Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 3121 - 3150 of 10866

Full-Text Articles in Entire DC Network

Influence Of Landscape Attributes On Virginia Opossum Density, David A. Bernasconi, Wesley C. Dixon, Matthew T. Hamilton, James L. Helton, Richard B. Chipman, Amy T. Gilbert, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan Jan 2022

Influence Of Landscape Attributes On Virginia Opossum Density, David A. Bernasconi, Wesley C. Dixon, Matthew T. Hamilton, James L. Helton, Richard B. Chipman, Amy T. Gilbert, James C. Beasley, Olin E. Rhodes Jr., Guha Dharmarajan

United States Department of Agriculture Wildlife Services: Staff Publications

TheVirginia opossum (Didelphis virginiana), North America's only marsupial, has a range extending from southern Ontario, Canada, to the Yucatan Peninsula, Mexico, and from the Atlantic seaboard to the Pacific. Despite the Virginia opossum's taxonomic uniqueness in relation to other mammals in North America and rapidly expanding distribution, its ecology remains relatively understudied. Our poor understanding of the ecology of this important mesopredator is especially pronounced in the rural southeastern United States. Our goal was to estimate effects of habitat on opossum density within an extensive multiyear spatial capture‐recapture study. Additionally, we compared the results of this spatial capture‐recapture …

Go to article

Contributions Of Agroforestry Systems To Food Provisioning Of Peasant Households: Conflicts And Synergies In Chiapas, Mexico, Lorena Soto-Pinto, Sandra Escobar Colmenares, Marina Benítez Kanter, Angelita López Cruz, Erin Estrada Lugo, Balente Herrera Hernández, Estelí Jiménez-Soto Jan 2022

Contributions Of Agroforestry Systems To Food Provisioning Of Peasant Households: Conflicts And Synergies In Chiapas, Mexico, Lorena Soto-Pinto, Sandra Escobar Colmenares, Marina Benítez Kanter, Angelita López Cruz, Erin Estrada Lugo, Balente Herrera Hernández, Estelí Jiménez-Soto

School of Geosciences Faculty and Staff Publications

Traditional agroforestry systems are widely recognized for their contributions to provisioning, support, regulation, and cultural services. However, because of the advancement of industrial agriculture and a corporative food system, peasants' food systems are rapidly undergoing transformation. We identify the contributions of four types of agroforestry systems (AFS)—shade cocoa agroforest, shade coffee agroforest, milpas and homegardens—to food provisioning in peasant families and discuss conflicts between traditional food systems and the contemporary industrial model of production and consumption confronted by peasants and semi-proletarian migrants. We carried out research in 17 peasant communities in Chiapas, Mexico, and conducted 97 semi-structured interviews and agroecological …

Go to article

Addressing Rice Waste In University Cafeterias Using Material Flow Analysis And System Dynamics Modeling, Abigail Marie T. Favis, Charlotte Kendra Z. Gotangco-Gonzales, Ana Erika Lareza Jan 2022

Addressing Rice Waste In University Cafeterias Using Material Flow Analysis And System Dynamics Modeling, Abigail Marie T. Favis, Charlotte Kendra Z. Gotangco-Gonzales, Ana Erika Lareza

Environmental Science Faculty Publications

Food waste has emerged as one of the focus areas in sustainability research. At the Ateneo de Manila University, previous studies have found that food waste is composed mainly of rice. This study, therefore, analyzed cafeteria rice systems in the university through a material flow analysis (MFA) to identify key factors for formulating effective rice waste reduction techniques and then applied the results toward developing system dynamics (SD) models as tools for decision-making. The MFA found that the total mass of produced known rice waste was 49.48 kg/d. The largest sources of rice wastes were the upstream processes of the …

Go to article

Determinants Of Sustainability: A Case Of Piloting Isard Models In Oriental Mindoro And Leyte, Philippines, Pedcris M. Orencio, Anna Gale Vallez, Ruth Jazrel M. Bandong Jan 2022

Determinants Of Sustainability: A Case Of Piloting Isard Models In Oriental Mindoro And Leyte, Philippines, Pedcris M. Orencio, Anna Gale Vallez, Ruth Jazrel M. Bandong

