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Whole-Body And Muscle Protein Metabolism Are Not Affected By Acute Deviations From Habitual Protein Intake In Older Men: The Hormonal Regulators Of Muscle And Metabolism In Aging (Horma) Study, Kevin E. Yarasheski, Carmen Castaneda-Sceppa, Jiaxiu He, Miwa Kawakubo, Shalender Bhasin, Ellen F. Binder, E. Todd Schroeder, Ronenn Roubenoff, Stan P. Azen, Fred R. Sattler

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

Background:

Acute deviations in protein intake before the quantification of protein kinetics in older humans may explain the controversy over the effects of older age on muscle protein synthesis and proteolysis rates.

Objective:

We hypothesized that an acute decrease in protein intake from the habitual intake is associated with lower muscle protein synthesis and higher proteolysis rates, whereas an acute increase in protein intake from the habitual intake is associated with higher muscle protein synthesis and lower proteolysis rates.

Design:

In 112 community-dwelling healthy men aged 65–90 y, we quantified resting whole-body [1,2-¹³C₂]leucine kinetics, muscle mixed …

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Energy Feedstock Production, John L. Kovar, Douglas L. Karlen

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

The use of corn (Zea mays L.) as a bio-energy feedstock has attracted the attention of many producers. Recently, the focus has shifted from grain-based to cellulose-based ethanol production. In addition to biological conversion of corn stover to ethanol, thermal conversion (pyrolysis) of stover is being explored. Regardless of post-harvest processing, the short- and long-term effects of both increasing grain yields and removing stover on soil nutrient cycling, physical properties, and biological activity must be understood to ensure that soil productivity and ecosystem services are maintained. Our objectives for 2010 were to evaluate: (i) the use of surface or …

Patterns Of Widespread Decline In North American Bumble Bees, Sidney A. Cameron, Jeffrey D. Lozier, James P. Strange, Jonathan B. Koch, Nils Cordes, Leellen F. Solter, Terry L. Griswold

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

Bumble bees (Bombus) are vitally important pollinators of wild plants and agricultural crops worldwide. Fragmentary observations, however, have suggested population declines in several North American species. Despite rising concern over these observations in the United States, highlighted in a recent National Academy of Sciences report, a national assessment of the geographic scope and possible causal factors of bumble bee decline is lacking. Here, we report results of a 3-y interdisciplinary study of changing distributions, population genetic structure, and levels of pathogen infection in bumble bee populations across the United States. We compare current and historical distributions of eight species, compiling …

Comparative Cryopreservation Of Avian Spermatozoa: Benefits Of Non-Permeating Osmoprotectants And Atp On Turkey And Crane Sperm Cryosurvival, Juan M. Blanco, Julie A. Long, George Gee, David E. Wildt, Ann M. Donoghue

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

A comparative approach was used to evaluate the cryosurvival of turkey and crane sperm frozen in a dimethylacetamide (DMA) cryodiluent supplemented with osmoprotectants and ATP. A range (6–26%) of DMA concentrations was used alone or in combination with ATP (30, 60 or 118mM) or one of the following osmoprotectants: (1) sucrose (turkey, 8.0%; crane, 5.0%); (2) 5.0% sucrose and 5.0% trehalose; or (3) betaine hydrochloride (0.1, 0.2 or 0.4 mM). The viability of thawed sperm was assessed using the nigrosin–eosin stain and sperm motility was determined using the hanging-drop technique. For semen frozen only with DMA, post-thaw sperm motility was …

Carbon Exchange By Establishing Biofuel Crops In Central Illinois, Marcelo Zeri, Kristina Anderson-Teixeira, George Hickman, Michael Masters, Evan Delucia, Carl J. Bernacchi

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

Perennial grass bio-fuels may contribute to long-term carbon sequestration in soils, thereby providing a broad range of environmental benefits. To quantify those benefits, the carbon balance was investigated over three perennial grass bio-fuel crops – miscanthus (Miscanthus×giganteus), switch-grass (Panicum virgatum) and a mixture of native prairie plants – and a row crop control (maize–maize–soy) in Central Illinois, USA, during the establishment phase of the perennial grasses (2008–2011). The eddy covariance technique was used to calculate fluxes of carbon dioxide and energy balance components, such as latent and sensible heat fluxes. Whereas maize attained the highest maximal …

