Adhere to figure guidelines

[sjspielman]

While tackling final figures for publication, bear these requirements in mind from https://www.cell.com/figureguidelines

• For final production, we prefer high-resolution TIFF, PDF, or CDX (ChemDraw) files; each file should be no more than 20 MB.
• For color figures, the resolution should be 300 dpi at the desired print size
• Always embed fonts and use only Arial fonts

[sjspielman]

The default/available font for sans family in our image is Helvetica, and using Arial would probably require additional dependencies. I'm therefore going to just stick with the default, since at least it's sans serif!

 > names(pdfFonts())
 [1] "serif"                "sans"                 "mono"                
 [4] "AvantGarde"           "Bookman"              "Courier"             
 [7] "Helvetica"            "Helvetica-Narrow"     "NewCenturySchoolbook"
[10] "Palatino"             "Times"                "URWGothic"           
[13] "URWBookman"           "NimbusMon"            "NimbusSan"           
[16] "URWHelvetica"         "NimbusSanCond"        "CenturySch"          
[19] "URWPalladio"          "NimbusRom"            "URWTimes"            
[22] "ArialMT"              "Japan1"               "Japan1HeiMin"        
[25] "Japan1GothicBBB"      "Japan1Ryumin"         "Korea1"              
[28] "Korea1deb"            "CNS1"                 "GB1"   

> quartzFonts()
$serif
[1] "Times-Roman"      "Times-Bold"       "Times-Italic"     "Times-BoldItalic"

$sans
[1] "Helvetica"             "Helvetica-Bold"        "Helvetica-Oblique"    
[4] "Helvetica-BoldOblique"

$mono
[1] "Courier"             "Courier-Bold"        "Courier-Oblique"    
[4] "Courier-BoldOblique"

[sjspielman]

Resolutions are all at the expected level, and all figure PDFs are well under 20 MB. We're still working to wrap up Figure 5 but all of these aspects have been implemented there as well, so this issue can be closed.