Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory

Neutron matter presents a unique system for chiral effective field theory (EFT), because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N3LO). We present the first complete N3LO calculation of the neutron matter energy. This includes the subleading three-nucleon (3N) forces for the first time and all leading four-nucleon (4N) forces. We find relatively large contributions from N3LO 3N forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.Comment: 5 pages, 4 figures; improved version, 3N ring and 2pi-contact contributions corrected, conclusions unchanged; v3: minor changes, published versio

Stem cell marker (Nanog) and Stat-3 signaling promote MicroRNA-21 expression and chemoresistance in hyaluronan/CD44-activated head and neck squamous cell carcinoma cells.

MicroRNAs are often associated with the pathogenesis of many cancers, including head and neck squamous cell carcinoma (HNSCC). In particular, microRNA-21 (miR-21) appears to have a critical role in tumor cell survival, chemoresistance and HNSCC progression. In this study, we investigated matrix hyaluronan (HA)-induced CD44 (a primary HA receptor) interaction with the stem cell markers, Nanog and Stat-3, in HNSCC cells (HSC-3 cells). Our results indicate that HA binding to CD44 promotes Nanog-Stat-3 (also tyrosine phosphorylated Stat-3) complex formation, nuclear translocation and transcriptional activation. Further analyses reveal that miR-21 is controlled by an upstream promoter containing Stat-3 binding site(s), while chromatin immunoprecipitation assays demonstrate that stimulation of miR-21 expression by HA/CD44 signaling is Nanog/Stat-3-dependent in HNSCC cells. This process results in a decrease of a tumor suppressor protein (PDCD4), and an upregulation of i nhibitors of the apoptosis family of proteins (IAPs) as well as chemoresistance in HSC-3 cells. Treatment of HSC-3 cells with Nanog- and/or Stat-3-specific small interfering RNAs effectively blocks HA-mediated Nanog-Stat-3 signaling events, abrogates miR-21 production and increases PDCD4 expression. Subsequently, this Nanog-Stat-3 signaling inhibition causes downregulation of survival protein (IAP) expression and enhancement of chemosensitivity. To further evaluate the role of miR-21 in tumor cell-specific functions, HSC-3 cells were also transfected with a specific anti-miR-21 inhibitor in order to silence miR-21 expression and block its target functions. Our results demonstrate that anti-miR-21 inhibitor not only upregulates PDCD4 expression but also decreases IAP expression and enhances chemosensitivity in HA-treated HNSCC cells. Together, these findings indicate that the HA-induced CD44 interaction with Nanog and Stat-3 has a pivotal role in miR-21 production leading to PDCD4 reduction, IAP upregulation and chemoresistance in HNSCC cells. This novel Nanog/Stat-3 signaling pathway-specific mechanism involved in miR-21 production is significant for the formation of future intervention strategies in the treatment of HA/CD44-activated HNSCC

The Status of Statewide Subscription Databases

This qualitative content analysis presents subscription databases available to school libraries through statewide purchases. The results may help school librarians evaluate grade and subject-area coverage, make comparisons to recommended databases, and note potential suggestions for their states to include in future contracts or for local purchase. All states had similar periodicals‘ indexing vendors; therefore, this study‘s focus was online subject reference databases. Results portrayed seventy-nine unique databases across thirty-three states analyzed. Most states studied (81 percent) had a wide variety of online reference subject content; twenty states (61 percent) included one or more general reference databases; seven states with no general reference had a range of titles in health, literary criticism, science, history, biography, and/or art. However, not all content areas were equally represented: examples: health (61 percent), literary criticism (55 percent), science (42 percent), history (39 percent), biography (33 percent), and arts (15 percent). There was disparity in six states with no general reference and gaps in subject coverage. In one state, the only secondary reference tool available was NoveList for readers‘ advisory. Another state‘s only secondary subject reference title was HeritageQuest. Additionally, pro/con databases, readers‘ advisory, and elementary general reference online databases were available in just over half of the states (51 percent); access to general encyclopedias online was offered by only 48 percent of states surveyed

A Case Study of a Rural Iowa School Preparing to Meet New State Guidelines for School Libraries

A qualitative case study highlighting one rural Iowa elementary school provided insight into the issue of small schools without library programs as they are preparing to meet the Iowa reinstatement of the requirement for school library programs. The site was purposefully chosen because it has been operating without a school library program or professional teacher-librarian district-wide. All eight teachers and the nonendorsed library associate from one elementary school participated in either a focus group or semistructured interviews. The four district administrators were interviewed individually. Related documents were consulted. This study examined the status of the school library program, analyzed the stakeholder’s perceptions and expectations for the school library program and instructional role, and identified supports and obstacles to implementing the new state teacher-librarian and school library program and requirements. Three themes emerged from the data, exemplifying the expectations surrounding this school’s library program: (a) a minimal role for school library programs in the vision and reality of participants, (b) the invisibility of the professional qualifications and instructional and collaborative qualities of the teacher-librarian needed to increase program sustainability, and (c) a disconnect between the school library program and literacy, technology, and other curricular area school improvement initiatives. The results showed this school’s library program denied students access to libraries and learning opportunities essential for a democratic education. The data from this case study support these conclusions by showing an inability of the local school district to create or sustain a high quality school library program without a state mandate and the inability of the current state mandate to instill a high quality school library program in this district