Investigating the utility of combining Phi 29 whole genome amplification and highly multiplexed single nucleotide polymorphism BeadArray (TM) genotyping

Background: Sustainable DNA resources and reliable high-throughput genotyping methods are required for large-scale, long-term genetic association studies. In the genetic dissection of common disease it is now recognised that thousands of samples and hundreds of thousands of markers, mostly single nucleotide polymorphisms (SNPs), will have to be analysed. In order to achieve these aims, both an ability to boost quantities of archived DNA and to genotype at low costs are highly desirable. We have investigated Phi29 polymerase Multiple Displacement Amplification (MDA)-generated DNA product (MDA product), in combination with highly multiplexed BeadArray(TM) genotyping technology. As part of a large-scale BeadArray genotyping experiment we made a direct comparison of genotyping data generated from MDA product with that from genomic DNA (gDNA) templates. Results: Eighty-six MDA product and the corresponding 86 gDNA samples were genotyped at 345 SNPs and a concordance rate of 98.8% was achieved. The BeadArray sample exclusion rate, blind to sample type, was 10.5% for MDA product compared to 5.8% for gDNA. Conclusions: We conclude that the BeadArray technology successfully produces high quality genotyping data from MDA product. The combination of these technologies improves the feasibility and efficiency of mapping common disease susceptibility genes despite limited stocks of gDNA samples

Additive manufacture of three dimensional nanocomposite based objects through multiphoton fabrication

Three dimensional structures prepared from a gold-polymer composite formulation have been fabricated using multiphoton lithography. In this process, gold nanoparticles were simultaneously formed through photoreduction whilst polymerisation of two possible monomers was promoted. The monomers, trimethylopropane triacrylate (TMPTA) and pentaerythritol triacrylate (PETA) were mixed with a gold salt, but it was found that the addition of a Ruthenium (II) complex enhanced both the geometrical uniformity and integrity of the polymerized / reduced material, enabling the first production of 3D gold-polymer structures by single step multiphoton lithography

Author Correction: Additive manufacture of complex 3D Au-containing nanocomposites by simultaneous two-photon polymerisation and photoreduction

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Additive manufacture of complex 3D Au-containing nanocomposites by simultaneous two-photon polymerisation and photoreduction

The fabrication of complex three-dimensional gold-containing nanocomposite structures by simultaneous two-photon polymerisation and photoreduction is demonstrated. Increased salt delivers reduced feature sizes down to line widths as small as 78nm, a level of structural intricacy that represents a significant advance in fabrication complexity. The development of a general methodology to efficiently mix pentaerythritol triacrylate (PETA) with gold chloride hydrate (HAuCl4∙3H2O) is reported, where the gold salt concentration is adjustable on demand from zero to 20wt%. For the frst-time 7-Diethylamino-3-thenoylcoumarin (DETC) is used as the photoinitiator. Only 0.5wt% of DETC was required to promote both polymerisation and photoreduction of up to 20wt% of gold salt. This efficiency is the highest reported for Au-containing composite fabrication by two-photon lithography. Transmission Electron Microscopy (TEM) analysis confirmed the presence of small metallic nanoparticles (5.4±1.4nm for long axis / 3.7±0.9nm for short axis) embedded within the polymer matrix, whilst X-ray Photoelectron Spectroscopy (XPS) confirmed that they exist in the zero valent oxidation state. UV-vis spectroscopy defined that they exhibit the property of localised surface plasmon resonance (LSPR). The capability demonstrated in this study opens up new avenues for a range of applications, including plasmonics, metamaterials, flexible electronics and biosensors

Active children through incentive vouchers – evaluation (ACTIVE): a mixed-method feasibility study

BackgroundAdolescents face many barriers to physical activity, demonstrated by the decline in physical activity levels in teenage populations. This study aimed to assess the feasibility of overcoming such barriers via the implementation of an activity-promoting voucher scheme to teenagers in deprived areas.MethodsAll Year 9 pupils (n = 115; 13.3 ± 0.48 years; 51 % boys) from one secondary school in Wales (UK) participated. Participants received £25 of activity vouchers every month for six months for physical activity or sporting equipment. Focus groups (n = 7), with 43 pupils, and qualitative interviews with teachers (n = 2) were conducted to assess feasibility, in addition to a process evaluation utilising the RE-AIM framework. Quantitative outcomes at baseline, five months (during intervention) and twelve months (follow-up) included: physical activity (accelerometer), aerobic fitness (12 min Cooper run) and self-reported activity (PAQ-A). Motivation to exercise (BREQ-2) was measured three months post-baseline and at follow-up.ResultsQualitative findings showed that vouchers encouraged friends to socialise through activity, provided opportunities to access local activities that pupils normally could not afford, and engaged both those interested and disinterested in physical education. Improvements in weekend moderate-to-vigorous physical activity and reductions in sedentary behaviour were observed in both sexes. Boys’ fitness significantly improved during the voucher scheme. ‘Non-active’ pupils (those not meeting recommended guidelines of 60 mins∙day−1) and those with higher motivation to exercise had higher voucher use.ConclusionsAdolescents, teachers and activity providers supported the voucher scheme and felt the vouchers enabled deprived adolescents to access more physical activity opportunities. Voucher usage was associated with improved attitudes to physical activity, increased socialisation with friends and improved fitness and physical activity; presenting interesting avenues for further exploration in a larger intervention trial

Loss of auditory sensitivity from inner hair cell synaptopathy can be centrally compensated in the young but not old brain

