bluuebunny/crossref_metadata_2025 huggingface dataset:
Fission yeast Opy1 is an endogenous PI(4,5)P2 sensor that binds to the phosphatidylinositol 4-phosphate 5-kinase Its3
Authors: Snider Chloe E. , Willet Alaina H. , Brown HannahSofia T. , Chen Jun-Song , Evers Joshua M. , Gould Kathleen L.
Published: November 2020

Phosphoinositides (PIPs) are a dynamic family of lipids that execute diverse roles in cell biology. PIP levels are regulated by numerous enzymes, but our understanding of how these enzymes are controlled in space and time is incomplete. One role of the PIP phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] is to anchor the cytokinetic ring (CR) to the plasma membrane (PM) in Schizosaccharomyces pombe. While examining potential PI(4,5)P2-binding proteins for roles in CR anchoring, we identified the dual pleckstrin homology (PH) domain-containing protein Opy1. Although related proteins are implicated in PIP regulation, we found no role for S. pombe Opy1 in CR anchoring, which would be expected if it modulated PM PI(4,5)P2 levels. Our data indicate that although Opy1 senses PM PI(4,5)P2 levels and binds to the phosphatidylinositol 4-phosphate 5-kinase (PI5-kinase) Its3, Opy1 does not regulate Its3 kinase activity or PM PI(4,5)P2 levels, a striking difference from its Saccharomyces cerevisiae homolog. However, overexpression of Opy1 resulted in cytokinesis defects, as might be expected if it sequestered PI(4,5)P2. Our results highlight the evolutionary divergence of dual PH domain-containing proteins and the need for caution when interpreting results based on their overexpression.

This article has an associated First Person interview with the first author of the paper.
Spatial constraints on chromosomes are instrumental to meiotic pairing
Authors: Tian Miao , Agreiter Christiane , Loidl Josef
Published: November 2020

In most eukaryotes, the meiotic chromosomal bouquet (comprising clustered chromosome ends) provides an ordered chromosome arrangement that facilitates pairing and recombination between homologous chromosomes. In the protist Tetrahymena thermophila, the meiotic prophase nucleus stretches enormously, and chromosomes assume a bouquet-like arrangement in which telomeres and centromeres are attached to opposite poles of the nucleus. We have identified and characterized three meiosis-specific genes [meiotic nuclear elongation 1-3 (MELG1-3)] that control nuclear elongation, and centromere and telomere clustering. The Melg proteins interact with cytoskeletal and telomere-associated proteins, and probably repurpose them for reorganizing the meiotic prophase nucleus. A lack of sequence similarity between the Tetrahymena proteins responsible for telomere clustering and bouquet proteins of other organisms suggests that the Tetrahymena bouquet is analogous, rather than homologous, to the conserved eukaryotic bouquet. We also report that centromere clustering is more important than telomere clustering for homologous pairing. Therefore, we speculate that centromere clustering may have been the primordial mechanism for chromosome pairing in early eukaryotes.
Evidence of predictive selective attention in fiddler crabs during escape in the natural environment
Authors: Bagheri Zahra M. , Donohue Callum G. , Hemmi Jan M.
Published: November 2020

Selective attention is of fundamental relevance to animals for performing a diversity of tasks such as mating, feeding, predation and avoiding predators. Within natural environments, prey animals are often exposed to multiple, simultaneous threats, which significantly complicates the decision-making process. However, selective attention is rarely studied in complex, natural environments or in the context of escape responses. We therefore asked how relatively simple animals integrate the information from multiple, concurrent threatening events. Do they identify and respond only to what they perceive as the most dangerous threat, or do they respond to multiple stimuli at the same time? Do simultaneous threats evoke an earlier or stronger response than single threats? We investigated these questions by conducting field experiments and compared escape responses of the fiddler crab Gelasimus dampieri when faced with either a single or two simultaneously approaching dummy predators. We used the dummies' approach trajectories to manipulate the threat level; a directly approaching dummy indicated higher risk while a tangentially approaching dummy that passed the crabs at a distance represented a lower risk. The crabs responded later, but on average more often, when approached more directly. However, when confronted with the two dummies simultaneously, the crabs responded as if approached only by the directly approaching dummy. This suggests that the crabs are able to predict how close the dummy's trajectory is to a collision course and selectively suppress their normally earlier response to the less dangerous dummy. We thus provide evidence of predictive selective attention within a natural environment.
Copper(I)-catalyzed Stereoselective Silylative Dearomatization of Indoles and Pyrroles Using Silylboronates
Authors: Hayama Keiichi , Takahashi Rikuro , Kubota Koji , Ito Hajime
Published: November 2020

Silylative dearomatizations of indole-2-carboxylates were accomplished using a copper(I) catalyst and silylboronates. This reaction presumably proceeds through regioselective addition of silylcopper(I) species to indole substrates followed by highly diastereoselective protonation of the resulting copper(I) enolate intermediates to afford the corresponding dearomative silylation products. The first silylative dearomatization of pyrroles using the developed catalytic system is also described.
Perfil demográfico e clínico de pacientes com diagnóstico de COVID-19 em um hospital público de referência na cidade de Fortaleza-Ceará
Authors: Nunes Rebouças Ellys Rhaiara , Da Costa Rayana Fialho , Miranda Larissa Rocha , Campos Nataly Gurgel
Published: November 2020

