objetivos. El primero, posicionando a sus integrantes dentro de la escala social del momento. El segundo, calibrando su alcance económico y su capacidad señorial en la Meseta Norte.AbstractThe Aza lineage was a modest Castilian aristocratic group that acquired quotas of power and certain fame during certain phases of its existence. However, it has received relatively little attention on the part of scholarship throughout the ages. In fact, for the period between the thirteenth and the fourteenth centuries, there is only one study by the early-modern genealogist Luis de Salazar y Castro, of questionable merit in certain aspects of his narrative. We seek to examine this aristocratic group over that same period, and with special attention to the trajectory between the reigns of Alfonso X and Alfonso XI of Castile, going beyond a merely descriptive dynastic approach by concentrating on two questions: Firstly, we will consider the position of the family members within the social hierarchy of the moment; and, secondly, we will gauge the family’s economic power and its seigneurial capacity in the northern plateau region (Meseta Norte).
Experimental evidence that fungal symbionts of beetles suppress wood decay by competing with decay fungi
Authors: Skelton James , Loyd Andrew , Smith Jason A. , Blanchette Robert A. , Held Benjamin W. , Hulcr Jiri
Published: April 2019

Throughout forests worldwide, bark and ambrosia beetles inoculate dead and dying trees with symbiotic fungi. We experimentally determined the effects of three common and widely distributed ascomycete symbionts, and one introduced Asian basidiomycete symbiont on the decay of pine sapwood. Ascomycetes caused less than 5% mass loss and no structural degradation, whereas the basidiomycete Flavodon ambrosius caused nearly 15% mass loss and visible degradation of wood structure. In co-inoculation experiments, the beetle symbionts Ophiostoma ips and Raffaelea fusca reduced white and brown rot decay through competition with Ganoderma curtisii and Phaeolus schweinitzii, respectively. The inhibitory effects of O. ips and R. fusca on decay were negated when co-inoculated with F. ambrosius, suggesting that widespread introduction of this beetle symbiont could alter forest carbon fluxes. In contrast to the predominant forest biology narrative, most bark and ambrosia beetles introduce fungi that delay rather than facilitate tree biomass recycling.
Diets containing edible cricket support a healthy gut microbiome in dogs
Authors: Jarett Jessica K , Carlson Anne , Rossoni Serao Mariana C , Strickland Jessica , Serfilippi Laurie , Ganz Holly H
Published: April 2019

The gut microbiome plays an important role in the health of dogs. Both beneficial microbes and overall diversity can be modulated by diet. Fermentable sources of fiber in particular often increase the abundance of beneficial microbes. House crickets (Acheta domesticus) contain the fermentable polysaccharides chitin and chitosan. In addition, crickets are an environmentally sustainable protein source. Considering crickets as a potential source of both novel protein and novel fiber for dogs, 4 diets ranging from 0% to 24% cricket content were fed to determine their effects on healthy dogs’ (n = 32) gut microbiomes. Fecal samples were collected serially at 0, 14, and 29 days, and processed using high-throughput sequencing of 16S rRNA gene PCR amplicons. Microbiomes were generally very similar across all diets at both the phylum and genus level, and alpha and beta diversities did not differ between the various diets at 29 days. A total of 12 ASVs (amplicon sequence variants) from nine genera significantly changed in abundance following the addition of cricket, often in a dose-response fashion with increasing amounts of cricket. A net increase was observed in Catenibacterium, Lachnospiraceae [Ruminococcus], and Faecalitalea, whereas Bacteroides, Faecalibacterium, Lachnospiracaeae NK4A136 group and others decreased in abundance. The changes in Catenibacterium and Bacteroides are predicted to be beneficial to gut health. However, the total magnitude of all changes was small and only a few specific taxa changed in abundance. Overall, we found that diets containing cricket supported the same level of gut microbiome diversity as a standard healthy balanced diet. These results support crickets as a potential healthy, novel food ingredient for dogs.
Myonuclear accretion is a determinant of exercise-induced remodeling in skeletal muscle
Authors: Goh Qingnian , Song Taejeong , Petrany Michael J , Cramer Alyssa AW , Sun Chengyi , Sadayappan Sakthivel , Lee Se-Jin , Millay Douglas P
Published: April 2019

