Prenatal anxiety, breastfeeding and child growth and puberty:linking evolutionary models with human cohort studies

Background: Stress experienced by mothers during pregnancy can have both immediate and long-term effects on child development, potentially mediated by breastfeeding. Aim: Using a UK birth cohort study, we asked how maternal stress relates to breastfeeding and consequences for growth and puberty onset. Subjects and methods: We analysed data from the Avon Longitudinal Study of Parents and Children, collected via questionnaires and clinic visits (N: 698–8,506). We used reports of prenatal anxiety, breastfeeding, early growth and age at menarche or first voice change. Confounding by maternal age, parity, smoking, education and body mass index (BMI) was considered. Results: Mothers with higher levels of reported anxiety were less likely to breastfeed (Odds ratio (OR): 0.83, 95% confidence interval (CI): 0.71, 0.97). Breastfed infants had slower growth before weaning, although growth differences were unclear thereafter. Being breastfed for more than six months was associated with later puberty onset in females (2.76 months later than non-breastfed; CI: 0.9, 4.63), although the association was attenuated by confounders and BMI (1.51 months, CI: −0.38, 3.40). No association between breastfeeding and puberty onset in males was found. Conclusion: Our studies fit results shown previously, and we consider these in light of evolutionary life history theory while discussing key challenges in such an approach

Pathways of shelf water export from the Hatteras shelf and slope

Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): C08023, doi:10.1029/2012JC007995.It has long been recognized that a massive flow of Middle Atlantic Bight (MAB) shelf water is exported to the deep ocean in the region near Cape Hatteras, North Carolina. We examine the details of this export using data from an extensive array of 26 moorings, deployed over the shelf and slope between Cape Hatteras and the Chesapeake Bay mouth (from 35° 27′ to 36° 40′ N) as part of the U.S. Department of Energy's Ocean Margins Program. Our analysis indicates that the flow of the MAB shelf-edge frontal jet, which typically extends over the MAB slope, falls victim to export over the length of the mooring array, essentially vanishing by the southern extreme of the array. By contrast, the flow of MAB shelf water entering the study region over the inner and middle shelf (to roughly the 40-m isobath) tends to experience very little loss over the extent of the OMP array. Based on our findings and those of previous studies, we hypothesize that this inner and middle shelf flow is diverted seaward upon encountering the Hatteras Front, which separates MAB and South Atlantic Bight shelf waters. Some fraction of this flow appears to return to the OMP array, moving northeastward over the upper slope en route to the deep ocean. Our analysis also suggests that the export of MAB shelf water is enhanced as the Gulf Stream approaches the shelf-edge near Diamond Shoals, a process we deem to be a high priority for future study.The Ocean Margins Program was funded by the U.S. Department of Energy through various grants. Our analysis was supported by a grant (OCE-0926999) from the National Science Foundation.2013-02-2

Dissolved organic carbon fluxes in the Middle Atlantic Bight: An integrated approach based on satellite data and ocean model products

Continental margins play an important role in global carbon cycle, accounting for 15-21% of the global marine primary production. Since carbon fluxes across continental margins from land to the open ocean are not well constrained, we undertook a study to develop satellite algorithms to retrieve dissolved organic carbon (DOC) and combined these satellite data with physical circulation model products to quantify the shelf boundary fluxes of DOC for the U.S. Middle Atlantic Bight (MAB). Satellite DOC was computed through seasonal relationships of DOC with colored dissolved organic matter absorption coefficients, which were derived from an extensive set of in situ measurements. The multiyear time series of satellite-derived DOC stocks (4.9TeragramsC; Tg) shows that freshwater discharge influences the magnitude and seasonal variability of DOC on the continental shelf. For the 2010-2012 period studied, the average total estuarine export of DOC into the MAB shelf is 0.77TgCyr(-1) (year). The integrated DOC tracer fluxes across the shelf boundaries are 12.1TgCyr(-1) entering the MAB from the southwest alongshore boundary, 18.5TgCyr(-1) entering the MAB from the northeast alongshore boundary, and 29.0TgCyr(-1) flowing out of the MAB across the entire length of the 100m isobath. The magnitude of the cross-shelf DOC flux is quite variable in time (monthly) and space (north to south). The highly dynamic exchange of water along the shelf boundaries regulates the DOC budget of the MAB at subseasonal time scales

Population Maintenance of the Scyphozoan Cyanea sp. Settled Planulae and the Distribution of Medusae in the Niantic River, Connecticut, USA