Objetivo: caracterizar o perfil demográfico e clínico de pacientes com diagnóstico de COVID-19 em um hospital público de referência na cidade de Fortaleza-Ceará. Métodos: estudo do tipo transversal e documental, realizado no período de março a junho de 2020. A amostra contemplou os prontuários dos pacientes com diagnóstico da doença e com idade igual ou superior a 18 anos. As variáveis foram gênero, idade, comorbidades, indicação de ventilação mecânica invasiva (VMI), uso de hidroxicloroquina, dias de internação e desfecho clínico. Resultados: foram analisados 127 prontuários. A maioria dos pacientes era do gênero masculino, pertencentes à faixa etária de 36 a 60 anos, que apresentaram alguma condição de doença prévia e que permaneceram internados, em ambiente hospitalar, de 1 a 10 dias. A obesidade isolada e a tríade hipertensão arterial, diabetes mellitus e obesidade foram as comorbidades mais contempladas. A hidroxicloroquina foi utilizada em mais da metade dos pacientes, e a VMI foi administrada em menos de 50%. Quanto à alta ou ao óbito, perceberam-se valores próximos entre ambos os desfechos. Conclusão: foi evidenciado que, quanto ao gênero dos pacientes, à faixa etária e ao uso ou não do fármaco em relação ao desfecho final, não foram encontradas diferenças estatisticamente significantes entre eles; em contrapartida, quando observada a alta ou o óbito com as comorbidades, foi constatada uma diferença estatisticamente significante.
Non-intertwined strands of plasmid DNA contradict the Watson and Crick model of DNA structure
Authors: Kumar Pawan
Published: November 2020

According to Watson and Crick (W/C) model of DNA structure, a DNA molecule consists of two antiparallel polynucleotide chains, intertwined with each other. Although W/C model is accepted widely, some researchers have raised questions against it and proposed alternative structures for DNA. In the present study, we examined W/C model using plasmid DNA. It was hypothesized that two strands of plasmid will remain intertwined (and not separate from each other) under denaturing conditions if it follows W/C model. To test this, plasmid DNA was denatured using sodium hydroxide (NaOH) and analyzed by agarose gel electrophoresis. It was observed that addition of 0.5 N NaOH to pUC19 or pBR322 plasmids resulted in a new form of DNA having higher electrophoretic mobility in agarose gel. Higher electrophoretic mobility DNA (HmDNA) in NaOH-denatured pUC19 was digestible with S1 nuclease, but not with HindIII and ‘exonuclease I + alkaline phosphatase’. These results demonstrated that HmDNA is single-stranded circular DNA, formed due to separation of two strands of NaOH-denatured plasmid. Single-stranded and circular nature of HmDNA was corroborated by its comparable electrophoretic mobility with purified top and bottom strands of plasmid DNA. Next, we examined whether HmDNA can re-anneal into the native plasmid. Interestingly, when subjected to renaturing conditions, HmDNA from NaOH-denatured pUC19 re-annealed to form native pUC19 plasmid, which was digestible with HindIII and induced ampicillin resistance in Escherichia coli. These findings demonstrated the reversible separation of two strands of plasmid DNA and contradicted the W/C model of DNA structure.
Use of 16s rRNA to identify non-lactose-fermenting bacilli and molecular detection of ESBL resistance genes associated with hospital-acquired infection in Soba University Hospital, Sudan
Authors: Al Hag Wissam Ahmed , Elbadawi Hana , Abdel Hamid Muzamil Mahdi
Published: November 2020

Background: Non-lactose-fermenting gram-negative bacilli (NLFGNB) have become significant nosocomial pathogens and often exhibit intrinsic multidrug resistance. Sequencing of 16s rRNA genes could be utilized for robust identification of NLFGNB. This study aimed to identify resistant NLFGNB associated with hospital-acquired infections using 16s rRNA sequencing and to detect the extended-spectrum β-lactamase (ESBL) genes of isolates in Soba Hospital, Khartoum State, Sudan.

Methods: A prospective, cross-sectional, laboratory-based study was conducted from October 2017 to March 2018 at the Microbiology Department of Soba University Hospital. A total of 100 randomly selected NLFGNB samples were isolated from blood and urine during the time of the study. All the isolates were identified using standard biochemical tests and antimicrobial sensitivity testing, 16s rRNA gene sequencing, and bioinformatics techniques.

Results: The biochemical tests revealed that, out of the 100 NLFGNB isolates, the Pseudomonas species was predominant (57 isolates), followed by gram-negative bacilli (33 isolates), Coccobacilli (9 isolates) and Coliform (1 isolate) species. Sequencing of 16s rRNA genes identified all the resistant isolates at the species level: Pseudomonas aeruginosa (26%), Acinetobacter baumannii (22%), Burkholderia cepacia (13%), Stenotrophomonas maltophilia (10%), Enterococcus species (E. faecalis, E. faecium) (10%), and other GNB (Acinetobacter variabilis, Klebsiella pneumoniae, Morganella morganii, Escherichia fergusonii, Enterobacter hormaechei and Pseudomonas stutzeri) (19%). The antimicrobial susceptibility tests indicated that 31 isolates were resistant to at least three classes of antibiotics and contain the highest level of ESBL resistance genes.

