bluuebunny/crossref_metadata_2025 huggingface dataset:
A cell wall-associated gene network shapes leaf boundary domains
Authors: Bouré Nathalie , Peaucelle Alexis , Goussot Magali , Adroher Bernard , Soubigou-Taconnat Ludivine , Borrega Néro , Biot Eric , Tariq Zakia , Martin-Magniette Marie-Laure , Pautot Véronique , Laufs Patrick , Arnaud Nicolas
Published: May 2022

Boundary domains delimit and organize organ growth throughout plant development almost relentlessly, building plant architecture and morphogenesis. Boundary domains display reduced growth and orchestrate development of adjacent tissues in a non-cell-autonomous manner. How these two functions are achieved remains elusive despite the identification of several boundary-specific genes. Here, we show using morphometrics at the organ and cellular levels that leaf boundary domain development requires SPINDLY (SPY), an O-fucosyltransferase, to act as cell growth repressor. Furthermore, we show that SPY acts redundantly with the CUP-SHAPED COTYLEDON transcription factors (CUC2 and CUC3), which are major determinants of boundaries development. Accordingly, at the molecular level CUC2 and SPY repress a common set of genes involved in cell wall loosening, providing a molecular framework for the growth repression associated with boundary domains. Atomic force microscopy confirmed that young leaf boundary domain cells have stiffer cell walls than marginal outgrowth. This differential cell wall stiffness was reduced in spy mutant plants. Taken together, our data reveal a concealed CUC2 cell wall-associated gene network linking tissue patterning with cell growth and mechanics.
Distinct contributions of ECM proteins to basement membrane mechanical properties in Drosophila
Authors: Töpfer Uwe , Guerra Santillán Karla Yanín , Fischer-Friedrich Elisabeth , Dahmann Christian
Published: May 2022

The basement membrane is a specialized extracellular matrix (ECM) that is crucial for the development of epithelial tissues and organs. In Drosophila, the mechanical properties of the basement membrane play an important role in the proper elongation of the developing egg chamber; however, the molecular mechanisms contributing to basement membrane mechanical properties are not fully understood. Here, we systematically analyze the contributions of individual ECM components towards the molecular composition and mechanical properties of the basement membrane underlying the follicle epithelium of Drosophila egg chambers. We find that the Laminin and Collagen IV networks largely persist in the absence of the other components. Moreover, we show that Perlecan and Collagen IV, but not Laminin or Nidogen, contribute greatly towards egg chamber elongation. Similarly, Perlecan and Collagen, but not Laminin or Nidogen, contribute towards the resistance of egg chambers against osmotic stress. Finally, using atomic force microscopy we show that basement membrane stiffness mainly depends on Collagen IV. Our analysis reveals how single ECM components contribute to the mechanical properties of the basement membrane controlling tissue and organ shape.
The lysine deacetylase activity of histone deacetylases 1 and 2 is required to safeguard zygotic genome activation in mice and cattle
Authors: Dang Yanna , Li Shuang , Zhao Panpan , Xiao Lieying , Wang Lefeng , Shi Yan , Luo Lei , Wang Shaohua , Wang Huanan , Zhang Kun
Published: May 2022

The genome is transcriptionally inert at fertilization and must be activated through a remarkable developmental process called zygotic genome activation (ZGA). Epigenetic reprogramming contributes significantly to the dynamic gene expression during ZGA; however, the mechanism has yet to be resolved. Here, we find histone deacetylases 1 and 2 (HDAC1/2) can regulate ZGA through lysine deacetylase activity. Notably, in mouse embryos, overexpression of a HDAC1/2 dominant-negative mutant leads to developmental arrest at the two-cell stage. RNA-seq reveals that 64% of downregulated genes are ZGA genes and 49% of upregulated genes are developmental genes. Inhibition of the deacetylase activity of HDAC1/2 causes a failure of histone deacetylation at multiple sites, including H4K5, H4K16, H3K14, H3K18 and H3K27. ChIP-seq analysis exhibits an increase and decrease of H3K27ac enrichment at promoters of up- and downregulated genes, respectively. Moreover, HDAC1 mutants prohibit the removal of H3K4me3 by impeding expression of Kdm5 genes. Importantly, the developmental block can be greatly rescued by Kdm5b injection and by partially correcting the expression of the majority of dysregulated genes. Similar functional significance of HDAC1/2 is conserved in bovine embryos. Overall, we propose that HDAC1/2 are indispensable for ZGA by creating correct transcriptional repressive and active states in mouse and bovine embryos.
Dissecting the phenotypic variability of osteogenesis imperfecta
Authors: Garibaldi Nadia , Besio Roberta , Dalgleish Raymond , Villani Simona , Barnes Aileen M. , Marini Joan C. , Forlino Antonella
Published: May 2022

