Ligand field design enables quantum manipulation of spins in Ni2+ complexes.

Creating the next generation of quantum systems requires control and tunability, which are key features of molecules. To design these systems, one must consider the ground-state and excited-state manifolds. One class of systems with promise for quantum sensing applications, which require water solubility, are d8 Ni2+ ions in octahedral symmetry. Yet, most Ni2+ complexes feature large zero-field splitting, precluding manipulation by commercial microwave sources due to the relatively large spin-orbit coupling constant of Ni2+ (630 cm-1). Since low lying excited states also influence axial zero-field splitting, D, a combination of strong field ligands and rigidly held octahedral symmetry can ameliorate these challenges. Towards these ends, we performed a theoretical and computational analysis of the electronic and magnetic structure of a molecular qubit, focusing on the impact of ligand field strength on D. Based on those results, we synthesized 1, [Ni(ttcn)2](BF4)2 (ttcn = 1,4,7-trithiacyclononane), which we computationally predict will have a small D (Dcalc = +1.15 cm-1). High-field high-frequency electron paramagnetic resonance (EPR) data yield spin Hamiltonian parameters: gx = 2.1018(15), gx = 2.1079(15), gx = 2.0964(14), D = +0.555(8) cm-1 and E = +0.072(5) cm-1, which confirm the expected weak zero-field splitting. Dilution of 1 in the diamagnetic Zn analogue, [Ni0.01Zn0.99(ttcn)2](BF4)2 (1') led to a slight increase in D to ∼0.9 cm-1. The design criteria in minimizing D in 1via combined computational and experimental methods demonstrates a path forward for EPR and optical addressability of a general class of S = 1 spins.

Structurally Defined Water-Soluble Metallofullerene Derivatives towards Biomedical Applications.

Endohedral metallofullerenes (EMFs) are excellent carriers of rare-earth element (REE) ions in biomedical applications because they preclude the release of toxic metal ions. However, existing approaches to synthesize water-soluble EMF derivatives yield mixtures that inhibit precise drug design. Here we report the synthesis of metallobuckytrio (MBT), a three-buckyball system, as a modular platform to develop structurally defined water-soluble EMF derivatives with ligands by choice. Demonstrated with PEG ligands, the resulting water-soluble MBTs show superb biocompatibility. The Gd MBTs exhibit superior T1 relaxivity than typical Gd complexes, potentially superseding current clinical MRI contrast agents in both safety and efficiency. The Lu MBTs generated reactive oxygen species upon light irradiation, showing promise as photosensitizers. With their modular nature to incorporate other ligands, we anticipate the MBT platform to open new paths towards bio-specific REE drugs.

Spin-Lattice Relaxation Decoherence Suppression in Vanishing Orbital Angular Momentum Qubits.

Multifrequency electron paramagnetic resonance spectroscopy on oriented single crystals of magnetically dilute Gd(III) ions in Gd0.004Y0.996(trensal) is used to determine the Hamiltonian parameters of the ground 8S7/2 term and its phase memory time, Tm, characterizing its coherent spin dynamics. The vanishing orbital angular momentum of the 8S7/2 term makes it relatively insensitive to spin-lattice relaxation mediated by magnetoelastic coupling and leads to a Tm of 12 µs at 3 K, which is not limited by spin-lattice relaxation.

Spinning-Driven Dynamic Nuclear Polarization with Optical Pumping.

We propose a new, more efficient, and potentially cost effective, solid-state nuclear spin hyperpolarization method combining the cross-effect mechanism and electron spin optical hyperpolarization in rotating solids. We first demonstrate optical hyperpolarization in the solid state at low temperatures and low field and then investigate its field dependence to obtain the optimal condition for high-field electron spin hyperpolarization. The results are then incorporated into advanced magic-angle spinning dynamic nuclear polarization (MAS-DNP) numerical simulations that show that optically pumped MAS-DNP could yield breakthrough enhancements at very high magnetic fields. Based on these investigations, enhancements greater than the ratio of electron to nucleus magnetic moments (>658 for 1H) are possible without microwave irradiation. This could solve at once the MAS-DNP performance decrease with increasing field and the high cost of MAS-DNP instruments at very high fields.