Conclusions: Pseudomonas aeruginosa and Acinetobacter baumannii were the most widely recognized NLFGNB identified from hospital-acquired infections in Soba hospital. Among the NLFGNB, antimicrobial resistance and ESBL resistance genes were observed at a high frequency.
Influence of Workplace management initiatives on talent engagement in the Nigerian pharmaceutical industry
Authors: Falola Hezekiah O. , Ogueyungbo Opeyemi O. , Ojebola Oluwatunmise O.
Published: November 2020

Background: Talent engagement is increasingly gaining the attention of pharmaceutical industry, particularly in developing nations like Nigeria. The existing literature shows that the subject of workplace management initiatives and talent engagement in the Nigerian pharmaceutical industry has not been sufficiently researched. This study investigates the influence of workplace management initiatives on talent engagement in some selected pharmaceutical companies in Nigeria.

Methods: In total, 600 respondents were surveyed across various departments and units of ten selected pharmaceutical companies in Nigeria using multiple sampling techniques. Only 429 copies of the questionnaire, representing a 71.5% response rate, were returned and analyzed using Smart PLS 3.0.

Results: The outcomes of the statistical analysis show that recognition, employees’ wellbeing, learning and development as well as diversity and inclusion had significant influence on talent, emotional, cognitive and behavioural engagements.

Conclusions: In line with the statistical results, the study concludes that workplace management initiatives influenced talent engagement. The study emphasized the need for the review of many workplace management initiatives in order to determine its suitability within the context of pharmaceutical industry in Nigeria.
Breastfeeding assessment tools for at-risk and malnourished infants aged under 6 months old: a systematic review
Authors: Brugaletta Concetta , Le Roch Karine , Saxton Jennifer , Bizouerne Cécile , McGrath Marie , Kerac Marko
Published: November 2020

Background: Many small and malnourished infants under 6 months of age have problems with breastfeeding and restoring effective exclusive breastfeeding is a common treatment goal. Assessment is a critical first step of case management, but most malnutrition guidelines do not specify how best to do this. We aimed to identify breastfeeding assessment tools for use in assessing at-risk and malnourished infants in resource-poor settings.

Methods: We systematically searched: Medline and Embase; Web of Knowledge; Cochrane Reviews; Eldis and Google Scholar databases. Also the World Health Organization (WHO), United Nations International Children’s Emergency Fund (UNICEF), CAse REport guidelines, Emergency Nutrition Network, and Field Exchange websites. Assessment tool content was analysed using a framework describing breastfeeding ‘domains’ (baby’s behaviour; mother’s behaviour; position; latching; effective feeding; breast health; baby’s health; mother’s view of  feed; number, timing and length of feeds).

Results: We identified 29 breastfeeding assessment tools and 45 validation studies. Eight tools had not been validated. Evidence underpinning most tools was low quality and mainly from high-income countries and hospital settings. The most comprehensive tools were the Breastfeeding, Evaluation and Education Tool, UNICEF Baby-Friendly Hospital Initiative tools and CARE training package. The tool with the strongest evidence was the WHO/UNICEF B-R-E-A-S-T-Feed Observation Form.

Conclusions: Despite many possible tools, there is currently no one gold standard. For assessing malnourished infants in resource-poor settings, UNICEF Baby-Friendly Hospital Initiative tools, Module IFE and the WHO/UNICEF B-R-E-A-S-T-Feed Observation Form are the best available tools but could be improved by adding questions from other tools. Allowing for context, one tool for rapid community-based assessment plus a more detailed one for clinic/hospital assessment might help optimally identify breastfeeding problems and the support required. Further research is important to refine existing tools and develop new ones. Rigorous testing, especially against outcomes such as breastfeeding status and growth, is key.
The Relationship between Adolescent's Free Verses Enforced Decision to Enroll in an out-of- Home Boarding School and Later Well-being
Authors: Lev-Wiesel Rachel , Dar Rotem , Paz Yael , Arazi-Aviram Anat , Yosef Efrat , Sonego Gali , Weinger Susan , Doron Hadas , Shenaar-Golan Vered
Published: November 2020

Boarding schools are the common ‘out-of-home’ placements for adolescents, due to various historical, religiously orthodox, and traditional reasons and due to dysfunction within families. The purpose of the current study is to examine the relationship between a free versus an enforced decision to enroll in a boarding school in terms of personal well-being among emancipated graduates. Ninety alumni graduates (aged range 20-41) of out-of- home boarding schools in Israel were recruited during 2019. Participants were administered a self-report anonymous questionnaire consisting of the following measures: Free versus enforced decision to enroll in a boarding school, retrospective satisfaction with the boarding school, personal well-being and traumatic events. Results indicated that a free decision to enroll in an out-of-home boarding school was associated with current satisfaction with social relationships but not with quality of life. Additionally, the longer the period spent in a boarding school, the higher was the satisfaction from the period at school. Older graduates reported less satisfaction from school retrospectively. It was concluded that involving the adolescent in life changing decisions such as leaving home to a boarding school is likely to influence the person's well-being during and after emancipation.
Knowledge mobilisation in orthopaedic surgery in England: why hierarchies of knowledge bear little relation to the hierarchy of evidence in professionally socialised groups
Authors: Grove Amy , Clarke Aileen , Currie Graeme
Published: November 2020

Background:

Healthcare policy encourages the use of scientific evidence in the delivery of healthcare services. However, the complexity of practice restricts the use of codified knowledge in clinical guidelines despite continued effort from policymakers to ensure their use in practice. This study adopts a knowledge mobilisation perspective to explore the multiple levels through which scientific evidence is enacted to generate variation in practice.

