454 research outputs found

    Beryllium fastener technology

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    Program was conducted to develop, produce, and test optimum-configuration, beryllium prestressed and blind fasteners. The program was carried out in four phases - phase 1, feasibility study, phase 2, development, phase 3, evaluation of beryllium alloys, and phase 4, fabrication and testing

    Climate Clever Beef : On-farm demonstration of adaptation and mitigation options for climate change in northern Australia

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    This project engaged with beef producers in five regions of northern Australia to identify management options that improve the performance and resilience of beef businesses. The work was done in the context of increasing the resilience of businesses to current climate variability as well as to projected changes in climate. The project also identified potential synergies and conflicts between improved business performance, climate adaptation practices and greenhouse gas emissions management. Three regions (Qld Gulf, Fitzroy Basin and Victoria River District) evaluated climate adaptation and greenhouse gas mitigation options via a benchmarking and options analysis approach with three “focal” properties. Five indicators of performance were evaluated for each property – profitability, productivity, land condition, climate change risk and greenhouse gas emissions. These detailed business analyses were complemented by demonstration sites in each region. Two other regions (Qld Mitchell grasslands and NT Barkly Tablelands) used on-property demonstration sites to showcase promising climate adaptation practices identified in a previous project. The focal property approach provided a systematic process for assessing current business performance as well as a ready means of estimating the impacts of management changes. For example, over a 15 year period, the Qld Gulf focal property improved its pasture condition dramatically by stocking around the long-term carrying capacity and undertaking wet season spelling. This, combined with herd management improvements, increased profitability and productivity, reduced greenhouse gas emissions by 15%, and improved greenhouse gas emission efficiency by >100%. The demonstration sites in each region effectively promoted and documented the benefits of key grazing practices for improving resilience to both current climate variability and potential climate change. For example, on a 16,118km² property in the Barkly, a paddock demonstration has documented initial land condition recovery at old bores, and the reduced risk of overgrazing around new bores, through best practice stocking rate management and wet season spelling. Qualitative analyses showed that many of the adaptation practices identified for improving resilience are consistent with existing best practice recommendations aimed at improving productivity and sustainability. Furthermore, these adaptation practices appear to have largely neutral implications for greenhouse gas emissions. In contrast, practices and options for reducing greenhouse gas emissions were more likely to create conflicts that leave enterprises more vulnerable to climate change. Examples of the negative consequences of mitigation measures include reduced pasture production associated with increased carbon sequestration in trees (i.e. woody vegetation thickening or regrowth retention) and increased operating costs associated with carbon pricing (if these are not offset with carbon credits). The project demonstration sites and focal property benchmarking process provided a solid base for focussed extension work targeting the drivers of profit, land condition, greenhouse gas emissions intensity and climate adaptation strategies

    Northern grazing carbon farming – integrating production and greenhouse gas outcomes 1 : Climate Clever Beef Final Report

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    This project targeted three large and diverse regions across northern Australia: the Queensland Gulf, the Queensland Fitzroy Basin and the Northern Territory (Victoria River District, Douglas Daly and Barkly Tableland regions). Eleven grazing businesses across three broad regions were engaged as case studies to undertake demonstrations and evaluations within their businesses. These businesses manage more than 1,281,000 ha and 97,600 cattle. The project provided an excellent opportunity to capitalize on established networks and genuine producer interest and participation built up in recent initiatives (e.g. CCRP Climate Clever Beef (Bray et al. 2014), Northern Grazing Systems project (Phelps et al. 2014), RELRP, SCaRP, SavannaPlan, CQ Beef). The project team included research and extension professionals with decades of combined experience working with northern beef producers. The knowledge and analytical tools developed during previous projects identified practices to: reduce the greenhouse gas emissions impact of beef businesses, manage climate variability, improve land condition and increase business profitability

    Northern grazing carbon farming – integrating production and greenhouse gas outcomes 1 : Climate Clever Beef Final Report

    Get PDF
    This project targeted three large and diverse regions across northern Australia: the Queensland Gulf, the Queensland Fitzroy Basin and the Northern Territory (Victoria River District, Douglas Daly and Barkly Tableland regions). Eleven grazing businesses across three broad regions were engaged as case studies to undertake demonstrations and evaluations within their businesses. These businesses manage more than 1,281,000 ha and 97,600 cattle. The project provided an excellent opportunity to capitalize on established networks and genuine producer interest and participation built up in recent initiatives (e.g. CCRP Climate Clever Beef (Bray et al. 2014), Northern Grazing Systems project (Phelps et al. 2014), RELRP, SCaRP, SavannaPlan, CQ Beef). The project team included research and extension professionals with decades of combined experience working with northern beef producers. The knowledge and analytical tools developed during previous projects identified practices to: reduce the greenhouse gas emissions impact of beef businesses, manage climate variability, improve land condition and increase business profitability

