.nlm-p{display:block;margin-bottom:20px}.nlm-italic{font-style:italic}.nlm-bold{font-weight:bold}.author-affiliation{padding-bottom:8px}div.panel-pane div.admin-links{font-size:xx-small;margin-right:1em}div.panel-pane div.admin-links li a{color:#ccc}div.panel-pane div.admin-links li{padding-bottom:2px;background:white;z-index:201}div.panel-pane div.admin-links:hover a,div.panel-pane div.admin-links-hover a{color:#000}div.panel-pane div.admin-links a:before{content:"["}div.panel-pane div.admin-links a:after{content:"]"}div.panel-pane div.panel-hide{display:none}div.panel-pane div.panel-hide-hover,div.panel-pane:hover div.panel-hide{display:block;position:absolute;z-index:200;margin-top:-1.5em}div.panel-pane div.node{margin:0;padding:0}div.panel-pane div.feed a{float:right}.block-nice-menus{line-height:normal;z-index:10}ul.nice-menu,ul.nice-menu ul{z-index:5;position:relative}ul.nice-menu li{position:relative}ul.nice-menu a{display:block;color:#027ac6}ul.nice-menu ul,#header-region ul.nice-menu ul{position:absolute;visibility:hidden}ul.nice-menu li.over ul{visibility:visible}ul.nice-menu ul li{display:block}ul.nice-menu:after{content:".";display:block;height:0;clear:both;visibility:hidden}ul.nice-menu li:hover ul,ul.nice-menu li.menuparent li:hover ul,ul.nice-menu li.menuparent li.menuparent li:hover ul,ul.nice-menu li.menuparent li.menuparent li.menuparent li:hover ul,ul.nice-menu li.over ul,ul.nice-menu li.menuparent li.over ul,ul.nice-menu li.menuparent li.menuparent li.over ul,ul.nice-menu li.menuparent li.menuparent li.menuparent li.over ul,#header-region ul.nice-menu li:hover ul,#header-region ul.nice-menu li.menuparent li:hover ul,#header-region ul.nice-menu li.menuparent li.menuparent li:hover ul,#header-region ul.nice-menu li.over ul,#header-region ul.nice-menu li.menuparent li.over ul,#header-region ul.nice-menu li.menuparent li.menuparent li.over ul{visibility:visible}ul.nice-menu li:hover ul ul,ul.nice-menu li:hover ul ul ul,ul.nice-menu li:hover li:hover ul ul,ul.nice-menu li:hover li:hover ul ul ul,ul.nice-menu li:hover li:hover li:hover ul ul,ul.nice-menu li:hover li:hover li:hover ul ul ul,ul.nice-menu li.over ul ul,ul.nice-menu li.over ul ul ul,ul.nice-menu li.over li.over ul ul,ul.nice-menu li.over li.over ul ul ul,ul.nice-menu li.over li.over li.over ul ul,ul.nice-menu li.over li.over li.over ul ul ul,#header-region ul.nice-menu li:hover ul ul,#header-region ul.nice-menu li:hover ul ul ul,#header-region ul.nice-menu li:hover li:hover ul ul,#header-region ul.nice-menu li:hover li:hover ul ul ul,#header-region ul.nice-menu li:hover li:hover li:hover ul ul,#header-region ul.nice-menu li:hover li:hover li:hover ul ul ul,#header-region ul.nice-menu li.over ul ul,#header-region ul.nice-menu li.over ul ul ul,#header-region ul.nice-menu li.over li.over ul ul,#header-region ul.nice-menu li.over li.over ul ul ul,#header-region ul.nice-menu li.over li.over li.over ul ul,#header-region ul.nice-menu li.over li.over li.over ul ul ul{visibility:hidden}ul.nice-menu li.menuparent ul,#header-region ul.nice-menu li.menuparent ul{overflow:visible !important}ul.nice-menu li.menuparent ul iframe,#header-region ul.nice-menu li.menuparent ul iframe{display:none;display:block;position:absolute;top:0;left:0;z-index:-1;filter:mask();width:20px;height:20px}ul.nice-menu,ul.nice-menu ul{list-style:none;padding:0;margin:0;border-top:1px solid #ccc}ul.nice-menu li{border:1px solid #ccc;border-top:0;float:left;background-color:#eee}ul.nice-menu a{padding:.3em 5px .3em 5px}ul.nice-menu ul{top:1.8em;left:-1px;border:0;border-top:1px solid #ccc;margin-right:0}ul.nice-menu ul li{width:12.5em}ul.nice-menu-right,ul.nice-menu-left,ul.nice-menu-right li,ul.nice-menu-left li{width:12.5em}ul.nice-menu-right ul{width:12.5em;left:12.5em;top:-1px}ul.nice-menu-right ul ul{width:12.5em;left:12.5em;top:-1px}ul.nice-menu-right li.menuparent,ul.nice-menu-right li li.menuparent{background:#eee url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-right.png) right center no-repeat}
