Magnetic and magnetocaloric effect study of a polycrystalline Gd0.5Sr0.5-xCaxMnO3 compound.

The magnetic and magnetocaloric properties of polycrystalline Gd0.5Sr0.5-xCaxMnO3 (x = 0.0, 0.2, 0.3, 0.4 and 0.5) compounds have been investigated. Depending upon the Ca and Sr proportions, fascinating magnetic ground states were observed in the Gd0.5Sr0.5-xCaxMnO3 compounds. Here, the dominating nature of the canted magnetic state (for the Gd0.5Ca0.5MnO3 compound) and glassy (disordered ferromagnetic) magnetic state (for the Gd0.5Sr0.5MnO3 compound) are observed. However, for the intermediate doped samples (x = 0.2, 0.3, 0.4), a competing nature is found in their magnetic and exchange bias properties. Additionally, in the low temperature region, a significantly large magnetocaloric effect is observed for all the samples. At a 70 kOe external magnetic field, the highest observed value of the magnetocaloric entropy change is 21.58 J kg-1 K-1 (for the Gd0.5Ca0.5MnO3 sample) and the lowest is 10.15 J kg-1 K-1 (for the Gd0.5Sr0.5MnO3 sample).

'Kodo poisoning': cause, science and management.

Many mycotoxigenic fungi infect the food crops and affect the quality of the produce due to production of mycotoxins. Kodo millet is one of the important minor millets cultivated in India, mostly confined to marginal lands and tribal regions but has high yield potential under good management. The grains are nutritious and have anti-oxidant properties besides having many medicinal properties. However, the consumption is often hindered by the condition called 'kodo poisoning' resulting from fungal contamination producing cyclopiazonic acid, a toxic fungal secondary metabolite. An attempt has been made here to review the limited information available on kodo poisoning, its causes and effects, and proposed management practices by which the contamination can be checked. Further research efforts are essential for identifying sources of natural resistance to fungal metabolite, induction of host resistance through antimicrobial compounds or microbial antagonism to the pathogens to achieve cleaner grains from this crop even under high humid and rainy conditions. By effective adoption of both pre- and post-harvest management the kodo millet grains can be made safe for human consumption and can be popularized as a nutritious grain.

Structural, magnetic, and magnetocaloric properties of the multiferroic host double perovskite compound Pr2FeCrO6.

We have investigated the crystal structure and the nature of the magnetic ground state of the polycrystalline compound Pr2FeCrO6 (PFCO) through X-ray diffraction (XRD), magnetization, and magnetocaloric effect studies. Analysis of the XRD pattern reveals that the PFCO compound exhibits a B-site disordered orthorhombic crystal structure. The random distribution of Fe3+ and Cr3+ magnetic sublattices at the B-sites of the crystallographic unit cell helps to generate several fascinating magnetic properties. The compound exhibits three distinct anomalies in both the temperature dependence of the magnetization and the magnetic entropy change (-ΔS) curves, namely, (i) a G-type canted antiferromagnetic (AFM) ordering of the transition metal ions (TN1), (ii) a progressive spin reorientation (SR) transition (TSR), and (iii) an AFM ordering of Pr3+ sublattices at very low temperature (TN2). Surprisingly, a novel "diamagnetism-like" behavior appears in the low-temperature region for low applied field values. Moreover, we have also constructed the thermal evolution of the magnetic crystal structures in different transition regions with the help of irreducible representations of the crystal symmetry. Overall, our study of B-site disordered PFCO may help to encourage basic fundamental and applied research on disordered rare-earth and transition metal-based perovskite systems due to their interesting magnetic properties over a broad temperature range.

Colonic microbiota can promote rapid local improvement of murine colitis by thioguanine independently of T lymphocytes and host metabolism.

