bluuebunny/crossref_metadata_2025 huggingface dataset:
Stage 2 Registered Report: How responsibility attributions to self and others relate to outcome ownership in group decisions
Authors: Jaquiery Matt , El Zein Marwa
Published: April 2022

Background: Responsibility judgements have important consequences in human society. Previous research focused on how someone's responsibility determines the outcome they deserve, for example, whether they are rewarded or punished. Here, in a pre-registered study (Stage 1 Registered Report: https://doi.org/10.12688/wellcomeopenres.16480.2), we investigate the opposite link: How outcome ownership influences responsibility attributions in a social context. 

Methods: In an online study, participants in a group of three perform a majority vote decision-making task between gambles that can lead to a reward or no reward. Only one group member receives the outcome and participants evaluate their and the other players' responsibility for the obtained outcome.

Results: We found that outcome ownership increases responsibility attributions even when the control over an outcome is similar. Moreover, ownership had an effect on the valence bias: participants’ higher responsibility attributions for positive vs negative outcomes was stronger for players who received the outcome. Finally, this effect was more pronounced when people rated their own responsibility as compared to when they were rating another’s player responsibility.

Conclusions: The findings of this study reveal how credit attributions can be biased toward particular individuals who receive outcomes as a result of collective work, both when people judge their own and someone else’s responsibility.
Mismarking in Mutual Funds
Authors: Atanasov Vladimir , Merrick John J. , Schuster Philipp
Published: April 2022

We study mismarking of newly purchased odd lot and two classes of round lot structured product positions in mutual funds. Such mismarking artificially inflates net asset values and overstates cumulative returns. Applied to funds launched after January 2010, a simulation-tested mismarking fund filter identifies 12 Highly Questionable funds managing $75 billion. The performance of these funds matches closely the predicted pattern of mismarking: extremely high alpha and skewness, particularly immediately after launch. We show that structured product mismarking can seriously inflate return-since-inception metrics. We also provide evidence consistent with return smoothing for one quarter of the sample structured product funds. The inflated performance metrics benefit fund managers through significantly higher Sharpe ratios, Morningstar ratings, and asset growth but cause material losses to later investor cohorts.

This paper was accepted by Agostino Capponi, finance.

Funding: P. Schuster gratefully acknowledges funding by the Deutsche Forschungsgemeinschaft [Grant SCHU 3049/1-1].

Supplemental Material: Data and the online appendices are available at https://doi.org/10.1287/mnsc.2022.4366 .
Female Directors and Firm Value: New Evidence from Directors’ Deaths
Authors: Schmid Thomas , Urban Daniel
Published: April 2022

This paper examines how female directors (FDs) affect firm value in the absence of mandatory gender quotas. Using a newly collected data set on director deaths around the globe, we find that stock prices decrease approximately 2% more when an FD passes away, compared with a male director. What explains this negative capital market reaction? We find evidence that finding successors for deceased FDs is challenging for firms: Succession delays are longer, and although firms try to replace FDs with women, two-thirds of their successors are male. Furthermore, their successors tend to be younger, less experienced, and more often externally hired. Stock prices decline less if more potential female successors exist in a country, the firm is larger, or FDs other than the deceased woman were on the board. Because observable characteristics such as age, tenure, education, and network centrality cannot explain the negative stock market reaction, unobserved differences across genders that lead to a lower fit of male successors to the existing board are the most likely explanation for the firm value loss after the death of an FD.

This paper was accepted by David Simchi-Levi, finance.

Supplemental Material: Data are available at https://doi.org/10.1287/mnsc.2022.4412 .
If the public can vaccinate, why not students? Review of a student nurse placement in a mass vaccination centre
Authors: Thornton Matthew , Jones Linda , Jones Rhiannon , Lusardi Gail
Published: April 2022

Delivery of the COVID-19 vaccine has been made possible in part through the use of mass vaccination centres (MVCs). The primary legal framework underpinning the MVC programme is a national protocol enabling registered and non-registered healthcare workers to contribute to the safe and effective administration of the vaccine. The national protocol provided a vehicle for an innovative supervised student nurse placement within an MVC in south Wales. This placement, for undergraduate pre-registration student nurses, formed part of a service improvement project. Through student feedback prior to, and following, the short placement, the learning was unequivocal in terms of knowledge and skills acquisition related to safe and effective vaccine administration, with students providing clear feedback on the positive nature of the placement experience. A placement within an MVC offers a rich educational experience for student nurses, which as yet appears to be underutilised across the UK.
Complication rates associated with traction removal of percutaneous endoscopic gastrostomy tubes
Authors: Melling Georgina , Farley Joshua
Published: April 2022

Background:

Percutaneous endoscopic gastrostomy (PEG) tubes are removed and/or replaced for reasons such as tube malfunction, degradation, patient's device preference, and when stopping enteral feeding.

Aims:

To identify the types and rate of complications associated with traction removal of a PEG tube and if this is associated with the size of the PEG or length of time it had been in situ prior to removal.

Methods:

This retrospective study looked at the tube removal/replacement reports written by the Enteral Feeding Nursing Service over an 8-year period at a large teaching hospital trust in the north of England.