Saving The Sagebrush Sea: An Ecosystem Conservation Plan For Big Sagebrush Plant Communities, Kirk W. Davies, Chad S. Boyd, Jeffrey L. Beck, Jon D. Bates, Tony J. Svejcar, Michael A. Gregg

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

Vegetation change and anthropogenic development are altering ecosystems and decreasing biodiversity. Successful management of ecosystems threatened by multiple stressors requires development of ecosystem conservation plans rather than single species plans. We selected the big sagebrush (Artemisia tridentata Nutt.) ecosystem to demonstrate this approach. The area occupied by the sagebrush ecosystem is declining and becoming increasingly fragmented at an alarming rate because of conifer encroachment, exotic annual grass invasion, and anthropogenic development. This is causing rangewide declines and localized extirpations of sagebrush associated fauna and flora. To develop an ecosystem conservation plan, a synthesis of existing knowledge is …

Effects Of Transmission Gear Selection On Tractor Performance And Fuel Costs During Deep Tillage Operations, C.M. Kichler, J.P. Fulton, R.L. Raper, T.P. Mcdonald, W.C. Zech

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

Deep tillage operations required to alleviate soil compaction common in the Southeastern US remain energy intensive and expensive. Equipment performance and in-field efficiency are two variables that can be improved to minimize fuel consumption and ultimately reduce input costs for crop production. The objective of this study was to investigate the effects of transmission gear selection on fuel costs, draft, and other equipment performance variables using two deep tillage implements. Three different transmission gears were selected which represented slow, normal, and fast operating speeds for two typical in-row, integral subsoilers (KMC generation I rip-strip and Bigham Brothers Paratill^TM). …

Differentially Expressed Genes In Populus Simonii×Populus Nigra In Response To Nacl Stress Using Cdna-Aflp, Lei Wang, Boru Zhou, Lili Wu, Baozhu Guo, Tingbo Jiang

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

Salinity is an important environmental factor limiting growth and productivity of plants, and affects almost every aspect of the plant physiology and biochemistry. The objective of this study was to apply cDNA-AFLP and to identify differentially expressed genes in response to NaCl stress vs. no-stress in Populus simonii × Populus nigra in order to develop genetic resources for genetic improvement. Selective amplification with 64 primer combinations allowed the visualization of 4407 transcript-derived fragments (TDFs), and 2027 were differentially expressed. Overall, 107 TDFs were re-sequenced successfully, and 86 unique sequences were identified in 10 functional categories based on their putative functions. …

Methodologies For Simulating Impacts Of Climate Change On Crop Production, Jeffrey W. White, Gerrit Hoogenboom, Bruce A. Kimball, Gerard W. Wall

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

Ecophysiological models are widely used to forecast potential impacts of climate change on future agricultural productivity and to examine options for adaptation by local stakeholders and policy makers. However, protocols followed in such assessments vary to such an extent that they constrain cross-study syntheses and increase the potential for bias in projected impacts. We reviewed 221 peer-reviewed papers that used crop simulation models to examine diverse aspects of how climate change might affect agricultural systems. Six subject areas were examined: target crops and regions; the crop model(s) used and their characteristics; sources and application of data on [CO₂] …

Evaluation Of Waxy Grain Sorghum For Ethanol Production, Shuping Yan, Xiaorong Wu, Scott R. Bean, Jeffery F. Pedersen, Tesfaye Tesso, Yuanhong Chen, Donghai Wang

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

The objective of this research was to investigate the fermentation performance of waxy grain sorghum for ethanol production. Twenty-five waxy grain sorghum varieties were evaluated with a laboratory dry-grind procedure. Total starch and amylose contents were measured following colorimetric procedures. Total starch and amylose contents ranged from 65.4 to 76.3% and from 5.5 to 7.3%, respectively. Fermentation efficiencies were in the range of 86.0-92.2%, corresponding to ethanol yields of 2.61-3.03 gallons/bushel. The advantages of using waxy sorghums for ethanol production include easier gelatinization and low viscosity during liquefaction, higher starch and protein digestibility, higher free amino nitrogen (FAN) content, and …

Anointing Chemicals And Hematophagous Arthropods: Responses By Ticks And Mosquitoes To Citrus (Rutaceae) Peel Exudates And Monoterpene Components, Paul J. Weldon, John F. Carroll, Matthew H. Kramer, Robert H. Bedoukian, Russell E. Coleman, Ulrich R. Bernier

