Magnetic exchange interactions and non-Debye relaxation in spin-3/2 frustrated Kagomé magnet Co3V2O8

We report the experimental determination of the magnetic exchange parameter (J/kB= 2.88 ± 0.02 K) for the Spin-3/2 ferromagnetic (FM) Kagomé lattice system: Co3V2O8using the temperature dependence of dc-magnetic susceptibilityχ(T) data by employing the fundamental Heisenberg linear chain model. Our results are quite consistent with the theoretically reported nearest neighbor dominant FM exchange coupling strengthJex-NN∼2.45 K. Five different magnetic phase transitions (6.2-11.2 K) and spin-flip transitions (9.6-7.7 kOe) have been probed using the∂(χT)/∂Tvs.T, heat capacity (CP-T) and differential isothermal magnetization curves. Among such sequence of transitions, the prominent ones being incommensurate antiferromagnetic (AFM) state at 11.2 K, commensurate AFM state at 8.8 K, and commensurate FM state across 6.2 K. All the successive magnetic phase transitions have been mapped onto a single H-T plane through which one can easily distinguish the above-mentioned different phases. The magnetic contribution of theCP-TnearTN(11.2 K) has been analyzed using the power-law expressionCM=A|T-TN|-αresulting in the critical exponentα= 0.18 ± 0.01 (0.15 ± 0.003) forTTN), respectively for the Co3V2O8. It is interesting to note that non-Debye type dipole relaxation is quite prominent in Co3V2O8and was evident from the Kohlrausch-Williams-Watts analysis of complex modulus and impedance spectra (0⩽β⩽1). Mott's variable-range hopping of charge carriers process is evident through the resistivity analysis (ρac-T-1/4) in the temperature range 275 ∘C-350 ∘C. Moreover, the frequency-dependent analysis ofσac(ω) follows Jonscher's power law yielding two distinct activation energies (Ea∼0.37 and 2.29 eV) between the temperature range 39 ∘C-99 ∘C and 240 ∘C-321 ∘C.

Expression profiling of Nuclear Factor-Y (NF-Y) transcription factors during dehydration and salt stress in finger millet reveals potential candidate genes for multiple stress tolerance

MAIN CONCLUSION

Expression profiling of NF-Y transcription factors during dehydration and salt stress in finger millet genotypes contrastingly differing in tolerance levels identifies candidate genes for further characterization and functional studies. The Nuclear Factor-Y (NF-Y) transcription factors are known for imparting abiotic stress tolerance in different plant species. However, there is no information on the role of this transcription factor family in naturally drought-tolerant crop finger millet (Eleusine coracana L.). Therefore, interpretation of expression profiles against drought and salinity stress may provide valuable insights into specific and/or overlapping expression patterns of Eleusine coracana Nuclear Factor-Y (EcNF-Y) genes. Given this, we identified 59 NF-Y (18 NF-YA, 23 NF-YB, and 18 NF-YC) encoding genes and designated them EcNF-Y genes. Expression profiling of these genes was performed in two finger millet genotypes, PES400 (dehydration and salt stress tolerant) and VR708 (dehydration and salt stress sensitive), subjected to PEG-induced dehydration and salt (NaCl) stresses at different time intervals (0, 6, and 12 h). The qRT-PCR expression analysis reveals that the six EcNF-Y genes namely EcNF-YA1, EcNF-YA5, EcNF-YA16, EcNF-YB6, EcNF-YB10, and EcNF-YC2 might be associated with tolerance to both dehydration and salinity stress in early stress condition (6 h), suggesting the involvement of these genes in multiple stress responses in tolerant genotype. In contrast, the transcript abundance of finger millet EcNF-YA5 genes was also observed in the sensitive genotype VR708 under late stress conditions (12 h) of both dehydration and salinity stress. Therefore, the EcNF-YA5 gene might be important for adaptation to salinity and dehydration stress in sensitive finger millet genotypes. Therefore, this gene could be considered as a susceptibility determinant, which can be edited to impart tolerance. The phylogenetic analyses revealed that finger millet NF-Y genes share strong evolutionary and functional relationship to NF-Ys governing response to abiotic stresses in rice, sorghum, maize, and wheat. This is the first report of expression profiling of EcNF-Ys genes identified from the finger millet genome and reveals potential candidate for enhancing dehydration and salt tolerance.

Spin glass states in multicomponent layered perovskites

Temperature-dependent dc-magnetization and ac-susceptibility curves have been recorded for series of single and double layered Ruddlesden-Popper multicomponent perovskites with chemical formula A2BO4 and A3B2O7, respectively, with (La, Sr) on A-sites and up to 7 different cations on the B-sites (Ti, Cr, Mn, Fe, Co, Ni, Cu). The phase purity and chemical homogeneity of the compounds were investigated by X-ray diffraction and energy dispersive X-ray spectroscopy. Independently of the composition, spin glassiness is observed in both systems. Scaling analyses suggest the materials undergo spin glass phase transitions at low temperatures. Yet, qualitative differences are observed between the single-layered and double-layered systems, which are discussed in the light of the spatial dimensionality and magnetic interaction in layered oxide perovskites.

