280 research outputs found
Colonial education policy and practice in Indonesia : 1900-1942
So far, no detailed study has been made - either in Dutch,
English, or Indonesian - of the history of education in Indonesia
in the crucial period 1900-1942. In this study an attempt will
he made to fill this gap. The only sizeable work in existence
is Brugmans1 ’Geschiedenis van het Onderwijs in Nederlandsch-
Indie1, published in 1937* In this work, the period under
discussion is treated in outline only. Brugmans, who was a
high colonial official and had been closely involved in some
of the major policy decisions concerning education in this
period, was obviously unable to disclose information which at
that time was still on the classified list. The other secondary
material is very limited, and consists mainly of journal articles
dealing with specific aspects or topics of colonial education
policy.
This study, however, is based in part on extensive research
in the Colonial Archives in the Hague and some hitherto unknown
material has been brought to light. In order to give English
speaking scholars some idea of the nature and the extent of the
archival material available, the narrative has been kept fairly
closely to the documents and a large number of excerpts
translated by the author from the original Dutch - a little
known language - have been included in the text
Development of the preterm gut microbiome in twins at risk of necrotising enterocolitis and sepsis
The preterm gut microbiome is a complex dynamic community influenced by genetic and environmental factors and is implicated in the pathogenesis of necrotising enterocolitis (NEC) and sepsis. We aimed to explore the longitudinal development of the gut microbiome in preterm twins to determine how shared environmental and genetic factors may influence temporal changes and compared this to the expressed breast milk (EBM) microbiome. Stool samples (n = 173) from 27 infants (12 twin pairs and 1 triplet set) and EBM (n = 18) from 4 mothers were collected longitudinally. All samples underwent PCR-DGGE (denaturing gradient gel electrophoresis) analysis and a selected subset underwent 454 pyrosequencing. Stool and EBM shared a core microbiome dominated by Enterobacteriaceae, Enterococcaceae, and Staphylococcaceae. The gut microbiome showed greater similarity between siblings compared to unrelated individuals. Pyrosequencing revealed a reduction in diversity and increasing dominance of Escherichia sp. preceding NEC that was not observed in the healthy twin. Antibiotic treatment had a substantial effect on the gut microbiome, reducing Escherichia sp. and increasing other Enterobacteriaceae.
This study demonstrates related preterm twins share similar gut microbiome development, even within the complex environment of neonatal intensive care. This is likely a result of shared genetic and immunomodulatory factors as well as exposure to the same maternal microbiome during birth, skin contact and exposure to EBM. Environmental factors including antibiotic exposure and feeding are additional significant determinants of community structure, regardless of host genetics
Mode of Delivery and Asthma at School Age in 9 European Birth Cohorts
Evidence on the association between mode of delivery and asthma at school age is inconclusive. We assessed the associations between specific modes of delivery and asthma in children from 9 European birth cohorts that enrolled participants between 1996 and 2006. Cohort-specific crude and adjusted risk ratios for asthma at ages 5–9 years were calculated using Poisson regression models and pooled. A sensitivity analysis was carried out in children born at term to reduce confounding due to perinatal factors. The study included 67,613 participants. Cohortspecific rates of cesarean delivery varied from 9.4% to 37.5%. Cesarean delivery, as opposed to vaginal delivery, was associated with an increased risk of asthma (adjusted risk ratio (aRR) = 1.22, 95% confidence interval (CI): 1.02, 1.46). Compared with spontaneous vaginal delivery, the adjusted risk ratio was 1.33 (95% CI: 1.02, 1.75) for elective cesarean delivery, 1.07 (95% CI: 0.94, 1.22) for emergency cesarean delivery, and 0.97 (95% CI: 0.84, 1.12) for operative vaginal delivery. In children born at term, the associations were strengthened only for elective cesarean delivery (aRR = 1.49, 95% CI: 1.13, 1.97). The large sample size allowed analysis of the associations between specific modes of delivery and asthma at school age. The increased risk of asthma associated with elective cesarean delivery, especially among children born at term, is relevant in counteracting the increasing use of this procedure, which is often performed without a clear medical indication.This work was supported by the European Community’s Seventh Framework Programme (FP7/2009–2013) under a grant agreement (grant 241604) and by the University of Turin and the San Paolo Foundation (Turin, Italy). Data collection was funded and the study teams of all participating birth cohorts were supported by local and/or national research organizations
Enteric dysbiosis and fecal calprotectin expression in premature infants.