Osteogenesis imperfecta (OI) is a heterogeneous family of collagen type I-related diseases characterized by bone fragility. OI is most commonly caused by single-nucleotide substitutions that replace glycine residues or exon splicing defects in the COL1A1 and COL1A2 genes that encode the α1(I) and α2(I) collagen chains. Mutant collagen is partially retained intracellularly, impairing cell homeostasis. Upon secretion, it assembles in disorganized fibrils, altering mineralization. OI is characterized by a wide range of clinical outcomes, even in the presence of identical sequence variants. Given the heterotrimeric nature of collagen I, its amino acid composition and the peculiarity of its folding, several causes may underlie the phenotypic variability of OI. A deep analysis of entries regarding glycine and splice site collagen substitution of the largest publicly available patient database reveals a higher risk of lethal phenotype for carriers of variants in α1(I) than in α2(I) chain. However, splice site variants are predominantly associated with lethal phenotype when they occur in COL1A2. In addition, lethality is increased when mutations occur in regions of importance for extracellular matrix interactions. Both extracellular and intracellular determinants of OI clinical severity are discussed in light of the findings from in vitro and in vivo OI models. Combined with meticulous tracking of clinical cases via a publicly available database, the available OI animal models have proven to be a unique tool to shed light on new modulators of phenotype determination for this rare heterogeneous disease.
A brainstem preparation allowing simultaneous access to respiratory motor output and cellular properties of motoneurons in American bullfrogs
Authors: Amaral-Silva Lara do , Santin Joseph M.
Published: May 2022

Breathing is generated by a complex neural circuit, and the ability to monitor the activity of multiple network components simultaneously is required to uncover the cellular basis of breathing. In neonatal rodents, a single brainstem slice can be obtained to record respiratory-related motor nerve discharge along with individual rhythm-generating cells or motoneurons because of the close proximity of these neurons in the brainstem. However, most ex vivo preparations in other vertebrates can only capture respiratory motor outflow or electrophysiological properties of putative respiratory neurons in slices without relevant synaptic inputs. Here, we detail a method to horizontally slice away the dorsal portion of the brainstem to expose fluorescently labeled motoneurons for patch-clamp recordings in American bullfrogs. This ‘semi-intact’ preparation allows tandem recordings of motor output and single motoneurons during respiratory-related synaptic inputs. The rhythmic motor patterns are comparable to those from intact preparations and operate at physiological temperature and [K+]. Thus, this preparation provides the ability to record network and cellular outputs simultaneously and may lead to new mechanistic insights into breathing control across vertebrates.
High Stabilization of Low Valency in a Homoleptic ortho-Hydroxybenzoate-bridged Paddlewheel Diruthenium(II,II) Complex
Authors: Kosaka Wataru , Watanabe Yudai , Itoh Chisa , Miyasaka Hitoshi
Published: May 2022

A paddlewheel-type homoleptic diruthenium(II,II) complex ([Ru2II,II]), [Ru2(o-OHPhCO2)4(THF)2] (o-OH), bridged by ortho-hydroxybenzoate (o-OHPhCO2−) and tetrahydrofuran (THF) coordinated at the axial position (Lax) was isolated. The use of meta- and para-substituted hydroxybenzoate (x-OHPhCO2−; x = m and p) produced the corresponding [Ru2II,III] species neutralized by deprotonation of one of the x-OHPhCO2− ligands. In the o-OH complex, the formation of intramolecular hydrogen bonds between the o-OH group and carboxylate oxygen atom stabilized the [Ru2II,II] species significantly.
Inclusive pedagogy in online simulation-based learning in undergraduate nursing education: A scoping review protocol
Authors: Langan Lisa , Halligan Phil , Frazer Kate , Darley Andrew , Goodman Lizbeth , Redmond Catherine
Published: May 2022

Background: Education is recognised as a constitutional right, however, access to and participation in higher education can be challenging for some students. This has led to the development of various international and local initiatives promoting inclusion, which has increased student representation from marginalised groups. In order to support growing student diversity, teaching and learning (T&L) strategies must encompass inclusive pedagogical principles. Technological advancements have improved opportunities for online T&L strategies and these are becoming an integral component of curricula in undergraduate nursing programmes. Online simulation-based learning (SBL) has gathered momentum in nursing education over the past twenty years. However, it is unclear from the evidence-base how inclusive this educational approach is, and how it can best support the growing diversity among nursing students. This paper outlines the protocol for a scoping review that aims to systematically and comprehensively map the available published and unpublished literature on inclusive pedagogy in online SBL in undergraduate nursing education. 

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for systematic review protocols (PRISMA-P) guided this protocol. Arksey and O'Malley (2015) six-stage methodology framework, the Joanna Briggs Institute (JBI) guidelines (2005) and the PRISMA extension for scoping reviews (PRISMA-ScR) will guide the proposed scoping review.

Conclusion: It is envisaged that this scoping review will give a broad overview of the evidence for inclusive pedagogy in online SBL at this point. The findings of this review will be used to inform future policy and the pedagogical and technological design of online SBL activities and assist nurse educators to meet the current requirement of inclusive practice.
Rewards and recognition for Canadian distributed medical education preceptors: a qualitative analysis
Authors: Bell Amanda , Johnston Aaron , Makwarimba Edward , Malhi Rebecca
Published: May 2022

Background: Recognition of Distributed Medical Education (DME) preceptors by medical institutions ensures that important community-based training opportunities remain available to learners. Yet the literature seldom explores what rewards are meaningful to this population of teachers. The goal of our national project was to provide guidance to medical schools about the financial remuneration and non-financial rewards that are most valued by DME preceptors.