Aim:

To explore how professionalised groups of clinicians mobilised knowledge in the highly-professionalised and organisationally-regulated context of orthopaedic surgery.

Methods:

Three contrasting NHS hospitals in England were examined using case study methods from 2014–15. Data included 64 interviews with surgeons and NHS staff, nine months of observation of day-to-day practice, and collection of 121 supplementary documents. A multilevel thematic analysis and cross-case comparison explored how individual surgeons, groups of professionals and hospital organisations mobilised knowledge.

Findings:

The findings described three themes to illustrate how variation in orthopaedic practice emerged: 1) professional identities; 2) knowledge acquisition; and 3) the contextual contingencies of practice. The professional groups which surgeons identified with had significant influence on how knowledge was mobilised within the organisations.

Conclusions:

Knowledge owned by professionally socialised surgical groups was central to explaining variation observed in the delivery of healthcare services. Hierarchies of knowledge in the practice of orthopaedic surgery bore little relation to the hierarchy of evidence which is foundational to the production of clinical guidance and guidelines. Knowledge defined and privileged within professional surgeon groups carried significant weight in practice, and generated contingent knowledge mobilisation.
Rolling angle recovery of flowing cells in holographic tomography exploiting the phase similarity
Authors: Pirone Daniele , Memmolo Pasquale , Merola Francesco , Miccio Lisa , Mugnano Martina , Capozzoli Amedeo , Curcio Claudio , Liseno Angelo , Ferraro Pietro
Published: November 2020

Holographic tomography allows the 3D mapping of the refractive index of biological samples thanks to reconstruction methods based on the knowledge of illumination directions or rotation angles of the imaged sample. Recently, phase contrast tomographic flow cytometry by digital holography has been demonstrated to reconstruct the three-dimensional refractive index distribution of single cells while they are flowing along microfluidic channels. In this system, the illumination direction is fixed while the sample’s rotation is not deterministically known a priori but induced by hydrodynamic forces. We propose here a technique to retrieve the rolling angles, based on a new phase images similarity metric that is capable of identifying a cell’s orientations from its 3D positioning while it is flowing along the microfluidic channel. The method is experimentally tested and also validated through appropriate numerical simulations. We provide demonstration of concept by achieving reconstruction of breast cancer cells tomography.
High throughput instrument to screen fluorescent proteins under two-photon excitation
Authors: Molina Rosana S. , King Jonathan , Franklin Jacob , Clack Nathan , McRaven Christopher , Goncharov Vasily , Flickinger Daniel , Svoboda Karel , Drobizhev Mikhail , Hughes Thomas E.
Published: November 2020

Two-photon microscopy together with fluorescent proteins and fluorescent protein-based biosensors are commonly used tools in neuroscience. To enhance their experimental scope, it is important to optimize fluorescent proteins for two-photon excitation. Directed evolution of fluorescent proteins under one-photon excitation is common, but many one-photon properties do not correlate with two-photon properties. A simple system for expressing fluorescent protein mutants is E. coli colonies on an agar plate. The small focal volume of two-photon excitation makes creating a high throughput screen in this system a challenge for a conventional point-scanning approach. We present an instrument and accompanying software that solves this challenge by selectively scanning each colony based on a colony map captured under one-photon excitation. This instrument, called the GIZMO, can measure the two-photon excited fluorescence of 10,000 E. coli colonies in 7 hours. We show that the GIZMO can be used to evolve a fluorescent protein under two-photon excitation.
Hyperspectral face recognition based on sparse spectral attention deep neural networks
Authors: Xie Zhihua , Li Yi , Niu Jieyi , Shi Ling , Wang Zhipeng , Lu Guoyu
Published: November 2020

Inspired by the robust capability and outstanding performance of convolutional neural networks (CNN) in image classification tasks, CNN-based hyperspectral face recognition methods are worthy of further exploration. However, hyperspectral imaging poses new challenges including high data dimensionality and interference between bands on spectral dimension. High data dimensionality can result in high computational costs. Moreover, not all bands are equally informative and discriminative. The usage of a useless spectral band may even introduce noises and weaken the performance. For the sake of solving those problems, we proposed a novel CNN framework, which adopted a channel-wise attention mechanism and Lasso algorithm to select the optimal spectral bands. The framework is termed as the sparse spectral channel-wise attention-based network (SSCANet) where the SSCA-block focuses on the inter-band channel relationship. Different from other methods which usually select the useful bands manually or in a greedy fashion, SSCA-block can adaptively recalibrate spectral bands by selectively emphasizing informative bands and suppressing less useful ones. Especially, a Lasso constraint strategy can zero out the bands during the training of the network, which can boost the training process by making the weights of bands sparser. Finally, we evaluate the performance of the proposed method in comparison of other state-of-the-art hyperspectral face recognition algorithms on three public datasets HK-PolyU, CMU, and UWA. The experimental results demonstrate that SSCANet based method outperforms the state-of-the-art methods for face recognition on the benchmark.
All-optical intrinsic atomic gradiometer with sub-20 fT/cm/√Hz sensitivity in a 22 µT earth-scale magnetic field
Authors: Perry A. R. , Bulatowicz M. D. , Larsen M. , Walker T. G. , Wyllie R.
Published: November 2020

