Diagnostic Bands Research Articles

Differentiating between Natural and Modified Cellulosic Fibres Using ATR-FTIR Spectroscopy

This paper presents the limitations and potential of ATR-FTIR spectroscopy applied to the study of cellulosic textile collections. The technique helps to differentiate natural fibres according to the content of lignin, pectin, hemicellulose, and wax, although some problematic issues should be considered. The spectral differences derived from the environmental humidity uptake and the plant composition are reviewed and discussed in the light of new experimental data. Diagnostic bands are proposed that can discriminate between different fibres from different plants. The contribution of ageing is also considered, demonstrating that sometimes aged fibres cannot be reliably recognised. In contrast, the potential of ATR-FTIR spectroscopy to discriminate between natural and modified fibres is discussed and proven. The best results were obtained when microinvasive ATR-FTIR spectroscopy was coupled with SEM observations. The proposed protocol was tested on microsamples of various cellulosic materials from traditional Japanese samurai armours dating from the 16th to the 20th centuries (Morigi Collection, Museo delle Culture, Lugano, Switzerland). The results facilitated a complete characterisation of the materials and demonstrated that the protocol can be used to study a wide variety of cellulosic materials, including both natural and man-modified fibres, and paper.

Fourier Transform Infrared Spectroscopy in the Study of Discrimination of Lobular Breast Cancers.

The early diagnosis of breast cancer plays an important role in reducing mortality and optimizing the prognosis of the disease. The existing visual and histopathological methods do not give any information at a molecular level. Fourier transform infrared spectroscopy does not require any preparation, such as fixation and histological stains. The collected infrared spectral "biomarker bands" give information at a molecular level and could be used for biomarker screening, in order to minimize the false-positive or false-negative results. For this prospective study, nine biopsies of lobular carcinoma (7 in situ and 2 invasive) and the adjacent healthy region of the biopsies were used. Each infrared spectrum consisted of 120 scans/spectrum (120 co-added spectra) at a spectral resolution of 4 cm -1 . The infrared spectral analysis revealed three important "diagnostic spectral regions" between 3,300-2,850 cm -1 , 1,700-1,500 cm -1 , and 850-800 cm -1 , which are related to membrane, collagen, and DNA configuration damage, respectively. The shift of the absorption band at 1,161 cm -1 at higher wave numbers up to 1,172 cm -1 is assigned to vC-O-C bonds due to membrane, protein, and DNA glycosylation. The "biomarker bands" at 1,172 cm -1 can be used as "diagnostic marker bands" for cancer progression. The shift of the absorbance band at 825 cm -1 of the native configuration of B-DNA to lower wavenumbers at 810 cm -1 Z-DNA in grade III, suggests the irreversible stage of the disease. The detection and possibility to differentiate the DNA structures may allow detection of carcinogenesis at the early stage of the disease, and development of new anticancer therapies.

