Life Sciences Commons^™

Crassostrea Gigas Invasion In Southern California: Macrofaunal Diversity And Local Community Impacts Of Ecosystem Engineers On Estuarine Habitats, Noah Jansen-Yee

Theses

Many marine ecosystems are facing the growing threat of biological invasions. These invasions can have a variety of different impacts on ecosystems and their inhabitants. The Pacific oyster, Crassostrea gigas, is currently in the relatively early stages of invasion in San Diego estuaries. Crassostrea gigas is a large, filter-feeding bivalve that forms dense oyster beds on hard substrate. These oysters are known to outcompete native counterparts and drastically alter habitats where they are present. Crassostrea gigas is an ecosystem engineer that, through shell creation and formation of a dense oyster matrix, impacts ecosystems in a variety of direct and indirect …

Data-Driven Modeling Predicts Gene Regulatory Network Dynamics During The Differentiation Of Multipotential Hematopoietic Progenitors, Joanna Handzlik, Manu

Biology Faculty Publications

Cellular differentiation during hematopoiesis is guided by gene regulatory networks (GRNs) comprising transcription factors (TFs) and the effectors of cytokine signaling. Based largely on analyses conducted at steady state, these GRNs are thought to be organized as a hierarchy of bistable switches, with antagonism between Gata1 and PU.1 driving red- and white-blood cell differentiation. Here, we utilize transient gene expression patterns to infer the genetic architecture—the type and strength of regulatory interconnections—and dynamics of a twelve-gene GRN including key TFs and cytokine receptors. We trained gene circuits, dynamical models that learn genetic architecture, on high temporal-resolution gene-expression data from the …

Reprogramming Of Sorghum Proteome In Response To Sugarcane Aphid Infestation, Sajjan Grover, Juan Betancurt Cardona, Prince Zogli, Sophie Alvarez, Michael J. Naldrett, Scott E. Sattler, Joe Louis

Department of Entomology: Faculty Publications

Sugarcane aphid (SCA; Melanaphis sacchari Zehntner) is a key piercing-sucking pest of sorghum (Sorghum bicolor) that cause significant yield losses. While feeding on host plants, complex signaling networks are invoked from recognition of insect attack to induction of plant defenses. Consequently, these signaling networks lead to the production of insecticidal compounds or limited access of nutrients to insects. Previously, several studies were published on the transcriptomics analysis of sorghum in response to SCA infestation, but no information is available on the physiological changes of sorghum at the proteome level. We used the SCA resistant sorghum genotype SC265 for …

Harnessing Mycobacterium Bovis Bcg Trained Immunity To Control Human And Bovine Babesiosis, Reginaldo G. Bastos, Heba F. Alzan, Vignesh A. Rathinasamy, Brian M. Cooke, Odir A. Dellagostin, Raul G. Barletta, Carlos E. Suarez

School of Veterinary and Biomedical Sciences: Faculty Publications

Babesiosis is a disease caused by tickborne hemoprotozoan apicomplexan parasites of the genus Babesia that negatively impacts public health and food security worldwide. Development of effective and sustainable vaccines against babesiosis is currently hindered in part by the absence of definitive host correlates of protection. Despite that, studies in Babesia microti and Babesia bovis, major causative agents of human and bovine babesiosis, respectively, suggest that early activation of innate immune responses is crucial for vertebrates to survive acute infection. Trained immunity (TI) is defined as the development of memory in vertebrate innate immune cells, allowing more efficient responses to subsequent …

Molecular Characterization Of Antibiotic Resistant Shiga Toxin-Producing Escherichia Coli From Clinical And Food Samples, Khulud Alotaibi

Theses and Dissertations

Antimicrobial resistance (AMR) in foodborne pathogens can be a consequence of using antimicrobial drugs in food-producing animals. The emergence of antimicrobial resistance in foodborne pathogens is of great concern due to adverse patient health outcomes and the possibility of transferring genes encoding AMR to other clinically relevant pathogens. One of these bacteria is Shiga toxin-producing Escherichia coli (STEC), which can cause serious illness in humans for a haemolytic uremic syndrome (HUS). This study characterized and determined the mechanism of antibiotic resistance in 46 Shiga toxin-producing Escherichia coli strains collected by the U.S. Food and Drug Administration from food and clinical …