Methods: In this qualitative study, we invited DME faculty members from all Canadian medical schools to participate in semi-structured interviews. Participants with a range of medical specialties, stages of career, and geographic locations were interviewed via Zoom videoconferencing. The sessions in English and French were audio-recorded and transcribed. We used line-by-line inductive coding and thematic analysis to examine participant talk about meaningful preceptor recognition.

Results: Fourteen participants from multiple provinces were interviewed. Results indicated that the DME faculty are a diverse group of people with diverse needs. Most of the interviewees appreciated the rewards and recognition provided by their institutions but felt that there are areas for improvement. Recognition is not necessarily monetary and should be tailored to the needs and the values of the recipient. Other themes included: benefits and challenges of being a preceptor, current institutional structures and supports, and the impact of the pandemic on preceptors.

Conclusions: The interviews highlighted the importance placed by preceptors on personal rewards and a wide variety of forms of recognition. Based on the findings, we suggest specific steps that medical institutions can take to support, engage, and recognize DME faculty.
Effect of nonsurgical periodontal therapy and smoking status on hematological variables related to anemia of chronic disease in chronic periodontitis patient: a case-control study
Authors: Show Sangita , Bagchi Somen , Dey Arka Kanti , Boyapati Ramanarayana , Pal Pritish Chandra , Tejaswi Kanikanti Siva
Published: May 2022

Background: Chronic infectious, inflammatory, or neoplastic disorders are associated with anemia of chronic disease. Chronic inflammatory diseases such as periodontitis may contribute to masked anemia, especially in smokers. This study was aimed at verifying and comparing the efficacy of nonsurgical periodontal therapy (NSPT) for improving anemia among chronic periodontitis patients with and without the habit of smoking. Methods: Thirty systemically healthy individuals with chronic periodontitis were divided into two groups of 15 each, smokers (group A) and nonsmokers (group B). The groups were compared based on hematological parameters such as serum erythropoietin (SE) and serum ferritin (SF) levels at baseline and 3 months after NSPT for anemia evaluation. Results: The baseline SE levels in groups A and B were 11.84 and 15.19 mIU/mL (p=0.031), respectively; the corresponding levels at 3 months after NSPT were 13.00 and 17.74 mIU/mL (p=0.022). The baseline SF levels in groups A and B were 95.49 and 44.86 ng/mL (p=0.018), respectively; the corresponding levels at 3 months after NSPT were 77.06 and 39.05 ng/mL (p=0.009). Group B showed a significant increase and decrease in the SE and SF levels, respectively, at 3 months after NSPT (p=0.035 and p=0.039, respectively), whereas group A showed insignificant changes (p=0.253 and p=0.618, respectively). Conclusion: NSPT led to an improvement in anemia among chronic periodontitis patients. However, the improvement is less in smokers compared to that in nonsmokers. Furthermore, SF and SE levels might serve as effective biomarkers for assessing anemia in smokers and nonsmokers with chronic periodontitis.
Injuries related to taekwondo training - short report based on experiences from Primary School No. 31 with sports championship classes in Bydgoszcz (Poland)
Authors: Wąs Sławomir , Siedlecki Zygmunt
Published: May 2022

Taekwondo has become a very popular sport in Poland and around the world, and training in this martial art begins with young children. Taekwondo trainings are organized in kindergartens and schools, clubs and master classes are organized in sports schools, and children take part in competitions. Taekwondo, like any martial art, carries a potential risk of injury. According to the literature, lower limb injuries are the most common, as in taekwondo the lower limbs are mainly used. Head and spine injuries as a result of falls are also described. The author emphasizes that despite the injuries described in the literature and the frequency of occurrence defined as about 2.5 - 8%, injuries in the sports school in Bydgoszcz are significantly less frequent. The author also points out that there are also injuries (fractures) of the upper limbs, which are ignored by numerous international publications. Despite this, it should be emphasized that taekwondo is a safe sport discipline. Its prevalence among school children is a favorable phenomenon.
Ovarian Vein Thrombosis in a Non-Puerperal Patient
Authors: Arora Ena , Mujumdar Vaidehi , Martin Alexander , Tuli Sandeep
Published: May 2022

Ovarian vein thrombosis (OVT) is a relatively rare, but serious disease more commonly seen in puerperal patients. In the postpartum period, there is an unequal incidence of OVT in women with vaginal delivery (0.18%) and caesarean section (2.0%).OVT is usually associated with other conditions like pelvic inflammatory disease, malignant tumours, sepsis, enteritis, and recent pelvic or abdominal surgery. The incidence of idiopathic OVT is extremely rare and only a few cases have been reported to date in healthy patients with unknown aetiology. Patients with OVT present with abdominal pain, nausea, vomiting, fever or abdominal mass. Complications of OVT include pulmonary embolism, ovarian infarction, sepsis and death. CT scanning of the abdomen provides reliable evidence for the diagnosis of idiopathic OVT. Thrombus in most patients with idiopathic OVT is located in the right ovarian vein. This may be due to the longer length of the right ovarian vein, right shift of the uterus and relative insufficiency of the right ovarian vein valve. Treatment of OVT includes systemic anticoagulation which will achieve resolution of symptoms and prevent life-threatening complications. Our case report documents a non-puerperal patient who underwent hysterectomy a year before presenting to the ED with complaints of diarrhoea and found to have OVT on a CT scan. Our case brings attention to the fact that OVT can occur outside the puerperium and might present as a rare complication of minimally invasive surgeries for endometrial cancer. Furthermore, we posit that OVT in the non-puerperal patient may be a separate clinical entity.
Recent progress in doped TiO2Photocatalysis and Hybrid Advanced Oxidation Processes for Organic Pollutant Removalfrom Wastewater
Authors: Bhatti Darshana Tushar , Parikh Sachin Prakashbhai
Published: May 2022