Reentrant canonical spin-glass dynamics and tunable field-induced transitions in (GeMn)Co2O4Kagomé lattice

We report on the reentrant canonical semi spin-glass characteristics and controllable field-induced transitions in distorted Kagomé symmetry of (GeMn)Co2O4. ThisB-site spinel exhibits complicated, yet interesting magnetic behaviour in which the longitudinal ferrimagnetic (FiM) order sets in below the Néel temperatureTFN∼ 77 K due to uneven moments of divalent Co (↑ 5.33μB) and tetravalent Mn (↓ 3.87μB) which coexists with transverse spin-glass state below 72.85 K. Such complicated magnetic behaviour is suggested to result from the competing anisotropic superexchange interactions (JAB/kB∼ 4.3 K,JAA/kB∼ -6.2 K andJBB/kB∼ -3.3 K) between the cations, which is extracted following the Néel's expression for the two-sublattice model of FiM. Dynamical susceptibility (χac(f, T)) and relaxation of thermoremanent magnetization,MTRM(t) data have been analysed by means of the empirical scaling-laws such as Vogel-Fulcher law and Power law of critical slowing down. Both of which reveal the reentrant spin-glass like character which evolves through a number of intermediate metastable states. The magnitude of Mydosh parameter (Ω ∼ 0.002), critical exponentzυ= (6.7 ± 0.07), spin relaxation timeτ0= (2.33 ± 0.1) × 10-18s, activation energyEa/kB= (69.8 ± 0.95) K and interparticle interaction strength (T0= 71.6 K) provide the experimental evidences for canonical spin-glass state below the spin freezing temperatureTF= 72.85 K. The field dependence ofTFobtained fromχac(T) follows the irreversibility in terms of de Almeida-Thouless mean-field instability in which the magnitude of crossover scaling exponent Φ turns out to be ∼2.9 for the (Ge0.8Mn0.2)Co2O4. Isothermal magnetization plots reveal two field-induced transitions across 9.52 kOe (HSF1) and 45.6 kOe (HSF2) associated with the FiM domains and spin-flip transition, respectively. Analysis of the inverse paramagnetic susceptibilityχp-1χp=χ-χ0after subtracting the temperature independent diamagnetic termχ0(=-3 × 10-3emu mol-1Oe-1) results in the effective magnetic momentμeff= 7.654μB/f.u. This agrees well with the theoretically obtainedμeff= 7.58μB/f.u. resulting the cation distributionMn0.24+↓A[Co22+↑]BO4in support of the Hund's ground state spin configurationS=3/2andS= 1/2of Mn4+and Co2+, respectively. TheH-Tphase diagram has been established by analysing all the parameters (TF(H),TFN(H),HSF1(T) andHSF2(T)) extracted from various magnetization measurements. This diagram enables clear differentiation among the different phases of the (GeMn)Co2O4and also illustrates the demarcation between short-range and long-range ordered regions.

Comparison of dehulling efficiency and grain nutritional parameters of two cultivated barnyard millet species (Echinochloa spp.)

Due to increased awareness regarding the health-promoting profile of millets, inclination towards their consumption has increased considerably. In the Himalayan region of India, cultivars of the two species of barnyard millet, namely Indian (Echinochloa frumentacea) and Japanese barnyard millet (E. esculenta), are grown. To compare the dehulled grain recovery, grain physical parameters, nutritional profile and antioxidant activity, an experiment was carried out at ICAR-VPKAS, Almora, Uttarakhand hills for two years using released and popular cultivars of Indian barnyard millet (VL 207 and VL 172) and Japanese barnyard millet (PRJ-1). The results indicated that the whole grain yield of Japanese barnyard millet cultivar PRJ-1 was significantly higher than Indian Barnyard millet cultivars VL 172 and VL 207; however, the dehulled grain recovery was considerably higher in VL 172 and VL 207 than PRJ-1. Similarly, the physical grain parameters were significantly higher in PRJ-1, but most dehulled grain parameters were at par in cultivars of both species. The nutritional estimation of dehulled grains of both species did not show remarkable differences for most traits. Still, crude fibre, Mn, and Zn were high in PRJ-1, while total digestible nutrients and phosphorous were high in VL 172 and VL 207. Dehulled grains exhibited much more crude protein, ash, minerals, and total digestible nutrients, but the husk accumulated significantly higher crude fibre and total polyphenols.

"Millet Models" for harnessing nuclear factor-Y transcription factors to engineer stress tolerance in plants: current knowledge and emerging paradigms

MAIN CONCLUSION

The main purpose of this review is to shed light on the role of millet models in imparting climate resilience and nutritional security and to give a concrete perspective on how NF-Y transcription factors can be harnessed for making cereals more stress tolerant. Agriculture faces significant challenges from climate change, bargaining, population, elevated food prices, and compromises with nutritional value. These factors have globally compelled scientists, breeders, and nutritionists to think of some options that can combat the food security crisis and malnutrition. To address these challenges, mainstreaming the climate-resilient and nutritionally unparalleled alternative crops like millet is a key strategy. The C4 photosynthetic pathway and adaptation to low-input marginal agricultural systems make millets a powerhouse of important gene and transcription factor families imparting tolerance to various kinds of biotic and abiotic stresses. Among these, the nuclear factor-Y (NF-Y) is one of the prominent transcription factor families that regulate diverse genes imparting stress tolerance. The primary purpose of this article is to shed light on the role of millet models in imparting climate resilience and nutritional security and to give a concrete perspective on how NF-Y transcription factors can be harnessed for making cereals more stress tolerant. Future cropping systems could be more resilient to climate change and nutritional quality if these practices were implemented.

Deciphering the genomic regions governing major agronomic traits and blast resistance using genome wide association mapping in finger millet

Finger millet (Eleusine coracana L.) is climate resilient minor millet of Asia and Africa with wide adaptation and unparallel nutritional profile. To date, genomic resources available in finger millet are scanty and genetic control of agronomic traits remains elusive. Here, a collection of eco-geographically diverse 186 genotypes was quantified for variation in 13 agronomic traits and reaction to blast to identify marker-trait associations (MTAs) using genotyping-by-sequencing (GBS) and genome-wide association study (GWAS). GBS generated 2977 high quality single nucleotide polymorphism (SNPs) markers and identified three subpopulations with varying admixture levels. General linear and mixed model approaches of GWAS to correct for population structure and genetic relatedness identified 132 common MTAs for agronomic traits across the years. The phenotypic variance explained by the makers varied from 4.8% (TP692389-flag leaf width) to 20% (TP714446-green fodder weight). Of these, 26 MTAs showed homology with candidate genes having role in plant growth, development and photosynthesis in the genomes of foxtail millet, rice, maize, wheat and barley. We also found 4 common MTAs for neck blast resistance, which explained 5.9-15.1% phenotypic variance. Three MTAs for neck blast resistance showed orthologues in related genera having putative functions in pathogen defense in plants. The results of this work lay a foundation for understanding the genetic architecture of agronomic traits and blast resistance in finger millet and provide a framework for genomics assisted breeding.