In this work we demonstrate a high sensitivity atomic gradiometer capable of operation in earth-field level environments. We apply a light-pulse sequence at four times the Larmor frequency to achieve gradiometer sensitivity <20 fT/cm/

H

z

at the finite field strength of 22 µT. The experimental timing sequence can be tuned to the field magnitude of interest. Our all-optical scalar gradiometer performs a differential measurement between two regions of a single vapor cell on a 4 cm baseline. Our results pave the way for extensions to operation in higher dimensions, vector sensitivity, and more advanced gradiometers.
Absolute phase retrieval for colored objects based on three phase-shifting amount codes
Authors: Yuan Han , Li HongRu , Feng GuoYing , Bao ZhongYi , Li Wei , Cui Lei
Published: November 2020

We propose an absolute phase retrieval method based on three phase-shifting amount codes (3-PSA-codes) to measure the colored object with one additional pattern. 3-PSA-codes adopt the coding concept of 3-digit-codes, in which the code elements of three consecutive periods are treated as a unique code word for one period. However, to measure the colored object more effectively in the proposed method, each code element is embedded into the PSA domain and retrieved from the phase difference. Fringe patterns for the wrapped phase are artfully employed in the code element retrieval. Hence, for the first time, to the best of our knowledge, the code element related to the phase can be determined by one additional pattern. It breaks the constraint that temporal methods require multiple additional patterns to overcome the adverse effect of the surface color of objects on absolute phase retrieval. Experimental results demonstrate that the proposed 3-PSA-codes have strong robustness in the measurement of the colored object.
Flexible GaAs photodetector arrays hetero-epitaxially grown on GaP/Si for a low-cost III-V wearable photonics platform
Authors: Hong Namgi , Chu Rafael Jumar , Kang Soo Seok , Ryu Geunhwan , Han Jae-Hoon , Yu Ki Jun , Jung Daehwan , Choi Won Jun
Published: November 2020

We demonstrate flexible GaAs photodetector arrays that were hetero-epitaxially grown on a Si wafer for a new cost-effective and reliable wearable optoelectronics platform. A high crystalline quality GaAs layer was transferred onto a flexible foreign substrate and excellent retention of device performance was demonstrated by measuring the optical responsivities and dark currents. Optical simulation proves that the metal stacks used for wafer bonding serve as a back-reflector and enhance GaAs photodetector responsivity via a resonant-cavity effect. Device durability was also tested by bending 1000 times and no performance degradation was observed. This work paves a way for a cost-effective and flexible III-V optoelectronics technology with high durability.
Fringe projection profilometry by conducting deep learning from its digital twin
Authors: Zheng Yi , Wang Shaodong , Li Qing , Li Beiwen
Published: November 2020

High-accuracy and high-speed three-dimensional (3D) fringe projection profilometry (FPP) has been widely applied in many fields. Recently, researchers discovered that deep learning can significantly improve fringe analysis. However, deep learning requires numerous objects to be scanned for training data. In this paper, we propose to build the digital twin of an FPP system and perform virtual scanning using computer graphics, which can significantly save cost and labor. The proposed method extracts 3D geometry directly from a single-shot fringe image, and real-world experiments have demonstrated the success of the virtually trained model. Our virtual scanning method can automatically generate 7,200 fringe images and 800 corresponding 3D scenes within 1.5 hours.
Optical encryption using uncorrelated characteristics of dynamic scattering media and spatially random sampling of a plaintext
Authors: Han Qing , Zhao Wenjing , Zhai Aiping , Wang Zhirun , Wang Dong
Published: November 2020

Scattering media are generally regarded as an obstacle in optical imaging. However, the scattering of a diffuser can be exactly taken as an advantage to act as random phase masks in the field of optical encryption to enhance information security. Here, we propose and demonstrate a dynamic diffuser based optical encryption method, which increases the ciphering strength by exploiting the uncorrelated characteristics of the dynamic diffuser as well as randomly sampling the plaintext multiple times. The light emitted from a randomly sampled plaintext passing through the dynamic diffuser generates noise-like speckles, and then SNR of the recorded speckles is further reduced for obtaining the ciphertexts, which makes COA using PRA almost impossible. The specific uncorrelated characteristics of the dynamic diffuser make the ciphertexts and the PSF keys of the optical encryption unique. Therefore, only authorized users who mastered the keys can decrypt the plaintext. The proposed method is very simple and flexible since it can also achieve the encryption offline by performing convolutions on partial-plaintexts with pre-recorded uncorrelated PSFs to generate speckle patterns and then reducing their SNR to obtain the ciphertexts. This type of encryption technique has a promising prospect in applications involving images and/or videos information encryption owing to its simplicity and flexibility.
Broadband and compact silicon mode converter designed using a wavefront matching method
Authors: Sawada Yusuke , Fujisawa Takeshi , Saitoh Kunimasa
Published: November 2020

