Recruitment variability in North Atlantic cod and match-mismatch dynamics.

BACKGROUND: Fisheries exploitation, habitat destruction, and climate are important drivers of variability in recruitment success. Understanding variability in recruitment can reveal mechanisms behind widespread decline in the abundance of key species in marine and terrestrial ecosystems. For fish populations, the match-mismatch theory hypothesizes that successful recruitment is a function of the timing and duration of larval fish abundance and prey availability. However, the underlying mechanisms of match-mismatch dynamics and the factors driving spatial differences between high and low recruitment remain poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We used empirical observations of larval fish abundance, a mechanistic individual-based model, and a reanalysis of ocean temperature data from 1960 to 2002 to estimate the survival of larval cod (Gadus morhua). From the model, we quantified how survival rates changed during the warmest and coldest years at four important cod spawning sites in the North Atlantic. The modeled difference in survival probability was not large for any given month between cold or warm years. However, the cumulative effect of higher growth rates and survival through the entire spawning season in warm years was substantial with 308%, 385%, 154%, and 175% increases in survival for Georges Bank, Iceland, North Sea, and Lofoten cod stocks, respectively. We also found that the importance of match-mismatch dynamics generally increased with latitude. CONCLUSIONS/SIGNIFICANCE: Our analyses indicate that a key factor for enhancing survival is the duration of the overlap between larval and prey abundance and not the actual timing of the peak abundance. During warm years, the duration of the overlap between larval fish and their prey is prolonged due to an early onset of the spring bloom. This prolonged season enhances cumulative growth and survival, leading to a greater number of large individuals with enhanced potential for survival to recruitment.

Safety of esophagoscopy in the irradiated esophagus.

Carcinoma of the esophagus is a disease with a poor prognosis. Surgery is considered the treatment of choice. Patients who are surgically unresectable may receive radiotherapy, plus or minus chemotherapy. While this offers reasonable palliation, a significant number of patients develop benign or malignant strictures. Frequent esophagoscopy with dilation is required if they are to swallow. Patients with strictures or malignancy of the esophagus are more prone to complications if they undergo an esophagoscopy. We examined the morbidity of esophagoscopy in a group of patients who had received radiotherapy for carcinoma of the esophagus. Over a 10-year period, 21 patients receiving irradiation for carcinoma of the esophagus were examined. All patients underwent esophagoscopy for staging and diagnosis. The tumor locations were upper (6), middle (6), and lower (9) esophagus. The T-stages were 1 (7), 2 (6), 3 (6), and 4 (2). Five patients had dilation of a malignant stricture at the time of diagnosis. Fever developed and resolved within 24 hours in 2 patients. Following completion of irradiation, a total of 83 esophagoscopies were performed (range 1 to 11 per patient). Six patients with no tumor or stricture underwent 8 esophagoscopies (3 rigid, 5 flexible). There was 1 episode of minimal bleeding and 1 fever that resolved within 24 hours. Ten patients with malignant strictures underwent 62 esophagoscopies (5 rigid, 57 flexible). There were 17 (27%) episodes of fever (all resolved within 24 hours) and 14 (22%) episodes of bleeding. Five patients with benign strictures underwent 13 esophagoscopies (2 rigid, 11 flexible). One patient had a perforation that resolved with conservative treatment, and 1 patient developed an epidural abscess 2 months following dilation. This patient is the only one that required surgical intervention and had prolonged hospitalization. Esophagoscopy of the irradiated esophagus can be performed relatively safely and excellent palliation obtained. Morbidity consisting of minimal bleeding, and fever lasting less than 24 hours, is frequent but self-limited.

Six month inhalation studies of pirbuterol acetate aerosol in the beagle dog and squirrel monkey.

Groups of Beagle dogs and Squirrel monkeys were exposed to aerosols of pirbuterol acetate, a new bronchodilator at doses of 0, 200, 400 and 800 micrograms of pirbuterol/kg body weight daily for 6 months. Each group consisted of 4 dogs or 6 monkeys per sex. Dogs were exposed by face mask and monkeys were exposed by head only in a manifold. Plasma drug concentrations indicated that expected levels of drug exposure were achieved in both species. No significant alterations were revealed in physical appearance and body weights, hematological and blood biochemical analyses, urinalyses, ophthalmoscopy, assessment of cardiovascular status, pulmonary function or gross and histopathology. Examination of the respiratory tract showed no morphological changes that could be attributed to pirbuterol acetate inhalation.