Findings:

The PEG tube removal reports of 127 patients were reviewed. Five types of complication were identified, categorised as retained bumper (5.5%); intraperitoneal placement of new device (3.17%); misplacement of replacement device into colon (a consequence of the insertion procedure not the removal of the PEG) (0.78%): gastrocutaneous fistula (0.78%); and inability to remove the tube (1.57%). The complication of retained bumpers was associated with an average length of time in situ prior to removal of the PEG tube of 29 months. In the cases of intraperitoneal placement, the PEG tube had been in situ for an average of 6 months. Nurses were unable to remove the PEG tube on two occasions; each had been in situ for approximately 4 years prior to attempted removal.

Conclusion:

the complication rates are low following removal of a PEG tube using a traction pull. There was no clear correlation between length of time in situ or tube size and complication rate.
Adipose tissue as a source of growth factors to promote wound healing: a human study of skin graft donor sites
Authors: López Jenny F , Mikkola Antti , Sarkanen Jertta-Riina , Kaartinen Ilkka S , Kuokkanen Hannu O , Ylikomi Timo
Published: April 2022

Objective:

In the microenvironment of wound sites, naturally occurring growth factors are crucial for cell migration, opsonisation, chemotaxis, differentiation and angiogenesis. Exogenous growth factors, such as platelet-rich plasma (PRP) and adipose tissue, also improve healing.

Method:

In the present within-subject study, we described the effects of PRP and adipose tissue extract (ATE) on skin graft donor site wound healing in patients requiring split-thickness skin grafts. Each patient, having at least two donor sites, received both control (no growth factor) and experimental (PRP or ATE) treatments. Wounds were evaluated on days 5, 7, 10, 15, 30 and 60. Digital photography and spectral images were used to analyse haemoglobin and melanin content, and re-epithelialisation area. Pain was assessed by visual analogue scale. Scar characteristics were scored on days 30 and 60. Biomaterial samples were analysed for growth factor and protein content.

Results:

The study included 24 patients (18 male and six female; mean age: 59.1 years). PRP was topically applied to wounds in 11 patients (13 donor sites) and ATE in 13 patients (15 sites). ATE-treated donor sites exhibited significantly accelerated wound re-epithelialisation on days 5 and 7 compared with control sites (p=0.003 and 0.04, respectively). PRP accelerated healing on day 7 compared with control sites (p=0.001). Additionally, the application of ATE improved scar quality on days 30 and 60 (p=0.0005 and 0.02, respectively). Pain scores did not differ significantly between treatments.

Conclusion:

In this study, both growth factor sources stimulated wound healing. ATE is an alternative source of growth factors that promote early wound healing and improve scar quality.
Bacterial protease activity: a prognostic biomarker of early wound infection
Authors: Serena Thomas E , Bayliff Simon W , Brosnan Patrick J
Published: April 2022

Objective:

High bacterial burden is one of several reasons that wounds fail to heal. At present, clinicians rely primarily on clinical signs and symptoms (CSS) to diagnose infection in hard-to-heal wounds; however, studies have demonstrated that CSS can be unreliable. This is especially true in the early stages of bacterial infection. Bacteria release proteases, virulence factors that promote invasive infection. This clinical trial evaluated the use of bacterial protease activity (BPA) as a biomarker to detect whether a wound was in the period of pathogenicity, prior to overt clinical signs.

Method:

Participants were drawn from six US wound centres and had their wounds assessed clinically for infection. In addition, wound fluid swabs were collected and analysed for BPA, inflammatory cytokines (interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)), and cultured for quantitative microbiology.

Results:

A total of 366 patients were recruited. The median BPA level increased with the increasing number of signs of infection. The majority of wounds tested positive for elevated BPA prior to exhibiting at least three CSS of infection, the level at which the criteria for infection are met. BPA tended to increase with the bioburden (colony forming unit (CFU)/ml) although some wounds with high bioburden were negative for BPA, and others with low bioburden were positive for BPA. The mean levels of IL-1β and TNF-α were significantly higher in BPA-positive wounds (p<0.0001 and p=0.0002, respectively).

Conclusion:

The results of this clinical trial suggest that measuring BPA can lead to the early detection of pathogenic bacteria in the wound that impede wound healing and may progress to invasive infection. In a large percentage of cases, BPA detected virulent bacteria in the absence of CSS of infection. As a biomarker, BPA has an advantage over measuring bacterial load—hard-to-heal wounds are often colonised with non-pathogenic bacteria that do not inhibit wound healing and, conversely, a low number of highly virulent species could disrupt the healing process.
Use of single-layer artificial dermal template in patients with trauma and burns
Authors: Karatan Berrak , Yamak Kamil
Published: April 2022

Objective:

Artificial dermal templates (ADTs), were designed initially to provide extracellular matrix and skin substitute for extensive burn injuries. Use of ADTs in a variety of other indications, has also been described in the literature. In this study, we describe our experience of using ADTs for different indications in burn contractures and wound coverage.

Method:

In this retrospective study, patients requiring burn scar contracture release, permanent wound coverage for acute traumatic wounds and temporary wound coverage to prepare for complex reconstructions, and where the ADT Pelnac (Gunze Ltd., Japan) was applied, were evaluated. Data regarding patient sex, age, type and location of injury, comorbidities, operations and complications were recorded.

