To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Background: As with other specialties, Royal College of Physicians and Surgeons of Canada (RCPSC) trainees in Neurosurgery have anecdotally had challenges securing full-time employment. This study presents the employment status, research pursuits, and fellowship choices of neurosurgery trainees in Canadian programs. Methods: RCPSC neurosurgery trainees (n = 143) who began their residency training between 1998 and 2008 were included in this study. Associations between year of residency completion, research pursuits, and fellowship choice with career outcomes were determined by Fisher’s exact test (p < 0.05, statistical significance). Results: In 2015, 60% and 26% of neurosurgery trainees had permanent positions in Canada and the USA, respectively. Underemployment, defined as locum and clinical associate positions, pursuit of multiple unrelated fellowships, unemployment, and career change to non-surgical career, was 12% in 2015. The proportion of neurosurgery trainees who had been underemployed at some point within 5 years since residency completion was 20%. Pursuit of in-folded research (MSc, PhD, or non-degree research greater than 1 year) was significantly associated with obtaining full employment (94% vs. 73%, p = 0.011). However, fellowship training was not significantly associated with obtaining full employment (78% vs. 75%, p = 1.000). Conclusions: Underemployment in neurosurgery has become a significant issue in Canada for various reasons. Pursuit of in-folded research, but not fellowship training, was associated with obtaining full employment.
This study assessed bioavailability and utilisation of vitamin D3 in two feeding trials using young, growing Sprague–Dawley male rats. Trial one fed animals standard AIN-93G diet (casein protein) containing no vitamin D3 and goat or cow skimmed milk supplemented with vitamin D3. Trial two fed animals modified dairy-free AIN-93G diet (egg albumin) containing no vitamin D3 and goat or cow skimmed or full-fat milk supplemented with vitamin D3. Control groups received AIN-93G diets with or without vitamin D, and water. At 8 weeks of age, blood samples were collected for vitamin and mineral analysis, and femurs and spines were collected for assessment of bone mineralisation and strength. In both trials, analyses showed differences in bioavailability of vitamin D3, with ratios of serum 25-hydroxyvitamin D3 to vitamin D3 intake more than 2-fold higher in groups drinking supplemented milk compared with groups fed supplemented solid food. Bone mineralisation was higher in groups drinking supplemented milk compared with groups fed supplemented solid food, for both trials (P<0·05). There was no difference in the parameters tested between skimmed milk and full-fat milk or between cow milk and goat milk. Comparison of the two trials suggested that dietary protein source promoted bone mineralisation in a growing rat model: modified AIN-93G with egg albumin produced lower bone mineralisation compared with standard AIN-93G with casein. Overall, this study showed that effects of vitamin D3 deficiency in solid diets were reversed by offering milk supplemented with vitamin D3, and suggests that using milk as a vehicle to deliver vitamin D is advantageous.
The rise in the occurrence of obesity to epidemic proportions has made it a global concern. Great difficulty has been experienced in efforts to control this growing problem with lifestyle interventions. Thus, attention has been directed to understanding the events of one of the most critical periods of development, perinatal life. Early life adversity driven by maternal obesity has been associated with an increased risk of metabolic disease and obesity in the offspring later in life. Although a mechanistic link explaining the relationship between maternal and offspring obesity is still under investigation, the gut microbiota has come forth as a new factor that may play a role modulating metabolic function of both the mother and the offspring. Emerging evidence suggests that the gut microbiota plays a much larger role in mediating the risk of developing non-communicable disease, including obesity and metabolic dysfunction in adulthood. With the observation that the early life colonization of the neonatal and postnatal gut is mediated by the perinatal environment, the number of studies investigating early life gut microbial establishment continues to grow. This paper will review early life gut colonization in experimental animal models, concentrating on the role of the early life environment in offspring gut colonization and the ability of the gut microbiota to dictate risk of disease later in life.