OBJECTIVE: Mercaptopurine (MP) and pro-drug azathioprine are 'first-line' oral therapies for maintaining remission in IBD. It is believed that their pharmacodynamic action is due to a slow cumulative decrease in activated lymphocytes homing to inflamed gut. We examined the role of host metabolism, lymphocytes and microbiome for the amelioration of colitis by the related thioguanine (TG). DESIGN: C57Bl/6 mice with or without specific genes altered to elucidate mechanisms responsible for TG's actions were treated daily with oral or intrarectal TG, MP or water. Disease activity was scored daily. At sacrifice, colonic histology, cytokine message, caecal luminal and mucosal microbiomes were analysed. RESULTS: Oral and intrarectal TG but not MP rapidly ameliorated spontaneous chronic colitis in Winnie mice (point mutation in Muc2 secretory mucin). TG ameliorated dextran sodium sulfate-induced chronic colitis in wild-type (WT) mice and in mice lacking T and B lymphocytes. Remarkably, colitis improved without immunosuppressive effects in the absence of host hypoxanthine (guanine) phosphoribosyltransferase (Hprt)-mediated conversion of TG to active drug, the thioguanine nucleotides (TGN). Colonic bacteria converted TG and less so MP to TGN, consistent with intestinal bacterial conversion of TG to so reduce inflammation in the mice lacking host Hprt. TG rapidly induced autophagic flux in epithelial, macrophage and WT but not Hprt-/- fibroblast cell lines and augmented epithelial intracellular bacterial killing. CONCLUSIONS: Treatment by TG is not necessarily dependent on the adaptive immune system. TG is a more efficacious treatment than MP in Winnie spontaneous colitis. Rapid local bacterial conversion of TG correlated with decreased intestinal inflammation and immune activation.

Ornament size and colour as alternative strategies for effective communication in gliding lizards.

Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity.

Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves.

Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population's habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds.

The emerging role of cardiovascular MRI for risk stratification in hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most common inheritable cardiovascular disorder. Although many HCM patients remain asymptomatic, sudden death (SD) can occur as the initial manifestation of the disease. It has been hypothesized that myocardial architectural disorganization and scarring represent an unstable electrophysiological substrate that creates susceptibility to malignant ventricular arrhythmias. Cardiovascular magnetic resonance imaging (CMR) is widely used for the diagnosis of HCM, especially in patients with an incomplete or inconclusive echocardiography study. CMR can provide precise non-invasive assessment of biventricular function, wall thickness, and assessment of myocardial fibrosis, using inversion recovery gadolinium-enhanced sequences. CMR is also one of the most promising avenues of research in HCM, and in recent years, has provided many new insights and identified a number of potential adverse prognostic indicators for SD. Future work is still needed to integrate CMR findings into traditional risk assessment algorithms. This paper reviews the evolving role of CMR for risk stratification in HCM including assessment of myocardial hypertrophy, fibrosis and ischaemia.

Structural, magnetic, magnetocaloric behavior and magneto-transport, electrical polarization study in 3d based bulk and nano-crystalline multiferroic double perovskite Dy2MnCoO6.

In this paper, we report a detailed investigation of the crystal structure, magnetic, magnetocaloric, magneto-transport and electrical polarization properties of a new multiferroic material in the polycrystalline and nanocrystalline form of the Dy2MnCoO6double perovskite. Both compounds crystallized in the monoclinic structure with P21/n space group. The magnetic properties of both systems are mainly dominant ferromagnetic (FM) and weak antiferromagnetic (AFM). The FM/AFM coupling is related by the competing and combining functions of the radius and the magnetic moments of rare earth ions (i.e. 3d-4f exchange interactions). The reduction of the saturation magnetization in the isothermal magnetization curves can be explained by the existence of anti-phase boundaries and local anti-site defects in the system. Moreover, these materials hold reasonable values of magnetocaloric parameters and the absence of hysteresis makes the system a potential candidate for magnetic refrigeration. These compounds revealed two magnetic phase transitions, according to the appearance of two peaks in the temperature dependence of magnetic entropy change curves. The temperature dependent resistivity data for both the systems display semiconductor nature near room temperature and insulating like behavior at low temperature regime. The variable-range hopping conduction mechanism is used to best understand their transport mechanism. In addition, the electrical polarization loop at low temperature confirms the presence of ferroelectricity for both the studied systems. The decreases polarization under an external magnetic field evidence the weak magnetoelectric coupling. The coexistence of FM ordering with insulating behavior and ferroelectricity at low temperature promises new opportunities and improvements in next generation applications for information storage, spintronic, and sensors.

Giant magnetoresistance resulting from superzone gap in spin-frustrated rare-earth-based aluminide: DyFe2Al10.