A 9.2-GHz clock transition in a Lu(II) molecular spin qubit arising from a 3,467-MHz hyperfine interaction.

Spins in molecules are particularly attractive targets for next-generation quantum technologies, enabling chemically programmable qubits and potential for scale-up via self-assembly. Here we report the observation of one of the largest hyperfine interactions for a molecular system, Aiso = 3,467 ± 50 MHz, as well as a very large associated clock transition. This is achieved through chemical control of the degree of s-orbital mixing into the spin-bearing d orbital associated with a series of spin-½ La(II) and Lu(II) complexes. Increased s-orbital character reduces spin-orbit coupling and enhances the electron-nuclear Fermi contact interaction. Both outcomes are advantageous for quantum applications. The former reduces spin-lattice relaxation, and the latter maximizes the hyperfine interaction, which, in turn, generates a 9-GHz clock transition, leading to an increase in phase memory time from 1.0 ± 0.4 to 12 ± 1 µs for one of the Lu(II) complexes. These findings suggest strategies for the development of molecular quantum technologies, akin to trapped ion systems.

Case Report: A Fatal Case of Babesiosis in a Splenectomized Male Patient from Western India.

Human babesiosis is a rare disease, caused by Babesia species and commonly transmitted by tick bite. Although human babesiosis is known to be asymptomatic in immunocompetent hosts, clinical cases of severe babesiosis have been reported from splenectomized or immunocompromised individuals. To our knowledge, only one case of human babesiosis in India has been previously reported. Here, we report a case of severe babesiosis with high parasitemia (∼70%) in a 30-year-old asplenic farmer. The patient presented with fever, yellowish discoloration of skin, oliguria, and anemia; he eventually developed multiorgan failure syndrome and died. Peripheral blood films were prepared and used to confirm the presence of piroplasms by microscopy. Total DNA isolated from blood was used for 18S ribosomal RNA gene fragment amplification by polymerase chain reaction, which was subject to Sanger sequencing. Although 18S sequence indicated that the Babesia species infecting the patient was similar to that of other Babesia species originating from wild mammals, species identification could not be done. Phylogenetic analysis revealed that the patient-derived pathogen is distinct because it forms a separate clade in the cladogram.

Quantification of Eimeria necatrix, E. acervulina and E. maxima genomes in commercial chicken farms by quantitative real time PCR.

Advent of quantitative polymerase chain reaction and its variants have enabled identification and quantification of seven known Eimeria species of poultry in biological samples. Attempts were made in the present study to identify and quantify three important pathogenic Eimeria species responsible for intestinal coccidiosis in domestic farmed chicken, E. necatrix, E. acervulina and E. maxima in droppings collected from thirty one poultry farms of North Indian states of Haryana, Punjab, Uttar Pradesh and Uttarakhand. The study included broiler, layer and backyard rearing units. Overall occurrence of E. necatrix, E. maxima and E. acervulina was 64.5%. E. necatrix was detected in 55% (11/20) broiler farms, 66.7% (4/6) layer farms and 100% (5/5) backyard rearing units studied. Thus, occurrence of E. necatrix was detected in 64.5% (20/31) farms studied. E. maxima and E. acervulina were detected in droppings of 65% (13/20) broiler farms, 66.7% (4/6) layer farms and 60% (3/5) back yard rearing units. Genome counts of each Eimeria species revealed maximum parasite load of E. necatrix followed by E. acervulina in broiler farms and least in layer farms. The mean parasite load (genome) copies for these parasite species were intermediate for backyard units while E. maxima had the lowest number of genome copies in droppings. Mean E. maxima counts were highest in boiler farms, while it was similar for layer and back yard units. However, statistically no significant differences were observed for parasite load existing either between the broiler, layer or back yard units or between the genome counts of E. necatrix, E. acervulina or E. maxima.