Montane Temperate-Boreal Forests Retain The Leaf Economic Spectrum Despite Intraspecific Variability, Matthew J. Hecking, Jenna M. Zukswert, John E. Drake, Martin Dovciak, Julia I. Burton

Michigan Tech Publications, Part 1

Trait-based analyses provide powerful tools for developing a generalizable, physiologically grounded understanding of how forest communities are responding to ongoing environmental changes. Key challenges lie in (1) selecting traits that best characterize the ecological performance of species in the community and (2) determining the degree and importance of intraspecific variability in those traits. Recent studies suggest that globally evident trait correlations (trait dimensions), such as the leaf economic spectrum, may be weak or absent at local scales. Moreover, trait-based analyses that utilize a mean value to represent a species may be misleading. Mean trait values are particularly problematic if species …

Larval Habitats, Species Composition And Distribution Of Malaria Vectors In Regions With Autochthonous And Imported Malaria In Roraima State, Brazil, Nathália Coelho Vargas De Almeida, Jaime Louzada, Maycon Sebastião Alberto Santos Neves, Thiago M. Carvalho, Júlio Castro‑Alves, Teresa Fernandes Silva‑Do‑Nascimento, Ananias A. Escalante, Joseli Oliveira‑Ferreira

Harold W. Manter Laboratory of Parasitology: Library Materials

Background: Malaria control requires local action. Assessing the vector diversity and abundance provides information on the local malariogenic potential or risk of transmission. This study aimed to determine the Anopheles species composition, habitats, seasonal occurrence, and distribution in areas with autochthonous and imported malaria cases in Roraima State.

Methods: A longitudinal study was conducted from January 2017 to October 2018, sampling larvae and adult mosquitoes in three municipalities of Roraima State: Boa Vista, Pacaraima and São João da Baliza. These areas have different risks of malaria importation. Four to six mosquito larval habitats were selected for larval sampling …

Effects Of Thickness Fraction Process On Physicochemical Properties, Cooking Qualities, And Sensory Characteristics Of Long-Grain Rice Samples, Sara E. Jarma Arroyo, Terry J. Siebenmorgen, Han-Seok Seo

Food Science Faculty Publications and Presentations

A process of removing thinner kernels of rough rice, i.e., thickness fraction process, has been suggested as a method for increasing milling yields in the rice industry. This study aimed at determining whether physicochemical properties, cooking qualities, and sensory characteristics of rice samples could be changed by the addition of a thickness fraction into the rice process stream. Each of four long-grain rice cultivar lots was assigned into two groups: unfractionated and thickness-fractionated. For the thickness-fractionated group, thin rice kernels (

Impact Of Enclosures On Range Productivity In Chepareria West Pokot County Kenya, Regina W. Waiganjo, P. N. Mwangi, Rebecca H. Karanja

IGC Proceedings (1977-2023)

In the semi-arid areas of West Pokot particularly Chepareria, majority of the people live semi sedentary lives while others are nomadic pastoralists. In the last three decades, there have been concerted efforts to restore and improve rangeland in this area. Use of enclosures, which is one of the key interventions, by the Vi Agro- forestry a Non-Governmental Organisation, enhancing with many ecological processes such as disturbance, is a method of rehabilitating degraded rangeland, which in turn affects vegetation dynamics. Adoption of these strategies by farmers has been gradual and some areas are still open and degraded. The aim of this …

Increased Above-Ground Biomass And Plant Species Decline Related To The Presence Of Eragrostis Curvula Across Multiple Grazing Grasslands In The Snowy Monaro Region Of Australia, J. Brown, L. Ingram

IGC Proceedings (1977-2023)

"It will be noticed that invasions most often come to cultivated land, or to land much modified by human practice." This quote was published in 1958 by Charles Elton, and holds true today, backed by empirical evidence suggesting mechanisms of disturbance, plant functional traits and propagule pressure can push a cultivated system towards an invaded state. 17 farms, with either a current or previous history of grazing and land modification, within the Snowy Monaro Region, NSW, Australia, were surveyed to explore the relationship between the non-native C4 perennial tussock grass Eragrostis curvula [Schrad.] Nees. and species richness. As E. curvula …