The magnetic properties of orthorhombic aluminides have recently been the subject of investigation, revealing several intriguing phenomena within this class of materials. However, the exploration of their magnetic and electrical transport phenomena has remained somewhat limited. In this study, we delve into the magnetic and electrical transport characteristics of one such material from that group which is DyFe2Al10(DFA). Our findings go beyond classifying this material as a simple antiferromagnet; but it posses a short range ferromagnetic ordering apart from helical spin structure of Dy3+. It exhibits a metamagnetic transition and spin glass behavior below its Néel temperature (TN). Our analysis of electrical magnetotransport behavior indicates the emergence of an antiferromagnetic superzone gap, resulting in a significant enhancement in magnetoresistance effect. This discovery paves the way for a class of materials with complex interactions and notable magnetoresistance properties.

Large magnetocaloric effect and giant magnetoresistance in rare earth based intermetallic compound ErAl3: construction of magnetic phase diagram.

This study explores the magnetic and magnetotransport behavior of polycrystalline ErAl3compound. The polycrystalline compound adopts HoAl3-type structures with the R-3m space group, No. 166-2 and hR60 configurations. Multiple magnetic orderings and two field-induced metamagnetic transitions are observed. ErAl3exhibits a significant magnetocaloric effect (MCE),-ΔSM= 15.25 J kg-1K-1and high relative cooling power of 383 J kg-1with applied magnetic field change (ΔH) of 70 kOe near the paramagnetic to ferromagnetic transition, showcasing its potential for magnetic refrigeration technology. The compound also demonstrates metallic behavior, with a notable magnetoresistance of 48.5%at 2 K due to the suppression of antiferromagnetism. The magnetic phase diagram reveals four distinct phases influenced by temperature and magnetic field, identified through the study of the MCE.

Exploring the diversity of virulence genes in the Magnaporthe population infecting millets and rice in India.

Blast pathogen, Magnaporthe spp., that infects ancient millet crops such pearl millet, finger millet, foxtail millet, barnyard millet, and rice was isolated from different locations of blast hotspots in India using single spore isolation technique and 136 pure isolates were established. Numerous growth characteristics were captured via morphogenesis analysis. Among the 10 investigated virulent genes, we could amplify MPS1 (TTK Protein Kinase) and Mlc (Myosin Regulatory Light Chain edc4) in majority of tested isolates, regardless of the crop and region where they were collected, indicating that these may be crucial for their virulence. Additionally, among the four avirulence (Avr) genes studied, Avr-Pizt had the highest frequency of occurrence, followed by Avr-Pia. It is noteworthy to mention that Avr-Pik was present in the least number of isolates (9) and was completely absent from the blast isolates from finger millet, foxtail millet, and barnyard millet. A comparison at the molecular level between virulent and avirulent isolates indicated observably large variation both across (44%) and within (56%) them. The 136 Magnaporthe spp isolates were divided into four groups using molecular markers. Regardless of their geographic distribution, host plants, or tissues affected, the data indicate that the prevalence of numerous pathotypes and virulence factors at the field level, which may lead to a high degree of pathogenic variation. This research could be used for the strategic deployment of resistant genes to develop blast disease-resistant cultivars in rice, pearl millet, finger millet, foxtail millet, and barnyard millet.

Asymptomatic transmission of Treponema pallidum (syphilis) through deceased donor liver transplantation.

A 55-year-old woman underwent liver transplantation (LT) with a graft from a deceased donor. Mandatory pre-donation investigations showed positive syphilis serology that was available only after the transplant, with high Treponema pallidum particle agglutination assay titer compatible with donor syphilis infection. Despite the institution of appropriate post-exposure prophylaxis, the recipient demonstrated latent seroconversion; however, liver graft function improved without evidence of syphilitic hepatitis or other manifestations of the disease. Through this first reported case of asymptomatic transmission of syphilis following LT, we highlight the investigations and treatment strategies for donor-derived syphilis in liver transplant recipients. This report supplements the existing limited evidence on safe use of infected grafts from syphilitic donors through appropriate post-exposure prophylaxis.

Use of daptomycin in complicated cases of infective endocarditis.