A metabolically engineered spin-labeling approach for studying glycans on cells.

Metabolic glycan engineering (MGE) coupled with nitroxide spin-labeling (SL) was utilized to investigate the heterogeneous environment of cell surface glycans in select cancer and normal cells. This approach exploited the incorporation of azides into cell surface glycans followed by a click reaction with a new nitroxide spin label. Both sialic acid and N-acetylglucosamine (GlcNAc) were targeted for spin labelling. Although each of these moieties experiences a diverse and heterogeneous glycan environment, their EPR spectra and hence mobility are both characterized as a linear combination of two distinct spectra where one component reflects a highly mobile or uncrowded micro-environment with the second component reflecting more restricted motion, reflective of increased crowding and packing within the glycocalyx. What differs among the spectra of the targeted glycans is the relative percentage of each component, with sialic acid moieties experiencing on average an ∼80% less crowded environment, where conversely GlcNAc/GalNAz labeled sites reported on average a ∼50% more crowded environment. These distinct environments are consistent with the organization of sugar moieties within cellular glycans where some residues occur close to the cell membrane/protein backbone (i.e. more restricted) and others are more terminal in the glycan (i.e. more mobile). Strikingly, different cell lines displayed varied relative populations of these two components, suggesting distinctive glycan packing, organization, and composition of different cells. This work demonstrates the capability of SDSL EPR to be a broadly useful tool for studying glycans on cells, and interpretation of the results provides insights for distinguishing the differences and changes in the local organization and heterogeneity of the cellular glycocalyx.

Mitochondrial cytochrome oxidase C subunit III (cox3) gene as a sensitive and specific target for molecular detection of Babesia gibsoni infection in dogs.

A PCR targeting mitochondrial cytochrome oxidase subunit III (cox3) for molecular detection of Babesia gibsoni infection in dogs has been developed in this study. Fifty blood samples from suspected clinical cases from dogs, brought to the veterinary college clinics, were examined for presence of B. gibsoni using conventional diagnosis by microscopic examination of Giemsa stained thin blood smears. In addition, species specific PCRs targeting ITS-1 region (BgITS-1 PCR) and nested PCR targeting 18S ribosomal RNA gene (Bg18SnPCR) were carried out. A 634 bp PCR fragment of B. gibsoni cox3 gene was amplified in positive samples from three geographical locations of Satara, Wai and Pune in Maharashtra state of India. From analysis of the sequence of the B. gibsoni cox3 gene, we found that the Indian isolate had 96-98% similarity to the isolate from Japan and China. Post sequencing, de-novo diagnostic primer pair for species specific amplification of 164 bp fragment of B. gibsonicox3 was designed and the PCR was standardized. The diagnostic results of de-novo Bgcox3 PCR were compared with BgITS-1 PCR and Bg18S nPCR. Thin blood smears detected 22% (11/50) samples positive for small form of Babesia species. The BgITS-1 PCR detected 25% samples (15/50) as positive and Bg18S nPCR detected 80% (40/50) B. gibsoni positive samples. The de-novo Bgcox3 PCR detected 66% (33/50) samples positive for B. gibsoni (at 95% CI). The analytical sensitivity of cox3 PCR was evaluated as 0.000003% parasitaemia or 09 parasites in 100  µl of blood. The de-novo diagnostic cox3 PCR did not cross react with control positive DNA from other haemoprotozoa and rickettsia like B. vogeli, Hepatozoon canis, Trypanosoma evansi, Ehrlichia canis and Anaplasma platys. Statistically, cox3 PCR had better diagnostic efficiency than ITS-1 PCR in terms of sensitivity (p = 0.0006). No statistically significant difference between results of cox3 PCR and 18S nPCR was observed (p = 0.1760). Kappa values estimated for each test pair showed fair to moderate agreement between the observations. Specificity of Bgcox3 PCR was 100% when compared with microscopy or BgITS-1 PCR. Sensitivity of Bgcox3 PCR was 100% when compared with that of Bg18S nPCR.

