bluuebunny/crossref_metadata_2025 huggingface dataset:
The potential of combining UAV and remote sensing in supporting precision mapping of irrigation systems for paddy land in urban agricultural areas: study case in the Hoa Vang district, Danang city, Central Vietnam
Authors: TRAN Phuong Thi , TRUONG Phuong Do Minh , HO Hoang Viet , NGUYEN Hai Thi , NGUYEN Ngoc Bich
Published: February 2021

This research was carried out to test the potential of combining unmanned aerial vehicle (UAV) and remote sensing (RS) to support precision mapping of irrigation systems for paddy land. The study area is an urban/agricultural area of Central Vietnam. The Sentinel-2A imagery acquired on 30 June 2018 was interpreted according an object-based classification method aiming to map paddy land and irrigation systems for the Hoa Vang district; the total accuracy was 91.33% with a Kappa coefficient of 0.87. However, with the spatial resolution from the Sentinel-2A images (20 meters x 20 meters) it was difficult to classify paddy land and water from other objects within small and scattered parcel areas. This research was designed on five experimental flying zones, collecting 2,085 images by the UAV. With the very high spatial resolution data of the UAV, it was possible to clearly identify the boundaries of paddy land parcels, water sources such as rivers and lakes, and other objects such as canals and concrete irrigation systems. This classification derived from the orthogonal images from the five experimental zones using an object-based classification method, correcting the interpretation results of the Sentinel 2A images. Outcomes indicate that, the combination of UAV and RS can be applied to support precision mapping of irrigation systems for paddy land in urban agricultural areas.

Nghiên cứu này được thực hiện nhằm thử nghiệm khả năng kết hợp giữa UAV với viễn thám trong hỗ trợ độ chính xác của bản đồ hệ thống nước tưới cho đất trồng lúa ở vùng nông nghiệp đô thị tại Miền trung Việt Nam. Ảnh viễn thám Sentinel- 2A thu nhận vào 30/6/2018 đã được giải đoán bằng phương pháp định hướng đối hướng để thành lập bản đồ hệ thống nguồn nước tưới cho huyện Hòa Vang vào năm 2018, với kết quả độ chính xác tổng số là 91,33% và hệ số kappa là 0,87. Mặc dù với kết quả giải đoán có độ chính xác cao nhưng với độ phân giải không gian của ảnh Sentinel-2A là 20m x 20m rất khó để phân loại được các vùng đất lúa có diện tích nhỏ và phân bố phân tán. Nghiên cứu này đã thiết kế 5 khu vực bay thử nghiệm với 2.085 ảnh để thu thập dữ liệu từ UAV. Có thể thấy rằng dữ liệu ảnh từ UAV với độ phân giải siêu cao có thể nhận diện và phân biệt được một cách rõ ràng không chỉ ranh giới của các thửa đất lúa, hệ thống nguồn nước như sông hồ, mà còn cả những đối tượng kênh mương thủy lợi nhỏ. Kết quả giải đoán các ảnh bay chụp bằng UAV sử dụng dụng phương pháp định hướng đối tượng, nghiên cứu này đã hiệu chỉnh được kết quả giải đoán ảnh Sentinel 2A. Kết quả cho thấy việc kết hợp dữ liệu viễn thám với UAV là hoàn toàn có khả năng sử dụng để hỗ trợ độ chính xác thành lập bản đồ hệ thống nguồn nước cho đất trồng lúa ở vùng nông nghiệp đô thị.
Las primeras mujeres juristas de Cataluña. Evolución del número de mujeres estudiantes de Derecho en Cataluña y colegiadas en Barcelona entre 1910 y 1968
Authors: Soler i Penya Patrícia
Published: February 2021

A principios del siglo XXI, al menos en los países más desarrollados, se ha conseguido la igualdad formal entre hombres y mujeres, aunque aún no la igualdad real. Es cierto que mujeres y hombres se han incorporado por igual al sistema educativo, pero esta incorporación ha supuesto un largo proceso de lucha, debido a las resistencias sociales, basadas principalmente, en la adjudicación de los roles tradicionales femeninos y masculinos. El artículo pretende hacer una revisión histórica del camino recorrido por las mujeres en el ámbito de los estudios universitarios en Cataluña, más concretamente el de las estudiantes de la Facultad de Derecho de la Universidad de Barcelona desde el año 1910 hasta el 1968. El estudio se ha realizado a partir del análisis de los libros de registro de matrículas y títulos de licenciado hallados en el Archivo Histórico de la Universidad de Barcelona, las guías judiciales ubicadas en el Ilustre Colegio de Abogados de Barcelona y los anuarios estadísticos del Fondo Documental del Instituto Nacional de Estadística. Los resultados muestran la relación entre el número de matriculadas, licenciadas, colegiadas y abogadas con y sin ejercicio a lo largo de estos años y cómo los diferentes acontecimientos históricos han repercutido en el desarrollo de la mujer jurista. Teniendo en cuenta el contexto de represión en el que la mujer se ha visto inmersa durante tantos años, no solo la matrícula femenina en la Facultad no ha dejado de crecer, sino que en buena medida, las mujeres ejercieron la abogacía, venciendo los obstáculos.
Habilidades en la alta gestión y política universitarias
Authors: Vallespín Pérez David
Published: February 2021

