Blunt force trauma and blast injuries to head and chest caused by a potent pyrotechnic device: a case report.

In times of peace and except for terrorist attacks, fatalities by explosions are rare. Fireworks have deadly potential, especially self-made or illegally acquired devices. The use of professional pyrotechnics by untrained persons poses a life-threatening hazard. We present a case of devastating blunt force and blast injuries to the head and chest of a young man. After ignition of a display shell (syn. a real shell or mortar shell) without the use of a launching pipe, the device hit the man's face, nearly simultaneously followed by the explosion of the burst charge. The autopsy revealed injuries to the face and forehead as well as extensive tissue structure damage and a massive contusion with a bloody edema of the lungs. Autopsy results are supplemented with CT imaging and 3D reconstruction of the fractured mid face, as well as histological and toxicological examinations. This case of a misused display shell demonstrates both its devastating destructive potential and the corresponding and rarely observed injury pattern.

Muscle attachment site (MAS) patterns for species determination in five species of Sarcophaga (Diptera: Sarcophagidae).

To further establish species determination using the muscle attachment site (MAS) pattern method, third instar larvae of five forensically important species of Sarcophaga Meigen were investigated: Sarcophaga argyrostoma (Robineau-Desvoidy), Sarcophaga caerulescens Zetterstedt, Sarcophaga melanura Meigen, Sarcophaga albiceps Meigen and Sarcophaga similis Meade. As in the previously investigated Calliphoridae, patterns were found to be species specific. The main feature of the Sarcophaga patterns is the divided central horizontal row of segment four. A genus pattern was established to be used as base for comparison in further species determination.

Muscle attachment site (MAS) patterns for species determination in European species of Lucilia (Diptera: Calliphoridae).

Species identification is generally assessed to be more difficult in larval stages than in adult forms. Especially closely related species such as Lucilia caesar and Lucilia illustris are difficult to identify. The aim of this study was to simplify species determination in Lucilia larvae for entomological and forensic purposes. Muscle attachment site (MAS) patterns were previously found to be a good tool for species determination in blowfly larvae. Here, distinctive MAS patterns are presented for European Lucilia ampullacea, L. caesar, L. illustris, L. richardsi, L. sericata, and L. silvarum. A joint pattern for the genus Lucilia is provided for a quick classification of a larva to the genus.

Muscle attachment sites of Phormia regina (Meigen).

An error was found in a previous publication on muscle attachment sites in forensically important blowfly larvae from 2012. The patterns we assigned to Lucilia illustris factually belong to Phormia regina.

Marked for life: muscle attachment site patterns in blowfly larvae are constant throughout development.

The muscular attachment sites (MAS) of blowfly larvae can be visualised as "dots" by removing and staining the cuticle. Each segment bears several rows of MAS. The silhouettes of a subset of those rows in the second, third, and fourth segments were previously shown to be specific for four species of L3 blowfly larvae. In this investigation, the MAS patterns are described for a fifth species (Protophormia terraenovae) and throughout larval development of Calliphora vicina and Calliphora vomitoria. The patterns of P. terraenovae show considerable differences to those of the Calliphora species (larger MAS, characteristic "M" shape in row 4A), thus providing further evidence for the viability of the method as tool for species determination. Larvae with a body length of only 3 mm already show a complete set of MAS expressing identical pattern characteristics as L3 larvae with maximal body length. These characteristics are largely unchanged throughout development. Plotting the row length as a function of the body length throughout development reveals a linear correlation. Therefore, in case of requirement (e.g. fragmentation), not only the species but also the approximate larval age can be calculated with this method.

Influence of food substrates on the development of the blowflies Calliphora vicina and Calliphora vomitoria (Diptera, Calliphoridae).

The blowflies Calliphora vicina and Calliphora vomitoria are among the first colonizers of human remains in Europe. Laboratory development studies with immature stages of these blowflies for postmortem interval (PMI) calculations are generally performed on different media such as processed food substrates or liver of various animals. The question arises whether these media per se influence the development of larvae and thus PMI calculations? In this systematic approach, the effects of an assortment of food substrates on the development of the larvae were analyzed. C. vomitoria showed much better growth on processed substrates such as beef, pork, turkey, and mixed minced meats than on unprocessed substrates such as beef and pork liver and turkey steak. Beef liver even impeded full development of the species and resulted in death of all individuals. C. vomitoria was therefore categorized as a specialist. Even though mixed minced meat yielded low pupariation rates for C. vicina, the species showed, otherwise, comparable growth rates on all substrates tested and was thus considered to be a generalist. These findings emphasize the importance of parameters besides temperature on the development rates of forensically important fly larvae.