Environmental Science Faculty Publications

SEARCA, in its 10th five-year plan (10th FYP), implemented the program, Inclusive and Sustainable Agricultural and Rural Development (ISARD). A pilot project was undertaken in a specific rural community following a well-defined scheme for an agroecosystem and through the integration of four inter-related components, technical assistance, capacity building, knowledge management, and linkage and networking. After the completion in 2020, evidences of well-developed agricultural system capable of contributing to the goals of food security and poverty alleviation emerged. In its 11th FYP, SEARCA endeavors to scale out the ARD model project in the Southeast Asian region. But, how will this benefit …

Go to article

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield Jan 2022

Targeted Browsing With Goats For Eastern Redcedar (Juniperus Virginiana L.) Control, Alanna M. Hartsfield

Electronic Theses and Dissertations

As eastern redcedar (ERC) (Juniperus virginiana L.) grassland encroachment progresses, all potential control methods should be explored in the interest of Great Plains grassland health and longevity. Targeted browsing with goats has been proven as an effective control method on some juniper species; however, little is known about its ability to control ERC. These studies intend to mend knowledge gaps of how targeted browsing with goats control ERC by causing tree death without chemicals or machinery. The first study is two 3x3 Latin squares comparing protein-supplemented diets. The second study is a randomized complete block design of five 0.224 ha …

Go to article

The Potential Of Bison Restoration As An Ecological Approach To Future Tribal Food Sovereignty On The Northern Great Plains, Hila Shamon, Olivia G. Cosby, Chamois L. Andersen, Helen Augare, Jony Bearcub Stiffarm, Claire E. Bresnan, Jeff M. Martin, Et Al. Jan 2022

The Potential Of Bison Restoration As An Ecological Approach To Future Tribal Food Sovereignty On The Northern Great Plains, Hila Shamon, Olivia G. Cosby, Chamois L. Andersen, Helen Augare, Jony Bearcub Stiffarm, Claire E. Bresnan, Jeff M. Martin, Et Al.

Natural Resource Management Faculty Publications

Future climate projections of warming, drying, and increased weather variability indicate that conventional agricultural and production practices within the Northern Great Plains (NGP) will become less sustainable, both ecologically and economically. As a result, the livelihoods of people that rely on these lands will be adversely impacted. This is especially true for Native American communities, who were relegated to reservations where the land is often vast but marginal and non-tribal operators have an outsized role in food production. In addition, NGP lands are expected to warm and dry disproportionately relative to the rest of the United States. It is therefore …

Go to article

Fertilizer Use In Aquaculture, Bartholomew W. Green Jan 2022

Fertilizer Use In Aquaculture, Bartholomew W. Green

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Aquaculture ponds traditionally are fertilized to stimulate primary productivity, which serves as the base of the pond natural food web and provides ancillary ecosystem services. Fertilizer can be made regularly or based on some water quality variable or measure of algal productivity. Nutrients from chemical fertilizers are available sooner for phytoplankton growth compared to organic fertilizers that first must undergo microbial decomposition before nitrogen and phosphorus concentrations increase. Primary production increases with increased fertilizer application if productivity is limited by primary nutrients rather than by light. In semi-intensive and intensive production systems, natural pond productivity enhanced by targeted fertilization protocols …

Go to article

Cultivation Of Industrial Hemp On And Near Airports: Implications For Wildlife Use And Risk To Aviation Safety, Bradley F. Blackwell, Page E. Klug, Lee A. Humberg, Zachary T. Brym, Bryan M. Kluever, Jenna Edwards Jan 2022

Cultivation Of Industrial Hemp On And Near Airports: Implications For Wildlife Use And Risk To Aviation Safety, Bradley F. Blackwell, Page E. Klug, Lee A. Humberg, Zachary T. Brym, Bryan M. Kluever, Jenna Edwards

United States Department of Agriculture Wildlife Services: Staff Publications

Industrial hemp (Cannabis sativa L.; hemp) is an emerging crop in the United States with little known about bird use or the potential for birds to become an agricultural pest. We identified birds associated with hemp fields, using repeated visits to oilseed plots in North Dakota, USA (n = 6) and cannabinoid (CBD) plots in Florida, USA (n = 4) from August to November 2020. We did not control for plot area or density; our observations were descriptive only. We observed 10 species in hemp, 12 species flying over hemp, and 11 species both foraging in and …

Go to article

Industrial Hemp As A Resource For Birds In Agroecosystems: Human-Wildlife Conflict Or Conservation Opportunity?, Emily A. Kotten, Iona Hennessy, Bryan M. Kluever, Bradley F. Blackwell, Lee A. Humberg, Page E. Klug Jan 2022