Canine babesiosis among working dogs of organised kennels in India: A comprehensive haematological, biochemical, clinicopathological and molecular epidemiological multiregional study.

Canine babesiosis is a serious disease among tick-borne haemoprotozoan diseases, globally. The present study was envisaged for carrying out thorough investigation of the disease among working dogs of organised kennels situated in different agro-climatic zones of India as comprehensive understanding of the disease from this country was pertinently lacking. During the study period of three years (2012-2014), 330 dogs suspected for babesiosis were examined for clinicopathology by their physical examination, haematological and biochemical parameters estimation, while the detection of apicomplexan parasites was confirmed by using various diagnostic techniques i.e. by conventional microscopy, by two different Babesia specific 18S rRNA based PCR protocols (conventional/simple PCR and nested PCR assays) followed by sequencing of obtained PCR amplicons for Babsesia spp. identification. Out of 330 clinical cases screened 5.15% (17/330), 9.09% (30/330) and 15.45% (51/330) were found to be positive in microscopic examination, simple- and nested- PCR assay, respectively. Comparative statistical analyses of these diagnostic assay results revealed that significant difference exists among the three diagnostic methodologies and thus it is recommended that the nested PCR technique be relied upon as a screening molecular assay and also for epidemiological studies of the disease in this country. Phylogenetic analysis based on 18S rRNA depicted the monophyletic nature and clonal expansion among all the B. gibsoni, under study. Sequencing results of PCR amplicons revealed that B. gibsoni has predominantly established itself over B. vogeli as former was incriminated in 47 cases while latter was confirmed in only four animals. Based on the clinical severity, these 51 affected animals were classified into three main groups' of 17 animals each viz., apparently healthy-, simple or uncomplicated babesiosis- and atypical or complicated babesiosis- group. Haematological and biochemical profiling of these dogs confirmed the characteristics findings of infection by both the Babesia spp. It was observed that the infection by small form of Babesia (B. gibsoni) is posing a significant therapeutic challenge and chemosterilization by commonly prescribed anti-protozoal drugs was not achieved as clinical relapses were often observed. The clinical signs, sequence based confirmation and severity of the infection suggested that there is a positive selection of B. gibsoni (smaller form) over B. vogeli (larger form) in this country and raises serious concerns as prognosis in former is considered to be poor compared to latter. Thus, these findings have opened new paradigms for planning of pragmatic control strategies against this emerging canine health problem.

The effects of sample conductivity on the efficacy of dynamic nuclear polarization for sensitivity enhancement in solid state NMR spectroscopy.

In recent years dynamic nuclear polarization (DNP) has greatly expanded the range of materials systems that can be studied by solid state NMR spectroscopy. To date, the majority of systems studied by DNP were insulating materials including organic and inorganic solids. However, many technologically-relevant materials used in energy conversion and storage systems are electrically conductive to some extent or are employed as composites containing conductive additives. Such materials introduce challenges in their study by DNP-NMR which include microwave absorption and sample heating that were not thoroughly investigated so far. Here we examine several commercial carbon allotropes, commonly employed as electrodes or conductive additives, and consider their effect on the extent of solvent polarization achieved in DNP from nitroxide biradicals. We then address the effect of sample conductivity systematically by studying a series of carbons with increasing electrical conductivity prepared via glucose carbonization. THz spectroscopy measurements are used to determine the extent of µw absorption. Our results show that while the DNP performance significantly drops in samples containing the highly conductive carbons, sufficient signal enhancement can still be achieved with some compromise on conductivity. Furthermore, we show that the deleterious effect of conductive additives on DNP enhancements can be partially overcome through pulse-DNP experiments.

