356 research outputs found
The origins and early development of Copenhagen International School, 1962-1973
This thesis critically examines the origins and early development of Copenhagen International School (CIS, Denmark), which evolved from an American outpost secondary school, attached to the American embassy, to one of the first International Baccalaureate (IB) trial schools, in 1968. The case study places the school’s history in the Danish context of the mid-1960s and early 1970s, and in the wider international and geopolitical configurations of the same period. Using an insider approach, as a full member of the school, I apply a participative method which includes the role of school’s informants particularly in the preservation and the access to the data. By drawing on cross-analysis of the school unexplored records, donated materials, unofficial written histories and oral testimonies from alumni and staff members, the research addresses three questions:
1 What does the school’s early history reveal about the inception of international schooling in the mid-1960s and early 1970s?
2 Why and how did the foundation years of the school embody and reflect broader aspects and interests at stake in the world order?
3 What does the school’s early history unveil about its institutional identity?
The findings provide insights on the interplay and power games between multiple actors in a small international institution under a strong American influence where many interests were at stake. More specifically, it shows how the concept of internationalism embodied a range of different interpretations and had to be negotiated in the school day-to-day life between the different board members, students, parents, headmasters and teachers. Finally, the findings give evidence on the sensitive role and newly increasing power given to international schooling in the changing world order of the mid-twentieth century
Absence of Nodal signaling promotes precocious neural differentiation in the mouse embryo
AbstractAfter implantation, mouse embryos deficient for the activity of the transforming growth factor-β member Nodal fail to form both the mesoderm and the definitive endoderm. They also fail to specify the anterior visceral endoderm, a specialized signaling center which has been shown to be required for the establishment of anterior identity in the epiblast. Our study reveals that Nodal−/− epiblast cells nevertheless express prematurely and ectopically molecular markers specific of anterior fate. Our analysis shows that neural specification occurs and regional identities characteristic of the forebrain are established precociously in the Nodal−/− mutant with a sequential progression equivalent to that of wild-type embryo. When explanted and cultured in vitro, Nodal−/− epiblast cells readily differentiate into neurons. Genes normally transcribed in organizer-derived tissues, such as Gsc and Foxa2, are also expressed in Nodal−/− epiblast. The analysis of Nodal−/−;Gsc−/− compound mutant embryos shows that Gsc activity plays no critical role in the acquisition of forebrain characters by Nodal-deficient cells. This study suggests that the initial steps of neural specification and forebrain development may take place well before gastrulation in the mouse and highlights a possible role for Nodal, at pregastrula stages, in the inhibition of anterior and neural fate determination
Reply to Worth et al
TO THE EDITOR—We thank Worth and colleagues for reflecting on some important points related to our recent study where we reported a 63% reduction in hospital-onset (HO) Staphylococcus aureus bacteremia (SAB) in Australia
Mechanisms of Colonisation and Colonisation Resistance of the Digestive Tract Part 1: Bacteria/host Interactions
The digestive microflora is characterized by a high degree of complexity and diversity. Variation in the composition of the digestive flora of an individual occurs in space and time. Two kinds of s..