Tripartite Crosstalk between Cytokine IL-1β, NMDA-R and Misplaced Mitochondrial Anchor in Neuronal Dendrites Is a Novel Pathway for Neurodegeneration in Inflammatory Diseases

The mitochondrial anchor syntaphilin (SNPH) is a key mitochondrial protein normally expressed in axons to maintain neuronal health by positioning mitochondria along axons for metabolic needs. However, in 2019 we discovered a novel form of excitotoxicity that results when SNPH is misplaced into neuronal dendrites in disease models. A key unanswered question about this SNPH excitotoxicity is the pathologic molecules that trigger misplacement or intrusion of SNPH into dendrites. Here, we identified two different classes of pathologic molecules that interact to trigger dendritic SNPH intrusion. Using primary hippocampal neuronal cultures from mice of either sex, we demonstrated that the pro-inflammatory cytokine IL-1β interacts with NMDA to trigger SNPH intrusion into dendrites. First, IL-1β and NMDA each individually triggers dendritic SNPH intrusion. Second, IL-1β and NMDA do not act independently but interact. Thus, blocking NMDAR by the antagonist MK-801 blocks IL-1β from triggering dendritic SNPH intrusion. Further, decoupling the known interaction between IL-1β and NMDAR by tyrosine inhibitors prevents either IL-1β or NMDA from triggering dendritic SNPH intrusion. Third, neuronal toxicity caused by IL-1β or NMDA is strongly ameliorated in SNPH-/- neurons. Together, we hypothesize that the known bipartite IL-1β/NMDAR crosstalk converges to trigger misplacement of SNPH in dendrites as a final common pathway to cause neurodegeneration. Targeting dendritic SNPH in this novel tripartite IL-1β/NMDAR/SNPH interaction could be a strategic downstream locus for ameliorating neurotoxicity in inflammatory diseases.SIGNIFICANCE STATEMENT SNPH is a key mitochondrial protein normally expressed specifically in healthy axons to help position mitochondria along axons to match metabolic needs. In 2019 we discovered that misplacement of SNPH into neuronal dendrites causes a novel form of excitotoxicity in rodent models of multiple sclerosis. A key unanswered question about this new form of dendritic SNPH toxicity concerns pathologic molecules that trigger toxic misplacement of SNPH into dendrites. Here, we identified two major categories of pathologic molecules, the pro-inflammatory cytokines and NMDA, that interact and converge to trigger toxic misplacement of SNPH into dendrites. We propose that a dendritic mitochondrial anchor provides a novel, single common target for ameliorating diverse inflammatory and excitatory injuries in neurodegenerative diseases.

2D crystal structure and anisotropic magnetism of GdAu6.75-xAl0.5+x (x ≈ 0.54)

Exploration of the gold-rich part of the ternary Gd–Au–Al system afforded the intermetallic compound GdAu_6.75−xAl_0.5+x (x ≈ 0.54) which was structurally characterized by single crystal X-ray diffraction (Pnma, a = 18.7847(4) Å, b = 23.8208(5) Å, c = 5.3010(1) Å). GdAu_6.75−xAl_0.5+x crystallizes in a previously unknown structure type featuring layers of Gd₂(Au, Al)₂₉ and Gd₂(Au, Al)₂₈ clusters which are arranged as in a close-packing parallel to the ac plane. The Gd substructure corresponds to slightly corrugated 3⁶ nets (d_Gd–Gd = 5.30–5.41 Å) which are stacked on top of each other along the b direction with alternating short (5.4, 5.6 Å, within layers) and long distances (6.4 Å, between layers). The title compound has been discussed with respect to a quasicrystal approximant (1/1 AC) GdAu_5.3Al in the same system. The magnetic properties of GdAu_6.75−xAl_0.5+x were found to be reminiscent to those of some ternary ACs, with sharp peaks in the temperature dependent magnetization, and metamagnetic-like transitions. The material becomes antiferromagnetic below 25 K; magnetometry results suggest that the antiferromagnetic state is composed of ferromagnetic ac planes, coupled antiferromagnetically along the b direction.

Mainstreaming Barahnaja cultivation for food and nutritional security in the Himalayan region

Selective production of input intensive crops in the present scenario have resulted in productivity stagnation or even decline due to excessive usage of chemicals, affecting the farmers economically. Sustainable agriculture is the way to increase agricultural productivity and economic prosperity by protecting all natural resources. It maintains a balance of soil fertility with crop productivity and nutritional quality. The mixed cropping systems followed earlier in different regions according to their tradition, climatic zone, soil and water conditions were climate-smart approaches to sustainable food production based on practical experiences over the years of old generations. The life style changes, imbalance in farming system in last 70 years and demand for more food as well as declining land resources resulted in intensive agriculture. Besides, least returns and less demand of ethnic crops gave more preference to major staple food crops. Barahnaja is a traditional orphan crops based mixed cropping system practiced in Himalayan region due to its sustainability and assured crop harvest during erratic weather conditions. This traditional farming method is an exemplary scientific approach to derive innovations with respect to productivity, quality, plant soil interactions and organic agriculture. The main focus of the review is to substantiate the characteristics of the traditional mixed cropping system by describing the advantages of the system and opportunities for scientific innovation towards new knowledge and sustainability.

Signatures of a Spin-1/2 Cooperative Paramagnet in the Diluted Triangular Lattice of Y_{2}CuTiO_{6}

We present a combination of thermodynamic and dynamic experimental signatures of a disorder driven dynamic cooperative paramagnet in a 50% site diluted triangular lattice spin-1/2 system: Y_{2}CuTiO_{6}. Magnetic ordering and spin freezing are absent down to 50 mK, far below the Curie-Weiss scale (-θ_{CW}) of ∼134  K. We observe scaling collapses of the magnetic field and temperature dependent magnetic heat capacity and magnetization data, respectively, in conformity with expectations from the random singlet physics. Our experiments establish the suppression of any freezing scale, if at all present, by more than 3 orders of magnitude, opening a plethora of interesting possibilities such as disorder stabilized long range quantum entangled ground states.

