Comprehensive Monosynaptic Rabies Virus Mapping of Host Connectivity with Neural Progenitor Grafts after Spinal Cord Injury.

Neural progenitor cells grafted to sites of spinal cord injury have supported electrophysiological and functional recovery in several studies. Mechanisms associated with graft-related improvements in outcome appear dependent on functional synaptic integration of graft and host systems, although the extent and diversity of synaptic integration of grafts with hosts are unknown. Using transgenic mouse spinal neural progenitor cell grafts expressing the TVA and G-protein components of the modified rabies virus system, we initiated monosynaptic tracing strictly from graft neurons placed in sites of cervical spinal cord injury. We find that graft neurons receive synaptic inputs from virtually every known host system that normally innervates the spinal cord, including numerous cortical, brainstem, spinal cord, and dorsal root ganglia inputs. Thus, implanted neural progenitor cells receive an extensive range of host neural inputs to the injury site, potentially enabling functional restoration across multiple systems

Psychometric Evaluation of an Instrument to Measure Prospective Pregnancy Preferences: The Desire to Avoid Pregnancy Scale.

BACKGROUND:Existing approaches to measuring women's pregnancy intentions suffer important limitations, including retrospective assessment, overly simple categories, and a presumption that all women plan pregnancies. No psychometrically valid scales exist to prospectively measure the ranges of women's pregnancy preferences. MATERIALS AND METHODS:Using a rigorous construct modeling approach, we developed a scale to measure desire to avoid pregnancy. We developed 60 draft items from existing research, assessed comprehension through 25 cognitive interviews, and administered items in surveys with 594 nonpregnant women in 7 primary and reproductive health care facilities in Arizona, New Jersey, New Mexico, South Carolina, and Texas in 2016-2017. We used item response theory to reduce the item set and assess the scale's reliability, internal structure validity, and external validity. Items were included based on fit to a random effects multinomial logistic regression model (partial credit item response model), correspondence of item difficulty with participants' pregnancy preference levels, and consistency of each item's response options with overall scale scores. RESULTS:The 14 final items covered 3 conceptual domains: cognitive preferences, affective feelings, and practical consequences. Items fit the unidimensional model, with a separation reliability of 0.90 (Cronbach α: 0.95). The scale met established criteria for internal validity, including correspondence between each item's response categories and overall scale scores. We found no important differential item functioning by participant characteristics. CONCLUSIONS:A robust measure is available to prospectively measure desire to avoid pregnancy. The measure can aid in identifying women who could benefit from contraceptive care and research on less desired pregnancy

Floral Resource Availability and Butterfly Community Characteristics in CP-42 Pollinator Habitat Plantings

Prairies once covered approximately 85% of Iowa, but due to extensive habitat loss less than 0.1% of native prairies remain (Smith 1998). Habitat loss in Iowa has been driven by agricultural expansion and intensification, and has resulted in the decline of many native insect pollinators. To curb habitat loss and restore habitat for pollinators, USDA’s Farm Service Agency (FSA) provides private landowners incentives to enroll agricultural land into the Conservation Reserve Program (CRP) Pollinator Habitat (CP-42) practice. The CP-42 conservation practice requires landowners to seed at least 9 species of pollinator friendly wildflowers, legumes, or shrubs on enrolled lands. CP-42 seed mixes must include least three species during each of three bloom periods (April-June 15, June 15- July, and August-October) (USDA 2011). About 50% of all CP42 acres are seeded in Iowa (USDA 2018). We have developed methods for evaluating floral resources and habitat quality for butterflies at CP-42 sites in central Iowa. Our study will produce data to assess the quality of habitat produced by the CP-42 program and to provide information about the effectiveness of the CP-42 program to Farm Service Agency

Stress, Sleep and Performance in International and Domestic University Students

Stress and poor sleep quality are serious and common problems among university students that could have detrimental effects on their academic performance. International students may experience greater difficulty than domestic students because they also need to deal with the challenges associated with moving to a new culture. The present study aims to investigate the relationship between stress (perceived and acculturative), sleep quality, and academic performance by comparing them between international and domestic students. Perceived stress negatively correlates with sleep quality. However, no relationship is found between acculturative stress and sleep quality, between sleep quality and academic performance, and between stress (perceived and acculturative) and academic performance. Differences in perceived stress and sleep quality between international and domestic students are found. Perceived stress is found to be an important factor that requires the university to focus on effective stress management programs that could be useful for achieving better sleep quality

