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Determination of thermal inactivation kinetics (D- and z-values) of Salmonella in brownie batter

Determination of thermal inactivation kinetics (D- and z-values) of Salmonella in brownie batter

Primary Author: Monipel Ansong

Faculty Sponsor: Minto Michael

 

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

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Principal Topic: Salmonella can be introduced into bakery products through ingredients such as flour, milk, cocoa powders, and eggs. Studies have shown that Salmonella can survive under adverse environmental conditions over time; therefore, it is vital to study the thermal inactivation kinetics (D- and z-values) of Salmonella in bakery products such as brownie batter. The aim of this study was to determine the D- and z-values of a 5-serovar Salmonella cocktail in brownie batter.

 

Methods: All-purpose flour was inoculated with a 5-serovar Salmonella cocktail (Enteritidis, Senftenberg, Typhimurium, Montevideo and Newport) and used to prepare brownie batter. This study implemented a randomized complete block design with three replications as blocks. The batter was subjected to heat treatment using thermal-death-time disks in hot water bath at 64, 68, 72 and 76C for 0, 3, 6, 9, 12 min, respectively. The Salmonella population was enumerated using injury-recovery media (brain heart infusion agar overlaid with xylose lysine deoxycholate agar). The graphs for calculating D- and z-values were plotted using Microsoft Excel, and D- and z-values were calculated as absolute values of the inverse of slopes.

 

Results/implications: The D-values of 5-serovar Salmonella cocktail in brownie batter were 53.4±5.38, 27.2±2.04, 10.7±0.72 and 4.6±0.49 min at 64, 68, 72 and 76C, respectively; whereas, z-value of the Salmonella cocktail was 11.1±0.71C. D-values from this study provide the basic information about the thermal resistance of Salmonella in brownie batter at the start of baking and could help the bakery industry to optimize cooking parameters ensuring the safety of brownies.

 

Cellulose nanocrystal dispersions protect reproductive buds of tree fruit from cold damage by forming a thermal barrier

Cellulose nanocrystal dispersions protect reproductive buds of tree fruit from cold damage by forming a thermal barrier

Primary Author: Brent Arnoldussen

Faculty Sponsor: Matthew Whiting

 

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

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Every year, tree fruit growers lose money from cold damage to reproductive buds or flowers eventually become the future fruit and yield. The Food and Agriculture Organization reported that cold damage has caused more economic losses to crops than any other weather hazard. The potential losses from cold damage are predicted to increase with variable weather patterns resulting from climate change. Cellulose nanocrystals (CNC) represents a new generation of renewable nano-biomaterials, with many unique physical and chemical properties, including their low thermal conductivity. Our team has synthesized a CNC dispersion that can be sprayed onto trees, forming a thin and durable insulating film on the surface of the buds. Thermal image analysis shows apple and cherry buds treated with 3% CNC dispersions lose 16.5% less thermal energy into the environment in cold conditions than the control. As such, analysis of internal freezing events of CNC coated apple buds with digital scanning calorimetry showed that lethal freezing occurred 3.2°C lower than in the control 1 day after application and 5.5°C lower after 3 days. Large scale field test of 2.5% CNC solutions applied using a commercially available orchard sprayer showed that CNC treated trees are given 5.8°C of protection as long as 7 days post application. The results of this work suggest that the use of CNC could represent an advancement in cold damage prevention in fruit crops. The significant and long-lasting protection offered by CNC could allow for a reduction in  economic losses from cold damage

Associative learning of food odors by paper wasps (Hymenoptera: Vespidae)

Associative learning of food odors by paper wasps (Hymenoptera: Vespidae)

Primary Author: Megan Asche

Faculty Sponsor: Richard Zack

 

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

Category: Agricultural and Natural Resource Sciences

Campus: Pullman

 

Abstract:

 

Principal topic

Traps and bait stations that utilize attractants can manage paper wasp populations without pesticides. The purpose of this experiment is to test the associative learning behavior of paper wasps and evaluate their level of attraction to three plant-based odors. The hypothesis tested was that wasps exposed to food inoculated with an odor would show a higher level of attraction to that odor than wasps that were not previously exposed.

Methods

Wasps were separated into two groups, “naïve” and “experienced.” Naive wasps were fed an odorless sugar water solution and experienced wasps received a sugar water solution with a 1% concentration of an odor. After the feeding, wasps were placed into a flight tunnel and the level of attraction to the odor was scored.

Results/implications

Strong evidence for associative learning behavior by spring queens and workers has been shown. However, the fall queens and males were less successful. The difference in learning ability between these groups may be because, in nature, spring queens and workers both forage for food, while fall queens and males do not.

This research was funded by U.S. Air Force. Paper wasps form swarms and aggregations on air control towers in late summer and autumn. These wasps can be a hazardous to people and negatively impact equipment. The ability of paper wasps to learn and respond to chemical cues associated with a food may provide an opportunity to manipulate them. These results suggest we can develop a “train and trap” strategy for controlling paper wasps.

 

Identifying and Exploring Learners’ Prior Knowledge about Technical Legal Vocabulary

Identifying and Exploring Learners’ Prior Knowledge about Technical Legal Vocabulary

Primary Author: Sandra Bancroft-Billings

Faculty Sponsor: Tom Salsbury

 

Primary College/Unit: College of Education

Category: Arts and Education Sciences

Campus: Pullman

 

Abstract:

Principal topic

Technical vocabulary is specific to a “particular topic, field or discipline” (Nation, 2001, p. 198). In U.S. law schools, technical legal vocabulary is a significant portion of the new language, legal English, that initiates must learn. Increasingly, those initiates are internationally-trained attorneys, enrolling in U.S. law schools because English has become the lingua franca of international commerce (Breeze, 2015). This study identifies and describes technical legal vocabulary used in a law school course and assesses students’ prior knowledge about that vocabulary. Principals of second-language acquisition (SLA) are used as a theoretical framework.

 

Method

In part one, transcripts of a contracts course were analyzed by comparing those transcripts to transcripts from an academic corpus that did not contain law courses. Additionally, transcripts were qualitatively coded to quantify and describe classroom discussions about legal vocabulary.

 

In part two, law school initiates who speak English as an additional language were tested on a 40-item sample of the vocabulary identified in part one. Participants’ self-reported vocabulary knowledge, and evidence of that knowledge were collected.

 

Results/implications

Keywords identified by comparing transcripts were found to more effectively identify useful vocabulary than did compiling a list of terms explicitly defined in class discussions. Further, keywords’ meanings as used in class tended to connect to core meanings of those terms. Ongoing analysis of initiates’ prior vocabulary knowledge indicates that they could benefit from exposure to specific vocabulary, particularly vocabulary that occurs with lower frequency in typical spoken English, before beginning U.S. law school courses.

 

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