5,341 research outputs found
Breastfeeding after Gestational Diabetes: Does Perceived Benefits Mediate the Relationship?
Introduction. Breastfeeding is recognized as one of the best ways to decrease infant mortality and morbidity. However, women with gestational diabetes mellitus (GDM) may have breastfeeding barriers due to the increased risk of neonatal and pregnancy complications. While the prevalence of GDM is increasing worldwide, it is important to understand the full implications of GDM on breastfeeding outcomes.The current study aims to investigate the (1) direct effect of GDM on breastfeeding duration and (2) indirect effect of GDM on breastfeeding duration through perceived benefits of breastfeeding. Methods. Prospective cohort data from the Infant Feeding and Practices Study II was analyzed (=4,902). Structural equation modeling estimated direct and indirect effects. Results. Perceived benefits of breastfeeding directly influenced breastfeeding duration ( = 0.392, ≤ 0.001). GDM was not directly associated with breastfeeding duration or perceived benefits of breastfeeding. Similarly, GDM did not have an indirect effect on breastfeeding duration through perceived benefits of breastfeeding. Conclusions. Perceived benefits of breastfeeding are an important factor associated with breastfeeding duration. Maternal and child health care professionals should enhance breastfeeding education efforts
The uptake and incorporation of exogenous fatty acids confer phenotypic advantages to acinetobacter baumannii
AIM: Acinetobacter baumannii is a ubiquitous gram-negative bacterium found on a variety of surfaces that include skin, hair, and soil. Some gram-negative bacteria like A. baumannii have the ability to acquire and incorporate fatty acids into their phospholipid membranes. Known as ‘Iraqibacter,’ A. baumannii has emerged as a significant cause of nosocomial infections in the United States and abroad. This study was designed to determine whether structural alterations occur in A. baumannii upon exposure to a wide range of polyunsaturated fatty acids (PUFAs) as well as the significance of this phenomenon in terms of survival and resistance to stress. Thin layer chromatography of isolated phospholipids indicated phospholipid profile variation depending on the exogenous PUFA supplied. To assess the incorporation of exogenous fatty acids with A. baumannii phospholipids, isolated lipids were analyzed by ultra-performance liquid chromatography/mass spectrometry (UPLC/MS). Membrane permeability was assessed with a crystal violet hydrophobic compound uptake assay. An assay for biofilm formation was performed to indicate the production of biofilms among bacterial growth in the presence of each fatty acid. To observe additional phenotypic responses, environmental stresses such as hydrogen peroxide, antimicrobial peptide, and antibiotic pressures were assayed. The fatty acids affected membrane permeability, as determined by a hydrophobic compound uptake test. At least a 20% range of uptake was observed between the PUFAs examined. Bacterial growth in the presence of each PUFA caused an increase in biofilm production. As expected, numerous unique phospholipid species were identified and were bioinformatically predicted to contain the exogenously supplied PUFA as one of their acyl chains. While no differences in minimum inhibitory concentrations were observed with peroxide and beta-lactam antibiotic stresses, sensitivity of A. baumannii to two different antimicrobial peptides, colistin and polymyxin B, increased following growth in several of the PUFAs, with arachidonic acid displaying the highest inhibition. Since cationic antimicrobial peptides are believed to interact with bacterial lipid membranes for eventual pore formation, these results implicate exogenous fatty acids as modification moieties that may impact resistance to environmental stresses
Pleasure, Politics, and Patriarchy: Women’s Intimacy in an Authoritarian Egypt
This research project explores the question: To what extent is Egypt’s patriarchal household structure, especially in regards to its treatment of female sexual autonomy, a pillar of authoritarianism and therefore an obstacle to democracy? This paper takes a deep look into the intimate sexual lives of Egyptians and explores its implications for regime type in the country. Widespread practices such as virginity testing, hymen reconstruction, female genital mutilation, etc. along with phenomena such as sexual dysfunctions, community morality policing and other normalized behaviors demonstrate the different ways in which women’s sexual autonomies are widely hindered. This is the result of historical and political conditions that stressed the maternal role of women in society, which underscored ties between virginity, moral family values, and national identity. The aim of this research is to use a combination of interviews, historical background, and socio-political analysis to identify the relationship between the personal and political when it comes to intimacy and democratization. Through theoretical frameworks and studies of practices in Egypt, we can see how authoritarian regimes use sex as a tool to maintain power and sustain systems of subjugation throughout the cornerstone of society- the household
Distillation of Bose-Einstein condensates in a double-well potential
Bose-Einstein condensates of sodium atoms, prepared in an optical dipole
trap, were distilled into a second empty dipole trap adjacent to the first one.
The distillation was driven by thermal atoms spilling over the potential
barrier separating the two wells and then forming a new condensate. This
process serves as a model system for metastability in condensates, provides a
test for quantum kinetic theories of condensate formation, and also represents
a novel technique for creating or replenishing condensates in new locations
Atom interferometry with Bose-Einstein condensates in a double-well potential
A trapped-atom interferometer was demonstrated using gaseous Bose-Einstein
condensates coherently split by deforming an optical single-well potential into
a double-well potential. The relative phase between the two condensates was
determined from the spatial phase of the matter wave interference pattern
formed upon releasing the condensates from the separated potential wells.
