bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection of wheat (Triticum aestivum) lines for the high altitude of Indonesia based on single- and multi-character adaptation
Authors: WAHYU YUDIWANTI , NURAENI ELIS , TRIKOESOEMANINGTYAS TRIKOESOEMANINGTYAS
Published: February 2022

Abstract. Nuraeni E, Wahyu Y, Trikoesoemaningtyas. 2021. Selection of wheat (Triticum aestivum) lines for the high altitude of Indonesia based on single- and multi-character adaptation. Biodiversitas 22: 5530-5535. The high demand for wheat in Indonesia encourages the assembly of wheat varieties adaptive to the tropical environment. The increase in wheat diversity has been carried out through the crossing process, and it is necessary to evaluate the adaptability of the genotypes resulting from the cross. This study aims to obtain information on the adaptation classes of the F5 population and the differential of agronomic character selection in single and multi-character selection. The study was conducted at the BB Biogen Experimental Garden, Ciwalen (925 masl), in August-December 2020. The F5 of HP1744/Selayar population was used as genetic material with two comparison varieties, namely Guri 1 and Guri 3. The adaptation class for a single character was determined based on seed weight per plant, while for multi-character based on the characters with a wedge between the high category heritability value and the correlation coefficient ?0.5. The result showed that the number of florets, seed weight per plant, number of tillers, number of productive tillers, and weight of seeds in the main panicle were selected as a reference for multi-character selection. The t-test showed that the adaptive and highly adaptive classes genotypes had higher yields than the comparison varieties. The selection differential shows an increase in the mean value for all reference characters. The adaptation class based on a single character resulted in a higher average value of seed weight in all classes compared to selection based on multi-character.
Floristic composition and species diversity in three habitat types of heath forest in Belitung Island, Indonesia
Authors: OKTAVIA DINA , PRATIWI SANTI DWI , MUNAWAROH SITI , HIKMAT AGUS , HILWAN IWAN
Published: February 2022

Oktavia D, Pratiwi SD, Munawaroh S, Hikmat A, Hilwan I. 2021. Floristic composition and species diversity in three habitat types of heath forest in Belitung Island, Indonesia. Biodiversitas 22: 5555-5563. Exploring plant diversity, structure, and composition of vegetation in forest ecosystems is necessary for understanding the mechanism of species coexistence and forest dynamics, moreover in a unique and vulnerable ecosystem such as tropical heath forest (kerangas). We investigated the composition and structure of vegetation of heath forests in East Belitung, Indonesia in three habitat types, namely primary heath forest (rimba), secondary heath forest (bebak), and grassland (padang). Vegetation analysis was conducted using the combination of transect and plot method to calculate the importance value index (IVI) for all species and biodiversity indicators for each habitat type. We recorded 157, 135, and 31 species in rimba, bebak, and padang, respectively. The top three dominant families of species found were Myrtaceae, Clusiaceae, and Euphorbiaceae. In rimba, Syzygium lepidocarpa had the highest IVI for seedlings, Calophyllum lanigerum had the highest IVI for saplings, and Schima walichii had the highest IVI for trees. In bebak, Guioa pleuropteris had the highest IVI for seedlings, Garcinia hombroniana had the highest IVI for saplings, and Schima walichii had the highest IVI for trees. In padang, Fimbristylis sp. had the highest IVI for seedlings, while Leptospermum flavescens had the highest IVI for saplings and trees. Some pioneer species were found such as Rhodomyrtus tomentosa, Rhodamnia cinerea, Syzygium buxifolium. We also found two carnivorous plants Drosera burmannii and Nepenthes gracilis in padang, indicating that this habitat type is poor in nutrients in the soils. We suggested that the presence of species composition in the three habitat types of heath forest is an essential plant resource to be conserved and sustainably utilized. Establishing reserve areas to protect natural habitat and biodiversity is encouraged to provide proper ecosystem function for the people and nature.
The environmental services of Pangarengan mangrove forest in Cirebon, Indonesia: conserving biodiversity and storing carbon
Authors: MULYANA BUDI , PURWANTO RIS HADI , INTAN SARI PUSPITA , FAQIH HIDAYATULLAH MUHAMAD , ATIKA MARPAUNG AFNI , SATRIA RADITYA PUTRA ILHAM , DWIKA PUTRA AGIK
Published: February 2022

Abstract. Purwanto RH, Mulyana B, Sari PI, Hidayatullah MF, Marpaung AA, Putra ISR, Putra AD. 2021. The environmental services of Pangarengan mangrove forest in Cirebon, Indonesia: conserving biodiversity and storing carbon. Biodiversitas 22: 5609-5616. Pangarengan mangrove forest in Cirebon, Indonesia, plays a vital role in providing ecosystem services, such as conserving biodiversity and storing carbon. The area of the Pangarengan mangrove forest is relatively small, but it is home to diverse flora and fauna. Also, it can mitigate climate change by storing carbon. Unfortunately, no specific records exist on biodiversity and carbon stock in the Pangarengan mangrove forest. This study aimed to record the diversity of flora and fauna of the Pangarengan mangrove using a survey approach and to estimate its carbon stocks using a non-destructive sampling method, except for seedlings, on 78 sampling plots, distributed randomly along the banks of the Cipaluh River. The results revealed that the flora consisted of 24 species, and the fauna was composed of 12 species. The mangrove species in the Pangarengan mangrove forest was dominated by Rhizophora mucronata. The carbon stocks varied among species or the life stages of plants (seedlings, saplings, poles, and trees). The carbon stock of Avicennia marina trees was the highest (110.810 MgC/ha), and the lowest was the seedlings of the Avicennia alba (0.005 MgC/ha). Furthermore, the interpretation of the images showed that the Pangarengan mangrove forest area is 21.5 ha. The mangrove forest is located in the coastal area of the Java Sea, 2.4 km from the residential area of Pangarengan village. It is crucial to preserve the Pangarengan mangrove forest because it functions as a source of biodiversity and carbon storage.
Pollen morphology of subfamily Malvoideae (Malvaceae sensu lato) in Thailand
Authors: SAENSOUK SURAPON , SAENSOUK PIYAPORN
Published: February 2022

