Skew in ovarian activation depends on domicile size in phyllode-glueing thrips.

Costs and benefits of group living are a fundamental topic in behavioural ecology. Resource availability affects individuals' breeding prospects alone and in groups, as well as how reproduction is distributed within groups ("reproductive skew"). Here, in facultatively social thrips, we provide correlational evidence that breeding resources are associated with (1) whether solitary or social living is favoured, and (2) the degree of ovarian skew. Dunatothrips aneurae (Thysanoptera, Phlaeothripidae) cooperatively build silk "domiciles" on Australian Acacias, feeding exclusively from internal phyllode surfaces. Per capita productivity scaled differently with group size depending on domicile volume - females in small domiciles did better alone than in groups, whereas in large domiciles single and group-nesting females did equally well. Ovarian dissections revealed that in small domiciles some females were nonreproductive, indicating ovarian (i.e. reproductive) skew. Skew increased as domicile size decreased and group size increased. Breeders had smaller oocyte volume in smaller domiciles, especially those containing nonreproductives. These findings suggest group formation and reproductive skew in D. aneurae may be influenced by reproductive competition for breeding resources. Nonreproductive females in small domiciles may be reproductively suppressed, subfertile, or accumulating resources to reproduce.

Increased copulation duration before ejaculate transfer is associated with larger spermatophores, and male genital titillators, across bushcricket taxa.

Copulation duration varies considerably across species, but few comparative studies have examined factors that might underlie such variation. We examined the relationship between copulation duration (prior to spermatophore transfer), the complexity of titillators (sclerotized male genital contact structures), spermatophore mass and male body mass across 54 species of bushcricket. Using phylogenetic comparative analyses, we found that copulation duration was much longer in species with titillators than those without, but it was not longer in species with complex compared with simple titillators. A positive relationship was found between spermatophore size and copulation duration prior to ejaculate transfer, which supports the hypothesis that this represents a period of mate assessment. The slope of this relationship was steeper in species with simple rather than complex titillators. Although the data suggest that the presence of titillators is necessary to maintain long copulation prior to ejaculate transfer, mechanisms underlying this association remain unclear.

Trachipleistophora hominis infection in the myocardium and skeletal muscle of a patient with AIDS.

OBJECTIVES: To review the literature relevant to microsporidial infection of muscle and to describe a case of human microsporidial infection involving both skeletal and cardiac muscle. METHODS: Samples from an AIDS patient with myositis have been examined by light and electron microscopy. RESULTS: We describe the findings at autopsy of a 47 year old Australian male with late stage AIDS, who had skeletal and cardiac muscle involvement with the microsporidian Trachipleistophora hominis. This is the third definitively identified case of human T. hominis infection and the first to describe infection of the myocardium. CONCLUSIONS: Microsporidial infection of muscle is rare in humans, but more work is needed to elucidate both the organisms and routes of transmission of this group of parasitic protozoa.

Suicide methods in the elderly in South Australia 1981-2000.

The files of the Forensic Science Centre in Adelaide, Australia were examined over a 20-year period from 1981 to 2000 for cases of suicide in individuals aged 65 years and over. A total of 445 cases were found (13.8% of all suicides) with an age range of 65-94 years (average= 73.5 years). All cases had undergone full autopsies and police investigation. There were significantly more male than female victims; M:F = 330:115 (p < 0.001). Hangings accounted for the highest proportion of cases (107/445; 24%) followed by gunshot wounds (96/445; 21.6%), drug toxicity (82/435; 18.9%), drowning (66/445; 14.8%), and carbon monoxide toxicity (52/445; 11.7%). A miscellaneous group accounted for 42 of 445 cases (9.2%). No significant changes occurred in either the total suicide rate or in the rates in males and females, except for drowning deaths in males, which showed a significant decrease over time (p < 0.01). Female victims tended to avoid violent methods such as gunshot wounds in favour of drug overdose. Gunshot wound deaths were far less common than published data from other countries would indicate, with relative increases in deaths due to hanging, drug toxicity, drowning and carbon monoxide toxicity. An awareness of the considerable variability that occurs among populations in suicide methods and rates is important in determining local requirements for suicide prevention campaigns.

Death due to electrocution in childhood and early adolescence.