Skeletal muscle adapts to external stimuli such as increased work. Muscle progenitors (MPs) control muscle repair due to severe damage, but the role of MP fusion and associated myonuclear accretion during exercise are unclear. While we previously demonstrated that MP fusion is required for growth using a supra-physiological model (Goh and Millay, 2017), questions remained about the need for myonuclear accrual during muscle adaptation in a physiological setting. Here, we developed an 8 week high-intensity interval training (HIIT) protocol and assessed the importance of MP fusion. In 8 month-old mice, HIIT led to progressive myonuclear accretion throughout the protocol, and functional muscle hypertrophy. Abrogation of MP fusion at the onset of HIIT resulted in exercise intolerance and fibrosis. In contrast, ablation of MP fusion 4 weeks into HIIT, preserved exercise tolerance but attenuated hypertrophy. We conclude that myonuclear accretion is required for different facets of exercise-induced adaptive responses, impacting both muscle repair and hypertrophic growth.
Preference classes in society for coastal marine protected areas
Authors: Ruiz-Frau Ana , Gibbons James M. , Hinz Hilmar , Edwards-Jones Gareth , Kaiser Michel J.
Published: April 2019

Marine protected areas (MPAs) are increasingly being used as conservation tools in the marine environment. Success of MPAs depends upon sound scientific design and societal support. Studies that have assessed societal preferences for temperate MPAs have generally done it without considering the existence of discrete groups of opinion within society and have largely considered offshore and deep-sea areas. This study quantifies societal preferences and economic support for coastal MPAs in Wales (UK) and assesses the presence of distinct groups of preference for MPA management, through a latent class choice experiment approach. Results show a general support for the protection of the marine environment in the form of MPAs and that society is willing to bear the costs derived from conservation. Despite a general opposition toward MPAs where human activities are completely excluded, there is some indication that three classes of preferences within society can be established regarding the management of potentially sea-floor damaging activities. This type of approach allows for the distinction between those respondents with positive preferences for particular types of management from those who experience disutility. We conclude that insights from these types of analyses can be used by policy-makers to identify those MPA designs and management combinations most likely to be supported by particular sectors of society.
Introgressive hybridization in a Spiny-Tailed Iguana,Ctenosaura pectinata, and its implications for taxonomy and conservation
Authors: Zarza Eugenia , Reynoso Víctor H. , Faria Christiana M. A. , Emerson Brent C.
Published: April 2019

Introgression, the transmission of genetic material of one taxon into another through hybridization, can have various evolutionary outcomes. Previous studies have detected signs of introgression between western populations of the Mexican endemic and threatened spiny-tailed iguana,Ctenosaura pectinata. However, the extent of this phenomenon along the geographic distribution of the species is unknown. Here, we use multilocus data together with detailed geographic sampling to (1) define genotypic clusters withinC. pectinata; (2) evaluate geographic concordance between maternally and biparentally inherited markers; (3) examine levels of introgression between genotypic clusters, and (4) suggest taxonomic modifications in light of this information. Applying clustering methods to genotypes of 341 individuals from 49 localities ofC. pectinataand the closely relatedC. acanthura, we inferred the existence of five genotypic clusters. Contact zones between genotypic clusters with signatures of interbreeding were detected, showing different levels of geographic discordance with mtDNA lineages. In northern localities, mtDNA and microsatellites exhibit concordant distributions, supporting the resurrection ofC. brachylopha. Similar concordance is observed along the distribution ofC. acanthura, confirming its unique taxonomic identity. Genetic and geographic concordance is also observed for populations within southwestern Mexico, where the recognition of a new species awaits in depth taxonomic revision. In contrast, in western localities a striking pattern of discordance was detected where up to six mtDNA lineages co-occur with only two genotypic clusters. Given that the type specimen originated from this area, we suggest that individuals from western Mexico keep the nameC. pectinata. Our results have profound implications for conservation, management, and forensics of Mexican iguanas.
Noblella thiunisp. n., a new (singleton) species of minute terrestrial-breeding frog (Amphibia, Anura, Strabomantidae) from the montane forest of the Amazonian Andes of Puno, Peru
Authors: Catenazzi Alessandro , Ttito Alex
Published: April 2019

We describe a new species of minute, terrestrial-breeding frog in the genusNoblella. We collected a single specimen in the leaf litter of primary montane forest (2,225 m a.s.l.) near Thiuni, in the Provice of Carabaya, Department of Puno, in the upper watershed of a tributary of the Inambari River of southern Peru, the same locality where we found the types ofPsychrophrynella glaucaCatenazzi & Ttito 2018. We placed the new species withinNoblellaon the basis of molecular data, minute size, and overall morphological resemblance with the type speciesN. peruvianaand other species ofNoblella, including having three phalanges on finger IV (as inN. coloma,N. heyeri,N. lynchi,N. madreselva,N. peruviana, andN. pygmaea), and terminal phalanges T-shaped and pointed.Noblella thiunisp. n. is distinguished from all other species ofNoblellaby having ventral surfaces of legs bright red, and chest and belly copper reddish with a profusion of silvery spots. The new species further differs from known Peruvian species ofNoblellaby the combination of the following characters: tympanic membrane absent, eyelids lacking tubercles, dorsal skin finely shagreen, tarsal tubercles or folds absent, three phalanges on Finger IV, tips of digits not expanded, no circumferential grooves on digits, inguinal spots present. The new species has a snout–vent length of 11.0 mm in one adult or subadult male. Our new finding confirms the high levels of endemism and beta diversity of small, terrestrial-breeding frogs inhabiting the moss layers and leaf litter in the montane forests of the Amazonian slopes of the Andes and adjacent moist puna grasslands, and suggests much work remains to be done to properly document this diversity.
Gastrocnemius fascicles are shorter and more pennate throughout the first month following acute Achilles tendon rupture
Authors: Hullfish Todd J. , O’Connor Kathryn M. , Baxter Josh R.
Published: April 2019

