We present a novel approach for designing non-uniform binary long-period gratings with predefined transmission characteristics by directly optimizing the coupling strengths and lengths of the ...constituent waveguides in all grating segments. The optimal grating parameters were determined by minimizing the deviation of the transmission characteristics calculated using the transfer matrix method from the predefined target functions using the multistart optimization procedure. We demonstrate the effectiveness of the proposed method by optimizing the performance of grating-based TE 0 /TE 1 mode converters in a few-mode buried waveguide composed of medium-contrast materials (TiO 2 :SiO 2 /SiO 2 ). Two converters with coupling caused by the lateral shift and step-like thickness change of adjacent waveguides were numerically optimized for the 1.3 and 1.55 μm bands. Each of the optimized devices has a total length of approximately 250 μm. For both types of converters, a spectral range of 150 nm with crosstalk lower than −20 dB was obtained for the two communication windows using at most nine grating segments, with twice lower excess loss for the grating with a step-like thickness change. Moreover, for such grating composed of only 9 segments it is possible to obtain the conversion band of 400 nm, covering both communication windows with an excess loss lower than 0.45 dB and crosstalk below −20 dB. We also numerically analyzed the impact of the fabrication tolerances on the converter characteristics.
The influence of alloying additions on the microstructure, mechanical, and magnetic properties of bulk Fe
79
B
20
Cu
1
, Fe
79
B
16
Ti
4
Cu
1
, Fe
79
B
16
Mo
4
Cu
1
and Fe
79
B
16
Mn
4
Cu
1
(at. pct) ...alloys was investigated. Nanocrystalline samples in the form of 3 mm rods were prepared directly by suction casting without additional heat treatment. Mössbauer spectroscopy, transmission electron microscopy and scanning electron microscopy studies confirmed that the investigated alloys consist
α
-Fe and Fe
2
B nanograins embedded in an amorphous matrix. The addition of alloying elements, such as Ti, Mo and Mn to Fe
79
B
20
Cu
1
alloy increases the amount of amorphous phase and decreases the presence of Fe
2
B phase in all examined alloys. The mechanical properties of the samples, such as hardness, elastic modulus, and elastic energy ratio, were analysed by an instrumented indentation technique performed on a 12 × 12 nanoindentation grid. These tests allowed to characterise the mechanical properties of the regions observed in the same material. For the Fe
79
B
20
Cu
1
alloy, the hardness of 1508 and 1999 HV, as well as Young’s modulus of 287 and 308 GPa, were estimated for the amorphous- and nanocrystalline-rich phase, respectively. The addition of Ti, Mo, and Mn atoms leads to a decrease in both hardness and elastic modulus for all regions in the investigated samples. Investigations of thermomagnetic characteristics show the soft magnetic properties of the studied materials. More detailed studies of magnetisation versus magnetic field curves for the Fe
79
B
20−
x
M
x
Cu
1
(where
x
= 0 or 4; M = Ti, Mo, Mn) alloy, recorded in a wide range of temperatures, followed by the law of approach to magnetic saturation revealed the relationship between microstructure and magneto-mechanical properties.
In the past few decades, several methods concerning optical thin films have been established to facilitate the development of integrated optics. This paper provides a brief depiction of different ...techniques for implementing optical waveguide thin films that involve chemical, physical, and refractive index modification methods. Recent advances in these fabrication methods are also been presented. Most of the methods developed for the realization of the thin-films are quite efficient, but they are expensive and require sophisticated equipment. The major interest of the scientists is to develop simple and cost-effective methods for mass production of optical thin films resulting in the effective commercialization of the waveguide technology. Our research group is focused on developing a silica-titania optical waveguide platform via the sol-gel dip-coating method and implementing active and passive optical elements via the wet etching method. We are also exploring the possibility of using nanoimprint lithography (NIL) for patterning these films so that the fabrication process is efficient and economical. The recent developments of this platform are discussed. We believe that silica-titania waveguide technology developed via the sol-gel dip-coating method is highly attractive and economical, such that it can be commercialized for applications such as sensing and optical interconnects.