Infective endocarditis (IE) is a serious form of infection with a high mortality. Medical management can be a challenge because of organ dysfunction, lack of clinical response or allergy to the recommended antibiotics. Daptomycin is a lipopeptide antibiotic with a potent bactericidal activity against Gram-positive bacteria. There are limited data on the use of daptomycin in complicated cases of IE. We aim to report our experience of daptomycin use in complicated cases of IE through a prospective observational study (from 1 October 2008 to 30 September 2009). Daptomycin was prescribed for cases that were either unresponsive or allergic to the standard therapy. Clinical characteristics and outcomes were reviewed. Success was defined as clinical improvement accompanied with the resolution of laboratory markers of sepsis and continuation of the above findings for at least 8 weeks after the end of therapy. Eight cases were evaluable. Native and prosthetic valves were involved in equal proportions. The range of organisms was wide: Staphylococcus aureus, two cases; S. epidermidis, two cases; streptococci, two cases; and Enterococcus faecalis, two cases. The median duration of therapy was 42 days. All patients were successfully treated. Daptomycin was well tolerated. Daptomycin is useful in the management of complicated cases of IE.

Spin-polarized tunneling and polaronic transport properties of polycrystalline (Sm1-yGdy)0.55Sr0.45MnO3(y= 0.5 and 0.7) compounds.

The detail investigations on the magneto-transport properties of the polycrystalline (Sm0.3Gd0.7)0.55Sr0.45MnO3(SGSMO-1) and (Sm0.5Gd0.5)0.55Sr0.45MnO3(SGSMO-2) compounds, having a glassy-like and ferromagnetic ground states respectively have been carried out in details. Due to the existence of two different magnetic ground states in the above mentioned systems, the magneto-transport properties are markedly differed from each other, specially at the low temperature region. The highly semi-conducting nature of the SGSMO-1 compound is suppressed with the application of magnetic field, whereas the SGSMO-2 compound exhibits a metal-insulator transition in its pristine state. The high-temperature semiconducting state of both the systems can be well-explained with the polaronic transport mechanisms via small-polaron hopping and variable-range-hopping models. The low-temperature metallic states for both the systems are explored by considering the various contributions arise from the grain boundary effect, electron-electron, electron-phonon, electron-magnon etc scattering processes. The spin-polarized tunneling transport mechanism at the grain boundaries plays a crucial role in the enhancement of low-field magnetoresistance in the studied systems.

Real-space imaging of magnetic phase transformation in single crystalline Sm-Ca-Sr based manganite compound.

Low-temperature-high-magnetic field magnetic force microscopy studies on colossal magnetoresistance material Sm0.5Ca0.25Sr0.25MnO3have been carried out. These measurements provide real-space visualization of antiferromagnetic-ferromagnetic (AFM-FM) transition on sub-micron length scale and explain the presence of AFM-FM transition in the temperature-dependent magnetization measurements, but the absence of corresponding metal-insulator transition in temperature-dependent resistivity measurements at the low magnetic field. Distribution of transition temperature over the scanned area indicates towards the quench disorder broadening of the first-order magnetic phase transition. It shows that the length scale of chemical inhomogeneity extends over several micrometers.

Anomalous structural behavior and antiferroelectricity in BiGdO3: detailed temperature and high-pressure study.

A comprehensive temperature and high-pressure investigation on BiGdO3is carried out by means of dielectric constant, piezoelectric current, polarization-electric field loop, Raman scattering and x-ray diffraction measurements. Temperature dependent dielectric constant and dielectric loss show two anomalies at about 290 K (Tr) and 720 K (TC). The latter anomaly is most likely due to antiferroelectric to paraelectric transition as hinted by piezoelectric current and polarization-electric field loop measurements at room temperature, while the former anomaly suggests reorientation of polarization. A small deviation from linear behaviour of both the Raman modes due to structural modification in the vicinity ofTC; and sharp decrease in integrated intensities of these two modes aboveTCprovide further proof for the above antiferroelectric to paraelectric transition. Cubic to monoclinic structural transition is observed at about 10 GPa in high-pressure x-ray diffraction studies accompanied by anisotropic lattice parameter changes and large unit cell volume collapse during the transition. This structural transition is corroborated by anomalous softening and large increase in full width half maximum of M2(640 cm-1) Raman mode above 10 GPa. We speculate that enhancement of large structural distortion and large reduction inc/aratio above 10 GPa might be associated with antiferroelectric to ferroelectric transition in the system.

Development of Sorghum Genotypes for Improved Yield and Resistance to Grain Mold Using Population Breeding Approach.