Abstract. Saensouk S, Saensouk P. 2021. Pollen morphology of subfamily Malvoideae (Malvaceae sensu lato) in Thailand. Biodiversitas 22: 5633-5643. The pollen morphology of 19 species with eight variants and ten genera of subfamily Malvoideae (Malvaceae sensu lato) were investigated by light and scanning electron microscopy. The pollen was monad, spheroidal shaped and 45.64-168.00 µm in size. The pollen grains of all species were pantoporate. All pollen had radial symmetry and were apolar. The spines pollen grain of the subfamily Malvoideae in Thailand can be divided into six types. The arrangement of spines on pollens in this study can be divided into two groups. The pollen had various exine sculptures (granulate, microreticulate, and subpsilate). Spines were found to be echinate, baculate, and spinule. Pollen size, aperture, exine sculpture and spine index can be used as characters to identify the subfamily Malvoideae species. Therefore, a key to the 19 species with eight variants and ten genera of subfamily Malvoideae in this study based on pollen morphology was provided. Eight species were studied for their pollen morphology for the first time.
Biodiversity and antibacterial activity of endophytic fungi isolated from jambu bol (Syzygium malaccense)
Authors: HAPIDA YUSTINA , ELFITA ELFITA , WIDJAJANTI HARY , SALNI SALNI
Published: February 2022

Abstract. Hapida Y, Elfita, Widjajanti H, Salni. 2021. Biodiversity and antibacterial activity of endophytic fungi isolated from jambu bol (Syzygium malaccense). Biodiversitas 22: 5668-5677. Infectious diseases caused by pathogenic bacteria are still high. The existence of bacterial resistance to antibiotics makes it necessary to search for new antibacterial substances from plants and microorganisms. Syzygium malaccense (L.) Merr and Perry (Myrtaceae), known as jambu bol, has been used as a traditional medicine in Indonesia and other countries. It is used to treat pathogenic bacterial infections. Therefore, this study aims to determine the diversity of endophytic fungi and their potential as antibacterial compound sources compared to their host plants. Specifically, screening for endophytic fungi that have antibacterial activities is intended. In this study, endophytic fungi were isolated from the leaves, stem bark, and root bark of the host plants. Each isolate was identified morphologically and cultivated in potato dextrose broth (PDB) medium for four weeks. After the incubation period, the liquid culture was extracted with ethyl acetate and evaporated to obtain a concentrated extract. The Kirby-Bauer method was used to evaluate the antibacterial activity of each endophytic fungal extract and the host plant parts extract. The concentration used was 400µg/mL and the antibiotic was used as a positive control (Tetracycline) is 30µg/mL. Seven endophytic fungi were isolated from the leaves (YD1, YD2, YD3, YD4, YD6, YD7, Y2D1), seven from the stem bark (YB1, YB2, YB3, YB4, YB5, Y2B5, and Y2B6 ), and six from the root bark (YA1, YA2, YA3, YA4, YA5, Y2A2). The endophytic fungi were morphologically identified, and the isolates were shown to be dominated by genera from the Ascomycota (e.g., Poaceascoma, Cladorrhinum, Penicillium, Madurella, Phytophthora, Phialemonium, Monascus, Trichoderma, Ramophialophora, Gliocladium, Wiesneriomyces) and the Zygomycota (e.g., Mucor, Mortierella, and Gongronella) phyla. The fungi isolates Y2D1, YB1, and YA4 were shown to have the highest (strong) antibacterial activity equivalent to their hosts in the performed screening. Endophytic fungi have significant and continued antibacterial activities that have been identified molecularly.
Tree species diversity of Pegunungan Bintang, Papua, Indonesia as potency of wood supply
Authors: MURDJOKO AGUSTINUS , DJITMAU DONY ARISTONE , SIRAMI ELIESER VIKTOR , SIBURIAN RIMA HERLINA SETIAWATI , UNGIRWALU ANTONI , MARDIYADI ZULFIKAR , WANMA JIMMY FRANS , MOFU WOLFRAM YAHYA , MARWA JONNI , SUSANTI CICILIA MARIA ERNA , TOKEDE MAX JONDUDAGO , IMBURI CHRISTIAN SOLEMAN , SAGRIM MEKY , MAMBOAI HANS , SONBAIT LUKAS YOWEL , DWIRANTI FEBRIZA , SALOSA YENNY YENDRI , PAEMBONAN JOHANA BETY , WIRADYO ESTIKO TRI , UNENOR ERNI , BENU NITHANEL MIKAEL HENDRIK , SARAGIH ANDI SASTRA BENNY
Published: February 2022

