instruction:
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.
question:
The objectives were to determine the median infective dose (ID 50 ) of Cryptosporidium parvum and to describe the dose-response relationship including associated clinical illness in experimentally challenged dairy calves. Within the first 24 h of life, 27 test calves were experimentally challenged with C. parvum oocysts and 3 control calves were sham dosed. Test calves received 1 of 8 possible doses (25, 50, 100, 500, 1 10 3 , 1 10 4 , 1 10 5 , and 1 10 6 oocysts). All 27 test calves developed diarrhea. Fecal oocyst shedding occurred in 25 (92.6%) test calves and in 0 control calves. The 2 non-shedding test calves both received 25 oocysts. There was an inverse relationship between dose and time to onset of fecal oocyst shedding (P = 0.005). There was no relationship found between dose and duration (P = 0.2) or cessation (P = 0.3) of fecal oocyst shedding. In addition, there was not a significant relationship between log-dose and the log-peak oocysts (P = 0.2) or log-total oocysts (P = 0.5) counted/g of feces across the dose groups. There was a positive dose-response relationship between log-dose and diarrhea (P = 0.01). However, when controlling for other factors, such as onset and cessation of fecal oocyst shedding, dose was not a significant predictor of diarrhea (P = 0.5). Onset and cessation of fecal oocyst shedding were found to be the best predictors of diarrhea (P = 0.0006 and P = 0.04, respectively). The ID 50 for fecal oocyst shedding was 5.8 oocysts, for diarrhea was 9.7 oocysts, and for fecal oocyst shedding with diarrhea was 16.6 oocysts. Given that the ID 50 of C. parvum is far less than would be excreted into the environment by a naturally infected calf, prevention and control of cryptosporidiosis is a formidable challenge.
answer:
Cryptosporidium parvum: Determination of ID 50 and the dose-response relationship in experimentally challenged dairy calves

question:
IFITM3 restricts cellular infection by multiple important viral pathogens, and is particularly critical for the innate immune response against influenza virus. Expression of IFITM3 expands acidic endolysosomal compartments and prevents fusion of endocytosed viruses, leading to their degradation. This small, 133 amino acid, antiviral protein is controlled by at least four distinct post-translational modifications. Positive regulation of IFITM3 antiviral activity is provided by Spalmitoylation, while negative regulatory mechanisms include lysine ubiquitination, lysine methylation and tyrosine phosphorylation. Herein, we describe specific insights into IFITM3 trafficking and activity that were provided by studies of IFITM3 post-translational modifications, and discuss evidence suggesting that IFITM3 adopts multiple membrane topologies involving at least one intramembrane domain in its antivirally active conformation.
answer:
Regulation of the trafficking and antiviral activity of IFITM3 by post-translational modifications

question:
Porcine reproductive and respiratory syndrome (PRRS) is a disease of domestic swine characterized by exceptionally high clinical variability. This study addresses the question of whether clinical variability in PRRS results from (a) genetic variation among viral isolates and/or (b) variation in management practices among farms on which isolates are found. Genetic data (open reading frame 5 gene sequences) and data on farm characteristics and associated clinical disease signs were collected for 62 PRRS virus (PRRSV) field isolates, representing 52 farms. Clinical disease signs were interrelated confirming that a true reproductive syndrome exists (involving abortions, infertility in sows, deaths of sows and preweaning mortality). Pairs of farms experiencing deaths in their sow populations also tended to share viral isolates which were more similar to one another than expected by chance alone. This implies that sow death (one of the more-severe manifestations of PRRS) is under genetic influence. Large herd size was a significant risk factor for the death of sows and for respiratory disease in nursery pigs. All-inallout management practices in the nursery were protective against reproductive signs in the sow herd. All-inall-out management practices in the finishing stages of production were protective against respiratory disease in nursery pigs but were paradoxically associated with an increased risk of infertility in sows. These results suggest that farm-management practices can also influence which PRRS clinical signs are manifested during an outbreak. In general, signs associated with PRRS appear to result from a combination of genetic factors and herd-management characteristics. The relative contributions of these two influences differ depending on the specific clinical sign in question. # : S 0 1 6 7 -5 8 7 7 ( 9 9 ) 0 0 1 0 4 -X
answer:
Associations between genetics, farm characteristics and clinical disease in field outbreaks of porcine reproductive and respiratory syndrome virus