Characterizing the degradation of alginate hydrogel for use in multilumen scaffolds for spinal cord repair

Alginate was studied as a degradable nerve guidance scaffold material in vitro and in vivo. In vitro degradation rates were determined using rheology to measure the change in shear modulus vs time. The shear modulus decreased from 155 kPa to 5 kPa within 2 days; however, alginate samples maintained their superficial geometry for over 28 days. The degradation behavior was supported by materials characterization data showing alginate consisted of high internal surface area (400 m2/g), which likely facilitated the release of cross‐linking cations resulting in the rapid decrease in shear modulus. To assess the degradation rate in vivo, multilumen scaffolds were fabricated using a fiber templating technique. The scaffolds were implanted in a 2‐mm‐long T3 full transection rodent spinal cord lesion model for 14 days. Although there was some evidence of axon guidance, in general, alginate scaffolds degraded before axons could grow over the 2‐mm‐long lesion. Enabling alginate‐based scaffolds for nerve repair will likely require approaches to slow its degradation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 611–619, 2016.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137597/1/jbma35600.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137597/2/jbma35600_am.pd

Improving coverage and compliance in mass drug administration for the elimination of LF in two 'Endgame' districts in Indonesia using micronarrative surveys

Author Summary This research describes the process used to assist two districts endemic for lymphatic filariasis (LF) in Indonesia to better understand the reasons why their LF elimination programs have had suboptimal results. A novel survey design was used to collect stories about people's direct experiences with mass drug administration (MDA) for LF. These questionnaires also explored the reasons community members took or did not take the LF drugs. Following MDA in 2013, two baseline surveys in endemic communities provided insight into the district MDA programs. Together with district health officials, feasible recommendations were provided before the next MDA round in 2014. Uptake of these recommendations by the districts was high, although no additional funding was made available for programmatic changes. As a result, both districts reported significant improvements in their MDA coverage and compliance rates after the endline surveys were completed in 2015. This demonstrated the utility of the survey tool and process to impact change and improvement in MDA programs

Response Style Differences in the Inattentive and Combined Subtypes of Attention-Deficit/Hyperactivity Disorder

This study examined potential differences between the inattentive and combined ADHD subtypes using laboratory tasks assessing behavioral inhibitory processes. Seventy-five children completed two tasks of behavioral inhibition believed to isolate different processes: the cued reaction time task (CRT), a basic inhibition task, and the go/no-go task (GNG), a complex inhibition task that incorporates motivational contingencies. Three groups of participants were identified, including ADHD/Inattentive (n = 17), ADHD/Combined (n = 37), and comparison (n = 21). Results indicated that rather than showing behavioral inhibition deficits, the ADHD/I children appeared overly inhibited, as evidenced by slower reaction times across the two tasks and significantly higher errors of omission in the GNG task. Additionally, the ADHD/I children did not demonstrate cue dependency effects on the CRT task, suggesting that they were failing to incorporate relevant information before making a response. The sluggish and inhibited performance of the ADHD/I group challenges the idea that it is a subtype of ADHD

Seasonal and ontogenetic variation in depth use by a critically endangered benthic elasmobranch and its implications for spatial management

The project was undertaken through the Movement Ecology of the Flapper skate project at St Andrews and received support from the Ecology and Conservation Group, Marine Scotland Science, and Marine Scotland Planning & Policy and NatureScot. It was funded by Marine Scotland projects SP004 and SP02B0 and NatureScot project 015960.Seasonal and ontogenetic variation in depth use by benthic species are often concomitant with changes in their spatial distribution. This has implications for the efficacy of spatial conservation measures such as Marine Protected Areas (MPAs). The critically endangered flapper skate (Dipturus intermedius) is the designation feature of an MPA in Scotland. This species is generally associated with deeper waters >100 m; however, little is known about its seasonal or ontogenetic variation in habitat use. This study used archival depth data from 25 immature and mature flapper skate tagged in the MPA over multiple years. Time series ranged from 3 to 772 (mean = 246) days. Generalised additive mixed models and highest density intervals were used to identify home (95%) and core (50%) highest density depth regions (HDDRs) to quantify depth use in relation to time of year and body size. Skate used a total depth range of 1 – 312 m, but home HDDRs typically occurred between 20 – 225 m. Core HDDRs displayed significant seasonal and ontogenetic variation. Summer core HDDRs (100 – 150 m) suggest high occupancy of the deep trenches in the region by skate of most size classes. There was an inverse relationship between body size and depth use, and a seasonal trend of skate moving into shallow water over winter months. These results suggest flapper skate are not solely associated with deep water, as skate, especially large females, are frequently found in shallow waters (25 – 75 m). The current management, which protects the entire depth range, is appropriate for the protection of flapper skate through much of its life-history. This research demonstrates why collecting data across seasonal scales and multiple ontogenetic stages is needed to assess the effectiveness of spatial management.Publisher PDFPeer reviewe

Peripheral nerve growth within a hydrogel microchannel scaffold supported by a kink‐resistant conduit

