X-Git-Url: http://mmka.chem.univ.gda.pl/gitweb/?p=unres.git;a=blobdiff_plain;f=doc%2F3.1%2Fascii-text%2FCLUSTER.TXT;fp=doc%2F3.1%2Fascii-text%2FCLUSTER.TXT;h=f952c76f6a58d57d7f6422b0a3260d868de33b63;hp=0000000000000000000000000000000000000000;hb=2a226bfc86eabc6e4eae0c3ad1cbc3cb5417a05a;hpb=a0e685f844163003749ba91dfbf4644bcc8cfa30 diff --git a/doc/3.1/ascii-text/CLUSTER.TXT b/doc/3.1/ascii-text/CLUSTER.TXT new file mode 100644 index 0000000..f952c76 --- /dev/null +++ b/doc/3.1/ascii-text/CLUSTER.TXT @@ -0,0 +1,671 @@ + CLUSTER + Cluster analysis of UNRES simulation results + --------------------------------------------- + +TABLE OF CONTENTS +----------------- + +1. License terms + +2. References + +3. Functions of the program + +4. Installation + +5. Running the program + +6. Input and output files + 6.1. Summary of files + 6.2. The main input file + 6.2.1. Title + 6.2.2. General data + 6.2.3. Energy-term weights and parameter files + 6.2.4 Molecule data + 6.2.4.1. Sequence information + 6.2.4.2. Dihedral angle restraint information + 6.2.4.3. Disulfide-bridge data + 6.2.5. Reference structure + 6.3. Main output file (out) + 6.4. Output coordinate files + 6.4.1. The internal coordinate (int) files + 6.4.2. The Cartesian coordinate (x) files + 6.4.3. The PDB files + 6.4.3.1. CLUST-UNRES runs + 6.4.3.2. CLUST-WHAM runs + 6.4.3.2.1. Conformation family files + 6.4.3.2.2. Average-structure file + 6.5. The conformation-distance file + 6.6. The clustering-tree PicTeX file + +7. Support + +1. LICENSE TERMS +---------------- + +* This software is provided free of charge to academic users, subject to the + condition that no part of it be sold or used otherwise for commercial + purposes, including, but not limited to its incorporation into commercial + software packages, without written consent from the authors. For permission + contact Prof. H. A. Scheraga, Cornell University. + +* This software package is provided on an "as is" basis. We in no way warrant + either this software or results it may produce. + +* Reports or publications using this software package must contain an + acknowledgment to the authors and the NIH Resource in the form commonly +used + in academic research. + +2. REFERENCES +------------- + +The program incorporates the hierarchical-clustering subroutine, hc.f written +by G. Murtagh (refs 1 and 2). The subroutine contains seven methods of +hierarchical clustering. + +[1] F. Murtagh. Multidimensional clustering algorithms; Physica-Verlag: + Vienna, Austria, 1985. +[2] F. Murtagh, A. Heck. MultiVariate data analysis; Kluwer Academic: + Dordrecht, Holland, 1987. +[3] A. Liwo, M. Khalili, C. Czaplewski, S. Kalinowski, S. Oldziej, K. Wachucik, + H.A. Scheraga. + Modification and optimization of the united-residue (UNRES) potential + energy function for canonical simulations. I. Temperature dependence of the + effective energy function and tests of the optimization method with single + training proteins. J. Phys. Chem. B, 2007, 111, 260-285. +[4] S. Oldziej, A. Liwo, C. Czaplewski, J. Pillardy, H.A. Scheraga. + Optimization of the UNRES force field by hierarchical design of the + potential-energy landscape. 2. Off-lattice tests of the method with single + proteins. J. Phys. Chem. B., 2004, 108, 16934-16949. + +3. FUNCTIONS OF THE PROGRAM +--------------------------- + +The program runs cluster analysis of UNRES simulation results. There are two +versions of the program depending on the origin of input conformation: + +1) CLUST-UNRES: performs cluster analysis of conformations that are obtained + directly from UNRES runs (CSA, MCM, MD, (M)REMD, multiple-conformation + energy minimization). The source code and other important files are + deposited in CLUST-UNRES subdirectory + + The source code of this version is deposited in clust-unres/src + +2) CLUST-WHAM: performs cluster analysis of conformations obtained in UNRES + MREMD simulations and then processed with WHAM (weighted histogram analysis + method). This enables the user to obtain clusters as