Industrial Hemp As A Resource For Birds In Agroecosystems: Human-Wildlife Conflict Or Conservation Opportunity?, Emily A. Kotten, Iona Hennessy, Bryan M. Kluever, Bradley F. Blackwell, Lee A. Humberg, Page E. Klug

United States Department of Agriculture Wildlife Services: Staff Publications

Industrial hemp (Cannabis sativa L.; hemp) is an emerging crop in the United States with little known about bird use or the potential for birds to become an agricultural pest. We identified birds associated with hemp fields, using repeated visits to oilseed plots in North Dakota, USA (n = 6) and cannabinoid (CBD) plots in Florida, USA (n = 4) from August to November 2020. We did not control for plot area or density; our observations were descriptive only. We observed 10 species in hemp, 12 species flying over hemp, and 11 species both foraging in and …

Go to article

Environmental Effects On Constructed Wetland Microbial Diversity And Function In The Context Of Wastewater Management, Sandrine Grandmont-Lemire Jan 2022

Environmental Effects On Constructed Wetland Microbial Diversity And Function In The Context Of Wastewater Management, Sandrine Grandmont-Lemire

Cal Poly Humboldt theses and projects

Microbial communities play a crucial role in ecosystems, yet we know little about how microbial diversity influences ecosystem functioning. An important gap in our understanding is how environmental change affects microbial Biodiversity-Ecosystem Function relationships (BEF). These complex interactions between microbial biodiversity and ecosystem function can influence major biogeochemical processes, such as the nitrogen cycle in wetland ecosystems, which play an important role in managing wastewater. To address the effect of biodiversity on function, my study investigates the BEF relationships between microbial diversity and the function in terms of ammonia removal from wastewater at the Arcata Wastewater Treatment Facility (AWTF) both …

Go to article

A Crash Course In Good And Bad Controls, Andrew Forney, Carlos Cinelli, Judea Pearl Jan 2022

A Crash Course In Good And Bad Controls, Andrew Forney, Carlos Cinelli, Judea Pearl

Computer Science Faculty Works

Many students of statistics and econometrics express frustration with the way a problem known as “bad control” is treated in the traditional literature. The issue arises when the addition of a variable to a regression equation produces an unintended discrepancy between the regression coefficient and the effect that the coefficient is intended to represent. Avoiding such discrepancies presents a challenge to all analysts in the data intensive sciences. This note describes graphical tools for understanding, visualizing, and resolving the problem through a series of illustrative examples. By making this “crash course” accessible to instructors and practitioners, we hope to avail …

Go to article

High Throughput Analysis Of Leaf Chlorophyll Content In Sorghum Using Rgb, Hyperspectral, And Fluorescence Imaging And Sensor Fusion, Huichun Zhang, Yufeng Ge, Xinyan Xie, Abbas Atefi, Nuwan Wijewardane,, Suresh Thapa Jan 2022

High Throughput Analysis Of Leaf Chlorophyll Content In Sorghum Using Rgb, Hyperspectral, And Fluorescence Imaging And Sensor Fusion, Huichun Zhang, Yufeng Ge, Xinyan Xie, Abbas Atefi, Nuwan Wijewardane,, Suresh Thapa

School of Computing: Faculty Publications

Leaf chlorophyll content plays an important role in indicating plant stresses and nutrient status. Traditional approaches for the quantification of chlorophyll content mainly include acetone ethanol extraction, spectrophotometry and high-performance liquid chromatography. Such destructive methods based on laboratory procedures are time consuming, expensive, and not suitable for high-throughput analysis. High throughput imaging techniques are now widely used for non-destructive analysis of plant phenotypic traits. In this study three imaging modules (RGB, hyperspectral, and fluorescence imaging) were, separately and in combination, used to estimate chlorophyll content of sorghum plants in a greenhouse environment. Color features, spectral indices, and chlorophyll fluorescence intensity …

Go to article

Sources Of Variability And Uncertainty In Food-Energy-Water Nexus Systems, Heydi Calderon-Ambelis, Deepak R. Keshwani Jan 2022

Sources Of Variability And Uncertainty In Food-Energy-Water Nexus Systems, Heydi Calderon-Ambelis, Deepak R. Keshwani