[Experimental throws with a knife to clarify a case of domestic violence]. / Messerwurf--Experimentelle Untersuchungen in einem Fall von "häuslicher Gewalt".

For an expert opinion, the course of events in a conflict resulting in a 3 cm deep and 1.8 cm wide stab wound on the neck of a woman was to be reconstructed. Based on the statements of witnesses, there were three possible scenarios: 1. The knife was thrown from a distance of about one meter. 2. The knife had accidentally slipped from the hand. 3. The knife was deliberately used for a stab to the neck of the victim. The experimental setup comprised the knife presumably causing the injury and four comparable knives. The victim was represented by a pig carcass. The results of the test throws are presented and the sequence of movements is assessed as to the most probable course of events. Four male and three female subjects performed test throws which were documented by video recordings and measurements of the penetration depth. Six of the seven subjects were able to generate stab wounds by throwing the knives, whereas a knife accidentally slipping from the hand never caused a stab wound in the tests.

Biomaterials: silk-like secretion from tarantula feet.

An unsuspected attachment mechanism may help these huge spiders to avoid catastrophic falls. Spiders spin silk from specialized structures known as abdominal spinnerets--a defining feature of the creatures--and this is deployed to capture prey, protect themselves, reproduce and disperse. Here we show that zebra tarantulas (Aphonopelma seemanni) from Costa Rica also secrete silk from their feet to provide adhesion during locomotion, enabling these spiders to cling to smooth vertical surfaces. Our discovery that silk is produced by the feet provides a new perspective on the origin and diversification of spider silk.

Cuticular muscle attachment sites as a tool for species determination in blowfly larvae.

First results of a new method for species determination in third instar larvae of saprophagous blowflies are introduced. Cuticular attachment sites of a limited number of transversal muscles are visualized for light microscopic analysis. After removing the muscles and staining the cuticle, the attachment sites become visible as laterally symmetrical segmental clusters of dark dots. The combined patterns of five such clusters, located in the second, third and fourth segments, show sufficient differences to allow reliable separation of externally very similar larval Lucilia sericata and Lucilia illustris as well as Calliphora vomitoria and Calliphora vicina, the most common saprophagous blowfly species in Europe. Species determination even in poorly conserved, discoloured and fragmented blowfly larvae becomes possible with this new method. The method can primarily be applied for postmortem interval (PMI) calculations in forensic entomology. Interspecific morphological similarity of the larvae and differences in growth rate make species determination an essential requisite for an exact PMI calculation.

Technical Note: Effects of Makeshift Storage in Different Liquors on Larvae of the Blowflies Calliphora vicina and Lucilia sericata (Diptera: Calliphoridae).

Unexpected findings of forensically important insects might prompt makeshift storage in alternative liquids if the proper equipment is lacking. The assessment of whether such evidence can still be used and correctly interpreted can be difficult. In this study, the effects of using alcoholic beverages as storing agents for post-feeding larvae of Calliphora vicina and Lucilia sericata were analyzed. Larvae were killed with boiling water (HWK) or placed alive into four alcoholic liquids: two spirits, vodka and brandy, and two liquors, Jägermeister and peppermint schnapps. Storage effects were documented after one day, nine days, and one month and compared to larvae treated according to guidelines for forensic entomology. Results show that the method of killing larvae is more important than the storing medium. Storage of HWK larvae in high-alcohol/low-sugar spirits had almost negligible effects on both species, while all fresh larvae shrank significantly. High sugar contents of the beverages might additionally lead to shrinkage of larvae.

Flies Do Not Jump to Conclusions: Estimation of the Minimum Post-Mortem Interval for a Partly Skeletonized Body Based on Larvae of Phromia regina (Diptera: Calliphoridae).

Skeletonization is often perceived as an indicator of long post-mortem intervals. The finding of feeding larvae of first colonizers, on the other hand, indicates days. We present a case in which both findings were present. Larvae of Phormia regina, aged 9 days, and skeletonization of the head and part of the thorax were both found on an unidentified female body. Identification of dentures eventually led to resolution of the case and a confession, which settled the seeming contradiction in favor of forensic entomology.

Muscle attachment site patterns for species determination in West Palaearctic Wohlfahrtia (Diptera: Sarcophagidae) of medical and veterinary importance.

