17,178 research outputs found
Control mechanisms and perceived organizational support: exploring the relationship between new and traditional forms of control
Purpose: Taking into account the need to make a clearer distinction between traditional and new organizational controls, this paper aims to investigate similarities and differences between those two forms and explore the extent to which new forms of control can be operationalized from a quantitative point of view. Design/methodology/approach: Suggesting that new organizational controls can be understood also in light of quantitative paradigms, we develop and test a scale to measure the existence of these types of controls, examine its construct validity and evaluate its convergent validity. Findings: The theoretical dimensions of new controls have empirical correspondence. Input and behaviour controls are strongly associated with the promotion of values and beliefs in organizations. New controls become responsible for employeesâ acceptance of companiesâ management, an aspect measured by Perceived-Organizational-Support (POS)
Explaining Jupiter's magnetic field and equatorial jet dynamics
Spacecraft data reveal a very Earth-like Jovian magnetic field. This is
surprising since numerical simulations have shown that the vastly different
interiors of terrestrial and gas planets can strongly affect the internal
dynamo process. Here we present the first numerical dynamo that manages to
match the structure and strength of the observed magnetic field by embracing
the newest models for Jupiter's interior. Simulated dynamo action primarily
occurs in the deep high electrical conductivity region while zonal flows are
dynamically constrained to a strong equatorial jet in the outer envelope of low
conductivity. Our model reproduces the structure and strength of the observed
global magnetic field and predicts that secondary dynamo action associated to
the equatorial jet produces banded magnetic features likely observable by the
Juno mission. Secular variation in our model scales to about 2000 nT per year
and should also be observable during the one year nominal mission duration.Comment: 7 pages, 4 figures, accepted for publication in Geophysical Research
Letter
Investigating Fatigue Performance on the Foamed Asphalt Specimens Generated Using Different Foam Properties
An evaluation of fatigue resistance for foamed asphalt mixture is very demanding since the binder is not continuously distributed on the aggregate surface and this mixtures contains water, the content of which dramatically affects the mechanical properties. This paper discusses the results of laboratory fatigue testingon the foamed asphalt mixtures in which the specimens are generated using three different foamed bitumen properties. Foamed bitumen as the binder was produced at three different foaming water content (FWC) at a temperature of 180oC using a 70/100 pen. The aggregates were mechanically mixed with foamed bitumen using a Hobart mixer. The resulting mixtures were then compacted using a gyratory compactor to generatespecimen with diameter of 100 mm. The specimens were fatigue tested at various stress levels at a temperature of 20oC following a curing period of 3 days at 40oC. Overall, fatigue performance of foamed asphalt can be identified based upon both stress and strain for mixtures produced at FWC 1%, 5%, and 10%
What controls the large-scale magnetic fields of M dwarfs?
Observations of active M dwarfs show a broad variety of large-scale magnetic
fields encompassing dipole-dominated and multipolar geometries. We detail the
analogy between some anelastic dynamo simulations and spectropolarimetric
observations of 23 M stars. In numerical models, the relative contribution of
inertia and Coriolis force in the global force balance -estimated by the
so-called local Rossby number- is known to have a strong impact on the magnetic
field geometry. We discuss the relevance of this parameter in setting the
large-scale magnetic field of M dwarfs.Comment: 4 pages, 3 figures, conference proceeding, IAUS 302 'Magnetic Fields
Throughout the Stellar Evolution', (26-30 Aug 2013, Biarritz, France
What controls the magnetic geometry of M dwarfs?
Context: observations of rapidly rotating M dwarfs show a broad variety of
large-scale magnetic fields encompassing dipole-dominated and multipolar
geometries. In dynamo models, the relative importance of inertia in the force
balance -- quantified by the local Rossby number -- is known to have a strong
impact on the magnetic field geometry. Aims: we aim to assess the relevance of
the local Rossby number in controlling the large-scale magnetic field geometry
of M dwarfs. Methods: we explore the similarities between anelastic dynamo
models in spherical shells and observations of active M-dwarfs, focusing on
field geometries derived from spectropolarimetric studies. To do so, we
construct observation-based quantities aimed to reflect the diagnostic
parameters employed in numerical models. Results: the transition between
dipole-dominated and multipolar large-scale fields in early to mid M dwarfs is
tentatively attributed to a Rossby number threshold. We interpret late M dwarfs
magnetism to result from a dynamo bistability occurring at low Rossby number.
By analogy with numerical models, we expect different amplitudes of
differential rotation on the two dynamo branches.Comment: 4 pages, 4 figures, accepted for publication in A&
Axial gravity, massless fermions and trace anomalies
This article deals with two main topics. One is odd parity trace anomalies in
Weyl fermion theories in a 4d curved background, the second is the introduction
of axial gravity. The motivation for reconsidering the former is to clarify the
theoretical background underlying the approach and complete the calculation of
the anomaly. The reference is in particular to the difference between Weyl and
massless Majorana fermions and to the possible contributions from tadpole and
seagull terms in the Feynman diagram approach. A first, basic, result of this
paper is that a more thorough treatment, taking account of such additional
terms { and using dimensional regularization}, confirms the earlier result. The
introduction of an axial symmetric tensor besides the usual gravitational
metric is instrumental to a different derivation of the same result using Dirac
fermions, which are coupled not only to the usual metric but also to the
additional axial tensor. The action of Majorana and Weyl fermions can be
obtained in two different limits of such a general configuration. The results
obtained in this way confirm the previously obtained ones.Comment: 55 pages, comments added in section 2 and 5. Sections 6.4, 6.6, 7,
7.1, 7.2 and Appendices 5.3, 5.5 partially modifie
Why Customers Value Mass-customized Products: The Importance of Process Effort and Enjoyment
We test our hypotheses on 186 participants designing their own scarves with an MC toolkit. After completing the process, they submitted binding bids for "their" products in Vickrey auctions. We therefore observe real buying behavior, not merely stated intentions. We find that the subjective value of a self-designed product (i.e., one's bid in the course of the auction) is indeed not only impacted by the preference fit the customer expects it to deliver, but also by (1) the process enjoyment the customer reports, (2) the interaction of preference fit and process enjoyment, and (3) the interaction of preference fit and perceived process effort. In addition to its main effect, we interpret preference fit as a moderator of the valuegenerating effect of process evaluation: In cases where the outcome of the process is perceived as positive (high preference fit), the customer also interprets process effort as a positive accomplishment, and this positive affect adds (further) value to the product. It appears that the perception of the self-design process as a good or bad experience is partly constructed on the basis of the outcome of the process. In the opposite case (low preference fit), effort creates a negative affect which further reduces the subjective value of the product. Likewise, process enjoyment is amplified by preference fit, although enjoyment also has a significant main effect, which means that regardless of the outcome, customers attribute higher value to a self-designed product if they enjoy the process. The importance of the self-design process found in this study bears clear relevance for companies which offer or plan to offer MC systems. It is not sufficient to design MC toolkits in such a way that they allow customers to design products according to their preferences. The affect caused by this process is also highly important. Toolkits should therefore stimulate positive affective reactions and at the same time keep negative affect to a minimum. (authors' abstract
High pCO 2 levels affect metabolic rate, but not feeding behavior and fitness, of farmed giant mussel Choromytilus chorus
IndexaciĂłn: Scopus.Acknowledgements. We thank Luisa Saavedra and Araceli Rodriguez-Romero for their help in the field and during laboratory activities. We also acknowledge Laura Ramajo for help with AT estimations. Emily Giles Neill provided valuable comments that greatly improved the manuscript. Special thanks are due to the reviewers and the editor for very constructive comments on the manuscript. This study was supported by the Millennium Nucleus Center for the Study of Multiple drivers on Marine Socio-Ecological Systems (MUSELS) funded by MINECON NC120086, PIA CONICYT ACT-172037 and FONDECYT grant nos. 1140938 and 1140092 to N.A.L. and M.A.L.Mar Ecol Prog Ser 454: 65â74 Findlay HS, Wood HL, Kendall MA, Spicer JI, Twitchett RJ, Widdicombe S (2009) Calcification, a physiological pro-cess to be considered in the context of the whole organ-ism. Biogeosciences 6: 2267â2284 Fitzer SC, Zhu W, Tanner KE, Phoenix VR, Kamenos NA, Cusack M (2015) Ocean acidification alters the material properties of Mytilus edulis shells. J R Soc Interface 12: 214â227 Freitas R, De Marchi L, Bastos M, Moreira A and others (2017) Effects of seawater acidification and salinity alter-ations on metabolic, osmoregulation and oxidative stress markers in Mytilus galloprovincialis. Ecol Indic 79: 54â62 Gattuso JP, Magnan A, BillĂ© R, Cheung WWL and others (2015) Contrasting futures for ocean and society from dif-ferent anthropogenic CO2 emissions scenarios. Science 349: aac4722 Gazeau F, Urbini L, Cox TE, Alliouane S, Gattuso JP (2015) Comparison of the alkalinity and calcium anomaly tech-niques to estimate rates of net calcification. Mar Ecol Prog Ser 527: 1â12 Gray MW, Langdon CJ, Waldbusser GG, Hales B, Kramer S (2017) Mechanistic understanding of ocean acidification impacts on larval feeding physiology and energy budg-ets of the mussel Mytilus californianus. Mar Ecol Prog Ser 563: 81â94 Griffiths CL, Griffiths RJ (1987) Animal energetics, Vol 2: Bivalvia through Reptilia. In: Pandian TJ, Vernberg FJ (eds) Bivalvia. Academic Press, New York, NY, p 1â88 Harvey BP, Dwynn-Jones D, Moore PJ (2013) Meta-analysis reveals complex marine biological responses to the inter-active effects of ocean acidification and warming. Ecol Evol 3: 1016â1030 Hiebenthal C, Philipp EER, Eisenhauer A, Wahl M (2013) Effects of seawater pCO2 and temperature on shell growth, shell stability, condition and cellular stress of western Baltic Sea Mytilus edulis (L.) and Arctica is - landica (L.). Mar Biol 160: 2073â2087 Ibarrola I, Arambalza U, Navarro JM, Urrutia MB, Navarro E (2012) Allometric relationships in feeding and diges-tion in the Chilean mytilids Mytilus chilensis (HupĂ©), Choromytilus chorus (Molina) and Aulacomya ater (Mo - lina): a comparative study. J Exp Mar Biol Ecol 426-427: 18â27 Lagos NA, BenĂtez S, Duarte C, Lardies MA and others (2016) Effects of temperature and ocean acidification on shell characteristics of Argopecten purpuratus: implica-tions for scallop aquaculture in an upwelling-influenced area. Aquacult Environ Interact 8: 357â370 Lardies MA, Arias MB, Poupin MJ, ManrĂquez PH and oth-ers (2014) Differential response to ocean acidification in physiological traits of Concholepas concholepas popula-tions. J Sea Res 90: 127â134 Lardies MA, BenĂtez S, Osores S, Vargas CA, Duarte C, Lohrmann KB, Lagos NA (2017) Physiological and histo - pathological impacts of increased carbon dioxide and temperature on the scallops Argopecten purpuratus cultured under upwelling influences in northern Chile. Aquaculture 479: 455â466 Lemasson AJ, Fletcher S, Hall-Spencer JM, Knights AM (2017) Linking the biological impacts of ocean acidifica-tion on oysters to changes in ecosystem services: a review. J Exp Mar Biol Ecol 492: 49â62 Mackenzie CL, Ormondroyd GA, Curling SF, Ball RJ, Whitely NM, Malham SK (2014) Ocean warming, more than acidification, reduces shell strength in a commercial shellfish species during food limitation. PLOS ONE 9: e86764 McElhany P (2017) CO2 sensitivity experiments are not suf-ficient to show an effect of ocean acidification. ICES J Mar Sci 74: 926â928 Mehrbach C, Culberson CH, Hawley JE, Pytkowicz RM (1973) Measurement of the apparent dissociation con-stants of carbonic acid in seawater at atmospheric pres-sure. Limnol Oceanogr 18: 897â907 Melzner F, Thomsen J, Koeve W, Oschlies A and others (2013) Future ocean acidification will be amplified by hypoxia in coastal habitats. Mar Biol 160: 1875â1888 Michaelidis B, Ouzounis C, Paleras A, Pörtner HO (2005) Effects of long-term moderate hypercapnia on acidâbase balance and growth rate in marine mussels Mytilus gal-loprovincialis. Mar Ecol Prog Ser 293: 109â118 Miller AW, Reynolds AC, Sobrino C, Riedel GF (2009) Shell-fish face uncertain future in high CO2 world: influence of acidification on oyster larvae calcification and growth in estuaries. PLOS ONE 4: e5661 Navarro JM (1988) The effects of salinity on the physio - logical ecology of Choromytilus chorus (Molina, 1782) (Bivalvia: Mytilidae). J Exp Mar Biol Ecol 122: 19â33 Navarro JM, Torres R, Acuña K, Duarte C and others (2013) Impact of medium-term exposure to elevated pCO2 lev-els on the physiological energetics of the mussel Mytilus chilensis. Chemosphere 90: 1242â1248 Navarro JM, Duarte C, ManrĂquez PH, Lardies MA and oth-ers (2016) Ocean warming and elevated carbon dioxide: multiple stressor impacts on juvenile mussels from south-ern Chile. ICES J Mar Sci 73: 764â771 Nienhuis S, Palmer AR, Harley CD (2010) Elevated CO2 affects shell dissolution rate but not calcification rate in a marine snail. Proc R Soc B 277: 2553â2558 Orr JC, Fabry VJ, Aumont O, Bopp L and others (2005) Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437: 681â686 Osores SJ, Lagos NA, San Martin V, ManrĂquez PH and others (2017) Plasticity and inter-population variability in physiological and life-history traits of the mussel Mytilus chilensis: a reciprocal transplant experiment. J Exp Mar Biol Ecol 490: 1â12 Palmer AR (1982) Growth in marine gastropods: a non-destructive technique for independently measuring shell and body weight. Malacologia 23: 63â73 Parker LM, Ross PM, OâConnor WA, Borysko L, Raftos DA, Pörtner HO (2012) Adult exposure influences offspring response to ocean acidification in oysters. Glob Change Biol 18: 82â92 Pierrot D, Lewis E, Wallace DWR (2006) MS Excel program developed for CO2 system calculations. ORNL/CDIAC-105a. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy, Oak Ridge, TN Ramajo L, Marba N, Prado L, Peron S and others (2016) Bio-mineralization changes with food supply confer juvenile scallops (Argopecten purpuratus) resistance to ocean acidification. Glob Change Biol 22: 2025â2037 Range P, ChĂcharo MA, Ben-Hamadou R, PilĂł D and others (2014) Impacts of CO2-induced seawater acidification on coastal Mediterranean bivalves and interactions with other climatic stressors. Reg Environ Change 14(Suppl 1): 19â30 Sabine C, Feely RA, Gruber N, Key RM and others (2004) The oceanic sink of anthropogenic CO2. Science 305: 367â371 SERNAPESCA (Servicio Nacional de Pesca y Acuicultura) (2014) Anuarios estadĂsticos del Servicio Nacional de Pesca y Acuicultura. www.sernapesca.cl SolĂłrzano L (1969) Determination of ammonia in natural waters by the phenolhypochlorite method. Limnol Oce - anogr 14: 799â801 Thomsen J, Melzner F (2010) Moderate seawater acidifica-tion does not elicit long-term metabolic depression in the blue mussel Mytilus edulis. Mar Biol 157: 2667â2676 Thomsen J, Casties I, Pansch C, Körtzinger A, Melzner F (2013) Food availability outweighs ocean acidification effects in juvenile Mytilus edulis: laboratory and field experiments. Glob Change Biol 19: 1017â1027 Thomsen J, Stapp LS, Haynert K, Schade H, Danelli M, Lannig G, Melzner F (2017) Naturally acidified habitat selects for ocean acidification-tolerant mussels. Sci Adv 3: e1602411 Toro B, Navarro JM, Palma-Fleming H (2003) Relationship between bioenergetics responses and organic pollutants in the giant mussel, Choromytilus chorus (Mollusca: Mytilidae). Aquat Toxicol 63: 257â269 Torres R, Pantoja S, Harada N, GonzĂĄlez HE, Daneri G, Frangopulos M, Fukasawa M (2011) Air-sea CO2 fluxes along the coast of Chile: from CO2 outgassing in central northern upwelling waters to CO2 uptake in southern Patagonian fjords. J Geophys Res 116: C09006 Torres R, Manriquez PH, Duarte C, Navarro JM, Lagos NA, Vargas CA, Lardies MA (2013) Evaluation of a semi - automatic system for long-term seawater carbonate chemistry manipulation. Rev Chil Hist Nat 86: 443â451 Vargas CA, Aguilera V, MartĂn V, ManrĂquez P and others (2015) CO2-driven ocean acidification disrupts the filter feeding behavior in Chilean gastropod and bivalve spe-cies from different geographic localities. Estuaries Coasts 38: 1163â1177 Vargas CA, Lagos NA, Lardies MA, Duarte C and others (2017) Species-specific responses to ocean acidification should account for local adaptation and adaptive plasti-city. Nature Ecol Evol 1: 0084 Vargas CA, Cuevas LA, Silva N, Gonzalez HE, Pol-Holz D, Narvaez DA (2018) Influence of glacier melting and river discharges on the nutrient distribution and DIC recycling in the southern Chilean Patagonia. J Geophys Res Bio-geosci 123: 256â270 Velasco LA, Navarro JM (2003) Energetic balance of infau-nal (Mulinia edulis King, 1831) and epifaunal (Mytilus chilensis HupĂ©, 1854) bivalves in response to wide varia-tions in concentration and quality of seston. J Exp Mar Biol Ecol 296: 79â92 Vihtakari M, Hendriks IE, Holding J, Renaud PE, Duarte CM, Havenhand JN (2013) Effects of ocean acidification and warming on sperm activity and early life stages of the Mediterranean mussel (Mytilus galloprovincialis). Water 5: 1890â1915 Wang Y, Li L, Hu M, Lu W (2015) Physiological energetic of the thick shell mussel Mytilus coruscus exposed to sea-water acidification and thermal stress. Sci Total Environ 514: 261â272 White MM, McCorkle DC, Mullineaux LS, Cohen AL (2013)Benthic habitats such as intertidal areas, sandy or rocky shores, upwelling zones, and estuaries are characterized by variable environmental conditions. This high variability of environmental stressors such as temperature, salinity, and pH/pCO 2 levels have been shown to impose restrictions on organismal performance. The giant mussel Choromytilus chorus forms intertidal and subtidal mussel beds in estuarine zones associated with fjords occurring in southern Chile and is an important aquacultural resource in Patagonia. In this study, we estimated the sensitivity of physiological traits and energy balance of C. chorus juveniles exposed to 3 pCO 2 treatments (500, 750, and 1200 ÎŒatm) for 30 d. Results showed that in acidified, high pCO 2 conditions, C. chorus juveniles had increased metabolic rates; however, other physiological traits (clearance and ingestion rates, ammonia excretion, absorption efficiency, growth rate, biomass production, net calcification, and dissolution rates) were not affected. These results suggest that when subjected to acidification, the adaptive response of C. chorus triggers tradeoffs among physiological traits that favor sustained feeding and growth in order to combat increased metabolic stress. As has been reported for other marine organisms, chronic exposure to variable pH/pCO 2 in their native habitats, such as estuarine zones, could explain the differential acclimatization capacity of giant mussels to cope with the increase in pCO 2 . Additionally, the fact that the mussels did not suffer from mortality indicates that increased pCO 2 levels may have chronic, but not lethal, effects on this species under these experimental conditions. © The authors 2017.https://www.int-res.com/abstracts/aei/v10/p267-278
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