AbstractA dramatic shift in societal demographics will lead to rapid growth in the number of older people with hearing deficits. Poorer performance in suprathreshold speech understanding and temporal processing with age has been previously linked with progressing inner hair cell (IHC) synaptopathy that precedes age-dependent elevation of auditory thresholds. We compared central sound responsiveness after acoustic trauma in young, middle-aged, and older rats. We demonstrate that IHC synaptopathy progresses from middle age onward and hearing threshold becomes elevated from old age onward. Interestingly, middle-aged animals could centrally compensate for the loss of auditory fiber activity through an increase in late auditory brainstem responses (late auditory brainstem response wave) linked to shortening of central response latencies. In contrast, old animals failed to restore central responsiveness, which correlated with reduced temporal resolution in responding to amplitude changes. These findings may suggest that cochlear IHC synaptopathy with age does not necessarily induce temporal auditory coding deficits, as long as the capacity to generate neuronal gain maintains normal sound-induced central amplitudes

Women’s experiences of disrespect and abuse in maternity care facilities in Benue State, Nigeria

Background Disrespect and abuse (D&A) of women in health facilities continues to be a prevailing public health issue in many countries. Studies have reported significantly high prevalence of D&A among women during pregnancy and childbirth in Nigeria, but little is known about women’s perceptions and experiences of D&A during maternity care in the country. The aim of this study was to explore: 1) how women perceived their experiences of D&A during pregnancy, childbirth, and in the postnatal period in Benue State, Nigeria; and 2) how women viewed the impact of D&A on the future use of health facilities for maternity care. Method Five focus group discussions with a sample of 32 women were conducted as part of a qualitative phenomenological study. All the women received maternity care in health facilities in Benue State, Nigeria and had experienced at least one incident of disrespect and abuse. Audio-recorded discussions were transcribed and analysed using a six-stage thematic analysis using NVivo11. Results The participants perceived incidents such as being shouted at and the use of abusive language as a common practice. Women described these incidents as devaluing and dehumanising to their sense of dignity. Some women perceived that professionals did not intend to cause harm by such behaviours. Emerged themes included: (1) ‘normative’ practice; (2) dehumanisation of women; (3) 'no harm intended' and (4) intentions about the use of maternity services in future. The women highlighted the importance of accessing health facilities for safe childbirth and expressed that the experiences of D&A may not impact their intended use of health facilities. However, the accounts reflected their perceptions about the inherent lack of choice and an underlying sense of helplessness. Conclusion Incidents of D&A that were perceived as commonplace carry substantial implications for the provision of respectful maternity care in Nigeria and other similar settings. As a country with one of the highest rates of maternal deaths, the findings point to the need for policy and practice to address the issue urgently through implementing preventive measures, including empowering women to reinforce their right to be treated with dignity and respect, and sensitising health care professionals

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Temporal Response Properties of the Auditory Nerve in Implanted Children with Auditory Neuropathy Spectrum Disorder and Implanted Children with Sensorineural Hearing Loss

OBJECTIVE: This study aimed to 1) characterize temporal response properties of the auditory nerve in implanted children with auditory neuropathy spectrum disorder (ANSD); and 2) compare results recorded in implanted children with ANSD with those measured in implanted children with sensorineural hearing loss (SNHL). DESIGN: Participants included 28 children with ANSD and 29 children with SNHL. All subjects used Cochlear Nucleus devices in their test ears. Both ears were tested in six children with ANSD and three children with SNHL. For all other subjects, only one ear was tested. The electrically-evoked compound action potential (ECAP) was measured in response to each of the 33 pulses in a pulse train (excluding the second pulse) for one apical, one middle-array, and one basal electrode. The pulse train was presented in a monopolar-coupled stimulation mode at four pulse rates: 500, 900, 1800 and 2400 pulses per second (pps). Response metrics included the averaged amplitude, latencies of response components and response width, the alternating depth and the amount of neural adaptation. These dependent variables were quantified based on the last six ECAPs or the six ECAPs occurring within a time window centered around 11–12 ms. A Generalized Linear Mixed Model (GLMM) was used to compare these dependent variables between the two subject groups. The slope of the linear fit of the normalized ECAP amplitudes (re. amplitude of the first ECAP response) over the duration of the pulse train was used to quantify the amount of ECAP increment over time for a subgroup of nine subjects. RESULTS: Pulse train evoked ECAPs were measured in all but eight subjects (five with ANSD and three with SNHL). ECAPs measured in children with ANSD had smaller amplitude, longer averaged P2 latency and greater response width than children with SNHL. However, differences in these two groups were only observed for some electrodes. No differences in averaged N1 latency or in the alternating depth were observed between children with ANSD and children with SNHL. Neural adaptation measured in these two subject groups was comparable for relatively short durations of stimulation (i.e. 11–12 ms). Children with ANSD showed greater neural adaptation than children with SNHL for a longer duration of stimulation. Amplitudes of ECAP responses rapidly declined within the first few milliseconds of stimulation, followed by a gradual decline up to 64 ms after stimulus onset in the majority of subjects. This decline exhibited an alternating pattern at some pulse rates. Further increases in pulse rate diminished this alternating pattern. In contrast, ECAPs recorded from at least one stimulating electrode in six ears with ANSD and three ears with SNHL showed a clear increase in amplitude over the time course of stimulation. The slope of linear regression functions measured in these subjects was significantly greater than zero. CONCLUSIONS: Some but not all aspects of temporal response properties of the auditory nerve measured in this study differ between implanted children with ANSD and implanted children with SNHL. These differences are observed for some but not all electrodes. A new neural response pattern is identified. Further studies investigating its underlying mechanism and clinical relevance are warranted