Characterization of Fowlpox Virus.

The complex cytoplasmic DNA virus known as the fowlpox virus (FWPV) is a member of the avipoxvirus genus, Subfamily Chordopoxvirinae, and Family Poxviridae. The large genome size of FWPV makes it a potential vector for the creation of vaccines against a range of serious veterinary and human ailments. It also allows for multiple gene insertion and the generation of abortive infection in mammalian cells. The virus, which causes fowlpox in chickens and turkeys, is mainly transmitted to poultry through aerosols or biting insects. Fowlpox is a highly contagious disease that affects both domestic and wild birds, causing cutaneous and/or diphtheritic illnesses. To control the illness, strict hygiene practices and immunization with FWPV attenuated strains or antigenically similar pigeon pox virus vaccines are employed. Recent years have seen an increase in fowlpox outbreaks in chicken flocks, primarily due to the introduction of novel forms of FWPV. It is believed that the pathogenic characteristics of these strains are enhanced by the integration of reticuloendotheliosis virus sequences of variable lengths into the FWPV genome. The standard laboratory diagnosis of FPV involves histopathological analysis, electron microscopy, virus isolation on chorioallantoic membrane (CAM) of embryonated chicken eggs or cell cultures, and serologic techniques. For quick and consistent diagnosis, polymerase chain reaction (PCR) has proven to be the most sensitive method. PCR is used in concert with restriction endonuclease enzyme analysis (REA) to identify, differentiate, and characterize the molecular makeup of isolates of the fowlpox virus. Sequencing of the amplified fragments is then done.

Superconducting properties of tungsten nanowires fabricated using focussed ion beam technique.

We report superconducting properties of tungsten meander structures fabricated using the focussed ion beam (FIB) induced technique. Three meander structures with individual line widths of ∼70, ∼300 and ∼450 nm were fabricated for evaluation and comparison of the superconducting properties. The resistance-temperature characteristics of the meanders were measured and analysed down to a temperature of 100 mK. The superconducting properties such as critical temperature (T C) and upper-critical field (H C2) of these wires are in comparison to the reported values of FIB deposited tungsten available in literature. While the normal state resistance increases sharply as the width of the wire decreases, the superconducting transition temperature registered a slight decrease. Significant amount of residual resistance (3.8% of normal state value at 100 mK) was observed for the sample with the lowest width (70 nm). The residual resistance trails as function of temperature was analysed invoking theoretical models governing the phase slip induced dissipations in superconducting nanowires. The results indicated signature of phase slips as the width of the wire decreases: thermally activated phase slips dominant near to the T C and quantum phase slip (QPS) near to T C as well as much below to the T C. The magneto-resistance isotherms indicated quantum phase transitions (QPT); typical of a superconductor-to-insulator transition (SIT) driven by magnetic field. The SIT transition which originates from the intrinsic disorder present in the sample can be tuned by an external parameter such as magnetic field, and can be modelled by standard theories of QPT for quasi 2D or (2 + 1) D XY models. The successful fabrication of meander structures of W using FIB and the demonstration of superconductivity suggest that FIB deposited W can be exploited for many of the technological applications of superconducting nanowires such as superconducting nanowire single photon detectors, bolometers, transition edge sensors and even for quantum current standard employing the QPS phenomenon.

Coherent Excitation of Heterosymmetric Spin Waves with Ultrashort Wavelengths.

In the emerging field of magnonics, spin waves are foreseen as signal carriers for future spintronic information processing and communication devices, owing to both the very low power losses and a high device miniaturization potential predicted for short-wavelength spin waves. Yet, the efficient excitation and controlled propagation of nanoscale spin waves remains a severe challenge. Here, we report the observation of high-amplitude, ultrashort dipole-exchange spin waves (down to 80 nm wavelength at 10 GHz frequency) in a ferromagnetic single layer system, coherently excited by the driven dynamics of a spin vortex core. We used time-resolved x-ray microscopy to directly image such propagating spin waves and their excitation over a wide range of frequencies. By further analysis, we found that these waves exhibit a heterosymmetric mode profile, involving regions with anti-Larmor precession sense and purely linear magnetic oscillation. In particular, this mode profile consists of dynamic vortices with laterally alternating helicity, leading to a partial magnetic flux closure over the film thickness, which is explained by a strong and unexpected mode hybridization. This spin-wave phenomenon observed is a general effect inherent to the dynamics of sufficiently thick ferromagnetic single layer films, independent of the specific excitation method employed.

Spin transfer torque driven higher-order propagating spin waves in nano-contact magnetic tunnel junctions.