BackgroundPremature infants often develop enteric dysbiosis with a preponderance of Gammaproteobacteria, which has been related to adverse clinical outcomes. We investigated the relationship between increasing fecal Gammaproteobacteria and mucosal inflammation, measured by fecal calprotectin (FC).MethodsStool samples were collected from very-low-birth weight (VLBW) infants at ≤2, 3, and 4 weeks' postnatal age. Fecal microbiome was surveyed using polymerase chain reaction amplification of the V4 region of 16S ribosomal RNA, and FC was measured by enzyme immunoassay.ResultsWe enrolled 45 VLBW infants (gestation 27.9 ± 2.2 weeks, birth weight 1126 ± 208 g) and obtained stool samples at 9.9 ± 3, 20.7 ± 4.1, and 29.4 ± 4.9 days. FC was positively correlated with the genus Klebsiella (r = 0.207, p = 0.034) and its dominant amplicon sequence variant (r = 0.290, p = 0.003), but not with the relative abundance of total Gammaproteobacteria. Klebsiella colonized the gut in two distinct patterns: some infants started with low Klebsiella abundance and gained these bacteria over time, whereas others began with very high Klebsiella abundance.ConclusionIn premature infants, FC correlated with relative abundance of a specific pathobiont, Klebsiella, and not with that of the class Gammaproteobacteria. These findings indicate a need to define dysbiosis at genera or higher levels of resolution
A 4-Week Diet Low or High in Advanced Glycation Endproducts Has Limited Impact on Gut Microbial Composition in Abdominally Obese Individuals : The deAGEing Trial
Dietary advanced glycation endproducts (AGEs), abundantly present in Westernized diets, are linked to negative health outcomes, but their impact on the gut microbiota has not yet been well investigated in humans. We investigated the effects of a 4-week isocaloric and macronutrient-matched diet low or high in AGEs on the gut microbial composition of 70 abdominally obese individuals in a double-blind parallel-design randomized controlled trial (NCT03866343). Additionally, we investigated the cross-sectional associations between the habitual intake of dietary dicarbonyls, reactive precursors to AGEs, and the gut microbial composition, as assessed by 16S rRNA amplicon-based sequencing. Despite a marked percentage difference in AGE intake, we observed no differences in microbial richness and the general community structure. Only the Anaerostipes spp. had a relative abundance >0.5% and showed differential abundance (0.5 versus 1.11%; p = 0.028, after low- or high-AGE diet, respectively). While the habitual intake of dicarbonyls was not associated with microbial richness or a general community structure, the intake of 3-deoxyglucosone was especially associated with an abundance of several genera. Thus, a 4-week diet low or high in AGEs has a limited impact on the gut microbial composition of abdominally obese humans, paralleling its previously observed limited biological consequences. The effects of dietary dicarbonyls on the gut microbiota composition deserve further investigation.Peer reviewe
Comparative Analysis of Fecal Microbiota in Infants with and without Eczema
Eczema is a chronic form of childhood disorder that is gaining in prevalence in affluent societies. Previous studies hypothesized that the development of eczema is correlated with changes in microbial profile and composition of early life endemic microbiota, but contradictory conclusions were obtained, possibly due to the lack of minimization of apparent non-health related confounders (e.g., age, antibiotic consumption, diet and mode of delivery). In this study, we recruited seven caesarean-delivered and total formula-fed infants, and comparatively examined the early-life endemic microbiota in these infants with and without eczema. Using 16S pyrosequencing, infants' fecal microbiota were observed to comprise Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes as the four main phyla, and the presence and absence of specific populations within these four phyla are primarily mediated by ageing. Quantitative analysis of bacterial targets on a larger sample size (n = 36 at 1, 3, and 12 months of age) revealed that the abundances of Bifidobacterium and Enterobacteriaceae were different among caesarean-delivered infants with and without eczema, and the bacterial targets may be potential biomarkers that can correlate to the health status of these infants. Our overall findings suggest that the minimization of possible confounders is essential prior to comparative evaluation and correlation of fecal microbiota to health status, and that stool samples collected from caesarean-delivered infants at less than 1 year of age may represent a good cohort to study for potential biomarkers that can distinguish infants with eczema from those without. These findings would greatly facilitate future efforts in understanding the possible pathogenesis behind certain bacterial targets, and may lead to a timely intervention that reduces the occurrence of early life eczema and possibly allergic disorders in later life
Robotic Wireless Sensor Networks
In this chapter, we present a literature survey of an emerging, cutting-edge,
and multi-disciplinary field of research at the intersection of Robotics and
Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor
Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system
that aims to achieve certain sensing goals while meeting and maintaining
certain communication performance requirements, through cooperative control,
learning and adaptation. While both of the component areas, i.e., Robotics and
WSN, are very well-known and well-explored, there exist a whole set of new
opportunities and research directions at the intersection of these two fields
which are relatively or even completely unexplored. One such example would be
the use of a set of robotic routers to set up a temporary communication path
between a sender and a receiver that uses the controlled mobility to the
advantage of packet routing. We find that there exist only a limited number of
articles to be directly categorized as RWSN related works whereas there exist a
range of articles in the robotics and the WSN literature that are also relevant
to this new field of research. To connect the dots, we first identify the core
problems and research trends related to RWSN such as connectivity,
localization, routing, and robust flow of information. Next, we classify the
existing research on RWSN as well as the relevant state-of-the-arts from
robotics and WSN community according to the problems and trends identified in
the first step. Lastly, we analyze what is missing in the existing literature,
and identify topics that require more research attention in the future
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Restricting Microbial Exposure in Early Life Negates the Immune Benefits Associated with Gut Colonization in Environments of High Microbial Diversity
Background: Acquisition of the intestinal microbiota in early life corresponds with the development of the mucosal immune system. Recent work on caesarean-delivered infants revealed that early microbial composition is influenced by birthing method and environment. Furthermore, we have confirmed that early-life environment strongly influences both the adult gut microbiota and development of the gut immune system. Here, we address the impact of limiting microbial exposure after initial colonization on the development of adult gut immunity.
Methodology/Principal Findings: Piglets were born in indoor or outdoor rearing units, allowing natural colonization in the
immediate period after birth, prior to transfer to high-health status isolators. Strikingly, gut closure and morphological
development were strongly affected by isolator-rearing, independent of indoor or outdoor origins of piglets. Isolator-reared
animals showed extensive vacuolation and disorganization of the gut epithelium, inferring that normal gut closure requires
maturation factors present in maternal milk. Although morphological maturation and gut closure were delayed in isolatorreared
animals, these hard-wired events occurred later in development. Type I IFN, IL-22, IL-23 and Th17 pathways were
increased in indoor-isolator compared to outdoor-isolator animals during early life, indicating greater immune activation in
pigs originating from indoor environments reflecting differences in the early microbiota. This difference was less apparent
later in development due to enhanced immune activation and convergence of the microbiota in all isolator-reared animals.
This correlated with elevation of Type I IFN pathways in both groups, although T cell pathways were still more affected in
indoor-reared animals.
Conclusions/Significance: Environmental factors, in particular microbial exposure, influence expression of a large number
of immune-related genes. However, the homeostatic effects of microbial colonization in outdoor environments require
sustained microbial exposure throughout development. Gut development in high-hygiene environments negatively
impacts on normal succession of the gut microbiota and promotes innate immune activation which may impair immune
homeostasis
Towards standards for human fecal sample processing in metagenomic studies
Technical variation in metagenomic analysis must be minimized to confidently assess the contributions of microbiota to human health. Here we tested 21 representative DNA extraction protocols on the same fecal samples and quantified differences in observed microbial community composition. We compared them with differences due to library preparation and sample storage, which we contrasted with observed biological variation within the same specimen or within an individual over time. We found that DNA extraction had the largest effect on the outcome of metagenomic analysis. To rank DNA extraction protocols, we considered resulting DNA quantity and quality, and we ascertained biases in estimates of community diversity and the ratio between Gram-positive and Gram-negative bacteria. We recommend a standardized DNA extraction method for human fecal samples, for which transferability across labs was established and which was further benchmarked using a mock community of known composition. Its adoption will improve comparability of human gut microbiome studies and facilitate meta-analyses
The Intestinal Microbiota Plays a Role in Salmonella-Induced Colitis Independent of Pathogen Colonization
The intestinal microbiota is composed of hundreds of species of bacteria, fungi
and protozoa and is critical for numerous biological processes, such as nutrient
acquisition, vitamin production, and colonization resistance against bacterial
pathogens. We studied the role of the intestinal microbiota on host resistance
to Salmonella enterica serovar Typhimurium-induced colitis.
Using multiple antibiotic treatments in 129S1/SvImJ mice, we showed that
disruption of the intestinal microbiota alters host susceptibility to infection.
Although all antibiotic treatments caused similar increases in pathogen
colonization, the development of enterocolitis was seen only when streptomycin
or vancomycin was used; no significant pathology was observed with the use of
metronidazole. Interestingly, metronidazole-treated and infected C57BL/6 mice
developed severe pathology. We hypothesized that the intestinal microbiota
confers resistance to infectious colitis without affecting the ability of
S. Typhimurium to colonize the intestine. Indeed, different
antibiotic treatments caused distinct shifts in the intestinal microbiota prior
to infection. Through fluorescence in situ hybridization,
terminal restriction fragment length polymorphism, and real-time PCR, we showed
that there is a strong correlation between the intestinal microbiota composition
before infection and susceptibility to Salmonella-induced
colitis. Members of the Bacteroidetes phylum were present at significantly
higher levels in mice resistant to colitis. Further analysis revealed that
Porphyromonadaceae levels were also increased in these mice. Conversely, there
was a positive correlation between the abundance of
Lactobacillus sp. and predisposition to colitis. Our data
suggests that different members of the microbiota might be associated with
S. Typhimurium colonization and colitis. Dissecting the
mechanisms involved in resistance to infection and inflammation will be critical
for the development of therapeutic and preventative measures against enteric
pathogens
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