For Windows users getting a EOF error, try the following:

counts_raw <- read.delim("data/counts-raw.txt.gz", quote = "",
                         check.names = FALSE)
colnames(counts_raw) <- gsub("\"", "", colnames(counts_raw))
colnames(counts_raw)
##  [1] "doi"                       "pubDate"                  
##  [3] "journal"                   "title"                    
##  [5] "articleType"               "authorsCount"             
##  [7] "f1000Factor"               "backtweetsCount"          
##  [9] "deliciousCount"            "pmid"                     
## [11] "plosSubjectTags"           "plosSubSubjectTags"       
## [13] "facebookShareCount"        "facebookLikeCount"        
## [15] "facebookCommentCount"      "facebookClickCount"       
## [17] "mendeleyReadersCount"      "almBlogsCount"            
## [19] "pdfDownloadsCount"         "xmlDownloadsCount"        
## [21] "htmlDownloadsCount"        "almCiteULikeCount"        
## [23] "almScopusCount"            "almPubMedCentralCount"    
## [25] "almCrossRefCount"          "plosCommentCount"         
## [27] "plosCommentResponsesCount" "wikipediaCites"           
## [29] "year"                      "daysSincePublished"       
## [31] "wosCountThru2010"          "wosCountThru2011"

For everybody else:

