Determining the mathematical dynamics and associated parameter values that should be used to accurately reflect tumor growth continues to be of interest to mathematical modelers, experimentalists and practitioners. However, while there are several competing canonical tumor growth models that are often implemented, how to determine which of the models should be used for which tumor types remains...

Evaluation is one of many fields where "systems thinking" is popular and is said to hold great promise. However, there is disagreement about what constitutes systems thinking. Its meaning is ambiguous, and systems scholars have made diverse and divergent attempts to describe it. Alternative origins include: von Bertalanffy, Aristotle, Lao Tsu or multiple aperiodic "waves." Some scholars describ...

Variation among individuals is an ubiquitous feature of natural populations. However, the relative roles of intrinsic individual differences and stochastic processes in generating variation remain poorly understood. For somatic growth, identifying the contribution of individual and stochastic processes to observed variation in size has important implications both for basic and applied biology. ...

Ages of schoolmaster (n = 136) from the southeastern Florida coast from 1981-2015 were determined using sectioned sagittal otoliths. Opaque zones were annular, forming March-July (peaking in May-June). Schoolmaster ranged in age from 1-42 years; the largest fish measured 505 mm total length (TL) and was 19 years old. The oldest fish measured 440 mm TL. Estimated body size relationships for scho...

This study was carried out during May 2010 – April 2011 in order to determine various biological properties of red mullet occurring in the Eastern Black Sea region. The average length and weight of 1435 specimens were determined as 13.13 cm and 23.14 g, respectively. Weight-length relationship was determined as W = 0.0088 L 3.0338 . The age distribution of this population ranged between I and V...

Age and growth parameters were estimated for bigeye tuna Thunnus obesus Lowe, 1839 sampled from China longline fisheries in the central Atlantic Ocean from October 2002 to July 2003 and from August 2004 to March 2005. The von Bertalanffy growth parameters were estimated at L(infinity)=217.9 cm fork length, k=0.23 year(-1), and t(0)=-0.44 year. The total mortality rate (Z) was estimated to be fr...

Age and growth analysis is essential to fisheries management. Indirect methods to calculate growth are widely used; however, length frequency data analysis in sea cucumbers is complicated by high data variability caused by body wall elasticity. Here we calculated Isostichopus badionotus parameters of the von Bertalanffy growth function. In order to address bias produced by body wall elasticity,...

A brief review of studies on the seasonal growth of fish is presented, followed by an equally brief review of length-converted catch curves. A new method for constructing catch curves from representative length-frequency data is presented. This new method explicitly accounts for seasonal growth and thus eliminates the bias in Z caused by such growth. Some practical and theoretical implications ...