No. 06: The Urban Food System of Nairobi, Kenya

Nairobi is a city of stark contrasts. Nearly half a million of its three million residents live in abject poverty in some of Africa’s largest slums, yet the Kenyan capital is also an international and regional hub. In East Africa, rapid urbanization is stretching existing food and agriculture systems as growing cities struggle to provide food and nutrition security for their inhabitants. Nairobi is no exception; it is a dynamically growing city and its food supply chains are constantly adapting and responding to changing local conditions. It is also an international city and the extent to which it is food secure is increasingly predicated on food imports from the regional East African Community and other international sources. Informal traditional value chains have a variety of actors and intermediaries that increase transaction costs and create an inefficient post-harvest procurement network, thereby pushing food products out of the reach of those who need them most. The majority of Nairobi’s food purchases are from informal food vendors. The city’s urban poor rely on the informal food sector for several reasons including that it provides food close to where they live and work, credit and barter are often available, small quantities can be purchased, and many items are sold more cheaply than at formal outlets. The leading income-generating activity for women in Nairobi’s poor communities is selling fruit and vegetables

Cost of inpatient rehabilitation care in the Department of Veterans Affairs

Abstract—We investigated the determinants of inpatient rehabilitation costs in the Department of Veterans Affairs (VA) and examined the relationship between length of stay (LOS) and discharge costs using data from VA and community rehabilitation hospitals. We estimated regression models to identify patient characteristics associated with specialized inpatient rehabilitation costs. VA data included 3,535 patients discharged from 63 facilities in fiscal year 2001. We compared VA costs to community rehabilitation hospitals using a sample from the Uniform Data System for Medical Rehabilitation of 190,112 patients discharged in 1999 from 697 facilities. LOS was a strong predictor of cost for VA and non-VA hospitals. Functional status, measured by Functional Independence Measure (FIM) scores at admission, was statistically significant but added little explanatory value after controlling for LOS. Although FIM scores were associated with LOS, FIM scores accounted for little variance in cost after controlling for LOS. These results are most applicable to researchers conducting cost-effectiveness analyses.average costs, billing, charges, cost, health economics, micro-cost methods, reimbursement, rehabilitation, VA, veterans

Automated trajectory design for impulsive and low thrust interplanetary mission analysis

This dissertation describes a hybrid optimization algorithm that is able to determine optimal trajectories for many complex mission analysis and design orbital mechanics problems. This new algorithm will be used to determine optimal trajectories for a variety of mission design problems, including asteroid rendezvous, multiple gravity-assist (MGA), multiple gravity-assist with deep-space maneuvers (MGA-DSM), and low-thrust trajectory missions. The research described here was conducted at the Asteroid Deflection Research Center (ADRC) at Iowa State University

Bartonella taylorii; : A Model Organism for Studying; Bartonella; Infection; in vitro; and; in vivo;

Bartonella; spp. are Gram-negative facultative intracellular pathogens that infect diverse mammals and cause a long-lasting intra-erythrocytic bacteremia in their natural host. These bacteria translocate; Bartonella; effector proteins (Beps) into host cells; via; their VirB/VirD4 type 4 secretion system (T4SS) in order to subvert host cellular functions, thereby leading to the downregulation of innate immune responses. Most studies on the functional analysis of the VirB/VirD4 T4SS and the Beps were performed with the major zoonotic pathogen; Bartonella henselae; for which efficient; in vitro; infection protocols have been established. However, its natural host, the cat, is unsuitable as an experimental infection model.; In vivo; studies were mostly confined to rodent models using rodent-specific; Bartonella; species, while the; in vitro; infection protocols devised for; B. henselae; are not transferable for those pathogens. The disparities of; in vitro; and; in vivo; studies in different species have hampered progress in our understanding of; Bartonella; pathogenesis. Here we describe the murine-specific strain; Bartonella taylorii; IBS296 as a new model organism facilitating the study of bacterial pathogenesis both; in vitro; in cell cultures and; in vivo; in laboratory mice. We implemented the split NanoLuc luciferase-based translocation assay to study BepD translocation through the VirB/VirD4 T4SS. We found increased effector-translocation into host cells if the bacteria were grown on tryptic soy agar (TSA) plates and experienced a temperature shift immediately before infection. The improved infectivity; in vitro; was correlating to an upregulation of the VirB/VirD4 T4SS. Using our adapted infection protocols, we showed BepD-dependent immunomodulatory phenotypes; in vitro; . In mice, the implemented growth conditions enabled infection by a massively reduced inoculum without having an impact on the course of the intra-erythrocytic bacteremia. The established model opens new avenues to study the role of the VirB/VirD4 T4SS and the translocated Bep effectors; in vitro; and; in vivo;

