Aligned cellular and acellular collagen guidance substrates for peripheral nerve repair

There is a clinical demand to shorten the delay of reinnervation and improve functional recovery after peripheral nerve injury. A peripheral nerve repair device with the ability to direct and promote axon growth across a lesion would be a promising alternative to nerve autograft repair, the current gold standard treatment. The growth of axons across a lesion is most effective when supported by columns of aligned Schwann cells, as found in an autograft. Here we report the development of a robust aligned cellular collagen biomaterial that supports and directs neuronal growth. We also investigate the potential of these aligned cells to precondition the collagen biomaterial, before they are freeze-killed, leaving an acellular guidance matrix

Identification of Microorganisms Isolated from Mars-Bound Spacecraft Using MALDI-TOF

The primary goal of the Biotechnology and Planetary Protection Group (BPPG) at the Jet Propulsion Laboratory (JPL) is to prevent microbial contamination between Earth and other planetary bodies. This helps preserve the ability to study other worlds as they exist in their natural states and protects our biosphere from extraterrestrial life. The process for identifying microbes located on space-bound hardware in JPL can be more efficient and precise by using the technique called matrix-assisted laser desorption and ionization time of flight (MALDI-TOF). Once this identification technique is fully implemented, the process time will be reduced from two weeks to one hour, and the cost will be reduced by a factor of five. The MALDI-TOF database contains 5,989 microorganism profiles, but because it was created with microbes found in a clinical setting, it was only comprehensive enough to identify 7% of JPL isolates. This called for the need of our own unique in-house MALDI database composed of the complete array of our microbial diversity. This database was created using bacterial isolates with known 16S rRNA sequences collected from various Mars mission hardware from the last 40 years. A mass spectral profile (MSP) was created and archived for each isolate, so in the future, unknown isolates can be identified by running them against the database using real time classification (RTC). After identifying 288 new operational taxonomic units (OTUs), a rarefaction curve was created which estimated that after studying 500 additional isolates our database will be comprehensive. During the summer of 2016, all stages of the MSP creation process were continued to finish constructing the JPL microbial database

Comparison of an Endangered Species’ Seed Bank Before and After Ungulate Removal

The purpose of this study was to assess the impact of the removal of ungulates on the soil seed bank of the endemic Santa Rosa Island manzanita (Arctostaphylos confertiflora). A. confertiflora was trampled and browsed by non-native ungulates between the years 1850 and 2011 which reduced its ability to produce seeds.This species is an obligate seeder, meaning that sprouting from seeds in the soil is its only method of reproduction. Due in part to the lack of its soil seed bank, this species was federally listed as endangered by the US Fish and Wildlife Service in 1997. In order to assess the trend in its seed bank density, researchers compared its density in 2004 to its density in 2018. There are three stands of of A. confertiflora on the island, and this study collected data on the seed banks in each location. The overall methodology for surveying the seed bank was by selecting sixteen random plants in each stand and collecting 12 soil samples under the canopy of each one, which were sieved to count the number of seeds. The number of seeds was extrapolated to determine the number of seeds per square meter (seeds/m2) of soil surface sampled. The data set examined for this poster focuses on only one of the three stands; data on the other two stands have yet to be examined. This pilot data set found a 213% increase in number of seeds/m2 in the stand from 2004 to 2018, although results were not statistically significant at the 95% confidence level (Mann-Whitney U=. A Mann-Whitney U test found that the 2018 seed bank at Telephone Road did not have a significantly higher number of seeds than the 2004 seed bank (U=88.5, p=0.13). These data can be used by agency scientists to evaluate status and plan further management for A. confertiflora conservation and recovery

What’s Good in Theory May Be Flawed in Practice: Potential Legal Consequences of Poor Implementation of a Theoretical Sample

This article discusses the problems with the use of statistical sampling in litigation. Sample-based research is increasingly used in a diverse array of cases including products liability, antitrust, intellectual property, and criminal law. Sample-based research provides objective evidence upon which decisions, damages, and liability may rest. Despite its importance, however, statistical evidence is often misused and misunderstood by attorneys unfamiliar with the underlying form of analysis. This article explores common errors when using litigative samples, comments upon best practices for the use in law of sample-based research, and demonstrates the importance of sound statistical sampling and data collection in a recent case