Theoretical Aspects of the Cross Effect Enhancement of Nuclear Polarization under Static Dynamic Nuclear Polarization Conditions.

In this study, we perform quantum calculations of the spin dynamics of a small spin system that includes nine coupled electrons and one nucleus placed in an external magnetic field and exposed to microwave irradiation. This is an extension of a previous work in which we have demonstrated on a system of 11 coupled electron spins the dynamics of the electron polarizations composing the electron paramagnetic resonance (EPR) line during static dynamic nuclear polarization (DNP) experiments. There we have shown that the electron polarizations are determined by a spectral diffusion process, induced by the dipolar interaction and cross-relaxation. Additionally, we showed that a distinction had to be made between strong and weak dipolar-coupled systems relative to the inhomogeneity of the EPR line with only the first behaving according to the thermal mixing DNP (with two electron spin temperatures) description. The EPR spectra in the weak and strong dipolar interaction cases show different types of spectral features. In the extended spin system, we again make a distinction between weak and strong electron-electron interactions and show that the DNP spectra for the two cases are different in nature but that the DNP spectra can be derived in all cases from the EPR line shapes using the indirect cross effect.

Experimental quantification of electron spectral-diffusion under static DNP conditions.

Dynamic Nuclear Polarization (DNP) is an efficient technique for enhancing NMR signals by utilizing the large polarization of electron spins to polarize nuclei. The mechanistic details of the polarization transfer process involve the depolarization of the electrons resulting from microwave (MW) irradiation (saturation), as well as electron-electron cross-relaxation occurring during the DNP experiment. Recently, electron-electron double resonance (ELDOR) experiments have been performed under DNP conditions to map the depolarization profile along the EPR spectrum as a consequence of spectral diffusion. A phenomenological model referred to as the eSD model was developed earlier to describe the spectral diffusion process and thus reproduce the experimental results of electron depolarization. This model has recently been supported by quantum mechanical calculations on a small dipolar coupled electron spin system, experiencing dipolar interaction based cross-relaxation. In the present study, we performed a series of ELDOR measurements on a solid glassy solution of TEMPOL radicals in an effort to substantiate the eSD model and test its predictability in terms of electron depolarization profiles, in the steady-state and under non-equilibrium conditions. The crucial empirical parameter in this model is ΛeSD, which reflects the polarization exchange rate among the electron spins. Here, we explore further the physical basis of this parameter by analyzing the ELDOR spectra measured in the temperature range of 3-20 K and radical concentrations of 20-40 mM. Simulations using the eSD model were carried out to determine the dependence of ΛeSD on temperature and concentration. We found that for the samples studied, ΛeSD is temperature independent. It, however, increases with a power of ∼2.6 of the concentration of TEMPOL, which is proportional to the average electron-electron dipolar interaction strength in the sample.

Abortions in an organized dairy farm from North India reveal the possibility of breed susceptibility to Bovine Brucellosis.

The present study was undertaken over a three year period (2012-2014) in an organized dairy farm located in North India to ascertain Brucella abortus as the putative cause of abortion. The dairy farm maintained cattle of Frieswal, Crossbred and Sahiwal breeds and followed calf-hood vaccination with Brucella abortus Strain 19 live vaccine in all the heifers. Even with the recommended vaccination schedule and good managemental practices in place, 88 cases of abortions clinically suspected of bovine brucellosis (40 from Frieswal breed, 17 from Crossbred cattle and 31 from Sahiwal breed) were reported from this farm. From these abortion cases, bacteriological isolation was possible in only four dams while 16 dams were found to be serologically positive in Serum Tube Agglutination Test (STAT). Molecular screening by PCR assay (specific for the bcsp31 gene of B. abortus) revealed that 24 dams were positive, out of which 20 were from Frieswal breed and rest four were from Crossbred herd. Prominently, all Sahiwal dams were found to be negative in bacteriological isolation and also in PCR assay. These results thus indicate towards the possibility of breed predisposition to abortions due to B. abortus infection. Statistical analysis by Fischer exact test (p < 0.01) too substantiated that breed susceptibility exists among these PCR positive cases. This study is novel as breed variation in abortions due to B. abortus in cattle is being documented for the first time. Seven representative PCR amplicons generated during the study were also sequenced and submitted to NCBI GenBank. Moreover, this study also accentuates the importance of PCR screening especially in vaccinated herd and raises concerns on over-dependence of serological assays when intensive vaccination is practised without any concomitant DIVA strategy. Thus, besides assisting in planning pragmatic control strategies against bovine brucellosis these findings are also imperative from 'One Health' context, also.

