Melatonin is absent from the system or undetectably low during daytime. Its onset in dim light, dim-light melatonin onset (DLMO), at roughly 21:00 (9 p.m.) can be measured in the blood or the saliva. Its major metabolite can also be measured in morning urine. Both DLMO and the midpoint (in time) of the presence of the hormone in the blood or saliva have been used as circadian markers. However, newer research indicates that the melatonin offset may be the more reliable marker. Benloucif et al. found that melatonin phase markers were more stable and more highly correlated with the timing of sleep than the core temperature minimum. They found that both sleep offset and melatonin offset are more strongly correlated with phase markers than the onset of sleep. In addition, the declining phase of the melatonin levels is more reliable and stable than the termination of melatonin synthesis.
At its onset, what can be measured in blood or saliva?
Melatonin

The Croatian Latin alphabet (Gajica) followed suit shortly afterwards, when Ljudevit Gaj defined it as standard Latin with five extra letters that had diacritics, apparently borrowing much from Czech, but also from Polish, and inventing the unique digraphs "lj", "nj" and "dz". These digraphs are represented as "l, n and g" respectively in the "Rjecnik hrvatskog ili srpskog jezika", published by the former Yugoslav Academy of Sciences and Arts in Zagreb. The latter digraphs, however, are unused in the literary standard of the language. All in all, this makes Serbo-Croatian the only Slavic language to officially use both the Latin and Cyrillic scripts, albeit the Latin version is more commonly used.
Which version, Latin or Cyrillic, is most commonly used?
Latin

In 2010 and 2011, state and federal funds were awarded to Connecticut (and Massachusetts) to construct the Hartford Line, with a southern terminus at New Haven's Union Station and a northern terminus at Springfield's Union Station. According to the White House, "This corridor [currently] has one train per day connecting communities in Connecticut and Massachusetts to the Northeast Corridor and Vermont. The vision for this corridor is to restore the alignment to its original route via the Knowledge Corridor in western Massachusetts, improving trip time and increasing the population base that can be served." Set for construction in 2013, the "Knowledge Corridor high speed intercity passenger rail" project will cost approximately $1 billion, and the ultimate northern terminus for the project is reported to be Montreal in Canada. Train speeds between will reportedly exceed 110 miles per hour (180 km/h) and increase both cities' rail traffic exponentially.
When does the Knowledge Corridor line begins it's construction?
in 2013