679 research outputs found

    Understanding how the Army\u27s Informal Leader Bonds Formal Leadership and the Complex Environment

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    Bullying and toxic leadership in the U. S. Army disrupt bonding processes between leaders and subordinates, which may jeopardize military operations, threaten resiliency initiatives, inhibit leader development, and stifle innovation. Little research, however, has looked at the role of informal leaders who operate outside the formal power structure in military environments. Using social exchange theory as the foundation, the purpose of this case study was to explore the activities of informal leaders who mediated the normal and disrupted leadership bonding processes in an Illinois Army National Guard Infantry Brigade. The research questions explored the informal leaders\u27 influence and behaviors to gain a greater understanding of the bonding processes. A maximum variation purposeful sampling was used to select 25 informal leaders from 8 company size units in an Illinois Army National Guard Infantry Brigade. Publicly available archival data were also considered. All data were coded inductively and then subjected to Braun and Clark\u27s thematic analysis procedure, revealing the perception that informal leaders improved bonding between soldiers and leaders and reduced stress associated with military service. The implications for positive social change include recommendations to the Illinois National Guard to provide support for using informal leaders as a mechanism to promote more cohesive relationships between leaders and subordinates and to explore the use of informal leadership to reduce stress

    Seinäjoki and the Community of the Land

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    Ovaj članak istražuje rad finskog arhitekta Alvara Aalta na sjedinjavanju "prirodnog" s "gradskim" u gradu Seinäjoki. Aaltov način planiranja i njegov formalni rječnik duboko su prožeti vezama sa svijetom prirode. Te analogije s pejsažom nisu tek hir arhitekta kao umjetnika, one čine ključni dio njegove kompozicije. Pažljiva analiza gradskog središta Seinäjokija, koje je projektirao Alvar Aalto, pokazuje nevjerojatno sjedinjavanje ljudske zajednice s doživljajem prirodnih pejsaža. Štoviše, Aalto isprepliće urbano i prirodno tako da mjesto dovodi u odnos s nacionalnim karakterom, time stvarajući originalan i važan model gradskog pejsaža.This paper investigates the integration of the "natural" with the "civic," in the town of Seinäjoki by the Finnish architect Alvar Aalto. Aalto\u27s design process, and his formal vocabulary are both imbued with references to the natural world. These landscape analogies are not merely the whim of the architect as artist, but central to his compositional gambits. A close analysis of Alvar Aalto\u27s town center of Seinäjoki reveals a remarkable integration of community with the experiences of natural landscapes. Further, Aalto intertwines the urban and the natural in order to relate place and national character, creating an original and significant model for a civic landscape

    A History of Collapse Factor Modeling and Empirical Data for Cryogenic Propellant Tanks

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    One of the major technical problems associated with cryogenic liquid propellant systems used to supply rocket engines and their subassemblies and components is the phenomenon of propellant tank pressurant and ullage gas collapse. This collapse is mainly caused by heat transfer from ullage gas to tank walls and interfacing propellant, which are both at temperatures well below those of this gas. Mass transfer between ullage gas and cryogenic propellant can also occur and have minor to significant secondary effects that can increase or decrease ullage gas collapse. Pressurant gas is supplied into cryogenic propellant tanks in order to initially pressurize these tanks and then maintain required pressures as propellant is expelled from these tanks. The net effect of pressurant and ullage gas collapse is increased total mass and mass flow rate requirements of pressurant gases. For flight vehicles this leads to significant and undesirable weight penalties. For rocket engine component and subassembly ground test facilities this results in significantly increased facility hardware, construction, and operational costs. "Collapse Factor" is a parameter used to quantify the pressurant and ullage gas collapse. Accurate prediction of collapse factors, through analytical methods and modeling tools, and collection and evaluation of collapse factor data has evolved over the years since the start of space exploration programs in the 1950 s. Through the years, numerous documents have been published to preserve results of studies associated with the collapse factor phenomenon. This paper presents a summary and selected details of prior literature that document the aforementioned studies. Additionally other literature that present studies and results of heat and mass transfer processes, related to or providing important insights or analytical methods for the studies of collapse factor, are presented

    Mechanisms underlying the endogenous dopaminergic inhibition of spinal locomotor circuit function in Xenopus tadpoles

