bluuebunny/crossref_metadata_2025 huggingface dataset:
Does socioeconomic inequality exist in minimum acceptable diet intake among children aged 6–23 months in sub-Saharan Africa? Evidence from 33 sub-Saharan African countries’ demographic and health surveys from 2010 to 2020
Authors: Belay Daniel Gashaneh , Taddese Asefa Adimasu , Gelaye Kassahun Alemu
Published: April 2022

Background

Child undernutrition is a major public health problem in many resource-poor communities in the world. More than two-thirds of malnutrition-related child deaths are associated with inappropriate feeding practices during the first 2 years of life. Socioeconomic inequalities are one of the most immediate determinants. Though sub-Saharan Africa (SSA) shares the huge burden of children undernutrition, as to our search of literature there is limited evidence on the pooled magnitude, socioeconomic inequalities of minimum acceptable diet intake and its contributing factors among children aged 6 to 23 months in the region. This study aimed to assess the level of socio-economic inequalities of minimum acceptable diet intake, and its contributor factors among children aged 6–23 months in SSA using recent 2010–2020 DHS data.

Methods

A total of 78,542 weighted samples from Demographic and Health Survey datasets of SSA countries were used for this study. The data were cleaned using MS excel and extracted and analyzed using STATA V.16 software. The concentration index and curve and wag staff type decomposition analysis were applied to examine wealth-related inequalities in the outcomes.P-value < 0.05 was taken to declare statistical significance.

Results

The pooled magnitude of MAD intake among children age 6–23 months in SSA was 9.89% [95%CI: 8.57, 11.21%] ranging from 3.10% in Guinea to 20.40% in Kenya. MAD intake in SSA was disproportionately concentrated on the rich households (pro-rich) [C = 0.191; 95% CI: 0.189, 0.193]. Residence (36.17%), media exposure (23.93%), and women’s education (11.63%) explained the pro-rich inequalities in MAD intake. The model explained 55.55% of the estimated socioeconomic inequality in MAD intake in SSA.

Conclusion and recommendations

Minimum acceptable diet intake in SSA is relatively low. There are moderate socioeconomic inequalities in MAD intake in SSA, mainly explained by residence, media exposure and women’s education. The government of sub-Saharan African countries should plan and work in short terms through the program that endorses women empowerment such as income generation, cash assistance for mothers who have under 2 years of children and women employment using affirmative actions, and nutrition education such as media campaigns and promoting breast feedings. Long-term plans are also needed for those SSA countries with lower income status through programs to enhance their country’s economy to the middle and higher economic level and to improve the wealth index of individual households to narrow the poor-rich gap in the minimum acceptable diet intake.
Comparison of fluid dynamics changes due to physical activity in 3D printed patient specific coronary phantoms with the Windkessel equivalent model of coronary flow
Authors: Sommer Kelsey N. , Bhurwani Mohammad Mahdi Shiraz , Iyer Vijay , Ionita Ciprian N.
Published: April 2022

Background

3D printing (3DP) used to replicate the geometry of normal and abnormal vascular pathologies has been demonstrated in many publications; however, reproduction of hemodynamic changes due to physical activities, such as rest versus moderate exercise, need to be investigated. We developed a new design for patient specific coronary phantoms, which allow adjustable physiological variables such as coronary distal resistance and coronary compliance in patients with coronary artery disease. The new design was tested in precise benchtop experiments and compared with a theoretical Windkessel electrical circuit equivalent, that models coronary flow and pressure using arterial resistance and compliance.

Methods

Five phantoms from patients who underwent clinically indicated elective invasive coronary angiography were built from CCTA scans using multi-material 3D printing. Each phantom was used in a controlled flow system where patient specific flow conditions were simulated by a programmable cardiac pump. To simulate the arteriole and capillary beds flow resistance and the compliance for various physical activities, we designed a three-chamber outlet system which controls the outflow dynamics of each coronary tree. Benchtop pressure measurements were recorded using sensors embedded in each of the main coronary arteries. Using the Windkessel model, patient specific flow equivalent electrical circuit models were designed for each coronary tree branch, and flow in each artery was determined for known inflow conditions. Local flow resistances were calculated through Poiseuille’s Law derived from the radii and lengths of the coronary arteries using CT angiography based multi-planar reconstructions. The coronary stenosis flow rates from the benchtop and the electrical models were compared to the localized flow rates calculated from invasive pressure measurements recorded in the angio-suites.

Results

The average Pearson correlations of the localized flow rates at the location of the stenosis between each of the models (Benchtop/Electrical, Benchtop/Angio, Electrical/Angio) are 0.970, 0.981, and 0.958 respectively.

