Predicting the population impact of chlamydia screening programmes: comparative mathematical modelling study

BACKGROUND: Published individual-based, dynamic sexual network modelling studies reach different conclusions about the population impact of screening for Chlamydia trachomatis. The objective of this study was to conduct a direct comparison of the effect of organised chlamydia screening in different models. METHODS: Three models simulating population-level sexual behaviour, chlamydia transmission, screening and partner notification were used. Parameters describing a hypothetical annual opportunistic screening program in 16-24 year olds were standardised, whereas other parameters from the three original studies were retained. Model predictions of the change in chlamydia prevalence were compared under a range of scenarios. RESULTS: Initial overall chlamydia prevalence rates were similar in women but not men and there were age and sex-specific differences between models. The number of screening tests carried out was comparable in all models but there were large differences in the predicted impact of screening. After 10 years of screening, the predicted reduction in chlamydia prevalence in women aged 16-44 years ranged from 4% to 85%. Screening men and women had a greater impact than screening women alone in all models. There were marked differences between models in assumptions about treatment seeking and sexual behaviour before the start of the screening intervention. CONCLUSIONS: Future models of chlamydia transmission should be fitted to both incidence and prevalence data. This meta-modelling study provides essential information for explaining differences between published studies and increasing the utility of individual-based chlamydia transmission models for policy making.

Casting materials and their application in research and teaching

From a biological point of view, casting refers to filling of anatomical and/or pathological spaces with extraneous material that reproduces a three-dimensional replica of the space. Casting may be accompanied by additional procedures such as corrosion, in which the soft tissue is digested out, leaving a clean cast, or the material may be mixed with radiopaque substances to allow x-ray photography or micro computed topography (µCT) scanning. Alternatively, clearing of the surrounding soft tissue increases transparency and allows visualization of the casted cavities. Combination of casting with tissue fixation allows anatomical dissection and didactic surgical procedures on the tissue. Casting materials fall into three categories namely, aqueous substances (India ink, Prussian blue ink), pliable materials (gelatins, latex, and silicone rubber), or hard materials (methyl methacrylates, polyurethanes, polyesters, and epoxy resins). Casting has proved invaluable in both teaching and research and many phenomenal biological processes have been discovered through casting. The choice of a particular material depends inter alia on the targeted use and the intended subsequent investigative procedures, such as dissection, microscopy, or µCT. The casting material needs to be pliable where anatomical and surgical manipulations are intended, and capillary-passable for ultrastructural investigations.

Biomechanical properties of the atlantoaxial joint with naturally-occurring instability in a toy breed dog. A comparative descriptive cadaveric study

The biomechanical properties of the atlanto-axial joint in a young Yorkshire Terrier dog with spontaneous atlantoaxial instability were compared to those of another young toy breed dog with a healthy atlantoaxial joint. The range-of-motion was increased in flexion and lateral bending in the unstable joint. In addition, lateral bending led to torsion and dorsal dislocation of the axis within the atlas. On gross examination, the dens ligaments were absent and a longitudinal tear of the tectorial membrane was observed. These findings suggest that both ventral and lateral flexion may lead to severe spinal cord compression, and that the tectorial membrane may play a protective role in some cases of atlantoaxial instability.

A collection of autograph letters and original documents relating to the Island of Barbados in the 18th century, ca. 1730-1778

A miscellaneous collection of letter and legal documents relating to Barbados, especially prize causes, inheritance and slaves.

Student notes from medical lectures by Benjamin Rush, undated

The volumes contain student notes on a course of medical lectures given by Dr. Benjamin Rush (1746-1813) while he was Professor of the Institutes of Medicine and Clinical Practice at the University of Pennsylvania Medical School, likely in circa 1800-1813. The notes indicate Rush often referenced the works or teachings of contemporaries such as Scottish physicians William Cullen, John Brown, John Gregory, and Robert Whytt, and Dutch physician Herman Boerhaave. He frequently included anecdotes and case histories of his own patients, as well as those of other doctors, to illustrate his lecture topics. He also advised students to take notes on the lectures after they ended to allow them to focus on what they were hearing. Volume 1 includes notes on: physician conduct during visits to patients; human and animal physiology; voice and speech; the nervous system; the five senses; and faculties of the mind. Volume 2 includes notes on: food, the sources of appetite and thirst, and digestion; the lymphatic system; secretions; excretions; theories of nutrition; differences in the minds and bodies of women and men; reproduction; pathology; a table outlining the stages of disease production; “disease and the origin of moral and natural evil”; contagions; the role of food, drink, and clothing in producing disease; worms; hereditary diseases; predisposition to diseases; proximate causes of diseases; and pulmonary conditions. Volume 3 includes notes on: the pulse; therapeutics, such as emetics, sedatives, and digitalis, and treatment of various illnesses like pulmonary consumption, kidney disease, palsy, and rheumatism; diagnosis and prognosis of fever; treatment of intermitting fever; and epidemics including plague, smallpox, and yellow fever, with an emphasis on the yellow fever outbreaks in Philadelphia in 1793 and 1797.

Research and teaching the European Union in Latin America. Jean Monnet/Robert Schuman Paper Series Special, December 2012

NOTE: there is an appendix to this document on the Archive at ei.pitt.edu/29784/ From the Introduction. The tasks of research, teaching and public opinion outreach activities on the European Union in the Latin American subcontinent2 are propelled by two principal motivations. In the first place, interest on the EU originates from the historical proximity between Europe and Latin America. There are no other two regions in the world with a deeper mutual affinity than the one existing between Europe and the conglomerate composed by Latin America and the Caribbean. Only the intimate relationship forged by the United States with the Europe continent is perhaps stronger, and even more special with the United Kingdom.