bluuebunny/crossref_metadata_2025 huggingface dataset:
TIAM-1 regulates polarized protrusions during dorsal intercalation in the Caenorhabditis elegans embryo through both its GEF and N-terminal domains
Authors: Zhu Yuyun , Tesone Zoe , Tan Minyi , Hardin Jeff
Published: February 2024

Mediolateral cell intercalation is a morphogenetic strategy used throughout animal development to reshape tissues. Dorsal intercalation in the Caenorhabditis elegans embryo involves the mediolateral intercalation of two rows of dorsal epidermal cells to create a single row that straddles the dorsal midline, and thus is a simple model to study cell intercalation. Polarized protrusive activity during dorsal intercalation requires the C. elegans Rac and RhoG orthologs CED-10 and MIG-2, but how these GTPases are regulated during intercalation has not been thoroughly investigated. In this study, we characterized the role of the Rac-specific guanine nucleotide exchange factor (GEF) TIAM-1 in regulating actin-based protrusive dynamics during dorsal intercalation. We found that TIAM-1 can promote formation of the main medial lamellipodial protrusion extended by intercalating cells through its canonical GEF function, whereas its N-terminal domains function to negatively regulate the generation of ectopic filiform protrusions around the periphery of intercalating cells. We also show that the guidance receptor UNC-5 inhibits these ectopic filiform protrusions in dorsal epidermal cells and that this effect is in part mediated via TIAM-1. These results expand the network of proteins that regulate basolateral protrusive activity during directed rearrangement of epithelial cells in animal embryos.
Culture substrate stiffness impacts human myoblast contractility-dependent proliferation and nuclear envelope wrinkling
Authors: Nguyen Jo , Wang Lu , Lei Wen , Hu Yechen , Gulati Nitya , Chavez-Madero Carolina , Ahn Henry , Ginsberg Howard J. , Krawetz Roman , Brandt Matthias , Betz Timo , Gilbert Penney M.
Published: February 2024

Understanding how biophysical and biochemical microenvironmental cues together influence the regenerative activities of muscle stem cells and their progeny is crucial in strategizing remedies for pathological dysregulation of these cues in aging and disease. In this study, we investigated the cell-level influences of extracellular matrix (ECM) ligands and culture substrate stiffness on primary human myoblast contractility and proliferation within 16 h of plating and found that tethered fibronectin led to stronger stiffness-dependent responses compared to laminin and collagen. A proteome-wide analysis further uncovered cell metabolism, cytoskeletal and nuclear component regulation distinctions between cells cultured on soft and stiff substrates. Interestingly, we found that softer substrates increased the incidence of myoblasts with a wrinkled nucleus, and that the extent of wrinkling could predict Ki67 (also known as MKI67) expression. Nuclear wrinkling and Ki67 expression could be controlled by pharmacological manipulation of cellular contractility, offering a potential cellular mechanism. These results provide new insights into the regulation of human myoblast stiffness-dependent contractility response by ECM ligands and highlight a link between myoblast contractility and proliferation.
Palmitoylation of proteolipid protein M6 promotes tricellular junction assembly in epithelia of Drosophila
Authors: Schleutker Raphael , Luschnig Stefan
Published: February 2024

Tricellular junctions (TCJs) seal epithelial cell vertices and are essential for tissue integrity and physiology, but how TCJs are assembled and maintained is poorly understood. In Drosophila, the transmembrane proteins Anakonda (Aka, also known as Bark), Gliotactin (Gli) and M6 organize occluding TCJs. Aka and M6 localize in an interdependent manner to vertices and act jointly to localize Gli, but how these proteins interact to assemble TCJs was not previously known. Here, we show that the proteolipid protein M6 physically interacts with Aka and with itself, and that M6 is palmitoylated on conserved juxta-membrane cysteine residues. This modification promotes vertex localization of M6 and binding to Aka, but not to itself, and becomes essential when TCJ protein levels are reduced. Abolishing M6 palmitoylation leads to delayed localization of M6 and Aka but does not affect the rate of TCJ growth or mobility of M6 or Aka. Our findings suggest that palmitoylation-dependent recruitment of Aka by M6 promotes initiation of TCJ assembly, whereas subsequent TCJ growth relies on different mechanisms that are independent of M6 palmitoylation.
2′-O-ribose methylation levels of ribosomal RNA distinguish different types of growth arrest in human dermal fibroblasts
Authors: Yang Guohuan , Schmid-Siegel Maximilian , Heissenberger Clemens , Kos-Braun Isabelle C. , Prechtl Martina , Meca-Laguna Gabriel , Rocha Marta , Wagner-Schrittwieser Anja , Pils Vera , Meixner Barbara , Tav Koray , Hengstschläger Markus , Grillari Johannes , Koš Martin , Schosserer Markus
Published: February 2024