Conclusions

3D printed coronary phantoms can be used to replicate the human arterial anatomy as well as blood flow conditions. It displays high levels of correlation when compared to hemodynamics calculated in electrically-equivalent coronary Windkessel models as well as invasive angio-suite pressure measurements.
Joint two-step inversion of porosity and saturation based on the Biot/squirt model with multiphase fluids
Authors: Wen Jin , Cheng Yuanfeng , Yang Dinghui , Qu Zhipeng , He Xijun
Published: April 2022

It is of great importance to predict reservoir petrophysical properties, such as porosity and saturation based on elastic properties, including density and wave propagation velocity, through quantitative seismic interpretation. A joint two-step inversion (JoiTSI) method is proposed for predicting porosity and saturation with a forward petrophysical model. As the forward model, the Biot/squirt model with multiphase fluids (gas, oil, and water) describes the nonlinear relationships between petrophysical and elastic properties. The first step of the two-step inversion is to invert porosity and saturation via a semianalytical approximation approach. The second step is a joint inversion at high porosities where porosity and saturation are simultaneously optimized using a hybrid genetic algorithm. In these steps, maximum a posteriori estimations are performed based on normal prior distributions, where the posterior distributions may differ between two steps because of the potential variability in reservoir properties. The numerical tests indicate that this JoiTSI method is more efficient and more accurate than the traditional inversion methods. In addition, Poisson’s ratio, P-wave impedance, and S-wave impedance are found to give better inversion results than those based on more commonly used attributes (density, P-wave impedance, and S-wave impedance). In the oilfield seismic example, the inversion accuracy of porosity and saturation is verified by actual well logs, and the major oil and water layers are correctly identified.
Pressure dependence of elastic wave velocities of unconsolidated cemented sands
Authors: Guo Junxin , Chen Xiaofei
Published: April 2022

We have developed lower and upper bounds for the pressure-dependent elastic wave velocities of unconsolidated cemented sands, which are due to variations in cement layer thickness and direct grain contact area with effective pressure, respectively. Investigating the factors influencing these bounds, we have found that the elastic wave (P- and S-wave) velocities increase with the effective pressure, whereas their ratio ([Formula: see text]) decreases. The elastic wave velocities and their ratio have an almost linear relationship with the effective pressure for the lower bound, whereas that for the upper bound is nonlinear. For both lower and upper bounds, the sensitivities of the elastic wave velocities and their ratio to the effective pressure increase with decreasing precompacted pressure, cement elastic moduli, and cement volume content. By comparing the theoretical predictions with ultrasonic measurements on heavy-oil sands and cemented glass beads, we have validated that the experimental data fall within the proposed lower and upper bounds. The experimental data shift from the lower bound to the upper bound as the effective pressure increases, revealing that the grain compaction pattern changes with increasing effective pressure.
An intercultural perspective toward supporting antipsychotic medication adherence in clinical practice
Authors: Zacharia Tharun
Published: April 2022

In the UK, the incidence of schizophrenia appears highest in Black Caribbean and Black African communities (four- to six-fold that of the White British population). The incidence of psychosis in other minority ethnic groups is also raised, but to a lesser magnitude. Although there are numerous environmental confounding factors, the data stresses the importance of optimising treatment in high-risk (minority) groups. Antipsychotic nonadherence is the most common reason for schizophrenia relapse, and is associated with increased rates of relapse, readmission to hospital and suicide. This article examines available literature to discover how culture can affect antipsychotic nonadherence, and considers culture-based solutions that could enhance antipsychotic adherence. Acknowledging the importance of the therapeutic alliance and sociocultural aspects in antipsychotic adherence, I argue that current cultural competence training provided to clinicians is inadequate. Organisational- and system-level approaches are required to reduce oppressive practise and promote culturally competent, person-centred care.
Beyond the Sexualized Colonial Narrative: Undoing the Visual History of Kisaeng in Colonial Korea
Authors: Rhee Jooyeon
Published: April 2022

This article examines visual representations of kisaeng (courtesans) in photographs and photo postcards, produced by Japanese entrepreneurs and kisaeng themselves, by viewing them as a contentious site of the historical memory of Japanese colonialism. It problematizes the nation-focused narratives on kisaeng in postcolonial South Korea as these narratives fail to recognize the complex dimension of the image-making process that cannot be fully grasped by the dialectic of the colonial aggressor and its victim. Instead, this article shows how kisaeng exercised their agency by actively engaging in producing visual images of themselves as a politically conscious response to the colonial reality. The author pays special attention to visual images appearing in the magazine Changhan, which was established by a group of kisaeng, to underscore women’s political intervention in the visual regime of colonial capitalism. The women’s voices embedded in Changhan are crucial, since they not only problematize their othered social position constructed by colonial capitalism and patriarchy but also lead us to investigate their interventions in the politics of representation that moved strategically across tradition and modernity while shifting their position from object to subject, and vice versa, revealing their tactical maneuver of the technological implications of visual politics.
A 3D molecular map of the cavefish neural plate illuminates eye-field organization and its borders in vertebrates
Authors: Agnès François , Torres-Paz Jorge , Michel Pauline , Rétaux Sylvie
Published: April 2022

