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.

Example Input: Background: Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms. Findings: Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10). The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.
Example Output: Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of São Paulo, Brazil

Example Input: Ebola virus (EboV) belongs to the Filoviridae family of viruses that causes severe and fatal hemhorragic fever. Infection by EboV involves fusion between the virus and host cell membranes mediated by the envelope glycoprotein GP2 of the virus. Similar to the envelope glycoproteins of other viruses, the central feature of the GP2 ectodomain postfusion structure is a six-helix bundle formed by the protein's N-and C-heptad repeat regions (NHR and CHR, respectively). Folding of this six-helix bundle provides the energetic driving force for membrane fusion; in other viruses, designed agents that disrupt formation of the six-helix bundle act as potent fusion inhibitors. To interrogate determinants of EboV GP2-mediated membrane fusion, we designed model proteins that consist of the NHR and CHR segments linked by short protein linkers. Circular dichroism and gel filtration studies indicate that these proteins adopt stable ahelical folds consistent with design. Thermal denaturation indicated that the GP2 six-helix bundle is highly stable at pH 5.3 (melting temperature, T m , of 86.8 6 2.0°C and van't Hoff enthalpy, DH vH , of 228.2 6 1.0 kcal/mol) and comparable in stability to other viral membrane fusion six-helix bundles. We found that the stability of our designed a-helical bundle proteins was dependent on buffering conditions with increasing stability at lower pH. Small pH differences (5.3-6.1) had dramatic effects (DT m 5 37°C) suggesting a mechanism for conformational control that is dependent on environmental pH. These results suggest a role for low pH in stabilizing six-helix bundle formation during the process of GP2-mediated viral membrane fusion.
Example Output: Designed protein mimics of the Ebola virus glycoprotein GP2 a-helical bundle: Stability and pH effects

Example Input: Porcine hemagglutinating encephalomyelitis (PHE) is caused by the coronavirus hemagglutinating encephalomyelitis virus (PHE-CoV), and the recent, rapid spread of PHE-CoV in piglets from many countries emphasizes the urgent need for a PHE-CoV vaccine. Here we use a murine model for evaluation of the induction of humoral and cellular immune responses by inactivated and PHE-CoV DNA vaccines in order to define the immune correlates for protection against PHE-CoV. The inactivated vaccine was composed of purified PHE-CoV and aluminum hydroxide gel (alum), which was chosen as an adjuvant because of its long history of safety for human use. The PHE-CoV DNA vaccine was constructed by subcloning the S1 gene of PHE-CoV into the pVAX1 vector to create the recombinant plasmid pV-S1. Our results showed that the inactivated PHE-CoV vaccine (IPV) elicited a high level of humoral immunity, resulting in good protection efficacy against PHE-CoV challenge. The IPV induced the IgG1 subclass of serum antibodies and expression of the cytokine interleukin-4 (IL-4), suggesting that the IPV generated a predominantly Th2-type immune response. The DNA vaccine was found to mediate primarily a cellular immune response with high levels of IgG2a and the cytokines IL-2 and gamma interferon (IFN-␥). However, mice that were vaccinated twice with the DNA vaccine and boosted with the IPV could mount a sufficient neutralizing antibody response against live PHE-CoV, with little variation in IgG1 and IgG2a levels, and showed high levels of IL-2 and IL-4. This response may activate both B and T cells to mount a specific humoral and cellular immune response that could, in turn, elicit a phagocyte-mediated defense against PHE-CoV infections to achieve viral clearance.
Example Output:
Comparative Evaluation of Two Hemagglutinating Encephalomyelitis Coronavirus Vaccine Candidates in Mice