The 2′-O-methylation (2′-O-Me) of ribosomal RNA (rRNA) shows plasticity that is potentially associated with cell phenotypes. We used RiboMeth-seq profiling to reveal growth arrest-specific 2′-O-Me patterns in primary human dermal fibroblasts from three different donors. We exposed cells to hydrogen peroxide to induce cellular senescence and to high cell densities to promote quiescence by contact inhibition. We compared both modes of cell cycle arrest to proliferating cells and could indeed distinguish these conditions by their overall 2′-O-Me patterns. Methylation levels at a small fraction of sites showed plasticity and correlated with the expression of specific small nucleolar RNAs (snoRNAs) but not with expression of fibrillarin. Moreover, we observed subtle senescence-associated alterations in ribosome biogenesis. Knockdown of the snoRNA SNORD87, which acts as a guide for modification of a hypermethylated position in non-proliferating cells, was sufficient to boost cell proliferation. Conversely, depletion of SNORD88A, SNORD88B and SNORD88C, which act as guides for modification of a hypomethylated site, caused decreased proliferation without affecting global protein synthesis or apoptosis. Taken together, our findings provide evidence that rRNA modifications can be used to distinguish and potentially influence specific growth phenotypes of primary cells.
Προσρόφηση και εκχυλίση νανοσωματιδίων και ιόντων ευγενών μετάλλων με υβριδικά μεταλλοργανικά πλέγματα ζιρκονίου
Authors: Τζιάσιου Χαρίκλεια
Published: February 2024

Σε αυτήν τη διδακτορική διατριβή, συντέθηκε ένα μεταλλο-οργανικό πλέγμα ζιρκονίου με μερκαπτοσουκινικό οξύ που φέρει ελεύθερες ομάδες θειόλης ως ροφητικό υλικό για την απομάκρυνση μεταλλικών νανοσωματιδίων και μεταλλικών ιόντων από το νερό. Διαπιστώθηκε ότι η ρόφηση λαμβάνει χώρα στην επιφάνεια του MOF μέσω του σχηματισμού ισχυρών χημικών δεσμών μετάλλου-θειόλης που επιτρέπουν τη γρήγορη πρόσληψη νανοσωματιδίων και ιόντων ευγενών μετάλλων από το νερό (<1 h). Η μέγιστη ικανότητα ρόφησης εξαρτάται από το μέγεθος των νανοσωματιδίων και κυμάνθηκε από 8-41,5 mg /g. Η λειτουργικότητα της επιφάνειας των νανοσωματιδίων δεν επηρέασε την απόδοση ρόφησης, η οποία διατηρήθηκε και σε φυσικά ύδατα μεταβλητής πολυπλοκότητας. Το υλικό ήταν επίσης αποτελεσματικό σε στήλες σταθερής κλίνης με εκτιμώμενη μέγιστη ικανότητα ρόφησης περίπου 7 mg /g, η οποία είναι σημαντικά υψηλότερη από τις περιβαλλοντικές συγκεντρώσεις των νανοσωματιδίων και επαρκής για την απομάκρυνσή τους από βιομηχανικά απόβλητα. Είναι σημαντικό ότι τα προσροφημένα νανοσωματίδια μπορούσαν να ανακτηθούν ποσοτικά (>90%) (εις βάρος όμως της διάσπασης του υλικού) επιτρέποντας την πιθανή επαναχρησιμοποίησή και ανακύκλωση τους για άλλες εφαρμογές. Επίσης, το ΜOF-SH χρησιμοποιήθηκε για την εκχύλιση νανοσωματιδίων ευγενών μετάλλων από υδατικά περιβαλλοντικά δείγματα. Λόγω της παρουσίας μιας ελεύθερης τερματικής ομάδας θειόλης, η εκχύλιση μεταλλικών νανοσωματιδίων πραγματοποιείται στη επιφάνεια του MOF, αντί των πόρων του, μειώνοντας έτσι σημαντικά τον χρόνο εκχύλισης. Τόσο τα νανοσωματίδια ευγενών μετάλλων όσο και τα ευγενή μέταλλα, μπορούν να εκχυλιστούν ποσοτικά από υδατικά δείγματα χρησιμοποιώντας εκχύλιση διασποράς στερεάς φάσης και να προσδιοριστούν με φασματοσκοπία ατομικής απορρόφησης. Το MOF-SH μπορεί να προσροφήσει αποτελεσματικά AuNPs διαφόρων μεγεθών και επικαλύψεων, επιτρέποντας έτσι τον προσδιορισμό της συνολικής συγκέντρωσης των AuNP στο δείγμα. Λόγω της ισχυρής συγγένειας των ειδών χρυσού με την ομάδα της θειόλης, ο διαχωρισμός των AuNPs από τα ιόντα χρυσού επιτυγχάνεται με υπερφυγοκέντρηση πριν από την εκχύλιση, ακολουθούμενη από ανεξάρτητη εκχύλιση για τον προσδιορισμό του κάθε είδους. Τέλος, η μέθοδος δίνει χαμηλά όρια ανίχνευσης και καλή αναπαραγωγιμότητα και είχε ικανοποιητικά αποτελέσματα που υποδεικνύουν την καταλληλότητά της για παρακολούθηση των AuNPs σε περιβαλλοντικά δείγματα.
An examination of the structural linkages between households and community health services in realization of accelerated primary healthcare delivery in Kisumu County, Kenya: a systematic review
Authors: Wakiaga James M. , Nalugala Reginald
Published: February 2024

