Factors associated with a low prevalence of exclusive breastfeeding during hospital stay in urban and semi-rural areas of southern Vietnam

Background

There is a paucity of data regarding risk factors associated with suboptimal breastfeeding practices in urbanized areas of low-middle income countries (LMICs).

Methods

Through a large prospective birth cohort, which enrolled 6706 infants in Vietnam between 2009 and 2013, we investigated the practice of exclusive breastfeeding during hospital stay in urban and semi-rural populations and aimed to identify factors associated with suboptimal breastfeeding practices. Univariate and multivariable logistic regression were performed to determine factors associated with not exclusive breastfeeding during hospital stay.

Results

Of 6076 mothers, 33% (2187) breastfed their infant exclusively before hospital discharge; 9% (364/4248) in urban and 74% (1823/2458) in semi-rural areas. Exclusive breastfeeding up to 4 months was recorded in 15% (959/6210) of participants; this declined to <?1% (56/6093) at 6 months. Delivery by Caesarean section (Odds Ratio [OR] 0.07; 95% Confidence Interval [CI] 0.04, 0.11 and OR 0.05; 95% CI 0.03, 0.08) and neonatal complications (OR 0.2; 95% CI 0.07, 0.47 and OR 0.25; 95% CI 0.14, 0.46) were common and highly significant risk factors associated with a lack of exclusive breastfeeding during hospital stay in urban and semi-rural settings, respectively.

Conclusions

To our knowledge, this is the first large-scale investigation aimed at identifying factors associated with exclusive breastfeeding during hospital stay in Vietnam. Breastfeeding promotion strategies should prioritize common risk factors in hospital, such as Caesarean section and neonatal complications, and other location specific factors associated with socioeconomics.

     

Stable isotopes of Lithosiini and lichens in Hong Kong show the biodindicator potential of lichenivorous moths

Urban landscapes provide unique environments for a wide variety of plants and animals, but their suitability may be limited by anthropogenic impacts such as pollution. We examined the potential utility of lichen and lichen-feeding moths as biodindicators of air pollution in Hong Kong by comparing carbon (C) and nitrogen (N) stable isotope values in lichens, lichenivorous and non-lichenivorous moths (Lepidoptera: Erebidae) and a moth outgroup (Lepidoptera: Geometridae). Our results show that stable isotope values for C and N were similar for lichens and lichen feeding moths, while non-lichen feeding moths formed a distinct group. In addition, we found consistent δ¹³C and δ¹⁵N values across moth body parts, indicating that any portion of the specimen is suitable for isotopic fingerprinting. Our results highlight that lichen feeding moths may be useful for integrating signals of atmospheric nitrogen pollution and could therefore have utility in monitoring and quantifying air quality over time and space.     

Biofluid spectroscopic disease diagnostics: A review on the processes and spectral impact of drying

The complex patterns observed from evaporated liquid drops have been examined extensively over the last 20 years. Complete understanding of drop deposition is vital in many medical processes, and one which is essential to the translation of biofluid spectroscopic disease diagnostics. The promising use of spectroscopy in disease diagnosis has been hindered by the complicated patterns left by dried biological fluids which may inhibit the clinical translation of this technology. Coffee‐ring formation, cracking and gelation patterns have all been observed in biofluid drops, and with surface homogeneity being a key element to many spectroscopic techniques, experimental issues have been found to arise. A better understanding of the fundamental processes involved in a drying droplet could allow efficient progression in this research field, and ultimately benefit the population with the development of a reliable cancer diagnostic.      

Spruce-fir growth form changes in the forest-tundra ecotone of Rocky Mountain National Park, Colorado, USA

Tree regeneration has traditionally been used as a measure of the response of treeline to climate Changes in growth form of krummholz trees may also indicate whether treeline is responding to changes in climate The purpose of this study was to determine whether krummholz trees m the forest-tundra ecotone of Rocky Mountain National Park, Colorado have experienced significant vertical stem growth, in the absence of mortality, and if this growth occurred in response to recent changes in climate We sampled and dated Engelmann spruce and subalpine fir krummholz leaders stratified by height class at three sampling locations to determine the dates leaders initiated growth above mean snow depth At one sampling location, 215 additional leaders were sampled to construct an age structure of leader release dates Dates of leader release taken from the age structure were compared with seasonal temperatures, seasonal precipitation, winter snow depths, and annual runoff using t-tests Dates of leader release were also compared to proxy climate records for the southern Rocky Mountain region Based on historical photos as well as the data presented here, both spruce and fir krummholz trees experienced significant height growth as early as the 1850's and continued to grow vertically, at least through the 1970's This vertical stem growth occurred in the absence of significant mortality Running mean annual temperature and May snow depth are both positively associated with years of leader release, suggesting that a warmer, wetter climate, possibly following the end of the Little Ice Age ca 1850, may have induced these changes in the ecotone     

