Copper acquisition is essential for plant colonization and virulence in a root-infecting vascular wilt fungus.

Plant pathogenic fungi provoke devastating agricultural losses and are difficult to control. How these organisms acquire micronutrients during growth in the host environment remains poorly understood. Here we show that efficient regulation of copper acquisition mechanisms is crucial for plant colonization and virulence in the soilborne ascomycete Fusarium oxysporum, the causal agent of vascular wilt disease in more than 150 different crops. Using a combination of RNA-seq and ChIP-seq, we establish a direct role of the transcriptional regulator Mac1 in activation of copper deficiency response genes, many of which are induced during plant infection. Loss of Mac1 impaired growth of F. oxysporum under low copper conditions and abolishes pathogenicity on tomato plants and on the invertebrate animal host Galleria mellonella. Importantly, overexpression of two Mac1 target genes encoding a copper reductase and a copper transporter was sufficient to restore virulence in the mac1 mutant background. Our results establish a previously unrecognized role of copper reduction and uptake in fungal infection of plants and reveal new ways to protect crops from phytopathogens.

The role of matrix metalloproteinase-9 in cardiac remodeling and dysfunction and as a possible blood biomarker in heart failure.

Heart failure (HF) is the leading cause of morbidity and mortality in cardiovascular diseases, being responsible for many hospitalizations annually. HF is considered a public health problem with significant economic and social impact, which makes searches essential for strategies that improve the ability to predict and diagnose HF. In this way, biomarkers can help in risk stratification for a more personalized approach to patients with HF. Preclinical and clinical evidence shows the participation of matrix metalloproteinase 9 (MMP-9) in the HF process. In this review, we will demonstrate the critical role that MMP-9 plays in cardiac remodeling and dysfunction. We will also show its importance as a blood biomarker in acute and chronic HF patients.

Increasing the power and spectral efficiencies of an OFDM-based VLC system through multi-objective optimization.

The nonlinearity induced by light-emitting diodes in visible light communication (VLC) systems presents a challenge to the parametrization of orthogonal frequency division multiplexing (OFDM). The goal of the multi-objective optimization problem presented in this study is to maximize the transmitted power (superimposed LED bias-current and signal amplification) for both conventional and constant envelope (CE) OFDM while also maximizing spectral efficiency. The bit error rate (BER) metric is used to evaluate the optimization using the non-dominated sorting genetic algorithm II. Simulation results show that for a BER of 1×10-3, the signal-to-noise ratio (SNR) required decreases with the guard band due to intermodulation distortions. In contrast to SNR values of approximately 13 and 25 dB achieved by traditional OFDM-based systems, the VLC system with CE signals achieves a guard band of 6% of the signal bandwidth with required SNR values of approximately 10.8 and 24 dB for 4-quadrature amplitude modulation (QAM) and 16-QAM modulation orders, respectively.

Performance evaluation of a simplified power-domain NOMA for visible light communications.

The performance of a visible light communication (VLC) system based on power-domain nonorthogonal multiple access (PD-NOMA) is experimentally evaluated in this paper. The simplicity of the adopted nonorthogonal scheme is provided by the fixed power allocation method at the transmitter and the single one-tap equalization executed before the successive interference cancellation at the receiver. The experimental results proved the successful transmission of the PD-NOMA scheme with three users in VLC links of up to 2.5 m, after a proper choice of the optical modulation index. All users achieved error vector magnitude (EVM) performances below forward error correction limits in all evaluated transmission distances. At 2.5 m, the user with the best performance reaches an E V M=2.3%.

Analysis of a photonic integrated circuit for passive optical network for 5G NR.

This work presents the performance analysis of a passive optical network (PON) proposal with photonic integrated circuits (PIC). The PON architecture was simulated on MATLAB, focusing on the main functionalities of the optical line terminal, distribution network, and network unity regarded its effects on the physical layer. We show a simulated PIC, implemented on MATLAB through its analytic transfer function equation, used to implement orthogonal frequency division multiplexing in the optical domain to enhance the current optical networks for the 5G New-Radio (NR) scenario. We analyzed the OOK and optical PAM4 compared with phase modulation formats such as the DPSK and DQPSK. All modulation formats can be directly detected for the case in the study, simplifying the reception. Consequently, this work achieved a maximum symmetric transmission capacity of 1.2 Tbps over 90 km of standard single-mode fiber with 128 carriers, 64 carriers for downstream and 64 for upstream, obtained from an optical frequency comb with 0.3 dB flatness. We concluded that phase modulation formats associated with PIC could increase PON capability and push further our current scenario to the 5G new era.