Background The provision of community health services (CHS) is critical in accelerating primary health care delivery to vulnerable and deprived populations. This systematic review study has been conducted to interrogate the interrelationship between households and community health services in accelerating primary healthcare delivery synthesizing the available empirical studies. The findings are to inform a primary research on structural linkages between households and CHS in Kisumu County, Kenya. Methods This study applied a descriptive approach using a systematic review technique to provide context and substance to the two main research questions: (1) how does the interaction between households and CHWs affect utilization of CHS to promote equity and right to health? (2) How do health-seeking behaviours of households influence their decision-making regarding choices of CHS? We screened the literature from Google scholar, JSTOR, SAGE and EBSCO based on our inclusion criteria, resulting in 21 studies. These studies were assessed for quality and eligibility and data extracted based on relevance to the research study. Results Households place primacy on trust and confidentiality in the interaction with CHWs and this affects uptake of CHS. The social determinants of health are also critical in influencing the health-seeking behaviour of households and individuals and their choice of CHS. The successful models of CHS share the characteristic of community ownership and participation and provides for comprehensive health care teams. Conclusion CHS are critical for the acceleration of primary health care delivery. It forms an important pathway for the achievement of universal health coverage, which is an outcome required for Sustainable Development Goal 3 on health.
FEATURES OF PROFESSIONALISM OF CORRECTIONAL INSTITUTION EMPLOYEES WITH DIFFERENT LEVELS OF MOTIVATION FOR PHYSICAL AND SPORTS ACTIVITIES
Authors: Kuklina Larisa V.
Published: February 2024

Professional development plays a key role in the career and personal growth of every specialist. It includes not only the acquisition of new knowledge and skills, but also the formation of professional self-awareness, which allows the employee to realize his importance and responsibility to society.

Therefore, the problem arises of searching for factors that influence the professionalism of employees at different stages of professional activity and developing a model of psychological and acmeological support that contributes to the formation of their professional competence.

Purpose of the work: to study the features of motivation for physical culture and sports activities of employees of the penal system and its relationship with professional competence

Materials and methods of research. The study was conducted on the basis of the institutions of the Federal Penitentiary Service of Russia in the Vologda region, 2 groups of respondents took part in it: group 1 – 25 employees of a special forces detachment involved in sports (athletes with ranks in wrestling) aged 23 to 27 years; group 2 – 25 correctional colony employees aged from 23 to 27 years old who are not involved in sports (employees of the educational department, administration employees).

The methods “Motives for Playing Sports” by A.V. Shaboltas, expert assessment of the professional competence of employees of the penal system using an adapted “methodology for a comprehensive assessment of the professional performance of a state civil servant.”

Research results and discussion. The results of the study showed that employees of the penitentiary system with different levels of motivation for physical education and sports activities have differences in professional competence. There is a relationship between professional competence and motivation for physical education and sports activities among correctional officers.

The practical significance of the study lies in the possibility of applying the results in the development of programs for the development of professional competence of correctional officers, designed on the basis of differences in their motivation for physical education and sports activities

The conducted research allows us to formulate the following recommendations:

Purposeful formation of motivation for physical culture and sports activities of employees of the penal system through the development of internal attitudes and external stimulation will also contribute to the formation of health-preserving competence of employees.

Creating conditions for the formation of motivation for physical culture and sports activities of employees of the penal system will contribute not only to increasing the level of physical fitness as a component of the professional competence of employees, but will also stimulate the manifestation of their subjectivity.
Polish mental and sexual health specialists working with transgender and gender diverse persons – who are they and what is their background?
Authors: Grabski Bartosz , Koziara Karolina , Kania Toni , Pliczko Mateusz Piotr , Mijas Magdalena Ewa
Published: February 2024

Cel pracy

Przedstawienie charakterystyki demograficznej i zawodowej polskich specjalistek, specjalistów i osób specjalizujących się w obszarze zdrowia psychicznego i seksualnego (mental and sexual health specialists, MSHS) mających doświadczenie w pracy klinicznej z osobami transpłciowymi i różnorodnymi płciowo (transgender and gender diverse; TGD).

Metoda

Badanie miało charakter przekrojowy i przeprowadzone zostało za pomocą platformy LimeSurvey. Udział w badaniu wzięło 239 MSHS o różnorodnym wykształceniu zawodowym i na różnych etapach kariery zawodowej, mających doświadczenie pracy z pacjentami/tkami TGD. Osoby uczestniczące w badaniu poproszone zostały o podanie podstawowych danych demograficznych (np. tożsamości płciowej i seksualnej) i zawodowych (np. znajomość wiodących standardów i wytycznych). Zastosowano metody statystyki opisowej.

Wyniki

Wiek badanej próby wynosił średnio 39,5 lat (SD 7,92) i większość stanowiły osoby o przypisanej płci żeńskiej (73,2%). W grupie badanej dominowali psychoterapeuci/tki (70%), inne grupy zawodowe to psychologowie/żki (53%), lekarze/rki (31%) i certyfikowani seksuolodzy/żki (5,9%). Większość (72%) praktykowała w dużych miastach (>500 tys.). 68,6% osób podało tożsamość kobiecą, 24,7% męską, a 6,3% TGD. 63,2% osób było heteroseksualnych, 12,1% homoseksualnych, 12,6% biseksualnych, a 12,1% podało inną tożsamość seksualną. Znaczenie i praktykowanie religii było znacząco mniejsze niż dla ogółu polskiego społeczeństwa. Większość osób, które wzięły udział w badaniu oceniła swoją znajomość podstawowych wytycznych w pracy z osobami TGD jako niesatysfakcjonującą lub złą, a szkolenia w trakcie kształcenia zawodowego jako niewystarczające.

