In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

[EX Q]: We previously identified unusual variants of Moloney and Friend ecotropic mouse gammaretroviruses that have altered host range and are cytopathic in cells of the wild mouse species Mus dunni. Cytopathicity was attributed to different amino acid substitutions at the same critical env residue involved in receptor interaction: S82F in the Moloney variant Spl574, and S84A in the Friend mouse leukemia virus F-S MLV. Because M. dunni cells carry a variant CAT-1 cell surface virus receptor (dCAT-1), we examined the role of this receptor variant in cytopathicity and host range. We expressed dCAT-1 or mCAT-1 of NIH 3T3 origin in cells that are not normally infectible with ecotropic MLVs and evaluated the transfectants for susceptibility to virus infection and to virus-induced syncytium formation. The dCAT-1 transfectants, but not the mCAT-1 transfectants, were susceptible to virus-induced cytopathicity, and this cytopathic response was accompanied by the accumulation of unintegrated viral DNA. The dCAT-1 transfectants, however, did not also reproduce the relative resistance of M. dunni cells to Moloney MLV, and the mCAT-1 transfectants did not show the relative resistance of NIH 3T3 cells to Spl574. Western analysis, use of glycosylation inhibitors and mutagenesis to remove receptor glycosylation sites identified a possible role for cell-specific glycosylation in the modulation of virus entry. Virus entry and virus-induced syncytium formation using the CAT-1 receptor are mediated by a small number of critical amino acid residues in receptor and virus Env. Virus entry is modulated by glycosylation of cellular proteins, and this effect is cell and virus-specific.
[EX A]: Role of receptor polymorphism and glycosylation in syncytium induction and host range variation of ecotropic mouse gammaretroviruses

[EX Q]: O. is a 37-year-old male with no significant past medical history who presented to the Emergency Department with a one week history of worsening dysphagia and odynophagia. He reported he was usually in good health until the current symptoms began. Scott said that he had been unable to swallow solid foods over the past week, largely due to increasing pain on swallowing, and was now unable to swallow liquids as well. Although he stated that his appetite was unchanged, he estimated a fivepound weight loss over the last week due to poor oral intake. He otherwise denied fever, respiratory or gastrointestinal symptoms, or any other complaints. He takes no medications at home except for rare acetaminophen. He is married, has a twoyear-old son, and works as an attorney. He denied use of tobacco, alcohol, or illicit drugs. Family history was noncontributory. On physical exam, he was afebrile and his vital signs were within normal limits. Cardiovascular, respiratory, abdominal, extremity, and neurologic exam were unremarkable. There was some mild oropharyngeal thrush, palpable bilateral inguinal lymphadenopathy, and a 1 cm painless ulceration on the penile shaft. Laboratory evaluation was unremarkable.
[EX A]: When a Diagnosis Is Reportable The Patient

[EX Q]: With the rapid development of the economy and the accelerated globalization process, the aviation industry plays a more and more critical role in today's world, in both developed and developing countries. As the infrastructure of aviation industry, the airport network is one of the most important indicators of economic growth. In this paper, we investigate the evolution of the Chinese airport network (CAN) via complex network theory. It is found that although the topology of CAN has remained steady during the past few years, there are many dynamic switchings inside the network, which have changed the relative importance of airports and airlines. Moreover, we investigate the evolution of traffic flow (passengers and cargoes) on CAN. It is found that the traffic continues to grow in an exponential form and has evident seasonal fluctuations. We also found that cargo traffic and passenger traffic are positively related but the correlations are quite different for different kinds of cities.
[EX A]:
Physica A Evolution of Chinese airport network