Problematic of the Pelagia noctiluca outbreaks in the Bay of Calvi (Corsica)
peer reviewedThe interannual variations of the Schyphozoan jellyfish Pelagia noctiluca is estimated by weekly measurements in the Bay of Calvi (Corsica) from 2003. The mean annual abundance reaches a dramatic maximum in 2006. The medusae appear by migration of active swarms on the shelf and at the external limit of the Bay. Degraded individuals drift as passive swarms, throughout inner side of the Bay and embayments
Five-year antimicrobial resistance patterns of urinary escherichia coli at an Australian tertiary hospital: Time series analyses of prevalence data
This study describes the antimicrobial resistance temporal trends and seasonal variation of Escherichia coli (E. coli) urinary tract infections (UTIs) over five years, from 2009 to 2013, and compares prevalence of resistance in hospital- and community-acquired E. coli UTI. A cross sectional study of E. coli UTIs from patients attending a tertiary referral hospital in Canberra, Australia was undertaken. Time series analysis was performed to illustrate resistance trends. Only the first positive E. coli UTI per patient per year was included in the analysis. A total of 15,022 positive cultures from 8724 patients were identified. Results are based on 5333 first E. coli UTIs, from 4732 patients, of which 84.2% were community-acquired. Five-year hospital and community resistance rates were highest for ampicillin (41.9%) and trimethoprim (20.7%). Resistance was lowest for meropenem (0.0%), nitrofurantoin (2.7%), piperacillin-tazobactam (2.9%) and ciprofloxacin (6.5%). Resistance to amoxycillin-clavulanate, cefazolin, gentamicin and piperacillin-tazobactam were significantly higher in hospital- compared to community-acquired UTIs (9.3% versus 6.2%; 15.4% versus 9.7%; 5.2% versus 3.7% and 5.2% versus 2.5%, respectively). Trend analysis showed significant increases in resistance over five years for amoxycillin-clavulanate, trimethoprim, ciprofloxacin, nitrofurantoin, trimethoprim-sulphamethoxazole, cefazolin, ceftriaxone and gentamicin (P < 0.05, for all) with seasonal pattern observed for trimethoprim resistance (augmented Dickey-Fuller statistic = 4.136; P = 0.006). An association between ciprofloxacin resistance, cefazolin resistance and ceftriaxone resistance with older age was noted. Given the relatively high resistance rates for ampicillin and trimethoprim, these antimicrobials should be reconsidered for empirical treatment of UTIs in this patient population. Our findings have important implications for UTI treatment based on setting of acquisition
Five-Year Antimicrobial Resistance Patterns of Urinary Escherichia Coli at an Australian Tertiary Hospital: Time Series Analyses of Prevalence Data
This study describes the antimicrobial resistance temporal trends and seasonal variation of Escherichia coli (E. coli) urinary tract infections (UTIs) over five years, from 2009 to 2013, and compares prevalence of resistance in hospital- and community-acquired E. coli UTI. A cross sectional study of E. coli UTIs from patients attending a tertiary referral hospital in Canberra, Australia was undertaken. Time series analysis was performed to illustrate resistance trends. Only the first positive E. coli UTI per patient per year was included in the analysis.
A total of 15,022 positive cultures from 8724 patients were identified. Results are based on 5333 first E. coli UTIs, from 4732 patients, of which 84.2% were community acquired. Five-year hospital and community resistance rates were highest for ampicillin (41.9%) and trimethoprim (20.7%). Resistance was lowest for meropenem (0.0%), nitrofurantoin (2.7%), piperacillin-tazobactam (2.9%) and ciprofloxacin (6.5%). Resistance to amoxycillin-clavulanate, cefazolin, gentamicin and piperacillin-tazobactam were significantly higher in hospital- compared to community-acquired UTIs (9.3% versus 6.2%; 15.4% versus 9.7%; 5.2% versus 3.7% and 5.2% versus 2.5%, respectively). Trend analysis showed significant increases in resistance over five years for amoxycillin-clavulanate, trimethoprim, ciprofloxacin, nitrofurantoin, trimethoprim-sulphamethoxazole, cefazolin, ceftriaxone and gentamicin (
Control of plankton phenology by climate variation in a Mediterranean coastal area : results from a long-term study (1979-2011)