Conflict between antipredator and antiparasite behaviour in larval damselflies

 Larval damselflies resist infestation by parasitic larval mites by exhibiting behaviours such as grooming, crawling, swimming, and striking at host-seeking mites. Larval damselflies are known to increase time spent in these behaviours in the presence of mites but reduce time spent in these behaviours in the presence of fish predators. The presence of both fish and larval mites presents an obvious conflict: a larval damselfly may actively avoid parasitism by mites, thus increasing its risk of predation, or it may reduce its activity when fish are present, thus increasing its risk of parasitism. We analysed the behaviour of larval Ischnura verticalis in an experiment where we crossed presence and absence of fish with presence and absence of larval mites. Presence of mites induced a large increase in activity of larval I. verticalis but fish had no effect and there were no interpretable interactions between effects of mites and fish. Subsequent experiments indicated that larval I. verticalis in the presence of both mites and fish were more likely to be attacked and killed by fish than those exposed only to fish. The high activity level of I. verticalis larvae in the presence of both fish and mites may suggest that costs of parasitism are high, or that under field conditions it is rare for larvae to be in the immediate presence of both fish predators and potentially parasitic mites. Received: 28 March 1996 / Accepted: 6 September 1996     

Rapid assimilation of recently fixed N2 in root nodules of Myrica gale

In Myrica gale L. plants the assimilation of ammonia released by symbiotic Frankia was observed by ¹⁵N₂ labelling and subsequent analysis of the isotopic enrichment of nodule amino acids over time by single ion monitoring gas chromatography-mass spectrometry. In detached nodules of Myrica , glutamine was the first amino acid labelled at 30 s and subsequently the amino acids glutamate, aspartate, alanine and γ-amino butyric acid (GABA) became labelled. This pattern of labelling is consistent with the incorporation of ammonium via glutamine synthetase [GS; EC 6.3.1.2]. No evidence for the ammonium assimilation via glutamate dehydrogenase [GDH; EC 1.4.1.2] was observed as glutamate became labelled only after glutamine. Using attached nodules and pulse-chase labelling, we observed synthesis of glutamine, glutamate, aspartate, alanine, GABA and asparagine, and followed the transport of fixed nitrogen in the xylem largely as glutamine and asparagine. Estimation of the cost of nitrogen fixation and asparagine synthesis in Myrica nodules suggests a minimum of one sucrose required per asparagine produced. Rapid translocation of recently fixed nitrogen was observed in Myrica gale nodules as 80% of the nitrogen fixed during a 1-h period was translocated out of the nodules within 9 h. The large pool of asparagine that is present in nodules may buffer the transport of nitrogen and thus act to regulate nitrogen fixation via a feedback mechanism.     

Changes in gravity inhibit lymphocyte locomotion through type I collagen

Summary Immunity relies on the circulation of lymphocytes through many different tissues including blood vessels, lymphatic channels, and lymphoid organs. The ability of lymphocytes to traverse the interstitium in both nonlymphoid and lymphoid tissues can be determined in vitro by assaying their capacity to locomote through Type I collagen. In an attempt to characterize potential causes of microgravity-induced immunosuppression, we investigated the effects of simulated microgravity on human lymphocyte function in vitro using a specialized rotating-wall vessel culture system developed at the Johnson Space Center. This very low shear culture system randomizes gravitational vectors and provides an in vitro approximation of microgravity. In the randomized gravity of the rotating-wall vessel culture system, peripheral blood lymphocytes did not locomote through Type I collagen, whereas static cultures supported normal movement. Although cells remained viable during the entire culture period, peripheral blood lymphocytes transferred to unit gravity (static culture) after 6 h in the rotating-wall vessel culture system were slow to recover and locomote into collagen matrix. After 72 h in the rotating-wall vessel culture system and an additional 72 h in static culture, peripheral blood lymphocytes did not recover their ability to locomote. Loss of locomotory activity in rotating-wall vessel cultures appears to be related to changes in the activation state of the lymphocytes and the expression of adhesion molecules. Culture in the rotating-wall vessel system blunted the ability of peripheral blood lymphocytes to respond to polyclonal activation with phytohemagglutinin. Locomotory response remained intact when peripheral blood lymphocytes were activated by anti-CD3 antibody and interleukin-2 prior to introduction into the rotating-wall vessel culture system. Thus, in addition to the systemic stress factors that may affect immunity, isolated lymphocytes respond to gravitational changes by ceasing locomotion through model interstitium. These in vitro investigations suggest that microgravity induces non-stress-related changes in cell function that may be critical to immunity. Preliminary analysis of locomotion in true microgravity revealed a substantial inhibition of cellular movement in Type I collagen. Thus, the rotating-wall vessel culture system provides a model for analyzing the microgravity-induced inhibition of lymphocyte locomotion and the investigation of the mechanisms related to lymphocyte movement.     