Hybrid advanced oxidation processes (HAPOs) for the removal of non-biodegradable organics from wastewater have been studied in recent literature. With the increase in industrial development, the quantity of wastewater generated from these industries also organic wastewater produced by industrial manufacturing has posed threats to the environment.AOP’s are one of the promising advanced technologies for mineralization of organics present in wastewater. Hybrid advanced oxidation process based on the ozonation, sonolysis, Photo-Fenton reagents and electrochemical method, has greater potential for complete mineralization of recalcitrantorganics. This review article includes recent progress in the research and application of TiO2 photocatalysis for the removal of nonbiodegradable organic pollutants present in water. It will provide a quick reference for various hybrid AOPs systems and their effectiveness. This review article provides quick insights into (1) hybrid AOP for treatment of various industrial effluents or model effluents, (2) work done on doped/co-doped photocatalyst as heterogeneous catalysts (3) study of parameters affecting the photocatalysis to enhance complete oxidation of organics present in wastewater. A mechanistic investigation of hybrid advanced oxidation processes with combinations of sonolysis and Fenton process coupled with UV, adsorption and addition of biochar has been discussed.
Covid-19 Pandemic- A Ray of Hope Towards Sustainable Nature-Based Tourism
Authors: Kumar Suneel , Sageena Geetanjali
Published: May 2022

As the world wrestles with the pandemic and the travel industry comes to a standstill, stories via online media are surfacing that guarantee untamed life is getting back to isolated urban areas and that the Earth is recuperating itself. Millions are confronting the possibility of joblessness, a worldwide financial downturn is on the cards, medical services frameworks are being over-burden as contaminations develop dramatically, and disease transmission experts caution that, conceivably, a great many individuals could bite the dust. The travel and tourism industry and the environment are firmly connected.The travel industry research is beginning to look into especially as it connects with environmental change. Since the COVID-19 pandemic carried the travel industry to an edge, this is beneficial for the recuperation of the environment for the time being, because of pandemic-related travel limitations queues to observe nature have vanished. But, amid the entirety of this catastrophe, a brief look at something positive has shown up.
Guru Ghasidas University Campus Greenery for off setting Carbon Dioxide and Improving Students’ Academic Performance
Authors: K K Chandra K K Chandra , V Omesh V Omesh , Bhadouria Rahul
Published: May 2022

The greenery in academic institution reduces CO2 and creates stress free environment to the students' learning. Guru Ghasidas Central University, Bilaspur, India, spread in 262 ha with ample green space, is an education hub for over 9000 students. The land use pattern, greenery, and tree CO2stock were assessed by laying out 54 sample plots (0.1 ha) across the university. Students’ likelihood of greenery and its effects on students' behavior and academic performance were evaluated during 2019-20.. The university has 2/3 green space, 10.64% area under water bodies, and a total built-up area restricted to 15.22%. A total of 61 tree species were identified with a population of 124662 trees on the campus with the highest abundance of Peltophorumferrugineum (17.31%), Eucalyptus globulus (13.69%) among planted tree species. In naturally occurring tree species, Acacia niloticaoccupied highest (88.35%) followed by Buteamonosperma (10.04%). The trees of the university campus stocked 10942.6 tons of CO2. Analysis showed that students rated higher preference to campus greenery with 2.71 points in 0-4 points Likert scale, and improved student’s academic performance.
Practical implications of calf housing systems in the UK
Authors: Mahendran Sophie A
Published: May 2022

One of the biggest environmental and management factors that impact calf health and welfare is the housing within which they are kept, particularly in the first few months of life. There are multiple housing systems used on farms in the UK, each providing its own challenges, with the additional pressure of changing weather systems adding to the difficulties faced in the calf housing across the changing seasons. Temperature and humidity levels can have a direct impact on disease pressures, so knowing how calf housing responds in the summer and winter can help manage these pressures. There has been an overall reduction in individual calf housing used in the UK, although there is still a perception that individual housing results in better calf health. There is mounting evidence to support the positive benefits of pair housing of calves on growth rates and solid feed intakes, and an uptake of computerised calf feeders can help to monitor large group sizes for signs of ill health.
The role of Clostridium perfringens in neonatal diarrhoea and the importance of effective control
Authors: Gale Christina , Velazquez Eduardo , Sperling Daniel
Published: May 2022