We present a comprehensive study of an in-line Mach-Zehnder intermodal interferometer fabricated in a boron-doped two-mode highly birefringent microstructured fiber. We observed different ...interference signals at the output of the interferometer, related to the intermodal interference of the fundamental and the first order modes of the orthogonal polarizations and a beating of the polarimetric signal related to the difference in the group modal birefringence between the fundamental and the first order modes, respectively. The proposed interferometer was tested for measurements of hydrostatic pressure and temperature for different alignments of the input polarizer with no analyzer at the output. The sensitivities to hydrostatic pressure of the intermodal interference signals for
- and
-polarizations had an opposite sign and were equal to 0.229 nm/MPa and -0.179 nm/MPa, respectively, while the temperature sensitivities for both polarizations were similar and equal 0.020 nm/°C and 0.019 nm/°C. In the case of pressure, for the simultaneous excitation of both polarization modes, we observed a displacement of intermodal fringes with a sensitivity depending on the azimuth of the input polarization state, as well as on the displacement of their envelope with a sensitivity of 2.14 nm/MPa, accompanied by a change in the fringes visibility. Such properties of the proposed interferometer allow for convenient adjustments to the pressure sensitivity of the intermodal fringes and possible applications for the simultaneous interrogation of temperature and pressure.
In the presented study, the effects of cadmium (Cd) stress and silicon (Si) supplementation on the pea plant (
Pisum sativum
L.) were investigated. The tendency to accumulate cadmium in the relevant ...morphological parts of the plant (roots and shoots respectively)—bioaccumulation, the transfer of this element in the plant (translocation) and the physiological parameters of the plant through indicators of oxidative stress were determined. Model studies were carried out at pH values 6.0 and 5.0 plant growth conditions in the hydroponic cultivation. It was shown that Cd accumulates mostly in plant roots at both pH levels. However, the Cd content is higher in the plants grown at lower pH. The Cd translocation factor was below 1.0, which indicates that the pea is an excluder plant. The contamination of the plant growth environment with Cd causes the increased antioxidant stress by the growing parameters of the total phenolic content (TPC), polyphenol oxidase activity (PPO), the malondialdehyde (MDA) and lipid peroxidation (LP). The results obtained showed that the supplementation with Si reduces these parameters, thus lowering the oxidative stress of the plant. Moreover, supplementation with Si leads to a lower content of Cd in the roots and reduces bioaccumulation of Cd in shoots and roots of pea plants.
Recent improvements in microbiology and molecular epidemiology were largely stimulated by whole- genome sequencing (WGS), which provides an unprecedented resolution in discriminating highly related ...genetic backgrounds. WGS is becoming the method of choice in epidemiology of fungal diseases, but its application is still in a pioneer stage, mainly due to the limited number of available genomes. Fungal pathogens often belong to complexes composed of numerous cryptic species. Detecting cryptic diversity is fundamental to understand the dynamics and the evolutionary relationships underlying disease outbreaks. In this study, we explore the value of whole-genome SNP analyses in identification of the pandemic pathogen
Fusarium graminearum sensu stricto
(
F.g
.). This species is responsible for cereal diseases and negatively impacts grain production worldwide. The fungus belongs to the monophyletic fungal complex referred to as
F. graminearum
species complex including at least sixteen cryptic species, a few among them may be involved in cereal diseases in certain agricultural areas. We analyzed WGS data from a collection of 99
F.g.
strains and 33 strains representing all known cryptic species belonging to the FGSC complex. As a first step, we performed a phylogenomic analysis to reveal species-specific clustering. A RAxML maximum likelihood tree grouped all analyzed strains of
F.g.
into a single clade, supporting the clustering-based identification approach. Although, phylogenetic reconstructions are essential in detecting cryptic species, a phylogenomic tree does not fulfill the criteria for rapid and cost-effective approach for identification of fungi, due to the time-consuming nature of the analysis. As an alternative, analysis of WGS information by mapping sequence data from individual strains against reference genomes may provide useful markers for the rapid identification of fungi. We provide a robust framework for typing
F.g.
through the web-based PhaME workflow available at EDGE bioinformatics. The method was validated through multiple comparisons of assembly genomes to
F.g.
reference strain PH-1. We showed that the difference between intra- and interspecies variability was at least two times higher than intraspecific variation facilitating successful typing of
F.g
. This is the first study which employs WGS data for typing plant pathogenic fusaria.