El presente artículo centra su atención en el examen de aquel conjunto de habilidades que deberían acompañar, en todo momento, a quienes desempeñan en la Universidad Pública labores de alta gestión y responsabilidad. A tal efecto, metodológicamente, se parte del análisis del liderazgo de la máxima autoridad académica de la Universidad con especial atención, de una parte, al papel que le debe corresponde al rector o rectora en la gestión de la toma de decisiones, la planificación e implementación de la dinámica de trabajo de su equipo de dirección y la gestión de conflictos entre los diferentes estamentos universitarios; y de otra, a lo que deben ser, desde su propio ejemplo, sus habilidades de negociación y comunicación. Utilizando un procedimiento interdisciplinar y transversal, en el que confluyen Educación, Psicología y Derecho, se termina por concluir, previo análisis comparado de los diferentes estilos de liderazgo (commanding, visionary, affiliative, democratic, pacesetting y coaching), que, dependiendo de las circunstancias de cada momento y en función de los problemas a resolver, todos y cada uno de ellos pueden resultar útiles en manos de un rector o rectora que, siendo líder, sepa ejercer como tal, tenga la habilidad de hacerse las preguntas oportunas en cada caso, escuchando activamente a toda la comunidad universitaria, y que proyecte su dedicación y voluntad de servicio en el interés común de la institución universitaria que dirige.
Alineamiento de competencias, actividades y evaluación continuada en grupos grandes. Una propuesta desde el Derecho penal
Authors: Baucells Lladós Joan , Antich Soler Jaume , Cardona Barber Antoni , Carrillo Ruíz Rosa , Cuenca García María José , Cugat Mauri Miriam , Riba Ciurana José , Rodríguez Puerta María José
Published: February 2021

El presente estudio expone la reflexión realizada por la Unidad de Derecho penal y Criminología de la UAB frente a la exigencia normativa de incrementar hasta el 50% de la nota final con la evaluación continuada. El reto era visto como una oportunidad para desarrollar resultados de aprendizaje mucho más prácticos; para diseñar e implementar un modelo de evaluación continuada sin que, en contextos de grupos grandes, necesariamente desbordara la capacidad de corrección de los profesores y de retorno de los resultados al alumnado; y, finalmente, para implementar una propuesta colectiva de alineamiento constructivo entre competencias, actividades propuestas a los alumnos dentro y fuera del aula y las actividades de evaluación continuada y final. La propuesta docente fue sometida a una encuesta de los alumnos y un grupo de discusión con los profesores dando como resultado una valoración positiva de los objetivos propuestos, así como de la necesidad de limitar el número de actividades evaluables para mejorar el rendimiento académico de los alumnos.
La propuesta de la Unión Europea relativa a un impuesto sobre el carbono en frontera y su compatibilidad con las normas de la Organización Mundial del Comercio
Authors: Fernández Pons Xavier
Published: February 2021

La Comisión Europea, en su reciente Comunicación sobre el Pacto Verde Europeo, vinculado estrechamente a la consecución de los Objetivos de Desarrollo Sostenible (ODS) de las Naciones Unidas, contempla un ambicioso plan para que la Unión Europea (UE) lidere efectivamente la lucha contra el cambio climático a escala mundial. Entre las múltiples medidas previstas en el Pacto Verde Europeo, éste programa una drástica reducción de las emisiones de carbono y otros gases de efecto invernadero dentro de la UE e incluye una propuesta para establecer un impuesto o mecanismo de ajuste sobre el carbono en frontera. Esta contribución se dedica a dicha concreta propuesta. Examina su finalidad, tendente a disminuir el riesgo de una fuga de carbono desde la UE por el traslado de empresas o el incremento de importaciones de terceros países menos comprometidos con la reducción de emisiones, y analiza su compatibilidad con las normas de la Organización Mundial del Comercio (OMC), teniendo en cuenta sus principios básicos, excepciones y, particularmente, su regulación sobre ajustes fiscales en frontera.
La falsa oposición entre teoría y práctica en la educación jurídica
Authors: Torres Ortega Ilsse Carolina
Published: February 2021

Este trabajo tiene por objeto discutir la pertinencia de la oposición entre teoría y práctica en la enseñanza del Derecho. Para llevar a cabo lo anterior, la autora explora la posibilidad de que tal oposición esté siendo utilizada como un mecanismo falaz que lleva a enfrentar cuestiones que, en realidad, están interrelacionadas. Esta exploración se desarrolla distinguiendo diversos sentidos de teoría y de práctica, concluyendo que es necesario reconstruir estas nociones de una manera más adecuada, atendiendo a las actividades que realizan –y/o deberían realizar– los juristas y que, por tanto, tendrían que estar presentes en la educación de los futuros profesionales del Derecho.
Buenas prácticas en la dirección de trabajos de fin de grado. Especial referencia al área jurídica
Authors: Legerén Molina Antonio
Published: February 2021

El objetivo de este trabajo es ofrecer orientaciones y modos prácticos de abordar la tarea de tutorizar la elaboración del Trabajo de Fin de Grado, culmen del proceso formativo de cualquier estudiante. Las reflexiones que se recogen en este texto son fruto de las opiniones de los estudiantes tutorizados, así como de la dirección a lo largo de los últimos años de más de medio centenar de TFG, y, aunque resultan útiles en general para cualquier tipo de Trabajo de Fin de Grado, tienen especial utilidad para los del área jurídica. Las buenas prácticas que aquí se desarrollan pretenden colmar buena parte de los problemas manifestados por los estudiantes y se agrupan en torno a tres bloques diferenciados: las relativas a la reunión inicial entre el tutor y el estudiante, las que conciernen a la operativa de la labor tutelar durante la confección del TFG y las atinentes a la fase que tiene lugar tras su conclusión.
Virtual Colloquium: Scholars Critically Unpack Race/Ethnicity/Diversity in Advertising
Authors: Chambers Jason P. , Davis Judy Foster , Tsai Wan-Hsiu Sunny , Scanlon Jennifer , O'Barr William M.
Published: February 2021

