GSR deposition along the bullet path in contact shots to composite models

In contact shots, all the materials emerging from the muzzle (combustion gases, soot, powder grains, and metals from the primer) will be driven into the depth of the entrance wound and the following sections of the bullet track. The so-called "pocket" ("powder cavity") under the skin containing soot and gunpowder particles is regarded as a significant indicator of a contact entrance wound since one would expect that the quantity of GSR deposited along the bullet's path rapidly declines towards the exit hole. Nevertheless, experience has shown that soot, powder particles, and carboxyhemoglobin may be found not only in the initial part of the wound channel, but also far away from the entrance and even at the exit. In order to investigate the propagation of GSRs under standardized conditions, contact test shots were fired against composite models of pig skin and 25-cm-long gelatin blocks using 9-mm Luger pistol cartridges with two different primers (Sinoxid® and Sintox®). Subsequently, 1-cm-thick layers of the gelatin blocks were examined as to their primer element contents (lead, barium, and antimony as discharge residues of Sinoxid® as well as zinc and titanium from Sintox®) by means of X-ray fluorescence spectroscopy. As expected, the highest element concentrations were found in the initial parts of the bullet tracks, but also the distal sections contained detectable amounts of the respective primer elements. The same was true for amorphous soot and unburned/partly burned powder particles, which could be demonstrated even at the exit site. With the help of a high-speed motion camera it was shown that for a short time the temporary cavitation extends from the entrance to the exit thus facilitating the unlimited spread of discharge residues along the whole bullet path.

Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation

Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect.

In vivo measurement of central corneal thickness in normal chicks (Gallus gallus domesticus) with the optical low-coherence reflectometer

OBJECTIVE To determine the practicability and accuracy of central corneal thickness (CCT) measurements in living chicks utilizing a noncontact, high-speed optical low-coherence reflectometer (OLCR) mounted on a slit lamp. ANIMALS STUDIED Twelve male chicks (Gallus gallus domesticus). Procedures  Measurements of CCT were obtained in triplicate in 24 eyes of twelve 1-day-old anaesthetized chicks using OLCR. Every single measurement taken by OLCR consisted of the average result of 20 scans obtained within seconds. Additionally, corneal thickness was determined histologically after immersion fixation in Karnovsky's solution alone (20 eyes) or with a previous injection of the fixative into the anterior chamber before enucleation (4 eyes). RESULTS Central corneal thickness measurements using OLCR in 1-day-old living chicks provide a rapid and feasible examination technique. Mean CCT measured with OLCR (189.7 ± 3.34 μm) was significantly lower than histological measurements (242.1 ± 47.27 μm) in eyes with fixation in Karnovsky's solution (P = 0.0005). In eyes with additional injection of Karnovsky's fixative into the anterior chamber, mean histologically determined CCT was 195.2 ± 8.25 μm vs. 191.9 ± 8.90 μm with OLCR. A trend for a lower variance was found compared to the eyes that had only been immersion fixed. CONCLUSION Optical low-coherence reflectometry is an accurate examination technique to measure in vivo CCT in the eye of newborn chicks. The knowledge of the thickness of the chick cornea and the ability to obtain noninvasive, noncontact measurements of CCT in the living animal may be of interest for research and development of eye diseases in chick models.

The evolution of antennal courtship in diplazontine parasitoid wasps (Hymenoptera, Ichneumonidae, Diplazontinae)