Results:

A total of 24 patients were included in the study, of whom 12 patients were operated on for burn contractures. ADTs were used with split-thickness skin grafts (STSGs) or Z-plasties in a single-stage procedure. In six patients, ADT and STSGs were used to cover defects with exposed bone or tendon. Of the patients, six had their wounds covered temporarily while they were stabilised for complex reconstructions or were awaiting definitive histopathological results. Revisional surgeries due to graft failures or insufficient contracture releases were required by 12 patients. All temporary wound coverage patients had successful flap reconstructions after stabilisation of their general status, had tumour-free margins in the histopathological examination, and no necrosis or infection was seen on follow-up.

Conclusion:

In this study, ADTs had positive effects on selected patients, but comprehensive and comparative clinical studies are needed for different indications to choose between these templates.
Influence of Physiological Donor of Nitric Oxide on Blood Serum Crystallostasis in Rats
Authors: Martusevich Andrew K. , Kovaleva Lida K. , A. Karuzin Konstantin , V. Surovegina Alexandra , Artamonov Mikhail Yu.
Published: April 2022

The aim of the work was to study the effect of intraperitoneal administration of dinitrosyl iron complexes with glutathione ligands on the initiated crystallogenesis of rat blood serum. The experiment was performed on 70 male Wistar rats divided into 7 equal groups. The first group of animals was intact (without any manipulation). Rats included in the other groups were administered intraperitoneal injection of 1 ml. 0.9% sodium chloride solution daily for 10 days. At the same time, animals of the third to sixth groups were additionally added to the injected solution with dinitrosyl iron complexes with glutathione ligands (the concentration of the agent was 0.15; 0.30; 0.45 and 0.60 mM, respectively). The rats of the seventh group received 1 ml. an aqueous solution of glutathione (0.15 mM). The study of the effect of DNIC on the crystallogenic properties of rat blood serum was carried out by the method of comparative tezioraphy using a special system of criteria. The data obtained as a result of this study indicate the presence of modification of the crystallogenic (initiating) properties of rat blood serum during the course intraperitoneal administration of a physiological donor of nitric oxide to animals – DNIC, and this effect turns out to be dose-dependent and having an extremum in the region of 0.3-0.45 mM. Taking into account the fact that the crystallogenic properties are a reflection of the component composition and one of the physico-chemical parameters of the biological fluid, it can be assumed that the metabolic response of the body to the use of the compound is also dose-dependent. At the same time, relatively low doses of the agent have the most optimal effect on metabolic processes, stimulating the antioxidant potential of blood serum with a corresponding decrease in the intensity of lipid peroxidation processes, contributing to the optimization of energy metabolism and increasing the activity of detoxification enzyme systems. The results of the teziographic evaluation of animal blood serum samples after a course of injections of DNIC in various concentrations clearly indicate the activating effect of the compound with respect to the crystallogenic (initiating) properties of biological fluid, which is most pronounced when using the substance in 0.3- and 0.45-millimolar aqueous solutions.
Cytotoxic Effect of Cypermethrin and Neem Extract on Human Lymphocytes
Authors: Khanna Asha , Patel Jyotsana , Pagare Saurabh , Gautam Daya Shankar , Ratoniya Vineeta
Published: April 2022

There is a need to increase our agricultural production of food grains and other crops to feed a continuously increasing population. To achieve this food security, use of insecticides/pesticides has become necessary. Cypermethrin is a pyrethroid insecticide used for control of pests of cereals, fruits, vegetables and cotton etc. but it has several toxic effects on human beings. Apart from being neurotoxic, it has harmful effects on lymphocytes also. Neem is also a potent insecticide of herbal and indigenous origin. In this investigation the cytotoxicity of cypermethrin (dissolved in DMSO) and aqueous extract of neem leaves to human lymphocytes was studied by MTT assay. It was found that after an exposure of two hours to LC50 concentration of cypermethrin viability of lymphocytes fell to 87.83%; however at lower concentration the viability fell further because of the increase in the DMSO concentration, proving the toxicity of DMSO. Treatment of lymphocytes with 45% of neem extract increased the viability by 196% but at lower concentrations lesser increase was noted due to the increase in concentration of PBS. Thus apart from being a safe insecticide neem extract can be used to promote viability and proliferation of cells of animal origin also.
Properties of Nonwoven Fabrics Containing Immobilized Superabsorbent Polymer Particles for Air Conditioning in Grain Dryers
Authors: Kimani Peter Kang´ethe , Mbuge Duncan , Gitau Ayub N.
Published: April 2022

Highlights

The SAP fabric adsorbed up to 1.05 times its dry weight, at room temperature SAP fabric had up to three times more adsorption capacity compared with silica gel.

SAP fabric moisture adsorption rate trends are best predicted using logarithmic models.

The fabric maintains high permeability in comparison with other desiccants, an average pressure drop of 0.10 millibar for 10 layers of SAP was recorded at 0.5 m/s air velocity.

SAP fabric adsorption capacity remained unchanged after several cycles of regeneration by oven drying at 105°C.

