Developing Graduate Educational Technology Programs from a Service Learning Platform

The graduate College of Education at the University of Massachusetts Lowell (UML), is in the second year of a service centered model for graduate coursework in educational technology. The two courses Technology and Learning Environments (T&LE, 1994), and Technology and Schools of the Future (T&SF, 1995) had previously been offered as traditional academic offerings. In cooperation with the Lawrence Public Schools, one of the poorest districts in the nation, these courses were modified as service learning experiences. A more detailed account of the first year of this project (LeBaron and Scribner-MacLean, 1995) is available on request to the authors. This paper discusses the lessons learned from Phase One, describes the changes implemented for Phase Two, and considers prospects for future project growth

Mechanism of eIF6 release from the nascent 60S ribosomal subunit.

SBDS protein (deficient in the inherited leukemia-predisposition disorder Shwachman-Diamond syndrome) and the GTPase EFL1 (an EF-G homolog) activate nascent 60S ribosomal subunits for translation by catalyzing eviction of the antiassociation factor eIF6 from nascent 60S ribosomal subunits. However, the mechanism is completely unknown. Here, we present cryo-EM structures of human SBDS and SBDS-EFL1 bound to Dictyostelium discoideum 60S ribosomal subunits with and without endogenous eIF6. SBDS assesses the integrity of the peptidyl (P) site, bridging uL16 (mutated in T-cell acute lymphoblastic leukemia) with uL11 at the P-stalk base and the sarcin-ricin loop. Upon EFL1 binding, SBDS is repositioned around helix 69, thus facilitating a conformational switch in EFL1 that displaces eIF6 by competing for an overlapping binding site on the 60S ribosomal subunit. Our data reveal the conserved mechanism of eIF6 release, which is corrupted in both inherited and sporadic leukemias.Supported by a Federation of European Biochemical Societies Long term Fellowship (to FW), Specialist Programme from Bloodwise [12048] (AJW), the Medical Research Council [MC_U105161083] (AJW) and [U105115237] (RRK), Wellcome Trust strategic award to the Cambridge Institute for Medal Research [100140], Tesni Parry Trust (AJW), Ted’s Gang (AJW) and the Cambridge NIHR Biomedical Research Centre.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nsmb.311

Surgical Site Infection in Endometriosis Surgery Is a Rare Complication: Results of a Single Center's Prospective Surveillance of Eight Hundred Ninety-Six Procedures

International audienceBACKGROUND:There are no studies reporting the rate of surgical site infection (SSI) after surgery for endometriosis, although this information is valuable when discussing the most appropriate treatment strategy with the patient.METHODS:We conducted a prospective cohort study in a university hospital and regional reference center for endometriosis. We sought to measure the rate of SSI after endometriosis surgery using prospective SSI post-discharge surveillance data and the hospital information system via an ad hoc algorithm using both diagnosis and procedure code classifications.RESULTS:Among 896 consecutive endometriosis surgical procedures, we identified 365 procedures with involvement of the gastrointestinal tract, defined as the deep invasive procedure (DIP) group, 107 procedures with involvement of an ovary, and 424 other procedures. Twelve SSI (all organ/space infections) were observed, all in the DIP group, corresponding to an overall SSI incidence of 1.3% 95% confidence interval (CI) 0.7-2.3, and an SSI incidence in the DIP group of 2.8%, 95% CI 1.5-4.9. The median delay between the procedure and the SSI was 6.5 days (range, 3-23). At least one micro-organism was found in 10 patients (four Escherichia coli, four Enterobacter cloacae, three Enteroccus faecalis, two Bacteroides fragilis, one Pseudomonas aeruginosa, one Candida albicans).CONCLUSION:A low overall rate of SSI after surgery for endometriosis was observed. Nevertheless, procedures with involvement of the intestinal tract were at risk of SSI

Microbial community structure in the sea surface microlayer at two contrasting coastal sites in the northwestern Mediterranean Sea

In an attempt to compare the microbial community structure between the sea surface microlayer (SML) and subsurface waters (SSW), we determined the enrichment factors (EF: the ratio of abundance or activity in the SML to abundance or activity in SSW) of 13 biological parameters. Samples were taken at 2 contrasting coastal sites in the Mediterranean Sea, corresponding to a high (Barcelona, Spain) and low (Banyuls-sur-Mer, France) urbanized area. Principal component analysis showed that temporal variability was much higher at Barcelona than at Banyuls, and that the characteristics of the SML and SSW samples were more closely related at Barcelona. At both sites, the SML was weakly enriched in heterotrophic bacteria (on average 1.1-fold), Synechococcus spp. (on average 1.1-fold), and photosynthetic picoeukaryotes (on average 1.5-fold) relative to SSW. In contrast, the SML was considerably enriched in chlorophyll a (chl a) (on average 1.9-fold), phaeophytin a (on average 7.4-fold), autotrophic (on average 6.1-fold) and heterotrophic nanoflagellates (on average 5.1-fold) relative to SSW. Enrichments in bacterial production and culturable bacteria were highly variable. EF were significantly different between the 2 sites only for concentrations of chl a, b, and c and the abundance of autotrophic nanoflagellates, with higher EF at the Barcelona site. Except for autotrophic flagellates, the abundance or activity of the parameters determined in the SML was highly correlated with that determined in SSW, suggesting that enrichment of the SML results mainly from upward transport of microorganisms attached to buoyant particles or bubble scavenging. In contrast, the high contribution of autotrophic nanoflagellates to overall phytoneuston biomass (mean=26%) is likely due to their rapid colonization of the SML. The high abundances of auto- and heterotrophic nanoflagellates in the SML indicated that these organisms play a key role in the functioning of the microbial food webs at the air-sea interface

