The trick in building a vented box is to get the right size enclosure and the right size vent. You can't be too far off on either of these factors or your speaker's performance will suffer. In particular, using a too-small box or a too-high vent tuning frequency can eliminate bass instead of increasing it.
1 Dengue fever is a disease caused by a family of viruses that are transmitted by mosquitoes. 2  Symptoms include severe joint and muscle pain, swollen lymph nodes, headache, fever, exhaustion, and rash. 3  The presence of fever, rash, and headache (the dengue triad) is characteristic of dengue fever.
The primary symptoms of dengue are high fever, severe headache, muscle and joint pains. Dengue virus can vary in severity from mild acute febrile illness to a fatal infection. In most people the symptoms of dengue fever start within 4 to 7 days of bite of an infected mosquito.