Poly(3,4-ethylenedioxythiophene) (PEDOT) is an organic conducting polymer that has been the focus of significant research over the last decade, in both energy and biological applications. Most commonly, PEDOT is doped by the artificial polymer polystyrene sulfonate due to the excellent electrical characteristics yielded by this pairing. The biopolymer dextran sulphate (DS) has been recently reported as a promising alternative to PEDOT:PSS for biological application, having electrical properties rivaling PEDOT:PSS, complimented by the potential bioactivity of the polysaccharide. In this work we compared chemical and electrochemical polymerisations of PEDOT:DS in terms of their impact on the electrical, morphological and biological properties of the resultant PEDOT:DS films. Post-growth cyclic voltammograms and UV-Vis analyses revealed comparable redox behaviour and absorbance profiles for the two synthesis approaches. Despite good intrinsic conductivity of particles, the addition of chemically produced PEDOT:DS did not markedly enhance the bulk conductivity of aqueous solutions due to the lack of interconnectivity between adjacent PEDOT:DS particles at achievable concentrations. Scanning electron microscopy revealed significantly greater roughness in films cast from chemically produced PEDOT:DS compared to electropolymerised samples, attributable to the formation of solution phase nanoparticles prior to casting. In cell studies with the L929 cell line, electrochemical polymerisation of PEDOT:DS afforded better integrity of resultant films for surface seeding, whilst chemically polymerised PEDOT:DS appeared to localised at the proliferating cells, suggesting possible applications in drug delivery.
Poly(3,4-ethylenedioxythiophene) (PEDOT) was polymerized with the biological dopants dextran sulphate and chondroitin sulphate. Polymer physical and mechanical properties were investigated using quartz crystal microgravimetry with dissipation monitoring and atomic force microscopy, revealing polymer shear modulus and interfacial roughness to be significantly altered as a function of the dopant species. The adsorption of fibronectin, an important extracellular protein that is critical for a range of cellular functions and processes, was investigated using QCM-D, revealing protein adsorption to be increased on the DS doped PEDOT film relative to the CS doped film. PEDOT films have traditionally been doped with synthetic counterions such as polystyrene sulphonate (PSS), however the incorporation of biological molecules as the counterion, which has been shown to improve polymer biofunctionality, has received far less attention. In particular, there has been little detailed study on the impact of incorporating polyelectrolyte biomolecules into the PEDOT polymer matrix on fundamental polymer properties which are critical for biomedical applications. This investigation provides a detailed characterization of the interfacial and mechanical properties of biologically doped PEDOT films, as well as the efficacy of the composite films to bind and retain extracellular proteins of the type that are critical to the biocompatibility of the polymeric material.
Larger portion sizes (PS) may be inciting over-eating and contributing to obesity rates. Currently, there is a paucity of data on the effectiveness of serving size (SS) guidance. The aims of the present review are to evaluate SS guidance; the understanding, usability and acceptability of such guidance, its impact on consumers and potential barriers to its uptake. A sample of worldwide SS guidance schemes (n 87) were identified using targeted and untargeted searches, overall these were found to communicate various inconsistent and often conflicting messages about PS selection. The available data suggest that consumers have difficulty in understanding terms such as ‘portion size’ and ‘serving size’, as these tend to be used interchangeably. In addition, discrepancies between recommended SS and those present on food labels add to the confusion. Consumers generally understand and visualise SS best when expressed in terms of household measures rather than actual weights. Only a limited number of studies have examined the direct impact of SS guidance on consumer behaviour with equivocal results. Although consumers recognise that guidance on selecting SS would be helpful, they are often unwilling to act on such guidance. The challenge of achieving consumer adherence to SS guidance is formidable due to several barriers including chronic exposure to larger PS, distorted consumption norms and perceptions, the habit of ‘cleaning one's plate’ and language barriers for ethnic minorities. In conclusion, the impact of SS guidance on consumers merits further investigation to ensure that future guidance resonates with consumers by being more understandable, usable and acceptable.