Toward streaked collective Thomson scattering measurements on an extreme ultraviolet plasma light source.

We show through forward modeling calculations that streaked collective Thomson scattering measurements are feasible on laser-produced tin plasmas generated under conditions relevant for extreme ultraviolet lithography. Using a 532 nm probe laser beam, the feasibility of simultaneous measurements of electron plasma wave (EPW) and ion acoustic wave (IAW) spectra is investigated. Absolute photon counts for laser scattering off both waves are calculated. Probe laser electron heating and bremsstrahlung background radiation effects are accounted for. While a large spatiotemporal region can be successfully probed based on the IAW feature, only one measurement location can be accessed through the EPW as a result of the low signal to noise ratio. A portable/traveling tabletop system is proposed.

Photon Acceleration in a Flying Focus.

A high-intensity laser pulse propagating through a medium triggers an ionization front that can accelerate and frequency upshift the photons of a second pulse. The maximum upshift is ultimately limited by the accelerated photons outpacing the ionization front or the ionizing pulse refracting from the plasma. Here, we apply the flying focus-a moving focal point resulting from a chirped laser pulse focused by a chromatic lens-to overcome these limitations. Theory and simulations demonstrate that the ionization front produced by a flying focus can frequency upshift an ultrashort optical pulse to the extreme ultraviolet over a centimeter of propagation. An analytic model of the upshift predicts that this scheme could be scaled to a novel tabletop source of spatially coherent x rays.

Picosecond Thermodynamics in Underdense Plasmas Measured with Thomson Scattering.

The rapid evolutions of the electron density and temperature in a laser-produced plasma were measured using collective Thomson scattering. Unprecedented picosecond time resolution, enabled by a pulse-front-tilt compensated spectrometer, revealed a transition in the plasma-wave dynamics from an initially cold, collisional state to a quasistationary, collisionless state. The Thomson-scattering spectra were compared with theoretical calculations of the fluctuation spectrum using either a conventional Bhatnagar-Gross-Krook (BGK) collision operator or the rigorous Landau collision terms: the BGK model overestimates the electron temperature by 50% in the most-collisional conditions.

Single-shot frequency-resolved optical gating for retrieving the pulse shape of high energy picosecond pulses.

Accurate characterization of laser pulses used in experiments is a crucial step to the analysis of their results. In this paper, a novel single-shot frequency-resolved optical gating (FROG) device is described, one that incorporates a dispersive element which allows it to fully characterize pulses up to 25 ps in duration with a 65 fs per pixel temporal resolution. A newly developed phase retrieval routine based on memetic algorithms is implemented and shown to circumvent the stagnation problem that often occurs with traditional FROG analysis programs when they encounter a local minimum.

Temporal changes in the trot between the first and third horse inspections at a CCI*** 3-day event.

Kinematic parameters were measured from horses competing in a CCI*** 3-day event. The horses were filmed during the first and third horse inspection. This provided a repeat sample on 16 horses. The horses were filmed using a panning lateral S-VHS video camera (50 Hz). Spatial measurements were taken for mean +/- s.d. 5.66 +/- 0.92 strides for the first inspection and 5.05 +/- 1.27 for the third inspection. Within the calibration zone, data of the horses accelerating and obtaining a constant velocity were collected. The horses trotted with a higher mean velocity during the third inspection (0.26 +/- 0.05 m/s, P < 0.001). During the third inspection the horses trotted with a shorter stride length (0.193 +/- 0.03 m, P < 0.001) and stride duration (31 +/- 42 m/s, P < 0.001). The third inspection was characterised by a decrease in retraction percentage for both the forelimbs (3.69 +/- 2.39%, P < 0.001) and the hindlimbs (2.48 +/- 2.16%, P < 0.001). However, no significant difference was found between the 2 inspections for other temporal parameters when measured as a percentage of stride. It is proposed that the event horses trot with a decreased stride length and duration during the third horse inspection but maintain a consistent temporal relationship.

Linear and temporal stride characteristics of 3-day event horses at a CCI*** 3-day event horse inspection.

AIMS: To quantify the linear and temporal characteristics of the trot of 3-day event horses during the preliminary horse inspection of an advanced grade CCI*** 3-day event. METHODS: A cross sectional study was made of the kinematics of 24 3-day-event horses during the first horse inspection at a CCI*** level S-day event. Video footage was digitised and linear and temporal measurements were made. RESULTS: The horses trotted for an average of 10.44+/-1.55 strides. Spatial measurements were made on an average of 5.66+/-0.92 consecutive strides when the horses were within the calibration zone. The horses increased and then obtained a constant velocity within the calibration zone. Trotting on the asphalt track did not alter the relationships between stride length, stride duration and velocity when compared with previously published values. Horse-specific differences in stance and retraction percentages were identified. CONCLUSION: Horse specific differences were identified that may contribute to each horse's unique gait or kinematic fingerprint. It is proposed that the initiation of, and completion of, stance by the hind limb first may represent engagement of the hind quarters and be a response to dressage training.