Probing the surface environment of large T-type asteroids

Context. The thermal and radiative environments encountered by asteroids have shaped their surface features. Recent observations have focused on asteroids in the main belt and showed indications for ices and organics in the interiors of the asteroids that were likely significant on prebiotic Earth. They stand out in reflectance spectra as darker, redder colours than most colocated asteroids. Aims. We probe the surface environment of large (>80km in diameter) T-type asteroids. This taxonomic type is relatively ill-constrained as an independent group. We discuss their place of origin based on our probing. Methods. We performed spectroscopic observations of two T-type asteroids, (96) Aegle and (570) Kythera, over the L band (2.8–4.0 µm) using the Subaru telescope. The spectra of other T-type asteroids are available in the literature, as are survey datasets. Based on this, we strove to find commonalities and global trends in this group. We also used the archival polarimetric data of the asteroids and meteorite spectra from laboratory experiments to constrain their surface texture and composition. Results. Our targets exhibit red L-band continuum slopes, (0.30±0.04) µm−1 for (96) Aegle and (0.31 ± 0.03) µm−1 for (570) Kythera, that are similar to those of (1) Ceres and 67P/Churyumov-Gerasimenko, and have an OH-absorption feature with band centres <2.8 µm. For (96) Aegle, we find an indication of a shallow N–H band near 3.1 µm and a C–H band of organic materials over 3.4–3.6 µm, whereas no diagnostic bands of water ice and other volatiles exceeding the noise of the data were seen for both asteroids. The large T-type asteroids except for (596) Scheila display spectral shapes similar to those of to our targets. About 50% of large T-type asteroids contain an absorption band near 0.6−0.65 µm that is likely associated with hydrated minerals. For T-type asteroids (except for Jupiter Trojans) of all sizes, we found a weak correlation that the smaller the diameter and the closer to the Sun, the redder the visible (0.5−0.8 µm) slope. Conclusions. The 2.9 µm band depths of large T-type asteroids suggest that they might have experienced aqueous alteration comparable to Ch-type asteroids, but that it was more intense than for most of the main-belt asteroids. The polarimetric phase curve of the T-type asteroids is well described by a particular surface structure. The 0.5−4.0 µm reflectance spectra of large T-type asteroids appear most similar to those of CI chondrites with grain sizes of ~25−35 µm. Taken as a whole, we propose that large T-type asteroids may have been dislodged roughly around 10 au in the early Solar System.

Exploring the capability of Gaofen-5 hyperspectral data for assessing soil salinity risks

Soil salinization has hampered the achievement of sustainable development goals (SDGs) in many countries worldwide. Several countries have recently launched hyperspectral remote sensing satellites, opening new avenues for accurate soil-salinity monitoring. Among them, Gaofen-5 (GF-5) from China has a high comprehensive performance, including a spectral resolution of 5 nm, 330 bands, and signal-to-noise ratio of 700. However, the potential of GF-5 for estimating soil salinity is not well understood. In this study, we proposed a strategy that includes bootstrap methods, fractional order derivative (FOD) techniques and decision-level fusion models to exploit the soil salinity diagnostic information and reduce estimation uncertainty in the Ebinur Lake oasis in northwestern China. The results showed that the GF-5 data were suitable for assessing soil salinity. The FOD technique enhanced the correlation between soil salinity and spectra, identified more diagnostic bands, improved the accuracy of soil salinity estimation, and reduced model uncertainty. The low-order FOD outperformed the high-order FOD. The spectra processed by the 0.9 order derivative were the most correlated with soil salinity (r = −0.76). The model driven by the 0.8 order derivative produced the optimal estimated model (R2 = 0.95, root mean square error (RMSE) = 3.20 dS m−1 and a ratio of performance to interquartile distance (RPIQ) = 5.96). The model driven by the 0.8 order derivative had less uncertainty than the models based on the original and integer-order derivative (first- and second- derivatives) spectra. This study provides a reference for estimating soil salinity from GF-5 data using the proposed framework with low uncertainty and high accuracy. GF-5 data have great potential for assessing environmental problems and facilitating further SDGs.

Classification of pine wilt disease at different infection stages by diagnostic hyperspectral bands

Pine wilt disease (PWD) is a very destructive forest disease that causes the mortality of pine. The infected trees usually die within three months, and the disease spreads fast with the long-horned beetle as the medium if the infected trees are not removed from the forest in time. Therefore, detecting the infected trees at different infection stage, especially the early infection, is crucial for preventing PWD spread. This study aims to exhibit the spectral differences of the pine needles between healthy pines and infected pines at different infection stages and reveal the diagnostic spectral bands for classifying the different infected stage trees. We collected needle samples from healthy, early-, middle-, late-stage infected trees in a Japanese pine (Pinus densiflora) forest and a Korean pine (Pinus koraiensis) forest in northern China to explore the spectral and biochemical properties differences of these four classes, and selected the sensitive bands combining competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA). The selected bands were used for the four infection stages classification by linear discriminant analysis (LDA) algorithm. The results show that Chlorophyll a, chlorophyll b, carotenoids, and moisture content decreases with the aggravation of infection. The green (510–530 nm), red-edge (680–760 nm), and short-wave infrared (1400–1420 nm and 1925–1965 nm) bands are the sensitive bands, and the overall accuracy is 77 % and 78 % for the Japanese pine and Korean pine respectively when using these bands for classifying healthy, early-, middle-, late-stage infected trees. The results demonstrate that physiological parameters including Chlorophyll a, chlorophyll b, carotenoids, and moisture content can be used as the diagnostic parameters of PWD, and the selected sensitive spectral bands are feasible for detecting the stress symptoms of the Japanese pine and Korean pine.