Random fields and apparent exchange bias in the dilute Ising antiferromagnet Fe0.6Zn0.4F2

Random field induced spontaneous excess moments appear in field cooled single crystals of diluted Ising antiferromagnets. Here we report results from low temperature measurements of field cooled (including zero field) magnetic hysteresis loops parallel and perpendicular to the c-axis of a single crystal of composition Fe0.6Zn0.4F2. We find that weak static ferromagnetic excess moments attained on field cooling give rise to an apparent exchange bias of the magnetic hysteresis loops, whose magnitude is controlled by temperature and the strength and direction of the cooling field. Random field induced temporal excess moments only become observable in cooling fields larger than 1 T applied along the c-axis direction of the Fe0.6Zn0.4F2 single crystal.

Inappropriate Intrusion of an Axonal Mitochondrial Anchor into Dendrites Causes Neurodegeneration

Syntaphilin (SNPH) is a major mitochondrial anchoring protein targeted to axons and excluded from dendrites. In this study, we provide in vivo evidence that this spatial specificity is lost in Shiverer (Shi) mice, a model for progressive multiple sclerosis (MS), resulting in inappropriate intrusion of SNPH into dendrites of cerebellar Purkinje cells with neurodegenerative consequences. Thus, reconstituting dendritic SNPH intrusion in SNPH-KO mice by viral transduction greatly sensitizes Purkinje cells to excitotoxicity when the glutamatergic climbing fibers are stimulated. Finally, we demonstrate in vitro that overexpression of SNPH in dendrites compromises neuronal viability by inducing N-methyl-D-aspartate (NMDA) excitotoxicity, reducing mitochondrial calcium uptake, and interfering with quality control of mitochondria by blocking somal mitophagy. Collectively, we propose that inappropriate immobilization of dendritic mitochondria by SNPH intrusion produces excitotoxicity and suggest that interception of dendritic SNPH intrusion is a therapeutic strategy to combat neurodegeneration.

Neutron diffraction evidence for local spin canting, weak Jahn-Teller distortion, and magnetic compensation in Ti1-x Mn x Co2O4 spinel

A systematic study using neutron diffraction and magnetic susceptibility is reported on Mn substituted ferrimagnetic inverse spinel Ti_1-x Mn _x Co₂O₄ in the temperature interval 1.6 K [Formula: see text] T [Formula: see text] 300 K. Our neutron diffraction study reveals cooperative distortions of the TO₆ octahedra in the Ti_1-x Mn _x Co₂O₄ system for all the Jahn-Teller active ions T  =  Mn³⁺ , Ti³⁺ and Co³⁺ , having the electronic configurations 3d ¹, 3d ⁴ and 3d ⁶, respectively which are confirmed by the x-ray photoelectron spectroscopy. Two specific compositions (x  =  0.2 and 0.4) have been chosen in this study because these two systems show unique features such as; (i) noncollinear Yafet-Kittel type magnetic ordering, and (ii) weak tetragonal distortion with c/a  <  1, in which the apical bond length d _c (T _B -O) is longer than the equatorial bond length d _ab (T _B -O) due to the splitting of the e _g level of Mn³⁺ ions into [Formula: see text] and [Formula: see text]. For the composition x  =  0.4, the distortion in the T _B O₆ octahedra is stronger as compared to x  =  0.2 because of the higher content of trivalent Mn. Ferrimagnetic ordering in Ti_0.6Mn_0.4Co₂O₄ and Ti_0.8Mn_0.2Co₂O₄ sets in at 110.3 and 78.2 K, respectively due to the presence of unequal magnetic moments of cations, where Ti³⁺ , Mn³⁺ , and Co³⁺ occupy the octahedral, whereas, Co²⁺ sits in the tetrahedral site. For both compounds an additional weak antiferromagnetic component could be observed lying perpendicular to the ferrimagnetic component. The analysis of static and dynamic magnetic susceptibilities combined with the heat-capacity data reveals a magnetic compensation phenomenon (MCP) at T _COMP  =  25.4 K in Ti_0.8Mn_0.2Co₂O₄ and a reentrant spin-glass behaviour in Ti_0.6Mn_0.4Co₂O₄ with a freezing temperature of  ∼110.1 K. The MCP in this compound is characterized by sign reversal of magnetization and bipolar exchange bias effect below T _COMP with its magnitude depending on the direction of external magnetic field and the cooling protocol.

Fagopyrum esculentum ssp. ancestrale-A Hybrid Species Between Diploid F. cymosum and F. esculentum

Fagopyrum cymosum is considered as most probable wild ancestor of cultivated buckwheat. However, the evolutionary route from F. cymosum to F. esculentum remains to be deciphered. We hypothesized that a hybrid species exists in natural habitats between diploid F. cymosum and F. esculentum. The aim of this research was to determine the phylogenetic position of F. esculentum ssp. ancestrale and to provide new thoughts on buckwheat evolution. Different methodologies including evaluation of morphological traits, determination of secondary metabolites, fluorescence in situ hybridization (FISH), comparative chloroplast genomics, and molecular markers were deployed to determine the phylogenetic relationship of F. esculentum ssp. ancestrale with F. cymosum and F. esculentum. The ambiguity observed in morphological pattern of genetic variation in three species revealed that F. esculentum ssp. ancestrale is closely related to F. cymosum and F. esculentum. Flavonoid analysis revealed that F. esculentum ssp. ancestrale is closely related to F. esculentum. Comparative chloroplast genome analysis further supported the close proximity of F. esculentum ssp. ancestrale with F. esculentum. Additionally, molecular marker analysis revealed that F. esculentum ssp. ancestrale exhibits co-dominance with the bands amplified by F. cymosum and F. esculentum. These finding provided supporting evidence in favor of the hypothesis that F. esculentum ssp. ancestrale is a hybrid species between F. cymosum to F. esculentum, which was probably originated by spontaneous hybridization under natural conditions.