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A nexus approach contributes to the strategic allocation of resources to secure food, energy, and water for the world population. Integrated models considering the complex interactions across food, energy, and water (FEW) enhance decision-making and strategic planning towards resilience. However, a significant number of the existing integrated models leave unaddressed the inherent variability and uncertainty present in the FEW sectors. Here, we review the importance of characterizing variability over spatial and temporal scales and the importance of decreasing the uncertainty present within a FEW nexus systems. The review also discusses existing modeling tools that address variability and uncertainty on single …

Go to article

Frugivory And Seed Dispersal By Carnivorans, John P. Draper, Julie K. Young, Eugene W. Schupp, Noelle G. Beckman, Trisha B. Atwood Jan 2022

Frugivory And Seed Dispersal By Carnivorans, John P. Draper, Julie K. Young, Eugene W. Schupp, Noelle G. Beckman, Trisha B. Atwood

United States Department of Agriculture Wildlife Services: Staff Publications

Seed dispersal is critical to the ecological performance of sexually reproducing plant species and the communities that they form. The Mammalian order Carnivora provide valuable and effective seed dispersal services but tend to be overlooked in much of the seed dispersal literature. Here we review the literature on the role of Carnivorans in seed dispersal, with a literature search in the Scopus reference database. Overall, we found that Carnivorans are prolific seed dispersers. Carnivorans’ diverse and plastic diets allow them to consume large volumes of over a hundred families of fruit and disperse large quantities of seeds across landscapes. Gut …

Go to article

Transmission Of Antibiotic Resistance At The Wildlife-Livestock Interface, Shinyoung Lee, Peixin Fan, Ting Liu, Anni Yang, Raoul K. Boughton, Kim M. Pepin, Ryan S. Miller, Kwangcheol Casey Jeong Jan 2022

Transmission Of Antibiotic Resistance At The Wildlife-Livestock Interface, Shinyoung Lee, Peixin Fan, Ting Liu, Anni Yang, Raoul K. Boughton, Kim M. Pepin, Ryan S. Miller, Kwangcheol Casey Jeong

United States Department of Agriculture Wildlife Services: Staff Publications

Antibiotic-resistant microorganisms (ARMs) are widespread in natural environments, animals (wildlife and livestock), and humans, which has reduced our capacity to control life threatening infectious disease. Yet, little is known about their transmission pathways, especially at the wildlife-livestock interface. This study investigated the potential transmission of ARMs and antibiotic resistance genes (ARGs) between cattle and wildlife by comparing gut microbiota and ARG profiles of feral swine (Sus scrofa), coyotes (Canis latrans), cattle (Bos taurus), and environmental microbiota. Unexpectedly, wild animals harbored more abundant ARMs and ARGs compared to grazing cattle. Gut microbiota of cattle was …

Go to article

Strength In Numbers: Avian Influenza A Virus Transmission To Poultry From A Flocking Passerine, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner Jan 2022

Strength In Numbers: Avian Influenza A Virus Transmission To Poultry From A Flocking Passerine, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

The effects of flock size of European starlings (Sturnus vulgaris) was experimentally manipulated to assess the potential of influenza A virus (IAV; H4N6) transmission from a flocking passerine to bobwhite quail (Colinus virginianus) through shared food and water resources to mimic starling intrusions into free-range and backyard poultry operations. Of the three starling flock sizes tested (n = 30, n = 20 and n = 10), all successfully transmitted the virus to all or most of the quail in each animal room (6/6, 6/6 and 5/6) by the end of the experimental period, as determined by seroconversion and/or viral RNAshedding. …

Go to article

Summer Habitat Use And Movements Of Invasive Wild Pigs (Sus Scrofa) In Canadian Agro-Ecosystems, Corey J. Kramer, Melanie R. Boudreau, Ryan S. Miller, Ryan Powers, Kurt C. Vercauteren, Ryan K. Brook Jan 2022

Summer Habitat Use And Movements Of Invasive Wild Pigs (Sus Scrofa) In Canadian Agro-Ecosystems, Corey J. Kramer, Melanie R. Boudreau, Ryan S. Miller, Ryan Powers, Kurt C. Vercauteren, Ryan K. Brook