A rapid, simple, and reliable assay to authenticate Peruvian kiwicha (A. caudatus) for food applications

Amaranth has acquired great economic impact as functional food, with species originating from Mexico dominating global trade. In contrast, the Peruvian A. caudatus (kiwicha) has been vastly neglected, although it is endowed with very promising nutritive traits. Morphological plasticity and taxonomic ambiguities render authentication of Amaranth difficult, such that the identity of commercial samples is often unclear. To safeguard the authenticity of kiwicha and, thus, consumer safety, we characterised a germplasm collection of 84 Amaranth accessions on both, the morphological and the genetic level. We show that kiwicha can be delineated phenotypically from other species by its late flowering, taller posture, and lower grain yields. Instead, flower and seed color, often used as proxy for identity, do not qualify as taxonomic markers. Using the plastidic barcoding marker psbA-trnH igs we were able to identify a specific Single Nucleotide Polymorphism (SNP) that separated kiwicha from all other species of Amaranth. This allowed us to develop a sequencing-free authentication assay using an Amplified Refractory Mutation System (ARMS) strategy. As a result kiwicha in commercial samples can be authenticated by a single duplex-PCR yielding a diagnostic side band reporting A. caudatus against all other species of Amaranthus. This fingerprinting assay will help to develop the nutritive potential of kiwicha and to safeguard seed material for A. caudatus against adulteration by the far more prevalent species from Mexico.

Microwave method based on curve fitting method for high-precision collision frequency diagnosis

In this work, the results of plasma microwave transmission diagnosis were analyzed. According to the attenuation and phase shift of the electromagnetic wave propagating in the plasma, the electron density and collision frequency of the plasma can be diagnosed. Since part of the electromagnetic wave is reflected or diffracted when propagating in the plasma, and is not absorbed by the plasma, and this part of the attenuation is still included in the measured attenuation, the attenuation is distorted. Therefore, a curve fitting method is proposed to remove the attenuation caused by the plasma reflection, thereby improving the accuracy of the diagnosis of the collision frequency. The calibration effect of this method on plasmas with different electron densities and collision frequencies is analyzed, and a diagnostic frequency band with good calibration results is given. The curve fitting method is verified by experiment and simulation. After adopting the newly proposed method, the diagnosis accuracy of collision frequency can be increased by 30%. This method can be widely used in various types of plasma diagnosis and provides a new idea for plasma diagnosis.

Spectral-spatial multi-layer perceptron network for hyperspectral image land cover classification

ABSTRACT This paper proposes a novel spectral-spatial multi-layer perceptron network for hyperspectral image land cover classification. Current deep learning-based methods have limitations in spectral and spatial feature representation of hyperspectral images, and these shortcomings will severely restrict the hyperspectral image classification performance. The proposed spectral-spatial multi-layer perceptron network exclusively utilizes multi-layer perceptron to represent and classify hyperspectral images. Specifically, the spectral multi-layer perceptron is investigated to model the long-range dependencies along the spectral dimension, because all diagnostic spectral bands contribute to classification performance. Then, we exploit the spatial multi-layer perceptron to extract local spatial features from hyperspectral data, which are also crucial for land cover classification. Furthermore, global spectral characteristics and local spatial features are integrated to perform the hyperspectral image spectral-spatial classification. Three benchmark hyperspectral datasets are employed for comparative classification experiments and ablation study, and experimental results certify the effectiveness and advancement of the proposed model in terms of collaborative classification accuracy.

