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3D Printing of Bioglass-TCP Scaffolds: Biological and Mechanical Property Evolution

3D Printing of Bioglass-TCP Scaffolds: Biological and Mechanical Property Evolution

Primary Author: Arjak Bhattacharjee

Faculty Sponsor: Susmita Bose

 

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Engineering and Environmental Science

Campus: Pullman

 

Abstract:

 

Primary Author: Arjak Bhattacharjee

Faculty Sponsor: Susmita Bose

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Engineering & Environmental Science

Campus: Pullman

Abstract:

The objective of this study is to prepare 3D printed cytocompatible bioglass-TCP scaffolds with an optimum combination of porosity gradient and mechanical properties. Bioactive glasses (bioglass) are an excellent candidate for bone tissue engineering applications because of their excellent biological response and high dissolution rate. Tricalcium phosphate (TCP) are used for craniomaxillofacial applications owing to their chemical similarities with natural bone. Our results indicate that upto 5 wt.% bioglass addition in TCP enhances the compressive strength of the prepared scaffolds ~ 26.675 ± 5.45 MPa as compared to ~ 8.50 ± 0.830 MPa of control TCP. Simulated body fluid (SBF) dissolution study reveals that bioglass addition in TCP significantly improves the dissolution precipitation. Thus, this work affirms that 3D printed bioglass-tcp scaffolds can be a promising material for various biomedical applications. This poster will discuss fabrication of 3D printed bioglass-tcp scaffolds with optimum mechanical properties and controlled dissolution rate.

 

A Comparative Analysis of Population Growth Rates in North America

A Comparative Analysis of Population Growth Rates in North America

Primary Author: Darcy Bird

Faculty Sponsor: Timothy Kohler

 

Primary College/Unit: Arts and Sciences

Category: Physical and Social Sciences

Campus: Pullman

 

Abstract:

Principal topic

When the climate improved at the start of the Holocene (ca. 11,650 years ago), human populations increased dramatically. Many researchers argue that the adoption of agriculture increased fertility to cause the Agricultural Demographic Transition (ADT), which would consequently lead to increased population growth. Zahid et al. 2016, however, found that Wyoming hunter-gatherers had a population growth rate of about 0.04% annually, which is comparable to agriculturalist growth rates. The goal of this research is to use the same methodology to calculate and compare hunter-gatherer and agriculturalist population growth rates.

 

Method

I used radiocarbon summed probability distributions (SPDs) to represent population. My dataset includes all freely available radiocarbon dates in North America between 6,000 and 300 cal BP.  I used a linear regression and linear mixed effects model to calculate population growth rates. I directly compared the SPD growth rates between early agricultural adopters (before 2000 cal BP), late agricultural adopters (between 2000 and 500 cal BP), and non-agricultural societies. I also subdivided the agricultural sequences to include hunter-gatherer, horticulture, and agriculture phases, as applicable, to see if growth rate changes dramatically within each sequence between each phase.

 

Results/implications

I found that early agriculture sequences have a higher mean exponential growth rate than non-agricultural societies, while late agricultural adopters have a mean growth rate in between. These results contradict Zahid et al.’s conclusion that hunter-gatherer and agriculturalist societies have comparable growth rates. They also support the conclusion that the ADT prompted a dramatic population increase during the Holocene.

 

Differences in Caregiver and Child Factors Considering the Birth Order of Children with ASD

Differences in Caregiver and Child Factors Considering the Birth Order of Children with ASD

Primary Author: Sarah Boland

Faculty Sponsor: Tammy Barry

 

Primary College/Unit: Arts and Sciences

Category: Physical and Social Sciences

Campus: Pullman

 

Abstract:

 

Principal Topic: Though research has investigated the ways in which caregiver factors are associated with one another (Kuhn & Carter, 2006), there is limited research on how these factors differ across varied family structures. Given the heightened distress among parents of children with autism spectrum disorder (ASD) and the reliance of parent report in clinical evaluation, it is essential to understand how nuances in family structure may impact such reports.

Method: Participants were 155 caregivers with either (1) a “first-born” child with ASD and then typically-developing (TD) child(ren); (2) TD child(ren) and then a “not-first-born” child with ASD, or (3) an “only child” with ASD. Caregivers completed questionnaires assessing parental and child factors.