Wnioski

Osoby świadczące usługi kliniczne dla klientów i klientek TGD stanowią zróżnicowaną zawodowo grupę. Istnieje pilna potrzeba poszerzenia i intensyfikacji szkoleń zawodowych kierowanych do MSHS w zakresie tematyki dotyczącej opieki nad zdrowiem osób TGD.
Macroeconomic Effects of Fiscal Policy during the Covid-19 Crisis: Evidence from Bolivia at a Regional Level
Authors: Chalup Calmotti Miguel Sebastiano , Escobar Caba Luis Fernando
Published: February 2024

This paper evaluates the impact of the fiscal policy applied in Bolivia during the Covid-19 crisis at a regional level. It includes two analyses: the economic slowdown at a regional level analyzed through a mixed frequency Bayesian var with a stochastic volatility model, and the impact and effectiveness of the fiscal policy using a time-varying parameter var model. The results indicate that the pandemic had a heterogeneous effect on the region’s economic activity and the capital expenditure from the national treasury was the most effective fiscal policy to reduce the recessive effects of the crisis. We also noted that some regions positively reacted to regional and local government capital expenditure.
Eosinophilic gastroenteritis following COVID-19 mRNA vaccination
Authors: Yoshino Yuta , Tsuboi Ken
Published: February 2024

Introduction: Large-scale clinical studies for COVID-19 vaccines have shown the infection-preventing effect and short-term adverse effects. Some rare illnesses such as eosinophilia can develop following COVID-19 vaccinations. Case description: We report a case of 65-year-old man with unexplained abdominal pain that developed 2 weeks after COVID-19 mRNA vaccination. The patient had received a second dose of COVID-19 mRNA vaccine and revealed eosinophilia at the first visit to our hospital. Eosinophil infiltration was observed in the lamina propria of the duodenum by a step biopsy. Montelukast 10 mg was administered as the initial treatment of eosinophilic gastroenteritis (EGE), and the abdominal pain was improved. Discussion: The strong influence of COVID-19 vaccination on the development of EGE remains unproven. Reports of eosinophilia following COVID-19 vaccination have discussed that COVID-19 mRNA vaccination triggered an eosinophilic response. Conclusion: This case presented EGE that developed following COVID-19 mRNA vaccination, which would be a rare adverse event.
Meeting the challenges of cyber security
Authors: Mansfield-Devine Steve
Published: February 2024

Cyber security isn't getting any easier. Both the threats and the solutions designed to combat them are becoming ever more complex. Smaller firms frequently struggle to keep up with the latest threats and bring the right skills to bear. And even the largest firms face challenges when it comes to assessing risks and implementing the solutions to tackle them.
AI as the bedrock for next-generation cyber security solutions
Authors: Sood Aditya K , Nagal Amit
Published: February 2024

Artificial intelligence (AI) and cyber security continue to evolve hand-in-hand, and organisations must maintain a proactive and adaptable mindset to use AI as a tool for handling cyber security challenges. This article discusses the effectiveness of AI in solving cyber security problems while handling data-at-scale.
Patterns of stability and change in media attention in Europe
Authors: Yildirim Tevfik Murat
Published: February 2024

Punctuated equilibrium theory (PET) has evolved into a comprehensive theory of organisational information processing over the past two decades, with hundreds of studies adopting it to examine various aspects of the policy process. Despite the growing number of studies building on PET, however, our understanding of stability and change in media agendas remains rather limited. I propose a theory that seeks to explain the conditions under which media agendas are more punctuated and test my hypotheses using a dataset of 7 million news stories from 15 newspapers in Belgium, Denmark, Norway, the Netherlands and the UK between 2000 and 2019. Results, based on an analysis of change distributions and a series of regression models, highlight two important findings: first, punctuations in the media agenda are less severe and frequent than those in other organisational agendas. Second, the severity of punctuations is greater in politicised news and diminished in issue areas related to ‘core functions of government’ (Jennings et al, 2011), relative to non-politicised news and issues outside the core areas, respectively. Results also suggest that despite the varying media and political characteristics of the countries examined in this study, change distributions of media attention are strikingly similar across the country cases. Through this novel and innovative study, the article contributes to PET theory by considering different elements of news stories, as well as re-engaging with the discussion of the relationship between the media and politics.
The role of coping strategies in subjective wellbeing indicators of non-profit workers
Authors: Uǧur Zeynep B.
Published: February 2024

This study examines the relationship between coping styles, job satisfaction, and subjective wellbeing among non-profit (NPO) workers serving refugees. A sample of 228 paid and volunteer NPO workers based in Turkey was analysed, revealing generally high levels of job satisfaction and widespread utilisation of coping mechanisms. The most common coping strategies among NPO workers include social support, exercise, and prayer/spirituality. Interestingly, while no significant variations were found in happiness and life satisfaction scores based on coping strategies, there were significant differences in job satisfaction scores. Specifically, employing prayer/spirituality as a coping strategy is associated with higher levels of happiness, life satisfaction, and job satisfaction. These results suggest the potential benefits of incorporating prayer/spirituality into coping mechanisms within the NPO work. Conversely, workers who did not utilise any coping strategies reported the lowest levels of job satisfaction, highlighting the importance of employing coping strategies to enhance job satisfaction in NPO work.
Bystander experiences of domestic violence and abuse during the COVID-19 pandemic
Authors: Walker Alex , Fenton Rachel A. , Parry Bryony , Barton Emma R. , Snowdon Lara C. , Donovan Catherine , Bellis Mark A. , Hughes Karen
Published: February 2024

This article seeks to understand the experiences of bystanders to domestic violence and abuse (DVA) during the COVID-19 pandemic in Wales. Globally, professionals voiced concern over the COVID-19 restrictions exacerbating conditions for DVA to occur. Yet evidence suggests this also increased opportunities for bystanders to become aware of DVA and take action against it. This mixed methods study consists of a quantitative online survey and follow-up interviews with survey respondents. Conducted in Wales, UK, during a national lockdown in 2021, this article reports on the experiences of 186 bystanders to DVA during the pandemic.