Abstract.In sub-Saharan Africa, maize and other cereal grains are normally sun-dried after harvesting. Post-harvest preservation techniques and conditions greatly contribute to the loss of the produce mainly due to mycotoxins infestation. There is lack of affordable and adequate technical facilities for post-harvest preservation of the produce. This research presents the findings of Superabsorbent Polymer (SAP) fabric properties, a material that is proposed for use in hybrid solar drying technology. The objective of the study was to determine the moisture adsorption capacity of SAP fabric. The experiments were carried out in an air conditioning unit, in each experiment the inlet air temperatures were maintained at a constant level of 20°C, 30°C, and 40°C, the inlet air relative humidity was varied between 50% and 90% in 10 unit intervals. It was found that the SAP Fabric had a high adsorption capacity of up to 105% of its dry weight at an air temperature of 20°C and 90% relative humidity. The adsorption rate trends are best predicted using logarithmic models which showed high initial moisture adsorption decreasing gradually to the equilibrium moisture content. The pressure drop across 3, 6, 10, and 15 layers was between 0.09 to 0.12 millibars, which showed that SAP fabric is a highly porous desiccant. There was no noticeable change in moisture adsorption capacity of the SAP when oven-dried at 105°C to regenerate it. It was established that SAP fabric is effective for use in drying air. Keywords: Air conditioning, Desiccant, Grain drying, Non-woven fabric, Superabsorbent Polymer (SAP).
Deep-Pest-Detector: Automated Detection and Localization of Processionary Moth Nests on Pine Trees via Aerial Drones and Deep Neural Networks
Authors: Jaber Nael , Daher Naseem , Asmar Daniel
Published: April 2022

Highlights

A deep learning architecture, which relies on multi-modal imagery from the RGB and thermal spectra, is proposed to detect PPM nests via aerial drones.

A GPS-based computation method is implemented to geo-tag the position of the detected nests in the drone’s perimeter.

A Kalman filter is utilized as a nest tracker to avoid reporting back the position of the same nest several times.

The system is tested in a pine forest and exhibits accurate detection and localization, as evidenced by reporting back the positions of the detected PPM nests.

Abstract.The pine processionary moth (PPM) is considered the main defoliator of pine trees and is a menacing threat to various other perennial species including oak and cedar. Given their negative secondary effects, spraying of pesticides has been banned as a means for the eradication of PPM; instead, an individualized approach is to be adopted, in which each nest is localized and destroyed. Detection of PPM nests using optical sensing is challenging because of the changing outdoor lighting conditions and the camouflaged appearance of moth in the underlying foliage. This article proposes a promising solution for nest detection by fusing sensory data from an RGB camera on one hand, and a thermal camera on the other, both mounted on an aerial drone. The proposed detection system is built on a two-channeled deep convolutional neural network, one for each spectrum of the collected sensory data. Experiments performed in a pine forest demonstrate successful detection rates with an average accuracy of 97% in various experiments and settings. Geo-localization is performed to report the position of the detected nests within a scanned forest map by means of an estimation scheme that is particularly designed for this purpose achieving centimeter accuracy (<20 cm). Keywords: Aerial robotics, Agriculture, Detection, Machine learning, Multi-stream CNN, Pest control.
Nondestructive Quantitative Analysis of Water Potential of Tomato Leaves Using Online Hyperspectral Imaging System
Authors: Tung Kuo-Chih , Yen Ping-Lang , Tsai Chao-Yin , Ong Pauline , Lin Jer-Wei , Chang Yung-Huei , Chen Suming
Published: April 2022

Highlights

We developed an online measurement system for water potential of tomato plants using hyperspectral imaging.

We used Linear Discriminant Analysis to automatically and quickly extract the leaf images.

We used SNV scattering correction to remove the spectral variations caused by collecting the defocused leaf images.

We developed a prediction model of leaf water potential based on spectral image information.

Abstract. Tomatoes have different water requirements in each growing period. Excessive water use or insufficient water supply will affect the growth and yield of tomato plants. Therefore, precise irrigation control is necessary during cultivation to increase crop productivity. Traditionally, the soil moisture content or leaf water potential has been used as an indicator of plant water status. These methods, however, have limited accuracy and are time-consuming, making it difficult to be put into practice in tomato production. This study developed an online hyperspectral imaging system to measure the leaf water potential of tomato nondestructively. Linear Discriminant Analysis was utilized to automatically and quickly extract the leaf images, with the recognition accuracy of 94.68% was achieved. The mathematical processing of Standard Normal Variate scattering correction was used to remove the spectral variations caused by the defocused leave images. The developed leaf water potential prediction model based on the spectral image information attained using the developed system achieved the standard error of calibration of 0.201, coefficient of determination in calibration set of 0.814 and standard error of cross-validation of 0.230, and one minus the variance ratio of 0.755. The obtained performance indicated the feasibility of applying the developed online hyperspectral imaging system as a real-time non-destructive measurement technique for the leaf water potential of tomato plants. Keywords: Hyperspectral imaging system, Machine learning, Tomato, Water potential.
Whole Farm Performance of Centrifuge Extraction of Phosphorus from Dairy Manure
Authors: Rotz C. Alan , Reiner Michael R. , Fishel Sarah K. , Church Clinton Dean
Published: April 2022

Highlights

A centrifuge can be used to extract manure phosphorus to a more concentrated form for easier transport.

Extraction for more efficient transport to distant cropland reduced production costs in a scraped manure system.

