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Establishing protective projects such as breakwaters and flood barriers is the key to preventing marine disasters caused by extreme sea conditions. One of the core technical problems in implementing these large-scale projects is how to determine the fortification criteria reasonably. In the past, research based on random variables studied the determined state of time for the stochastic process. For the first time, this paper studies the statistical characteristics of ocean environment elements from both the time and space with the real perspective of the stochastic process and introduces the concept of stopping time in stochastic processes into the analysis of storm surge. The relationship between the stopping time and threshold selection for the measured data is discussed. The relationship between the wave front displacement and the time exceeding the threshold $$\lambda$$ is given as $$\tau = \inf \left\{ {t \ge 0:\xi \left( t \right) > \lambda } \right\}$$. When the distribution is symmetrical and has Markov characteristics, there is $$P\left( {\tau \le t} \right) = 2P\left( {\xi \left( t \right) > \lambda } \right)$$. Additionally, the relationship between the calculation and the return period of the wave height is given. It is proved that the stopping time $$N = \inf \left\{ {n \ge 1:X_{n} > x_{0} } \right\}$$ obeys the geometric distribution, and the expectation of the stopping time is the return period in the ocean engineering. Through the analysis of the stopping time parameters, the rationality of applying the Gumbel distribution in extreme sea conditions for calculating return period is given. With the relationship between the service life of marine engineering and the commonly used parameters, the average life expectancy of offshore engineering is: $${\text{ET}} = 5$$.

Australia has the highest incidence of melanoma in the world. General practitioners encounter melanoma in 9.9 per 10,000 clinical encounters and play a key role in diagnosis. A systematic review was conducted to study the efficacy of training methods to improve general practitioners’ diagnostic skills in melanoma. Article abstracts (1307) were screened, from a Medline search. Four trials met our criteria and were highly variable in their intervention methods and outcome measures. The Cochrane risk of bias tool was used to assess study quality with only one good, one poor, and two of questionable quality. Our results showed limited evidence via one study that training of general practitioners in surface microscopy improved melanoma diagnosis, from a clinical (naked eye) pre-intervention score of 54.6 % to a post-intervention surface microscopy score of 75.9 % in 74 general practitioners. Future work should explore the barriers to implementing this strategy in clinical practice.

Actinic keratoses (AK) commonly occur in the caucasian population living in environments of high levels of sun exposure, and are considered to be a marker for chronic sun damage. This article reviews the epidemiology, pathogenesis, and current debate on AK as precancerous lesions. The various treatment options for AK, including combination therapy, are also discussed.