Results suggest that bystanders had increased opportunity to become aware of DVA due to the pandemic restrictions. Results support the bystander situational model whereby respondents have to become aware of the behaviour, recognise it as a problem, feel that they possess the correct skills, and have confidence in their skills, before they will take action. Having received bystander training was a significant predictor variable in bystanders taking action against DVA; this is an important finding that should be utilised to upskill general members of the community.
“Hidden phase” in two-wavelength adaptive optics
Authors: Hyde Milo W. , McCrae Jack E. , Kalensky Matthew , Spencer Mark F.
Published: February 2024

Two-wavelength adaptive optics (AO), where sensing and correcting (from a beacon) are performed at one wavelength λ
B
and compensation and observation (after transmission through the atmosphere) are performed at another λ
T
, has historically been analyzed and practiced assuming negligible irradiance fluctuations (i.e., weak scintillation). Under these conditions, the phase corrections measured at λ
B
are robust over a relatively large range of wavelengths, resulting in a negligible decrease in AO performance. In weak-to-moderate scintillation conditions, which result from distributed-volume atmospheric aberrations, the pupil-phase function becomes discontinuous, producing what Fried called the “hidden phase” because it is not sensed by traditional least-squares phase reconstructors or unwrappers. Neglecting the hidden phase has a significant negative impact on AO performance even with perfect least-squares phase compensation. To the authors’ knowledge, the hidden phase has not been studied in the context of two-wavelength AO. In particular, how does the hidden phase sensed at λ
B
relate to the compensation (or observation) wavelength λ
T
? If the hidden phase is highly correlated across λ
B
and λ
T
, like the least-squares phase, it is worth sensing and correcting; otherwise, it is not. Through a series of wave optics simulations, we find an approximate expression for the hidden-phase correlation coefficient as a function of λ
B
, λ
T
, and the scintillation strength. In contrast to the least-squares phase, we determine that the hidden phase (when present) is correlated over a small band of wavelengths centered on λ
T
. Over the range λ
B
,λ
T
∈[1,3]µm and in weak-to-moderate scintillation conditions (spherical-wave log-amplitude variance σ
χ
2∈[0.1,0.5]), we find the average hidden-phase correlation linewidth to be approximately 0.35 µm. Consequently, for |λ
B
−λ
T
| greater than this linewidth, including the hidden phase does not significantly improve AO performance over least-squares phase compensation.
All-optical Stern-Gerlach effect in the time domain
Authors: Bashan Gil , Eyal Avishay , Tur Moshe , Arie Ady
Published: February 2024

The Stern-Gerlach experiment, a seminal quantum physics experiment, demonstrated the intriguing phenomenon of particle spin quantization, leading to applications in matter-wave interferometry and weak-value measurements. Over the years, several optical experiments have exhibited similar behavior to the Stern-Gerlach experiment, revealing splitting in both spatial and angular domains. Here we show, theoretically and experimentally, that the Stern-Gerlach effect can be extended into the time and frequency domains. By harnessing Kerr nonlinearity in optical fibers, we couple signal and idler pulses using two pump pulses, resulting in the emergence of two distinct eigenstates whereby the signal and idler are either in phase or out of phase. This nonlinear coupling emulates a synthetic magnetization, and by varying it linearly in time, one eigenstate deflects towards a higher frequency, while the other deflects towards a lower frequency. This effect can be utilized to realize an all-optical, phase-sensitive frequency beam splitter, establishing a new paradigm for classical and quantum data processing of frequency-bin superposition states.
Shipborne single-photon fluorescence oceanic lidar: instrumentation and inversion
Authors: Shangguan Mingjia , Guo Yirui , Liao Zhuoyang
Published: February 2024

Laser-induced fluorescence (LIF) technology has been widely applied in remote sensing of aquatic phytoplankton. However, due to the weak fluorescence signal induced by laser excitation and the significant attenuation of laser in water, profiling detection becomes challenging. Moreover, it remains difficult to simultaneously retrieve the attenuation coefficient (K
l
i
d
a
r

m
f
) and the fluorescence volume scattering function at 180° (βf) through a single fluorescence lidar. To address these issues, a novel all-fiber fluorescence oceanic lidar is proposed, characterized by: 1) obtaining subsurface fluorescence profiles using single-photon detection technology, and 2) introducing the Klett inversion method for fluorescence lidar to simultaneously retrieve K
l
i
d
a
r

m
f
and βf. According to theoretical analysis, the maximum relative error of βf for the chlorophyll concentration ranging from 0.01 mg/m3 to 10 mg/m3 within a water depth of 10 m is less than 20%, while the maximum relative error of K
l
i
d
a
r

m
f
is less than 10%. Finally, the shipborne single-photon fluorescence lidar was deployed on the experimental vessel for continuous experiments of over 9 hours at fixed stations in the offshore area, validating its profiling detection capability. These results demonstrate the potential of lidar in profiling detection of aquatic phytoplankton, providing support for studying the dynamic changes and environmental responses of subsurface phytoplankton.
Multi-channel graphene-based perfect absorbers utilizing Tamm plasmon and Fabry-Perot resonances
Authors: Orojloo Maryam Heidary , Jabbari Masoud , Solooki Nejad Ghahraman , Sohrabi Foozieh
Published: February 2024

