{"id":25360,"date":"2014-08-19T13:43:57","date_gmt":"2014-08-19T11:43:57","guid":{"rendered":"https:\/\/ocasapiens-dweb.blogautore.repubblica.it\/?p=25360"},"modified":"2021-10-10T14:55:37","modified_gmt":"2021-10-10T12:55:37","slug":"la-punta-delliceberg","status":"publish","type":"post","link":"https:\/\/archivio.ocasapiens.org\/index.php\/2014\/08\/19\/la-punta-delliceberg\/","title":{"rendered":"La punta dell&#039;iceberg"},"content":{"rendered":"<p>Con un altro contributo impareggiabile all&#8217;educazione sessuale, l&#8217;amata moscerina ha rivelato a <strong><a href=\"http:\/\/www.genetics.org\/content\/early\/2014\/08\/04\/genetics.114.169268\" target=\"_blank\" rel=\"noopener\">Delphine Fagegaltier et al.<\/a> <\/strong>la fonte della differenza tra maschio e femmina.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/c1.staticflickr.com\/9\/8246\/8589795947_939804f6f2_z.jpg\" alt=\"\" width=\"532\" height=\"355\" \/><br \/>\nNon sta solo in qualche gene Sex-lethal, Sisterless o Deadpan (che nomi&#8230;) nei cromosomi X o Y (nel suo caso l&#8217;Y \u00e8 femminile) i quali determinano banalmente ovaie o testicoli, ma bens\u00ec in piccoli geni sparsi che codificano per il micro-RNA e rendono quegli organi utili oppure ornamentali.<\/p>\n<p>A sua volta infatti, il micro-RNA &#8220;accende&#8221; o &#8220;spegne&#8221; geni per la produzione di proteine decisive perch\u00e9 la cellula sia maschia o femmina, a prescindere del sesso e dall&#8217;et\u00e0 del\/la titolare.<\/p>\n<p>Dal <a href=\"http:\/\/www.cshl.org\/1228-more-than-just-x-and-y-a-new-genetic-basis-for-sex-determination.html\" target=\"_blank\" rel=\"noopener\">com.\u00a0stampa <\/a>di Cold Spring Harbor Lab:<\/p>\n<ul>\n<li><em>&#8220;They send signals that allow germ cells, i.e., eggs and sperm, to develop, ensuring fertility,&#8221; Fagegaltier explains. &#8220;Removing one miRNA from mature, adult flies causes infertility.&#8221; More than that, these flies begin to produce both male and female sex-determinants. &#8220;In a sense, once they have lost this miRNA, the flies become male and female at the same time,&#8221; according to Fagegaltier. &#8220;It is amazing that the very smallest genes can have such a big effect on sexual identity.&#8221;<\/em><\/li>\n<\/ul>\n<p>La scoperta ci riguarda, come sempre<\/p>\n<ul>\n<li><em>Some miRNAs examined in the study, such as let-7, have been preserved by evolution because of their utility; humans and many other animals carry versions of them. &#8220;This is probably just the tip of the iceberg,&#8221; says Fagegaltier. &#8220;There are likely many more miRNAs regulating sexual identity at the cellular and tissue level, but we still have a lot to learn about these differences in humans, and how they could contribute to developmental defects and disease.&#8221;<\/em><\/li>\n<\/ul>\n<p style=\"text-align: center;\">***<\/p>\n<p>Sui PNAS, George Wittemyer (uno dei fondatori di <a href=\"http:\/\/savetheelephants.org\/\" target=\"_blank\" rel=\"noopener\">Save the Elephants<\/a>) et al. <strong><a href=\"http:\/\/www.pnas.org\/content\/early\/2014\/08\/14\/1403984111\" target=\"_blank\" rel=\"noopener\">stimano<\/a><\/strong> che il numero di adulti uccisi ogni anno dai contrabbandieri d&#8217;avorio supera quello delle nascite.<\/p>\n<p style=\"text-align: center;\">***<\/p>\n<p style=\"text-align: left;\"><strong>Ma davvero?