Physical processes are known to play major roles in marine plankton succession. However, few studies have addressed the mechanisms that regulate phyto- and zooplankton phenology in a context of changing climate. Here we used a unique long-term (1979-2011) time series performed in a Mediterranean coastal area unbiased by local anthropogenic pressure (PHYTOCLY station, Bay of Calvi, Corsica) to understand how environmental forcing affects the timing, duration and magnitude of the winter-spring phyto- and zooplankton blooms. We showed that phyto- and zooplankton blooms were bottom-up controlled by the establishment of favourable abiotic conditions, i.e. nutrient replenishment by vertical mixing under specific water temperature and wind conditions, for which thresholds were defined. According to the intensity of winter characteristics, there were strong differences in both the abundance and composition of phyto- and zooplankton during the winter-spring period. Our study is consistent with the recent reports that, when occurring, diatoms peaks were added to the initial phytoplankton groups instead of replacing them. In contrast, zooplankton groups followed a replacement sequence. Based on the results provided by our time series, we show that plankton phenology in the Bay of Calvi is highly controlled by climate variation and exhibits contrasted patterns in response to different scenarios of environmental forcing
Surface-layer (S-layer) of Human and Animal Clostridium Difficile Strains and Their Behaviour in Adherence to Epithelial Cells and Intestinal Colonization
Clostridium difficile is a frequent cause of severe, recurrent post-antibiotic diarrhoea and pseudomembranous colitis. The surface layer (S-layer) is the predominant outer surface component of C. difficile which is involved in pathogen-host interactions critical to pathogenesis. In this study, we characterized the S-layer protein A (SIpA) of animal and human strains belonging to different PCR-ribotypes (PR) and compared the in vitro adherence and in vivo colonization properties of strains showing different SIpA variants. Since each SIpA variant has been recently associated with an S-layer cassette, we were able to deduce the cassette for each of our strains. In this study, an identity of 99-100% was found among the SIpA of isolates belonging to PR 012, 014/020, 045 and 078. One exception was the SIpA of a poultry isolate, PR 014/020, which showed 99% identity with that of strain 0160, another PR 014/020 which contains an S-layer cassette 6. Interestingly, this cassette has also been found in a PR 018 strain, an emerging virulent type currently predominant in Italy. Five other SIpA variants (v014/020a-e) were identified in strains PR 014/020. In vitro adherence assays and in vivo colonization experiments were performed on five PR 014/020 strains: human 1064 (v014/020e), human 4684/08 (v014/020b), human Ill 106 (v078a), poultry P30 (v014/020d) and poultry PB90 (v014/020b) strains. Adhesion assays indicate that C. difficile strains vary in their capacity to adhere to cells in culture and that adhesion seems to be independent of the SIpA variant. Colonization properties were assessed in vivo using a dixenic mouse model of colonization. The kinetics of faecal shedding and caecal colonization were similar when human 4684/08 (v014/020b) strain was compared with human 1064 (v014/020e) and poultry PB90 (v014/02013) strain. In contrast, poultry P30 (v014/020d) strain outcompeted both human 4684/08 (v014/020b) and IT1106 (v078a) strains and its adherence to caeca at day 7 was significantly higher. The peculiar characteristics of C. difficile P30 seem to advantage it in colonizing the intestinal mice niche, increasing its ability to compete and adapt. The results obtained underline the need of an increased attention to the genetic evolution of C. difficile to prevent and limit the consequences of the emergence of increasingly virulent strains
Automatic activies of the spinal cord concerned with the respiratory movements
1. After spinal transection at the medulla-spinal junction the thoracic respiratory movements no longer appear in the adult animals, nevertheless the sporadic spike discharges can be recorded from the intercostal muscles. 2. Both in the acute and chronic experiments the spinal cord is transected at the two levels of Th7 and Thl1 respectively and all the dorsal rootlets coming into that part of the cord lying between the transections are severed. The sporadic spike discharges with irregular intervals varying about 0.5 to 3.0 sec. can be recorded from intercostal muscles in the 8th to 10th segments of the spinal cord isolated. There can never be found any reflex influence of the skin stimulation upon the discharges, which also disappear provided the intercostal nerves innervating the muscles are severed. 3. From these results it may be concluded that the spinal cord is endowed
with an ability to initiate the impulses autochthonously to excite the intercostal muscles, even though it is only poorly developed in the adult animals.</p
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