United States Department of Agriculture Wildlife Services: Staff Publications

Resource selection informs understanding of a species’ ecology and is especially pertinent for invasive species. Since introduced to Canada, wild pigs (Sus scrofa Linnaeus, 1978) remain understudied despite recognized negative impacts on native and agricultural systems globally. Elsewhere in North America, pigs typically use forests and forage in agricultural crops. We hypothesized Canadian wild pigs would behave similarly, and using GPS locations from 15 individuals, we examined diel and seasonal resource selection and movement in the Canadian prairie region. Forests were predominately selected during the day, while corn (Zea mays L.), oilseeds, and wheat (Triticum aestivum L.) …

Go to article

Influence Of Abiotic Drivers On 1-Year Seedling Survival Of Six Mangrove Species In Southeast Asia, Taylor M. Sloey, Kiah Eng Lim, Jared Moore, Jie Min Heng, Jia Min Heng, Michiel Van Breugel Jan 2022

Influence Of Abiotic Drivers On 1-Year Seedling Survival Of Six Mangrove Species In Southeast Asia, Taylor M. Sloey, Kiah Eng Lim, Jared Moore, Jie Min Heng, Jia Min Heng, Michiel Van Breugel

Biological Sciences Faculty Publications

Establishment and survival of plant species in systems with dominant environmental drivers (i.e. factors that exert disproportionate control over species establishment and survival) is often thought to be dominated by one master variable. In forested wetlands such as mangroves, hydrology is typically considered the dominant limiting driver. At the same time, light is a major driver of plant community dynamics, with some of the best understood plant life-history tradeoffs related to fast growth under high-light conditions versus survival under low-light conditions. Yet light is given relatively limited consideration in mangrove research compared to other drivers. Understanding the relative importance of …

Go to article

Impact Of Sleep And Training On Game Performance And Injury In Division-1 Women’S Basketball Amidst The Pandemic, Samah Senbel, S. Sharma, S. M. Raval, Christopher B. Taber, Julie K. Nolan, N. S. Artan, Diala Ezzeddine, Kaya Tolga Jan 2022

Impact Of Sleep And Training On Game Performance And Injury In Division-1 Women’S Basketball Amidst The Pandemic, Samah Senbel, S. Sharma, S. M. Raval, Christopher B. Taber, Julie K. Nolan, N. S. Artan, Diala Ezzeddine, Kaya Tolga

School of Computer Science & Engineering Faculty Publications

We investigated the impact of sleep and training load of Division - 1 women’s basketball players on their game performance and injury prediction using machine learning algorithms. The data was collected during a pandemic-condensed season with unpredictable interruptions to the games and athletic training schedules. We collected data from sleep monitoring devices, training data from coaches, injury reports from medical staff, and weekly survey data from athletes for 22 weeks.With proper data imputation, interpretable feature set, data balancing, and classifiers, we showed that we could predict game performance and injuries with more than 90% accuracy. More importantly, our F1 and …

Go to article

Isolation Of Ace2 Inhibitors From Rice Bran Oil By-Product, Muhammad Waqar Nasir Jan 2022

Isolation Of Ace2 Inhibitors From Rice Bran Oil By-Product, Muhammad Waqar Nasir

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to isolate γ-oryzanol from the crude oil acid fraction (a by-product of rice bran oil refinery) and to evaluate their Angiotensin-Converting Enzyme 2 (ACE2) inhibitory activity. Chromatographic fractionation of the crude oil acid fraction gave 3 isolated fractions of γ-oryzanol containing cycloartenyl ferulate, campesteryl ferulate, sitosteryl ferulate, stigmasteryl ferulate, and cyclobranyl ferulate. The γ-oryzanol containing cycloartenyl ferulate and campesteryl ferulate as major component showed good ACE2 inhibitory activity with the IC50 value 10.57 μg/mL. Furthermore, the 19 structures of γ-oryzanol were also studied for its interaction against ACE2 through molecular docking. Based on the in-silico study, ADME …

Go to article

Application Of Pork Checkoff We Care Sustainability Principles To Pork Production: Water, Nutrition, And Biosecurity, Hannah Miller Jan 2022

Application Of Pork Checkoff We Care Sustainability Principles To Pork Production: Water, Nutrition, And Biosecurity, Hannah Miller

Electronic Theses and Dissertations

The Pork Checkoff program was founded in 1986 as a means to strengthen U.S. pork in the market place (Pork Checkoff). Under this program all U.S. pork producers and importers pay $0.40 for every $100 worth of pigs is sold (Pork Checkoff). Funds are then used for pork promotion, research, and education for producers and consumers (Pork Checkoff). The Pork Checkoff program uses the We Care ethical principles as a means to address “continuous improvement in the pork industry’s production practices and promote a strong record of responsible farming to those outside of the industry” (National Pork Board, 2018a). The …

