Systematic differences in validity of self-reported mammography behavior: A problem for intergroup comparisons?

BACKGROUND: Prior studies of recall accuracy for screening mammogram behavior have examined relatively homogeneous groups. Data are limited on possible systematic group differences, so we evaluated women's recall accuracy in two separate care systems in one city. Methods. Women 50 to 70 years old with and without screening mammograms 10 to 14 months prior were identified from fiscal, clinic, and radiology records at a military care system (MCS) and a county-funded system (CFS) for indigents. Mammogram status was verified through radiology records. Women were excluded if mammograms were diagnostic, done for other than annual screening, or had abnormal results. Interviewers blinded to mammogram status surveyed randomly selected eligible women. RESULTS: For 62 screened/31 unscreened MCS women and 78 screened/61 unscreened CFS women, specificity was similar, at 65 and 62%, respectively. In contrast, sensitivity varied significantly: 95% versus 79% (P = 0. 011). Primary ethonocultural groups were Euro-American (MCS-60%) and Mexican American (CFS-85%). Although not different in specificity of recall (67% versus 61%), these major subgroups significantly differed in sensitivity (97% versus 80%, P = 0.017), proportion of true negatives due to never having a mammogram (35% versus 57%, P = 0.003), and proportion with >/=high school education (78% versus 19%, P < 0.00001). CONCLUSION: Systematic differences in recall validity may exist and compromise the accuracy of intergroup comparisons.

Capture techniques and morphological measurements of the mona monkey (Cercopithecus mona) on the island of Grenada, West Indies.

Morphological measurements were collected from 12 wild and 12 captive mona monkeys (Cercopithecus mona) on the Caribbean island of Grenada. Mona monkeys were introduced to Grenada from Africa approximately 200 to 300 years ago during the slave trade era. Wild monkeys were captured using either 1) a baited treadle-door trap and anesthetic-filled darts fired from a blowpipe, or 2) rifle-fired anesthetic-filled darts. All wild monkeys were released back into the forest after capture and were seen with their original groups within 24 hours of release. Captive monkeys were anesthetized using blowpipe-fired darts. A Ketaset/Rompun mixture was the most effective anesthetic for wild monkeys while Ketaset alone was suitable for captive monkeys. Responses to and recovery times from both drugs varied among individuals. Data on eight linear body measurements, canine length, testicle size, and weight were collected from all monkeys. Adult monkeys were significantly sexually dimorphic across all measurements. Mean adult male weight (mean = 4.7, SD = 0.9, n = 13) was almost twice that of adult females (mean = 2.8, SD = 0.8, n = 7). No significant differences in weight or measurements were found between adult wild and captive males. Preliminary comparisons with morphometrics for African C. mona from the literature showed the upper limit of Grenada mona body length and weight to be smaller than that of African monas for both sexes. These differences may be due to genetic divergence, ecological adaptation, inter-African geographic variation, and/or small sample sizes.

Group size and group composition of the mona monkey (Cercopithecus mona) on the Island of Grenada, West Indies.

Cercopithecus, the genus of guenons, is the largest of the African primate genera, and yet more than half of the species belonging to this group have never been the focus of a long-term field study. In this paper, I present data on group size and composition for a previously unstudied population of guenons on the Caribbean island of Grenada. The mona monkey, Cercopithecus mona, was introduced to Grenada from Africa approximately 200-300 years ago. Two types of social groups were found for Cercopithecus mona on Grenada: all-male groups consisting of two to four individuals and bisexual groups containing 5-32 individuals. All-male groups of Grenada mona monkeys contained any combination of juveniles, subadults, and/or adults. All-male groups were a common occurrence on Grenada but have never been reported for African C. mona and have been reported only in two other forest Cercopithecus species. Bisexual groups appeared to consist of one adult male, one to six adult females, subadult females, and juveniles and infants of both sexes. Even though no more than one adult male was ever seen in each bisexual group of monas on Grenada, other males were heard giving copulation calls simultaneously with resident adult male loud calls, suggesting that other males occasionally infiltrate bisexual groups.

Mycotic pulmonary infections.

Mycotic infections involve the lungs in the majority of cases. Some of the infections are limited in geographic location, while others are worldwide. Often the patients may present with minimal symptoms, unlike bacterial infections, and these symptoms may persist for a longer duration. In this article the authors describe the clinical and radiographic findings of mycotic infections in humans with emphasis on common features.

Image compression for medical imaging systems.

The physical size of typical digital images, in terms of the number of bytes of data one image contains, is large; e.g., a 1024 X 1024 image with 8 bits of data per pixel contains a megabyte of data. To transmit many such images over a network, sometimes over low-capacity phone lines to remote sites, or to store large numbers of images over a long period of time as part of the medical records for patients, the need for image compression arises to alleviate these large demands for image data storage and transmission capacity. This paper discusses image compression in terms of the information theory upon which it is based. The two basic categories of algorithms for implementing image compression are presented along with considerations for image quality and accuracy, which are of primary importance to the medical imaging community.