Abstract: Advertising & Society Quarterly held its fourth annual Colloquium on December 3–4, 2020. During this virtual event, three panels took different perspectives on race/ethnicity/diversity in advertising. This article presents the colloquium's third panel featuring scholars providing a critical analysis of the politics of race/ethnicity/diversity in advertising. Jason P. Chambers examines the relationship between advertising and social justice activism for Black Americans over the last 60 years. Judy Foster Davis discusses the role of the advertising industry's image makers in reinforcing White cultural superiority. Wan-Hsiu Sunny Tsai unpacks the politics of multicultural advertising and the fine line between emphasizing cultural uniqueness and relying upon stereotypes.
Key Concepts in Advertising: Social Tableaux
Authors: Timke Edward
Published: February 2021

Abstract: Key Concepts in Advertising articles provide a short lecture on an important concept to help understand advertising's place in society, culture, history, and the economy. This article focuses on the concept of social tableaux , which is defined and applied extensively in historian Roland Marchand's book Advertising the American Dream . A series of short videos provide background information about Marchand's book, define social tableaux, and encourage viewers to apply the concept in their own creation and analysis of advertisements. In the end, viewers learn that social tableaux allow the unpacking of the idealized social and material relations captured through advertisements' representations of people, places, products, and services at a given moment in time. A recommended reading list provides other sources to learn more about the concept and its associated topics.
Modeling photon pair generation by second-order surface nonlinearity in silica nanofibers
Authors: Azzoune Abderrahim , Delaye Philippe , Pauliat Gilles
Published: February 2021

In this paper, we present a design of an all-fiber source of correlated photon pairs based on standard telecommunications tapered fibers. We examine the generation of correlated photon pairs using parametric process

χ

(
2
)

in silica tapered optical fibers. This nonlinear process is ensured thanks to surface dipole and bulk multipole nonlinearities. The process of photon creation is modeled by taking into account the vector aspect of the propagation of the optical field in a silica nanofiber. The phase matching is provided by propagating the pump field in one spatial mode while generating a photon pair in another spatial mode. The generation efficiency of photon pairs depends on diameter uniformity of the nanofiber after the manufacturing process. We size this nanofiber for a good optimization of photon pair generation efficiency, and we report that the tolerance in diameter uniformity is

Δ
d
=
2

n
m

for a generation rate of photon pairs estimated to

N

ph

≈
22

000

p
a
i
r
s

/

s

, for 1 W power pump and a nanofiber length of 1.1 mm. Deposits on the nanofiber can be used in order to relax the manufacturing constraints on diameter to maximize the generation rate of photon pairs. As an example, the use of polytetrafluoroethylene on the nanofiber applied as a cladding whose thickness is infinite makes it possible to relax the constraints on the nanofiber diameter. For the same

Δ
d
=
2

n
m

, a generation rate of photon pairs estimated to

N

ph

≈
78

000

p
a
i
r
s

/

s

for 1 W power pump and a nanofiber length of 2.4 mm is predicted.
Rapid prototyping of flexible terahertz metasurfaces using a microplotter
Authors: Salmon A. , Lavancier M. , Brulon C. , Coudrat L. , Fix B. , Ducournau G. , Peretti R. , Bouchon P.
Published: February 2021

Additive manufacturing is a promising tool for the rapid prototyping of terahertz metamaterials at low-cost. In this letter, a terahertz metamaterial is fabricated using a microplotter system on a flexible polyimide film. The limits of the rapid prototyping technique is investigated both experimentally and numerically in order to determine the spectral range accessible by the fabricated metamaterials. Here, the metamaterial is composed of four arrays of metal-insulator-metal (MIM) antennas exhibiting a Fabry Perot resonance at frequencies from 0.25 to 0.8 THz. From a structural analysis of the printed antennas, we determined that the printing resolution is limited to about 5 μm. The arrays are analyzed by terahertz time-domain spectroscopy (THz-TDS). The good agreement between THz-TDS measurements and numerical simulations showed that the microplotter system can be used for rapid prototyping by adjusting a limited number of fabrication parameters.
Femtosecond laser ablation by bibursts in the MHz and GHz pulse repetition rates
Authors: Žemaitis Andrius , Gaidys Mantas , Gečys Paulius , Barkauskas Martynas , Gedvilas Mindaugas
Published: February 2021

Here, to the best of our knowledge, for the first time we report an in-depth experimental study of high ultrafast laser ablation efficiency for processing of copper and steel with single-pulses, MHz, GHz, and burst-in-the-burst (biburst) regimes. The comparison of burst, biburst, and single-pulse ablation efficiencies was performed for beam-size-optimised regimes, showing the real advantages and disadvantages of milling and drilling processing approaches. Highly efficient ultrashort pulse laser processing was achieved for ∼1 µm optical wavelength: 8.8 µm3/µJ for copper drilling, 5.6 µm3/µJ for copper milling, and 6.9 µm3/µJ for steel milling. We believe that the huge experimental data collected in this study will serve well for the better understanding of laser burst-matter interaction and theoretical modelling.
Mode-resolved dual-comb spectroscopy using error correction based on single optical intermedium
Authors: Yu Haoyang , Zhou Qian , Li Xinghui , Wang Xiaohao , Ni Kai
Published: February 2021