Background As predicted by theory, traits associated with reproduction often evolve at a comparatively high speed. This is especially the case for courtship behaviour which plays a central role in reproductive isolation. On the other hand, courtship behavioural traits often involve morphological and behavioural adaptations in both sexes; this suggests that their evolution might be under severe constraints, for instance irreversibility of character loss. Here, we use a recently proposed method to retrieve data on a peculiar courtship behavioural trait, i.e. antennal coiling, for 56 species of diplazontine parasitoid wasps. On the basis of a well-resolved phylogeny, we reconstruct the evolutionary history of antennal coiling and associated morphological modifications to study the mode of evolution of this complex character system. Results Our study reveals a large variation in shape, location and ultra-structure of male-specific modifications on the antennae. As for antennal coiling, we find either single-coiling, double-coiling or the absence of coiling; each state is present in multiple genera. Using a model comparison approach, we show that the possession of antennal modifications is highly correlated with antennal coiling behaviour. Ancestral state reconstruction shows that both antennal modifications and antennal coiling are highly congruent with the molecular phylogeny, implying low levels of homoplasy and a comparatively low speed of evolution. Antennal coiling is lost on two independent occasions, and never reacquired. A zero rate of regaining antennal coiling is supported by maximum parsimony, maximum likelihood and Bayesian approaches. Conclusions Our study provides the first comparative evidence for a tight correlation between male-specific antennal modifications and the use of the antennae during courtship. Antennal coiling in Diplazontinae evolved at a comparatively low rate, and was never reacquired in any of the studied taxa. This suggests that the loss of antennal coiling is irreversible on the timescale examined here, and therefore that evolutionary constraints have greatly influenced the evolution of antennal courtship in this group of parasitoid wasps. Further studies are needed to ascertain whether the loss of antennal coiling is irreversible on larger timescales, and whether evolutionary constraints have influenced courtship behavioural traits in a similar way in other groups.

[Aiming at the chest, but hitting the back]

Gunshot injuries in the back may suggest the unjustified use of firearms. A wound in the back inflicted by a firearm should not automatically imply that the shooter aimed at the back. A previous study demonstrated that it is possible for men to turn their trunk faster than it takes for a shooter to fire or throw a hand-operated weapon. With a high speed motion camera the authors were able to demonstrate that it is also possible for women to turn their trunk fast enough, so that a shot in the back could have been aimed at the front of the body. This conclusion is also likely to apply to hand-operated or thrown weapons, since the velocity of their projectiles is considerably lower than that of firearms.

Full body low radiation radiography using Lodox Statscan

Lodox Statscan provides high-speed, high-quality, low radiation, full body imaging in a single scan, combined with three-dimensional reconstructive and zooming functionality. Several trauma centres have incorporated it into their advanced trauma life support protocol. This review gives a brief overview of the system.

New aspects of airway mechanics in pre-term infants

High-frequency respiratory impedance data measured noninvasively by the high-speed interrupter technique (HIT), particularly the first antiresonance frequency (f(ar,1)), is related to airway wall mechanics. The aim of this study was to evaluate the feasibility and repeatability of HIT in unsedated pre-term infants, and to compare values of f(ar,1) from 18 pre-term (post-conceptional age 32-37 weeks, weight 1,730-2,910 g) and 18 full-term infants (42-47 weeks, 3,920-5,340 g). Among the pre-term infants, there was good short-term repeatability of f(ar,1) within a single sleep epoch (mean (sd) coefficient of variance: 8 (1.7)%), but 95% limits of agreement for repeated measures of f(ar,1) after 3-8 h were relatively wide (-41 Hz; 37 Hz). f(ar,1) was significantly lower in pre-term infants (199 versus 257 Hz), indicating that wave propagation characteristics in pre-term airways are different from those of full-term infants. The present authors suggest that this is consistent with developmental differences in airway wall structure and compliance, including the influence of the surrounding tissue. Since flow limitation is determined by wave propagation velocity and airway cross-sectional area, it was hypothesised that the physical ability of the airways to carry large flows is fundamentally different in pre-term than in full-term infants.

