A naturally DNase-free CRISPR-Cas12c enzyme silences gene expression.

Used widely for genome editing, CRISPR-Cas enzymes provide RNA-guided immunity to microbes by targeting foreign nucleic acids for cleavage. We show here that the native activity of CRISPR-Cas12c protects bacteria from phage infection by binding to DNA targets without cleaving them, revealing that antiviral interference can be accomplished without chemical attack on the invader or general metabolic disruption in the host. Biochemical experiments demonstrate that Cas12c is a site-specific ribonuclease capable of generating mature CRISPR RNAs (crRNAs) from precursor transcripts.

CRISPR-Cas12a exploits R-loop asymmetry to form double-strand breaks.

Type V CRISPR-Cas interference proteins use a single RuvC active site to make RNA-guided breaks in double-stranded DNA substrates, an activity essential for both bacterial immunity and genome editing. The best-studied of these enzymes, Cas12a, initiates DNA cutting by forming a 20-nucleotide R-loop in which the guide RNA displaces one strand of a double-helical DNA substrate, positioning the DNase active site for first-strand cleavage. However, crystal structures and biochemical data have not explained how the second strand is cut to complete the double-strand break.

Conserved CxC Motifs in Kaposi's Sarcoma-Associated Herpesvirus ORF66 Are Required for Viral Late Gene Expression and Are Essential for Its Interaction with ORF34.

Late gene transcription in the beta- and gammaherpesviruses depends on a set of virally encoded transcriptional activators (vTAs) that hijack the host transcriptional machinery and direct it to a subset of viral genes that are required for completion of the viral replication cycle and capsid assembly. In Kaposi's sarcoma-associated herpesvirus (KSHV), these vTAs are encoded by ORF18, ORF24, ORF30, ORF31, ORF34, and ORF66. Assembly of the vTAs into a complex is critical for late gene transcription, and thus, deciphering the architecture of the complex is central to understanding its transcriptional regulatory activity.

Investments in children's health and the Kenyan cash transfer for orphans and vulnerable children: evidence from an unconditional cash transfer scheme.

Child mortality is one of the most pressing global health and policy issues in the developing world. The leading drivers of death-pneumonia, diarrhea and malaria-are preventable and treatable. However, these illnesses are exacerbated by a lack of accessible nutrition, water, basic and preventive health services, and sanitary living conditions-all factors which are more likely to disproportionately impact the poor.

Impact of the Kenya Cash Transfer for Orphans and Vulnerable Children on early pregnancy and marriage of adolescent girls.

There is promising evidence that poverty-targeted cash transfer programs can have positive impacts on adolescent transitions to adulthood in resource poor settings, however existing research is typically from small scale programs in diverse geographic and cultural settings. We provide estimates of the impact of a national unconditional cash transfer program, the Kenya Cash Transfer for Orphans and Vulnerable Children, on pregnancy and early marriage among females aged 12 to 24, four years after program initiation. The evaluation was designed as a clustered randomized controlled trial and ran from 2007 to 2011, capitalizing on the existence of a control group, which was delayed entry to the program due to budget constraints.

Ghana's National Health insurance scheme and maternal and child health: a mixed methods study.

Background: Ghana is attracting global attention for efforts to provide health insurance to all citizens through the National Health Insurance Scheme (NHIS). With the program's strong emphasis on maternal and child health, an expectation of the program is that members will have increased use of relevant services.

Methods: This paper uses qualitative and quantitative data from a baseline assessment for the Maternal and Newborn errals Evaluation from the Northern and Central Regions to describe women's experiences with the NHIS and to study associations between insurance and skilled facility delivery, antenatal care and early care-seeking for sick children.