Dual-comb spectroscopy (DCS) is an emerging and promising spectrometric technique with high resolution, high sensitivity, broad spectral range, and fast acquisition speed. For the recovery of the information encoded on comb modes without resolution loss, two continuous wave lasers are commonly utilized as optical intermedia to track the real-time jitter of dual-comb interferograms. This paper presents a simplified error correction method based on single optical intermedium for quasi-free-running fiber DCS. This method combines the strengths of conventional optical referencing and self-referencing error correction. We acquired whole P branch H13C14N transmittance spectra in the near infrared as a demonstration. In contrast to that of conventional dual intermedium error correction, the standard deviation of our method was merely 0.01 over the 4 THz spectral range. Our method provides a balanced and practical postprocessing routine for high-performance mode-resolved DCS applications.
Phase noise of electro-optic dual frequency combs
Authors: Deakin Callum , Zhou Zichuan , Liu Zhixin
Published: February 2021

Dual frequency combs are emerging as new tools for spectroscopy and signal processing. The relative phase noise of the tone pairs determines the performance (e.g., signal-to-noise ratio) of the detected spectral components. Although previous research has shown that the signal quality generally degrades with an increase in frequency difference between tone pairs, the scaling of the relative phase noise of dual frequency comb systems has not been fully characterized. In this Letter, we model and characterize the phase noise of a coherent electro-optic dual frequency comb system. Our results show that at high offset frequencies, the phase noise is an incoherent sum of the timing phase noise of the two combs, multiplied by line number. At low offset frequencies, however, the phase noise scales more slowly due to the coherence of the common frequency reference.
Efficient reservoir computing using field programmable gate array and electro-optic modulation
Authors: Kumar Prajnesh , Jin Mingwei , Bu Ting , Kumar Santosh , Huang Yu-Ping
Published: February 2021

We experimentally demonstrate a hybrid reservoir computing system consisting of an electro-optic modulator and field programmable gate array (FPGA). It implements delay lines and filters digitally for flexible dynamics and high connectivity, while supporting a large number of reservoir nodes. To evaluate the system’s performance and versatility, three benchmark tests are performed. The first is the 10th order Nonlinear Auto-Regressive Moving Average test (NARMA-10), where the predictions of 1000 and 25,000 steps yield impressively low normalized root mean square errors (NRMSE’s) of 0.142 and 0.148, respectively. Such accurate predictions over into the far future speak to its capability of large sample size processing, as enabled by the present hybrid design. The second is the Santa Fe laser data prediction, where a normalized mean square error (NMSE) of 6.73 × 10−3 is demonstrated. The third is the isolate spoken digit recognition, with a word error rate close to 0.34%. Accurate, versatile, flexibly reconfigurable, and capable of long-term prediction, this reservoir computing system could find a wealth of impactful applications in real-time information processing, weather forecasting, and financial analysis.
Regulation of ddb2 expression in blind cavefish and zebrafish reveals plasticity in the control of sunlight-induced DNA damage repair
Authors: Zhao Haiyu , Li Hongxiang , Du Juan , Di Mauro Giuseppe , Lungu-Mitea Sebastian , Geyer Nathalie , Vallone Daniela , Bertolucci Cristiano , Foulkes Nicholas S.
Published: February 2021

We have gained considerable insight into the mechanisms which recognize and repair DNA damage, but how they adapt to extreme environmental challenges remains poorly understood. Cavefish have proven to be fascinating models for exploring the evolution of DNA repair in the complete absence of UV-induced DNA damage and light. We have previously revealed that the Somalian cavefishPhreatichthys andruzzii, lacks photoreactivation repair via the loss of light, UV and ROS-inducedphotolyasegene transcription mediated by D-box enhancer elements. Here, we explore whether other systems repairing UV-induced DNA damage have been similarly affected in this cavefish model. By performing a comparative study usingP.andruzziiand the surface-dwelling zebrafish, we provide evidence for a conservation of sunlight-regulated Nucleotide Excision Repair (NER). Specifically, the expression of theddb2gene which encodes a key NER recognition factor is robustly induced following exposure to light, UV and oxidative stress in both species. As in the case of thephotolyasegenes, D-boxes in theddb2promoter are sufficient to induce transcription in zebrafish. Interestingly, despite the loss of D-box-regulated photolyase gene expression inP.andruzzii, the D-box is required forddb2induction by visible light and oxidative stress in cavefish. However, in the cavefishddb2gene this D-box-mediated induction requires cooperation with an adjacent, highly conserved E2F element. Furthermore, while in zebrafish UV-inducedddb2expression results from transcriptional activation accompanied by stabilization of theddb2mRNA, inP.andruzziiUV inducesddb2expression exclusively via an increase in mRNA stability. Thus, we reveal plasticity in the transcriptional and post transcriptional mechanisms regulating the repair of sunlight-induced DNA damage under long-term environmental challenges.
Comprehensive live-cell imaging analysis of cryptotanshinone and synergistic drug-screening effects in various human and canine cancer cell lines
Authors: Bittner Michael L. , Lopes Rosana , Hua Jianping , Sima Chao , Datta Aniruddha , Wilson-Robles Heather
Published: February 2021

Background

Several studies have highlighted both the extreme anticancer effects of Cryptotanshinone (CT), a Stat3 crippling component from Salvia miltiorrhiza, as well as other STAT3 inhibitors to fight cancer.