Static and Dynamic Multiparameter Assessment of Structural Elements Using Chirped Fiber Bragg Gratings.

This paper presents the development, analysis, and application of chirped fiber Bragg gratings (CFBGs) for dynamic and static measurements of beams of different materials in the single-cantilever configuration. In this case, the beams were numerically analyzed using the finite-element method (FEM) for the assessment of the natural frequencies and vibration modes of the beam for the dynamic analysis of the structural element. Furthermore, the static numerical analysis was performed using a load at the free end of the beam, where the maximum strain and its distribution along the beam were analyzed, especially in the region at which the FBG was positioned. The experimental evaluation of the proposed CFBG sensor was performed in static conditions for forces from 0 to 50 N (in 10 N steps) applied at the free end of the beam, whereas the dynamic evaluation was performed by means of positioning an unbalanced motor at the end of the beam, which was excited at 16 Hz, 65 Hz, 100 Hz, and 131 Hz. The results showed the feasibility of the proposed device for the simultaneous assessment of the force and strain distribution along the CFBG region using the wavelength shift and the full-width at half-maximum (FWHM), respectively. In these cases, the determination coefficients of the spectral features as a function of the force and strain distribution were higher than 0.99 in all analyzed cases, where a potential resolution of 0.25 N was obtained on the force assessment. In the dynamic tests, the frequency spectrum of the sensor responses indicated a frequency peak at the excited frequency in all analyzed cases. Therefore, the proposed sensor device is a suitable option to extend the performance of sensors for structural health assessment, since it is possible to simultaneously measure different parameters in dynamic and static conditions using only one sensor device, which, due to its multiplexing capabilities, can be integrated with additional optical fiber sensors for the complete shape reconstruction with millimeter-range spatial resolution.

Soft-Sensor System for Grasp Type Recognition in Underactuated Hand Prostheses.

This paper presents the development of an intelligent soft-sensor system to add haptic perception to the underactuated hand prosthesis PrHand. Two sensors based on optical fiber were constructed, one for finger joint angles and the other for fingertips' contact force. Three sensor fabrications were tested for the angle sensor by axially rotating the sensors in four positions. The configuration with the most similar response in the four rotations was chosen. The chosen sensors presented a polynomial response with R2 higher than 92%. The tactile force sensors tracked the force made over the objects. Almost all sensors presented a polynomial response with R2 higher than 94%. The system monitored the prosthesis activity by recognizing grasp types. Six machine learning algorithms were tested: linear regression, k-nearest neighbor, support vector machine, decision tree, k-means clustering, and hierarchical clustering. To validate the algorithms, a k-fold test was used with a k = 10, and the accuracy result for k-nearest neighbor was 98.5%, while that for decision tree was 93.3%, enabling the classification of the eight grip types.

Liquid Level Sensor with Two FBGs Embedded in a PDMS Diaphragm: Analysis of the Linearity and Sensitivity.

This paper presents a fiber optic, liquid level sensor system based on a pair of fiber Bragg gratings (FBGs), embedded in a circular silicone (PDMS-polydimethylsiloxane) rubber diaphragm. The measurement principles of this sensor, whose diaphragm structure is about 2.2 mm thick with 45 mm in diameter, are introduced. To analyze the linearity and sensitivity of the sensor, the diaphragm was subjected to compression tests as well as to liquid level loading and unloading. The force and liquid level increase tests showed that inserting two FBGs (0.99453 for force and 0.99163 for liquid level) in the diaphragm resulted in a system with greater linearity than that with individual FBGs. This occurred where FBG1 showed 0.97684 for force and 0.98848 for liquid level and FBG2 presented 0.89461 for force and 0.93408 for liquid level. However, the compression and water level decrease tests showed that the system (R2 = 0.97142) had greater linearity with FBG2 (0.94123) and lower linearity with FBG1 (0.98271). Temperature characterization was also performed, and we found that sensitivity to FBG1 temperature variation was 11.73 pm/°C and for FGB2 it was 10.29 pm/°C. Temperature sensitivity was improved for both FBGs when compared with uncoated FBGs with typical values of 9.75 pm/°C. Therefore, the proposed FBG-based sensor system is capable of simultaneous measurement of force and temperature in a compact diaphragm-embedded system.