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

Some birds and mammals roll on or wipe themselves with the fruits or leaves of Citrus spp. or other Rutaceae. These anointing behaviors, as with anointing in general, are thought to function in the topical acquisition of chemicals that deter consumers, including hematophagous arthropods. We measured avoidance and other responses by nymphal lone star ticks (Amblyomma americanum) and adult female yellow fever mosquitoes (Aedes aegypti) to lemon peel exudate and to 24 volatile monoterpenes (racemates and isomers), including hydrocarbons, alcohols, aldehydes, acetates, ketones, and oxides, present in citrus fruits and leaves in order to examine their …

The Acute Toxicity Of The Death Camas (Zigadenus Species) Alkaloid Zygacine In Mice, Including The Effect Of The Methyllycaconitine Coadministration On Zygacine Toxicity, K. D. Welch, K. E. Panter, D. R. Gardner, B. L. Stegelmeier, B. T. Green, J. A. Pfister, D. Cook

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

Death camas (Zigadenus spp.) is a common poisonous plant on foothill rangelands in western North America. The steroidal alkaloid zygacine is believed to be the primary toxic component in death camas. Poisonings on rangelands generally occur in the spring when death camas is abundant, whereas other more desirable forage species are limited in availability. In most cases where livestock are poisoned by plants in a range setting, there is more than one potential poisonous plant in that area. One common poisonous plant that is often found growing simultaneously in the same area as death camas is low larkspur ( …

Discriminating Microsatellites From Macrophomina Phaseolina And Their Potential Association To Biological Functions, R. S. Arias, J. D. Ray, A. Mengistu, B. E. Scheffler

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

One hundred and eighty-two microsatellites or simple-sequence-repeat (SSR) markers for Macrophomina phaseolina were developed. These were tested on 24 isolates of M. phaseolina obtained from seven plant species, and the genetic variation of isolates was studied in relation to potential biological processes that could be affected in this fungus. A total of 120 SSR markers were polymorphic, amplifying >90% of the 24 isolates tested. Thirty percent of the markers showed multiple alleles on individual samples. A large number of markers showed unique alleles in isolates collected from pumpkin and snap bean. DNA sequences corresponding to 43 markers had significant hits …

Field-Scale Soil Property Changes Under Switchgrass Managed For Bioenergy, Marty R. Schmer, M. A. Liebig, K. P. Vogel, Robert B. Mitchell

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

The capacity of perennial grasses to affect change in soil properties is well documented but information on switchgrass (Panicum virgatum L.) managed for bioenergy is limited. An on-farm study (10 fields) in North Dakota, South Dakota, and Nebraska was sampled before switchgrass establishment and after 5 years to determine changes in soil bulk density (SBD), pH, soil phosphorus (P), and equivalent mass soil organic carbon (SOC). Changes in SBD were largely constrained to near-surface depths (0–0.05 m). SBD increased (0–0.05 m) at the Nebraska locations (mean=0.16 Mgm^-3), while most South Dakota and North Dakota locations showed declines …

Community Structures Of Fecal Bacteria In Cattle From Different Animal Feeding Operations, Orin C. Shanks, Catherine A. Kelty, Shawn Archibeque, Michael Jenkins, Ryan Newton, Sandra L. Mclellan, Susan M. Huse, Mitchell L. Sogin

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

The fecal microbiome of cattle plays a critical role not only in animal health and productivity but also in food safety, pathogen shedding, and the performance of fecal pollution detection methods. Unfortunately, most published molecular surveys fail to provide adequate detail about variability in the community structures of fecal bacteria within and across cattle populations. Using massively parallel pyrosequencing of a hypervariable region of the rRNA coding region, we profiled the fecal microbial communities of cattle from six different feeding operations where cattle were subjected to consistent management practices for a minimum of 90 days. We obtained a total of …

Use Of Gis-Based Site-Specific Nitrogen Management For Improving Energy Efficiency, Kevin F. Bronson, Peter C. Scharf, Newell R. Kitchen

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

To our knowledge, geographical information system (GIS)-based site-specific nitrogen management (SSNM) techniques have not been used to assess agricultural energy costs and efficiency. This chapter uses SSNM case studies for corn (Zea mays L.) grown in Missouri and cotton (Gossypium hirsutum L.) grown in Texas. In five case studies, the impact of SSNM will be compared with blanket N fertilizer recommendations. The five case studies are investigating (I) the impact N on energy produced in cotton production, (2) the impact of variable-rate N for cotton production based on soil nitrate and crop reflectance, (3) the feasibility of variable-rate …