In this paper, a multi-channel narrowband absorption structure utilizing the Tamm plasmon and Fabry-Perot resonances in the 1-2 THz range is presented. The structure consists of a graphene sheet, followed by a spacer layer and a dielectric-metal photonic crystal. The transfer matrix method (TMM) is employed to evaluate the effect of different parameters such as the constituent materials and thicknesses of the layers as well as the graphene chemical potential on the spectral response of the structure. Simulation results show that the number of channels, resonance frequencies, and absorption peaks can be easily adjusted by controlling the thicknesses and materials of the layers. The absorption value can reach as high as 99.23% for normal incidents. Additionally, perfect absorption of 100% is achievable by changing the angle of the incident light. Owing to high absorption and straightforward fabrication process, the proposed structure can find various applications such as filtering, sensing, optical switches, and thermal emissions.
Pure optical twist with zero net torque
Authors: Han Zhenyu , Zhang Lei , Li Xiao , Li Yaxin , Qu Tiantao , Yu Xinning , Yu Xudong , Ng Jack , Lin Zhifang , Chen Jun
Published: February 2024

In photonic systems, bilayer or multilayer systems exhibit numerous exciting phenomena induced by twisting. Thus, it is highly desired to explore the twisting effect by engineering the light-matter interactions. Optical torque, an important means in optical micromanipulation, can rotate micro-objects in various ways, enabling a wide range of promising applications. In this study, we present an interesting phenomenon called “pure optical twist” (POT), which emerges when a bilayer structure with specific symmetry is illuminated by counter-propagating lights with opposite spin and/or orbital angular momentum. Remarkably, this leads to zero net optical torque but yet possesses an interesting mechanical effect of bilayer system twisting. The crucial determinant of this phenomenon is the rotational symmetries of each layer, which govern the allowed azimuthal channels of the scattered wave. When the rotational symmetries do not allow these channels to overlap, no resultant torque is observed. Our work will encourage further exploration of the twisting effect through engineered light-matter interactions. This opens up the possibility of creating twisted bilayer systems using optical means, and constructing a stable bilayer optical motor that maintains identical rotation frequencies for both layers.
Technique for enhancing the accuracy of the Rayleigh–Sommerfeld convolutional diffraction through the utilization of independent spatial sampling
Authors: Zhao Wanli , Lu Jing , Ma Jun , Yuan Caojin , Chang Chenliang , Zhu Rihong
Published: February 2024

The Rayleigh–Sommerfeld diffraction integral (RSD) is a rigorous solution that precisely satisfies both Maxwell’s equations and Helmholtz’s equations. It seamlessly integrates Huygens’ principle, providing an accurate description of the coherent light propagation within the entire diffraction field. Therefore, the rapid and precise computation of the RSD is crucial for light transport simulation and optical technology applications based on it. However, the current FFT-based Rayleigh–Sommerfeld integral convolution algorithm (CRSD) exhibits poor performance in the near field, thereby limiting its applicability and impeding further development across various fields. The present study proposes, to our knowledge, a novel approach to enhance the accuracy of the Rayleigh–Sommerfeld convolution algorithm by employing independent sampling techniques in both spatial and frequency domains. The crux of this methodology involves segregating the spatial and frequency domains, followed by autonomous sampling within each domain. The proposed method significantly enhances the accuracy of RSD during the short distance while ensuring computational efficiency.
Low in-band spurious arbitrary waveform generator based on a 1-bit time-wavelength interleaved photonic digital-to-analog conversion
Authors: Yu Jinghan , Li Shangyuan , Bai Zhuoya , Hou Weichen , Xue Xiaoxiao , Zheng Xiaoping , Zhou BingKun
Published: February 2024

We proposed an arbitrary waveform generator based on a 1-bit photonic digital-to-analog conversion (PDAC). The system is based on the principle of photonic pulse sampling and time interleaving. High-speed optical pulses are generated and modulated by digital signals and then synthesized in one path. The analog signals are obtained by an optical-to-electrical conversion of the time-interleaved pulses. Due to the 1-bit structure, there are no spurious components in principle. In the experiment, a 1-bit PDAC of 50 GSa/s is realized, and the X-band linear frequency-modulated (LFM) waveform with a bandwidth of 4 GHz is generated, the signal-to-spur-rejection ratio is as high as 50 dB, and the millimeter-wave 64QAM signal is generated, with an EVM of 4.27%.
Heterogeneous integration of an on-chip Nd:YAG whispering gallery mode laser with a lithium-niobate-on-insulator platform
Authors: Li Huiqi , Wang Zhaocong , Lu Qingming , wang Lei , Tan Yang , Chen Feng
Published: February 2024

The integration of heterogeneous optical components onto an optical platform is crucial for the advancement of photonic chips. To achieve this, efficient coupling of optical signals between components and the platform is essential. Here, we have successfully integrated a Nd:YAG microdisk laser with a lithium-niobate-on-insulator (LNOI) photonic platform by modulating the propagation modes of LNOI. Ridge waveguides are fabricated on the LNOI by carefully adjusting the cross-sectional dimensions to enable the propagation of higher-order propagation modes. This ridge waveguide ensures that the effective refractive index of the higher-order mode closely matches that of the fundamental mode of the Nd:YAG microdisk, ensuring efficient waveguide–microdisk coupling. This on-chip laser, consisting of an Nd:YAG microdisk and LNOI integration, achieves a maximum output power of 23 µW, and a mode suppression ratio of 53.6 dB. This research presents an efficient approach for constructing highly functional heterogeneous integrated optical chips.
Lateral GeSn p-i-n photodetectors on insulator prepared by the rapid melting growth method
Authors: Huang Qinxing , Zheng Jun , Zhu Yupeng , Liu Xiangquan , Liu ZhiPeng , Yang Yazhou , Cui Jinlai , Liu Zhi , Zuo Yuhua , Cheng Buwen
Published: February 2024