Go to article

Cooking Up A Data Literacy Course, Claire Nickerson Mlis Jan 2022

Cooking Up A Data Literacy Course, Claire Nickerson Mlis

Library Faculty Publications

This asynchronous online course, Interdisciplinary Studies 815: Introduction to Data, was developed for graduate students in the information analysis and communication concentration of the Fort Hays State University master of liberal studies degree. The course is designed for professionals who need to make data-driven decisions such as educators, policy makers, and nonprofit employees. It is a survey course, so it does not go into great depth on any of the topics covered but rather provides a basic grounding for developing further data literacy skills. It exclusively uses zero-cost resources, including openly licensed content, library-licensed e-books and articles, and free online …

Go to article

The Design And Synthesis Of New Organic Dithiols For Environmental Applications, Shashika Nadishani Bandara Jan 2022

The Design And Synthesis Of New Organic Dithiols For Environmental Applications, Shashika Nadishani Bandara

Theses and Dissertations--Chemistry

A thiol molecule, 2,6-pyridinediamidoethanethiol (PB9), was synthesized based on the pyridine-2,6-dicarboxamide scaffold with appended cysteamine groups. PB9 acts as an effective chelator for Pb(II) due to multiple binding sites (N3S2) through irreversible binding precipitating Pb(II). Removal of aqueous Pb(II) from solution was demonstrated by exploring the effects of time, initial PB9:Pb(II) ratios, pH, exposure time, and solution temperature. After 15 min the Pb(II) concentrations were reduced from 50.00 ppm to 0.30 ppm (99.4%) and 0.25 ppm (99.5%) for PB9:Pb ratios of 1:1 and 2:1, respectively. Removal of > 93% Pb(II) was observed over multiple pH values with …

Go to article

Healthcare Management Strategies For Achieving Sustainable Departmental Productivity Improvements, Timothy Hargrove Jan 2022

Healthcare Management Strategies For Achieving Sustainable Departmental Productivity Improvements, Timothy Hargrove

Walden Dissertations and Doctoral Studies

Healthcare organizations’ leaders' lack of strategies to effectively deploy and monitor departments’ productivity goals affect overall organizations’ performance. Healthcare leaders who fail to deploy and monitor departmental productivity strategies effectively are limited to enhancing healthcare organizations’ performance outcomes. Grounded in transformational leadership theory, the purpose of this qualitative multiple case study was to explore strategies healthcare organizations’ leaders use to effectively identify, deploy, and monitor departments’ goals for improving their overall organization's performance. The participants were 20 healthcare leaders who successfully demonstrated success in improving their organizations’ departmental-specific productivity performance. Data were collected using semistructured interviews and a review of …

Go to article

Policy Sustainability Issues: Case Study Of Cassava Farmers In Ikorodu. Lagos, Nigeria, Medinat Oluwatoyin Adetunji Jan 2022

Policy Sustainability Issues: Case Study Of Cassava Farmers In Ikorodu. Lagos, Nigeria, Medinat Oluwatoyin Adetunji

Walden Dissertations and Doctoral Studies

The inconsistency and lack of continuity of Nigeria's agricultural policies impact the cassava sector. Despite being the world's biggest producer, the country is yet to benefit from the advantage due to a lack of sustainable growth. The situation manifests in terms of low productivity, low production level, and poor income to the farmers. The purpose of this qualitative study was to investigate the experiences and perceptions of the cassava farmers on cassava policies and the effect on their income and livelihoods in the Ikorodu local government of Lagos State. This qualitative study adopted a case study research design using participatory …

Go to article

Length Of Stay In A Homeless Shelter And Mitigating Homelessness, Uwemedimo S. Etteyit Jan 2022

Length Of Stay In A Homeless Shelter And Mitigating Homelessness, Uwemedimo S. Etteyit

Walden Dissertations and Doctoral Studies

AbstractHomelessness is a major public health issue in the United States. Every night, thousands of people have no residence to call their own. Most homeless persons turn to homeless shelters for help. Despite the homeless shelters, the problem of homelessness persists. This study examined the concept that the length of time spent at a homeless shelter is related to the homeless persons mitigating their homelessness through home placement, jobs, and healthcare access. Homelessness was examined using the socioecological model with its attendant levels of influence. On the intrapersonal level, socioeconomic status, education, old age, veteran status, and disability were factors. …

