instruction:
Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
question:
A common challenge in pathogen discovery by deep sequencing approaches is to recognize viral or subviral pathogens in samples of diseased tissue that share no significant homology with a known pathogen. Here we report a homology-independent approach for discovering viroids, a distinct class of free circular RNA subviral pathogens that encode no protein and are known to infect plants only. Our approach involves analyzing the sequences of the total small RNAs of the infected plants obtained by deep sequencing with a unique computational algorithm, progressive filtering of overlapping small RNAs (PFOR). Viroid infection triggers production of viroid-derived overlapping siRNAs that cover the entire genome with high densities. PFOR retains viroid-specific siRNAs for genome assembly by progressively eliminating nonoverlapping small RNAs and those that overlap but cannot be assembled into a direct repeat RNA, which is synthesized from circular or multimeric repeated-sequence templates during viroid replication. We show that viroids from the two known families are readily identified and their full-length sequences assembled by PFOR from small RNAs sequenced from infected plants. PFOR analysis of a grapevine library further identified a viroid-like circular RNA 375 nt long that shared no significant sequence homology with known molecules and encoded active hammerhead ribozymes in RNAs of both plus and minus polarities, which presumably self-cleave to release monomer from multimeric replicative intermediates. A potential application of the homology-independent approach for viroid discovery in plant and animal species where RNA replication triggers the biogenesis of siRNAs is discussed.
answer:
Which are the smallest known subviral pathogens of plants?


question:
Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. A bathymetric map is like a topographic map with the contour lines representing depth below sea level, rather than height above. Numbers are low near sea level and become higher with depth. Kilauea is the youngest volcano found above sea level in Hawaii. On the flank of Kilauea is an even younger volcano called Loihi. The bathymetric map pictured in the Figure 1.2 shows the form of Loihi. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. A geologic map of the region around Old Faithful, Yellowstone National Park. A geologic map shows the geological features of a region (see Figure 1.3 for an example). Rock units are color- coded and identified in a key. Faults and folds are also shown on geologic maps. The geology is superimposed on a topographic map to give a more complete view of the geology of the region. Click image to the left or use the URL below. URL:
answer:
this type of map shows rock units and features like faults and folds.


question:
The film begins in Sicily in 1940 during World War II just as Italy enters the war. A young boy, 12-year-old Renato, experiences three major events in one day: First, Italy goes to war; second, he gets a new bike; and third, he first sees the beautiful lady, Malena. Malena's husband, Nino Scordia, has been taken away to fight in Africa and Malena is left alone with her father, an elderly and almost-deaf man. Malena tries to cope with her loneliness, as the town she has moved to tries to deal with this beautiful woman who gets the attention of all the local men, including Renato. However, in spite of the gossip, she continues to be faithful to her husband. Renato becomes obsessed with Malena and starts fantasizing about her. His fantasies become increasingly elaborate and he becomes obsessed with the shy young woman, peeping in her window often as she waits sadly for her beloved husband to return. Renato eventually steals Malena's underwear and begins to fantasize about her in bed, to the horror of his parents. They do everything to stop his behavior, but it is all in vain. Malena soon receives word that her husband has been killed and her grief consumes her. Renato continues to watch Malena as she suffers from grief. Malena is shunned by the townspeople who begin to believe the worst about her, simply because of her beauty. Women spread terrible rumors and men encourage the rumors by lurking around the poor widow, who does nothing to defend herself; she just wants to be left alone. She visits her father regularly and helps him with his chores, but when a slanderous letter reaches his hands, their relationship suffers a catastrophic blow. Things only get worse when the wife of the local dentist takes Malena to court, accusing her of having an affair with her husband, but Malena is acquitted. The Court is told that Malena is being harassed for being beautiful, as other ladies feel insecure and threatened by her. The only man that the lonely and sad Malena has a romance with, an army officer, is sent away after saying he and Malena were "just friends". The betrayal cuts deeply, but Malena says nothing to condemn the officer. After her acquittal, Malena's lawyer Centorbi comes to her home and asks for a dance and during the dance, using her unpaid legal fee as leverage, rapes her while Renato peeps in from outside her house. Renato increasingly sees himself as Malena's protector, but he does not even realize that his views of her are little better than those of the townspeople. While he asks God to protect her and personally performs little acts of vengeance against those who slander Malena, he takes no time to realize how Malena herself feels. He even rationalizes the rape as a choice Malena made to pay her legal fee. Meanwhile, the war reaches Sicily and the town is bombed. Malena's father dies and she is left completely alone. Desperate for food, Malena's poverty finally forces her to become a prostitute. She cuts off her long black hair and begins to dress provocatively. When the German army comes to town, Malena gives herself to Germans as well. The townspeople smugly watch as she is forced into the role of whore; they are almost more content now than when she was a virtuous young wife. Renato sees her in the company of two German officers and faints. His mother and the older ladies think that he has been possessed and take him to church for an exorcism. His father, however, takes him to a brothel; Renato has sex with one of the prostitutes while fantasizing that she is Malena. As Sicily is liberated by the Americans in 1943, the women gather and publicly beat and humiliate Malena viciously, forcefully shaving her hair and stripping her in the square. A depressed Malena leaves for Messina to escape further persecution. A few days later, Nino Scordia, Malena's husband, returns looking for her, to the shock of all the residents. He finds his house occupied by people displaced by the war and nobody willing to tell him what became of his wife
answer:

How old is Renato at the beginning of the film?