Results/Implications: Correlations among parent and child variables by birth order indicated many significant correlations across conditions; however, the correlation between efficacy and knowledge was only significant for the only-child group, r = -.243, p = .03. One-way ANOVAs indicated the three birth orders did not differ significantly on caregiver distress, family resources, ASD symptom severity, and child externalizing behaviors. However, some group differences emerged: not-first-born higher for satisfaction; first-born lower for efficacy; only-child lower for ASD knowledge and higher for child internalizing behaviors (overall) and perceived social support (compared to first-born). Results suggest having a TD child first may enhance feelings of readiness as a parent. Having multiple children may also increase parents’ actual knowledge of ASD. This finding, in combination with the only-child condition’s negative correlation between efficacy and knowledge, prompts the need for further research.Bottom of Form

 

Parenting Daily Hassles and Pessimism Moderate the Relation between ASD Symptom Severity and Parental Expressed Emotion

Parenting Daily Hassles and Pessimism Moderate the Relation between ASD Symptom Severity and Parental Expressed Emotion

Primary Author: Aurora Brinkman

Faculty Sponsor: Tammy Barry

 

Primary College/Unit: Arts and Sciences

Category: Physical and Social Sciences

Campus: Pullman

 

Abstract:

Principle Topic: Expressed emotion (EE) is the amount of criticism, hostility, and emotional over-involvement in family relationships. EE is common in families who have a child with autism spectrum disorder (ASD) and can lead to worse outcomes for families, including greater physical and mental health problems for the caregivers and more severe child behavior problems. Past research has shown that stress and parenting style affect EE, but more research is needed to understand factors that impact EE. This study examined how intensity of parenting daily hassles and pessimism (both risk factors) impacts the relation between ASD symptom severity and EE (specifically criticism) over time.

 

Method: Participants were 127 caregivers who completed two online surveys (via Qualtrics) one year apart. At Time 1, caregivers completed measures assessing demographics, child ASD symptom severity, intensity of parenting daily hassles, and parental pessimism. At Time 2, they completed a questionnaire assessing parental criticism.

 

Results/Implications: Overall, ASD symptom severity related to parental criticism over time. Intensity of parenting daily hassles and pessimism at Time 1 each interacted with ASD symptom severity in predicting parental criticism. Parental criticism was high when the intensity of parenting daily hassles was also high, regardless of ASD symptom severity, or when both pessimism and ASD symptom severity were high.

 

The results indicate areas for clinical intervention when working with families with children with ASD. Addressing daily parenting hassles and reducing pessimism through positive coping strategies may lead to a reduction in EE, improving caregiver mental health and child behavior.

 

Predictors of Successful College Adjustment for First-Year Students

Predictors of Successful College Adjustment for First-Year Students

Primary Author: Kathryn Bruzios

Faculty Sponsor: Brittany Cooper

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Physical and Social Sciences

Campus: Pullman

 

Abstract:

 

PRINCIPAL TOPIC

First-year students face transitional challenges and may struggle with developing their own identity, making friends, and becoming independent. Securely attached students, and those who actively seek out social support tend to achieve better social adjustment to college. Research assessing links between students’ self-esteem and college adjustment remain inconclusive as does the impact of social media use. For first-year students, the pressure to adjust quickly and successfully is a strong force to bear. Therefore, the present study sought to examine possible predictors of successful college adjustment.

METHOD

First-year students (n = 42) from a small liberal arts university, completed a series of assessments measuring possible predictors of college adjustment including parental and peer attachment, social support, self-esteem, and Facebook use. Secure individuals with better social support were expected to have better adjustment overall. Some motivations of using Facebook were also expected to play a role. Independent samples t-tests were conducted to examine whether dating status, student status, or sex were significant covariates. Zero order correlations and multiple regressions were conducted for each possible predictor.

RESULTS/IMPLICATIONS

Findings consistently supported that secure attachment with peers, higher self-esteem, and student status were predictors of a more successful adjustment to college. This research has implications for colleges and departments with an influential role in easing students into the college environment. Empirical support of successful adjustment predictors should be applied to interventions implemented in the first-year experience in future studies. Further attention to intricacies of residential and commuter students’ experiences is also warranted.