In this work, GeSn lateral p-i-n photodetectors (PDs) on insulator were fabricated with an active GeSn layer grown by the rapid melting growth (RMG) method. Taking advantages of the defect-free GeSn strips, GeSn PDs with 5.3% Sn content have low dark current and high responsivities, which are about 0.48, 0.47, and 0.24 A/W for wavelengths of 1550, 1630, and 2000 nm, respectively. The radio frequency of the lateral GeSn PDs was also studied and a 3 dB bandwidth of about 3.8 GHz was achieved. These results indicate that the GeSn grown by the rapid melting growth method is capable of fabricating high-performance Si-based optoelectronic devices.
Slotted surface gratings fabricated by selective area growth of the p-InP cladding layer for BH lasers
Authors: Guo Jing , Li Huan , Xiong Xinkai , Zhou Daibing , Zhao Linhgjuan , Liang Song
Published: February 2024

In this paper, we present a novel, to our knowledge, method for the fabrication of slotted surface gratings for buried heterostructure (BH) lasers. In the device fabrication process, SiO2 strips needed for InP current blocking layer growth are reused for the formation of slot grating pattern masks. In the following growth of the p-InP cladding layer, because the slot areas are covered by SiO2, the InP material is grown selectively in only the areas outside the slot areas, forming slots of the surface gratings in the p-InP layer at the same time as the cladding layer growth. Single longitude mode BH lasers having slotted surface gratings have been fabricated successfully, and the spectra show higher than 40 dB side mode suppression ratio (SMSR). The adoption of the method helps to simply the device fabrication and thus lower the device fabrication cost notably.
Accurate Eye-Tracking from Deflectometric Information using Deep Learning
Authors: Choi Jiwon , Wang Jiazhang , Wang Tianfu , Willomitzer Florian
Published: February 2024

We introduce an accurate eye-tracking method that exploits deflectometric information and uses deep learning to reconstruct the gaze direction. We demonstrate real world experiments with evaluated gaze errors below 1°.
Serological surveillance reveals a high exposure to SARS-CoV-2 and altered immune response among COVID-19 unvaccinated Cameroonian individuals
Authors: Moguem Soubgui Arlette Flore , Ndeme Mboussi Wilfred Steve , Kojom Foko Loick Pradel , Embolo Enyegue Elisée Libert , Koanga Mogtomo Martin Luther
Published: February 2024

Surveillance of COVID-19/SARS-CoV-2 dynamics is crucial to understanding natural history and providing insights into the population’s exposure risk and specific susceptibilities. This study investigated the seroprevalence of SARS-CoV-2 antibodies, its predictors, and immunological status among unvaccinated patients in Cameroon. A multicentre cross-sectional study was conducted between January and September 2022 in the town of Douala. Patients were consecutively recruited, and data of interest were collected using a questionnaire. Blood samples were collected to determine Immunoglobin titres (IgM and IgG), interferon gamma (IFN- γ) and interleukin-6 (IL-6) by ELISA, and CD4+ cells by flow cytometry. A total of 342 patients aged 41.5 ± 13.9 years were included. Most participants (75.8%) were asymptomatic. The overall crude prevalence of IgM and IgG was 49.1% and 88.9%, respectively. After adjustment, the seroprevalence values were 51% for IgM and 93% for IgM. Ageusia and anosmia have displayed the highest positive predictive values (90.9% and 82.4%) and specificity (98.9% and 98.3%). The predictors of IgM seropositivity were being diabetic (aOR = 0.23, p = 0.01), frequently seeking healthcare (aOR = 1.97, p = 0.03), and diagnosed with ageusia (aOR = 20.63, p = 0.005), whereas those of IgG seropositivity included health facility (aOR = 0.15, p = 0.01), age of 40–50 years (aOR = 8.78, p = 0.01), married (aOR = 0.21, p = 0.02), fever (aOR = 0.08, p = 0.01), and ageusia (aOR = 0.08, p = 0.01). CD4+, IFN-γ, and IL-6 were impaired in seropositive individuals, with a confounding role of socio-demographic factors or comorbidities. Although the WHO declared the end of COVID-19 as a public health emergency, the findings of this study indicate the need for continuous surveillance to adequately control the disease in Cameroon.
Using visual attention estimation on videos for automated prediction of autism spectrum disorder and symptom severity in preschool children
Authors: de Belen Ryan Anthony J. , Eapen Valsamma , Bednarz Tomasz , Sowmya Arcot
Published: February 2024

Atypical visual attention in individuals with autism spectrum disorders (ASD) has been utilised as a unique diagnosis criterion in previous research. This paper presents a novel approach to the automatic and quantitative screening of ASD as well as symptom severity prediction in preschool children. We develop a novel computational pipeline that extracts learned features from a dynamic visual stimulus to classify ASD children and predict the level of ASD-related symptoms. Experimental results demonstrate promising performance that is superior to using handcrafted features and machine learning algorithms, in terms of evaluation metrics used in diagnostic tests. Using a leave-one-out cross-validation approach, we obtained an accuracy of 94.59%, a sensitivity of 100%, a specificity of 76.47% and an area under the receiver operating characteristic curve (AUC) of 96% for ASD classification. In addition, we obtained an accuracy of 94.74%, a sensitivity of 87.50%, a specificity of 100% and an AUC of 99% for ASD symptom severity prediction.
The impact of city size on income inclusive growth: A human capital perspective and evidence from China
Authors: He Shao-ling , Zhong Yuan , He Wei-wei
Published: February 2024