The purpose of this study was to characterize the short-term effects of Achilles tendon ruptures on medial gastrocnemius. We hypothesized that the fascicles of the medial gastrocnemius muscle of the injured Achilles tendon would be shorter and more pennate immediately following the injury and would persist throughout 4 weeks post-injury. B-mode longitudinal ultrasound images of the medial gastrocnemius were acquired in 10 adults who suffered acute Achilles tendon ruptures and were treated non-operatively. Ultrasound images were acquired during the initial clinical visit following injury as well as 2 and 4 weeks following this initial clinical visit. Resting muscle structure was characterized by measuring fascicle length, pennation angle, muscle thickness, and muscle echo intensity in both the injured and contralateral (control) limbs. Fascicle length was 15% shorter (P< 0.001) and pennation angle was 21% greater (P< 0.001) in the injured muscle compared to the uninjured (control) muscle at the presentation of injury (week 0). These differences in fascicle length persisted through 4 weeks after injury (P< 0.002) and pennation angle returned to pre-injury levels. Muscle thickness changes were not detected at any of the post-injury visits (difference < 4%,P> 0.026). Echo intensity of the injured limb was 8% lower at the presentation of the injury but was not different compared to the contralateral muscle at 2 and 4 weeks post-injury. Our results suggest that Achilles tendon ruptures elicit rapid changes in the configuration of the medial gastrocnemius, which may explain long-term functional deficits.
I’taamohkanoohsin (everyone comes together): A Blackfoot cultural program supporting people with concurrent mental health challenges and other complex needs
Authors: Victor Janice , De Groot Chelsey , Vonkeman Les
Published: April 2019

Trauma, addiction, and homelessness for Indigenous people are interwoven with colonialism and the loss of culture. I’taamohkanoohsin is a grassroots program that was developed to support healing and recovery for a highly marginalized Indigenous population with concurrent mental health challenges and other complex needs in a downtown core neighbourhood.
Effects of Climate Shocks and Climate Adaptation through Livelihood Diversification on Gendered Welfare Gaps in Northern Ghana
Authors: Adzawla William , Kane Abou
Published: April 2019

Globally, addressing poverty levels and inequality remained one of the topmost priorities and has been accorded the first position in the Sustainable Development Goals (SDGs). Although Ghana as a whole is faring well in poverty reduction over the past decades, poverty levels and inequalities remains high in the northern parts. This study analysed the gendered welfare gap and the effects of climate change and livelihood diversification on the welfare gap. Through multistage sampling, 432 households were selected and interviewed using a questionnaire. A selectivity bias corrected Oaxaca Blinder model was estimated using household per capita consumption expenditure as a measure of households’ welfare. The result shows that there is a significant welfare gap of $45.85 (GH₵211.85), an equivalent of 11.4% between male headed and female headed households. Controlling for selectivity bias revealed that the observed gender welfare gap was underestimated. Livelihood diversification had positive significant effect on the explained component of gender welfare gap. Climate change/variability had positive significant effect on welfare gap through the explained component and a negative significant effect through the unexplained component. Therefore, observed climate change and variability led to an increase in gender welfare gap by 64.62%, while the unobservable returns from climate factors contributed to a reduction in gender welfare gap by 193.26%. Since addressing unobservable climate factors is limited, there is the need to improve the climate characteristics of women. Although livelihood diversification is a necessary condition, policies such as training and education that would ensure that females also have higher returns from such strategies are sufficient to address gender welfare gaps. To improve the welfare of farmers in the midst of climate change, animal rearing should be promoted among maize crop farmers. Similarly, government’s policy of one district one factory should consider improving agro-processing opportunities in the region into commercial activities.
Identification and Management of Pests and Diseases of Garden Crops in Santa, Cameroon
Authors: C. N. Konje , A. N. Abdulai , Tange Achiri Denis , D. Nsobinenyui , D. N. Tarla , Tita Margaret Awah
Published: April 2019

Aims: This work sought to identify the pests and diseases that hinder successful gardening and the pesticides used to manage these pests and their frequencies of application.

