sigmoid

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sigmoid

[sig´moid]

1. shaped like the letter C or S.

2. the sigmoid colon, the distal part of the colon from the level of the iliac crest to the rectum.

sig·moid

(sig'moyd),

Resembling in outline the letter S or one of the forms of the Greek sigma.

[G. sigma, the letter S, + eidos, resemblance]

Farlex Partner Medical Dictionary © Farlex 2012

sigmoid

(sĭg′moid′) also

sigmoidal

(sĭg-moid′l)

adj.

1. Having the shape of the letter S.

2. Of or relating to the sigmoid colon.

sig·moid

(sig'moyd)

Resembling in outline the letter S or one of the forms of the Greek character, sigma.

[G. sigma, the letter S, + eidos, resemblance]

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

sigmoid

sigmoidal

S-shaped.

2. Pertaining to the SIGMOID COLON.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

sigmoid

S-shaped.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Sigmoid

The S-shaped curve of the large intestine where the colon joins the rectum.

Mentioned in: Intestinal Polyps

sig·moid

(sig'moyd)

Resembling in outline the letter S or one of the forms of the Greek sigma σ or ς.

[G. sigma, the letter S, + eidos, resemblance]

References in periodicals archive ?

At year 200, the log abundance-rank abundance curve for the 625 cells is a rotated sigmoid [ILLUSTRATION FOR FIGURE 4A OMITTED], and the correlation between abundances in years 180 and 200 is [r.sub.s] = 0.46 [ILLUSTRATION FOR FIGURE 4B OMITTED].

Spatial variation in abundance created by stochastic temporal variation

Although, consolidated in the description of growth curves with a simple sigmoid, in curves with double sigmoid pattern these models are still not widely used, possibly due to the lack of knowledge on how to obtain a double sigmoid expression.

The few researchs using double sigmoid models are related to animal growth (SANTORO et al., 2005; MENDES et al., 2008; VASQUEZ et al., 2012).

In this context, the goal of this study was to verify if the growth pattern of coffee berries, explaining the accumulated fresh mass over time, is double sigmoid and selecting the most suitable nonlinear model to describe such curve.

The Logistic and Gompertz nonlinear regressionmodelswereused, in their simple and double sigmoid versions, because even if the information in the literature indicates a pattern of double sigmoid growth, it is necessary to verify if doubling the number of parameters of the model really attains a gain in the quality of fit, thus prevailing the parsimony principle.

Double sigmoidal models describing the growth of coffee berries/Modelos duplo sigmoidais na descricao do crescimento de frutos do cafeeiro

where C is the classification for this sigmoid, a is the value of this threshold, and t is a variable equivalent to the current temperature in a simulated annealing algorithm.