The vertebrate retinas originate from a specific anlage in the anterior neural plate called the eye field. Its identity is conferred by a set of ‘eye transcription factors’, whose combinatorial expression has been overlooked. Here, we use the dimorphic teleost Astyanax mexicanus, which develops proper eyes in the wild type and smaller colobomatous eyes in the blind cavefish embryos, to unravel the molecular anatomy of the eye field and its variations within a species. Using a series of markers (rx3, pax6a, cxcr4b, zic1, lhx2, emx3 and nkx2.1a), we draw a comparative 3D expression map at the end of gastrulation/onset of neurulation, which highlights hyper-regionalization of the eye field into sub-territories of distinct sizes, shapes, cell identities and combinatorial gene expression levels along the three body axes. All these features show significant variations in the cavefish natural mutant. We also discover sub-domains within the prospective telencephalon and characterize cell identities at the frontiers of the eye field. We propose putative fates for some of the characterized eye-field subdivisions, and suggest the existence of a trade-off between some subdivisions in the two Astyanax morphs on a micro-evolutionary scale.
Premeiotic endoreplication is essential for obligate parthenogenesis in geckos
Authors: Dedukh Dmitrij , Altmanová Marie , Klíma Jiří , Kratochvíl Lukáš
Published: April 2022

Obligate parthenogenesis evolved in reptiles convergently several times, mainly through interspecific hybridization. The obligate parthenogenetic complexes typically include both diploid and triploid lineages. Offspring of parthenogenetic hybrids are genetic copies of their mother; however, the cellular mechanism enabling the production of unreduced cells is largely unknown. Here, we show that oocytes go through meiosis in three widespread, or even strongly invasive, obligate parthenogenetic complexes of geckos, namely in diploid and triploid Lepidodactylus lugubris, and triploid Hemiphyllodactylus typus and Heteronotia binoei. In all four lineages, the majority of oocytes enter the pachytene at the original ploidy level, but their chromosomes cannot pair properly and instead form univalents, bivalents and multivalents. Unreduced eggs with clonally inherited genomes are formed from germ cells that had undergone premeiotic endoreplication, in which appropriate segregation is ensured by the formation of bivalents made from copies of identical chromosomes. We conclude that the induction of premeiotic endoreplication in reptiles was independently co-opted at least four times as an essential component of parthenogenetic reproduction and that this mechanism enables the emergence of fertile polyploid lineages within parthenogenetic complexes.
Dopey proteins are essential but overlooked regulators of membrane trafficking
Authors: Molière Adrian , Beer Katharina B. , Wehman Ann M.
Published: April 2022

Dopey family proteins play crucial roles in diverse processes from morphogenesis to neural function and are conserved from yeast to mammals. Understanding the mechanisms behind these critical functions could have major clinical significance, as dysregulation of Dopey proteins has been linked to the cognitive defects in Down syndrome, as well as neurological diseases. Dopey proteins form a complex with the non-essential GEF-like protein Mon2 and an essential lipid flippase from the P4-ATPase family. Different combinations of Dopey, Mon2 and flippases have been linked to regulating membrane remodeling, from endosomal recycling to extracellular vesicle formation, through their interactions with lipids and other membrane trafficking regulators, such as ARL1, SNX3 and the kinesin-1 light chain KLC2. Despite these important functions and their likely clinical significance, Dopey proteins remain understudied and their roles elusive. Here, we review the major scientific discoveries relating to Dopey proteins and detail key open questions regarding their function to draw attention to these fascinating enigmas.
The capture of crude oil droplets by filter feeders at high and low Reynolds numbers
Authors: Letendre Francis , Cameron Christopher B.
Published: April 2022

Crustacean filter feeders capture oil droplets with the use of their ramified appendages. These appendages behave as paddles or sieves, based on the system's Reynolds number. Here, we used high-speed videography, scanning electron microscopy and fluid mechanics to study the capturing mechanisms of crude oil droplets and the filtering appendage's wettability by two species of barnacles (Balanus glandula and Balanus crenatus) and of the freshwater cladoceran Daphnia magna. Our results show that barnacle appendages behave as paddles and capture droplets in their boundary layers at low Reynolds number. At high Reynolds number, droplets are most likely to be captured via direct interception. There is an intermediate range of Reynolds number where droplets can be captured by both mechanisms at the same time. Daphnia magna captures droplets in the boundary layers of the third and fourth pair of thoracic legs with a metachronal motion of the appendages. All studied surfaces were revealed to be highly lipophobic, demonstrating captured oil droplets with high contact angles. We also discuss implications of such capture mechanisms and wettability on potential ingestion of crude oil by filter feeders. These results further our understanding of the capture of crude oil by filter feeders, shedding light on the main entry point of oil in marine food webs.
Relative Skeletal Maturity and Performance Test Outcomes in Elite Youth Middle Eastern Soccer Players
Authors: LOLLI LORENZO , JOHNSON AMANDA , MONACO MAURICIO , DI SALVO VALTER , GREGSON WARREN
Published: April 2022

Purpose

This study aimed to explore the influence of differences in relative skeletal maturity on performance test outcomes in elite youth soccer players from the Middle East.

Methods

We integrated skeletal age and performance assessments using mixed-longitudinal data available for 199 outfield players (chronological age range, 11.7 to 17.8 yr) enrolled as academy student-athletes (annual screening range, 1 to 5 visits). Skeletal age was determined as per the Tanner–Whitehouse II protocol. Relative maturity was calculated as the difference (∆) between Tanner–Whitehouse II skeletal age minus chronological age. Performance test outcomes of interest were 10-m sprinting, 40-m sprinting, countermovement jump height, and maximal aerobic speed. Separate random-effects generalized additive models quantified differences in performance test outcomes by relative skeletal maturity. Estimated differences were deemed practically relevant based on the location of the confidence interval (95% CI) against minimal detectable change values for each performance test outcome.