Scyphozoan jellyfish are seasonally conspicuous in coastal waters, but relatively little is known about the factors that control their distribution and population dynamics.Cyanea sp is a seasonally abundant medusa in the Niantic River, Connecticut, U.S. and appears to maintain a population entirely within the estuary. To better understand the factors controlling their occurrence, we examined the temporal and spatial distribution of settled scyphistomae in relation to that of the medusae. Planula settlement patterns mirrored the presence of mature female medusae. The planulae settled primarily near the bottom. After settlement, planulacysts and polyps on the settlement plates were out competed by large barnacle and ascidian larvae, resulting in a sharp decline in cyst and polyp abundance. This stage-specific mortality may represent a population bottleneck in the life cycle of scyphozoans

Regulation of vascular tone, molecular mechanisms

The goal of this survey was to review briefly the molecular mechanisms that regulate vascular smooth muscle function. Components of the machinery involved in the contraction and relaxation of vascular smooth muscle include the following.Contractile proteins. The force generated by vascular smooth muscle is the result of thin (actin) and thick (myosin) filaments being pulled by one another so that the cell tends to shorten. The processes by which this intereaction is regulated are a matter of some debate. However, most observations indicate that the process that initiates contraction is a calcium-dependent phosphorylation of the myosin light chain.Cellular sites for the regulation of myoplasmic calcium concentration. The final event that initiates the contractile process is an increase in the intracellular concentration of ionized calcium. Cellular sites that may contribute to the raising and lowering of ionized calcium include the following: (A) cell membrane, (B) sarcoplasmic reticulum, and (C) mitochondria.Membrane electrical events. The electrical state of the cell membrane influences contractile responses of vascular smooth muscle. Over the physiologic range, an elevation in the membrane potential has a reciprocal influence on muscle excitability. The membrane potential is the sum of the diffusion potentials and the electrogenic pump.Excitation-contraction coupling. The excitatory events of the cell membrane (changes in membrane potential and the generation of action potentials) are coupled to the interaction of the contractile proteins by an increase in myoplasmic ionized calcium.Cyclic nucleotides and calcium. Cyclic AMP and cyclic GMP may link contraction and relaxation to the release and uptake of activator calcium by subcellular organelles. These nucleotides also influence the level of phosphorylation of the myosin light chain.Energy metabolism and hypoxia. The chemical energy source for cellular processes in vascular smooth muscle is ATP. Vascular tone, or maintenance of a contractile force, in this muscle is a relatively efficient process that may reflect a special noncycling link between myosin and actin. Current evidence suggests that hypoxic conditions influence vascular tone by altering the activity of the electrogenic sodium pump.This listing of statements is by no means the final word in molecular mechanisms that govern vascular tone. Indeed, vascular smooth muscle remains to be a constant source of surprises for the interested investigator.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24206/1/0000465.pd

Exploring UK medical school differences: the MedDifs study of selection, teaching, student and F1 perceptions, postgraduate outcomes and fitness to practise.

BACKGROUND: Medical schools differ, particularly in their teaching, but it is unclear whether such differences matter, although influential claims are often made. The Medical School Differences (MedDifs) study brings together a wide range of measures of UK medical schools, including postgraduate performance, fitness to practise issues, specialty choice, preparedness, satisfaction, teaching styles, entry criteria and institutional factors. METHOD: Aggregated data were collected for 50 measures across 29 UK medical schools. Data include institutional history (e.g. rate of production of hospital and GP specialists in the past), curricular influences (e.g. PBL schools, spend per student, staff-student ratio), selection measures (e.g. entry grades), teaching and assessment (e.g. traditional vs PBL, specialty teaching, self-regulated learning), student satisfaction, Foundation selection scores, Foundation satisfaction, postgraduate examination performance and fitness to practise (postgraduate progression, GMC sanctions). Six specialties (General Practice, Psychiatry, Anaesthetics, Obstetrics and Gynaecology, Internal Medicine, Surgery) were examined in more detail. RESULTS: Medical school differences are stable across time (median alpha = 0.835). The 50 measures were highly correlated, 395 (32.2%) of 1225 correlations being significant with p < 0.05, and 201 (16.4%) reached a Tukey-adjusted criterion of p < 0.0025. Problem-based learning (PBL) schools differ on many measures, including lower performance on postgraduate assessments. While these are in part explained by lower entry grades, a surprising finding is that schools such as PBL schools which reported greater student satisfaction with feedback also showed lower performance at postgraduate examinations. More medical school teaching of psychiatry, surgery and anaesthetics did not result in more specialist trainees. Schools that taught more general practice did have more graduates entering GP training, but those graduates performed less well in MRCGP examinations, the negative correlation resulting from numbers of GP trainees and exam outcomes being affected both by non-traditional teaching and by greater historical production of GPs. Postgraduate exam outcomes were also higher in schools with more self-regulated learning, but lower in larger medical schools. A path model for 29 measures found a complex causal nexus, most measures causing or being caused by other measures. Postgraduate exam performance was influenced by earlier attainment, at entry to Foundation and entry to medical school (the so-called academic backbone), and by self-regulated learning. Foundation measures of satisfaction, including preparedness, had no subsequent influence on outcomes. Fitness to practise issues were more frequent in schools producing more male graduates and more GPs. CONCLUSIONS: Medical schools differ in large numbers of ways that are causally interconnected. Differences between schools in postgraduate examination performance, training problems and GMC sanctions have important implications for the quality of patient care and patient safety