Food security and access in northern Colorado

October 2010.Food security is a complex issue: limited resource households, distance to food markets and other barriers to securing adequate, safe and nutritious foods all combine to create a food landscape that may not be conducive to good health in our communities. Recent data from the Northern Colorado region suggest there is increasing need for food assistance from government, community and school programs. Data on food assistance, food stamps outlays, and reduced/free school lunch eligibility are consistent in illustrating increased need for programs to mitigate food insecurity during this economic downturn. Community gardens and efforts to "map" food assets are explored as new approaches to improve access to raw foods and appropriate food market outlets for those who might otherwise have their dietary choices constrained by what is readily available

Same Rules, Higher Costs: Women’s Pathways to Candidacy in Zambia

Under embargo until: 2023-09-01acceptedVersio

What We Can Learn from Provincial Governments in Solomon Islands: A Personal Perspective - Part 2: Using Provincial Revenue for Peace and Localised Solutions

This is the second In Brief about what we can learn from provincial governments in Solomon Islands. Both papers draw heavily on the author’s experiences of working as the legal adviser to the Ministry of Provincial Government and Institutional Strengthening based in Honiara. In this role she observed corruption — and plenty of it — but also saw examples of real creativity and adaptability. From this, she highlights valuable lessons to be learnt. In the first In Brief, the author discussed the importance of recruiting locally and the way that some provincial governments had prioritised local recruitment over secondments from Honiara. At the end of that In Brief she alluded to the importance of provincial revenue. The author picks up on this point here and discusses what she thinks we can learn from how provinces raise and spend money

Fabrication of an endoneurium using engineered neural tissue within a peripheral nerve repair conduit

Peripheral nerve injury as a result of trauma affects approximately 1 million people in Europe and America annually. The current clinical gold standard treatment for repairing long gaps is the nerve autograft, in which only ~50% of cases result in satisfactory functional recovery. Tissue-engineered cellular bridging devices for peripheral nerve repair could provide an attractive alternative to autografts. Sheets of engineered neural tissue (EngNT), which is formed from columns of Schwann cells within a 3D aligned collagen matrix, can promote directed neurite outgrowth in vitro. These sheets of EngNT can be arranged to form the ‘endoneurium’ of a peripheral nerve repair device. Two different arrangements, rod-based and sheet-based designs, were tested within a clinically approved tube, NeuraWrap™, in a 5mm gap in the rat sciatic nerve. Cross sections were stained to detect neurofilament after 4 weeks in vivo and revealed where the axons were growing in relation to the EngNT structures (this was divided into three zones for the analysis). The axon density was significantly greater in zone 1 than in zone 3 in the devices (P2 (mean ± SEM), compared to the sheet-based arrangement (B) (2920 ± 587 axons/mm2). The rod-based arrangement was more stable; there were no observed changes to its structure or orientation as a result of surgical handling or limb movement post-implantation. The designs are modular and can be adapted for the repair of bigger nerves by, for example, having multiple rod structures in the core of outer tubes or sheath wraps. Aligned cellular EngNT rods can form the basis of a functional conduit for peripheral nerve repair

A 3D <i>in vitro</i> model reveals differences in the astrocyte response elicited by potential stem cell therapies for CNS injury.

Aim: This study aimed to develop a 3D culture model to test the extent to which transplanted stem cells modulate astrocyte reactivity, where exacerbated glial cell activation could be detrimental to CNS repair success. Materials & methods: The reactivity of rat astrocytes to bone marrow mesenchymal stem cells, neural crest stem cells (NCSCs) and differentiated adipose-derived stem cells was assessed after 5 days. Schwann cells were used as a positive control. Results: NCSCs and differentiated Schwann cell-like adipose-derived stem cells did not increase astrocyte reactivity. Highly reactive responses to bone marrow mesenchymal stem cells and Schwann cells were equivalent. Conclusion: This approach can screen therapeutic cells prior to in vivo testing, allowing cells likely to trigger a substantial astrocyte response to be identified at an early stage. NCSCs and differentiated Schwann cell-like adipose-derived stem cells may be useful in treating CNS damage without increasing astrogliosis