A broadband and compact TE0-TE1 mode converter for a mode division multiplexing system designed using a wavefront matching method is realized. We present the first experimental demonstration of a silicon waveguide device designed by a wavefront matching method. In order to achieve broadband operation of the silicon mode converter, seven wavelengths are considered in its optimization process. The designed silicon mode converter is fabricated via a standard complementary metal–oxide–semiconductor technology, which enables low-cost mass production. Measurements performed using the fabricated mode converter correlate strongly with the calculated results.
Ultra-broadband solar absorbers for high-efficiency thermophotovoltaics
Authors: Zhou Jin , Liu Zhengqi , Liu Guiqiang , Pan Pingping , Liu Xiaoshan , Tang Chaojun , Liu Zhongmin , Wang Junqiao
Published: November 2020

Metamaterial absorbers have attracted great attention over the past few years and exhibited a promising prospect in solar energy harvesting and solar thermophotovoltaics (STPVs). In this work, we introduce a solar absorber scheme, which enables efficient solar irradiance harvesting, superb thermal robustness and high solar thermal energy conversion for STPV systems. The optimum structure demonstrates an average absorbance of 97.85% at the spectral region from 200 nm to 2980 nm, indicating the near-unity absorption in the main energy range of the solar radiance. The solar-thermal conversion efficiencies surpassing 90% are achieved over an ultra-wide temperature range (100-800 °C). Meanwhile, the analysis indicates that this metamaterial has strong tolerance for fabrication errors. By utilizing the simple two-dimensional (2D) titanium (Ti) gratings, this design is able to get beyond the limit of costly and sophisticated nanomanufacturing techniques. These impressive features can hold the system with wide applications in metamaterial and other optoelectronic devices.
Single-mode fiber coupling with a M-SPGD algorithm for long-range quantum communications
Authors: Yang Kui-Xing , Abulizi Maimaiti , Li Yu-huai , Zhang Bo-Yang , Li Shuang-Lin , Liu Wei-yue , Yin Juan , Cao Yuan , Ren Ji-gang , Peng Cheng-zhi
Published: November 2020

Satellite-based quantum communication is a promising approach for realizing global-scale quantum networks. For free-space quantum channel, single-mode fiber coupling is particularly important for improving the signal-to-noise ratio of daylight quantum key distribution (QKD) and compatibility with standard fiber-based QKD. However, achieving a highly efficient and stable single-mode coupling efficiency under strong atmospheric turbulence remains experimentally challenging. Here, we develop a single-mode receiver with an adaptive optics (AO) system based on a modal version of the stochastic parallel gradient descent (M-SPGD) algorithm and test its performance over an 8 km urban terrestrial free-space channel. Under strong atmospheric turbulence, the M-SPGD AO system obtains an improvement of about 3.7 dB in the single-mode fiber coupling efficiency and a significant suppression of fluctuation, which can find its applications in free-space long-range quantum communications.
Light manipulation via spontaneous four-wave mixing in a warm double-Λ-type atomic ensemble
Authors: Jeong Taek , Chough Young-Tak , Moon Han Seb
Published: November 2020

We report on the dynamic manipulation of light in a warm 87Rb atomic ensemble using light storage based on the atomic spin coherence arising from the electromagnetically induced transparency (EIT) and spontaneous four-wave mixing (FWM) processes. We demonstrate that, subsequent to the generation of atomic spin coherence between two hyperfine ground states via the EIT storage process, it is possible to control the delay time, direction, and optical frequency of the retrieved light according to the timing sequence and powers of the coupling, probe, and driving lasers used for atomic-spin-coherence generation and the spontaneous FWM process. We believe that our results provide useful ideas in photon frequency conversion and photon control in connection with the quantum memories that is essential in the quantum communications technology.
Ge-on-insulator lateral p-i-n waveguide photodetectors for optical communication
Authors: Cheng Chin-Yuan , Tsai Cheng-Hsun , Yeh Po-Lun , Hung Sheng-Feng , Bao Shuyu , Lee Kwang Hong , Tan Chuan Seng , Chang Guo-En
Published: November 2020

We report high-performance lateral

p

-

i

-

n

Ge waveguide photodetectors (WGPDs) on a Ge-on-insulator (GOI) platform that could be integrated with electronic–photonic integrated circuits (EPICs) for communication applications. The high-quality Ge layer affords a low absolute dark current. A tensile strain of 0.144% in the Ge active layers narrows the direct bandgap to enable efficient photodetection over the entire range of C- and L-bands. The low-index insulator layer enhances optical confinement, resulting in a good optical responsivity. These results demonstrate the feasibility of planar Ge WGPDs for monolithic GOI-based EPICs.
Thermal lens astigmatism in glass and in cubic crystals with [001] orientation
Authors: Yakovlev Alexey , Snetkov Ilya
Published: November 2020

The thermal lens was investigated in

C
a
F

2

and

T
b

3

G
a

5

O

12

cubic crystals with [001] crystallographic axes orientation and in magneto-optical glass MOG103 by the method of phase-shifting interferometry. It was demonstrated experimentally that the thermal lens has astigmatism determined by the incident radiation polarization state and by the optical anisotropy parameter

ξ

. A method of

ξ

determination by measuring thermal lens astigmatism in cubic crystals with [001] orientation was proposed and verified. It was shown that thermally induced depolarization and the amplitude of phase astigmatism depend on the position of the crystal with [001] orientation in antiphase.
Individual transducer impulse response characterization method to improve image quality of array-based handheld optoacoustic tomography
Authors: Chowdhury Kaushik Basak , Bader Maximilian , Dehner Christoph , Jüstel Dominik , Ntziachristos Vasilis
Published: November 2020