Results

For 40-m sprinting, differences of +0.51 s (95% CI, +0.35 to +0.67 s) and +0.62 s (95% CI, +0.45 to +0.78 s) were practically relevant for relative maturity status of ∆ = −1.5 yr versus ∆ = +0.5 and ∆ = +1 yr, respectively. For countermovement jump height, a difference of −8 cm (95% CI, −10 to −5 cm) was practically relevant for ∆ = −1.5 yr versus ∆ = +1 yr relative maturity status comparison. Effects for 10-m sprinting and maximal aerobic speed were unclear.

Conclusions

Integration of skeletal age and performance assessments indicated that conventional maturity status classification criteria were inconsistent to inform player development processes in our sample. Between-player differences in test performance may depend on a substantial delay in skeletal maturation (∆ ≤ −1.5 yr) and the performance outcome measure.
Mitochondrial Mass of Naïve T Cells Is Associated with Aerobic Fitness and Energy Expenditure of Active and Inactive Adults
Authors: ALLEY JESSICA R. , VALENTINE RUDY J. , KOHUT MARIAN L.
Published: April 2022

Purpose

Chronic exercise training is known to induce metabolic changes, but whether these adaptations extend to lymphocytes and how this may affect immune function remains largely unknown. This study was conducted to determine the extent to which mitochondrial characteristics of naïve T cells differ according to fitness status and to further examine the energy production pathways of cells from aerobically trained and inactive participants.

Methods

Blood was collected from 30 aerobically active (>6 h·wk−1) or inactive (<90 min·wk−1) men and women. Naïve T cell mitochondrial mass, membrane potential, and biogenesis were assessed with flow cytometry. Participants completed a treadmill maximal oxygen consumption (V̇O2peak) test and wore a physical activity monitor for 1 wk. In a subset of participants, naïve CD8+ T cell activation-induced glycolytic and mitochondrial ATP production was measured.

Results

Active participants exhibited 16.7% more naïve CD8+ T cell mitochondrial mass (P = 0.046), 34% greater daily energy expenditure (P < 0.001), and 39.6% higher relative V̇O2peak (P < 0.001), along with 33.9% lower relative body fatness (P < 0.001). Among all participants, naïve CD8+ T cell mitochondrial mass was correlated with estimated energy expenditure (r = 0.36, P = 0.048) and V̇O2peak (r = 0.47, P = 0.009). There were no significant differences in ATP production, mitochondrial biogenesis, or mitochondrial membrane potential between active and inactive groups.

Conclusions

This is the first study to examine the effects of aerobic exercise training status on metabolic parameters within human naïve T cells. Findings suggest that mitochondrial adaptations in certain immune cell types are positively associated with aerobic fitness and energy expenditure. This study provides a foundation for future development of prophylactic and therapeutic interventions targeting specific immune cell subsets to improve the immune response and overall health.
Effects of Exercise Training on PPARβ/δ Expression in Skeletal Muscle of Rats with Spontaneous Hypertension
Authors: YANG MINGXUAN , PAN YANXIA , LI KUNHUI , CHEN XIUYUN , LI MINYAN , LIN JIANPING , LI MING , LIN CHENG
Published: April 2022

Purpose

This study aimed to identify the relationship and mechanism between skeletal muscle peroxisome proliferator–activated receptor β/δ (PPARβ/δ) and spontaneous hypertension.

Methods

Rats were divided into four groups (n = 10): spontaneous hypertensive rats exercise group (SHR-E), spontaneous hypertensive rats sedentary group (SHR-S), Wistar-Kyoto control rats exercise group (WKY-E), and Wistar-Kyoto control rats sedentary group (WKY-S). Although the sedentary groups were placed on the treadmill without moving during the training sessions, the exercise groups were forced to run on a treadmill for 8 wk, 1 h·d−1, 5 d·wk−1. After training, the density and area of gastrocnemius microvessels were observed. PPARβ/δ, vascular endothelial growth factor A (VEGFA), superoxide dismutase 2 (SOD-2), and nitric oxide synthase in gastrocnemius were measured by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot.

Results

Except the sixth week of age, the systolic blood pressure of SHR-S was significantly higher than that of WKY-S at all time periods. Exercise significantly reduced systolic blood pressure in SHR rats. Compared with the SHR-S group, the WKY-S group had significantly higher PPARβ/δ protein level and density of skeletal muscle microvessels. Eight weeks of exercise increased the PPARβ/δ, SOD-2, VEGFA, and microvessel density and area in the skeletal muscle of SHR.