Use of a centrifuge in a flush manure system was less practical and economical due to handling of much more material.

The cost of producing highly concentrated phosphorus material for export was greater than phosphate fertilizer prices.

Abstract. As the size of dairy farms has increased, feeds produced on the farm as well as those purchased from off-farm sources can be transported long distances to feed the herd. Transporting the manure back to the cropland used to produce the feed can be difficult and uneconomical. Technology such as a centrifuge can be used to extract nutrients into a more concentrated form for more efficient transport. A dairy farm with 2000 cows and 1400 ha of land in Pennsylvania was simulated with the Integrated Farm System Model to evaluate the feasibility of extracting phosphorus (P) to reduce transport requirements on farm or to produce a concentrated P product for off-farm use. On this farm where manure must be transported to distant cropland to obtain uniform distribution, P extraction with a centrifuge provided a better ratio of nitrogen and P contents for use on nearby cropland and reduced transport costs for nutrients applied to more distant cropland. The centrifuge was found to be more practical and economical when used with manure scraped from the barn floor than with flushed manure because much less material was handled. Moving less material through the centrifuge both improved extraction efficiency and reduced electricity consumption, providing more economical P extraction. To avoid long-term accumulation of soil P on the farm with less land (2000 cows and 1100 ha) where concentrate feed (27% of total feed) was imported, centrifuge extraction provided a material with a high P concentration exported from the farm for other uses. Extracting the P for off-farm use cost about $2.51/kg P, which was greater than the price of phosphate fertilizer, but the extract also included other nutrients and micronutrients of value to crops. A centrifuge provides a useful tool for extracting and concentrating manure P, but the economic benefit to the producer depends upon the value of the full array of nutrient contents in the product, other manure handling practices, and the end use of the extracted material. Reducing the risk of eutrophication of surface waters provides additional benefit to society. Keywords: Dairy farm, Integrated Farm System Model, Manure handling, Manure management.
An Overview of the Effectiveness of Agricultural Conservation Practices for Water Quality Improvement
Authors: Yuan Yongping , Book Ruth S. , Mankin Kyle R. , Koropeckyj-Cox Lydia , Christianson Laura , Messer Tiffany , Christianson Reid
Published: April 2022

Highlights

Denitrifying bioreactor and nutrient management effectively reduced nitrate-N loads from subsurface drainage.

Constructed wetland was effective in removing total N, nitrate-N, and total P from wetland influent water.

Filter strip was the most effective practice in reducing sediment, total N, and total P loads from surface runoff.

Cover crop was effective in reducing sediment and total P loads from surface runoff.

More research is needed on conservation practice effectiveness in reducing dissolved P loss from agricultural fields.

Abstract. This article introduces a Special Collection of literature reviews documenting the performance and cost-effectiveness of six agricultural conservation practices (ACPs): conservation crop rotation, cover crop, filter strip, nutrient management, denitrifying bioreactor, and constructed wetland. The overall objectives of the Special Collection are to: (1) review published studies on ACP effectiveness in reducing nutrient and sediment losses from agricultural fields; (2) compare, integrate, and synthesize the results from those studies to obtain a systematic understanding of the mitigation efficacy of each ACP in a consistent format across the selected ACPs; and (3) assemble cost analyses and obtain general insights on performance-based costs of the ACPs. The specific objectives of this introductory article are to summarize key information from each of the six review articles and develop a comparative understanding of the performance and cost-effectiveness of the six ACPs. Among the selected ACPs, denitrifying bioreactor, constructed wetland, cover crop, crop rotation, and nutrient management were all effective in reducing nitrate-N loads in subsurface drainage, with performance effectiveness in load reduction ranging from 23% to 40%. A corn-soybean rotation (relative to continuous corn) was the most cost-effective among the selected ACPs and can reduce nitrate-N load at a net benefit of about USD $5 per kg nitrate-N compared to continuous corn. Filter strip was most effective in reducing sediment, total nitrogen (N), and total phosphorus (P) loads from surface runoff and can be effective in reducing nitrate-N and dissolved P. Cover crop was also effective in reducing sediment and total P loads. Studies of the selected ACPs for their performance effectiveness for dissolved P are limited, and results varied among the ACPs included; thus, more research is needed relative to ACP effectiveness in reducing dissolved P loss, particularly in subsurface flow. Finally, although each review article included cost-analysis information, more data and analyses are needed to better understand the cost-effectiveness of ACPs and their ecological benefits. Keywords: Constructed wetland, Cost-effectiveness, Cover crop, Crop rotation, Filter strip, Nutrient management, Denitrifying bioreactor, Reduction effectiveness.
Mechanisms of corneal intrastromal laser dissection for refractive surgery: ultra-high-speed photographic investigation at up to 50 million frames per second
Authors: Freidank Sebastian , Vogel Alfred , Linz Norbert
Published: April 2022

Every year, more than a million refractive eye surgeries using femtosecond lasers are performed but the intrastromal cutting process remains an area of development. We investigated the mechanisms of laser dissection in cornea by ultra-high-speed photography. We found that the intrastromal bubble forms multiple lobes along the elongated laser plasma and the overlying lobes expand along the corneal lamellae. Videography demonstrated that the cutting process relies on crack propagation in the stroma along the bubble lobes with the crack originating from the pre-existing bubble layer. These insights are important for further improvement of the cutting mechanisms in refractive surgery.
Analysis of filtering and refractive index sensing characteristics based on gold-coated photonic crystal fiber
Authors: Gao Zhigang , Jing Xili , Li Shuguang , Chen Hailiang , Liu Yundong , Guo Ying
Published: April 2022