The Use Of Open Communal Grazing Designs To Screen Options For Grazing Management, David R. Kemp, D. L. Michalk, P. M. Dowling, G. Millar

IGC Proceedings (1977-2023)

An open communal grazing design is described that enables a large number of grazing tactics to be concurrently evaluated in small plots under common grazing conditions. Pasture data indicated that the same level of utilisation occurred inside the experimental plots as in the surrounding field. However, differential grazing may occur where plots have divergent composition. The open communal design was economical using < 5% of the land, livestock and fencing resources of alternative designs. The limitations of the open communal design as a research tool are also discussed.

Stocking Rate And Supplementation Effects On Performance Of Lambs Grazing Triticale And Ryegrass Sward In Uruguay, R. San Julián, Fabio Montossi, L. Guarino, F. Pittaluga

IGC Proceedings (1977-2023)

An experiment was carried out from 9 June to 2 October 1997, using a Lolium multiflorum Lom. (Ryegrass) and X Triticosecale Wittmack (triticale) sward to evaluate the effect of stocking rate (SR; 20, 30 and 40 lambs/ha), and supplementation (S; with or without) on Corriedale lamb performance. SR had a significant effect on: liveweight gain (160, 130 and 90 g/an/d, P< 0.01); greasy fleece weight (2.8, 2.7 and 2.3 kg, P< 0.01); fiber diameter (28, 27, and 26 microns, P< 0.05); rib eye depth (2.4, 2.1 and 2.0 cm, P< 0.05); fat cover (3.2, 2.1 and 1.5 cm, P< 0.01); hot carcass weight (17.7, 15.6 and 13.5 kg/an, P< 0.01); GR (10.5, 6.6 and 4.2 mm, P< 0.01) and boneless leg weight (1.56, 1.42 and 1.24 kg, P< 0.05), for 20, 30 and 40 lambs per ha, respectively. At the highest SR, lambs increased grazing time (59 vs 52%) and biting rate (29 vs 26 bites/lamb/min). The mayor influence of S on lamb performance was found in grazing behavior variables: (grazing time (63 vs 50%, P< 0.01); biting rate (26.8 vs 28.4 bites/lamb/min, P< 0.01)), carcass characteristics: (hot carcass weight (15.3 vs 16.0 kg, P< 0.05); GR (7.9 and 6.3 mm, P< 0.05)) for with and without supplement, respectively. Over the experimental period (115 days), liveweight production and wool production ranged from 358 to 437 kg/ha for 20 and 30 lambs/ha respectively, and wool production from 55 to 93 kg/ha for 20 and 40 lambs/ha respectively. These results show the potential use of mixed ryegrass and triticale swards to produce high quality lamb meat even at high SRs, and the convenience of using supplements only when sward conditions are not sufficient to maintain an adequate lamb performance, particularly when high lamb SRs are used.

Lamb Stocking Rate And Supplementation Effects On Mixed Triticale And Ryegrass Swards Characteristics, R. San Julián, Fabio Montossi, L. Guarino, F. Pittaluga

IGC Proceedings (1977-2023)

An experiment was carried out from 9 June to 22 October 1997, using a Lolium multiflorum L. (ryegrass) and Triticosecale Wittmack (triticale) mixed sward grazed by lambs in a rotational grazing system, to determine the effect of stocking rate (SR; 20, 30 and 40 lambs/ha) and supplementation (S; with or without) on herbage production, composition and nutritive value. SR affected significantly before and after grazing herbage mass and sward height, being higher the values of these variables at the lower SR (3232, 2611 and 2345 kg DM ha^-1, P < 0.05; 2557, 1761 and 1612 kg DM ha^-1, P < 0.01; 17, 11 and 9 cm, P < 0.01 respectively). Increments in SR had an effect on post grazing sward composition, increasing the proportion of ryegrass (32, 36 and 47 %, P< 0.05) and decreasing triticale contribution (68, 64 and 55 %, P< 0.05) for 20, 30 and 40 lambs/ha. The effect of SR on sward nutritive value was not very clear. Before grazing, S affected significantly herbage mass, being higher the values at the supplemented treatments (2787 vs. 2672 kg DM ha^-1, P < 0.10). This experiment showed the high potential of forage production and nutritive value of ryegrass and triticale swards for lamb production in the sandy soil region of Uruguay, and the dominant effect of SR, compared to S, on most of the sward variables considered.

