Needs["Statistics`NonlinearFit`"]
Needs["Graphics`"]

brian1 = {32, 44, 30, 55, 55, 40, 36, 34, 38, 43, 48, 22, 36}
time1  =  
      Table[0.5*i, {i, 1, Length[brian1]}]
data = 
      Table[{time1[[i]], brian1[[i]]}, {i, 1, 
          Length[brian1]}]

myfit=NonlinearRegress[data,B,{x},{B},Weights->(Sqrt[#]  &),
RegressionReport -> {BestFit, 
              BestFitParameters, EstimatedVariance, ParameterTable, 
              StartingParameters}]

chi2  =  
      Sum[((((data[[i, 2]]  -  40.55) )^2)/data)[[i, 2]], {i, 1, Length[data]}]
reducedChi2  =  (chi2/(Length[data]  -  2))

<< /home/gilfoyle/tmp/MultipleLogListPlot.m

\(\(\( (*\ 
      array\ with\ uncertainties\ for\ a\ semi - 
        log\ \(\(plot\)\(.\)\)\ *) \)\(
\)\(\(data2 = \ 
        Table[{data[\([\)\(i, 1\)\(]\)], 
            data[\([\)\(i, 2\)\(]\)], \@data[\([\)\(i, 2\)\(]\)]}, {i, 1, 
            Length[data]}];\)

 (*\ 
      Plot\ the\ data\ on\ a\ semi - 
        log\ scale\ with\ error\ \(\(bars\)\(.\)\)\ *) 

    p1\  = \ 
      ErrorListPlot[
        data2, \ 
GridLines -> 
          None, 
PlotRange -> {Automatic, {0, 
              70.0}}, 
Frame -> 
          True, 
FrameLabel -> {"Time (Minutes)", "Counts", "Background Measurement", ""}, 
ImageSize -> 
          6.5*72]


    p2 = Plot[40.55, {x, 0, 7}, 
        PlotStyle -> {RGBColor[1, 0, 0], 
            Thickness[
              0.01]}
]


    p3 = Show[{p1, p2}]\)\)\)