Developmental Changes in GABAergic Mechanisms in Human Visual Cortex Across the Lifespan

Functional maturation of visual cortex is linked with dynamic changes in synaptic expression of GABAergic mechanisms. These include setting the excitation–inhibition balance required for experience-dependent plasticity, as well as, intracortical inhibition underlying development and aging of receptive field properties. Animal studies have shown that there is developmental regulation of GABAergic mechanisms in visual cortex. In this study, we show for the first time how these mechanisms develop in the human visual cortex across the lifespan. We used Western blot analysis of postmortem tissue from human primary visual cortex (n = 30, range: 20 days to 80 years) to quantify expression of eight pre- and post-synaptic GABAergic markers. We quantified the inhibitory modulating cannabinoid receptor (CB1), GABA vesicular transporter (VGAT), GABA synthesizing enzymes (GAD65/GAD67), GABAA receptor anchoring protein (Gephyrin), and GABAA receptor subunits (GABAAα1, GABAAα2, GABAAα3). We found a complex pattern of different developmental trajectories, many of which were prolonged and continued well into the teen, young adult, and even older adult years. These included a monotonic increase or decrease (GABAAα1, GABAAα2), a biphasic increase then decrease (GAD65, Gephyrin), or multiple increases and decreases (VGAT, CB1) across the lifespan. Comparing the balances between the pre- and post-synaptic markers we found three main transition stages (early childhood, early teen years, aging) when there were rapid switches in the composition of the GABAergic signaling system, indicating that functioning of the GABAergic system must change as the visual cortex develops and ages. Furthermore, these results provide key information for translating therapies developed in animal models into effective treatments for amblyopia in humans

Heterogeneous ketonic decarboxylation of dodecanoic acid: studying reaction parameters

Ketonic decarboxylation has gained significant attention in recent years as a pathway to reduce the oxygen content within biomass-derived oils, and to produce sustainable ketones. The reaction is base catalysed, with MgO an economic, accessible and highly basic heterogeneous catalyst. Here we use MgO to catalyse the ketonic decarboxylation of dodecanoic acid to form 12-tricosanone at moderate temperatures (250 °C, 280 °C and 300 °C) with low catalyst loads of 1% (w/w), 3% (w/w) and 5% (w/w) with respect to the dodecanoic acid, with a reaction time of 1 hour under batch conditions. Three different particle sizes for the MgO were tested (50 nm, 100 nm and 44 μm). Ketone yield was found to increase with increasing reaction temperature, reaching approximately 75% yield for all the samples tested. Temperature was found to be the main control on reaction yield, rather than surface area or particle size

Finding sexual partners online: prevalence and associations with sexual behaviour, STI diagnoses and other sexual health outcomes in the British population.

OBJECTIVES: Online venues might facilitate sexual encounters, but the extent to which finding partners online is associated with sexual risk behaviour and sexual health outcomes is unclear. We describe use of the internet to find sexual partners in a representative sample in Britain. METHODS: The third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) was a cross-sectional probability survey of 15 162 adults (aged 16-74 years) undertaken 2010-2012. We estimated prevalence of, and identified factors associated with, finding sexual partners online among those reporting ≥1 new sexual partners in the past year. RESULTS: Finding sexual partners online in the past year was reported by 17.6% (95% CI 15.6 to 19.9) of men and 10.1% (8.5-11.9) of women, and most common among those aged 35-44 years. After age-adjustment, those reporting a non-heterosexual identity were more likely to report this. Finding partners online was also associated with reporting sexual risk behaviours: condomless sex with ≥2 partners (adjusted OR (aOR) men: 1.52 (1.03 to 2.23); women: 1.62 (1.06 to 2.49)), concurrent partnerships (aOR men: 2.33 (1.62 to 3.35); women: 2.41 (1.49 to 3.87)) and higher partner numbers (reporting ≥5 partners aOR men: 5.95 (3.78 to 9.36); women: 7.00 (3.77 to 13.00)) (all past year). STI diagnoses and HIV testing were more common among men reporting finding partners online (adjusted for age, partner numbers, same-sex partnerships), but not women. CONCLUSIONS: Finding partners online was associated with markers of sexual risk, which might be important for clinical risk assessment, but this was not matched by uptake of sexual health services. Online opportunities to find partners have increased, so these data might underestimate the importance of this social phenomenon for public health and STI control

Study protocol for a randomised controlled trial of invasive versus conservative management of primary spontaneous pneumothorax

INTRODUCTION: Current management of primary spontaneous pneumothorax (PSP) is variable, with little evidence from randomised controlled trials to guide treatment. Guidelines emphasise intervention in many patients, which involves chest drain insertion, hospital admission and occasionally surgery. However, there is evidence that conservative management may be effective and safe, and it may also reduce the risk of recurrence. Significant questions remain regarding the optimal initial approach to the management of PSP

Local structure change evidenced by temperature-dependent elastic measurements: Case study on Bi1/2Na1/2TiO3-based lead-free relaxor piezoceramics