Bio-Membrane Internalization Mechanisms Of Arginine-Rich Cell-Penetrating Peptides In Various Species, Betty Revon Liu, Shiow Her Chiou, Yue-Wern Huang, Han Jung Lee

Biological Sciences Faculty Research & Creative Works

Recently, membrane-active peptides or proteins that include antimicrobial peptides (AMPs), cytolytic proteins, and cell-penetrating peptides (CPPs) have attracted attention due to their potential applications in the biomedical field. Among them, CPPs have been regarded as a potent drug/molecules delivery system. Various cargoes, such as DNAs, RNAs, bioactive proteins/peptides, nanoparticles and drugs, can be carried by CPPs and delivered into cells in either covalent or non-covalent manners. Here, we focused on four arginine-rich CPPs and reviewed the mechanisms that these CPPs used for intracellular uptake across cellular plasma membranes. The varying trans-duction efficiencies of them alone or with cargoes were discussed, …

Reef Sediments Can Act As A Stony Coral Tissue Loss Disease Vector, Michael S. Studivan, Ashley M. Rossin, Ewelina Rubin, Nash Soderberg, Daniel M. Holstein, Ian C. Enochs

Faculty Publications

Stony coral tissue loss disease (SCTLD) was first observed in 2014 near Virginia Key in Miami-Dade County, Florida. Field sampling, lab experiments, and modeling approaches have suggested that reef sediments may play a role in SCTLD transmission, though a positive link has not been tested experimentally. We conducted an ex situ transmission assay using a statistically-independent disease apparatus to test whether reef sediments can transmit SCTLD in the absence of direct contact between diseased and healthy coral tissue. We evaluated two methods of sediment inoculation: batch inoculation of sediments collected from southeast Florida using whole colonies of diseased Montastraea cavernosa, …

Diversity And Time-Series Analyses Of Caribbean Deep-Sea Coral And Sponge Assemblages On The Tropical Island Slope Of Isla De Roatán, Honduras, Peter J. Etnoyer, Charles G. Messing, Karl A. Stanley, Tomasz K. Baumiller, Kate Lavelle, Thomas C. Shirley

Marine & Environmental Sciences Faculty Articles

Shore-based submersible operations, from 2006 to 2020, have allowed us to examine megabenthic assemblages along the island margin of Isla de Roatán from depths of about 150 to 750 m, including repeated observations of the same organisms. These dives were used to photo-document a diverse benthic assemblage and observe the health and condition of the sessile fauna in a well-explored but relatively undocumented area of the Mesoamerican Reef. Samples were collected by dip net, and some dives profiled the water column chemistry in the year 2011. The deep-sea coral assemblage observed off Roatan exhibits high abundance and diversity. The sessile …

Influence Of Beef Carcass Chilling Rate On Steak Case Life And Quality Traits, Trevor Dehaan, Lydia Hite, Erin Gubbels, Christina Elaine Bakker, Amanda D. Blair, Judson Grubbs, Keith Underwood

SDSU Beef Day 2022 Summary Publication

Study Description:

Twelve head of fed beef cattle were harvested at the SDSU Meat Laboratory over two days. Carcasses were allotted into two weight groups based on hot carcass weight (HCW): Heavyweight (HW) and Lightweight (LW). Data logging thermometers were placed in the left side of each carcass within the round, loin, rib, and chuck primals to track temperature decline. Carcass measurements including 12th rib fat thickness, ribeye area and marbling score were collected approximately 48 hours postmortem. Steaks from each primal were collected to measure Warner-Bratzler shear force (WBSF), objective and subjective color.