The Analysis of Teaching of Medical Schools (AToMS) survey: an analysis of 47,258 timetabled teaching events in 25 UK medical schools relating to timing, duration, teaching formats, teaching content, and problem-based learning.

BACKGROUND: What subjects UK medical schools teach, what ways they teach subjects, and how much they teach those subjects is unclear. Whether teaching differences matter is a separate, important question. This study provides a detailed picture of timetabled undergraduate teaching activity at 25 UK medical schools, particularly in relation to problem-based learning (PBL). METHOD: The Analysis of Teaching of Medical Schools (AToMS) survey used detailed timetables provided by 25 schools with standard 5-year courses. Timetabled teaching events were coded in terms of course year, duration, teaching format, and teaching content. Ten schools used PBL. Teaching times from timetables were validated against two other studies that had assessed GP teaching and lecture, seminar, and tutorial times. RESULTS: A total of 47,258 timetabled teaching events in the academic year 2014/2015 were analysed, including SSCs (student-selected components) and elective studies. A typical UK medical student receives 3960 timetabled hours of teaching during their 5-year course. There was a clear difference between the initial 2 years which mostly contained basic medical science content and the later 3 years which mostly consisted of clinical teaching, although some clinical teaching occurs in the first 2 years. Medical schools differed in duration, format, and content of teaching. Two main factors underlay most of the variation between schools, Traditional vs PBL teaching and Structured vs Unstructured teaching. A curriculum map comparing medical schools was constructed using those factors. PBL schools differed on a number of measures, having more PBL teaching time, fewer lectures, more GP teaching, less surgery, less formal teaching of basic science, and more sessions with unspecified content. DISCUSSION: UK medical schools differ in both format and content of teaching. PBL and non-PBL schools clearly differ, albeit with substantial variation within groups, and overlap in the middle. The important question of whether differences in teaching matter in terms of outcomes is analysed in a companion study (MedDifs) which examines how teaching differences relate to university infrastructure, entry requirements, student perceptions, and outcomes in Foundation Programme and postgraduate training

FCM_PASS software aids extracellular vesicle light scatter standardization’

The study of extracellular vesicles (EVs) is a rapidly growing field due to their great potential in many areas of clinical medicine including diagnostics, prognostics, theranostics, and therapeutics. Flow cytometry is currently one of the most popular methods of analysing EVs due to it being a high-throughput, multi-parametric technique, that is readily available in the majority of research labs. Despite its wide use, few commercial flow cytometers are designed specifically for the detection of EVs. Many flow cytometers used for EV analysis are working at their detection limits and are unable to detect the majority of EVs. Currently, very little standardisation exists for EV flow cytometry which is an issue because flow cytometers vary considerably in the way they collect scattered or fluorescent light from particles being interrogated. This makes published research hard-to-interpret, compare,and in some cases, impossible to reproduce. Here we demonstrate a method of flow cytometer light scatter standardisation, utilising flow cytometer post-acquisition analysis software (FCMPASS). FCMPASS is built upon Mie theory and enables the approximation of flow cytometer geometric parameters either by analyzing beads of known diameter and refractive index or by inputting the collection angle if known. The software is then able to create a scatter-diameter curve and scatter-refractive index curve that enables researchers to convert scattering data and instrument sensitivity into standardised units. Furthermore, with the correct controls, light scatter data can be converted to diameter distributions or refractive index distributions. FCMPASS therefore offers a freely available and ergonomic method of standardizing and further extending EV characterization using flow cytometry