Place and Duration of Study: This work was carried out in the Santa Area of the North West Region of Cameroon. It was conducted from June 2013 to February 2014.

Methodology: The study was carried out on six farms in Santa, a Sub-division in Mezam Division of the North West Region of Cameroon. On each of these farms, an area of 20 x 20 m was mapped and the plants therein observed. Insect pests, diseases and the pesticides used for their mitigation were identified at each growth stage.

Results: The main diseases identified were clubroot (Plasmodiophora brassicae) and late blight (Phythophthora infestans) while Aphids (Myzus persicae S.), whiteflies (Bemisia tabaci) fruit worms (Helicoverpa amigera), Cutworms, fruitfly (Dacus punctatifrons) and grasshoppers (Zonocerus variegatus) were the prominent insect pests. The most applied pesticides were Cypermethrine and Dimethoate against insects, and Mancozeb and Maneb against fungi.

Conclusion: From this study the most prominent pest of cabbage was the black cutworm (Agrotis ipsilon), which affected the early growing stage. The main disease that affected tomato was blight, seen in both seasons but its severity was greater in the rainy season.  Insect pests were a major problem in the dry season causing high economic losses than in the wet season.
PERSONAL FACTORS AS PREDICTORS OF INTENTION TO USE IT
Authors: Arsanti Tutuk Ari , Yuliasari Emalia
Published: April 2019

The relative power of personal factors such as innovativeness, perceived usefulness, ease of use, and attitude in predicting intention to use IT was tested with 35 students through a field experiment. A common employment website in Indonesia called jobstreet. com is used as a treatment channeling instrument as well as relevant audio and visual media. Simple and multiple regression were used to test the hypotheses. Our findings show that the personal factors such as personal innovation could predict perceived ease of use better than perceived usefulness. The other personal factors such as individual perception (perceived ease of use and perceived usefulness) could predict attitude for the next to effect intention to use IT
Stenosis and Pseudostenosis of the Upper Extremity Arteries in Large‐Vessel Vasculitis
Authors: Marinelli Kathleen C. , Ahlman Mark A. , Quinn Kaitlin A. , Malayeri Ashkan A. , Evers Robert , Grayson Peter C.
Published: April 2019

Objective

Pseudostenosis is a magnetic resonance angiography (MRA) artifact that mimics arterial stenosis. The study objective was to compare imaging and clinical aspects of stenosis and pseudostenosis in a cohort of large‐vessel vasculitis (LVV), including giant‐cell arteritis (GCA) and Takayasu's arteritis (TAK).

Methods

Patients with LVV and comparator conditions (healthy or vasculopathies) underwent MRA of the aortic arch vessels. The subclavian and axillary arteries were systematically assessed for presence of stenosis and pseudostenosis by two independent readers. Serial and delayed imaging and clinical assessments were used to confirm suspected pseudostenoses. Multivariable regression analyses were used to identify associations between angiographic pathology and clinical findings.

Results

One hundred eighty‐four MRA scans were analyzed from patients with GCA (n = 36), TAK (n = 47), and comparators (n = 25). Pseudostenoses were frequently observed (48 of 184 scans, 26%) in the distal subclavian artery only on the side of injection and were shorter in length compared with true stenoses (25 mm vs 78 mm, P < 0.01). There was no difference in prevalence of pseudostenosis by diagnosis (GCA = 33%, TAK = 23%, comparator = 20%, P = 0.44), disease activity status (P = 0.31), or treatment status (P = 1.00). Percent and length of true stenosis were independently associated with pulse and blood pressure abnormalities in the upper extremity. Adjusting for length and stenosis degree, absence of collateral arteries was associated with arm claudication (odds ratio = 2.37, P = 0.03).

Conclusion

Although a pseudostenosis could be falsely interpreted as an arterial stenosis, radiographic and associated clinical features can help distinguish true disease from arterial susceptibility artifacts. In addition, the peripheral vascular examination can help to confirm a suspected true stenosis, as specific aspects of angiographic pathology are associated with vascular examination abnormalities in LVV.
Obfuscation of Embedded Codes in Additive Manufactured Components for Product Authentication
Authors: Chen Fei , Yu Jian H. , Gupta Nikhil
Published: April 2019