Drought Mitigation For Cow/Calf Producers: Depopulation Strategies, Reganne K. Briggs, Joshua Dallin, Jacob Hadfield, Matthew D. Garcia

All Current Publications

Drought is a recurring event faced by many cow/calf producers across the nation. As drought events increase in their severity, it is important for cattle producers to have a management plan to mitigate the economic effects of drought. Two of the most common strategies for mitigating the effects of drought include buying additional feed and depopulating a portion of the herd. This fact sheet reviews strategies that will guide the decision-making process to cull cattle during drought.

Spatial Personalities: A Meta-Analysis Of Consistent Individual Differences In Spatial Behavior, Erica F. Stuber, Ben S. Carlson, Brett R. Jesmer

Wildland Resources Faculty Publications

Individual variation in behavior, particularly consistent among-individual differences (i.e., personality), has important ecological and evolutionary implications for population and community dynamics, trait divergence, and patterns of speciation. Nevertheless, individual variation in spatial behaviors, such as home range behavior, movement characteristics, or habitat use has yet to be incorporated into the concepts or methodologies of ecology and evolutionary biology. To evaluate evidence for the existence of consistent among-individual differences in spatial behavior – which we refer to as “spatial personality” – we performed a meta-analysis of 200 repeatability estimates of home range size, movement metrics, and habitat use. We found that …

Prevalence And Amounts Of Common Ingredients Found In Energy Drinks And Shots, Andrew R. Jagim, Patrick S. Harty, Abdelrahman R. Barakat, Jacob L. Erickson, Victoria Carvalho, Chinguun Khurelbaatar, Clayton L. Camic, Chad M. Kerksick

Faculty Scholarship

Background: Energy drinks are one of the most popular packaged beverage products consumed within the United States (US). Energy drinks are considered a functional beverage, a category that also includes sports drinks and nutraceutical beverages. Purpose: The focus of the current study was to examine the nutrition fact panels of the top selling commercially available energy drink and energy shot products within the US to characterize common ingredient profiles to help establish a standard definition and ingredient profile of energy drinks and energy shots for consumers, health care practitioners, and researchers. Methods: The top 75 commercially available energy drinks and …

A Whole-Exome Case-Control Association Study To Characterize The Contribution Of Rare Coding Variation To Pancreatic Cancer Risk, Yao Yu, Kyle Chang, Jiun-Sheng Chen, Ryan J Bohlender, Jerry Fowler, Maosheng Huang, Yanan Li, Justin Wong, Huamin Wang, Jian Gu, Xifeng Wu, Joellen Schildkraut, Lisa Cannon-Albright, Yuanqing Ye, Hua Zhao, Michelle A T Hildebrandt, Jennifer B Permuth, Donghui Li, Paul Scheet, Chad D Huff

Faculty, Staff and Student Publications

Pancreatic cancer is a deadly disease that accounts for approximately 5% of cancer deaths worldwide, with a dismal 5-year survival rate of 10%. Known genetic risk factors explain only a modest proportion of the heritable risk of pancreatic cancer. We conducted a whole-exome case-control sequencing study in 1,591 pancreatic cancer cases and 2,134 cancer-free controls of European ancestry. In our gene-based analysis, ATM ranked first, with a genome-wide significant p value of 1 × 10-8. The odds ratio for protein-truncating variants in ATM was 24, which is substantially higher than prior estimates, although ours includes a broad 95% confidence interval …

Habitat, Phenology, And Seed Studies Of Citrullus Colocynthis In Lut Desert, Iran, Nastaran Kahrom, Mohammad Farzam, Mansour Mesdaghi

IGC Proceedings (1977-2023)

Colocynth is one of the major medicinal plants that naturally grows in deserts of Middle East and North Africa. Extending cultivation of this species is useful for sand dune fixation and for making incomes for the needy inhabitants. Despite of numerous studies on seed germination, there are still debates on best method of seed dormancy breaking for colocynth. Moreover, seed morphology, phonological stages, and habitat conditions of this species are not fully studied. In a flat plain of Gonabad, located at the edge Lut desert, we established line transects of 200 m and plots of 4×4 m, where vegetation parameters, …