Development and validation of sex-specific markers in Piaractus mesopotamicus

The development of genetic markers for genomic screening is essential for addressing more accurate breeding programs in aquaculture and to ascertain the genetic architecture of productive traits, particularly the mechanisms underlying sex determination in fish. Sex determination systems display huge variation in fish, ranging from those strictly determined by genetic factors to others influenced by environmental ones. Understanding the genetic basis of sex determination is important in aquaculture, because economically valuable traits are usually associated with sex. Piaractus mesopotamicus, popularly known as pacu, is a freshwater neotropical native fish of major importance for South American aquaculture. Despite its commercial importance, genomic information about this species is limited. Available information indicates that genetic breeding programs could be essential for improving production in pacu and to adjust to market demands. Growth rate is currently the main target for pacu farming and it shows sex dimorphism, with females growing faster than males. Since pacu lacks morphological sex dimorphism, it would be useful to develop a simple cost-effective technique for sexual identification. In this study, we searched for genomic regions including markers associated with sex which allowed designing a simple PCR protocol for sex identification. First, we assembled de novo a reference genome for P. mesopotamicus from a male. Then, we performed a genome-wide association study (GWAS) by re-sequencing 59 females and 74 males taking the assembled genome as a reference. More than 12 millions variable sites were identified, mostly single nucleotide polymorphisms (SNP). After filtering SNPs by p-value, we selected four contigs that contained those pre-selected sites, to which a read coverage analysis was performed. Thus, we were able to identify one indel (insertion / deletion) associated with sex and two regions that only were observed in male genomes. Finally, three pairs of primers spanning those regions were designed and tested, obtaining sex diagnostic bands of females and males. These markers were validated on a large sample, confirming their usefulness for sexual identification in pacu.

Discovery of Stishovite in the Prismatine-Bearing Granulite from Waldheim, Germany: A Possible Role of Supercritical Fluids of Ultrahigh-Pressure Origin

For the first time in the sixty years since the synthesis of stishovite, we report unambiguous evidence of stishovite formed in the deep Earth. A minimum pressure of about 7.5 GPa at 1000 °C is necessary for the formation of stishovite, corresponding to a depth of about 230 km. In this manuscript we report the identification of stishovite along with coesite as inclusions in mineral grains from the Waldheim granulite. This implies that the stishovite was transported upwards, probably very rapidly to a depth of about 130 km, corresponding to the highest pressure indicated by newly identified coesite in the prismatine of the Waldheim granulite, and continuing up to the depth of emplacement of the Waldheim prismatine granulite. The analysis of the Raman spectra obtained from a metastable trapped stishovite micro-crystal show that all the diagnostic Raman bands are present. However, given the metastability of the stishovite at room temperatures and pressures, this mineral breaks down step-by-step into stable polymorphs, first coesite and then quartz and cristobalite, during the Raman stimulation. The rare coesite crystals in prismatine have also resulted from the irreversible transformation from stishovite. Although the Waldheim occurrence may be unique, we suggest that Raman analysis of co-trapped crystals in similar deep-seated rocks, an area of limited previous research, may prove an important innovation in the study of mantle processes.