 

No Such Thing as Trash: A 3D-Printable Polymer Composite Composed of Oil-Extracted Spent Coffee Grounds and Polylactic Acid with Enhanced Impact Toughness

No Such Thing as Trash: A 3D-Printable Polymer Composite Composed of Oil-Extracted Spent Coffee Grounds and Polylactic Acid with Enhanced Impact Toughness

Primary Author: Yu-Chung Chang

Faculty Sponsor: Yuehe Lin

 

Primary College/Unit: Voiland College of Engineering and Architecture

Category: Engineering and Environmental Science

Campus: Pullman

 

Abstract:

 

Principal topic: As one of the most popular beverages in the world, a large amount of coffee wastes known as the spent coffee grounds (SCGs) is generated daily. It would be a waste if these SCGs is directly dumped to landfills. The advantage of SCGs it contains a lot of cellulose fibers that can be repurposed for new sustainable materials for a variety of applications.

Methods: In this study, we report a polylactic acid (PLA) composite filament with a high loading of oil-extracted spent coffee grounds (Ox-SCGs) up to 20% by weight and is three-dimensional (3D)-printable with a commercially available consumer-level 3D printer. The Ox-SCG-loaded PLA was found to be able to increase impact energy absorption. As a result, the PLA/Ox-SCG composite exhibited a 418.7% increase in toughness with a measure of 25.24 MJ/m3 at a 20 wt % Ox-SCG loading and only a 26% storage modulus reduction from the 100% PLA specimens at room temperature.

Results: The experimental results indicate that as a waste product from human consumptions and post biodiesel extraction, the Ox-SCG is proven to be a promising additive for composite property modification. Ox-SCG can not only increase the impact of toughness but also reduce the cost of overall 3D-printing materials. The applications of this composite materials are endless consider 3D printers are getting cheaper and the only limits are people’s imaginations

Customers’ Attitudes toward the Acceptance of AI Service Devices Cross Different Service Contexts

Customers’ Attitudes toward the Acceptance of AI Service Devices Cross Different Service Contexts

Primary Author: Hengxuan Chi

Faculty Sponsor: Dogan Gursoy

 

Primary College/Unit: Carson College of Business

Category: Business, Communication, and Politial Sciences

Campus: Pullman

 

Abstract:

 

Principal topic

Nowadays, service providers introduced Artificially intelligent (AI) service devices (e.g., robots) into their regular service operations. These devices are used to directly interact with customers and provide services that were originally delivered by human employees. As a result, the use of these AI devices challenges not only customers’ perceptions of service but also employees’ job security. Therefore, it is critical to understand when (service contexts) customers want to use AI and when they prefer to be served by humans.

 

Method

This study hypothesized that consumers’ attitudes towards the use of AI devices differ across hedonic (enjoyment-focused) and utilitarian (task-focused) service contexts. A conceptual model was proposed using the theory of Artificially Intelligent Device Use Acceptance. The data was collected from the customers of hospitality and airline industries, which are dominated by either more utilitarian or hedonic offerings (airline and hospitality services, respectively). A cross-group SEM analysis and a series of t-test were performed to test the hypotheses.

 

Results/implications

This study confirms the applicability of the AIDUA theory in both service contexts. Findings indicate that social influence is a stronger determinant of AI device acceptance in hedonic services (e.g. hospitality services); individuals have higher performance expectancy toward the use of AI device in utilitarian services (e.g., airline services); individuals’ willingness to use AI devices is lower in hedonic services due to the need for human-human interaction. This result highlights that, in hedonic services, AI devices should be used to empower rather than to replace human employees.

 

Pinpointing regions of the barley genome contributing to hybrid disease susceptibility

Pinpointing regions of the barley genome contributing to hybrid disease susceptibility

Primary Author: Shaun Clare

Faculty Sponsor: Robert Brueggeman

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Principal topic

Barley is an essential ingredient in beer and whiskey. Barley breeding allows for the improvement of barley by crossing two different parents to contribute favorably to offspring for traits such as yield and disease resistance. The increased use of hybrid varieties that possess genes from each parent (heterozygous) rather than favorable genes from either parent (homozygous) has allowed increased yield termed hybrid vigor. However, two lines that are resistant to a disease called net blotch have been shown to be susceptible to the disease when in a heterozygous state. Identifying the mechanism that allows two resistant parents to produce susceptible offspring is important to avoid releasing varieties that do not perform for growers.