Effect Of Winter Grazing Management Of Stockpiled Native Pastures Of Basaltic Soils Of Uruguay On Daily Gains Of Heifers, G. Pigurina, R. Castells, G. Reyes, E. J. Berretta

IGC Proceedings (1977-2023)

The effect of three grazing systems of fall stockpiled native pastures on the winter gains of 66 Hereford heifers (135 kg) was studied. Treatments were: continuos grazing (CG); (C7) the plot was divided in 12 and each was grazed for 7 days and (C28), the plot was divided in 3 and each were grazed for 28 days. Heifers were weighed every 14 days and grazing behaviour was recorded. Stockpiled HM was greater (P< 0.05) in C7 and C28 than in CG (988, 912, and 604 kg DM/ha, respectively). Herbage allowance (HA) was greater (P< 0.01) in CG followed by C28 and C7 (11.7, 6.6 and 5.9 kg DM/100 kg LW, respectively). Post-grazing HM was greater (P0.05) in all pastures (CP 10.2%, NDF 71.2%, ADF 41.3% and ash 14.4%). Final LW of heifers were similar (P> 0.05) (167, 162 and 160 kg for CG, C7 and C28, respectively). A very mild winter favoured exceptional gains which tended to be higher in CG (0.353 …

Influence Of Stocking Rate And Grazing System On Lamb Performance Of Mixed Oat And Ryegrass Swards In Uruguay, Fabio Montossi, R. San Julián, C. Arocena, A. Dighiero

IGC Proceedings (1977-2023)

An experiment was conducted at INIA-Tacuarembó Research Station (Uruguay) during 15 June to 4 October 1998, using a Avena Sativa (oat) and Lolium multiflorum (ryegrass) sward to examine the effect of stocking rate (SR; 25 and 35 lambs/ha) and grazing system (GS; strip and 7 days rotational grazing) on sward and lamb performance. SR had a significant effect on lamb performance, being higher the liveweight gain (LWG; 120 vs 98 g/a/d, P < 0.01), hot carcass weight (HCW; 17.7 vs 16.1 kg/a, P < 0.05) and carcass fat cover (GR; 12 vs 8 mm, P < 0.01) of those lambs managed at the lower SR. At the high SR, lambs increased grazing time (405 vs 376 min., P < 0.05). SG did not affect lamb performance, but strip GS reduces lamb grazing time (367 vs 414 min., P < 0.01) and biting rates (22 vs 24 bites/lamb/min., P < 0.01). Post grazing sward height (SH) was highly associated with LWG (LW = - 101,7 + 32.7 SH – 1.49 SH², R² = 0.66). This experiment demonstrated that: (a) the productive potential of ryegrass and oat swards to produce high quality …

Lamb Stocking, Grazing System And Supplementation Effects On Triticale And Ryegrass Swards Performance In Uruguay, Fabio Montossi, R. San Julián, D. Correa, F. Gonzales, V. Porcile

IGC Proceedings (1977-2023)

An experiment was carried out from 3 of July to 22 of October 1998, using a Lolium multiflorum Lom. (ryegrass) and Triticosecale Wittmack (triticale) sward grazed by lambs, to examine the effect of stocking rate (SR; 25 and 35 lambs/ha), grazing system (GS; strip and 7 days rotational grazing) and supplementation (S; with or without) on sward structure, production, composition and nutritive value. SR affected significantly pre and post grazing herbage mass and sward height, being higher at the lower SR (3211 vs 2832 kg DM ha^-1, P < 0.01; 2443 vs 1939 kg DM ha^-1, P < 0.01; 19 vs 17 cm, P < 0.01 and 10 vs 8 cm, P < 0.01 respectively), increasing, at the high SR, the proportions of the ryegrass green leaf component, particularly in the uppermost layers of the sward canopy. In comparison with 7 days rotational GS, strip GS resulted in higher post grazing herbage mass, sward height and nutritive value (2387 vs 1996 DM ha^-1, P < 0.01; 10 vs 9 cm, P …