The physical properties of each transducer element play a vital role in the quality of images generated in optoacoustic (photoacoustic) tomography using transducer arrays. Thorough experimental characterization of such systems is often laborious and impractical. A shortcoming of the existing impulse response correction methods, however, is the assumption that all transducers in the array are identical and therefore share one electrical impulse response (EIR). In practice, the EIRs of the transducer elements in the array vary, and the effect of this element-to-element variability on image quality has not been investigated so far, to the best of our knowledge. We hereby propose a robust EIR derivation for individual transducer elements in an array using sparse measurements of the total impulse response (TIR) and by solving the linear system for temporal convolution. Thereafter, we combine a simulated spatial impulse response with the derived individual EIRs to obtain a full characterization of the TIR, which we call individual synthetic TIR. Correcting for individual transducer responses, we demonstrate significant improvement in isotropic resolution, which further enhances the clinical potential of array-based handheld transducers.
High-efficiency chirped grating couplers on lithium niobate on insulator
Authors: Kang Shuting , Zhang Ru , Hao Zhenzhong , Jia Di , Gao Feng , Bo Fang , Zhang Guoquan , Xu Jingjun
Published: November 2020

High-efficiency chirped grating couplers (GCs) with coupling efficiencies (CE) approaching 90%/coupler were designed by using a particle swarm optimization algorithm. These GCs were fabricated on

-cut lithium niobate on insulator (LNOI) with an Au layer on the lithium niobate substrate. The maximum CEs for transverse electric and transverse magnetic polarization input were measured up to

/coupler and

/coupler, respectively, which are the state-of-the-art values for LNOI GCs as far as we know. These GCs contribute to the realization of high-efficiency LNOI on-chip integrated optics.
Temporal coding of echo spectral shape in the bat auditory cortex
Authors: Macias Silvio , Bakshi Kushal , Garcia-Rosales Francisco , Hechavarria Julio C. , Smotherman Michael
Published: November 2020

Echolocating bats rely upon spectral interference patterns in echoes to reconstruct fine details of a reflecting object’s shape. However, the acoustic modulations required to do this are extremely brief, raising questions about how their auditory cortex encodes and processes such rapid and fine spectrotemporal details. Here, we tested the hypothesis that biosonar target shape representation in the primary auditory cortex (A1) is more reliably encoded by changes in spike timing (latency) than spike rates and that latency is sufficiently precise to support a synchronization-based ensemble representation of this critical auditory object feature space. To test this, we measured how the spatiotemporal activation patterns of A1 changed when naturalistic spectral notches were inserted into echo mimic stimuli. Neurons tuned to notch frequencies were predicted to exhibit longer latencies and lower mean firing rates due to lower signal amplitudes at their preferred frequencies, and both were found to occur. Comparative analyses confirmed that significantly more information was recoverable from changes in spike times relative to concurrent changes in spike rates. With this data, we reconstructed spatiotemporal activation maps of A1 and estimated the level of emerging neuronal spike synchrony between cortical neurons tuned to different frequencies. The results support existing computational models, indicating that spectral interference patterns may be efficiently encoded by a cascading tonotopic sequence of neural synchronization patterns within an ensemble of network activity that relates to the physical features of the reflecting object surface.
Ten simple rules for writing Dockerfiles for reproducible data science
Authors: Nüst Daniel , Sochat Vanessa , Marwick Ben , Eglen Stephen J. , Head Tim , Hirst Tony , Evans Benjamin D.
Published: November 2020

Computational science has been greatly improved by the use of containers for packaging software and data dependencies. In a scholarly context, the main drivers for using these containers are transparency and support of reproducibility; in turn, a workflow’s reproducibility can be greatly affected by the choices that are made with respect to building containers. In many cases, the build process for the container’s image is created from instructions provided in a Dockerfile format. In support of this approach, we present a set of rules to help researchers write understandable Dockerfiles for typical data science workflows. By following the rules in this article, researchers can create containers suitable for sharing with fellow scientists, for including in scholarly communication such as education or scientific papers, and for effective and sustainable personal workflows.
The role of carbon nanoparticle in lymph node detection and parathyroid gland protection during thyroidectomy for non-anaplastic thyroid carcinoma- a meta-analysis
Authors: Xu Shaowei , Li Zhifeng , Xu Manbin , Peng Hanwei
Published: November 2020

Objective

To assess the efficiency of the carbon nanoparticles (CNs) in lymph node identification and parathyroid gland (PG) protection during thyroidectomy for non-anaplastic thyroid carcinoma (N-ATC).

Methods

A systematic literature search for relevant literatures published up to December 2018 in PubMed, EMBASE, Web of Science and Cochrane Library was performed. Both English and Chinese literatures were retrieved and analyzed. Randomized controlled trials or nonrandomized controlled trials comparing the use of CNs with the use of methylene blue or a blank control in patients undergoing thyroidectomy for N-ATC were enrolled in this study. The primary outcomes included the number of lymph nodes harvested, the rate of lymph nodes involved, and the rates of accidental parathyroidectomy, hypoparathyroidism, and hypocalcemia. Weighted mean differences (WMDs), odds ratios (ORs) and risk differences (RDs) were calculated for the dichotomous outcome variables. Between study heterogeneity was tested using the Q tests and the I2 statistics. All analyses were performed using Review Manager (version 5.3.5).