Abstract. Murdjoko A, Djitmau DA, Sirami EV, Siburian RHS, Ungirwalu A, Mardiyadi Z, Wanma JF, Mofu WY, Marwa J, Susanti CME, Tokede MJ, Imburi CS, Sagrim M, Mamboai H, Sonbait LY, Dwiranti F, Salosa YY, Paembonan JB, Wiradyo ET, Unenor E, Benu NMH, Saragih ASB. 2021. Tree species diversity of Pegunungan Bintang, Papua, Indonesia as potency of wood supply. Biodiversitas 22: 5645-5655. The tropical rainforest is a primary global concern in many aspects. Therefore, this study aimed to describe the tree diversity in Pegunungan Bintang Forest, Papua, Indonesia. There are 10 dominant species from seedlings, saplings, poles, and trees, indicating the timber production potency. This study set systematic plots in Murkim and Teiraplu Sub-districts to collect taxonomic information, diameter, and clear bole height samples. The results showed that the forest was categorized as a tropical mixed due to diverse tree species. The leading plant families included Moraceae, Myrtaceae, Euphorbiaceae, Lauraceae, and Anacardiaceae, with various seedlings, saplings, poles, and trees. The potency of timber was reflected through sample distribution using the reverse J-shaped curve, identifying the merchantable trees with larger and smaller diameters as re-established. However, timber utilization management requires silvicultural treatments using selective logging by diameter limit and logging cycle for forest sustainability.
Biodiversity of Escherichia coli bacterial resistance to multidrug isolated on the Dumai coast of Indonesia
Authors: FELIATRA FELI , MARDALISA MARDALISA , EFFENDI IRWAN , ADELINA ADELINA , FELIATRA VANESA ADIBA
Published: February 2022

Abstract. Feliatra F, Mardalisa M, Efendi I, Adelina A, Feliatra VA. 2021. Biodiversity of Escherichia coli bacterial resistance to multidrug isolated on the Dumai coast of Indonesia. Biodiversitas 23: 10-16. Anthropogenic pollution around the Dumai coast of Indonesia disturbs marine microorganisms, including commensal bacteria such as fecal Escherichia coli. Escherichia coli have often been used as a sensitive indicator for the spread of Antibiotic Resistance Genes (ARGs) among pathogens. This study aimed to analyze the development of E. coli resistance, originating from the Dumai sea waters using six antibiotics against seven E. coli isolates (E1, E4, E6, E8, E11, E13, and E15) at the five stations. Furthermore, a sensitivity test was performed on Mueller Hinton Agar (MHA) solid media, based on the Kirby-Bauer disk diffusion method. The results showed 100% E. coli isolates resistant to narrow-spectrum antibiotics (Penicillin, Isoniazid, Streptomycin, and Erythromycin) at the five stations. Meanwhile, high resistance of E. coli against the broad-spectrum antibiotics was observed in station 4 (mangrove habitat) existed in Chloramphenicol, whilst no resistance was found in Ciprofloxacin. Escherichia coli isolates showed Multidrug Resistant (MDR) index value higher than 0.2 which suggests there is a high-risk of antibiotics pollution in Dumai seawater. Bioinformatics analysis of 16S rRNA gene sequences represents the identity of E. coli isolates at the species level (97.84% - 99.74%). This study revealed the presence of antibiotic pollution in Dumai seawater which may impact public health. Hence, the local community must be discipline about the use of antibiotics freely.
DIY injuries
Authors: Winter George
Published: February 2022

George Winter explores the increase in DIY-related injuries during COVID-19.
When the patient knows best?
Authors: Slop
Published: February 2022

Our columnist reflects on an interesting patient encounter.
Make surgery your legacy
Authors: Extance-Vaughan Nicola
Published: February 2022

How a gift could help the College make a difference.
Irksome side effects
Authors: Slop Mr
Published: February 2022

Our columnist suffers a bout of shingles.
Winter resolve
Authors: Glass Jonathan
Published: February 2022

We must endeavour to reduce waiting times and improve patient care.
Patient preferences for long-term follow-up after hip replacement
Authors: Smith LK , Turner E , Dures E
Published: February 2022

Background

Reports of surgical training and experiences vary across the 16 UK foundation schools. Little is known about whether foundation school choice is associated with later performance in surgical training. We investigated choice of school in relation to performance in the MRCS Part A.

Materials and methods

A retrospective cohort study of foundation programme trainees who attempted MRCS Part A between 2017 and 2020 (n = 553). Chi-square tests examined associations between foundation programme school and first–attempt MRCS Part A performance. Multinomial regression models identified the likelihood of MRCS part A success depending on foundation school.

Results

A statistically significant association was found between MRCS Part A first attempt pass rates and foundation school (P < 0.001). Mean Part A pass rates ranged from 23.8% to 81.8% between schools. Two foundation schools – Thames Valley and North, Central and East London – were found to be independent predictors of success at MRCS Part A at first attempt after adjusting for age, gender and ethnicity (P < 0.05). There was no significant correlation between MRCS Part A performance and subjective reports of training quality (the National Training Survey training satisfaction scores; P =0.256).