OBJECTIVES: To delineate the clinicopathological features of fatal childhood electrocutions and to identify specific risk factors. METHODS: Coronial files in Adelaide (Australia) were searched from 1967 to 2001 and Medical Examiners' files in San Diego (USA) were searched from 1988 to 2001, for cases of deaths of children and adolescents younger than 16 years attributed to electrocution. RESULTS: Sixteen cases were identified aged between 10 months and 15 years (mean 8.0 years) with a male : female ratio of 5 : 3. Deaths were due to accidents occurring while playing with or near faulty electrical equipment at home or at school (n = 8), electrical equipment while in the bath (n = 2), damaged outdoor electrical equipment (n = 1), overhead wires (n = 1), and a high voltage electricity substation (n = 1). In addition, one death was due to suicide involving an electrical appliance placed in a bath, and two other deaths occurred in older children who were moving equipment under overhead wires. No homicides were identified. CONCLUSIONS: Childhood deaths due to electrocution are rare and are more likely to occur when children are playing around electrical wires or equipment, and often result from either faulty apparatus, or a lack of understanding of the potential dangers involved. The majority of deaths (11/16; 69%) occur in the home environment. In contrast to adult electrical deaths, high-voltage electrocutions, suicides and workplace deaths are uncommon. Strategies for eliminating childhood electrocution should concentrate on ensuring safe domestic environments with properly maintained electrical devices.

Childhood sporting deaths.

Exercise-induced collapse and sudden death are unusual in childhood. For this reason, a study was undertaken of a series of 12 cases of sudden death in childhood occurring during physical exertion associated with sporting activities. The age range was 7 to 16 years (mean 12.3 years, M:F ratio 5:1). Deaths resulted from trauma associated with the sporting activity, from an idiosyncratic response to exertion, or from exacerbation of a known underlying disease. Trauma was directly fatal (n = 4: vascular trauma in 1, head injury in 2, drowning in 1), exacerbated an underlying medical condition (n = 1: hypertrophic obstructive cardiomyopathy), or followed collapse from underlying organic disease (n = 1: drowning in epilepsy). Deaths after exertion occurred when there was an unexpected response to underlying occult disease (n = 4: aortic stenosis in 1, cerebral arteriovenous malformation in 1, hypertrophic obstructive cardiomyopathy in 1, coronary atherosclerosis in 1) or to preexisting known disease (n = 2: surgically corrected transposition of the great vessels in 1, asthma in 1). The fatal episodes often resulted from a complex interplay of a variety of factors, including physical exertion, possible trauma, and underlying organic disease. Testing of other family members may be indicated in cases where a rare, possibly familial, disease is found. Evaluation of cases required descriptions of activities before death, information from the medical history of the deceased, and detailed findings from the autopsy.

Epithelial cell mitotic arrest--a useful postmortem histologic marker in cases of possible colchicine toxicity.

Following ingestion of 30 mg of presumed benztropine (Cogentin) a 39-year-old male developed nausea, vomiting and diarrhea. His admission to hospital was soon followed by collapse and death. Histological examination, however, revealed increased numbers of mitotic figures in otherwise normal epithelial cells of the esophagus and bronchioles, a feature characteristic of colchicine toxicity. Subsequent toxicological analyses confirmed the presence of colchicine in the urine, but not in the blood. A dispensing error had resulted in substitution of colchicine for Cogentin. Histological findings had, therefore, provided evidence of colchicine toxicity and had guided subsequent toxicological evaluation. In suspected cases of colchicine toxicity, histological samples should, therefore, be taken from multiple sites along the gastrointestinal and respiratory tract in addition to other organs and tissues so that diagnostic morphological changes can be looked for.

Fatal childhood vascular injuries associated with seat belt use.

The deaths of two children who were passengers in motor vehicles involved in accidents were directly attributable to vascular injuries derived from seat belts. In the first case, a 10-year-old boy died as a result of abdominal aortic transection by a lap seat belt, and in the second case a 15-year-old boy died as a result of transection of his common carotid artery by a lap-shoulder seat belt. Although these cases demonstrate rare fatalities associated with seat belt use, there is no doubt that seat belts have significantly reduced mortality and morbidity from traffic accidents. Although it is possible that a fatal outcome might have occurred in each of these cases from other injuries that might have been sustained had seat belts not been worn, appropriate positioning and size of seat belt harnesses might have avoided the lethal injuries.

Adolescent suicide due to inhalation of insect spray.