A gold-coated photonic crystal fiber (PCF) with dual functions of filtering and refractive index sensing is proposed. The gold layer is deposited in two open grooves, which make it easy to manufacture. For the filtering characteristics, it can achieve high loss at the wavelength of 1550 nm. The results show that the confinement losses of the

x

- and

y

-polarized modes are 0.012 dB/cm and 445.10 dB/cm, respectively. When the crosstalk is greater than 20 dB, it shows high bandwidth of 910 nm for the PCF length of 3 mm. For the sensing characteristics, it shows a maximum sensitivity of 4000 nm/RIU for an analyte range of 1.39–1.40. It also has a high figure of merit with a maximum value of

45.45

R
I
U

−
1

and a low detection limit (56.13 nm). Owing to the excellent performance of the gold-coated PCF in filtering and sensing, it will become a suitable candidate for optical communication and sensing systems.
Airy-like beam-based light-sheet microscopy with improved FOV for zebrafish intracerebral hemorrhage
Authors: Liu Pengfei , Chen Hongyu , Pang Meijun , Liu Xiuyun , Wang JIWEI , Zhang Xiao-Dong , Ming Dong
Published: April 2022

Airy light-sheet microscopy is rapidly gaining importance for imaging intact biological specimens because of the rapid speed, high resolution, and wide field nature of the imaging method. However, the depth of field (DOF) of the detection objective imposes limitations on the modulation transfer function (MTF) of the light sheet, which in turn affects the size of the field of view (FOV). Here we present an optimized phase modulation model, based on ‘Airy-like’ beam family, to stretch the curved lobes, which brings a wider FOV while maintaining high resolution. In addition, we further develop a planar ‘Airy-like’ light-sheet by two-photon excitation which can avoid the deconvolution process. We validated the new imaging method by performing a real-time monitoring of the dynamic process of cerebral hemorrhage in zebrafish larva. The proposed Airy-like beam-based light-sheet microscopy has great potential to be applied to the precise screening of cerebral hemorrhage-related drugs to help precision medicine in the future.
Electromagnetically induced transparency based on a carbon nanotube film terahertz metasurface
Authors: Zhou Tao , Chen Suguo , Zhang Xiaoju , Zhang Xiang , Hu Hui , Wang Yue
Published: April 2022

In this work, we present a study of bright-bright mode electromagnetically induced transparency based on carbon nanotube films terahertz metasurface consisting of an array of two asymmetric split rings. Under the excitation of terahertz wave, the electromagnetically induced transparency window can be obviously observed. The simulation results agree with the theoretical results. The formation mechanism of the transparent window in bright-bright mode electromagnetically induced transparency is further analyzed. Moreover, the sensing performance of the proposed terahertz metasurface is investigated and the sensitivity can reach to 320 GHz/RIU. To verify the slow light characteristics of the device, the group delay of the terahertz metasurface is calculated and the value is 2.12 ps. The proposed metasurface device and the design strategies provide opportunities for electromagnetically induced transparency applications, such as sensors, optical memories, and flexible terahertz functional devices.
Quadratic Peregrine solitons resonantly radiating without higher-order dispersion
Authors: Bu Lili , Baronio Fabio , Chen Shihua , Trillo Stefano
Published: April 2022

We show that two-color Peregrine solitary waves in quadratic nonlinear
media can resonantly radiate dispersive waves even in the absence of
higher-order dispersion, owing to a phase-matching mechanism that
involves the weaker second-harmonic component. We give very simple
criteria for calculating the radiated frequencies in terms of material
parameters, finding excellent agreement with numerical
simulations.
Chaotic optical communications at 56 Gbit/s over 100-km fiber transmission based on a chaos generation model driven by long short-term memory networks
Authors: Jiang Lin , Feng Jiacheng , Yan Lianshan , Yi Anlin , Li Song-Sui , Yang Hui , Dong Yixian , Wang Longsheng , Wang Anbang , Wang Yuncai , Pan Wei , Luo Bin
Published: April 2022

Chaotic optical communication technology is considered as an effective secure communication technology, which can protect information from a physical layer and is compatible with the existing optical networks. At present, to realize long-distance chaos synchronization is still a very difficult problem, mainly because well-matched hardware cannot always be guaranteed between the transmitter and receiver. In this Letter, we introduce long short-term memory (LSTM) networks to learn a nonlinear dynamics model of an opto-electronic feedback loop, and then apply the trained deep learning model to generate a chaotic waveform for encryption and decryption at the transmitter and receiver. Furthermore, to improve the security, we establish a deep learning model pool which consists of different gain trained models and different delay trained models, and use a digital signal to drive chaos synchronization between the receiver and transmitter. The proposed scheme is experimentally verified in chaotic-encrypted 56-Gbit/s PAM-4 systems, and a decrypted performance below 7%FEC threshold (BER = 3.8×10−3) can be achieved over a 100-km fiber transmission.
Sub-60-fs ultralow threshold and efficient Kerr-lens mode-locked Yb,Gd:CaSrF2 laser
Authors: Su Xiancui , Wang Yiran , Li Guoru , Su Liangbi , Liu Shande , Zheng Lihe , Zhang Bingyuan , Zhang Baitao
Published: April 2022