Doxycycline Decreases Atherosclerotic Lesions in the Aorta of ApoE-/- and Ovariectomized Mice with Correlation to Reduced MMP-2 Activity.

Atherogenic events promote changes in vessel walls, with alteration of the redox state, and increased activity of matrix metalloproteinases (MMPs). Thus, this study aims to evaluate aortic remodeling, MMP activity, and reactive oxygen species (ROS) levels after treatment with doxycycline in ApoE-/- and ovariectomized mice (OVX). Female ApoE-/--knockout mice (5 weeks) were submitted to ovariectomy surgery to induce experimental menopause. They then received chow enriched with 1% cholesterol to induce hypercholesterolemia. The animals were divided into two experimental groups: ApoE-/-/OVX vehicle and ApoE-/-/OVX doxycycline (30 mg/kg) administered by gavage once a day for 28 days (15th to the 18th week of life). Blood samples were collected to measure total cholesterol and fractions. The aorta was used for morphometry and to measure the activity and expression of MMP-2 and ROS levels. The ApoE-/-/OVX doxycycline group showed no change in total and fraction cholesterol levels. However, there was a reduction in ROS levels, MMP-2 expression, and activity that correlated with a decrease in atherosclerotic lesions relative to the ApoE-/-/OVX vehicle (p > 0.05). Therefore, we conclude that doxycycline in ApoE-/-/OVX animals promotes a reduction in atherosclerotic lesions by reducing ROS and MMP-2 activity and expression.

Polymer Optical Fiber-Based Integrated Instrumentation in a Robot-Assisted Rehabilitation Smart Environment: A Proof of Concept.

Advances in robotic systems for rehabilitation purposes have led to the development of specialized robot-assisted rehabilitation clinics. In addition, advantageous features of polymer optical fiber (POF) sensors such as light weight, multiplexing capabilities, electromagnetic field immunity and flexibility have resulted in the widespread use of POF sensors in many areas. Considering this background, this paper presents an integrated POF intensity variation-based sensor system for the instrumentation of different devices. We consider different scenarios for physical rehabilitation, resembling a clinic for robot-assisted rehabilitation. Thus, a multiplexing technique for POF intensity variation-based sensors was applied in which an orthosis for flexion/extension movement, a modular exoskeleton for gait assistance and a treadmill were instrumented with POF angle and force sensors, where all the sensors were integrated in the same POF system. In addition, wearable sensors for gait analysis and physiological parameter monitoring were also proposed and applied in gait exercises. The results show the feasibility of the sensors and methods proposed, where, after the characterization of each sensor, the system was implemented with three volunteers: one for the orthosis on the flexion/extension movements, one for the exoskeleton for gait assistance and the other for the free gait analysis using the proposed wearable POF sensors. To the authors' best knowledge, this is the first time that optical fiber sensors have been used as a multiplexed and integrated solution for the simultaneous assessment of different robotic devices and rehabilitation protocols, where such an approach results in a compact, fully integrated and low-cost system, which can be readily employed in any clinical environment.

Transcriptome analysis of Aspergillus niger xlnR and xkiA mutants grown on corn Stover and soybean hulls reveals a highly complex regulatory network.

