Converting Crested Wheatgrass Stands to Enhance Big Sagebrush: A Literature Review

Greater sage-grouse (Centrocercus urophasianus) is a high priority species for federal and state land management agencies. Sage-grouse are sagebrush (Artemisia spp.) obligates requiring sagebrush for their survival throughout the year. Sagebrush has been removed and replaced with crested wheatgrass (Agropyron cristatum & A. desertorum) throughout the West. The objectives of this paper were to review the literature (99 papers), as well as consult experts, to determine which methods are most likely to eliminate crested wheatgrass and establish sagebrush. No technique eliminates crested wheatgrass in a single application. Grazing and fire have no long-term impacts on crested wheatgrass. Mechanical treatments, such as plowing, disking, and cultivating reduce and eradicate crested wheatgrass, but a flush of invasive annual grasses following mechanical disturbance can make establishment of seeded species difficult. It appears that the best way to reduce crested wheatgrass cover and establish sagebrush is to spray crested wheatgrass with glyphosate in early spring for two consecutive years at a rate of 1.1 kg/ha of active ingredient. Then, sagebrush should be seeded in the late fall using a compact row seeder or Brillion cultipacker at a rate of 0.22 kg/ha pure live seed

A critical evaluation of the activity-regulated cytoskeleton-associated protein (Arc/Arg3.1)'s putative role in regulating dendritic plasticity, cognitive processes, and mood in animal models of depression

Major depressive disorder (MDD) is primarily conceptualized as a mood disorder but cognitive dysfunction is also prevalent, and may limit the daily function of MDD patients. Current theories on MDD highlight disturbances in dendritic plasticity in its pathophysiology, which could conceivably play a role in the production of both MDD-related mood and cognitive symptoms. This paper attempts to review the accumulated knowledge on the basic biology of the activity-regulated cytoskeleton-associated protein (Arc or Arg3.1), its effects on neural plasticity, and how these may be related to mood or cognitive dysfunction in animal models of MDD. On a cellular level, Arc is found to play an important role in modulating dendritic spine density and remodeling. Arc is also found to have a close, bidirectional relationship with postsynaptic glutamate neurotransmission, since it is stimulated by multiple glutamatergic receptor mechanisms but also modulates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor internalization. The effects on AMPA receptor trafficking are likely related to Arc’s ability to modulate phenomena such as long-term potentiation, long-term depression, and synaptic scaling, each of which are important for maintaining proper cognitive function. Animal studies of chronic stress models of MDD show suppressed Arc expression in the frontal cortex but elevation in the amygdala. Interestingly, cognitive tasks depending on the frontal cortex are generally impaired by chronic stress, while those depending on the amygdala are enhanced, and antidepressant treatments stimulate cortical Arc expression with a timeline that is reminiscent of the treatment efficacy lag observed in the clinic or in preclinical models. However, pharmacological treatments that stimulate regional Arc expression do not universally improve relevant cognitive functions, and this highlights a need to further refine our understanding of Arc on a subcellular and network level

Reversal of age-associated cognitive deficits is accompanied by increased plasticity-related gene expression after chronic antidepressant administration in middle-aged mice

AbstractCognitive decline occurs during healthy aging, even in middle-aged subjects, via mechanisms that could include reduced stem cell proliferation, changed growth factor expression and/or reduced expression of synaptic plasticity genes. Although antidepressants alter these mechanisms in young rodents, their effects in older animals are unclear. In middle-aged mice, we examined the effects of a selective serotonin reuptake inhibitor (fluoxetine) and a multimodal antidepressant (vortioxetine) on cognitive and affective behaviors, brain stem cell proliferation, growth factor and gene expression. Twelve-month-old female C57BL/6 mice exhibited impaired visuospatial memory in the novel object placement (location) task associated with reduced expression of several plasticity-related genes. Chronic treatment with vortioxetine, but not fluoxetine, improved visuospatial memory and reduced depression-like behavior in the forced swim test in middle-aged mice. Vortioxetine, but not fluoxetine, increased hippocampal expression of several neuroplasticity-related genes in middle-aged mice (e.g., Nfkb1, Fos, Fmr1, Camk2a, Arc, Shank1, Nlgn2, and Rab3a). Neither drug reversed the age-associated decrease in stem cell proliferation. Hippocampal growth factor levels were not consistent with behavioral outcomes. Thus, a change in the expression of multiple genes involved in neuronal plasticity by antidepressant treatment was associated with improved cognitive function and a reduction in depression-like behavior in middle-aged mice

Organic selenium supplementation increased selenium concentrations in ewe and newborn lamb blood and in slaughter lamb meat compared to inorganic selenium supplementation

Background Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs. Methods Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements. Results In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 μg/g) than ewe pens that received inorganic selenium (mean 0.24 μg/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 μg/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 μg/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight). Conclusion Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation

SEASONAL VARIATION OF PHENOLS, NITROGEN, FIBER, AND IN VITRO DIGESTIBILITY IN SWEDISH MOOSE

Understanding how different components of food are processed and digested within the compartments of the digestive tract of large herbivores has important implications in their foraging behaviour, nutritional ecology, and techniques for measuring diet composition and nutritional quality of forage. Analysis of contents from different compartments of the digestive tract of moose in central Sweden showed that neutral detergent fiber (NDF) and nitrogen (N) content varied throughout the digestive tract and among individual moose (Alces alces). Total phenols (TP) had an inconsistent pattern throughout the digestive tract, possibly reflecting variation in diet composition and phenol patterns. The study moose were divided into 2 groups; the winter group had low N in the digestive tract and high NDF and dry matter content, and the summer group had high levels of N and low NDF and dry matter content. The phenol platyphyllane, indicative of consumption of dormant silver birch (Betula pendula), was detected throughout the contents of the digestive tract in 2 animals in the winter group. The winter moose had higher NDF than summer moose, indicating the seasonal change in diet quality. In vitro organic matter digestibility (IVOMD) was not different between the summer and winter diets. The effect of birch phenols on IVOMD was concentration-dependent; differences between seasons were apparent at only the highest concentration. The 2 groups had marked differences in digestive content of major nutrients, NDF, and ability to digest forage which were consistent with typical variation in seasonal diet quality

SEASONAL VARIATION OF PHENOLS, NITROGEN, FIBER, AND IN VITRO DIGESTIBILITY IN SWEDISH MOOSE

Understanding how different components of food are processed and digested within the compartments of the digestive tract of large herbivores has important implications in their foraging behaviour, nutritional ecology, and techniques for measuring diet composition and nutritional quality of forage. Analysis of contents from different compartments of the digestive tract of moose in central Sweden showed that neutral detergent fiber (NDF) and nitrogen (N) content varied throughout the digestive tract and among individual moose (Alces alces). Total phenols (TP) had an inconsistent pattern throughout the digestive tract, possibly reflecting variation in diet composition and phenol patterns. The study moose were divided into 2 groups; the winter group had low N in the digestive tract and high NDF and dry matter content, and the summer group had high levels of N and low NDF and dry matter content. The phenol platyphyllane, indicative of consumption of dormant silver birch (Betula pendula), was detected throughout the contents of the digestive tract in 2 animals in the winter group. The winter moose had higher NDF than summer moose, indicating the seasonal change in diet quality. In vitro organic matter digestibility (IVOMD) was not different between the summer and winter diets. The effect of birch phenols on IVOMD was concentration-dependent; differences between seasons were apparent at only the highest concentration. The 2 groups had marked differences in digestive content of major nutrients, NDF, and ability to digest forage which were consistent with typical variation in seasonal diet quality

Neuroplasticity pathways and protein-interaction networks are modulated by vortioxetine in rodents

Additional file 2: Figure S1. Merged mouse and rat network (mapped to human proteins) and summary of biological functions of each sub-network. Biological functions were manually extracted from the Function and Gene Ontology fields of the UniProt protein entries. The genes with dark, bold borders were used to build the network of protein–protein interaction partners. Squares with bold borders represent upregulated targets from the rat network, and circles with bold borders indicate differentially-regulated targets from the mouse network. The arrowheads indicate the common targets found in mouse and rat networks. This network of physically-interacting proteins containing clusters related to synaptic plasticity, synaptic transmission, neurodevelopment, cell growth, metabolism, and apoptosis, was significantly modulated in both mouse and rat

Angle of Incidence Effects on Far-Field Positive and Negative Phase Blast Parameters

The blast overpressure acting on a rigid target is known to vary between the normally reflected overpressure and the incident overpressure as a function of the angle between the target and the direction of travel of the blast wave. Literature guidance for determining the exact effects of angle of incidence are unclear, particularly when considering the negative phase. This paper presents the results from a series of well controlled experiments where pressure transducers are used to record the pressure-time history acting on the face of a large, rigid target at various angles of incidence for varying sizes of hemispherical PE4 charge and stand-off distances. The test data demonstrated remarkable repeatability, and excellent agreement with semi-empirical predictions for normally reflected overpressures. The oblique results show that peak overpressure, impulse and duration are highly dependent on angle of incidence for the positive phase, and are invariant of angle of incidence for the negative phase

Adaptations in the Temporalis Muscles of Rabbits after Masseter Muscle Removal

Masseter muscles were surgically removed in six young female rabbits so that we could study adaptations of the superficial temporalis muscles (ST) to increased functional requirements. Eight weeks following surgery, we used morphological measurements, histochemistry, contractile properties in situ, and occlusal force in vivo to compare the muscles in the experimental animals and six control rabbits. Analysis of the results demonstrated a decrease in fatigability of ST after masseter myectomy. Incisal occlusal force decreased by 65% during the first two weeks, and no recovery was observed during the following six weeks. At eight weeks post-surgery, the mass, twitch tensions, and tetanic tensions of ST were not significantly different from those of the controls. An increase in the percent of the cross-sectional area composed of fast fatigue-resistant fibers, a slower time-to-peak twitch tension, and a decrease in fatigability suggest an increase in oxidative metabolism. Analysis of these results suggests that muscles used for highly repetitious activities with submaximal loadings adapt to increased functional requirements by increasing fatigue-resistant properties.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68261/2/10.1177_00220345860650110201.pd