ul.nice-menu-right li.menuparent:hover,ul.nice-menu-right li li.menuparent:hover{background:#ccc url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-right.png) right center no-repeat}ul.nice-menu-left li ul{width:12.5em;left:-12.65em;top:-1px}ul.nice-menu-left li ul li ul{width:12.5em;left:-12.65em;top:-1px}ul.nice-menu-left li.menuparent,ul.nice-menu-left li li.menuparent{background:#eee url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-left.png) left center no-repeat}ul.nice-menu-left li.menuparent:hover,ul.nice-menu-left li li.menuparent:hover{background:#ccc url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-left.png) left center no-repeat}ul.nice-menu-left a,ul.nice-menu-left ul a{padding-left:14px}ul.nice-menu-down{float:left;border:0}ul.nice-menu-down li{border-top:1px solid #ccc}ul.nice-menu-down li li{border-top:0}ul.nice-menu-down ul{left:0}ul.nice-menu-down ul li{clear:both}ul.nice-menu-down li ul li ul{left:12.5em;top:-1px}ul.nice-menu-down .menuparent a{padding-right:15px}ul.nice-menu-down li.menuparent{background:#eee url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-down.png) right center no-repeat}ul.nice-menu-down li.menuparent:hover{background:#ccc url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-down.png) right center no-repeat}ul.nice-menu-down li li.menuparent{background:#eee url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-right.png) right center no-repeat}ul.nice-menu-down li li.menuparent:hover{background:#ccc url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-right.png) right center no-repeat}ul.nice-menu li{margin:0;padding-left:0;background-image:none}#header-region ul.nice-menu li{margin:0;padding-top:.1em;padding-bottom:.1em;background:#eee}#header-region ul.nice-menu ul{top:1.8em;left:-1px;border:0;border-top:1px solid #ccc;margin-right:0}#header-region ul.nice-menu ul{top:1.7em}#header-region ul.nice-menu-down li ul li ul{left:12.5em;top:-1px}#header-region ul.nice-menu-down li.menuparent{background:#eee url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-down.png) right center no-repeat}#header-region ul.nice-menu-down li.menuparent:hover{background:#ccc url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-down.png) right center no-repeat}#header-region ul.nice-menu-down li li.menuparent{background:#eee url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-right.png) right center no-repeat}#header-region ul.nice-menu-down li li.menuparent:hover{background:#ccc url(https://www.pnas.org/sites/all/modules/contrib/nice_menus/images/arrow-right.png) right center no-repeat}.highwire-responsive-toggle-group{background:#424242}.highwire-responsive-toggle-group .panel-pane .pane-content{background:#222;padding:.4em .75em}.highwire-responsive-toggle-group .pane-highwire-seach-quicksearch,.highwire-responsive-advanced-search-link p,.highwire-responsive-toggle-group .pane-highwire-seach-quicksearch .form-item,.highwire-responsive-toggle-group [class*="menu"] .pane-content{margin:0;padding:0}.highwire-responsive-toggle-group .pane-highwire-seach-quicksearch .highwire-quicksearch .form-item-keywords+.button-wrapper.button-mini .icon-search{cursor:pointer}.highwire-responsive-toggle-group .pane-highwire-seach-quicksearch .highwire-quicksearch .form-item-keywords+.button-wrapper.button-mini{top:0}.highwire-responsive-toggle-group .pane-highwire-seach-quicksearch .form-text{border:0;border-radius:0;background:transparent;color:#acacac;font-size:inherit}ul.highwire-responsive-toggle-triggers,ul.highwire-responsive-toggle-triggers li{margin:0;padding:0;display:inline-block;list-style-type:none;color:#efefef}html.js .highwire-responsive-toggle-group .panel-pane .pane-title{display:none}ul.highwire-responsive-toggle-triggers