Sevoflurane has less effect than halothane on pulmonary afferent activity in the rabbit.

We have compared the effects of sevoflurane and halothane on the discharge frequencies of 19 slowly adapting and four rapidly adapting lung receptors in the rabbit by recording from single vagal fibres. Both agents reduced the discharge frequency of slowly adapting receptors during expiration (P < 0.0005), halothane having a greater effect than sevoflurane (P < 0.0005). Neither agent had any effect on discharge frequency at the end of inspiration when discharge frequency is at a maximum. Neither agent affected the discharge frequency of rapidly adapting receptors.

Collagen fibril diameter distributions in ligaments and tendons of the carpal region of the horse.

Since horses bred for the racing industry are subject to rigorous training procedures there is a real need to understand how the stresses experienced by their tendons and ligaments in vivo relate to the major load-bearing elements-the collagen fibrils. Consequently, an age-related study has been made of the collagen fibril diameter distributions of nine ligaments in and around the equine carpus. This is the first stage of a larger study aimed at understanding the ultrastructural changes that occur as a result of exercise. Most of the ligaments showed a bimodal diameter distribution at maturity, and decreased diameters at old age as the fibrils break down. The scaphocapitate ligament, however, was unique in that the constituent fibrils were small, almost invariant in diameter with age, and had a unimodal distribution of sizes. The mechanical attributes of these tissues, as deduced from a theoretical analysis of the diameter distributions, are consistent with observation.

The use of a shotgun for the emergency slaughter or euthanasia of large mature pigs.

The isolated heads of a Friesian bull and three large, Large White pigs were shot from various aspects with a 12-gauge shotgun using both a single 28 g solid lead projectile and buckshot, the latter consisting of nine individual lead pellets with a combined mass of 28 g. The sites of impact to the skull included the conventional frontal region, an occipital site and immediately behind the ear. A live mature Large White sow was shot with buckshot in the depression just caudal to the right ear, resulting in immediate insensibility and death. The damage caused to the isolated heads indicated that similar effects could be expected if the heads had been part of intact living animals. It is suggested that buckshot (nine lead pellets with a combined mass of 28 g) fired from a 12-gauge shotgun may be suitable for the emergency slaughter or euthanasia of a wide variety of domestic livestock and other species of animal.

The use of a shotgun for euthanasia of stranded cetaceans.

A 12-gauge shotgun, loaded with either a solid 28 g lead slug or buckshot consisting of nine individual lead pellets with a total mass of 28 g, was used to shoot the heads of one dead common dolphin (Delphinus delphis) and five dead long-finned pilot whales (Globicephala melaena) varying in length from 2.5 m to 5 m. The dolphin and the smallest pilot whale were shot with both projectiles from the dorsal surface of the head. The projectiles penetrated the head and dorsal surface of the skull, but not the base of the cranium. This site using buckshot was not effective in the larger animals. Two whales between 3 and 4 m in length were shot with buckshot through the lateral side of the head caudal to and above the eye, without penetration of the contralateral side of the head. It is concluded that shooting smaller cetaceans with a shotgun can be effective and safe. Further work is required to develop more suitable projectiles for cetaceans up to the size of mature pilot whales.

The function of the equine carpal joint: a review.

The most consistent published ideas on the function of the carpal joint of the horse concern the elasticity of the joint, and its limits to extension. Most of these are not well substantiated experimentally. Compression stress appears to be absorbed by the intercarpal ligaments as the carpal bones are separated by a wedge action during loading. Overextension is prevented by occlusion of dorsally located stop facets on the rows of carpal bones, and by the support of a stay apparatus.

A preliminary study of hyperextension of the carpal joint in the racing Thoroughbred.

A photographic study of the angles of 71 carpal joints of horses at the end of a race has shown that overextension of the joint is normal at this stage. Further study is needed to determine the factors which may influence hyperextension, and whether they are relevant to carpal injury.

Vergleichende Untersuchungen zur Struktur der Haarfollikelgruppen bei neuseeländischen Cashmere-, Angora- und Cashgoraziegen.