Conclusions

MRCS success is associated with foundation school but not subjective reports of training quality. Given that more competitive foundation schools attract the highest-achieving applicants, Occam's razor suggests this pattern is most likely due to individual differences such as innate academic ability rather than foundation school training experiences.
Welcome back, Diplomates!
Authors: Roberts Jane
Published: February 2022

RCS England once more welcomes our new fellows and members to our new home of surgery.
Reflections from an oral surgery team redeployed for COVID-19
Authors: Winterburn Julia
Published: February 2022

How did dental professionals fare during the pandemic?
Wrong site tooth extraction: no longer a never event
Authors: Shah Anika , Bhujel Nabina
Published: February 2022

Wrong site tooth extraction was removed from NHS England’s list of ‘never events’ in February 2021 as the systemic barriers put in place to prevent these events were not considered strong enough. This opinion article discusses the risk factors leading to wrong site tooth extractions, including the effects of human factors, the implications for dental professionals and the different methods dental professionals can implement to minimise risk.
Comparing dental services in the US and the UK with a focus on socioeconomic status
Authors: Nathan Monica , Ahmed Bilal
Published: February 2022

The US and the UK have very different structures to their healthcare system. This article examines some of the variations in dental services according to socioeconomic status (age, ethnicity, income and access), examining strengths and weakness of each system and possible lessons that can be learnt from each.
Impact of the COVID-19 pandemic on dental students: a cross-sectional study across UK universities
Authors: Al-Attar Sumaya , Jiagbogu Miriam , O’Malley Lucy , Lin Yin-Ling
Published: February 2022

INTRODUCTION

The COVID-19 pandemic led to closure of the 16 UK dental schools and a shift to remote learning. The aim of this study was to explore the impact on the teaching and learning experiences of undergraduate dental students, including their clinical confidence and mental health.

METHODS

An online survey was distributed to students enrolled at UK dental schools during the time of closure. Paired samples t-tests were employed to analyse the results.

RESULTS

A total of 312 students responded to the survey. Eighty-five per cent felt that the university closure had a negative impact on their overall learning. Ninety-seven per cent thought their clinical skills would be affected; perceived confidence in treating patients decreased by 27%. The mental health of all respondents was negatively affected although their stress about their studies was not affected. Positive aspects of closure included remote learning and online examinations.

CONCLUSIONS

The pandemic had both negative and positive impacts on dental students’ education. Universities should adapt their response to future crises and incorporate the positive impacts in future curriculums. Further studies could explore the long-term impact on students’ mental health and clinical skills.
Burnout in dentistry
Authors: Simmons Gerald
Published: February 2022

How can we prevent or cure burnout experienced by dentists?
‘You may have to fight a battle more than once to win it’
Authors: Crean Stjohn
Published: February 2022

Although we are slowly returning back to normality, it is as important as ever to keep protecting ourselves and those around us.
The impact of COVID-19 on dental core training: a single centre experience
Authors: Siodlak Francesca , Pandya Rishi , Walton Gary
Published: February 2022

The dental core training programme acts as a springboard for postgraduate dentists to consider specialisation or further training. In January 2020, the outbreak of the coronavirus disease resulted in a restructuring of the National Health Service, directly affecting trainees across all specialties. At University Hospitals Coventry and Warwickshire NHS Trust, dental core trainees were transferred to an alternative COVID rota with skeleton teams deployed to cover on-call duties. This paper examines whether the repercussions of the pandemic have had an objective impact on the clinical exposure of and training opportunities for dental core trainees.
DMF (different, missed, forgotten): oral health inequalities experienced by people with severe mental illness
Authors: Browne Maeve , Beenstock Jane
Published: February 2022

In England, there are over half a million people living with severe mental illness (SMI) such as schizophrenia and bipolar disorder. These people die on average up to 20 years earlier than the general population and 2 in 3 deaths are from physical illnesses that can be prevented.

Recent government publications such as the NHS Long Term Plan and NHS England's mental health implementation plan have highlighted the need to address the physical health needs of people with SMI in order to reduce the serious inequality of health outcomes experienced. Disappointingly, however, neither document mentions the poor oral health experienced by this cohort of the population, nor do they recognise the link between poor oral health and poor general health. This article examines the available literature and results from a recent survey that explored the oral health behaviours of service users at a secure mental health facility to raise awareness of the oral health needs of this population.

Oral health is an integral aspect of general health and can positively influence wellbeing. A healthy mouth ensures individuals can eat, speak and interact socially, free from pain and embarrassment. Poor oral health can therefore not only have a profound impact on a person's quality of life (QoL) but it can also have wider implications for systemic disease.
Delivering a remote induction programme for dental core trainees: an innovative learner-centric approach during the COVID-19 pandemic
Authors: Payne Karl , Tahim Arpan , Goodson Alexander , O'Connor Rory , Ahmed Nabeela , Evans Martin , Gruber Elizabeth , Gallagher James , Sharp Ian , Dickenson Andrew
Published: February 2022

The absence of face-to-face teaching during the COVID-19 pandemic has created particular challenges for clinical postgraduate educators. Induction for dental core trainees (DCTs) entering secondary care posts for the first time is of prime importance, with the aim of delivering a comprehensive course covering core topics, fundamental to patient safety.

This paper describes the adaptation and delivery of a remote DCT induction programme for the Midlands and East of England area. Using a 'flipped classroom' approach, prior induction content was adapted to provide online pre-recorded lectures and learning resources to prepare for web-based video conferencing case-based discussions. In order to assess the quality of teaching and success of the course, participants completed three questionnaires: identical assessments before and after the course to evaluate a change in knowledge and confidence, and a course evaluation survey. In total, 126 DCTs attended the induction course, with response rates of 82%, 75% and 61% for the 3 questionnaires respectively.