BACKGROUND: Enzymatic plant biomass degradation by fungi is a highly complex process and one of the leading challenges in developing a biobased economy. Some industrial fungi (e.g. Aspergillus niger) have a long history of use with respect to plant biomass degradation and for that reason have become 'model' species for this topic. A. niger is a major industrial enzyme producer that has a broad ability to degrade plant based polysaccharides. A. niger wild-type, the (hemi-)cellulolytic regulator (xlnR) and xylulokinase (xkiA1) mutant strains were grown on a monocot (corn stover, CS) and dicot (soybean hulls, SBH) substrate. The xkiA1 mutant is unable to utilize the pentoses D-xylose and L-arabinose and the polysaccharide xylan, and was previously shown to accumulate inducers for the (hemi-)cellulolytic transcriptional activator XlnR and the arabinanolytic transcriptional activator AraR in the presence of pentoses, resulting in overexpression of their target genes. The xlnR mutant has reduced growth on xylan and down-regulation of its target genes. The mutants therefore have a similar phenotype on xylan, but an opposite transcriptional effect. D-xylose and L-arabinose are the most abundant monosaccharides after D-glucose in nearly all plant-derived biomass materials. In this study we evaluated the effect of the xlnR and xkiA1 mutation during growth on two pentose-rich substrates by transcriptome analysis. RESULTS: Particular attention was given to CAZymes, metabolic pathways and transcription factors related to the plant biomass degradation. Genes coding for the main enzymes involved in plant biomass degradation were down-regulated at the beginning of the growth on CS and SBH. However, at a later time point, significant differences were found in the expression profiles of both mutants on CS compared to SBH. CONCLUSION: This study demonstrates the high complexity of the plant biomass degradation process by fungi, by showing that mutant strains with fairly straightforward phenotypes on pure mono- and polysaccharides, have much less clear-cut phenotypes and transcriptomes on crude plant biomass.

l-Arabinose induces d-galactose catabolism via the Leloir pathway in Aspergillus nidulans.

l-Arabinose and d-galactose are the principal constituents of l-arabinogalactan, and also co-occur in other hemicelluloses and pectins. In this work we hypothesized that similar to the induction of relevant glycoside hydrolases by monomers liberated from these plant heteropolymers, their respective catabolisms in saprophytic and phytopathogenic fungi may respond to the presence of the other sugar to promote synergistic use of the complex growth substrate. We showed that these two sugars are indeed consumed simultaneously by Aspergillus nidulans, while l-arabinose is utilised faster in the presence than in the absence of d-galactose. Furthermore, the first two genes of the Leloir pathway for d-galactose catabolism - encoding d-galactose 1-epimerase and galactokinase - are induced more rapidly by l-arabinose than by d-galactose eventhough deletion mutants thereof grow as well as a wild type strain on the pentose. d-Galactose 1-epimerase is hyperinduced by l-arabinose, d-xylose and l-arabitol but not by xylitol. The results suggest that in A. nidulans, l-arabinose and d-xylose - both requiring NADPH for their catabolisation - actively promote the enzyme infrastructure necessary to convert ß-d-galactopyranose via the Leloir pathway with its α-anomer specific enzymes, into ß-d-glucose-6-phosphate (the starting substrate of the oxidative part of the pentose phosphate pathway) even in the absence of d-galactose.

Long period grating in a multimode cyclic transparent optical polymer fiber inscribed using a femtosecond laser.

In this Letter, we report, to the best of our knowledge, the first inscription of long period gratings (LPGs) in a multimode cyclic transparent optical polymer (CYTOP) fiber using a femtosecond laser inscription method. The LPG was inscribed directly in the center of the fiber core, tailored for operation at 1560 nm. The CYTOP-LPG was characterized in transmission, and its response for relative humidity and temperature was measured. The humidity measurements, to the best our knowledge, are the first for a POF-LPG, whereas the temperature sensitivity is significantly higher than reported in other works. In addition, dynamic mechanical measurements were performed comparing the mechanical characteristics of the laser exposed sections of the polymer fiber, where the LPG was inscribed, with the unexposed regions.

Stable dark pulses produced by a graphite oxide saturable absorber in a fiber laser cavity.

In this paper, we report for the first time, to the best of our knowledge, the experimental generation of dark pulses in the 1.5 µm band from a passively $Q$Q-switched fiber laser employing graphite oxide as the saturable absorber, generating tunable microsecond pulses with kHz repetition rates. The graphite oxide samples were obtained by recycling the graphite present in Li-ion batteries used in cell phones through a chemical separation and oxidation process. Sample characterization employing x-ray diffraction, solid-state $ ^{{13}}{\rm C} $13C nuclear magnetic resonance, and Raman spectroscopy showed that the produced graphite oxide exhibited a homogeneously oxidized structure. Dark pulse emission could be observed at a relatively low pump threshold of 35 mW in a short 20 m laser cavity, indicating that the graphite oxide acted as a saturable absorber, significantly enhancing the nonlinearity of the laser cavity. Additionally, dark pulse operation was demonstrated at a high stability with a signal-to-noise ratio of 56 dB and a pulse-to-pulse timing jitter of 159.84 fs.