Enhancement in the capabilities of additive manufacturing (AM) methods has led to development of many high‐value components for aerospace, automotive, and medical fields. Security concerns, such as (a) a predominantly cloud based process chain of AM may be breached and stolen files can be used for unauthorized reproduction of parts and (b) legitimately acquired parts can be reverse engineered, need to be addressed for this field to protect intellectual property (IP) and deter counterfeiting or unauthorized production. In the present work, a method of embedding an identification code inside the parts manufactured by AM methods is presented, which takes advantage of the layer‐by‐layer manufacturing process. The code is obfuscated by segmenting it into a specific number of parts, which are distributed throughout a large number of printed layers. In this case, viewing the code only from a specific direction provides the correct visualization. A further obfuscation scheme is demonstrated that embeds multiple identification codes in the interpenetrating format. Only a specific set of processing conditions can lead to printing of the authentic code inside the part correctly. Numerous other conditions lead to printing of wrong code inside the part, which will lead to positive identification of counterfeit or unauthorized parts. Securing the AM process chain can help in accelerating the industrial applications of this versatile method.
Tailoring the Functionality of Organic Spacer Cations for Efficient and Stable Quasi‐2D Perovskite Solar Cells
Authors: Fu Weifei , Liu Hongbin , Shi Xueliang , Zuo Lijian , Li Xiaosong , Jen Alex K.‐Y.
Published: April 2019

The recent development of quasi‐2D perovskite solar cells have drawn significant attention due to the improved stability of these materials and devices against moisture compared to their 3D counterparts. However, the optoelectronic properties of 2D perovskites need to be optimized in order to achieve high efficiency. In this work, the effect of spacer cations, i.e., phenethylammonium (PEA), 4‐fluorophenethylammonium (F‐PEA), and 4‐methoxyphenethylammonium (MeO‐PEA) on the optoelectronic properties and device performance of quasi‐2D perovskites is systematically studied. It is observed that both larger and more hydrophobic cations can improve perovskite stability against moisture, while larger size can adversely influence the device performance. Interestingly, with F‐PEA or MeO‐PEA, distribution of n value can be shifted toward high 3D content in quasi‐2D perovskite layers, which enables lower bandgaps and possibly lower exciton binding energy. Due to the best charge transport and lowest bandgap, the F‐PEAI‐based quasi‐2D perovskite (n = 5) solar cell shows a highest power conversion efficiency (PCE) of 14.5% with excellent stability in air with a humidity of 40–50%, keeping 90% of the original PCE after 40 d. It is believed that the approach may open a way for the design of new organic spacer cations for stable low‐dimensional hybrid perovskites with high performance.
Bright Aggregation‐Induced Emission Dots for Dynamic Tracking and Grading of Patient‐Derived Xenografts in Zebrafish
Authors: Teh Cathleen , Manghnani Purnima Naresh , Boon Grace Ng Hwee , De Cheng Terrence You , Lim Wan‐Teck , Lim Elaine Hsuen , Chua Boon Tin , Liu Bin
Published: April 2019

Cancer prognosis will benefit from a scoring system that could grade malignant traits of patient‐derived cells by assessing their growth and metastasis in a living system. Specific tracking of patient‐derived cells requires labeling by contrast agents with good signal‐to‐noise ratio and no specific stain of host tissues. Towards this aim, aggregation‐induced emission (AIE) dots are developed for in vivo cancer tracking with emphasis on reproducible optimized formulation and specific fluorescent labeling of cells that enable enhanced spatial temporal resolution in vivo. The importance of energy‐dependent AIE dots uptake for patient‐derived cell labeling is emphasized to reveal their specific uptake by viable cancer cells. Using optically transparent zebrafish embryo, the ability is demonstrated to follow the engraftment of transplanted AIE dot labeled cells in zebrafish brains over one week. Cells detected outside the brain after 7 d are quantified as metastatic cells. Results from seven clinical samples demonstrate the utility of this methodology to differentiate low engraftment level of benign neoplasms from higher engraftment level and metastasis detected in malignant ovarian cancer specimens. Achieving clinically validated results supports the use of AIE dot labeled patient derived cells in zebrafish xenografts for future cancer prognosis.
Toward Design of Novel Materials for Organic Electronics
Authors: Friederich Pascal , Fediai Artem , Kaiser Simon , Konrad Manuel , Jung Nicole , Wenzel Wolfgang
Published: April 2019