The mechanical response of fire ant rafts

Fire ants (Solenopsis invicta) cohesively aggregate via the formation of voluntary ant-to-ant attachments when under confinement or exposed to water. Once formed, these aggregations act as viscoelastic solids due to dynamic bond exchange between neighboring ants as demonstrated by rate-dependent mechanical response of 3D aggregations, confined in rheometers. We here investigate the mechanical response of 2D, planar ant rafts roughly as they form in nature. Specifically, we load rafts under uniaxial tension to failure, as well as to 50% strain for two cycles with various recovery times between. We do so while measuring raft reaction force (to estimate network-scale stress), as well as the networks' instantaneous velocity fields and topological damage responses to elucidate the ant-scale origins of global mechanics. The rafts display brittle-like behavior even at slow strain rates (relative to the unloaded bond detachment rate) for which Transient Network Theory predicts steady-state creep. This provides evidence that loaded ant-to-ant bonds undergo mechanosensitive bond stabilization or act as \say{catch bonds}. This is further supported by the coalescence of voids that nucleate due to biaxial stress conditions and merge due to bond dissociation. The characteristic timescales of void coalescence due to chain dissociation provide evidence that the local detachment of stretched bonds is predominantly strain- (as opposed to bond lifetime-) dependent, even at slow strain rates, implying that bond detachment rates diminish significantly under stretch. Significantly, when the voids are closed by restoring the rafts to unstressed conditions, mechanical recovery occurs, confirming the presence of concentration-dependent bond association that - combined with force-diminished dissociation - could further bolster network cohesion under certain stress states

Discovery of an introduced Florida Flagfish (\u3ci\u3eJordanella floridae\u3c/i\u3e) population in Coastal Mississippi

The recent discovery of Jordanella floridae (Florida Flagfish) in Harrison County, Mississippi represents the first known occurrence of the species in the state. Native along the Atlantic and Gulf Coasts of Florida from Jacksonville to Tallahassee, this species has been introduced outside of its range via aquarium introductions. We hypothesize that an aquarium introduction was also the source of the newly discovered population, which has persisted at the location since 2020. Multiple collections of the species have been taken from a small waterbody which has a direct connection to the Tchoutacabouffa River (25mm-47mm TL). While it is unknown if this represents the only population in the system, further surveys should be conducted to determine population numbers at the site of collection, the extent of the invasion within the Tchoutacabouffa, and the impact to the native fish fauna

Molecular epidemiology of multi-drug resistant Escherichia coli in companion animal species

This study focused on a group of multi-drug resistant (MDR) E. coli collected between 2002 and 2011 at the Small Animal Hospital, Royal (Dick) Veterinary School; isolated from urinary tract infections in dogs. The MDR E. coli isolates were compared against a group of fully susceptible E. coli, also collected from canine urinary tract infections. The MDR isolates were notable for their AmpC β-lactamase resistance phenotype (12/18) and resistance genotype (blaCMY-2, 8/12). Phylogenetic comparisons between the MDR and susceptible groups of isolates showed a large degree of separation between the two groups. Susceptible isolates strongly associated the the pathogenic B2 phylogroup (67%), which was expected. The MDR group was much more mixed, with isolates more associated with commensal A (28%) and B1 (22%) phylogroups. Virulence marker abundance, evaluated using an Identibac microarray, showed a much reduced presence of virulence markers in the MDR group, as compared with the susceptible isolates. An infection model, using Galleria mellonella larvae, was used to better test the phenotypic virulence of the MDR and susceptible E. coli isolates. An asymptomatic bacteriurea strain (ABU83972) and a virulent pyelonephritis strain (CFT073) were used as non-virulent and virulent control strains of uropathogenic E. coli. The model produced consistent and expected differences in lethality between ABU8392 (non-lethal) and CFT073 (lethal) strains. However, the model showed no differences between the MDR and susceptible isolates. Second generation Illumina short-read sequencing and third generation single-molecule real-time sequencing were used to further dissect the genetic background of both the E. coli and the MDR genotype. Core-genomic sequence comparisons of the E. coli showed no clonal relatedness amongst the different MDR and susceptible strains. Most strikingly, sequencing revealed extensive plasmid carriage of the MDR genotype. Plasmid mediated blaCMY-2 was associated with a clonal group of IncI1 plasmids. The IncI1 plasmids show favorable sequence comparisons to a plasmid backbone previously reported in dogs and other animals, with a global distribution. The remaining resistance genes were associated with a group of IncFII plasmid sequences. This study highlights a broader range of commensal E. coli, which have resulted in opportunistic infections in their canine hosts. As such, they act as a potential reservoir of resistance, which is as yet uncharacterized

SAE-Baja 4WD Redesign

In collaboration with the Baja SAE club, this senior design team is tasked with designing and fabricating a Baja vehicle with the goal of competing with competitive success in a 2021-22 Baja SAE Collegiate Design Series competition. The project will include all aspects of the vehicle, including but not limited to: roll cage, suspension, steering/control, and drivetrain. Also, a goal of the project is to design the vehicle with the future AWD/4WD Baja requirement in mind, while making every effort to meet that goal for this upcoming Baja competition. The team will also manage the ONU Baja SAE Club which includes but is not limited to creating a competition checklist to ensure reliable operation during competition, coordinating the work assignments for club members not on the senior design team, preparing all required documentation/presentations to SAE, and ensuring the team’s vehicle adheres to all rules outlined in the official Baja SAE Rules