gnu: Add r-birta.

* gnu/packages/bioconductor.scm (r-birta): New variable.

gnu/packages/bioconductor.scm

@@ -4577,3 +4577,32 @@ (define-public r-birewire
 the introduced randomness across the switching steps and several other
 routines to analyse the resulting networks and their natural projections.")
     (license license:gpl3)))
+
+(define-public r-birta
+  (package
+    (name "r-birta")
+    (version "1.28.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (bioconductor-uri "birta" version))
+       (sha256
+        (base32
+         "12xjyvgmh4h0b7hi4qg50kcpb9003gnh2xyfgncb8l9mzvsbkxc2"))))
+    (build-system r-build-system)
+    (propagated-inputs
+     `(("r-biobase" ,r-biobase)
+       ("r-limma" ,r-limma)
+       ("r-mass" ,r-mass)))
+    (home-page "https://bioconductor.org/packages/birta")
+    (synopsis "Bayesian inference of regulation of transcriptional activity")
+    (description
+     "Expression levels of mRNA molecules are regulated by different
+processes, comprising inhibition or activation by transcription factors and
+post-transcriptional degradation by microRNAs.  @dfn{birta} (Bayesian
+Inference of Regulation of Transcriptional Activity) uses the regulatory
+networks of transcription factors and miRNAs together with mRNA and miRNA
+expression data to predict switches in regulatory activity between two
+conditions.  A Bayesian network is used to model the regulatory structure and
+Markov-Chain-Monte-Carlo is applied to sample the activity states.")
+    (license license:gpl2+)))