Comparing DCT knowledge and confidence in treating patients before and after the course, there was a statistically significant increase in 13 of 14 domains. Despite being a web-based course, 100% of participants described the case-based small group discussions as ‘interactive and enjoyable’, with overall positive feedback for the delivery of a remote induction course

We demonstrate how a remote web-based induction course for DCTs is achievable and has potential advantages with regard to pooling of resources and faculty. Several key learning points are discussed, in addition to the potential for a standardised framework for national DCT induction.
High-performance dual-band radio-over-fiber link for future 5G radio access applications
Authors: Shi Fangjing , Fan Yangyu , Wang Xinyuan , Zhang Wu , Gao Yongsheng
Published: February 2022

For the fronthaul between the baseband unit and the remote radio unit (RRU), radio over fiber (RoF) is promising to replace the Common Public Radio Interface in beyond fifth-generation and the sixth-generation wireless communication systems. The weight, size, and power consumption of the RRU can be greatly reduced, along with easy support for the millimeter-wave band. In this paper, a dual-band RoF link is proposed, where flexible switching between high-frequency (28 GHz) and low-frequency (3.5 GHz) RF channels is realized through polarization control. Single-sideband modulation is performed on 28 GHz signals to avoid periodic power fading during long-distance fiber transmission. By adjusting the DC bias, the third-order intermodulation distortion component in the 3.5 GHz signal is suppressed, and the spur-free dynamic range (SFDR) is improved. Experimental results show a channel isolation of above 43 dB. The link gain of the 28 GHz signal channel is flat, and the SFDR of the 3.5 GHz signal channel can reach

118.6

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B
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H

z

4

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5

. In the case of RF vector signal transmission, the adjacent channel power ratio of the 3.5 GHz signal channel is optimally up to 48 dB, and the error vector magnitude is 2.9%.
Toward higher-radix switches with co-packaged optics for improved network locality in data center and HPC networks [Invited]
Authors: Maniotis Pavlos , Schares Laurent , Kuchta Daniel M. , Karacali Bengi
Published: February 2022

We study the network locality improvements that can be achieved by using co-packaged optics in data center and high-performance computing (HPC) networks. The increased escape bandwidth offered by co-packaged optics can enable switches with speeds of 51.2 Tb/s and beyond. From a network architecture perspective, the key advantages of introducing co-packaged optics at the switch points include the implementation of large-scale topologies of

>

12,000

end points with

4
×

higher bisection bandwidth and the reduction of the required number of switches by

>

40

%

compared with state-of-the-art approaches. From a network operation perspective, improved network locality and faster operation can be achieved since the higher-radix switches can mitigate the impact of network contention. Placing applications under fewer leaf switches reduces the number of packets that cross the spine switches in a leaf-spine topology. The proposed scheme is evaluated via discrete-event simulations: we initially evaluate the network locality properties of the system by using virtual-machine traces from a production data center, and we subsequently quantify the performance improvements by simulating an all-to-all pattern for a variety of message sizes over a number of nodes. The results suggest that co-packaged optics form a promising solution for keeping up with bandwidth scaling in future networks. The virtual-machine analysis shows that large-scale applications can be placed under up to 50% fewer first-level switches, while the network analysis shows speedups of up to 7.1, which translates to execution time reductions of up to 26% and 42.7% for applications with communication ratios of 0.3 and 0.5, respectively.
Photonic metacrystal: design methodology and experimental characterization
Authors: Hu S. , Khater M. , Kratschmer E. , Engelmann S. , Green W. M. J. , Weiss S. M.
Published: February 2022

We report a design methodology for creating high-performance photonic crystals with arbitrary geometric shapes. This design approach enables the inclusion of subwavelength shapes into the photonic crystal unit cell, synergistically combining metamaterials concepts with on-chip guided-wave photonics. Accordingly, we use the term “photonic metacrystal” to describe this class of photonic structures. Photonic metacrystals exploiting three different design freedoms are demonstrated experimentally. With these additional degrees of freedom in the design space, photonic metacrystals enable added control of light-matter interactions and hold the promise of significantly increasing temporal confinement in all-dielectric metamaterials.
Fiber pigtailed DFB laser-based optical feedback cavity enhanced absorption spectroscopy with a fiber-coupled EOM for phase correction
Authors: Zhou Xiaobin , Zhao Gang , Liu Jianxin , Zhou Yueting , Yan Xiaojuan , Li Zhixin , Ma Weiguang , Jia Suotang
Published: February 2022

A novel technique for performing fiber pigtailed DFB laser and linear Fabry-Pérot cavity based optical feedback cavity enhanced absorption spectroscopy (OF-CEAS) is proposed. A fiber-coupled electro-optic modulator (f-EOM) with x-cut y-propagation LiNbO3 waveguide is employed, instead of PZT used in traditional OF-CEAS, to correct the feedback phase, which improves the compactness and applicability of OF-CEAS. Through the efficient and real-time control of the feedback phase by actively changing the input voltage of the f-EOM, a good long-term stability of the signal has been achieved. Consequently, a detection sensitivity down to 7.8×10−10 cm−1, better than the previous by PZT based OF-CEAS, has been achieved over the integration time of 200 s, even by use of a cavity with moderate finesse of 2850.
Ultra-wideband signal generation and fusion algorithm for high-resolution terahertz FMCW radar imaging
Authors: Hu Weidong , Xu Zhihao , Han Zhongde , Jiang Huanyu , Liu Yang , Lu Yuyao , Ligthart Leo P.
Published: February 2022

