miR-27 regulates chondrogenesis by suppressing focal adhesion kinase during pharyngeal arch development.

Cranial neural crest cells are a multipotent cell population that generate all the elements of the pharyngeal cartilage with differentiation into chondrocytes tightly regulated by temporal intracellular and extracellular cues. Here, we demonstrate a novel role for miR-27, a highly enriched microRNA in the pharyngeal arches, as a positive regulator of chondrogenesis. Knock down of miR-27 led to nearly complete loss of pharyngeal cartilage by attenuating proliferation and blocking differentiation of pre-chondrogenic cells.

Influenza activity in Kenya, 2007-2013: timing, association with climatic factors, and implications for vaccination campaigns.

Background: Information on the timing of influenza circulation remains scarce in Tropical regions of Africa.

Objectives: We assessed the relationship between influenza activity and several meteorological factors (temperature, specific humidity, precipitation) and characterized the timing of influenza circulation and its implications to vaccination strategies in Kenya.

Methods: We analyzed virologically confirmed influenza data for outpatient influenza-like illness (ILI), hospitalized for severe acute respiratory infections (SARI), and cases of severe pneumonia over the period 2007-2013.