Conclusions

Exercise training promoted PPARβ/δ mRNA and protein-level expression of PPARβ/δ, SOD-2 and VEGFA in skeletal muscle, thus increasing the density and area of skeletal muscle blood vessels. These regulations contribute to the reduction of peripheral vascular resistance. This may be a potential mechanism of exercise to reduce blood pressure.
An Evidence-Based Narrative Review of Mechanisms of Resistance Exercise–Induced Human Skeletal Muscle Hypertrophy
Authors: LIM CHANGHYUN , NUNES EVERSON A. , CURRIER BRAD S. , MCLEOD JONATHAN C. , THOMAS AARON C. Q. , PHILLIPS STUART M.
Published: April 2022

Skeletal muscle plays a critical role in physical function and metabolic health. Muscle is a highly adaptable tissue that responds to resistance exercise (RE; loading) by hypertrophying, or during muscle disuse, RE mitigates muscle loss. Resistance exercise training (RET)–induced skeletal muscle hypertrophy is a product of external (e.g., RE programming, diet, some supplements) and internal variables (e.g., mechanotransduction, ribosomes, gene expression, satellite cells activity). RE is undeniably the most potent nonpharmacological external variable to stimulate the activation/suppression of internal variables linked to muscular hypertrophy or countering disuse-induced muscle loss. Here, we posit that despite considerable research on the impact of external variables on RET and hypertrophy, internal variables (i.e., inherent skeletal muscle biology) are dominant in regulating the extent of hypertrophy in response to external stimuli. Thus, identifying the key internal skeletal muscle–derived variables that mediate the translation of external RE variables will be pivotal to determining the most effective strategies for skeletal muscle hypertrophy in healthy persons. Such work will aid in enhancing function in clinical populations, slowing functional decline, and promoting physical mobility. We provide up-to-date, evidence-based perspectives of the mechanisms regulating RET-induced skeletal muscle hypertrophy.
Firm-Induced Migration Paths and Strategic Human-Capital Outcomes
Authors: Choudhury Prithwiraj (Raj) , Khanna Tarun , Sevcenko Victoria
Published: April 2022

Firm-induced migration typically entails firms relocating workers to fill value-creating positions at destination locations. But such relocated workers are often exposed to external employment opportunities at their destinations, possibly triggering turnover. We conceptualize the firm-induced migration path, consisting of the relocated workers’ place of origin and destination, as relevant in determining worker performance and turnover postrelocation. Using a unique data set from a large Indian technology firm that hires talent from both large cities and smaller towns, we document robust econometric patterns by exploiting the firm’s randomized assignment of workers to production centers across the country. These production centers are located in the largest technology cluster in India (Bangalore), smaller technology clusters, and noncluster locations. We find that the firm-induced migration path shapes both worker performance and turnover. Compared with workers from large cities, workers from smaller towns achieve higher performance when relocated to Bangalore than to other production centers, but are also more likely to join competing firms. Fine-grained data on employment and human-capital-augmentation opportunities at workers’ destination locations, and on socioeconomic conditions in workers’ places of origin, help us rule in an abductive explanation: across firm-induced migration paths, differences in external labor-market opportunities between workers’ places of origin and their destinations, as well as intrafirm skill-development opportunities at the destination, are related to heterogeneous human-capital outcomes.

This paper was accepted by Alfonso Gambardella, business strategy.

Supplemental Material: The e-companion and data files are available at https://doi.org/10.1287/mnsc.2022.4361 .
Comparative Study to Evaluate Ethanol and Ethyl Acetate Extracts of Different 'Vidanga' Species for Antioxidant Efficacy and Phyto-Constituents Screening
Authors: Jagtap Kartikey , Mulik Anuradha , A. Singh E. , Jagtap Suresh
Published: April 2022

In Ayurveda, ‘Vidanga’ is one such species high in demand for its various uses. All the species of genus Embelia and Maesa belonging to the family Myrsinaceae are reported as ‘Vidanga’. Considering the availability of plant material in the market there is an ambiguity in supplying the authentic species as ‘Vidanga’. In the present study, a comparative analysis was carried out to determine the efficacy of different 'Vidanga’ spp. in terms of their phyto-constituents, antioxidant potential, and free radical scavenging activity. The highest total phenolic contents (TPCs) and total flavonoid contents (TFCs) were found to be in ethanolic and ethyl acetate extract. Quantitative measurements also showed that abundance of phenolic and flavonoid phytoconstituents was significantly (P<0.001) greater in ethanolic extract of all the ‘Vidanga’ fractions (1.773±0.01 to 137.17±0.19 mg/g GAE and 4.84±0.001 to 302.29±0.07 mg/g of quercetin respectively) than in ethyl acetate extract (1.15±0.003 to 15.12±0.01 mg/g GAE and 7.94±0.05 to 25.20±0.001 mg/g of quercetin respectively). Ethanolic extract of Embelia ribes had significant activity in terms of IC50 than ethyl acetate extracts in the case of 2,2-diphenyl,1- picryl hydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and anti-lipid peroxidation (ALP) (9.53, 9.73 and 6.21 µg/mL respectively) indicates Embelia ribes found to be most effective species as ‘Vidanga’. Pearson’s correlation (r2) analysis also suggests a significant correlation between different antioxidant parameters and bioactive constituents. This study may helpful to draw attention of researchers to characterize the various bioactive compounds from the Embelia ribes in terms of their antioxidant prospective.
Cotidianidad y Otredad en las zonas fronterizas entre México/ EEUU y Holanda/Alemania
Authors: Aparna Kolar , Kramsch Olivier
Published: April 2022