Materials for organic electronics are presently used in prominent applications, such as displays in mobile devices, while being intensely researched for other purposes, such as organic photovoltaics, large‐area devices, and thin‐film transistors. Many of the challenges to improve and optimize these applications are material related and there is a nearly infinite chemical space that needs to be explored to identify the most suitable material candidates. Established experimental approaches struggle with the size and complexity of this chemical space. Herein, the development of simulation methods is addressed, with a particular emphasis on predictive multiscale protocols, to complement experimental research in the identification of novel materials and illustrate the potential of these methods with a few prominent recent applications. Finally, the potential of machine learning and methods based on artificial intelligence is discussed to further accelerate the search for new materials.
A Thermodynamically Favored Crystal Orientation in Mixed Formamidinium/Methylammonium Perovskite for Efficient Solar Cells
Authors: Xu Ziqi , Liu Zonghao , Li Nengxu , Tang Gang , Zheng Guanhaojie , Zhu Cheng , Chen Yihua , Wang Ligang , Huang Yuan , Li Liang , Zhou Ning , Hong Jiawang , Chen Qi , Zhou Huanping
Published: April 2019

Crystal orientation has a great impact on the properties of perovskite films and the resultant device performance. Up to now, the exquisite control of crystal orientation (the preferred crystallographic planes and the crystal stacking mode with respect to the particular planes) in mixed‐cation perovskites has received limited success, and the underlying mechanism that governs device performance is still not clear. Here, a thermodynamically favored crystal orientation in formamidinium/methylammonium (FA/MA) mixed‐cation perovskites is finely tuned by composition engineering. Density functional theory calculations reveal that the FA/MA ratio affects the surface energy of the mixed perovskites, leading to the variation of preferential orientation consequently. The preferable growth along the (001) crystal plane, when lying parallel to the substrates, affects their charge transportation and collection properties. Under the optimized condition, the mixed‐cation perovskite (FA1–x
MAx
PbI2.87Br0.13 (Cl)) solar cells deliver a champion power conversion efficiency over 21%, with a certified efficiency of 20.50 ± 0.50%. The present work not only provides a vital step in understanding the intrinsic properties of mixed‐cation perovskites but also lays the foundation for further investigation and application in perovskite optoelectronics.
Color Patterning of Luminescent Perovskites via Light‐Mediated Halide Exchange with Haloalkanes
Authors: Wong Ying‐Chieh , Wu Wen‐Bin , Wang Tian , Ng Jun De Andrew , Khoo Khoong Hong , Wu Jie , Tan Zhi‐Kuang
Published: April 2019

Lead halide perovskite possesses a semiconductor bandgap that is readily tunable by a variation in its halide composition. Here, a photo‐activated halide exchange process between perovskite nanocrystals and molecular haloalkanes is reported, which enables the perovskite luminescence to be controllably shifted across the entire visible spectrum. Mechanistic investigations reveal a mutual exchange of halogens between the perovskite crystal surface and a chemisorbed haloalkane, yielding nanocrystals and haloalkanes with mixed halide contents. Exchange kinetics studies involving primary, secondary, and tertiary haloalkanes show that the rate of reaction is governed by the activation barrier in the breakage of the covalent carbon–halogen (CX) bond, which is a function of the CX bond energy and carbon radical stability. Employing this halide exchange approach, a micrometer‐scale trichromatic patterning of perovskites is demonstrated using a light‐source‐integrated inkjet printer and tertiary haloalkanes as color‐conversion inks. The haloalkanes volatilize after halide exchange and leave no residues, thereby offering significant processing advantage over conventional salt‐based exchange techniques. Beyond the possible applications in new‐generation micro‐LED and electroluminescent quantum dot displays, this work exemplifies the rich surface and photochemistry of perovskite nanocrystals, and could lead to further opportunities in perovskite‐based photocatalysis and photochemical sensing.
Review on the Electroluminescence Study of Lanthanide Complexes
Authors: Wang Liding , Zhao Zifeng , Wei Chen , Wei Huibo , Liu Zhiwei , Bian Zuqiang , Huang Chunhui
Published: April 2019

Thanks to their characteristic photophysical properties, lanthanide complexes are of great value in many fields. Especially, high‐purity green and red lights from Tb(III) and Eu(III) complexes are particularly suitable for displays, and near‐infrared (NIR) emissions from Nd(III), Er(III), and Yb(III) complexes have huge potential in night‐vision devices. Therefore, since shortly after the birth of organic light‐emitting diodes (OLEDs), electroluminescence studies on lanthanide complexes have attracted much attention. This review comprehensively summarizes advances in the electroluminescence study of all lanthanide complexes in the past 30 years, where the lanthanide complexes are basically classified according to their emission wavelengths, i.e., visible light, near‐infrared (NIR) light, and simultaneous visible and NIR light. On this basis, the challenges and opportunities faced by electroluminescence of lanthanide complexes are also discussed.
Dirac Fermion and Plasmon Dynamics in Graphene and 3D Topological Insulators
Authors: In Chihun , Choi Hyunyong
Published: April 2019