li,.highwire-responsive-toggle-group .panel-pane ul.menu li a{padding:.75em;-webkit-touch-callout:none;-webkit-user-select:none;-khtml-user-select:none;-moz-user-select:none;-ms-user-select:none;-o-user-select:none;user-select:none}ul.highwire-responsive-toggle-triggers li [class^="icon-"],ul.highwire-responsive-toggle-triggers li [class*=" icon-"]{font-size:1.5em;vertical-align:bottom}ul.highwire-responsive-toggle-triggers li.expanded{color:#fff;display:inline-block}ul.highwire-responsive-toggle-triggers li{display:inline-block;margin:0;padding-right:1em;padding-left:1em;cursor:pointer}.highwire-responsive-toggle-group .panel-pane,.highwire-responsive-toggle-group .panel-separator{display:inline;margin:0}html.js .highwire-responsive-toggle-group .panel-pane .pane-content{display:none}html.js .highwire-responsive-toggle-group .expanded .pane-content{display:block}.highwire-responsive-toggle-group .expanded .pane-content,ul.highwire-responsive-toggle-triggers li.expanded{background:#222}
.highwire-responsive-toggle-group .panel-pane ul.menu{padding:0}.highwire-responsive-toggle-group .panel-pane ul.menu li{display:block;margin:0;padding:0}.highwire-responsive-toggle-group .panel-pane ul.menu li a,.highwire-responsive-toggle-group .panel-pane .panel-pane{display:block;border-bottom:solid 1px #777;margin:0;color:#fff;background:#222}.highwire-responsive-toggle-group .panel-pane .panel-pane{padding:.75em}.highwire-responsive-toggle-group .panel-pane .panel-pane.highwire-responsive-advanced-search-link,.highwire-responsive-toggle-group .panel-pane .pane-menu-tree,.highwire-responsive-toggle-group .panel-pane .pane-menu{padding:0;border-bottom:0}.highwire-responsive-toggle-group .panel-pane .pane-highwire-seach-quicksearch{padding:.4em}.highwire-responsive-toggle-group .panel-pane .panel-pane.float-me-right,.highwire-responsive-toggle-group .panel-pane .panel-pane.float-me-left{background:transparent;border-bottom:0}.highwire-responsive-toggle-group .panel-pane ul.menu ul li a{padding-left:2.5em}.highwire-responsive-toggle-group .panel-pane ul.menu li.expanded.show a{background:#444}html.js .highwire-responsive-toggle-group .panel-pane ul.menu li.expanded ul{display:none;-webkit-transition:opacity 300ms ease-in;-moz-transition:opacity 300ms ease-in;-ms-transition:opacity 300ms ease-in;-o-transition:opacity 300ms ease-in;transition:opacity 300ms ease-in}html.js .highwire-responsive-toggle-group .panel-pane ul.menu li.show ul{display:block}.highwire-responsive-toggle-group .panel-pane ul li a:hover,.highwire-responsive-toggle-group .panel-pane ul li.expanded.show a:hover,.highwire-responsive-toggle-group ul.menu li.expanded>a:hover:before{background:#333;color:#fff}.highwire-responsive-toggle-group .panel-pane ul.menu ul ul{display:none}.highwire-responsive-toggle-group ul.menu li.expanded>a:before{float:right;color:#fff;font-size:1.1em;margin-right:.75em;font-family:FontAwesome;content:'\f067'}.highwire-responsive-toggle-group ul.menu li.show>a:before{content:'\f068'}.highwire-responsive-toggle-group .pane-highwire-article-nav .highwire-article-nav ul li a,.highwire-responsive-toggle-group .pane-highwire-article-nav .highwire-article-nav ul li a:hover{color:#fff;background:transparent}.highwire-responsive-toggle-group .highwire-inst-branding img{max-height:1.5em}.panel-2col .panel-col-first .inside{margin:0}.panel-1col .panel-col{width:100%}#panels-edit-display .panel-pane,#panels-edit-display .helperclass{margin:.5em}.panel-2col .panel-separator{margin:0 0 1em 0}#sliding-popup{margin:0;padding:0;width:100%;z-index:99999;left:0;text-align:center}.sliding-popup-bottom,.sliding-popup-top{background:url(https://www.pnas.org/sites/all/modules/contrib/eu_cookie_compliance/images/gradient.png) center center scroll repeat-y transparent}.sliding-popup-bottom{position:fixed}.sliding-popup-top{position:relative}#sliding-popup .popup-content{margin:0 