In this Letter, using a Yb,Gd:CaSrF2 co-doping mixed crystal, an ultra-low threshold and efficient Kerr-lens mode-locked femtosecond oscillator is realized with a mode-locking threshold as low as 150 mW. With a 200-mW pump power, the shortest pulses are obtained with a pulse duration of 57 fs. A maximum mode-locked output power of 185 mW is observed under a 500-mW pump power, corresponding to an optical-to-optical efficiency of up to 37%. To the best of our knowledge, the 150-mW threshold is the lowest pump power to realize Kerr-lens mode-locking operation in Yb-doped bulk lasers. Furthermore, an optical efficiency of 37% is the highest efficiency in Yb-doped fluoride bulk lasers to date. Our results provide a new basis for high-efficiency and low-threshold Yb-doped ultrafast bulk lasers.
Handheld volumetric photoacoustic/ultrasound imaging using an internal scanning mechanism
Authors: Pang Zhan , Wang Yike , Qin Wei , Qi Weizhi , Xi Lei
Published: April 2022

Photoacoustic/ultrasound (PA/US) dual-modality imaging has been evolving rapidly for the last two decades. Handheld PA/US probes with different implementations have attracted particular attention due to their convenience and high applicability. However, developing a volumetric dual-modality PA/US imaging probe with a compact design remains a challenge. Here, we develop a handheld volumetric PA/US imaging probe with a special light–ultrasound coupling design and an internal scanning mechanism. A coaxial design for the excitation and detection paths in a customized 3D-printed housing with a size of 110 × 90 × 64 mm3 is proposed to optimize the signal-to-noise ratio (SNR) of the handheld probe for deep tissue imaging. Two parallel and synchronously rotational acoustic reflectors allow for volumetric imaging with an effective field of view (FOV) of more than 30 mm × 20 mm × 8 mm. In addition to simulation and phantom validations, in vivo human trials are successfully carried out, demonstrating the high imaging quality and stability of the system for potential clinical translations.
Ray tracing in metasurfaces
Authors: Castañeda-Almanza C. P. , Moreno Ivan
Published: April 2022

Ray tracing in a metasurface is the process to obtain the three-dimensional (3D) light path under reflection and transmission, which may be helpful in the optical design of metalenses and other metaoptical devices. In this work, first we deduce the 3D vector form of Snell's law for metasurfaces by using a geometric approach. And then, we deduce the general equations to calculate the direction of the reflected and refracted beams in any metasurface, and for any incident beam. In other words, we derive vector form equations for the 3D direction of transmitted and reflected beams at a metasurface with arbitrary 2D phase profile, and for any 3D direction of incident light.
Versatile few-cycle high-energy MID-IR OPCPA for nonlinear optics, spectroscopy and imaging
Authors: Namboodiri Mahesh , Luo Cheng , Indorf Gregor F. H. , Buss Jan H. , Schulz Michael , Riedel Robert , Prandolini Mark J. , Laarmann Tim
Published: April 2022

High-power, high-energy, ultrashort, mid-infrared (MID-IR) laser systems operating at high repetition rates are of considerable interest for many science applications, such as coherent vibrational spectroscopy, label-free imaging, time-resolved pump-probe and high-harmonic generation studies. We developed an optical parametric chirped-pulse amplifier (OPCPA) system employing a difference-frequency generation in a lithium gallium sulfide nonlinear crystal in the final amplifier stage, which provides in principle the possibility for passive carrier-envelop-phase (CEP) stability. The OPCPA efficiently down-converts a 1 μm 200 μJ Yb-YAG pump pulse into the MID-IR spectral range generating μJ-level pulses at a repetition rate of 200 kHz. Two modes of operations providing complimentary MID-IR pulse properties are presented. Depending on the envisaged application, one can switch between (a) a wavelength-tunable (4.2–11 μm) source and (b) a broadband source centered at ≈8.5 μm by controlling the group-delay dispersion of the signal pulse. The broadband, high-energy MID-IR pulses have a short pulse duration of 74±2 fs, which corresponds to only ≈3 optical cycles at the central wavelength of 8.5 μm.
Relevanz und Bedeutung der Nachhaltigkeit – Green IT/IS als Nischenthema in KMU der DACH-Region
Authors: Alsdorf Helge , Kosmol Linda , Rivera Fernandez Zaira
Published: April 2022