<\/strong><\/p>\n<p>In Usa e in altri paesi \u00e8 lecito usare antibiotici per far ingrassare velocemente gli animali da allevamento, su <a href=\"http:\/\/www.cell.com\/cell\/abstract\/S0092-8674(14)00821-6\" target=\"_blank\" rel=\"noopener\"><em>Cell<\/em>\u00a0<em>Symposia<\/em>\u00a0<\/a>Laura Cox et al. dimostrano che 2+2 = 4 con esperimenti sui topi:<br \/>\n<em>\u2022Early life is a critical window of host-microbe metabolic interaction<\/em><br \/>\n<em>\u2022Low-dose penicillin treatment amplifies diet-induced obesity<\/em><br \/>\n<em>\u2022A transient early microbiota perturbation leads to long-term increased adiposity<\/em><br \/>\n<em>\u2022The penicillin-altered microbiota has a causal role in inducing metabolic changes<\/em><\/p>\n<p style=\"text-align: center;\"><strong>***<\/strong><\/p>\n<p style=\"text-align: left;\"><strong>Me l&#8217;ero persa<\/strong><\/p>\n<p style=\"text-align: left;\">Nella disinformazione sul clima, c&#8217;\u00e8 un nuovo verbo per gli attacchi personali. Al posto di <em>to shoot the messenger<\/em>, si dice <strong><em><a href=\"http:\/\/www.buzzfeed.com\/climatebrad\/pielked-111-ways-nate-silvers-climate-guy-attack-gt89\" target=\"_blank\" rel=\"noopener\">to pielke<\/a><\/em><\/strong>. Deriva dalle esternazioni rabbiose di Roger Pielke Jr &#8211; che ora non scrive pi\u00f9 per il giornale di Nat Silver (h\/t Michael Mann).<\/p>\n<p style=\"text-align: left;\"><strong>Spoiler alert<\/strong><\/p>\n<p style=\"text-align: left;\">Sou di Hot whopper <strong><a href=\"http:\/\/blog.hotwhopper.com\/2014\/08\/denier-weirdness-weight-of-atmosphere.html\" target=\"_blank\" rel=\"noopener\">ha scoperto<\/a><\/strong> una nuova teoria dell&#8217;effetto serra proposta da Fred Berple<\/p>\n<blockquote><p><em>Since the molecular weight of CO2 is 44, and the molecular weight of H2O is 18, it takes (44\/18) = 2.44 molecules of H2O to equal the weight of 1 CO2 molecule. What is interesting is that this would yield a negative H2O feedback of 2.4, which almost exactly balances the 3 time positive water feedback assumed by climate science. Since the H2O will tend to come out of the atmosphere more rapidly than temps will rise, it could well be that partial pressure law causes a net negative feedback.<\/em><\/p><\/blockquote>\n<p>Per cui nella pentola a pressione fa pi\u00f9 freddo che in quella con il coperchio normale e i modelli climatici sono tutti sbagliati:<\/p>\n<blockquote><p><em>Which would explain why the models are running hot. They fail to allow for partial pressure law to reduce H2O in their calculations, as CO2 increases.<\/em><\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>Con un altro contributo impareggiabile all&#8217;educazione sessuale, l&#8217;amata moscerina ha rivelato a Delphine Fagegaltier et al. la fonte della differenza tra maschio e femmina. Non sta solo in qualche gene Sex-lethal, Sisterless o Deadpan (che nomi&#8230;) nei cromosomi X o Y (nel suo caso l&#8217;Y \u00e8 femminile) i quali determinano banalmente ovaie o testicoli, ma&hellip; <a class=\"more-link\" href=\"https:\/\/archivio.ocasapiens.org\/index.php\/2014\/08\/19\/la-punta-delliceberg\/\">Continua a leggere <span class=\"screen-reader-text\">La punta dell&#039;iceberg<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,13,17],"tags":[1228,1450,1587,2189,2483,4491,4500,4921],"class_list":["post-25360","post","type-post","status-publish","format-standard","hentry","category-altri-animali","category-drosophila-fanzine","category-genetica","tag-cellule-sessuate","tag-climate-wars","tag-contrabbando","tag-elefanti-africani","tag-evoluzione","tag-microbioma-umano","tag-microrna","tag-obesita","entry"],"_links":{"self":[{"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/posts\/25360","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/comments?post=25360"}],"version-history":[{"count":2,"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/posts\/25360\/revisions"}],"predecessor-version":[{"id":42540,"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/posts\/25360\/revisions\/42540"}],"wp:attachment":[{"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/media?parent=25360"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/categories?post=25360"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/archivio.ocasapiens.org\/index.php\/wp-json\/wp\/v2\/tags?post=25360"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}