Fast outdoor screening and discrimination of carotenoids of halophilic microorganisms using miniaturized Raman spectrometers

Eight miniaturized Raman spectrometers were used to perform a fast outdoor screening and discrimination of carotenoids of a series of halophilic and non-halophilic microorganisms on a set of eight lyophilized samples, each containing high concentrations of a specific dominant carotenoid pigment. Raman spectra were acquired using different excitations (532, 785, sequentially shifted excitation of 785 and 853, and 1064 nm), based on the model of each Raman spectrometer, in order to ascertain the feasibility of individual wavelengths. The wavenumber positions of diagnostic Raman bands of carotenoids were observed for the different carotenoid species. Characteristic carotenoid Raman bands of the pigment bacterioruberin were reported (using the 532 nm excitation) at 1504–1509 cm−1, salinixanthin at 1510–1513 cm−1, spirilloxanthin at 1509–1513 cm−1, decaprenoxanthin at 1519 cm−1, β–carotene at 1526 cm−1, and sarcinaxanthin at 1526–1528 cm−1. A 532 nm excitation consistently provided best results due to the significant resonance signal enhancement (both quantitative and qualitative carotenoid detection). Good results were also obtained using the sequentially shifted excitation combining two lasers in the near infrared spectral region, and similarly good results were acquired using a standard 1064 nm excitation. The least suitable was a 785 nm excitation, with the carotenoid Raman signal almost always weaker compared to major fluorescence signal arising from other types of pigments or biomolecules in the samples. A thorough light shielding was essential in order to acquire good quality data. This study shows that miniaturized Raman spectrometers, some even equipped with longer wavelength excitation, are able to detect different carotenoid pigments under non-laboratory conditions in a fast way, and discriminate between them, to a certain degree. The implications of this type of research are especially useful in astrobiology, where the searching, detection and discrimination of biomarkers such as carotenoids is receiving significant attention.

Chagas Immunochromatographic Rapid Test in the Serological Diagnosis of Trypanosoma cruzi Infection in Wild and Domestic Canids.

Canis lupus familiaris (domestic dog) represents a reliable sentinel for the occurrence of a well-established transmission cycle of Trypanosoma cruzi among wild mammals in the surroundings and, consequently, where the risk of human infection exists. Serological diagnosis is the chosen method to identify T. cruzi infection in dogs that, in Brazil, rarely present positive parasitological tests. The use of recombinant chimeric parasitic antigens results in a sensitive and specific serological diagnostic test in contrast to the use of crude T. cruzi antigens. Our objective was to evaluate the Chagas/Bio-Manguinhos Lateral Flow Immunochromatographic Rapid Test (Chagas-LFRT) for the diagnosis of T. cruzi infection in domestic dogs and the potential of application of this diagnostic platform to wild canid species. Two recombinant proteins (IBMP-8.1 and IBMP-8.4) that displayed the best performance in the enzyme immunoassay (ELISA) in previous studies were tested in a platform with two diagnostic bands. A panel of 281 dog serum samples was evaluated: 133 positive for T. cruzi by serological diagnosis, including 20 samples with positive blood cultures belonging to different discrete typing units (DTUs); 129 negative samples; and 19 samples from dogs infected by other trypanosomatids: Leishmania infantum, Trypanosoma rangeli, Trypanosoma caninum and Crithidia mellificae, in addition to samples infected by Anaplasma platys, Dirofilaria immitis and Erlichia sp. that were employed to evaluate eventual cross-reactions. We also evaluated the Chagas-LFRT to detect T. cruzi infection in 9 serum samples from six wild canid species. We observed that the intensity pattern of the bands was directly proportional to the serological titer observed in IFAT. The sensitivity was 94%, the specificity was 91% according to the ROC curve, and the defined cutoff was an optical density of 4.8. The agreement obtained was considered substantial by the kappa analysis (84%). From T. cruzi positive hemoculture samples, 88.9% were positive by Chagas-LFRT. The test was efficient in recognizing infections by five of the six T. cruzi DTUs. Cross-reactions were not observed in infections by L. infantum, T. rangeli, T. caninum and D. immitis; however, they were observed in sera of dogs infected by Crithidia mellificae, Anaplasma sp. and Erlichia sp. A strong reaction was observed when serum samples from wild canids were submitted to the Protein A affinity test, confirming its applicability for these species. This test will allow rapid preventive actions in areas with high risk to the emergence of Chagas disease in a safer, reliable, low-cost and immediate manner, without the need for more complex laboratory tests.

