Comments on and extracts from: the death of a twin: mourning and anniversary reactions - fragments of 10 years of self-analysis by George Engel.

Only recently has the special bereavement associated with the loss of a twin been generally recognised. With the notable exception of Joan Woodward, few have written on the subject. We, therefore, offer a shortened version of a paper written nearly 30 years ago. George Engel was himself a lone twin as well as being an eminent psychiatrist and psychoanalyst in the United States. The length of the paper precludes reprinting the totality but we hope readers will be encouraged to seek out the original published in The International Journal of Psycho-analysis in 1975, Vol 56 part 1, 23-40.     

Fifty Years of Anthropology and Education 1950-2000: A Spindler Anthology. George Spindler and Louise Spindler

Fifty Years of Anthropology and Education 1950-2000:. Spindler Anthology. George Spindler and Louise Spindler. George Spindler, ed. Mahwah, NY: Lawrence Erlbaum Associates, Publishers, 2000.434 pp.     

Trends in pulmonary embolism death rates for Canada and the United States, 1962-87.

To investigate the effect of advances in the prevention and treatment of pulmonary embolism, we examined the rates of death from pulmonary embolism in Canada for 1965-87 and compared them with those for the United States for 1962-84. The direct method of age standardization was used on sex-specific and age-specific death rates, with the 1960 US population as the standard. In both countries the death rates increased then decreased, although the changes in the Canadian rates occurred later and were less pronounced than those in the US rates. Men and elderly people were at higher risk of death from pulmonary embolism than women and younger people. Prevention strategies, possibly including encouraging a more active lifestyle and targetting high-risk groups, may further reduce pulmonary embolism death rates in both countries.     

Fifty years of muscle and the sliding filament hypothesis.

This review describes the early beginnings of X-ray diffraction work on muscle structure and the contraction mechanism in the MRC Unit in the Cavendish Laboratory, Cambridge, and later work in the MRC Molecular Biology Laboratory in Hills Road, Cambridge, where the author worked for many years, and elsewhere. The work has depended heavily on instrumentation development, for which the MRC laboratory had made excellent provision. The search for ever higher X-ray intensity for time-resolved studies led to the development of synchrotron radiation as an exceptionally powerful X-ray source. This led to the first direct evidence for cross-bridge tilting during force generation in muscle. Further improvements in technology have made it possible to study the fine structure of some of the X-ray reflections from contracting muscle during mechanical transients, and these are currently providing remarkable insights into the detailed mechanism of force development by myosin cross-bridges.     

John N. Brady (1952-2009): a Generous Spirit

John N. Brady, Chief of the Virus Tumor Biology Section of the Laboratory of Cellular Oncology, National Institutes of Health, died of cancer on 27 April 2009. John was a stellar member of the virology community. He was a longtime Journal of Virology reviewer and a member of the editorial board. He will be missed. Fatah Kashanchi of the George Washington University Medical Center has written John''s memorial. Fatah worked with John at the NIH and published more than 30 papers with him. Fatah thanks all the people who contributed to John''s obituary, including Kuan-Teh Jeang, Lou Laimins, Mary Loeken, Renaud Mehieux, Paul Lambert, Graziella Piras, Scott Gitlin, Paul Lindholm, Nadia Rosenthal, Sergi Nekhai, Brian Wigdahl, David Price, Susan J. Marriott, Cynthia Masison, Jurgen Dittmer, Eric Verdin, Bassel E. Sawaya, and John''s longtime assistants Janet Duvall Grimm and Michael Radonovich, who gave immense support to all the individuals who went through John''s lab.     

The Western Rock lobster Panulirus cygnus (George, 1962) (Decapoda: Palinuridae): the effect of temperature and developmental stage on energy requirements of pueruli

Pueruli of the Western Rock Lobster Panulirus cygnus (George, 1962) are thought to be nonfeeding. Consequently, the metabolic rate is expected to be low during this stage in order to conserve energy reserves. Furthermore, since water temperature potentially has a substantial impact on energetic needs, the puerulus possibly exhibits mechanisms to reduce the effect of temperature on energy consumption. To test these propositions the metabolic rate was measured in post-settlement pueruli and in juveniles at two water temperatures. A respirometer of variable volume (10–50 ml) was designed for this purpose, incorporating a dark-type oxygen sensor. Results were compared with data available from the literature.

Oxygen consumption in pre-molt pueruli and in intermolt juveniles (1.48 to 5.65 μmol O₂· individual⁻¹·h⁻¹ on average) was substantially higher than in post-settlement pueruli (1.06–1.41μmol O₂·ind.⁻¹h⁻¹). These significant changes could only partly be explained through changes in biomass. Furthermore, no significant effect of an increased water temperature (from 18 to 23 ° C) could be detected on the metabolic rate in post-settlement pueruli, and the effect is moderate in pre-molt pueruli (Q₁₀ = 1.95). The water temperature has, however, a substantially greater impact on first and second molt juveniles (Q₁₀ = 2.46 to 4.80).

The energetic demand was calculated from oxygen consumption and indicate that energetic needs of post-settlement pueruli is low compared with both pre-molt pueruli and juveniles. A low energetic demand and a reduced effect of temperature on energy consumption is of considerable benefit to a non-feeding larva, and may provide the puerulus with a means of extending the duration of the non-feeding stage and increasing the chance for survival beyond metamorphosis to the first feeding stage. Results indicate that the energetic demand during metamorphosis may be considerable. It is postulated that energetic requirements of the planktonic (actively swimming) puerulus larvae are considerably higher and are likely to be more temperature dependent.     

Chlamydia: five years A.G. (after genome)

The obligate intracellular pathogens Chlamydiaceae are the agents of several human diseases. They cannot be genetically manipulated and they survive and replicate in a unique intracellular organelle called the inclusion. In the past five years, publications of the genome sequences of several strains have opened new areas of research. Some of these new advances are presented here.