Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

The overlap between symptoms of PTSD and MDD is substantial. PTSD symptoms arise after a traumatic experience and the trauma is present in all of the diagnostic clusters. In individuals who have experienced a trauma a long time before, it is difficult to establish the exact moment of onset of their symptoms in relation to the trauma suffered. We proposed to raise awareness among operators who may encounter this problem, with the aim of providing them with valuable help in order to achieve a correct differential diagnosis. A sample of subjects suffering from PTSD without comorbidity was assessed to confirm the diagnosis and the severity of post-traumatic symptoms. The Kruskal-Wallis test was used to compare any modifications in the parameters analyzed through the Davidson Trauma Scale with the presence and severity of depressive symptoms as evaluated by the Hamilton-D scale. Half of the PSTD patients recruited showed values of HAM-D > 18, although an active Major Depressive Episode was clinically excluded. Symptom of "numbing", despite being different from the apathy experienced in depression, is identified as a depressive symptom by the HAM-D. Giving prevalence to depressive symptoms may be misleading for diagnosis and may ultimately result in inappropriate treatment.
Symptoms of which disorder are evaluated with the Davidson Trauma Scale?

Heroes of Gaia (Chinese: ; pinyin: Yingxiong Zhi Cheng), known in the separate European version as Castle of Heroes, is a massively multiplayer online fantasy browser-based strategy game developed by the Chinese developer Snail Games and published in the United States by its U.S. publishing division, Snail Games USA.
Who worked on Heroes of Gaia?

Here, we report the biochemical and genetic basis of the Vel blood group antigen, which has been a vexing mystery for decades, especially as anti-Vel regularly causes severe haemolytic transfusion reactions. The protein carrying the Vel blood group antigen was biochemically purified from red blood cell membranes. Mass spectrometry-based de novo peptide sequencing identified this protein to be small integral membrane protein 1 (SMIM1), a previously uncharacterized single-pass membrane protein. Expression of SMIM1 cDNA in Vel- cultured cells generated anti-Vel cell surface reactivity, confirming that SMIM1 encoded the Vel blood group antigen. A cohort of 70 Vel- individuals was found to be uniformly homozygous for a 17 nucleotide deletion in the coding sequence of SMIM1. The genetic homogeneity of the Vel- blood type, likely having a common origin, facilitated the development of two highly specific DNA-based tests for rapid Vel genotyping, which can be easily integrated into blood group genotyping platforms. These results answer a 60-year-old riddle and provide tools of immediate assistance to all clinicians involved in the care of Vel- patients.

Which gene-defect causes the Vel-blood type?