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    This work was supported by the Biotechnology and Biological Science Research Council (BBSRC) [grant number BB/J01446X/1].Dopamine plays important roles in the development and modulation of motor control circuits. Here we show that dopamine exerts potent effects on the central pattern generator circuit controlling locomotory swimming in post-embryonic Xenopus tadpoles. Dopamine (0.5–100 μM) reduced fictive swim bout occurrence and caused both spontaneous and evoked episodes to become shorter, slower and weaker. The D2-like receptor agonist quinpirole mimicked this repertoire of inhibitory effects on swimming, whilst the D4 receptor antagonist, L745,870, had the opposite effects. The dopamine reuptake inhibitor bupropion potently inhibited fictive swimming, demonstrating that dopamine constitutes an endogenous modulatory system. Both dopamine and quinpirole also inhibited swimming in spinalised preparations, suggesting spinally located dopamine receptors. Dopamine and quinpirole hyperpolarised identified rhythmically active spinal neurons, increased rheobase and reduced spike probability both during swimming and in response to current injection. The hyperpolarisation was TTX-resistant and was accompanied by decreased input resistance, suggesting that dopamine opens a K+ channel. The K+ channel blocker barium chloride (but not TEA, glybenclamide or tertiapin-Q) significantly occluded the hyperpolarisation. Overall, we show that endogenously released dopamine acts upon spinally located D2-like receptors, leading to a rapid inhibitory modulation of swimming via the opening of a K+ channel.Publisher PDFPeer reviewe

    An Archaeological Analysis of a Possible Slave Quarter on the Little Falls Plantation in Southern Stafford County

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    Students in the introductory archaeology class at the University of Mary Washington conducted a preliminary shovel test pit survey of the site currently referred to as Little Falls-Norton Property in March and April 2018 and March 2019. These investigations were undertaken at the request of the landowners, who discovered archaeological material while doing yard work. The site is currently a residential lot, near Little Falls Plantation, which is in southern Stafford County, Virginia. The analysis and interpretation of the site was undertaken by the authors for a class project. Analysis of the artifacts, combined with archival research, indicates the site was likely an Antebellum slave quarter/Postbellum tenant site. This mid-19th-century site was likely an outlying field quarter associated with the larger Little Falls Plantation. This poster will detail the historical and archaeological evidence uncovered during the course of this project and outline suggestions for future research

    One hundred twenty-five concomitant endovascular and open procedures for lower extremity arterial disease

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    AbstractObjective: Although the results of staged endovascular and open surgical reconstructions have been well documented, the safety and efficacy of concomitant procedures in the operating room are less well defined. Suboptimal performance of endovascular procedures in an operative setting, or inappropriate reliance on endovascular techniques, might theoretically compromise graft patency. We questioned whether late graft thrombosis is frequently attributable to failure at the endovascularly treated site in this setting. Materials and Methods: Between May 1, 1993, and June 30, 2001, we performed 125 concomitant endovascular and open arterial reconstructions (73 primary reconstructions, 52 graft revisions) in 106 patients. Endovascular techniques were used to treat inflow lesions in 72 cases, outflow lesions in 14 cases, both in four cases, and the graft itself in 35 cases. Fifty-five iliac, 18 femoral, 13 popliteal, six tibial, and 35 graft lesions were treated. For primary bypasses, 33 were to the popliteal level (21 prosthetic, 12 autogenous), 19 were to the tibial or pedal arteries (16 autogenous, three prosthetic or composite), and 12 were to the femoral arteries (one autogenous, 11 prosthetic). Nine patch angioplasties (eight femoral, one popliteal) were performed. For graft revisions, endovascular intervention was for inflow in 13 cases, outflow in three cases, both in one case, and of the graft itself in 35 cases. Surgical revisions involved segmental grafts in 33 cases, patch angioplasty in 18 cases, and both in one case. Results: In the primary group, the initial technical success rate of the endovascular procedure was 93% (68/73), with five patients needing open conversion. The 30-day mortality rate was 1.4%, and the morbidity rate was 11.0%. Of the 19 grafts in the primary group that occluded during the follow-up period (mean, 11.9 months), five thromboses could possibly be attributed to failure at the endovascular site. In the revision group, the initial technical success rate of the endovascular procedure was 88% (46/52), with six patients undergoing conversion to open procedure. The 30-day mortality rate was 0%, and the morbidity rate was 15.4%. Of 22 late graft occlusions in the revision group, only three were attributed to failure at the endovascular site. Conclusion: This largest report to date of concomitant lower extremity endovascular and open revascularization procedures shows the approach to be safe. Few late graft occlusions were attributable to failure at the endovascularly treated site. The concomitant approach offers the efficiency and convenience of single stage therapy and allows immediate treatment for inadequate endovascular results or their complications and potential cost savings. (J Vasc Surg 2003;37:316-22.