    Motor contagion: the contribution of trajectory and end-points

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    Increased involuntary arm movement deviation when observing an incongruent human arm movement has been interpreted as a strong indicator of motor contagion. Here, we examined the contribution of trajectory and end-point information on motor contagion by altering congruence between the stimulus and arm movement. Participants performed cyclical horizontal arm movements whilst simultaneously observing a stimulus representing human arm movement. The stimuli comprised congruent horizontal movements or vertical movements featuring incongruent trajectory and end-points. A novel, third, stimulus comprised curvilinear movements featuring congruent end-points, but an incongruent trajectory. In Experiment 1, our dependent variables indicated increased motor contagion when observing the vertical compared to horizontal movement stimulus. There was even greater motor contagion in the curvilinear stimulus condition indicating an additive effect of an incongruent trajectory comprising congruent end-points. In Experiment 2, this additive effect was also present when facing perpendicular to the display, and thus with end-points represented as a product of the movement rather than an external spatial reference. Together, these findings support the theory of event coding (Hommel et al., Behav Brain Sci 24:849–878, 2001), and the prediction that increased motor contagion takes place when observed and executed actions share common features (i.e., movement end-points)

    Cerebral activations related to ballistic, stepwise interrupted and gradually modulated movements in parkinson patients

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    Patients with Parkinson's disease (PD) experience impaired initiation and inhibition of movements such as difficulty to start/stop walking. At single-joint level this is accompanied by reduced inhibition of antagonist muscle activity. While normal basal ganglia (BG) contributions to motor control include selecting appropriate muscles by inhibiting others, it is unclear how PD-related changes in BG function cause impaired movement initiation and inhibition at single-joint level. To further elucidate these changes we studied 4 right-hand movement tasks with fMRI, by dissociating activations related to abrupt movement initiation, inhibition and gradual movement modulation. Initiation and inhibition were inferred from ballistic and stepwise interrupted movement, respectively, while smooth wrist circumduction enabled the assessment of gradually modulated movement. Task-related activations were compared between PD patients (N = 12) and healthy subjects (N = 18). In healthy subjects, movement initiation was characterized by antero-ventral striatum, substantia nigra (SN) and premotor activations while inhibition was dominated by subthalamic nucleus (STN) and pallidal activations, in line with the known role of these areas in simple movement. Gradual movement mainly involved antero-dorsal putamen and pallidum. Compared to healthy subjects, patients showed reduced striatal/SN and increased pallidal activation for initiation, whereas for inhibition STN activation was reduced and striatal-thalamo-cortical activation increased. For gradual movement patients showed reduced pallidal and increased thalamo-cortical activation. We conclude that PD-related changes during movement initiation fit the (rather static) model of alterations in direct and indirect BG pathways. Reduced STN activation and regional cortical increased activation in PD during inhibition and gradual movement modulation are better explained by a dynamic model that also takes into account enhanced responsiveness to external stimuli in this disease and the effects of hyper-fluctuating cortical inputs to the striatum and STN in particular

    Moving Just Like You: Motor Interference Depends on Similar Motility of Agent and Observer

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    Recent findings in neuroscience suggest an overlap between brain regions involved in the execution of movement and perception of another’s movement. This so-called “action-perception coupling” is supposed to serve our ability to automatically infer the goals and intentions of others by internal simulation of their actions. A consequence of this coupling is motor interference (MI), the effect of movement observation on the trajectory of one’s own movement. Previous studies emphasized that various features of the observed agent determine the degree of MI, but could not clarify how human-like an agent has to be for its movements to elicit MI and, more importantly, what ‘human-like’ means in the context of MI. Thus, we investigated in several experiments how different aspects of appearance and motility of the observed agent influence motor interference (MI). Participants performed arm movements in horizontal and vertical directions while observing videos of a human, a humanoid robot, or an industrial robot arm with either artificial (industrial) or human-like joint configurations. Our results show that, given a human-like joint configuration, MI was elicited by observing arm movements of both humanoid and industrial robots. However, if the joint configuration of the robot did not resemble that of the human arm, MI could longer be demonstrated. Our findings present evidence for the importance of human-like joint configuration rather than other human-like features for perception-action coupling when observing inanimate agents