Biochemical characteristics and bacterial community structure of the sea surface microlayer in the South Pacific Ocean

International audienceThe chemical and biological characteristics of the surface microlayer were determined during a transect across the South Pacific Ocean in October-December 2004. Concentrations of particulate organic carbon (1.3 to 7.6-fold) and nitrogen (1.4 to 7-fold), and POC:PON ratios were consistently higher in the surface microlayer as compared to surface waters (5 m). The large variability in particulate organic matter enrichment was negatively correlated to wind speed. No enhanced concentrations of dissolved organic carbon were detectable in the surface microlayer as compared to 5 m, but chromophoric dissolved organic matter was markedly enriched (by 2 to 4-fold) at all sites. Based on pigment analysis and cell counts, no consistent enrichment of any of the major components of the autotrophic and het-erotrophic microbial community was detectable. CE-SSCP fingerprints and CARD FISH revealed that the bacterial communities present in the surface microlayer had close similarity (>76%) to those in surface waters. By contrast, bacterial heterotrophic production (3 H-leucine incorporation) was consistently lower in the surface microlayer than in surface waters. By applying CARD-FISH and microautoradiogra-phy, we observed that Bacteroidetes and Gammaproteobac-teria dominated leucine uptake in the surface microlayer, while in surface waters Bacteroidetes and Alphaproteobacte-ria were the major groups accounting for leucine incorporation. Our results demonstrate that the microbial community in the surface microlayer closely resembles that of the surface Correspondence to: I. Obernosterer ([email protected]) waters of the open ocean. Even a short residence in the surface microlayer influences leucine incorporation by different bacterial groups, probably as a response to the differences in the physical and chemical nature of the two layers

Comparison of samplers for the biological characterization of the sea surface microlayer

International audienceThe surface film of the hydrosphere covers more than 70% of the world’s surface. The sea surface microlayer(SML) or “skin” of the ocean is a sink for natural and anthropogenic material originating from the atmosphereand the water column. Organisms living in this SML are called “neuston.” Our knowledge of the biology of theSML is still in its infancy. Research of the sea surface microlayer requires the use of appropriate sampling techniques and strategies, and the question of what is the most suitable device has not yet been answered. In the present study, we have compared the efficiency of the Harvey glass plate (GP) and the Garrett metal screen (MS) to analyze a wide range of microbiological parameters in SML samples collected at two coastal stations in the NWMediterranean Sea. Two types of membranes (Teflon and polycarbonate) were also used to collect bacterioneuston. The MS was the most appropriate technique for most biological parameters providing higher enrichment factors as compared to the GP and, therefore, the highest enrichment factors compared with underlying waters (UW). Control experiments with UW demonstrated that the enrichment reported for the MS was not biased by any selectivity of the sampler itself. Therefore, we recommend the use of the MS when the aim is to compare different biological parameters. In contrast, there is clear evidence that hydrophobic and hydrophilic membranes have an important drawback and should not be used for quantification purposes

Flow Cytometric Assessment of Viability of Lactic Acid Bacteria

The viability of lactic acid bacteria is crucial for their applications as dairy starters and as probiotics. We investigated the usefulness of flow cytometry (FCM) for viability assessment of lactic acid bacteria. The esterase substrate carboxyfluorescein diacetate (cFDA) and the dye exclusion DNA binding probes propidium iodide (PI) and TOTO-1 were tested for live/dead discrimination using a Lactococcus, a Streptococcus, three Lactobacillus, two Leuconostoc, an Enterococcus, and a Pediococcus species. Plate count experiments were performed to validate the results of the FCM assays. The results showed that cFDA was an accurate stain for live cells; in exponential-phase cultures almost all cells were labeled, while 70°C heat-killed cultures were left unstained. PI did not give clear live/dead discrimination for some of the species. TOTO-1, on the other hand, gave clear discrimination between live and dead cells. The combination of cFDA and TOTO-1 gave the best results. Well-separated subpopulations of live and dead cells could be detected with FCM. Cell sorting of the subpopulations and subsequent plating on agar medium provided direct evidence that cFDA labels the culturable subpopulation and that TOTO-1 labels the nonculturable subpopulation. Applied to cultures exposed to deconjugated bile salts or to acid, cFDA and TOTO-1 proved to be accurate indicators of culturability. Our experiments with lactic acid bacteria demonstrated that the combination of cFDA and TOTO-1 makes an excellent live/dead assay with versatile applications