counts_raw <- read.delim("data/counts-raw.txt.gz")
is.na(counts_raw$authorsCount[1:10])
##  [1] FALSE FALSE  TRUE  TRUE FALSE FALSE  TRUE  TRUE  TRUE FALSE
counts_raw$authorsCount[1:10] > 7
##  [1] FALSE  TRUE    NA    NA FALSE  TRUE    NA    NA    NA FALSE
counts_raw$authorsCount[counts_raw$backtweetsCount > 1]
##    [1]  NA   6   7   3  NA   7  NA   5   3   2  NA   2  NA   6  NA  NA  10
##   [18]  NA  NA  NA   2   9  NA  NA  NA  18   5  NA   3  NA  NA  NA   2   4
##   [35]  NA   4   2   5   2   5   5   4  NA   1   6   4   2   5  14  NA   6
##   [52]   6   3   1   8   4   6  15  NA   4  11   2   3  15   3  22  25  18
##   [69]   7  12   3 120   4  NA  NA  NA  NA   6   7  NA  NA  NA  NA  16  NA
##   [86]  NA  NA   6  NA  13  NA  NA  NA  NA   7   4  NA   8  NA  NA  NA  15
##  [103]  NA  NA   4   8   8  20  NA  NA   8   9   2   3   6   3   8   5   6
##  [120]   1   4   9   5   9   3   6   6   3   2   5  19   3   2   5   4   6
##  [137]   1  11   9   8   6  11   3   5  15   5   3   5   9   5   4   3   6
##  [154]   2  12   5   4   9   4   2   5   7  13  15   4   2   7   4   3   9
##  [171]   9   8   7   6   1   7   5   8   2   4   2   5   4   3   5   5  13
##  [188]   2  12   8  10   5   7   3   3   2   5   5  13   2   5   5   6   8
##  [205]  10   1  12   3   6   2   3   4   2   8  19   6   4   3   5   1   9
##  [222]   5  12   3   3  10   8   8   4   7   7   4  10   7   1   6   3  13
##  [239]   9   8  13   8   6   7   5   3   7   2   7   8  10   8  16  10   5
##  [256]   8   4   3   2   4   4   8   4   4   7   9   5   5   2   7   8   7
##  [273]   6   4   2   4   5   5   3  13   4   5   4   6   5   5   6   6   3
##  [290]   7   5   3   2   8   1   3   7   8   4   2   6   2   7   5   7   7
##  [307]   8   8   7  16   9  10   3  10   7   1   5   2  17   9   6   7   4
##  [324]  11   9   9   6   5   3   2   3   3   3   6   3   3  16   2   2  25
##  [341]   6   4   6   3   5   4   7   5   5   9   2   5   3   2   8   2   2
##  [358]   8   1  15   7  16   5   5   8  11  11  10   8  11   2   7   7  13
##  [375]   8   9   7   3  12   8   5  13   3   8   3   4   6   9   4   2  11
##  [392]   5   8   6  10   7   8   6   6   6  13   9   5   3   7   4   9   5
##  [409]   6   8   4   3   3   4   7  11   5   8   4   8   7   4   3   4   6
##  [426]   4   3   5   7   5   5   8  14   8  11   8   6   2   7  12   3   4
##  [443]   5   3   4   4   4   9   8   9   2   2   4   3  15   5   5   7  10
##  [460]   2   4   5   3   8   2   5  10   7   3  11  13   2   5  14   2   9
##  [477]   7   7   3   5   8   9  13   8   6   6   3   4   3   5  11  14   5
##  [494]   4   4   6   5   6  10   3   5   7   4   7   5   4  14   1   3  11
##  [511]  11   2  12  17   3  10   2   6   7   4   5   3   7   3   3  16   8
##  [528]   4   8   3   7   9   9   7   4  13   5   4   3   2  16   8   5   2
##  [545]   9   3   7   4   6   5   6   4   5   9  12   2   3   3   9   8   3
##  [562]  11  11   6   3   6  12   4   4   8  15   7   2   4   2   2   6   3
##  [579]   3  11  16   4  17   7   3   6   5   9   2   6  14   3   3   2   9
##  [596]   5   4   7   6   5  10   6   3   2   7   3   5   5   1   1   5   6
##  [613]   5   6   5   3   4   3   3   8   3   2   6   3   9   5   5   2   2
##  [630]   7   8   2   3  11   5   7   1   2   6  21   7   4   3   4   3   7
##  [647]   3   7   8   2   3   5   3  14  15  18  13   1   4   4  18   7  13
##  [664]  13   2   3   2   4   7   2  16   7   9   5  12   5  27   2   9   4
##  [681]   3   2  14   3   3  13   7   4   4   4   7   3   6  10   1   7   6
##  [698]   5   6  17  11   6   5   3   7   7   4   3   8   4   3   5   4   6
##  [715]   5   2  11   1   7   5   6   4  15   2   2   9   4  10  19   3  12
##  [732]   3   7   7   5   3   3   9   2   5   4  10   8   6   3  10   2   2
##  [749]   5   5   4   5   2   4   4   4   1   3   3   2   9   5   3   6   2
##  [766]   6   2  27   4   7   7   5   8   2   8   4  11   5   3   6  11   5
##  [783]  19   5   2   5  14   3   6   5   6   5  18   8   4   5   3   6   8
##  [800]  10   3   1   2   5   2   2  10   6   7   5   4   7   8   6   5   4
##  [817]   2   6   5   2   4  11   4   9  11   9   9   6   6   7   3   5   6
##  [834]   2   6   3   5   8   5   8   6  10   3   2   2  18   4   3   7   5
##  [851]   4  16   2   4   3   3   2  16   3   6   7  17   5   3   7   5  10
##  [868]   3   2   2   5   4   7   6   3   6   4   7   5   4   6   9   2  13
##  [885]   3   2   4   6   5   5   6   3   7  12  12   3   4   4   5   7   3
##  [902]   7   9   2   2   7   6   5   3   3   4   3   8   6   3   5   3   4
##  [919]   9   3   4  15  11   7  13   3   6   5   3   9   8   8   2   5   4
##  [936]   6  17  13   7   8  10   9   9   7   3   2   4   3   5   3  10   3
##  [953]   4   3  10   4   4   7   8   4   3   2   7   3   3   3   5   8  12
##  [970]   3   2   1   4   2   3   2   9   4   5   6   6   1   8   6   2  13
##  [987]   5   3   4   9   5   5   5   8  39   4   7   4   7   5   4  10   5
## [1004]   3   7   8   8  12   5   4   3   5   3   4   4   4   9   6   2   9
## [1021]   8   8  16   5   6   5  14   4   2   5  11  21   8   4   7   5  12
## [1038]   2   6   5   4   7  NA  NA  10  15  12   6  NA  14  20
dim(counts_raw[counts_raw$journal == "pone", ])
## [1] 14099    32

& -> and | -> or %in% -> in

dim(counts_raw[counts_raw$journal == "pone" |
            counts_raw$journal == "pgen", ])
## [1] 15868    32
dim(counts_raw[counts_raw$journal %in% 
                 c("pone", "pgen", "pmed"),])
## [1] 17826    32
dim(counts_raw[!(counts_raw$journal %in% 
                 c("pone", "pgen", "pmed")),])
## [1] 6505   32

== -> equals != -> not equal

the function grepl

head(counts_raw$plosSubjectTags)
## [1] Cell Biology|Immunology|Molecular Biology                                             
## [2] Biotechnology|Genetics and Genomics|Infectious Diseases|Virology                      
## [3] Computational Biology|Biotechnology|Genetics and Genomics|Infectious Diseases|Virology
## [4] Cell Biology|Immunology|Molecular Biology                                             
## [5] Genetics and Genomics|Infectious Diseases|Microbiology                                
## [6] Ecology|Evolutionary Biology|Genetics and Genomics                                    
## 6715 Levels: Anesthesiology and Pain Management ...
dim(counts_raw[grepl("Immunology", counts_raw$plosSubjectTags), ])
## [1] 2708   32