auto;max-width:80%;display:inline-block;text-align:left;width:100%}#sliding-popup .popup-content #popup-buttons{float:right;margin:0 0 1em 0;max-width:40%}#sliding-popup .eu-cookie-compliance-more-button{cursor:pointer;display:inline;height:auto;margin:0;padding:0;border:0;text-decoration:underline;background:none}#sliding-popup .eu-cookie-compliance-secondary-button{cursor:pointer;border:0;background:none;margin-top:1em;padding:0 8px;vertical-align:middle}#sliding-popup .eu-cookie-compliance-default-button,#sliding-popup .eu-cookie-compliance-hide-button,#sliding-popup .eu-cookie-compliance-more-button-thank-you,#sliding-popup .eu-cookie-withdraw-button{cursor:pointer;margin-right:5px;margin-top:1em;vertical-align:middle;overflow:visible;width:auto;-moz-box-shadow:inset 0 1px 0 0 #fff;-webkit-box-shadow:inset 0 1px 0 0 #fff;box-shadow:inset 0 1px 0 0 #fff;background-color:#ededed;background-image:-moz-linear-gradient(top,#ededed 5%,#dfdfdf 100%);background-image:-webkit-gradient(linear,left top,left bottom,color-stop(5%,#ededed),color-stop(100%,#dfdfdf));background-image:-webkit-linear-gradient(top,#ededed 5%,#dfdfdf 100%);background-image:-o-linear-gradient(top,#ededed 5%,#dfdfdf 100%);background-image:-ms-linear-gradient(top,#ededed 5%,#dfdfdf 100%);background-image:linear-gradient(to bottom,#ededed 5%,#dfdfdf 100%);-moz-border-radius:6px;-webkit-border-radius:6px;border-radius:6px;border:1px solid #dcdcdc;color:#000;font-family:Arial,sans-serif;font-weight:bold;padding:4px 8px;text-decoration:none;text-shadow:1px 1px 0 #fff}#sliding-popup .eu-cookie-compliance-default-button:hover,#sliding-popup .eu-cookie-compliance-hide-button:hover,#sliding-popup .eu-cookie-compliance-more-button-thank-you:hover,#sliding-popup .eu-cookie-withdraw-button:hover{background-color:#dfdfdf;background-image:-moz-linear-gradient(top,#dfdfdf 5%,#ededed 100%);background-image:-webkit-gradient(linear,left top,left bottom,color-stop(5%,#dfdfdf),color-stop(100%,#ededed));background-image:-webkit-linear-gradient(top,#dfdfdf 5%,#ededed 100%);background-image:-o-linear-gradient(top,#dfdfdf 5%,#ededed 100%);background-image:-ms-linear-gradient(top,#dfdfdf 5%,#ededed 100%);background-image:linear-gradient(to bottom,#dfdfdf 5%,#ededed 100%)}
#sliding-popup .eu-cookie-compliance-default-button:active,#sliding-popup .eu-cookie-compliance-hide-button:active,#sliding-popup .eu-cookie-compliance-more-button-thank-you:active,#sliding-popup .eu-cookie-withdraw-button:active{position:relative;top:1px}#sliding-popup .popup-content #popup-text{color:#fff;float:left;font-weight:bold;margin:5px 0 0;max-width:60%}#sliding-popup .popup-content #popup-text h1,#sliding-popup .popup-content #popup-text h2,#sliding-popup .popup-content #popup-text h3,#sliding-popup .popup-content #popup-text p{color:#fff;font-size:16px;font-weight:bold;line-height:1.4;margin:0 0 5px 0}#sliding-popup .popup-content #popup-text h1{font-size:24px}#sliding-popup .popup-content #popup-text h3{font-size:12px}#sliding-popup .popup-content #popup-text p{font-size:12px;display:inline}.eu-cookie-withdraw-tab{padding:4px 7px;cursor:pointer}.sliding-popup-bottom .eu-cookie-withdraw-tab{border-width:2px 2px 0;border-radius:5px 5px 0 0}.sliding-popup-top .eu-cookie-withdraw-tab{border-width:0 2px 2px;border-radius:0 0 5px 5px}.eu-cookie-withdraw-wrapper.sliding-popup-top,.eu-cookie-withdraw-wrapper.sliding-popup-top .eu-cookie-withdraw-banner{transform:scaleY(-1)}.eu-cookie-withdraw-tab{position:absolute;top:0;transform:translate(-50%,-100%);left:50%}.eu-cookie-withdraw-wrapper.sliding-popup-top .eu-cookie-withdraw-tab{transform:translate(-50%,-100%) scaleY(-1)}@media screen and (max-width:600px){#sliding-popup .popup-content{max-width:95%}#sliding-popup .popup-content #popup-text{max-width:100%}#sliding-popup .popup-content #popup-buttons{clear:both;float:none;margin:5px 0 1em;max-width:100%}}