The flesh fly genus Wohlfahrtia Brauer & Bergenstamm contains at least six species of medical and veterinary importance. Traditional methods of species identification in specimens of Wohlfahrtia, however, are restricted mostly to adult forms. Muscle attachment site (MAS) patterns allow for species determination in larval forms. MAS patterns in third instar larvae of six common West Palearctic species of Wohlfahrtia have been analyzed for this study. As in previously investigated Calliphoridae and Sarcophagidae, MAS patterns were found to be species specific. A genus pattern was established to be used as base for comparison in further species determination. For the first time a tool is provided for species identification of such broad range in larvae of Wohlfahrtia species. Wohlfahrtia patterns are composed of a significantly higher number of MAS than patterns found in Sarcophaga. Specifics of the six species analyzed are explained in detail. The larvae of the well-known species W. magnifica, an obligate traumatic myiasis agent, had to be excluded from the analysis as a great number of spines on the outside obscure muscle attachment sites on the inside of the cuticle.

Connecting the Dots: From an Easy Method to Computerized Species Determination.

Differences in growth rate of forensically important dipteran larvae make species determination an essential requisite for an accurate estimation of time since colonization of the body. Interspecific morphological similarities, however, complicate species determination. Muscle attachment site (MAS) patterns on the inside of the cuticula of fly larvae are species specific and grow proportionally with the animal. The patterns can therefore be used for species identification, as well as age estimation in forensically important dipteran larvae. Additionally, in species where determination has proven to be difficult-even when employing genetic methods-this easy and cheap method can be successfully applied. The method was validated for a number of Calliphoridae, as well as Sarcophagidae; for Piophilidae species, however, the method proved to be inapt. The aim of this article is to assess the utility of the MAS method for applications in forensic entomology. Furthermore, the authors are currently engineering automation for pattern acquisition in order to expand the scope of the method. Automation is also required for the fast and reasonable application of MAS for species determination. Using filters on digital microscope pictures and cross-correlating them within their frequency range allows for a calculation of the correlation coefficients. Such pattern recognition permits an automatic comparison of one larva with a database of MAS reference patterns in order to find the correct, or at least the most likely, species. This facilitates species determination in immature stages of forensically important flies and economizes time investment, as rearing to adult flies will no longer be required.

Case report: Time of death estimation of a buried body by modeling a decomposition matrix for a pig carcass.

Estimating time of death of buried human bodies is a very difficult task. Casper's rule from 1860 is still widely used which illustrates the lack of suitable methods. In this case study excavations in an arbor revealed the crouching body of a human being, dressed only in boxer shorts and socks. Witnesses were not able to generate a concise answer as to when the person in question was last seen alive; the pieces of information opened a window of 2-6 weeks for the possible time of death. To determine the post mortem interval (PMI) an experiment using a pig carcass was conducted to set up a decomposition matrix. Fitting the autopsy findings of the victim into the decomposition matrix yielded a time of death estimation of 2-3 weeks. This time frame was later confirmed by a new witness. The authors feel confident that a widespread conduction of decomposition matrices using pig carcasses can lead to a great increase of experience and knowledge in PMI estimation of buried bodies and will eventually lead to applicable new methods.

Tarsal movements in flies during leg attachment and detachment on a smooth substrate.

In order to understand the attachment mechanism of flies, it is important to clarify the question of how the adhesive pad (pulvillus) builds and breaks the contact with the substrate. By using normal and high-speed video recordings, the present study revealed that pulvilli are positioned on the surface in a particular way. The pulvilli are apparently loaded or pressed upon the substrate after leg contact, as evidenced by splaying of the claws. Detachment of pulvilli from the substrate may be achieved in four different modes depending on the leg (fore-, mid- or hindleg): pulling, shifting, twisting, and lifting. Lifting is the only detachment mode depending on the claws' action. Kinematics of the tarsal chain is studied in leg preparations, in which the tendon of the claw flexor muscle was pulled by tweezers and video recorded. The morphological background of tarsal movements during attachment and detachment is studied by scanning electron microscopy, fluorescent microscopy, and bright field light microscopy followed by serial semithin sectioning of pretarsal structures. Several resilin-bearing springs are involved in the recoil of the tarsal segments to their initial position, when the tendon is released after pull.

Simple clearing technique as species determination tool in blowfly larvae.

A simple clearing technique is presented by which species specific structures and organs of blowfly larvae can easily be visualized and displayed without any danger of mechanical damages or dislocations of delicate formations and without fixation of the object.