Electron-Electron Cross-Relaxation and Spectral Diffusion during Dynamic Nuclear Polarization Experiments on Solids.

Recently it has been shown that experimental electron-electron double resonance (ELDOR) spectra of amorphous glasses containing free radicals with inhomogeneously broadened electron paramagnetic resonance (EPR) spectra can be analyzed using a set of coupled rate equations for the electron polarizations of frequency bins composing these spectra, named the eSD (electron spectral diffusion) model. The rate matrix defining these equations has elements depending on the microwave, the spin-lattice relaxation rates and on eSD rate constants responsible for polarization exchange. In this study, we show that in addition to the static dipolar flip-flop terms in the Hamiltonian a zero-quantum electron cross-relaxation mechanism can be responsible for the polarization exchange process in our samples. This conclusion was reached by calculating the EPR lineshapes of a system of 11 coupled electrons exposed to microwave irradiation using an eigenstate population rate equation derived from the spin density vector rate equation in Liouville space. These equations involve all terms of the Hamiltonian and in addition rate constants representing longitudinal relaxation and cross-relaxation mechanisms as well as MW irradiation. The results of these calculations are compared with the results obtained from the eSD model.

Canine Monocytic Ehrlichiosis among working dogs of organised kennels in India: A comprehensive analyses of clinico-pathology, serological and molecular epidemiological approach.

Canine Monocytic Ehrlichiosis (CME) is a serious tick-borne rickettsial disease affecting canine populations globally. Besides few reports from stray and pet dogs from localised geographical regions (cities/towns/small states), a comprehensive study on prevalence of Ehrlichia canis (E. canis) among working dogs from different geo-climatic zones of India was pertinently lacking. Study of CME among these dog populations was thus carried out, encompassing clinical aspects and different diagnostic methodologies viz., microscopy, serology and molecular biology. During the two-year study period, clinical specimens from 225 cases suspected of canine ehrlichiosis were examined for clinical pathology and presence of the haemoparasites. Overall prevalence of ehrlichiosis by microscopic examination, commercial dot-ELISA kit and nested PCR assay was estimated to be 1.3%, 19.1% and 5.8%, respectively, which were found to be statistically significant by McNemar Chi squared test (p<0.05). It was also observed that possibly due to widespread use of doxycycline therapy in field, CME presently does not remain a potential threat which it uses to pose earlier. However, concurrent infections of E. canis and Babesia gibsoni were found to be mostly fatal. Keeping in view of high number of apparently healthy dogs (24) out of total positive cases (46) observed during the study, it is recommended that prevalence studies on CME should also involve screening of apparently healthy dogs. Phylogenetic analysis carried on partial sequencing of 16S rRNA of E. canis strains revealed that all of the Indian strains clustered in a single clade with other E. canis species from India and rest of the world. Molecular divergence was observed among the sequences of Brazilian and American isolates which were also included in the present study. These findings have thus opened a new paradigm for planning of pragmatic control strategies against CME.

Humoral and cytokine response elicited during immunisation with recombinant Immune Mapped protein-1 (EtIMP-1) and oocysts of Eimeria tenella.