Neonatal diarrhoea is a large economic and animal health problem on pig farms worldwide. There are numerous factors involved in the disease, one of which being the pathogen Clostridum perfringens. Various types of Clostridium perfringens exist, including Type A (CpA), which produces toxins that have pathogenic effects on the pig. The alpha (CPA) and beta2 toxins (CPB2) are suggested as contributors to the virulence of the pathogen as they result in damage and changes to the gastrointestinal tract of the pig. Therefore, performance losses can be observed as well as the clinical diarrhoea seen on farm. It is important that this pathogen is controlled, which can be achieved via implementation of good hygiene and management practices, including a vaccination protocol for breeding stock. Correct diagnosis of the pathogen, types and toxins will ensure that the correct vaccine is put onto the farm, therefore providing the best protection. Vaccination has been shown to be effective in reducing the impact of Clostridium perfringens on farm.
Medicine storage
Authors: Carr John , Howells Mark , Hersey William
Published: May 2022

Veterinary care for medicines used on farm is a priority. The farm health team must receive specific training in how to use, manage and dispose of the medicines used on the farm. The veterinary surgeon, as a coach and leader, is in the ideal position to offer this training and auditing. It is vital to ensure that all medicines, both those prescribed by the veterinarian and others, are stored and used appropriately, to ensure maximum welfare benefits to the pigs and benefit to mankind. Good medicine storage and use, results in reduced costs to the farm health team through reducing wasted product. This article, primarily uses pig farms as examples where training provided the necessary resolution to enhanced medicine storage.
Changing patterns of Nematodirus battus infection
Authors: Castro Alberto Luque , Sargison Neil
Published: May 2022

Nematodirus battus is a gastrointestinal parasite which has a huge impact in UK sheep flocks as a result of lamb mortality and reduction in growth. Farmers and veterinary surgeons conventionally focus their efforts on preventing outbreaks of nematodirosis during the spring, but the incidence of autumn infections is a growing concern. The aim of this article is to highlight the changes in the behaviour of N. battus and provide some guidance on how to approach the challenges that this creates.
EquineReview
Authors: Fiske-Jackson Andy
Published: May 2022

Introduction:

This Equine Review looks at the role of rib fractures in poor performance, the effect of a class 4 laser on healing of suspensory branch lesions and long-term outcomes following arthroscopically confirmed stifle meniscal injuries.
Assessing Depression and Suicidality Among Recently Unemployed Persons with Obstructive Sleep Apnea and Socioeconomic Inequality
Authors:   Division of Sleep and Circadian Disorders, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA  USA, Singh Vijay , Haynes Patricia , Quan Stuart
Published: May 2022

Background: Obstructive Sleep Apnea (OSA) is a common sleep-related breathing disorder that often is associated with several psychiatric conditions. Job loss is a stressful life event that can also affect mental health and socioeconomic status (SES). We investigated whether there was an association between the prevalence of OSA and several psychiatric conditions within a cohort of persons who recently became unemployed and whether SES was a contributing factor. Methods: Data from 292 participants who completed the screening evaluation of the Assessing Daily Activity Patterns through occupational Transitions (ADAPT) Study were used to assess the association between the prevalence of OSA, and current and past depression, and past suicidality. A type III sleep home sleep monitor was used to identify the presence of OSA and assess its severity. Depression and suicidality were ascertained using the Mini-international neuropsychiatric interview. Years of education was used as a proxy for SES. Results: There were no significant associations between severity of OSA, SES and current depression, past depression, and suicidality. Past suicidality was noted to be more common among those who were single/widowed (17.4%) or those who were divorced or separated (11.1%) (p=0.027). Current depression was more common among Hispanics in comparison to non-Hispanics. Furthermore, prevalence rates of both depression and past suicidality were higher than previous reports in general populations. Conclusions: Within a cohort of individuals who experienced recent job loss, there was no association between OSA and depression or past suicidality. Prevalence rates of both depression and past suicidality were higher than previous reports in the general population.
Wavelength selection of multispectral imaging for oil palm fresh fruit
ripeness classification
Authors: Shiddiq Minarni , Herman Herman , Arief Dodi Sofyan , Fitra Edy , Husein Ikhsan Rahman , Ningsih Sinta Afria
Published: May 2022

Multispectral imaging has been
recently proposed for high-speed sorting and grading machine vision of
fruits. It is a prospective method applied in yet traditional sorting
and grading of oil palm fresh fruit bunches (FFB). The ripeness of oil
palm FFBs determines the quality of crude palm oil (CPO).
Implementation of multispectral imaging for the task needs wavelength
selection from hyperspectral datasets. This study aimed to obtain the
optimum wavelengths and use them for oil palm FFB classification based
on three ripeness levels. We have selected eight optimum wavelengths
using principal component analysis (PCA) regression which represented
the ripeness levels.
Designing reflective imaging systems with multiple-surfaces-integrated elements using a Gaussian function freeform surface
Authors: Yang Tong , Zhou Lijun , Cheng Dewen , Wang Yongtian
Published: May 2022

We propose a design scheme and method of a freeform off-axis reflective imaging system with multiple mirrors integrated into one element. The use of a multiple-surfaces-integrated element, described by the Gaussian basis functions freeform surface with local and nonsymmetric properties, significantly decreases the system complexity, as well as reduces the assembly and fabrication difficulty, and achieves high imaging performance. The design theory and process including the initial system design, surface conversion, and system optimization are demonstrated in detail. Three design examples are demonstrated to validate the effect and feasibility of the proposed method, and good imaging performance is obtained.
Label free optical transmission tomography for biosystems: intracellular structures and dynamics
Authors: Mazlin Viacheslav , Thouvenin Olivier , Alhaddad Samer , Boccara Martine , Boccara Claude
Published: May 2022