The terahertz frequency modulated continuous wave (THz FMCW) imaging has proved to be a novel nondestructive testing (NDT) technology for non-metal materials, and the large bandwidth is usually required to meet high range resolution demands in many applications such as multilayer sample under test (SUT). However, broadband THz hardware is difficult to design. In this paper, an ultra-wideband THz FMCW generation method is proposed, which provides frequency modulation bandwidths of up to 386 GHz by time-division multiplexing. Furthermore, an ultra-wideband signal fusion algorithm (USFA) is also proposed and significantly improves the range resolution to 0.46 mm in air. Results from the artificially constructed multilayer structure demonstrate the superiority and effectiveness of our method quantitatively.
Distributed temperature sensor combining centimeter resolution with hundreds of meters sensing range
Authors: Gasser Julien , Warpelin Daryl , Bussières Félix , Extermann Jérôme , Pomarico Enrico
Published: February 2022

We present a Raman distributed temperature sensor based on standard telecom single mode fibers and efficient polarization-independent superconducting nanowire single photon detectors. Our device shows 3 cm and 1.5 °C resolution on a 5 m fiber upon one minute integration. We show that spatial resolution is limited by the laser pulse width and not by the detection system. Moreover, for long fibers the minimum distance for a measurable temperature step change increases of around 4 cm per km length, because of chromatic dispersion at the Stokes and Anti-Stokes wavelengths. Temperature resolution is mainly affected by the drop in the laser repetition rate when long fibers are tested. On a 500 m fiber, a trade-off of 10 cm and 8 °C resolution is achieved with 3 minutes integration. Fiber-based distributed temperature sensing, combining centimetric spatial resolution with hundreds of meters sensing range, could pave the way for a new kind of applications, such as 2D and 3D temperature mapping of complex electronic devices, particles detectors, cryogenic and aerospace instrumentation.
Optical design and pupil swim analysis of a compact, large EPD and immersive VR head mounted display
Authors: Cheng Dewen , Hou Qichao , Li Yang , Zhang Tian , Li Danyang , Huang Yilun , Liu Yue , Wang Qiwei , Hou Weihong , Yang Tong , Feng Zexin , Wang Yongtian
Published: February 2022

Virtual reality head-mounted displays (VR-HMDs) are crucial to Metaverse which appears to be one of the most popular terms to have been adopted over the internet recently. It provides basic infrastructure and entrance to cater for the next evolution of social interaction, and it has already been widely used in many fields. The VR-HMDs with traditional aspherical or Fresnel optics are not suitable for long-term usage because of the image quality, system size, and weight. In this study, we designed and developed a large exit pupil diameter (EPD), compact, and lightweight VR-HMD with catadioptric optics. The mathematical formula for designing the catadioptric VR optics is derived. The reason why this kind of immersive VR optics could achieve a compact size and large EPD simultaneously is answered. Various catadioptric forms are systematically proposed and compared. The design can achieve a diagonal field of view (FOV) of 96° at -1 diopter, with an EPD of 10 mm at 11 mm eye relief (ERF). The overall length (OAL) of the system was less than 20 mm. A prototype of a compact catadioptric VR-HMD system was successfully developed.
Channel response-aware photonic neural network accelerators for high-speed inference through bandwidth-limited optics
Authors: Mourgias-Alexandris G. , Moralis-Pegios M. , Tsakyridis A. , Passalis N. , Kirtas M. , Tefas A. , Rutirawut T. , Gardes F. Y. , Pleros N.
Published: February 2022

Photonic neural network accelerators (PNNAs) have been lately brought into the spotlight as a new class of custom hardware that can leverage the maturity of photonic integration towards addressing the low-energy and computational power requirements of deep learning (DL) workloads. Transferring, however, the high-speed credentials of photonic circuitry into analogue neuromorphic computing necessitates a new set of DL training methods aligned along certain analogue photonic hardware characteristics. Herein, we present a novel channel response-aware (CRA) DL architecture that can address the implementation challenges of high-speed compute rates on bandwidth-limited photonic devices by incorporating their frequency response into the training procedure. The proposed architecture was validated both through software and experimentally by implementing the output layer of a neural network (NN) that classifies images of the MNIST dataset on an integrated SiPho coherent linear neuron (COLN) with a 3dB channel bandwidth of 7 GHz. A comparative analysis between the baseline and CRA model at 20, 25 and 32GMAC/sec/axon revealed respective experimental accuracies of 98.5%, 97.3% and 92.1% for the CRA model, outperforming the baseline model by 7.9%, 12.3% and 15.6%, respectively.
Spatial solitons with complicated structure in nonlocal nonlinear media: erratum
Authors: Liang Guo , Hong ,Weiyi , Guo Qi
Published: February 2022

This erratum corrects the range of the degree of nonlocality σ, in which the out-of-phase bound-state solitons can stably exist in our paper [Opt. Express 24, 28784 (2016)10.1364/OE.24.028784].
Thermo-optical reshaping of second-harmonic emission from dimer all-dielectric nanoresonators
Authors: Pashina Olesia , Frizyuk Kristina , Zograf George , Petrov Mihail
Published: February 2022