Synthesis, Spectral Study and Theoretical Treatment of 2-(2-(4-bromocyclohexa-1, 3-dienyl)-4-oxo-2H- benz [1, 3] oxazin-3(4H)-ylamino)-2-oxoethyl carbamimidothioate and Derivatives.

The standard heat of formation (ΔHof) and binding energy (ΔEb) for the free compound and their derivatives are calculated by using the PM3 method at 273K of Hyperchem.-8.07 program. The compound is more stable than their derivatives. furthermore to investigate the reactive site of the molecules the electrostatic potential of free derivatives is measured and pm3 is used to evaluate the vibrational spectra of the free derivatives, the frequencies are obtained approximately agreed with those values experimentally found; in addition, the calculation helps to assign clearly the most diagnostic bands .

Deep Hierarchical Vision Transformer for Hyperspectral and LiDAR Data Classification.

In this study, we develop a novel deep hierarchical vision transformer (DHViT) architecture for hyperspectral and light detection and ranging (LiDAR) data joint classification. Current classification methods have limitations in heterogeneous feature representation and information fusion of multi-modality remote sensing data (e.g., hyperspectral and LiDAR data), these shortcomings restrict the collaborative classification accuracy of remote sensing data. The proposed deep hierarchical vision transformer architecture utilizes both the powerful modeling capability of long-range dependencies and strong generalization ability across different domains of the transformer network, which is based exclusively on the self-attention mechanism. Specifically, the spectral sequence transformer is exploited to handle the long-range dependencies along the spectral dimension from hyperspectral images, because all diagnostic spectral bands contribute to the land cover classification. Thereafter, we utilize the spatial hierarchical transformer structure to extract hierarchical spatial features from hyperspectral and LiDAR data, which are also crucial for classification. Furthermore, the cross attention (CA) feature fusion pattern could adaptively and dynamically fuse heterogeneous features from multi-modality data, and this contextual aware fusion mode further improves the collaborative classification performance. Comparative experiments and ablation studies are conducted on three benchmark hyperspectral and LiDAR datasets, and the DHViT model could yield an average overall classification accuracy of 99.58%, 99.55%, and 96.40% on three datasets, respectively, which sufficiently certify the effectiveness and superior performance of the proposed method.

Synthesis and Spectroscopic Characterization of Co-Crystals of Fluconazole with Succinic Acid and Urea as Coformer

Co-crystal engineering is an important aspect of pharmaceutical development as it enables the obtainment of structural varieties of drug forms of same active pharmaceutical compounds while maintaining or improving physico-chemical and therapeutic activities of the active pharmaceutical compounds. In this work, we report the green synthesis of two co-crystals of fluconazole with succinic acid and urea. White block single crystals were obtained after slow evaporation of ethanolic solution of fluconazole (FLU) with the coformers (succinic acid and urea) in 1:1 molar ratio and were characterized using UV and Fourier Transform Infrared (FTIR) spectroscopy. FTIR spectra of the co-crystals confirms the formation of the co-crystals in solid state with the appearance of diagnostic FTIR bands of both fluconazole functional groups and those of the coformers (succinic acid and urea) in succinic acid-fluconazole (SFLU) and urea-fluconazole (UFU) respectively. UV-Vis spectra also features the π-π* absorption maxima of fluconazole in the co-crystals, providing additional evidence for the formation of the co-crystals.

