Photoperiod and the timing of pupping in the Pacific harbor seal (Phoca vitulina richardsi) with notes on reproduction in northern fur seals and Dall porpoises

Birth and pupping season records of Pacific harbor seals (Phoca vitulina richardsi) were used in an analysis of photoperiod effect on the timing of birth in this species. Dates and latitudes of births were converted into photoperiods using a photoperiod equation. Sequential dates from parturition were converted into photoperiods and plotted as a function of latitude. The resulting functions of latitude vs. photoperiod were regressed to determine the point during the reproductive cycle at which latitude did not have an effect on photoperiod. The Pacific harbor seal can be divided into two geographic subgroups by their respective pupping seasons. Seals inhabiting the Puget Sound / Strait of Georgia (PS/SG) System give birth to pups an average of 88 days (P < 0.01) later than do seals of the North American west coast. The dine in the pupping season of coastal harbor seals can be defined by a 13.8 h/day photoperiod occurring at 68 days post partum. PS/SG harbor seals experience a significantly different photoperiod (P <0.001) of 10.8 h/day at 68 days post partum. Progesterone and testosterone levels support an hypothesis that these two populations may be reproductively isolated, as coastal male seals show low testosterone levels during the breeding season for PS/Sc seals. A proposed photoresponse at 68 days post partum occurs at the midpoint between estrus and implantation. This period is characterized by secondary follicular activity in the ipsilateral ovary and other changes occurring in the uterus and corpus luteum. A response to a specific photoperiod terminating the follicular activity and leading to a specific implantation date is suggested

Rapid Assessment of Agents of Biological Terrorism: Defining the Differential Diagnosis of Inhalational Anthrax Using Electronic Communication in a Practice-Based Research Network

PURPOSE Early detection of bioterrorism requires assessment of diagnoses assigned to cases of rare diseases with which clinicians have little experience. In this study, we evaluated the process of defining the differential diagnosis for inhalational anthrax using electronic communication within a practice-based research network (PBRN) and compared the results with those obtained from a nationwide random sample of family physicians with a mailed instrument. METHODS We distributed survey instruments by e-mail to 55 physician members of the Wisconsin Research Network (WReN), a regional PBRN. The instruments consisted of 3 case vignettes randomly drawn from a set describing 11 patients with inhalational anthrax, 2 with influenza A, and 1 with Legionella pneumonia. Physicians provided their most likely nonanthrax diagnosis, along with their responses to 4 yes-or-no management questions for each case. Physicians who had not responded at 1 week received a second e-mail with the survey instrument. The comparison group consisted of the nationwide sample of physicians who completed mailed survey instruments. Primary outcome measures were response rate, median response time, and frequencies of diagnostic categories assigned to cases of inhalational anthrax. RESULTS The PBRN response rate compared favorably with that of the national sample (47.3% vs 37.0%; P = not significant). The median response time for the PBRN was significantly shorter than that for the national sample (2 vs 28 days; P <.001). No significant differences were found between the PBRN and the Midwest subset of the national sample in the frequencies of major diagnostic categories or in case management. CONCLUSIONS Electronic means of creating differential diagnoses for rare infectious diseases of national significance is feasible within PBRNs. Information is much more rapidly acquired and is consistent with that obtained by conventional methods

The Primary Care Differential Diagnosis of Inhalational Anthrax

PURPOSE Inhalational anthrax is an extremely rare infectious disease with nonspecific initial symptoms, thus making diagnosis on clinical grounds difficult. After a covert release of anthrax spores, primary care physicians will be among the first to evaluate cases. This study defines the primary care differential diagnosis of inhalational anthrax. METHODS In May 2002, we mailed survey instruments consisting of 3 randomly chosen case vignettes describing patients with inhalational anthrax to a nationwide random sample of 665 family physicians. Nonrespondents received additional mailings. Physicians were asked to provide their most likely nonanthrax diagnosis for each case. RESULTS The response rate was 36.9%. Diagnoses for inhalational anthrax were grouped into 35 diagnostic categories, with pneumonia (42%), influenza (10%), viral syndrome (9%), septicemia (8%), bronchitis (7%), central nervous system infection (6%), and gastroenteritis (4%) accounting for 86% of all diagnoses. Diagnoses differed significantly between cases that proved to be fatal and those that proved to be nonfatal. CONCLUSIONS Inhalational anthrax resembles common diagnoses in primary care. Surveillance systems for early detection of bioterrorism events that rely only on diagnostic codes will be hampered by false-positive alerts. Consequently, educating front-line physicians to recognize and respond to bioterrorism is of the highest priority