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The southern Porcupine Basin is characterized by axial stretching factors that are greater than six and typical of rifted margins. As such, the basin can be regarded as a natural laboratory to investigate the evolution and symmetry of rifting leading towards continental separation and breakup. A bright reflection (here named P) cuts down to the west from the base of the sedimentary section, is overlain by small fault blocks and appears to represent a detachment fault. P may in part follow the top of partially serpentinized mantle: this interpretation is consistent with gravity modelling, and with numerical models of crustal embrittlement and mantle serpentinization during extension. Furthermore, P closely resembles the S reflection west of Iberia, where such serpentinites are well documented. Although overall the basin remains symmetrical, the consistent westward structural dip of the detachment implies that, at high stretching factors, extension became asymmetric. Farther south, the 'Porcupine Median High', appearing lens-shaped in cross-section, overlies the tilted fault blocks and is onlapped by postrift sediment. Despite no evidence for synrift magmatism, this high has previously been interpreted as a basaltic structure. However, it develops above the line of intersection of the crust-mantle boundary with the P detachment, and hence may be related to the spatial limit of serpentinization. The median high may represent a serpentinite mud volcano or diapir; we suggest that such structures produce the serpentinite breccias found within the rifted continent-ocean transition of nonvolcanic margins. Keywords: Porcupine Basin, seismic reflection, rifting, detachment faults, serpentinization.

We surveyed 1,500 primary care physicians in Massachusetts regarding their current attitudes and practices, as well as their interests and preferences in regard to a continuing education course, in cancer prevention and screening. Thirty-three percent (n = 488) of physicians returned questionnaires, with equal distribution among internists, family practitioners, and gynecologists. Our findings are based on physicians' self-report: 80%-92% of physicians routinely perform or order breast, cervical, skin, prostate, and colon examinations (with the exception of proctoscopy) for asymptomatic patients 50 years of age and older. Perceived barriers reported were as follows: for mammography, patient age older than 75; for sigmoidoscopy, cost; for counseling, lack of educational materials. Ninety-one percent of physicians rated a comprehensive course on cancer detection and prevention emphasizing practical matters and offering opportunity to upgrade clinical skills in physical exam and in counseling as somewhat to very useful. Specific topic preferences varied by specialty, but first preference for all three primary care groups was a course in improving their office management of cancer prevention and screening activities. Most appealing to practitioners was a one-day course leading to accreditation in screening and prevention and to reduction in malpractice premiums.

In order to improve compliance with the National Cancer Institute's breast cancer screening guidelines, we developed a multifaceted intervention designed to alter physician screening practice. A pre-post test, two-community design was used. Primary care physicians in one community served as the control. Data were collected by two mailed surveys (1987 and 1990). Response rates were 61% and 64%, respectively. The physician intervention program consisted of a hospital-based continuing medical education program and an outreach component which focused on implementing a reminder system. Outcome measures were self-reported attitudinal, knowledge, and screening practices changes. In spite of an impressive change in comparison community physicians' practice, the difference in change over time in the intervention community physicians' ordering of annual mammography compared to the change in the comparison community physicians' ordering was significant (P = 0.04). The adjusted odds ratio is nearly 8. We conclude that our in-service continuing medical education program was successful in improving breast cancer screening practices among primary care physicians.

Objective: To study the association of two well known risk factors for breast cancer and the association of knowledge of those risk factors with mammography utilization., Design: Cross sectional: two independent random telephone surveys., Setting: Two Northeastern metropolitan communities surveyed in 1987 and in 1989., Participants: Women without breast cancer who spoke English and who were between 45 and 75 years of age., Main Outcome Measures: The two risk factors measured were a family history of breast cancer and being 65 or older. Participants were surveyed about their knowledge of risk factors, presence of risk factors, selected beliefs, attitudes, reinforcing factors and mammography use. Results were analyzed for women 50-75., Results: There was a substantial increase in mammography use over the 2-year period. Having a positive family history or being older is not associated with increased mammography utilization. Knowledge that family history and/or age are risks is associated with increased utilization. However, knowledge of risk factors is not associated with having those risks. Older women have lower utilization than younger women regardless of their knowledge of age as a risk. Increased physician recommendation is associated with increased utilization., Conclusion: Since knowing that a factor is a risk and having a physician recommend mammography are each associated with increased use, we conclude that the primary care physicians' role in increasing mammography utilization is critical.