Method

To identify the gene responsible for the hybrid susceptibility, ~2000 offspring were propagated with mosaic genomes of each parent. Single nucleotide changes in the genome that are known to be different between each parent were used on the susceptible offspring as a roadmap through the mosaic to pinpoint the region of the genome responsible for susceptibility.

Results/implications

The susceptibility region of the genome has been pinpointed to a five million nucleotide region within the barley genome that contains over five billion nucleotides. Next steps include adding additional markers by sequencing genes and validating which genes in the region are responsible for susceptibility. Removal of this gene will allow for the development of barley varieties that are healthy under disease pressure to ensure secure production of quality barley to feed the beer and whiskey industry.

 

Effects of water stress on transmission of ‘Candidatus Liberibacter solanacearum’ pathogen by the vector Bactericera cockerelli

Effects of water stress on transmission of ‘Candidatus Liberibacter solanacearum’ pathogen by the vector Bactericera cockerelli

Primary Author: Abigail Cohen

Faculty Sponsor: David Crowder

 

Primary College/Unit: Agricultural, Human and Natural Resource Sciences

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Principle Topic

Both plant pathogens and insects cause damage to crops and be financially ruinous to growers, and do even more damage when a damaging pest transmits the pathogen. However, environmental factors moderate how plant, pest, and pathogen interact with one another. This experiment looks at how water stress alters potato plant defenses when exposed to the pest Bactericera cockerelli, or potato psyllid. The potato psyllid feeds on solanaceous plants, and pierces plant veins to extract phloem sap. This makes it a capable vector for the bacterial pathogen Candidatus Liberibacter solanacearum (Lso), which causes an economically damaging disease known as zebra chip.

Method

To test the effect of water stress on transmission of the Lso pathogen and potato plant defenses, we exposed potato plants with and without water stress to infected B. cockerelli over 3h, 24h, 28h, and 120 h, while stress-free uninfected plants were used as control. Potato psyllids have a wide range and multiple sub-populations, so we ran the experiment twice, first with the Northwestern sub-population, then with Western.

Results/Implications

These results indicate that water stress in the plant has a negative effect on transmission or circulation of the bacterial pathogen through the plant, in both sub-populations. Furthermore, testing the level of defensive hormones in the exposed plants showed that water stress correlates to higher levels of the hormone associated with defense induction, suggesting that stress primes the plant for infection. This indicates that managed water stress may have the potential to reduce Lso infection in potato plants.

 

A Methodology for the Identification and Measurement of Corporate Social Responsibility Constructs with Existing Analyst Data

A Methodology for the Identification and Measurement of Corporate Social Responsibility Constructs with Existing Analyst Data

Primary Author: Michael Craven

Faculty Sponsor: Bernard Wong-On-Wing

 

Primary College/Unit: Carson College of Business

Category: Business, Communication, and Politial Sciences

Campus: Pullman

 

Abstract:

PRINCIPAL TOPIC

Research on Corporate Social Responsibility (CSR) and business outcomes has produced inconsistent results, which may be associated with difficulties in measuring CSR. Prevailing measurement methodologies use existing databases with indicators of strengths and weaknesses on environmental, social, and governance (ESG) issues including MSCI ESG KLD STATS. However, current research assumes that the strengths and weaknesses of each category accurately reflect differentiable constructs, that strengths are equivalently reduced by weaknesses, and that each indicator is equal when measuring those constructs.

 

METHOD

A scale development methodology is created to overcome the limitations of the existing data and to empirically identify and measure CSR constructs from the analyst data. Because indicators are added and removed, the indicators are screened with a co-measurement based variation of Cronbach’s Alpha to ensure sufficient covariance for further analysis. These indicators are then analyzed with logistic regression based exploratory factor analysis to identify the latent CSR constructs represented by the data and confirmatory factor analysis to provide continuous measures from the dichotomous indicators.

 

RESULTS AND IMPLICATIONS

The results indicate that prior measurement models for CSR poorly reflect the underlying aspects of CSR. In most categories, the assumption of differentiable strengths and weaknesses misidentifies the extant constructs. The assumption of equal weighting of indicators does not hold. Work is needed to validate these new measures against know CSR outcomes, such as fines for pollution. These empirically identified CSR constructs and measurements will resolve a long-standing issue and contribute to resolving the inconsistent results of prior CSR research.