ClpX-mediated remodeling of mu transpososomes: selective unfolding of subunits destabilizes the entire complex.

E. coli ClpX, a member of the Clp/Hsp100 family of ATPases, remodels multicomponent complexes and facilitates ATP-dependent degradation. Here, we analyze the mechanism by which ClpX destabilizes the exceedingly stable Mu transpososome, a natural substrate for remodeling rather than degradation. We find that ClpX has the capacity to globally unfold transposase monomers, the building blocks of the transpososome. A biochemical probe for protein unfolding reveals that ClpX also unfolds MuA subunits during remodeling reactions, but that not all subunits have their structure extensively modified. In fact, direct recognition and unfolding of a single transposase subunit are sufficient for ClpX to destabilize the entire transpososome. Thus, the ability of ClpX to unfold proteins is sufficient to explain its role in both complex destabilization and ATP-dependent proteolysis.     

STATUS, RELATIONSHIPS, AND DISTRIBUTION OF MESOPLODON BOWDOINI ANDREWS, 1908 (CETACEA: ZIPHIIDAE)

The specific status of Mesoplodon bowdoini Andrews is reviewed and new information on its morphology, reproduction, and distribution is presented. This species of beaked whale, known only from 35 specimens, has a southern, circumpolar distribution north of the Antarctic convergence, between 32° and 54°30'S. It shares with M. bahamondi Reyes, Van Waerebeek, Cárdenas and Yáñez from the south Pacific Ocean including New Zealand (this paper) and M. carlhubbsi Moore from the north Pacific, a number of morphological features such as prominential notches in the maxillary bones in the skull. It is less similar to M. stejnegeri True from the north Pacific and M. ginkgodens Nishiwaki and Kamiya from the tropical Indo-Pacific. Mesoplodon bowdoini can be distinguished from all other species of Mesoplodon by the shape of its teeth (male and female), and differences in the morphology of its skull, especially the proportions of the rostrum, separation of the nasals, the shape of the prominential notches, and the nature of the antorbital processes. The species' distinguishing external characteristics are: a robust body up to about 4.50 m long; a low melon and short, thick beak; an elevated jawline posteriorly; and a low, blunt-tipped, triangular dorsal fin. The occurrence of fetuses of M. bowdoini in May and September, and perinatal juveniles in May and June, indicates a summer-autumn breeding season in the New Zealand region; the length at birth is estimated at about 2.20 m.     

Epithelial cell distribution and abundance in rhesus monkey airways during postnatal lung growth and development.

Lung development is both a pre- and postnatal process. Although many lung diseases have their origins in early childhood, few quantitative data are available on the normal growth and differentiation of both the conducting airways and the airway epithelium during the postnatal period. We examined rhesus monkey lungs from five postnatal ages: 4-6 days and 1, 2, 3, and 6 mo. Airways increase significantly in both length and circumference as monkeys increase significantly in body weight from 5 days to 6 mo. In this study we asked: as basement membrane surface area increases, does the epithelial cell organization change? To answer this question, we quantified total epithelial cell mass using high-resolution light micrographs and morphometric techniques on sections from defined airway regions: trachea, proximal intrapulmonary bronchus (generations 1 or 2), and distal intrapulmonary bronchus (generations 6-8). Epithelial thickness decreased in the smaller, more distal, airways compared with trachea but did not change with age in the trachea and proximal bronchus. The volume fraction of all cell types measured did not change significantly. Ciliated cells in the distal bronchus and goblet cells in the trachea both decreased in abundance with increasing age. Overall, the epithelial cell populations changed little in terms of mass or relative abundance to each other during this period of active postnatal lung growth. Regarding the proximal conducting airway epithelium, we conclude that 1) the steady-state abundance is tightly regulated to keep the proportion of cell types constant, and 2) establishment of these cell types occurs before 4-6 days postnatal age. We conclude that growth of the proximal airways occurs primarily in length and lags behind that of the lung parenchyma.