    Control of <i>Xenopus</i> tadpole locomotion via selective expression of Ih in excitatory interneurons

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    The authors are grateful for the support of the Biotechnology and Biological Science Research Council (BBSRC) [grant number BB/J01446X/1 and BB/M024946/1] and the Wellcome Trust-University of Edinburgh Institutional Strategic Support Fund (ISSF).Locomotion relies on the coordinated activity of rhythmic neurons in the hindbrain and spinal cord, and depends critically on the intrinsic properties of excitatory interneurons. Therefore, understanding how ion channels sculpt the properties of these interneurons, and the consequences for circuit function and behavior, is an important task. The hyperpolarization-activated cation current, Ih, is known to play important roles in shaping neuronal properties and for rhythm generation in many neuronal networks. We show in stage 42 Xenopus laevis frog tadpoles that Ih is strongly expressed only in excitatory descending interneurons (dINs), an important ipsilaterally projecting population that drives swimming activity. The voltage-dependent HCN channel blocker ZD7288 completely abolished a prominent depolarising sag potential in response to hyperpolarization, the hallmark of Ih, and hyperpolarized dINs. ZD7288 also affected dIN post-inhibitory rebound firing, upon which locomotor rhythm generation relies, and disrupted locomotor output. Block of Ih also unmasked an activity-dependent ultraslow afterhyperpolarization (usAHP) in dINs following swimming, mediated by a dynamic Na/K pump current. This usAHP, unmasked in dINs by ZD7288, resulted in suprathreshold stimuli failing to evoke swimming at short inter-swim intervals, indicating an important role for Ih in maintaining swim generation capacity and in setting the post-swim refractory period of the network. Collectively, our data suggest that the selective expression of Ih in dINs determines specific dIN properties that are important for rhythm generation and counteracts an activity- dependent usAHP to ensure that dINs can maintain coordinated swimming over a wide range of inter-swim intervals.Publisher PDFPeer reviewe

    The effect of adding comorbidities to current centers for disease control and prevention central-line–associated bloodstream infection risk-adjustment methodology

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    BACKGROUNDRisk adjustment is needed to fairly compare central-line–associated bloodstream infection (CLABSI) rates between hospitals. Until 2017, the Centers for Disease Control and Prevention (CDC) methodology adjusted CLABSI rates only by type of intensive care unit (ICU). The 2017 CDC models also adjust for hospital size and medical school affiliation. We hypothesized that risk adjustment would be improved by including patient demographics and comorbidities from electronically available hospital discharge codes.METHODSUsing a cohort design across 22 hospitals, we analyzed data from ICU patients admitted between January 2012 and December 2013. Demographics and International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) discharge codes were obtained for each patient, and CLABSIs were identified by trained infection preventionists. Models adjusting only for ICU type and for ICU type plus patient case mix were built and compared using discrimination and standardized infection ratio (SIR). Hospitals were ranked by SIR for each model to examine and compare the changes in rank.RESULTSOverall, 85,849 ICU patients were analyzed and 162 (0.2%) developed CLABSI. The significant variables added to the ICU model were coagulopathy, paralysis, renal failure, malnutrition, and age. The C statistics were 0.55 (95% CI, 0.51–0.59) for the ICU-type model and 0.64 (95% CI, 0.60–0.69) for the ICU-type plus patient case-mix model. When the hospitals were ranked by adjusted SIRs, 10 hospitals (45%) changed rank when comorbidity was added to the ICU-type model.CONCLUSIONSOur risk-adjustment model for CLABSI using electronically available comorbidities demonstrated better discrimination than did the CDC model. The CDC should strongly consider comorbidity-based risk adjustment to more accurately compare CLABSI rates across hospitals.Infect Control Hosp Epidemiol 2017;38:1019–1024</jats:sec
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