Results

25 studies comprising 3266 patients were included in this analysis. The total number of lymph nodes harvested in the CNs groups was significantly higher than that in the control groups (WMD, 2.36; 95% CI, 1.40 to 3.32; P <0.01). Administrating CNs was associated with a lower incidence of accidental PG removal (OR = 0.28, 95% CI = 0.21 to 0.37, P<0.01) and lower rates of both postoperative transient hypoparathyroidism (OR = 0.46, 95% CI = 0.33 to 0.64, P <0.01) and transient hypocalcemia (OR = 0.46, 95% CI = 0.33 to 0.65, P <0.01). No significant difference was found concerning lymph node metastatic rates between CNs group and control group. Subgroup analysis indicated that the application of CNs in reoperation thyroidectomy reduced both the rate of transient hypoparathyroidism (OR = 0.21, 95% CI = 0.06 to 0.75, P = 0.02) and the possibility of accidental PGs removal (OR = 0.21, 95% CI = 0.07 to 0.62, P = 0.004, P<0.05).

Conclusions

The application of CNs in thyroidectomy for N-ATC results in higher number of lymph node harvested and better PG protection during both initial and reoperation thyroidectomy.
National-level effectiveness of ART to prevent early mother to child transmission of HIV in Namibia
Authors: Agabu Andrew , Baughman Andrew L. , Fischer-Walker Christa , de Klerk Michael , Mutenda Nicholus , Rusberg Francina , Diergaardt Dorothea , Pentikainen Ndumbu , Sawadogo Souleymane , Agolory Simon , Dinh Thu-Ha
Published: November 2020

Background

Namibia introduced the prevention of mother to child HIV transmission (MTCT) program in 2002 and lifelong antiretroviral therapy (ART) for pregnant women (option B-plus) in 2013. We sought to quantify MTCT measured at 4–12 weeks post-delivery.

Methods

During Aug 2014-Feb 2015, we recruited a nationally representative sample of 1040 pairs of mother and infant aged 4–12 weeks at routine immunizations in 60 public health clinics using two stage sampling approach. Of these, 864 HIV exposed infants had DNA-PCR HIV test results available. We defined an HIV exposed infant if born to an HIV-positive mother with documented status or diagnosed at enrollment using rapid HIV tests. Dried Blood Spots samples from HIV exposed infants were tested for HIV. Interview data and laboratory results were collected on smartphones and uploaded to a central database. We measured MTCT prevalence at 4–12 weeks post-delivery and evaluated associations between infant HIV infection and maternal and infant characteristics including maternal treatment and infant prophylaxis. All statistical analyses accounted for the survey design.

Results

Based on the 864 HIV exposed infants with test results available, nationally weighted early MTCT measured at 4–12 weeks post-delivery was 1.74% (95% confidence interval (CI): 1.00%-3.01%). Overall, 62% of mothers started ART pre-conception, 33.6% during pregnancy, 1.2% post-delivery and 3.2% never received ART. Mothers who started ART before pregnancy and during pregnancy had low MTCT prevalence, 0.78% (95% CI: 0.31%-1.96%) and 0.98% (95% CI: 0.33%-2.91%), respectively. MTCT rose to 4.13% (95% CI: 0.54%-25.68%) when the mother started ART after delivery and to 11.62% (95% CI: 4.07%-28.96%) when she never received ART. The lowest MTCT of 0.76% (95% CI: 0.36% - 1.61%) was achieved when mother received ART and ARV prophylaxis within 72hrs for infant and highest 22.32% (95%CI: 2.78% -74.25%) when neither mother nor infant received ARVs. After adjusting for mother’s age, maternal ART (Prevalence Ratio (PR) = 0.10, 95% CI: 0.03–0.29) and infant ARV prophylaxis (PR = 0.32, 95% CI: 0.10–0.998) remained strong predictors of HIV transmission.

Conclusion

As of 2015, Namibia achieved MTCT of 1.74%, measured at 4–12 weeks post-delivery. Women already on ART pre-conception had the lowest prevalence of MTCT emphasizing the importance of early HIV diagnosis and treatment initiation before pregnancy. Studies are needed to measure MTCT and maternal HIV seroconversion during breastfeeding.
Split-based points from the Swabian Jura highlight Aurignacian regional signatures
Authors: Kitagawa Keiko , Conard Nicholas J.
Published: November 2020

The systematic use of antlers and other osseous materials by modern humans marks a set of cultural and technological innovations in the early Upper Paleolithic, as is seen most clearly in the Aurignacian. Split-based points, which are one of the most common osseous tools, are present throughout most regions where the Aurignacian is documented. Using results from recent and ongoing excavations at Geißenklösterle, Hohle Fels and Vogelherd, we nearly tripled the sample of split-based points from 31 to 87 specimens, and thereby enhance our understanding of the technological economy surrounding the production of osseous tools. Aurignacian people of the Swabian Jura typically left spit-based points at sites that appear to be base camps rich with numerous examples of personal ornaments, figurative art, symbolic imagery, and musical instruments. The artifact assemblages from SW Germany highlight a production sequence that resembles that of SW France and Cantabria, except for the absence of tongued pieces. Our study documents the life histories of osseous tools and demonstrates templates for manufacture, use, recycling, and discard of these archetypal artifacts from the Aurignacian. The study also underlines the diversified repertoire of modern humans in cultural and technological realms highlighting their adaptive capabilities.