conformational + ensembles at a given temperature and to compute their probabilities + (section 2.5 of ref 3). This version is deposited in the CLUST-WHAM + subdirectory. This version has single- and multichain variants, whose + source codes are deposited in the following subdirectories: + + a) clust-wham/src single-chain proteins + + b) clust-wham/src-M oligomeric proteins + +The version developed for oligomeric proteins treats whole system as a single +chain with dummy residues inserted. It also works for single chains but is +not fully checked and it is recommended to use single-chain version for +single-chain proteins. + +4. INSTALLATION +--------------- + +Customize Makefile to your system. See section 7 of the description of UNRES +for compiler flags that are used to created executables for a particular +force field. There are already several Makefiles prepared for various +systems and force fields. + +Run make in the appropriate source directory version. CLUST-UNRES runs +only in single-processor mode an CLUST-WHAM runs in both serial and parallel +mode [only conformation-distance (rmsd) calculations are parallelized]. +The parallel version uses MPI. + +5. RUNNING THE PROGRAM +---------------------- + +The program requires a parallel system to run. Depending on system, +either the wham.csh C-shell script (in WHAM/bin directory) can be started +using mpirun or the binary in the C-shell script must be executed through +mpirun. See the wham.csh C-shell script and section 6 for the files +processed by the program. + +6. INPUT AND OUTPUT FILES +------------------------- + +6.1. SUMMARY OF THE FILES +------------------------- + +The C-shell script wham.csh is used to run the program (see the +bin/WHAM directory). The data files that the script needs are mostly the same as +for UNRES (see section 6 of UNRES description). In addition, the environmental +variable CONTFUN specifies the method to assess whether two side chains +are at contact; if EONTFUN=GB, the criterion defined by eq 8 of ref 4 is +used to assess whether two side chains are at contact. Also, the parameter +files from the C-shell scripts are overridden if the data from Hamiltonian +MREMD are processed; if so, the parameter files are defined in the main +input file. + +The main input file must have inp extension. If it is INPUT.inp, the output +files are as follows: + +Coordinate input file COORD.ext, where ext denotes file extension in one of the +following formats: + +INT (extension int; UNRES angles theta, gamma, alpha, and beta), +X (extension x; UNRES Cartesian coordinate format; from MD), +PDB (extension pdb; Protein Data Bank format; fro MD), +CX (extension cx; xdrf format; from WHAM). + +INPUT_clust.out (single-processor mode) or INPUT_clust.out_xxx (parallel mode) - + output file(s) (INPUT.out_000 is the main output file for parallel mode). + +COORD_clust.int: leading (lowest-energy) members of the families + in internal-coordinate format. +COORD_clust.x: leading members of the families in UNRES Cartesian coordinate + format. +COORD_xxxx.pdb or COORD_xxxx_yyy.pdb (CLUST-UNRES): PDB file of member yyy + of family xxxx; yyy is omitted if the family contains only one member + within a given energy cut-off. +COORD_TxxxK_yyyy.pdb: concatenated conformations in PDB format of the + members of family yyyy clustered at T=xxxK ranked by probabilities in + descending order at this temperature (CLUST-WHAM). +COORD_T_xxxK_ave.pdb: cluster-averaged coordinates and coordinates of a + member of each family that is closest to the cluster average in PDB + format, concatenated in a single file (CLUST-WHAM). + +INPUT_clust.tex: PicTeX code of the cluster tree. + +INPUT.rms: rmsds between conformations. + +6.2. MAIN INPUT FILE +-------------------- + +This file has the same structure as the UNRES input file; most of the data are +input in a keyword-based form (see section 7.1 of UNRES description). The data +are grouped into records, referred to as lines. Each record, except for the +records that are input in