A partir del descontento con los estudios fronterizos por su incapacidad de definir las frontera neerlandesa/alemana y las fronteras EEUU/México más allá de la separación ontológica entre las llamadas fronteras “espectaculares” /violentas (usualmente la frontera México/EEUU o las fronteras exteriores de la UE) y las fronteras “aburridas” (a menudo las fronteras internas de la UE, como la neerlandesa/ alemana), nosotros nos preguntamos: ¿Qué conecta las fronteras entre México/EEUU (Tijuana/San Diego) y las holandesas/alemanas (Nijmegen/Kranenburg/Kleve)? Nos basamos en la noción de Bustamante sobre la cotidianidad y la Otredad en las zonas fronterizas para cartografiar tres dimensiones de las asimetrías de poder que producen estas zonas fronterizas relacionalmente. Se trata de las asimetrías de las inmovilidades, las in/visibilizaciones de la infraestructura fronteriza en la vida cotidiana, y del uso de la proximidad de la frontera para mejorar la vida. Basándonos en esto, sostenemos que la sintonía con las formas en que las asimetrías de poder de la frontera juegan de manera diferencial en la producción de un sentido relacional del lugar de las tierras fronterizas, abre un camino para traer espacios fronterizos aparentemente dispares en las relaciones de convertirse en Otro.
La migración como (f)actor geopolítico: Una aproximación desde la autonomía de las migraciones
Authors: Casas Cortés Maribel , Cobarrubias Baglietto Sebastian
Published: April 2022

En este artículo sugerimos interpretar la migración como factor geopolítico, un factor que no esta siempre sujeto a las decisiones estatales.  Realizamos una revisión de la literatura sobre la geopolítica de las migraciones, sobre todo centrado en el control migratorio, identificando sus limites y potencialidades. Después, presentamos la Autonomía de las Migraciones como una manera de complementar o retar conceptos asumidos dentro la literatura de la geopolítica de las migraciones como la primacía analítica de las actuaciones de los estados en materia migratoria.  En base al trabajo de Yann Moulier Boutang, proponemos prestar atención a la capacidad propia de los movimientos migratorios para intervenir en transformaciones estructurales de tipo económico, político, cultural y legal. Este enfoque en las migraciones como factor geopolítico puede guiar futuras investigaciones y enriquecer nuestra comprensión de las transformaciones en las fronteras y de la geopolítica misma.
Parques eólicos e rede natura: unha análise desde o marco da xustiza enerxética para o caso da serra do xistral
Authors: Copena Rodríguez Damián , Simón Fernández Xavier
Published: April 2022

Galicia é un territorio cun forte desenvolvemento da enerxía eólica. A instalación de parques eólicos tivo lugar rapidamente afectando a espazos con relevancia ambiental. Este feito é especialmente importante no caso da Serra do Xistral, un espazo que forma parte da Rede Natura 2000 e que conta con hábitats prioritarios, especialmente os vinculados coas turbeiras. O presente traballo analiza, a partir do marco da xustiza enerxética, como foi o proceso de desenvolvemento eólico neste espazo natural facendo fincapé en dúas compoñentes do marco analítico: a xustiza procedimental e a xustiza distributiva. Deste xeito, o traballo identifica e caracteriza os parques eólicos que se atopan dentro do espazo protexido, estuda os procedementos e a participación pública nas avaliacións ambientais dos parques eólicos proxectados dentro da Serra do Xistral e discute sobre as implicacións ambientais das políticas públicas no desenvolvemento de parques eólicos na Rede Natura.
At the intersection of optics and deep learning: statistical inference, computing, and inverse design
Authors: Mengu Deniz , Sakib Rahman Md Sadman , Luo Yi , Li Jingxi , Kulce Onur , Ozcan Aydogan
Published: April 2022

Deep learning has been revolutionizing information processing in many
fields of science and engineering owing to the massively growing
amounts of data and the advances in deep neural network architectures.
As these neural networks are expanding their capabilities toward
achieving state-of-the-art solutions for demanding statistical
inference tasks in various applications, there appears to be a global
need for low-power, scalable, and fast computing hardware beyond what
existing electronic systems can offer. Optical computing might
potentially address some of these needs with its inherent parallelism,
power efficiency, and high speed. Recent advances in optical
materials, fabrication, and optimization techniques have significantly
enriched the design capabilities in optics and photonics, leading to
various successful demonstrations of guided-wave and free-space
computing hardware for accelerating machine learning tasks using
light. In addition to statistical inference and computing, deep
learning has also fundamentally affected the field of inverse
optical/photonic design. The approximation power of deep neural
networks has been utilized to develop optics/photonics systems with
unique capabilities, all the way from nanoantenna design to end-to-end
optimization of computational imaging and sensing systems. In this
review, we attempt to provide a broad overview of the current state of
this emerging symbiotic relationship between deep learning and
optics/photonics.
Use of nanosecond excitation pulses in fluorescence lifetime measurement via phasor analysis
Authors: Kim Dongeun , Moon Sucbei , Hwang Wonsang , Young Kim Dug
Published: April 2022