Water quality in dental chair units. A random sample in the canton of St. Gallen

This study aimed to identify the microbial contamination of water from dental chair units (DCUs) using the prevalence of Pseudomonas aeruginosa, Legionella species and heterotrophic bacteria as a marker of pollution in water in the area of St. Gallen, Switzerland. Water (250 ml) from 76 DCUs was collected twice (early on a morning before using all the instruments and after using the DCUs for at least two hours) either from the high-speed handpiece tube, the 3 in 1 syringe or the micromotor for water quality testing. An increased bacterial count (>300 CFU/ml) was found in 46 (61%) samples taken before use of the DCU, but only in 29 (38%) samples taken two hours after use. Pseudomonas aeruginosa was found in both water samples in 6/76 (8%) of the DCUs. Legionella were found in both samples in 15 (20%) of the DCUs tested. Legionella anisa was identified in seven samples and Legionella pneumophila was found in eight. DCUs which were less than five years old were contaminated less often than older units (25% und 77%, p<0.001). This difference remained significant (0=0.0004) when adjusted for manufacturer and sampling location in a multivariable logistic regression. A large proportion of the DCUs tested did not comply with the Swiss drinking water standards nor with the recommendations of the American Centers for Disease Control and Prevention (CDC).

Gait analysis in normal and spinal contused mice using the TreadScan system

Advances in spinal cord injury (SCI) research are dependent on quality animal models, which in turn rely on sensitive outcome measures able to detect functional differences in animals following injury. To date, most measurements of dysfunction following SCI rely either on the subjective rating of observers or the slow throughput of manual gait assessment. The present study compares the gait of normal and contusion-injured mice using the TreadScan system. TreadScan utilizes a transparent treadmill belt and a high-speed camera to capture the footprints of animals and automatically analyze gait characteristics. Adult female C57Bl/6 mice were introduced to the treadmill prior to receiving either a standardized mild, moderate, or sham contusion spinal cord injury. TreadScan gait analyses were performed weekly for 10 weeks and compared with scores on the Basso Mouse Scale (BMS). Results indicate that this software successfully differentiates sham animals from injured animals on a number of gait characteristics, including hindlimb swing time, stride length, toe spread, and track width. Differences were found between mild and moderate contusion injuries, indicating a high degree of sensitivity within the system. Rear track width, a measure of the animal's hindlimb base of support, correlated strongly both with spared white matter percentage and with terminal BMS. TreadScan allows for an objective and rapid behavioral assessment of locomotor function following mild-moderate contusive SCI, where the majority of mice still exhibit hindlimb weight support and plantar paw placement during stepping.

Using virtual reality to teach special populations how to cope in crisis: the case of a virtual earthquake

The unique characteristics of special populations such as pre-school children and Down syndrome kids in crisis and their distorted self-image were never studied before, because of the difficulty of crisis reproduction. This study proposes a VR setting that tries to model some special population's behaviour in the time of crises and offers them a training scenario. The sample population consisted of 30 pre-school children and 20 children with Down syndrome. The VR setting involved a high-speed PC, a VPL EyePhone 1, a MR toolkit, a vibrations plate, a motion capture system and other sensors. The system measured and modelled the typical behaviour of these special populations in a Virtual Earthquake scenario with sight and sound and calculated a VR anthropomorphic model that reproduced their behaviour and emotional state. Afterwards one group received an emotionally enhanced VR self-image as feedback for their training, one group received a plain VR self-image and another group received verbal instructions. The findings strongly suggest that the training was a lot more biased by the emotionally enhanced VR self-image than the other approaches. These findings could highlight the special role of the self-image to therapy and training and the interesting role of imagination to emotions, motives and learning. Further studies could be done with various scenarios in order to measure the best-biased behaviour and establish the most natural and affective VR model. This presentation is going to highlight the main findings and some theories behind them.