Ferromagnetic excess moments and apparent exchange bias in FeF2 single crystals

The anisotropic antiferromagnet FeF2 has been extensively used as an antiferromagnetic layer to induce exchange bias effects in ferromagnetic/antiferromagnetic bilayers and heterostructures. In this work, an apparent exchange bias occurring in the low temperature hysteresis loops of FeF2 single crystals is investigated. A detailed investigation of the hysteresis and remnant magnetization indicates that the observation of an apparent exchange bias in FeF2 stems from an intrinsic excess moment associated with a distortion of the antiferromagnetic structure of piezomagnetic origin.

Strategic enhancement of genetic gain for nutraceutical development in buckwheat: A genomics-driven perspective

Buckwheat (Fagopyrum spp.) under the family Polygonaceae is an ancient pseudocereal with stupendous but less studied nutraceutical properties. The gluten free nature of protein, balanced amino acid profile and health promoting bioactive flavonoids make it a golden crop of future. Besides a scanty basic research, not much attention has been paid to the improvement of plant type and breeding of nutraceutical traits. Scanning of scientific literature indicates that adequate genetic variation exists for agronomic and nutritional traits in mainstream and wild gene pool of buckwheat. However, the currently employed conventional approaches together with poorly understood genetic mechanisms restrict effective utilization of the existing genetic variation in nutraceutical breeding of buckwheat. The latest trends in buckwheat genomics, particularly avalilabity of draft genome sequences for both the cultivated species (F. esculentum and F.tataricum) hold immense potential to overcome these limitations. Utilizing the transgenic hairy rot cultures, role of various transcription factors and gene families have been deduced in production and biosynthesis of bioactive flavonoids. Further, the acquisition of high-density genomics data coupled with the next-generation phenotyping will certainly improve our understanding of underlying genetic regulation of nutraceutical traits. The present paper highlights the application of multilayered omics interventions for tailoring a nutrient rich buckwheat cultivar and nutraceutical product development.

Revisiting the versatile buckwheat: reinvigorating genetic gains through integrated breeding and genomics approach

Emerging insights in buckwheat molecular genetics allow the integration of genomics driven breeding to revive this ancient crop of immense nutraceutical potential from Asia. Out of several thousand known edible plant species, only four crops-rice, wheat, maize and potato provide the largest proportion of daily nutrition to billions of people. While these crops are the primary supplier of carbohydrates, they lack essential amino acids and minerals for a balanced nutrition. The overdependence on only few crops makes the future cropping systems vulnerable to the predicted climate change. Diversifying food resources through incorporation of orphan or minor crops in modern cropping systems is one potential strategy to improve the nutritional security and mitigate the hostile weather patterns. One such crop is buckwheat, which can contribute to the agricultural sustainability as it grows in a wide range of environments, requires relatively low inputs and possess balanced amino acid and micronutrient profiles. Additionally, gluten-free nature of protein and nutraceutical properties of secondary metabolites make the crop a healthy alternative of wheat-based diet in developed countries. Despite enormous potential, efforts for the genetic improvement of buckwheat are considerably lagged behind the conventional cereal crops. With the draft genome sequences in hand, there is a great scope to speed up the progress of genetic improvement of buckwheat. This article outlines the state of the art in buckwheat research and provides concrete perspectives how modern breeding approaches can be implemented to accelerate the genetic gain. Our suggestions are transferable to many minor and underutilized crops to address the issue of limited genetic gain and low productivity.

Rice bean: a lesser known pulse with well-recognized potential

Required genetic resources for the improvement of agronomic, nutritional and economic value of rice bean are available in the world collection. International cooperative effort is required to utilize and conserve them. Rice bean [Vigna umbellata (Thunb.) Ohwi and Ohashi], a lesser known pulse among the Asiatic Vigna, has long been considered as a food security crop of small and marginal farmers of Southeast Asia. Considered as a nutritionally rich food and fodder, it is also a source of genes for biotic and abiotic stress tolerance including drought, soil acidity and storage pest. Although it spread from its centre of domestication in the Indo-China region to other parts around the world, it never became an important crop anywhere probably because of agronomic disadvantages. Crop improvement for determinate nature, good yield, less variable seed colour, pleasant organoleptic properties and lower antinutrients is required. Scanning of scientific literature indicates that genetic resources with desirable agronomic and nutritional traits exist within the current collection but are spread across countries. Genomic studies in the species indicate that except for insect resistance and aluminium toxicity tolerance, not much attention has been paid to decipher and utilize other stress tolerance and nutritional quality traits. Collaborative efforts towards improving farming, food, trade value and off-farm conservation of rice bean would not only help marginal farmers but will also help to preserve the yet to be explored genomic resources available in this sturdy pulse.

Phenomics and genomics of finger millet: current status and future prospects

Diverse gene pool, advanced plant phenomics and genomics methods enhanced genetic gain and understanding of important agronomic, adaptation and nutritional traits in finger millet. Finger millet (Eleusine coracana L. Gaertn) is an important minor millet for food and nutritional security in semi-arid regions of the world. The crop has wide adaptability and can be grown right from high hills in Himalayan region to coastal plains. It provides food grain as well as palatable straw for cattle, and is fairly climate resilient. The crop has large gene pool with distinct features of both Indian and African germplasm types. Interspecific hybridization between Indian and African germplasm has resulted in greater yield enhancement and disease resistance. The crop has shown numerous advantages over major cereals in terms of stress adaptation, nutritional quality and health benefits. It has indispensable repository of novel genes for the benefits of mankind. Although rapid strides have been made in allele mining in model crops and major cereals, the progress in finger millet genomics is lacking. Comparative genomics have paved the way for the marker-assisted selection, where resistance gene homologues of rice for blast and sequence variants for nutritional traits from other cereals have been invariably used. Transcriptomics studies have provided preliminary understanding of the nutritional variation, drought and salinity tolerance. However, the genetics of many important traits in finger millet is poorly understood and need systematic efforts from biologists across disciplines. Recently, deciphered finger millet genome will enable identification of candidate genes for agronomically and nutritionally important traits. Further, improvement in genome assembly and application of genomic selection as well as genome editing in near future will provide plethora of information and opportunity to understand the genetics of complex traits.