All-dielectric nanophotonics offers a wide range of possibilities for thermally induced light manipulation at the nanoscale. High quality resonances allow for efficient light-to-heat conversion supported by various temperature detection approaches based on thermally sensitive intrinsic optical responses. In this work, we study theoretically a phenomenon of the photothermal reshaping of the radiation pattern of second-harmonic generation (SHG) that occurs in resonant all-dielectric systems. In the suggested geometry, a near-IR pulsed laser is used for SHG while a continuous wave visible laser simultaneously heats the structure. The thermo-optical switching of the resonant optical states in the nanostructures governs the reconfiguration of the emission pattern, without significant loss in the magnitude of the SHG. We believe, that our findings will pave the way for subwavelength-size near-IR thermally switchable nonlinear optical devices.
Energy flow inversion in an intensity-invariant focusing field
Authors: Zhou Jiakang , Ma Haixiang , Zhang Yuquan , Zhang Shuoshuo , Min Changjun , Yuan Xiaocong
Published: February 2022

Dependence of light intensity on energy flow is the most intuitive presentation of an optical field. This dependence, however, also limits the applications to the interaction of the light field with matter. For further insight into this, we demonstrate a novel case of the optical field, named as the counterintuitive chiral intensity field (CCIF), in the highly focusing situation: the energy flow reverses during the propagation but the intensity distribution pattern is kept approximately invariant. Our results show that, in this process, the mode correlation decreases rapidly while the intensity correlation remains invariant in the focus area. Furthermore, this property is still valid even if the pattern helicity and number of spiral arms are changed. This work deepens the understanding of the relationship between energy flow and field intensity, and it will offer diversified operations in many applications, such as optical micromanipulation, optical fabrication, etc.
Influence of surface roughness on the lasing characteristics of optically pumped thin-film GaN microdisks
Authors: Zi Hui , Fai Cheung Yuk , Damilano Benjamin , Frayssinet Eric , Alloing Blandine , Duboz Jean-Yves , Boucaud Philippe , Semond Fabrice , Choi Hoi Wai
Published: February 2022

Optically pumped whispering-gallery mode (WGM) lasing is observed from a thin-film GaN microdisk processed from GaN-on-Si InGaN/GaN multi-quantum well wafers by selective wet-etch removal of the substrate. Compared with thin-film microdisks processed from GaN-on-sapphire wafers through laser lift-off of the sapphire substrate, the exposed surface is significantly smoother as laser-induced damage is avoided, with a root-mean-square roughness of 1.3 nm compared with 5.8 nm of the latter wafer. The ∼8-

μ

m diameter microdisks, fabricated by pattern transfer from a silica microsphere and dry etching, benefit from the surface smoothness to offer superior optical confinement within the cavity. WGM lasing thresholds of ∼2.9 mJ/cm2 and ∼3.5 mJ/cm2 with quality (Q)-factors of ∼3100 and ∼1700 are observed at the peak lasing wavelengths of ∼453 nm and ∼532 nm, respectively, which are significantly better than thin-film microdisks processed from GaN-on-sapphire wafers despite lower internal quantum efficiency, highlighting the importance of surface smoothness in such optical cavities.
Modeling of ultraviolet propagation from air to human epidermis with wavelength range of 200–300 nm
Authors: Wu Tianfeng , Yang Fang , Cao Tian , Song Jian
Published: February 2022

Ultraviolet (UV) technology plays an important role in the fields of sterilization, disinfection, and short-range wireless optical communications. In this Letter, a theoretical model to determine the UV radiation intensity (UVRI) on human skin is put forward based on the Monte Carlo method, where the UV wavelength ranges from 200 to 300 nm. Meanwhile, the UVRI evaluation algorithm is provided to reproduce the simulation results. Furthermore, the penetration depth of UV radiation in the human epidermis is investigated, which can be used to assess whether UV radiation causes damage to human health. Simulation results coincide with the existing experimental results that the 222-nm UV radiation is harmless to humans at the given dose of 1.7 mJ/cm2. This work provides theoretical guidelines for the power control of a UV system when humans are in the vicinity.
Quill-free additive manufacturing of fused silica glass
Authors: Maniewski Pawel , Laurell Fredrik , Fokine Michael
Published: February 2022

Additive manufacturing of high-quality macroscopic fused silica glass structures, with deposition rates of up to 1.2 mm3/s, is presented. Three co-axial nozzles were used to avoid the so-called quill effect. Homogeneous, crack-free, multilayer, as well as free-standing objects were printed using cluster-free sub-µm powders delivered to a CO2 laser-induced melt pool. Structures with an overhang of up to 45° were possible to print. Laser post-processing was used to improve the surface roughness and transparency. This system can be suitable for fabrication of advanced optical elements and devices, such as waveguides or fiber preforms.
Evaluation of a simple, rapid and field-adapted diagnostic assay for enterotoxigenic E. coli and Shigella
Authors: Connor Sean , Velagic Mirza , Zhang Xueyan , Johura Fatema-Tuz , Chowdhury Goutam , Mukhopadhyay Asish K. , Dutta Shanta , Alam Munirul , Sack David A. , Wierzba Thomas F. , Chakraborty Subhra
Published: February 2022