The water vapour flux above Switzerland and its role in the August 2005 extreme precipitation and flooding

The water budget approach is applied to an atmospheric box above Switzerland (hereafter referred to as the “Swiss box”) to quantify the atmospheric water vapour flux using ECMWF ERA-Interim reanalyses. The results confirm that the water vapour flux through the Swiss box is highly temporally variable, ranging from 1 to 5 · 107 kg/s during settled anticyclonic weather, but increasing in size by a factor of ten or more during high speed currents of water vapour. Overall, Switzerland and the Swiss box “import” more water vapour than it “exports”, but the amount gained remains only a small fraction (1% to 5%) of the total available water vapour passing by. High inward water vapour fluxes are not necessarily linked to high precipitation episodes. The water vapour flux during the August 2005 floods, which caused severe damage in central Switzerland, is examined and an assessment is made of the computed water vapour fluxes compared to high spatio-temporal rain gauge and radar observations. About 25% of the incoming water vapour flux was stored in Switzerland. The computed water vapour fluxes from ECMWF data compare well with the mean rain gauge observations and the combined rain-gauge radar precipitation products.

Fatal contact shot to the chest caused by the gas jet from a muzzle-loading pistol discharging only black powder and no bullet: case study and experimental simulation of the wounding effect.

In modern medico-legal literature, only a small number of publications deal with fatal injuries from black powder guns. Most of them focus on the morphological features such as intense soot soiling, blast tattooing and burn effects in close-range shots or describe the wound ballistics of spherical lead bullets. Another kind of "unusual" and potentially lethal weapons are handguns destined for firing only blank cartridges such as starter and alarm pistols. The dangerousness of these guns is restricted to very close and contact range shots and results from the gas jet produced by the deflagration of the propellant. The present paper reports on a suicide committed with a muzzle-loading percussion pistol cal. 45. An unusually large stellate entrance wound was located in the precordial region, accompanied by an imprint mark from the ramrod and a faint greenish discoloration (apparently due to the formation of sulfhemoglobin). Autopsy revealed an oversized powder cavity, multiple fractures of the anterior thoracic wall as well as ruptures of the heart, the aorta, the left hepatic lobe and the diaphragm. In total, the zone of mechanical destruction had a diameter of approx. 15 cm. As there was no exit wound and no bullet lodged in the body, the injury was caused exclusively by the inrushing combustion gases of the propellant (black powder) comparable with the gas jet of a blank cartridge gun. In contact shots to ballistic gelatine using the suicide's pistol loaded with black powder but no projectile, the formation of a nearly spherical cavity could be demonstrated by means of a high-speed camera. The extent of the temporary cavity after firing with 5 g of black powder roughly corresponded to the zone of destruction found in the suicide's body.

Mobility and bandwidth prediction in virtualized LTE systems: Architecture and challenges

Long Term Evolution (LTE) represents the fourth generation (4G) technology which is capable of providing high data rates as well as support of high speed mobility. The EU FP7 Mobile Cloud Networking (MCN) project integrates the use of cloud computing concepts in LTE mobile networks in order to increase LTE's performance. In this way a shared distributed virtualized LTE mobile network is built that can optimize the utilization of virtualized computing, storage and network resources and minimize communication delays. Two important features that can be used in such a virtualized system to improve its performance are the user mobility and bandwidth prediction. This paper introduces the architecture and challenges that are associated with user mobility and bandwidth prediction approaches in virtualized LTE systems.

Local changes in neocortical circuit dynamics coincide with the spread of seizures to thalamus in a model of epilepsy

During the generalization of epileptic seizures, pathological activity in one brain area recruits distant brain structures into joint synchronous discharges. However, it remains unknown whether specific changes in local circuit activity are related to the aberrant recruitment of anatomically distant structures into epileptiform discharges. Further, it is not known whether aberrant areas recruit or entrain healthy ones into pathological activity. Here we study the dynamics of local circuit activity during the spread of epileptiform discharges in the zero-magnesium in vitro model of epilepsy. We employ high-speed multi-photon imaging in combination with dual whole-cell recordings in acute thalamocortical (TC) slices of the juvenile mouse to characterize the generalization of epileptic activity between neocortex and thalamus. We find that, although both structures are exposed to zero-magnesium, the initial onset of focal epileptiform discharge occurs in cortex. This suggests that local recurrent connectivity that is particularly prevalent in cortex is important for the initiation of seizure activity. Subsequent recruitment of thalamus into joint, generalized discharges is coincident with an increase in the coherence of local cortical circuit activity that itself does not depend on thalamus. Finally, the intensity of population discharges is positively correlated between both brain areas. This suggests that during and after seizure generalization not only the timing but also the amplitude of epileptiform discharges in thalamus is entrained by cortex. Together these results suggest a central role of neocortical activity for the onset and the structure of pathological recruitment of thalamus into joint synchronous epileptiform discharges.