    ERK1 Regulates the Hematopoietic Stem Cell Niches

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    The mitogen-activated protein kinases (MAPK) ERK1 and ERK2 are among the major signal transduction molecules but little is known about their specific functions in vivo. ERK activity is provided by two isoforms, ERK1 and ERK2, which are ubiquitously expressed and share activators and substrates. However, there are not in vivo studies which have reported a role for ERK1 or ERK2 in HSCs and the bone marrow microenvironment. The present study shows that the ERK1-deficient mice present a mild osteopetrosis phenotype. The lodging and the homing abilities of the ERK1−/− HSC are impaired, suggesting that the ERK1−/−-defective environment may affect the engrafment of HSCs. Serial transplantations demonstrate that ERK1 is involved in the maintenance of an appropriate medullar microenvironment, but that the intrinsic properties of HSCs are not altered by the ERK1−/− defective microenvironment. Deletion of ERK1 impaired in vitro and in vivo osteoclastogenesis while osteoblasts were unaffected. As osteoclasts derive from precursors of the monocyte/macrophage lineage, investigation of the monocytic compartment was performed. In vivo analysis of the myeloid lineage progenitors revealed that the frequency of CMPs increased by approximately 1.3-fold, while the frequency of GMPs significantly decreased by almost 2-fold, compared with the respective WT compartments. The overall mononuclear-phagocyte lineage development was compromised in these mice due to a reduced expression of the M-CSF receptor on myeloid progenitors. These results show that the cellular targets of ERK1 are M-CSFR-responsive cells, upstream to osteoclasts. While ERK1 is well known to be activated by M-CSF, the present results are the first to point out an ERK1-dependent M-CSFR regulation on hematopoietic progenitors. This study reinforces the hypothesis of an active cross-talk between HSCs, their progeny and bone cells in the maintenance of the homeostasis of these compartments

    Dendritic Cell Subtypes from Lymph Nodes and Blood Show Contrasted Gene Expression Programs upon Bluetongue Virus Infection

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    Chantier qualité GAHuman and animal hemorrhagic viruses initially target dendritic cells (DCs). It has been proposed, but not documented, that both plasmacytoid DCs (pDCs) and conventional DCs (cDCs) may participate in the cytokine storm encountered in these infections. In order to evaluate the contribution of DCs in hemorrhagic virus pathogenesis, we performed a genome-wide expression analysis during infection by Bluetongue virus (BTV), a double-stranded RNA virus that induces hemorrhagic fever in sheep and initially infects cDCs. Both pDCs and cDCs accumulated in regional lymph nodes and spleen during BTV infection. The gene response profiles were performed at the onset of the disease and markedly differed with the DC subtypes and their lymphoid organ location. An integrative knowledge-based analysis revealed that blood pDCs displayed a gene signature related to activation of systemic inflammation and permeability of vasculature. In contrast, the gene profile of pDCs and cDCs in lymph nodes was oriented to inhibition of inflammation, whereas spleen cDCs did not show a clear functional orientation. These analyses indicate that tissue location and DC subtype affect the functional gene expression program induced by BTV and suggest the involvement of blood pDCs in the inflammation and plasma leakage/hemorrhage during BTV infection in the real natural host of the virus. These findings open the avenue to target DCs for therapeutic interventions in viral hemorrhagic diseases

    Inhibition of E2-induced expression of BRCA1 by persistent organochlorines

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    BACKGROUND: Environmental persistent organochlorines (POCs) biomagnify in the food chain, and the chemicals are suspected of being involved in a broad range of human malignancies. It is speculated that some POCs that can interfere with estrogen receptor-mediated responses are involved in the initiation and progression of human breast cancer. The tumor suppressor gene BRCA1 plays a role in cell-cycle control, in DNA repair, and in genomic stability, and it is often downregulated in sporadic mammary cancers. The aim of the present study was to elucidate whether POCs have the potential to alter the expression of BRCA1. METHODS: Using human breast cancer cell lines MCF-7 and MDA-MB-231, the effect on BRCA1 expression of chemicals belonging to different classes of organochlorine chemicals (the pesticide toxaphene, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and three polychlorinated biphenyls [PCB#138, PCB#153 and PCB#180]) was measured by a reporter gene construct carrying 267 bp of the BRCA1 promoter. A twofold concentration range was analyzed in MCF-7, and the results were supported by northern blot analysis of BRCA1 mRNA using the highest concentrations of the chemicals. RESULTS: All three polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin reduced 17β-estradiol (E2)-induced expression as well as basal reporter gene expression in both cell lines, whereas northern blot analysis only revealed a downregulation of E2-induced BRCA1 mRNA expression in MCF-7 cells. Toxaphene, like E2, induced BRCA1 expression in MCF-7. CONCLUSION: The present study shows that some POCs have the capability to alter the expression of the tumor suppressor gene BRCA1 without affecting the cell-cycle control protein p21(Waf/Cip1). Some POCs therefore have the potential to affect breast cancer risk
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