Methods

Data presented in this experiment incorporates 2 years of in vitro studies applying a comprehensive live-cell drug-screening analysis of human and canine cancer cells exposed to CT at 20 μM concentration, as well as to other drug combinations. As previously observed in other studies, dogs are natural cancer models, given to their similarity in cancer genetics, epidemiology and disease progression compared to humans.

Results

Results obtained from several types of human and canine cancer cells exposed to CT and varied drug combinations, verified CT efficacy at combating cancer by achieving an extremely high percentage of apoptosis within 24 hours of drug exposure.

Conclusions

CT anticancer efficacy in various human and canine cancer cell lines denotes its ability to interact across different biological processes and cancer regulatory cell networks, driving inhibition of cancer cell survival.
Genetic characterization of a mild isolate of papaya ringspot virus type-P (PRSV-P) and assessment of its cross-protection potential under greenhouse and field conditions
Authors: Medina-Salguero Andres X. , Cornejo-Franco Juan F. , Grinstead Sam , Mowery Joseph , Mollov Dimitre , Quito-Avila Diego F.
Published: February 2021

A mild isolate of Papaya ringspot virus type-P, abbreviated as PRSV-mild, from Ecuador was sequenced and characterized. The most distinguishing symptom induced by PRSV-mild was gray powder-like leaf patches radiating from secondary veins. In greenhouse experiments, PRSV-mild did not confer durable protection against a severe isolate of the virus (PRSV-sev), obtained from the same field. Furthermore, isolate specific detection in mixed-infected plants showed that PRSV-sev becomes dominant in infections, rendering PRSV-mild undetectable at 90–120 days post superinfection. Virus testing using isolate-specific primers detected PRSV-mild in two out of five surveyed provinces, with 10% and 48% of incidence in Santo Domingo and Los Ríos, respectively. Comparative genomics showed that PRSV-mild lacks two amino acids from the coat protein region, whereas amino acid determinants for asymptomatic phenotypes were not identified. Recombination events were not predicted in the genomes of the Ecuadorean isolates. Phylogenetic analyses placed both PRSV-mild and PRSV-sev in a clade that includes an additional PRSV isolate from Ecuador and others from South America.
Characterisation and chemometric evaluation of 17 elements in ten seaweed species from Greenland
Authors: Kreissig Katharina J. , Hansen Lisbeth Truelstrup , Jensen Pernille Erland , Wegeberg Susse , Geertz-Hansen Ole , Sloth Jens J.
Published: February 2021

Several Greenland seaweed species have potential as foods or food ingredients, both for local consumption and export. However, knowledge regarding their content of beneficial and deleterious elements on a species specific and geographical basis is lacking. This study investigated the content of 17 elements (As, Ca, Cd, Cr, Cu, Fe, Hg, I, K, Mg, Mn, Na, Ni, P, Pb, Se and Zn) in 77 samples of ten species (Agarum clathratum, Alaria esculenta, Ascophyllum nodosum, Fucus distichus, Fucus vesiculosus, Hedophyllum nigripes, Laminaria solidungula, Palmaria palmata, Saccharina latissima and Saccharina longicruris). Element profiles differed between species but showed similar patterns within the same family. For five species, different thallus parts were investigated separately, and showed different element profiles. A geographic origin comparison of Fucus species indicated regional differences. The seaweeds investigated were especially good sources of macrominerals (K > Na > Ca > Mg) and trace minerals, such as Fe. Iodine contents were high, especially in macroalgae of the family Laminariaceae. None of the samples exceeded the EU maximum levels for Cd, Hg or Pb, but some exceeded the stricter French regulations, especially for Cd and I. In conclusion, these ten species are promising food items.
Resting state EEG biomarkers of cognitive decline associated with Alzheimer’s disease and mild cognitive impairment
Authors: Meghdadi Amir H. , Stevanović Karić Marija , McConnell Marissa , Rupp Greg , Richard Christian , Hamilton Joanne , Salat David , Berka Chris
Published: February 2021

In this paper, we explore the utility of resting-state EEG measures as potential biomarkers for the detection and assessment of cognitive decline in mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Neurophysiological biomarkers of AD derived from EEG and FDG-PET, once characterized and validated, would expand the set of existing diagnostic molecular biomarkers of AD pathology with associated biomarkers of disease progression and neural dysfunction. Since symptoms of AD often begin to appear later in life, successful identification of EEG-based biomarkers must account for age-related neurophysiological changes that occur even in healthy individuals. To this end, we collected EEG data from individuals with AD (n = 26), MCI (n = 53), and cognitively normal healthy controls stratified by age into three groups: 18–40 (n = 129), 40–60 (n = 62) and 60–90 (= 55) years old. For each participant, we computed power spectral density at each channel and spectral coherence between pairs of channels. Compared to age matched controls, in the AD group, we found increases in both spectral power and coherence at the slower frequencies (Delta, Theta). A smaller but significant increase in power of slow frequencies was observed for the MCI group, localized to temporal areas. These effects on slow frequency spectral power opposed that of normal aging observed by a decrease in the power of slow frequencies in our control groups. The AD group showed a significant decrease in the spectral power and coherence in the Alpha band consistent with the same effect in normal aging. However, the MCI group did not show any significant change in the Alpha band. Overall, Theta to Alpha ratio (TAR) provided the largest and most significant differences between the AD group and controls. However, differences in the MCI group remained small and localized. We proposed a novel method to quantify these small differences between Theta and Alpha bands’ power using empirically derived distributions of spectral power across the time domain as opposed to averaging power across time. We defined Power Distribution Distance Measure (PDDM) as a distance measure between probability distribution functions (pdf) of Theta and Alpha power. Compared to average TAR, using PDDF enhanced the statistical significance, the effect size, and the spatial distribution of significant effects in the MCI group. We designed classifiers for differentiating individual MCI and AD participants from age-matched controls. The classification performance measured by the area under ROC curve after cross-validation were AUC = 0.85 and AUC = 0.6, for AD and MCI classifiers, respectively. Posterior probability of AD, TAR, and the proposed PDDM measure were all significantly correlated with MMSE score and neuropsychological tests in the AD group.
Assessing lumbar paraspinal muscle cross-sectional area and fat composition with T1 versus T2-weighted magnetic resonance imaging: Reliability and concurrent validity
Authors: Cooley J. R. , Hebert J. J. , de Zoete A. , Jensen T. S. , Algra P. R. , Kjaer P. , Walker B. F.
Published: February 2021

Purpose

Studies using magnetic resonance imaging to assess lumbar multifidus cross-sectional area frequently utilize T1 or T2-weighted sequences, but seldom provide the rationale for their sequence choice. However, technical considerations between their acquisition protocols could impact on the ability to assess lumbar multifidus anatomy or its fat/muscle distinction. Our objectives were to examine the concurrent validity of lumbar multifidus morphology measures of T2 compared to T1-weighted sequences, and to assess the reliability of repeated lumbar multifidus measures.

Methods

The lumbar multifidus total cross-sectional area of 45 patients was measured bilaterally at L4 and L5, with histogram analysis determining the muscle/fat threshold values per muscle. Images were later re-randomized and re-assessed for intra-rater reliability. Matched images were visually rated for consistency of outlining between both image sequences. Bland-Altman bias, limits of agreement, and plots were calculated for differences in total cross-sectional area and percentage fat between and within sequences, and intra-rater reliability analysed.

Results

T1-weighted total cross-sectional area measures were systematically larger than T2 (0.2 cm2), with limits of agreement <±10% at both spinal levels. For percentage fat, no systematic bias occurred, but limits of agreement approached ±15%. Visually, muscle outlining was consistent between sequences, with substantial mismatches occurring in <5% of cases. Intra-rater reliability was excellent (ICC: 0.981–0.998); with bias and limits of agreement less than 1% and ±5%, respectively.

Conclusion

Total cross-sectional area measures and outlining of muscle boundaries were consistent between sequences, and intra-rater reliability for total cross-sectional area and percentage fat was high indicating that either MRI sequence could be used interchangeably for this purpose. However, further studies comparing the accuracy of various methods for distinguishing fat from muscle are recommended.
Aedes aegypti mosquito saliva ameliorates acetaminophen-induced liver injury in mice
Authors: Assis Josiane B. , Cogliati Bruno , Esteves Eliane , Capurro Margareth L. , Fonseca Denise M. , Sá-Nunes Anderson
Published: February 2021

Acetaminophen (N-acetyl-p-aminophenol, APAP) overdose is the most common cause of drug-induced liver injury (DILI). Although the primary hepatic damage is induced by APAP-derived toxic intermediates resulting from cytochrome P450 metabolism, immune components also play an important role in DILI pathophysiology.Aedes aegyptisaliva is a source of bioactive molecules within vitroanti-inflammatory and immunomodulatory activities. However, evidences on the therapeutic use ofAe.aegyptisalivary preparations in animal models of relevant clinical conditions are still scarce. Thus, the present study was designed to evaluate the protective role ofAe.aegyptisaliva in a murine model of APAP-induced DILI. C57BL/6 mice were exposed toAe.aegyptibites 2 hours after APAP overdose. Biochemical and immunological parameters were evaluated in blood and liver samples at different time points after APAP administration. Exposure toAe.aegyptisaliva attenuated liver damage, as demonstrated by reduced hepatic necrosis and serum levels of alanine aminotransferase in APAP-overdosed mice. The levels of hepatic CYP2E1, the major enzyme responsible for the bioactivation of APAP, were not changed inAe.aegyptiexposed animals, suggesting no effects in the generation of hepatotoxic metabolites. On the other hand, mice treated withAe.aegyptisaliva following APAP overdose presented lower serum concentration of TNF-α, IL-6, IL-1β and IL-10, as well as reduced frequency of inflammatory cell populations in the liver, such as NKT cells, macrophages and dendritic cells. These findings show thatAe.aegyptisaliva has bioactive molecules with therapeutic properties and may represent a prospective source of new compounds in the management of DILI-associated inflammatory disorders and, perhaps, many other inflammatory/autoimmune diseases.
Comparing the effect of cross-group friendship on generalized trust to its effect on prejudice: The mediating role of threat perceptions and negative affect
Authors: Achbari Wahideh , Geys Benny , Doosje Bertjan
Published: February 2021

Intergroup relations theory posits that cross-group friendship reduces threat perceptions and negative emotions about outgroups. This has been argued to mitigate the negative effects of ethnic diversity on generalized trust. Yet, direct tests of this friendship-trust relation, especially including perceptions of threat and negative affect as mediators, have remained rare at the individual level. In this article, we bridge this research gap using representative data from eight European countries (Group-Focused Enmity). We employ structural equation modelling (SEM) to model mediated paths of cross-group friendship on generalized trust via perceptions of threat and negative affect. We find that both the total effect as well as the (mediated) total indirect effect of cross-group friendship on generalized trust are weak when compared with similar paths estimated for prejudice.
Association between Toxoplasma gondii seropositivity and serointensity and brain volume in adults: A cross-sectional study
Authors: Erickson Lance D. , Brown Bruce L. , Gale Shawn D. , Hedges Dawson W.
Published: February 2021