There is an increasing need for label free methods that could reveal intracellular structures and dynamics. In this context, we develop a new optical tomography method working in transmission - full-field optical transmission tomography (FF-OTT). The method can measure the forward scattering signals and reveals the time-dependent metabolic signals in living cells. FF-OTT is a common path interferometer taking advantage of the Gouy phase shift - a π phase shift that the light wave experiences around the focus. By modulating the position of the focus one can alter the phase of the scattered light. Demodulation of images with different phases rejects the background and enhances the light from the depth-of-field, thus producing an optical section. We test FF-OTT by imaging single-cell diatoms and ex vivo biological samples. In fresh samples, we show that the intracellular motions create visible intensity fluctuations in FF-OTT so that the method is able to reveal a metabolic dynamic contrast. FF-OTT was found to be an efficient label free technique that can be readily implemented thanks to a robust common-path speckle-free interferometer design using an incoherent light source.
High-resolution sub-millimetre diameter side-viewing all-optical ultrasound transducer based on a single dual-clad optical fibre
Authors: Colchester Richard J. , Zhang Edward Z. , Beard Paul C. , Desjardins Adrien E.
Published: May 2022

All-optical ultrasound (OpUS), where ultrasound is both generated and received using light, has emerged as a modality well-suited to highly miniaturised applications. In this work we present a proof-of-concept OpUS transducer built onto a single optical fibre with a highly miniaturised lateral dimension (<0.8 mm). A key innovation was to use a dual-clad optical fibre (DCF) to provide multimode light for ultrasound generation and single mode light for ultrasound reception. The transducer comprised a proximal section of DCF spliced to a short section of single mode fibre (SMF). Multimode light was outcoupled at the splice joint and guided within a square capillary to provide excitation for ultrasound generation. Whilst single mode light was guided to the distal tip of the SMF to a plano-concave microresonator for ultrasound reception. The device was capable of generating ultrasound with pressures >0.4 MPa and a corresponding bandwidth >27 MHz. Concurrent ultrasound generation and reception from the transducer enabled imaging via motorised pull-back allowing image acquisition times of 4 s for an aperture of 20 mm. Image resolution was as low as ~50 µm and 190 µm in the axial and lateral extents, respectively, without the need for image reconstruction. Porcine aorta was imaged ex vivo demonstrating detailed ultrasound images. The unprecedented level of miniaturisation along with the high image quality produced by this device represents a radical new paradigm for minimally invasive imaging.
Quantum terahertz Cherenkov radiation: theory and experimental feasibility
Authors: Fares Hesham
Published: May 2022

A quantum approach is developed for describing the behavior of
Cherenkov radiation (CR). Then we propose a scheme of terahertz CR
operating in a quantum regime for which the discreteness of momentum
exchange in the free electrons–light interaction is significant. In
this quantum regime, the spectrum of the emitted radiation appears as
discrete spectral lines with a significantly narrow linewidth. The
resonant wavelength, wavelength spacing, and linewidth of the emission
lines can be tuned by adjusting the parameters of electron beam and
waveguide. It is verified that the criteria and constraints of the
requirements for essential experimental parameters are practically
feasible. This work has implications for future studies of the quantum
interaction of free electrons with light as well as visualization of
quantum light applications in sensing, imaging, and spectroscopy.
Cloaked near-field probe for non-invasive near-field optical microscopy
Authors: Bernal Arango Felipe , Alpeggiani Filippo , Conteduca Donato , Opheij Aron , Chen Aobo , Abdelrahman Mohamed I. , Krauss Thomas F. , Alù Andrea , Monticone Francesco , Kuipers Laurens
Published: May 2022

Near-field scanning optical microscopy is a powerful technique for
imaging below the diffraction limit, which has been extensively used
in biomedical imaging and nanophotonics. However, when the
electromagnetic fields under measurement are strongly confined, they
can be heavily perturbed by the presence of the near-field probe
itself. Here, taking inspiration from scattering-cancellation
invisibility cloaks, Huygens–Kerker scatterers, and cloaked sensors,
we design and fabricate a cloaked near-field probe. We show that, by
suitably nanostructuring the probe, its electric and magnetic
polarizabilities can be controlled and balanced. As a result,
probe-induced perturbations can be largely suppressed, effectively
cloaking the near-field probe without preventing its ability to
measure. We experimentally demonstrate the cloaking effect by
comparing the interaction of conventional and nanostructured probes
with a representative nanophotonic structure, namely, a 1D
photonic-crystal cavity. Our results show that, by engineering the
structure of the probe, one can systematically control its back action
on the resonant fields of the sample and decrease the perturbation by

>

70
%

with most of our modified probes, and
by up to 1 order of magnitude for the best probe, at probe-sample
distances of 100 nm. Our work paves the way for non-invasive
near-field optical microscopy of classical and quantum
nanosystems.
Attosecond investigation of extreme-ultraviolet multi-photon multi-electron ionization
Authors: Kretschmar M. , Hadjipittas A. , Major B. , Tümmler J. , Will I. , Nagy T. , Vrakking M. J. J. , Emmanouilidou A. , Schütte B.
Published: May 2022