non-keyword based form, can be continued by placing +an ampersand (&) in column 80. Such a format is referred to as the data list +format. + +In the following description, the default values are given in parentheses. + +6.2.1. Title (80-character string) +---------------------------------- + +6.2.2. General data (data list format) +-------------------------------------- + +NRES (0) - the number of residues + +ONE_LETTER - if present, the sequence is input in one-letter code. + +SYM (1) - number of chains with same sequence (for oligomeric proteins only), + +WITH_DIHED_CONSTR - if present, dihedral-angle restraints were imposed in the + processed MREMD simulations + +RESCALE (1) - Choice of the type of temperature dependence of the force field. +0 - no temperature dependence +1 - homographic dependence (not implemented yet with any force field) +2 - hyperbolic tangent dependence [3]. + +DISTCHAINMAX (50.0) - for oligomeric proteins, distance between the chains + above which restraints will be switched on to keep the chains at a + reasonable distance. + +PDBOUT - clusters will be printed in PDB format. + +ECUT - energy cut-off criterion to print conformations (UNRES-CLUST runs). + Only those families will be output the energy of the lowest-energy + conformation of which is within ECUT kcal/mol above that of the + lowest-energy conformation and for a family only those members will be + output which have energy within ECUT kcal/mol above the energy of the + lowest-energy member of the family. + +PRINT_CART - output leading members of the families in UNRES x format. + +PRINT_INT - output leading members of the families in UNRES int format. + +REF_STR - if present, reference structure is input and rmsd will be computed + with respect to it (CLUST-UNRES only; rmsd is provided in the cx file + from WHAM for CLUST-WHAM runs). + +PDBREF - if present, reference structure will be read in from a pdb file. + +SIDE - side chains will be considered in superposition when calculating rmsd + +CA_ONLY - only the Calpha atoms will be used in rmsd calculation + +NSTART (0) - first residue to superpose + +NEND (0) - last residue to superpose + +NTEMP (1) - number of temperatures at which probabilities will be calculated + and clustering performed (CLUST-WHAM) + +TEMPER (NTEMP tiles) - temperatures at which clustering will be performed + (CLUST-WHAM) + +EFREE - if present, conformation entropy factor is read if the conformation + is input from an x or pdb file + +PROB (0.99) - cut-off on the summary probability of the conformations that + are clustered at a given temperature (CLUST-WHAM) + +IOPT (2) - clustering algorithm: + +1 - Ward's minimum variance method +2 - single link method +3 - complete link method +4 - average link (or group average) method +5 - McQuitty's method +6 - Median (Gower's) method +7 - centroid method + +Instead of IOPT=1, MINTREE and instead of IOPT=2 MINVAR can be specified + +NCUT (1) - number of cut-offs in clustering + +CUTOFF (-1.0; NCUT values) cut-offs at which clustering will be performed; + at the cut-off flagged by a "-" sign clustering will be performed with + cutoff value=abs(cutoff(i)) and conformations corresponding to clusters + will be output in the desired format. + +MAKE_TREE - if present, produce a clustering-tree graph + +PLOT_TREE - if present, the tree is written in PicTeX format to a file + +PRINT_DIST - if present, distance (rmsd) matrix is printed to main output + file +PUNCH_DIST - if present, the upper-triangle of the distance matrix will be + printed to a file + +6.2.3. Energy-term weights and parameter files +---------------------------------------------- + +WSC (1.0) - side-chain-side-chain interaction energy + +WSCP (1.0) - side chain-peptide group interaction energy + +WELEC (1.0) - peptide-group-peptide group interaction energy + +WEL_LOC (1.0)- third-order backbone-local correlation energy + +WCORR (1.0) - fourth-order backbone-local correlation energy + +WCORR5 (1.0) - fifth-order backbone-local correlation energy + +WCORR6 (1.0) - sixth-order backbone-local correlation energy + +WTURN3 (1.0) - third-order backbone-local correlation energy of pairs of + peptide groups separated by a single peptide group + +WTURN4 (1.0) - fourth-order backbone-local correlation energy of pairs of + peptide groups separated by two peptide groups + +WTURN6 (1.0) - sixth-order backbone-local correlation energy for pairs of + peptide groups separated by four peptide groups + +WBOND (1.0) - virtual-bond-stretching energy + +WANG (1.0) - virtual-bond-angle-bending energy + +WTOR (1.0) - virtual-bond-torsional energy + +WTORD (1.0) - virtual-bond-double-torsional energy + +WSCCOR (1.0) - sequence-specific virtual-bond-torsional energy + +WDIHC (0.0) - dihedral-angle-restraint energy + +WHPB (1.0) - distance-restraint energy + +SCAL14 (0.4) - scaling factor of 1,4-interactions + +6.2.4. Molecule information +----------------------------- + +6.2.4.1. Sequence information +----------------------------- + +Amino-acid sequence + +3-letter code: Sequence is input in format 20(1X,A3) + +1-letter code: Sequence is input in format 80A1 + +6.2.4.2. Dihedral angle restraint information +--------------------------------------------- + +This is the information about dihedral-angle restraints, if any are present. +It is specified only when WITH_DIHED_CONSTR is present in the first record. + +1st line: ndih_constr - number of restraints (free format) + +2nd line: ftors - force constant (free format) + +Each of the following ndih_constr lines: + +idih_constr(i),phi0(i),drange(i) (free format) + +idih_constr(i) - the number of the dihedral angle gamma corresponding to the +ith restraint + +phi0(i) - center of dihedral-angle restraint + +drange(i) - range of flat well (no restraints for phi0(i) +/- drange(i)) + +6.2.4.3. Disulfide-bridge data +------------------------------ + +1st line: NS, (ISS(I),I=1,NS) (free format) + +NS - number of cystine residues forming disulfide bridges + +ISS(I) - the number of the Ith disulfide-bonding cystine in the sequence + +2nd line: NSS, (IHPB(I),JHPB(I),I=1,NSS) (free format) + +NSS - number of disulfide bridges + +IHPB(I),JHPB(I) - the first and the second residue of ith disulfide link + +Because the input is in free format, each line can be split + +6.2.5. Reference structure +-------------------------- + +If PDBREF is specified, filename with reference (experimental) structure, +otherwise UNRES internal coordinates as the theta, gamma, alpha, and beta +angles. + +6.3. Main output file (out) +------------------------------------------------ + +The main (with name INPUT_clust.out or INPUT_clust.out_000 for parallel runs) +output file contains the results of clustering (numbers of families +at different cut-off values, probabilities of clusters, composition of +families, and rmsd values corresponding to families (0 if rmsd was not +computed or read from WHAM-generated cx file). + +The output files corresponding to non-master processors +(INPUT_clust.out_xxx where xxx>0 contain only the information up to the +clustering protocol. These files can be deleted right after the run. + +Excerpts from the a sample output file are given below: + +CLUST-UNRES: + +THERE ARE 20 FAMILIES OF CONFORMATIONS + +FAMILY 1 CONTAINS 2 CONFORMATION(S): + 42 -2.9384E+03 50 -2.9134E+03 + + +Max. distance in the family: 14.0; average distance in the family: 14.0 + +FAMILY 2 CONTAINS 3 CONFORMATION(S): + 13 -2.9342E+03 7 -2.8827E+03 10 -2.8682E+03 + +CLUST-WHAM: + +AT CUTOFF: 200.00000 +Maximum distance found: 137.82 +Free energies and probabilities of clusters at 325.0 K +clust efree prob sumprob + 1 -76.5 0.25035 0.25035 + 2 -76.5 0.24449 0.49484 + 3 -76.4 0.21645 0.71129 + 4 -76.4 0.20045 0.91174 + 5 -75.8 0.08826 1.00000 + + +THERE ARE 5 FAMILIES OF CONFORMATIONS + +FAMILY 1 WITH TOTAL FREE ENERGY -7.65228E+01 CONTAINS 548 CONFORMATION(S): +8363 -7.332E+013939 -7.332E+012583 -7.332E+017395 -7.332E+019932 -7.332E+01 +5816 -7.332E+013096 -7.332E+012663 -7.332E+014099 -7.332E+016822 -7.332E+01 +3176 -7.332E+017542 -7.332E+018933 -7.332E+017315 -7.332E+01 200 -7.332E+01. +. +5637 -7.062E+018060 -7.061E+013797 -7.060E+018800 -7.057E+016295 -7.057E+01 +6298 -7.057E+012332 -7.057E+012709 -7.057E+01 + +Max. distance in the family: 16.5; average distance in the family: 8.8 +Average RMSD 8.22 A + +6.4. Output coordinate files +---------------------------- + +6.4.1. The internal coordinate (int) files +------------------------------------------ + +The file with name COORD_clust.int contains the angles theta, gamma, alpha, +and beta of all residues of the leaders (lowest UNRES energy conformations +from consecutive families for CLUST-UNRES runs and lowest free energy +conformations for CLUST-WHAM runs). The format is the same as that of the +file output by UNRES; see section 9.1.1 of UNRES description. + +For CLUST-WHAM runs, the first line contains more items: + +number of family (format i5) +UNRES free energy of the conformation (format f12.3) +Free energy of the entire family (format f12.3) +number of disulfide bonds (format i2) +list disulfide-bonded pairs (format 2i3) +conformation class number (0 if not provided) (format i10) + +6.4.2. The Cartesian coordinate (x) files +----------------------------------------- + +The file with name COORD_clust.x contains the Cartesian coordinates of the +alpha-carbon and side-chain-center coordinates. The coordinate format is +as in section 9.1.2 of UNRES description and the first line contains the +following items: + +Number of the family (format I5) +UNRES free energy of the conformation (format f12.3) +Free energy of the entire family (format f12.3) +number of disulfide bonds (format i2) +list disulfide-bonded pairs (format 2i3) +conformation class number (0 if not provided) (format i10) + +6.4.3. The PDB files +-------------------- + +The PDB files are in standard format (see +ftp://ftp.wwpdb.org/pub/pdb/doc/format_descriptions/Format_v33_Letter.pdf). +The ATOM records contain Calpha coordinates (CA) or UNRES side-chain-center +coordinates (CB). For oligomeric proteins chain identifiers are present +(A, B, ..., etc.) and each chain ends with a TER record. Coordinates of a +single conformation or multiple conformations The header (REMARK) records +and the contents depends on cluster run type. The next subsections are devoted +to different run types. + +6.4.3.1. CLUST-UNRES runs +--------------------------- + +The files contain the members of the families obtained from clustering such +that the lowest-energy conformation of a family is within ECUT kcal/mol higher +in energy than the lowest-energy conformation. Again, within a family, only +those conformations are output whose energy is within ECUT kcal/mol above +that of the lowest-energy member of the family. Families and the members +of a family within a family are ranked by increasing energy. The file names are: + +COORD_xxxx.pdb where xxxx is the number of the family, if the family contains + only one member of if only one member is output. + +COORD_xxxx_yyy.pdb where xxxx is the number of the family and yyy is the number + of the member of this family. + +An example is the following: + +REMARK R0001 ENERGY -2.93843E+03 +ATOM 1 CA GLY 1 0.000 0.000 0.000 +ATOM 2 CA HIS 2 3.800 0.000 0.000 +ATOM 3 CB HIS 2 5.113 1.656 0.015 +ATOM 4 CA VAL 3 5.927 -3.149 0.000 +. +. +. +ATOM 346 CB GLU 183 -43.669 -32.853 -7.320 +TER +CONECT 1 2 +CONECT 2 4 3 +. +. +. +CONECT 341 343 342 +CONECT 343 344 +CONECT 345 346 + +where ENERGY is the UNRES energy. The CONECT records defined the Calpha-Calpha +and Calpha-SC connection. + +6.4.3.2. CLUST-WHAM runs +-------------------------- + +The program generates a file for each family with its members and a summary +file with ensemble-averaged conformations for all families. These are described +in the two next sections. + +6.4.3.2.1. Conformation family files +------------------------------------ + +For each family, the file name is COORD_TxxxK_yyyy.pdb, where yyyy is the +number of the family and xxx is the integer part of the temperature (K). +The first