A 17-year-old female who had been expressing suicidal ideation following domestic problems was found dead in her room next to a towel and an empty can of insect spray. There were no suspicious circumstances and it appeared that the deceased had inhaled insect spray using the towel to maintain the concentration of vapour around her nose and mouth. There was no history of recreational inhalation of volatile substances or other illicit drug use. Inhalation of insect spray is a rare method of suicide in keeping with the suggestion that young suicide victims utilize unusual methods of self-destruction determined to some degree by availability and accessibility.

Upper airway occlusion by soil--an unusual cause of death in vehicle accidents.

Upper airway obstruction by soil is a rare cause of death in motor vehicle accidents. Four cases were found in a search of the records of the Forensic Science Centre in Adelaide, South Australia over a twenty-year period from January 1982 to December 2001. Case 1: A 68-year-old male driver died from sand inhalation after he was trapped in his vehicle following an accident. His mouth and upper airway were packed with sand. Case 2: A 33-year-old male pedestrian died from smothering after he had been knocked over and had his head pressed face down into sandy soil by a vehicle wheel. Case 3: A 12-year-old male passenger died from soil inhalation after the vehicle in which he was travelling rolled over and filled with soil. His mouth and upper airway were packed with soil. In these cases the victims had been trapped with the face covered in fine, or loose, soil or sand. In Case 4 a 41-year-old male passenger was ejected from a vehicle. He died from blunt chest trauma exacerbated by occlusion of the mouth and nose by soil. Careful scene descriptions are required in the assessment of such cases, in addition to evaluation of the relative contribution of injuries and asphyxia to the fatal episode.

Glycine toxicity and unexpected intra-operative death.

A rare complication of the use of glycine irrigation fluid during prostatic surgery in a 69-year-old man is described. Following cystolithopexy and transurethral resection of the prostate for benign prostatomegaly, abdominal distension developed with increasing ventilatory pressures. Despite retroperitoneal fluid evacuation at subsequent urgent laparotomy, cardiac arrest occurred that was not amenable to resuscitation. At autopsy a traumatic defect in the posterior bladder wall filled with calculus debris was confirmed that did not communicate with the peritoneal cavity. Hyponatremia with markedly elevated levels of blood, urine, and body fluid glycine were demonstrated. Death was, therefore, attributed to glycine toxicity following tracking of glycine through a surgical defect in the posterior bladder wall. Careful dissection of surgical sites is required in such cases to demonstrate any additional trauma that may be associated with the fatal episode. Analysis of body fluids for glycine and electrolytes is also necessary to assist in the determination of possible mechanisms of death.

Hepatic abscess formation and unexpected death: a delayed complication of occult intraabdominal foreign body.

A case of unexpected death in a 65-year-old woman, caused by a migrating foreign body that resulted in multifocal hepatic abscesses, is reported. The foreign body was subsequently identified as a portion of chicken fibula. The prolonged time course of the illness, with relatively nonspecific symptoms and signs, resulted in establishment of the diagnosis only at autopsy.

Traditional punishment and unexpected death in Central Australia.

Three cases of traditional punishment in Central Australian Aboriginal men are presented in which the thighs were speared or stabbed as part of a "payback" system. In two cases, an unexpected effect of the stabbing or spearing was death due to severing of major leg vessels. The relationship between customary Aboriginal law and general law in Australia has not been clearly defined; however, these cases demonstrate that significant and untoward effects may result from traditional punishments. Pathologists working near traditional Australian Aboriginal communities may still encounter such injuries at autopsy.

Septo-optic dysplasia and unexpected adult death--an autopsy approach.

A 20-year-old woman who suffered from septo-optic dysplasia died unexpectedly following a presumed viral gastroenteritis. Autopsy and neuropathological examination confirmed optic nerve hypoplasia with absence of the septum pellucidum. Marked adrenal gland hypoplasia reflected hypothalamic hypopituitarism. The small and large intestines were dilated and filled with liquid fecal material. This case demonstrates that individuals with septo-optic dysplasia may be at risk of unexpected death at all ages. The complexity of mechanisms of death in rare dysmorphic conditions may be overlooked if relevant clinical information is not available at the time of autopsy and unless specific steps are taken to clearly delineate the underlying features of the condition.

Characteristic features of suicidal drownings: a 20-year study.