Short wavelength exchange-dominated propagating spin waves will enable magnonic devices to operate at higher frequencies and higher data transmission rates. While giant magnetoresistance (GMR)-based magnetic nanocontacts are efficient injectors of propagating spin waves, the generated wavelengths are 2.6 times the nano-contact diameter, and the electrical signal strength remains too weak for applications. Here we demonstrate nano-contact-based spin wave generation in magnetic tunnel junctions and observe large-frequency steps consistent with the hitherto ignored possibility of second- and third-order propagating spin waves with wavelengths of 120 and 74 nm, i.e., much smaller than the 150-nm nanocontact. Mutual synchronization is also observed on all three propagating modes. These higher-order propagating spin waves will enable magnonic devices to operate at much higher frequencies and greatly increase their transmission rates and spin wave propagating lengths, both proportional to the much higher group velocity.

Studies on incidence and evaluation of the closed medial patellar desmotomy in lateral recumbency in bovines.

AIM: The present study was conducted to find out the incidence and to evaluate the effectiveness of medial patellar desmotomy (MPD) in lateral recumbency in bovines. MATERIAL AND METHODS: One hundred and fifteen clinical cases of upward fixation of the patella in cattle and buffaloes were treated by closed MPD in lateral recumbency. Probable etiologies, symptoms and site of surgery including disease occurrence with respect to species, sex and season were also recorded. RESULTS: In the present study, the highest incidence was reported in bullocks. A high success rate was obtained with the closed method in lateral recumbency. CONCLUSION: Based on the findings of this study, it can be concluded that the bullocks were more prone to upward fixation of patella and symptoms were exaggerated in winter season. Closed method of MPD was more suited in both cattle and buffaloes.

Magneto-optical spectrum analyzer.

We present a method for the investigation of gigahertz magnetization dynamics of single magnetic nano elements. By combining a frequency domain approach with a micro focus Kerr effect detection, a high sensitivity to magnetization dynamics with submicron spatial resolution is achieved. It allows spectra of single nanostructures to be recorded. Results on the uniform precession in soft magnetic platelets are presented.

Using acellular aortic matrix to repair umbilical hernias of calves.

BACKGROUND: Umbilical hernias are a relatively common, possibly hereditary, condition in calves. Acellular aortic matrix (AAM) was evaluated for the repair of umbilical hernias in nine calves. METHODS: Fresh buffalo aorta to be used as a graft was decellularised using 1% sodium dodecyl sulfate and 0.25% trypsin. Under xylazine sedation and local analgesia, the hernial ring was exposed and repaired with the AAM graft using an inlay technique. RESULTS: All animals had an uneventful recovery without clinical signs of wound dehiscence, infection or recurrence of hernias during the 6-month follow-up period. CONCLUSION: AAM of buffalo origin has adequate strength to be used safely for the repair of umbilical hernias in calves.

Acellular dermal graft for repair of abdominal wall defects in rabbits.

Sixteen clinically healthy New Zealand white rabbits of either sex were divided into 2 equal groups (I and II) of 8 animals each. Under thiopental sodium (2.5%) anaesthesia a 2 x 3 cm full-thickness abdominal wall defect in the mid-ventral abdominal wall was created and repaired with an acellular dermal graft (ADG) in all the animals of group I (test group). In animals of group II (control group) a full-thickness linear midline abdominal muscular wall incision was made and repaired with a continuous suture pattern using 2-0 nylon.

In vitro plantlet regeneration in Panax sikkimensis.

A three-step procedure for complete plantlet regeneration via somatic embryogenesis has been developed in Panax sikkimensis. Somatic embryos (SE) were induced in root callus upon lowering the level of 2,4-D from 1.0 mg/l to 0.25 mg/l in the callusing medium. Maturation of SE occurred on a half-strength MS medium with 0.5 mg/l each of BAP and GA3. An exposure for 15 days of cotyledonary and heart-shaped SE to 1.0 mg/l IBA in liquid shake 1/2 MS medium significantly improved the rate of embryo-to-plantlet conversion and plantlet quality. The procedure has now allowed the retention of high regeneration potential of the root callus for over three years.

Development of a novel plant system as biosensor for detecting environmental hazards and bioactive molecules through distinct responses.

Currently, chemicals are used excessively in medicine, industry, and agriculture throughout the world. Because of the current rise in environmental pollutants and hazardous exposures of human beings, there is an imperative need for monitoring the environment for biosafety. In addition, the importance of natural products with novel activity for drug or agrochemical scopes is being more and more realized. We report on a novel test system that can act as biosensors for detecting useful compounds while simultaneously monitoring or forecasting the biohazard exposure of organisms to chemicals as well as to physical factors in a given environment. Using different compounds and factors with known biological and cytotoxic activities, a detail plant test procedure has been developed that can be used in detecting and analyzing the value and/or danger of any given compound or treatment, including cell division inhibition, cytotoxicity, growth inhibition, and anticancer activities. The method provides a highly efficient single biosensor system that can replace several individual biotesting procedures. This plant assay procedure is a highly sensitive system for monitoring physical stress factors in the environment, including ionizing and nonionizing radiation. The procedure can be followed throughout the year because of the rapid growth rate of the plant used and its regeneration in ambient conditions. Therefore, the described system is highly useful to thoroughly monitor the environment and detection of new chemicals/compounds.