Seit längerem sind Green IT/IS ein Diskussionsthema und werden für Unternehmen zu einer zunehmend wichtigen Komponente auf dem Weg zu ökologischer Nachhaltigkeit. Unklar ist jedoch, wie verbreitet nachhaltige IT- und IS-Maßnahmen in der Praxis sind, mit welchem Ziel sie eingesetzt werden und wie ihre Wirkung gemessen wird. Um diese Fragen zu adressieren, haben wir eine Umfragestudie mit KMU in der deutschsprachigen DACH-Region durchgeführt. Dieser Beitrag gibt einen Einblick in die Antworten von 1535 Unternehmen und zeigt, dass die Mehrheit die ökologische Nachhaltigkeit zwar als relevant betrachtet (70,8 %), aber nur wenige (23,7 %) Kennzahlen zur Untersuchung der Nachhaltigkeit ihres Unternehmens eingeführt haben. Ein noch geringerer Teil hat Green IT- (11,2 %) oder Green IS-Praktiken (9,4 %) eingeführt. Dies deutet auf Forschungsbedarf zur erfolgreichen Einführung und Nutzung von Green IT/IS in Unternehmen und ihrem positiven Beitrag für das Unternehmen und die Umwelt hin.
Computational drug repurposing against SARS-CoV-2 reveals plasma membrane cholesterol depletion as key factor of antiviral drug activity
Authors: Barsi Szilvia , Papp Henrietta , Valdeolivas Alberto , Tóth Dániel J. , Kuczmog Anett , Madai Mónika , Hunyady László , Várnai Péter , Saez-Rodriguez Julio , Jakab Ferenc , Szalai Bence
Published: April 2022

Comparing SARS-CoV-2 infection-induced gene expression signatures to drug treatment-induced gene expression signatures is a promising bioinformatic tool to repurpose existing drugs against SARS-CoV-2. The general hypothesis of signature-based drug repurposing is that drugs with inverse similarity to a disease signature can reverse disease phenotype and thus be effective against it. However, in the case of viral infection diseases, like SARS-CoV-2, infected cells also activate adaptive, antiviral pathways, so that the relationship between effective drug and disease signature can be more ambiguous. To address this question, we analysed gene expression data from in vitro SARS-CoV-2 infected cell lines, and gene expression signatures of drugs showing anti-SARS-CoV-2 activity. Our extensive functional genomic analysis showed that both infection and treatment with in vitro effective drugs leads to activation of antiviral pathways like NFkB and JAK-STAT. Based on the similarity—and not inverse similarity—between drug and infection-induced gene expression signatures, we were able to predict the in vitro antiviral activity of drugs. We also identified SREBF1/2, key regulators of lipid metabolising enzymes, as the most activated transcription factors by several in vitro effective antiviral drugs. Using a fluorescently labeled cholesterol sensor, we showed that these drugs decrease the cholesterol levels of plasma-membrane. Supplementing drug-treated cells with cholesterol reversed the in vitro antiviral effect, suggesting the depleting plasma-membrane cholesterol plays a key role in virus inhibitory mechanism. Our results can help to more effectively repurpose approved drugs against SARS-CoV-2, and also highlights key mechanisms behind their antiviral effect.
Soil carbon sequestration through regenerative agriculture in the U.S. state of Vermont
Authors: Wiltshire Serge , Beckage Brian
Published: April 2022

This study investigates the extent to which land use and management transitions on Vermont’s farmland could sequester atmospheric carbon in the soil. We weigh the sequestration potential of several types of regenerative agricultural practices against both business as usual and afforestation scenarios using the Rothamsted Carbon Model. We split the study area into 13 Ecoregions for a finer spatial scale of analysis, with key climate, soil, and land use data specified for each. Empirical soil laboratory data are used to initialize the model to mirror current conditions under each of three agricultural land uses (crops, hay, and pasture) in each Ecoregion. We consult experts as well as the literature to parameterize the anticipated effects of alternative agricultural management practices on soil carbon inputs. In the simulation runs, we find that all non-business-as-usual scenarios sequester carbon over time, with a higher rate of sequestration in the decades immediately after a land use or management change. Among the regenerative agriculture scenarios, conversion to rotational grazing offers the highest soil carbon sequestration potential, at 1,269 kt, or 5.3% above current stocks after ten years. Of all scenarios, afforestation of farmland to non-harvested forest stores the most soil carbon, increasing stocks by 6.5% after ten years, and continuing to sequester at a high rate many decades into the future. We discuss tradeoffs and policy implications, especially in the context of the 2020 Vermont Global Warming Solutions Act, and suggest that payments for ecosystem services for farmers sequestering carbon may have strategic value.
A spatially aware likelihood test to detect sweeps from haplotype distributions
Authors: DeGiorgio Michael , Szpiech Zachary A.
Published: April 2022

The inference of positive selection in genomes is a problem of great interest in evolutionary genomics. By identifying putative regions of the genome that contain adaptive mutations, we are able to learn about the biology of organisms and their evolutionary history. Here we introduce a composite likelihood method that identifies recently completed or ongoing positive selection by searching for extreme distortions in the spatial distribution of the haplotype frequency spectrum along the genome relative to the genome-wide expectation taken as neutrality. Furthermore, the method simultaneously infers two parameters of the sweep: the number of sweeping haplotypes and the “width” of the sweep, which is related to the strength and timing of selection. We demonstrate that this method outperforms the leading haplotype-based selection statistics, though strong signals in low-recombination regions merit extra scrutiny. As a positive control, we apply it to two well-studied human populations from the 1000 Genomes Project and examine haplotype frequency spectrum patterns at theLCTand MHC loci. We also apply it to a data set of brown rats sampled in NYC and identify genes related to olfactory perception. To facilitate use of this method, we have implemented it in user-friendly open source software.