UNLABELLED: ZUSAMMENFASSUNG: Die Haarfollikelgruppen neuseeländischer Cashmere-, Angora- und Cashgoraziegen wurden auf histologischer Basis untersucht. Dabei stand die strukturelle Zusammensetzung (Anteile an Primär- und Sekundärhaarfollikeln bzw. Sekundärhaarfollikelbündeln) ebenso im Mittelpunkt wie die Erfassung der Größe der Haarfollikelgruppen und deren Prozentanteil pro Flächeneinheit. Ergänzend wurde eine Studie der Haardurchmesser durchgeführt. Der Vergleich der drei Ziegenrassen machte deutlich, daß für alle untersuchten Parameter signifikante Unterschiede zwischen der Cashmere- und der Angoraziege bestanden, während die Werte für die Cashgoraziege zwischen denen der beiden anderen Rassen lagen. Insgesamt gesehen war die Cashgoraziege jedoch der Cashmereziege recht ähnlich. Die Ergebnisse werden in Relation zu den in Neuseeland vorhandenen züchterischen Möglichkeiten diskutiert und die Wichtigkeit der S/P ratio betont. SUMMARY: Comparative investigations into the structure of hair-follicle groups in New Zealand Cashmere, Angora, and Cashgora goats The structure of hair-follicle groups was examined histologically in New Zealand Cashmere, Angora, and Cashgora goats. The specific composition (numbers of primary and secondary hair follicles, or hair-follicle bundles) as well as the size of hair-follicle groups and their percentage distribution per unit area of the skin was evaluated. Additionally, fibre diameters were measured. The comparison of the results obtained revealed significant differences between the three goat breeds concerning the important structural parameters. Generally, however, the structure of hair-follicle groups in the Cashgora goat seems to be more similar to the Cashmere goat than to the Angora goat. Ways of improving fleece quality in New Zealand goats are discussed with special regard to the S/P ratio.

The perivascular spaces of ovine and canine brains.

Abstract The specialised histology and anatomy of the central nervous system (CNS) is reflected in its pathology. This is particularly so for the perivenular/periarterial spaces in which inflammatory cells accumulate in inflammation. These spaces, although structurally not lymphatics, act as lymphatics draining fluid from brain to subarachnoid space and to lymphatics draining to deep cervical lymph nodes. Inflammatory cells may enter or leave the CNS by this route. In immune-based inflammation, they are colonised by subsets of immune cells allowing the processing of antigen, synthesis of antibody and development of cell mediated immune reactions.

Meat quality and muscle fibre type characteristics of Southdown Rams from high and low backfat selection lines.

Characteristics of the meat of 15-18-month Southdown rams from lines selected for high or low backfat depths (assessed ultrasonically at position C over the last rib) were compared. Half of the carcasses were electrically stimulated (ES) and within each carcass post-mortem treatments chosen to produce effects on meat tenderness were ageing periods of 1 or 15 days (Semimembranosus), early or delayed chilling (Biceps femoris), and trimming of the s.c. fat cover (Longissimus dorsi). These treatments had the expected effects on shear values, but the sizes of the effects were little affected by selection line or ES treatment. Selection line did not have any direct effects on shear values, reflectance values at several wavelengths, waterholding capacity, cooking loss or sarcomere length. The Semitendinosus muscle had a higher proportion of predominantly oxidative fibres for the high-backfat line, based on succinic dehydrogenase activity (P < 0·05), but there was no line difference in alkaline-stable ATPase activity in the same muscle. Muscle fibre diameter was similar for the two lines.

A large dermoid cyst of the neck. Case report.

An elderly patient presented with a large asymptomatic submental swelling which had been present for about fifteen years. The clinical diagnosis was a dermoid cyst and the lesion was removed in toto. Histological examination confirmed the clinical diagnosis. Unless such lesions are very large and cause displacement of the tongue, there is usually no associated dyspnoea, dysphagia or dysphonia.

An objective measure of muscularity: Changes with animal growth and differences between Genetic lines of southdown sheep.

A measure of muscularity, based on objective measurements, and expressed in terms of muscle depth relative to skeletal dimensions, is proposed and investigated using a simulation model. Average muscle depth is assessed as the square root of the muscle weight per unit length of a bone adjacent to the muscle. Muscularity is then defined as average muscle depth divided by bone length. Evidence based on a theoretical model, results from the literature and data from backfat selection lines of Southdown sheep is used to illustrate how muscularity defined in this way changes with growth, and the extent to which it parallels changes in muscle to bone ratio. It is concluded that although these two characteristics often change together there are situations where differences in muscularity are not accompanied by differences in muscle to bone ratio and vice versa.

Postnatal development of the lower canine and cheek teeth of the pig.

Postnatal development of the teeth of German Landrace and Göttingen Miniature pigs was studied by measuring the areas of each tooth visible on lateral radiographs of the mandibles. It was concluded that the appearance of the teeth at each stage, and the relation of their growth to that of the rest of the masticatory apparatus, relates mainly to postnatal changes in the relative location of the jaw pivot.