Feel the heat: The effect of temperature on development, behavior and central pattern generation in 3rd instar Calliphora vicina larvae.

Like in all poikilothermic animals, higher temperatures increase developmental rate and activity in Calliphora vicina larvae. We therefore could expect temperature to have a persistent effect on the output of the feeding and crawling central pattern generators (CPGs). When confronted with a steep temperature gradient, larvae show evasive behavior after touching the substrate with the cephalic sense organs. Beside this reflex behavior the terminal- and dorsal organ might also mediate long term CPG modulation. Both organs were thermally stimulated while their response was recorded from the maxillary- or antennal nerve. The terminal organ showed a tonic response characteristic while the dorsal organ was not sensitive to temperature. Thermal stimulation of the terminal organ did not affect the ongoing patterns of fictive feeding or crawling, recorded from the antennal- or abdominal nerve respectively. A selective increase of the central nervous system (CNS) temperature accelerated the motor patterns of both feeding and crawling. We propose that temperature affects centrally generated behavior via two pathways: short term changes like thermotaxis are mediated by the terminal organ, while long term adaptations like increased feeding rate are caused by temperature sensitive neurons in the CNS which were recently shown to exist in Drosophila larvae.

Gustatory feedback affects feeding related motor pattern generation in starved 3rd instar larvae of Calliphora vicina.

Gustatory feedback allows animals to distinguish between edible and noxious food and adapts centrally generated feeding motor patterns to environmental demands. In reduced preparations obtained from starved Calliphora larvae, putatively appetitive (ethanol), aversive (sodium acetate) and neutral (glucose) gustatory stimuli were applied to the anterior sense organs. The resulting sensory response was recorded from the maxillary and antennal nerves. All three stimuli increased the neural activity in both nerves. Recordings obtained from the antennal nerve to monitor the activation pattern of the cibarial dilator muscles, demonstrated an effect of gustatory input on the central pattern generator for feeding. Ethanol consistently enhanced the rhythmic activity of the CDM motor neurons either by speeding up the rhythm or by increasing the burst duration. Ethanol also had an enhancing effect on the motor patterns of a protractor muscle which moves the cephalopharyngeal skeleton relative to the body. Sodium acetate showed a state dependent effect: in preparations without spontaneous CDM activity it initiated rhythmic motor patterns, while an ongoing CDM rhythm was inhibited. Surprisingly glucose had an enhancing effect which was less pronounced than that of ethanol. Gustatory feedback therefore can modify and adapt the motor output of the multifunctional central pattern generator for feeding.

Preliminary studies of the influence of fluctuating temperatures on the development of various forensically relevant flies.

Development of larvae of different forensically important flies under constant low, medium and high temperatures as well as under daily fluctuating temperatures in a climatic chamber was investigated and compared. Results suggest faster development under fluctuating temperatures for Sarcophaga argyrostoma and Lucilia illustris but slower development for Calliphora vicina and Calliphora vomitoria. Fluctuating temperatures had a higher impact on larvae in feeding stages than in post-feeding stages. Moreover an ability to develop at constant low temperatures was noted for some species. Negligence of fluctuating temperatures in legal cases can lead to distinctly wrong estimates of the post-mortem interval (PMI).

The cephalic and pharyngeal sense organs of Calliphora vicina 3rd instar larvae are mechanosensitive but have no profound effect on ongoing feeding related motor patterns.

The anterior segments of cyclorraphous Diptera larvae bear various sense organs: the dorsal- and terminal organ located on the cephalic lobes, the ventral- and labial organs associated with the mouthplate and the internal labral organ which lies on the dorsal surface of the esophagus. The sense organs are connected to the brain via the antennal nerve (dorsal- and labral organ) or the maxillary nerve (terminal-, ventral-, labial organ). Although their ultrastructure suggests also a mechanosensory function only their response to olfactory and gustatory stimuli has been investigated electrophysiologically. Here we stimulated the individual organs with step-, ramp-, and sinusoidal stimuli of different amplitude while extracellulary recording their afferents from the respective nerves. The external organs show a threshold of approximately 2 microm. All organs responded phasically and did not habituate to repetitive stimuli. The low threshold of the external organs combined with their rhythmically exposure to the substrate suggested a putative role in the temporal coordination of feeding. We therefore repetitively stimulated individual organs while simultaneously monitoring the centrally generated motor pattern for food ingestion. Neither the dorsal-, terminal- or ventral organ afferents had an obvious effect on the ongoing motor rhythm. Various reasons explaining these results are discussed.