The infection caused by grain mold in rainy season grown sorghum deteriorates the physical and chemical quality of the grain, which causes a reduction in grain size, blackening, and making them unfit for human consumption. Therefore, the breeding for grain mold resistance has become a necessity. Pedigree breeding has been widely used across the globe to tackle the problem of grain mold. In the present study, a population breeding approach was employed to develop genotypes resistant to grain mold. The complex genotype × environment interactions (GEIs) make the task of identifying stable grain mold-resistant lines with good grain yield (GY) challenging. In this study, the performance of the 33 population breeding derivatives selected from the four-location evaluation of 150 genotypes in 2017 was in turn evaluated over four locations during the rainy season of 2018. The Genotype plus genotype-by-environment interaction (GGE) biplot analysis was used to analyze a significant GEI observed for GY, grain mold resistance, and all other associated traits. For GY, the location explained a higher proportion of variation (51.7%) while genotype (G) × location (L) contributed to 21.9% and the genotype contributed to 11.2% of the total variation. For grain mold resistance, G × L contributed to a higher proportion of variation (30.7%). A graphical biplot approach helped in identifying promising genotypes for GY and grain mold resistance. Among the test locations, Dharwad was an ideal location for both GY and grain mold resistance. The test locations were partitioned into three clusters for GY and two clusters for grain mold resistance through a "which-won-where" study. Best genotypes in each of these clusters were selected. The breeding for a specific cluster is suggested. Genotype-by-trait biplots indicated that GY is influenced by flowering time, 100-grain weight (HGW), and plant height (PH), whereas grain mold resistance is influenced by glume coverage and PH. Because GY and grain mold score were independent of each other, there is a scope to improve both yield and resistance together.

Determination of the depth dose distribution of proton beam using PRESAGE™ dosimeter.

PRESAGE™ dosimeter dosimeter has been proved useful for 3D dosimetry in conventional photon therapy and IMRT [1-5]. Our objective is to examine the use of PRESAGE™ dosimeter for verification of depth dose distribution in proton beam therapy. Three PRESAGE™ samples were irradiated with a 79 MeV un-modulated proton beam. Percent depth dose profile measured from the PRESAGE™ dosimeter is compared with data obtained in a water phantom using a parallel plate Advanced Markus chamber. The Bragg-peak position determined from the PRESAGE™ is within 2 mm compared to measurements in water. PRESAGE™ shows a highly linear response to proton dose. However, PRESAGE™ also reveals an underdosage around the Bragg peak position due to LET effects. Depth scaling factor and quenching correction factor need further investigation. Our initial result shows that PRESAGE™ has promising dosimetric characteristics that could be suitable for proton beam dosimetry.

Utilisation of waste medicine wrappers as an efficient low-cost electrode material for microbial fuel cell.

Waste generation from healthcare facilities now has become a concerning issue as it contain plastic and metals. Medicine wrappers are one of the major portions of healthcare solid waste, which impel intensive solid waste management practice due to fewer possibilities of deriving by-products. However, it can be recycled and used as an electrode material in microbial fuel cells (MFCs). An electrode material for application in MFCs is a crucial component, which governs total fabrication cost as well as power recovery, thus a cost-effective, stable and durable electrode is essential. In this endeavour, a new metallic (aluminium) waste material, a waste medicine wrapper (WMW), was evaluated for feasibility to be used as anode/cathode in MFCs. Based on the stability test under corrosive environment (1 N KCl), the WMW electrode sustained a maximum current of 46 mA during cyclic voltammetry (CV) and noted only 14% reduction in current at an applied voltage of +0.4 V after 2500 s in chronoamperometry, indicating its good stability. Power recovery from MFC using WMW was higher than the MFC using bare carbon felt as an anode (27 vs. 21 mW/m2). The entire analytical test results viz. CV, electrochemical impedance spectroscopy and power performance established WMW as an excellent anode rather than cathode material.

Low temperature conductivity in ferromagnetic manganite thin films: quantum corrections and inter-granular transport.

The interplay between inter-granular transport and quantum corrections to low temperature transport properties of La(0.67)Sr(0.33)MnO(3) (LSMO) and Nd(0.67)Sr(0.33)MnO(3) (NSMO) thin films has been discussed. All the samples exhibit characteristics of renormalized electron-electron interaction in two dimensions. The contrasting response of the low temperature transport to magnetic field in the LSMO and NSMO films is attributed to the strikingly different magnetic field sensitivity of the inter-granular transport.