Multi-electron dynamics in atoms and molecules very often occur on sub- to few-femtosecond time scales. The available intensities of extreme-ultraviolet (XUV) attosecond pulses have previously allowed the time-resolved investigation of two-photon, two-electron interactions. Here we study double and triple ionization of argon atoms involving the absorption of up to five XUV photons using a pair of intense attosecond pulse trains (APTs). By varying the time delay between the two APTs with attosecond precision and the spatial overlap with nanometer precision, we obtain information on complex nonlinear multi-photon ionization pathways. Our experimental and numerical results show that

A

r

2
+

is predominantly formed by a sequential two-photon process, whereas the delay dependence of the

A

r

3
+

ion yield exhibits clear signatures of the involvement of a simultaneous two-photon absorption process. Our experiment suggests that it is possible to investigate multi-electron dynamics using attosecond pulses for both pumping and probing the dynamics.
General practitioners’ perceptions of using virtual primary care during the COVID-19 pandemic: An international cross-sectional survey study
Authors: Li Edmond , Tsopra Rosy , Jimenez Geronimo , Serafini Alice , Gusso Gustavo , Lingner Heidrun , Fernandez Maria Jose , Irving Greg , Petek Davorina , Hoffman Robert , Lazic Vanja , Memarian Ensieh , Koskela Tuomas , Collins Claire , Espitia Sandra Milena , Clavería Ana , Nessler Katarzyna , O’Neill Braden Gregory , Hoedebecke Kyle , Ungan Mehmet , Laranjo Liliana , Ghafur Saira , Fontana Gianluca , Majeed Azeem , Car Josip , Darzi Ara , Neves Ana Luisa
Published: May 2022

With the onset of COVID-19, general practitioners (GPs) and patients worldwide swiftly transitioned from face-to-face to digital remote consultations. There is a need to evaluate how this global shift has impacted patient care, healthcare providers, patient and carer experience, and health systems. We explored GPs’ perspectives on the main benefits and challenges of using digital virtual care. GPs across 20 countries completed an online questionnaire between June–September 2020. GPs’ perceptions of main barriers and challenges were explored using free-text questions. Thematic analysis was used to analyse the data. A total of 1,605 respondents participated in our survey. The benefits identified included reducing COVID-19 transmission risks, guaranteeing access and continuity of care, improved efficiency, faster access to care, improved convenience and communication with patients, greater work flexibility for providers, and hastening the digital transformation of primary care and accompanying legal frameworks. Main challenges included patients’ preference for face-to-face consultations, digital exclusion, lack of physical examinations, clinical uncertainty, delays in diagnosis and treatment, overuse and misuse of digital virtual care, and unsuitability for certain types of consultations. Other challenges include the lack of formal guidance, higher workloads, remuneration issues, organisational culture, technical difficulties, implementation and financial issues, and regulatory weaknesses. At the frontline of care delivery, GPs can provide important insights on what worked well, why, and how during the pandemic. Lessons learned can be used to inform the adoption of improved virtual care solutions and support the long-term development of platforms that are more technologically robust and secure.
Antibiotic-resistant pathogenic bacterial isolates from patients attending the outpatient department of university of Cape Coast hospital, Ghana: A retrospective study between 2013–2015
Authors: Asare Kwame Kumi , Amoah Samuel , Coomson Cornelius Agyeman , Banson Cecil , Yaro Derrick , Mbata Jennifer , Arthur Rudolf Aaron , Mayeem Peter Bilatam , Afrifa Justice , Bentsi-Enchill Felicity , Opoku Yeboah Kwaku
Published: May 2022

Uropathogenic Escherichia coli (E. coli) is an important urinary tract infection (UTI) that has been associated with both complicated and uncomplicated disease conditions. The global emergence of multiple drug-resistant (MDR) and extended-spectrum β-lactamase (ESBL) is of public health concern as the resistance limits the current treatment options. The objective of this study was to analyze the antibiotic-resistant patterns among the uropathogenic E. coli isolates at the University of Cape Coast (UCC) hospital between 2013 and 2015 as baseline data to understand the current antibiotic resistance situation within UCC and its environs. A retrospective cross-sectional study of bacteria isolates at UCC hospital from January 2013 to December 2015 were analyzed. A standard biochemical and antibiotic susceptibility tests were performed using Kirby-Bauer NCCLs modified disc diffusion technique. The network of interaction between pathogenic isolates and antibiotic resistance was performed using Cytoscape software. Statistical significance was tested using ANOVA and one-sample Wilcoxon test. The overall E. coli prevalence was 15.76% (32/203); females had the highest infection of 17.33% (26/150) compared to male subjects who had 11.32% (6/53) out of all the pathogenic infections. The E. coli prevalence among the age categories were 2/21 (9.52%), 27/154 (17.53%) and 4/21 (19.05%) among ≤20 years, 21–40 years and 41–60 years respectively. The isolated resistant pathogens exhibited different antibiotic resistance patterns. An interaction network of nodes connecting to other nodes indicating positive correlations between the pathogens and antibiotic resistance was established. Escherichia coli, Citrobacter spp, Klebsiella spp among other isolated pathogens formed higher centrality in the network of interaction with antibiotic resistance. The individual E. coli isolates showed a significant difference in the mean ± SD (95% CI) pattern of antibiotic resistance, 2.409±1.205 (1.828–2.990), χ2 = 36.68, p<0.0001. In conclusion, the study reports the interaction of E. coli isolates at UCC hospital and its antibiotic-resistant status between 2013 and 2015. This data forms the baseline information for assessing the current antibiotic status in UCC and its environs.
Association between history of HBV vaccine response and anti-SARS-CoV-2 spike antibody response to the BioNTech/Pfizer’s BNT162b2 mRNA SARS-CoV-2 vaccine among healthcare workers in Japan: A prospective observational study
Authors: Iwamoto Momoko , Ukimura Akira , Ogawa Taku , Kawanishi Fumiko , Osaka Naofumi , Kubota Mari , Mori Tatsuhiko , Sawamura Ritsuko , Nishihara Masami , Suzuki Tomio , Uchiyama Kazuhisa
Published: May 2022