New Records And Ecological Remarks Regarding The Tribe Stomoxyini (Diptera: Muscidae) From Israel, Günter Müller, Jerome Hogsette, Vasiliy Kravchenko, Edita Revay, Yosef Schlein

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

The Stomoxyini is a small tribe with only ten genera and 49 known species worldwide (Zumpt 1973) belonging to the Muscidae, one of the largest dipteran. Apart from feeding occasionally on nectar (Müller et al. 2011a), the adult flies of this tribe are obligate blood feeders and can easily be recognized by their conspicuous proboscis adapted for biting and sucking blood (Zumpt 1973). Several members of the tribe, especially Stomoxys and Haematobia species, are major pests of domestic livestock. Two species, Stomoxys calcitrans (Linnaeus 1758) and Haematobia irritans (Linnaeus 1758), cause billions of USD in damages annually in the cattle …

Evapotranspiration Information Reporting: I. Factors Governing Measurement Accuracy, Richard G. Allen, Luis S. Pereira, Terry A. Howell, Marvin E. Jensen

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

More and more evapotranspiration models, evapotranspiration crop coefficients and associated measurements of evapotranspiration (ET) are being reported in the literature and used to develop, calibrate and test important ET process models. ET data are derived from a range of measurement systems including lysimeters, eddy covariance, Bowen ratio, water balance (gravimetric, neutron meter, other soil water sensing), sap flow, scintillometry and even satellite-based remote sensing and direct modeling. All of these measurement techniques require substantial experimental care and are prone to substantial biases in reported results. Reporting of data containing measurement biases causes substantial confusion and impedance to the advancement of …

Beneath The Surface Of Global Change: Impacts Of Climate Change On Groundwater, Timothy R. Green, Makoto Taniguchi, Henk Kooi, Jason J. Gurdak, Diana M. Allen, Kevin M. Hiscock, Holger Treidel, Alice Aureli

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

Global change encompasses changes in the characteristics of inter-related climate variables in space and time, and derived changes in terrestrial processes, including human activities that affect the environment. As such, projected global change includes groundwater systems. Here, groundwater is defined as all subsurface water including soil water, deeper vadose zone water, and unconfined and confined aquifer waters. Potential effects of climate change combined with land and water management on surface waters have been studied in some detail. Equivalent studies of groundwater systems have lagged behind these advances, but research and broader interest in projected climate effects on groundwater have been …

Landform, Soil, And Plant Relationships To Nitrate Accumulation, Central Nevada, W.D. Nettleton, F.F. Peterson

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

Nitrate (NO₃ ⁻¹) accumulates in Haplocambids and Torrifluvents in inset fan and fan skirt positions in central Nevada. The soils store as much as 17,600 kg of NO3 −1 N ha−1 within the upper 208 cm. This paper provides an explanation. These Holocene soils receive NO₃ ⁻¹ N from mineralization of organic matter and other NO₃ ⁻¹ N sources including snowmelt. The NO₃ ⁻¹ is delivered to soils in the first part of snowmelt in run-off from the higher surfaces. The last part of the melt and the run-off, when sufficient, serve to move the …

Spider Cognition, Robert R. Jackson, Fiona R. Cross

All Peer-Reviewed Publications

Spiders, having minute brains, were once considered simple, instinct-driven automatons, but research on spider biology is revealing increasing evidence of their cognitive abilities. In this review, we discuss the complex, flexible behaviour of spiders, especially salticids, and highlight how sometimes the cognitive character of spider behaviour closely parallels that of much bigger animals. This includes the use of selective attention (both visual and olfactory) and the use of planned detours. The implications of these findings, and how they relate to bigger issues traditionally associated with big-brain animals, such as 'representation' and 'mind', are discussed. Also discussed are issues relating to …

Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …

Control Of Invasive Liriomyza Leafminer Species And Compliance With Food Safety Standards By Small Scale Snow Pea Farmers In Kenya, Zachary Maina Gitonga, Adenirin Chabi-Olaye, Dagmar Mithöfer, Julius Juma Okello, Cecilia Nyawira Ritho