Eimeria tenella, the causative agent of caecal coccidiosis, is a pathogenic gut dwelling protozoan which can cause severe morbidity and mortality in farmed chickens. Immune mapped protein-1 (IMP-1) has been identified as an anticoccidial vaccine candidate; in the present study allelic polymorphism was assessed across the IMP-1 coding sequence in E. tenella isolates from four countries and compared with the UK reference Houghton strain. Nucleotide diversity was low, limited to expansion/contraction of a CAG triplet repeat and five substitutions, three of which were non-synonymous. The EtIMP-1 coding sequence from a cloned Indian E. tenella isolate was expressed in E. coli and purified as a His-tagged thioredoxin fusion protein. An in-vivo vaccination and challenge trial was conducted to test the vaccine potential of recombinant EtIMP-1 (rEtIMP-1) and to compare post-vaccination immune responses of chickens to those stimulated by live oocyst infection. Following challenge, parasite replication measured using quantitative PCR was significantly reduced in chickens that had been vaccinated with rEtIMP-1 (rIC group; 67% reduction compared to UC or unimmunised controls; 79% reduction compared to rTC group or recombinant thioredoxin mock-immunised controls, p<0.05), or the birds vaccinated by infection with oocysts (OC group, 90% compared to unimmunised controls). Chickens vaccinated with oocysts (OC) had significantly higher levels of interferon gamma in their serum post-challenge, compared to rEtIMP-1 vaccinated birds (rIC). Conversely rEtIMP-1 (rIC) vaccinated birds had significantly higher antigen specific serum IgY responses, correlating with higher serum IL-4 (both p<0.05).

Cryptic Eimeria genotypes are common across the southern but not northern hemisphere.

The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere.

Performance and exhaust emission characteristics of variable compression ratio diesel engine fuelled with esters of crude rice bran oil.

As a substitute to petroleum-derived diesel, biodiesel has high potential as a renewable and environment friendly energy source. For petroleum importing countries the choice of feedstock for biodiesel production within the geographical region is a major influential factor. Crude rice bran oil is found to be good and viable feedstock for biodiesel production. A two step esterification is carried out for higher free fatty acid crude rice bran oil. Blends of 10, 20 and 40 % by vol. crude rice bran biodiesel are tested in a variable compression ratio diesel engine at compression ratio 15, 16, 17 and 18. Engine performance and exhaust emission parameters are examined. Cylinder pressure-crank angle variation is also plotted. The increase in compression ratio from 15 to 18 resulted in 18.6 % decrease in brake specific fuel consumption and 14.66 % increase in brake thermal efficiency on an average. Cylinder pressure increases by 15 % when compression ratio is increased. Carbon monoxide emission decreased by 22.27 %, hydrocarbon decreased by 38.4 %, carbon dioxide increased by 17.43 % and oxides of nitrogen as NOx emission increased by 22.76 % on an average when compression ratio is increased from 15 to 18. The blends of crude rice bran biodiesel show better results than diesel with increase in compression ratio.

Cloning and sequencing of beta-tubulin and internal transcribed spacer-2 (ITS-2) of Eimeria tenella isolate from India.

Beta-tubulin is an important multifunctional protein of eukaryotes abundant in the cytoskeleton and responsible for the formation of tubulin, structures responsible for cell morphology and which aid in motility and intracellular transportation. It has been used as a genotypic marker for studying the evolutionary history and phylogenetic relationships between eukaryotic organisms. Internal transcribed spacers of the ribosomal RNA genes have been widely used for typing inter-species and intra-species variation. An Indian isolate of Eimeria tenella was genotyped following the cloning and sequencing of beta-tubulin and internal transcribed spacer-2 (ITS-2) and compared with other reference isolates of E. tenella. The ß-tubulin has 99 % intra-species similarity at the gene level and the functional homology of the protein is very high with more than 95 % amino-acid similarity across the Apicomplexa. The ITS-2 sequence had a similar pattern of nucleotide base arrangement with 99 % homology to Houghton and Nippon strains of E. tenella.