Go to article

Effects Of Substrate Types On Nitrogen Removal Efficacy And Growth Of Canna Indica L., Arunothai Jampeetong, Pakawat Janyasupab Jan 2022

Effects Of Substrate Types On Nitrogen Removal Efficacy And Growth Of Canna Indica L., Arunothai Jampeetong, Pakawat Janyasupab

Applied Environmental Research

Constructed wetlands (CWs), a cost effective technology for wastewater treatment, consist of substrates and wetland plants, which should be selected carefully to gain highest treatment efficiency. However, studies on plant growth and responses to different types of substrates are very few. This study aims to assess the effects of substrate types on growth and root morphology of Canna indica L. and nitrogen (N) removal. Twenty-four similar sized approximately 1 month old C. indica plants were selected and grown on different substrates (gravel, pumice and biochar). All plants were supplied with a standard growth medium to which 14 mg L-1 NH4+, …

Go to article

Risk Assessment Of Total Mercury (T-Hg) In Commercial Seafood Marketed In Bangkok, Thailand, Irwan Ramadhan Ritonga, Sujaree Bureekul, Penjai Sompongchaiyakul Jan 2022

Risk Assessment Of Total Mercury (T-Hg) In Commercial Seafood Marketed In Bangkok, Thailand, Irwan Ramadhan Ritonga, Sujaree Bureekul, Penjai Sompongchaiyakul

Applied Environmental Research

Seafood is recognized as the high protein source of human consumption. However, it is hampered by mercury contamination. The objectives of this study are to determine total mercury (T-Hg) levels in edible portions of commercial seafood available in Bangkok’s supermarkets, and to evaluate the potential risks from mercury through seafood consumption. Total 32 species, including 22 fish, 4 cephalopod and 6 shellfish, were purchased from super-markets. Fish samples were dissected in 3 parts comprised of flesh, gill and viscera. While, cephalopod and shellfish were separated for edible tissues. The samples were digested in hot acid and were determined using cold-vapor …

Go to article

Assessment Of Organophosphorus Pesticide Residues In Water And Sediment Collected From The Southern Caspian Sea, Reza Golshani, Ghasem Ghorbanzadeh Zafarani, Maksim Rebezov, Samaneh Karbalaei, Tony R. Walker Jan 2022

Assessment Of Organophosphorus Pesticide Residues In Water And Sediment Collected From The Southern Caspian Sea, Reza Golshani, Ghasem Ghorbanzadeh Zafarani, Maksim Rebezov, Samaneh Karbalaei, Tony R. Walker

Applied Environmental Research

Pollution of water resources by uncontrolled pesticide use is a serious health and environmental issue. In this study, concentrations of three organophosphorus pesticides (diazinon, malathion, and azinphos-methyl) in water and sediment samples from five estuaries (Sefidrud, Chalus, Babolrud, Tajan, and Gorganrud) along the Caspian Sea were investigated. Samples were collected from surface water and sediment during summer to autumn, and pesticides were analysed by gas chromatography-mass spectrometry (GC-MS). Results indicated that salinity and turbidity in Gorganrud were higher (salinity: range 2–8%; turbidity: range 1–9%) compared to other stations. Higher diazinon (water: 0.08±0.06, sediment: 0.04±0.01), malathion (water: 0.09±0.06, sediment: 0.05±0.01) and …

Go to article

Dynamics Of Mutualism In A Two Prey, One Predator System With Variable Carrying Capacity, Randy Huy Lee Jan 2022

Dynamics Of Mutualism In A Two Prey, One Predator System With Variable Carrying Capacity, Randy Huy Lee

UNF Graduate Theses and Dissertations

We considered the livelihood of two prey species in the presence of a predator species. To understand this phenomenon, we developed and analyzed two mathematical models considering indirect and direct mutualism of two prey species and the influence of one predator species. Both types of mutualism are represented by an increase in the preys' carrying capacities based on direct and indirect interactions between the prey. Because of mutualism, as the death rate parameter of the predator species goes through some critical value, the model shows transcritical bifurcation. Additionally, in the direct mutualism model, as the death rate parameter decreases to …

Go to article

First Prev Next Last