The temperature-dependent Young's modulus Y(T) of the lead-free piezoceramics of 0.8Bi(1/2)Na(1/2)TiO(3)-0.2Bi(1/2)K(1/2)TiO(3) (20BKT) and 0.96(0.8Bi(1/2)Na(1/2)TiO(3)-0.2Bi(1/2)K(1/2)TiO(3))-0.04 BiZn1/2Ti1/2O3 (4BZT) is measured with the impulse excitation technique and contrasted with corresponding dielectric and structural data. While the dielectric properties suggest a phase transition, the high resolution XRD patterns remain virtually unchanged from room temperature up to high temperatures, confirming no change in their long-range order. In contrast, the elastic properties indicate a broad and diffuse ferroelastic transition denoted by a minimum in Y(T). By analogy to the elastic and dielectric data of PbZrxTi1-xO3 and PLZT, it is concluded that 20BKT and 4BZT are relaxors with polar nanoregions embedded in a metrically cubic matrix. Interestingly, no indication for the freezing temperature was reflected in any of the employed measurement techniques. From the saturation of Y(T), it is suggested that the Burns temperature may be approximated as 700 degrees C. Moreover, it is found that the modification with the ternary end-member BiZn1/2Ti1/2O3 results in an increase in Young's modulus. A comparison with the Bi1/2Na1/2TiO3-BaTiO3-K0.5Na0.5NbO3 yields the same results.open0

Electrical Control of Second-Harmonic Generation in a WSe2 Monolayer Transistor

Nonlinear optical frequency conversion, in which optical fields interact with a nonlinear medium to produce new field frequencies, is ubiquitous in modern photonic systems. However, the nonlinear electric susceptibilities that give rise to such phenomena are often challenging to tune in a given material, and so far, dynamical control of optical nonlinearities remains confined to research labs as a spectroscopic tool. Here, we report a mechanism to electrically control second-order optical nonlinearities in monolayer WSe2, an atomically thin semiconductor. We show that the intensity of second-harmonic generation at the A-exciton resonance is tunable by over an order of magnitude at low temperature and nearly a factor of 4 at room temperature through electrostatic doping in a field-effect transistor. Such tunability arises from the strong exciton charging effects in monolayer semiconductors, which allow for exceptional control over the oscillator strengths at the exciton and trion resonances. The exciton-enhanced second-harmonic generation is counter-circularly polarized to the excitation laser, arising from the combination of the two-photon and one-photon valley selection rules that have opposite helicity in the monolayer. Our study paves the way towards a new platform for chip-scale, electrically tunable nonlinear optical devices based on two-dimensional semiconductors.Comment: Published in Nature Nanotechnolog

The prevalence of, and factors associated with, paying for sex among men resident in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

OBJECTIVES: Men who pay for sex (MPS) are considered a bridging population for sexually transmitted infections (STI). However, the extent, characteristics and role of MPS in transmission is poorly understood. We investigate these questions using data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3). METHODS: We performed complex survey analyses of data from 6293 men aged 16-74 years resident in Britain who completed Natsal-3, a probability sample survey undertaken during 2010-2012, using computer-assisted personal interviewing and computer-assisted self-interview. RESULTS: 11.0% (95% CI10.1% to 11.9%) of all men reported ever paying for sex. Among MPS, 18.4% (95% CI 18.2% to 18.7%) of their lifetime sexual partners were paid. 3.6% (95% CI 3.1% to 4.2%) of men had paid for sex in the past 5 years. Partners of MPS constitute 14.7% of all reported partners and MPS report 15.6% of all reported STI diagnoses in the past 5 years. Paying for sex in the past 5 years was strongly associated with reporting larger numbers of sexual partners (adjusted OR, AOR for 5+ partners, past 5 years, 31.50, 95% CI 18.69 to 53.09). After adjusting for partner numbers, paying for sex remained strongly associated with reporting new foreign partners outside the UK (AOR 7.96; 95% CI 4.97 to 12.73) and STI diagnosis/es (AOR 2.34; 95% CI 1.44 to 3.81), all in the past 5 years. Among men ever paying for sex, 62.6% (95% CI 58.3% to 66.8%) reported paying for sex outside the UK, most often in Europe and Asia. CONCLUSIONS: MPS in Britain remain at greater risk of STI acquisition and onward transmission than men who do not. They report high numbers of partners, but the minority are paid partners. They are an important core group in STI transmission

Actual and preferred contraceptive sources among young people: findings from the British National Survey of Sexual Attitudes and Lifestyles

OBJECTIVE: To describe actual and preferred contraceptive sources among young people in Britain and whether discordance between these is associated with markers of sexual risk behaviour or poor sexual health. DESIGN: Cross-sectional probability sample survey. SETTING: British general population. PARTICIPANTS: 3869 men and women aged 16-24 years interviewed for the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) between 2010 and 2012. MAIN OUTCOME MEASURES: Reported source of contraceptive method(s) and preferred source if all were available and easily accessible. RESULTS: Of the 75% of young people (aged 16-24) who were heterosexually active (1619 women, 1233 men), >86% reported obtaining contraceptives in the past year. Most common sources were general practice (women, 63%) and retail (men, 60%): using multiple sources was common (women 40%, men 45%). Healthcare sources were preferred by 81% of women and 57% of men. Overall, 32% of women and 39% of men had not used their preferred source. This discordance was most common among men who preferred general practice (69%) and women who preferred retail (52%). Likelihood of discordance was higher among women who usually used a less effective contraceptive method or had an abortion. It was less likely among men who usually used a less effective method of contraception and men who were not in a steady relationship. CONCLUSIONS: Most young people in Britain obtained contraception in the past year but one-third had not used their preferred source. Healthcare sources were preferred. Discordance was associated with using less effective contraception and abortion among young women. Meeting young people's preference for obtaining contraception from healthcare sources could improve uptake of effective contraception to reduce unwanted pregnancies