Soybean is an important, high protein source of food and feed. However, like other agricultural grains, soybean may pose a risk to human and animal health due to contamination of the grains with ...toxigenic Fusaria and associated mycotoxins. In this study, we investigated the diversity of Fusaria on a panel of 104 field isolates obtained from soybean grains during the growing seasons in 2017-2020. The results of species-specific PCR analyses showed that
was the most common (
= 40) species associated with soybean grains in Poland, followed by
(
= 22) and
(11 isolates). A set of isolates, which was not determined based on PCR analyses, was whole genome sequenced. Multiple sequence analyses using
,
,
,
,
and
genes showed that most of them belonged to Equiseti clade. Three cryptic species from this clade:
and FIESC 31 (lacking Latin binomial) were found on soybean for the first time. This is the first report demonstrating the prevalence of Fusaria on soybean grains in Poland.
Soybean yields are influenced by numerous factors, including environmental conditions, location, and agricultural practices. Sowing date affects plant growth, development, and yields, and it plays a ...particularly important role in soybean cultivation. The optimal sowing date should be selected based on soil temperature, precipitation, and rainfall distribution in a given region. The aim of this study was to determine the effect of various sowing dates (I—early, II—optimal, III—late) on the time from sowing to emergence of soybean seedlings, length of the growing season, morphological traits of soybean plants, yield components, and seed yields of soybeans grown in north-eastern Poland. Sowing date considerably affected the time from sowing to the emergence of soybean seedlings and seed yields. In north-eastern Poland, soybeans should be sown in the first half of May to minimize the risk of ground frost damage, which can occur even in late May. Sowing date also influenced soybean yields. In north-eastern Poland (Region of Warmia and Mazury), yields were maximized when soybeans were sown late (in mid-May), which was decisively influenced by climatic conditions, mainly temperature. The linear regression analysis revealed that the length of the growing season was correlated with the seed yields of soybeans sown on different dates.
Cadmium (Cd) is a key stress factor that affects plant development. To examine the influence of Cd stress, we analysed the tissue localisation of polysaccharides (Periodic Acid Schiff reaction), ...qualitative and quantitative changes in soluble carbohydrates (High-Resolution Gas Chromatography), and the expression of the galactinol synthase (PsGolS) and raffinose synthase (PsRS) genes in 4-week-old Pisum sativum L. ‘Pegaz’. The plants were treated with 10, 50, 100, and 200 µM CdSO4 for one week and analysed on the 1st, 7th, and 28th days after Cd application. Pea as an excluder plant accumulated Cd mainly in the roots. Cd induced starch grain storage in the stems and the accumulation of soluble carbohydrates in roots and shoots after 28 days of Cd treatment. In controls, soluble carbohydrate levels decreased during the plant growth. In addition, Cd increased galactinol and raffinose levels, indicating their important role in response to Cd stress in peas. Moreover, the analysis confirmed that the expression of PsGolS was induced by Cd. Overall, the results of the distribution of carbohydrates in pea plants, together with the inhibition of seed production by Cd, indicate that plants tend to allocate energy to stress response mechanisms rather than to reproductive processes.
Fusarium head blight (FHB) of cereals is the major head disease negatively affecting grain production worldwide. In 2016 and 2017, serious outbreaks of FHB occurred in wheat crops in Poland. In this ...study, we characterized the diversity of Fusaria responsible for these epidemics using TaqMan assays. From a panel of 463 field isolates collected from wheat, four
species were identified. The predominant species were
s.s. (81%) and, to a lesser extent,
(15%). The emergence of the 15ADON genotype was found ranging from 83% to 87% of the total trichothecene genotypes isolated in 2016 and 2017, respectively. Our results indicate two dramatic shifts within fungal field populations in Poland. The first shift is associated with the displacement of
by
s.s. The second shift resulted from a loss of nivalenol genotypes. We suggest that an emerging prevalence of
s.s. may be linked to boosted maize production, which has increased substantially over the last decade in Poland. To detect variation within
core clusters, we compared sequence data from randomly selected field isolates with a panel of strains from geographically diverse origins. We found that the newly emerged 15ADON genotypes do not exhibit a specific pattern of polymorphism enabling their clear differentiation from the other European strains.
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