Kinetics and kinematics of the tölt: effects of rider interaction and shoeing manipulations

Introduction . Compared to most equine horse breeds which are able to walk, trot and canter /gallop, the gait repertoire of the Icelandic horses additionally includes the lateral gait tölt and frequently also the pace. With respect to the tölt gait, special shoeing, saddling and riding techniques have been developed for Icelandic horses in order to enhance its expressiveness and regularity. Toes are left unnaturally long and heavy shoes and paddings, as well as weighted boots are used to enforce the individual gait predisposition. For the same reason, the rider is placed more caudally to the horse's centre of mass as compared to other riding techniques. The biomechanical impact of these methods on the health of the locomotor system has so far never been subject of systematic research. Objectives . The aims of the presented study are (1) to describe the kinetic and kinematic characteristics of the tölt performed on a treadmill, (2) to understand the mechanical consequences of shoeing manipulation (long hooves, weighted boots) on the loading and protraction movement of the limbs, as well as (3) to study the pressure distribution and effects on the gait pattern of 3 different saddle types used for riding Icelandic horses. Materials and methods . Gait analysis was carried out in 13 Icelandic horses at walk and at slow and medium tölting and trotting speeds on a high-speed treadmill instrumented for measuring vertical ground reaction forces as well as temporal and spatial gait variables. Kinematic data of horse, rider and saddle were measured simultaneously. Gait analysis was first carried out with high, long hooves (SH) without and in combination with weighted boots (ad aim (2)). Afterwards, horses were re-shod according to current horseshoeing standards (SN) and gait analysis was repeated (ad aims (1) and (2)). In a second trial, horses were additionally equipped with a pressure sensitive saddle mat and were ridden with a dressage-like saddle (SDres), an Icelandic saddle (Slcel) and a saddle cushion (SCush) in the standard saddle position (ad aim 3). Results and conclusions . Compared to trot at the same speed, tölting horses had a higher stride rate and lower stride impulses. At the tölt loading of the forelimbs was increased in form of higher peak vertical forces (Fzpeak) due to shorter relative stance durations (StDrel). Conversely, in the hindlimbs, longer StDrel resulted in lower Fzpeak. Despite the higher head-neck position at tölt, there was no measurable shift in weight to the hindlimbs. Footfall rhythm was in most horses laterally coupled at the tölt and frequently had a slight fourbeat and a very short suspension phase at trot; underlining the fact that performance of correct gaits in Icelandic horses needs special training. Gait performance as it is currently judged in competition could be improved using a shoeing with SH, resulting in a 21 ± 5 mm longer dorsal hoof wall, but also a weight gain of 273 ± 50 g at the distal limb due to heavier shoeing material. Compared to SN, SH led to a lower stride rate, a longer stride length and a higher, but not wider, forelimb protraction arc, which were also positively associated with speed. At the tölt, the footfall rhythm showed less tendency to lateral couplets and at the trot, the suspension phase was longer. However, on the long term, SH may have negative implications for the health of the palmar structures of the distal foot by increased limb impulses, higher torques at breakover (up to 20%); as well as peak vertical forces at faster speeds. Compared to the shoeing style, the saddle type had less influence on limb forces or movements. The slight weight shift to the rear with SCush and Slcel may be explained by the more caudal position of the rider relative to the horse's back. With SCush, pressure was highest under the cranial part of the saddle, whereas the saddles with trees had more pressure under the caudal area.