Background: Primary care physicians are increasingly the gatekeepers to clinical preventive services including mammography utilization. Moreover, lack of physician recommendation is a major reason for patient failure to obtain screening. A study was designed to examine the attitudes, beliefs, and practices with regard to breast cancer screening as self-reported by primary care physicians. The variables associated with compliance or lack of compliance with screening guidelines are emphasized., Methods: One hundred sixteen primary care physicians practicing in two New England communities responded to a mailed survey. The survey included questions on attitudes and beliefs about breast cancer screening, as well as questions about perceived barriers and actual screening practices., Results: Fifty-seven percent of the respondents reported ordering annual mammograms for their female patients aged 50 to 75 years. An additional 21 percent reported ordering biannual mammograms for women in this age group. Strongly associated with ordering annual mammograms were beliefs in the benefits of mammography and the perception of community consensus regarding breast cancer screening. A strong positive association of practicing in a group setting and mammography guideline compliance was documented. Middle-aged physicians in solo practice reported the poorest screening compliance., Conclusions: The level of physician compliance with the standard of annual mammography screening is low (57 percent). The three most important determinants of annual screening suggest ways to improve physician compliance: improve physician attitudes about the benefits of mammography, build further on the medical community's consensus regarding the appropriateness and importance of the annual guidelines, target the poorest compliers with special messages or programs.

It is estimated that 44,500 American women will die of breast cancer in 1991. The breast cancer screening guidelines of the American Cancer Society and the National Cancer Institute calling for annual mammography for all women older than 50 years have been endorsed by numerous professional groups. Third-party reimbursement for screening mammography is becoming more prevalent, and payment for screening mammography is now a Medicare benefit. Our studies, conducted as part of a National Cancer Institute grant to increase the routine use of screening mammography and clinical breast examination in women 50 to 75 years of age, have uncovered a number of significant barriers to the implementation of screening guidelines among women, primary care physicians, and providers of mammography services. These barriers, as well as methods to assure the quality of mammography, need to be addressed before universal screening is feasible.

Periodic screening mammography and clinical breast examination have significantly reduced the breast cancer mortality rate in the United States for women 50 years of age and older. The Breast Cancer Screening Project of the University of Massachusetts, Worcester, developed a pilot mammography continuing-education program for radiologic technologists that included a didactic and a clinical on-site, hands-on training workshop with preinstruction, postinstruction, and six-month follow-up evaluations to improve their mammography skills. Because of a small sample size, a high dropout rate, and limitations in study design, posttest gains cannot be attributed to the program. Most significant is the finding of wide variability in radiologic technologists' mammography skills, which may compromise mammogram quality and the value of such screening.

The University of Massachusetts Medical School's two year preclinical curriculum is organized by organ system and controlled by the basic science departments. It is followed by two years of required and elective clinical clerkships. An evaluation of cancer teaching in the preclinical curriculum using criteria derived from the Cancer Education Objectives for Medical Schools was conducted. Deficiencies in cancer teaching were documented and the need for an organized cancer education program established. The administration then allotted 18 hours for cancer teaching spread over the two years of the preclinical curriculum. Supported by an R25 Cancer Education Grant, the Longitudinal Cancer course (LCC), was developed in an attempt to effectively utilize the scattered class time to meet a significant number of American Association for Cancer Education Objectives. In addition, interdisciplinary teaching of the more common cancers was facilitated and faculty were supported in their use of cancer related examples to illustrate relevant materials in the basic sciences. Evaluation of the LCC after a three-year trial has shown that, without strong administrative support, it is a very inefficient method of cancer teaching. While students appreciated class content and met a significant number of course objectives, they found the longitudinal format of the course unsatisfactory and recommended that the course be consolidated into a block. R25 grant support was being sought to implement a proposal to consolidate cancer teaching when the R25 program was suspended. Without external support, implementation will be difficult because it will require serious disruption of an established course. Such a change will require resources that are not readily available in this era of fiscal constraint.