All Peer-Reviewed Publications

The Kenyan horticultural industry faces a new challenge following invasion by the quarantine Liriomyza leafminer species Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii which have recently become pests of economic importance. Controlling Liriomyza leafminers poses serious difficulties due to their biology and quarantine status. This paper examines farmers' awareness of the pests and difficulties faced in controlling them. (1) A questionnaire survey showed that snow pea farmers in Kenya rely mainly on pesticides for control of invasive Liriomyza leafminers; (2) Sixty five percent of respondents perceived pesticides to be ineffective; (3) As a result, 74% of respondents increased the frequency …

Guano Exploitation In Madagascar, Christina Buliga

Independent Study Project (ISP) Collection

Agriculture in Madagascar continues to remain largely undeveloped. Out of the eighty percent of Malagasy individuals that live in rural areas an overwhelming sixty five percent practice subsistence agriculture. With respect to the country as a whole this means that out of Madagascar's 58.2 million hectares of available land only 5.2 percent (3 million hectares) are farmed. And out of these 3 million hectares only 67% are cultivated permanently and only 11% are fertilized.

While there are several reasons for why Madagascar’s agriculture has remained largely undeveloped and for why Madagascar continues to rely on imported crops to meet its …

Summaries Of Arkansas Cotton Research 2009, Derrick M. Oosterhuis

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

B. R. Wells Rice Research Studies 2009, R. J. Norman, K. A. K. Moldenhauer

Arkansas Agricultural Experiment Station Research Series

No abstract provided.

Geographic Distribution, Host Range And Perennation Of Cotesia Sesamiae And Cotesia Flavipes Cameron In Cultivated And Natural Habitats In Kenya, Duna Madu Mailafiya, Bruno Pierre Le Ru, Eunice Waitherero Kairu, Paul André Calatayud, Stéphane Dupas

All Peer-Reviewed Publications

Field surveys were carried out in four agroecological zones to assess the geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes in cultivated and natural habitats in Kenya. The distribution of the two Cotesia species in different ecological regions was most affected by the suitability of the local stem borer species for parasitoid development, and temperature, as both species were found in localities dominated by their suitable host(s) where temperature favoured their occurrence. Fourteen years after its release, C. flavipes has maintained a high level of specificity to its target host Chilo partellus on maize and sorghum …

Following Tetraploidy In Maize, A Short Deletion Mechanism Removed Genes Preferentially From One Of The Two Homeologs, Margaret R. Woodhouse, James C. Schnable, Brent S. Pedersen, Eric Lyons, Damon Lisch, Shabarinath Subramaniam, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Previous work in Arabidopsis showed that after an ancient tetraploidy event, genes were preferentially removed from one of the two homeologs, a process known as fractionation. The mechanism of fractionation is unknown. We sought to determine whether such preferential, or biased, fractionation exists in maize and, if so, whether a specific mechanism could be implicated in this process. We studied the process of fractionation using two recently sequenced grass species: sorghum and maize. The maize lineage has experienced a tetraploidy since its divergence from sorghum approximately 12 million years ago, and fragments of many knocked-out genes retain enough sequence similarity …

Poisonous Rangeland Plants In San Luis Obispo County, Sara Litten, Amanda Ou

Animal Science

Poisonous Rangeland Plants in San Luis Obispo County is a comprehensive educational guide to rangeland plants that are toxic to domestic livestock. This guide begins with an exploration of how the biological systems are affected by the poisonous plant toxins. The biochemistry behind these toxins is included in the discussion. Next, reference material for fourteen plants that inhabit San Luis Obispo County is provided. This information includes specific toxins found in poisonous plants, affected animals, symptoms of poisoning, stages of growth, lethal dose, and distribution of the plant in California. This section of the guide is filled with helpful photos …

Good Agricultural Practices For Food Safety Of Fresh Produce, Laurie Hodges

Department of Agronomy and Horticulture: Faculty Publications

What are the guiding principles of food safety for fresh produce?

• Once contaminated, removing or killing pathogens on produce is very difficult.

• Preventing microbial contamination at all steps, from production to distribution, is strongly favored over treatments to eliminate contamination that may have occurred.

• Document the implementation of prevention programs, and educate workers at all levels of the agricultural and packing environments on food safety.

Key Signatures of a Credible Food Safety Program

The following is a condensed checklist of practices and conditions that reduce the potential for fresh produce to be exposed to pathogenic microbes. Review …