BACI design

Baseline monitoring can be combined with a before-after design, where data are collected both before and after treatment and thus replicated in time rather than space [11]. A before-after control-impact (BACI) design is often used. The control site is evaluated over a period and compared to the monitoring of the treatment site. A BACI design allows temporal variabilities in the control and treatment site to be compared. 

Before-after-control-impact (BACI) design... 

BACI design involves collection of data prior to wetland impact and compares the data after the impact (Figure 15.8). However, in many instances, there may be little or no data available prior to impact. An ideal BACI design consists of the following features (Green, 1979 USEPA, 2006) ... 

The basic approach used in BACI design is to collect data over a brief period (such as 1-2 years with monthly sampling before and after) and treat time series data as independent samples and compare the samples between impacted and unimpacted sites using appropriate statistical methods (Smith, 2002). Any difference found between these two groups of samples is attributed to the impact on... 

See the lUPAC rules Guthrie, R.D. Pure Appl. Chem., 1989, 61, 23. As given here, the lUPAC designations for BacI and BalI are the same, but Rule A.2 adds further symbols so that they can be distinguished Su-AL for BalI and Su-AC for BacI- por reviews of the mechanisms of ester hydrolysis and formation, see Kirby, A.J. in Bamford Tipper, Ref 193, vol. 10, 1972, p. 57 Euranto, E.K. in Patai, Ref 216, p. 505. This is an Sn 1 mechanism with OR as leaving group, which does not happen. 

As given here, the IUPAC designations for BacI and BalI arc the same, but Rule A.2 adds further symbols so that they can be distinguished Su-AL for BalI and Su-AC for BacI. See the IUPAC rules Guthrie Pure Appl. Chem. 1989, 61, 23-56. p. 49. 

Underwood, A.J. (1991) Beyond BACI experimental designs for detecting human environmental impacts on temporal variations in natural populations. Australian Journal of Marine and Freshwater Research, 42, 569-587. 

Benedetti-Cecchi, L. 2001. Beyond BACI optimization of environmental sampling designs through monitoring and simulation. Ecol. Appl. 11 783-799. 

Underwood, A. J. 1994. On beyond BACI sampling designs that might reliably detect environmental disturbances. Ecol. Appl. 4 3-15. 

Both Langhoff et al. and Balasubramanian and Wang predicted the ground state of YH to be in noticeable disagreement with Bernard and Bacis (1977) who had carried out the rotational analysis of a system which they designated as a system. 

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