Estandarización y validación de un western blot para el diagnóstico del virus de inmunodeficiencia humana

Objectives: To standardize and validate a western blot test for the diagnosis of human immunodeficiency virus. Methods: A prospective observational study was carried out during 2017 and 2018. The western blot test was standardized, using the polyacrylamide gel electrophoresis technique with sodium dodecyl sulfate (SDS PAGE), being the nitrocellulose blot strips prepared with an Optimal HIV-1 antigen concentration of 2.71 µg / mm. The western blot was validated in the laboratory against 400 reference samples (300 sera and 100 plasmas): 200 positive and 200 negatives for antibodies against HIV-1, being the reference test the Immunoblot of the Fujirebio brand. Diagnostic performance parameters were estimated using Epidat v3.1 and Excel. Results: Eight important bands of the HIV-1 antigen were identified: p17, p24, p31, p39, gp41, p55, p66, and gp120. According to the Consortium for the normalization of serology for retroviruse, those that were taken as specific diagnostic bands were: p24, p31, gp41, and gp120. The sensitivity, specificity, positive and negative predictive value and validity index against sera were: 96.7%, 96.0%, 96.0%, 96.6%, 96.3%; and against plasmas: 98.0%, 100.0%, 100.0%, 98.0%, 99.0% respectively. No false positives and negatives were found, but some were undetermined. Conclusion: The development of this western blot test with proprietary technology presented similar diagnostic performance to the reference test, without showing cross-reactions, being useful for confirming HIV.

Label-free identification of Erythropoietin isoforms by surface enhanced Raman spectroscopy

We present a sensitive label-free surface enhanced Raman spectroscopy (SERS) method for the discrimination between the recombinant and endogenous human Erythropoietin (EPO) isoforms. The proposed methodology comprises a lectin-functionalised extractor chip for the extraction of the recombinant human EPO (rhuEPO) and the endogenous EPO (enEPO) from blood plasma. The disulfide bond molecular structure of the purified isoforms was modified to chemisorb the biomolecules onto a SERS substrate in a unified orientation, thus maximizing the reproducibility and sensitivity of the SERS measurements. The acquired SERS spectra of the EPO isoforms showed diagnostic Raman bands that allowed for the discrimination between rhuEPO and enEPO. The method was also used for the SERS quantification of rhuEPO and enEPO down to 0.1 pM and 0.5 pM, respectively. The SERS determination of the protein isoforms was cross validated against ELISA. The new SERS method has strong potential for the rapid screening of rhuEPO doping in athletes and for the therapeutic drug monitoring of rhuEPO treatment in cancer patients.

Assessment of plant species distribution and diversity along a climatic gradient from Mediterranean woodlands to semi-arid shrublands

ABSTRACT Climate and land-use change profoundly affect plant species distribution (SD) and composition, and the impact of these processes is expected to increase in the coming years. As a proxy of global changes, knowledge of SD and diversity along climatic gradients is essential to determine the efforts needed for species conservation. Plant spectral diversity is an emerging approach used as a proxy for species diversity based on remote sensing. Thus, the research aim was to develop a comprehensive methodology based on spectral diversity for SD and richness mapping and to study their relations with environmental and human-derived factors, demonstrated along Mediterranean to semi-arid climatic gradient. The study addresses two main knowledge gaps regarding spectral diversity: (1) improving the accuracy of woody species classification by features extraction and selection, and by using texture analysis in an ecosystem characterized by high spatial variability and relatively small-sized and sparse woody vegetation; and (2) developing a better estimate of the local species ‎richness and their response to environmental and human-derived factors (i.e. climate, topography, substrate, and land cover factors) across a transition zone between Mediterranean woodlands and semi-arid dwarf shrublands. A hyperspectral image was acquired for a 43-km strip along the study area using an airborne flight of AISA-FENIX (380–2500 nm, 420 bands) at the end of the 2017 rainy season. The dominant species were surveyed, with a total number of 247 trees and shrubs, to train a machine learning support vector machine (SVM) classification for species distribution mapping, which yielded an overall accuracy of 86.1%. A feature extraction and selection methodology was developed, combining principal component analysis and neighborhood component analysis techniques, facilitating the identification of 33 spectral diagnostic bands out of 330 spectral bands. The classification accuracy was decreased by about 2% to 84.2% using only 33 spectral bands. The classification accuracy improved by about 7.1% for the seven large crown species (93.3%) by adding texture information. Later, the local species richness was calculated by utilizing the alpha diversity index (i.e. the Shannon Index) for 30-m grid cells and was tested in response to environmental (i.e. climate, substrate, and topography) and human-derived factors (i.e. land cover). The highest sensitivity to alpha diversity factors was mean annual precipitation, slope, and land surface temperature. The alpha diversity showed higher richness in the natural Mediterranean shrubland and the guarrigue located in the northern part of the climate gradient. We suggest that the approach presented here significantly improves the estimation of woody species distribution and diversity in areas characterized by high spatial heterogeneity along steep climatic gradients.