We investigated the possibility of using long excitation pulses in fluorescence lifetime imaging microscopy (FLIM) using phasor analysis. It has long been believed that the pulse width of an excitation laser must be shorter than the lifetime of a fluorophore in a time-domain FLIM system. Even though phasor analysis can effectively minimize the pulse effect by using deconvolution, the precision of a measured lifetime can be degraded seriously. Here, we provide a fundamental theory on pulse-width-dependent measurement precisions in lifetime measurement in the phasor plane. Our theory predicts that high-precision lifetimes can be obtained even with a laser whose pulse width is four times larger than the lifetime of a fluorophore. We have experimentally demonstrated this by measuring the lifetimes of fluorescence probes with 2.57 ns and 3.75 ns lifetimes by using various pulse widths (0.52–38 ns) and modulation frequencies (10–200 MHz). We believe our results open a new possibility of using long pulse-width lasers for high-precision FLIM.
Monocular vision aided optical tracking for underwater optical wireless communications
Authors: Tang Jingyi , Jiang Rui , Chen Zhen , Zhu Zhengjia
Published: April 2022

Underwater optical wireless communication (UOWC) has received increasing attention due to its distinctive characteristics such as high bandwidth and low latency. However, the UOWC link is usually vulnerable to water flow, underwater turbulence and the terminals’ own vibration. Thus, to maintain a stable transmission link, an accurate tracking method is essential for UOWC systems. In this paper, a monocular vision aided optical tracking method is proposed, where the deviation degree of the laser spot is employed to realize autonomous real-time alignment of the receiver with the transmitter. Experimental results verify that with the proposed tracking method, the bit error ratio can be ensured to be below the forward error correction (FEC) limit of 3.8×10−3 even under strong disturbance for the practical UOWC system.
Learning-based digital back propagation to compensate for fiber nonlinearity considering self-phase and cross-phase modulation for wavelength-division multiplexed systems
Authors: Inoue Takashi , Matsumoto Ryosuke , Namiki Shu
Published: April 2022

We propose a learning-based digital back propagation (LDBP) technique that addresses self-phase modulation (SPM) and cross-phase modulation (XPM) of a wavelength-division multiplexed (WDM) optical signal. The LDBP has a structure defined for each of the individual channels of a WDM signal, and connections between the channels address the XPM to effectively compensate for nonlinear waveform distortion of the signal in long-distance optical transmission systems. We attempt to optimize the limited number of parameters used in the structure such as the dispersion, nonlinear coefficient, and walkoff parameter to compensate for the nonlinear phase shift induced by the XPM. We derive equations to update the parameters through an iterative process based on the stochastic gradient descent algorithm. We verify the effectiveness of the proposed LDBP technique through a transmission experiment that uses an 11-channel WDM, 32-Gbaud, dual-polarization 16 quadrature amplitude modulation (QAM), and probabilistically shaped (PS) 64QAM signals. With the focus on the LDBP with a 1-step/span configuration, we operate the learning process using the received 16QAM signal in the experiment. We confirmed the successful convergence of particular parameters of the model of the transmission line after the developed learning procedure. We apply the LDBP with fixed optimized parameters to the received waveforms of the PS-64QAM signals and compare the performance with some DBPs. We observed that the proposed LDBP technique that considers XPM with 1-step/span configuration exhibits the best performance in compensating for nonlinear waveform distortion. Additionally, the learning process is effective for the case considering both SPM and XPM compared with the case of SPM only. Finally, we investigate the computational complexity of the LDBP and reveal that the total calculation cost is of the same order as that of a conventional DBP considering only SPM with a 2-step/span configuration.
Experimental observation of optically generated unipolar electromagnetic precursors
Authors: Ilyakov I. E. , Shishkin B. V. , Efimenko E. S. , Bodrov S. B. , Bakunov M. I.
Published: April 2022

It was recently predicted [Phys. Rev. A 95(6), 063817 (2017) 10.1103/PhysRevA.95.063817] that an intense femtosecond laser pulse propagating in an electro-optic crystal and producing free carriers via multiphoton ionization can generate a unipolar electromagnetic precursor propagating ahead of the laser pulse. Here we report the experimental observation of this phenomenon in a GaP crystal excited by an amplified Ti:sapphire laser.
Machine learning analysis of instabilities in noise-like pulse lasers
Authors: Mabed Mehdi , Meng Fanchao , Salmela Lauri , Finot Christophe , Genty Goëry , Dudley John M.
Published: April 2022

Neural networks have been recently shown to be highly effective in predicting time-domain properties of optical fiber instabilities based only on analyzing spectral intensity profiles. Specifically, from only spectral intensity data, a suitably trained neural network can predict temporal soliton characteristics in supercontinuum generation, as well as the presence of temporal peaks in modulation instability satisfying rogue wave criteria. Here, we extend these previous studies of machine learning prediction for single-pass fiber propagation instabilities to the more complex case of noise-like pulse dynamics in a dissipative soliton laser. Using numerical simulations of highly chaotic behaviour in a noise-like pulse laser operating around 1550 nm, we generate large ensembles of spectral and temporal data for different regimes of operation, from relatively narrowband laser spectra of 70 nm bandwidth at the -20 dB level, to broadband supercontinuum spectra spanning 200 nm at the -20 dB level and with dispersive wave and long wavelength Raman extension spanning from 1150–1700 nm. Using supervised learning techniques, a trained neural network is shown to be able to accurately correlate spectral intensity profiles with time-domain intensity peaks and to reproduce the associated temporal intensity probability distributions.
Parametric amplification in lossy nonlinear waveguides with spatially dependent coupling
Authors: Ribeiro Vitor , Perego Auro M.
Published: April 2022