Light–matter interactions illuminate the nature of solids and provide a second look on associated carrier dynamics. In particular, graphene and 3D topological insulators (3D TI) with broadband electromagnetic excitation have revealed to host exotic dynamic interactions. Much of Dirac‐point physics arises from discrete lattice symmetries and nontrivial Z2 classification of Bloch states. In this review, ongoing spectroscopic works on graphene and 3D TI are presented, where special attention is on the far‐infrared terahertz (THz) spectroscopy that characterizes the intraband dynamics. The constant absorbance of graphene upon interband particle–hole generation exhibits nonclassical results of gapless dispersion, which can be elucidated by the relativistic Dirac equations with zero rest mass. The massless Dirac fermions on graphene and 3D TI surface exhibit distinct phenomena compared to the conventional systems. First, the transient responses after pulse excitation reveal the semimetallic states of the gapless electronic dispersion, where the Fermi energy in equilibrium determines the crossover from metallic to semiconducting states. Second, the 2D Dirac plasmon dispersion of graphene and 3D TI surface exhibits unconventional density dependence in comparison to the massive electronic systems. The novel optical phenomena in graphene and 3D TI surface can serve for advanced optoelectronic and optospintronic applications.
Magneto‐Optical Bi:YIG Films with High Figure of Merit for Nonreciprocal Photonics
Authors: Fakhrul Takian , Tazlaru Stana , Beran Lukáš , Zhang Yan , Veis Martin , Ross Caroline A.
Published: April 2019

Thin film magneto‐optical (MO) materials are enablers for integrated nonreciprocal photonic devices such as isolators and circulators. Films of polycrystalline bismuth‐substituted yttrium iron garnet (Bi:YIG) have been grown on silicon substrates and waveguide devices, in which an yttrium iron garnet (YIG) seedlayer is placed either above or below the active Bi:YIG layer to promote crystallization. The films exhibit a high MO figure of merit of up to 769° dB−1 at 1550 nm wavelength. Growth of single phase Bi:YIG on the sidewalls of waveguides is demonstrated, which can be used in nonreciprocal transverse electric (TE)‐mode devices.
Weight Programming in DNN Analog Hardware Accelerators in the Presence of NVM Variability
Authors: Mackin Charles , Tsai Hsinyu , Ambrogio Stefano , Narayanan Pritish , Chen An , Burr Geoffrey W.
Published: April 2019

Crossbar arrays of nonvolatile memory (NVM) can potentially accelerate development of deep neural networks (DNNs) by implementing crucial multiply–accumulate (MAC) operations at the location of data. Effective weight‐programming procedures can both minimize the performance impact during training and reduce the down time for inference, where new parameter sets may need to be loaded. Simultaneous weight programming along an entire dimension (e.g., row or column) of a crossbar array in the context of forward inference and training is shown to be important. A framework for determining the optimal hardware conditions in which to program weights is provided, and its efficacy in the presence of considerable NVM variability is explored through simulations. This strategy is shown capable of programming 98–99% of weights effectively, in a manner that is both largely independent of the target weight distribution and highly tolerant to variability in NVM conductance‐versus‐pulse characteristics. The probability that a weight fails to reach its target value, termed Pfail, is quantified and the fundamental trade‐off between Pfail and weight programming speed is explored. Lastly, the impact of imperfectly programmed weights on DNN test accuracies is examined for various networks, including multi‐layer perceptrons (MLPs) and long short‐term memory (LSTM).
Interfacial Solar‐to‐Heat Conversion for Desalination
Authors: Liu Huidong , Huang Zhi , Liu Kang , Hu Xuejiao , Zhou Jun
Published: April 2019

Solar desalination is a promising and sustainable solution for water shortages in the future. Interfacial solar‐to‐heat conversion for desalination has attracted increasing attention in the past decades, due to the heat localization induced high thermal efficiency, simple structure, and low cost. In this review, the authors summarize and analyze the critical processes involved in such a solar desalination system, including the thermal conversion and transport, salt dissipation, and vapor manipulation. Mathematical models of heat transfer and salt dissipation are also built for quantitative analysis of systematic performance relative to properties of employed materials and system designs. Recent efforts devoted to improving the overall thermal efficiency, salt rejection, and water yield are then summarized. Based on the analysis and previous results, opportunities for further interfacial solar desalination development are highlighted.
Peroxydisulfate‐Mediated Transition‐Metal‐Free Oxidative C(sp3)−H Bond Lactonization
Authors: Nozawa‐Kumada Kanako , Kurosu Satoshi , Shigeno Masanori , Kondo Yoshinori
Published: April 2019