Hand-Injectable Acrylic Bone Cement Applicator for Skull Base Bone Replacement

One of the only existing procedures to remove brain tumors at the skull base is endoscopic endonasal neurosurgery. The most difficult part of this surgery is closing the hole created in the skull, which currently is solved by stuffing fat and biocompatible foam in the hole and sealing it with glue. A better way of sealing this hole would be to use poly methyl methacrylate (PMMA) so that the hole is replaced with a material which more closely resembles bone. In order to better understand the delivery and application of PMMA bone cement into a patient?s skull through the nasal passages by a surgeon, we modeled three-dimensional viscous fluid flow within a surgical device prototype. The model is comprised of a 5-mm diameter tube with a 1-mm diameter wire running through its center. This wire is secured in place with vertical and horizontal supports. We analyzed the effects of the supports and wire on velocity and pressure drop of PMMA material moving through the tube to see if there was any resistance created in the tube that would be unmanageable by an unaided surgeon. To model the fluid flow, we created a three dimensional geometric schematic of the device in COMSOL. We acquired material properties from related literature and ran multiple simulations with several mesh sizes with COMSOL using the 3-D incompressible Navier-Stokes steady state application mode. The overall goal of this project was to determine if a surgeon could push PMMA through the tube without assistance from machines. Using this model we could then determine the manual pressure needed to administer the PMMA into a patient?s skull at an appropriate velocity. Our results indicated that the amount of applied pressure required would be 1.7 lbf, which is much less than the minimal value (~17 lbf) found in the literature regarding thumb strength. From simulations we obtained multiple velocity profiles and plots of pressure drop. Pressure decreases at a constant rate until the tube bends, the wire is introduced, or fluid passes by an obstruction at each point drop in pressure increases. The total amount of pressure drop in the tube was found to be 380 kPa. As we increased inlet velocity, the required applied pressure increased significantly, but not to a magnitude that would be unbearable to a human thumb. The model also gives valuable insight on the effects of obstructions on continuous, viscous fluid flow in a narrow tube

Resilience of New Zealand indigenous forest fragments to impacts of livestock and pest mammals

A number of factors have combined to diminish ecosystem integrity in New Zealand indigenous lowland forest fragments surrounded by intensively grazed pasture. Livestock grazing, mammalian pests, adventive weeds and altered nutrient input regimes are important drivers compounding the changes in fragment structure and function due to historical deforestation and fragmentation. We used qualitative systems modelling and empirical data from Beilschmiedia tawa dominated lowland forest fragments in the Waikato Region to explore the relevance of two common resilience paradigms – engineering resilience and ecological resilience – for addressing the conservation management of forest fragments into the future. Grazing by livestock and foraging/predation by introduced mammalian pests both have direct detrimental impacts on key structural and functional attributes of forest fragments. Release from these perturbations through fencing and pest control leads to partial or full recovery of some key indicators (i.e. increased indigenous plant regeneration and cover, increased invertebrate populations and litter mass, decreased soil fertility and increased nesting success) relative to levels seen in larger forest systems over a range of timescales. These changes indicate that forest fragments do show resilience consistent with adopting an engineering resilience paradigm for conservation management, in the landscape context studied. The relevance of the ecological resilience paradigm in these ecosystems is obscured by limited data. We characterise forest fragment dynamics in terms of changes in indigenous species occupancy and functional dominance, and present a conceptual model for the management of forest fragment ecosystems

PENALIZED LIKELIHOOD AND BAYESIAN METHODS FOR SPARSE CONTINGENCY TABLES: AN ANALYSIS OF ALTERNATIVE SPLICING IN FULL-LENGTH cDNA LIBRARIES

We develop methods to perform model selection and parameter estimation in loglinear models for the analysis of sparse contingency tables to study the interaction of two or more factors. Typically, datasets arising from so-called full-length cDNA libraries, in the context of alternatively spliced genes, lead to such sparse contingency tables. Maximum Likelihood estimation of log-linear model coefficients fails to work because of zero cell entries. Therefore new methods are required to estimate the coefficients and to perform model selection. Our suggestions include computationally efficient penalization (Lasso-type) approaches as well as Bayesian methods using MCMC. We compare these procedures in a simulation study and we apply the proposed methods to full-length cDNA libraries, yielding valuable insight into the biological process of alternative splicing

Novel Inducers of the Envelope Stress Response BaeSR in Salmonella Typhimurium: BaeR Is Critically Required for Tungstate Waste Disposal

The RpoE and CpxR regulated envelope stress responses are extremely important for SalmonellaTyphimurium to cause infection in a range of hosts. Until now the role for BaeSR in both the Salmonella Typhimurium response to stress and its contribution to infection have not been fully elucidated. Here we demonstrate stationary phase growth, iron and sodium tungstate as novel inducers of the BaeRregulon, with BaeR critically required for Salmonella resistance to sodium tungstate. We show that functional overlap between the resistance nodulation-cell division (RND) multidrug transporters, MdtA, AcrD and AcrB exists for the waste disposal of tungstate from the cell. We also point to a role for enterobactinsiderophores in the protection of enteric organisms from tungstate, akin to the scenario in nitrogen fixing bacteria. Surprisingly, BaeR is the first envelope stress response pathway investigated in S. Typhimurium that is not required for murine typhoid in either ityS or ityR mouse backgrounds. BaeR is therefore either required for survival in larger mammals such as pigs or calves, an avian host such as chickens, or survival out with the host altogether where Salmonella and related enterics must survive in soil and water