Coherent phase evolution was observed for condensates held separated by 13
m for up to 5 ms and was controlled by applying ac Stark shift potentials
to either of the two separated condensates.Comment: 4 pages, 4 figure
Genetic characterization of clinical and environmental Vibrio parahaemolyticus from the Northeast USA reveals emerging resident and non-indigenous pathogen lineages
Gastric infections caused by the environmentally transmitted pathogen, Vibrio parahaemolyticus, have increased over the last two decades, including in many parts of the United States (US). However, until recently, infections linked to shellfish from the cool northeastern US waters were rare. Cases have risen in the Northeast, consistent with changes in local V. parahaemolyticus populations toward greater abundance or a shift in constituent pathogens. We examined 94 clinical isolates from a period of increasing disease in the region and compared them to 200 environmental counterparts to identify resident and non-indigenous lineages and to gain insight into the emergence of pathogenic types. Genotyping and multi-locus sequence analysis (MLSA) of clinical isolates collected from 2010 to 2013 in Massachusetts, New Hampshire, and Maine revealed their polyphyletic nature. Although 80% of the clinical isolates harbored the trh hemolysin either alone or with tdh, and were urease positive, 14% harbored neither hemolysin exposing a limitation for these traits in pathogen detection. Resident sequence type (ST) 631 strains caused seven infections, and show a relatively recent history of recombination with other clinical and environmental lineages present in the region. ST34 and ST674 strains were each linked to a single infection and these strain types were also identified from the environment as isolates harboring hemolysin genes. Forty-two ST36 isolates were identified from the clinical collection, consistent with reports that this strain type caused a rise in regional infections starting in 2012. Whole-genome phylogenies that included three ST36 outbreak isolates traced to at least two local sources demonstrated that the US Atlantic coastal population of this strain type was indeed derived from the Pacific population. This study lays the foundation for understanding dynamics within natural populations associated with emergence and invasion of pathogenic strain types in the region
Target labelling for the detection and profiling of microRNAs expressed in CNS tissue using microarrays
BACKGROUND: MicroRNAs (miRNA) are a novel class of small, non-coding, gene regulatory RNA molecules that have diverse roles in a variety of eukaryotic biological processes. High-throughput detection and differential expression analysis of these molecules, by microarray technology, may contribute to a greater understanding of the many biological events regulated by these molecules. In this investigation we compared two different methodologies for the preparation of labelled miRNAs from mouse CNS tissue for microarray analysis. Labelled miRNAs were prepared either by a procedure involving linear amplification of miRNAs (labelled-aRNA) or using a direct labelling strategy (labelled-cDNA) and analysed using a custom miRNA microarray platform. Our aim was to develop a rapid, sensitive methodology to profile miRNAs that could be adapted for use on limited amounts of tissue. RESULTS: We demonstrate the detection of an equivalent set of miRNAs from mouse CNS tissues using both amplified and non-amplified labelled miRNAs. Validation of the expression of these miRNAs in the CNS by multiplex real-time PCR confirmed the reliability of our microarray platform. We found that although the amplification step increased the sensitivity of detection of miRNAs, we observed a concomitant decrease in specificity for closely related probes, as well as increased variation introduced by dye bias. CONCLUSION: The data presented in this investigation identifies several important sources of systematic bias that must be considered upon linear amplification of miRNA for microarray analysis in comparison to directly labelled miRNA
Use of Whole Genome Phylogeny and Comparisons in the Development of a Multiplex-PCR Assay to Identify Sequence Type 36 Vibrio parahaemolyticus
Vibrio parahaemolyticus sequence type (ST) 36 strains that are native to the Pacific Ocean have recently caused multi-state outbreaks of gastroenteritis linked to shellfish harvested from the Atlantic Ocean. Whole genome comparisons of 295 genomes of V. parahaemolyticus, including several traced to northeastern US sources, were used to identify diagnostic loci: one putatively encoding an endonuclease (prp), and two others potentially conferring O-antigenic properties (cps and flp). The combination of all three loci was present only in one clade of closely-related strains, of ST36, ST59 and one additional unknown sequence type. However, each locus was also identified outside this clade, with prp and flp occurring in only two non-clade isolates, and cps in four. Based on the distribution of these loci in sequenced genomes, prp could identify clade strains with \u3e99% accuracy, but the addition of one more locus would increase accuracy to 100%. Oligonucleotide primers targeting prp and cps were combined in a multiplex PCR method that defines species using the tlh locus, and determines presence of both the tdh and trh hemolysin-encoding genes which are also present in ST36. Application of the method in vitro to a collection of 94 clinical isolates collected over a four year period in three Northeastern US, and 87 environmental isolates, revealed the prp and cps amplicons were only detected in clinical isolates identified as belonging to the ST36-clade, and in no environmental isolates from the region. The assay should improve detection and surveillance, thereby reducing infections
Quantum reflection of atoms from a solid surface at normal incidence
We observed quantum reflection of ultracold atoms from the attractive
potential of a solid surface. Extremely dilute Bose-Einstein condensates of
^{23}Na, with peak density 10^{11}-10^{12}atoms/cm^3, confined in a weak
gravito-magnetic trap were normally incident on a silicon surface. Reflection
probabilities of up to 20 % were observed for incident velocities of 1-8 mm/s.
The velocity dependence agrees qualitatively with the prediction for quantum
reflection from the attractive Casimir-Polder potential. Atoms confined in a
harmonic trap divided in half by a solid surface exhibited extended lifetime
due to quantum reflection from the surface, implying a reflection probability
above 50 %.Comment: To appear in Phys. Rev. Lett. (December 2004)5 pages, 4 figure
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