The intracellular protozoal parasite Toxoplasma gondii has been associated with worsened cognitive function in animal models and in humans. Despite these associations, the mechanisms by which Toxoplasma gondii might affect cognitive function remain unknown, although Toxoplasma gondii does produce physiologically active intraneuronal cysts and appears to affect dopamine synthesis. Using data from the UK Biobank, we sought to determine whether Toxoplasma gondii is associated with decreased prefrontal, hippocampal, and thalamic gray-matter volumes and with decreased total gray-matter and total white-matter volumes in an adult community-based sample. The results from adjusted multivariable regression modelling showed no associations between Toxoplasma gondii and prefrontal, hippocampal, and thalamic brain gray-matter volumes. In contrast, natural-log transformed antibody levels against the Toxoplasma gondii p22 (b = -3960, 95-percent confidence interval, -6536 to -1383, p < .01) and sag1 (b = -4863, 95-percent confidence interval, –8301 to -1425, p < .01) antigens were associated with smaller total gray-matter volume, as was the mean of natural-log transformed p22 and sag1 titers (b = -6141, 95-percent confidence interval, -9886 to -2397, p < .01). There were no associations between any of the measures of Toxoplasma gondii and total white-matter volume. These findings suggest that Toxoplasma gondii might be associated with decreased total gray-matter in middle-aged and older middle-aged adults in a community-based sample from the United Kingdom.
Procalcitonin, C-reactive protein, neutrophil gelatinase-associated lipocalin, resistin and the APTT waveform for the early diagnosis of serious bacterial infection and prediction of outcome in critically ill children
Authors: Nielsen Maryke J. , Baines Paul , Jennings Rebecca , Siner Sarah , Kolamunnage-Dona Ruwanthi , Newland Paul , Peak Matthew , Chesters Christine , Jeffers Graham , Downey Colin , Broughton Caroline , McColl Lynsey , Preston Jennifer , McKeever Anthony , Paulus Stephane , Cunliffe Nigel , Carrol Enitan D.
Published: February 2021

Objective

Bacterial Infections remains a leading cause of death in the Paediatric Intensive Care Unit (PICU). In this era of rising antimicrobial resistance, new tools are needed to guide antimicrobial use. The aim of this study was to investigate the accuracy of procalcitonin (PCT), neutrophil gelatinase-associated lipocalin (NGAL), resistin, activated partial thromboplastin time (aPTT) waveform and C-reactive protein (CRP) for the diagnosis of serious bacterial infection (SBI) in children on admission to PICU and their use as prognostic indicators.

Setting

A regional PICU in the United Kingdom.

Patients

Consecutive PICU admissions between October 2010 and June 2012.

Measurements

Blood samples were collected daily for biomarker measurement. The primary outcome measure was performance of study biomarkers for diagnosis of SBI on admission to PICU based on clinical, radiological and microbiological criteria. Secondary outcomes included durations of PICU stay and invasive ventilation and 28-day mortality. Patients were followed up to day 28 post-admission.

Main results

A total of 657 patients were included in the study. 92 patients (14%) fulfilled criteria for SBI. 28-day mortality was 2.6% (17/657), but 8.7% (8/92) for patients with SBI. The combination of PCT, resistin, plasma NGAL and CRP resulted in the greatest net reclassification improvement compared to CRP alone (0.69, p<0.005) with 10.5% reduction in correct classification of patients with SBI (p 0.52) but a 78% improvement in correct classification of patients without events (p <0.005). A statistical model of prolonged duration of PICU stay found log-transformed maximum values of biomarkers performed better than first recorded biomarkers. The final model included maximum values of CRP, plasma NGAL, lymphocyte and platelet count (AUC 79%, 95% CI 73.7% to 84.2%). Longitudinal profiles of biomarkers showed PCT levels to decrease most rapidly following admission SBI.

Conclusion

Combinations of biomarkers, including PCT, may improve accurate and timely identification of SBI on admission to PICU.
Associations of gamma-glutamyl transferase with cardio-metabolic diseases in people living with HIV infection in South Africa
Authors: Nguyen Kim A. , Peer Nasheeta , Kengne Andre P.
Published: February 2021

Background

Gamma-glutamyl transferase (GGT) has recently been reported as a biomarker for cardiovascular (CVD) risk in general populations. We investigated the associations of GGT with cardio-metabolic diseases and CVD risk in South Africans living with HIV.

Methods

In this cross-sectional study, HIV-infected adults were randomly recruited across 17 HIV clinics in the Western Cape Province. Homeostatic model assessment for insulin resistance (HOMA-IR), hypertension, diabetes, metabolic syndrome by Joint Interim Statement criteria (JIS-MS), a ≥5% and ≥10% predicted risk for a CVD event within 10 years by the Framingham risk score (10-years-CVD risk) were computed. Associations between GGT and cardio-metabolic trait were explored using linear and binomial logistic regressions adjusted for age, gender, lifestyle behaviours and HIV-related characteristics.