We present an analytical and numerical study of optical parametric amplification in coupled waveguides amplifiers accounting for presence of losses and spatially dependent coupling. Spatially dependent coupling enables to compensate for mismatch dynamically arising from pump attenuation and to achieve improved performances in terms of bandwidth and bandwidth-gain product compared to standard single-waveguide solutions. Our results suggest the effective design of a novel class of parametric amplifiers and could be especially relevant for integrated silicon nitride devices.
Quantifying viscosity and elasticity using holographic imaging by Rayleigh wave dispersion
Authors: Singh Amandeep , Pati Falguni , John Renu
Published: April 2022

Viscoelasticity is an important diagnostic parameter to investigate physiological dysfunctions in biological tissues. This Letter reports the quantification of viscoelastic parameters by Rayleigh wave tracing on the surface of tissue-mimicking phantoms using holographic imaging. The Rayleigh wave is induced by an electromechanical actuator on the surface of oil-in-gelatin phantoms and a biological tissue sample followed by holographic imaging and reconstruction of the wave. The frequency-dependent velocity dispersion is fitted to a Voigt model for the quantification of viscous and elastic moduli. The viscoelastic parameters calculated by the proposed method are validated by comparing the results from a conventional mechanical rheometer.
Zero-order-term elimination by using two hologram subtraction based on reference wave polarization adjustment in off-axis digital holography
Authors: Liu Yiwei , Chen Hao , Sun Qiuya , Jiang Zhuqing
Published: April 2022

We propose a method for the removal of the zero-order term by the subtraction of two off-axis holograms based on a reference wave polarization adjustment. The zero-order elimination hologram is generated by the subtraction of two off-axis holograms that are formed by the interference of two reference waves of different linear-polarization orientations with the same s-polarization object wave. The expression about the zero-order elimination hologram is derived according to the essential formula of holographic recording, which proves the validity of this method in principle. The experimental results show that imaging reconstruction from the zero-order elimination hologram can achieve a higher resolution than conventional reconstruction.
Third harmonic generation enhancement from silicon-based multilayer guided mode resonance structures under a conical mounting condition
Authors: Menon Sruti , Jyothsna K. M. , Biswas Rabindra , Prosad Asish , Lal Krishna A. S. , Raghunathan Varun
Published: April 2022

We experimentally demonstrate more than four-orders of magnitude enhancement in third harmonic generation from an amorphous silicon layer as thin as 10 nm deposited above silicon nitride guided mode resonance (GMR) structures under a conical mounting condition using a rectangular aperture as a pupil plane mask for the fundamental excitation. The multilayer GMR structure studied here consists of shallow etched one-dimensional silicon dioxide gratings with a silicon nitride intermediate layer and an amorphous silicon nonlinear medium. Under conical mounting, by restricting the fundamental excitation angles along the grating vector direction, while retaining the angles supported by the objective lens along the grating lines, the resonances are made angle insensitive. The forward detected THG enhancement increases from 2860 in the absence of any pupil plane mask, with a uniform fundamental excitation angular span of 2.3° to 4740 and 1.7 × 104 in the presence of rectangular apertures that selectively reduce the excitation angular span along the grating vector direction to 0.86° and 0.43°, respectively. Conical mounting using rectangular aperture pupil masks to engineer the fundamental excitation is a promising approach to enhance nonlinear optical processes from angle sensitive GMR structures.
Hasty sensorimotor decisions rely on an overlap of broad and selective changes in motor activity
Authors: Derosiere Gerard , Thura David , Cisek Paul , Duque Julie
Published: April 2022

Humans and other animals are able to adjust their speed–accuracy trade-off (SAT) at will depending on the urge to act, favoring either cautious or hasty decision policies in different contexts. An emerging view is that SAT regulation relies on influences exerting broad changes on the motor system, tuning its activity up globally when hastiness is at premium. The present study aimed to test this hypothesis. A total of 50 participants performed a task involving choices between left and right index fingers, in which incorrect choices led either to a high or to a low penalty in 2 contexts, inciting them to emphasize either cautious or hasty policies. We applied transcranial magnetic stimulation (TMS) on multiple motor representations, eliciting motor-evoked potentials (MEPs) in 9 finger and leg muscles. MEP amplitudes allowed us to probe activity changes in the corresponding finger and leg representations, while participants were deliberating about which index to choose. Our data indicate that hastiness entails a broad amplification of motor activity, although this amplification was limited to the chosen side. On top of this effect, we identified a local suppression of motor activity, surrounding the chosen index representation. Hence, a decision policy favoring speed over accuracy appears to rely on overlapping processes producing a broad (but not global) amplification and a surround suppression of motor activity. The latter effect may help to increase the signal-to-noise ratio of the chosen representation, as supported by single-trial correlation analyses indicating a stronger differentiation of activity changes in finger representations in the hasty context.