A retrospective study of cases of drowning suicide was undertaken at the Forensic Science Centre in Adelaide, South Australia for the period April 1980 to March 2000. A total of 123 cases were found, with 76 males (age, 16-88 years; average, 50.5 years; standard deviation [SD], 20.1 years) and 47 females (age, 34-88 years; average, 60.6 years; SD, 13.9 years). There were 66 fresh water drownings and 57 saltwater drownings. Female victims were significantly older than male victims for both fresh water and saltwater drownings (P < .05 and P < .01, respectively). Deaths in young women were rare. No temporal trend in drowning suicides could be shown, with annual numbers varying from 0 to 12 cases (average, 6.15; median, 7). Women preferentially chose the ocean or bath to drown themselves in, whereas males chose rivers, ditches, and lakes. Swimming pools were rarely used for suicide in this population; alcohol use was not usual; and there was often a significant history of mental illness.

Arrhythmogenic left ventricular dysplasia' and sudden death.

A 32-year-old man who died suddenly and unexpectedly was found at autopsy to have prominent fatty infiltration of his left ventricle with fibrous scarring, in the presence of normal coronary arteries. The right ventricle was minimally involved. A diagnosis of ventricular dysplasia largely limited to the left ventricle was made. Subsequent family screening identified a brother with clinical manifestations of ventricular dysplasia. This case provides further evidence for the association of left ventricular dysplasia with sudden death, and demonstrates that left ventricular involvement may also be inheritable. Whether predominantly left ventricular dysplasia is a manifestation of right ventricular dysplasia, or is a separate entity, is yet to be determined.

Death due to malathion poisoning.

Malathion is a commonly available insecticide with relatively low toxicity. A study was undertaken in South Australia over a 20-year period to assess the characteristic features of deaths associated with malathion. A total of 5 cases were found, in each of which exposure to malathion had been intentional. The male to female ratio was 2:3 with an age range of 32 to 80 years (mean = 57 yr). In four cases malathion had been ingested and in one case death had resulted from an intravenous injection of insecticide. Ingestion of large volumes of malathion was associated with contamination of the mortuary due to postmortem regurgitation in at least one case. The study also demonstrates that suicides due to malathion poisoning were uncommon in thispopulation, representing only 0.2% of the 3,202 suicides recorded at the Forensic Science Centre over the 20year period.

Diagnostic issues in unusual asphyxial deaths.

Upper airway occlusion may be due to a variety of causes and may result from accidents, suicides or homicides. Underlying natural diseases may also predispose to lethal choking episodes. A series of nine cases is reported to illustrate a range of circumstances that resulted in fatal upper airway compromise. These included suicide from upper airway obstruction due to an impacted blanket, and accidental deaths due to inhalation of soil, a rock, and a video cassette sticker. One death resulted from glottic obstruction due to a mucosal cavernous haemangioma, another from an enlarged tonsil, and two deaths were precipitated by underlying organic disease in the form of dementia and insulin-dependent diabetes mellitus. The manner of death was not clear cut in two cases where there was evidence of possible accidental death or suicide.

Pathologic features of fatal shark attacks.

To examine the pattern of injuries in cases of fatal shark attack in South Australian waters, the authors examined the files of their institution for all cases of shark attack in which full autopsies had been performed over the past 25 years, from 1974 to 1998. Of the seven deaths attributed to shark attack during this period, full autopsies were performed in only two cases. In the remaining five cases, bodies either had not been found or were incomplete. Case 1 was a 27-year-old male surfer who had been attacked by a shark. At autopsy, the main areas of injury involved the right thigh, which displayed characteristic teeth marks, extensive soft tissue damage, and incision of the femoral artery. There were also incised wounds of the right wrist. Bony injury was minimal, and no shark teeth were recovered. Case 2 was a 26-year-old male diver who had been attacked by a shark. At autopsy, the main areas of injury involved the left thigh and lower leg, which displayed characteristic teeth marks, extensive soft tissue damage, and incised wounds of the femoral artery and vein. There was also soft tissue trauma to the left wrist, with transection of the radial artery and vein. Bony injury was minimal, and no shark teeth were recovered. In both cases, death resulted from exsanguination following a similar pattern of soft tissue and vascular damage to a leg and arm. This type of injury is in keeping with predator attack from underneath or behind, with the most severe injuries involving one leg. Less severe injuries to the arms may have occurred during the ensuing struggle. Reconstruction of the damaged limb in case 2 by sewing together skin, soft tissue, and muscle bundles not only revealed that no soft tissue was missing but also gave a clearer picture of the pattern of teeth marks, direction of the attack, and species of predator.