Results

Among 709 participants (561 women, mean age 38.6 years), log-GGT was positively associated with waist circumference (β=2.75; p<0.001), diastolic blood pressure (β=1.65; p=0.006), total cholesterol (β=0.21; p<0.001), low-density lipoprotein-cholesterol (β=0.16; p<0.001), high-density lipoprotein-cholesterol and log-triglycerides (both β=0.12; p<0.001), fasting plasma glucose (β=0.19; p=0.031), 2-hour-post-glucose-load plasma glucose (β=0.26; p=0.007), HOMA-IR (β=0.13; p=0.001), log-high-sensitivity C-reactive-protein (β=0.3; p<0.001) in linear regression analyses; with hypertension [OR=1.41 (95%CI, 1.13-1.75); p=0.001], JIS-MS [OR=1.33 (1.05-1.68); p=0.016], ≥5% 10-year-CVD risk [OR=1.55 (1.24-1.9400); p<0.001] and ≥10% 10-year-CVD risk [OR=1.56 (1.08-2.23); p=0.016] but not with diabetes [OR=1.24 (0.88-1.71), p=0.205] in logistic regression analyses.

Conclusions

In this study, GGT levels were associated with cardio-metabolic variables independent of HIV specific attributes. If confirmed in longitudinal studies, GGT evaluation maybe included in CVD risk monitoring strategies in people living with HIV.
Abnormal neuroinflammation in fibromyalgia and CRPS using [11C]-(R)-PK11195 PET
Authors: Seo Seongho , Jung Ye-Ha , Lee Dasom , Lee Won Joon , Jang Joon Hwan , Lee Jae-Yeon , Choi Soo-Hee , Moon Jee Youn , Lee Jae Sung , Cheon Gi Jeong , Kang Do-Hyung
Published: February 2021

Purpose

Fibromyalgia (FM) and complex regional pain syndrome (CRPS) share many pathological mechanisms related to chronic pain and neuroinflammation, which may contribute to the multifactorial pathological mechanisms in both FM and CRPS. The aim of this study was to assess neuroinflammation in FM patients compared with that in patients with CRPS and healthy controls.

Methods

Neuroinflammation was measured as the distribution volume ratio (DVR) of [11C]-(R)-PK11195 positron emission tomography (PET) in 12 FM patients, 11 patients with CRPS and 15 healthy controls.

Results

Neuroinflammation in FM patients was significantly higher in the left pre (primary motor cortex) and post (primary somatosensory cortex) central gyri (p < 0.001), right postcentral gyrus (p < 0.005), left superior parietal and superior frontal gyri (p < 0.005), left precuneus (p < 0.01), and left medial frontal gyrus (p = 0.036) compared with healthy controls. Furthermore, the DVR of [11C]-(R)-PK11195 in FM patients demonstrated decreased neuroinflammation in the medulla (p < 0.005), left superior temporal gyrus (p < 0.005), and left amygdala (p = 0.020) compared with healthy controls.

Conclusions

To the authors’ knowledge, this report is the first to describe abnormal neuroinflammation levels in the brains of FM patients compared with that in patients with CRPS using [11C]-(R)-PK11195 PET. The results suggested that abnormal neuroinflammation can be an important pathological factor in FM. In addition, the identification of common and different critical regions related to abnormal neuroinflammation in FM, compared with patients with CRPS and healthy controls, may contribute to improved diagnosis and the development of effective medical treatment for patients with FM.
Impact of postpartum tenofovir-based antiretroviral therapy on bone mineral density in breastfeeding women with HIV enrolled in a randomized clinical trial
Authors: Stranix-Chibanda Lynda , Tierney Camlin , Sebikari Dorothy , Aizire Jim , Dadabhai Sufia , Zanga Admire , Mukwasi-Kahari Cynthia , Vhembo Tichaona , Violari Avy , Theron Gerard , Moodley Dhayandre , George Kathleen , Fan Bo , Sommer Markus J. , Browning Renee , Mofenson Lynne M. , Shepherd John , Nelson Bryan , Fowler Mary Glenn , Siberry George K. ,   for the PROMISE P1084s study team
Published: February 2021

Objectives

We set out to evaluate the effect of postnatal exposure to tenofovir-containing antiretroviral therapy on bone mineral density among breastfeeding women living with HIV.

Design

IMPAACT P1084s is a sub-study of the PROMISE randomized trial conducted in four African countries (ClinicalTrials.gov number NCT01066858).

Methods

IMPAACT P1084s enrolled eligible mother-infant pairs previously randomised in the PROMISE trial at one week after delivery to receive either maternal antiretroviral therapy (Tenofovir disoproxil fumarate / Emtricitabine + Lopinavir/ritonavir–maternal TDF-ART) or administer infant nevirapine, with no maternal antiretroviral therapy, to prevent breastmilk HIV transmission. Maternal lumbar spine and hip bone mineral density were measured using dual-energy x-ray absorptiometry (DXA) at postpartum weeks 1 and 74. We studied the effect of the postpartum randomization on percent change in maternal bone mineral density in an intention-to-treat analysis with a t-test; mean and 95% confidence interval (95%CI) are presented.

Results

Among 398/400 women included in this analysis, baseline age, body-mass index, CD4 count, mean bone mineral density and alcohol use were comparable between study arms. On average, maternal lumbar spine bone mineral density declined significantly through week 74 in the maternal TDF-ART compared to the infant nevirapine arm; mean difference (95%CI) -2.86 (-4.03, -1.70) percentage points (p-value <0.001). Similarly, maternal hip bone mineral density declined significantly more through week 74 in the maternal TDF-ART compared to the infant nevirapine arm; mean difference -2.29% (-3.20, -1.39) (p-value <0.001). Adjusting for covariates did not change the treatment effect.

Conclusions

Bone mineral density decline through week 74 postpartum was greater among breastfeeding HIV-infected women randomized to receive maternal TDF-ART during breastfeeding compared to those mothers whose infants received nevirapine prophylaxis.