Fisetin targets YB-1/RSK axis independent of its effect on ERK signaling: insights from in vitro and in vivo melanoma models

The anti-proliferative activity of dietary flavonoid fisetin has been validated in various cancer models. Establishing its precise mechanism of action has proved somewhat challenging given the multiplicity of its targets. We demonstrated that YB-1 promotes epithelial-to-mesenchymal transition and its inhibition suppressed tumor cell proliferation and invasion. The p90 ribosomal S6 kinase (RSK), an important ERK effector, activates YB-1 to drive melanoma growth. We found that fisetin treatment of monolayer/3-D melanoma cultures resulted in YB-1 dephosphorylation and reduced transcript levels. In parallel, fisetin suppressed mesenchymal markers and matrix-metalloproteinases in melanoma cells. Data from cell-free/cell-based systems indicated that fisetin inhibited RSK activity through binding to the kinase. Affinity studies for RSK isoforms evaluated stronger interaction for RSK2 than RSK1. Competition assays performed to monitor binding responses revealed that YB-1 and RSK2 do not compete, rather binding of fisetin to RSK2 promotes its binding to YB-1. Fisetin suppressed YB-1/RSK signaling independent of its effect on ERK, and reduced MDR1 levels. Comparable efficacy of fisetin and vemurafenib for inhibiting melanoma growth was noted albeit through divergent modulation of ERK. Our studies provide insight into additional modes of regulation through which fisetin interferes with melanoma growth underscoring its potential therapeutic efficacy in disease progression.

From zero to hero: the past, present and future of grain amaranth breeding

Grain amaranth is an underutilized crop with high nutritional quality from the Americas. Emerging genomic and biotechnological tools are becoming available that allow the integration of novel breeding techniques for rapid improvement of amaranth and other underutilized crops. Out of thousands of edible plants, only three cereals-maize, wheat and rice-are the major food sources for a majority of people worldwide. While these crops provide high amounts of calories, they are low in protein and other essential nutrients. The dependence on only few crops, with often narrow genetic basis, leads to a high vulnerability of modern cropping systems to the predicted climate change and accompanying weather extremes. Broadening our food sources through the integration of so-called orphan crops can help to mitigate the effects of environmental change and improve qualitative food security. Thousands of traditional crops are known, but have received little attention in the last century and breeding efforts were limited. Amaranth is such an underutilized pseudocereal that is of particular interest because of its balanced amino acid and micronutrient profiles. Additionally, the C₄ photosynthetic pathway and ability to withstand environmental stress make the crop a suitable choice for future agricultural systems. Despite the potential of amaranth, efforts of genetic improvement lag considerably behind those of major crops. The progress in novel breeding methods and molecular techniques developed in model plants and major crops allow a rapid improvement of underutilized crops. Here, we review the history of amaranth and recent advances in genomic tools and give a concrete perspective how novel breeding techniques can be implemented into breeding programs. Our perspectives are transferable to many underutilized crops. The implementation of these could improve the nutritional quality and climate resilience of future cropping systems.

WBSCR16 Is a Guanine Nucleotide Exchange Factor Important for Mitochondrial Fusion

Regulated inter-mitochondrial fusion/fission is essential for maintaining optimal mitochondrial respiration and control of apoptosis and autophagy. In mammals, mitochondrial fusion is controlled by outer membrane GTPases MFN1 and MFN2 and by inner membrane (IM) GTPase OPA1. Disordered mitochondrial fusion/fission contributes to various pathologies, and MFN2 or OPA1 mutations underlie neurodegenerative diseases. Here, we show that the WBSCR16 protein is primarily associated with the outer face of the inner mitochondrial membrane and is important for mitochondrial fusion. We provide evidence of a WBSCR16/OPA1 physical interaction in the intact cell and of a WBSCR16 function as an OPA1-specific guanine nucleotide exchange factor (GEF). Homozygosity for a Wbscr16 mutation causes early embryonic lethality, whereas neurons of mice heterozygous for the mutation have mitochondria with reduced membrane potential and increased susceptibility to fragmentation upon exposure to stress, suggesting roles for WBSCR16 deficits in neuronal pathologies.

Development of a phenotyping platform for high throughput screening of nodal root angle in sorghum

BACKGROUND

In sorghum, the growth angle of nodal roots is a major component of root system architecture. It strongly influences the spatial distribution of roots of mature plants in the soil profile, which can impact drought adaptation. However, selection for nodal root angle in sorghum breeding programs has been restricted by the absence of a suitable high throughput phenotyping platform. The aim of this study was to develop a phenotyping platform for the rapid, non-destructive and digital measurement of nodal root angle of sorghum at the seedling stage.

RESULTS

The phenotyping platform comprises of 500 soil filled root chambers (50 × 45 × 0.3 cm in size), made of transparent perspex sheets that were placed in metal tubs and covered with polycarbonate sheets. Around 3 weeks after sowing, once the first flush of nodal roots was visible, roots were imaged in situ using an imaging box that included two digital cameras that were remotely controlled by two android tablets. Free software (openGelPhoto.tcl) allowed precise measurement of nodal root angle from the digital images. The reliability and efficiency of the platform was evaluated by screening a large nested association mapping population of sorghum and a set of hybrids in six independent experimental runs that included up to 500 plants each. The platform revealed extensive genetic variation and high heritability (repeatability) for nodal root angle. High genetic correlations and consistent ranking of genotypes across experimental runs confirmed the reproducibility of the platform.

CONCLUSION

This low cost, high throughput root phenotyping platform requires no sophisticated equipment, is adaptable to most glasshouse environments and is well suited to dissect the genetic control of nodal root angle of sorghum. The platform is suitable for use in sorghum breeding programs aiming to improve drought adaptation through root system architecture manipulation.

