The Importance of Retrieval Failures to Long-term Retention: A Metacognitive Explanation of the Spacing Effect

Encoding strategies vary in their duration of effectiveness, and individuals can best identify and modify strategies that yield effects of short duration on the basis of retrieval failures. Multiple study sessions with long inter-session intervals are better than massed training at providing discriminative feedback that identifies encoding strategies of short duration. We report two investigations in which long intervals between study sessions yield substantial benefits to long-term retention, at a cost of only moderately longer individual study sessions. When individuals monitor and control encoding over an extended period, targets yielding the largest number of retrieval failures contribute substantially to the spacing advantage. These findings are relevant to theory and to educators whose primary interest in memory pertains to long-term maintenance of knowledge

Cerebrospinal Fluid Leaks and Encephaloceles

Encephaloceles and cereberospinal fluid (CSF) leaks of the ventral skull base resulting from trauma (surgical and non-surgical), neoplasm, congenital, and spontaneous are a complex problem typically managed by rhinologists/skull base surgeons. Conservative management is often the first step in managing these complex problems. Endoscopic repair of CSF leaks and encephaloceles has greatly evolved with the evolution of endoscopic visualization and instrumentation. Endoscopic repairs of CSF leaks are effective and offer decreased morbidity compared to open approaches with comparative success rates. Meticulous technique is key to success in repair of skull base defects. Materials used are often less important than quality of repair

The Development, Management and Support of Smart Strategic Alliances

Despite the increasing number of strategic alliances, how to ensure their success is poorly understood. Studies suggest that up to seventy-five percent of alliances fail to meet their initial objectives due to a multitude of cultural, political, technological and human factors. If such an eclectic set of competencies is required for success, alliance management is clearly a difficult task for today’s manager. Traditionally, managers wishing to develop strategic alliance competencies have relied on ad-hoc consultancy services and training. This has not, to date, resulted in a notable improvement in alliance success. The SMART project redresses this growing need by developing a knowledge-based software support system to help managers conceptualise, implement and manage strategic alliances. First, this paper introduces the field of strategic alliances; then the foundations of knowledgebased support systems are discussed. Finally, how the SMART approach will create value for managers is relayed

Systematic screens of proteins binding to synthetic microRNA precursors

We describe a new, broadly applicable methodology for screening in parallel interactions of RNA-binding proteins (RBPs) with large numbers of microRNA (miRNA) precursors and for determining their affinities in native form in the presence of cellular factors. The assays aim at identifying pre-miRNAs that are potentially affected by the selected RBP during their biogenesis. The assays are carried out in microtiter plates and use chemiluminescent readouts. Detection of bound RBPs is achieved by protein or tag-specific antibodies allowing crude cell lysates to be used as a source of RBP. We selected 70 pre-miRNAs with phylogenetically conserved loop regions and 25 precursors of other well-characterized miRNAs for chemical synthesis in 3′-biotinylated form. An equivalent set in unmodified form served as inhibitors in affinity determinations. By testing three RBPs known to regulate miRNA biogenesis on this set of pre-miRNAs, we demonstrate that Lin28 and hnRNP A1 from cell lysates or as recombinant protein domains recognize preferentially precursors of the let-7 family, and that KSRP binds strongly to pre-miR-1-

The Hubble Deep Field South Flanking Fields

As part of the Hubble Deep Field South program, a set of shorter 2-orbit observations were obtained of the area adjacent to the deep fields. The WFPC2 flanking fields cover a contiguous solid angle of 48 square arcminutes. Parallel observations with the STIS and NICMOS instruments produce a patchwork of additional fields with optical and near-infrared (1.6 micron) response. Deeper parallel exposures with WFPC2 and NICMOS were obtained when STIS observed the NICMOS deep field. These deeper fields are offset from the rest, and an extended low surface brightness object is visible in the deeper WFPC2 flanking field. In this data paper, which serves as an archival record of the project, we discuss the observations and data reduction, and present SExtractor source catalogs and number counts derived from the data. Number counts are broadly consistent with previous surveys from both ground and space. Among other things, these flanking field observations are useful for defining slit masks for spectroscopic follow-up over a wider area around the deep fields, for studying large-scale structure that extends beyond the deep fields, for future supernova searches, and for number counts and morphological studies, but their ultimate utility will be defined by the astronomical community.Comment: 46 pages, 15 figures. Images and full catalogs available via the HDF-S at http://www.stsci.edu/ftp/science/hdfsouth/hdfs.html at present. The paper is accepted for the February 2003 Astronomical Journal. Full versions of the catalogs will also be available on-line from AJ after publicatio

The medical student

The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine

The Search for Gravitational Waves

Experiments aimed at searching for gravitational waves from astrophysical sources have been under development for the last 40 years, but only now are sensitivities reaching the level where there is a real possibility of detections being made within the next five years. In this article a history of detector development will be followed by a description of current detectors such as LIGO, VIRGO, GEO 600, TAMA 300, Nautilus and Auriga. Preliminary results from these detectors will be discussed and related to predicted detection rates for some types of sources. Experimental challenges for detector design are introduced and discussed in the context of detector developments for the future.Comment: 21 pages, 7 figures, accepted J. Phys. B: At. Mol. Opt. Phy

Amenability of groups and GG-sets

This text surveys classical and recent results in the field of amenability of groups, from a combinatorial standpoint. It has served as the support of courses at the University of G\"ottingen and the \'Ecole Normale Sup\'erieure. The goals of the text are (1) to be as self-contained as possible, so as to serve as a good introduction for newcomers to the field; (2) to stress the use of combinatorial tools, in collaboration with functional analysis, probability etc., with discrete groups in focus; (3) to consider from the beginning the more general notion of amenable actions; (4) to describe recent classes of examples, and in particular groups acting on Cantor sets and topological full groups