Understanding the global burden of enterotoxigenic E. coli (ETEC) and Shigella diarrhea as well as estimating the cost effectiveness of vaccines to control these two significant pathogens have been hindered by the lack of a diagnostic test that is rapid, simple, sensitive, and can be applied to the endemic countries. We previously developed a simple and rapid assay, Rapid Loop mediated isothermal amplification based Diagnostic Test (RLDT) for the detection of ETEC and Shigella spp. (Shigella). In this study, the RLDT assay was evaluated in comparison with quantitative PCR (qPCR), culture and conventional PCR for the detection of ETEC and Shigella. This validation was performed using previously collected stool samples from endemic countries, from the travelers to the endemic countries, as well as samples from a controlled human infection model study of ETEC. The performance of RLDT from dried stool spots was also validated. RLDT resulted in excellent sensitivity and specificity compared to qPCR (99% and 99.2% respectively) ranging from 92.3 to 100% for the individual toxin genes of ETEC and 100% for Shigella. Culture was less sensitive compared to RLDT. No significant differences were noted in the performance of RLDT using samples from various sources or stool samples from moderate to severe diarrhea or asymptomatic infections. RLDT performed equally well in detection of ETEC and Shigella from the dried stool samples on filter papers. This study established that RLDT is sufficiently sensitive and specific to be used as a simple and rapid diagnostic assay to detect ETEC and Shigella in endemic countries to determine disease burden of these pathogens in the national and subnational levels. This information will be important to guide public health and policy makers to prioritize resources for accelerating the development and introduction of effective preventative and/or treatment interventions against these enteric infections.
Virulence and antimicrobial resistance profile of non-typhoidal Salmonella enterica serovars recovered from poultry processing environments at wet markets in Dhaka, Bangladesh
Authors: Siddiky Nure Alam , Sarker Samun , Khan Shahidur Rahman , Rahman Tanvir , Kafi Abdul , Samad Mohammed A.
Published: February 2022

The rapid emergence of virulent and multidrug-resistant (MDR) non-typhoidalSalmonella(NTS)entericaserovars is a growing public health concern globally. The present study focused on the assessment of the pathogenicity and antimicrobial resistance (AMR) profiling of NTSentericaserovars isolated from the chicken processing environments at wet markets in Dhaka, Bangladesh. A total of 870 samples consisting of carcass dressing water (CDW), chopping board swabs (CBS), and knife swabs (KS) were collected from 29 wet markets. The prevalence ofSalmonellawas found to be 20% in CDW, 19.31% in CBS, and 17.58% in KS, respectively. Meanwhile, the MDRSalmonellawas found to be 72.41%, 73.21%, and 68.62% in CDW, CBS, and KS, respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namelyinvA,agfA,IpfA,hilA,sivH,sefA,sopE, andspvC. TheS. Enteritidis and untypedSalmonellaisolates harbored all virulence genes whileS. Typhimurium isolates carried six virulence genes, exceptsefA andspvC. Phenotypic resistance revealed decreased susceptibility to ciprofloxacin, streptomycin, ampicillin, tetracycline, gentamicin, sulfamethoxazole-trimethoprim, amoxicillin-clavulanic acid, and azithromycin. Genotypic resistance showed a higher prevalence of plasmid-mediatedblaTEM followed bytetA,sul1,sul2,sul3, andstrA/B genes. The phenotypic and genotypic resistance profiles of the isolates showed a harmonic and symmetrical trend. According to the findings, MDR and virulent NTSentericaserovars predominate in wet market conditions and can easily enter the human food chain. The chi-square analysis showed significantly higher associations among the phenotypic resistance, genotypic resistance and virulence genes in CDW, CBS, and KS respectively (p < 0.05).
Increased mitochondrial proline metabolism sustains proliferation and survival of colorectal cancer cells
Authors: Alaqbi Saif Sattar , Burke Lynsey , Guterman Inna , Green Caleb , West Kevin , Palacios-Gallego Raquel , Cai Hong , Alexandrou Constantinos , Myint Ni Ni Moe , Parrott Emma , Howells Lynne M. , Higgins Jennifer A. , Jones Donald J. L. , Singh Rajinder , Britton Robert G. , Tufarelli Cristina , Thomas Anne , Rufini Alessandro
Published: February 2022

Research into the metabolism of the non-essential amino acid (NEAA) proline in cancer has gained traction in recent years. The last step in the proline biosynthesis pathway is catalyzed by pyrroline-5-carboxylate reductase (PYCR) enzymes. There are three PYCR enzymes: mitochondrial PYCR1 and 2 and cytosolic PYCR3 encoded by separate genes. The expression of the PYCR1 gene is increased in numerous malignancies and correlates with poor prognosis. PYCR1 expression sustains cancer cells’ proliferation and survival and several mechanisms have been implicated to explain its oncogenic role. It has been suggested that the biosynthesis of proline is key to sustain protein synthesis, support mitochondrial function and nucleotide biosynthesis. However, the links between proline metabolism and cancer remain ill-defined and are likely to be tissue specific. Here we use a combination of human dataset, human tissue and mouse models to show that the expression levels of the proline biosynthesis enzymes are significantly increased during colorectal tumorigenesis. Functionally, the expression of mitochondrial PYCRs is necessary for cancer cells’ survival and proliferation. However, the phenotypic consequences of PYCRs depletion could not be rescued by external supplementation with either proline or nucleotides. Overall, our data suggest that, despite the mechanisms underlying the role of proline metabolism in colorectal tumorigenesis remain elusive, targeting the proline biosynthesis pathway is a suitable approach for the development of novel anti-cancer therapies.