Optimization of pretreatments and process parameters for sorghum popping in microwave oven using response surface methodology

Sorghum is a popular healthy snack food. Popped sorghum was prepared in a domestic microwave oven. A 3 factor 3 level Box and Behneken design was used to optimize the pretreatment conditions. Grains were preconditioned to 12-20 % moisture content by the addition of 0-2 % salt solutions. Oil was applied (0-10 % w/w) to the preconditioned grains. Optimization of the pretreatments was based on popping yield, volume expansion ratio, and sensory score. The optimized condition was found at 16.62 % (wb), 0.55 % salt and 10 % oil with popping yield of 82.228 %, volume expansion ratio of 14.564 and overall acceptability of 8.495. Further, the microwave process parameters were optimized using a 2 factor 3 level design having microwave power density ranging from 9 to 18 W/g and residence time ranging from 100 to 180 s. For the production of superior quality pop sorghum, the optimized microwave process parameters were microwave power density of 18 Wg(-1) and residence time of 140 s.

YB-1 expression promotes epithelial-to-mesenchymal transition in prostate cancer that is inhibited by a small molecule fisetin

Epithelial-to-mesenchymal transition (EMT) plays an important role in prostate cancer (PCa) metastasis. The transcription/translation regulatory Y-box binding protein-1 (YB-1) is known to be associated with cancer metastasis. We observed that YB-1 expression increased with tumor grade and showed an inverse relationship with E-cadherin in a human PCa tissue array. Forced YB-1 expression induced a mesenchymal morphology that was associated with down regulation of epithelial markers. Silencing of YB-1 reversed mesenchymal features and decreased cell proliferation, migration and invasion in PCa cells. YB-1 is activated directly via Akt mediated phosphorylation at Ser102 within the cold shock domain (CSD). We next identified fisetin as an inhibitor of YB-1 activation. Computational docking and molecular dynamics suggested that fisetin binds on the residues from β1 - β4 strands of CSD, hindering Akt's interaction with YB-1. Calculated free binding energy ranged from -11.9845 to -9.6273 kcal/mol. Plasmon Surface Resonance studies showed that fisetin binds to YB-1 with an affinity of approximately 35 µM, with both slow association and dissociation. Fisetin also inhibited EGF induced YB-1 phosphorylation and markers of EMT both in vitro and in vivo. Collectively our data suggest that YB-1 induces EMT in PCa and identify fisetin as an inhibitor of its activation.

Irritant Dermatitis to Staphylinid Beetle in Indian Troops in Congo

BACKGROUND

Contact dermatitis to Staphylinid beetle is a well known entity worldwide. Paederus sabaeus (Econda) species of this insect was responsible for a widespread occurrence of this dermatitis in United Nations (UN) troops posted in Congo. This study was undertaken to observe the various aspects of this unique dermatitis in the mission area.

METHODS

All clinically diagnosed cases of contact dermatitis to Econda occurring in Indian troops posted to UN mission in Congo during the study period were included. Their epidemiological and clinical characteristics with treatment options were studied in detail.

RESULT

A wide range of dermatological manifestations were seen in the subjects under study. Few of the manifestations observed in the study have not been reported earlier in literature. Most of the reactions occurred on the exposed areas. Treatment options were guided by the site and the severity of the reaction.

CONCLUSION

Contact dermatitis to Staphylinid beetle can mimic various other dermatoses and has to be considered in the differential diagnosis in all dermatological consultations during the peak season in the Congo mission area. The insect was found to have certain definite behavioural patterns, the knowledge of which would help in preventing this dermatosis.

AMPA induced Ca2+ influx in motor neurons occurs through voltage gated Ca2+ channel and Ca2+ permeable AMPA receptor

The rise in intracellular Ca(2+) mediated by AMPA subtype of glutamate receptors has been implicated in the pathogenesis of motor neuron disease, but the exact route of Ca(2+) entry into motor neurons is not clearly known. In the present study, we examined the role of voltage gated calcium channels (VGCCs) in AMPA induced Ca(2+) influx and subsequent intracellular signaling events responsible for motor neuron degeneration. AMPA stimulation caused sodium influx in spinal neurons that would depolarize the plasma membrane. The AMPA induced [Ca(2+)](i) rise in motor neurons as well as other spinal neurons was drastically reduced when extracellular sodium was replaced with NMDG, suggesting the involvement of voltage gated calcium channels. AMPA mediated rise in [Ca(2+)](i) was significantly inhibited by L-type VGCC blocker nifedipine, whereas ω-agatoxin-IVA and ω-conotoxin-GVIA, specific blockers of P/Q type and N-type VGCC were not effective. 1-Napthyl-acetyl spermine (NAS), an antagonist of Ca(2+) permeable AMPA receptors partially inhibited the AMPA induced [Ca(2+)](i) rise but selectively in motor neurons. Measurement of AMPA induced currents in whole cell voltage clamp mode suggests that a moderate amount of Ca(2+) influx occurs through Ca(2+) permeable AMPA receptors in a subpopulation of motor neurons. The AMPA induced mitochondrial calcium loading [Ca(2+)](m), mitochondrial depolarization and neurotoxicity were also significantly reduced in presence of nifedipine. Activation of VGCCs by depolarizing concentration of KCl (30mM) in extracellular medium increased the [Ca(2+)](i) but no change was observed in mitochondrial Ca(2+) and membrane potential. Our results demonstrate that a subpopulation of motor neurons express Ca(2+) permeable AMPA receptors, however the larger part of Ca(2+) influx occurs through L-type VGCCs subsequent to AMPA receptor activation and consequent mitochondrial dysfunction is the trigger for motor neuron degeneration. Nifedipine is an effective protective agent against AMPA induced mitochondrial stress and degeneration of motor neurons.