Introduction

Inadequate vaccine response is a common concern among healthcare workers at the frontlines of the COVID-19 pandemic. We aimed to investigate if healthcare workers with history of weak immune response to HBV vaccination are more likely to have weak responses against the BioNTech/Pfizer’s BNT162b2 mRNA SARS-CoV-2 vaccine.

Methods

We prospectively tested 954 healthcare workers for the Anti-SARS-CoV-2 spike (S) protein antibody titers prior to the first and second BNT162b2 vaccination doses and after four weeks after the second dose using Roche’s Elecsys® assay. We calculated the percentage of patients who seroconverted after the first and second doses. We estimated the relative risk of non-seroconversion after the first BNT162b2 vaccine (defined as anti-SARS-CoV-2-S titer <15 U/mL) among HBV vaccine non-responders (HBs-Ab titer <10 mIU/mL) and weak responders (≥10 and <100 mIU/mL) compared to normal responders (≥100 mIU/mL).

Results

Among 954 healthcare workers recruited between March 9 and March 24, 2021 at Osaka Medical and Pharmaceutical University, weak and normal HBV vaccine responders had comparable S-protein titers after the first BNT162b2 dose (51.4 [95% confidence interval 25.2–137.0] versus 59.7 [29.8–138.0] U/mL, respectively). HBV vaccine non-responders were more likely than normal responders to not seroconvert after a single dose (age and sex-adjusted relative risk 1.85 95% confidence interval [1.10–3.13]) although nearly all participants seroconverted after the second dose. After limiting the analysis to 382 patients with baseline comorbidity data, the comorbidity-adjusted relative risk of non-seroconversion among HBV vaccine non-responders to normal responders was 1.32 (95% confidence interval [0.59–2.98]).

Discussion

Long term follow-up studies are needed to understand if protective immunity against SARS-CoV-2 wanes faster among those with history of HBV vaccine non-response and when booster doses are warranted for these healthcare workers.
Producing locality at night: From Lagos hometown meetings to Galway’s G Afro Vibez
Authors: Young Katie
Published: May 2022

This article charts the life experiences of Mitchell Okeke, a party organizer who runs the monthly night-time event ‘G Afro Vibez’ in the city of Galway, Ireland. Throughout, Okeke explores a range of diverse experiences gathering for music events and parties across his life as he moves between Lagos, New York and Galway. In doing so, Okeke shows how moments of gathering around music in migratory contexts were ‘watering his roots’, building the foundations for the development of ‘G Afro Vibez’, a large-scale nocturnal event designed for Galway’s youth, inclusive of Black-Irish and Afrodiasporic communities. By exploring the development of G Afro Vibez event, this article further details Black-Irish youth’s experiences of discrimination and exclusion in Galway’s nightclub scenes.
Temporary Autonomous Home: Free parties and migration on the margins of the urban night
Authors: Giaever López María
Published: May 2022

This article explores the relationship between migration, do-it-yourself late-night leisure and integration in the margins of the urban city. While the study of migration and leisure has been widely addressed, a focus on underground tekno ‘free parties’ within migrant communities remains unexamined. This article draws on the notion of ‘Temporary Autonomous Zone’, which grasps the horizontal and momentary time-spaces of self-organization, creativity and freedom that articulate the tekno ‘free party’ culture. Departing from this notion, the concept of TAH (‘Temporary Autonomous Home’) explores the night and how these are felt and articulated for a group of migrants from southern European countries in the city of Bristol (United Kingdom). Using the TAH as a live metaphor, this article argues that these are non-traditional ways of participating in the foreign culture that pluralizes the processes of integration in contrast with the scarce sense of integration participants otherwise feel.
Sex work and the city: Liminal lives in Chika Unigwe’s On Black Sisters’ Street
Authors: Flynn Deirdre
Published: May 2022

Chika Unigwe’s 2007 novel On Black Sisters’ Street centres on the lives of four women illegally trafficked from Nigeria to the sex district of Antwerp. Documenting how these characters negotiate the dark spaces of the city, Unigwe highlights the structural inequalities and legislative failures that keep these women in a state of exception. The novel offers a portrait of the contemporary city and the precarious position of those locked out of legal protection of the state. This article focuses on the urban spaces of Sisi, Efe, Joyce and Ama, and how they become commodities of underground migration system. Visible in the windows of the red-light district each night, they are considered persona non-grata by the legal infrastructure that fails to protect them.