REMARK line in the file contains the information about the free +energy and average rmsd of the entire cluster and, for each conformation, +the initial REMARK line contains these quantities for this conformation. +Same applies to oligomeric proteins, for which the TER records separate the +chains and the ENDMDL record separates conformations. +An example is given below. + +REMARK CLUSTER 1 FREE ENERGY -7.65228E+01 AVE RMSD 8.22 +REMARK 1BDD L18G full clust ENERGY -7.33241E+01 RMS 10.40 +ATOM 1 CA VAL 1 18.059 -33.585 4.616 1.00 5.00 +ATOM 2 CB VAL 1 18.720 -32.797 3.592 1.00 5.00 +. +. +. +ATOM 115 CA LYS 58 29.641 -44.596 -8.159 1.00 5.00 +ATOM 116 CB LYS 58 27.593 -45.927 -8.930 1.00 5.00 +TER +CONECT 1 3 2 +CONECT 3 5 4 +. +. +CONECT 113 114 +CONECT 115 116 +TER +REMARK 1BDD L18G full clust ENERGY -7.33240E+01 RMS 10.04 +ATOM 1 CA VAL 1 3.174 2.833 -34.386 1.00 5.00 +ATOM 2 CB VAL 1 3.887 2.811 -33.168 1.00 5.00 +. +. +ATOM 115 CA LYS 58 16.682 6.695 -20.438 1.00 5.00 +ATOM 116 CB LYS 58 18.925 5.540 -20.776 1.00 5.00 +TER +CONECT 1 3 2 +CONECT 3 5 4 +CONECT 113 114 +CONECT 115 116 +TER + +6.4.3.2.2. Average-structure file +--------------------------------- + +The file name is COORD_T_xxxK_ave.pdb. The entries are in pairs; the first +one is cluster-averaged conformation and the second is a family member which +has the lowest rmsd from this average conformation. Computing average +conformations is explained in section 2.5 of ref 3. Example excerpts from +an entry corresponding to a given family are shown below. The last +number in each ATOM record is the rmsd of the mean coordinate of a given +atom averaged over the cluster. + +REMAR AVERAGE CONFORMATIONS AT TEMPERATURE 300.00 +REMARK CLUSTER 1 +REMARK 2HEP clustering 300K ENERGY -8.22572E+01 RMS 3.29 +ATOM 1 CA MET 1 -17.748 48.148 -19.284 1.00 5.96 +ATOM 2 CB MET 1 -17.373 47.911 -19.294 1.00 6.34 +ATOM 3 CA ILE 2 -18.770 49.138 -18.133 1.00 3.98 +. +. +. +ATOM 80 CB PHE 41 -14.353 44.680 -15.642 1.00 2.62 +ATOM 81 CA ARG 42 -11.619 41.645 -13.117 1.00 4.06 +ATOM 82 CB ARG 42 -11.330 40.378 -13.313 1.00 5.19 +TER +CONECT 1 3 2 +CONECT 3 5 4 +. +. +. +CONECT 76 78 77 +CONECT 78 79 +CONECT 79 80 +CONECT 81 82 +TER +REMARK 2HEP clustering 300K ENERGY -8.22572E+01 RMS 3.29 +ATOM 1 CA MET 1 -37.698 40.489 -32.408 1.00 5.96 +ATOM 2 CB MET 1 -38.477 39.426 -34.159 1.00 6.34 +. +. +. +ATOM 80 CB PHE 41 -35.345 50.342 -31.371 1.00 2.62 +ATOM 81 CA ARG 42 -33.603 54.332 -27.130 1.00 4.06 +ATOM 82 CB ARG 42 -33.832 53.074 -24.415 1.00 5.19 +TER +CONECT 1 3 2 +CONECT 3 5 4 +. +. +. +CONECT 76 78 77 +CONECT 78 79 +CONECT 79 80 +CONECT 81 82 +TER + + +6.5. The conformation-distance file +----------------------------------- + +The file name is INPUT_clust.rms. It contains the upper-diagonal part of +the matrix of rmsds between conformations and differences between their +energies: + +i,j,rmsd,energy(j)-energy(i) (format 2i5,2f10.5) + +where i and j, j>i are the numbers of the conformations, rmsd is the rmsd +between conformation i and conformation j and energy(i) and energy(j) are +the UNRES energies of conformations i and j, respectively. + +6.6. The clustering-tree PicTeX file +------------------------------------ + +This file contains the PicTeX code of the clustering tree. The file name is +INPUT_clust.tex. It should be supplemented with LaTeX preamble and final +commands or incorporated into a LaTeX source and compiled with LaTeX. The +picture is produced by running LaTeX followed by dvips, dvipdf or other command +to convert LaTeX-generated dvi files into a human-readable files. + +7. SUPPORT +---------- + + Dr. Adam Liwo + Faculty of Chemistry, University of Gdansk + ul. Sobieskiego 18, 80-952 Gdansk Poland. + phone: +48 58 523 5430 + fax: +48 58 523 5472 + e-mail: adam@chem.univ.gda.pl + + Dr. Cezary Czaplewski + Faculty of Chemistry, University of Gdansk + ul. Sobieskiego 18, 80-952 Gdansk Poland. + phone: +48 58 523 5430 + fax: +48 58 523 5472 + e-mail: czarek@chem.univ.gda.pl + +Prepared by Adam Liwo, 02/19/12