An inexpensive, powerful, and eco‐friendly method for transition‐metal‐free oxidative C(sp3)−H bond lactonization was developed using sodium peroxydisulfate as the sole oxidant. The cyclization of 2‐alkylbenzoic acids containing a primary, secondary or tertiary carbon at the benzylic position proceeded smoothly, affording a variety of lactone derivatives. Furthermore, various functional groups such as halogen, cyano, nitro and hydroxy groups were tolerated under the reaction conditions.
Household composition and the infant fecal microbiome: The INSPIRE study
Authors: Lane Avery A. , McGuire Michelle K. , McGuire Mark A. , Williams Janet E. , Lackey Kimberly A. , Hagen Edward H. , Kaul Abhishek , Gindola Debela , Gebeyehu Dubale , Flores Katherine E. , Foster James A. , Sellen Daniel W. , Kamau‐Mbuthia Elizabeth W. , Kamundia Egidioh W. , Mbugua Samwel , Moore Sophie E. , Prentice Andrew M. , Kvist Linda J. , Otoo Gloria E. , Rodríguez Juan M. , Ruiz Lorena , Pareja Rossina G. , Bode Lars , Price William J. , Meehan Courtney L.
Published: April 2019

Objectives

Establishment and development of the infant gastrointestinal microbiome (GIM) varies cross‐culturally and is thought to be influenced by factors such as gestational age, birth mode, diet, and antibiotic exposure. However, there is little data as to how the composition of infants' households may play a role, particularly from a cross‐cultural perspective. Here, we examined relationships between infant fecal microbiome (IFM) diversity/composition and infants' household size, number of siblings, and number of other household members.

Materials and methods

We analyzed 377 fecal samples from healthy, breastfeeding infants across 11 sites in eight different countries (Ethiopia, The Gambia, Ghana, Kenya, Peru, Spain, Sweden, and the United States). Fecal microbial community structure was determined by amplifying, sequencing, and classifying (to the genus level) the V1–V3 region of the bacterial 16S rRNA gene. Surveys administered to infants' mothers identified household members and composition.

Results

Our results indicated that household composition (represented by the number of cohabitating siblings and other household members) did not have a measurable impact on the bacterial diversity, evenness, or richness of the IFM. However, we observed that variation in household composition categories did correspond to differential relative abundances of specific taxa, namely: Lactobacillus, Clostridium, Enterobacter, and Klebsiella.

Discussion

This study, to our knowledge, is the largest cross‐cultural study to date examining the association between household composition and the IFM. Our results indicate that the social environment of infants (represented here by the proxy of household composition) may influence the bacterial composition of the infant GIM, although the mechanism is unknown. A higher number and diversity of cohabitants and potential caregivers may facilitate social transmission of beneficial bacteria to the infant gastrointestinal tract, by way of shared environment or through direct physical and social contact between the maternal–infant dyad and other household members. These findings contribute to the discussion concerning ways by which infants are influenced by their social environments and add further dimensionality to the ongoing exploration of social transmission of gut microbiota and the “old friends” hypothesis.
Validation of a rhinologic virtual surgical simulator for performing a Draf 3 endoscopic frontal sinusotomy
Authors: Won Tae‐Bin , Cho Sung‐Woo , Sung Myung‐Whun , Paek Sun Ha , Chan Sonny , Salisbury Kenneth , Blevins Nikolas H. , Vaisbuch Yona , Hwang Peter
Published: April 2019

Background

We recently introduced a patient‐specific rhinologic virtual surgical environment (VSE) that has shown potential for surgical rehearsal of various skull base lesions. Our aim in this study was to validate the usefulness of the rhinology VSE in performing the Draf 3 procedure.

Methods

An outside‐in Draf 3 procedure was performed on 4 cadaver heads. Computed tomography (CT) scans were obtained before and after cadaver dissection (CD). Pre‐dissection CT scans were used to construct a cadaver‐specific VSE. A virtual Draf 3 dissection (VD) was performed using the same technique. Validation was conducted by comparing the final common frontal outflow tract. A subjective comparison of the post‐dissection endoscopic findings (CD vs VD) and an objective measurement using the post‐dissection CT scan for the CD and the reconstructed CT scan obtained from the data after the VD was performed.

Results

Subjective overall resemblance of the 2 dissections (CD vs VD) assessed by the 4‐point Likert scale (0‐3) was 2.5 (median interquartile range [IQR], 0.25) for the 4 cadavers. The median difference for the anteroposterior dimension of the frontal neo‐ostium (CD vs VD) assessed in the midsagittal view was 0.11 mm, whereas the median difference for the lateral dimension assessed in the coronal view was 2.71 mm. Thus, no statistical difference was observed.

Conclusion

VD showed nearly matching results with the actual cadaver dissection. With further validation, our rhinologic VSE may be used for presurgical planning and rehearsal before the actual Draf 3 procedure is performed in the operating room.