3D-Printing Techniques on the Development of Multiparameter Sensors Using One FBG.

We report the development of a fiber Bragg grating (FBG) sensor for multiparameter sensing using only one FBG. The FBG was half-embedded in a 3D-printed structure, which resulted in a division of the grating spectrum creating two peaks with different sensitivities with respect to different physical parameters. A numerical analysis of the proposed technique was performed using the coupled-mode theory with modified transfer matrix formulation. Then, experimental analyses were performed as function of temperature, strain and force, where the peaks showed different sensitivities in all analyzed cases. Such results enable the application of a technique for simultaneous measurement of multiple physical parameters using both peaks and the full width half maximum of the FBG embedded in a 3D structure. In the simultaneous multiparameter assessment, the proposed sensor system was able to estimate the three tested parameters (strain, temperature and force) with relative errors as low as 4%.

Polymer Optical Fiber Sensors in Healthcare Applications: A Comprehensive Review.

Advances in medicine and improvements in life quality has led to an increase in the life expectancy of the general population. An ageing world population have placed demands on the use of assistive technology and, in particular, towards novel healthcare devices and sensors. Besides the electromagnetic field immunity, polymer optical fiber (POF) sensors have additional advantages due to their material features such as high flexibility, lower Young's modulus (enabling high sensitivity for mechanical parameters), higher elastic limits, and impact resistance. Such advantages are well-aligned with the instrumentation requirements of many healthcare devices and in movement analysis. Aiming at these advantages, this review paper presents the state-of-the-art developments of POF sensors for healthcare applications. A plethora of healthcare applications are discussed, which include movement analysis, physiological parameters monitoring, instrumented insoles, as well as instrumentation of healthcare robotic devices such as exoskeletons, smart walkers, actuators, prostheses, and orthosis. This review paper shows the feasibility of using POF sensors in healthcare applications and, due to the aforementioned advantages, it is possible to envisage a further widespread use of such sensors in this research field in the next few years.

Perrogator: A Portable Energy-Efficient Interrogator for Dynamic Monitoring of Wavelength-Based Sensors in Wearable Applications.

In this paper, we report the development of a portable energy-efficient interrogator (Perrogator) for wavelength-based optical sensors. The interrogator is based on a compact solution encompassing a white light source and the spectral convolution between the sensor and a tunable filter, which is acquired by a photodetector, where a microcontroller has two functions: (i) To control the filter tuning and to (ii) acquire the photodetector signal. Then, the data is sent to a single-board computer for further signal processing. Furthermore, the employed single-board computer has a Wi-Fi module, which can be used to send the sensors data to the cloud. The proposed approach resulted in an interrogator with a resolution as high as 3.82 pm (for 15.64 nm sweeping range) and maximum acquisition frequency of about 210 Hz (with lower resolution ~15.30 pm). Perrogator was compared with a commercial fiber Bragg grating (FBG) interrogator for strain measurements and good agreement between both devices was found (1.226 pm/µÎµ for the commercial interrogator and 1.201 pm/µÎµ for the proposed approach with root mean square error of 0.0144 and 0.0153, respectively), where the Perrogator has the additional advantages of lower cost, higher portability and lower energy consumption. In order to demonstrate such advantages in conjunction with the high acquisition frequency allowed us to demonstrate two wearable applications using the proposed interrogation device over FBG and Fabry-Perot interferometer (FPI) sensors. In the first application, an FBG-embedded smart textile for knee angle assessment was used to analyze the gait of a healthy person. Due to the capability of reconstructing the FBG spectra, it was possible to employ a technique based on the FBG wavelength shift and reflectivity to decouple the effects of the bending angle and axial strain on the FBG response. The measurement of the knee angle as well as the estimation of the angular and axial displacements on the grating that can be correlated to the variations of the knee center of rotation were performed. In the second application, a FPI was embedded in a chest band for simultaneous measurement of breath and heart rates, where good agreement (error below 5%) was found with the reference sensors in all analyzed cases.