Vaterite in a decrepitated diamond-bearing inclusion in zircon from a stromatic migmatite in the Chinese Sulu ultrahigh-pressure metamorphic belt

Abstract Vaterite was identified in a decrepitated carbonaceous material (CM) bearing inclusion in zircon from a stromatic migmatite in the Chinese Sulu ultrahigh-pressure (UHP) metamorphic terrane. It is associated with nanometer to micrometer anhedral diamonds, aragonite, calcite, amorphous C-Si-O, and amorphous Zr-Si-O materials. The inclusion developed offshoots and abundant indigenous holes. The C-Si-O material is carbon-rich and porous and shows diagnostic Raman bands of highly disordered CM, whereas the Zr-Si-O material is spherulitic or banded with little or no carbon. The observations from focused ion beam–scanning electron microscope (FIB-SEM) and transmission electron microscope (TEM) verify that both diamond and highly disordered CM are of indigenous origin. The formation pathway of vaterite means that an amorphous calcium carbonate (ACC) phase occurred as the precursor of vaterite. The highly disordered CM contains the subsidiary bands at 1150 and 1250 cm−1 on the low-frequency side of the D1 band, suggesting that there exist aliphatic hydrocarbon chains. Thus, the highly disordered CM was derived from carbonization of some kind of organic species in the fluid inclusion. Decrepitation of inclusion resulted in an extremely high supersaturation state of the fluid that induced the precipitation of amorphous materials and released residual fluid out of the inclusion, which became dry and preserved vaterite and amorphous materials.

Durable Modification of Wood by Benzoylation-Proof of Covalent Bonding by Solution State NMR and DOSY NMR Quick-Test.

A convenient, broadly applicable and durable wood protection was recently published by Kaufmann and Namyslo. This procedure efficiently allows for esterification of wood hydroxyl groups with (1H-benzotriazolyl)-activated functionalized benzoic acids. The result of such wood-modifying reactions is usually monitored by an increase in mass of the wood material (weight percent gain value, WPG) and by infrared spectroscopy (IR). However, diagnostic IR bands suffer from overlap with naturally occurring ester groups, mainly in the hemicellulose part of unmodified wood. In contrast to known NMR spectroscopy approaches that use the non-commonly available solid state techniques, herein we present solution state NMR proof of the covalent attachment of our organic precursors to wood. The finding is based on a time-efficient, non-uniformly sampled (NUS) solution state 1H,13C-HMBC experiment that only needs a tenth of the regular recording time. The appropriate NMR sample of thoroughly dissolved modified wood was prepared by a mild and non-destructive method. The 2D-HMBC shows a specific cross-signal caused by spin–spin coupling over three bonds from the ester carbonyl carbon atom to the α-protons of the esterified wood hydroxyl groups. This specific coupling pathway requires a covalent bonding as a conditio sine qua non. An even more rapid test to monitor the covalent bonding was achieved with an up-to-date diffusion-ordered spectroscopy sequence (Oneshot—DOSY) based on 1H or 19F as the sensitive nucleus. The control experiment in a series of DOSY spectra gave a by far higher D value of (1.22 ± 0.06)∙10−10 m2∙s−1, which is in accordance with fast diffusion of the “free” and thus rapidly moving small precursor molecule provided as its methyl ester. In the case of a covalent attachment to wood, a significantly smaller D value of (0.12 ± 0.01)∙10−10 m2∙s−1 was obtained.