Nerve repair in several mm‐long nerve gaps often requires an interventional technology. Microchannel scaffolds have proven effective for bridging nerve gaps and guiding axons in the peripheral nervous system (PNS). Nonetheless, fabricating microchannel scaffolds at this length scale remains a challenge and/or is time consuming and cumbersome. In this work, a simple computer‐aided microdrilling technique was used to fabricate 10 mm‐long agarose scaffolds consisting of 300 µm‐microchannels and 85 µm‐thick walls in less than an hour. The agarose scaffolds alone, however, did not exhibit adequate stiffness and integrity to withstand the mechanical stresses during implantation and suturing. To provide mechanical support and enable suturing, poly caprolactone (PCL) conduits were fabricated and agarose scaffolds were placed inside. A modified salt‐leaching technique was developed to introduce interconnected porosity in PCL conduits to allow for tuning of the mechanical properties such as elastic modulus and strain to failure. It was shown that the PCL conduits were effective in stabilizing the agarose scaffolds in 10 mm‐long sciatic nerve gaps of rats for at least 8 weeks. Robust axon ingress and Schwann cell penetration were observed within the microchannel scaffolds without using growth factors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3392–3399, 2017.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139110/1/jbma36186_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139110/2/jbma36186.pd

Analysis of Neptune's 2017 Bright Equatorial Storm

We report the discovery of a large ($\sim$8500 km diameter) infrared-bright storm at Neptune's equator in June 2017. We tracked the storm over a period of 7 months with high-cadence infrared snapshot imaging, carried out on 14 nights at the 10 meter Keck II telescope and 17 nights at the Shane 120 inch reflector at Lick Observatory. The cloud feature was larger and more persistent than any equatorial clouds seen before on Neptune, remaining intermittently active from at least 10 June to 31 December 2017. Our Keck and Lick observations were augmented by very high-cadence images from the amateur community, which permitted the determination of accurate drift rates for the cloud feature. Its zonal drift speed was variable from 10 June to at least 25 July, but remained a constant $237.4 \pm 0.2$ m s$^{-1}$ from 30 September until at least 15 November. The pressure of the cloud top was determined from radiative transfer calculations to be 0.3-0.6 bar; this value remained constant over the course of the observations. Multiple cloud break-up events, in which a bright cloud band wrapped around Neptune's equator, were observed over the course of our observations. No "dark spot" vortices were seen near the equator in HST imaging on 6 and 7 October. The size and pressure of the storm are consistent with moist convection or a planetary-scale wave as the energy source of convective upwelling, but more modeling is required to determine the driver of this equatorial disturbance as well as the triggers for and dynamics of the observed cloud break-up events.Comment: 42 pages, 14 figures, 6 tables; Accepted to Icaru

Oral Human Papillomavirus Prevalence and Genotyping Among a Healthy Adult Population in the US

IMPORTANCE In the US, oropharyngeal cancer, predominantly caused by high-risk (HR) human papillomavirus (HPV) infection, is the most frequent HPV-associated cancer, surpassing cervical cancer. However, little is known about oral HPV prevalence and genotype distribution in the general population. OBJECTIVE To assess oral HPV prevalence and factors associated with HR and low-risk infection in a general US population. DESIGN, SETTING, AND PARTICIPANTS PROGRESS (Prevalence of Oral HPV Infection, a Global Assessment) was a cross-sectional observational study conducted between November 2021 and March 2022 in 43 dental offices in the US (24 urban, 13 urban cluster, and 6 rural sites), spanning 21 states. Eligible participants were aged 18 to 60 years, visiting dental clinics for routine dental examination. Dental clinics used targeted sampling to recruit equal distributions of men and women and across age groups. EXPOSURE Participants provided an oral gargle specimen for HPV DNA and genotyping and completed behavioral questionnaires, and dentists reported oral health status. Detection of HPV DNA and genotyping was performed using the SPF10/DEIA/LiPA25 system at a central laboratory. MAIN OUTCOME Oral HPV prevalence. RESULTS Of the 3196 participants enrolled, mean (SD) age was 39.6 (12.1) years, and 55.5% were women. Oral HPV prevalence was 6.6%(95% CI, 5.7%-7.4%) for any HPV genotype, and 2.0% (95% CI, 1.5%-2.5%), 0.7%(95% CI, 0.4%-1.0%), and 1.5%(95% CI, 1.1%-1.9%) for HR, HPV-16, and 9-valent-HPV vaccine types, respectively. Among HPV-positive participants, HPV-16 was the most prevalent genotype (12.4% among men and 8.6% among women). Prevalence of HPV was higher in men than women and highest among men aged 51 to 60 years (16.8%, 6.8%, and 2.1% for any HPV, HR HPV, and HPV-16, respectively). Factors associated with HR oral infection included being male (adjusted odds ratio [AOR], 3.1; 95% CI, 1.2-8.5), being aged 51 to 60 years (AOR, 3.3; 95% CI, 1.5-7.3), having 26 or more lifetime male sex partners (AOR, 6.5; 95% CI, 2.3-18.7), and having 6 to 25 lifetime female oral sex partners (AOR, 3.4; 95% CI, 1.3-8.7). CONCLUSIONS AND RELEVANCE In this cross-sectional study, oral HPV burden was highest among older men who may be at higher risk of developing oropharyngeal cancer. In addition to male sex and older age, HR oral HPV infection was also associated with sexual behaviors, including increasing number of male sex partners and female oral sex partners

Evaluation Research and Institutional Pressures: Challenges in Public-Nonprofit Contracting

This article examines the connection between program evaluation research and decision-making by public managers. Drawing on neo-institutional theory, a framework is presented for diagnosing the pressures and conditions that lead alternatively toward or away the rational use of evaluation research. Three cases of public-nonprofit contracting for the delivery of major programs are presented to clarify the way coercive, mimetic, and normative pressures interfere with a sound connection being made between research and implementation. The article concludes by considering how public managers can respond to the isomorphic pressures in their environment that make it hard to act on data relating to program performance.This publication is Hauser Center Working Paper No. 23. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers