Factors Related to Performance Variation Among Logging-Machine Operators

La performance et le rendement des opérateurs de machines utilisées en exploitation forestière varient considérablement. Les compagnies forestières désirent évidemment embaucher des opérateurs qui fourniront un rendement élevé et soutenu. Elles aimeraient également pouvoir sélectionner et former des stagiaires aptes à devenir d'excellents opérateurs. L'embauche, la mobilité de la main d'oeuvre et la formation professionnelle sont des activités coûteuses et les employeurs cherchent donc des méthodes de sélection qui faciliteraient le choix des candidats les plus prometteurs. Une sélection plus efficace est possible à condition de mieux comprendre comment certaines caractéristiques d'un opérateur telles qu'aptitudes physiques et intellectuelles, histoire personnelle, motivation et expérience peuvent influer sur son rendement au travail.Les variations dans le rendement de 34 opérateurs de machines équipées de sécateurs hydrauliques sont le sujet de la présente étude dont les buts étaient de: (1) documenter les variations dans le rendement et de mesurer la variabilité « intra-opérateurs », « inter-opérateurs » et « inter-compagnies » ; (2) établir la relation entre les caractéristiques de l'opérateur et son rendement; et (3) proposer des méthodes susceptibles d'augmenter les niveaux moyens de rendement.Ces études, effectuées dans le centre-nord de la Colombie Britannique au cours de la période juin-décembre 1973, ont fourni des données sur 757 quarts d'abattage dans 86 parterres de coupe identifiés. Durant chaque quart d'abattage d'une durée moyenne de 6.2 heures-machines productives (HMP), 115 arbres par HMP furent abattus pour une production moyenne totale de 701 arbres marchands. Le niveau moyen de production par opérateur variait de moins de 50 à plus de 150 arbres par HMP.L'analyse des données a démontré qu'environ V3 de la variabilité dans le rendement était imputable aux différences quotidiennes intra-opérateurs et qu'environ2h était attribuable aux différences inter-opérateurs... La variabilité inter-compagnie s'est avérée presque nulle.Des entrevues et tests ont fourni des renseignements sur l'histoire personnelle, l'expérience professionnelle, l'attitude, la motivation, et sur certaines caractéristiques physiques et intellectuelles des opérateurs.Compte tenu des différences entre les conditions de peuplement, des ajustements furent effectués et il fut ensuite possible d'établir une relation significative entre le rendement et les caractéristiques suivantes de l'opérateur:— perception des distances— durée de l'expérience sur la machine en cause— dextérité manuelle— degré de motivationLa perception des distances, l'expérience et la dextérité manuelle pourraient facilement être évaluées au cours d'un procédé de sélection. La motivation est plus immédiatement influencée par la modification des structures d'organisation et de supervision à l'intérieur de chaque compagnie.Les suggestions proposées pour accélérer la progression des travaux dans ce domaine sont:— Le développement de procédés pour évaluer non seulement les aspects quantitatifs, mais aussi les aspects qualitatifs du rendement, dans divers emplois de l'exploitation forestière.— L'amélioration des modèles théoriques établissant la relation entre les caractéristiques des opérateurs et des groupes de travail en rapport avec le rendement.— L'examen des facteurs humains dans la conception de machines (ergonomie) pour augmenter le rendement au travail, diminuer le temps de formation, améliorer la sécurité au travail et le bien-être des opérateurs.— La préparation d'un recueil de renseignements sur les techniques supérieures de travail dans divers emplois pour le bénéfice des opérateurs et des contremaîtres à tous les niveaux.— La formulation d'un programme pratique pour vérifier l'utilité des procédés d'évaluation du personnel afin de prédire le rendement éventuel de nouveaux employés, ou de stagiaires, dans divers emplois de l'exploitation forestière.Despite the economic importance of large variations in individual productivity of logging-machine operators, few studies have attempted to examine the source of such variations. Based on data obtained for a total of 757 shifts of tree-felling activity, this exploratory study attempted to: (a) document variation in on-the-job performance and assign the variation to sources « within individual operators », « between operators », or « between firms »; (b) relate ob-served performance measured operator characteristics (ability and motivation); and (c) suggest ways in which average levels of job performance could be improved

Dynamic and Transient Performance of Turbofan/Turboshaft Convertible Engine With Variable Inlet Guide Vanes

A convertible engine called the CEST TF34, using the variable inlet guide vane method of power change, was tested on an outdoor stand at the NASA Lewis Research Center with a waterbrake dynamometer for the shaft load. A new digital electronic system, in conjunction with a modified standard TF34 hydromechanical fuel control, kept engine operation stable and safely within limits. All planned testing was completed successfully. Steady-state performance and acoustic characteristics were reported previously and are referenced. This report presents results of transient and dynamic tests. The transient tests measured engine response to several rapid changes in thrust and torque commands at constant fan (shaft) speed. Limited results from dynamic tests using the pseudorandom binary noise technique are also presented. Performance of the waterbrake dynamometer is discussed in an appendix

N17 Modifies mutant Huntingtin nuclear pathogenesis and severity of disease in HD BAC transgenic mice.

The nucleus is a critical subcellular compartment for the pathogenesis of polyglutamine disorders, including Huntington's disease (HD). Recent studies suggest the first 17-amino-acid domain (N17) of mutant huntingtin (mHTT) mediates its nuclear exclusion in cultured cells. Here, we test whether N17 could be a molecular determinant of nuclear mHTT pathogenesis in vivo. BAC transgenic mice expressing mHTT lacking the N17 domain (BACHD-ΔN17) show dramatically accelerated mHTT pathology exclusively in the nucleus, which is associated with HD-like transcriptionopathy. Interestingly, BACHD-ΔN17 mice manifest more overt disease-like phenotypes than the original BACHD mice, including body weight loss, movement deficits, robust striatal neuron loss, and neuroinflammation. Mechanistically, N17 is necessary for nuclear exclusion of small mHTT fragments that are part of nuclear pathology in HD. Together, our study suggests that N17 modifies nuclear pathogenesis and disease severity in HD mice by regulating subcellular localization of known nuclear pathogenic mHTT species

Combined TLR and CD40 Triggering Induces Potent CD8+ T Cell Expansion with Variable Dependence on Type I IFN

Toll-like receptors are important in the activation of innate immunity, and CD40 is a molecule critical for many T and B cell responses. Whereas agonists for either pathway have been used as vaccine adjuvants, we show that a combination of Toll-like receptor (TLR)7 and CD40 agonists synergize to stimulate CD8+ T cell responses 10–20-fold greater than the use of either agonist alone. Antigen-specific CD8+ T cells elicited from combination CD40/TLR7 treatment demonstrated both lytic activities and interferon (IFN)γ production and an enhanced secondary response to antigenic challenge. Agonists for TLRs 2/6, 3, 4, and 9 also synergized with CD40 stimulation, demonstrating that synergy with the CD40 pathway is a property of TLR-derived stimuli in general. The CD8+ T cell expansion induced by CD40/TLR7 triggering was independent of CD4+ T cells, IFNγ, and IL-12 but dependent on B7-mediated costimulation and surprisingly on type I IFN. These studies provide the rational basis for the use of TLR and CD40 agonists together as essential adjuvants to optimize vaccines designed to elicit protective or therapeutic immunity

Science goals and new mission concepts for future exploration of Titan’s atmosphere, geology and habitability: titan POlar scout/orbitEr and in situ lake lander and DrONe explorer (POSEIDON)

In response to ESA’s “Voyage 2050” announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn’s largest moon Titan. Titan, a “world with two oceans”, is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan is also one of the few places in the Solar System with habitability potential. Titan’s remarkable nature was only partly revealed by the Cassini-Huygens mission and still holds mysteries requiring a complete exploration using a variety of vehicles and instruments. The proposed mission concept POSEIDON (Titan POlar Scout/orbitEr and In situ lake lander DrONe explorer) would perform joint orbital and in situ investigations of Titan. It is designed to build on and exceed the scope and scientific/technological accomplishments of Cassini-Huygens, exploring Titan in ways that were not previously possible, in particular through full close-up and in situ coverage over long periods of time. In the proposed mission architecture, POSEIDON consists of two major elements: a spacecraft with a large set of instruments that would orbit Titan, preferably in a low-eccentricity polar orbit, and a suite of in situ investigation components, i.e. a lake lander, a “heavy” drone (possibly amphibious) and/or a fleet of mini-drones, dedicated to the exploration of the polar regions. The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. The exploration of Titan’s northern latitudes with an orbiter and in situ element(s) would be highly complementary in terms of timing (with possible mission timing overlap), locations, and science goals with the upcoming NASA New Frontiers Dragonfly mission that will provide in situ exploration of Titan’s equatorial regions, in the mid-2030s

The Lick AGN Monitoring Project 2011: Dynamical Modeling of the Broad Line Region in Mrk 50

We present dynamical modeling of the broad line region (BLR) in the Seyfert 1 galaxy Mrk 50 using reverberation mapping data taken as part of the Lick AGN Monitoring Project (LAMP) 2011. We model the reverberation mapping data directly, constraining the geometry and kinematics of the BLR, as well as deriving a black hole mass estimate that does not depend on a normalizing factor or virial coefficient. We find that the geometry of the BLR in Mrk 50 is a nearly face-on thick disk, with a mean radius of 9.6(+1.2,-0.9) light days, a width of the BLR of 6.9(+1.2,-1.1) light days, and a disk opening angle of 25\pm10 degrees above the plane. We also constrain the inclination angle to be 9(+7,-5) degrees, close to face-on. Finally, the black hole mass of Mrk 50 is inferred to be log10(M(BH)/Msun) = 7.57(+0.44,-0.27). By comparison to the virial black hole mass estimate from traditional reverberation mapping analysis, we find the normalizing constant (virial coefficient) to be log10(f) = 0.78(+0.44,-0.27), consistent with the commonly adopted mean value of 0.74 based on aligning the M(BH)-{\sigma}* relation for AGN and quiescent galaxies. While our dynamical model includes the possibility of a net inflow or outflow in the BLR, we cannot distinguish between these two scenarios.Comment: Accepted for publication in ApJ. 8 pages, 6 figure

Effect of Mobile Device-Assisted N-of-1 Trial Participation on Analgesic Prescribing for Chronic Pain: Randomized Controlled Trial

ObjectivesOpioids and non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed for chronic musculoskeletal pain, despite limited evidence of effectiveness and well-documented adverse effects. We assessed the effects of participating in a structured, personalized self-experiment ("N-of-1 trial") on analgesic prescribing in patients with chronic musculoskeletal pain.MethodsWe randomized 215 patients with chronic pain to participate in an N-of-1 trial facilitated by a mobile health app or to receive usual care. Medical records of participating patients were reviewed at enrollment and 6 months later to assess analgesic prescribing. We established thresholds of ≥ 50, ≥ 20, and > 0 morphine milligram equivalents (MMEs) per day to capture patients taking relatively high doses only, patients taking low-moderate as well as relatively high doses, and patients taking any dose of opioids, respectively.ResultsThere was no significant difference between the N-of-1 and control groups in the percentage of patients prescribed any opioids (relative odds ratio (ROR) = 1.05; 95% confidence interval [CI] = 0.61 to 1.80, p = 0.87). There was a clinically substantial but statistically not significant reduction of the percentage of patients receiving ≥ 20 MME (ROR = 0.58; 95% CI = 0.33 to 1.04, p = 0.07) and also in the percentage receiving ≥ 50 MME (ROR = 0.50; 95% CI = 0.19 to 1.34, p = 0.17). There was a significant reduction in the proportion of patients in the N-of-1 group prescribed NSAIDs compared with control (relative odds ratio = 0.53; 95% CI = 0.29 to 0.96, p = 0.04), with no concomitant increase in average pain intensity. There was no significant change in use of adjunctive medications (acetaminophen, gabapentenoids, or topicals).DiscussionThese exploratory results suggest that participation in N-of-1 trials may reduce long-term use of NSAIDs; there is also a weak signal for an effect on use of opioids. Additional research is needed to confirm these results and elucidate possible mechanisms.Trial registrationClinicalTrials.gov Identifier: NCT02116621

Measuring the mass of the central black hole in the bulgeless galaxy ngc 4395 from gas dynamical modeling

NGC 4395 is a bulgeless spiral galaxy, harboring one of the nearest known type 1 Seyfert nuclei. Although there is no consensus on the mass of its central engine, several estimates suggest it is one of the lightest massive black holes (MBHs) known. We present the first direct dynamical measurement of the mass of this MBH from a combination of two-dimensional gas kinematic data, obtained with the adaptive optics assisted near-infrared integral field spectrograph Gemini/NIFS and high-resolution multiband photometric data from Hubble Space Telescope's Wide Field Camera 3. We use the photometric data to model the shape and stellar mass-to-light ratio of the nuclear star cluster (NSC). From the Gemini/NIFS observations, we derive the kinematics of warm molecular hydrogen gas as traced by emission through the H2 1–0 S(1) transition. These kinematics show a clear rotational signal, with a position angle orthogonal to NGC 4395's radio jet. Our best-fitting tilted ring models of the kinematics of the molecular hydrogen gas contain a black hole with mass M={4}-3+8× {10}5 M⊙ (3σ uncertainties) embedded in an NSC of mass M=2× {10}6 M⊙. Our black hole mass measurement is in excellent agreement with the reverberation mapping mass estimate of Peterson et al. but shows some tension with other mass measurement methods based on accretion signals

The Fictive Reflex : A Fresh Look at Reflexiveness and Narrative Representation

Reflexiveness in literary contexts tends to be assimilated to self-reference; to the various ways in which a work may foreground the artifice and conventionality of its own features as representation, narrative or language. In this sense it is equated with metafiction, and regarded as a sophisticated and highly self-conscious use of narrative; here, however, I offer a contrary view of reflexiveness, one which sees it as elementary, pervasive, and constitutive of fictionality. In this view, there is a continuity between the basic logic of mimesis and the self-conscious “baring of the device” that, for the Russian Formalists, defines the literary. I begin by clarifying the nature of (fictive) representation as an act, and identify its intrinsic reflexiveness, and go on to compare this perspective with both the metafictional notion of reflexiveness and the theoretical discourse on reflexiveness around “mirror neurons” in cognitive literary studies. I then situate reflexiveness within a broader interdisciplinary environment, framed by complex systems science and the conceptualization of emergence in terms of representational recursiveness, which allows the two sides of the discussion so far to be understood as complementary aspects of reflexiveness, one of which aligns with the cultivation of (self-) consciousness, the other with the simple enactment of systemic relations. Finally I address the conceptual challenge presented by an account of narrative, and fiction, based upon reflexiveness, and suggest some ways in which it can be understood