Blocking hexose entry into glycolysis activates alternative metabolic conversion of these sugars and upregulates pentose metabolism in Aspergillus nidulans.

BACKGROUND: Plant biomass is the most abundant carbon source for many fungal species. In the biobased industry fungi, are used to produce lignocellulolytic enzymes to degrade agricultural waste biomass. Here we evaluated if it would be possible to create an Aspergillus nidulans strain that releases, but does not metabolize hexoses from plant biomass. For this purpose, metabolic mutants were generated that were impaired in glycolysis, by using hexokinase (hxkA) and glucokinase (glkA) negative strains. To prevent repression of enzyme production due to the hexose accumulation, strains were generated that combined these mutations with a deletion in creA, the repressor involved in regulating preferential use of different carbon catabolic pathways. RESULTS: Phenotypic analysis revealed reduced growth for the hxkA1 glkA4 mutant on wheat bran. However, hexoses did not accumulate during growth of the mutants on wheat bran, suggesting that glucose metabolism is re-routed towards alternative carbon catabolic pathways. The creAΔ4 mutation in combination with preventing initial phosphorylation in glycolysis resulted in better growth than the hxkA/glkA mutant and an increased expression of pentose catabolic and pentose phosphate pathway genes. This indicates that the reduced ability to use hexoses as carbon sources created a shift towards the pentose fraction of wheat bran as a major carbon source to support growth. CONCLUSION: Blocking the direct entry of hexoses to glycolysis activates alternative metabolic conversion of these sugars in A. nidulans during growth on plant biomass, but also upregulates conversion of other sugars, such as pentoses.

The physiology of Agaricus bisporus in semi-commercial compost cultivation appears to be highly conserved among unrelated isolates.

The white button mushroom Agaricus bisporus is one of the most widely produced edible fungus with a great economical value. Its commercial cultivation process is often performed on wheat straw and animal manure based compost that mainly contains lignocellulosic material as a source of carbon and nutrients for the mushroom production. As a large portion of compost carbohydrates are left unused in the current mushroom cultivation process, the aim of this work was to study wild-type A. bisporus strains for their potential to convert the components that are poorly utilized by the commercial strain A15. We therefore focused our analysis on the stages where the fungus is producing fruiting bodies. Growth profiling was used to identify A. bisporus strains with different abilities to use plant biomass derived polysaccharides, as well as to transport and metabolize the corresponding monomeric sugars. Six wild-type isolates with diverse growth profiles were compared for mushroom production to A15 strain in semi-commercial cultivation conditions. Transcriptome and proteome analyses of the three most interesting wild-type strains and A15 indicated that the unrelated A. bisporus strains degrade and convert plant biomass polymers in a highly similar manner. This was also supported by the chemical content of the compost during the mushroom production process. Our study therefore reveals a highly conserved physiology for unrelated strains of this species during growth in compost.

Temporal transcriptome analysis of the white-rot fungus Obba rivulosa shows expression of a constitutive set of plant cell wall degradation targeted genes during growth on solid spruce wood.

The basidiomycete white-rot fungus Obba rivulosa, a close relative of Gelatoporia (Ceriporiopsis) subvermispora, is an efficient degrader of softwood. The dikaryotic O. rivulosa strain T241i (FBCC949) has been shown to selectively remove lignin from spruce wood prior to depolymerization of plant cell wall polysaccharides, thus possessing potential in biotechnological applications such as pretreatment of wood in pulp and paper industry. In this work, we studied the time-course of the conversion of spruce by the genome-sequenced monokaryotic O. rivulosa strain 3A-2, which is derived from the dikaryon T241i, to get insight into transcriptome level changes during prolonged solid state cultivation. During 8-week cultivation, O. rivulosa expressed a constitutive set of genes encoding putative plant cell wall degrading enzymes. High level of expression of the genes targeted towards all plant cell wall polymers was detected at 2-week time point, after which majority of the genes showed reduced expression. This implicated non-selective degradation of lignin by the O. rivulosa monokaryon and suggests high variation between mono- and dikaryotic strains of the white-rot fungi with respect to their abilities to convert plant cell wall polymers.