Determination of mitochondrial membrane potential and reactive oxygen species in live rat cortical neurons

Mitochondrial membrane potential (ΔΨm) is critical for maintaining the physiological function of the respiratory chain to generate ATP. A significant loss of ΔΨm renders cells depleted of energy with subsequent death. Reactive oxygen species (ROS) are important signaling molecules, but their accumulation in pathological conditions leads to oxidative stress. The two major sources of ROS in cells are environmental toxins and the process of oxidative phosphorylation. Mitochondrial dysfunction and oxidative stress have been implicated in the pathophysiology of many diseases; therefore, the ability to determine ΔΨm and ROS can provide important clues about the physiological status of the cell and the function of the mitochondria.

Several fluorescent probes (Rhodamine 123, TMRM, TMRE, JC-1) can be used to determine Δψm in a variety of cell types, and many fluorescence indicators (Dihydroethidium, Dihydrorhodamine 123, H₂DCF-DA) can be used to determine ROS. Nearly all of the available fluorescence probes used to assess ΔΨm or ROS are single-wavelength indicators, which increase or decrease their fluorescence intensity proportional to a stimulus that increases or decreases the levels of ΔΨm or ROS. Thus, it is imperative to measure the fluorescence intensity of these probes at the baseline level and after the application of a specific stimulus. This allows one to determine the percentage of change in fluorescence intensity between the baseline level and a stimulus. This change in fluorescence intensity reflects the change in relative levels of ΔΨm or ROS. In this video, we demonstrate how to apply the fluorescence indicator, TMRM, in rat cortical neurons to determine the percentage change in TMRM fluorescence intensity between the baseline level and after applying FCCP, a mitochondrial uncoupler. The lower levels of TMRM fluorescence resulting from FCCP treatment reflect the depolarization of mitochondrial membrane potential. We also show how to apply the fluorescence probe H₂DCF-DA to assess the level of ROS in cortical neurons, first at baseline and then after application of H₂O₂. This protocol (with minor modifications) can be also used to determine changes in ∆Ψm and ROS in different cell types and in neurons isolated from other brain regions.

SPG20 protein spartin associates with cardiolipin via its plant-related senescence domain and regulates mitochondrial Ca2+ homeostasis

Hereditary spastic paraplegias (HSPs) are a group of neurological disorders characterized clinically by spasticity of lower limbs and pathologically by degeneration of the corticospinal tract. Troyer syndrome is an autosomal recessive HSP caused by a frameshift mutation in the spartin (SPG20) gene. Previously, we established that this mutation results in a lack of expression of the truncated mutant spartin protein. Spartin is involved in many cellular processes and associates with several intracellular organelles, including mitochondria. Spartin contains a conserved plant-related senescence domain at its C-terminus. However, neither the function of this domain nor the roles of spartin in mitochondrial physiology are currently known. In this study, we determined that the plant-related senescence domain of spartin interacts with cardiolipin but not with two other major mitochondrial phospholipids, phosphatidylcholine and phosphatidylethanolamine. We also found that knockdown of spartin by small interfering RNA in a human neuroblastoma cell line resulted in depolarization of the mitochondrial membrane. In addition, depletion of spartin resulted in a significant decrease in both mitochondrial calcium uptake and mitochondrial membrane potential in cells treated with thapsigargin. Our results suggest that impairment of mitochondrial calcium uptake might contribute to the neurodegeneration of long corticospinal axons and the pathophysiology of Troyer syndrome.

NMDA and non-NMDA receptor-mediated differential Ca2+ load and greater vulnerability of motor neurons in spinal cord cultures

Glutamate receptor activated neuronal cell death has been implicated in the pathogenesis of motor neuron disease but the molecular mechanism responsible for neuronal dysfunction needs to be elucidated. In the present study, we examined the contribution of NMDA and non-NMDA sub-types of glutamate receptors in selective vulnerability of motor neurons. Glutamate receptor activated Ca2+ signaling, mitochondrial functions and neurotoxicity in motor neurons and other spinal neurons were studied in mixed spinal cord primary cultures. Exposure of cells to glutamate receptor agonists glutamate, NMDA and AMPA elevated the intracellular Ca2+, mitochondrial Ca2+ and caused mitochondrial depolarization and cytotoxicity in both motor neurons and other spinal neurons but a striking difference was observed in the magnitude and temporal patterns of the [Ca2+]i responses between the two neuronal cell types. The motor neurons elicited higher Ca2+ load than the other spinal neurons and the [Ca2+]i levels were elevated for a longer duration in motor neurons. AMPA receptor stimulation was more effective than NMDA. Both the NMDA and non-NMDA receptor antagonists APV and NBQX inhibited the Ca2+ entry and decreased the cell death significantly; however, NBQX was more potent than APV. Our results demonstrate that both NMDA and non-NMDA sub-types of glutamate receptors contribute to glutamate-mediated motor neuron damage but AMPA receptors play the major role. AMPA receptor-mediated excessive Ca2+ load and differential handling/regulation of Ca2+ buffering by mitochondria in motor neurons could be central in their selective vulnerability to excitotoxicity.

Occurrence of the leech Limnatis paluda as a respiratory parasite in man: case report from Saudi Arabia

The leech Limnatis paluda is known to occur as a parasite in the respiratory tract of herbivorous animals. We report the occurrence of Limnatis paluda as a respiratory parasite in man in an area of Saudi Arabia from which it had not been previously described.

Socioeconomic factors and prevalence of endemic goitre

The present study was conducted on 2611 school children of a rural area of Meerut, with the objectives to find out the prevalence and distribution of endemic goitre and the socioeconomic variables associated with the distribution of the endemic goitre. Grading of goitre was done as per the criteria laid down by the WHO-1979 (1). The overall prevalence rate of endemic goitre was 50.1%, the prevalence was more among females (55.1%) as compared to males (47.2%). Maximum number of goitre cases were having grade Ia enlargement (46.9%) followed by grade Ib (34.1%), grade 2(15.0%) and grade 3 (4.0%). Prevalence increased with increase in age. Statistically significant differences were found in the prevalence of endemic goitre in relation to different religions and caste groups, different occupations of the parents/guardians of children and types of houses used for the purpose of living.