This paper methodically investigates the influence of inclusive income growth on city size, examining it through the dual lenses of "income" and "distribution." The analysis leverages meticulously collected panel data encompassing 276 Chinese cities at the prefecture level and above, spanning the period from 2005 to 2019. Theoretical analysis indicates that the effect of city size expansion on per capita income adheres to a ’U’-shaped trajectory, while its influence on the urban-rural income gap manifests an ’inverted U’ pattern. Moreover, the inclusive income growth stemming from city size demonstrates notable heterogeneity across various geographic locations and city hierarchies. The findings reveal that human capital serves as the primary mechanism through which city size influences inclusive income growth. After decomposing the income inclusiveness index, it becomes evident that the expansion of city size exerts a more potent direct driving effect on the income of urban residents. On the one hand, city size expansion directly increases rural residents’ income levels by improving labor productivity. On the other hand, it facilitates leapfrog income development by inducing the rural labor force to move to cities.
Pomegranate extract-loaded sphingosomes for the treatment of cancer: Phytochemical investigations, formulation, and antitumor activity evaluation
Authors: AlMadalli Huda Jamal , Abdul Rasool Bazigha K. , Shehab Naglaa Gamil , Sala Francesca Della , Borzacchiello Assunta
Published: February 2024

Aim

Formulation of Pomegranate Extracts (PE)-loaded sphingosomes as an antitumor therapy for the intravenous and passive targeted delivery to various tumor types, especially that of the breast, colon, and uterus; to increase the therapeutic activity and decrease the adverse effects profile.

Methods

The pericarp and seeds’ juice of Punica granatum were each extracted using D.W. and ethanol. Phytochemical investigation of all extracts was carried out including total phenolics, flavonoids, and anthocyanins contents, the antioxidant activity, as well as HPLC analysis of phenolics and flavonoids. The antitumor potential of all extracts was also tested utilizing three cell lines: MCF-7, HeLa, and HCT116. The candidate extract was chosen for the formulation phase and was entrapped into the sphingosomes using the thin-film hydration method and employing three different PE: lipids weight ratios. The synthesized formulations were characterized for their size, morphological features, zeta potential, entrapment efficiency, and in vitro drug release and kinetics modeling studies. The optimized formula was further analyzed by FTIR spectroscopy and electron microscopy. The antitumor activity of F2 was also investigated using the same cancer cell lines compared to the plant extract.

Results

The highest phenolics, flavonoids, and anthocyanins contents were observed in the ethanolic pericarps extract (EPE), followed by the ethanolic seeds extract (ESE). Consequently, EPE showed a higher antitumor activity hence it was selected for the formulation phase. PE-loaded sphingosomes formula (F2) was selected for having the highest EE% (71.64%), and a sustained release profile with the highest in vitro release (42.5±9.44%). By employing the DDSolver, the Weibull model was found the most suitable to describe the PE release kinetics compared to other models. The release mechanism was found to follow Fickian diffusion. Simulated pharmacokinetic parameters have portrayed F2 as the candidate formula, with the highest AUC (536.095) and slowest MDT (0.642 h). In addition, F2 exhibited a significant (p>0.05) stronger and prolonged anticancer effect against MCF-7, HeLa, and HCT116 cell lines at all concentrations tested compared to the free extract.

Conclusion

The results proved that sphingosomes are an effective delivery system, improving pharmacological efficacy and reducing serious side effects of anticancer medications and natural products.
Detection of lymphoproliferative disease virus in Iowa Wild Turkeys (Meleagris gallopavo): Comparison of two sections of the proviral genome
Authors: Smith Kelsey C. , Blanchong Julie A.
Published: February 2024

An accurate diagnostic test is an essential aspect of successfully monitoring and managing wildlife diseases. Lymphoproliferative Disease Virus (LPDV) is an avian retrovirus that was first identified in domestic turkeys in Europe and was first reported in a Wild Turkey (Meleagris gallopavo) in the United States in 2009. It has since been found to be widely distributed throughout North America. The majority of studies have utilized bone marrow and PCR primers targeting a 413-nucleotide sequence of the gag gene of the provirus to detect infection. While prior studies have evaluated the viability of other tissues for LPDV detection (whole blood, spleen, liver, cloacal swabs) none to date have studied differences in detection rates when utilizing different genomic regions of the provirus. This study examined the effectiveness of another section of the provirus, a 335-nucleotide sequence starting in the U3 region of the LTR (Long Terminal Repeat) and extending into the Matrix of the gag region (henceforth LTR), for detecting LPDV. Bone marrow samples from hunter-harvested Wild Turkeys (n = 925) were tested for LPDV with the gag gene and a subset (n = 417) including both those testing positive and those where LPDV was not detected was re-tested with LTR. The positive percent agreement (PPA) was 97.1% (68 of 70 gag positive samples tested positive with LTR) while the negative percent agreement (NPA) was only 68.0% (236 of 347 gag negative samples tested negative with LTR). Cohen’s Kappa (κ = 0.402, Z = 10.26, p<0.0001) and the McNemar test (OR = 55.5, p<0.0001) indicated weak agreement between the two gene regions. We found that in Iowa Wild Turkeys use of the LTR region identified LPDV in many samples in which we failed to detect LPDV using the gag region and that LTR may be more appropriate for LPDV surveillance and monitoring. However, neither region of the provirus resulted in perfect detection and additional work is necessary to determine if LTR is more reliable in other geographic regions where LPDV occurs.